xref: /dragonfly/contrib/gcc-4.7/gcc/genemit.c (revision cfd1aba3)
1 /* Generate code from machine description to emit insns as rtl.
2    Copyright (C) 1987, 1988, 1991, 1994, 1995, 1997, 1998, 1999, 2000, 2001,
3    2003, 2004, 2005, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
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 #include "bconfig.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tm.h"
26 #include "rtl.h"
27 #include "errors.h"
28 #include "read-md.h"
29 #include "gensupport.h"
30 
31 
32 static int insn_code_number;
33 static int insn_index_number;
34 
35 /* Data structure for recording the patterns of insns that have CLOBBERs.
36    We use this to output a function that adds these CLOBBERs to a
37    previously-allocated PARALLEL expression.  */
38 
39 struct clobber_pat
40 {
41   struct clobber_ent *insns;
42   rtx pattern;
43   int first_clobber;
44   struct clobber_pat *next;
45   int has_hard_reg;
46 } *clobber_list;
47 
48 /* Records one insn that uses the clobber list.  */
49 
50 struct clobber_ent
51 {
52   int code_number;		/* Counts only insns.  */
53   struct clobber_ent *next;
54 };
55 
56 static void print_code			(RTX_CODE);
57 static void gen_exp			(rtx, enum rtx_code, char *);
58 static void gen_insn			(rtx, int);
59 static void gen_expand			(rtx);
60 static void gen_split			(rtx);
61 static void output_add_clobbers		(void);
62 static void output_added_clobbers_hard_reg_p (void);
63 static void gen_rtx_scratch		(rtx, enum rtx_code);
64 static void output_peephole2_scratches	(rtx);
65 
66 
67 static void
68 print_code (RTX_CODE code)
69 {
70   const char *p1;
71   for (p1 = GET_RTX_NAME (code); *p1; p1++)
72     putchar (TOUPPER(*p1));
73 }
74 
75 static void
76 gen_rtx_scratch (rtx x, enum rtx_code subroutine_type)
77 {
78   if (subroutine_type == DEFINE_PEEPHOLE2)
79     {
80       printf ("operand%d", XINT (x, 0));
81     }
82   else
83     {
84       printf ("gen_rtx_SCRATCH (%smode)", GET_MODE_NAME (GET_MODE (x)));
85     }
86 }
87 
88 /* Print a C expression to construct an RTX just like X,
89    substituting any operand references appearing within.  */
90 
91 static void
92 gen_exp (rtx x, enum rtx_code subroutine_type, char *used)
93 {
94   RTX_CODE code;
95   int i;
96   int len;
97   const char *fmt;
98 
99   if (x == 0)
100     {
101       printf ("NULL_RTX");
102       return;
103     }
104 
105   code = GET_CODE (x);
106 
107   switch (code)
108     {
109     case MATCH_OPERAND:
110     case MATCH_DUP:
111       if (used)
112 	{
113 	  if (used[XINT (x, 0)])
114 	    {
115 	      printf ("copy_rtx (operand%d)", XINT (x, 0));
116 	      return;
117 	    }
118 	  used[XINT (x, 0)] = 1;
119 	}
120       printf ("operand%d", XINT (x, 0));
121       return;
122 
123     case MATCH_OP_DUP:
124       printf ("gen_rtx_fmt_");
125       for (i = 0; i < XVECLEN (x, 1); i++)
126 	printf ("e");
127       printf (" (GET_CODE (operand%d), ", XINT (x, 0));
128       if (GET_MODE (x) == VOIDmode)
129 	printf ("GET_MODE (operand%d)", XINT (x, 0));
130       else
131 	printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
132       for (i = 0; i < XVECLEN (x, 1); i++)
133 	{
134 	  printf (",\n\t\t");
135 	  gen_exp (XVECEXP (x, 1, i), subroutine_type, used);
136 	}
137       printf (")");
138       return;
139 
140     case MATCH_OPERATOR:
141       printf ("gen_rtx_fmt_");
142       for (i = 0; i < XVECLEN (x, 2); i++)
143 	printf ("e");
144       printf (" (GET_CODE (operand%d)", XINT (x, 0));
145       printf (", %smode", GET_MODE_NAME (GET_MODE (x)));
146       for (i = 0; i < XVECLEN (x, 2); i++)
147 	{
