1 /* Subroutines used for code generation on the Lattice Mico32 architecture.
2 Contributed by Jon Beniston <jon@beniston.com>
3
4 Copyright (C) 2009-2020 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published
10 by the Free Software Foundation; either version 3, or (at your
11 option) any later version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT
14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
16 License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22 #define IN_TARGET_CODE 1
23
24 #include "config.h"
25 #include "system.h"
26 #include "coretypes.h"
27 #include "backend.h"
28 #include "target.h"
29 #include "rtl.h"
30 #include "tree.h"
31 #include "stringpool.h"
32 #include "attribs.h"
33 #include "df.h"
34 #include "memmodel.h"
35 #include "tm_p.h"
36 #include "optabs.h"
37 #include "regs.h"
38 #include "emit-rtl.h"
39 #include "recog.h"
40 #include "output.h"
41 #include "calls.h"
42 #include "alias.h"
43 #include "explow.h"
44 #include "expr.h"
45 #include "tm-constrs.h"
46 #include "builtins.h"
47
48 /* This file should be included last. */
49 #include "target-def.h"
50
51 struct lm32_frame_info
52 {
53 HOST_WIDE_INT total_size; /* number of bytes of entire frame. */
54 HOST_WIDE_INT callee_size; /* number of bytes to save callee saves. */
55 HOST_WIDE_INT pretend_size; /* number of bytes we pretend caller did. */
56 HOST_WIDE_INT args_size; /* number of bytes for outgoing arguments. */
57 HOST_WIDE_INT locals_size; /* number of bytes for local variables. */
58 unsigned int reg_save_mask; /* mask of saved registers. */
59 };
60
61 /* Prototypes for static functions. */
62 static rtx emit_add (rtx dest, rtx src0, rtx src1);
63 static void expand_save_restore (struct lm32_frame_info *info, int op);
64 static void stack_adjust (HOST_WIDE_INT amount);
65 static bool lm32_in_small_data_p (const_tree);
66 static void lm32_setup_incoming_varargs (cumulative_args_t cum,
67 const function_arg_info &,
68 int *pretend_size, int no_rtl);
69 static bool lm32_rtx_costs (rtx x, machine_mode mode, int outer_code, int opno,
70 int *total, bool speed);
71 static bool lm32_can_eliminate (const int, const int);
72 static bool
73 lm32_legitimate_address_p (machine_mode mode, rtx x, bool strict);
74 static HOST_WIDE_INT lm32_compute_frame_size (int size);
75 static void lm32_option_override (void);
76 static rtx lm32_function_arg (cumulative_args_t, const function_arg_info &);
77 static void lm32_function_arg_advance (cumulative_args_t cum,
78 const function_arg_info &);
79 static bool lm32_hard_regno_mode_ok (unsigned int, machine_mode);
80 static bool lm32_modes_tieable_p (machine_mode, machine_mode);
81 static HOST_WIDE_INT lm32_starting_frame_offset (void);
82
83 #undef TARGET_OPTION_OVERRIDE
84 #define TARGET_OPTION_OVERRIDE lm32_option_override
85 #undef TARGET_ADDRESS_COST
86 #define TARGET_ADDRESS_COST hook_int_rtx_mode_as_bool_0
87 #undef TARGET_RTX_COSTS
88 #define TARGET_RTX_COSTS lm32_rtx_costs
89 #undef TARGET_IN_SMALL_DATA_P
90 #define TARGET_IN_SMALL_DATA_P lm32_in_small_data_p
91 #undef TARGET_PROMOTE_FUNCTION_MODE
92 #define TARGET_PROMOTE_FUNCTION_MODE default_promote_function_mode_always_promote
93 #undef TARGET_SETUP_INCOMING_VARARGS
94 #define TARGET_SETUP_INCOMING_VARARGS lm32_setup_incoming_varargs
95 #undef TARGET_FUNCTION_ARG
96 #define TARGET_FUNCTION_ARG lm32_function_arg
97 #undef TARGET_FUNCTION_ARG_ADVANCE
98 #define TARGET_FUNCTION_ARG_ADVANCE lm32_function_arg_advance
99 #undef TARGET_PROMOTE_PROTOTYPES
100 #define TARGET_PROMOTE_PROTOTYPES hook_bool_const_tree_true
101 #undef TARGET_MIN_ANCHOR_OFFSET
102 #define TARGET_MIN_ANCHOR_OFFSET -0x8000
103 #undef TARGET_MAX_ANCHOR_OFFSET
104 #define TARGET_MAX_ANCHOR_OFFSET 0x7fff
105 #undef TARGET_CAN_ELIMINATE
106 #define TARGET_CAN_ELIMINATE lm32_can_eliminate
107 #undef TARGET_LRA_P
108 #define TARGET_LRA_P hook_bool_void_false
109 #undef TARGET_LEGITIMATE_ADDRESS_P
110 #define TARGET_LEGITIMATE_ADDRESS_P lm32_legitimate_address_p
111 #undef TARGET_HARD_REGNO_MODE_OK
112 #define TARGET_HARD_REGNO_MODE_OK lm32_hard_regno_mode_ok
113 #undef TARGET_MODES_TIEABLE_P
114 #define TARGET_MODES_TIEABLE_P lm32_modes_tieable_p
115
116 #undef TARGET_CONSTANT_ALIGNMENT
117 #define TARGET_CONSTANT_ALIGNMENT constant_alignment_word_strings
118
119 #undef TARGET_STARTING_FRAME_OFFSET
120 #define TARGET_STARTING_FRAME_OFFSET lm32_starting_frame_offset
121
122 struct gcc_target targetm = TARGET_INITIALIZER;
123
