xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/genemit.c (revision 8feb0f0b7eaff0608f8350bbfa3098827b4bb91b)
1 /* Generate code from machine description to emit insns as rtl.
2    Copyright (C) 1987-2020 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10 
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3.  If not see
18 <http://www.gnu.org/licenses/>.  */
19 
20 
21 #include "bconfig.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "tm.h"
25 #include "rtl.h"
26 #include "errors.h"
27 #include "read-md.h"
28 #include "gensupport.h"
29 
30 
31 /* Data structure for recording the patterns of insns that have CLOBBERs.
32    We use this to output a function that adds these CLOBBERs to a
33    previously-allocated PARALLEL expression.  */
34 
35 struct clobber_pat
36 {
37   struct clobber_ent *insns;
38   rtx pattern;
39   int first_clobber;
40   struct clobber_pat *next;
41   int has_hard_reg;
42 } *clobber_list;
43 
44 /* Records one insn that uses the clobber list.  */
45 
46 struct clobber_ent
47 {
48   int code_number;		/* Counts only insns.  */
49   struct clobber_ent *next;
50 };
51 
52 static void output_peephole2_scratches	(rtx);
53 
54 /* True for <X>_optab if that optab isn't allowed to fail.  */
55 static bool nofail_optabs[NUM_OPTABS];
56 
57 static void
print_code(RTX_CODE code)58 print_code (RTX_CODE code)
59 {
60   const char *p1;
61   for (p1 = GET_RTX_NAME (code); *p1; p1++)
62     putchar (TOUPPER (*p1));
63 }
64 
65 static void
gen_rtx_scratch(rtx x,enum rtx_code subroutine_type)66 gen_rtx_scratch (rtx x, enum rtx_code subroutine_type)
67 {
68   if (subroutine_type == DEFINE_PEEPHOLE2)
69     {
70       printf ("operand%d", XINT (x, 0));
71     }
72   else
73     {
74       printf ("gen_rtx_SCRATCH (%smode)", GET_MODE_NAME (GET_MODE (x)));
75     }
76 }
77 
78 /* Print a C expression to construct an RTX just like X,
79    substituting any operand references appearing within.  */
80 
81 static void
gen_exp(rtx x,enum rtx_code subroutine_type,char * used,md_rtx_info * info)82 gen_exp (rtx x, enum rtx_code subroutine_type, char *used, md_rtx_info *info)
83 {
84   RTX_CODE code;
85   int i;
86   int len;
87   const char *fmt;
88   const char *sep = "";
89 
90   if (x == 0)
91     {
92       printf ("NULL_RTX");
93       return;
94     }
95 
96   code = GET_CODE (x);
97 
98   switch (code)
99     {
100     case MATCH_OPERAND:
101     case MATCH_DUP:
102       if (used)
103 	{
104 	  if (used[XINT (x, 0)])
105 	    {
106 	      printf ("copy_rtx (operand%d)", XINT (x, 0));
107 	      return;
108 	    }
109 	  used[XINT (x, 0)] = 1;
110 	}
111       printf ("operand%d", XINT (x, 0));
112       return;
113 
114     case MATCH_OP_DUP:
115       printf ("gen_rtx_fmt_");
116       for (i = 0; i < XVECLEN (x, 1); i++)
117 	printf ("e");
118       printf (" (GET_CODE (operand%d), ", XINT (x, 0));
119       if (GET_MODE (x) == VOIDmode)
120 	printf ("GET_MODE (operand%d)", XINT (x, 0));
121       else
122 	printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
123       for (i = 0; i < XVECLEN (x, 1); i++)
124 	{
125 	  printf (",\n\t\t");
126 	  gen_exp (XVECEXP (x, 1, i), subroutine_type, used, info);
127 	}
128       printf (")");
129       return;
130 
131     case MATCH_OPERATOR:
132       printf ("gen_rtx_fmt_");
133       for (i = 0; i < XVECLEN (x, 2); i++)
134 	printf ("e");
135       printf (" (GET_CODE (operand%d)", XINT (x, 0));
136       printf (", %smode", GET_MODE_NAME (GET_MODE (x)));
137       for (i = 0; i < XVECLEN (x, 2); i++)
138 	{
139 	  printf (",\n\t\t");
140 	  gen_exp (XVECEXP (x, 2, i), subroutine_type, used, info);
141 	}
142       printf (")");
143       return;
