xref: /dragonfly/contrib/gcc-8.0/gcc/genextract.c (revision ec21d9fb)
1 /* Generate code from machine description to extract operands from insn as rtl.
2    Copyright (C) 1987-2018 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 /* This structure contains all the information needed to describe one
31    set of extractions methods.  Each method may be used by more than
32    one pattern if the operands are in the same place.
33 
34    The string for each operand describes that path to the operand and
35    contains `0' through `9' when going into an expression and `a' through
36    `z' then 'A' through to 'Z' when going into a vector.  We assume here that
37    only the first operand of an rtl expression is a vector.  genrecog.c makes
38    the same assumption (and uses the same representation) and it is currently
39    true.  */
40 
41 typedef char *locstr;
42 
43 struct extraction
44 {
45   unsigned int op_count;
46   unsigned int dup_count;
47   locstr *oplocs;
48   locstr *duplocs;
49   int *dupnums;
50   struct code_ptr *insns;
51   struct extraction *next;
52 };
53 
54 /* Holds a single insn code that uses an extraction method.  */
55 struct code_ptr
56 {
57   int insn_code;
58   struct code_ptr *next;
59 };
60 
61 /* All extractions needed for this machine description.  */
62 static struct extraction *extractions;
63 
64 /* All insn codes for old-style peepholes.  */
65 static struct code_ptr *peepholes;
66 
67 /* This structure is used by gen_insn and walk_rtx to accumulate the
68    data that will be used to produce an extractions structure.  */
69 
70 
71 struct accum_extract
72 {
73   accum_extract () : oplocs (10), duplocs (10), dupnums (10), pathstr (20) {}
74 
75   auto_vec<locstr> oplocs;
76   auto_vec<locstr> duplocs;
77   auto_vec<int> dupnums;
78   auto_vec<char> pathstr;
79 };
80 
81 /* Forward declarations.  */
82 static void walk_rtx (md_rtx_info *, rtx, struct accum_extract *);
83 
84 #define UPPER_OFFSET ('A' - ('z' - 'a' + 1))
85 
86 /* Convert integer OPERAND into a character - either into [a-zA-Z] for vector
87    operands or [0-9] for integer operands - and push onto the end of the path
88    in ACC.  */
89 static void
90 push_pathstr_operand (int operand, bool is_vector,
91 		     struct accum_extract *acc)
92 {
93   if (is_vector && 'a' + operand > 'z')
94     acc->pathstr.safe_push (operand + UPPER_OFFSET);
95   else if (is_vector)
96     acc->pathstr.safe_push (operand + 'a');
97   else
98     acc->pathstr.safe_push (operand + '0');
99 }
100 
101 static void
102 gen_insn (md_rtx_info *info)
103 {
104   int i;
105   unsigned int op_count, dup_count, j;
106   struct extraction *p;
107   struct code_ptr *link;
108   struct accum_extract acc;
109 
110   /* Walk the insn's pattern, remembering at all times the path
111      down to the walking point.  */
112 
113   rtx insn = info->def;
114   if (XVECLEN (insn, 1) == 1)
115     walk_rtx (info, XVECEXP (insn, 1, 0), &acc);
116   else
117     for (i = XVECLEN (insn, 1) - 1; i >= 0; i--)
118       {
119 	push_pathstr_operand (i, true, &acc);
120 	walk_rtx (info, XVECEXP (insn, 1, i), &acc);
121 	acc.pathstr.pop ();
122       }
123 
124   link = XNEW (struct code_ptr);
125   link->insn_code = info->index;
126 
127   /* See if we find something that already had this extraction method.  */
128 
129   op_count = acc.oplocs.length ();
130   dup_count = acc.duplocs.length ();
131   gcc_assert (dup_count == acc.dupnums.length ());
132 
133   for (p = extractions; p; p = p->next)
134     {
135       if (p->op_count != op_count || p->dup_count != dup_count)