124 /* Current frame information calculated by lm32_compute_frame_size. */
125 static struct lm32_frame_info current_frame_info;
126
127 /* Return non-zero if the given return type should be returned in memory. */
128
129 int
lm32_return_in_memory(tree type)130 lm32_return_in_memory (tree type)
131 {
132 HOST_WIDE_INT size;
133
134 if (!AGGREGATE_TYPE_P (type))
135 {
136 /* All simple types are returned in registers. */
137 return 0;
138 }
139
140 size = int_size_in_bytes (type);
141 if (size >= 0 && size <= UNITS_PER_WORD)
142 {
143 /* If it can fit in one register. */
144 return 0;
145 }
146
147 return 1;
148 }
149
150 /* Generate an emit a word sized add instruction. */
151
152 static rtx
emit_add(rtx dest,rtx src0,rtx src1)153 emit_add (rtx dest, rtx src0, rtx src1)
154 {
155 rtx insn;
156 insn = emit_insn (gen_addsi3 (dest, src0, src1));
157 return insn;
158 }
159
160 /* Generate the code to compare (and possibly branch) two integer values
161 TEST_CODE is the comparison code we are trying to emulate
162 (or implement directly)
163 RESULT is where to store the result of the comparison,
164 or null to emit a branch
165 CMP0 CMP1 are the two comparison operands
166 DESTINATION is the destination of the branch, or null to only compare
167 */
168
169 static void
gen_int_relational(enum rtx_code code,rtx result,rtx cmp0,rtx cmp1,rtx destination)170 gen_int_relational (enum rtx_code code,
171 rtx result,
172 rtx cmp0,
173 rtx cmp1,
174 rtx destination)
175 {
176 machine_mode mode;
177 int branch_p;
178
179 mode = GET_MODE (cmp0);
180 if (mode == VOIDmode)
181 mode = GET_MODE (cmp1);
182
183 /* Is this a branch or compare. */
184 branch_p = (destination != 0);
185
186 /* Instruction set doesn't support LE or LT, so swap operands and use
187 GE, GT. */
188 switch (code)
189 {
190 case LE:
191 case LT:
192 case LEU:
193 case LTU:
194 {
195 rtx temp;
196
197 code = swap_condition (code);
198 temp = cmp0;
199 cmp0 = cmp1;
200 cmp1 = temp;
201 break;
202 }
203 default:
204 break;
205 }
206
207 if (branch_p)
208 {
209 rtx insn, cond, label;
210
211 /* Operands must be in registers. */
212 if (!register_operand (cmp0, mode))
213 cmp0 = force_reg (mode, cmp0);
214 if (!register_operand (cmp1, mode))
215 cmp1 = force_reg (mode, cmp1);
216
217 /* Generate conditional branch instruction. */
218 cond = gen_rtx_fmt_ee (code, mode, cmp0, cmp1);
219 label = gen_rtx_LABEL_REF (VOIDmode, destination);
220 insn = gen_rtx_SET (pc_rtx, gen_rtx_IF_THEN_ELSE (VOIDmode,
221 cond, label, pc_rtx));
222 emit_jump_insn (insn);
223 }
224 else
225 {
226 /* We can't have const_ints in cmp0, other than 0. */
227 if ((GET_CODE (cmp0) == CONST_INT) && (INTVAL (cmp0) != 0))
228 cmp0 = force_reg (mode, cmp0);
229
230 /* If the comparison is against an int not in legal range
231 move it into a register. */
232 if (GET_CODE (cmp1) == CONST_INT)
233 {
234 switch (code)
235 {
236 case EQ:
237 case NE:
238 case LE:
239 case LT:
240 case GE:
241 case GT:
242 if (!satisfies_constraint_K (cmp1))
243 cmp1 = force_reg (mode, cmp1);
244 break;
245 case LEU:
246 case LTU:
247 case GEU:
248 case GTU:
249 if (!satisfies_constraint_L (cmp1))
250 cmp1 = force_reg (mode, cmp1);
251 break;
252 default:
253 gcc_unreachable ();
254 }
255 }
256
257 /* Generate compare instruction. */
258 emit_move_insn (result, gen_rtx_fmt_ee (code, mode, cmp0, cmp1));
259 }
260 }
261
262 /* Try performing the comparison in OPERANDS[1], whose arms are OPERANDS[2]
263 and OPERAND[3]. Store the result in OPERANDS[0]. */
264
265 void
lm32_expand_scc(rtx operands[])266 lm32_expand_scc (rtx operands[])
267 {
268 rtx target = operands[0];
269 enum rtx_code code = GET_CODE (operands[1]);
270 rtx op0 = operands[2];
271 rtx op1 = operands[3];
272
273 gen_int_relational (code, target, op0, op1, NULL_RTX);
274 }
275
276 /* Compare OPERANDS[1] with OPERANDS[2] using comparison code
277 CODE and jump to OPERANDS[3] if the condition holds. */
278
279 void
lm32_expand_conditional_branch(rtx operands[])280 lm32_expand_conditional_branch (rtx operands[])
281 {
282 enum rtx_code code = GET_CODE (operands[0]);
283 rtx op0 = operands[1];
284 rtx op1 = operands[2];
285 rtx destination = operands[3];
286
287 gen_int_relational (code, NULL_RTX, op0, op1, destination);
288 }
289
290 /* Generate and emit RTL to save or restore callee save registers. */
291 static void
expand_save_restore(struct lm32_frame_info * info,int op)292 expand_save_restore (struct lm32_frame_info *info, int op)
293 {
