gcc/genpeep.c

   1 /* Generate code from machine description to perform peephole optimizations.
   2    Copyright (C) 1987, 1989, 1992, 1997, 1998, 1999, 2000, 2003, 2004,
   3    2007, 2010, 2012  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 "gensupport.h"
  29
  30
  31 /* While tree-walking an instruction pattern, we keep a chain
  32    of these `struct link's to record how to get down to the
  33    current position.  In each one, POS is the operand number,
  34    and if the operand is a vector VEC is the element number.
  35    VEC is -1 if the operand is not a vector.  */
  36
  37 struct link
  38 {
  39   struct link *next;
  40   int pos;
  41   int vecelt;
  42 };
  43
  44 static int max_opno;
  45
  46 /* Number of operands used in current peephole definition.  */
  47
  48 static int n_operands;
  49
  50 static void gen_peephole (rtx, int);
  51 static void match_rtx (rtx, struct link *, int);
  52 static void print_path (struct link *);
  53 static void print_code (RTX_CODE);
  54 \f
  55 static void
  56 gen_peephole (rtx peep, int insn_code_number)
  57 {
  58   int ninsns = XVECLEN (peep, 0);
  59   int i;
  60
  61   n_operands = 0;
  62
  63   printf ("  insn = ins1;\n");
  64
  65   for (i = 0; i < ninsns; i++)
  66     {
  67       if (i > 0)
  68         {
  69           printf ("  do { insn = NEXT_INSN (insn);\n");
  70           printf ("       if (insn == 0) goto L%d; }\n",
  71                   insn_code_number);
  72           printf ("  while (NOTE_P (insn)\n");
  73           printf ("\t || (NONJUMP_INSN_P (insn)\n");
  74           printf ("\t     && (GET_CODE (PATTERN (insn)) == USE\n");
  75           printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n");
  76
  77           printf ("  if (LABEL_P (insn)\n\
  78       || BARRIER_P (insn))\n    goto L%d;\n",
  79                   insn_code_number);
  80         }
  81
  82       printf ("  pat = PATTERN (insn);\n");
  83
  84       /* Walk the insn's pattern, remembering at all times the path
  85          down to the walking point.  */
  86
  87       match_rtx (XVECEXP (peep, 0, i), NULL, insn_code_number);
  88     }
  89
  90   /* We get this far if the pattern matches.
  91      Now test the extra condition.  */
  92
  93   if (XSTR (peep, 1) && XSTR (peep, 1)[0])
  94     printf ("  if (! (%s)) goto L%d;\n",
  95             XSTR (peep, 1), insn_code_number);
  96
  97   /* If that matches, construct new pattern and put it in the first insn.