136 	continue;
137 
138       for (j = 0; j < op_count; j++)
139 	{
140 	  char *a = p->oplocs[j];
141 	  char *b = acc.oplocs[j];
142 	  if (a != b && (!a || !b || strcmp (a, b)))
143 	    break;
144 	}
145 
146       if (j != op_count)
147 	continue;
148 
149       for (j = 0; j < dup_count; j++)
150 	if (p->dupnums[j] != acc.dupnums[j]
151 	    || strcmp (p->duplocs[j], acc.duplocs[j]))
152 	  break;
153 
154       if (j != dup_count)
155 	continue;
156 
157       /* This extraction is the same as ours.  Just link us in.  */
158       link->next = p->insns;
159       p->insns = link;
160       return;
161     }
162 
163   /* Otherwise, make a new extraction method.  We stash the arrays
164      after the extraction structure in memory.  */
165 
166   p = XNEWVAR (struct extraction, sizeof (struct extraction)
167 	       + op_count*sizeof (char *)
168 	       + dup_count*sizeof (char *)
169 	       + dup_count*sizeof (int));
170   p->op_count = op_count;
171   p->dup_count = dup_count;
172   p->next = extractions;
173   extractions = p;
174   p->insns = link;
175   link->next = 0;
176 
177   p->oplocs = (char **)((char *)p + sizeof (struct extraction));
178   p->duplocs = p->oplocs + op_count;
179   p->dupnums = (int *)(p->duplocs + dup_count);
180 
181   memcpy (p->oplocs, acc.oplocs.address (), op_count * sizeof (locstr));
182   memcpy (p->duplocs, acc.duplocs.address (), dup_count * sizeof (locstr));
183   memcpy (p->dupnums, acc.dupnums.address (), dup_count * sizeof (int));
184 }
185 
186 /* Helper subroutine of walk_rtx: given a vec<locstr>, an index, and a
187    string, insert the string at the index, which should either already
188    exist and be NULL, or not yet exist within the vector.  In the latter
189    case the vector is enlarged as appropriate.  INFO describes the
190    containing define_* expression.  */
191 static void
192 VEC_safe_set_locstr (md_rtx_info *info, vec<locstr> *vp,
193 		     unsigned int ix, char *str)
194 {
195   if (ix < (*vp).length ())
196     {
197       if ((*vp)[ix])
198 	{
199 	  message_at (info->loc, "repeated operand number %d", ix);
200 	  have_error = 1;
201 	}
202       else
203         (*vp)[ix] = str;
204     }
205   else
206     {
207       while (ix > (*vp).length ())
208 	vp->safe_push (NULL);
209       vp->safe_push (str);
210     }
211 }
212 
213 /* Another helper subroutine of walk_rtx: given a vec<char>, convert it
214    to a NUL-terminated string in malloc memory.  */
215 static char *
216 VEC_char_to_string (vec<char> v)
217 {
218   size_t n = v.length ();
219   char *s = XNEWVEC (char, n + 1);
220   memcpy (s, v.address (), n);
221   s[n] = '\0';
222   return s;
223 }
224 
225 static void
226 walk_rtx (md_rtx_info *info, rtx x, struct accum_extract *acc)
227 {
228   RTX_CODE code;
229   int i, len;
230   const char *fmt;
231 
232   if (x == 0)
233     return;
234 
235   code = GET_CODE (x);
236   switch (code)
237     {
238     case PC:
239     case CC0:
240     case CONST_INT:
241     case SYMBOL_REF:
242       return;
243 
244     case MATCH_OPERAND:
245     case MATCH_SCRATCH:
246       VEC_safe_set_locstr (info, &acc->oplocs, XINT (x, 0),
247 			   VEC_char_to_string (acc->pathstr));
248       break;
249 
250     case MATCH_OPERATOR:
251     case MATCH_PARALLEL:
252       VEC_safe_set_locstr (info, &acc->oplocs, XINT (x, 0),
253 			   VEC_char_to_string (acc->pathstr));
254 
255       for (i = XVECLEN (x, 2) - 1; i >= 0; i--)
256 	{
257 	  push_pathstr_operand (i, code != MATCH_OPERATOR, acc);
