1 /* Code for RTL transformations to satisfy insn constraints.
2    Copyright (C) 2010-2022 Free Software Foundation, Inc.
3    Contributed by Vladimir Makarov <vmakarov@redhat.com>.
4 
5    This file is part of GCC.
6 
7    GCC is free software; you can redistribute it and/or modify it under
8    the terms of the GNU General Public License as published by the Free
9    Software Foundation; either version 3, or (at your option) any later
10    version.
11 
12    GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13    WARRANTY; without even the implied warranty of MERCHANTABILITY or
14    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15    for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with GCC; see the file COPYING3.  If not see
19    <http://www.gnu.org/licenses/>.  */
20 
21 
22 /* This file contains code for 3 passes: constraint pass,
23    inheritance/split pass, and pass for undoing failed inheritance and
24    split.
25 
26    The major goal of constraint pass is to transform RTL to satisfy
27    insn and address constraints by:
28      o choosing insn alternatives;
29      o generating *reload insns* (or reloads in brief) and *reload
30        pseudos* which will get necessary hard registers later;
31      o substituting pseudos with equivalent values and removing the
32        instructions that initialized those pseudos.
33 
34    The constraint pass has biggest and most complicated code in LRA.
35    There are a lot of important details like:
36      o reuse of input reload pseudos to simplify reload pseudo
37        allocations;
38      o some heuristics to choose insn alternative to improve the
39        inheritance;
40      o early clobbers etc.
41 
42    The pass is mimicking former reload pass in alternative choosing
43    because the reload pass is oriented to current machine description
44    model.  It might be changed if the machine description model is
45    changed.
46 
47    There is special code for preventing all LRA and this pass cycling
48    in case of bugs.
49 
50    On the first iteration of the pass we process every instruction and
51    choose an alternative for each one.  On subsequent iterations we try
52    to avoid reprocessing instructions if we can be sure that the old
53    choice is still valid.
54 
55    The inheritance/spilt pass is to transform code to achieve
56    ineheritance and live range splitting.  It is done on backward
57    traversal of EBBs.
58 
59    The inheritance optimization goal is to reuse values in hard
60    registers. There is analogous optimization in old reload pass.  The
61    inheritance is achieved by following transformation:
62 
63        reload_p1 <- p	     reload_p1 <- p
64        ...		     new_p <- reload_p1
65        ...		=>   ...
66        reload_p2 <- p	     reload_p2 <- new_p
67 
68    where p is spilled and not changed between the insns.  Reload_p1 is
69    also called *original pseudo* and new_p is called *inheritance
70    pseudo*.
71 
72    The subsequent assignment pass will try to assign the same (or
73    another if it is not possible) hard register to new_p as to
74    reload_p1 or reload_p2.
75 
76    If the assignment pass fails to assign a hard register to new_p,
77    this file will undo the inheritance and restore the original code.
78    This is because implementing the above sequence with a spilled
79    new_p would make the code much worse.  The inheritance is done in
80    EBB scope.  The above is just a simplified example to get an idea
81    of the inheritance as the inheritance is also done for non-reload
82    insns.
83 
84    Splitting (transformation) is also done in EBB scope on the same
85    pass as the inheritance:
86 
87        r <- ... or ... <- r		 r <- ... or ... <- r
88        ...				 s <- r (new insn -- save)
89        ...			  =>
90        ...				 r <- s (new insn -- restore)
91        ... <- r				 ... <- r
92 
93     The *split pseudo* s is assigned to the hard register of the
94     original pseudo or hard register r.
95 
96     Splitting is done:
97       o In EBBs with high register pressure for global pseudos (living
98 	in at least 2 BBs) and assigned to hard registers when there
99 	are more one reloads needing the hard registers;
100       o for pseudos needing save/restore code around calls.
101 
102     If the split pseudo still has the same hard register as the
103     original pseudo after the subsequent assignment pass or the
104     original pseudo was split, the opposite transformation is done on
105     the same pass for undoing inheritance.  */
106 
107 #undef REG_OK_STRICT
108 
109 #include "config.h"
110 #include "system.h"
111 #include "coretypes.h"
112 #include "backend.h"
113 #include "target.h"
114 #include "rtl.h"
115 #include "tree.h"
116 #include "predict.h"
117 #include "df.h"
118 #include "memmodel.h"
119 #include "tm_p.h"
120 #include "expmed.h"
121 #include "optabs.h"
122 #include "regs.h"
123 #include "ira.h"
124 #include "recog.h"
125 #include "output.h"
126 #include "addresses.h"
127 #include "expr.h"
128 #include "cfgrtl.h"
129 #include "rtl-error.h"
130 #include "lra.h"
131 #include "lra-int.h"
132 #include "print-rtl.h"
133 #include "function-abi.h"
134 #include "rtl-iter.h"
135 
136 /* Value of LRA_CURR_RELOAD_NUM at the beginning of BB of the current
137    insn.  Remember that LRA_CURR_RELOAD_NUM is the number of emitted
138    reload insns.  */
139 static int bb_reload_num;
140 
141 /* The current insn being processed and corresponding its single set
142    (NULL otherwise), its data (basic block, the insn data, the insn
143    static data, and the mode of each operand).  */
144 static rtx_insn *curr_insn;
145 static rtx curr_insn_set;
146 static basic_block curr_bb;
147 static lra_insn_recog_data_t curr_id;
148 static struct lra_static_insn_data *curr_static_id;
149 static machine_mode curr_operand_mode[MAX_RECOG_OPERANDS];
150 /* Mode of the register substituted by its equivalence with VOIDmode
151    (e.g. constant) and whose subreg is given operand of the current
152    insn.  VOIDmode in all other cases.  */
153 static machine_mode original_subreg_reg_mode[MAX_RECOG_OPERANDS];
154 
155 
156 
157 /* Start numbers for new registers and insns at the current constraints
158    pass start.	*/
159 static int new_regno_start;
160 static int new_insn_uid_start;
161 
162 /* If LOC is nonnull, strip any outer subreg from it.  */
163 static inline rtx *
strip_subreg(rtx * loc)164 strip_subreg (rtx *loc)
165 {
166   return loc && GET_CODE (*loc) == SUBREG ? &SUBREG_REG (*loc) : loc;
167 }
168 
169 /* Return hard regno of REGNO or if it is was not assigned to a hard
170    register, use a hard register from its allocno class.  */
171 static int
get_try_hard_regno(int regno)172 get_try_hard_regno (int regno)
173 {
174   int hard_regno;
175   enum reg_class rclass;
176 
177   if ((hard_regno = regno) >= FIRST_PSEUDO_REGISTER)
178     hard_regno = lra_get_regno_hard_regno (regno);
179   if (hard_regno >= 0)
180     return hard_regno;
181   rclass = lra_get_allocno_class (regno);
182   if (rclass == NO_REGS)
183     return -1;
184   return ira_class_hard_regs[rclass][0];
185 }
186 
187 /* Return the hard regno of X after removing its subreg.  If X is not
188    a register or a subreg of a register, return -1.  If X is a pseudo,
189    use its assignment.  If FINAL_P return the final hard regno which will
190    be after elimination.  */
191 static int
get_hard_regno(rtx x,bool final_p)192 get_hard_regno (rtx x, bool final_p)
193 {
194   rtx reg;
195   int hard_regno;
196 
197   reg = x;
198   if (SUBREG_P (x))
199     reg = SUBREG_REG (x);
200   if (! REG_P (reg))
201     return -1;
202   if (! HARD_REGISTER_NUM_P (hard_regno = REGNO (reg)))
203     hard_regno = lra_get_regno_hard_regno (hard_regno);
204   if (hard_regno < 0)
205     return -1;
206   if (final_p)
207     hard_regno = lra_get_elimination_hard_regno (hard_regno);
208   if (SUBREG_P (x))
209     hard_regno += subreg_regno_offset (hard_regno, GET_MODE (reg),
210 				       SUBREG_BYTE (x),  GET_MODE (x));
211   return hard_regno;
212 }
213 
214 /* If REGNO is a hard register or has been allocated a hard register,
215    return the class of that register.  If REGNO is a reload pseudo
216    created by the current constraints pass, return its allocno class.
217    Return NO_REGS otherwise.  */
218 static enum reg_class
get_reg_class(int regno)219 get_reg_class (int regno)
220 {
221   int hard_regno;
222 
223   if (! HARD_REGISTER_NUM_P (hard_regno = regno))
224     hard_regno = lra_get_regno_hard_regno (regno);
225   if (hard_regno >= 0)
226     {
227       hard_regno = lra_get_elimination_hard_regno (hard_regno);
228       return REGNO_REG_CLASS (hard_regno);
229     }
230   if (regno >= new_regno_start)
231     return lra_get_allocno_class (regno);
232   return NO_REGS;
233 }
234 
235 /* Return true if REG satisfies (or will satisfy) reg class constraint
236    CL.  Use elimination first if REG is a hard register.  If REG is a
237    reload pseudo created by this constraints pass, assume that it will
238    be allocated a hard register from its allocno class, but allow that
239    class to be narrowed to CL if it is currently a superset of CL and
240    if either:
241 
242    - ALLOW_ALL_RELOAD_CLASS_CHANGES_P is true or
243    - the instruction we're processing is not a reload move.
244 
245    If NEW_CLASS is nonnull, set *NEW_CLASS to the new allocno class of
246    REGNO (reg), or NO_REGS if no change in its class was needed.  */
247 static bool
in_class_p(rtx reg,enum reg_class cl,enum reg_class * new_class,bool allow_all_reload_class_changes_p=false)248 in_class_p (rtx reg, enum reg_class cl, enum reg_class *new_class,
249 	    bool allow_all_reload_class_changes_p = false)
250 {
251   enum reg_class rclass, common_class;
252   machine_mode reg_mode;
253   rtx src;
254   int class_size, hard_regno, nregs, i, j;
255   int regno = REGNO (reg);
256 
257   if (new_class != NULL)
258     *new_class = NO_REGS;
259   if (regno < FIRST_PSEUDO_REGISTER)
260     {
261       rtx final_reg = reg;
262       rtx *final_loc = &final_reg;
263 
264       lra_eliminate_reg_if_possible (final_loc);
265       return TEST_HARD_REG_BIT (reg_class_contents[cl], REGNO (*final_loc));
266     }
267   reg_mode = GET_MODE (reg);
268   rclass = get_reg_class (regno);
269   src = curr_insn_set != NULL ? SET_SRC (curr_insn_set) : NULL;
270   if (regno < new_regno_start
271       /* Do not allow the constraints for reload instructions to
272 	 influence the classes of new pseudos.  These reloads are
273 	 typically moves that have many alternatives, and restricting
274 	 reload pseudos for one alternative may lead to situations
275 	 where other reload pseudos are no longer allocatable.  */
276       || (!allow_all_reload_class_changes_p
277 	  && INSN_UID (curr_insn) >= new_insn_uid_start
278 	  && src != NULL
279 	  && ((REG_P (src) || MEM_P (src))
280 	      || (GET_CODE (src) == SUBREG
281 		  && (REG_P (SUBREG_REG (src)) || MEM_P (SUBREG_REG (src)))))))
282     /* When we don't know what class will be used finally for reload
283        pseudos, we use ALL_REGS.  */
284     return ((regno >= new_regno_start && rclass == ALL_REGS)
285 	    || (rclass != NO_REGS && ira_class_subset_p[rclass][cl]
286 		&& ! hard_reg_set_subset_p (reg_class_contents[cl],
287 					    lra_no_alloc_regs)));
288   else
289     {
290       common_class = ira_reg_class_subset[rclass][cl];
291       if (new_class != NULL)
292 	*new_class = common_class;
293       if (hard_reg_set_subset_p (reg_class_contents[common_class],
294 				 lra_no_alloc_regs))
295 	return false;
296       /* Check that there are enough allocatable regs.  */
297       class_size = ira_class_hard_regs_num[common_class];
298       for (i = 0; i < class_size; i++)
299 	{
300 	  hard_regno = ira_class_hard_regs[common_class][i];
301 	  nregs = hard_regno_nregs (hard_regno, reg_mode);
302 	  if (nregs == 1)
303 	    return true;
304 	  for (j = 0; j < nregs; j++)
305 	    if (TEST_HARD_REG_BIT (lra_no_alloc_regs, hard_regno + j)
306 		|| ! TEST_HARD_REG_BIT (reg_class_contents[common_class],
307 					hard_regno + j))
308 	      break;
309 	  if (j >= nregs)
310 	    return true;
311 	}
312       return false;
313     }
314 }
315 
316 /* Return true if REGNO satisfies a memory constraint.	*/
317 static bool
in_mem_p(int regno)318 in_mem_p (int regno)
319 {
320   return get_reg_class (regno) == NO_REGS;
321 }
322 
323 /* Return 1 if ADDR is a valid memory address for mode MODE in address
324    space AS, and check that each pseudo has the proper kind of hard
325    reg.	 */
326 static int
valid_address_p(machine_mode mode ATTRIBUTE_UNUSED,rtx addr,addr_space_t as)327 valid_address_p (machine_mode mode ATTRIBUTE_UNUSED,
328 		 rtx addr, addr_space_t as)
329 {
330 #ifdef GO_IF_LEGITIMATE_ADDRESS
331   lra_assert (ADDR_SPACE_GENERIC_P (as));
332   GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
333   return 0;
334 
335  win:
336   return 1;
337 #else
338   return targetm.addr_space.legitimate_address_p (mode, addr, 0, as);
339 #endif
340 }
341 
342 namespace {
343   /* Temporarily eliminates registers in an address (for the lifetime of
344      the object).  */
345   class address_eliminator {
346   public:
347     address_eliminator (struct address_info *ad);
348     ~address_eliminator ();
349 
350   private:
351     struct address_info *m_ad;
352     rtx *m_base_loc;
353     rtx m_base_reg;
354     rtx *m_index_loc;
355     rtx m_index_reg;
356   };
357 }
358 
address_eliminator(struct address_info * ad)359 address_eliminator::address_eliminator (struct address_info *ad)
360   : m_ad (ad),
361     m_base_loc (strip_subreg (ad->base_term)),
362     m_base_reg (NULL_RTX),
363     m_index_loc (strip_subreg (ad->index_term)),
364     m_index_reg (NULL_RTX)
365 {
366   if (m_base_loc != NULL)
367     {
368       m_base_reg = *m_base_loc;
369       /* If we have non-legitimate address which is decomposed not in
370 	 the way we expected, don't do elimination here.  In such case
371 	 the address will be reloaded and elimination will be done in
372 	 reload insn finally.  */
373       if (REG_P (m_base_reg))
374 	lra_eliminate_reg_if_possible (m_base_loc);
375       if (m_ad->base_term2 != NULL)
376 	*m_ad->base_term2 = *m_ad->base_term;
377     }
378   if (m_index_loc != NULL)
379     {
380       m_index_reg = *m_index_loc;
381       if (REG_P (m_index_reg))
382 	lra_eliminate_reg_if_possible (m_index_loc);
383     }
384 }
385 
~address_eliminator()386 address_eliminator::~address_eliminator ()
387 {
388   if (m_base_loc && *m_base_loc != m_base_reg)
389     {
390       *m_base_loc = m_base_reg;
391       if (m_ad->base_term2 != NULL)
392 	*m_ad->base_term2 = *m_ad->base_term;
393     }
394   if (m_index_loc && *m_index_loc != m_index_reg)
395     *m_index_loc = m_index_reg;
396 }
397 
398 /* Return true if the eliminated form of AD is a legitimate target address.
399    If OP is a MEM, AD is the address within OP, otherwise OP should be
400    ignored.  CONSTRAINT is one constraint that the operand may need
401    to meet.  */
402 static bool
valid_address_p(rtx op,struct address_info * ad,enum constraint_num constraint)403 valid_address_p (rtx op, struct address_info *ad,
404 		 enum constraint_num constraint)
405 {
406   address_eliminator eliminator (ad);
407 
408   /* Allow a memory OP if it matches CONSTRAINT, even if CONSTRAINT is more
409      forgiving than "m".
410      Need to extract memory from op for special memory constraint,
411      i.e. bcst_mem_operand in i386 backend.  */
412   if (MEM_P (extract_mem_from_operand (op))
413       && insn_extra_relaxed_memory_constraint (constraint)
414       && constraint_satisfied_p (op, constraint))
415     return true;
416 
417   return valid_address_p (ad->mode, *ad->outer, ad->as);
418 }
419 
420 /* For special_memory_operand, it could be false for MEM_P (op),
421    i.e. bcst_mem_operand in i386 backend.
422    Extract and return real memory operand or op.  */
423 rtx
extract_mem_from_operand(rtx op)424 extract_mem_from_operand (rtx op)
425 {
426   for (rtx x = op;; x = XEXP (x, 0))
427     {
428       if (MEM_P (x))
429 	return x;
430       if (GET_RTX_LENGTH (GET_CODE (x)) != 1
431 	  || GET_RTX_FORMAT (GET_CODE (x))[0] != 'e')
432 	break;
433     }
434   return op;
435 }
436 
437 /* Return true if the eliminated form of memory reference OP satisfies
438    extra (special) memory constraint CONSTRAINT.  */
439 static bool
satisfies_memory_constraint_p(rtx op,enum constraint_num constraint)440 satisfies_memory_constraint_p (rtx op, enum constraint_num constraint)
441 {
442   struct address_info ad;
443   rtx mem = extract_mem_from_operand (op);
444   if (!MEM_P (mem))
445     return false;
446 
447   decompose_mem_address (&ad, mem);
448   address_eliminator eliminator (&ad);
449   return constraint_satisfied_p (op, constraint);
450 }
451 
452 /* Return true if the eliminated form of address AD satisfies extra
453    address constraint CONSTRAINT.  */
454 static bool
satisfies_address_constraint_p(struct address_info * ad,enum constraint_num constraint)455 satisfies_address_constraint_p (struct address_info *ad,
456 				enum constraint_num constraint)
457 {
458   address_eliminator eliminator (ad);
459   return constraint_satisfied_p (*ad->outer, constraint);
460 }
461 
462 /* Return true if the eliminated form of address OP satisfies extra
463    address constraint CONSTRAINT.  */
464 static bool
satisfies_address_constraint_p(rtx op,enum constraint_num constraint)465 satisfies_address_constraint_p (rtx op, enum constraint_num constraint)
466 {
467   struct address_info ad;
468 
469   decompose_lea_address (&ad, &op);
470   return satisfies_address_constraint_p (&ad, constraint);
471 }
472 
473 /* Initiate equivalences for LRA.  As we keep original equivalences
474    before any elimination, we need to make copies otherwise any change
475    in insns might change the equivalences.  */
476 void
lra_init_equiv(void)477 lra_init_equiv (void)
478 {
479   ira_expand_reg_equiv ();
480   for (int i = FIRST_PSEUDO_REGISTER; i < max_reg_num (); i++)
481     {
482       rtx res;
483 
484       if ((res = ira_reg_equiv[i].memory) != NULL_RTX)
485 	ira_reg_equiv[i].memory = copy_rtx (res);
486       if ((res = ira_reg_equiv[i].invariant) != NULL_RTX)
487 	ira_reg_equiv[i].invariant = copy_rtx (res);
488     }
489 }
490 
491 static rtx loc_equivalence_callback (rtx, const_rtx, void *);
492 
493 /* Update equivalence for REGNO.  We need to this as the equivalence
494    might contain other pseudos which are changed by their
495    equivalences.  */
496 static void
update_equiv(int regno)497 update_equiv (int regno)
498 {
499   rtx x;
500 
501   if ((x = ira_reg_equiv[regno].memory) != NULL_RTX)
502     ira_reg_equiv[regno].memory
503       = simplify_replace_fn_rtx (x, NULL_RTX, loc_equivalence_callback,
504 				 NULL_RTX);
505   if ((x = ira_reg_equiv[regno].invariant) != NULL_RTX)
506     ira_reg_equiv[regno].invariant
507       = simplify_replace_fn_rtx (x, NULL_RTX, loc_equivalence_callback,
508 				 NULL_RTX);
509 }
510 
511 /* If we have decided to substitute X with another value, return that
512    value, otherwise return X.  */
513 static rtx
get_equiv(rtx x)514 get_equiv (rtx x)
515 {
516   int regno;
517   rtx res;
518 
519   if (! REG_P (x) || (regno = REGNO (x)) < FIRST_PSEUDO_REGISTER
520       || ! ira_reg_equiv[regno].defined_p
521       || ! ira_reg_equiv[regno].profitable_p
522       || lra_get_regno_hard_regno (regno) >= 0)
523     return x;
524   if ((res = ira_reg_equiv[regno].memory) != NULL_RTX)
525     {
526       if (targetm.cannot_substitute_mem_equiv_p (res))
527 	return x;
528       return res;
529     }
530   if ((res = ira_reg_equiv[regno].constant) != NULL_RTX)
531     return res;
532   if ((res = ira_reg_equiv[regno].invariant) != NULL_RTX)
533     return res;
534   gcc_unreachable ();
535 }
536 
537 /* If we have decided to substitute X with the equivalent value,
538    return that value after elimination for INSN, otherwise return
539    X.  */
540 static rtx
get_equiv_with_elimination(rtx x,rtx_insn * insn)541 get_equiv_with_elimination (rtx x, rtx_insn *insn)
542 {
543   rtx res = get_equiv (x);
544 
545   if (x == res || CONSTANT_P (res))
546     return res;
547   return lra_eliminate_regs_1 (insn, res, GET_MODE (res),
548 			       false, false, 0, true);
549 }
550 
551 /* Set up curr_operand_mode.  */
552 static void
init_curr_operand_mode(void)553 init_curr_operand_mode (void)
554 {
555   int nop = curr_static_id->n_operands;
556   for (int i = 0; i < nop; i++)
557     {
558       machine_mode mode = GET_MODE (*curr_id->operand_loc[i]);
559       if (mode == VOIDmode)
560 	{
561 	  /* The .md mode for address operands is the mode of the
562 	     addressed value rather than the mode of the address itself.  */
563 	  if (curr_id->icode >= 0 && curr_static_id->operand[i].is_address)
564 	    mode = Pmode;
565 	  else
566 	    mode = curr_static_id->operand[i].mode;
567 	}
568       curr_operand_mode[i] = mode;
569     }
570 }
571 
572 
573 
574 /* The page contains code to reuse input reloads.  */
575 
576 /* Structure describes input reload of the current insns.  */
577 struct input_reload
578 {
579   /* True for input reload of matched operands.  */
580   bool match_p;
581   /* Reloaded value.  */
582   rtx input;
583   /* Reload pseudo used.  */
584   rtx reg;
585 };
586 
587 /* The number of elements in the following array.  */
588 static int curr_insn_input_reloads_num;
589 /* Array containing info about input reloads.  It is used to find the
590    same input reload and reuse the reload pseudo in this case.	*/
591 static struct input_reload curr_insn_input_reloads[LRA_MAX_INSN_RELOADS];
592 
593 /* Initiate data concerning reuse of input reloads for the current
594    insn.  */
595 static void
init_curr_insn_input_reloads(void)596 init_curr_insn_input_reloads (void)
597 {
598   curr_insn_input_reloads_num = 0;
599 }
600 
601 /* The canonical form of an rtx inside a MEM is not necessarily the same as the
602    canonical form of the rtx outside the MEM.  Fix this up in the case that
603    we're reloading an address (and therefore pulling it outside a MEM).  */
604 static rtx
canonicalize_reload_addr(rtx addr)605 canonicalize_reload_addr (rtx addr)
606 {
607   subrtx_var_iterator::array_type array;
608   FOR_EACH_SUBRTX_VAR (iter, array, addr, NONCONST)
609     {
610       rtx x = *iter;
611       if (GET_CODE (x) == MULT && CONST_INT_P (XEXP (x, 1)))
612 	{
613 	  const HOST_WIDE_INT ci = INTVAL (XEXP (x, 1));
614 	  const int pwr2 = exact_log2 (ci);
615 	  if (pwr2 > 0)
616 	    {
617 	      /* Rewrite this to use a shift instead, which is canonical when
618 		 outside of a MEM.  */
619 	      PUT_CODE (x, ASHIFT);
620 	      XEXP (x, 1) = GEN_INT (pwr2);
621 	    }
622 	}
623     }
624 
625   return addr;
626 }
627 
628 /* Create a new pseudo using MODE, RCLASS, EXCLUDE_START_HARD_REGS, ORIGINAL or
629    reuse an existing reload pseudo.  Don't reuse an existing reload pseudo if
630    IN_SUBREG_P is true and the reused pseudo should be wrapped up in a SUBREG.
631    The result pseudo is returned through RESULT_REG.  Return TRUE if we created
632    a new pseudo, FALSE if we reused an existing reload pseudo.  Use TITLE to
633    describe new registers for debug purposes.  */
634 static bool
get_reload_reg(enum op_type type,machine_mode mode,rtx original,enum reg_class rclass,HARD_REG_SET * exclude_start_hard_regs,bool in_subreg_p,const char * title,rtx * result_reg)635 get_reload_reg (enum op_type type, machine_mode mode, rtx original,
636 		enum reg_class rclass, HARD_REG_SET *exclude_start_hard_regs,
637 		bool in_subreg_p, const char *title, rtx *result_reg)
638 {
639   int i, regno;
640   enum reg_class new_class;
641   bool unique_p = false;
642 
643   if (type == OP_OUT)
644     {
645       /* Output reload registers tend to start out with a conservative
646 	 choice of register class.  Usually this is ALL_REGS, although
647 	 a target might narrow it (for performance reasons) through
648 	 targetm.preferred_reload_class.  It's therefore quite common
649 	 for a reload instruction to require a more restrictive class
650 	 than the class that was originally assigned to the reload register.
651 
652 	 In these situations, it's more efficient to refine the choice
653 	 of register class rather than create a second reload register.
654 	 This also helps to avoid cycling for registers that are only
655 	 used by reload instructions.  */
656       if (REG_P (original)
657 	  && (int) REGNO (original) >= new_regno_start
658 	  && INSN_UID (curr_insn) >= new_insn_uid_start
659 	  && in_class_p (original, rclass, &new_class, true))
660 	{
661 	  unsigned int regno = REGNO (original);
662 	  if (lra_dump_file != NULL)
663 	    {
664 	      fprintf (lra_dump_file, "	 Reuse r%d for output ", regno);
665 	      dump_value_slim (lra_dump_file, original, 1);
666 	    }
667 	  if (new_class != lra_get_allocno_class (regno))
668 	    lra_change_class (regno, new_class, ", change to", false);
669 	  if (lra_dump_file != NULL)
670 	    fprintf (lra_dump_file, "\n");
671 	  *result_reg = original;
672 	  return false;
673 	}
674       *result_reg
675 	= lra_create_new_reg_with_unique_value (mode, original, rclass,
676 						exclude_start_hard_regs, title);
677       return true;
678     }
679   /* Prevent reuse value of expression with side effects,
680      e.g. volatile memory.  */
681   if (! side_effects_p (original))
682     for (i = 0; i < curr_insn_input_reloads_num; i++)
683       {
684 	if (! curr_insn_input_reloads[i].match_p
685 	    && rtx_equal_p (curr_insn_input_reloads[i].input, original)
686 	    && in_class_p (curr_insn_input_reloads[i].reg, rclass, &new_class))
687 	  {
688 	    rtx reg = curr_insn_input_reloads[i].reg;
689 	    regno = REGNO (reg);
690 	    /* If input is equal to original and both are VOIDmode,
691 	       GET_MODE (reg) might be still different from mode.
692 	       Ensure we don't return *result_reg with wrong mode.  */
693 	    if (GET_MODE (reg) != mode)
694 	      {
695 		if (in_subreg_p)
696 		  continue;
697 		if (maybe_lt (GET_MODE_SIZE (GET_MODE (reg)),
698 			      GET_MODE_SIZE (mode)))
699 		  continue;
700 		reg = lowpart_subreg (mode, reg, GET_MODE (reg));
701 		if (reg == NULL_RTX || GET_CODE (reg) != SUBREG)
702 		  continue;
703 	      }
704 	    *result_reg = reg;
705 	    if (lra_dump_file != NULL)
706 	      {
707 		fprintf (lra_dump_file, "	 Reuse r%d for reload ", regno);
708 		dump_value_slim (lra_dump_file, original, 1);
709 	      }
710 	    if (new_class != lra_get_allocno_class (regno))
711 	      lra_change_class (regno, new_class, ", change to", false);
712 	    if (lra_dump_file != NULL)
713 	      fprintf (lra_dump_file, "\n");
714 	    return false;
715 	  }
716 	/* If we have an input reload with a different mode, make sure it
717 	   will get a different hard reg.  */
718 	else if (REG_P (original)
719 		 && REG_P (curr_insn_input_reloads[i].input)
720 		 && REGNO (original) == REGNO (curr_insn_input_reloads[i].input)
721 		 && (GET_MODE (original)
722 		     != GET_MODE (curr_insn_input_reloads[i].input)))
723 	  unique_p = true;
724       }
725   *result_reg = (unique_p
726 		 ? lra_create_new_reg_with_unique_value
727 		 : lra_create_new_reg) (mode, original, rclass,
728 					exclude_start_hard_regs, title);
729   lra_assert (curr_insn_input_reloads_num < LRA_MAX_INSN_RELOADS);
730   curr_insn_input_reloads[curr_insn_input_reloads_num].input = original;
731   curr_insn_input_reloads[curr_insn_input_reloads_num].match_p = false;
732   curr_insn_input_reloads[curr_insn_input_reloads_num++].reg = *result_reg;
733   return true;
734 }
735 
736 
737 /* The page contains major code to choose the current insn alternative
738    and generate reloads for it.	 */
739 
740 /* Return the offset from REGNO of the least significant register
741    in (reg:MODE REGNO).
742 
743    This function is used to tell whether two registers satisfy
744    a matching constraint.  (reg:MODE1 REGNO1) matches (reg:MODE2 REGNO2) if:
745 
746          REGNO1 + lra_constraint_offset (REGNO1, MODE1)
747 	 == REGNO2 + lra_constraint_offset (REGNO2, MODE2)  */
748 int
lra_constraint_offset(int regno,machine_mode mode)749 lra_constraint_offset (int regno, machine_mode mode)
750 {
751   lra_assert (regno < FIRST_PSEUDO_REGISTER);
752 
753   scalar_int_mode int_mode;
754   if (WORDS_BIG_ENDIAN
755       && is_a <scalar_int_mode> (mode, &int_mode)
756       && GET_MODE_SIZE (int_mode) > UNITS_PER_WORD)
757     return hard_regno_nregs (regno, mode) - 1;
758   return 0;
759 }
760 
761 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
762    if they are the same hard reg, and has special hacks for
763    auto-increment and auto-decrement.  This is specifically intended for
764    process_alt_operands to use in determining whether two operands
765    match.  X is the operand whose number is the lower of the two.
766 
767    It is supposed that X is the output operand and Y is the input
768    operand.  Y_HARD_REGNO is the final hard regno of register Y or
769    register in subreg Y as we know it now.  Otherwise, it is a
770    negative value.  */
771 static bool
operands_match_p(rtx x,rtx y,int y_hard_regno)772 operands_match_p (rtx x, rtx y, int y_hard_regno)
773 {
774   int i;
775   RTX_CODE code = GET_CODE (x);
776   const char *fmt;
777 
778   if (x == y)
779     return true;
780   if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x))))
781       && (REG_P (y) || (GET_CODE (y) == SUBREG && REG_P (SUBREG_REG (y)))))
782     {
783       int j;
784 
785       i = get_hard_regno (x, false);
786       if (i < 0)
787 	goto slow;
788 
789       if ((j = y_hard_regno) < 0)
790 	goto slow;
791 
792       i += lra_constraint_offset (i, GET_MODE (x));
793       j += lra_constraint_offset (j, GET_MODE (y));
794 
795       return i == j;
796     }
797 
798   /* If two operands must match, because they are really a single
799      operand of an assembler insn, then two post-increments are invalid
800      because the assembler insn would increment only once.  On the
801      other hand, a post-increment matches ordinary indexing if the
802      post-increment is the output operand.  */
803   if (code == POST_DEC || code == POST_INC || code == POST_MODIFY)
804     return operands_match_p (XEXP (x, 0), y, y_hard_regno);
805 
806   /* Two pre-increments are invalid because the assembler insn would
807      increment only once.  On the other hand, a pre-increment matches
808      ordinary indexing if the pre-increment is the input operand.  */
809   if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC
810       || GET_CODE (y) == PRE_MODIFY)
811     return operands_match_p (x, XEXP (y, 0), -1);
812 
813  slow:
814 
815   if (code == REG && REG_P (y))
816     return REGNO (x) == REGNO (y);
817 
818   if (code == REG && GET_CODE (y) == SUBREG && REG_P (SUBREG_REG (y))
819       && x == SUBREG_REG (y))
820     return true;
821   if (GET_CODE (y) == REG && code == SUBREG && REG_P (SUBREG_REG (x))
822       && SUBREG_REG (x) == y)
823     return true;
824 
825   /* Now we have disposed of all the cases in which different rtx
826      codes can match.  */
827   if (code != GET_CODE (y))
828     return false;
829 
830   /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.  */
831   if (GET_MODE (x) != GET_MODE (y))
832     return false;
833 
834   switch (code)
835     {
836     CASE_CONST_UNIQUE:
837       return false;
838 
839     case CONST_VECTOR:
840       if (!same_vector_encodings_p (x, y))
841 	return false;
842       break;
843 
844     case LABEL_REF:
845       return label_ref_label (x) == label_ref_label (y);
846     case SYMBOL_REF:
847       return XSTR (x, 0) == XSTR (y, 0);
848 
849     default:
850       break;
851     }
852 
853   /* Compare the elements.  If any pair of corresponding elements fail
854      to match, return false for the whole things.  */
855 
856   fmt = GET_RTX_FORMAT (code);
857   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
858     {
859       int val, j;
860       switch (fmt[i])
861 	{
862 	case 'w':
863 	  if (XWINT (x, i) != XWINT (y, i))
864 	    return false;
865 	  break;
866 
867 	case 'i':
868 	  if (XINT (x, i) != XINT (y, i))
869 	    return false;
870 	  break;
871 
872 	case 'p':
873 	  if (maybe_ne (SUBREG_BYTE (x), SUBREG_BYTE (y)))
874 	    return false;
875 	  break;
876 
877 	case 'e':
878 	  val = operands_match_p (XEXP (x, i), XEXP (y, i), -1);
879 	  if (val == 0)
880 	    return false;
881 	  break;
882 
883 	case '0':
884 	  break;
885 
886 	case 'E':
887 	  if (XVECLEN (x, i) != XVECLEN (y, i))
888 	    return false;
889 	  for (j = XVECLEN (x, i) - 1; j >= 0; --j)
890 	    {
891 	      val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j), -1);
892 	      if (val == 0)
893 		return false;
894 	    }
895 	  break;
896 
897 	  /* It is believed that rtx's at this level will never
898 	     contain anything but integers and other rtx's, except for
899 	     within LABEL_REFs and SYMBOL_REFs.	 */
900 	default:
901 	  gcc_unreachable ();
902 	}
903     }
904   return true;
905 }
906 
907 /* True if X is a constant that can be forced into the constant pool.
908    MODE is the mode of the operand, or VOIDmode if not known.  */
909 #define CONST_POOL_OK_P(MODE, X)		\
910   ((MODE) != VOIDmode				\
911    && CONSTANT_P (X)				\
912    && GET_CODE (X) != HIGH			\
913    && GET_MODE_SIZE (MODE).is_constant ()	\
914    && !targetm.cannot_force_const_mem (MODE, X))
915 
916 /* True if C is a non-empty register class that has too few registers
917    to be safely used as a reload target class.	*/
918 #define SMALL_REGISTER_CLASS_P(C)		\
919   (ira_class_hard_regs_num [(C)] == 1		\
920    || (ira_class_hard_regs_num [(C)] >= 1	\
921        && targetm.class_likely_spilled_p (C)))
922 
923 /* If REG is a reload pseudo, try to make its class satisfying CL.  */
924 static void
narrow_reload_pseudo_class(rtx reg,enum reg_class cl)925 narrow_reload_pseudo_class (rtx reg, enum reg_class cl)
926 {
927   enum reg_class rclass;
928 
929   /* Do not make more accurate class from reloads generated.  They are
930      mostly moves with a lot of constraints.  Making more accurate
931      class may results in very narrow class and impossibility of find
932      registers for several reloads of one insn.	 */
933   if (INSN_UID (curr_insn) >= new_insn_uid_start)
934     return;
935   if (GET_CODE (reg) == SUBREG)
936     reg = SUBREG_REG (reg);
937   if (! REG_P (reg) || (int) REGNO (reg) < new_regno_start)
938     return;
939   if (in_class_p (reg, cl, &rclass) && rclass != cl)
940     lra_change_class (REGNO (reg), rclass, "      Change to", true);
941 }
942 
943 /* Searches X for any reference to a reg with the same value as REGNO,
944    returning the rtx of the reference found if any.  Otherwise,
945    returns NULL_RTX.  */
946 static rtx
regno_val_use_in(unsigned int regno,rtx x)947 regno_val_use_in (unsigned int regno, rtx x)
948 {
949   const char *fmt;
950   int i, j;
951   rtx tem;
952 
953   if (REG_P (x) && lra_reg_info[REGNO (x)].val == lra_reg_info[regno].val)
954     return x;
955 
956   fmt = GET_RTX_FORMAT (GET_CODE (x));
957   for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
958     {
959       if (fmt[i] == 'e')
960 	{
961 	  if ((tem = regno_val_use_in (regno, XEXP (x, i))))
962 	    return tem;
963 	}
964       else if (fmt[i] == 'E')
965 	for (j = XVECLEN (x, i) - 1; j >= 0; j--)
966 	  if ((tem = regno_val_use_in (regno , XVECEXP (x, i, j))))
967 	    return tem;
968     }
969 
970   return NULL_RTX;
971 }
972 
973 /* Return true if all current insn non-output operands except INS (it
974    has a negaitve end marker) do not use pseudos with the same value
975    as REGNO.  */
976 static bool
check_conflict_input_operands(int regno,signed char * ins)977 check_conflict_input_operands (int regno, signed char *ins)
978 {
979   int in;
980   int n_operands = curr_static_id->n_operands;
981 
982   for (int nop = 0; nop < n_operands; nop++)
983     if (! curr_static_id->operand[nop].is_operator
984 	&& curr_static_id->operand[nop].type != OP_OUT)
985       {
986 	for (int i = 0; (in = ins[i]) >= 0; i++)
987 	  if (in == nop)
988 	    break;
989 	if (in < 0
990 	    && regno_val_use_in (regno, *curr_id->operand_loc[nop]) != NULL_RTX)
991 	  return false;
992       }
993   return true;
994 }
995 
996 /* Generate reloads for matching OUT and INS (array of input operand numbers
997    with end marker -1) with reg class GOAL_CLASS and EXCLUDE_START_HARD_REGS,
998    considering output operands OUTS (similar array to INS) needing to be in
999    different registers.  Add input and output reloads correspondingly to the
1000    lists *BEFORE and *AFTER.  OUT might be negative.  In this case we generate
1001    input reloads for matched input operands INS.  EARLY_CLOBBER_P is a flag
1002    that the output operand is early clobbered for chosen alternative.  */
1003 static void
match_reload(signed char out,signed char * ins,signed char * outs,enum reg_class goal_class,HARD_REG_SET * exclude_start_hard_regs,rtx_insn ** before,rtx_insn ** after,bool early_clobber_p)1004 match_reload (signed char out, signed char *ins, signed char *outs,
1005 	      enum reg_class goal_class, HARD_REG_SET *exclude_start_hard_regs,
1006 	      rtx_insn **before, rtx_insn **after, bool early_clobber_p)
1007 {
1008   bool out_conflict;
1009   int i, in;
1010   rtx new_in_reg, new_out_reg, reg;
1011   machine_mode inmode, outmode;
1012   rtx in_rtx = *curr_id->operand_loc[ins[0]];
1013   rtx out_rtx = out < 0 ? in_rtx : *curr_id->operand_loc[out];
1014 
1015   inmode = curr_operand_mode[ins[0]];
1016   outmode = out < 0 ? inmode : curr_operand_mode[out];
1017   push_to_sequence (*before);
1018   if (inmode != outmode)
1019     {
1020       /* process_alt_operands has already checked that the mode sizes
1021 	 are ordered.  */
1022       if (partial_subreg_p (outmode, inmode))
1023 	{
1024 	  reg = new_in_reg
1025 	    = lra_create_new_reg_with_unique_value (inmode, in_rtx, goal_class,
1026 						    exclude_start_hard_regs,
1027 						    "");
1028 	  new_out_reg = gen_lowpart_SUBREG (outmode, reg);
1029 	  LRA_SUBREG_P (new_out_reg) = 1;
1030 	  /* If the input reg is dying here, we can use the same hard
1031 	     register for REG and IN_RTX.  We do it only for original
1032 	     pseudos as reload pseudos can die although original
1033 	     pseudos still live where reload pseudos dies.  */
1034 	  if (REG_P (in_rtx) && (int) REGNO (in_rtx) < lra_new_regno_start
1035 	      && find_regno_note (curr_insn, REG_DEAD, REGNO (in_rtx))
1036 	      && (!early_clobber_p
1037 		  || check_conflict_input_operands(REGNO (in_rtx), ins)))
1038 	    lra_assign_reg_val (REGNO (in_rtx), REGNO (reg));
1039 	}
1040       else
1041 	{
1042 	  reg = new_out_reg
1043 	    = lra_create_new_reg_with_unique_value (outmode, out_rtx,
1044 						    goal_class,
1045 						    exclude_start_hard_regs,
1046 						    "");
1047 	  new_in_reg = gen_lowpart_SUBREG (inmode, reg);
1048 	  /* NEW_IN_REG is non-paradoxical subreg.  We don't want
1049 	     NEW_OUT_REG living above.  We add clobber clause for
1050 	     this.  This is just a temporary clobber.  We can remove
1051 	     it at the end of LRA work.  */
1052 	  rtx_insn *clobber = emit_clobber (new_out_reg);
1053 	  LRA_TEMP_CLOBBER_P (PATTERN (clobber)) = 1;
1054 	  LRA_SUBREG_P (new_in_reg) = 1;
1055 	  if (GET_CODE (in_rtx) == SUBREG)
1056 	    {
1057 	      rtx subreg_reg = SUBREG_REG (in_rtx);
1058 
1059 	      /* If SUBREG_REG is dying here and sub-registers IN_RTX
1060 		 and NEW_IN_REG are similar, we can use the same hard
1061 		 register for REG and SUBREG_REG.  */
1062 	      if (REG_P (subreg_reg)
1063 		  && (int) REGNO (subreg_reg) < lra_new_regno_start
1064 		  && GET_MODE (subreg_reg) == outmode
1065 		  && known_eq (SUBREG_BYTE (in_rtx), SUBREG_BYTE (new_in_reg))
1066 		  && find_regno_note (curr_insn, REG_DEAD, REGNO (subreg_reg))
1067 		  && (! early_clobber_p
1068 		      || check_conflict_input_operands (REGNO (subreg_reg),
1069 							ins)))
1070 		lra_assign_reg_val (REGNO (subreg_reg), REGNO (reg));
1071 	    }
1072 	}
1073     }
1074   else
1075     {
1076       /* Pseudos have values -- see comments for lra_reg_info.