148 	  printf (",\n\t\t");
149 	  gen_exp (XVECEXP (x, 2, i), subroutine_type, used);
150 	}
151       printf (")");
152       return;
153 
154     case MATCH_PARALLEL:
155     case MATCH_PAR_DUP:
156       printf ("operand%d", XINT (x, 0));
157       return;
158 
159     case MATCH_SCRATCH:
160       gen_rtx_scratch (x, subroutine_type);
161       return;
162 
163     case ADDRESS:
164       fatal ("ADDRESS expression code used in named instruction pattern");
165 
166     case PC:
167       printf ("pc_rtx");
168       return;
169     case RETURN:
170       printf ("ret_rtx");
171       return;
172     case SIMPLE_RETURN:
173       printf ("simple_return_rtx");
174       return;
175     case CLOBBER:
176       if (REG_P (XEXP (x, 0)))
177 	{
178 	  printf ("gen_hard_reg_clobber (%smode, %i)", GET_MODE_NAME (GET_MODE (XEXP (x, 0))),
179 			  			     REGNO (XEXP (x, 0)));
180 	  return;
181 	}
182       break;
183 
184     case CC0:
185       printf ("cc0_rtx");
186       return;
187 
188     case CONST_INT:
189       if (INTVAL (x) == 0)
190 	printf ("const0_rtx");
191       else if (INTVAL (x) == 1)
192 	printf ("const1_rtx");
193       else if (INTVAL (x) == -1)
194 	printf ("constm1_rtx");
195       else if (-MAX_SAVED_CONST_INT <= INTVAL (x)
196 	  && INTVAL (x) <= MAX_SAVED_CONST_INT)
197 	printf ("const_int_rtx[MAX_SAVED_CONST_INT + (%d)]",
198 		(int) INTVAL (x));
199       else if (INTVAL (x) == STORE_FLAG_VALUE)
200 	printf ("const_true_rtx");
201       else
202 	{
203 	  printf ("GEN_INT (");
204 	  printf (HOST_WIDE_INT_PRINT_DEC_C, INTVAL (x));
205 	  printf (")");
206 	}
207       return;
208 
209     case CONST_DOUBLE:
210     case CONST_FIXED:
211       /* These shouldn't be written in MD files.  Instead, the appropriate
212 	 routines in varasm.c should be called.  */
213       gcc_unreachable ();
214 
215     default:
216       break;
217     }
218 
219   printf ("gen_rtx_");
220   print_code (code);
221   printf (" (%smode", GET_MODE_NAME (GET_MODE (x)));
222 
223   fmt = GET_RTX_FORMAT (code);
224   len = GET_RTX_LENGTH (code);
225   for (i = 0; i < len; i++)
226     {
227       if (fmt[i] == '0')
228 	break;
229       printf (",\n\t");
230       switch (fmt[i])
231 	{
232 	case 'e': case 'u':
233 	  gen_exp (XEXP (x, i), subroutine_type, used);
234 	  break;
235 
236 	case 'i':
237 	  printf ("%u", XINT (x, i));
238 	  break;
239 
240 	case 's':
241 	  printf ("\"%s\"", XSTR (x, i));
242 	  break;
243 
244 	case 'E':
245 	  {
246 	    int j;
247 	    printf ("gen_rtvec (%d", XVECLEN (x, i));
248 	    for (j = 0; j < XVECLEN (x, i); j++)
249 	      {
250 		printf (",\n\t\t");
251 		gen_exp (XVECEXP (x, i, j), subroutine_type, used);
252 	      }
253 	    printf (")");
254 	    break;
255 	  }
256 
257 	default:
258 	  gcc_unreachable ();
259 	}
260     }
261   printf (")");
262 }
263 
264 /* Generate the `gen_...' function for a DEFINE_INSN.  */
265 
266 static void
267 gen_insn (rtx insn, int lineno)
268 {
269   struct pattern_stats stats;
270   int i;
271 
272   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
273      registers or MATCH_SCRATCHes.  If so, store away the information for
274      later.  */
275 
276   if (XVEC (insn, 1))
277     {
278       int has_hard_reg = 0;
279 
280       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
281 	{
282 	  if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER)
283 	    break;
284 
285 	  if (REG_P (XEXP (XVECEXP (insn, 1, i), 0)))
286 	    has_hard_reg = 1;
287 	  else if (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH)
288 	    break;
289 	}
290 
291       if (i != XVECLEN (insn, 1) - 1)