294 unsigned int reg_save_mask = info->reg_save_mask;
295 int regno;
296 HOST_WIDE_INT offset;
297 rtx insn;
298
299 /* Callee saves are below locals and above outgoing arguments. */
300 offset = info->args_size + info->callee_size;
301 for (regno = 0; regno <= 31; regno++)
302 {
303 if ((reg_save_mask & (1 << regno)) != 0)
304 {
305 rtx offset_rtx;
306 rtx mem;
307
308 offset_rtx = GEN_INT (offset);
309 if (satisfies_constraint_K (offset_rtx))
310 {
311 mem = gen_rtx_MEM (word_mode,
312 gen_rtx_PLUS (Pmode,
313 stack_pointer_rtx,
314 offset_rtx));
315 }
316 else
317 {
318 /* r10 is caller saved so it can be used as a temp reg. */
319 rtx r10;
320
321 r10 = gen_rtx_REG (word_mode, 10);
322 insn = emit_move_insn (r10, offset_rtx);
323 if (op == 0)
324 RTX_FRAME_RELATED_P (insn) = 1;
325 insn = emit_add (r10, r10, stack_pointer_rtx);
326 if (op == 0)
327 RTX_FRAME_RELATED_P (insn) = 1;
328 mem = gen_rtx_MEM (word_mode, r10);
329 }
330
331 if (op == 0)
332 insn = emit_move_insn (mem, gen_rtx_REG (word_mode, regno));
333 else
334 insn = emit_move_insn (gen_rtx_REG (word_mode, regno), mem);
335
336 /* only prologue instructions which set the sp fp or save a
337 register should be marked as frame related. */
338 if (op == 0)
339 RTX_FRAME_RELATED_P (insn) = 1;
340 offset -= UNITS_PER_WORD;
341 }
342 }
343 }
344
345 static void
stack_adjust(HOST_WIDE_INT amount)346 stack_adjust (HOST_WIDE_INT amount)
347 {
348 rtx insn;
349
350 if (!IN_RANGE (amount, -32776, 32768))
351 {
352 /* r10 is caller saved so it can be used as a temp reg. */
353 rtx r10;
354 r10 = gen_rtx_REG (word_mode, 10);
355 insn = emit_move_insn (r10, GEN_INT (amount));
356 if (amount < 0)
357 RTX_FRAME_RELATED_P (insn) = 1;
358 insn = emit_add (stack_pointer_rtx, stack_pointer_rtx, r10);
359 if (amount < 0)
360 RTX_FRAME_RELATED_P (insn) = 1;
361 }
362 else
363 {
364 insn = emit_add (stack_pointer_rtx,
365 stack_pointer_rtx, GEN_INT (amount));
366 if (amount < 0)
367 RTX_FRAME_RELATED_P (insn) = 1;
368 }
369 }
370
371
372 /* Create and emit instructions for a functions prologue. */
373 void
lm32_expand_prologue(void)374 lm32_expand_prologue (void)
375 {
376 rtx insn;
377
378 lm32_compute_frame_size (get_frame_size ());
379
380 if (current_frame_info.total_size > 0)
381 {
382 /* Add space on stack new frame. */
383 stack_adjust (-current_frame_info.total_size);
384
385 /* Save callee save registers. */
386 if (current_frame_info.reg_save_mask != 0)
387 expand_save_restore (¤t_frame_info, 0);
388
389 /* Setup frame pointer if it's needed. */
390 if (frame_pointer_needed == 1)
391 {
392 /* Move sp to fp. */
393 insn = emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
394 RTX_FRAME_RELATED_P (insn) = 1;
395
396 /* Add offset - Don't use total_size, as that includes pretend_size,
397 which isn't part of this frame? */
398 insn = emit_add (frame_pointer_rtx,
399 frame_pointer_rtx,
400 GEN_INT (current_frame_info.args_size +
401 current_frame_info.callee_size +
402 current_frame_info.locals_size));
403 RTX_FRAME_RELATED_P (insn) = 1;
404 }
405
406 /* Prevent prologue from being scheduled into function body. */
407 emit_insn (gen_blockage ());
408 }
409 }
410
411 /* Create an emit instructions for a functions epilogue. */
412 void
lm32_expand_epilogue(void)413 lm32_expand_epilogue (void)
414 {
415 rtx ra_rtx = gen_rtx_REG (Pmode, RA_REGNUM);
416
417 lm32_compute_frame_size (get_frame_size ());
418
419 if (current_frame_info.total_size > 0)
420 {
421 /* Prevent stack code from being reordered. */
422 emit_insn (gen_blockage ());
423
424 /* Restore callee save registers. */
425 if (current_frame_info.reg_save_mask != 0)
426 expand_save_restore (¤t_frame_info, 1);
427
428 /* Deallocate stack. */
429 stack_adjust (current_frame_info.total_size);
430
431 /* Return to calling function. */
432 emit_jump_insn (gen_return_internal (ra_rtx));
433 }
434 else
435 {
436 /* Return to calling function. */
437 emit_jump_insn (gen_return_internal (ra_rtx));
438 }
439 }
440
441 /* Return the bytes needed to compute the frame pointer from the current
442 stack pointer. */
443 static HOST_WIDE_INT
lm32_compute_frame_size(int size)444 lm32_compute_frame_size (int size)
445 {
446 int regno;
447 HOST_WIDE_INT total_size, locals_size, args_size, pretend_size, callee_size;
448 unsigned int reg_save_mask;
449
450 locals_size = size;
451 args_size = crtl->outgoing_args_size;
452 pretend_size = crtl->args.pretend_args_size;
453 callee_size = 0;
454 reg_save_mask = 0;
455