144 
145     case MATCH_PARALLEL:
146     case MATCH_PAR_DUP:
147       printf ("operand%d", XINT (x, 0));
148       return;
149 
150     case MATCH_SCRATCH:
151       gen_rtx_scratch (x, subroutine_type);
152       return;
153 
154     case PC:
155       printf ("pc_rtx");
156       return;
157     case RETURN:
158       printf ("ret_rtx");
159       return;
160     case SIMPLE_RETURN:
161       printf ("simple_return_rtx");
162       return;
163     case CLOBBER:
164       if (REG_P (XEXP (x, 0)))
165 	{
166 	  printf ("gen_hard_reg_clobber (%smode, %i)",
167 		  GET_MODE_NAME (GET_MODE (XEXP (x, 0))),
168 		  REGNO (XEXP (x, 0)));
169 	  return;
170 	}
171       break;
172     case CC0:
173       printf ("cc0_rtx");
174       return;
175 
176     case CONST_INT:
177       if (INTVAL (x) == 0)
178 	printf ("const0_rtx");
179       else if (INTVAL (x) == 1)
180 	printf ("const1_rtx");
181       else if (INTVAL (x) == -1)
182 	printf ("constm1_rtx");
183       else if (-MAX_SAVED_CONST_INT <= INTVAL (x)
184 	       && INTVAL (x) <= MAX_SAVED_CONST_INT)
185 	printf ("const_int_rtx[MAX_SAVED_CONST_INT + (%d)]",
186 		(int) INTVAL (x));
187       else if (INTVAL (x) == STORE_FLAG_VALUE)
188 	printf ("const_true_rtx");
189       else
190 	{
191 	  printf ("GEN_INT (");
192 	  printf ("HOST_WIDE_INT_C (");
193 	  printf (HOST_WIDE_INT_PRINT_DEC, INTVAL (x));
194 	  printf (")");
195 	  printf (")");
196 	}
197       return;
198 
199     case CONST_DOUBLE:
200     case CONST_FIXED:
201     case CONST_WIDE_INT:
202       /* These shouldn't be written in MD files.  Instead, the appropriate
203 	 routines in varasm.c should be called.  */
204       gcc_unreachable ();
205 
206     default:
207       break;
208     }
209 
210   printf ("gen_rtx_");
211   print_code (code);
212   printf (" (");
213   if (!always_void_p (code))
214     {
215       printf ("%smode", GET_MODE_NAME (GET_MODE (x)));
216       sep = ",\n\t";
217     }
218 
219   fmt = GET_RTX_FORMAT (code);
220   len = GET_RTX_LENGTH (code);
221   for (i = 0; i < len; i++)
222     {
223       if (fmt[i] == '0')
224 	break;
225       fputs (sep, stdout);
226       switch (fmt[i])
227 	{
228 	case 'e': case 'u':
229 	  gen_exp (XEXP (x, i), subroutine_type, used, info);
230 	  break;
231 
232 	case 'i':
233 	  printf ("%u", XINT (x, i));
234 	  break;
235 
236 	case 'r':
237 	  printf ("%u", REGNO (x));
238 	  break;
239 
240 	case 'p':
241 	  /* We don't have a way of parsing polynomial offsets yet,
242 	     and hopefully never will.  */
243 	  printf ("%d", SUBREG_BYTE (x).to_constant ());
244 	  break;
245 
246 	case 's':
247 	  printf ("\"%s\"", XSTR (x, i));
248 	  break;
249 
250 	case 'E':
251 	  {
252 	    int j;
253 	    printf ("gen_rtvec (%d", XVECLEN (x, i));
254 	    for (j = 0; j < XVECLEN (x, i); j++)
255 	      {
256 		printf (",\n\t\t");
257 		gen_exp (XVECEXP (x, i, j), subroutine_type, used, info);
258 	      }
259 	    printf (")");
260 	    break;
261 	  }
262 
263 	default:
264 	  gcc_unreachable ();
265 	}
266       sep = ",\n\t";
267     }
268   printf (")");
269 }
270 
271 /* Output code to emit the instruction patterns in VEC, with each element
272    becoming a separate instruction.  USED is as for gen_exp.  */
273 
274 static void
gen_emit_seq(rtvec vec,char * used,md_rtx_info * info)275 gen_emit_seq (rtvec vec, char *used, md_rtx_info *info)
276 {
277   for (int i = 0, len = GET_NUM_ELEM (vec); i < len; ++i)
278     {
279       bool last_p = (i == len - 1);
280       rtx next = RTVEC_ELT (vec, i);
281       if (const char *name = get_emit_function (next))
282 	{
283 	  printf ("  %s (", name);
284 	  gen_exp (next, DEFINE_EXPAND, used, info);