292 	{
293 	  struct clobber_pat *p;
294 	  struct clobber_ent *link = XNEW (struct clobber_ent);
295 	  int j;
296 
297 	  link->code_number = insn_code_number;
298 
299 	  /* See if any previous CLOBBER_LIST entry is the same as this
300 	     one.  */
301 
302 	  for (p = clobber_list; p; p = p->next)
303 	    {
304 	      if (p->first_clobber != i + 1
305 		  || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
306 		continue;
307 
308 	      for (j = i + 1; j < XVECLEN (insn, 1); j++)
309 		{
310 		  rtx old_rtx = XEXP (XVECEXP (p->pattern, 1, j), 0);
311 		  rtx new_rtx = XEXP (XVECEXP (insn, 1, j), 0);
312 
313 		  /* OLD and NEW_INSN are the same if both are to be a SCRATCH
314 		     of the same mode,
315 		     or if both are registers of the same mode and number.  */
316 		  if (! (GET_MODE (old_rtx) == GET_MODE (new_rtx)
317 			 && ((GET_CODE (old_rtx) == MATCH_SCRATCH
318 			      && GET_CODE (new_rtx) == MATCH_SCRATCH)
319 			     || (REG_P (old_rtx) && REG_P (new_rtx)
320 				 && REGNO (old_rtx) == REGNO (new_rtx)))))
321 		    break;
322 		}
323 
324 	      if (j == XVECLEN (insn, 1))
325 		break;
326 	    }
327 
328 	  if (p == 0)
329 	    {
330 	      p = XNEW (struct clobber_pat);
331 
332 	      p->insns = 0;
333 	      p->pattern = insn;
334 	      p->first_clobber = i + 1;
335 	      p->next = clobber_list;
336 	      p->has_hard_reg = has_hard_reg;
337 	      clobber_list = p;
338 	    }
339 
340 	  link->next = p->insns;
341 	  p->insns = link;
342 	}
343     }
344 
345   /* Don't mention instructions whose names are the null string
346      or begin with '*'.  They are in the machine description just
347      to be recognized.  */
348   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
349     return;
350 
351   printf ("/* %s:%d */\n", read_md_filename, lineno);
352 
353   /* Find out how many operands this function has.  */
354   get_pattern_stats (&stats, XVEC (insn, 1));
355   if (stats.max_dup_opno > stats.max_opno)
356     fatal ("match_dup operand number has no match_operand");
357 
358   /* Output the function name and argument declarations.  */
359   printf ("rtx\ngen_%s (", XSTR (insn, 0));
360   if (stats.num_generator_args)
361     for (i = 0; i < stats.num_generator_args; i++)
362       if (i)
363 	printf (",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
364       else
365 	printf ("rtx operand%d ATTRIBUTE_UNUSED", i);
366   else
367     printf ("void");
368   printf (")\n");
369   printf ("{\n");
370 
371   /* Output code to construct and return the rtl for the instruction body.  */
372 
373   if (XVECLEN (insn, 1) == 1)
374     {
375       printf ("  return ");
376       gen_exp (XVECEXP (insn, 1, 0), DEFINE_INSN, NULL);
377       printf (";\n}\n\n");
378     }
379   else
380     {
381       char *used = XCNEWVEC (char, stats.num_generator_args);
382 
383       printf ("  return gen_rtx_PARALLEL (VOIDmode, gen_rtvec (%d",
384 	      XVECLEN (insn, 1));
385 
386       for (i = 0; i < XVECLEN (insn, 1); i++)
387 	{
388 	  printf (",\n\t\t");
389 	  gen_exp (XVECEXP (insn, 1, i), DEFINE_INSN, used);
390 	}
391       printf ("));\n}\n\n");
392       XDELETEVEC (used);
393     }
394 }
395 
396 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
397 
398 static void
399 gen_expand (rtx expand)
400 {
401   struct pattern_stats stats;
402   int i;
403   char *used;
404 
405   if (strlen (XSTR (expand, 0)) == 0)
406     fatal ("define_expand lacks a name");
407   if (XVEC (expand, 1) == 0)
408     fatal ("define_expand for %s lacks a pattern", XSTR (expand, 0));
409 
410   /* Find out how many operands this function has.  */