456 /* Build mask that actually determines which regsiters we save
457 and calculate size required to store them in the stack. */
458 for (regno = 1; regno < SP_REGNUM; regno++)
459 {
460 if (df_regs_ever_live_p (regno) && !call_used_or_fixed_reg_p (regno))
461 {
462 reg_save_mask |= 1 << regno;
463 callee_size += UNITS_PER_WORD;
464 }
465 }
466 if (df_regs_ever_live_p (RA_REGNUM) || ! crtl->is_leaf
467 || !optimize)
468 {
469 reg_save_mask |= 1 << RA_REGNUM;
470 callee_size += UNITS_PER_WORD;
471 }
472 if (!(reg_save_mask & (1 << FP_REGNUM)) && frame_pointer_needed)
473 {
474 reg_save_mask |= 1 << FP_REGNUM;
475 callee_size += UNITS_PER_WORD;
476 }
477
478 /* Compute total frame size. */
479 total_size = pretend_size + args_size + locals_size + callee_size;
480
481 /* Align frame to appropriate boundary. */
482 total_size = (total_size + 3) & ~3;
483
484 /* Save computed information. */
485 current_frame_info.total_size = total_size;
486 current_frame_info.callee_size = callee_size;
487 current_frame_info.pretend_size = pretend_size;
488 current_frame_info.locals_size = locals_size;
489 current_frame_info.args_size = args_size;
490 current_frame_info.reg_save_mask = reg_save_mask;
491
492 return total_size;
493 }
494
495 void
lm32_print_operand(FILE * file,rtx op,int letter)496 lm32_print_operand (FILE * file, rtx op, int letter)
497 {
498 enum rtx_code code;
499
500 code = GET_CODE (op);
501
502 if (code == SIGN_EXTEND)
503 op = XEXP (op, 0), code = GET_CODE (op);
504 else if (code == REG || code == SUBREG)
505 {
506 int regnum;
507
508 if (code == REG)
509 regnum = REGNO (op);
510 else
511 regnum = true_regnum (op);
512
513 fprintf (file, "%s", reg_names[regnum]);
514 }
515 else if (code == HIGH)
516 output_addr_const (file, XEXP (op, 0));
517 else if (code == MEM)
518 output_address (GET_MODE (op), XEXP (op, 0));
519 else if (letter == 'z' && GET_CODE (op) == CONST_INT && INTVAL (op) == 0)
520 fprintf (file, "%s", reg_names[0]);
521 else if (GET_CODE (op) == CONST_DOUBLE)
522 {
523 if ((CONST_DOUBLE_LOW (op) != 0) || (CONST_DOUBLE_HIGH (op) != 0))
524 output_operand_lossage ("only 0.0 can be loaded as an immediate");
525 else
526 fprintf (file, "0");
527 }
528 else if (code == EQ)
529 fprintf (file, "e ");
530 else if (code == NE)
531 fprintf (file, "ne ");
532 else if (code == GT)
533 fprintf (file, "g ");
534 else if (code == GTU)
535 fprintf (file, "gu ");
536 else if (code == LT)
537 fprintf (file, "l ");
538 else if (code == LTU)
539 fprintf (file, "lu ");
540 else if (code == GE)
541 fprintf (file, "ge ");
542 else if (code == GEU)
543 fprintf (file, "geu");
544 else if (code == LE)
545 fprintf (file, "le ");
546 else if (code == LEU)
547 fprintf (file, "leu");
548 else
549 output_addr_const (file, op);
550 }
551
552 /* A C compound statement to output to stdio stream STREAM the
553 assembler syntax for an instruction operand that is a memory
554 reference whose address is ADDR. ADDR is an RTL expression.
555
556 On some machines, the syntax for a symbolic address depends on
557 the section that the address refers to. On these machines,
558 define the macro `ENCODE_SECTION_INFO' to store the information
559 into the `symbol_ref', and then check for it here. */
560
561 void
lm32_print_operand_address(FILE * file,rtx addr)562 lm32_print_operand_address (FILE * file, rtx addr)
563 {
564 switch (GET_CODE (addr))
565 {
566 case REG:
567 fprintf (file, "(%s+0)", reg_names[REGNO (addr)]);
568 break;
569
570 case MEM:
571 output_address (VOIDmode, XEXP (addr, 0));
572 break;
573
574 case PLUS:
575 {
576 rtx arg0 = XEXP (addr, 0);
577 rtx arg1 = XEXP (addr, 1);
578
579 if (GET_CODE (arg0) == REG && CONSTANT_P (arg1))
580 {
581 if (GET_CODE (arg1) == CONST_INT)
582 fprintf (file, "(%s+%ld)", reg_names[REGNO (arg0)],
583 INTVAL (arg1));
584 else
585 {
586 fprintf (file, "(%s+", reg_names[REGNO (arg0)]);
587 output_addr_const (file, arg1);
588 fprintf (file, ")");
589 }
590 }
591 else if (CONSTANT_P (arg0) && CONSTANT_P (arg1))
592 output_addr_const (file, addr);
593 else
594 fatal_insn ("bad operand", addr);
595 }
596 break;
597
598 case SYMBOL_REF:
599 if (SYMBOL_REF_SMALL_P (addr))
600 {
601 fprintf (file, "gp(");
602 output_addr_const (file, addr);
603 fprintf (file, ")");
604 }
605 else
606 fatal_insn ("can't use non gp relative absolute address", addr);
607 break;
608
609 default:
610 fatal_insn ("invalid addressing mode", addr);
611 break;
612 }
613 }
614
615 /* Determine where to put an argument to a function.