285 	  printf (");\n");
286 	  if (!last_p && needs_barrier_p (next))
287 	    printf ("  emit_barrier ();");
288 	}
289       else
290 	{
291 	  printf ("  emit (");
292 	  gen_exp (next, DEFINE_EXPAND, used, info);
293 	  printf (", %s);\n", last_p ? "false" : "true");
294 	}
295     }
296 }
297 
298 /* Emit the given C code to the output file.  The code is allowed to
299    fail if CAN_FAIL_P.  NAME describes what we're generating,
300    for use in error messages.  */
301 
302 static void
emit_c_code(const char * code,bool can_fail_p,const char * name)303 emit_c_code (const char *code, bool can_fail_p, const char *name)
304 {
305   if (can_fail_p)
306     printf ("#define FAIL return (end_sequence (), _val)\n");
307   else
308     printf ("#define FAIL _Pragma (\"GCC error \\\"%s cannot FAIL\\\"\")"
309 	    " (void)0\n", name);
310   printf ("#define DONE return (_val = get_insns (), "
311 	  "end_sequence (), _val)\n");
312 
313   rtx_reader_ptr->print_md_ptr_loc (code);
314   printf ("%s\n", code);
315 
316   printf ("#undef DONE\n");
317   printf ("#undef FAIL\n");
318 }
319 
320 /* Generate the `gen_...' function for a DEFINE_INSN.  */
321 
322 static void
gen_insn(md_rtx_info * info)323 gen_insn (md_rtx_info *info)
324 {
325   struct pattern_stats stats;
326   int i;
327 
328   /* See if the pattern for this insn ends with a group of CLOBBERs of (hard)
329      registers or MATCH_SCRATCHes.  If so, store away the information for
330      later.  */
331 
332   rtx insn = info->def;
333   if (XVEC (insn, 1))
334     {
335       int has_hard_reg = 0;
336 
337       for (i = XVECLEN (insn, 1) - 1; i > 0; i--)
338 	{
339 	  if (GET_CODE (XVECEXP (insn, 1, i)) != CLOBBER)
340 	    break;
341 
342 	  if (REG_P (XEXP (XVECEXP (insn, 1, i), 0)))
343 	    has_hard_reg = 1;
344 	  else if (GET_CODE (XEXP (XVECEXP (insn, 1, i), 0)) != MATCH_SCRATCH)
345 	    break;
346 	}
347 
348       if (i != XVECLEN (insn, 1) - 1)
349 	{
350 	  struct clobber_pat *p;
351 	  struct clobber_ent *link = XNEW (struct clobber_ent);
352 	  int j;
353 
354 	  link->code_number = info->index;
355 
356 	  /* See if any previous CLOBBER_LIST entry is the same as this
357 	     one.  */
358 
359 	  for (p = clobber_list; p; p = p->next)
360 	    {
361 	      if (p->first_clobber != i + 1
362 		  || XVECLEN (p->pattern, 1) != XVECLEN (insn, 1))
363 		continue;
364 
365 	      for (j = i + 1; j < XVECLEN (insn, 1); j++)
366 		{
367 		  rtx old_rtx = XEXP (XVECEXP (p->pattern, 1, j), 0);
368 		  rtx new_rtx = XEXP (XVECEXP (insn, 1, j), 0);
369 
370 		  /* OLD and NEW_INSN are the same if both are to be a SCRATCH
371 		     of the same mode,
372 		     or if both are registers of the same mode and number.  */
373 		  if (! (GET_CODE (old_rtx) == GET_CODE (new_rtx)
374 			 && GET_MODE (old_rtx) == GET_MODE (new_rtx)
375 			 && ((GET_CODE (old_rtx) == MATCH_SCRATCH
376 			      && GET_CODE (new_rtx) == MATCH_SCRATCH)
377 			     || (REG_P (old_rtx) && REG_P (new_rtx)
378 				 && REGNO (old_rtx) == REGNO (new_rtx)))))
379 		    break;
380 		}
381 
382 	      if (j == XVECLEN (insn, 1))
383 		break;
384 	    }
385 
386 	  if (p == 0)
387 	    {
388 	      p = XNEW (struct clobber_pat);
389 
390 	      p->insns = 0;
391 	      p->pattern = insn;
392 	      p->first_clobber = i + 1;
393 	      p->next = clobber_list;
394 	      p->has_hard_reg = has_hard_reg;
395 	      clobber_list = p;
396 	    }
397 
398 	  link->next = p->insns;
399 	  p->insns = link;
400 	}
401     }
402 
403   /* Don't mention instructions whose names are the null string
404      or begin with '*'.  They are in the machine description just
405      to be recognized.  */