411   get_pattern_stats (&stats, XVEC (expand, 1));
412 
413   /* Output the function name and argument declarations.  */
414   printf ("rtx\ngen_%s (", XSTR (expand, 0));
415   if (stats.num_generator_args)
416     for (i = 0; i < stats.num_generator_args; i++)
417       if (i)
418 	printf (",\n\trtx operand%d", i);
419       else
420 	printf ("rtx operand%d", i);
421   else
422     printf ("void");
423   printf (")\n");
424   printf ("{\n");
425 
426   /* If we don't have any C code to write, only one insn is being written,
427      and no MATCH_DUPs are present, we can just return the desired insn
428      like we do for a DEFINE_INSN.  This saves memory.  */
429   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
430       && stats.max_opno >= stats.max_dup_opno
431       && XVECLEN (expand, 1) == 1)
432     {
433       printf ("  return ");
434       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND, NULL);
435       printf (";\n}\n\n");
436       return;
437     }
438 
439   /* For each operand referred to only with MATCH_DUPs,
440      make a local variable.  */
441   for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
442     printf ("  rtx operand%d;\n", i);
443   for (; i <= stats.max_scratch_opno; i++)
444     printf ("  rtx operand%d ATTRIBUTE_UNUSED;\n", i);
445   printf ("  rtx _val = 0;\n");
446   printf ("  start_sequence ();\n");
447 
448   /* The fourth operand of DEFINE_EXPAND is some code to be executed
449      before the actual construction.
450      This code expects to refer to `operands'
451      just as the output-code in a DEFINE_INSN does,
452      but here `operands' is an automatic array.
453      So copy the operand values there before executing it.  */
454   if (XSTR (expand, 3) && *XSTR (expand, 3))
455     {
456       printf ("  {\n");
457       if (stats.num_operand_vars > 0)
458 	printf ("    rtx operands[%d];\n", stats.num_operand_vars);
459 
460       /* Output code to copy the arguments into `operands'.  */
461       for (i = 0; i < stats.num_generator_args; i++)
462 	printf ("    operands[%d] = operand%d;\n", i, i);
463 
464       /* Output the special code to be executed before the sequence
465 	 is generated.  */
466       print_md_ptr_loc (XSTR (expand, 3));
467       printf ("%s\n", XSTR (expand, 3));
468 
469       /* Output code to copy the arguments back out of `operands'
470 	 (unless we aren't going to use them at all).  */
471       if (XVEC (expand, 1) != 0)
472 	{
473 	  for (i = 0; i < stats.num_operand_vars; i++)
474 	    {
475 	      printf ("    operand%d = operands[%d];\n", i, i);
476 	      printf ("    (void) operand%d;\n", i);
477 	    }
478 	}
479       printf ("  }\n");
480     }
481 
482   /* Output code to construct the rtl for the instruction bodies.
483      Use emit_insn to add them to the sequence being accumulated.
484      But don't do this if the user's code has set `no_more' nonzero.  */
485 
486   used = XCNEWVEC (char, stats.num_operand_vars);
487 
488   for (i = 0; i < XVECLEN (expand, 1); i++)
489     {
490       rtx next = XVECEXP (expand, 1, i);
491       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
492 	  || (GET_CODE (next) == PARALLEL
493 	      && ((GET_CODE (XVECEXP (next, 0, 0)) == SET
494 		   && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
495 		  || ANY_RETURN_P (XVECEXP (next, 0, 0))))
496 	  || ANY_RETURN_P (next))
497 	printf ("  emit_jump_insn (");
498       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
499 	       || GET_CODE (next) == CALL
500 	       || (GET_CODE (next) == PARALLEL
501 		   && GET_CODE (XVECEXP (next, 0, 0)) == SET