616 Value is zero to push the argument on the stack,
617 or a hard register in which to store the argument.
618
619 CUM is a variable of type CUMULATIVE_ARGS which gives info about
620 the preceding args and about the function being called.
621 ARG is a description of the argument. */
622
623 static rtx
lm32_function_arg(cumulative_args_t cum_v,const function_arg_info & arg)624 lm32_function_arg (cumulative_args_t cum_v, const function_arg_info &arg)
625 {
626 CUMULATIVE_ARGS *cum = get_cumulative_args (cum_v);
627
628 if (arg.end_marker_p ())
629 /* Compute operand 2 of the call insn. */
630 return GEN_INT (0);
631
632 if (targetm.calls.must_pass_in_stack (arg))
633 return NULL_RTX;
634
635 if (!arg.named
636 || *cum + LM32_NUM_REGS2 (arg.mode, arg.type) > LM32_NUM_ARG_REGS)
637 return NULL_RTX;
638
639 return gen_rtx_REG (arg.mode, *cum + LM32_FIRST_ARG_REG);
640 }
641
642 static void
lm32_function_arg_advance(cumulative_args_t cum,const function_arg_info & arg)643 lm32_function_arg_advance (cumulative_args_t cum,
644 const function_arg_info &arg)
645 {
646 *get_cumulative_args (cum) += LM32_NUM_REGS2 (arg.mode, arg.type);
647 }
648
649 HOST_WIDE_INT
lm32_compute_initial_elimination_offset(int from,int to)650 lm32_compute_initial_elimination_offset (int from, int to)
651 {
652 HOST_WIDE_INT offset = 0;
653
654 switch (from)
655 {
656 case ARG_POINTER_REGNUM:
657 switch (to)
658 {
659 case FRAME_POINTER_REGNUM:
660 offset = 0;
661 break;
662 case STACK_POINTER_REGNUM:
663 offset =
664 lm32_compute_frame_size (get_frame_size ()) -
665 current_frame_info.pretend_size;
666 break;
667 default:
668 gcc_unreachable ();
669 }
670 break;
671 default:
672 gcc_unreachable ();
673 }
674
675 return offset;
676 }
677
678 static void
lm32_setup_incoming_varargs(cumulative_args_t cum_v,const function_arg_info & arg,int * pretend_size,int no_rtl)679 lm32_setup_incoming_varargs (cumulative_args_t cum_v,
680 const function_arg_info &arg,
681 int *pretend_size, int no_rtl)
682 {
683 CUMULATIVE_ARGS *cum = get_cumulative_args (cum_v);
684 int first_anon_arg;
685 tree fntype;
686
687 fntype = TREE_TYPE (current_function_decl);
688
689 if (stdarg_p (fntype))
690 first_anon_arg = *cum + LM32_FIRST_ARG_REG;
691 else
692 {
693 /* this is the common case, we have been passed details setup
694 for the last named argument, we want to skip over the
695 registers, if any used in passing this named parameter in
696 order to determine which is the first registers used to pass
697 anonymous arguments. */
698 int size = arg.promoted_size_in_bytes ();
699
700 first_anon_arg =
701 *cum + LM32_FIRST_ARG_REG +
702 ((size + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
703 }
704
705 if ((first_anon_arg < (LM32_FIRST_ARG_REG + LM32_NUM_ARG_REGS)) && !no_rtl)
706 {
707 int first_reg_offset = first_anon_arg;
708 int size = LM32_FIRST_ARG_REG + LM32_NUM_ARG_REGS - first_anon_arg;
709 rtx regblock;
710
711 regblock = gen_rtx_MEM (BLKmode,
712 plus_constant (Pmode, arg_pointer_rtx,
713 FIRST_PARM_OFFSET (0)));
714 move_block_from_reg (first_reg_offset, regblock, size);
715
716 *pretend_size = size * UNITS_PER_WORD;
717 }
718 }
719
720 /* Override command line options. */
721 static void
lm32_option_override(void)722 lm32_option_override (void)
723 {
724 /* We must have sign-extend enabled if barrel-shift isn't. */
725 if (!TARGET_BARREL_SHIFT_ENABLED && !TARGET_SIGN_EXTEND_ENABLED)
726 target_flags |= MASK_SIGN_EXTEND_ENABLED;
727 }
728
729 /* Return nonzero if this function is known to have a null epilogue.