406   if (XSTR (insn, 0)[0] == 0 || XSTR (insn, 0)[0] == '*')
407     return;
408 
409   printf ("/* %s:%d */\n", info->loc.filename, info->loc.lineno);
410 
411   /* Find out how many operands this function has.  */
412   get_pattern_stats (&stats, XVEC (insn, 1));
413   if (stats.max_dup_opno > stats.max_opno)
414     fatal_at (info->loc, "match_dup operand number has no match_operand");
415 
416   /* Output the function name and argument declarations.  */
417   printf ("rtx\ngen_%s (", XSTR (insn, 0));
418   if (stats.num_generator_args)
419     for (i = 0; i < stats.num_generator_args; i++)
420       if (i)
421 	printf (",\n\trtx operand%d ATTRIBUTE_UNUSED", i);
422       else
423 	printf ("rtx operand%d ATTRIBUTE_UNUSED", i);
424   else
425     printf ("void");
426   printf (")\n");
427   printf ("{\n");
428 
429   /* Output code to construct and return the rtl for the instruction body.  */
430 
431   rtx pattern = add_implicit_parallel (XVEC (insn, 1));
432   /* ??? This is the traditional behavior, but seems suspect.  */
433   char *used = (XVECLEN (insn, 1) == 1
434 		? NULL
435 		: XCNEWVEC (char, stats.num_generator_args));
436   printf ("  return ");
437   gen_exp (pattern, DEFINE_INSN, used, info);
438   printf (";\n}\n\n");
439   XDELETEVEC (used);
440 }
441 
442 /* Generate the `gen_...' function for a DEFINE_EXPAND.  */
443 
444 static void
gen_expand(md_rtx_info * info)445 gen_expand (md_rtx_info *info)
446 {
447   struct pattern_stats stats;
448   int i;
449   char *used;
450 
451   rtx expand = info->def;
452   if (strlen (XSTR (expand, 0)) == 0)
453     fatal_at (info->loc, "define_expand lacks a name");
454   if (XVEC (expand, 1) == 0)
455     fatal_at (info->loc, "define_expand for %s lacks a pattern",
456 	      XSTR (expand, 0));
457 
458   /* Find out how many operands this function has.  */
459   get_pattern_stats (&stats, XVEC (expand, 1));
460   if (stats.min_scratch_opno != -1
461       && stats.min_scratch_opno <= MAX (stats.max_opno, stats.max_dup_opno))
462     fatal_at (info->loc, "define_expand for %s needs to have match_scratch "
463 			 "numbers above all other operands", XSTR (expand, 0));
464 
465   /* Output the function name and argument declarations.  */
466   printf ("rtx\ngen_%s (", XSTR (expand, 0));
467   if (stats.num_generator_args)
468     for (i = 0; i < stats.num_generator_args; i++)
469       if (i)
470 	printf (",\n\trtx operand%d", i);
471       else
472 	printf ("rtx operand%d", i);
473   else
474     printf ("void");
475   printf (")\n");
476   printf ("{\n");
477 
478   /* If we don't have any C code to write, only one insn is being written,
479      and no MATCH_DUPs are present, we can just return the desired insn
480      like we do for a DEFINE_INSN.  This saves memory.  */
481   if ((XSTR (expand, 3) == 0 || *XSTR (expand, 3) == '\0')
482       && stats.max_opno >= stats.max_dup_opno
483       && XVECLEN (expand, 1) == 1)
484     {
485       printf ("  return ");
486       gen_exp (XVECEXP (expand, 1, 0), DEFINE_EXPAND, NULL, info);
487       printf (";\n}\n\n");
488       return;
489     }
490 
491   /* For each operand referred to only with MATCH_DUPs,
492      make a local variable.  */
493   for (i = stats.num_generator_args; i <= stats.max_dup_opno; i++)
494     printf ("  rtx operand%d;\n", i);
495   printf ("  rtx_insn *_val = 0;\n");
496   printf ("  start_sequence ();\n");
497 
498   /* The fourth operand of DEFINE_EXPAND is some code to be executed
499      before the actual construction.
500      This code expects to refer to `operands'
501      just as the output-code in a DEFINE_INSN does,
502      but here `operands' is an automatic array.