258 	  walk_rtx (info, XVECEXP (x, 2, i), acc);
259 	  acc->pathstr.pop ();
260         }
261       return;
262 
263     case MATCH_DUP:
264     case MATCH_PAR_DUP:
265     case MATCH_OP_DUP:
266       acc->duplocs.safe_push (VEC_char_to_string (acc->pathstr));
267       acc->dupnums.safe_push (XINT (x, 0));
268 
269       if (code == MATCH_DUP)
270 	break;
271 
272       for (i = XVECLEN (x, 1) - 1; i >= 0; i--)
273         {
274 	  push_pathstr_operand (i, code != MATCH_OP_DUP, acc);
275 	  walk_rtx (info, XVECEXP (x, 1, i), acc);
276 	  acc->pathstr.pop ();
277         }
278       return;
279 
280     default:
281       break;
282     }
283 
284   fmt = GET_RTX_FORMAT (code);
285   len = GET_RTX_LENGTH (code);
286   for (i = 0; i < len; i++)
287     {
288       if (fmt[i] == 'e' || fmt[i] == 'u')
289 	{
290 	  push_pathstr_operand (i, false, acc);
291 	  walk_rtx (info, XEXP (x, i), acc);
292 	  acc->pathstr.pop ();
293 	}
294       else if (fmt[i] == 'E')
295 	{
296 	  int j;
297 	  for (j = XVECLEN (x, i) - 1; j >= 0; j--)
298 	    {
299 	      push_pathstr_operand (j, true, acc);
300 	      walk_rtx (info, XVECEXP (x, i, j), acc);
301 	      acc->pathstr.pop ();
302 	    }
303 	}
304     }
305 }
306 
307 /* Given a PATH, representing a path down the instruction's
308    pattern from the root to a certain point, output code to
309    evaluate to the rtx at that point.  */
310 
311 static void
312 print_path (const char *path)
313 {
314   int len = strlen (path);
315   int i;
316 
317   if (len == 0)
318     {
319       /* Don't emit "pat", since we may try to take the address of it,
320 	 which isn't what is intended.  */
321       fputs ("PATTERN (insn)", stdout);
322       return;
323     }
324 
325   /* We first write out the operations (XEXP or XVECEXP) in reverse
326      order, then write "pat", then the indices in forward order.  */
327 
328   for (i = len - 1; i >= 0 ; i--)
329     {
330       if (ISLOWER (path[i]) || ISUPPER (path[i]))
331 	fputs ("XVECEXP (", stdout);
332       else if (ISDIGIT (path[i]))
333 	fputs ("XEXP (", stdout);
334       else
335 	gcc_unreachable ();
336     }
337 
338   fputs ("pat", stdout);
339 
340   for (i = 0; i < len; i++)
341     {
342       if (ISUPPER (path[i]))
343 	printf (", 0, %d)", path[i] - UPPER_OFFSET);
344       else if (ISLOWER (path[i]))
345 	printf (", 0, %d)", path[i] - 'a');
346       else if (ISDIGIT (path[i]))
347 	printf (", %d)", path[i] - '0');
348       else
349 	gcc_unreachable ();
350     }
351 }
352 
353 static void
354 print_header (void)
355 {
356   /* N.B. Code below avoids putting squiggle braces in column 1 inside
357      a string, because this confuses some editors' syntax highlighting
358      engines.  */
359 
360   puts ("\
361 /* Generated automatically by the program `genextract'\n\
362    from the machine description file `md'.  */\n\
363 \n\
364 #define IN_TARGET_CODE 1\n\
365 #include \"config.h\"\n\
366 #include \"system.h\"\n\
367 #include \"coretypes.h\"\n\
368 #include \"tm.h\"\n\
369 #include \"rtl.h\"\n\
370 #include \"insn-config.h\"\n\
371 #include \"recog.h\"\n\
372 #include \"diagnostic-core.h\"\n\
373 \n\
374 /* This variable is used as the \"location\" of any missing operand\n\
375    whose numbers are skipped by a given pattern.  */\n\
376 static rtx junk ATTRIBUTE_UNUSED;\n");
377 
378   puts ("\
379 void\n\
380 insn_extract (rtx_insn *insn)\n{\n\
381   rtx *ro = recog_data.operand;\n\
382   rtx **ro_loc = recog_data.operand_loc;\n\
383   rtx pat = PATTERN (insn);\n\
384   int i ATTRIBUTE_UNUSED; /* only for peepholes */\n\