1077 	 Different pseudos with the same value do not conflict even if
1078 	 they live in the same place.  When we create a pseudo we
1079 	 assign value of original pseudo (if any) from which we
1080 	 created the new pseudo.  If we create the pseudo from the
1081 	 input pseudo, the new pseudo will have no conflict with the
1082 	 input pseudo which is wrong when the input pseudo lives after
1083 	 the insn and as the new pseudo value is changed by the insn
1084 	 output.  Therefore we create the new pseudo from the output
1085 	 except the case when we have single matched dying input
1086 	 pseudo.
1087 
1088 	 We cannot reuse the current output register because we might
1089 	 have a situation like "a <- a op b", where the constraints
1090 	 force the second input operand ("b") to match the output
1091 	 operand ("a").  "b" must then be copied into a new register
1092 	 so that it doesn't clobber the current value of "a".
1093 
1094 	 We cannot use the same value if the output pseudo is
1095 	 early clobbered or the input pseudo is mentioned in the
1096 	 output, e.g. as an address part in memory, because
1097 	 output reload will actually extend the pseudo liveness.
1098 	 We don't care about eliminable hard regs here as we are
1099 	 interesting only in pseudos.  */
1100 
1101       /* Matching input's register value is the same as one of the other
1102 	 output operand.  Output operands in a parallel insn must be in
1103 	 different registers.  */
1104       out_conflict = false;
1105       if (REG_P (in_rtx))
1106 	{
1107 	  for (i = 0; outs[i] >= 0; i++)
1108 	    {
1109 	      rtx other_out_rtx = *curr_id->operand_loc[outs[i]];
1110 	      if (outs[i] != out && REG_P (other_out_rtx)
1111 		  && (regno_val_use_in (REGNO (in_rtx), other_out_rtx)
1112 		      != NULL_RTX))
1113 		{
1114 		  out_conflict = true;
1115 		  break;
1116 		}
1117 	    }
1118 	}
1119 
1120       new_in_reg = new_out_reg
1121 	= (! early_clobber_p && ins[1] < 0 && REG_P (in_rtx)
1122 	   && (int) REGNO (in_rtx) < lra_new_regno_start
1123 	   && find_regno_note (curr_insn, REG_DEAD, REGNO (in_rtx))
1124 	   && (! early_clobber_p
1125 	       || check_conflict_input_operands (REGNO (in_rtx), ins))
1126 	   && (out < 0
1127 	       || regno_val_use_in (REGNO (in_rtx), out_rtx) == NULL_RTX)
1128 	   && !out_conflict
1129 	   ? lra_create_new_reg (inmode, in_rtx, goal_class,
1130 				 exclude_start_hard_regs, "")
1131 	   : lra_create_new_reg_with_unique_value (outmode, out_rtx, goal_class,
1132 						   exclude_start_hard_regs,
1133 						   ""));
1134     }
1135   /* In operand can be got from transformations before processing insn
1136      constraints.  One example of such transformations is subreg
1137      reloading (see function simplify_operand_subreg).  The new
1138      pseudos created by the transformations might have inaccurate
1139      class (ALL_REGS) and we should make their classes more
1140      accurate.  */
1141   narrow_reload_pseudo_class (in_rtx, goal_class);
1142   lra_emit_move (copy_rtx (new_in_reg), in_rtx);
1143   *before = get_insns ();
1144   end_sequence ();
1145   /* Add the new pseudo to consider values of subsequent input reload
1146      pseudos.  */
1147   lra_assert (curr_insn_input_reloads_num < LRA_MAX_INSN_RELOADS);
1148   curr_insn_input_reloads[curr_insn_input_reloads_num].input = in_rtx;
1149   curr_insn_input_reloads[curr_insn_input_reloads_num].match_p = true;
1150   curr_insn_input_reloads[curr_insn_input_reloads_num++].reg = new_in_reg;
1151   for (i = 0; (in = ins[i]) >= 0; i++)
1152     if (GET_MODE (*curr_id->operand_loc[in]) == VOIDmode
1153 	|| GET_MODE (new_in_reg) == GET_MODE (*curr_id->operand_loc[in]))
1154       *curr_id->operand_loc[in] = new_in_reg;
1155     else
1156       {
1157 	lra_assert
1158 	  (GET_MODE (new_out_reg) == GET_MODE (*curr_id->operand_loc[in]));
1159 	*curr_id->operand_loc[in] = new_out_reg;
1160       }
1161   lra_update_dups (curr_id, ins);
1162   if (out < 0)
1163     return;
1164   /* See a comment for the input operand above.  */
1165   narrow_reload_pseudo_class (out_rtx, goal_class);
1166   if (find_reg_note (curr_insn, REG_UNUSED, out_rtx) == NULL_RTX)
1167     {
1168       reg = SUBREG_P (out_rtx) ? SUBREG_REG (out_rtx) : out_rtx;
1169       start_sequence ();
1170       /* If we had strict_low_part, use it also in reload to keep other
1171 	 parts unchanged but do it only for regs as strict_low_part
1172 	 has no sense for memory and probably there is no insn pattern
1173 	 to match the reload insn in memory case.  */
1174       if (out >= 0 && curr_static_id->operand[out].strict_low && REG_P (reg))
1175 	out_rtx = gen_rtx_STRICT_LOW_PART (VOIDmode, out_rtx);
1176       lra_emit_move (out_rtx, copy_rtx (new_out_reg));
1177       emit_insn (*after);
1178       *after = get_insns ();
1179       end_sequence ();
1180     }
1181   *curr_id->operand_loc[out] = new_out_reg;
1182   lra_update_dup (curr_id, out);
1183 }
1184 
1185 /* Return register class which is union of all reg classes in insn
1186    constraint alternative string starting with P.  */
1187 static enum reg_class
reg_class_from_constraints(const char * p)1188 reg_class_from_constraints (const char *p)
1189 {
1190   int c, len;
1191   enum reg_class op_class = NO_REGS;
1192 
1193   do
1194     switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
1195       {
1196       case '#':
1197       case ',':
1198 	return op_class;
1199 
1200       case 'g':
1201 	op_class = reg_class_subunion[op_class][GENERAL_REGS];
1202 	break;
1203 
1204       default:
1205 	enum constraint_num cn = lookup_constraint (p);
1206 	enum reg_class cl = reg_class_for_constraint (cn);
1207 	if (cl == NO_REGS)
1208 	  {
1209 	    if (insn_extra_address_constraint (cn))
1210 	      op_class
1211 		= (reg_class_subunion
1212 		   [op_class][base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
1213 					      ADDRESS, SCRATCH)]);
1214 	    break;
1215 	  }
1216 
1217 	op_class = reg_class_subunion[op_class][cl];
1218  	break;
1219       }
1220   while ((p += len), c);
1221   return op_class;
1222 }
1223 
1224 /* If OP is a register, return the class of the register as per
1225    get_reg_class, otherwise return NO_REGS.  */
1226 static inline enum reg_class
get_op_class(rtx op)1227 get_op_class (rtx op)
1228 {
1229   return REG_P (op) ? get_reg_class (REGNO (op)) : NO_REGS;
1230 }
1231 
1232 /* Return generated insn mem_pseudo:=val if TO_P or val:=mem_pseudo
1233    otherwise.  If modes of MEM_PSEUDO and VAL are different, use
1234    SUBREG for VAL to make them equal.  */
1235 static rtx_insn *
emit_spill_move(bool to_p,rtx mem_pseudo,rtx val)1236 emit_spill_move (bool to_p, rtx mem_pseudo, rtx val)
1237 {
1238   if (GET_MODE (mem_pseudo) != GET_MODE (val))
1239     {
1240       /* Usually size of mem_pseudo is greater than val size but in
1241 	 rare cases it can be less as it can be defined by target
1242 	 dependent macro HARD_REGNO_CALLER_SAVE_MODE.  */
1243       if (! MEM_P (val))
1244 	{
1245 	  val = gen_lowpart_SUBREG (GET_MODE (mem_pseudo),
1246 				    GET_CODE (val) == SUBREG
1247 				    ? SUBREG_REG (val) : val);
1248 	  LRA_SUBREG_P (val) = 1;
1249 	}
1250       else
1251 	{
1252 	  mem_pseudo = gen_lowpart_SUBREG (GET_MODE (val), mem_pseudo);
1253 	  LRA_SUBREG_P (mem_pseudo) = 1;
1254 	}
1255     }
1256   return to_p ? gen_move_insn (mem_pseudo, val)
1257 	      : gen_move_insn (val, mem_pseudo);
1258 }
1259 
1260 /* Process a special case insn (register move), return true if we
1261    don't need to process it anymore.  INSN should be a single set
1262    insn.  Set up that RTL was changed through CHANGE_P and that hook
1263    TARGET_SECONDARY_MEMORY_NEEDED says to use secondary memory through
1264    SEC_MEM_P.  */
1265 static bool
check_and_process_move(bool * change_p,bool * sec_mem_p ATTRIBUTE_UNUSED)1266 check_and_process_move (bool *change_p, bool *sec_mem_p ATTRIBUTE_UNUSED)
1267 {
1268   int sregno, dregno;
1269   rtx dest, src, dreg, sreg, new_reg, scratch_reg;
1270   rtx_insn *before;
1271   enum reg_class dclass, sclass, secondary_class;
1272   secondary_reload_info sri;
1273 
1274   lra_assert (curr_insn_set != NULL_RTX);
1275   dreg = dest = SET_DEST (curr_insn_set);
1276   sreg = src = SET_SRC (curr_insn_set);
1277   if (GET_CODE (dest) == SUBREG)
1278     dreg = SUBREG_REG (dest);
1279   if (GET_CODE (src) == SUBREG)
1280     sreg = SUBREG_REG (src);
1281   if (! (REG_P (dreg) || MEM_P (dreg)) || ! (REG_P (sreg) || MEM_P (sreg)))
1282     return false;
1283   sclass = dclass = NO_REGS;
1284   if (REG_P (dreg))
1285     dclass = get_reg_class (REGNO (dreg));
1286   gcc_assert (dclass < LIM_REG_CLASSES && dclass >= NO_REGS);
1287   if (dclass == ALL_REGS)
1288     /* ALL_REGS is used for new pseudos created by transformations
1289        like reload of SUBREG_REG (see function
1290        simplify_operand_subreg).  We don't know their class yet.  We
1291        should figure out the class from processing the insn
1292        constraints not in this fast path function.  Even if ALL_REGS
1293        were a right class for the pseudo, secondary_... hooks usually
1294        are not define for ALL_REGS.  */
1295     return false;
1296   if (REG_P (sreg))
1297     sclass = get_reg_class (REGNO (sreg));
1298   gcc_assert (sclass < LIM_REG_CLASSES && sclass >= NO_REGS);
1299   if (sclass == ALL_REGS)
1300     /* See comments above.  */
1301     return false;
1302   if (sclass == NO_REGS && dclass == NO_REGS)
1303     return false;
1304   if (targetm.secondary_memory_needed (GET_MODE (src), sclass, dclass)
1305       && ((sclass != NO_REGS && dclass != NO_REGS)
1306 	  || (GET_MODE (src)
1307 	      != targetm.secondary_memory_needed_mode (GET_MODE (src)))))
1308     {
1309       *sec_mem_p = true;
1310       return false;
1311     }
1312   if (! REG_P (dreg) || ! REG_P (sreg))
1313     return false;
1314   sri.prev_sri = NULL;
1315   sri.icode = CODE_FOR_nothing;
1316   sri.extra_cost = 0;
1317   secondary_class = NO_REGS;
1318   /* Set up hard register for a reload pseudo for hook
1319      secondary_reload because some targets just ignore unassigned
1320      pseudos in the hook.  */
1321   if (dclass != NO_REGS && lra_get_regno_hard_regno (REGNO (dreg)) < 0)
1322     {
1323       dregno = REGNO (dreg);
1324       reg_renumber[dregno] = ira_class_hard_regs[dclass][0];
1325     }
1326   else
1327     dregno = -1;
1328   if (sclass != NO_REGS && lra_get_regno_hard_regno (REGNO (sreg)) < 0)
1329     {
1330       sregno = REGNO (sreg);
1331       reg_renumber[sregno] = ira_class_hard_regs[sclass][0];
1332     }
1333   else
1334     sregno = -1;
1335   if (sclass != NO_REGS)
1336     secondary_class
1337       = (enum reg_class) targetm.secondary_reload (false, dest,
1338 						   (reg_class_t) sclass,
1339 						   GET_MODE (src), &sri);
1340   if (sclass == NO_REGS
1341       || ((secondary_class != NO_REGS || sri.icode != CODE_FOR_nothing)
1342 	  && dclass != NO_REGS))
1343     {
1344       enum reg_class old_sclass = secondary_class;
1345       secondary_reload_info old_sri = sri;
1346 
1347       sri.prev_sri = NULL;
1348       sri.icode = CODE_FOR_nothing;
1349       sri.extra_cost = 0;
1350       secondary_class
1351 	= (enum reg_class) targetm.secondary_reload (true, src,
1352 						     (reg_class_t) dclass,
1353 						     GET_MODE (src), &sri);
1354       /* Check the target hook consistency.  */
1355       lra_assert
1356 	((secondary_class == NO_REGS && sri.icode == CODE_FOR_nothing)
1357 	 || (old_sclass == NO_REGS && old_sri.icode == CODE_FOR_nothing)
1358 	 || (secondary_class == old_sclass && sri.icode == old_sri.icode));
1359     }
1360   if (sregno >= 0)
1361     reg_renumber [sregno] = -1;
1362   if (dregno >= 0)
1363     reg_renumber [dregno] = -1;
1364   if (secondary_class == NO_REGS && sri.icode == CODE_FOR_nothing)
1365     return false;
1366   *change_p = true;
1367   new_reg = NULL_RTX;
1368   if (secondary_class != NO_REGS)
1369     new_reg = lra_create_new_reg_with_unique_value (GET_MODE (src), NULL_RTX,
1370 						    secondary_class, NULL,
1371 						    "secondary");
1372   start_sequence ();
1373   if (sri.icode == CODE_FOR_nothing)
1374     lra_emit_move (new_reg, src);
1375   else
1376     {
1377       enum reg_class scratch_class;
1378 
1379       scratch_class = (reg_class_from_constraints
1380 		       (insn_data[sri.icode].operand[2].constraint));
1381       scratch_reg = (lra_create_new_reg_with_unique_value
1382 		     (insn_data[sri.icode].operand[2].mode, NULL_RTX,
1383 		      scratch_class, NULL, "scratch"));
1384       emit_insn (GEN_FCN (sri.icode) (new_reg != NULL_RTX ? new_reg : dest,
1385 				      src, scratch_reg));
1386     }
1387   before = get_insns ();
1388   end_sequence ();
1389   lra_process_new_insns (curr_insn, before, NULL, "Inserting the move");
1390   if (new_reg != NULL_RTX)
1391     SET_SRC (curr_insn_set) = new_reg;
1392   else
1393     {
1394       if (lra_dump_file != NULL)
1395 	{
1396 	  fprintf (lra_dump_file, "Deleting move %u\n", INSN_UID (curr_insn));
1397 	  dump_insn_slim (lra_dump_file, curr_insn);
1398 	}
1399       lra_set_insn_deleted (curr_insn);
1400       return true;
1401     }
1402   return false;
1403 }
1404 
1405 /* The following data describe the result of process_alt_operands.
1406    The data are used in curr_insn_transform to generate reloads.  */
1407 
1408 /* The chosen reg classes which should be used for the corresponding
1409    operands.  */
1410 static enum reg_class goal_alt[MAX_RECOG_OPERANDS];
1411 /* Hard registers which cannot be a start hard register for the corresponding
1412    operands.  */
1413 static HARD_REG_SET goal_alt_exclude_start_hard_regs[MAX_RECOG_OPERANDS];
1414 /* True if the operand should be the same as another operand and that
1415    other operand does not need a reload.  */
1416 static bool goal_alt_match_win[MAX_RECOG_OPERANDS];
1417 /* True if the operand does not need a reload.	*/
1418 static bool goal_alt_win[MAX_RECOG_OPERANDS];
1419 /* True if the operand can be offsetable memory.  */
1420 static bool goal_alt_offmemok[MAX_RECOG_OPERANDS];
1421 /* The number of an operand to which given operand can be matched to.  */
1422 static int goal_alt_matches[MAX_RECOG_OPERANDS];
1423 /* The number of elements in the following array.  */
1424 static int goal_alt_dont_inherit_ops_num;
1425 /* Numbers of operands whose reload pseudos should not be inherited.  */
1426 static int goal_alt_dont_inherit_ops[MAX_RECOG_OPERANDS];
1427 /* True if the insn commutative operands should be swapped.  */
1428 static bool goal_alt_swapped;
1429 /* The chosen insn alternative.	 */
1430 static int goal_alt_number;
1431 
1432 /* True if the corresponding operand is the result of an equivalence
1433    substitution.  */
1434 static bool equiv_substition_p[MAX_RECOG_OPERANDS];
1435 
1436 /* The following five variables are used to choose the best insn
1437    alternative.	 They reflect final characteristics of the best
1438    alternative.	 */
1439 
1440 /* Number of necessary reloads and overall cost reflecting the
1441    previous value and other unpleasantness of the best alternative.  */
1442 static int best_losers, best_overall;
1443 /* Overall number hard registers used for reloads.  For example, on
1444    some targets we need 2 general registers to reload DFmode and only
1445    one floating point register.	 */
1446 static int best_reload_nregs;
1447 /* Overall number reflecting distances of previous reloading the same
1448    value.  The distances are counted from the current BB start.  It is
1449    used to improve inheritance chances.  */
1450 static int best_reload_sum;
1451 
1452 /* True if the current insn should have no correspondingly input or
1453    output reloads.  */
1454 static bool no_input_reloads_p, no_output_reloads_p;
1455 
1456 /* True if we swapped the commutative operands in the current
1457    insn.  */
1458 static int curr_swapped;
1459 
1460 /* if CHECK_ONLY_P is false, arrange for address element *LOC to be a
1461    register of class CL.  Add any input reloads to list BEFORE.  AFTER
1462    is nonnull if *LOC is an automodified value; handle that case by
1463    adding the required output reloads to list AFTER.  Return true if
1464    the RTL was changed.
1465 
1466    if CHECK_ONLY_P is true, check that the *LOC is a correct address
1467    register.  Return false if the address register is correct.  */
1468 static bool
process_addr_reg(rtx * loc,bool check_only_p,rtx_insn ** before,rtx_insn ** after,enum reg_class cl)1469 process_addr_reg (rtx *loc, bool check_only_p, rtx_insn **before, rtx_insn **after,
1470 		  enum reg_class cl)
1471 {
1472   int regno;
1473   enum reg_class rclass, new_class;
1474   rtx reg;
1475   rtx new_reg;
1476   machine_mode mode;
1477   bool subreg_p, before_p = false;
1478 
1479   subreg_p = GET_CODE (*loc) == SUBREG;
1480   if (subreg_p)
1481     {
1482       reg = SUBREG_REG (*loc);
1483       mode = GET_MODE (reg);
1484 
1485       /* For mode with size bigger than ptr_mode, there unlikely to be "mov"
1486 	 between two registers with different classes, but there normally will
1487 	 be "mov" which transfers element of vector register into the general
1488 	 register, and this normally will be a subreg which should be reloaded
1489 	 as a whole.  This is particularly likely to be triggered when
1490 	 -fno-split-wide-types specified.  */
1491       if (!REG_P (reg)
1492 	  || in_class_p (reg, cl, &new_class)
1493 	  || known_le (GET_MODE_SIZE (mode), GET_MODE_SIZE (ptr_mode)))
1494        loc = &SUBREG_REG (*loc);
1495     }
1496 
1497   reg = *loc;
1498   mode = GET_MODE (reg);
1499   if (! REG_P (reg))
1500     {
1501       if (check_only_p)
1502 	return true;
1503       /* Always reload memory in an address even if the target supports
1504 	 such addresses.  */
1505       new_reg = lra_create_new_reg_with_unique_value (mode, reg, cl, NULL,
1506 						      "address");
1507       before_p = true;
1508     }
1509   else
1510     {
1511       regno = REGNO (reg);
1512       rclass = get_reg_class (regno);
1513       if (! check_only_p
1514 	  && (*loc = get_equiv_with_elimination (reg, curr_insn)) != reg)
1515 	{
1516 	  if (lra_dump_file != NULL)
1517 	    {
1518 	      fprintf (lra_dump_file,
1519 		       "Changing pseudo %d in address of insn %u on equiv ",
1520 		       REGNO (reg), INSN_UID (curr_insn));
1521 	      dump_value_slim (lra_dump_file, *loc, 1);
1522 	      fprintf (lra_dump_file, "\n");
1523 	    }
1524 	  *loc = copy_rtx (*loc);
1525 	}
1526       if (*loc != reg || ! in_class_p (reg, cl, &new_class))
1527 	{
1528 	  if (check_only_p)
1529 	    return true;
1530 	  reg = *loc;
1531 	  if (get_reload_reg (after == NULL ? OP_IN : OP_INOUT,
1532 			      mode, reg, cl, NULL,
1533 			      subreg_p, "address", &new_reg))
1534 	    before_p = true;
1535 	}
1536       else if (new_class != NO_REGS && rclass != new_class)
1537 	{
1538 	  if (check_only_p)
1539 	    return true;
1540 	  lra_change_class (regno, new_class, "	   Change to", true);
1541 	  return false;
1542 	}
1543       else
1544 	return false;
1545     }
1546   if (before_p)
1547     {
1548       push_to_sequence (*before);
1549       lra_emit_move (new_reg, reg);
1550       *before = get_insns ();
1551       end_sequence ();
1552     }
1553   *loc = new_reg;
1554   if (after != NULL)
1555     {
1556       start_sequence ();
1557       lra_emit_move (before_p ? copy_rtx (reg) : reg, new_reg);
1558       emit_insn (*after);
1559       *after = get_insns ();
1560       end_sequence ();
1561     }
1562   return true;
1563 }
1564 
1565 /* Insert move insn in simplify_operand_subreg. BEFORE returns
1566    the insn to be inserted before curr insn. AFTER returns the
1567    the insn to be inserted after curr insn.  ORIGREG and NEWREG
1568    are the original reg and new reg for reload.  */
1569 static void
insert_move_for_subreg(rtx_insn ** before,rtx_insn ** after,rtx origreg,rtx newreg)1570 insert_move_for_subreg (rtx_insn **before, rtx_insn **after, rtx origreg,
1571 			rtx newreg)
1572 {
1573   if (before)
1574     {
1575       push_to_sequence (*before);
1576       lra_emit_move (newreg, origreg);
1577       *before = get_insns ();
1578       end_sequence ();
1579     }
1580   if (after)
1581     {
1582       start_sequence ();
1583       lra_emit_move (origreg, newreg);
1584       emit_insn (*after);
1585       *after = get_insns ();
1586       end_sequence ();
1587     }
1588 }
1589 
1590 static int valid_address_p (machine_mode mode, rtx addr, addr_space_t as);
1591 static bool process_address (int, bool, rtx_insn **, rtx_insn **);
1592 
1593 /* Make reloads for subreg in operand NOP with internal subreg mode
1594    REG_MODE, add new reloads for further processing.  Return true if
1595    any change was done.  */
1596 static bool
simplify_operand_subreg(int nop,machine_mode reg_mode)1597 simplify_operand_subreg (int nop, machine_mode reg_mode)
1598 {
1599   int hard_regno, inner_hard_regno;
1600   rtx_insn *before, *after;
1601   machine_mode mode, innermode;
1602   rtx reg, new_reg;
1603   rtx operand = *curr_id->operand_loc[nop];
1604   enum reg_class regclass;
1605   enum op_type type;
1606 
1607   before = after = NULL;
1608 
1609   if (GET_CODE (operand) != SUBREG)
1610     return false;
1611 
1612   mode = GET_MODE (operand);
1613   reg = SUBREG_REG (operand);
1614   innermode = GET_MODE (reg);
1615   type = curr_static_id->operand[nop].type;
1616   if (MEM_P (reg))
1617     {
1618       const bool addr_was_valid
1619 	= valid_address_p (innermode, XEXP (reg, 0), MEM_ADDR_SPACE (reg));
1620       alter_subreg (curr_id->operand_loc[nop], false);
1621       rtx subst = *curr_id->operand_loc[nop];
1622       lra_assert (MEM_P (subst));
1623       const bool addr_is_valid = valid_address_p (GET_MODE (subst),
1624 						  XEXP (subst, 0),
1625 						  MEM_ADDR_SPACE (subst));
1626       if (!addr_was_valid
1627 	  || addr_is_valid
1628 	  || ((get_constraint_type (lookup_constraint
1629 				    (curr_static_id->operand[nop].constraint))
1630 	       != CT_SPECIAL_MEMORY)
1631 	      /* We still can reload address and if the address is
1632 		 valid, we can remove subreg without reloading its
1633 		 inner memory.  */
1634 	      && valid_address_p (GET_MODE (subst),
1635 				  regno_reg_rtx
1636 				  [ira_class_hard_regs
1637 				   [base_reg_class (GET_MODE (subst),
1638 						    MEM_ADDR_SPACE (subst),
1639 						    ADDRESS, SCRATCH)][0]],
1640 				  MEM_ADDR_SPACE (subst))))
1641 	{
1642 	  /* If we change the address for a paradoxical subreg of memory, the
1643 	     new address might violate the necessary alignment or the access
1644 	     might be slow; take this into consideration.  We need not worry
1645 	     about accesses beyond allocated memory for paradoxical memory
1646 	     subregs as we don't substitute such equiv memory (see processing
1647 	     equivalences in function lra_constraints) and because for spilled
1648 	     pseudos we allocate stack memory enough for the biggest
1649 	     corresponding paradoxical subreg.
1650 
1651 	     However, do not blindly simplify a (subreg (mem ...)) for
1652 	     WORD_REGISTER_OPERATIONS targets as this may lead to loading junk
1653 	     data into a register when the inner is narrower than outer or
1654 	     missing important data from memory when the inner is wider than
1655 	     outer.  This rule only applies to modes that are no wider than
1656 	     a word.
1657 
1658 	     If valid memory becomes invalid after subreg elimination
1659 	     and address might be different we still have to reload
1660 	     memory.
1661 	  */
1662 	  if ((! addr_was_valid
1663 	       || addr_is_valid
1664 	       || known_eq (GET_MODE_SIZE (mode), GET_MODE_SIZE (innermode)))
1665 	      && !(maybe_ne (GET_MODE_PRECISION (mode),
1666 			     GET_MODE_PRECISION (innermode))
1667 		   && known_le (GET_MODE_SIZE (mode), UNITS_PER_WORD)
1668 		   && known_le (GET_MODE_SIZE (innermode), UNITS_PER_WORD)
1669 		   && WORD_REGISTER_OPERATIONS)
1670 	      && (!(MEM_ALIGN (subst) < GET_MODE_ALIGNMENT (mode)
1671 		    && targetm.slow_unaligned_access (mode, MEM_ALIGN (subst)))
1672 		  || (MEM_ALIGN (reg) < GET_MODE_ALIGNMENT (innermode)
1673 		      && targetm.slow_unaligned_access (innermode,
1674 							MEM_ALIGN (reg)))))
1675 	    return true;
1676 
1677 	  *curr_id->operand_loc[nop] = operand;
1678 
1679 	  /* But if the address was not valid, we cannot reload the MEM without
1680 	     reloading the address first.  */
1681 	  if (!addr_was_valid)
1682 	    process_address (nop, false, &before, &after);
1683 
1684 	  /* INNERMODE is fast, MODE slow.  Reload the mem in INNERMODE.  */
1685 	  enum reg_class rclass
1686 	    = (enum reg_class) targetm.preferred_reload_class (reg, ALL_REGS);
1687 	  if (get_reload_reg (curr_static_id->operand[nop].type, innermode,
1688 			      reg, rclass, NULL,
1689 			      TRUE, "slow/invalid mem", &new_reg))
1690 	    {
1691 	      bool insert_before, insert_after;
1692 	      bitmap_set_bit (&lra_subreg_reload_pseudos, REGNO (new_reg));
1693 
1694 	      insert_before = (type != OP_OUT
1695 			       || partial_subreg_p (mode, innermode));
1696 	      insert_after = type != OP_IN;
1697 	      insert_move_for_subreg (insert_before ? &before : NULL,
1698 				      insert_after ? &after : NULL,
1699 				      reg, new_reg);
1700 	    }
1701 	  SUBREG_REG (operand) = new_reg;
1702 
1703 	  /* Convert to MODE.  */
1704 	  reg = operand;
1705 	  rclass
1706 	    = (enum reg_class) targetm.preferred_reload_class (reg, ALL_REGS);
1707 	  if (get_reload_reg (curr_static_id->operand[nop].type, mode, reg,
1708 			      rclass, NULL,
1709 			      TRUE, "slow/invalid mem", &new_reg))
1710 	    {
1711 	      bool insert_before, insert_after;
1712 	      bitmap_set_bit (&lra_subreg_reload_pseudos, REGNO (new_reg));
1713 
1714 	      insert_before = type != OP_OUT;
1715 	      insert_after = type != OP_IN;
1716 	      insert_move_for_subreg (insert_before ? &before : NULL,
1717 				      insert_after ? &after : NULL,
1718 				      reg, new_reg);
1719 	    }
1720 	  *curr_id->operand_loc[nop] = new_reg;
1721 	  lra_process_new_insns (curr_insn, before, after,
1722 				 "Inserting slow/invalid mem reload");
1723 	  return true;
1724 	}
1725 
1726       /* If the address was valid and became invalid, prefer to reload
1727 	 the memory.  Typical case is when the index scale should
1728 	 correspond the memory.  */
1729       *curr_id->operand_loc[nop] = operand;
1730       /* Do not return false here as the MEM_P (reg) will be processed
1731 	 later in this function.  */
1732     }
1733   else if (REG_P (reg) && REGNO (reg) < FIRST_PSEUDO_REGISTER)
1734     {
1735       alter_subreg (curr_id->operand_loc[nop], false);
1736       return true;
1737     }
1738   else if (CONSTANT_P (reg))
1739     {
1740       /* Try to simplify subreg of constant.  It is usually result of
1741 	 equivalence substitution.  */
1742       if (innermode == VOIDmode
1743 	  && (innermode = original_subreg_reg_mode[nop]) == VOIDmode)
1744 	innermode = curr_static_id->operand[nop].mode;
1745       if ((new_reg = simplify_subreg (mode, reg, innermode,
1746 				      SUBREG_BYTE (operand))) != NULL_RTX)
1747 	{
1748 	  *curr_id->operand_loc[nop] = new_reg;
1749 	  return true;
1750 	}
1751     }
1752   /* Put constant into memory when we have mixed modes.  It generates
1753      a better code in most cases as it does not need a secondary
1754      reload memory.  It also prevents LRA looping when LRA is using
1755      secondary reload memory again and again.  */
1756   if (CONSTANT_P (reg) && CONST_POOL_OK_P (reg_mode, reg)
1757       && SCALAR_INT_MODE_P (reg_mode) != SCALAR_INT_MODE_P (mode))
1758     {
1759       SUBREG_REG (operand) = force_const_mem (reg_mode, reg);
1760       alter_subreg (curr_id->operand_loc[nop], false);
1761       return true;
1762     }
1763   /* Force a reload of the SUBREG_REG if this is a constant or PLUS or
1764      if there may be a problem accessing OPERAND in the outer
1765      mode.  */
1766   if ((REG_P (reg)
1767        && REGNO (reg) >= FIRST_PSEUDO_REGISTER
1768        && (hard_regno = lra_get_regno_hard_regno (REGNO (reg))) >= 0
1769        /* Don't reload paradoxical subregs because we could be looping
1770 	  having repeatedly final regno out of hard regs range.  */
1771        && (hard_regno_nregs (hard_regno, innermode)
1772 	   >= hard_regno_nregs (hard_regno, mode))
1773        && simplify_subreg_regno (hard_regno, innermode,
1774 				 SUBREG_BYTE (operand), mode) < 0
1775        /* Don't reload subreg for matching reload.  It is actually
1776 	  valid subreg in LRA.  */
1777        && ! LRA_SUBREG_P (operand))
1778       || CONSTANT_P (reg) || GET_CODE (reg) == PLUS || MEM_P (reg))
1779     {
1780       enum reg_class rclass;
1781 
1782       if (REG_P (reg))
1783 	/* There is a big probability that we will get the same class
1784 	   for the new pseudo and we will get the same insn which
1785 	   means infinite looping.  So spill the new pseudo.  */
1786 	rclass = NO_REGS;
1787       else
1788 	/* The class will be defined later in curr_insn_transform.  */
1789 	rclass
1790 	  = (enum reg_class) targetm.preferred_reload_class (reg, ALL_REGS);
1791 
1792       if (get_reload_reg (curr_static_id->operand[nop].type, reg_mode, reg,
1793 			  rclass, NULL,
1794 			  TRUE, "subreg reg", &new_reg))
1795 	{
1796 	  bool insert_before, insert_after;
1797 	  bitmap_set_bit (&lra_subreg_reload_pseudos, REGNO (new_reg));
1798 
1799 	  insert_before = (type != OP_OUT
1800 			   || read_modify_subreg_p (operand));
1801 	  insert_after = (type != OP_IN);
1802 	  insert_move_for_subreg (insert_before ? &before : NULL,
1803 				  insert_after ? &after : NULL,
1804 				  reg, new_reg);
1805 	}
1806       SUBREG_REG (operand) = new_reg;
1807       lra_process_new_insns (curr_insn, before, after,
1808 			     "Inserting subreg reload");
1809       return true;
1810     }
1811   /* Force a reload for a paradoxical subreg. For paradoxical subreg,
1812      IRA allocates hardreg to the inner pseudo reg according to its mode
1813      instead of the outermode, so the size of the hardreg may not be enough
1814      to contain the outermode operand, in that case we may need to insert
1815      reload for the reg. For the following two types of paradoxical subreg,
1816      we need to insert reload:
1817      1. If the op_type is OP_IN, and the hardreg could not be paired with
1818         other hardreg to contain the outermode operand
1819         (checked by in_hard_reg_set_p), we need to insert the reload.
1820      2. If the op_type is OP_OUT or OP_INOUT.
1821 
1822      Here is a paradoxical subreg example showing how the reload is generated:
1823 
1824      (insn 5 4 7 2 (set (reg:TI 106 [ __comp ])
1825         (subreg:TI (reg:DI 107 [ __comp ]) 0)) {*movti_internal_rex64}
1826 
1827      In IRA, reg107 is allocated to a DImode hardreg. We use x86-64 as example
1828      here, if reg107 is assigned to hardreg R15, because R15 is the last
1829      hardreg, compiler cannot find another hardreg to pair with R15 to
1830      contain TImode data. So we insert a TImode reload reg180 for it.
1831      After reload is inserted:
1832 
1833      (insn 283 0 0 (set (subreg:DI (reg:TI 180 [orig:107 __comp ] [107]) 0)
1834         (reg:DI 107 [ __comp ])) -1
1835      (insn 5 4 7 2 (set (reg:TI 106 [ __comp ])
1836         (subreg:TI (reg:TI 180 [orig:107 __comp ] [107]) 0)) {*movti_internal_rex64}
1837 
1838      Two reload hard registers will be allocated to reg180 to save TImode data
1839      in LRA_assign.