503      So copy the operand values there before executing it.  */
504   if (XSTR (expand, 3) && *XSTR (expand, 3))
505     {
506       printf ("  {\n");
507       if (stats.num_operand_vars > 0)
508 	printf ("    rtx operands[%d];\n", stats.num_operand_vars);
509 
510       /* Output code to copy the arguments into `operands'.  */
511       for (i = 0; i < stats.num_generator_args; i++)
512 	printf ("    operands[%d] = operand%d;\n", i, i);
513 
514       /* Output the special code to be executed before the sequence
515 	 is generated.  */
516       optab_pattern p;
517       bool can_fail_p = true;
518       if (find_optab (&p, XSTR (expand, 0)))
519 	{
520 	  gcc_assert (p.op < NUM_OPTABS);
521 	  if (nofail_optabs[p.op])
522 	    can_fail_p = false;
523 	}
524       emit_c_code (XSTR (expand, 3), can_fail_p, XSTR (expand, 0));
525 
526       /* Output code to copy the arguments back out of `operands'
527 	 (unless we aren't going to use them at all).  */
528       if (XVEC (expand, 1) != 0)
529 	{
530 	  for (i = 0; i <= MAX (stats.max_opno, stats.max_dup_opno); i++)
531 	    {
532 	      printf ("    operand%d = operands[%d];\n", i, i);
533 	      printf ("    (void) operand%d;\n", i);
534 	    }
535 	}
536       printf ("  }\n");
537     }
538 
539   used = XCNEWVEC (char, stats.num_operand_vars);
540   gen_emit_seq (XVEC (expand, 1), used, info);
541   XDELETEVEC (used);
542 
543   /* Call `get_insns' to extract the list of all the
544      insns emitted within this gen_... function.  */
545 
546   printf ("  _val = get_insns ();\n");
547   printf ("  end_sequence ();\n");
548   printf ("  return _val;\n}\n\n");
549 }
550 
551 /* Like gen_expand, but generates insns resulting from splitting SPLIT.  */
552 
553 static void
gen_split(md_rtx_info * info)554 gen_split (md_rtx_info *info)
555 {
556   struct pattern_stats stats;
557   int i;
558   rtx split = info->def;
559   const char *const name =
560     ((GET_CODE (split) == DEFINE_PEEPHOLE2) ? "peephole2" : "split");
561   const char *unused;
562   char *used;
563 
564   if (XVEC (split, 0) == 0)
565     fatal_at (info->loc, "%s lacks a pattern",
566 	      GET_RTX_NAME (GET_CODE (split)));
567   else if (XVEC (split, 2) == 0)
568     fatal_at (info->loc, "%s lacks a replacement pattern",
569 	      GET_RTX_NAME (GET_CODE (split)));
570 
571   /* Find out how many operands this function has.  */
572 
573   get_pattern_stats (&stats, XVEC (split, 2));
574   unused = (stats.num_operand_vars == 0 ? " ATTRIBUTE_UNUSED" : "");
575   used = XCNEWVEC (char, stats.num_operand_vars);
576 
577   /* Output the prototype, function name and argument declarations.  */
578   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
579     {
580       printf ("extern rtx_insn *gen_%s_%d (rtx_insn *, rtx *);\n",
581 	      name, info->index);
582       printf ("rtx_insn *\ngen_%s_%d (rtx_insn *curr_insn ATTRIBUTE_UNUSED,"
583 	      " rtx *operands%s)\n",
584 	      name, info->index, unused);
585     }
586   else
587     {
588       printf ("extern rtx_insn *gen_split_%d (rtx_insn *, rtx *);\n",
589 	      info->index);
590       printf ("rtx_insn *\ngen_split_%d "
591 	      "(rtx_insn *curr_insn ATTRIBUTE_UNUSED, rtx *operands%s)\n",
592 	      info->index, unused);
593     }
594   printf ("{\n");
595 
596   /* Declare all local variables.  */
597   for (i = 0; i < stats.num_operand_vars; i++)
598     printf ("  rtx operand%d;\n", i);
599   printf ("  rtx_insn *_val = NULL;\n");
600 
601   if (GET_CODE (split) == DEFINE_PEEPHOLE2)
602     output_peephole2_scratches (split);
603 
604   const char *fn = info->loc.filename;
605   for (const char *p = fn; *p; p++)
606     if (*p == '/')
607       fn = p + 1;
608 
609   printf ("  if (dump_file)\n");
610   printf ("    fprintf (dump_file, \"Splitting with gen_%s_%d (%s:%d)\\n\");\n",