502 		   && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
503 	       || (GET_CODE (next) == PARALLEL
504 		   && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
505 	printf ("  emit_call_insn (");
506       else if (LABEL_P (next))
507 	printf ("  emit_label (");
508       else if (GET_CODE (next) == MATCH_OPERAND
509 	       || GET_CODE (next) == MATCH_DUP
510 	       || GET_CODE (next) == MATCH_OPERATOR
511 	       || GET_CODE (next) == MATCH_OP_DUP
512 	       || GET_CODE (next) == MATCH_PARALLEL
513 	       || GET_CODE (next) == MATCH_PAR_DUP
514 	       || GET_CODE (next) == PARALLEL)
515 	printf ("  emit (");
516       else
517 	printf ("  emit_insn (");
518       gen_exp (next, DEFINE_EXPAND, used);
519       printf (");\n");
520       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
521 	  && GET_CODE (SET_SRC (next)) == LABEL_REF)
522 	printf ("  emit_barrier ();");
523     }
524 
525   XDELETEVEC (used);
526 
527   /* Call `get_insns' to extract the list of all the
528      insns emitted within this gen_... function.  */
529 
530   printf ("  _val = get_insns ();\n");
531   printf ("  end_sequence ();\n");
532   printf ("  return _val;\n}\n\n");
533 }
534 
535 /* Like gen_expand, but generates insns resulting from splitting SPLIT.  */
536 
537 static void
538 gen_split (rtx split)
539 {
540   struct pattern_stats stats;
541   int i;
542   const char *const name =
543     ((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
544   const char *unused;
545   char *used;
546 
547   if (XVEC (split, 0) == 0)
548     fatal ("define_%s (definition %d) lacks a pattern", name,
549 	   insn_index_number);
550   else if (XVEC (split, 2) == 0)
551     fatal ("define_%s (definition %d) lacks a replacement pattern", name,
552 	   insn_index_number);
553 
554   /* Find out how many operands this function has.  */
555 
556   get_pattern_stats (&stats, XVEC (split, 2));
557   unused = (stats.num_operand_vars == 0 ? " ATTRIBUTE_UNUSED" : "");
558   used = XCNEWVEC (char, stats.num_operand_vars);
559 
560   /* Output the prototype, function name and argument declarations.  */
561   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
562     {
563       printf ("extern rtx gen_%s_%d (rtx, rtx *);\n",
564 	      name, insn_code_number);
565       printf ("rtx\ngen_%s_%d (rtx curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
566 	      name, insn_code_number, unused);
567     }
568   else
569     {
570       printf ("extern rtx gen_split_%d (rtx, rtx *);\n", insn_code_number);
571       printf ("rtx\ngen_split_%d (rtx curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
572 	      insn_code_number, unused);
573     }
574   printf ("{\n");
575 
576   /* Declare all local variables.  */
577   for (i = 0; i < stats.num_operand_vars; i++)
578     printf ("  rtx operand%d;\n", i);
579   printf ("  rtx _val = 0;\n");
580 
581   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
582     output_peephole2_scratches (split);
583 
584   printf ("  start_sequence ();\n");
585 
586   /* The fourth operand of DEFINE_SPLIT is some code to be executed
587      before the actual construction.  */
588 
589   if (XSTR (split, 3))
590     {
591       print_md_ptr_loc (XSTR (split, 3));
592       printf ("%s\n", XSTR (split, 3));
593     }
594 
595   /* Output code to copy the arguments back out of `operands'  */
596   for (i = 0; i < stats.num_operand_vars; i++)
597     {
598       printf ("  operand%d = operands[%d];\n", i, i);
599       printf ("  (void) operand%d;\n", i);
600     }
601 
602   /* Output code to construct the rtl for the instruction bodies.
