gcc/genpeep.c

   1 /* Generate code from machine description to perform peephole optimizations.
   2    Copyright (C) 1987-2013 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 "gensupport.h"
  28
  29
  30 /* While tree-walking an instruction pattern, we keep a chain
  31    of these `struct link's to record how to get down to the
  32    current position.  In each one, POS is the operand number,
  33    and if the operand is a vector VEC is the element number.
  34    VEC is -1 if the operand is not a vector.  */
  35
  36 struct link
  37 {
  38   struct link *next;
  39   int pos;
  40   int vecelt;
  41 };
  42
  43 static int max_opno;
  44
  45 /* Number of operands used in current peephole definition.  */
  46
  47 static int n_operands;
  48
  49 static void gen_peephole (rtx, int);
  50 static void match_rtx (rtx, struct link *, int);
  51 static void print_path (struct link *);
  52 static void print_code (RTX_CODE);
  53 \f
  54 static void
  55 gen_peephole (rtx peep, int insn_code_number)
  56 {
  57   int ninsns = XVECLEN (peep, 0);
  58   int i;
  59
  60   n_operands = 0;
  61
  62   printf ("  insn = ins1;\n");
  63
  64   for (i = 0; i < ninsns; i++)
  65     {
  66       if (i > 0)
  67         {
  68           printf ("  do { insn = NEXT_INSN (insn);\n");
  69           printf ("       if (insn == 0) goto L%d; }\n",
  70                   insn_code_number);
  71           printf ("  while (NOTE_P (insn)\n");
  72           printf ("\t || (NONJUMP_INSN_P (insn)\n");
  73           printf ("\t     && (GET_CODE (PATTERN (insn)) == USE\n");
  74           printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n");
  75
  76           printf ("  if (LABEL_P (insn)\n\
  77       || BARRIER_P (insn))\n    goto L%d;\n",
  78                   insn_code_number);
  79         }
  80
  81       printf ("  pat = PATTERN (insn);\n");
  82
  83       /* Walk the insn's pattern, remembering at all times the path
  84          down to the walking point.  */
  85
  86       match_rtx (XVECEXP (peep, 0, i), NULL, insn_code_number);
  87     }
  88
  89   /* We get this far if the pattern matches.
  90      Now test the extra condition.  */
  91
  92   if (XSTR (peep, 1) && XSTR (peep, 1)[0])
  93     printf ("  if (! (%s)) goto L%d;\n",
  94             XSTR (peep, 1), insn_code_number);
  95
  96   /* If that matches, construct new pattern and put it in the first insn.
  97      This new pattern will never be matched.
  98      It exists only so that insn-extract can get the operands back.
  99      So use a simple regular form: a PARALLEL containing a vector
 100      of all the operands.  */
 101
 102   printf ("  PATTERN (ins1) = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands);
 103
 104   /* Record this define_peephole's insn code in the insn,
 105      as if it had been recognized to match this.  */
 106   printf ("  INSN_CODE (ins1) = %d;\n",
 107           insn_code_number);
 108
 109   /* Delete the remaining insns.  */
 110   if (ninsns > 1)
 111     printf ("  delete_for_peephole (NEXT_INSN (ins1), insn);\n");
 112
 113   /* See reload1.c for insertion of NOTE which guarantees that this
 114      cannot be zero.  */
 115   printf ("  return NEXT_INSN (insn);\n");
 116
 117   printf (" L%d:\n\n", insn_code_number);
 118 }
 119 \f
 120 static void
 121 match_rtx (rtx x, struct link *path, int fail_label)
 122 {
 123   RTX_CODE code;
 124   int i;
 125   int len;
 126   const char *fmt;
 127   struct link link;
 128
 129   if (x == 0)
 130     return;
 131
 132
 133   code = GET_CODE (x);
 134
 135   switch (code)
 136     {
 137     case MATCH_OPERAND:
 138       if (XINT (x, 0) > max_opno)
 139         max_opno = XINT (x, 0);
 140       if (XINT (x, 0) >= n_operands)
 141         n_operands = 1 + XINT (x, 0);
 142
 143       printf ("  x = ");
 144       print_path (path);
 145       printf (";\n");
 146
 147       printf ("  operands[%d] = x;\n", XINT (x, 0));
 148       if (XSTR (x, 1) && XSTR (x, 1)[0])
 149         printf ("  if (! %s (x, %smode)) goto L%d;\n",
 150                 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