730 This allows the optimizer to omit jumps to jumps if no stack
731 was created. */
732 int
lm32_can_use_return(void)733 lm32_can_use_return (void)
734 {
735 if (!reload_completed)
736 return 0;
737
738 if (df_regs_ever_live_p (RA_REGNUM) || crtl->profile)
739 return 0;
740
741 if (lm32_compute_frame_size (get_frame_size ()) != 0)
742 return 0;
743
744 return 1;
745 }
746
747 /* Support function to determine the return address of the function
748 'count' frames back up the stack. */
749 rtx
lm32_return_addr_rtx(int count,rtx frame)750 lm32_return_addr_rtx (int count, rtx frame)
751 {
752 rtx r;
753 if (count == 0)
754 {
755 if (!df_regs_ever_live_p (RA_REGNUM))
756 r = gen_rtx_REG (Pmode, RA_REGNUM);
757 else
758 {
759 r = gen_rtx_MEM (Pmode,
760 gen_rtx_PLUS (Pmode, frame,
761 GEN_INT (-2 * UNITS_PER_WORD)));
762 set_mem_alias_set (r, get_frame_alias_set ());
763 }
764 }
765 else if (flag_omit_frame_pointer)
766 r = NULL_RTX;
767 else
768 {
769 r = gen_rtx_MEM (Pmode,
770 gen_rtx_PLUS (Pmode, frame,
771 GEN_INT (-2 * UNITS_PER_WORD)));
772 set_mem_alias_set (r, get_frame_alias_set ());
773 }
774 return r;
775 }
776
777 /* Return true if EXP should be placed in the small data section. */
778
779 static bool
lm32_in_small_data_p(const_tree exp)780 lm32_in_small_data_p (const_tree exp)
781 {
782 /* We want to merge strings, so we never consider them small data. */
783 if (TREE_CODE (exp) == STRING_CST)
784 return false;
785
786 /* Functions are never in the small data area. Duh. */
787 if (TREE_CODE (exp) == FUNCTION_DECL)
788 return false;
789
790 if (TREE_CODE (exp) == VAR_DECL && DECL_SECTION_NAME (exp))
791 {
792 const char *section = DECL_SECTION_NAME (exp);
793 if (strcmp (section, ".sdata") == 0 || strcmp (section, ".sbss") == 0)
794 return true;
795 }
796 else
797 {
798 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (exp));
799
800 /* If this is an incomplete type with size 0, then we can't put it
801 in sdata because it might be too big when completed. */
802 if (size > 0 && size <= g_switch_value)
803 return true;
804 }
805
806 return false;
807 }
808
809 /* Emit straight-line code to move LENGTH bytes from SRC to DEST.
810 Assume that the areas do not overlap. */
811
812 static void
lm32_block_move_inline(rtx dest,rtx src,HOST_WIDE_INT length,HOST_WIDE_INT alignment)813 lm32_block_move_inline (rtx dest, rtx src, HOST_WIDE_INT length,
814 HOST_WIDE_INT alignment)
815 {
816 HOST_WIDE_INT offset, delta;
817 unsigned HOST_WIDE_INT bits;
818 int i;
819 machine_mode mode;
820 rtx *regs;
821
822 /* Work out how many bits to move at a time. */
823 switch (alignment)
824 {
825 case 1:
826 bits = 8;
827 break;
828 case 2:
829 bits = 16;
830 break;
831 default:
832 bits = 32;
833 break;
834 }
835
836 mode = int_mode_for_size (bits, 0).require ();
837 delta = bits / BITS_PER_UNIT;
838
839 /* Allocate a buffer for the temporary registers. */
840 regs = XALLOCAVEC (rtx, length / delta);
841
842 /* Load as many BITS-sized chunks as possible. */
843 for (offset = 0, i = 0; offset + delta <= length; offset += delta, i++)
844 {
845 regs[i] = gen_reg_rtx (mode);
846 emit_move_insn (regs[i], adjust_address (src, mode, offset));
847 }
848
849 /* Copy the chunks to the destination. */
850 for (offset = 0, i = 0; offset + delta <= length; offset += delta, i++)
851 emit_move_insn (adjust_address (dest, mode, offset), regs[i]);
852
853 /* Mop up any left-over bytes. */
854 if (offset < length)
855 {
856 src = adjust_address (src, BLKmode, offset);
857 dest = adjust_address (dest, BLKmode, offset);
858 move_by_pieces (dest, src, length - offset,
859 MIN (MEM_ALIGN (src), MEM_ALIGN (dest)), RETURN_BEGIN);
860 }
861 }
862
863 /* Expand string/block move operations.
864
865 operands[0] is the pointer to the destination.
866 operands[1] is the pointer to the source.
867 operands[2] is the number of bytes to move.
868 operands[3] is the alignment. */
869
870 int
lm32_expand_block_move(rtx * operands)871 lm32_expand_block_move (rtx * operands)
872 {
873 if ((GET_CODE (operands[2]) == CONST_INT) && (INTVAL (operands[2]) <= 32))
874 {
875 lm32_block_move_inline (operands[0], operands[1], INTVAL (operands[2]),
876 INTVAL (operands[3]));
877 return 1;
878 }
879 return 0;
880 }
881
882 /* Return TRUE if X references a SYMBOL_REF or LABEL_REF whose symbol
883 isn't protected by a PIC unspec. */
884 int