603      Use emit_insn to add them to the sequence being accumulated.
604      But don't do this if the user's code has set `no_more' nonzero.  */
605 
606   for (i = 0; i < XVECLEN (split, 2); i++)
607     {
608       rtx next = XVECEXP (split, 2, i);
609       if ((GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC)
610 	  || (GET_CODE (next) == PARALLEL
611 	      && GET_CODE (XVECEXP (next, 0, 0)) == SET
612 	      && GET_CODE (SET_DEST (XVECEXP (next, 0, 0))) == PC)
613 	  || ANY_RETURN_P (next))
614 	printf ("  emit_jump_insn (");
615       else if ((GET_CODE (next) == SET && GET_CODE (SET_SRC (next)) == CALL)
616 	       || GET_CODE (next) == CALL
617 	       || (GET_CODE (next) == PARALLEL
618 		   && GET_CODE (XVECEXP (next, 0, 0)) == SET
619 		   && GET_CODE (SET_SRC (XVECEXP (next, 0, 0))) == CALL)
620 	       || (GET_CODE (next) == PARALLEL
621 		   && GET_CODE (XVECEXP (next, 0, 0)) == CALL))
622 	printf ("  emit_call_insn (");
623       else if (LABEL_P (next))
624 	printf ("  emit_label (");
625       else if (GET_CODE (next) == MATCH_OPERAND
626 	       || GET_CODE (next) == MATCH_OPERATOR
627 	       || GET_CODE (next) == MATCH_PARALLEL
628 	       || GET_CODE (next) == MATCH_OP_DUP
629 	       || GET_CODE (next) == MATCH_DUP
630 	       || GET_CODE (next) == PARALLEL)
631 	printf ("  emit (");
632       else
633 	printf ("  emit_insn (");
634       gen_exp (next, GET_CODE (split), used);
635       printf (");\n");
636       if (GET_CODE (next) == SET && GET_CODE (SET_DEST (next)) == PC
637 	  && GET_CODE (SET_SRC (next)) == LABEL_REF)
638 	printf ("  emit_barrier ();");
639     }
640 
641   /* Call `get_insns' to make a list of all the
642      insns emitted within this gen_... function.  */
643 
644   printf ("  _val = get_insns ();\n");
645   printf ("  end_sequence ();\n");
646   printf ("  return _val;\n}\n\n");
647 
648   free (used);
649 }
650 
651 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
652    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
653    the end of the vector.  */
654 
655 static void
656 output_add_clobbers (void)
657 {
658   struct clobber_pat *clobber;
659   struct clobber_ent *ent;
660   int i;
661 
662   printf ("\n\nvoid\nadd_clobbers (rtx pattern ATTRIBUTE_UNUSED, int insn_code_number)\n");
663   printf ("{\n");
664   printf ("  switch (insn_code_number)\n");
665   printf ("    {\n");
666 
667   for (clobber = clobber_list; clobber; clobber = clobber->next)
668     {
669       for (ent = clobber->insns; ent; ent = ent->next)
670 	printf ("    case %d:\n", ent->code_number);
671 
672       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
673 	{
674 	  printf ("      XVECEXP (pattern, 0, %d) = ", i);
675 	  gen_exp (XVECEXP (clobber->pattern, 1, i),
676 		   GET_CODE (clobber->pattern), NULL);
677 	  printf (";\n");
678 	}
679 
680       printf ("      break;\n\n");
681     }
682 
683   printf ("    default:\n");
684   printf ("      gcc_unreachable ();\n");
685   printf ("    }\n");
686   printf ("}\n");
687 }
688 
689 /* Write a function, `added_clobbers_hard_reg_p' that is given an insn_code
690    number that will have clobbers added (as indicated by `recog') and returns
691    1 if those include a clobber of a hard reg or 0 if all of them just clobber
692    SCRATCH.  */
693 
694 static void
695 output_added_clobbers_hard_reg_p (void)
696 {
697   struct clobber_pat *clobber;
698   struct clobber_ent *ent;
699   int clobber_p, used;
700 
701   printf ("\n\nint\nadded_clobbers_hard_reg_p (int insn_code_number)\n");
702   printf ("{\n");
703   printf ("  switch (insn_code_number)\n");
704   printf ("    {\n");
705 
706   for (clobber_p = 0; clobber_p <= 1; clobber_p++)
707     {
708       used = 0;
709       for (clobber = clobber_list; clobber; clobber = clobber->next)
710 	if (clobber->has_hard_reg == clobber_p)
711 	  for (ent = clobber->insns; ent; ent = ent->next)
712 	    {
713 	      printf ("    case %d:\n", ent->code_number);
714 	      used++;
715 	    }
716 
717       if (used)
718 	printf ("      return %d;\n\n", clobber_p);
719     }
720 
721   printf ("    default:\n");
722   printf ("      gcc_unreachable ();\n");
723   printf ("    }\n");