1840 
1841      For LRA pseudos this should normally be handled by the biggest_mode
1842      mechanism.  However, it's possible for new uses of an LRA pseudo
1843      to be introduced after we've allocated it, such as when undoing
1844      inheritance, and the allocated register might not then be appropriate
1845      for the new uses.  */
1846   else if (REG_P (reg)
1847 	   && REGNO (reg) >= FIRST_PSEUDO_REGISTER
1848 	   && paradoxical_subreg_p (operand)
1849 	   && (inner_hard_regno = lra_get_regno_hard_regno (REGNO (reg))) >= 0
1850 	   && ((hard_regno
1851 		= simplify_subreg_regno (inner_hard_regno, innermode,
1852 					 SUBREG_BYTE (operand), mode)) < 0
1853 	       || ((hard_regno_nregs (inner_hard_regno, innermode)
1854 		    < hard_regno_nregs (hard_regno, mode))
1855 		   && (regclass = lra_get_allocno_class (REGNO (reg)))
1856 		   && (type != OP_IN
1857 		       || !in_hard_reg_set_p (reg_class_contents[regclass],
1858 					      mode, hard_regno)
1859 		       || overlaps_hard_reg_set_p (lra_no_alloc_regs,
1860 						   mode, hard_regno)))))
1861     {
1862       /* The class will be defined later in curr_insn_transform.  */
1863       enum reg_class rclass
1864 	= (enum reg_class) targetm.preferred_reload_class (reg, ALL_REGS);
1865 
1866       if (get_reload_reg (curr_static_id->operand[nop].type, mode, reg,
1867                           rclass, NULL,
1868 			  TRUE, "paradoxical subreg", &new_reg))
1869         {
1870 	  rtx subreg;
1871 	  bool insert_before, insert_after;
1872 
1873 	  PUT_MODE (new_reg, mode);
1874           subreg = gen_lowpart_SUBREG (innermode, new_reg);
1875 	  bitmap_set_bit (&lra_subreg_reload_pseudos, REGNO (new_reg));
1876 
1877 	  insert_before = (type != OP_OUT);
1878 	  insert_after = (type != OP_IN);
1879 	  insert_move_for_subreg (insert_before ? &before : NULL,
1880 				  insert_after ? &after : NULL,
1881 				  reg, subreg);
1882 	}
1883       SUBREG_REG (operand) = new_reg;
1884       lra_process_new_insns (curr_insn, before, after,
1885                              "Inserting paradoxical subreg reload");
1886       return true;
1887     }
1888   return false;
1889 }
1890 
1891 /* Return TRUE if X refers for a hard register from SET.  */
1892 static bool
uses_hard_regs_p(rtx x,HARD_REG_SET set)1893 uses_hard_regs_p (rtx x, HARD_REG_SET set)
1894 {
1895   int i, j, x_hard_regno;
1896   machine_mode mode;
1897   const char *fmt;
1898   enum rtx_code code;
1899 
1900   if (x == NULL_RTX)
1901     return false;
1902   code = GET_CODE (x);
1903   mode = GET_MODE (x);
1904 
1905   if (code == SUBREG)
1906     {
1907       /* For all SUBREGs we want to check whether the full multi-register
1908 	 overlaps the set.  For normal SUBREGs this means 'get_hard_regno' of
1909 	 the inner register, for paradoxical SUBREGs this means the
1910 	 'get_hard_regno' of the full SUBREG and for complete SUBREGs either is
1911 	 fine.  Use the wider mode for all cases.  */
1912       rtx subreg = SUBREG_REG (x);
1913       mode = wider_subreg_mode (x);
1914       if (mode == GET_MODE (subreg))
1915 	{
1916 	  x = subreg;
1917 	  code = GET_CODE (x);
1918 	}
1919     }
1920 
1921   if (REG_P (x) || SUBREG_P (x))
1922     {
1923       x_hard_regno = get_hard_regno (x, true);
1924       return (x_hard_regno >= 0
1925 	      && overlaps_hard_reg_set_p (set, mode, x_hard_regno));
1926     }
1927   fmt = GET_RTX_FORMAT (code);
1928   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1929     {
1930       if (fmt[i] == 'e')
1931 	{
1932 	  if (uses_hard_regs_p (XEXP (x, i), set))
1933 	    return true;
1934 	}
1935       else if (fmt[i] == 'E')
1936 	{
1937 	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
1938 	    if (uses_hard_regs_p (XVECEXP (x, i, j), set))
1939 	      return true;
1940 	}
1941     }
1942   return false;
1943 }
1944 
1945 /* Return true if OP is a spilled pseudo. */
1946 static inline bool
spilled_pseudo_p(rtx op)1947 spilled_pseudo_p (rtx op)
1948 {
1949   return (REG_P (op)
1950 	  && REGNO (op) >= FIRST_PSEUDO_REGISTER && in_mem_p (REGNO (op)));
1951 }
1952 
1953 /* Return true if X is a general constant.  */
1954 static inline bool
general_constant_p(rtx x)1955 general_constant_p (rtx x)
1956 {
1957   return CONSTANT_P (x) && (! flag_pic || LEGITIMATE_PIC_OPERAND_P (x));
1958 }
1959 
1960 static bool
reg_in_class_p(rtx reg,enum reg_class cl)1961 reg_in_class_p (rtx reg, enum reg_class cl)
1962 {
1963   if (cl == NO_REGS)
1964     return get_reg_class (REGNO (reg)) == NO_REGS;
1965   return in_class_p (reg, cl, NULL);
1966 }
1967 
1968 /* Return true if SET of RCLASS contains no hard regs which can be
1969    used in MODE.  */
1970 static bool
prohibited_class_reg_set_mode_p(enum reg_class rclass,HARD_REG_SET & set,machine_mode mode)1971 prohibited_class_reg_set_mode_p (enum reg_class rclass,
1972 				 HARD_REG_SET &set,
1973 				 machine_mode mode)
1974 {
1975   HARD_REG_SET temp;
1976 
1977   lra_assert (hard_reg_set_subset_p (reg_class_contents[rclass], set));
1978   temp = set & ~lra_no_alloc_regs;
1979   return (hard_reg_set_subset_p
1980 	  (temp, ira_prohibited_class_mode_regs[rclass][mode]));
1981 }
1982 
1983 
1984 /* Used to check validity info about small class input operands.  It
1985    should be incremented at start of processing an insn
1986    alternative.  */
1987 static unsigned int curr_small_class_check = 0;
1988 
1989 /* Update number of used inputs of class OP_CLASS for operand NOP
1990    of alternative NALT.  Return true if we have more such class operands
1991    than the number of available regs.  */
1992 static bool
update_and_check_small_class_inputs(int nop,int nalt,enum reg_class op_class)1993 update_and_check_small_class_inputs (int nop, int nalt,
1994 				     enum reg_class op_class)
1995 {
1996   static unsigned int small_class_check[LIM_REG_CLASSES];
1997   static int small_class_input_nums[LIM_REG_CLASSES];
1998 
1999   if (SMALL_REGISTER_CLASS_P (op_class)
2000       /* We are interesting in classes became small because of fixing
2001 	 some hard regs, e.g. by an user through GCC options.  */
2002       && hard_reg_set_intersect_p (reg_class_contents[op_class],
2003 				   ira_no_alloc_regs)
2004       && (curr_static_id->operand[nop].type != OP_OUT
2005 	  || TEST_BIT (curr_static_id->operand[nop].early_clobber_alts, nalt)))
2006     {
2007       if (small_class_check[op_class] == curr_small_class_check)
2008 	small_class_input_nums[op_class]++;
2009       else
2010 	{
2011 	  small_class_check[op_class] = curr_small_class_check;
2012 	  small_class_input_nums[op_class] = 1;
2013 	}
2014       if (small_class_input_nums[op_class] > ira_class_hard_regs_num[op_class])
2015 	return true;
2016     }
2017   return false;
2018 }
2019 
2020 /* Major function to choose the current insn alternative and what
2021    operands should be reloaded and how.	 If ONLY_ALTERNATIVE is not
2022    negative we should consider only this alternative.  Return false if
2023    we cannot choose the alternative or find how to reload the
2024    operands.  */
2025 static bool
process_alt_operands(int only_alternative)2026 process_alt_operands (int only_alternative)
2027 {
2028   bool ok_p = false;
2029   int nop, overall, nalt;
2030   int n_alternatives = curr_static_id->n_alternatives;
2031   int n_operands = curr_static_id->n_operands;
2032   /* LOSERS counts the operands that don't fit this alternative and
2033      would require loading.  */
2034   int losers;
2035   int addr_losers;
2036   /* REJECT is a count of how undesirable this alternative says it is
2037      if any reloading is required.  If the alternative matches exactly
2038      then REJECT is ignored, but otherwise it gets this much counted
2039      against it in addition to the reloading needed.  */
2040   int reject;
2041   /* This is defined by '!' or '?' alternative constraint and added to
2042      reject.  But in some cases it can be ignored.  */
2043   int static_reject;
2044   int op_reject;
2045   /* The number of elements in the following array.  */
2046   int early_clobbered_regs_num;
2047   /* Numbers of operands which are early clobber registers.  */
2048   int early_clobbered_nops[MAX_RECOG_OPERANDS];
2049   enum reg_class curr_alt[MAX_RECOG_OPERANDS];
2050   HARD_REG_SET curr_alt_set[MAX_RECOG_OPERANDS];
2051   HARD_REG_SET curr_alt_exclude_start_hard_regs[MAX_RECOG_OPERANDS];
2052   bool curr_alt_match_win[MAX_RECOG_OPERANDS];
2053   bool curr_alt_win[MAX_RECOG_OPERANDS];
2054   bool curr_alt_offmemok[MAX_RECOG_OPERANDS];
2055   int curr_alt_matches[MAX_RECOG_OPERANDS];
2056   /* The number of elements in the following array.  */
2057   int curr_alt_dont_inherit_ops_num;
2058   /* Numbers of operands whose reload pseudos should not be inherited.	*/
2059   int curr_alt_dont_inherit_ops[MAX_RECOG_OPERANDS];
2060   rtx op;
2061   /* The register when the operand is a subreg of register, otherwise the
2062      operand itself.  */
2063   rtx no_subreg_reg_operand[MAX_RECOG_OPERANDS];
2064   /* The register if the operand is a register or subreg of register,
2065      otherwise NULL.  */
2066   rtx operand_reg[MAX_RECOG_OPERANDS];
2067   int hard_regno[MAX_RECOG_OPERANDS];
2068   machine_mode biggest_mode[MAX_RECOG_OPERANDS];
2069   int reload_nregs, reload_sum;
2070   bool costly_p;
2071   enum reg_class cl;
2072 
2073   /* Calculate some data common for all alternatives to speed up the
2074      function.	*/
2075   for (nop = 0; nop < n_operands; nop++)
2076     {
2077       rtx reg;
2078 
2079       op = no_subreg_reg_operand[nop] = *curr_id->operand_loc[nop];
2080       /* The real hard regno of the operand after the allocation.  */
2081       hard_regno[nop] = get_hard_regno (op, true);
2082 
2083       operand_reg[nop] = reg = op;
2084       biggest_mode[nop] = GET_MODE (op);
2085       if (GET_CODE (op) == SUBREG)
2086 	{
2087 	  biggest_mode[nop] = wider_subreg_mode (op);
2088 	  operand_reg[nop] = reg = SUBREG_REG (op);
2089 	}
2090       if (! REG_P (reg))
2091 	operand_reg[nop] = NULL_RTX;
2092       else if (REGNO (reg) >= FIRST_PSEUDO_REGISTER
2093 	       || ((int) REGNO (reg)
2094 		   == lra_get_elimination_hard_regno (REGNO (reg))))
2095 	no_subreg_reg_operand[nop] = reg;
2096       else
2097 	operand_reg[nop] = no_subreg_reg_operand[nop]
2098 	  /* Just use natural mode for elimination result.  It should
2099 	     be enough for extra constraints hooks.  */
2100 	  = regno_reg_rtx[hard_regno[nop]];
2101     }
2102 
2103   /* The constraints are made of several alternatives.	Each operand's
2104      constraint looks like foo,bar,... with commas separating the
2105      alternatives.  The first alternatives for all operands go
2106      together, the second alternatives go together, etc.
2107 
2108      First loop over alternatives.  */
2109   alternative_mask preferred = curr_id->preferred_alternatives;
2110   if (only_alternative >= 0)
2111     preferred &= ALTERNATIVE_BIT (only_alternative);
2112 
2113   for (nalt = 0; nalt < n_alternatives; nalt++)
2114     {
2115       /* Loop over operands for one constraint alternative.  */
2116       if (!TEST_BIT (preferred, nalt))
2117 	continue;
2118 
2119       bool matching_early_clobber[MAX_RECOG_OPERANDS];
2120       curr_small_class_check++;
2121       overall = losers = addr_losers = 0;
2122       static_reject = reject = reload_nregs = reload_sum = 0;
2123       for (nop = 0; nop < n_operands; nop++)
2124 	{
2125 	  int inc = (curr_static_id
2126 		     ->operand_alternative[nalt * n_operands + nop].reject);
2127 	  if (lra_dump_file != NULL && inc != 0)
2128 	    fprintf (lra_dump_file,
2129 		     "            Staticly defined alt reject+=%d\n", inc);
2130 	  static_reject += inc;
2131 	  matching_early_clobber[nop] = 0;
2132 	}
2133       reject += static_reject;
2134       early_clobbered_regs_num = 0;
2135 
2136       for (nop = 0; nop < n_operands; nop++)
2137 	{
2138 	  const char *p;
2139 	  char *end;
2140 	  int len, c, m, i, opalt_num, this_alternative_matches;
2141 	  bool win, did_match, offmemok, early_clobber_p;
2142 	  /* false => this operand can be reloaded somehow for this
2143 	     alternative.  */
2144 	  bool badop;
2145 	  /* true => this operand can be reloaded if the alternative
2146 	     allows regs.  */
2147 	  bool winreg;
2148 	  /* True if a constant forced into memory would be OK for
2149 	     this operand.  */
2150 	  bool constmemok;
2151 	  enum reg_class this_alternative, this_costly_alternative;
2152 	  HARD_REG_SET this_alternative_set, this_costly_alternative_set;
2153 	  HARD_REG_SET this_alternative_exclude_start_hard_regs;
2154 	  bool this_alternative_match_win, this_alternative_win;
2155 	  bool this_alternative_offmemok;
2156 	  bool scratch_p;
2157 	  machine_mode mode;
2158 	  enum constraint_num cn;
2159 
2160 	  opalt_num = nalt * n_operands + nop;
2161 	  if (curr_static_id->operand_alternative[opalt_num].anything_ok)
2162 	    {
2163 	      /* Fast track for no constraints at all.	*/
2164 	      curr_alt[nop] = NO_REGS;
2165 	      CLEAR_HARD_REG_SET (curr_alt_set[nop]);
2166 	      curr_alt_win[nop] = true;
2167 	      curr_alt_match_win[nop] = false;
2168 	      curr_alt_offmemok[nop] = false;
2169 	      curr_alt_matches[nop] = -1;
2170 	      continue;
2171 	    }
2172 
2173 	  op = no_subreg_reg_operand[nop];
2174 	  mode = curr_operand_mode[nop];
2175 
2176 	  win = did_match = winreg = offmemok = constmemok = false;
2177 	  badop = true;
2178 
2179 	  early_clobber_p = false;
2180 	  p = curr_static_id->operand_alternative[opalt_num].constraint;
2181 
2182 	  this_costly_alternative = this_alternative = NO_REGS;
2183 	  /* We update set of possible hard regs besides its class
2184 	     because reg class might be inaccurate.  For example,
2185 	     union of LO_REGS (l), HI_REGS(h), and STACK_REG(k) in ARM
2186 	     is translated in HI_REGS because classes are merged by
2187 	     pairs and there is no accurate intermediate class.	 */
2188 	  CLEAR_HARD_REG_SET (this_alternative_set);
2189 	  CLEAR_HARD_REG_SET (this_costly_alternative_set);
2190 	  CLEAR_HARD_REG_SET (this_alternative_exclude_start_hard_regs);
2191 	  this_alternative_win = false;
2192 	  this_alternative_match_win = false;
2193 	  this_alternative_offmemok = false;
2194 	  this_alternative_matches = -1;
2195 
2196 	  /* An empty constraint should be excluded by the fast
2197 	     track.  */
2198 	  lra_assert (*p != 0 && *p != ',');
2199 
2200 	  op_reject = 0;
2201 	  /* Scan this alternative's specs for this operand; set WIN
2202 	     if the operand fits any letter in this alternative.
2203 	     Otherwise, clear BADOP if this operand could fit some
2204 	     letter after reloads, or set WINREG if this operand could
2205 	     fit after reloads provided the constraint allows some
2206 	     registers.	 */
2207 	  costly_p = false;
2208 	  do
2209 	    {
2210 	      switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
2211 		{
2212 		case '\0':
2213 		  len = 0;
2214 		  break;
2215 		case ',':
2216 		  c = '\0';
2217 		  break;
2218 
2219 		case '&':
2220 		  early_clobber_p = true;
2221 		  break;
2222 
2223 		case '$':
2224 		  op_reject += LRA_MAX_REJECT;
2225 		  break;
2226 		case '^':
2227 		  op_reject += LRA_LOSER_COST_FACTOR;
2228 		  break;
2229 
2230 		case '#':
2231 		  /* Ignore rest of this alternative.  */
2232 		  c = '\0';
2233 		  break;
2234 
2235 		case '0':  case '1':  case '2':	 case '3':  case '4':
2236 		case '5':  case '6':  case '7':	 case '8':  case '9':
2237 		  {
2238 		    int m_hregno;
2239 		    bool match_p;
2240 
2241 		    m = strtoul (p, &end, 10);
2242 		    p = end;
2243 		    len = 0;
2244 		    lra_assert (nop > m);
2245 
2246 		    /* Reject matches if we don't know which operand is
2247 		       bigger.  This situation would arguably be a bug in
2248 		       an .md pattern, but could also occur in a user asm.  */
2249 		    if (!ordered_p (GET_MODE_SIZE (biggest_mode[m]),
2250 				    GET_MODE_SIZE (biggest_mode[nop])))
2251 		      break;
2252 
2253 		    /* Don't match wrong asm insn operands for proper
2254 		       diagnostic later.  */
2255 		    if (INSN_CODE (curr_insn) < 0
2256 			&& (curr_operand_mode[m] == BLKmode
2257 			    || curr_operand_mode[nop] == BLKmode)
2258 			&& curr_operand_mode[m] != curr_operand_mode[nop])
2259 		      break;
2260 
2261 		    m_hregno = get_hard_regno (*curr_id->operand_loc[m], false);
2262 		    /* We are supposed to match a previous operand.
2263 		       If we do, we win if that one did.  If we do
2264 		       not, count both of the operands as losers.
2265 		       (This is too conservative, since most of the
2266 		       time only a single reload insn will be needed
2267 		       to make the two operands win.  As a result,
2268 		       this alternative may be rejected when it is
2269 		       actually desirable.)  */
2270 		    match_p = false;
2271 		    if (operands_match_p (*curr_id->operand_loc[nop],
2272 					  *curr_id->operand_loc[m], m_hregno))
2273 		      {
2274 			/* We should reject matching of an early
2275 			   clobber operand if the matching operand is
2276 			   not dying in the insn.  */
2277 			if (!TEST_BIT (curr_static_id->operand[m]
2278 				       .early_clobber_alts, nalt)
2279 			    || operand_reg[nop] == NULL_RTX
2280 			    || (find_regno_note (curr_insn, REG_DEAD,
2281 						 REGNO (op))
2282 				|| REGNO (op) == REGNO (operand_reg[m])))
2283 			  match_p = true;
2284 		      }
2285 		    if (match_p)
2286 		      {
2287 			/* If we are matching a non-offsettable
2288 			   address where an offsettable address was
2289 			   expected, then we must reject this
2290 			   combination, because we can't reload
2291 			   it.	*/
2292 			if (curr_alt_offmemok[m]
2293 			    && MEM_P (*curr_id->operand_loc[m])
2294 			    && curr_alt[m] == NO_REGS && ! curr_alt_win[m])
2295 			  continue;
2296 		      }
2297 		    else
2298 		      {
2299 			/* If the operands do not match and one
2300 			   operand is INOUT, we can not match them.
2301 			   Try other possibilities, e.g. other
2302 			   alternatives or commutative operand
2303 			   exchange.  */
2304 			if (curr_static_id->operand[nop].type == OP_INOUT
2305 			    || curr_static_id->operand[m].type == OP_INOUT)
2306 			  break;
2307 			/* Operands don't match.  If the operands are
2308 			   different user defined explicit hard
2309 			   registers, then we cannot make them match
2310 			   when one is early clobber operand.  */
2311 			if ((REG_P (*curr_id->operand_loc[nop])
2312 			     || SUBREG_P (*curr_id->operand_loc[nop]))
2313 			    && (REG_P (*curr_id->operand_loc[m])
2314 				|| SUBREG_P (*curr_id->operand_loc[m])))
2315 			  {
2316 			    rtx nop_reg = *curr_id->operand_loc[nop];
2317 			    if (SUBREG_P (nop_reg))
2318 			      nop_reg = SUBREG_REG (nop_reg);
2319 			    rtx m_reg = *curr_id->operand_loc[m];
2320 			    if (SUBREG_P (m_reg))
2321 			      m_reg = SUBREG_REG (m_reg);
2322 
2323 			    if (REG_P (nop_reg)
2324 				&& HARD_REGISTER_P (nop_reg)
2325 				&& REG_USERVAR_P (nop_reg)
2326 				&& REG_P (m_reg)
2327 				&& HARD_REGISTER_P (m_reg)
2328 				&& REG_USERVAR_P (m_reg))
2329 			      {
2330 				int i;
2331 
2332 				for (i = 0; i < early_clobbered_regs_num; i++)
2333 				  if (m == early_clobbered_nops[i])
2334 				    break;
2335 				if (i < early_clobbered_regs_num
2336 				    || early_clobber_p)
2337 				  break;
2338 			      }
2339 			  }
2340 			/* Both operands must allow a reload register,
2341 			   otherwise we cannot make them match.  */
2342 			if (curr_alt[m] == NO_REGS)
2343 			  break;
2344 			/* Retroactively mark the operand we had to
2345 			   match as a loser, if it wasn't already and
2346 			   it wasn't matched to a register constraint
2347 			   (e.g it might be matched by memory). */
2348 			if (curr_alt_win[m]
2349 			    && (operand_reg[m] == NULL_RTX
2350 				|| hard_regno[m] < 0))
2351 			  {
2352 			    losers++;
2353 			    reload_nregs
2354 			      += (ira_reg_class_max_nregs[curr_alt[m]]
2355 				  [GET_MODE (*curr_id->operand_loc[m])]);
2356 			  }
2357 
2358 			/* Prefer matching earlyclobber alternative as
2359 			   it results in less hard regs required for
2360 			   the insn than a non-matching earlyclobber
2361 			   alternative.  */
2362 			if (TEST_BIT (curr_static_id->operand[m]
2363 				      .early_clobber_alts, nalt))
2364 			  {
2365 			    if (lra_dump_file != NULL)
2366 			      fprintf
2367 				(lra_dump_file,
2368 				 "            %d Matching earlyclobber alt:"
2369 				 " reject--\n",
2370 				 nop);
2371 			    if (!matching_early_clobber[m])
2372 			      {
2373 				reject--;
2374 				matching_early_clobber[m] = 1;
2375 			      }
2376 			  }
2377 			/* Otherwise we prefer no matching
2378 			   alternatives because it gives more freedom
2379 			   in RA.  */
2380 			else if (operand_reg[nop] == NULL_RTX
2381 				 || (find_regno_note (curr_insn, REG_DEAD,
2382 						      REGNO (operand_reg[nop]))
2383 				     == NULL_RTX))
2384 			  {
2385 			    if (lra_dump_file != NULL)
2386 			      fprintf
2387 				(lra_dump_file,
2388 				 "            %d Matching alt: reject+=2\n",
2389 				 nop);
2390 			    reject += 2;
2391 			  }
2392 		      }
2393 		    /* If we have to reload this operand and some
2394 		       previous operand also had to match the same
2395 		       thing as this operand, we don't know how to do
2396 		       that.  */
2397 		    if (!match_p || !curr_alt_win[m])
2398 		      {
2399 			for (i = 0; i < nop; i++)
2400 			  if (curr_alt_matches[i] == m)
2401 			    break;
2402 			if (i < nop)
2403 			  break;
2404 		      }
2405 		    else
2406 		      did_match = true;
2407 
2408 		    this_alternative_matches = m;
2409 		    /* This can be fixed with reloads if the operand
2410 		       we are supposed to match can be fixed with
2411 		       reloads. */
2412 		    badop = false;
2413 		    this_alternative = curr_alt[m];
2414 		    this_alternative_set = curr_alt_set[m];
2415 		    this_alternative_exclude_start_hard_regs
2416 			= curr_alt_exclude_start_hard_regs[m];
2417 		    winreg = this_alternative != NO_REGS;
2418 		    break;
2419 		  }
2420 
2421 		case 'g':
2422 		  if (MEM_P (op)
2423 		      || general_constant_p (op)
2424 		      || spilled_pseudo_p (op))
2425 		    win = true;
2426 		  cl = GENERAL_REGS;
2427 		  goto reg;
2428 
2429 		default:
2430 		  cn = lookup_constraint (p);
2431 		  switch (get_constraint_type (cn))
2432 		    {
2433 		    case CT_REGISTER:
2434 		      cl = reg_class_for_constraint (cn);
2435 		      if (cl != NO_REGS)
2436 			goto reg;
2437 		      break;
2438 
2439 		    case CT_CONST_INT:
2440 		      if (CONST_INT_P (op)
2441 			  && insn_const_int_ok_for_constraint (INTVAL (op), cn))
2442 			win = true;
2443 		      break;
2444 
2445 		    case CT_MEMORY:
2446 		    case CT_RELAXED_MEMORY:
2447 		      if (MEM_P (op)
2448 			  && satisfies_memory_constraint_p (op, cn))
2449 			win = true;
2450 		      else if (spilled_pseudo_p (op))
2451 			win = true;
2452 
2453 		      /* If we didn't already win, we can reload constants
2454 			 via force_const_mem or put the pseudo value into
2455 			 memory, or make other memory by reloading the
2456 			 address like for 'o'.  */
2457 		      if (CONST_POOL_OK_P (mode, op)
2458 			  || MEM_P (op) || REG_P (op)
2459 			  /* We can restore the equiv insn by a
2460 			     reload.  */
2461 			  || equiv_substition_p[nop])
2462 			badop = false;
2463 		      constmemok = true;
2464 		      offmemok = true;
2465 		      break;
2466 
2467 		    case CT_ADDRESS:
2468 		      /* An asm operand with an address constraint
2469 			 that doesn't satisfy address_operand has
2470 			 is_address cleared, so that we don't try to
2471 			 make a non-address fit.  */
2472 		      if (!curr_static_id->operand[nop].is_address)
2473 			break;
2474 		      /* If we didn't already win, we can reload the address
2475 			 into a base register.  */
2476 		      if (satisfies_address_constraint_p (op, cn))
2477 			win = true;
2478 		      cl = base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
2479 					   ADDRESS, SCRATCH);
2480 		      badop = false;
2481 		      goto reg;
2482 
2483 		    case CT_FIXED_FORM:
2484 		      if (constraint_satisfied_p (op, cn))
2485 			win = true;
2486 		      break;
2487 
2488 		    case CT_SPECIAL_MEMORY:
2489 		      if (satisfies_memory_constraint_p (op, cn))
2490 			win = true;
2491 		      else if (spilled_pseudo_p (op))
2492 			win = true;
2493 		      break;
2494 		    }
2495 		  break;
2496 
2497 		reg:
2498 		  if (mode == BLKmode)
2499 		    break;
2500 		  this_alternative = reg_class_subunion[this_alternative][cl];
2501 		  if (hard_reg_set_subset_p (this_alternative_set,
2502 					     reg_class_contents[cl]))
2503 		    this_alternative_exclude_start_hard_regs
2504 		      = ira_exclude_class_mode_regs[cl][mode];
2505 		  else if (!hard_reg_set_subset_p (reg_class_contents[cl],
2506 						   this_alternative_set))
2507 		    this_alternative_exclude_start_hard_regs
2508 		      |= ira_exclude_class_mode_regs[cl][mode];
2509 		  this_alternative_set |= reg_class_contents[cl];
2510 		  if (costly_p)
2511 		    {
2512 		      this_costly_alternative
2513 			= reg_class_subunion[this_costly_alternative][cl];
2514 		      this_costly_alternative_set |= reg_class_contents[cl];
2515 		    }
2516 		  winreg = true;
2517 		  if (REG_P (op))
2518 		    {
2519 		      if (hard_regno[nop] >= 0
2520 			  && in_hard_reg_set_p (this_alternative_set,
2521 						mode, hard_regno[nop])
2522 			  && !TEST_HARD_REG_BIT
2523 			      (this_alternative_exclude_start_hard_regs,
2524 			       hard_regno[nop]))
2525 			win = true;
2526 		      else if (hard_regno[nop] < 0
2527 			       && in_class_p (op, this_alternative, NULL))
2528 			win = true;
2529 		    }
2530 		  break;
2531 		}
2532 	      if (c != ' ' && c != '\t')
2533 		costly_p = c == '*';
2534 	    }
2535 	  while ((p += len), c);
2536 
2537 	  scratch_p = (operand_reg[nop] != NULL_RTX
2538 		       && ira_former_scratch_p (REGNO (operand_reg[nop])));
2539 	  /* Record which operands fit this alternative.  */
2540 	  if (win)
2541 	    {
2542 	      this_alternative_win = true;
2543 	      if (operand_reg[nop] != NULL_RTX)
2544 		{
2545 		  if (hard_regno[nop] >= 0)
2546 		    {
2547 		      if (in_hard_reg_set_p (this_costly_alternative_set,
2548 					     mode, hard_regno[nop]))
2549 			{
2550 			  if (lra_dump_file != NULL)
2551 			    fprintf (lra_dump_file,
2552 				     "            %d Costly set: reject++\n",
2553 				     nop);
2554 			  reject++;
2555 			}
2556 		    }
2557 		  else
2558 		    {
2559 		      /* Prefer won reg to spilled pseudo under other
2560 			 equal conditions for possibe inheritance.  */
2561 		      if (! scratch_p)
2562 			{
2563 			  if (lra_dump_file != NULL)
2564 			    fprintf
2565 			      (lra_dump_file,
2566 			       "            %d Non pseudo reload: reject++\n",
2567 			       nop);
2568 			  reject++;
2569 			}
2570 		      if (in_class_p (operand_reg[nop],
2571 				      this_costly_alternative, NULL))
2572 			{
2573 			  if (lra_dump_file != NULL)
2574 			    fprintf
2575 			      (lra_dump_file,
2576 			       "            %d Non pseudo costly reload:"
2577 			       " reject++\n",
2578 			       nop);
2579 			  reject++;
2580 			}
2581 		    }
2582 		  /* We simulate the behavior of old reload here.
2583 		     Although scratches need hard registers and it
2584 		     might result in spilling other pseudos, no reload
2585 		     insns are generated for the scratches.  So it
2586 		     might cost something but probably less than old
2587 		     reload pass believes.  */
2588 		  if (scratch_p)
2589 		    {
2590 		      if (lra_dump_file != NULL)
2591 			fprintf (lra_dump_file,
2592 				 "            %d Scratch win: reject+=2\n",
2593 				 nop);
2594 		      reject += 2;
2595 		    }
2596 		}
2597 	    }
2598 	  else if (did_match)
2599 	    this_alternative_match_win = true;
2600 	  else
2601 	    {
2602 	      int const_to_mem = 0;
2603 	      bool no_regs_p;
2604 
2605 	      reject += op_reject;
2606 	      /* Never do output reload of stack pointer.  It makes
2607 		 impossible to do elimination when SP is changed in
2608 		 RTL.  */
2609 	      if (op == stack_pointer_rtx && ! frame_pointer_needed
2610 		  && curr_static_id->operand[nop].type != OP_IN)
2611 		goto fail;
2612 
2613 	      /* If this alternative asks for a specific reg class, see if there
2614 		 is at least one allocatable register in that class.  */
2615 	      no_regs_p
2616 		= (this_alternative == NO_REGS
2617 		   || (hard_reg_set_subset_p
2618 		       (reg_class_contents[this_alternative],
2619 			lra_no_alloc_regs)));
2620 
2621 	      /* For asms, verify that the class for this alternative is possible
2622 		 for the mode that is specified.  */
2623 	      if (!no_regs_p && INSN_CODE (curr_insn) < 0)
2624 		{
2625 		  int i;
2626 		  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
2627 		    if (targetm.hard_regno_mode_ok (i, mode)
2628 			&& in_hard_reg_set_p (reg_class_contents[this_alternative],
2629 					      mode, i))
2630 		      break;
2631 		  if (i == FIRST_PSEUDO_REGISTER)
2632 		    winreg = false;
2633 		}
2634 
2635 	      /* If this operand accepts a register, and if the
2636 		 register class has at least one allocatable register,
2637 		 then this operand can be reloaded.  */
2638 	      if (winreg && !no_regs_p)
2639 		badop = false;
2640 
2641 	      if (badop)
2642 		{
2643 		  if (lra_dump_file != NULL)
2644 		    fprintf (lra_dump_file,
2645 			     "            alt=%d: Bad operand -- refuse\n",
2646 			     nalt);
2647 		  goto fail;
2648 		}
2649 
2650 	      if (this_alternative != NO_REGS)
2651 		{
2652 		  HARD_REG_SET available_regs
2653 		    = (reg_class_contents[this_alternative]
2654 		       & ~((ira_prohibited_class_mode_regs
2655 			    [this_alternative][mode])
2656 			   | lra_no_alloc_regs));
2657 		  if (hard_reg_set_empty_p (available_regs))
2658 		    {
2659 		      /* There are no hard regs holding a value of given
2660 			 mode.  */
2661 		      if (offmemok)
2662 			{
2663 			  this_alternative = NO_REGS;
2664 			  if (lra_dump_file != NULL)
2665 			    fprintf (lra_dump_file,
2666 				     "            %d Using memory because of"
2667 				     " a bad mode: reject+=2\n",
2668 				     nop);
2669 			  reject += 2;
2670 			}
2671 		      else
2672 			{
2673 			  if (lra_dump_file != NULL)
2674 			    fprintf (lra_dump_file,
2675 				     "            alt=%d: Wrong mode -- refuse\n",
2676 				     nalt);
2677 			  goto fail;
2678 			}
2679 		    }
2680 		}
2681 
2682 	      /* If not assigned pseudo has a class which a subset of
2683 		 required reg class, it is a less costly alternative
2684 		 as the pseudo still can get a hard reg of necessary
2685 		 class.  */
2686 	      if (! no_regs_p && REG_P (op) && hard_regno[nop] < 0
2687 		  && (cl = get_reg_class (REGNO (op))) != NO_REGS
2688 		  && ira_class_subset_p[this_alternative][cl])
2689 		{
2690 		  if (lra_dump_file != NULL)
2691 		    fprintf
2692 		      (lra_dump_file,
2693 		       "            %d Super set class reg: reject-=3\n", nop);
2694 		  reject -= 3;
2695 		}
2696 
2697 	      this_alternative_offmemok = offmemok;
2698 	      if (this_costly_alternative != NO_REGS)
2699 		{
2700 		  if (lra_dump_file != NULL)
2701 		    fprintf (lra_dump_file,
2702 			     "            %d Costly loser: reject++\n", nop);
2703 		  reject++;
2704 		}
2705 	      /* If the operand is dying, has a matching constraint,
2706 		 and satisfies constraints of the matched operand
2707 		 which failed to satisfy the own constraints, most probably
2708 		 the reload for this operand will be gone.  */
2709 	      if (this_alternative_matches >= 0
2710 		  && !curr_alt_win[this_alternative_matches]
2711 		  && REG_P (op)
2712 		  && find_regno_note (curr_insn, REG_DEAD, REGNO (op))
2713 		  && (hard_regno[nop] >= 0
2714 		      ? in_hard_reg_set_p (this_alternative_set,
2715 					   mode, hard_regno[nop])
2716 		      : in_class_p (op, this_alternative, NULL)))
2717 		{
2718 		  if (lra_dump_file != NULL)
2719 		    fprintf
2720 		      (lra_dump_file,
2721 		       "            %d Dying matched operand reload: reject++\n",
2722 		       nop);
2723 		  reject++;
2724 		}
2725 	      else
2726 		{
2727 		  /* Strict_low_part requires to reload the register
2728 		     not the sub-register.  In this case we should
2729 		     check that a final reload hard reg can hold the
2730 		     value mode.  */
2731 		  if (curr_static_id->operand[nop].strict_low
2732 		      && REG_P (op)
2733 		      && hard_regno[nop] < 0
2734 		      && GET_CODE (*curr_id->operand_loc[nop]) == SUBREG
2735 		      && ira_class_hard_regs_num[this_alternative] > 0
2736 		      && (!targetm.hard_regno_mode_ok
2737 			  (ira_class_hard_regs[this_alternative][0],
2738 			   GET_MODE (*curr_id->operand_loc[nop]))))
2739 		    {
2740 		      if (lra_dump_file != NULL)
2741 			fprintf
2742 			  (lra_dump_file,
2743 			   "            alt=%d: Strict low subreg reload -- refuse\n",
2744 			   nalt);
2745 		      goto fail;
2746 		    }
2747 		  losers++;
2748 		}
2749 	      if (operand_reg[nop] != NULL_RTX
2750 		  /* Output operands and matched input operands are
2751 		     not inherited.  The following conditions do not
2752 		     exactly describe the previous statement but they
2753 		     are pretty close.  */
2754 		  && curr_static_id->operand[nop].type != OP_OUT
2755 		  && (this_alternative_matches < 0
2756 		      || curr_static_id->operand[nop].type != OP_IN))
2757 		{
2758 		  int last_reload = (lra_reg_info[ORIGINAL_REGNO
2759 						  (operand_reg[nop])]
2760 				     .last_reload);
2761 
2762 		  /* The value of reload_sum has sense only if we
2763 		     process insns in their order.  It happens only on
2764 		     the first constraints sub-pass when we do most of
2765 		     reload work.  */
2766 		  if (lra_constraint_iter == 1 && last_reload > bb_reload_num)
2767 		    reload_sum += last_reload - bb_reload_num;
2768 		}
2769 	      /* If this is a constant that is reloaded into the
2770 		 desired class by copying it to memory first, count
2771 		 that as another reload.  This is consistent with
2772 		 other code and is required to avoid choosing another
2773 		 alternative when the constant is moved into memory.
2774 		 Note that the test here is precisely the same as in
2775 		 the code below that calls force_const_mem.  */
2776 	      if (CONST_POOL_OK_P (mode, op)
2777 		  && ((targetm.preferred_reload_class
2778 		       (op, this_alternative) == NO_REGS)
2779 		      || no_input_reloads_p))
2780 		{
2781 		  const_to_mem = 1;
2782 		  if (! no_regs_p)
2783 		    losers++;
2784 		}
2785 
2786 	      /* Alternative loses if it requires a type of reload not
2787 		 permitted for this insn.  We can always reload
2788 		 objects with a REG_UNUSED note.  */
2789 	      if ((curr_static_id->operand[nop].type != OP_IN
2790 		   && no_output_reloads_p
2791 		   && ! find_reg_note (curr_insn, REG_UNUSED, op))
2792 		  || (curr_static_id->operand[nop].type != OP_OUT
2793 		      && no_input_reloads_p && ! const_to_mem)
2794 		  || (this_alternative_matches >= 0
2795 		      && (no_input_reloads_p
2796 			  || (no_output_reloads_p
2797 			      && (curr_static_id->operand
2798 				  [this_alternative_matches].type != OP_IN)
2799 			      && ! find_reg_note (curr_insn, REG_UNUSED,
2800 						  no_subreg_reg_operand
2801 						  [this_alternative_matches])))))
2802 		{
2803 		  if (lra_dump_file != NULL)
2804 		    fprintf
2805 		      (lra_dump_file,
2806 		       "            alt=%d: No input/output reload -- refuse\n",
2807 		       nalt);
2808 		  goto fail;
2809 		}
2810 
2811 	      /* Alternative loses if it required class pseudo cannot
2812 		 hold value of required mode.  Such insns can be
2813 		 described by insn definitions with mode iterators.  */
2814 	      if (GET_MODE (*curr_id->operand_loc[nop]) != VOIDmode
2815 		  && ! hard_reg_set_empty_p (this_alternative_set)
2816 		  /* It is common practice for constraints to use a
2817 		     class which does not have actually enough regs to
2818 		     hold the value (e.g. x86 AREG for mode requiring
2819 		     more one general reg).  Therefore we have 2
2820 		     conditions to check that the reload pseudo cannot
2821 		     hold the mode value.  */
2822 		  && (!targetm.hard_regno_mode_ok
2823 		      (ira_class_hard_regs[this_alternative][0],
2824 		       GET_MODE (*curr_id->operand_loc[nop])))
2825 		  /* The above condition is not enough as the first
2826 		     reg in ira_class_hard_regs can be not aligned for
2827 		     multi-words mode values.  */
2828 		  && (prohibited_class_reg_set_mode_p
2829 		      (this_alternative, this_alternative_set,
2830 		       GET_MODE (*curr_id->operand_loc[nop]))))
2831 		{
2832 		  if (lra_dump_file != NULL)
2833 		    fprintf (lra_dump_file,
2834 			     "            alt=%d: reload pseudo for op %d "
2835 			     "cannot hold the mode value -- refuse\n",
2836 			     nalt, nop);
2837 		  goto fail;
2838 		}
2839 
2840 	      /* Check strong discouragement of reload of non-constant
2841 		 into class THIS_ALTERNATIVE.  */
2842 	      if (! CONSTANT_P (op) && ! no_regs_p
2843 		  && (targetm.preferred_reload_class
2844 		      (op, this_alternative) == NO_REGS
2845 		      || (curr_static_id->operand[nop].type == OP_OUT
2846 			  && (targetm.preferred_output_reload_class
2847 			      (op, this_alternative) == NO_REGS))))
2848 		{
2849 		  if (offmemok && REG_P (op))
2850 		    {
2851 		      if (lra_dump_file != NULL)
2852 			fprintf
2853 			  (lra_dump_file,
2854 			   "            %d Spill pseudo into memory: reject+=3\n",
2855 			   nop);
2856 		      reject += 3;
2857 		    }
2858 		  else
2859 		    {
2860 		      if (lra_dump_file != NULL)
2861 			fprintf
2862 			  (lra_dump_file,
2863 			   "            %d Non-prefered reload: reject+=%d\n",
2864 			   nop, LRA_MAX_REJECT);
2865 		      reject += LRA_MAX_REJECT;
2866 		    }
2867 		}
2868 
2869 	      if (! (MEM_P (op) && offmemok)
2870 		  && ! (const_to_mem && constmemok))
2871 		{
2872 		  /* We prefer to reload pseudos over reloading other
2873 		     things, since such reloads may be able to be
2874 		     eliminated later.  So bump REJECT in other cases.
2875 		     Don't do this in the case where we are forcing a
2876 		     constant into memory and it will then win since
2877 		     we don't want to have a different alternative
2878 		     match then.  */
2879 		  if (! (REG_P (op) && REGNO (op) >= FIRST_PSEUDO_REGISTER))
2880 		    {
2881 		      if (lra_dump_file != NULL)
2882 			fprintf
2883 			  (lra_dump_file,
2884 			   "            %d Non-pseudo reload: reject+=2\n",
2885 			   nop);
2886 		      reject += 2;
2887 		    }
2888 
2889 		  if (! no_regs_p)
2890 		    reload_nregs
2891 		      += ira_reg_class_max_nregs[this_alternative][mode];
2892 
2893 		  if (SMALL_REGISTER_CLASS_P (this_alternative))
2894 		    {
2895 		      if (lra_dump_file != NULL)
2896 			fprintf
2897 			  (lra_dump_file,
2898 			   "            %d Small class reload: reject+=%d\n",
2899 			   nop, LRA_LOSER_COST_FACTOR / 2);
2900 		      reject += LRA_LOSER_COST_FACTOR / 2;
2901 		    }
2902 		}
2903 
2904 	      /* We are trying to spill pseudo into memory.  It is
2905 		 usually more costly than moving to a hard register
2906 		 although it might takes the same number of
2907 		 reloads.