 151       return;
 152
 153     case MATCH_DUP:
 154     case MATCH_PAR_DUP:
 155       printf ("  x = ");
 156       print_path (path);
 157       printf (";\n");
 158
 159       printf ("  if (!rtx_equal_p (operands[%d], x)) goto L%d;\n",
 160               XINT (x, 0), fail_label);
 161       return;
 162
 163     case MATCH_OP_DUP:
 164       printf ("  x = ");
 165       print_path (path);
 166       printf (";\n");
 167
 168       printf ("  if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0));
 169       printf ("      || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n",
 170               XINT (x, 0), fail_label);
 171       printf ("  operands[%d] = x;\n", XINT (x, 0));
 172       link.next = path;
 173       link.vecelt = -1;
 174       for (i = 0; i < XVECLEN (x, 1); i++)
 175         {
 176           link.pos = i;
 177           match_rtx (XVECEXP (x, 1, i), &link, fail_label);
 178         }
 179       return;
 180
 181     case MATCH_OPERATOR:
 182       if (XINT (x, 0) > max_opno)
 183         max_opno = XINT (x, 0);
 184       if (XINT (x, 0) >= n_operands)
 185         n_operands = 1 + XINT (x, 0);
 186
 187       printf ("  x = ");
 188       print_path (path);
 189       printf (";\n");
 190
 191       printf ("  operands[%d] = x;\n", XINT (x, 0));
 192       if (XSTR (x, 1) && XSTR (x, 1)[0])
 193         printf ("  if (! %s (x, %smode)) goto L%d;\n",
 194                 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
 195       link.next = path;
 196       link.vecelt = -1;
 197       for (i = 0; i < XVECLEN (x, 2); i++)
 198         {
 199           link.pos = i;
 200           match_rtx (XVECEXP (x, 2, i), &link, fail_label);
 201         }
 202       return;
 203
 204     case MATCH_PARALLEL:
 205       if (XINT (x, 0) > max_opno)
 206         max_opno = XINT (x, 0);
 207       if (XINT (x, 0) >= n_operands)
 208         n_operands = 1 + XINT (x, 0);
 209
 210       printf ("  x = ");
 211       print_path (path);
 212       printf (";\n");
 213
 214       printf ("  if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label);
 215       printf ("  operands[%d] = x;\n", XINT (x, 0));
 216       if (XSTR (x, 1) && XSTR (x, 1)[0])
 217         printf ("  if (! %s (x, %smode)) goto L%d;\n",
 218                 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
 219       link.next = path;
 220       link.pos = 0;
 221       for (i = 0; i < XVECLEN (x, 2); i++)
 222         {
 223           link.vecelt = i;
 224           match_rtx (XVECEXP (x, 2, i), &link, fail_label);
 225         }
 226       return;
 227
 228     default:
 229       break;
 230     }
 231
 232   printf ("  x = ");
 233   print_path (path);
 234   printf (";\n");
 235
 236   printf ("  if (GET_CODE (x) != ");
 237   print_code (code);
 238   printf (") goto L%d;\n", fail_label);
 239
 240   if (GET_MODE (x) != VOIDmode)
 241     {
 242       printf ("  if (GET_MODE (x) != %smode) goto L%d;\n",
 243               GET_MODE_NAME (GET_MODE (x)), fail_label);
 244     }
 245
 246   link.next = path;
 247   link.vecelt = -1;
 248   fmt = GET_RTX_FORMAT (code);
 249   len = GET_RTX_LENGTH (code);
 250   for (i = 0; i < len; i++)
 251     {
 252       link.pos = i;
 253       if (fmt[i] == 'e' || fmt[i] == 'u')
 254         match_rtx (XEXP (x, i), &link, fail_label);
 255       else if (fmt[i] == 'E')
 256         {
 257           int j;
 258           printf ("  if (XVECLEN (x, %d) != %d) goto L%d;\n",
 259                   i, XVECLEN (x, i), fail_label);
 260           for (j = 0; j < XVECLEN (x, i); j++)
 261             {
 262               link.vecelt = j;
 263               match_rtx (XVECEXP (x, i, j), &link, fail_label);
 264             }
 265         }
 266       else if (fmt[i] == 'i')
 267         {
 268           /* Make sure that at run time `x' is the RTX we want to test.  */
 269           if (i != 0)
 270             {
 271               printf ("  x = ");
 272               print_path (path);
 273               printf (";\n");
 274             }
 275
 276           printf ("  if (XINT (x, %d) != %d) goto L%d;\n",