385 \n\
386   if (flag_checking)\n\
387     {\n\
388       memset (ro, 0xab, sizeof (*ro) * MAX_RECOG_OPERANDS);\n\
389       memset (ro_loc, 0xab, sizeof (*ro_loc) * MAX_RECOG_OPERANDS);\n\
390     }\n");
391 
392   puts ("\
393   switch (INSN_CODE (insn))\n\
394     {\n\
395     default:\n\
396       /* Control reaches here if insn_extract has been called with an\n\
397          unrecognizable insn (code -1), or an insn whose INSN_CODE\n\
398          corresponds to a DEFINE_EXPAND in the machine description;\n\
399          either way, a bug.  */\n\
400       if (INSN_CODE (insn) < 0)\n\
401         fatal_insn (\"unrecognizable insn:\", insn);\n\
402       else\n\
403         fatal_insn (\"insn with invalid code number:\", insn);\n");
404 }
405 
406 int
407 main (int argc, const char **argv)
408 {
409   unsigned int i;
410   struct extraction *p;
411   struct code_ptr *link;
412   const char *name;
413 
414   progname = "genextract";
415 
416   if (!init_rtx_reader_args (argc, argv))
417     return (FATAL_EXIT_CODE);
418 
419   /* Read the machine description.  */
420 
421   md_rtx_info info;
422   while (read_md_rtx (&info))
423     switch (GET_CODE (info.def))
424       {
425       case DEFINE_INSN:
426 	gen_insn (&info);
427 	break;
428 
429       case DEFINE_PEEPHOLE:
430 	{
431 	  struct code_ptr *link = XNEW (struct code_ptr);
432 
433 	  link->insn_code = info.index;
434 	  link->next = peepholes;
435 	  peepholes = link;
436 	}
437 	break;
438 
439       default:
440 	break;
441     }
442 
443   if (have_error)
444     return FATAL_EXIT_CODE;
445 
446   print_header ();
447 
448   /* Write out code to handle peepholes and the insn_codes that it should
449      be called for.  */
450   if (peepholes)
451     {
452       for (link = peepholes; link; link = link->next)
453 	printf ("    case %d:\n", link->insn_code);
454 
455       /* The vector in the insn says how many operands it has.
456 	 And all it contains are operands.  In fact, the vector was
457 	 created just for the sake of this function.  We need to set the
458 	 location of the operands for sake of simplifications after
459 	 extraction, like eliminating subregs.  */
460       puts ("      for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)\n"
461 	    "          ro[i] = *(ro_loc[i] = &XVECEXP (pat, 0, i));\n"
462 	    "      break;\n");
463     }
464 
465   /* Write out all the ways to extract insn operands.  */
466   for (p = extractions; p; p = p->next)
467     {
468       for (link = p->insns; link; link = link->next)
469 	{
470 	  i = link->insn_code;
471 	  name = get_insn_name (i);
472 	  if (name)
473 	    printf ("    case %d:  /* %s */\n", i, name);
474 	  else
475 	    printf ("    case %d:\n", i);
476 	}
477 
478       for (i = 0; i < p->op_count; i++)
479 	{
480 	  if (p->oplocs[i] == 0)
481 	    {
482 	      printf ("      ro[%d] = const0_rtx;\n", i);
483 	      printf ("      ro_loc[%d] = &junk;\n", i);
484 	    }
485 	  else
486 	    {
487 	      printf ("      ro[%d] = *(ro_loc[%d] = &", i, i);
488 	      print_path (p->oplocs[i]);
489 	      puts (");");
490 	    }
491 	}
492 
493       for (i = 0; i < p->dup_count; i++)
494 	{
495 	  printf ("      recog_data.dup_loc[%d] = &", i);
496 	  print_path (p->duplocs[i]);
497 	  puts (";");
498 	  printf ("      recog_data.dup_num[%d] = %d;\n", i, p->dupnums[i]);
499 	}
500 
501       puts ("      break;\n");
502     }
503 
504   puts ("    }\n}");
505   fflush (stdout);
506   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
507 }
508