2908 
2909 		 Non-pseudo spill may happen also.  Suppose a target allows both
2910 		 register and memory in the operand constraint alternatives,
2911 		 then it's typical that an eliminable register has a substition
2912 		 of "base + offset" which can either be reloaded by a simple
2913 		 "new_reg <= base + offset" which will match the register
2914 		 constraint, or a similar reg addition followed by further spill
2915 		 to and reload from memory which will match the memory
2916 		 constraint, but this memory spill will be much more costly
2917 		 usually.
2918 
2919 		 Code below increases the reject for both pseudo and non-pseudo
2920 		 spill.  */
2921 	      if (no_regs_p
2922 		  && !(MEM_P (op) && offmemok)
2923 		  && !(REG_P (op) && hard_regno[nop] < 0))
2924 		{
2925 		  if (lra_dump_file != NULL)
2926 		    fprintf
2927 		      (lra_dump_file,
2928 		       "            %d Spill %spseudo into memory: reject+=3\n",
2929 		       nop, REG_P (op) ? "" : "Non-");
2930 		  reject += 3;
2931 		  if (VECTOR_MODE_P (mode))
2932 		    {
2933 		      /* Spilling vectors into memory is usually more
2934 			 costly as they contain big values.  */
2935 		      if (lra_dump_file != NULL)
2936 			fprintf
2937 			  (lra_dump_file,
2938 			   "            %d Spill vector pseudo: reject+=2\n",
2939 			   nop);
2940 		      reject += 2;
2941 		    }
2942 		}
2943 
2944 	      /* When we use an operand requiring memory in given
2945 		 alternative, the insn should write *and* read the
2946 		 value to/from memory it is costly in comparison with
2947 		 an insn alternative which does not use memory
2948 		 (e.g. register or immediate operand).  We exclude
2949 		 memory operand for such case as we can satisfy the
2950 		 memory constraints by reloading address.  */
2951 	      if (no_regs_p && offmemok && !MEM_P (op))
2952 		{
2953 		  if (lra_dump_file != NULL)
2954 		    fprintf
2955 		      (lra_dump_file,
2956 		       "            Using memory insn operand %d: reject+=3\n",
2957 		       nop);
2958 		  reject += 3;
2959 		}
2960 
2961 	      /* If reload requires moving value through secondary
2962 		 memory, it will need one more insn at least.  */
2963 	      if (this_alternative != NO_REGS
2964 		  && REG_P (op) && (cl = get_reg_class (REGNO (op))) != NO_REGS
2965 		  && ((curr_static_id->operand[nop].type != OP_OUT
2966 		       && targetm.secondary_memory_needed (GET_MODE (op), cl,
2967 							   this_alternative))
2968 		      || (curr_static_id->operand[nop].type != OP_IN
2969 			  && (targetm.secondary_memory_needed
2970 			      (GET_MODE (op), this_alternative, cl)))))
2971 		losers++;
2972 
2973 	      if (MEM_P (op) && offmemok)
2974 		addr_losers++;
2975 	      else
2976 		{
2977 		  /* Input reloads can be inherited more often than
2978 		     output reloads can be removed, so penalize output
2979 		     reloads.  */
2980 		  if (!REG_P (op) || curr_static_id->operand[nop].type != OP_IN)
2981 		    {
2982 		      if (lra_dump_file != NULL)
2983 			fprintf
2984 			  (lra_dump_file,
2985 			   "            %d Non input pseudo reload: reject++\n",
2986 			   nop);
2987 		      reject++;
2988 		    }
2989 
2990 		  if (curr_static_id->operand[nop].type == OP_INOUT)
2991 		    {
2992 		      if (lra_dump_file != NULL)
2993 			fprintf
2994 			  (lra_dump_file,
2995 			   "            %d Input/Output reload: reject+=%d\n",
2996 			   nop, LRA_LOSER_COST_FACTOR);
2997 		      reject += LRA_LOSER_COST_FACTOR;
2998 		    }
2999 		}
3000 	    }
3001 
3002 	  if (early_clobber_p && ! scratch_p)
3003 	    {
3004 	      if (lra_dump_file != NULL)
3005 		fprintf (lra_dump_file,
3006 			 "            %d Early clobber: reject++\n", nop);
3007 	      reject++;
3008 	    }
3009 	  /* ??? We check early clobbers after processing all operands
3010 	     (see loop below) and there we update the costs more.
3011 	     Should we update the cost (may be approximately) here
3012 	     because of early clobber register reloads or it is a rare
3013 	     or non-important thing to be worth to do it.  */
3014 	  overall = (losers * LRA_LOSER_COST_FACTOR + reject
3015 		     - (addr_losers == losers ? static_reject : 0));
3016 	  if ((best_losers == 0 || losers != 0) && best_overall < overall)
3017             {
3018               if (lra_dump_file != NULL)
3019 		fprintf (lra_dump_file,
3020 			 "            alt=%d,overall=%d,losers=%d -- refuse\n",
3021 			 nalt, overall, losers);
3022               goto fail;
3023             }
3024 
3025 	  if (update_and_check_small_class_inputs (nop, nalt,
3026 						   this_alternative))
3027 	    {
3028 	      if (lra_dump_file != NULL)
3029 		fprintf (lra_dump_file,
3030 			 "            alt=%d, not enough small class regs -- refuse\n",
3031 			 nalt);
3032 	      goto fail;
3033 	    }
3034 	  curr_alt[nop] = this_alternative;
3035 	  curr_alt_set[nop] = this_alternative_set;
3036 	  curr_alt_exclude_start_hard_regs[nop]
3037 	    = this_alternative_exclude_start_hard_regs;
3038 	  curr_alt_win[nop] = this_alternative_win;
3039 	  curr_alt_match_win[nop] = this_alternative_match_win;
3040 	  curr_alt_offmemok[nop] = this_alternative_offmemok;
3041 	  curr_alt_matches[nop] = this_alternative_matches;
3042 
3043 	  if (this_alternative_matches >= 0
3044 	      && !did_match && !this_alternative_win)
3045 	    curr_alt_win[this_alternative_matches] = false;
3046 
3047 	  if (early_clobber_p && operand_reg[nop] != NULL_RTX)
3048 	    early_clobbered_nops[early_clobbered_regs_num++] = nop;
3049 	}
3050 
3051       if (curr_insn_set != NULL_RTX && n_operands == 2
3052 	  /* Prevent processing non-move insns.  */
3053 	  && (GET_CODE (SET_SRC (curr_insn_set)) == SUBREG
3054 	      || SET_SRC (curr_insn_set) == no_subreg_reg_operand[1])
3055 	  && ((! curr_alt_win[0] && ! curr_alt_win[1]
3056 	       && REG_P (no_subreg_reg_operand[0])
3057 	       && REG_P (no_subreg_reg_operand[1])
3058 	       && (reg_in_class_p (no_subreg_reg_operand[0], curr_alt[1])
3059 		   || reg_in_class_p (no_subreg_reg_operand[1], curr_alt[0])))
3060 	      || (! curr_alt_win[0] && curr_alt_win[1]
3061 		  && REG_P (no_subreg_reg_operand[1])
3062 		  /* Check that we reload memory not the memory
3063 		     address.  */
3064 		  && ! (curr_alt_offmemok[0]
3065 			&& MEM_P (no_subreg_reg_operand[0]))
3066 		  && reg_in_class_p (no_subreg_reg_operand[1], curr_alt[0]))
3067 	      || (curr_alt_win[0] && ! curr_alt_win[1]
3068 		  && REG_P (no_subreg_reg_operand[0])
3069 		  /* Check that we reload memory not the memory
3070 		     address.  */
3071 		  && ! (curr_alt_offmemok[1]
3072 			&& MEM_P (no_subreg_reg_operand[1]))
3073 		  && reg_in_class_p (no_subreg_reg_operand[0], curr_alt[1])
3074 		  && (! CONST_POOL_OK_P (curr_operand_mode[1],
3075 					 no_subreg_reg_operand[1])
3076 		      || (targetm.preferred_reload_class
3077 			  (no_subreg_reg_operand[1],
3078 			   (enum reg_class) curr_alt[1]) != NO_REGS))
3079 		  /* If it is a result of recent elimination in move
3080 		     insn we can transform it into an add still by
3081 		     using this alternative.  */
3082 		  && GET_CODE (no_subreg_reg_operand[1]) != PLUS
3083 		  /* Likewise if the source has been replaced with an
3084 		     equivalent value.  This only happens once -- the reload
3085 		     will use the equivalent value instead of the register it
3086 		     replaces -- so there should be no danger of cycling.  */
3087 		  && !equiv_substition_p[1])))
3088 	{
3089 	  /* We have a move insn and a new reload insn will be similar
3090 	     to the current insn.  We should avoid such situation as
3091 	     it results in LRA cycling.  */
3092 	  if (lra_dump_file != NULL)
3093 	    fprintf (lra_dump_file,
3094 		     "            Cycle danger: overall += LRA_MAX_REJECT\n");
3095 	  overall += LRA_MAX_REJECT;
3096 	}
3097       ok_p = true;
3098       curr_alt_dont_inherit_ops_num = 0;
3099       for (nop = 0; nop < early_clobbered_regs_num; nop++)
3100 	{
3101 	  int i, j, clobbered_hard_regno, first_conflict_j, last_conflict_j;
3102 	  HARD_REG_SET temp_set;
3103 
3104 	  i = early_clobbered_nops[nop];
3105 	  if ((! curr_alt_win[i] && ! curr_alt_match_win[i])
3106 	      || hard_regno[i] < 0)
3107 	    continue;
3108 	  lra_assert (operand_reg[i] != NULL_RTX);
3109 	  clobbered_hard_regno = hard_regno[i];
3110 	  CLEAR_HARD_REG_SET (temp_set);
3111 	  add_to_hard_reg_set (&temp_set, biggest_mode[i], clobbered_hard_regno);
3112 	  first_conflict_j = last_conflict_j = -1;
3113 	  for (j = 0; j < n_operands; j++)
3114 	    if (j == i
3115 		/* We don't want process insides of match_operator and
3116 		   match_parallel because otherwise we would process
3117 		   their operands once again generating a wrong
3118 		   code.  */
3119 		|| curr_static_id->operand[j].is_operator)
3120 	      continue;
3121 	    else if ((curr_alt_matches[j] == i && curr_alt_match_win[j])
3122 		     || (curr_alt_matches[i] == j && curr_alt_match_win[i]))
3123 	      continue;
3124 	    /* If we don't reload j-th operand, check conflicts.  */
3125 	    else if ((curr_alt_win[j] || curr_alt_match_win[j])
3126 		     && uses_hard_regs_p (*curr_id->operand_loc[j], temp_set))
3127 	      {
3128 		if (first_conflict_j < 0)
3129 		  first_conflict_j = j;
3130 		last_conflict_j = j;
3131 		/* Both the earlyclobber operand and conflicting operand
3132 		   cannot both be user defined hard registers.  */
3133 		if (HARD_REGISTER_P (operand_reg[i])
3134 		    && REG_USERVAR_P (operand_reg[i])
3135 		    && operand_reg[j] != NULL_RTX
3136 		    && HARD_REGISTER_P (operand_reg[j])
3137 		    && REG_USERVAR_P (operand_reg[j]))
3138 		  {
3139 		    /* For asm, let curr_insn_transform diagnose it.  */
3140 		    if (INSN_CODE (curr_insn) < 0)
3141 		      return false;
3142 		    fatal_insn ("unable to generate reloads for "
3143 				"impossible constraints:", curr_insn);
3144 		  }
3145 	      }
3146 	  if (last_conflict_j < 0)
3147 	    continue;
3148 
3149 	  /* If an earlyclobber operand conflicts with another non-matching
3150 	     operand (ie, they have been assigned the same hard register),
3151 	     then it is better to reload the other operand, as there may
3152 	     exist yet another operand with a matching constraint associated
3153 	     with the earlyclobber operand.  However, if one of the operands
3154 	     is an explicit use of a hard register, then we must reload the
3155 	     other non-hard register operand.  */
3156 	  if (HARD_REGISTER_P (operand_reg[i])
3157 	      || (first_conflict_j == last_conflict_j
3158 		  && operand_reg[last_conflict_j] != NULL_RTX
3159 		  && !curr_alt_match_win[last_conflict_j]
3160 		  && !HARD_REGISTER_P (operand_reg[last_conflict_j])))
3161 	    {
3162 	      curr_alt_win[last_conflict_j] = false;
3163 	      curr_alt_dont_inherit_ops[curr_alt_dont_inherit_ops_num++]
3164 		= last_conflict_j;
3165 	      losers++;
3166 	      if (lra_dump_file != NULL)
3167 		fprintf
3168 		  (lra_dump_file,
3169 		   "            %d Conflict early clobber reload: reject--\n",
3170 		   i);
3171 	    }
3172 	  else
3173 	    {
3174 	      /* We need to reload early clobbered register and the
3175 		 matched registers.  */
3176 	      for (j = 0; j < n_operands; j++)
3177 		if (curr_alt_matches[j] == i)
3178 		  {
3179 		    curr_alt_match_win[j] = false;
3180 		    losers++;
3181 		    overall += LRA_LOSER_COST_FACTOR;
3182 		  }
3183 	      if (! curr_alt_match_win[i])
3184 		curr_alt_dont_inherit_ops[curr_alt_dont_inherit_ops_num++] = i;
3185 	      else
3186 		{
3187 		  /* Remember pseudos used for match reloads are never
3188 		     inherited.  */
3189 		  lra_assert (curr_alt_matches[i] >= 0);
3190 		  curr_alt_win[curr_alt_matches[i]] = false;
3191 		}
3192 	      curr_alt_win[i] = curr_alt_match_win[i] = false;
3193 	      losers++;
3194 	      if (lra_dump_file != NULL)
3195 		fprintf
3196 		  (lra_dump_file,
3197 		   "            %d Matched conflict early clobber reloads: "
3198 		   "reject--\n",
3199 		   i);
3200 	    }
3201 	  /* Early clobber was already reflected in REJECT. */
3202 	  if (!matching_early_clobber[i])
3203 	    {
3204 	      lra_assert (reject > 0);
3205 	      reject--;
3206 	      matching_early_clobber[i] = 1;
3207 	    }
3208 	  overall += LRA_LOSER_COST_FACTOR - 1;
3209 	}
3210       if (lra_dump_file != NULL)
3211 	fprintf (lra_dump_file, "          alt=%d,overall=%d,losers=%d,rld_nregs=%d\n",
3212 		 nalt, overall, losers, reload_nregs);
3213 
3214       /* If this alternative can be made to work by reloading, and it
3215 	 needs less reloading than the others checked so far, record
3216 	 it as the chosen goal for reloading.  */
3217       if ((best_losers != 0 && losers == 0)
3218 	  || (((best_losers == 0 && losers == 0)
3219 	       || (best_losers != 0 && losers != 0))
3220 	      && (best_overall > overall
3221 		  || (best_overall == overall
3222 		      /* If the cost of the reloads is the same,
3223 			 prefer alternative which requires minimal
3224 			 number of reload regs.  */
3225 		      && (reload_nregs < best_reload_nregs
3226 			  || (reload_nregs == best_reload_nregs
3227 			      && (best_reload_sum < reload_sum
3228 				  || (best_reload_sum == reload_sum
3229 				      && nalt < goal_alt_number))))))))
3230 	{
3231 	  for (nop = 0; nop < n_operands; nop++)
3232 	    {
3233 	      goal_alt_win[nop] = curr_alt_win[nop];
3234 	      goal_alt_match_win[nop] = curr_alt_match_win[nop];
3235 	      goal_alt_matches[nop] = curr_alt_matches[nop];
3236 	      goal_alt[nop] = curr_alt[nop];
3237 	      goal_alt_exclude_start_hard_regs[nop]
3238 		= curr_alt_exclude_start_hard_regs[nop];
3239 	      goal_alt_offmemok[nop] = curr_alt_offmemok[nop];
3240 	    }
3241 	  goal_alt_dont_inherit_ops_num = curr_alt_dont_inherit_ops_num;
3242 	  for (nop = 0; nop < curr_alt_dont_inherit_ops_num; nop++)
3243 	    goal_alt_dont_inherit_ops[nop] = curr_alt_dont_inherit_ops[nop];
3244 	  goal_alt_swapped = curr_swapped;
3245 	  best_overall = overall;
3246 	  best_losers = losers;
3247 	  best_reload_nregs = reload_nregs;
3248 	  best_reload_sum = reload_sum;
3249 	  goal_alt_number = nalt;
3250 	}
3251       if (losers == 0)
3252 	/* Everything is satisfied.  Do not process alternatives
3253 	   anymore.  */
3254 	break;
3255     fail:
3256       ;
3257     }
3258   return ok_p;
3259 }
3260 
3261 /* Make reload base reg from address AD.  */
3262 static rtx
base_to_reg(struct address_info * ad)3263 base_to_reg (struct address_info *ad)
3264 {
3265   enum reg_class cl;
3266   int code = -1;
3267   rtx new_inner = NULL_RTX;
3268   rtx new_reg = NULL_RTX;
3269   rtx_insn *insn;
3270   rtx_insn *last_insn = get_last_insn();
3271 
3272   lra_assert (ad->disp == ad->disp_term);
3273   cl = base_reg_class (ad->mode, ad->as, ad->base_outer_code,
3274                        get_index_code (ad));
3275   new_reg = lra_create_new_reg (GET_MODE (*ad->base), NULL_RTX, cl, NULL,
3276 				"base");
3277   new_inner = simplify_gen_binary (PLUS, GET_MODE (new_reg), new_reg,
3278                                    ad->disp_term == NULL
3279                                    ? const0_rtx
3280                                    : *ad->disp_term);
3281   if (!valid_address_p (ad->mode, new_inner, ad->as))
3282     return NULL_RTX;
3283   insn = emit_insn (gen_rtx_SET (new_reg, *ad->base));
3284   code = recog_memoized (insn);
3285   if (code < 0)
3286     {
3287       delete_insns_since (last_insn);
3288       return NULL_RTX;
3289     }
3290 
3291   return new_inner;
3292 }
3293 
3294 /* Make reload base reg + DISP from address AD.  Return the new pseudo.  */
3295 static rtx
base_plus_disp_to_reg(struct address_info * ad,rtx disp)3296 base_plus_disp_to_reg (struct address_info *ad, rtx disp)
3297 {
3298   enum reg_class cl;
3299   rtx new_reg;
3300 
3301   lra_assert (ad->base == ad->base_term);
3302   cl = base_reg_class (ad->mode, ad->as, ad->base_outer_code,
3303 		       get_index_code (ad));
3304   new_reg = lra_create_new_reg (GET_MODE (*ad->base_term), NULL_RTX, cl, NULL,
3305 				"base + disp");
3306   lra_emit_add (new_reg, *ad->base_term, disp);
3307   return new_reg;
3308 }
3309 
3310 /* Make reload of index part of address AD.  Return the new
3311    pseudo.  */
3312 static rtx
index_part_to_reg(struct address_info * ad)3313 index_part_to_reg (struct address_info *ad)
3314 {
3315   rtx new_reg;
3316 
3317   new_reg = lra_create_new_reg (GET_MODE (*ad->index), NULL_RTX,
3318 				INDEX_REG_CLASS, NULL, "index term");
3319   expand_mult (GET_MODE (*ad->index), *ad->index_term,
3320 	       GEN_INT (get_index_scale (ad)), new_reg, 1);
3321   return new_reg;
3322 }
3323 
3324 /* Return true if we can add a displacement to address AD, even if that
3325    makes the address invalid.  The fix-up code requires any new address
3326    to be the sum of the BASE_TERM, INDEX and DISP_TERM fields.  */
3327 static bool
can_add_disp_p(struct address_info * ad)3328 can_add_disp_p (struct address_info *ad)
3329 {
3330   return (!ad->autoinc_p
3331 	  && ad->segment == NULL
3332 	  && ad->base == ad->base_term
3333 	  && ad->disp == ad->disp_term);
3334 }
3335 
3336 /* Make equiv substitution in address AD.  Return true if a substitution
3337    was made.  */
3338 static bool
equiv_address_substitution(struct address_info * ad)3339 equiv_address_substitution (struct address_info *ad)
3340 {
3341   rtx base_reg, new_base_reg, index_reg, new_index_reg, *base_term, *index_term;
3342   poly_int64 disp;
3343   HOST_WIDE_INT scale;
3344   bool change_p;
3345 
3346   base_term = strip_subreg (ad->base_term);
3347   if (base_term == NULL)
3348     base_reg = new_base_reg = NULL_RTX;
3349   else
3350     {
3351       base_reg = *base_term;
3352       new_base_reg = get_equiv_with_elimination (base_reg, curr_insn);
3353     }
3354   index_term = strip_subreg (ad->index_term);
3355   if (index_term == NULL)
3356     index_reg = new_index_reg = NULL_RTX;
3357   else
3358     {
3359       index_reg = *index_term;
3360       new_index_reg = get_equiv_with_elimination (index_reg, curr_insn);
3361     }
3362   if (base_reg == new_base_reg && index_reg == new_index_reg)
3363     return false;
3364   disp = 0;
3365   change_p = false;
3366   if (lra_dump_file != NULL)
3367     {
3368       fprintf (lra_dump_file, "Changing address in insn %d ",
3369 	       INSN_UID (curr_insn));
3370       dump_value_slim (lra_dump_file, *ad->outer, 1);
3371     }
3372   if (base_reg != new_base_reg)
3373     {
3374       poly_int64 offset;
3375       if (REG_P (new_base_reg))
3376 	{
3377 	  *base_term = new_base_reg;
3378 	  change_p = true;
3379 	}
3380       else if (GET_CODE (new_base_reg) == PLUS
3381 	       && REG_P (XEXP (new_base_reg, 0))
3382 	       && poly_int_rtx_p (XEXP (new_base_reg, 1), &offset)
3383 	       && can_add_disp_p (ad))
3384 	{
3385 	  disp += offset;
3386 	  *base_term = XEXP (new_base_reg, 0);
3387 	  change_p = true;
3388 	}
3389       if (ad->base_term2 != NULL)
3390 	*ad->base_term2 = *ad->base_term;
3391     }
3392   if (index_reg != new_index_reg)
3393     {
3394       poly_int64 offset;
3395       if (REG_P (new_index_reg))
3396 	{
3397 	  *index_term = new_index_reg;
3398 	  change_p = true;
3399 	}
3400       else if (GET_CODE (new_index_reg) == PLUS
3401 	       && REG_P (XEXP (new_index_reg, 0))
3402 	       && poly_int_rtx_p (XEXP (new_index_reg, 1), &offset)
3403 	       && can_add_disp_p (ad)
3404 	       && (scale = get_index_scale (ad)))
3405 	{
3406 	  disp += offset * scale;
3407 	  *index_term = XEXP (new_index_reg, 0);
3408 	  change_p = true;
3409 	}
3410     }
3411   if (maybe_ne (disp, 0))
3412     {
3413       if (ad->disp != NULL)
3414 	*ad->disp = plus_constant (GET_MODE (*ad->inner), *ad->disp, disp);
3415       else
3416 	{
3417 	  *ad->inner = plus_constant (GET_MODE (*ad->inner), *ad->inner, disp);
3418 	  update_address (ad);
3419 	}
3420       change_p = true;
3421     }
3422   if (lra_dump_file != NULL)
3423     {
3424       if (! change_p)
3425 	fprintf (lra_dump_file, " -- no change\n");
3426       else
3427 	{
3428 	  fprintf (lra_dump_file, " on equiv ");
3429 	  dump_value_slim (lra_dump_file, *ad->outer, 1);
3430 	  fprintf (lra_dump_file, "\n");
3431 	}
3432     }
3433   return change_p;
3434 }
3435 
3436 /* Skip all modifiers and whitespaces in constraint STR and return the
3437    result.  */
3438 static const char *
skip_constraint_modifiers(const char * str)3439 skip_constraint_modifiers (const char *str)
3440 {
3441   for (;;str++)
3442     switch (*str)
3443       {
3444       case '+': case '&' : case '=': case '*': case ' ': case '\t':
3445       case '$': case '^' : case '%': case '?': case '!':
3446 	break;
3447       default: return str;
3448       }
3449 }
3450 
3451 /* Major function to make reloads for an address in operand NOP or
3452    check its correctness (If CHECK_ONLY_P is true). The supported
3453    cases are:
3454 
3455    1) an address that existed before LRA started, at which point it
3456    must have been valid.  These addresses are subject to elimination
3457    and may have become invalid due to the elimination offset being out
3458    of range.
3459 
3460    2) an address created by forcing a constant to memory
3461    (force_const_to_mem).  The initial form of these addresses might
3462    not be valid, and it is this function's job to make them valid.
3463 
3464    3) a frame address formed from a register and a (possibly zero)
3465    constant offset.  As above, these addresses might not be valid and
3466    this function must make them so.
3467 
3468    Add reloads to the lists *BEFORE and *AFTER.  We might need to add
3469    reloads to *AFTER because of inc/dec, {pre, post} modify in the
3470    address.  Return true for any RTL change.
3471 
3472    The function is a helper function which does not produce all
3473    transformations (when CHECK_ONLY_P is false) which can be
3474    necessary.  It does just basic steps.  To do all necessary
3475    transformations use function process_address.  */
3476 static bool
process_address_1(int nop,bool check_only_p,rtx_insn ** before,rtx_insn ** after)3477 process_address_1 (int nop, bool check_only_p,
3478 		   rtx_insn **before, rtx_insn **after)
3479 {
3480   struct address_info ad;
3481   rtx new_reg;
3482   HOST_WIDE_INT scale;
3483   rtx op = *curr_id->operand_loc[nop];
3484   rtx mem = extract_mem_from_operand (op);
3485   const char *constraint;
3486   enum constraint_num cn;
3487   bool change_p = false;
3488 
3489   if (MEM_P (mem)
3490       && GET_MODE (mem) == BLKmode
3491       && GET_CODE (XEXP (mem, 0)) == SCRATCH)
3492     return false;
3493 
3494   constraint
3495     = skip_constraint_modifiers (curr_static_id->operand[nop].constraint);
3496   if (IN_RANGE (constraint[0], '0', '9'))
3497     {
3498       char *end;
3499       unsigned long dup = strtoul (constraint, &end, 10);
3500       constraint
3501 	= skip_constraint_modifiers (curr_static_id->operand[dup].constraint);
3502     }
3503   cn = lookup_constraint (*constraint == '\0' ? "X" : constraint);
3504   /* If we have several alternatives or/and several constraints in an
3505      alternative and we can not say at this stage what constraint will be used,
3506      use unknown constraint.  The exception is an address constraint.  If
3507      operand has one address constraint, probably all others constraints are
3508      address ones.  */
3509   if (constraint[0] != '\0' && get_constraint_type (cn) != CT_ADDRESS
3510       && *skip_constraint_modifiers (constraint
3511 				     + CONSTRAINT_LEN (constraint[0],
3512 						       constraint)) != '\0')
3513     cn = CONSTRAINT__UNKNOWN;
3514   if (insn_extra_address_constraint (cn)
3515       /* When we find an asm operand with an address constraint that
3516 	 doesn't satisfy address_operand to begin with, we clear
3517 	 is_address, so that we don't try to make a non-address fit.
3518 	 If the asm statement got this far, it's because other
3519 	 constraints are available, and we'll use them, disregarding
3520 	 the unsatisfiable address ones.  */
3521       && curr_static_id->operand[nop].is_address)
3522     decompose_lea_address (&ad, curr_id->operand_loc[nop]);
3523   /* Do not attempt to decompose arbitrary addresses generated by combine
3524      for asm operands with loose constraints, e.g 'X'.
3525      Need to extract memory from op for special memory constraint,
3526      i.e. bcst_mem_operand in i386 backend.  */
3527   else if (MEM_P (mem)
3528 	   && !(INSN_CODE (curr_insn) < 0
3529 		&& get_constraint_type (cn) == CT_FIXED_FORM
3530 		&& constraint_satisfied_p (op, cn)))
3531     decompose_mem_address (&ad, mem);
3532   else if (GET_CODE (op) == SUBREG
3533 	   && MEM_P (SUBREG_REG (op)))
3534     decompose_mem_address (&ad, SUBREG_REG (op));
3535   else
3536     return false;
3537   /* If INDEX_REG_CLASS is assigned to base_term already and isn't to
3538      index_term, swap them so to avoid assigning INDEX_REG_CLASS to both
3539      when INDEX_REG_CLASS is a single register class.  */
3540   if (ad.base_term != NULL
3541       && ad.index_term != NULL
3542       && ira_class_hard_regs_num[INDEX_REG_CLASS] == 1
3543       && REG_P (*ad.base_term)
3544       && REG_P (*ad.index_term)
3545       && in_class_p (*ad.base_term, INDEX_REG_CLASS, NULL)
3546       && ! in_class_p (*ad.index_term, INDEX_REG_CLASS, NULL))
3547     {
3548       std::swap (ad.base, ad.index);
3549       std::swap (ad.base_term, ad.index_term);
3550     }
3551   if (! check_only_p)
3552     change_p = equiv_address_substitution (&ad);
3553   if (ad.base_term != NULL
3554       && (process_addr_reg
3555 	  (ad.base_term, check_only_p, before,
3556 	   (ad.autoinc_p
3557 	    && !(REG_P (*ad.base_term)
3558 		 && find_regno_note (curr_insn, REG_DEAD,
3559 				     REGNO (*ad.base_term)) != NULL_RTX)
3560 	    ? after : NULL),
3561 	   base_reg_class (ad.mode, ad.as, ad.base_outer_code,
3562 			   get_index_code (&ad)))))
3563     {
3564       change_p = true;
3565       if (ad.base_term2 != NULL)
3566 	*ad.base_term2 = *ad.base_term;
3567     }
3568   if (ad.index_term != NULL
3569       && process_addr_reg (ad.index_term, check_only_p,
3570 			   before, NULL, INDEX_REG_CLASS))
3571     change_p = true;
3572 
3573   /* Target hooks sometimes don't treat extra-constraint addresses as
3574      legitimate address_operands, so handle them specially.  */
3575   if (insn_extra_address_constraint (cn)
3576       && satisfies_address_constraint_p (&ad, cn))
3577     return change_p;
3578 
3579   if (check_only_p)
3580     return change_p;
3581 
3582   /* There are three cases where the shape of *AD.INNER may now be invalid:
3583 
3584      1) the original address was valid, but either elimination or
3585      equiv_address_substitution was applied and that made
3586      the address invalid.
3587 
3588      2) the address is an invalid symbolic address created by
3589      force_const_to_mem.
3590 
3591      3) the address is a frame address with an invalid offset.
3592 
3593      4) the address is a frame address with an invalid base.
3594 
3595      All these cases involve a non-autoinc address, so there is no
3596      point revalidating other types.  */
3597   if (ad.autoinc_p || valid_address_p (op, &ad, cn))
3598     return change_p;
3599 
3600   /* Any index existed before LRA started, so we can assume that the
3601      presence and shape of the index is valid.  */
3602   push_to_sequence (*before);
3603   lra_assert (ad.disp == ad.disp_term);
3604   if (ad.base == NULL)
3605     {
3606       if (ad.index == NULL)
3607 	{
3608 	  rtx_insn *insn;
3609 	  rtx_insn *last = get_last_insn ();
3610 	  int code = -1;
3611 	  enum reg_class cl = base_reg_class (ad.mode, ad.as,
3612 					      SCRATCH, SCRATCH);
3613 	  rtx addr = *ad.inner;
3614 
3615 	  new_reg = lra_create_new_reg (Pmode, NULL_RTX, cl, NULL, "addr");
3616 	  if (HAVE_lo_sum)
3617 	    {
3618 	      /* addr => lo_sum (new_base, addr), case (2) above.  */
3619 	      insn = emit_insn (gen_rtx_SET
3620 				(new_reg,
3621 				 gen_rtx_HIGH (Pmode, copy_rtx (addr))));
3622 	      code = recog_memoized (insn);
3623 	      if (code >= 0)
3624 		{
3625 		  *ad.inner = gen_rtx_LO_SUM (Pmode, new_reg, addr);
3626 		  if (!valid_address_p (op, &ad, cn))
3627 		    {
3628 		      /* Try to put lo_sum into register.  */
3629 		      insn = emit_insn (gen_rtx_SET
3630 					(new_reg,
3631 					 gen_rtx_LO_SUM (Pmode, new_reg, addr)));
3632 		      code = recog_memoized (insn);
3633 		      if (code >= 0)
3634 			{
3635 			  *ad.inner = new_reg;
3636 			  if (!valid_address_p (op, &ad, cn))
3637 			    {
3638 			      *ad.inner = addr;
3639 			      code = -1;
3640 			    }
3641 			}
3642 
3643 		    }
3644 		}
3645 	      if (code < 0)
3646 		delete_insns_since (last);
3647 	    }
3648 
3649 	  if (code < 0)
3650 	    {
3651 	      /* addr => new_base, case (2) above.  */
3652 	      lra_emit_move (new_reg, addr);
3653 
3654 	      for (insn = last == NULL_RTX ? get_insns () : NEXT_INSN (last);
3655 		   insn != NULL_RTX;
3656 		   insn = NEXT_INSN (insn))
3657 		if (recog_memoized (insn) < 0)
3658 		  break;
3659 	      if (insn != NULL_RTX)
3660 		{
3661 		  /* Do nothing if we cannot generate right insns.
3662 		     This is analogous to reload pass behavior.  */
3663 		  delete_insns_since (last);
3664 		  end_sequence ();
3665 		  return false;
3666 		}
3667 	      *ad.inner = new_reg;
3668 	    }
3669 	}
3670       else
3671 	{
3672 	  /* index * scale + disp => new base + index * scale,
3673 	     case (1) above.  */
3674 	  enum reg_class cl = base_reg_class (ad.mode, ad.as, PLUS,
3675 					      GET_CODE (*ad.index));
3676 
3677 	  lra_assert (INDEX_REG_CLASS != NO_REGS);
3678 	  new_reg = lra_create_new_reg (Pmode, NULL_RTX, cl, NULL, "disp");
3679 	  lra_emit_move (new_reg, *ad.disp);
3680 	  *ad.inner = simplify_gen_binary (PLUS, GET_MODE (new_reg),
3681 					   new_reg, *ad.index);
3682 	}
3683     }
3684   else if (ad.index == NULL)
3685     {
3686       int regno;
3687       enum reg_class cl;
3688       rtx set;
3689       rtx_insn *insns, *last_insn;
3690       /* Try to reload base into register only if the base is invalid
3691          for the address but with valid offset, case (4) above.  */
3692       start_sequence ();
3693       new_reg = base_to_reg (&ad);
3694 
3695       /* base + disp => new base, cases (1) and (3) above.  */
3696       /* Another option would be to reload the displacement into an
3697 	 index register.  However, postreload has code to optimize
3698 	 address reloads that have the same base and different
3699 	 displacements, so reloading into an index register would
3700 	 not necessarily be a win.  */
3701       if (new_reg == NULL_RTX)
3702 	{
3703 	  /* See if the target can split the displacement into a
3704 	     legitimate new displacement from a local anchor.  */
3705 	  gcc_assert (ad.disp == ad.disp_term);
3706 	  poly_int64 orig_offset;
3707 	  rtx offset1, offset2;
3708 	  if (poly_int_rtx_p (*ad.disp, &orig_offset)
3709 	      && targetm.legitimize_address_displacement (&offset1, &offset2,
3710 							  orig_offset,
3711 							  ad.mode))
3712 	    {
3713 	      new_reg = base_plus_disp_to_reg (&ad, offset1);
3714 	      new_reg = gen_rtx_PLUS (GET_MODE (new_reg), new_reg, offset2);
3715 	    }
3716 	  else
3717 	    new_reg = base_plus_disp_to_reg (&ad, *ad.disp);
3718 	}
3719       insns = get_insns ();
3720       last_insn = get_last_insn ();
3721       /* If we generated at least two insns, try last insn source as
3722 	 an address.  If we succeed, we generate one less insn.  */
3723       if (REG_P (new_reg)
3724 	  && last_insn != insns
3725 	  && (set = single_set (last_insn)) != NULL_RTX
3726 	  && GET_CODE (SET_SRC (set)) == PLUS
3727 	  && REG_P (XEXP (SET_SRC (set), 0))
3728 	  && CONSTANT_P (XEXP (SET_SRC (set), 1)))
3729 	{
3730 	  *ad.inner = SET_SRC (set);
3731 	  if (valid_address_p (op, &ad, cn))
3732 	    {
3733 	      *ad.base_term = XEXP (SET_SRC (set), 0);
3734 	      *ad.disp_term = XEXP (SET_SRC (set), 1);
3735 	      cl = base_reg_class (ad.mode, ad.as, ad.base_outer_code,
3736 				   get_index_code (&ad));
3737 	      regno = REGNO (*ad.base_term);
3738 	      if (regno >= FIRST_PSEUDO_REGISTER
3739 		  && cl != lra_get_allocno_class (regno))
3740 		lra_change_class (regno, cl, "      Change to", true);
3741 	      new_reg = SET_SRC (set);
3742 	      delete_insns_since (PREV_INSN (last_insn));
3743 	    }
3744 	}
3745       end_sequence ();
3746       emit_insn (insns);
3747       *ad.inner = new_reg;
3748     }
3749   else if (ad.disp_term != NULL)
3750     {
3751       /* base + scale * index + disp => new base + scale * index,
3752 	 case (1) above.  */
3753       gcc_assert (ad.disp == ad.disp_term);
3754       new_reg = base_plus_disp_to_reg (&ad, *ad.disp);
3755       *ad.inner = simplify_gen_binary (PLUS, GET_MODE (new_reg),
3756 				       new_reg, *ad.index);
3757     }
3758   else if ((scale = get_index_scale (&ad)) == 1)
3759     {
3760       /* The last transformation to one reg will be made in
3761 	 curr_insn_transform function.  */
3762       end_sequence ();
3763       return false;
3764     }
3765   else if (scale != 0)
3766     {
3767       /* base + scale * index => base + new_reg,
3768 	 case (1) above.
3769       Index part of address may become invalid.  For example, we
3770       changed pseudo on the equivalent memory and a subreg of the
3771       pseudo onto the memory of different mode for which the scale is
3772       prohibitted.  */
3773       new_reg = index_part_to_reg (&ad);
3774       *ad.inner = simplify_gen_binary (PLUS, GET_MODE (new_reg),
3775 				       *ad.base_term, new_reg);
3776     }
3777   else
3778     {
3779       enum reg_class cl = base_reg_class (ad.mode, ad.as,
3780 					  SCRATCH, SCRATCH);
3781       rtx addr = *ad.inner;
3782 
3783       new_reg = lra_create_new_reg (Pmode, NULL_RTX, cl, NULL, "addr");
3784       /* addr => new_base.  */
3785       lra_emit_move (new_reg, addr);
3786       *ad.inner = new_reg;
3787     }
3788   *before = get_insns ();
3789   end_sequence ();
3790   return true;
3791 }
3792 
3793 /* If CHECK_ONLY_P is false, do address reloads until it is necessary.
3794    Use process_address_1 as a helper function.  Return true for any
3795    RTL changes.
3796 
3797    If CHECK_ONLY_P is true, just check address correctness.  Return
3798    false if the address correct.  */
3799 static bool
process_address(int nop,bool check_only_p,rtx_insn ** before,rtx_insn ** after)3800 process_address (int nop, bool check_only_p,
3801 		 rtx_insn **before, rtx_insn **after)
3802 {
3803   bool res = false;
3804 
3805   while (process_address_1 (nop, check_only_p, before, after))
3806     {
3807       if (check_only_p)
3808 	return true;
3809       res = true;
3810     }
3811   return res;
3812 }
3813 
3814 /* Emit insns to reload VALUE into a new register.  VALUE is an
3815    auto-increment or auto-decrement RTX whose operand is a register or
3816    memory location; so reloading involves incrementing that location.
3817    IN is either identical to VALUE, or some cheaper place to reload
3818    value being incremented/decremented from.
3819 
3820    INC_AMOUNT is the number to increment or decrement by (always
3821    positive and ignored for POST_MODIFY/PRE_MODIFY).