611 	  name, info->index, fn, info->loc.lineno);
612 
613   printf ("  start_sequence ();\n");
614 
615   /* The fourth operand of DEFINE_SPLIT is some code to be executed
616      before the actual construction.  */
617 
618   if (XSTR (split, 3))
619     emit_c_code (XSTR (split, 3), true, name);
620 
621   /* Output code to copy the arguments back out of `operands'  */
622   for (i = 0; i < stats.num_operand_vars; i++)
623     {
624       printf ("  operand%d = operands[%d];\n", i, i);
625       printf ("  (void) operand%d;\n", i);
626     }
627 
628   gen_emit_seq (XVEC (split, 2), used, info);
629 
630   /* Call `get_insns' to make a list of all the
631      insns emitted within this gen_... function.  */
632 
633   printf ("  _val = get_insns ();\n");
634   printf ("  end_sequence ();\n");
635   printf ("  return _val;\n}\n\n");
636 
637   free (used);
638 }
639 
640 /* Write a function, `add_clobbers', that is given a PARALLEL of sufficient
641    size for the insn and an INSN_CODE, and inserts the required CLOBBERs at
642    the end of the vector.  */
643 
644 static void
output_add_clobbers(md_rtx_info * info)645 output_add_clobbers (md_rtx_info *info)
646 {
647   struct clobber_pat *clobber;
648   struct clobber_ent *ent;
649   int i;
650 
651   printf ("\n\nvoid\nadd_clobbers (rtx pattern ATTRIBUTE_UNUSED, int insn_code_number)\n");
652   printf ("{\n");
653   printf ("  switch (insn_code_number)\n");
654   printf ("    {\n");
655 
656   for (clobber = clobber_list; clobber; clobber = clobber->next)
657     {
658       for (ent = clobber->insns; ent; ent = ent->next)
659 	printf ("    case %d:\n", ent->code_number);
660 
661       for (i = clobber->first_clobber; i < XVECLEN (clobber->pattern, 1); i++)
662 	{
663 	  printf ("      XVECEXP (pattern, 0, %d) = ", i);
664 	  gen_exp (XVECEXP (clobber->pattern, 1, i),
665 		   GET_CODE (clobber->pattern), NULL, info);
666 	  printf (";\n");
667 	}
668 
669       printf ("      break;\n\n");
670     }
671 
672   printf ("    default:\n");
673   printf ("      gcc_unreachable ();\n");
674   printf ("    }\n");
675   printf ("}\n");
676 }
677 
678 /* Write a function, `added_clobbers_hard_reg_p' that is given an insn_code
679    number that will have clobbers added (as indicated by `recog') and returns
680    1 if those include a clobber of a hard reg or 0 if all of them just clobber
681    SCRATCH.  */
682 
683 static void
output_added_clobbers_hard_reg_p(void)684 output_added_clobbers_hard_reg_p (void)
685 {
686   struct clobber_pat *clobber;
687   struct clobber_ent *ent;
688   int clobber_p, used;
689 
690   printf ("\n\nint\nadded_clobbers_hard_reg_p (int insn_code_number)\n");
691   printf ("{\n");
692   printf ("  switch (insn_code_number)\n");
693   printf ("    {\n");
694 
695   for (clobber_p = 0; clobber_p <= 1; clobber_p++)
696     {
697       used = 0;
698       for (clobber = clobber_list; clobber; clobber = clobber->next)
699 	if (clobber->has_hard_reg == clobber_p)
700 	  for (ent = clobber->insns; ent; ent = ent->next)
701 	    {
702 	      printf ("    case %d:\n", ent->code_number);
703 	      used++;
704 	    }
705 
706       if (used)
707 	printf ("      return %d;\n\n", clobber_p);
708     }
709 
710   printf ("    default:\n");
711   printf ("      gcc_unreachable ();\n");
712   printf ("    }\n");
713   printf ("}\n");
714 }
715 
716 /* Generate code to invoke find_free_register () as needed for the
717    scratch registers used by the peephole2 pattern in SPLIT.  */
718 
719 static void
output_peephole2_scratches(rtx split)720 output_peephole2_scratches (rtx split)
721 {
722   int i;
723   int insn_nr = 0;
724   bool first = true;
725 
726   for (i = 0; i < XVECLEN (split, 0); i++)
727     {
728       rtx elt = XVECEXP (split, 0, i);
729       if (GET_CODE (elt) == MATCH_SCRATCH)