  98      This new pattern will never be matched.
  99      It exists only so that insn-extract can get the operands back.
 100      So use a simple regular form: a PARALLEL containing a vector
 101      of all the operands.  */
 102
 103   printf ("  PATTERN (ins1) = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands);
 104
 105   /* Record this define_peephole's insn code in the insn,
 106      as if it had been recognized to match this.  */
 107   printf ("  INSN_CODE (ins1) = %d;\n",
 108           insn_code_number);
 109
 110   /* Delete the remaining insns.  */
 111   if (ninsns > 1)
 112     printf ("  delete_for_peephole (NEXT_INSN (ins1), insn);\n");
 113
 114   /* See reload1.c for insertion of NOTE which guarantees that this
 115      cannot be zero.  */
 116   printf ("  return NEXT_INSN (insn);\n");
 117
 118   printf (" L%d:\n\n", insn_code_number);
 119 }
 120 \f
 121 static void
 122 match_rtx (rtx x, struct link *path, int fail_label)
 123 {
 124   RTX_CODE code;
 125   int i;
 126   int len;
 127   const char *fmt;
 128   struct link link;
 129
 130   if (x == 0)
 131     return;
 132
 133
 134   code = GET_CODE (x);
 135
 136   switch (code)
 137     {
 138     case MATCH_OPERAND:
 139       if (XINT (x, 0) > max_opno)
 140         max_opno = XINT (x, 0);
 141       if (XINT (x, 0) >= n_operands)
 142         n_operands = 1 + XINT (x, 0);
 143
 144       printf ("  x = ");
 145       print_path (path);
 146       printf (";\n");
 147
 148       printf ("  operands[%d] = x;\n", XINT (x, 0));
 149       if (XSTR (x, 1) && XSTR (x, 1)[0])
 150         printf ("  if (! %s (x, %smode)) goto L%d;\n",
 151                 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
 152       return;
 153
 154     case MATCH_DUP:
 155     case MATCH_PAR_DUP:
 156       printf ("  x = ");
 157       print_path (path);
 158       printf (";\n");
 159
 160       printf ("  if (!rtx_equal_p (operands[%d], x)) goto L%d;\n",
 161               XINT (x, 0), fail_label);
 162       return;
 163
 164     case MATCH_OP_DUP:
 165       printf ("  x = ");
 166       print_path (path);
 167       printf (";\n");
 168
 169       printf ("  if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0));
 170       printf ("      || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n",
 171               XINT (x, 0), fail_label);
 172       printf ("  operands[%d] = x;\n", XINT (x, 0));
 173       link.next = path;
 174       link.vecelt = -1;
 175       for (i = 0; i < XVECLEN (x, 1); i++)
 176         {
 177           link.pos = i;
 178           match_rtx (XVECEXP (x, 1, i), &link, fail_label);
 179         }
 180       return;
 181
 182     case MATCH_OPERATOR:
 183       if (XINT (x, 0) > max_opno)
 184         max_opno = XINT (x, 0);
 185       if (XINT (x, 0) >= n_operands)
 186         n_operands = 1 + XINT (x, 0);
 187
 188       printf ("  x = ");
 189       print_path (path);
 190       printf (";\n");
 191
 192       printf ("  operands[%d] = x;\n", XINT (x, 0));
 193       if (XSTR (x, 1) && XSTR (x, 1)[0])
 194         printf ("  if (! %s (x, %smode)) goto L%d;\n",
 195                 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
 196       link.next = path;
 197       link.vecelt = -1;
 198       for (i = 0; i < XVECLEN (x, 2); i++)
 199         {
 200           link.pos = i;
 201           match_rtx (XVECEXP (x, 2, i), &link, fail_label);
 202         }
 203       return;
 204
 205     case MATCH_PARALLEL:
 206       if (XINT (x, 0) > max_opno)
 207         max_opno = XINT (x, 0);
 208       if (XINT (x, 0) >= n_operands)
 209         n_operands = 1 + XINT (x, 0);
 210
 211       printf ("  x = ");
 212       print_path (path);
 213       printf (";\n");
 214
 215       printf ("  if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label);
 216       printf ("  operands[%d] = x;\n", XINT (x, 0));
 217       if (XSTR (x, 1) && XSTR (x, 1)[0])
 218         printf ("  if (! %s (x, %smode)) goto L%d;\n",
 219                 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
 220       link.next = path;
 221       link.pos = 0;
 222       for (i = 0; i < XVECLEN (x, 2); i++)