nonpic_symbol_mentioned_p(rtx x)885 nonpic_symbol_mentioned_p (rtx x)
886 {
887 const char *fmt;
888 int i;
889
890 if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF
891 || GET_CODE (x) == PC)
892 return 1;
893
894 /* We don't want to look into the possible MEM location of a
895 CONST_DOUBLE, since we're not going to use it, in general. */
896 if (GET_CODE (x) == CONST_DOUBLE)
897 return 0;
898
899 if (GET_CODE (x) == UNSPEC)
900 return 0;
901
902 fmt = GET_RTX_FORMAT (GET_CODE (x));
903 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
904 {
905 if (fmt[i] == 'E')
906 {
907 int j;
908
909 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
910 if (nonpic_symbol_mentioned_p (XVECEXP (x, i, j)))
911 return 1;
912 }
913 else if (fmt[i] == 'e' && nonpic_symbol_mentioned_p (XEXP (x, i)))
914 return 1;
915 }
916
917 return 0;
918 }
919
920 /* Compute a (partial) cost for rtx X. Return true if the complete
921 cost has been computed, and false if subexpressions should be
922 scanned. In either case, *TOTAL contains the cost result. */
923
924 static bool
lm32_rtx_costs(rtx x,machine_mode mode,int outer_code,int opno ATTRIBUTE_UNUSED,int * total,bool speed)925 lm32_rtx_costs (rtx x, machine_mode mode, int outer_code,
926 int opno ATTRIBUTE_UNUSED, int *total, bool speed)
927 {
928 int code = GET_CODE (x);
929 bool small_mode;
930
931 const int arithmetic_latency = 1;
932 const int shift_latency = 1;
933 const int compare_latency = 2;
934 const int multiply_latency = 3;
935 const int load_latency = 3;
936 const int libcall_size_cost = 5;
937
938 /* Determine if we can handle the given mode size in a single instruction. */
939 small_mode = (mode == QImode) || (mode == HImode) || (mode == SImode);
940
941 switch (code)
942 {
943
944 case PLUS:
945 case MINUS:
946 case AND:
947 case IOR:
948 case XOR:
949 case NOT:
950 case NEG:
951 if (!speed)
952 *total = COSTS_N_INSNS (LM32_NUM_REGS (mode));
953 else
954 *total =
955 COSTS_N_INSNS (arithmetic_latency + (LM32_NUM_REGS (mode) - 1));
956 break;
957
958 case COMPARE:
959 if (small_mode)
960 {
961 if (!speed)
962 *total = COSTS_N_INSNS (1);
963 else
964 *total = COSTS_N_INSNS (compare_latency);
965 }
966 else
967 {
968 /* FIXME. Guessing here. */
969 *total = COSTS_N_INSNS (LM32_NUM_REGS (mode) * (2 + 3) / 2);
970 }
971 break;
972
973 case ASHIFT:
974 case ASHIFTRT:
975 case LSHIFTRT:
976 if (TARGET_BARREL_SHIFT_ENABLED && small_mode)
977 {
978 if (!speed)
979 *total = COSTS_N_INSNS (1);
980 else
981 *total = COSTS_N_INSNS (shift_latency);
982 }
983 else if (TARGET_BARREL_SHIFT_ENABLED)
984 {
985 /* FIXME: Guessing here. */
986 *total = COSTS_N_INSNS (LM32_NUM_REGS (mode) * 4);
987 }
988 else if (small_mode && GET_CODE (XEXP (x, 1)) == CONST_INT)
989 {
990 *total = COSTS_N_INSNS (INTVAL (XEXP (x, 1)));
991 }
992 else
993 {
994 /* Libcall. */
995 if (!speed)
996 *total = COSTS_N_INSNS (libcall_size_cost);
997 else
998 *total = COSTS_N_INSNS (100);
999 }
1000 break;
1001
1002 case MULT:
1003 if (TARGET_MULTIPLY_ENABLED && small_mode)
1004 {
1005 if (!speed)
1006 *total = COSTS_N_INSNS (1);
1007 else
1008 *total = COSTS_N_INSNS (multiply_latency);
1009 }
1010 else
1011 {
1012 /* Libcall. */
1013 if (!speed)
1014 *total = COSTS_N_INSNS (libcall_size_cost);
1015 else
1016 *total = COSTS_N_INSNS (100);
1017 }
1018 break;
1019
1020 case DIV:
1021 case MOD:
1022 case UDIV:
1023 case UMOD:
1024 if (TARGET_DIVIDE_ENABLED && small_mode)
1025 {
1026 if (!speed)
1027 *total = COSTS_N_INSNS (1);
1028 else
1029 {
1030 if (GET_CODE (XEXP (x, 1)) == CONST_INT)
1031 {
1032 int cycles = 0;
1033 unsigned HOST_WIDE_INT i = INTVAL (XEXP (x, 1));
1034
1035 while (i)
1036 {
1037 i >>= 2;
1038 cycles++;
1039 }
1040 if (IN_RANGE (i, 0, 65536))
1041 *total = COSTS_N_INSNS (1 + 1 + cycles);
1042 else
1043 *total = COSTS_N_INSNS (2 + 1 + cycles);
1044 return true;
1045 }
1046 else if (GET_CODE (XEXP (x, 1)) == REG)
1047 {
1048 *total = COSTS_N_INSNS (1 + GET_MODE_SIZE (mode) / 2);
1049 return true;
1050 }
1051 else
1052 {
1053 *total = COSTS_N_INSNS (1 + GET_MODE_SIZE (mode) / 2);
1054 return false;
1055 }
1056 }
1057 }
1058 else
1059 {
1060 /* Libcall. */
1061 if (!speed)
1062 *total = COSTS_N_INSNS (libcall_size_cost);
1063 else
1064 *total = COSTS_N_INSNS (100);
1065 }
1066 break;
1067
1068 case HIGH:
1069 case LO_SUM:
1070 if (!speed)
1071 *total = COSTS_N_INSNS (1);
1072 else