 277                   i, XINT (x, i), fail_label);
 278         }
 279       else if (fmt[i] == 'w')
 280         {
 281           /* Make sure that at run time `x' is the RTX we want to test.  */
 282           if (i != 0)
 283             {
 284               printf ("  x = ");
 285               print_path (path);
 286               printf (";\n");
 287             }
 288
 289           printf ("  if (XWINT (x, %d) != ", i);
 290           printf (HOST_WIDE_INT_PRINT_DEC, XWINT (x, i));
 291           printf (") goto L%d;\n", fail_label);
 292         }
 293       else if (fmt[i] == 's')
 294         {
 295           /* Make sure that at run time `x' is the RTX we want to test.  */
 296           if (i != 0)
 297             {
 298               printf ("  x = ");
 299               print_path (path);
 300               printf (";\n");
 301             }
 302
 303           printf ("  if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n",
 304                   i, XSTR (x, i), fail_label);
 305         }
 306     }
 307 }
 308
 309 /* Given a PATH, representing a path down the instruction's
 310    pattern from the root to a certain point, output code to
 311    evaluate to the rtx at that point.  */
 312
 313 static void
 314 print_path (struct link *path)
 315 {
 316   if (path == 0)
 317     printf ("pat");
 318   else if (path->vecelt >= 0)
 319     {
 320       printf ("XVECEXP (");
 321       print_path (path->next);
 322       printf (", %d, %d)", path->pos, path->vecelt);
 323     }
 324   else
 325     {
 326       printf ("XEXP (");
 327       print_path (path->next);
 328       printf (", %d)", path->pos);
 329     }
 330 }
 331 \f
 332 static void
 333 print_code (RTX_CODE code)
 334 {
 335   const char *p1;
 336   for (p1 = GET_RTX_NAME (code); *p1; p1++)
 337     putchar (TOUPPER(*p1));
 338 }
 339
 340 extern int main (int, char **);
 341
 342 int
 343 main (int argc, char **argv)
 344 {
 345   rtx desc;
 346
 347   max_opno = -1;
 348
 349   progname = "genpeep";
 350
 351   if (!init_rtx_reader_args (argc, argv))
 352     return (FATAL_EXIT_CODE);
 353
 354   printf ("/* Generated automatically by the program `genpeep'\n\
 355 from the machine description file `md'.  */\n\n");
 356
 357   printf ("#include \"config.h\"\n");
 358   printf ("#include \"system.h\"\n");
 359   printf ("#include \"coretypes.h\"\n");
 360   printf ("#include \"tm.h\"\n");
 361   printf ("#include \"insn-config.h\"\n");
 362   printf ("#include \"rtl.h\"\n");
 363   printf ("#include \"tm_p.h\"\n");
 364   printf ("#include \"regs.h\"\n");
 365   printf ("#include \"output.h\"\n");
 366   printf ("#include \"recog.h\"\n");
 367   printf ("#include \"except.h\"\n");
 368   printf ("#include \"function.h\"\n");
 369   printf ("#include \"diagnostic-core.h\"\n");
 370   printf ("#include \"flags.h\"\n");
 371   printf ("#include \"tm-constrs.h\"\n\n");
 372
 373   printf ("#ifdef HAVE_peephole\n");
 374   printf ("extern rtx peep_operand[];\n\n");
 375   printf ("#define operands peep_operand\n\n");
 376
 377   printf ("rtx\npeephole (rtx ins1)\n{\n");
 378   printf ("  rtx insn ATTRIBUTE_UNUSED, x ATTRIBUTE_UNUSED, pat ATTRIBUTE_UNUSED;\n\n");
 379
 380   /* Early out: no peepholes for insns followed by barriers.  */
 381   printf ("  if (NEXT_INSN (ins1)\n");
 382   printf ("      && BARRIER_P (NEXT_INSN (ins1)))\n");
 383   printf ("    return 0;\n\n");
 384
 385   /* Read the machine description.  */
 386
 387   while (1)
 388     {
 389       int line_no;
 390       int insn_code_number;
 391
 392       desc = read_md_rtx (&line_no, &insn_code_number);
 393       if (desc == NULL)
 394         break;
 395
 396       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 397         gen_peephole (desc, insn_code_number);
 398     }
 399
 400   printf ("  return 0;\n}\n\n");
 401
 402   if (max_opno == -1)
 403     max_opno = 1;
 404
 405   printf ("rtx peep_operand[%d];\n", max_opno + 1);
 406   printf ("#endif\n");
 407
 408   fflush (stdout);
 409   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 410 }