730 	{
731 	  int last_insn_nr = insn_nr;
732 	  int cur_insn_nr = insn_nr;
733 	  int j;
734 	  for (j = i + 1; j < XVECLEN (split, 0); j++)
735 	    if (GET_CODE (XVECEXP (split, 0, j)) == MATCH_DUP)
736 	      {
737 		if (XINT (XVECEXP (split, 0, j), 0) == XINT (elt, 0))
738 		  last_insn_nr = cur_insn_nr;
739 	      }
740 	    else if (GET_CODE (XVECEXP (split, 0, j)) != MATCH_SCRATCH)
741 	      cur_insn_nr++;
742 
743 	  if (first)
744 	    {
745 	      printf ("  HARD_REG_SET _regs_allocated;\n");
746 	      printf ("  CLEAR_HARD_REG_SET (_regs_allocated);\n");
747 	      first = false;
748 	    }
749 
750 	  printf ("  if ((operands[%d] = peep2_find_free_register (%d, %d, \"%s\", %smode, &_regs_allocated)) == NULL_RTX)\n\
751     return NULL;\n",
752 		  XINT (elt, 0),
753 		  insn_nr, last_insn_nr,
754 		  XSTR (elt, 1),
755 		  GET_MODE_NAME (GET_MODE (elt)));
756 
757 	}
758       else if (GET_CODE (elt) != MATCH_DUP)
759 	insn_nr++;
760     }
761 }
762 
763 /* Print "arg<N>" parameter declarations for each argument N of ONAME.  */
764 
765 static void
print_overload_arguments(overloaded_name * oname)766 print_overload_arguments (overloaded_name *oname)
767 {
768   for (unsigned int i = 0; i < oname->arg_types.length (); ++i)
769     printf ("%s%s arg%d", i == 0 ? "" : ", ", oname->arg_types[i], i);
770 }
771 
772 /* Print code to test whether INSTANCE should be chosen, given that
773    argument N of the overload is available as "arg<N>".  */
774 
775 static void
print_overload_test(overloaded_instance * instance)776 print_overload_test (overloaded_instance *instance)
777 {
778   for (unsigned int i = 0; i < instance->arg_values.length (); ++i)
779     printf ("%sarg%d == %s", i == 0 ? "  if (" : "\n      && ",
780 	    i, instance->arg_values[i]);
781   printf (")\n");
782 }
783 
784 /* Emit a maybe_code_for_* function for ONAME.  */
785 
786 static void
handle_overloaded_code_for(overloaded_name * oname)787 handle_overloaded_code_for (overloaded_name *oname)
788 {
789   /* Print the function prototype.  */
790   printf ("\ninsn_code\nmaybe_code_for_%s (", oname->name);
791   print_overload_arguments (oname);
792   printf (")\n{\n");
793 
794   /* Use a sequence of "if" statements for each instance.  */
795   for (overloaded_instance *instance = oname->first_instance;
796        instance; instance = instance->next)
797     {
798       print_overload_test (instance);
799       printf ("    return CODE_FOR_%s;\n", instance->name);
800     }
801 
802   /* Return null if no match was found.  */
803   printf ("  return CODE_FOR_nothing;\n}\n");
804 }
805 
806 /* Emit a maybe_gen_* function for ONAME.  */
807 
808 static void
handle_overloaded_gen(overloaded_name * oname)809 handle_overloaded_gen (overloaded_name *oname)
810 {
811   unsigned HOST_WIDE_INT seen = 0;
812   /* All patterns must have the same number of operands.  */
813   for (overloaded_instance *instance = oname->first_instance->next;
814        instance; instance = instance->next)
815     {
816       pattern_stats stats;
817       get_pattern_stats (&stats, XVEC (instance->insn, 1));
818       unsigned HOST_WIDE_INT mask
819 	= HOST_WIDE_INT_1U << stats.num_generator_args;
820       if (seen & mask)
821 	continue;
822 
823       seen |= mask;
824 
825       /* Print the function prototype.  */
826       printf ("\nrtx\nmaybe_gen_%s (", oname->name);
827       print_overload_arguments (oname);
828       for (int i = 0; i < stats.num_generator_args; ++i)
829 	printf (", rtx x%d", i);
830       printf (")\n{\n");
831 
832       /* Use maybe_code_for_*, instead of duplicating the selection
833 	 logic here.  */
834       printf ("  insn_code code = maybe_code_for_%s (", oname->name);
835       for (unsigned int i = 0; i < oname->arg_types.length (); ++i)