1073 *total = COSTS_N_INSNS (arithmetic_latency);
1074 break;
1075
1076 case ZERO_EXTEND:
1077 if (MEM_P (XEXP (x, 0)))
1078 *total = COSTS_N_INSNS (0);
1079 else if (small_mode)
1080 {
1081 if (!speed)
1082 *total = COSTS_N_INSNS (1);
1083 else
1084 *total = COSTS_N_INSNS (arithmetic_latency);
1085 }
1086 else
1087 *total = COSTS_N_INSNS (LM32_NUM_REGS (mode) / 2);
1088 break;
1089
1090 case CONST_INT:
1091 {
1092 switch (outer_code)
1093 {
1094 case HIGH:
1095 case LO_SUM:
1096 *total = COSTS_N_INSNS (0);
1097 return true;
1098
1099 case AND:
1100 case XOR:
1101 case IOR:
1102 case ASHIFT:
1103 case ASHIFTRT:
1104 case LSHIFTRT:
1105 case ROTATE:
1106 case ROTATERT:
1107 if (satisfies_constraint_L (x))
1108 *total = COSTS_N_INSNS (0);
1109 else
1110 *total = COSTS_N_INSNS (2);
1111 return true;
1112
1113 case SET:
1114 case PLUS:
1115 case MINUS:
1116 case COMPARE:
1117 if (satisfies_constraint_K (x))
1118 *total = COSTS_N_INSNS (0);
1119 else
1120 *total = COSTS_N_INSNS (2);
1121 return true;
1122
1123 case MULT:
1124 if (TARGET_MULTIPLY_ENABLED)
1125 {
1126 if (satisfies_constraint_K (x))
1127 *total = COSTS_N_INSNS (0);
1128 else
1129 *total = COSTS_N_INSNS (2);
1130 return true;
1131 }
1132 /* Fall through. */
1133
1134 default:
1135 if (satisfies_constraint_K (x))
1136 *total = COSTS_N_INSNS (1);
1137 else
1138 *total = COSTS_N_INSNS (2);
1139 return true;
1140 }
1141 }
1142
1143 case SYMBOL_REF:
1144 case CONST:
1145 switch (outer_code)
1146 {
1147 case HIGH:
1148 case LO_SUM:
1149 *total = COSTS_N_INSNS (0);
1150 return true;
1151
1152 case MEM:
1153 case SET:
1154 if (g_switch_value)
1155 {
1156 *total = COSTS_N_INSNS (0);
1157 return true;
1158 }
1159 break;
1160 }
1161 /* Fall through. */
1162
1163 case LABEL_REF:
1164 case CONST_DOUBLE:
1165 *total = COSTS_N_INSNS (2);
1166 return true;
1167
1168 case SET:
1169 *total = COSTS_N_INSNS (1);
1170 break;
1171
1172 case MEM:
1173 if (!speed)
1174 *total = COSTS_N_INSNS (1);
1175 else
1176 *total = COSTS_N_INSNS (load_latency);
1177 break;
1178
1179 }
1180
1181 return false;
1182 }
1183
1184 /* Implemenent TARGET_CAN_ELIMINATE. */
1185
1186 bool
lm32_can_eliminate(const int from ATTRIBUTE_UNUSED,const int to)1187 lm32_can_eliminate (const int from ATTRIBUTE_UNUSED, const int to)
1188 {
1189 return (to == STACK_POINTER_REGNUM && frame_pointer_needed) ? false : true;
1190 }
1191
1192 /* Implement TARGET_LEGITIMATE_ADDRESS_P. */
1193
1194 static bool
lm32_legitimate_address_p(machine_mode mode ATTRIBUTE_UNUSED,rtx x,bool strict)1195 lm32_legitimate_address_p (machine_mode mode ATTRIBUTE_UNUSED, rtx x, bool strict)
1196 {
1197 /* (rM) */
1198 if (strict && REG_P (x) && STRICT_REG_OK_FOR_BASE_P (x))
1199 return true;
1200 if (!strict && REG_P (x) && NONSTRICT_REG_OK_FOR_BASE_P (x))
1201 return true;
1202
1203 /* (rM)+literal) */
1204 if (GET_CODE (x) == PLUS
1205 && REG_P (XEXP (x, 0))
1206 && ((strict && STRICT_REG_OK_FOR_BASE_P (XEXP (x, 0)))
1207 || (!strict && NONSTRICT_REG_OK_FOR_BASE_P (XEXP (x, 0))))
1208 && GET_CODE (XEXP (x, 1)) == CONST_INT
1209 && satisfies_constraint_K (XEXP ((x), 1)))
1210 return true;
1211
1212 /* gp(sym) */
1213 if (GET_CODE (x) == SYMBOL_REF && SYMBOL_REF_SMALL_P (x))
1214 return true;
1215
1216 return false;
1217 }
1218
1219 /* Check a move is not memory to memory. */
1220
1221 bool
lm32_move_ok(machine_mode mode,rtx operands[2])1222 lm32_move_ok (machine_mode mode, rtx operands[2]) {
1223 if (memory_operand (operands[0], mode))
1224 return register_or_zero_operand (operands[1], mode);
1225 return true;
1226 }
1227
1228 /* Implement TARGET_HARD_REGNO_MODE_OK. */
1229
1230 static bool
lm32_hard_regno_mode_ok(unsigned int regno,machine_mode)1231 lm32_hard_regno_mode_ok (unsigned int regno, machine_mode)
1232 {
1233 return G_REG_P (regno);
1234 }
1235
1236 /* Implement TARGET_MODES_TIEABLE_P. */
1237
1238 static bool
lm32_modes_tieable_p(machine_mode mode1,machine_mode mode2)1239 lm32_modes_tieable_p (machine_mode mode1, machine_mode mode2)
1240 {
1241 return (GET_MODE_CLASS (mode1) == MODE_INT
1242 && GET_MODE_CLASS (mode2) == MODE_INT
1243 && GET_MODE_SIZE (mode1) <= UNITS_PER_WORD
1244 && GET_MODE_SIZE (mode2) <= UNITS_PER_WORD);
1245 }
1246
1247 /* Implement TARGET_STARTING_FRAME_OFFSET. */
1248
1249 static HOST_WIDE_INT
lm32_starting_frame_offset(void)1250 lm32_starting_frame_offset (void)
1251 {
1252 return UNITS_PER_WORD;
1253 }
1254