3822 
3823    Return pseudo containing the result.	 */
3824 static rtx
emit_inc(enum reg_class new_rclass,rtx in,rtx value,poly_int64 inc_amount)3825 emit_inc (enum reg_class new_rclass, rtx in, rtx value, poly_int64 inc_amount)
3826 {
3827   /* REG or MEM to be copied and incremented.  */
3828   rtx incloc = XEXP (value, 0);
3829   /* Nonzero if increment after copying.  */
3830   int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC
3831 	      || GET_CODE (value) == POST_MODIFY);
3832   rtx_insn *last;
3833   rtx inc;
3834   rtx_insn *add_insn;
3835   int code;
3836   rtx real_in = in == value ? incloc : in;
3837   rtx result;
3838   bool plus_p = true;
3839 
3840   if (GET_CODE (value) == PRE_MODIFY || GET_CODE (value) == POST_MODIFY)
3841     {
3842       lra_assert (GET_CODE (XEXP (value, 1)) == PLUS
3843 		  || GET_CODE (XEXP (value, 1)) == MINUS);
3844       lra_assert (rtx_equal_p (XEXP (XEXP (value, 1), 0), XEXP (value, 0)));
3845       plus_p = GET_CODE (XEXP (value, 1)) == PLUS;
3846       inc = XEXP (XEXP (value, 1), 1);
3847     }
3848   else
3849     {
3850       if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC)
3851 	inc_amount = -inc_amount;
3852 
3853       inc = gen_int_mode (inc_amount, GET_MODE (value));
3854     }
3855 
3856   if (! post && REG_P (incloc))
3857     result = incloc;
3858   else
3859     result = lra_create_new_reg (GET_MODE (value), value, new_rclass, NULL,
3860 				 "INC/DEC result");
3861 
3862   if (real_in != result)
3863     {
3864       /* First copy the location to the result register.  */
3865       lra_assert (REG_P (result));
3866       emit_insn (gen_move_insn (result, real_in));
3867     }
3868 
3869   /* We suppose that there are insns to add/sub with the constant
3870      increment permitted in {PRE/POST)_{DEC/INC/MODIFY}.  At least the
3871      old reload worked with this assumption.  If the assumption
3872      becomes wrong, we should use approach in function
3873      base_plus_disp_to_reg.  */
3874   if (in == value)
3875     {
3876       /* See if we can directly increment INCLOC.  */
3877       last = get_last_insn ();
3878       add_insn = emit_insn (plus_p
3879 			    ? gen_add2_insn (incloc, inc)
3880 			    : gen_sub2_insn (incloc, inc));
3881 
3882       code = recog_memoized (add_insn);
3883       if (code >= 0)
3884 	{
3885 	  if (! post && result != incloc)
3886 	    emit_insn (gen_move_insn (result, incloc));
3887 	  return result;
3888 	}
3889       delete_insns_since (last);
3890     }
3891 
3892   /* If couldn't do the increment directly, must increment in RESULT.
3893      The way we do this depends on whether this is pre- or
3894      post-increment.  For pre-increment, copy INCLOC to the reload
3895      register, increment it there, then save back.  */
3896   if (! post)
3897     {
3898       if (real_in != result)
3899 	emit_insn (gen_move_insn (result, real_in));
3900       if (plus_p)
3901 	emit_insn (gen_add2_insn (result, inc));
3902       else
3903 	emit_insn (gen_sub2_insn (result, inc));
3904       if (result != incloc)
3905 	emit_insn (gen_move_insn (incloc, result));
3906     }
3907   else
3908     {
3909       /* Post-increment.
3910 
3911 	 Because this might be a jump insn or a compare, and because
3912 	 RESULT may not be available after the insn in an input
3913 	 reload, we must do the incrementing before the insn being
3914 	 reloaded for.
3915 
3916 	 We have already copied IN to RESULT.  Increment the copy in
3917 	 RESULT, save that back, then decrement RESULT so it has
3918 	 the original value.  */
3919       if (plus_p)
3920 	emit_insn (gen_add2_insn (result, inc));
3921       else
3922 	emit_insn (gen_sub2_insn (result, inc));
3923       emit_insn (gen_move_insn (incloc, result));
3924       /* Restore non-modified value for the result.  We prefer this
3925 	 way because it does not require an additional hard
3926 	 register.  */
3927       if (plus_p)
3928 	{
3929 	  poly_int64 offset;
3930 	  if (poly_int_rtx_p (inc, &offset))
3931 	    emit_insn (gen_add2_insn (result,
3932 				      gen_int_mode (-offset,
3933 						    GET_MODE (result))));
3934 	  else
3935 	    emit_insn (gen_sub2_insn (result, inc));
3936 	}
3937       else
3938 	emit_insn (gen_add2_insn (result, inc));
3939     }
3940   return result;
3941 }
3942 
3943 /* Return true if the current move insn does not need processing as we
3944    already know that it satisfies its constraints.  */
3945 static bool
simple_move_p(void)3946 simple_move_p (void)
3947 {
3948   rtx dest, src;
3949   enum reg_class dclass, sclass;
3950 
3951   lra_assert (curr_insn_set != NULL_RTX);
3952   dest = SET_DEST (curr_insn_set);
3953   src = SET_SRC (curr_insn_set);
3954 
3955   /* If the instruction has multiple sets we need to process it even if it
3956      is single_set.  This can happen if one or more of the SETs are dead.
3957      See PR73650.  */
3958   if (multiple_sets (curr_insn))
3959     return false;
3960 
3961   return ((dclass = get_op_class (dest)) != NO_REGS
3962 	  && (sclass = get_op_class (src)) != NO_REGS
3963 	  /* The backend guarantees that register moves of cost 2
3964 	     never need reloads.  */
3965 	  && targetm.register_move_cost (GET_MODE (src), sclass, dclass) == 2);
3966  }
3967 
3968 /* Swap operands NOP and NOP + 1. */
3969 static inline void
swap_operands(int nop)3970 swap_operands (int nop)
3971 {
3972   std::swap (curr_operand_mode[nop], curr_operand_mode[nop + 1]);
3973   std::swap (original_subreg_reg_mode[nop], original_subreg_reg_mode[nop + 1]);
3974   std::swap (*curr_id->operand_loc[nop], *curr_id->operand_loc[nop + 1]);
3975   std::swap (equiv_substition_p[nop], equiv_substition_p[nop + 1]);
3976   /* Swap the duplicates too.  */
3977   lra_update_dup (curr_id, nop);
3978   lra_update_dup (curr_id, nop + 1);
3979 }
3980 
3981 /* Main entry point of the constraint code: search the body of the
3982    current insn to choose the best alternative.  It is mimicking insn
3983    alternative cost calculation model of former reload pass.  That is
3984    because machine descriptions were written to use this model.  This
3985    model can be changed in future.  Make commutative operand exchange
3986    if it is chosen.
3987 
3988    if CHECK_ONLY_P is false, do RTL changes to satisfy the
3989    constraints.  Return true if any change happened during function
3990    call.
3991 
3992    If CHECK_ONLY_P is true then don't do any transformation.  Just
3993    check that the insn satisfies all constraints.  If the insn does
3994    not satisfy any constraint, return true.  */
3995 static bool
curr_insn_transform(bool check_only_p)3996 curr_insn_transform (bool check_only_p)
3997 {
3998   int i, j, k;
3999   int n_operands;
4000   int n_alternatives;
4001   int n_outputs;
4002   int commutative;
4003   signed char goal_alt_matched[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
4004   signed char match_inputs[MAX_RECOG_OPERANDS + 1];
4005   signed char outputs[MAX_RECOG_OPERANDS + 1];
4006   rtx_insn *before, *after;
4007   bool alt_p = false;
4008   /* Flag that the insn has been changed through a transformation.  */
4009   bool change_p;
4010   bool sec_mem_p;
4011   bool use_sec_mem_p;
4012   int max_regno_before;
4013   int reused_alternative_num;
4014 
4015   curr_insn_set = single_set (curr_insn);
4016   if (curr_insn_set != NULL_RTX && simple_move_p ())
4017     {
4018       /* We assume that the corresponding insn alternative has no
4019 	 earlier clobbers.  If it is not the case, don't define move
4020 	 cost equal to 2 for the corresponding register classes.  */
4021       lra_set_used_insn_alternative (curr_insn, LRA_NON_CLOBBERED_ALT);
4022       return false;
4023     }
4024 
4025   no_input_reloads_p = no_output_reloads_p = false;
4026   goal_alt_number = -1;
4027   change_p = sec_mem_p = false;
4028 
4029   /* CALL_INSNs are not allowed to have any output reloads.  */
4030   if (CALL_P (curr_insn))
4031     no_output_reloads_p = true;
4032 
4033   n_operands = curr_static_id->n_operands;
4034   n_alternatives = curr_static_id->n_alternatives;
4035 
4036   /* Just return "no reloads" if insn has no operands with
4037      constraints.  */
4038   if (n_operands == 0 || n_alternatives == 0)
4039     return false;
4040 
4041   max_regno_before = max_reg_num ();
4042 
4043   for (i = 0; i < n_operands; i++)
4044     {
4045       goal_alt_matched[i][0] = -1;
4046       goal_alt_matches[i] = -1;
4047     }
4048 
4049   commutative = curr_static_id->commutative;
4050 
4051   /* Now see what we need for pseudos that didn't get hard regs or got
4052      the wrong kind of hard reg.  For this, we must consider all the
4053      operands together against the register constraints.  */
4054 
4055   best_losers = best_overall = INT_MAX;
4056   best_reload_sum = 0;
4057 
4058   curr_swapped = false;
4059   goal_alt_swapped = false;
4060 
4061   if (! check_only_p)
4062     /* Make equivalence substitution and memory subreg elimination
4063        before address processing because an address legitimacy can
4064        depend on memory mode.  */
4065     for (i = 0; i < n_operands; i++)
4066       {
4067 	rtx op, subst, old;
4068 	bool op_change_p = false;
4069 
4070 	if (curr_static_id->operand[i].is_operator)
4071 	  continue;
4072 
4073 	old = op = *curr_id->operand_loc[i];
4074 	if (GET_CODE (old) == SUBREG)
4075 	  old = SUBREG_REG (old);
4076 	subst = get_equiv_with_elimination (old, curr_insn);
4077 	original_subreg_reg_mode[i] = VOIDmode;
4078 	equiv_substition_p[i] = false;
4079 	if (subst != old)
4080 	  {
4081 	    equiv_substition_p[i] = true;
4082 	    subst = copy_rtx (subst);
4083 	    lra_assert (REG_P (old));
4084 	    if (GET_CODE (op) != SUBREG)
4085 	      *curr_id->operand_loc[i] = subst;
4086 	    else
4087 	      {
4088 		SUBREG_REG (op) = subst;
4089 		if (GET_MODE (subst) == VOIDmode)
4090 		  original_subreg_reg_mode[i] = GET_MODE (old);
4091 	      }
4092 	    if (lra_dump_file != NULL)
4093 	      {
4094 		fprintf (lra_dump_file,
4095 			 "Changing pseudo %d in operand %i of insn %u on equiv ",
4096 			 REGNO (old), i, INSN_UID (curr_insn));
4097 		dump_value_slim (lra_dump_file, subst, 1);
4098 		fprintf (lra_dump_file, "\n");
4099 	      }
4100 	    op_change_p = change_p = true;
4101 	  }
4102 	if (simplify_operand_subreg (i, GET_MODE (old)) || op_change_p)
4103 	  {
4104 	    change_p = true;
4105 	    lra_update_dup (curr_id, i);
4106 	  }
4107       }
4108 
4109   /* Reload address registers and displacements.  We do it before
4110      finding an alternative because of memory constraints.  */
4111   before = after = NULL;
4112   for (i = 0; i < n_operands; i++)
4113     if (! curr_static_id->operand[i].is_operator
4114 	&& process_address (i, check_only_p, &before, &after))
4115       {
4116 	if (check_only_p)
4117 	  return true;
4118 	change_p = true;
4119 	lra_update_dup (curr_id, i);
4120       }
4121 
4122   if (change_p)
4123     /* If we've changed the instruction then any alternative that
4124        we chose previously may no longer be valid.  */
4125     lra_set_used_insn_alternative (curr_insn, LRA_UNKNOWN_ALT);
4126 
4127   if (! check_only_p && curr_insn_set != NULL_RTX
4128       && check_and_process_move (&change_p, &sec_mem_p))
4129     return change_p;
4130 
4131  try_swapped:
4132 
4133   reused_alternative_num = check_only_p ? LRA_UNKNOWN_ALT : curr_id->used_insn_alternative;
4134   if (lra_dump_file != NULL && reused_alternative_num >= 0)
4135     fprintf (lra_dump_file, "Reusing alternative %d for insn #%u\n",
4136 	     reused_alternative_num, INSN_UID (curr_insn));
4137 
4138   if (process_alt_operands (reused_alternative_num))
4139     alt_p = true;
4140 
4141   if (check_only_p)
4142     return ! alt_p || best_losers != 0;
4143 
4144   /* If insn is commutative (it's safe to exchange a certain pair of
4145      operands) then we need to try each alternative twice, the second
4146      time matching those two operands as if we had exchanged them.  To
4147      do this, really exchange them in operands.
4148 
4149      If we have just tried the alternatives the second time, return
4150      operands to normal and drop through.  */
4151 
4152   if (reused_alternative_num < 0 && commutative >= 0)
4153     {
4154       curr_swapped = !curr_swapped;
4155       if (curr_swapped)
4156 	{
4157 	  swap_operands (commutative);
4158 	  goto try_swapped;
4159 	}
4160       else
4161 	swap_operands (commutative);
4162     }
4163 
4164   if (! alt_p && ! sec_mem_p)
4165     {
4166       /* No alternative works with reloads??  */
4167       if (INSN_CODE (curr_insn) >= 0)
4168 	fatal_insn ("unable to generate reloads for:", curr_insn);
4169       error_for_asm (curr_insn,
4170 		     "inconsistent operand constraints in an %<asm%>");
4171       lra_asm_error_p = true;
4172       if (! JUMP_P (curr_insn))
4173 	{
4174 	  /* Avoid further trouble with this insn.  Don't generate use
4175 	     pattern here as we could use the insn SP offset.  */
4176 	  lra_set_insn_deleted (curr_insn);
4177 	}
4178       else
4179 	{
4180 	  lra_invalidate_insn_data (curr_insn);
4181 	  ira_nullify_asm_goto (curr_insn);
4182 	  lra_update_insn_regno_info (curr_insn);
4183 	}
4184       return true;
4185     }
4186 
4187   /* If the best alternative is with operands 1 and 2 swapped, swap
4188      them.  Update the operand numbers of any reloads already
4189      pushed.  */
4190 
4191   if (goal_alt_swapped)
4192     {
4193       if (lra_dump_file != NULL)
4194 	fprintf (lra_dump_file, "  Commutative operand exchange in insn %u\n",
4195 		 INSN_UID (curr_insn));
4196 
4197       /* Swap the duplicates too.  */
4198       swap_operands (commutative);
4199       change_p = true;
4200     }
4201 
4202   /* Some targets' TARGET_SECONDARY_MEMORY_NEEDED (e.g. x86) are defined
4203      too conservatively.  So we use the secondary memory only if there
4204      is no any alternative without reloads.  */
4205   use_sec_mem_p = false;
4206   if (! alt_p)
4207     use_sec_mem_p = true;
4208   else if (sec_mem_p)
4209     {
4210       for (i = 0; i < n_operands; i++)
4211 	if (! goal_alt_win[i] && ! goal_alt_match_win[i])
4212 	  break;
4213       use_sec_mem_p = i < n_operands;
4214     }
4215 
4216   if (use_sec_mem_p)
4217     {
4218       int in = -1, out = -1;
4219       rtx new_reg, src, dest, rld;
4220       machine_mode sec_mode, rld_mode;
4221 
4222       lra_assert (curr_insn_set != NULL_RTX && sec_mem_p);
4223       dest = SET_DEST (curr_insn_set);
4224       src = SET_SRC (curr_insn_set);
4225       for (i = 0; i < n_operands; i++)
4226 	if (*curr_id->operand_loc[i] == dest)
4227 	  out = i;
4228 	else if (*curr_id->operand_loc[i] == src)
4229 	  in = i;
4230       for (i = 0; i < curr_static_id->n_dups; i++)
4231 	if (out < 0 && *curr_id->dup_loc[i] == dest)
4232 	  out = curr_static_id->dup_num[i];
4233 	else if (in < 0 && *curr_id->dup_loc[i] == src)
4234 	  in = curr_static_id->dup_num[i];
4235       lra_assert (out >= 0 && in >= 0
4236 		  && curr_static_id->operand[out].type == OP_OUT
4237 		  && curr_static_id->operand[in].type == OP_IN);
4238       rld = partial_subreg_p (GET_MODE (src), GET_MODE (dest)) ? src : dest;
4239       rld_mode = GET_MODE (rld);
4240       sec_mode = targetm.secondary_memory_needed_mode (rld_mode);
4241       new_reg = lra_create_new_reg (sec_mode, NULL_RTX, NO_REGS, NULL,
4242 				    "secondary");
4243       /* If the mode is changed, it should be wider.  */
4244       lra_assert (!partial_subreg_p (sec_mode, rld_mode));
4245       if (sec_mode != rld_mode)
4246         {
4247 	  /* If the target says specifically to use another mode for
4248 	     secondary memory moves we cannot reuse the original
4249 	     insn.  */
4250 	  after = emit_spill_move (false, new_reg, dest);
4251 	  lra_process_new_insns (curr_insn, NULL, after,
4252 				 "Inserting the sec. move");
4253 	  /* We may have non null BEFORE here (e.g. after address
4254 	     processing.  */
4255 	  push_to_sequence (before);
4256 	  before = emit_spill_move (true, new_reg, src);
4257 	  emit_insn (before);
4258 	  before = get_insns ();
4259 	  end_sequence ();
4260 	  lra_process_new_insns (curr_insn, before, NULL, "Changing on");
4261 	  lra_set_insn_deleted (curr_insn);
4262 	}
4263       else if (dest == rld)
4264         {
4265 	  *curr_id->operand_loc[out] = new_reg;
4266 	  lra_update_dup (curr_id, out);
4267 	  after = emit_spill_move (false, new_reg, dest);
4268 	  lra_process_new_insns (curr_insn, NULL, after,
4269 				 "Inserting the sec. move");
4270 	}
4271       else
4272 	{
4273 	  *curr_id->operand_loc[in] = new_reg;
4274 	  lra_update_dup (curr_id, in);
4275 	  /* See comments above.  */
4276 	  push_to_sequence (before);
4277 	  before = emit_spill_move (true, new_reg, src);
4278 	  emit_insn (before);
4279 	  before = get_insns ();
4280 	  end_sequence ();
4281 	  lra_process_new_insns (curr_insn, before, NULL,
4282 				 "Inserting the sec. move");
4283 	}
4284       lra_update_insn_regno_info (curr_insn);
4285       return true;
4286     }
4287 
4288   lra_assert (goal_alt_number >= 0);
4289   lra_set_used_insn_alternative (curr_insn, goal_alt_number);
4290 
4291   if (lra_dump_file != NULL)
4292     {
4293       const char *p;
4294 
4295       fprintf (lra_dump_file, "	 Choosing alt %d in insn %u:",
4296 	       goal_alt_number, INSN_UID (curr_insn));
4297       for (i = 0; i < n_operands; i++)
4298 	{
4299 	  p = (curr_static_id->operand_alternative
4300 	       [goal_alt_number * n_operands + i].constraint);
4301 	  if (*p == '\0')
4302 	    continue;
4303 	  fprintf (lra_dump_file, "  (%d) ", i);
4304 	  for (; *p != '\0' && *p != ',' && *p != '#'; p++)
4305 	    fputc (*p, lra_dump_file);
4306 	}
4307       if (INSN_CODE (curr_insn) >= 0
4308           && (p = get_insn_name (INSN_CODE (curr_insn))) != NULL)
4309         fprintf (lra_dump_file, " {%s}", p);
4310       if (maybe_ne (curr_id->sp_offset, 0))
4311 	{
4312 	  fprintf (lra_dump_file, " (sp_off=");
4313 	  print_dec (curr_id->sp_offset, lra_dump_file);
4314 	  fprintf (lra_dump_file, ")");
4315 	}
4316       fprintf (lra_dump_file, "\n");
4317     }
4318 
4319   /* Right now, for any pair of operands I and J that are required to
4320      match, with J < I, goal_alt_matches[I] is J.  Add I to
4321      goal_alt_matched[J].  */
4322 
4323   for (i = 0; i < n_operands; i++)
4324     if ((j = goal_alt_matches[i]) >= 0)
4325       {
4326 	for (k = 0; goal_alt_matched[j][k] >= 0; k++)
4327 	  ;
4328 	/* We allow matching one output operand and several input
4329 	   operands.  */
4330 	lra_assert (k == 0
4331 		    || (curr_static_id->operand[j].type == OP_OUT
4332 			&& curr_static_id->operand[i].type == OP_IN
4333 			&& (curr_static_id->operand
4334 			    [goal_alt_matched[j][0]].type == OP_IN)));
4335 	goal_alt_matched[j][k] = i;
4336 	goal_alt_matched[j][k + 1] = -1;
4337       }
4338 
4339   for (i = 0; i < n_operands; i++)
4340     goal_alt_win[i] |= goal_alt_match_win[i];
4341 
4342   /* Any constants that aren't allowed and can't be reloaded into
4343      registers are here changed into memory references.	 */
4344   for (i = 0; i < n_operands; i++)
4345     if (goal_alt_win[i])
4346       {
4347 	int regno;
4348 	enum reg_class new_class;
4349 	rtx reg = *curr_id->operand_loc[i];
4350 
4351 	if (GET_CODE (reg) == SUBREG)
4352 	  reg = SUBREG_REG (reg);
4353 
4354 	if (REG_P (reg) && (regno = REGNO (reg)) >= FIRST_PSEUDO_REGISTER)
4355 	  {
4356 	    bool ok_p = in_class_p (reg, goal_alt[i], &new_class);
4357 
4358 	    if (new_class != NO_REGS && get_reg_class (regno) != new_class)
4359 	      {
4360 		lra_assert (ok_p);
4361 		lra_change_class (regno, new_class, "      Change to", true);
4362 	      }
4363 	  }
4364       }
4365     else
4366       {
4367 	const char *constraint;
4368 	char c;
4369 	rtx op = *curr_id->operand_loc[i];
4370 	rtx subreg = NULL_RTX;
4371 	machine_mode mode = curr_operand_mode[i];
4372 
4373 	if (GET_CODE (op) == SUBREG)
4374 	  {
4375 	    subreg = op;
4376 	    op = SUBREG_REG (op);
4377 	    mode = GET_MODE (op);
4378 	  }
4379 
4380 	if (CONST_POOL_OK_P (mode, op)
4381 	    && ((targetm.preferred_reload_class
4382 		 (op, (enum reg_class) goal_alt[i]) == NO_REGS)
4383 		|| no_input_reloads_p))
4384 	  {
4385 	    rtx tem = force_const_mem (mode, op);
4386 
4387 	    change_p = true;
4388 	    if (subreg != NULL_RTX)
4389 	      tem = gen_rtx_SUBREG (mode, tem, SUBREG_BYTE (subreg));
4390 
4391 	    *curr_id->operand_loc[i] = tem;
4392 	    lra_update_dup (curr_id, i);
4393 	    process_address (i, false, &before, &after);
4394 
4395 	    /* If the alternative accepts constant pool refs directly
4396 	       there will be no reload needed at all.  */
4397 	    if (subreg != NULL_RTX)
4398 	      continue;
4399 	    /* Skip alternatives before the one requested.  */
4400 	    constraint = (curr_static_id->operand_alternative
4401 			  [goal_alt_number * n_operands + i].constraint);
4402 	    for (;
4403 		 (c = *constraint) && c != ',' && c != '#';
4404 		 constraint += CONSTRAINT_LEN (c, constraint))
4405 	      {
4406 		enum constraint_num cn = lookup_constraint (constraint);
4407 		if ((insn_extra_memory_constraint (cn)
4408 		     || insn_extra_special_memory_constraint (cn)
4409 		     || insn_extra_relaxed_memory_constraint (cn))
4410 		    && satisfies_memory_constraint_p (tem, cn))
4411 		  break;
4412 	      }
4413 	    if (c == '\0' || c == ',' || c == '#')
4414 	      continue;
4415 
4416 	    goal_alt_win[i] = true;
4417 	  }
4418       }
4419 
4420   n_outputs = 0;
4421   for (i = 0; i < n_operands; i++)
4422     if (curr_static_id->operand[i].type == OP_OUT)
4423       outputs[n_outputs++] = i;
4424   outputs[n_outputs] = -1;
4425   for (i = 0; i < n_operands; i++)
4426     {
4427       int regno;
4428       bool optional_p = false;
4429       rtx old, new_reg;
4430       rtx op = *curr_id->operand_loc[i];
4431 
4432       if (goal_alt_win[i])
4433 	{
4434 	  if (goal_alt[i] == NO_REGS
4435 	      && REG_P (op)
4436 	      /* When we assign NO_REGS it means that we will not
4437 		 assign a hard register to the scratch pseudo by
4438 		 assigment pass and the scratch pseudo will be
4439 		 spilled.  Spilled scratch pseudos are transformed
4440 		 back to scratches at the LRA end.  */
4441 	      && ira_former_scratch_operand_p (curr_insn, i)
4442 	      && ira_former_scratch_p (REGNO (op)))
4443 	    {
4444 	      int regno = REGNO (op);
4445 	      lra_change_class (regno, NO_REGS, "      Change to", true);
4446 	      if (lra_get_regno_hard_regno (regno) >= 0)
4447 		/* We don't have to mark all insn affected by the
4448 		   spilled pseudo as there is only one such insn, the
4449 		   current one.  */
4450 		reg_renumber[regno] = -1;
4451 	      lra_assert (bitmap_single_bit_set_p
4452 			  (&lra_reg_info[REGNO (op)].insn_bitmap));
4453 	    }
4454 	  /* We can do an optional reload.  If the pseudo got a hard
4455 	     reg, we might improve the code through inheritance.  If
4456 	     it does not get a hard register we coalesce memory/memory
4457 	     moves later.  Ignore move insns to avoid cycling.  */
4458 	  if (! lra_simple_p
4459 	      && lra_undo_inheritance_iter < LRA_MAX_INHERITANCE_PASSES
4460 	      && goal_alt[i] != NO_REGS && REG_P (op)
4461 	      && (regno = REGNO (op)) >= FIRST_PSEUDO_REGISTER
4462 	      && regno < new_regno_start
4463 	      && ! ira_former_scratch_p (regno)
4464 	      && reg_renumber[regno] < 0
4465 	      /* Check that the optional reload pseudo will be able to
4466 		 hold given mode value.  */
4467 	      && ! (prohibited_class_reg_set_mode_p
4468 		    (goal_alt[i], reg_class_contents[goal_alt[i]],
4469 		     PSEUDO_REGNO_MODE (regno)))
4470 	      && (curr_insn_set == NULL_RTX
4471 		  || !((REG_P (SET_SRC (curr_insn_set))
4472 			|| MEM_P (SET_SRC (curr_insn_set))
4473 			|| GET_CODE (SET_SRC (curr_insn_set)) == SUBREG)
4474 		       && (REG_P (SET_DEST (curr_insn_set))
4475 			   || MEM_P (SET_DEST (curr_insn_set))
4476 			   || GET_CODE (SET_DEST (curr_insn_set)) == SUBREG))))
4477 	    optional_p = true;
4478 	  else if (goal_alt_matched[i][0] != -1
4479 		   && curr_static_id->operand[i].type == OP_OUT
4480 		   && (curr_static_id->operand_alternative
4481 		       [goal_alt_number * n_operands + i].earlyclobber)
4482 		   && REG_P (op))
4483 	    {
4484 	      for (j = 0; goal_alt_matched[i][j] != -1; j++)
4485 		{
4486 		  rtx op2 = *curr_id->operand_loc[goal_alt_matched[i][j]];
4487 
4488 		  if (REG_P (op2) && REGNO (op) != REGNO (op2))
4489 		    break;
4490 		}
4491 	      if (goal_alt_matched[i][j] != -1)
4492 		{
4493 		  /* Generate reloads for different output and matched
4494 		     input registers.  This is the easiest way to avoid
4495 		     creation of non-existing register conflicts in
4496 		     lra-lives.cc.  */
4497 		  match_reload (i, goal_alt_matched[i], outputs, goal_alt[i],
4498 				&goal_alt_exclude_start_hard_regs[i], &before,
4499 				&after, TRUE);
4500 		}
4501 	      continue;
4502 	    }
4503 	  else
4504 	    continue;
4505 	}
4506 
4507       /* Operands that match previous ones have already been handled.  */
4508       if (goal_alt_matches[i] >= 0)
4509 	continue;
4510 
4511       /* We should not have an operand with a non-offsettable address
4512 	 appearing where an offsettable address will do.  It also may
4513 	 be a case when the address should be special in other words
4514 	 not a general one (e.g. it needs no index reg).  */
4515       if (goal_alt_matched[i][0] == -1 && goal_alt_offmemok[i] && MEM_P (op))
4516 	{
4517 	  enum reg_class rclass;
4518 	  rtx *loc = &XEXP (op, 0);
4519 	  enum rtx_code code = GET_CODE (*loc);
4520 
4521 	  push_to_sequence (before);
4522 	  rclass = base_reg_class (GET_MODE (op), MEM_ADDR_SPACE (op),
4523 				   MEM, SCRATCH);
4524 	  if (GET_RTX_CLASS (code) == RTX_AUTOINC)
4525 	    new_reg = emit_inc (rclass, *loc, *loc,
4526 				/* This value does not matter for MODIFY.  */
4527 				GET_MODE_SIZE (GET_MODE (op)));
4528 	  else if (get_reload_reg (OP_IN, Pmode, *loc, rclass,
4529 				   NULL, FALSE,
4530 				   "offsetable address", &new_reg))
4531 	    {
4532 	      rtx addr = *loc;
4533 	      enum rtx_code code = GET_CODE (addr);
4534 	      bool align_p = false;
4535 
4536 	      if (code == AND && CONST_INT_P (XEXP (addr, 1)))
4537 		{
4538 		  /* (and ... (const_int -X)) is used to align to X bytes.  */
4539 		  align_p = true;
4540 		  addr = XEXP (*loc, 0);
4541 		}
4542 	      else
4543 		addr = canonicalize_reload_addr (addr);
4544 
4545 	      lra_emit_move (new_reg, addr);
4546 	      if (align_p)
4547 		emit_move_insn (new_reg, gen_rtx_AND (GET_MODE (new_reg), new_reg, XEXP (*loc, 1)));
4548 	    }
4549 	  before = get_insns ();
4550 	  end_sequence ();
4551 	  *loc = new_reg;
4552 	  lra_update_dup (curr_id, i);
4553 	}
4554       else if (goal_alt_matched[i][0] == -1)
4555 	{
4556 	  machine_mode mode;
4557 	  rtx reg, *loc;
4558 	  int hard_regno;
4559 	  enum op_type type = curr_static_id->operand[i].type;
4560 
4561 	  loc = curr_id->operand_loc[i];
4562 	  mode = curr_operand_mode[i];
4563 	  if (GET_CODE (*loc) == SUBREG)
4564 	    {
4565 	      reg = SUBREG_REG (*loc);
4566 	      poly_int64 byte = SUBREG_BYTE (*loc);
4567 	      if (REG_P (reg)
4568 		  /* Strict_low_part requires reloading the register and not
4569 		     just the subreg.  Likewise for a strict subreg no wider
4570 		     than a word for WORD_REGISTER_OPERATIONS targets.  */
4571 		  && (curr_static_id->operand[i].strict_low
4572 		      || (!paradoxical_subreg_p (mode, GET_MODE (reg))
4573 			  && (hard_regno
4574 			      = get_try_hard_regno (REGNO (reg))) >= 0
4575 			  && (simplify_subreg_regno
4576 			      (hard_regno,
4577 			       GET_MODE (reg), byte, mode) < 0)
4578 			  && (goal_alt[i] == NO_REGS
4579 			      || (simplify_subreg_regno
4580 				  (ira_class_hard_regs[goal_alt[i]][0],
4581 				   GET_MODE (reg), byte, mode) >= 0)))
4582 		      || (partial_subreg_p (mode, GET_MODE (reg))
4583 			  && known_le (GET_MODE_SIZE (GET_MODE (reg)),
4584 				       UNITS_PER_WORD)
4585 			  && WORD_REGISTER_OPERATIONS)))
4586 		{
4587 		  /* An OP_INOUT is required when reloading a subreg of a
4588 		     mode wider than a word to ensure that data beyond the
4589 		     word being reloaded is preserved.  Also automatically
4590 		     ensure that strict_low_part reloads are made into
4591 		     OP_INOUT which should already be true from the backend
4592 		     constraints.  */
4593 		  if (type == OP_OUT
4594 		      && (curr_static_id->operand[i].strict_low
4595 			  || read_modify_subreg_p (*loc)))
4596 		    type = OP_INOUT;
4597 		  loc = &SUBREG_REG (*loc);
4598 		  mode = GET_MODE (*loc);
4599 		}
4600 	    }
4601 	  old = *loc;
4602 	  if (get_reload_reg (type, mode, old, goal_alt[i],
4603 			      &goal_alt_exclude_start_hard_regs[i],
4604 			      loc != curr_id->operand_loc[i], "", &new_reg)
4605 	      && type != OP_OUT)
4606 	    {
4607 	      push_to_sequence (before);
4608 	      lra_emit_move (new_reg, old);
4609 	      before = get_insns ();
4610 	      end_sequence ();
4611 	    }
4612 	  *loc = new_reg;
4613 	  if (type != OP_IN
4614 	      && find_reg_note (curr_insn, REG_UNUSED, old) == NULL_RTX)
4615 	    {
4616 	      start_sequence ();
4617 	      lra_emit_move (type == OP_INOUT ? copy_rtx (old) : old, new_reg);
4618 	      emit_insn (after);
4619 	      after = get_insns ();
4620 	      end_sequence ();
4621 	      *loc = new_reg;
4622 	    }
4623 	  for (j = 0; j < goal_alt_dont_inherit_ops_num; j++)
4624 	    if (goal_alt_dont_inherit_ops[j] == i)
4625 	      {
4626 		lra_set_regno_unique_value (REGNO (new_reg));
4627 		break;
4628 	      }
4629 	  lra_update_dup (curr_id, i);
4630 	}
4631       else if (curr_static_id->operand[i].type == OP_IN
4632 	       && (curr_static_id->operand[goal_alt_matched[i][0]].type
4633 		   == OP_OUT
4634 		   || (curr_static_id->operand[goal_alt_matched[i][0]].type
4635 		       == OP_INOUT
4636 		       && (operands_match_p
4637 			   (*curr_id->operand_loc[i],
4638 			    *curr_id->operand_loc[goal_alt_matched[i][0]],
4639 			    -1)))))
4640 	{
4641 	  /* generate reloads for input and matched outputs.  */
4642 	  match_inputs[0] = i;
4643 	  match_inputs[1] = -1;
4644 	  match_reload (goal_alt_matched[i][0], match_inputs, outputs,
4645 			goal_alt[i], &goal_alt_exclude_start_hard_regs[i],
4646 			&before, &after,
4647 			curr_static_id->operand_alternative
4648 			[goal_alt_number * n_operands + goal_alt_matched[i][0]]
4649 			.earlyclobber);
4650 	}
4651       else if ((curr_static_id->operand[i].type == OP_OUT
4652 		|| (curr_static_id->operand[i].type == OP_INOUT
4653 		    && (operands_match_p
4654 			(*curr_id->operand_loc[i],
4655 			 *curr_id->operand_loc[goal_alt_matched[i][0]],
4656 			 -1))))
4657 	       && (curr_static_id->operand[goal_alt_matched[i][0]].type
4658 		    == OP_IN))
4659 	/* Generate reloads for output and matched inputs.  */
4660 	match_reload (i, goal_alt_matched[i], outputs, goal_alt[i],
4661 		      &goal_alt_exclude_start_hard_regs[i], &before, &after,
4662 		      curr_static_id->operand_alternative
4663 		      [goal_alt_number * n_operands + i].earlyclobber);
4664       else if (curr_static_id->operand[i].type == OP_IN
4665 	       && (curr_static_id->operand[goal_alt_matched[i][0]].type
4666 		   == OP_IN))
4667 	{
4668 	  /* Generate reloads for matched inputs.  */
4669 	  match_inputs[0] = i;
4670 	  for (j = 0; (k = goal_alt_matched[i][j]) >= 0; j++)
4671 	    match_inputs[j + 1] = k;
4672 	  match_inputs[j + 1] = -1;
4673 	  match_reload (-1, match_inputs, outputs, goal_alt[i],
4674 			&goal_alt_exclude_start_hard_regs[i],
4675 			&before, &after, false);
4676 	}
4677       else
4678 	/* We must generate code in any case when function
4679 	   process_alt_operands decides that it is possible.  */
4680 	gcc_unreachable ();
4681 
4682       if (optional_p)
4683 	{
4684 	  rtx reg = op;
4685 
4686 	  lra_assert (REG_P (reg));
4687 	  regno = REGNO (reg);
4688 	  op = *curr_id->operand_loc[i]; /* Substitution.  */
4689 	  if (GET_CODE (op) == SUBREG)
4690 	    op = SUBREG_REG (op);
4691 	  gcc_assert (REG_P (op) && (int) REGNO (op) >= new_regno_start);
4692 	  bitmap_set_bit (&lra_optional_reload_pseudos, REGNO (op));
4693 	  lra_reg_info[REGNO (op)].restore_rtx = reg;
4694 	  if (lra_dump_file != NULL)
4695 	    fprintf (lra_dump_file,
4696 		     "      Making reload reg %d for reg %d optional\n",
4697 		     REGNO (op), regno);
4698 	}
4699     }
4700   if (before != NULL_RTX || after != NULL_RTX
4701       || max_regno_before != max_reg_num ())
4702     change_p = true;
4703   if (change_p)
4704     {
4705       lra_update_operator_dups (curr_id);
4706       /* Something changes -- process the insn.	 */
4707       lra_update_insn_regno_info (curr_insn);
4708     }
4709   lra_process_new_insns (curr_insn, before, after, "Inserting insn reload");
4710   return change_p;
4711 }
4712 
4713 /* Return true if INSN satisfies all constraints.  In other words, no
4714    reload insns are needed.  */
4715 bool
lra_constrain_insn(rtx_insn * insn)4716 lra_constrain_insn (rtx_insn *insn)
4717 {
4718   int saved_new_regno_start = new_regno_start;
4719   int saved_new_insn_uid_start = new_insn_uid_start;
4720   bool change_p;
4721 
4722   curr_insn = insn;
4723   curr_id = lra_get_insn_recog_data (curr_insn);
4724   curr_static_id = curr_id->insn_static_data;
4725   new_insn_uid_start = get_max_uid ();
4726   new_regno_start = max_reg_num ();
4727   change_p = curr_insn_transform (true);
4728   new_regno_start = saved_new_regno_start;
4729   new_insn_uid_start = saved_new_insn_uid_start;
4730   return ! change_p;
4731 }
4732 
4733 /* Return true if X is in LIST.	 */
4734 static bool
in_list_p(rtx x,rtx list)4735 in_list_p (rtx x, rtx list)
4736 {
4737   for (; list != NULL_RTX; list = XEXP (list, 1))
4738     if (XEXP (list, 0) == x)
4739       return true;
4740   return false;
4741 }
4742 
4743 /* Return true if X contains an allocatable hard register (if
4744    HARD_REG_P) or a (spilled if SPILLED_P) pseudo.  */
4745 static bool
contains_reg_p(rtx x,bool hard_reg_p,bool spilled_p)4746 contains_reg_p (rtx x, bool hard_reg_p, bool spilled_p)
4747 {
4748   int i, j;
4749   const char *fmt;
4750   enum rtx_code code;
4751 
4752   code = GET_CODE (x);
4753   if (REG_P (x))
4754     {
4755       int regno = REGNO (x);
4756       HARD_REG_SET alloc_regs;
4757 
4758       if (hard_reg_p)
4759 	{
4760 	  if (regno >= FIRST_PSEUDO_REGISTER)
4761 	    regno = lra_get_regno_hard_regno (regno);
4762 	  if (regno < 0)
4763 	    return false;
4764 	  alloc_regs = ~lra_no_alloc_regs;
4765 	  return overlaps_hard_reg_set_p (alloc_regs, GET_MODE (x), regno);
4766 	}
4767       else
4768 	{
4769 	  if (regno < FIRST_PSEUDO_REGISTER)
4770 	    return false;
4771 	  if (! spilled_p)
4772 	    return true;
4773 	  return lra_get_regno_hard_regno (regno) < 0;
4774 	}
4775     }
4776   fmt = GET_RTX_FORMAT (code);
4777   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4778     {
4779       if (fmt[i] == 'e')
4780 	{
4781 	  if (contains_reg_p (XEXP (x, i), hard_reg_p, spilled_p))
4782 	    return true;
4783 	}
4784       else if (fmt[i] == 'E')
4785 	{
4786 	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
4787 	    if (contains_reg_p (XVECEXP (x, i, j), hard_reg_p, spilled_p))
4788 	      return true;
4789 	}
4790     }
4791   return false;
4792 }
4793 
4794 /* Process all regs in location *LOC and change them on equivalent
4795    substitution.  Return true if any change was done.  */
4796 static bool
loc_equivalence_change_p(rtx * loc)4797 loc_equivalence_change_p (rtx *loc)
4798 {
4799   rtx subst, reg, x = *loc;
4800   bool result = false;
4801   enum rtx_code code = GET_CODE (x);
4802   const char *fmt;
4803   int i, j;
4804 
4805   if (code == SUBREG)
4806     {
4807       reg = SUBREG_REG (x);
4808       if ((subst = get_equiv_with_elimination (reg, curr_insn)) != reg
4809 	  && GET_MODE (subst) == VOIDmode)
4810 	{
4811 	  /* We cannot reload debug location.  Simplify subreg here
4812 	     while we know the inner mode.  */
4813 	  *loc = simplify_gen_subreg (GET_MODE (x), subst,
4814 				      GET_MODE (reg), SUBREG_BYTE (x));
4815 	  return true;
4816 	}
4817     }
4818   if (code == REG && (subst = get_equiv_with_elimination (x, curr_insn)) != x)
4819     {
4820       *loc = subst;
4821       return true;
4822     }
4823 
4824   /* Scan all the operand sub-expressions.  */
4825   fmt = GET_RTX_FORMAT (code);
4826   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4827     {
4828       if (fmt[i] == 'e')
4829 	result = loc_equivalence_change_p (&XEXP (x, i)) || result;
4830       else if (fmt[i] == 'E')
4831 	for (j = XVECLEN (x, i) - 1; j >= 0; j--)
4832 	  result
4833 	    = loc_equivalence_change_p (&XVECEXP (x, i, j)) || result;
4834     }
4835   return result;
4836 }
4837 
4838 /* Similar to loc_equivalence_change_p, but for use as
4839    simplify_replace_fn_rtx callback.  DATA is insn for which the
4840    elimination is done.  If it null we don't do the elimination.  */
4841 static rtx
loc_equivalence_callback(rtx loc,const_rtx,void * data)4842 loc_equivalence_callback (rtx loc, const_rtx, void *data)
4843 {
4844   if (!REG_P (loc))
4845     return NULL_RTX;
4846 
4847   rtx subst = (data == NULL
4848 	       ? get_equiv (loc) : get_equiv_with_elimination (loc, (rtx_insn *) data));
4849   if (subst != loc)
4850     return subst;
4851 
4852   return NULL_RTX;
4853 }
4854 
4855 /* Maximum number of generated reload insns per an insn.  It is for
4856    preventing this pass cycling in a bug case.	*/
4857 #define MAX_RELOAD_INSNS_NUMBER LRA_MAX_INSN_RELOADS
4858 
4859 /* The current iteration number of this LRA pass.  */
4860 int lra_constraint_iter;
4861 
4862 /* True if we should during assignment sub-pass check assignment
4863    correctness for all pseudos and spill some of them to correct
4864    conflicts.  It can be necessary when we substitute equiv which
4865    needs checking register allocation correctness because the
4866    equivalent value contains allocatable hard registers, or when we
4867    restore multi-register pseudo, or when we change the insn code and
4868    its operand became INOUT operand when it was IN one before.  */
4869 bool check_and_force_assignment_correctness_p;
4870 
4871 /* Return true if REGNO is referenced in more than one block.  */
4872 static bool
multi_block_pseudo_p(int regno)4873 multi_block_pseudo_p (int regno)
4874 {
4875   basic_block bb = NULL;
4876   unsigned int uid;
4877   bitmap_iterator bi;
4878 
4879   if (regno < FIRST_PSEUDO_REGISTER)
4880     return false;
4881 
4882   EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi)
4883     if (bb == NULL)
4884       bb = BLOCK_FOR_INSN (lra_insn_recog_data[uid]->insn);
4885     else if (BLOCK_FOR_INSN (lra_insn_recog_data[uid]->insn) != bb)
4886       return true;
4887   return false;
4888 }
4889 
4890 /* Return true if LIST contains a deleted insn.  */
4891 static bool
contains_deleted_insn_p(rtx_insn_list * list)4892 contains_deleted_insn_p (rtx_insn_list *list)
4893 {
4894   for (; list != NULL_RTX; list = list->next ())
4895     if (NOTE_P (list->insn ())
4896 	&& NOTE_KIND (list->insn ()) == NOTE_INSN_DELETED)
4897       return true;
4898   return false;
4899 }
4900 
4901 /* Return true if X contains a pseudo dying in INSN.  */
4902 static bool
dead_pseudo_p(rtx x,rtx_insn * insn)4903 dead_pseudo_p (rtx x, rtx_insn *insn)
4904 {
4905   int i, j;
4906   const char *fmt;
4907   enum rtx_code code;
4908 
4909   if (REG_P (x))
4910     return (insn != NULL_RTX
4911 	    && find_regno_note (insn, REG_DEAD, REGNO (x)) != NULL_RTX);
4912   code = GET_CODE (x);
4913   fmt = GET_RTX_FORMAT (code);
4914   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4915     {
4916       if (fmt[i] == 'e')
4917 	{
4918 	  if (dead_pseudo_p (XEXP (x, i), insn))
4919 	    return true;
4920 	}
4921       else if (fmt[i] == 'E')
4922 	{
4923 	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
4924 	    if (dead_pseudo_p (XVECEXP (x, i, j), insn))
4925 	      return true;
4926 	}
4927     }
4928   return false;
4929 }
4930 
4931 /* Return true if INSN contains a dying pseudo in INSN right hand
4932    side.  */
4933 static bool
insn_rhs_dead_pseudo_p(rtx_insn * insn)4934 insn_rhs_dead_pseudo_p (rtx_insn *insn)
4935 {
4936   rtx set = single_set (insn);
4937 
4938   gcc_assert (set != NULL);
4939   return dead_pseudo_p (SET_SRC (set), insn);
4940 }
4941 
4942 /* Return true if any init insn of REGNO contains a dying pseudo in
4943    insn right hand side.  */
4944 static bool
init_insn_rhs_dead_pseudo_p(int regno)4945 init_insn_rhs_dead_pseudo_p (int regno)
4946 {
4947   rtx_insn_list *insns = ira_reg_equiv[regno].init_insns;
4948 
4949   if (insns == NULL)
4950     return false;
4951   for (; insns != NULL_RTX; insns = insns->next ())
4952     if (insn_rhs_dead_pseudo_p (insns->insn ()))
4953       return true;
4954   return false;
4955 }
4956 
4957 /* Return TRUE if REGNO has a reverse equivalence.  The equivalence is
4958    reverse only if we have one init insn with given REGNO as a
4959    source.  */
4960 static bool
reverse_equiv_p(int regno)4961 reverse_equiv_p (int regno)
4962 {
4963   rtx_insn_list *insns = ira_reg_equiv[regno].init_insns;
4964   rtx set;
4965 
4966   if (insns == NULL)
4967     return false;
4968   if (! INSN_P (insns->insn ())
4969       || insns->next () != NULL)
4970     return false;
4971   if ((set = single_set (insns->insn ())) == NULL_RTX)
4972     return false;
4973   return REG_P (SET_SRC (set)) && (int) REGNO (SET_SRC (set)) == regno;
4974 }
4975 
4976 /* Return TRUE if REGNO was reloaded in an equivalence init insn.  We
4977    call this function only for non-reverse equivalence.  */
4978 static bool
contains_reloaded_insn_p(int regno)4979 contains_reloaded_insn_p (int regno)
4980 {
4981   rtx set;
4982   rtx_insn_list *list = ira_reg_equiv[regno].init_insns;
4983 
4984   for (; list != NULL; list = list->next ())
4985     if ((set = single_set (list->insn ())) == NULL_RTX
4986 	|| ! REG_P (SET_DEST (set))
4987 	|| (int) REGNO (SET_DEST (set)) != regno)
4988       return true;
4989   return false;
4990 }
4991 
4992 /* Entry function of LRA constraint pass.  Return true if the
4993    constraint pass did change the code.	 */
4994 bool
lra_constraints(bool first_p)4995 lra_constraints (bool first_p)
4996 {
4997   bool changed_p;
4998   int i, hard_regno, new_insns_num;
4999   unsigned int min_len, new_min_len, uid;
5000   rtx set, x, reg, dest_reg;
5001   basic_block last_bb;
5002   bitmap_iterator bi;
5003 
5004   lra_constraint_iter++;
5005   if (lra_dump_file != NULL)
5006     fprintf (lra_dump_file, "\n********** Local #%d: **********\n\n",
5007 	     lra_constraint_iter);
5008   changed_p = false;
5009   if (pic_offset_table_rtx
5010       && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER)
5011     check_and_force_assignment_correctness_p = true;
5012   else if (first_p)
5013     /* On the first iteration we should check IRA assignment
5014        correctness.  In rare cases, the assignments can be wrong as
5015        early clobbers operands are ignored in IRA or usages of
5016        paradoxical sub-registers are not taken into account by
5017        IRA.  */
5018     check_and_force_assignment_correctness_p = true;
5019   new_insn_uid_start = get_max_uid ();
5020   new_regno_start = first_p ? lra_constraint_new_regno_start : max_reg_num ();
5021   /* Mark used hard regs for target stack size calulations.  */
5022   for (i = FIRST_PSEUDO_REGISTER; i < new_regno_start; i++)
5023     if (lra_reg_info[i].nrefs != 0
5024 	&& (hard_regno = lra_get_regno_hard_regno (i)) >= 0)
5025       {
5026 	int j, nregs;
5027 
5028 	nregs = hard_regno_nregs (hard_regno, lra_reg_info[i].biggest_mode);
5029 	for (j = 0; j < nregs; j++)
5030 	  df_set_regs_ever_live (hard_regno + j, true);
5031       }
5032   /* Do elimination before the equivalence processing as we can spill
5033      some pseudos during elimination.  */
5034   lra_eliminate (false, first_p);
5035   auto_bitmap equiv_insn_bitmap (&reg_obstack);
5036   for (i = FIRST_PSEUDO_REGISTER; i < new_regno_start; i++)
5037     if (lra_reg_info[i].nrefs != 0)
5038       {
5039 	ira_reg_equiv[i].profitable_p = true;
5040 	reg = regno_reg_rtx[i];
5041 	if (lra_get_regno_hard_regno (i) < 0 && (x = get_equiv (reg)) != reg)
5042 	  {
5043 	    bool pseudo_p = contains_reg_p (x, false, false);
5044 
5045 	    /* After RTL transformation, we cannot guarantee that
5046 	       pseudo in the substitution was not reloaded which might
5047 	       make equivalence invalid.  For example, in reverse
5048 	       equiv of p0
5049 
5050 	       p0 <- ...