836 	printf ("%sarg%d", i == 0 ? "" : ", ", i);
837       printf (");\n"
838 	      "  if (code != CODE_FOR_nothing)\n"
839 	      "    {\n"
840 	      "      gcc_assert (insn_data[code].n_generator_args == %d);\n"
841 	      "      return GEN_FCN (code) (", stats.num_generator_args);
842       for (int i = 0; i < stats.num_generator_args; ++i)
843 	printf ("%sx%d", i == 0 ? "" : ", ", i);
844       printf (");\n"
845 	      "    }\n"
846 	      "  else\n"
847 	      "    return NULL_RTX;\n"
848 	      "}\n");
849     }
850 }
851 
852 int
main(int argc,const char ** argv)853 main (int argc, const char **argv)
854 {
855   progname = "genemit";
856 
857   if (!init_rtx_reader_args (argc, argv))
858     return (FATAL_EXIT_CODE);
859 
860 #define DEF_INTERNAL_OPTAB_FN(NAME, FLAGS, OPTAB, TYPE) \
861   nofail_optabs[OPTAB##_optab] = true;
862 #include "internal-fn.def"
863 
864   /* Assign sequential codes to all entries in the machine description
865      in parallel with the tables in insn-output.c.  */
866 
867   printf ("/* Generated automatically by the program `genemit'\n\
868 from the machine description file `md'.  */\n\n");
869 
870   printf ("#define IN_TARGET_CODE 1\n");
871   printf ("#include \"config.h\"\n");
872   printf ("#include \"system.h\"\n");
873   printf ("#include \"coretypes.h\"\n");
874   printf ("#include \"backend.h\"\n");
875   printf ("#include \"predict.h\"\n");
876   printf ("#include \"tree.h\"\n");
877   printf ("#include \"rtl.h\"\n");
878   printf ("#include \"alias.h\"\n");
879   printf ("#include \"varasm.h\"\n");
880   printf ("#include \"stor-layout.h\"\n");
881   printf ("#include \"calls.h\"\n");
882   printf ("#include \"memmodel.h\"\n");
883   printf ("#include \"tm_p.h\"\n");
884   printf ("#include \"flags.h\"\n");
885   printf ("#include \"insn-config.h\"\n");
886   printf ("#include \"expmed.h\"\n");
887   printf ("#include \"dojump.h\"\n");
888   printf ("#include \"explow.h\"\n");
889   printf ("#include \"emit-rtl.h\"\n");
890   printf ("#include \"stmt.h\"\n");
891   printf ("#include \"expr.h\"\n");
892   printf ("#include \"insn-codes.h\"\n");
893   printf ("#include \"optabs.h\"\n");
894   printf ("#include \"dfp.h\"\n");
895   printf ("#include \"output.h\"\n");
896   printf ("#include \"recog.h\"\n");
897   printf ("#include \"df.h\"\n");
898   printf ("#include \"resource.h\"\n");
899   printf ("#include \"reload.h\"\n");
900   printf ("#include \"diagnostic-core.h\"\n");
901   printf ("#include \"regs.h\"\n");
902   printf ("#include \"tm-constrs.h\"\n");
903   printf ("#include \"ggc.h\"\n");
904   printf ("#include \"target.h\"\n\n");
905 
906   /* Read the machine description.  */
907 
908   md_rtx_info info;
909   while (read_md_rtx (&info))
910     switch (GET_CODE (info.def))
911       {
912       case DEFINE_INSN:
913 	gen_insn (&info);
914 	break;
915 
916       case DEFINE_EXPAND:
917 	printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
918 	gen_expand (&info);
919 	break;
920 
921       case DEFINE_SPLIT:
922 	printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
923 	gen_split (&info);
924 	break;
925 
926       case DEFINE_PEEPHOLE2:
927 	printf ("/* %s:%d */\n", info.loc.filename, info.loc.lineno);
928 	gen_split (&info);
929 	break;
930 
931       default:
932 	break;
933       }
934 
935   /* Write out the routines to add CLOBBERs to a pattern and say whether they
936      clobber a hard reg.  */
937   output_add_clobbers (&info);
938   output_added_clobbers_hard_reg_p ();
939 
940   for (overloaded_name *oname = rtx_reader_ptr->get_overloads ();
941        oname; oname = oname->next)
942     {
943       handle_overloaded_code_for (oname);
944       handle_overloaded_gen (oname);
945     }
946 
947   fflush (stdout);
948   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
949 }
950