724   printf ("}\n");
725 }
726 
727 /* Generate code to invoke find_free_register () as needed for the
728    scratch registers used by the peephole2 pattern in SPLIT.  */
729 
730 static void
731 output_peephole2_scratches (rtx split)
732 {
733   int i;
734   int insn_nr = 0;
735   bool first = true;
736 
737   for (i = 0; i < XVECLEN (split, 0); i++)
738     {
739       rtx elt = XVECEXP (split, 0, i);
740       if (GET_CODE (elt) == MATCH_SCRATCH)
741 	{
742 	  int last_insn_nr = insn_nr;
743 	  int cur_insn_nr = insn_nr;
744 	  int j;
745 	  for (j = i + 1; j < XVECLEN (split, 0); j++)
746 	    if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
747 	      {
748 		if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
749 		  last_insn_nr = cur_insn_nr;
750 	      }
751 	    else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
752 	      cur_insn_nr++;
753 
754 	  if (first)
755 	    {
756 	      printf ("  HARD_REG_SET _regs_allocated;\n");
757 	      printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
758 	      first = false;
759 	    }
760 
761 	  printf ("  if ((operands[%d] = peep2_find_free_register (%d, %d, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
762     return NULL;\n",
763 		  XINT (elt, 0),
764 		  insn_nr, last_insn_nr,
765 		  XSTR (elt, 1),
766 		  GET_MODE_NAME (GET_MODE (elt)));
767 
768 	}
769       else if (GET_CODE (elt) != MATCH_DUP)
770 	insn_nr++;
771     }
772 }
773 
774 int
775 main (int argc, char **argv)
776 {
777   rtx desc;
778 
779   progname = "genemit";
780 
781   if (!init_rtx_reader_args (argc, argv))
782     return (FATAL_EXIT_CODE);
783 
784   /* Assign sequential codes to all entries in the machine description
785      in parallel with the tables in insn-output.c.  */
786 
787   insn_code_number = 0;
788   insn_index_number = 0;
789 
790   printf ("/* Generated automatically by the program `genemit'\n\
791 from the machine description file `md'.  */\n\n");
792 
793   printf ("#include \"config.h\"\n");
794   printf ("#include \"system.h\"\n");
795   printf ("#include \"coretypes.h\"\n");
796   printf ("#include \"tm.h\"\n");
797   printf ("#include \"rtl.h\"\n");
798   printf ("#include \"tm_p.h\"\n");
799   printf ("#include \"function.h\"\n");
800   printf ("#include \"expr.h\"\n");
801   printf ("#include \"optabs.h\"\n");
802   printf ("#include \"dfp.h\"\n");
803   printf ("#include \"flags.h\"\n");
804   printf ("#include \"output.h\"\n");
805   printf ("#include \"insn-config.h\"\n");
806   printf ("#include \"hard-reg-set.h\"\n");
807   printf ("#include \"recog.h\"\n");
808   printf ("#include \"resource.h\"\n");
809   printf ("#include \"reload.h\"\n");
810   printf ("#include \"diagnostic-core.h\"\n");
811   printf ("#include \"regs.h\"\n");
812   printf ("#include \"tm-constrs.h\"\n");
813   printf ("#include \"ggc.h\"\n");
814   printf ("#include \"basic-block.h\"\n");
815   printf ("#include \"integrate.h\"\n\n");
816   printf ("#define FAIL return (end_sequence (), _val)\n");
817   printf ("#define DONE return (_val = get_insns (), end_sequence (), _val)\n\n");
818 
819   /* Read the machine description.  */
820 
821   while (1)
822     {
823       int line_no;
824 
825       desc = read_md_rtx (&line_no, &insn_code_number);
826       if (desc == NULL)
827 	break;
828 
829       switch (GET_CODE (desc))
830 	{
831 	case DEFINE_INSN:
832 	  gen_insn (desc, line_no);
833 	  break;
834 
835 	case DEFINE_EXPAND:
836 	  printf ("/* %s:%d */\n", read_md_filename, line_no);
837 	  gen_expand (desc);
838 	  break;
839 
840 	case DEFINE_SPLIT:
841 	  printf ("/* %s:%d */\n", read_md_filename, line_no);
842 	  gen_split (desc);
843 	  break;
844 
845 	case DEFINE_PEEPHOLE2:
846 	  printf ("/* %s:%d */\n", read_md_filename, line_no);
847 	  gen_split (desc);
848 	  break;
849 
850 	default:
851 	  break;
852 	}
853       ++insn_index_number;
854     }
855 
856   /* Write out the routines to add CLOBBERs to a pattern and say whether they
857      clobber a hard reg.  */
858   output_add_clobbers ();
859   output_added_clobbers_hard_reg_p ();
860 
861   fflush (stdout);
862   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
863 }
864