5051 	       ...
5052 	       equiv_mem <- p0
5053 
5054 	       the memory address register was reloaded before the 2nd
5055 	       insn.  */
5056 	    if ((! first_p && pseudo_p)
5057 		/* We don't use DF for compilation speed sake.  So it
5058 		   is problematic to update live info when we use an
5059 		   equivalence containing pseudos in more than one
5060 		   BB.  */
5061 		|| (pseudo_p && multi_block_pseudo_p (i))
5062 		/* If an init insn was deleted for some reason, cancel
5063 		   the equiv.  We could update the equiv insns after
5064 		   transformations including an equiv insn deletion
5065 		   but it is not worthy as such cases are extremely
5066 		   rare.  */
5067 		|| contains_deleted_insn_p (ira_reg_equiv[i].init_insns)
5068 		/* If it is not a reverse equivalence, we check that a
5069 		   pseudo in rhs of the init insn is not dying in the
5070 		   insn.  Otherwise, the live info at the beginning of
5071 		   the corresponding BB might be wrong after we
5072 		   removed the insn.  When the equiv can be a
5073 		   constant, the right hand side of the init insn can
5074 		   be a pseudo.  */
5075 		|| (! reverse_equiv_p (i)
5076 		    && (init_insn_rhs_dead_pseudo_p (i)
5077 			/* If we reloaded the pseudo in an equivalence
5078 			   init insn, we cannot remove the equiv init
5079 			   insns and the init insns might write into
5080 			   const memory in this case.  */
5081 			|| contains_reloaded_insn_p (i)))
5082 		/* Prevent access beyond equivalent memory for
5083 		   paradoxical subregs.  */
5084 		|| (MEM_P (x)
5085 		    && maybe_gt (GET_MODE_SIZE (lra_reg_info[i].biggest_mode),
5086 				 GET_MODE_SIZE (GET_MODE (x))))
5087 		|| (pic_offset_table_rtx
5088 		    && ((CONST_POOL_OK_P (PSEUDO_REGNO_MODE (i), x)
5089 			 && (targetm.preferred_reload_class
5090 			     (x, lra_get_allocno_class (i)) == NO_REGS))
5091 			|| contains_symbol_ref_p (x))))
5092 	      ira_reg_equiv[i].defined_p = false;
5093 	    if (contains_reg_p (x, false, true))
5094 	      ira_reg_equiv[i].profitable_p = false;
5095 	    if (get_equiv (reg) != reg)
5096 	      bitmap_ior_into (equiv_insn_bitmap, &lra_reg_info[i].insn_bitmap);
5097 	  }
5098       }
5099   for (i = FIRST_PSEUDO_REGISTER; i < new_regno_start; i++)
5100     update_equiv (i);
5101   /* We should add all insns containing pseudos which should be
5102      substituted by their equivalences.  */
5103   EXECUTE_IF_SET_IN_BITMAP (equiv_insn_bitmap, 0, uid, bi)
5104     lra_push_insn_by_uid (uid);
5105   min_len = lra_insn_stack_length ();
5106   new_insns_num = 0;
5107   last_bb = NULL;
5108   changed_p = false;
5109   while ((new_min_len = lra_insn_stack_length ()) != 0)
5110     {
5111       curr_insn = lra_pop_insn ();
5112       --new_min_len;
5113       curr_bb = BLOCK_FOR_INSN (curr_insn);
5114       if (curr_bb != last_bb)
5115 	{
5116 	  last_bb = curr_bb;
5117 	  bb_reload_num = lra_curr_reload_num;
5118 	}
5119       if (min_len > new_min_len)
5120 	{
5121 	  min_len = new_min_len;
5122 	  new_insns_num = 0;
5123 	}
5124       if (new_insns_num > MAX_RELOAD_INSNS_NUMBER)
5125 	internal_error
5126 	  ("maximum number of generated reload insns per insn achieved (%d)",
5127 	   MAX_RELOAD_INSNS_NUMBER);
5128       new_insns_num++;
5129       if (DEBUG_INSN_P (curr_insn))
5130 	{
5131 	  /* We need to check equivalence in debug insn and change
5132 	     pseudo to the equivalent value if necessary.  */
5133 	  curr_id = lra_get_insn_recog_data (curr_insn);
5134 	  if (bitmap_bit_p (equiv_insn_bitmap, INSN_UID (curr_insn)))
5135 	    {
5136 	      rtx old = *curr_id->operand_loc[0];
5137 	      *curr_id->operand_loc[0]
5138 		= simplify_replace_fn_rtx (old, NULL_RTX,
5139 					   loc_equivalence_callback, curr_insn);
5140 	      if (old != *curr_id->operand_loc[0])
5141 		{
5142 		  lra_update_insn_regno_info (curr_insn);
5143 		  changed_p = true;
5144 		}
5145 	    }
5146 	}
5147       else if (INSN_P (curr_insn))
5148 	{
5149 	  if ((set = single_set (curr_insn)) != NULL_RTX)
5150 	    {
5151 	      dest_reg = SET_DEST (set);
5152 	      /* The equivalence pseudo could be set up as SUBREG in a
5153 		 case when it is a call restore insn in a mode
5154 		 different from the pseudo mode.  */
5155 	      if (GET_CODE (dest_reg) == SUBREG)
5156 		dest_reg = SUBREG_REG (dest_reg);
5157 	      if ((REG_P (dest_reg)
5158 		   && (x = get_equiv (dest_reg)) != dest_reg
5159 		   /* Remove insns which set up a pseudo whose value
5160 		      cannot be changed.  Such insns might be not in
5161 		      init_insns because we don't update equiv data
5162 		      during insn transformations.
5163 
5164 		      As an example, let suppose that a pseudo got
5165 		      hard register and on the 1st pass was not
5166 		      changed to equivalent constant.  We generate an
5167 		      additional insn setting up the pseudo because of
5168 		      secondary memory movement.  Then the pseudo is
5169 		      spilled and we use the equiv constant.  In this
5170 		      case we should remove the additional insn and
5171 		      this insn is not init_insns list.  */
5172 		   && (! MEM_P (x) || MEM_READONLY_P (x)
5173 		       /* Check that this is actually an insn setting
5174 			  up the equivalence.  */
5175 		       || in_list_p (curr_insn,
5176 				     ira_reg_equiv
5177 				     [REGNO (dest_reg)].init_insns)))
5178 		  || (((x = get_equiv (SET_SRC (set))) != SET_SRC (set))
5179 		      && in_list_p (curr_insn,
5180 				    ira_reg_equiv
5181 				    [REGNO (SET_SRC (set))].init_insns)))
5182 		{
5183 		  /* This is equiv init insn of pseudo which did not get a
5184 		     hard register -- remove the insn.	*/
5185 		  if (lra_dump_file != NULL)
5186 		    {
5187 		      fprintf (lra_dump_file,
5188 			       "      Removing equiv init insn %i (freq=%d)\n",
5189 			       INSN_UID (curr_insn),
5190 			       REG_FREQ_FROM_BB (BLOCK_FOR_INSN (curr_insn)));
5191 		      dump_insn_slim (lra_dump_file, curr_insn);
5192 		    }
5193 		  if (contains_reg_p (x, true, false))
5194 		    check_and_force_assignment_correctness_p = true;
5195 		  lra_set_insn_deleted (curr_insn);
5196 		  continue;
5197 		}
5198 	    }
5199 	  curr_id = lra_get_insn_recog_data (curr_insn);
5200 	  curr_static_id = curr_id->insn_static_data;
5201 	  init_curr_insn_input_reloads ();
5202 	  init_curr_operand_mode ();
5203 	  if (curr_insn_transform (false))
5204 	    changed_p = true;
5205 	  /* Check non-transformed insns too for equiv change as USE
5206 	     or CLOBBER don't need reloads but can contain pseudos
5207 	     being changed on their equivalences.  */
5208 	  else if (bitmap_bit_p (equiv_insn_bitmap, INSN_UID (curr_insn))
5209 		   && loc_equivalence_change_p (&PATTERN (curr_insn)))
5210 	    {
5211 	      lra_update_insn_regno_info (curr_insn);
5212 	      changed_p = true;
5213 	    }
5214 	}
5215     }
5216 
5217   /* If we used a new hard regno, changed_p should be true because the
5218      hard reg is assigned to a new pseudo.  */
5219   if (flag_checking && !changed_p)
5220     {
5221       for (i = FIRST_PSEUDO_REGISTER; i < new_regno_start; i++)
5222 	if (lra_reg_info[i].nrefs != 0
5223 	    && (hard_regno = lra_get_regno_hard_regno (i)) >= 0)
5224 	  {
5225 	    int j, nregs = hard_regno_nregs (hard_regno,
5226 					     PSEUDO_REGNO_MODE (i));
5227 
5228 	    for (j = 0; j < nregs; j++)
5229 	      lra_assert (df_regs_ever_live_p (hard_regno + j));
5230 	  }
5231     }
5232   return changed_p;
5233 }
5234 
5235 static void initiate_invariants (void);
5236 static void finish_invariants (void);
5237 
5238 /* Initiate the LRA constraint pass.  It is done once per
5239    function.  */
5240 void
lra_constraints_init(void)5241 lra_constraints_init (void)
5242 {
5243   initiate_invariants ();
5244 }
5245 
5246 /* Finalize the LRA constraint pass.  It is done once per
5247    function.  */
5248 void
lra_constraints_finish(void)5249 lra_constraints_finish (void)
5250 {
5251   finish_invariants ();
5252 }
5253 
5254 
5255 
5256 /* Structure describes invariants for ineheritance.  */
5257 struct lra_invariant
5258 {
5259   /* The order number of the invariant.  */
5260   int num;
5261   /* The invariant RTX.  */
5262   rtx invariant_rtx;
5263   /* The origin insn of the invariant.  */
5264   rtx_insn *insn;
5265 };
5266 
5267 typedef lra_invariant invariant_t;
5268 typedef invariant_t *invariant_ptr_t;
5269 typedef const invariant_t *const_invariant_ptr_t;
5270 
5271 /* Pointer to the inheritance invariants.  */
5272 static vec<invariant_ptr_t> invariants;
5273 
5274 /* Allocation pool for the invariants.  */
5275 static object_allocator<lra_invariant> *invariants_pool;
5276 
5277 /* Hash table for the invariants.  */
5278 static htab_t invariant_table;
5279 
5280 /* Hash function for INVARIANT.  */
5281 static hashval_t
invariant_hash(const void * invariant)5282 invariant_hash (const void *invariant)
5283 {
5284   rtx inv = ((const_invariant_ptr_t) invariant)->invariant_rtx;
5285   return lra_rtx_hash (inv);
5286 }
5287 
5288 /* Equal function for invariants INVARIANT1 and INVARIANT2.  */
5289 static int
invariant_eq_p(const void * invariant1,const void * invariant2)5290 invariant_eq_p (const void *invariant1, const void *invariant2)
5291 {
5292   rtx inv1 = ((const_invariant_ptr_t) invariant1)->invariant_rtx;
5293   rtx inv2 = ((const_invariant_ptr_t) invariant2)->invariant_rtx;
5294 
5295   return rtx_equal_p (inv1, inv2);
5296 }
5297 
5298 /* Insert INVARIANT_RTX into the table if it is not there yet.  Return
5299    invariant which is in the table.  */
5300 static invariant_ptr_t
insert_invariant(rtx invariant_rtx)5301 insert_invariant (rtx invariant_rtx)
5302 {
5303   void **entry_ptr;
5304   invariant_t invariant;
5305   invariant_ptr_t invariant_ptr;
5306 
5307   invariant.invariant_rtx = invariant_rtx;
5308   entry_ptr = htab_find_slot (invariant_table, &invariant, INSERT);
5309   if (*entry_ptr == NULL)
5310     {
5311       invariant_ptr = invariants_pool->allocate ();
5312       invariant_ptr->invariant_rtx = invariant_rtx;
5313       invariant_ptr->insn = NULL;
5314       invariants.safe_push (invariant_ptr);
5315       *entry_ptr = (void *) invariant_ptr;
5316     }
5317   return (invariant_ptr_t) *entry_ptr;
5318 }
5319 
5320 /* Initiate the invariant table.  */
5321 static void
initiate_invariants(void)5322 initiate_invariants (void)
5323 {
5324   invariants.create (100);
5325   invariants_pool
5326     = new object_allocator<lra_invariant> ("Inheritance invariants");
5327   invariant_table = htab_create (100, invariant_hash, invariant_eq_p, NULL);
5328 }
5329 
5330 /* Finish the invariant table.  */
5331 static void
finish_invariants(void)5332 finish_invariants (void)
5333 {
5334   htab_delete (invariant_table);
5335   delete invariants_pool;
5336   invariants.release ();
5337 }
5338 
5339 /* Make the invariant table empty.  */
5340 static void
clear_invariants(void)5341 clear_invariants (void)
5342 {
5343   htab_empty (invariant_table);
5344   invariants_pool->release ();
5345   invariants.truncate (0);
5346 }
5347 
5348 
5349 
5350 /* This page contains code to do inheritance/split
5351    transformations.  */
5352 
5353 /* Number of reloads passed so far in current EBB.  */
5354 static int reloads_num;
5355 
5356 /* Number of calls passed so far in current EBB.  */
5357 static int calls_num;
5358 
5359 /* Index ID is the CALLS_NUM associated the last call we saw with
5360    ABI identifier ID.  */
5361 static int last_call_for_abi[NUM_ABI_IDS];
5362 
5363 /* Which registers have been fully or partially clobbered by a call
5364    since they were last used.  */
5365 static HARD_REG_SET full_and_partial_call_clobbers;
5366 
5367 /* Current reload pseudo check for validity of elements in
5368    USAGE_INSNS.	 */
5369 static int curr_usage_insns_check;
5370 
5371 /* Info about last usage of registers in EBB to do inheritance/split
5372    transformation.  Inheritance transformation is done from a spilled
5373    pseudo and split transformations from a hard register or a pseudo
5374    assigned to a hard register.	 */
5375 struct usage_insns
5376 {
5377   /* If the value is equal to CURR_USAGE_INSNS_CHECK, then the member
5378      value INSNS is valid.  The insns is chain of optional debug insns
5379      and a finishing non-debug insn using the corresponding reg.  The
5380      value is also used to mark the registers which are set up in the
5381      current insn.  The negated insn uid is used for this.  */
5382   int check;
5383   /* Value of global reloads_num at the last insn in INSNS.  */
5384   int reloads_num;
5385   /* Value of global reloads_nums at the last insn in INSNS.  */
5386   int calls_num;
5387   /* It can be true only for splitting.	 And it means that the restore
5388      insn should be put after insn given by the following member.  */
5389   bool after_p;
5390   /* Next insns in the current EBB which use the original reg and the
5391      original reg value is not changed between the current insn and
5392      the next insns.  In order words, e.g. for inheritance, if we need
5393      to use the original reg value again in the next insns we can try
5394      to use the value in a hard register from a reload insn of the
5395      current insn.  */
5396   rtx insns;
5397 };
5398 
5399 /* Map: regno -> corresponding pseudo usage insns.  */
5400 static struct usage_insns *usage_insns;
5401 
5402 static void
setup_next_usage_insn(int regno,rtx insn,int reloads_num,bool after_p)5403 setup_next_usage_insn (int regno, rtx insn, int reloads_num, bool after_p)
5404 {
5405   usage_insns[regno].check = curr_usage_insns_check;
5406   usage_insns[regno].insns = insn;
5407   usage_insns[regno].reloads_num = reloads_num;
5408   usage_insns[regno].calls_num = calls_num;
5409   usage_insns[regno].after_p = after_p;
5410   if (regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] >= 0)
5411     remove_from_hard_reg_set (&full_and_partial_call_clobbers,
5412 			      PSEUDO_REGNO_MODE (regno),
5413 			      reg_renumber[regno]);
5414 }
5415 
5416 /* The function is used to form list REGNO usages which consists of
5417    optional debug insns finished by a non-debug insn using REGNO.
5418    RELOADS_NUM is current number of reload insns processed so far.  */
5419 static void
add_next_usage_insn(int regno,rtx_insn * insn,int reloads_num)5420 add_next_usage_insn (int regno, rtx_insn *insn, int reloads_num)
5421 {
5422   rtx next_usage_insns;
5423 
5424   if (usage_insns[regno].check == curr_usage_insns_check
5425       && (next_usage_insns = usage_insns[regno].insns) != NULL_RTX
5426       && DEBUG_INSN_P (insn))
5427     {
5428       /* Check that we did not add the debug insn yet.	*/
5429       if (next_usage_insns != insn
5430 	  && (GET_CODE (next_usage_insns) != INSN_LIST
5431 	      || XEXP (next_usage_insns, 0) != insn))
5432 	usage_insns[regno].insns = gen_rtx_INSN_LIST (VOIDmode, insn,
5433 						      next_usage_insns);
5434     }
5435   else if (NONDEBUG_INSN_P (insn))
5436     setup_next_usage_insn (regno, insn, reloads_num, false);
5437   else
5438     usage_insns[regno].check = 0;
5439 }
5440 
5441 /* Return first non-debug insn in list USAGE_INSNS.  */
5442 static rtx_insn *
skip_usage_debug_insns(rtx usage_insns)5443 skip_usage_debug_insns (rtx usage_insns)
5444 {
5445   rtx insn;
5446 
5447   /* Skip debug insns.  */
5448   for (insn = usage_insns;
5449        insn != NULL_RTX && GET_CODE (insn) == INSN_LIST;
5450        insn = XEXP (insn, 1))
5451     ;
5452   return safe_as_a <rtx_insn *> (insn);
5453 }
5454 
5455 /* Return true if we need secondary memory moves for insn in
5456    USAGE_INSNS after inserting inherited pseudo of class INHER_CL
5457    into the insn.  */
5458 static bool
check_secondary_memory_needed_p(enum reg_class inher_cl ATTRIBUTE_UNUSED,rtx usage_insns ATTRIBUTE_UNUSED)5459 check_secondary_memory_needed_p (enum reg_class inher_cl ATTRIBUTE_UNUSED,
5460 				 rtx usage_insns ATTRIBUTE_UNUSED)
5461 {
5462   rtx_insn *insn;
5463   rtx set, dest;
5464   enum reg_class cl;
5465 
5466   if (inher_cl == ALL_REGS
5467       || (insn = skip_usage_debug_insns (usage_insns)) == NULL_RTX)
5468     return false;
5469   lra_assert (INSN_P (insn));
5470   if ((set = single_set (insn)) == NULL_RTX || ! REG_P (SET_DEST (set)))
5471     return false;
5472   dest = SET_DEST (set);
5473   if (! REG_P (dest))
5474     return false;
5475   lra_assert (inher_cl != NO_REGS);
5476   cl = get_reg_class (REGNO (dest));
5477   return (cl != NO_REGS && cl != ALL_REGS
5478 	  && targetm.secondary_memory_needed (GET_MODE (dest), inher_cl, cl));
5479 }
5480 
5481 /* Registers involved in inheritance/split in the current EBB
5482    (inheritance/split pseudos and original registers).	*/
5483 static bitmap_head check_only_regs;
5484 
5485 /* Reload pseudos cannot be involded in invariant inheritance in the
5486    current EBB.  */
5487 static bitmap_head invalid_invariant_regs;
5488 
5489 /* Do inheritance transformations for insn INSN, which defines (if
5490    DEF_P) or uses ORIGINAL_REGNO.  NEXT_USAGE_INSNS specifies which
5491    instruction in the EBB next uses ORIGINAL_REGNO; it has the same
5492    form as the "insns" field of usage_insns.  Return true if we
5493    succeed in such transformation.
5494 
5495    The transformations look like:
5496 
5497      p <- ...		  i <- ...
5498      ...		  p <- i    (new insn)
5499      ...	     =>
5500      <- ... p ...	  <- ... i ...
5501    or
5502      ...		  i <- p    (new insn)
5503      <- ... p ...	  <- ... i ...
5504      ...	     =>
5505      <- ... p ...	  <- ... i ...
5506    where p is a spilled original pseudo and i is a new inheritance pseudo.
5507 
5508 
5509    The inheritance pseudo has the smallest class of two classes CL and
5510    class of ORIGINAL REGNO.  */
5511 static bool
inherit_reload_reg(bool def_p,int original_regno,enum reg_class cl,rtx_insn * insn,rtx next_usage_insns)5512 inherit_reload_reg (bool def_p, int original_regno,
5513 		    enum reg_class cl, rtx_insn *insn, rtx next_usage_insns)
5514 {
5515   if (optimize_function_for_size_p (cfun))
5516     return false;
5517 
5518   enum reg_class rclass = lra_get_allocno_class (original_regno);
5519   rtx original_reg = regno_reg_rtx[original_regno];
5520   rtx new_reg, usage_insn;
5521   rtx_insn *new_insns;
5522 
5523   lra_assert (! usage_insns[original_regno].after_p);
5524   if (lra_dump_file != NULL)
5525     fprintf (lra_dump_file,
5526 	     "    <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
5527   if (! ira_reg_classes_intersect_p[cl][rclass])
5528     {
5529       if (lra_dump_file != NULL)
5530 	{
5531 	  fprintf (lra_dump_file,
5532 		   "    Rejecting inheritance for %d "
5533 		   "because of disjoint classes %s and %s\n",
5534 		   original_regno, reg_class_names[cl],
5535 		   reg_class_names[rclass]);
5536 	  fprintf (lra_dump_file,
5537 		   "    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
5538 	}
5539       return false;
5540     }
5541   if ((ira_class_subset_p[cl][rclass] && cl != rclass)
5542       /* We don't use a subset of two classes because it can be
5543 	 NO_REGS.  This transformation is still profitable in most
5544 	 cases even if the classes are not intersected as register
5545 	 move is probably cheaper than a memory load.  */
5546       || ira_class_hard_regs_num[cl] < ira_class_hard_regs_num[rclass])
5547     {
5548       if (lra_dump_file != NULL)
5549 	fprintf (lra_dump_file, "    Use smallest class of %s and %s\n",
5550 		 reg_class_names[cl], reg_class_names[rclass]);
5551 
5552       rclass = cl;
5553     }
5554   if (check_secondary_memory_needed_p (rclass, next_usage_insns))
5555     {
5556       /* Reject inheritance resulting in secondary memory moves.
5557 	 Otherwise, there is a danger in LRA cycling.  Also such
5558 	 transformation will be unprofitable.  */
5559       if (lra_dump_file != NULL)
5560 	{
5561 	  rtx_insn *insn = skip_usage_debug_insns (next_usage_insns);
5562 	  rtx set = single_set (insn);
5563 
5564 	  lra_assert (set != NULL_RTX);
5565 
5566 	  rtx dest = SET_DEST (set);
5567 
5568 	  lra_assert (REG_P (dest));
5569 	  fprintf (lra_dump_file,
5570 		   "    Rejecting inheritance for insn %d(%s)<-%d(%s) "
5571 		   "as secondary mem is needed\n",
5572 		   REGNO (dest), reg_class_names[get_reg_class (REGNO (dest))],
5573 		   original_regno, reg_class_names[rclass]);
5574 	  fprintf (lra_dump_file,
5575 		   "    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
5576 	}
5577       return false;
5578     }
5579   new_reg = lra_create_new_reg (GET_MODE (original_reg), original_reg,
5580 				rclass, NULL, "inheritance");
5581   start_sequence ();
5582   if (def_p)
5583     lra_emit_move (original_reg, new_reg);
5584   else
5585     lra_emit_move (new_reg, original_reg);
5586   new_insns = get_insns ();
5587   end_sequence ();
5588   if (NEXT_INSN (new_insns) != NULL_RTX)
5589     {
5590       if (lra_dump_file != NULL)
5591 	{
5592 	  fprintf (lra_dump_file,
5593 		   "    Rejecting inheritance %d->%d "
5594 		   "as it results in 2 or more insns:\n",
5595 		   original_regno, REGNO (new_reg));
5596 	  dump_rtl_slim (lra_dump_file, new_insns, NULL, -1, 0);
5597 	  fprintf (lra_dump_file,
5598 		   "	>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
5599 	}
5600       return false;
5601     }
5602   lra_substitute_pseudo_within_insn (insn, original_regno, new_reg, false);
5603   lra_update_insn_regno_info (insn);
5604   if (! def_p)
5605     /* We now have a new usage insn for original regno.  */
5606     setup_next_usage_insn (original_regno, new_insns, reloads_num, false);
5607   if (lra_dump_file != NULL)
5608     fprintf (lra_dump_file, "    Original reg change %d->%d (bb%d):\n",
5609 	     original_regno, REGNO (new_reg), BLOCK_FOR_INSN (insn)->index);
5610   lra_reg_info[REGNO (new_reg)].restore_rtx = regno_reg_rtx[original_regno];
5611   bitmap_set_bit (&check_only_regs, REGNO (new_reg));
5612   bitmap_set_bit (&check_only_regs, original_regno);
5613   bitmap_set_bit (&lra_inheritance_pseudos, REGNO (new_reg));
5614   if (def_p)
5615     lra_process_new_insns (insn, NULL, new_insns,
5616 			   "Add original<-inheritance");
5617   else
5618     lra_process_new_insns (insn, new_insns, NULL,
5619 			   "Add inheritance<-original");
5620   while (next_usage_insns != NULL_RTX)
5621     {
5622       if (GET_CODE (next_usage_insns) != INSN_LIST)
5623 	{
5624 	  usage_insn = next_usage_insns;
5625 	  lra_assert (NONDEBUG_INSN_P (usage_insn));
5626 	  next_usage_insns = NULL;
5627 	}
5628       else
5629 	{
5630 	  usage_insn = XEXP (next_usage_insns, 0);
5631 	  lra_assert (DEBUG_INSN_P (usage_insn));
5632 	  next_usage_insns = XEXP (next_usage_insns, 1);
5633 	}
5634       lra_substitute_pseudo (&usage_insn, original_regno, new_reg, false,
5635 			     DEBUG_INSN_P (usage_insn));
5636       lra_update_insn_regno_info (as_a <rtx_insn *> (usage_insn));
5637       if (lra_dump_file != NULL)
5638 	{
5639 	  basic_block bb = BLOCK_FOR_INSN (usage_insn);
5640 	  fprintf (lra_dump_file,
5641 		   "    Inheritance reuse change %d->%d (bb%d):\n",
5642 		   original_regno, REGNO (new_reg),
5643 		   bb ? bb->index : -1);
5644 	  dump_insn_slim (lra_dump_file, as_a <rtx_insn *> (usage_insn));
5645 	}
5646     }
5647   if (lra_dump_file != NULL)
5648     fprintf (lra_dump_file,
5649 	     "	  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
5650   return true;
5651 }
5652 
5653 /* Return true if we need a caller save/restore for pseudo REGNO which
5654    was assigned to a hard register.  */
5655 static inline bool
need_for_call_save_p(int regno)5656 need_for_call_save_p (int regno)
5657 {
5658   lra_assert (regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] >= 0);
5659   if (usage_insns[regno].calls_num < calls_num)
5660     {
5661       unsigned int abis = 0;
5662       for (unsigned int i = 0; i < NUM_ABI_IDS; ++i)
5663 	if (last_call_for_abi[i] > usage_insns[regno].calls_num)
5664 	  abis |= 1 << i;
5665       gcc_assert (abis);
5666       if (call_clobbered_in_region_p (abis, full_and_partial_call_clobbers,
5667 				      PSEUDO_REGNO_MODE (regno),
5668 				      reg_renumber[regno]))
5669 	return true;
5670     }
5671   return false;
5672 }
5673 
5674 /* Global registers occurring in the current EBB.  */
5675 static bitmap_head ebb_global_regs;
5676 
5677 /* Return true if we need a split for hard register REGNO or pseudo
5678    REGNO which was assigned to a hard register.
5679    POTENTIAL_RELOAD_HARD_REGS contains hard registers which might be
5680    used for reloads since the EBB end.	It is an approximation of the
5681    used hard registers in the split range.  The exact value would
5682    require expensive calculations.  If we were aggressive with
5683    splitting because of the approximation, the split pseudo will save
5684    the same hard register assignment and will be removed in the undo
5685    pass.  We still need the approximation because too aggressive
5686    splitting would result in too inaccurate cost calculation in the
5687    assignment pass because of too many generated moves which will be
5688    probably removed in the undo pass.  */
5689 static inline bool
need_for_split_p(HARD_REG_SET potential_reload_hard_regs,int regno)5690 need_for_split_p (HARD_REG_SET potential_reload_hard_regs, int regno)
5691 {
5692   int hard_regno = regno < FIRST_PSEUDO_REGISTER ? regno : reg_renumber[regno];
5693 
5694   lra_assert (hard_regno >= 0);
5695   return ((TEST_HARD_REG_BIT (potential_reload_hard_regs, hard_regno)
5696 	   /* Don't split eliminable hard registers, otherwise we can
5697 	      split hard registers like hard frame pointer, which
5698 	      lives on BB start/end according to DF-infrastructure,
5699 	      when there is a pseudo assigned to the register and
5700 	      living in the same BB.  */
5701 	   && (regno >= FIRST_PSEUDO_REGISTER
5702 	       || ! TEST_HARD_REG_BIT (eliminable_regset, hard_regno))
5703 	   && ! TEST_HARD_REG_BIT (lra_no_alloc_regs, hard_regno)
5704 	   /* Don't split call clobbered hard regs living through
5705 	      calls, otherwise we might have a check problem in the
5706 	      assign sub-pass as in the most cases (exception is a
5707 	      situation when check_and_force_assignment_correctness_p value is
5708 	      true) the assign pass assumes that all pseudos living
5709 	      through calls are assigned to call saved hard regs.  */
5710 	   && (regno >= FIRST_PSEUDO_REGISTER
5711 	       || !TEST_HARD_REG_BIT (full_and_partial_call_clobbers, regno))
5712 	   /* We need at least 2 reloads to make pseudo splitting
5713 	      profitable.  We should provide hard regno splitting in
5714 	      any case to solve 1st insn scheduling problem when
5715 	      moving hard register definition up might result in
5716 	      impossibility to find hard register for reload pseudo of
5717 	      small register class.  */
5718 	   && (usage_insns[regno].reloads_num
5719 	       + (regno < FIRST_PSEUDO_REGISTER ? 0 : 3) < reloads_num)
5720 	   && (regno < FIRST_PSEUDO_REGISTER
5721 	       /* For short living pseudos, spilling + inheritance can
5722 		  be considered a substitution for splitting.
5723 		  Therefore we do not splitting for local pseudos.  It
5724 		  decreases also aggressiveness of splitting.  The
5725 		  minimal number of references is chosen taking into
5726 		  account that for 2 references splitting has no sense
5727 		  as we can just spill the pseudo.  */
5728 	       || (regno >= FIRST_PSEUDO_REGISTER
5729 		   && lra_reg_info[regno].nrefs > 3
5730 		   && bitmap_bit_p (&ebb_global_regs, regno))))
5731 	  || (regno >= FIRST_PSEUDO_REGISTER && need_for_call_save_p (regno)));
5732 }
5733 
5734 /* Return class for the split pseudo created from original pseudo with
5735    ALLOCNO_CLASS and MODE which got a hard register HARD_REGNO.	 We
5736    choose subclass of ALLOCNO_CLASS which contains HARD_REGNO and
5737    results in no secondary memory movements.  */
5738 static enum reg_class
choose_split_class(enum reg_class allocno_class,int hard_regno ATTRIBUTE_UNUSED,machine_mode mode ATTRIBUTE_UNUSED)5739 choose_split_class (enum reg_class allocno_class,
5740 		    int hard_regno ATTRIBUTE_UNUSED,
5741 		    machine_mode mode ATTRIBUTE_UNUSED)
5742 {
5743   int i;
5744   enum reg_class cl, best_cl = NO_REGS;
5745   enum reg_class hard_reg_class ATTRIBUTE_UNUSED
5746     = REGNO_REG_CLASS (hard_regno);
5747 
5748   if (! targetm.secondary_memory_needed (mode, allocno_class, allocno_class)
5749       && TEST_HARD_REG_BIT (reg_class_contents[allocno_class], hard_regno))
5750     return allocno_class;
5751   for (i = 0;
5752        (cl = reg_class_subclasses[allocno_class][i]) != LIM_REG_CLASSES;
5753        i++)
5754     if (! targetm.secondary_memory_needed (mode, cl, hard_reg_class)
5755 	&& ! targetm.secondary_memory_needed (mode, hard_reg_class, cl)
5756 	&& TEST_HARD_REG_BIT (reg_class_contents[cl], hard_regno)
5757 	&& (best_cl == NO_REGS
5758 	    || ira_class_hard_regs_num[best_cl] < ira_class_hard_regs_num[cl]))
5759       best_cl = cl;
5760   return best_cl;
5761 }
5762 
5763 /* Copy any equivalence information from ORIGINAL_REGNO to NEW_REGNO.
5764    It only makes sense to call this function if NEW_REGNO is always
5765    equal to ORIGINAL_REGNO.  */
5766 
5767 static void
lra_copy_reg_equiv(unsigned int new_regno,unsigned int original_regno)5768 lra_copy_reg_equiv (unsigned int new_regno, unsigned int original_regno)
5769 {
5770   if (!ira_reg_equiv[original_regno].defined_p)
5771     return;
5772 
5773   ira_expand_reg_equiv ();
5774   ira_reg_equiv[new_regno].defined_p = true;
5775   if (ira_reg_equiv[original_regno].memory)
5776     ira_reg_equiv[new_regno].memory
5777       = copy_rtx (ira_reg_equiv[original_regno].memory);
5778   if (ira_reg_equiv[original_regno].constant)
5779     ira_reg_equiv[new_regno].constant
5780       = copy_rtx (ira_reg_equiv[original_regno].constant);
5781   if (ira_reg_equiv[original_regno].invariant)
5782     ira_reg_equiv[new_regno].invariant
5783       = copy_rtx (ira_reg_equiv[original_regno].invariant);
5784 }
5785 
5786 /* Do split transformations for insn INSN, which defines or uses
5787    ORIGINAL_REGNO.  NEXT_USAGE_INSNS specifies which instruction in
5788    the EBB next uses ORIGINAL_REGNO; it has the same form as the
5789    "insns" field of usage_insns.  If TO is not NULL, we don't use
5790    usage_insns, we put restore insns after TO insn.  It is a case when
5791    we call it from lra_split_hard_reg_for, outside the inheritance
5792    pass.
5793 
5794    The transformations look like:
5795 
5796      p <- ...		  p <- ...
5797      ...		  s <- p    (new insn -- save)
5798      ...	     =>
5799      ...		  p <- s    (new insn -- restore)
5800      <- ... p ...	  <- ... p ...
5801    or
5802      <- ... p ...	  <- ... p ...
5803      ...		  s <- p    (new insn -- save)
5804      ...	     =>
5805      ...		  p <- s    (new insn -- restore)
5806      <- ... p ...	  <- ... p ...
5807 
5808    where p is an original pseudo got a hard register or a hard
5809    register and s is a new split pseudo.  The save is put before INSN
5810    if BEFORE_P is true.	 Return true if we succeed in such
5811    transformation.  */
5812 static bool
split_reg(bool before_p,int original_regno,rtx_insn * insn,rtx next_usage_insns,rtx_insn * to)5813 split_reg (bool before_p, int original_regno, rtx_insn *insn,
5814 	   rtx next_usage_insns, rtx_insn *to)
5815 {
5816   enum reg_class rclass;
5817   rtx original_reg;
5818   int hard_regno, nregs;
5819   rtx new_reg, usage_insn;
5820   rtx_insn *restore, *save;
5821   bool after_p;
5822   bool call_save_p;
5823   machine_mode mode;
5824 
5825   if (original_regno < FIRST_PSEUDO_REGISTER)
5826     {
5827       rclass = ira_allocno_class_translate[REGNO_REG_CLASS (original_regno)];
5828       hard_regno = original_regno;
5829       call_save_p = false;
5830       nregs = 1;
5831       mode = lra_reg_info[hard_regno].biggest_mode;
5832       machine_mode reg_rtx_mode = GET_MODE (regno_reg_rtx[hard_regno]);
5833       /* A reg can have a biggest_mode of VOIDmode if it was only ever seen as
5834 	 part of a multi-word register.  In that case, just use the reg_rtx
5835 	 mode.  Do the same also if the biggest mode was larger than a register
5836 	 or we can not compare the modes.  Otherwise, limit the size to that of
5837 	 the biggest access in the function or to the natural mode at least.  */
5838       if (mode == VOIDmode
5839 	  || !ordered_p (GET_MODE_PRECISION (mode),
5840 			 GET_MODE_PRECISION (reg_rtx_mode))
5841 	  || paradoxical_subreg_p (mode, reg_rtx_mode)
5842 	  || maybe_gt (GET_MODE_PRECISION (reg_rtx_mode), GET_MODE_PRECISION (mode)))
5843 	{
5844 	  original_reg = regno_reg_rtx[hard_regno];
5845 	  mode = reg_rtx_mode;
5846 	}
5847       else
5848 	original_reg = gen_rtx_REG (mode, hard_regno);
5849     }
5850   else
5851     {
5852       mode = PSEUDO_REGNO_MODE (original_regno);
5853       hard_regno = reg_renumber[original_regno];
5854       nregs = hard_regno_nregs (hard_regno, mode);
5855       rclass = lra_get_allocno_class (original_regno);
5856       original_reg = regno_reg_rtx[original_regno];
5857       call_save_p = need_for_call_save_p (original_regno);
5858     }
5859   lra_assert (hard_regno >= 0);
5860   if (lra_dump_file != NULL)
5861     fprintf (lra_dump_file,
5862 	     "	  ((((((((((((((((((((((((((((((((((((((((((((((((\n");
5863 
5864   if (call_save_p)
5865     {
5866       mode = HARD_REGNO_CALLER_SAVE_MODE (hard_regno,
5867 					  hard_regno_nregs (hard_regno, mode),
5868 					  mode);
5869       new_reg = lra_create_new_reg (mode, NULL_RTX, NO_REGS, NULL, "save");
5870     }
5871   else
5872     {
5873       rclass = choose_split_class (rclass, hard_regno, mode);
5874       if (rclass == NO_REGS)
5875 	{
5876 	  if (lra_dump_file != NULL)
5877 	    {
5878 	      fprintf (lra_dump_file,
5879 		       "    Rejecting split of %d(%s): "
5880 		       "no good reg class for %d(%s)\n",
5881 		       original_regno,
5882 		       reg_class_names[lra_get_allocno_class (original_regno)],
5883 		       hard_regno,
5884 		       reg_class_names[REGNO_REG_CLASS (hard_regno)]);
5885 	      fprintf
5886 		(lra_dump_file,
5887 		 "    ))))))))))))))))))))))))))))))))))))))))))))))))\n");
5888 	    }
5889 	  return false;
5890 	}
5891       /* Split_if_necessary can split hard registers used as part of a
5892 	 multi-register mode but splits each register individually.  The
5893 	 mode used for each independent register may not be supported
5894 	 so reject the split.  Splitting the wider mode should theoretically
5895 	 be possible but is not implemented.  */
5896       if (!targetm.hard_regno_mode_ok (hard_regno, mode))
5897 	{
5898 	  if (lra_dump_file != NULL)
5899 	    {
5900 	      fprintf (lra_dump_file,
5901 		       "    Rejecting split of %d(%s): unsuitable mode %s\n",
5902 		       original_regno,
5903 		       reg_class_names[lra_get_allocno_class (original_regno)],
5904 		       GET_MODE_NAME (mode));
5905 	      fprintf
5906 		(lra_dump_file,
5907 		 "    ))))))))))))))))))))))))))))))))))))))))))))))))\n");
5908 	    }
5909 	  return false;
5910 	}
5911       new_reg = lra_create_new_reg (mode, original_reg, rclass, NULL, "split");
5912       reg_renumber[REGNO (new_reg)] = hard_regno;
5913     }
5914   int new_regno = REGNO (new_reg);
5915   save = emit_spill_move (true, new_reg, original_reg);
5916   if (NEXT_INSN (save) != NULL_RTX && !call_save_p)
5917     {
5918       if (lra_dump_file != NULL)
5919 	{
5920 	  fprintf
5921 	    (lra_dump_file,
5922 	     "	  Rejecting split %d->%d resulting in > 2 save insns:\n",
5923 	     original_regno, new_regno);
5924 	  dump_rtl_slim (lra_dump_file, save, NULL, -1, 0);
5925 	  fprintf (lra_dump_file,
5926 		   "	))))))))))))))))))))))))))))))))))))))))))))))))\n");
5927 	}
5928       return false;
5929     }
5930   restore = emit_spill_move (false, new_reg, original_reg);
5931   if (NEXT_INSN (restore) != NULL_RTX && !call_save_p)
5932     {
5933       if (lra_dump_file != NULL)
5934 	{
5935 	  fprintf (lra_dump_file,
5936 		   "	Rejecting split %d->%d "
5937 		   "resulting in > 2 restore insns:\n",
5938 		   original_regno, new_regno);
5939 	  dump_rtl_slim (lra_dump_file, restore, NULL, -1, 0);
5940 	  fprintf (lra_dump_file,
5941 		   "	))))))))))))))))))))))))))))))))))))))))))))))))\n");
5942 	}
5943       return false;
5944     }
5945   /* Transfer equivalence information to the spill register, so that
5946      if we fail to allocate the spill register, we have the option of
5947      rematerializing the original value instead of spilling to the stack.  */
5948   if (!HARD_REGISTER_NUM_P (original_regno)
5949       && mode == PSEUDO_REGNO_MODE (original_regno))
5950     lra_copy_reg_equiv (new_regno, original_regno);
5951   lra_reg_info[new_regno].restore_rtx = regno_reg_rtx[original_regno];
5952   bitmap_set_bit (&lra_split_regs, new_regno);
5953   if (to != NULL)
5954     {
5955       lra_assert (next_usage_insns == NULL);
5956       usage_insn = to;
5957       after_p = TRUE;
5958     }
5959   else
5960     {
5961       /* We need check_only_regs only inside the inheritance pass.  */
5962       bitmap_set_bit (&check_only_regs, new_regno);
5963       bitmap_set_bit (&check_only_regs, original_regno);
5964       after_p = usage_insns[original_regno].after_p;
5965       for (;;)
5966 	{
5967 	  if (GET_CODE (next_usage_insns) != INSN_LIST)
5968 	    {
5969 	      usage_insn = next_usage_insns;
5970 	      break;
5971 	    }
5972 	  usage_insn = XEXP (next_usage_insns, 0);
5973 	  lra_assert (DEBUG_INSN_P (usage_insn));
5974 	  next_usage_insns = XEXP (next_usage_insns, 1);
5975 	  lra_substitute_pseudo (&usage_insn, original_regno, new_reg, false,
5976 				 true);
5977 	  lra_update_insn_regno_info (as_a <rtx_insn *> (usage_insn));
5978 	  if (lra_dump_file != NULL)
5979 	    {
5980 	      fprintf (lra_dump_file, "    Split reuse change %d->%d:\n",
5981 		       original_regno, new_regno);
5982 	      dump_insn_slim (lra_dump_file, as_a <rtx_insn *> (usage_insn));
5983 	    }
5984 	}
5985     }
5986   lra_assert (NOTE_P (usage_insn) || NONDEBUG_INSN_P (usage_insn));
5987   lra_assert (usage_insn != insn || (after_p && before_p));
5988   lra_process_new_insns (as_a <rtx_insn *> (usage_insn),
5989 			 after_p ? NULL : restore,
5990 			 after_p ? restore : NULL,
5991 			 call_save_p
5992 			 ?  "Add reg<-save" : "Add reg<-split");
5993   lra_process_new_insns (insn, before_p ? save : NULL,
5994 			 before_p ? NULL : save,
5995 			 call_save_p
5996 			 ?  "Add save<-reg" : "Add split<-reg");
5997   if (nregs > 1 || original_regno < FIRST_PSEUDO_REGISTER)
5998     /* If we are trying to split multi-register.  We should check
5999        conflicts on the next assignment sub-pass.  IRA can allocate on
6000        sub-register levels, LRA do this on pseudos level right now and
6001        this discrepancy may create allocation conflicts after
6002        splitting.
6003 
6004        If we are trying to split hard register we should also check conflicts
6005        as such splitting can create artificial conflict of the hard register
6006        with another pseudo because of simplified conflict calculation in
6007        LRA.  */
6008     check_and_force_assignment_correctness_p = true;
6009   if (lra_dump_file != NULL)
6010     fprintf (lra_dump_file,
6011 	     "	  ))))))))))))))))))))))))))))))))))))))))))))))))\n");
6012   return true;
6013 }
6014 
6015 /* Split a hard reg for reload pseudo REGNO having RCLASS and living
6016    in the range [FROM, TO].  Return true if did a split.  Otherwise,
6017    return false.  */
6018 bool
spill_hard_reg_in_range(int regno,enum reg_class rclass,rtx_insn * from,rtx_insn * to)6019 spill_hard_reg_in_range (int regno, enum reg_class rclass, rtx_insn *from, rtx_insn *to)
6020 {
6021   int i, hard_regno;
6022   int rclass_size;
6023   rtx_insn *insn;
6024   unsigned int uid;
6025   bitmap_iterator bi;
6026   HARD_REG_SET ignore;
6027 
6028   lra_assert (from != NULL && to != NULL);
6029   ignore = lra_no_alloc_regs;
6030   EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi)
6031     {
6032       lra_insn_recog_data_t id = lra_insn_recog_data[uid];
6033       struct lra_static_insn_data *static_id = id->insn_static_data;
6034       struct lra_insn_reg *reg;
6035 
6036       for (reg = id->regs; reg != NULL; reg = reg->next)
6037 	if (reg->regno < FIRST_PSEUDO_REGISTER)
6038 	  SET_HARD_REG_BIT (ignore, reg->regno);
6039       for (reg = static_id->hard_regs; reg != NULL; reg = reg->next)
6040 	SET_HARD_REG_BIT (ignore, reg->regno);
6041     }
6042   rclass_size = ira_class_hard_regs_num[rclass];
6043   for (i = 0; i < rclass_size; i++)
6044     {
6045       hard_regno = ira_class_hard_regs[rclass][i];
6046       if (! TEST_HARD_REG_BIT (lra_reg_info[regno].conflict_hard_regs, hard_regno)
6047 	  || TEST_HARD_REG_BIT (ignore, hard_regno))
6048 	continue;
6049       for (insn = from; insn != NEXT_INSN (to); insn = NEXT_INSN (insn))
6050 	{
6051 	  struct lra_static_insn_data *static_id;
6052 	  struct lra_insn_reg *reg;
6053 
6054 	  if (!INSN_P (insn))
6055 	      continue;
6056 	  if (bitmap_bit_p (&lra_reg_info[hard_regno].insn_bitmap,
6057 			    INSN_UID (insn)))
6058 	    break;
6059 	  static_id = lra_get_insn_recog_data (insn)->insn_static_data;
6060 	  for (reg = static_id->hard_regs; reg != NULL; reg = reg->next)
6061 	    if (reg->regno == hard_regno)
6062 	      break;
6063 	  if (reg != NULL)
6064 	    break;
6065 	}
6066       if (insn != NEXT_INSN (to))
6067 	continue;
6068       if (split_reg (TRUE, hard_regno, from, NULL, to))
6069 	return true;
6070     }
6071   return false;
6072 }
6073 
6074 /* Recognize that we need a split transformation for insn INSN, which
6075    defines or uses REGNO in its insn biggest MODE (we use it only if
6076    REGNO is a hard register).  POTENTIAL_RELOAD_HARD_REGS contains
6077    hard registers which might be used for reloads since the EBB end.
6078    Put the save before INSN if BEFORE_P is true.  MAX_UID is maximla
6079    uid before starting INSN processing.  Return true if we succeed in
6080    such transformation.  */
6081 static bool
split_if_necessary(int regno,machine_mode mode,HARD_REG_SET potential_reload_hard_regs,bool before_p,rtx_insn * insn,int max_uid)6082 split_if_necessary (int regno, machine_mode mode,
6083 		    HARD_REG_SET potential_reload_hard_regs,
6084 		    bool before_p, rtx_insn *insn, int max_uid)
6085 {
6086   bool res = false;
6087   int i, nregs = 1;
6088   rtx next_usage_insns;
6089 
6090   if (regno < FIRST_PSEUDO_REGISTER)
6091     nregs = hard_regno_nregs (regno, mode);
6092   for (i = 0; i < nregs; i++)
6093     if (usage_insns[regno + i].check == curr_usage_insns_check
6094 	&& (next_usage_insns = usage_insns[regno + i].insns) != NULL_RTX
6095 	/* To avoid processing the register twice or more.  */
6096 	&& ((GET_CODE (next_usage_insns) != INSN_LIST
6097 	     && INSN_UID (next_usage_insns) < max_uid)
6098 	    || (GET_CODE (next_usage_insns) == INSN_LIST
6099 		&& (INSN_UID (XEXP (next_usage_insns, 0)) < max_uid)))
6100 	&& need_for_split_p (potential_reload_hard_regs, regno + i)
6101 	&& split_reg (before_p, regno + i, insn, next_usage_insns, NULL))
6102     res = true;
6103   return res;
6104 }
6105 
6106 /* Return TRUE if rtx X is considered as an invariant for
6107    inheritance.  */
6108 static bool
invariant_p(const_rtx x)6109 invariant_p (const_rtx x)
6110 {
6111   machine_mode mode;
6112   const char *fmt;
6113   enum rtx_code code;
6114   int i, j;
6115 
6116   if (side_effects_p (x))
6117     return false;
6118 
6119   code = GET_CODE (x);
6120   mode = GET_MODE (x);
6121   if (code == SUBREG)
6122     {
6123       x = SUBREG_REG (x);
6124       code = GET_CODE (x);
6125       mode = wider_subreg_mode (mode, GET_MODE (x));
6126     }
6127 
6128   if (MEM_P (x))
6129     return false;
6130 
6131   if (REG_P (x))
6132     {
6133       int i, nregs, regno = REGNO (x);
6134 
6135       if (regno >= FIRST_PSEUDO_REGISTER || regno == STACK_POINTER_REGNUM
6136 	  || TEST_HARD_REG_BIT (eliminable_regset, regno)
6137 	  || GET_MODE_CLASS (GET_MODE (x)) == MODE_CC)
6138 	return false;
6139       nregs = hard_regno_nregs (regno, mode);
6140       for (i = 0; i < nregs; i++)
6141 	if (! fixed_regs[regno + i]
6142 	    /* A hard register may be clobbered in the current insn
6143 	       but we can ignore this case because if the hard
6144 	       register is used it should be set somewhere after the
6145 	       clobber.  */
6146 	    || bitmap_bit_p (&invalid_invariant_regs, regno + i))
6147 	  return false;
6148     }
6149   fmt = GET_RTX_FORMAT (code);
6150   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6151     {
6152       if (fmt[i] == 'e')
6153 	{
6154 	  if (! invariant_p (XEXP (x, i)))
6155 	    return false;
6156 	}
6157       else if (fmt[i] == 'E')
6158 	{
6159 	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6160 	    if (! invariant_p (XVECEXP (x, i, j)))
6161 	      return false;
6162 	}
6163     }
6164   return true;
6165 }
6166 
6167 /* We have 'dest_reg <- invariant'.  Let us try to make an invariant
6168    inheritance transformation (using dest_reg instead invariant in a
6169    subsequent insn).  */
6170 static bool
process_invariant_for_inheritance(rtx dst_reg,rtx invariant_rtx)6171 process_invariant_for_inheritance (rtx dst_reg, rtx invariant_rtx)
6172 {
6173   invariant_ptr_t invariant_ptr;
6174   rtx_insn *insn, *new_insns;
6175   rtx insn_set, insn_reg, new_reg;
6176   int insn_regno;
6177   bool succ_p = false;
6178   int dst_regno = REGNO (dst_reg);
6179   machine_mode dst_mode = GET_MODE (dst_reg);
6180   enum reg_class cl = lra_get_allocno_class (dst_regno), insn_reg_cl;
6181 
6182   invariant_ptr = insert_invariant (invariant_rtx);
6183   if ((insn = invariant_ptr->insn) != NULL_RTX)
6184     {
6185       /* We have a subsequent insn using the invariant.  */
6186       insn_set = single_set (insn);
6187       lra_assert (insn_set != NULL);
6188       insn_reg = SET_DEST (insn_set);
6189       lra_assert (REG_P (insn_reg));
6190       insn_regno = REGNO (insn_reg);
6191       insn_reg_cl = lra_get_allocno_class (insn_regno);
6192 
6193       if (dst_mode == GET_MODE (insn_reg)
6194 	  /* We should consider only result move reg insns which are
6195 	     cheap.  */
6196 	  && targetm.register_move_cost (dst_mode, cl, insn_reg_cl) == 2
6197 	  && targetm.register_move_cost (dst_mode, cl, cl) == 2)
6198 	{
6199 	  if (lra_dump_file != NULL)
6200 	    fprintf (lra_dump_file,
6201 		     "    [[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[\n");
6202 	  new_reg = lra_create_new_reg (dst_mode, dst_reg, cl, NULL,
6203 					"invariant inheritance");
6204 	  bitmap_set_bit (&lra_inheritance_pseudos, REGNO (new_reg));
6205 	  bitmap_set_bit (&check_only_regs, REGNO (new_reg));
6206 	  lra_reg_info[REGNO (new_reg)].restore_rtx = PATTERN (insn);
6207 	  start_sequence ();
6208 	  lra_emit_move (new_reg, dst_reg);
6209 	  new_insns = get_insns ();
6210 	  end_sequence ();
6211 	  lra_process_new_insns (curr_insn, NULL, new_insns,
6212 				 "Add invariant inheritance<-original");
6213 	  start_sequence ();
6214 	  lra_emit_move (SET_DEST (insn_set), new_reg);
6215 	  new_insns = get_insns ();
6216 	  end_sequence ();
6217 	  lra_process_new_insns (insn, NULL, new_insns,
6218 				 "Changing reload<-inheritance");
6219 	  lra_set_insn_deleted (insn);
6220 	  succ_p = true;
6221 	  if (lra_dump_file != NULL)
6222 	    {
6223 	      fprintf (lra_dump_file,
6224 		       "    Invariant inheritance reuse change %d (bb%d):\n",
6225 		       REGNO (new_reg), BLOCK_FOR_INSN (insn)->index);
6226 	      dump_insn_slim (lra_dump_file, insn);
6227 	      fprintf (lra_dump_file,
6228 		       "	  ]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]\n");
6229 	    }
6230 	}
6231     }
6232   invariant_ptr->insn = curr_insn;
6233   return succ_p;
6234 }
6235 
6236 /* Check only registers living at the current program point in the
6237    current EBB.	 */
6238 static bitmap_head live_regs;
6239 
6240 /* Update live info in EBB given by its HEAD and TAIL insns after
6241    inheritance/split transformation.  The function removes dead moves
6242    too.	 */
6243 static void
update_ebb_live_info(rtx_insn * head,rtx_insn * tail)6244 update_ebb_live_info (rtx_insn *head, rtx_insn *tail)
6245 {
6246   unsigned int j;
6247   int i, regno;
6248   bool live_p;
6249   rtx_insn *prev_insn;
6250   rtx set;
6251   bool remove_p;
6252   basic_block last_bb, prev_bb, curr_bb;
6253   bitmap_iterator bi;
6254   struct lra_insn_reg *reg;
6255   edge e;
6256   edge_iterator ei;
6257 
6258   last_bb = BLOCK_FOR_INSN (tail);
6259   prev_bb = NULL;
6260   for (curr_insn = tail;
6261        curr_insn != PREV_INSN (head);
6262        curr_insn = prev_insn)
6263     {
6264       prev_insn = PREV_INSN (curr_insn);
6265       /* We need to process empty blocks too.  They contain
6266 	 NOTE_INSN_BASIC_BLOCK referring for the basic block.  */
6267       if (NOTE_P (curr_insn) && NOTE_KIND (curr_insn) != NOTE_INSN_BASIC_BLOCK)
6268 	continue;
6269       curr_bb = BLOCK_FOR_INSN (curr_insn);
6270       if (curr_bb != prev_bb)
6271 	{
6272 	  if (prev_bb != NULL)
6273 	    {
6274 	      /* Update df_get_live_in (prev_bb):  */
6275 	      EXECUTE_IF_SET_IN_BITMAP (&check_only_regs, 0, j, bi)
6276 		if (bitmap_bit_p (&live_regs, j))
6277 		  bitmap_set_bit (df_get_live_in (prev_bb), j);
6278 		else
6279 		  bitmap_clear_bit (df_get_live_in (prev_bb), j);
6280 	    }
6281 	  if (curr_bb != last_bb)
6282 	    {
6283 	      /* Update df_get_live_out (curr_bb):  */
6284 	      EXECUTE_IF_SET_IN_BITMAP (&check_only_regs, 0, j, bi)
6285 		{
6286 		  live_p = bitmap_bit_p (&live_regs, j);
6287 		  if (! live_p)
6288 		    FOR_EACH_EDGE (e, ei, curr_bb->succs)
6289 		      if (bitmap_bit_p (df_get_live_in (e->dest), j))
6290 			{
6291 			  live_p = true;
6292 			  break;
6293 			}
6294 		  if (live_p)
6295 		    bitmap_set_bit (df_get_live_out (curr_bb), j);
6296 		  else
6297 		    bitmap_clear_bit (df_get_live_out (curr_bb), j);
6298 		}
6299 	    }
6300 	  prev_bb = curr_bb;
6301 	  bitmap_and (&live_regs, &check_only_regs, df_get_live_out (curr_bb));
6302 	}
6303       if (! NONDEBUG_INSN_P (curr_insn))
6304 	continue;
6305       curr_id = lra_get_insn_recog_data (curr_insn);
6306       curr_static_id = curr_id->insn_static_data;
6307       remove_p = false;
6308       if ((set = single_set (curr_insn)) != NULL_RTX
6309 	  && REG_P (SET_DEST (set))
6310 	  && (regno = REGNO (SET_DEST (set))) >= FIRST_PSEUDO_REGISTER
6311 	  && SET_DEST (set) != pic_offset_table_rtx
6312 	  && bitmap_bit_p (&check_only_regs, regno)
6313 	  && ! bitmap_bit_p (&live_regs, regno))
6314 	remove_p = true;
6315       /* See which defined values die here.  */
6316       for (reg = curr_id->regs; reg != NULL; reg = reg->next)
6317 	if (reg->type == OP_OUT && ! reg->subreg_p)
6318 	  bitmap_clear_bit (&live_regs, reg->regno);
6319       for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next)
6320 	if (reg->type == OP_OUT && ! reg->subreg_p)
6321 	  bitmap_clear_bit (&live_regs, reg->regno);
6322       if (curr_id->arg_hard_regs != NULL)
6323 	/* Make clobbered argument hard registers die.  */
6324 	for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++)
6325 	  if (regno >= FIRST_PSEUDO_REGISTER)
6326 	    bitmap_clear_bit (&live_regs, regno - FIRST_PSEUDO_REGISTER);
6327       /* Mark each used value as live.  */
6328       for (reg = curr_id->regs; reg != NULL; reg = reg->next)
6329 	if (reg->type != OP_OUT
6330 	    && bitmap_bit_p (&check_only_regs, reg->regno))
6331 	  bitmap_set_bit (&live_regs, reg->regno);
6332       for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next)
6333 	if (reg->type != OP_OUT
6334 	    && bitmap_bit_p (&check_only_regs, reg->regno))
6335 	  bitmap_set_bit (&live_regs, reg->regno);
6336       if (curr_id->arg_hard_regs != NULL)
6337 	/* Make used argument hard registers live.  */
6338 	for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++)
6339 	  if (regno < FIRST_PSEUDO_REGISTER
6340 	      && bitmap_bit_p (&check_only_regs, regno))
6341 	    bitmap_set_bit (&live_regs, regno);
6342       /* It is quite important to remove dead move insns because it
6343 	 means removing dead store.  We don't need to process them for
6344 	 constraints.  */
6345       if (remove_p)
6346 	{
6347 	  if (lra_dump_file != NULL)
6348 	    {
6349 	      fprintf (lra_dump_file, "	    Removing dead insn:\n ");
6350 	      dump_insn_slim (lra_dump_file, curr_insn);
6351 	    }
6352 	  lra_set_insn_deleted (curr_insn);
6353 	}
6354     }
6355 }
6356 
6357 /* The structure describes info to do an inheritance for the current
6358    insn.  We need to collect such info first before doing the
6359    transformations because the transformations change the insn
6360    internal representation.  */
6361 struct to_inherit
6362 {
6363   /* Original regno.  */
6364   int regno;
6365   /* Subsequent insns which can inherit original reg value.  */
6366   rtx insns;
6367 };
6368 
6369 /* Array containing all info for doing inheritance from the current
6370    insn.  */
6371 static struct to_inherit to_inherit[LRA_MAX_INSN_RELOADS];
6372 
6373 /* Number elements in the previous array.  */
6374 static int to_inherit_num;
6375 
6376 /* Add inheritance info REGNO and INSNS. Their meaning is described in
6377    structure to_inherit.  */
6378 static void
add_to_inherit(int regno,rtx insns)6379 add_to_inherit (int regno, rtx insns)
6380 {
6381   int i;
6382 
6383   for (i = 0; i < to_inherit_num; i++)
6384     if (to_inherit[i].regno == regno)
6385       return;
6386   lra_assert (to_inherit_num < LRA_MAX_INSN_RELOADS);
6387   to_inherit[to_inherit_num].regno = regno;
6388   to_inherit[to_inherit_num++].insns = insns;
6389 }
6390 
6391 /* Return the last non-debug insn in basic block BB, or the block begin
6392    note if none.  */
6393 static rtx_insn *
get_last_insertion_point(basic_block bb)6394 get_last_insertion_point (basic_block bb)
6395 {
6396   rtx_insn *insn;
6397 
6398   FOR_BB_INSNS_REVERSE (bb, insn)
6399     if (NONDEBUG_INSN_P (insn) || NOTE_INSN_BASIC_BLOCK_P (insn))
6400       return insn;
6401   gcc_unreachable ();
6402 }
6403 
6404 /* Set up RES by registers living on edges FROM except the edge (FROM,
6405    TO) or by registers set up in a jump insn in BB FROM.  */
6406 static void
get_live_on_other_edges(basic_block from,basic_block to,bitmap res)6407 get_live_on_other_edges (basic_block from, basic_block to, bitmap res)
6408 {
6409   rtx_insn *last;
6410   struct lra_insn_reg *reg;
6411   edge e;
6412   edge_iterator ei;
6413 
6414   lra_assert (to != NULL);
6415   bitmap_clear (res);
6416   FOR_EACH_EDGE (e, ei, from->succs)
6417     if (e->dest != to)
6418       bitmap_ior_into (res, df_get_live_in (e->dest));
6419   last = get_last_insertion_point (from);
6420   if (! JUMP_P (last))
6421     return;
6422   curr_id = lra_get_insn_recog_data (last);
6423   for (reg = curr_id->regs; reg != NULL; reg = reg->next)
6424     if (reg->type != OP_IN)
6425       bitmap_set_bit (res, reg->regno);
6426 }
6427 
6428 /* Used as a temporary results of some bitmap calculations.  */
6429 static bitmap_head temp_bitmap;
6430 
6431 /* We split for reloads of small class of hard regs.  The following
6432    defines how many hard regs the class should have to be qualified as
6433    small.  The code is mostly oriented to x86/x86-64 architecture
6434    where some insns need to use only specific register or pair of
6435    registers and these register can live in RTL explicitly, e.g. for
6436    parameter passing.  */
6437 static const int max_small_class_regs_num = 2;
6438 
6439 /* Do inheritance/split transformations in EBB starting with HEAD and
6440    finishing on TAIL.  We process EBB insns in the reverse order.
6441    Return true if we did any inheritance/split transformation in the
6442    EBB.
6443 
6444    We should avoid excessive splitting which results in worse code
6445    because of inaccurate cost calculations for spilling new split
6446    pseudos in such case.  To achieve this we do splitting only if
6447    register pressure is high in given basic block and there are reload
6448    pseudos requiring hard registers.  We could do more register
6449    pressure calculations at any given program point to avoid necessary
6450    splitting even more but it is to expensive and the current approach
6451    works well enough.  */
6452 static bool
inherit_in_ebb(rtx_insn * head,rtx_insn * tail)6453 inherit_in_ebb (rtx_insn *head, rtx_insn *tail)
6454 {
6455   int i, src_regno, dst_regno, nregs;
6456   bool change_p, succ_p, update_reloads_num_p;
6457   rtx_insn *prev_insn, *last_insn;
6458   rtx next_usage_insns, curr_set;
6459   enum reg_class cl;
6460   struct lra_insn_reg *reg;
6461   basic_block last_processed_bb, curr_bb = NULL;
6462   HARD_REG_SET potential_reload_hard_regs, live_hard_regs;
6463   bitmap to_process;
6464   unsigned int j;
6465   bitmap_iterator bi;
6466   bool head_p, after_p;
6467 
6468   change_p = false;
6469   curr_usage_insns_check++;
6470   clear_invariants ();
6471   reloads_num = calls_num = 0;
6472   for (unsigned int i = 0; i < NUM_ABI_IDS; ++i)
6473     last_call_for_abi[i] = 0;
6474   CLEAR_HARD_REG_SET (full_and_partial_call_clobbers);
6475   bitmap_clear (&check_only_regs);
6476   bitmap_clear (&invalid_invariant_regs);
6477   last_processed_bb = NULL;
6478   CLEAR_HARD_REG_SET (potential_reload_hard_regs);
6479   live_hard_regs = eliminable_regset | lra_no_alloc_regs;
6480   /* We don't process new insns generated in the loop.	*/
6481   for (curr_insn = tail; curr_insn != PREV_INSN (head); curr_insn = prev_insn)
6482     {
6483       prev_insn = PREV_INSN (curr_insn);
6484       if (BLOCK_FOR_INSN (curr_insn) != NULL)
6485 	curr_bb = BLOCK_FOR_INSN (curr_insn);
6486       if (last_processed_bb != curr_bb)
6487 	{
6488 	  /* We are at the end of BB.  Add qualified living
6489 	     pseudos for potential splitting.  */
6490 	  to_process = df_get_live_out (curr_bb);
6491 	  if (last_processed_bb != NULL)
6492 	    {
6493 	      /* We are somewhere in the middle of EBB.	 */
6494 	      get_live_on_other_edges (curr_bb, last_processed_bb,
6495 				       &temp_bitmap);
6496 	      to_process = &temp_bitmap;
6497 	    }
6498 	  last_processed_bb = curr_bb;
6499 	  last_insn = get_last_insertion_point (curr_bb);
6500 	  after_p = (! JUMP_P (last_insn)
6501 		     && (! CALL_P (last_insn)
6502 			 || (find_reg_note (last_insn,
6503 					   REG_NORETURN, NULL_RTX) == NULL_RTX
6504 			     && ! SIBLING_CALL_P (last_insn))));
6505 	  CLEAR_HARD_REG_SET (potential_reload_hard_regs);
6506 	  EXECUTE_IF_SET_IN_BITMAP (to_process, 0, j, bi)
6507 	    {
6508 	      if ((int) j >= lra_constraint_new_regno_start)
6509 		break;
6510 	      if (j < FIRST_PSEUDO_REGISTER || reg_renumber[j] >= 0)
6511 		{
6512 		  if (j < FIRST_PSEUDO_REGISTER)
6513 		    SET_HARD_REG_BIT (live_hard_regs, j);
6514 		  else
6515 		    add_to_hard_reg_set (&live_hard_regs,
6516 					 PSEUDO_REGNO_MODE (j),
6517 					 reg_renumber[j]);
6518 		  setup_next_usage_insn (j, last_insn, reloads_num, after_p);
6519 		}
6520 	    }
6521 	}
6522       src_regno = dst_regno = -1;
6523       curr_set = single_set (curr_insn);
6524       if (curr_set != NULL_RTX && REG_P (SET_DEST (curr_set)))
6525 	dst_regno = REGNO (SET_DEST (curr_set));
6526       if (curr_set != NULL_RTX && REG_P (SET_SRC (curr_set)))
6527 	src_regno = REGNO (SET_SRC (curr_set));
6528       update_reloads_num_p = true;
6529       if (src_regno < lra_constraint_new_regno_start
6530 	  && src_regno >= FIRST_PSEUDO_REGISTER
6531 	  && reg_renumber[src_regno] < 0
6532 	  && dst_regno >= lra_constraint_new_regno_start
6533 	  && (cl = lra_get_allocno_class (dst_regno)) != NO_REGS)
6534 	{
6535 	  /* 'reload_pseudo <- original_pseudo'.  */
6536 	  if (ira_class_hard_regs_num[cl] <= max_small_class_regs_num)
6537 	    reloads_num++;
6538 	  update_reloads_num_p = false;
6539 	  succ_p = false;
6540 	  if (usage_insns[src_regno].check == curr_usage_insns_check
6541 	      && (next_usage_insns = usage_insns[src_regno].insns) != NULL_RTX)
6542 	    succ_p = inherit_reload_reg (false, src_regno, cl,
6543 					 curr_insn, next_usage_insns);
6544 	  if (succ_p)
6545 	    change_p = true;
6546 	  else
6547 	    setup_next_usage_insn (src_regno, curr_insn, reloads_num, false);
6548 	  if (hard_reg_set_subset_p (reg_class_contents[cl], live_hard_regs))
6549 	    potential_reload_hard_regs |= reg_class_contents[cl];
6550 	}
6551       else if (src_regno < 0
6552 	       && dst_regno >= lra_constraint_new_regno_start
6553 	       && invariant_p (SET_SRC (curr_set))
6554 	       && (cl = lra_get_allocno_class (dst_regno)) != NO_REGS
6555 	       && ! bitmap_bit_p (&invalid_invariant_regs, dst_regno)
6556 	       && ! bitmap_bit_p (&invalid_invariant_regs,
6557 				  ORIGINAL_REGNO(regno_reg_rtx[dst_regno])))
6558 	{
6559 	  /* 'reload_pseudo <- invariant'.  */
6560 	  if (ira_class_hard_regs_num[cl] <= max_small_class_regs_num)
6561 	    reloads_num++;
6562 	  update_reloads_num_p = false;
6563 	  if (process_invariant_for_inheritance (SET_DEST (curr_set), SET_SRC (curr_set)))
6564 	    change_p = true;
6565 	  if (hard_reg_set_subset_p (reg_class_contents[cl], live_hard_regs))
6566 	    potential_reload_hard_regs |= reg_class_contents[cl];
6567 	}
6568       else if (src_regno >= lra_constraint_new_regno_start
6569 	       && dst_regno < lra_constraint_new_regno_start
6570 	       && dst_regno >= FIRST_PSEUDO_REGISTER
6571 	       && reg_renumber[dst_regno] < 0
6572 	       && (cl = lra_get_allocno_class (src_regno)) != NO_REGS
6573 	       && usage_insns[dst_regno].check == curr_usage_insns_check
6574 	       && (next_usage_insns
6575 		   = usage_insns[dst_regno].insns) != NULL_RTX)
6576 	{
6577 	  if (ira_class_hard_regs_num[cl] <= max_small_class_regs_num)
6578 	    reloads_num++;
6579 	  update_reloads_num_p = false;
6580 	  /* 'original_pseudo <- reload_pseudo'.  */
6581 	  if (! JUMP_P (curr_insn)
6582 	      && inherit_reload_reg (true, dst_regno, cl,
6583 				     curr_insn, next_usage_insns))
6584 	    change_p = true;
6585 	  /* Invalidate.  */
6586 	  usage_insns[dst_regno].check = 0;
6587 	  if (hard_reg_set_subset_p (reg_class_contents[cl], live_hard_regs))
6588 	    potential_reload_hard_regs |= reg_class_contents[cl];
6589 	}
6590       else if (INSN_P (curr_insn))
6591 	{
6592 	  int iter;
6593 	  int max_uid = get_max_uid ();
6594 
6595 	  curr_id = lra_get_insn_recog_data (curr_insn);
6596 	  curr_static_id = curr_id->insn_static_data;
6597 	  to_inherit_num = 0;
6598 	  /* Process insn definitions.	*/
6599 	  for (iter = 0; iter < 2; iter++)
6600 	    for (reg = iter == 0 ? curr_id->regs : curr_static_id->hard_regs;
6601 		 reg != NULL;
6602 		 reg = reg->next)
6603 	      if (reg->type != OP_IN
6604 		  && (dst_regno = reg->regno) < lra_constraint_new_regno_start)
6605 		{
6606 		  if (dst_regno >= FIRST_PSEUDO_REGISTER && reg->type == OP_OUT
6607 		      && reg_renumber[dst_regno] < 0 && ! reg->subreg_p
6608 		      && usage_insns[dst_regno].check == curr_usage_insns_check
6609 		      && (next_usage_insns
6610 			  = usage_insns[dst_regno].insns) != NULL_RTX)
6611 		    {
6612 		      struct lra_insn_reg *r;
6613 
6614 		      for (r = curr_id->regs; r != NULL; r = r->next)
6615 			if (r->type != OP_OUT && r->regno == dst_regno)
6616 			  break;
6617 		      /* Don't do inheritance if the pseudo is also
6618 			 used in the insn.  */
6619 		      if (r == NULL)
6620 			/* We cannot do inheritance right now
6621 			   because the current insn reg info (chain
6622 			   regs) can change after that.  */
6623 			add_to_inherit (dst_regno, next_usage_insns);
6624 		    }
6625 		  /* We cannot process one reg twice here because of
6626 		     usage_insns invalidation.  */
6627 		  if ((dst_regno < FIRST_PSEUDO_REGISTER
6628 		       || reg_renumber[dst_regno] >= 0)
6629 		      && ! reg->subreg_p && reg->type != OP_IN)
6630 		    {
6631 		      HARD_REG_SET s;
6632 
6633 		      if (split_if_necessary (dst_regno, reg->biggest_mode,
6634 					      potential_reload_hard_regs,
6635 					      false, curr_insn, max_uid))
6636 			change_p = true;
6637 		      CLEAR_HARD_REG_SET (s);
6638 		      if (dst_regno < FIRST_PSEUDO_REGISTER)
6639 			add_to_hard_reg_set (&s, reg->biggest_mode, dst_regno);
6640 		      else
6641 			add_to_hard_reg_set (&s, PSEUDO_REGNO_MODE (dst_regno),
6642 					     reg_renumber[dst_regno]);
6643 		      live_hard_regs &= ~s;
6644 		      potential_reload_hard_regs &= ~s;
6645 		    }
6646 		  /* We should invalidate potential inheritance or
6647 		     splitting for the current insn usages to the next
6648 		     usage insns (see code below) as the output pseudo
6649 		     prevents this.  */
6650 		  if ((dst_regno >= FIRST_PSEUDO_REGISTER
6651 		       && reg_renumber[dst_regno] < 0)
6652 		      || (reg->type == OP_OUT && ! reg->subreg_p
6653 			  && (dst_regno < FIRST_PSEUDO_REGISTER
6654 			      || reg_renumber[dst_regno] >= 0)))
6655 		    {
6656 		      /* Invalidate and mark definitions.  */
6657 		      if (dst_regno >= FIRST_PSEUDO_REGISTER)
6658 			usage_insns[dst_regno].check = -(int) INSN_UID (curr_insn);
6659 		      else
6660 			{
6661 			  nregs = hard_regno_nregs (dst_regno,
6662 						    reg->biggest_mode);
6663 			  for (i = 0; i < nregs; i++)
6664 			    usage_insns[dst_regno + i].check
6665 			      = -(int) INSN_UID (curr_insn);
6666 			}
6667 		    }
6668 		}
6669 	  /* Process clobbered call regs.  */
6670 	  if (curr_id->arg_hard_regs != NULL)
6671 	    for (i = 0; (dst_regno = curr_id->arg_hard_regs[i]) >= 0; i++)
6672 	      if (dst_regno >= FIRST_PSEUDO_REGISTER)
6673 		usage_insns[dst_regno - FIRST_PSEUDO_REGISTER].check
6674 		  = -(int) INSN_UID (curr_insn);
6675 	  if (! JUMP_P (curr_insn))
6676 	    for (i = 0; i < to_inherit_num; i++)
6677 	      if (inherit_reload_reg (true, to_inherit[i].regno,
6678 				      ALL_REGS, curr_insn,
6679 				      to_inherit[i].insns))
6680 	      change_p = true;
6681 	  if (CALL_P (curr_insn))
6682 	    {
6683 	      rtx cheap, pat, dest;
6684 	      rtx_insn *restore;
6685 	      int regno, hard_regno;
6686 
6687 	      calls_num++;
6688 	      function_abi callee_abi = insn_callee_abi (curr_insn);
6689 	      last_call_for_abi[callee_abi.id ()] = calls_num;
6690 	      full_and_partial_call_clobbers
6691 		|= callee_abi.full_and_partial_reg_clobbers ();
6692 	      if ((cheap = find_reg_note (curr_insn,
6693 					  REG_RETURNED, NULL_RTX)) != NULL_RTX
6694 		  && ((cheap = XEXP (cheap, 0)), true)
6695 		  && (regno = REGNO (cheap)) >= FIRST_PSEUDO_REGISTER
6696 		  && (hard_regno = reg_renumber[regno]) >= 0
6697 		  && usage_insns[regno].check == curr_usage_insns_check
6698 		  /* If there are pending saves/restores, the
6699 		     optimization is not worth.	 */
6700 		  && usage_insns[regno].calls_num == calls_num - 1
6701 		  && callee_abi.clobbers_reg_p (GET_MODE (cheap), hard_regno))
6702 		{
6703 		  /* Restore the pseudo from the call result as
6704 		     REG_RETURNED note says that the pseudo value is
6705 		     in the call result and the pseudo is an argument
6706 		     of the call.  */
6707 		  pat = PATTERN (curr_insn);
6708 		  if (GET_CODE (pat) == PARALLEL)
6709 		    pat = XVECEXP (pat, 0, 0);
6710 		  dest = SET_DEST (pat);
6711 		  /* For multiple return values dest is PARALLEL.
6712 		     Currently we handle only single return value case.  */
6713 		  if (REG_P (dest))
6714 		    {
6715 		      start_sequence ();
6716 		      emit_move_insn (cheap, copy_rtx (dest));
6717 		      restore = get_insns ();
6718 		      end_sequence ();
6719 		      lra_process_new_insns (curr_insn, NULL, restore,
6720 					     "Inserting call parameter restore");
6721 		      /* We don't need to save/restore of the pseudo from
6722 			 this call.	 */
6723 		      usage_insns[regno].calls_num = calls_num;
6724 		      remove_from_hard_reg_set
6725 			(&full_and_partial_call_clobbers,
6726 			 GET_MODE (cheap), hard_regno);
6727 		      bitmap_set_bit (&check_only_regs, regno);
6728 		    }
6729 		}
6730 	    }
6731 	  to_inherit_num = 0;
6732 	  /* Process insn usages.  */
6733 	  for (iter = 0; iter < 2; iter++)
6734 	    for (reg = iter == 0 ? curr_id->regs : curr_static_id->hard_regs;
6735 		 reg != NULL;
6736 		 reg = reg->next)
6737 	      if ((reg->type != OP_OUT
6738 		   || (reg->type == OP_OUT && reg->subreg_p))
6739 		  && (src_regno = reg->regno) < lra_constraint_new_regno_start)
6740 		{
6741 		  if (src_regno >= FIRST_PSEUDO_REGISTER
6742 		      && reg_renumber[src_regno] < 0 && reg->type == OP_IN)
6743 		    {
6744 		      if (usage_insns[src_regno].check == curr_usage_insns_check
6745 			  && (next_usage_insns
6746 			      = usage_insns[src_regno].insns) != NULL_RTX
6747 			  && NONDEBUG_INSN_P (curr_insn))
6748 			add_to_inherit (src_regno, next_usage_insns);
6749 		      else if (usage_insns[src_regno].check
6750 			       != -(int) INSN_UID (curr_insn))
6751 			/* Add usages but only if the reg is not set up
6752 			   in the same insn.  */
6753 			add_next_usage_insn (src_regno, curr_insn, reloads_num);
6754 		    }
6755 		  else if (src_regno < FIRST_PSEUDO_REGISTER
6756 			   || reg_renumber[src_regno] >= 0)
6757 		    {
6758 		      bool before_p;
6759 		      rtx_insn *use_insn = curr_insn;
6760 
6761 		      before_p = (JUMP_P (curr_insn)
6762 				  || (CALL_P (curr_insn) && reg->type == OP_IN));
6763 		      if (NONDEBUG_INSN_P (curr_insn)
6764 			  && (! JUMP_P (curr_insn) || reg->type == OP_IN)
6765 			  && split_if_necessary (src_regno, reg->biggest_mode,
6766 						 potential_reload_hard_regs,
6767 						 before_p, curr_insn, max_uid))
6768 			{
6769 			  if (reg->subreg_p)
6770 			    check_and_force_assignment_correctness_p = true;
6771 			  change_p = true;
6772 			  /* Invalidate. */
6773 			  usage_insns[src_regno].check = 0;
6774 			  if (before_p)
6775 			    use_insn = PREV_INSN (curr_insn);
6776 			}
6777 		      if (NONDEBUG_INSN_P (curr_insn))
6778 			{
6779 			  if (src_regno < FIRST_PSEUDO_REGISTER)
6780 			    add_to_hard_reg_set (&live_hard_regs,
6781 						 reg->biggest_mode, src_regno);
6782 			  else
6783 			    add_to_hard_reg_set (&live_hard_regs,
6784 						 PSEUDO_REGNO_MODE (src_regno),
6785 						 reg_renumber[src_regno]);
6786 			}
6787 		      if (src_regno >= FIRST_PSEUDO_REGISTER)
6788 			add_next_usage_insn (src_regno, use_insn, reloads_num);
6789 		      else
6790 			{
6791 			  for (i = 0; i < hard_regno_nregs (src_regno, reg->biggest_mode); i++)
6792 			    add_next_usage_insn (src_regno + i, use_insn, reloads_num);
6793 			}
6794 		    }
6795 		}
6796 	  /* Process used call regs.  */
6797 	  if (curr_id->arg_hard_regs != NULL)
6798 	    for (i = 0; (src_regno = curr_id->arg_hard_regs[i]) >= 0; i++)
6799 	      if (src_regno < FIRST_PSEUDO_REGISTER)
6800 		{
6801 	           SET_HARD_REG_BIT (live_hard_regs, src_regno);
6802 	           add_next_usage_insn (src_regno, curr_insn, reloads_num);
6803 		}
6804 	  for (i = 0; i < to_inherit_num; i++)
6805 	    {
6806 	      src_regno = to_inherit[i].regno;
6807 	      if (inherit_reload_reg (false, src_regno, ALL_REGS,
6808 				      curr_insn, to_inherit[i].insns))
6809 		change_p = true;
6810 	      else
6811 		setup_next_usage_insn (src_regno, curr_insn, reloads_num, false);
6812 	    }
6813 	}
6814       if (update_reloads_num_p
6815 	  && NONDEBUG_INSN_P (curr_insn) && curr_set != NULL_RTX)
6816 	{
6817 	  int regno = -1;
6818 	  if ((REG_P (SET_DEST (curr_set))
6819 	       && (regno = REGNO (SET_DEST (curr_set))) >= lra_constraint_new_regno_start
6820 	       && reg_renumber[regno] < 0
6821 	       && (cl = lra_get_allocno_class (regno)) != NO_REGS)
6822 	      || (REG_P (SET_SRC (curr_set))
6823 	          && (regno = REGNO (SET_SRC (curr_set))) >= lra_constraint_new_regno_start
6824 	          && reg_renumber[regno] < 0
6825 	          && (cl = lra_get_allocno_class (regno)) != NO_REGS))
6826 	    {
6827 	      if (ira_class_hard_regs_num[cl] <= max_small_class_regs_num)
6828 		reloads_num++;
6829 	      if (hard_reg_set_subset_p (reg_class_contents[cl], live_hard_regs))
6830 		potential_reload_hard_regs |= reg_class_contents[cl];
6831 	    }
6832 	}
6833       if (NONDEBUG_INSN_P (curr_insn))
6834 	{
6835 	  int regno;
6836 
6837 	  /* Invalidate invariants with changed regs.  */
6838 	  curr_id = lra_get_insn_recog_data (curr_insn);
6839 	  for (reg = curr_id->regs; reg != NULL; reg = reg->next)
6840 	    if (reg->type != OP_IN)
6841 	      {
6842 		bitmap_set_bit (&invalid_invariant_regs, reg->regno);
6843 		bitmap_set_bit (&invalid_invariant_regs,
6844 				ORIGINAL_REGNO (regno_reg_rtx[reg->regno]));
6845 	      }
6846 	  curr_static_id = curr_id->insn_static_data;
6847 	  for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next)
6848 	    if (reg->type != OP_IN)
6849 	      bitmap_set_bit (&invalid_invariant_regs, reg->regno);
6850 	  if (curr_id->arg_hard_regs != NULL)
6851 	    for (i = 0; (regno = curr_id->arg_hard_regs[i]) >= 0; i++)
6852 	      if (regno >= FIRST_PSEUDO_REGISTER)
6853 		bitmap_set_bit (&invalid_invariant_regs,
6854 				regno - FIRST_PSEUDO_REGISTER);
6855 	}
6856       /* We reached the start of the current basic block.  */
6857       if (prev_insn == NULL_RTX || prev_insn == PREV_INSN (head)
6858 	  || BLOCK_FOR_INSN (prev_insn) != curr_bb)
6859 	{
6860 	  /* We reached the beginning of the current block -- do
6861 	     rest of spliting in the current BB.  */
6862 	  to_process = df_get_live_in (curr_bb);
6863 	  if (BLOCK_FOR_INSN (head) != curr_bb)
6864 	    {
6865 	      /* We are somewhere in the middle of EBB.	 */
6866 	      get_live_on_other_edges (EDGE_PRED (curr_bb, 0)->src,
6867 				       curr_bb, &temp_bitmap);
6868 	      to_process = &temp_bitmap;
6869 	    }
6870 	  head_p = true;
6871 	  EXECUTE_IF_SET_IN_BITMAP (to_process, 0, j, bi)
6872 	    {
6873 	      if ((int) j >= lra_constraint_new_regno_start)
6874 		break;
6875 	      if (((int) j < FIRST_PSEUDO_REGISTER || reg_renumber[j] >= 0)
6876 		  && usage_insns[j].check == curr_usage_insns_check
6877 		  && (next_usage_insns = usage_insns[j].insns) != NULL_RTX)
6878 		{
6879 		  if (need_for_split_p (potential_reload_hard_regs, j))
6880 		    {
6881 		      if (lra_dump_file != NULL && head_p)
6882 			{
6883 			  fprintf (lra_dump_file,
6884 				   "  ----------------------------------\n");
6885 			  head_p = false;
6886 			}
6887 		      if (split_reg (false, j, bb_note (curr_bb),
6888 				     next_usage_insns, NULL))
6889 			change_p = true;
6890 		    }
6891 		  usage_insns[j].check = 0;
6892 		}
6893 	    }
6894 	}
6895     }
6896   return change_p;
6897 }
6898 
6899 /* This value affects EBB forming.  If probability of edge from EBB to
6900    a BB is not greater than the following value, we don't add the BB
6901    to EBB.  */
6902 #define EBB_PROBABILITY_CUTOFF \
6903   ((REG_BR_PROB_BASE * param_lra_inheritance_ebb_probability_cutoff) / 100)
6904 
6905 /* Current number of inheritance/split iteration.  */
6906 int lra_inheritance_iter;
6907 
6908 /* Entry function for inheritance/split pass.  */
6909 void
lra_inheritance(void)6910 lra_inheritance (void)
6911 {
6912   int i;
6913   basic_block bb, start_bb;
6914   edge e;
6915 
6916   lra_inheritance_iter++;
6917   if (lra_inheritance_iter > LRA_MAX_INHERITANCE_PASSES)
6918     return;
6919   timevar_push (TV_LRA_INHERITANCE);
6920   if (lra_dump_file != NULL)
6921     fprintf (lra_dump_file, "\n********** Inheritance #%d: **********\n\n",
6922 	     lra_inheritance_iter);
6923   curr_usage_insns_check = 0;
6924   usage_insns = XNEWVEC (struct usage_insns, lra_constraint_new_regno_start);
6925   for (i = 0; i < lra_constraint_new_regno_start; i++)
6926     usage_insns[i].check = 0;
6927   bitmap_initialize (&check_only_regs, &reg_obstack);
6928   bitmap_initialize (&invalid_invariant_regs, &reg_obstack);
6929   bitmap_initialize (&live_regs, &reg_obstack);
6930   bitmap_initialize (&temp_bitmap, &reg_obstack);
6931   bitmap_initialize (&ebb_global_regs, &reg_obstack);
6932   FOR_EACH_BB_FN (bb, cfun)
6933     {
6934       start_bb = bb;
6935       if (lra_dump_file != NULL)
6936 	fprintf (lra_dump_file, "EBB");
6937       /* Form a EBB starting with BB.  */
6938       bitmap_clear (&ebb_global_regs);
6939       bitmap_ior_into (&ebb_global_regs, df_get_live_in (bb));
6940       for (;;)
6941 	{
6942 	  if (lra_dump_file != NULL)
6943 	    fprintf (lra_dump_file, " %d", bb->index);
6944 	  if (bb->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)
6945 	      || LABEL_P (BB_HEAD (bb->next_bb)))
6946 	    break;
6947 	  e = find_fallthru_edge (bb->succs);
6948 	  if (! e)
6949 	    break;
6950 	  if (e->probability.initialized_p ()
6951 	      && e->probability.to_reg_br_prob_base () < EBB_PROBABILITY_CUTOFF)
6952 	    break;
6953 	  bb = bb->next_bb;
6954 	}
6955       bitmap_ior_into (&ebb_global_regs, df_get_live_out (bb));
6956       if (lra_dump_file != NULL)
6957 	fprintf (lra_dump_file, "\n");
6958       if (inherit_in_ebb (BB_HEAD (start_bb), BB_END (bb)))
6959 	/* Remember that the EBB head and tail can change in
6960 	   inherit_in_ebb.  */
6961 	update_ebb_live_info (BB_HEAD (start_bb), BB_END (bb));
6962     }
6963   bitmap_release (&ebb_global_regs);
6964   bitmap_release (&temp_bitmap);
6965   bitmap_release (&live_regs);
6966   bitmap_release (&invalid_invariant_regs);
6967   bitmap_release (&check_only_regs);
6968   free (usage_insns);
6969 
6970   timevar_pop (TV_LRA_INHERITANCE);
6971 }
6972 
6973 
6974 
6975 /* This page contains code to undo failed inheritance/split
6976    transformations.  */
6977 
6978 /* Current number of iteration undoing inheritance/split.  */
6979 int lra_undo_inheritance_iter;
6980 
6981 /* Fix BB live info LIVE after removing pseudos created on pass doing
6982    inheritance/split which are REMOVED_PSEUDOS.	 */
6983 static void
fix_bb_live_info(bitmap live,bitmap removed_pseudos)6984 fix_bb_live_info (bitmap live, bitmap removed_pseudos)
6985 {
6986   unsigned int regno;
6987   bitmap_iterator bi;
6988 
6989   EXECUTE_IF_SET_IN_BITMAP (removed_pseudos, 0, regno, bi)
6990     if (bitmap_clear_bit (live, regno)
6991 	&& REG_P (lra_reg_info[regno].restore_rtx))
6992       bitmap_set_bit (live, REGNO (lra_reg_info[regno].restore_rtx));
6993 }
6994 
6995 /* Return regno of the (subreg of) REG. Otherwise, return a negative
6996    number.  */
6997 static int
get_regno(rtx reg)6998 get_regno (rtx reg)
6999 {
7000   if (GET_CODE (reg) == SUBREG)
7001     reg = SUBREG_REG (reg);
7002   if (REG_P (reg))
7003     return REGNO (reg);
7004   return -1;
7005 }
7006 
7007 /* Delete a move INSN with destination reg DREGNO and a previous
7008    clobber insn with the same regno.  The inheritance/split code can
7009    generate moves with preceding clobber and when we delete such moves
7010    we should delete the clobber insn too to keep the correct life
7011    info.  */
7012 static void
delete_move_and_clobber(rtx_insn * insn,int dregno)7013 delete_move_and_clobber (rtx_insn *insn, int dregno)
7014 {
7015   rtx_insn *prev_insn = PREV_INSN (insn);
7016 
7017   lra_set_insn_deleted (insn);
7018   lra_assert (dregno >= 0);
7019   if (prev_insn != NULL && NONDEBUG_INSN_P (prev_insn)
7020       && GET_CODE (PATTERN (prev_insn)) == CLOBBER
7021       && dregno == get_regno (XEXP (PATTERN (prev_insn), 0)))
7022     lra_set_insn_deleted (prev_insn);
7023 }
7024 
7025 /* Remove inheritance/split pseudos which are in REMOVE_PSEUDOS and
7026    return true if we did any change.  The undo transformations for
7027    inheritance looks like
7028       i <- i2
7029       p <- i	  =>   p <- i2
7030    or removing
7031       p <- i, i <- p, and i <- i3
7032    where p is original pseudo from which inheritance pseudo i was
7033    created, i and i3 are removed inheritance pseudos, i2 is another
7034    not removed inheritance pseudo.  All split pseudos or other
7035    occurrences of removed inheritance pseudos are changed on the
7036    corresponding original pseudos.
7037 
7038    The function also schedules insns changed and created during
7039    inheritance/split pass for processing by the subsequent constraint
7040    pass.  */
7041 static bool
remove_inheritance_pseudos(bitmap remove_pseudos)7042 remove_inheritance_pseudos (bitmap remove_pseudos)
7043 {
7044   basic_block bb;
7045   int regno, sregno, prev_sregno, dregno;
7046   rtx restore_rtx;
7047   rtx set, prev_set;
7048   rtx_insn *prev_insn;
7049   bool change_p, done_p;
7050 
7051   change_p = ! bitmap_empty_p (remove_pseudos);
7052   /* We cannot finish the function right away if CHANGE_P is true
7053      because we need to marks insns affected by previous
7054      inheritance/split pass for processing by the subsequent
7055      constraint pass.  */
7056   FOR_EACH_BB_FN (bb, cfun)
7057     {
7058       fix_bb_live_info (df_get_live_in (bb), remove_pseudos);
7059       fix_bb_live_info (df_get_live_out (bb), remove_pseudos);
7060       FOR_BB_INSNS_REVERSE (bb, curr_insn)
7061 	{
7062 	  if (! INSN_P (curr_insn))
7063 	    continue;
7064 	  done_p = false;
7065 	  sregno = dregno = -1;
7066 	  if (change_p && NONDEBUG_INSN_P (curr_insn)
7067 	      && (set = single_set (curr_insn)) != NULL_RTX)
7068 	    {
7069 	      dregno = get_regno (SET_DEST (set));
7070 	      sregno = get_regno (SET_SRC (set));
7071 	    }
7072 
7073 	  if (sregno >= 0 && dregno >= 0)
7074 	    {
7075 	      if (bitmap_bit_p (remove_pseudos, dregno)
7076 		  && ! REG_P (lra_reg_info[dregno].restore_rtx))
7077 		{
7078 		  /* invariant inheritance pseudo <- original pseudo */
7079 		  if (lra_dump_file != NULL)
7080 		    {
7081 		      fprintf (lra_dump_file, "	   Removing invariant inheritance:\n");
7082 		      dump_insn_slim (lra_dump_file, curr_insn);
7083 		      fprintf (lra_dump_file, "\n");
7084 		    }
7085 		  delete_move_and_clobber (curr_insn, dregno);
7086 		  done_p = true;
7087 		}
7088 	      else if (bitmap_bit_p (remove_pseudos, sregno)
7089 		       && ! REG_P (lra_reg_info[sregno].restore_rtx))
7090 		{
7091 		  /* reload pseudo <- invariant inheritance pseudo */
7092 		  start_sequence ();
7093 		  /* We cannot just change the source.  It might be
7094 		     an insn different from the move.  */
7095 		  emit_insn (lra_reg_info[sregno].restore_rtx);
7096 		  rtx_insn *new_insns = get_insns ();
7097 		  end_sequence ();
7098 		  lra_assert (single_set (new_insns) != NULL
7099 			      && SET_DEST (set) == SET_DEST (single_set (new_insns)));
7100 		  lra_process_new_insns (curr_insn, NULL, new_insns,
7101 					 "Changing reload<-invariant inheritance");
7102 		  delete_move_and_clobber (curr_insn, dregno);
7103 		  done_p = true;
7104 		}
7105 	      else if ((bitmap_bit_p (remove_pseudos, sregno)
7106 			&& (get_regno (lra_reg_info[sregno].restore_rtx) == dregno
7107 			    || (bitmap_bit_p (remove_pseudos, dregno)
7108 				&& get_regno (lra_reg_info[sregno].restore_rtx) >= 0
7109 				&& (get_regno (lra_reg_info[sregno].restore_rtx)
7110 				    == get_regno (lra_reg_info[dregno].restore_rtx)))))
7111 		       || (bitmap_bit_p (remove_pseudos, dregno)
7112 			   && get_regno (lra_reg_info[dregno].restore_rtx) == sregno))
7113 		/* One of the following cases:
7114 		     original <- removed inheritance pseudo
7115 		     removed inherit pseudo <- another removed inherit pseudo
7116 		     removed inherit pseudo <- original pseudo
7117 		   Or
7118 		     removed_split_pseudo <- original_reg
7119 		     original_reg <- removed_split_pseudo */
7120 		{
7121 		  if (lra_dump_file != NULL)
7122 		    {
7123 		      fprintf (lra_dump_file, "	   Removing %s:\n",
7124 			       bitmap_bit_p (&lra_split_regs, sregno)
7125 			       || bitmap_bit_p (&lra_split_regs, dregno)
7126 			       ? "split" : "inheritance");
7127 		      dump_insn_slim (lra_dump_file, curr_insn);
7128 		    }
7129 		  delete_move_and_clobber (curr_insn, dregno);
7130 		  done_p = true;
7131 		}
7132 	      else if (bitmap_bit_p (remove_pseudos, sregno)
7133 		       && bitmap_bit_p (&lra_inheritance_pseudos, sregno))
7134 		{
7135 		  /* Search the following pattern:
7136 		       inherit_or_split_pseudo1 <- inherit_or_split_pseudo2
7137 		       original_pseudo <- inherit_or_split_pseudo1
7138 		    where the 2nd insn is the current insn and
7139 		    inherit_or_split_pseudo2 is not removed.  If it is found,
7140 		    change the current insn onto:
7141 		       original_pseudo <- inherit_or_split_pseudo2.  */
7142 		  for (prev_insn = PREV_INSN (curr_insn);
7143 		       prev_insn != NULL_RTX && ! NONDEBUG_INSN_P (prev_insn);
7144 		       prev_insn = PREV_INSN (prev_insn))
7145 		    ;
7146 		  if (prev_insn != NULL_RTX && BLOCK_FOR_INSN (prev_insn) == bb
7147 		      && (prev_set = single_set (prev_insn)) != NULL_RTX
7148 		      /* There should be no subregs in insn we are
7149 			 searching because only the original reg might
7150 			 be in subreg when we changed the mode of
7151 			 load/store for splitting.  */
7152 		      && REG_P (SET_DEST (prev_set))
7153 		      && REG_P (SET_SRC (prev_set))
7154 		      && (int) REGNO (SET_DEST (prev_set)) == sregno
7155 		      && ((prev_sregno = REGNO (SET_SRC (prev_set)))
7156 			  >= FIRST_PSEUDO_REGISTER)
7157 		      && (lra_reg_info[prev_sregno].restore_rtx == NULL_RTX
7158 			  ||
7159 			  /* As we consider chain of inheritance or
7160 			     splitting described in above comment we should
7161 			     check that sregno and prev_sregno were
7162 			     inheritance/split pseudos created from the
7163 			     same original regno.  */
7164 			  (get_regno (lra_reg_info[sregno].restore_rtx) >= 0
7165 			   && (get_regno (lra_reg_info[sregno].restore_rtx)
7166 			       == get_regno (lra_reg_info[prev_sregno].restore_rtx))))
7167 		      && ! bitmap_bit_p (remove_pseudos, prev_sregno))
7168 		    {
7169 		      lra_assert (GET_MODE (SET_SRC (prev_set))
7170 				  == GET_MODE (regno_reg_rtx[sregno]));
7171 		      /* Although we have a single set, the insn can
7172 			 contain more one sregno register occurrence
7173 			 as a source.  Change all occurrences.  */
7174 		      lra_substitute_pseudo_within_insn (curr_insn, sregno,
7175 							 SET_SRC (prev_set),
7176 							 false);
7177 		      /* As we are finishing with processing the insn
7178 			 here, check the destination too as it might
7179 			 inheritance pseudo for another pseudo.  */
7180 		      if (bitmap_bit_p (remove_pseudos, dregno)
7181 			  && bitmap_bit_p (&lra_inheritance_pseudos, dregno)
7182 			  && (restore_rtx
7183 			      = lra_reg_info[dregno].restore_rtx) != NULL_RTX)
7184 			{
7185 			  if (GET_CODE (SET_DEST (set)) == SUBREG)
7186 			    SUBREG_REG (SET_DEST (set)) = restore_rtx;
7187 			  else
7188 			    SET_DEST (set) = restore_rtx;
7189 			}
7190 		      lra_push_insn_and_update_insn_regno_info (curr_insn);
7191 		      lra_set_used_insn_alternative_by_uid
7192 			(INSN_UID (curr_insn), LRA_UNKNOWN_ALT);
7193 		      done_p = true;
7194 		      if (lra_dump_file != NULL)
7195 			{
7196 			  fprintf (lra_dump_file, "    Change reload insn:\n");
7197 			  dump_insn_slim (lra_dump_file, curr_insn);
7198 			}
7199 		    }
7200 		}
7201 	    }
7202 	  if (! done_p)
7203 	    {
7204 	      struct lra_insn_reg *reg;
7205 	      bool restored_regs_p = false;
7206 	      bool kept_regs_p = false;
7207 
7208 	      curr_id = lra_get_insn_recog_data (curr_insn);
7209 	      for (reg = curr_id->regs; reg != NULL; reg = reg->next)
7210 		{
7211 		  regno = reg->regno;
7212 		  restore_rtx = lra_reg_info[regno].restore_rtx;
7213 		  if (restore_rtx != NULL_RTX)
7214 		    {
7215 		      if (change_p && bitmap_bit_p (remove_pseudos, regno))
7216 			{
7217 			  lra_substitute_pseudo_within_insn
7218 			    (curr_insn, regno, restore_rtx, false);
7219 			  restored_regs_p = true;
7220 			}
7221 		      else
7222 			kept_regs_p = true;
7223 		    }
7224 		}
7225 	      if (NONDEBUG_INSN_P (curr_insn) && kept_regs_p)
7226 		{
7227 		  /* The instruction has changed since the previous
7228 		     constraints pass.  */
7229 		  lra_push_insn_and_update_insn_regno_info (curr_insn);
7230 		  lra_set_used_insn_alternative_by_uid
7231 		    (INSN_UID (curr_insn), LRA_UNKNOWN_ALT);
7232 		}
7233 	      else if (restored_regs_p)
7234 		/* The instruction has been restored to the form that
7235 		   it had during the previous constraints pass.  */
7236 		lra_update_insn_regno_info (curr_insn);
7237 	      if (restored_regs_p && lra_dump_file != NULL)
7238 		{
7239 		  fprintf (lra_dump_file, "   Insn after restoring regs:\n");
7240 		  dump_insn_slim (lra_dump_file, curr_insn);
7241 		}
7242 	    }
7243 	}
7244     }
7245   return change_p;
7246 }
7247 
7248 /* If optional reload pseudos failed to get a hard register or was not
7249    inherited, it is better to remove optional reloads.  We do this
7250    transformation after undoing inheritance to figure out necessity to
7251    remove optional reloads easier.  Return true if we do any
7252    change.  */
7253 static bool
undo_optional_reloads(void)7254 undo_optional_reloads (void)
7255 {
7256   bool change_p, keep_p;
7257   unsigned int regno, uid;
7258   bitmap_iterator bi, bi2;
7259   rtx_insn *insn;
7260   rtx set, src, dest;
7261   auto_bitmap removed_optional_reload_pseudos (&reg_obstack);
7262 
7263   bitmap_copy (removed_optional_reload_pseudos, &lra_optional_reload_pseudos);
7264   EXECUTE_IF_SET_IN_BITMAP (&lra_optional_reload_pseudos, 0, regno, bi)
7265     {
7266       keep_p = false;
7267       /* Keep optional reloads from previous subpasses.  */
7268       if (lra_reg_info[regno].restore_rtx == NULL_RTX
7269 	  /* If the original pseudo changed its allocation, just
7270 	     removing the optional pseudo is dangerous as the original
7271 	     pseudo will have longer live range.  */
7272 	  || reg_renumber[REGNO (lra_reg_info[regno].restore_rtx)] >= 0)
7273 	keep_p = true;
7274       else if (reg_renumber[regno] >= 0)
7275 	EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi2)
7276 	  {
7277 	    insn = lra_insn_recog_data[uid]->insn;
7278 	    if ((set = single_set (insn)) == NULL_RTX)
7279 	      continue;
7280 	    src = SET_SRC (set);
7281 	    dest = SET_DEST (set);
7282 	    if ((! REG_P (src) && ! SUBREG_P (src))
7283 		|| (! REG_P (dest) && ! SUBREG_P (dest)))
7284 	      continue;
7285 	    if (get_regno (dest) == (int) regno
7286 		/* Ignore insn for optional reloads itself.  */
7287 		&& (get_regno (lra_reg_info[regno].restore_rtx)
7288 		    != get_regno (src))
7289 		/* Check only inheritance on last inheritance pass.  */
7290 		&& get_regno (src) >= new_regno_start
7291 		/* Check that the optional reload was inherited.  */
7292 		&& bitmap_bit_p (&lra_inheritance_pseudos, get_regno (src)))
7293 	      {
7294 		keep_p = true;
7295 		break;
7296 	      }
7297 	  }
7298       if (keep_p)
7299 	{
7300 	  bitmap_clear_bit (removed_optional_reload_pseudos, regno);
7301 	  if (lra_dump_file != NULL)
7302 	    fprintf (lra_dump_file, "Keep optional reload reg %d\n", regno);
7303 	}
7304     }
7305   change_p = ! bitmap_empty_p (removed_optional_reload_pseudos);
7306   auto_bitmap insn_bitmap (&reg_obstack);
7307   EXECUTE_IF_SET_IN_BITMAP (removed_optional_reload_pseudos, 0, regno, bi)
7308     {
7309       if (lra_dump_file != NULL)
7310 	fprintf (lra_dump_file, "Remove optional reload reg %d\n", regno);
7311       bitmap_copy (insn_bitmap, &lra_reg_info[regno].insn_bitmap);
7312       EXECUTE_IF_SET_IN_BITMAP (insn_bitmap, 0, uid, bi2)
7313 	{
7314 	  /* We may have already removed a clobber.  */
7315 	  if (!lra_insn_recog_data[uid])
7316 	    continue;
7317 	  insn = lra_insn_recog_data[uid]->insn;
7318 	  if ((set = single_set (insn)) != NULL_RTX)
7319 	    {
7320 	      src = SET_SRC (set);
7321 	      dest = SET_DEST (set);
7322 	      if ((REG_P (src) || SUBREG_P (src))
7323 		  && (REG_P (dest) || SUBREG_P (dest))
7324 		  && ((get_regno (src) == (int) regno
7325 		       && (get_regno (lra_reg_info[regno].restore_rtx)
7326 			   == get_regno (dest)))
7327 		      || (get_regno (dest) == (int) regno
7328 			  && (get_regno (lra_reg_info[regno].restore_rtx)
7329 			      == get_regno (src)))))
7330 		{
7331 		  if (lra_dump_file != NULL)
7332 		    {
7333 		      fprintf (lra_dump_file, "  Deleting move %u\n",
7334 			       INSN_UID (insn));
7335 		      dump_insn_slim (lra_dump_file, insn);
7336 		    }
7337 		  delete_move_and_clobber (insn, get_regno (dest));
7338 		  continue;
7339 		}
7340 	      /* We should not worry about generation memory-memory
7341 		 moves here as if the corresponding inheritance did
7342 		 not work (inheritance pseudo did not get a hard reg),
7343 		 we remove the inheritance pseudo and the optional
7344 		 reload.  */
7345 	    }
7346 	  if (GET_CODE (PATTERN (insn)) == CLOBBER
7347 	      && REG_P (SET_DEST (insn))
7348 	      && get_regno (SET_DEST (insn)) == (int) regno)
7349 	    /* Refuse to remap clobbers to preexisting pseudos.  */
7350 	    gcc_unreachable ();
7351 	  lra_substitute_pseudo_within_insn
7352 	    (insn, regno, lra_reg_info[regno].restore_rtx, false);
7353 	  lra_update_insn_regno_info (insn);
7354 	  if (lra_dump_file != NULL)
7355 	    {
7356 	      fprintf (lra_dump_file,
7357 		       "  Restoring original insn:\n");
7358 	      dump_insn_slim (lra_dump_file, insn);
7359 	    }
7360 	}
7361     }
7362   /* Clear restore_regnos.  */
7363   EXECUTE_IF_SET_IN_BITMAP (&lra_optional_reload_pseudos, 0, regno, bi)
7364     lra_reg_info[regno].restore_rtx = NULL_RTX;
7365   return change_p;
7366 }
7367 
7368 /* Entry function for undoing inheritance/split transformation.	 Return true
7369    if we did any RTL change in this pass.  */
7370 bool
lra_undo_inheritance(void)7371 lra_undo_inheritance (void)
7372 {
7373   unsigned int regno;
7374   int hard_regno;
7375   int n_all_inherit, n_inherit, n_all_split, n_split;
7376   rtx restore_rtx;
7377   bitmap_iterator bi;
7378   bool change_p;
7379 
7380   lra_undo_inheritance_iter++;
7381   if (lra_undo_inheritance_iter > LRA_MAX_INHERITANCE_PASSES)
7382     return false;
7383   if (lra_dump_file != NULL)
7384     fprintf (lra_dump_file,
7385 	     "\n********** Undoing inheritance #%d: **********\n\n",
7386 	     lra_undo_inheritance_iter);
7387   auto_bitmap remove_pseudos (&reg_obstack);
7388   n_inherit = n_all_inherit = 0;
7389   EXECUTE_IF_SET_IN_BITMAP (&lra_inheritance_pseudos, 0, regno, bi)
7390     if (lra_reg_info[regno].restore_rtx != NULL_RTX)
7391       {
7392 	n_all_inherit++;
7393 	if (reg_renumber[regno] < 0
7394 	    /* If the original pseudo changed its allocation, just
7395 	       removing inheritance is dangerous as for changing
7396 	       allocation we used shorter live-ranges.  */
7397 	    && (! REG_P (lra_reg_info[regno].restore_rtx)
7398 		|| reg_renumber[REGNO (lra_reg_info[regno].restore_rtx)] < 0))
7399 	  bitmap_set_bit (remove_pseudos, regno);
7400 	else
7401 	  n_inherit++;
7402       }
7403   if (lra_dump_file != NULL && n_all_inherit != 0)
7404     fprintf (lra_dump_file, "Inherit %d out of %d (%.2f%%)\n",
7405 	     n_inherit, n_all_inherit,
7406 	     (double) n_inherit / n_all_inherit * 100);
7407   n_split = n_all_split = 0;
7408   EXECUTE_IF_SET_IN_BITMAP (&lra_split_regs, 0, regno, bi)
7409     if ((restore_rtx = lra_reg_info[regno].restore_rtx) != NULL_RTX)
7410       {
7411 	int restore_regno = REGNO (restore_rtx);
7412 
7413 	n_all_split++;
7414 	hard_regno = (restore_regno >= FIRST_PSEUDO_REGISTER
7415 		      ? reg_renumber[restore_regno] : restore_regno);
7416 	if (hard_regno < 0 || reg_renumber[regno] == hard_regno)
7417 	  bitmap_set_bit (remove_pseudos, regno);
7418 	else
7419 	  {
7420 	    n_split++;
7421 	    if (lra_dump_file != NULL)
7422 	      fprintf (lra_dump_file, "	     Keep split r%d (orig=r%d)\n",
7423 		       regno, restore_regno);
7424 	  }
7425       }
7426   if (lra_dump_file != NULL && n_all_split != 0)
7427     fprintf (lra_dump_file, "Split %d out of %d (%.2f%%)\n",
7428 	     n_split, n_all_split,
7429 	     (double) n_split / n_all_split * 100);
7430   change_p = remove_inheritance_pseudos (remove_pseudos);
7431   /* Clear restore_regnos.  */
7432   EXECUTE_IF_SET_IN_BITMAP (&lra_inheritance_pseudos, 0, regno, bi)
7433     lra_reg_info[regno].restore_rtx = NULL_RTX;
7434   EXECUTE_IF_SET_IN_BITMAP (&lra_split_regs, 0, regno, bi)
7435     lra_reg_info[regno].restore_rtx = NULL_RTX;
7436   change_p = undo_optional_reloads () || change_p;
7437   return change_p;
7438 }
7439