 223         {
 224           link.vecelt = i;
 225           match_rtx (XVECEXP (x, 2, i), &link, fail_label);
 226         }
 227       return;
 228
 229     default:
 230       break;
 231     }
 232
 233   printf ("  x = ");
 234   print_path (path);
 235   printf (";\n");
 236
 237   printf ("  if (GET_CODE (x) != ");
 238   print_code (code);
 239   printf (") goto L%d;\n", fail_label);
 240
 241   if (GET_MODE (x) != VOIDmode)
 242     {
 243       printf ("  if (GET_MODE (x) != %smode) goto L%d;\n",
 244               GET_MODE_NAME (GET_MODE (x)), fail_label);
 245     }
 246
 247   link.next = path;
 248   link.vecelt = -1;
 249   fmt = GET_RTX_FORMAT (code);
 250   len = GET_RTX_LENGTH (code);
 251   for (i = 0; i < len; i++)
 252     {
 253       link.pos = i;
 254       if (fmt[i] == 'e' || fmt[i] == 'u')
 255         match_rtx (XEXP (x, i), &link, fail_label);
 256       else if (fmt[i] == 'E')
 257         {
 258           int j;
 259           printf ("  if (XVECLEN (x, %d) != %d) goto L%d;\n",
 260                   i, XVECLEN (x, i), fail_label);
 261           for (j = 0; j < XVECLEN (x, i); j++)
 262             {
 263               link.vecelt = j;
 264               match_rtx (XVECEXP (x, i, j), &link, fail_label);
 265             }
 266         }
 267       else if (fmt[i] == 'i')
 268         {
 269           /* Make sure that at run time `x' is the RTX we want to test.  */
 270           if (i != 0)
 271             {
 272               printf ("  x = ");
 273               print_path (path);
 274               printf (";\n");
 275             }
 276
 277           printf ("  if (XINT (x, %d) != %d) goto L%d;\n",
 278                   i, XINT (x, i), fail_label);
 279         }
 280       else if (fmt[i] == 'w')
 281         {
 282           /* Make sure that at run time `x' is the RTX we want to test.  */
 283           if (i != 0)
 284             {
 285               printf ("  x = ");
 286               print_path (path);
 287               printf (";\n");
 288             }
 289
 290           printf ("  if (XWINT (x, %d) != ", i);
 291           printf (HOST_WIDE_INT_PRINT_DEC, XWINT (x, i));
 292           printf (") goto L%d;\n", fail_label);
 293         }
 294       else if (fmt[i] == 's')
 295         {
 296           /* Make sure that at run time `x' is the RTX we want to test.  */
 297           if (i != 0)
 298             {
 299               printf ("  x = ");
 300               print_path (path);
 301               printf (";\n");
 302             }
 303
 304           printf ("  if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n",
 305                   i, XSTR (x, i), fail_label);
 306         }
 307     }
 308 }
 309
 310 /* Given a PATH, representing a path down the instruction's
 311    pattern from the root to a certain point, output code to
 312    evaluate to the rtx at that point.  */
 313
 314 static void
 315 print_path (struct link *path)
 316 {
 317   if (path == 0)
 318     printf ("pat");
 319   else if (path->vecelt >= 0)
 320     {
 321       printf ("XVECEXP (");
 322       print_path (path->next);
 323       printf (", %d, %d)", path->pos, path->vecelt);
 324     }
 325   else
 326     {
 327       printf ("XEXP (");
 328       print_path (path->next);
 329       printf (", %d)", path->pos);
 330     }
 331 }
 332 \f
 333 static void
 334 print_code (RTX_CODE code)
 335 {
 336   const char *p1;
 337   for (p1 = GET_RTX_NAME (code); *p1; p1++)
 338     putchar (TOUPPER(*p1));
 339 }
 340
 341 extern int main (int, char **);
 342
 343 int
 344 main (int argc, char **argv)
 345 {
 346   rtx desc;
 347
 348   max_opno = -1;
 349
 350   progname = "genpeep";
 351
 352   if (!init_rtx_reader_args (argc, argv))
 353     return (FATAL_EXIT_CODE);
 354
 355   printf ("/* Generated automatically by the program `genpeep'\n\
 356 from the machine description file `md'.  */\n\n");
 357
 358   printf ("#include \"config.h\"\n");
 359   printf ("#include \"system.h\"\n");
 360   printf ("#include \"coretypes.h\"\n");
 361   printf ("#include \"tm.h\"\n");
 362   printf ("#include \"insn-config.h\"\n");
 363   printf ("#include \"rtl.h\"\n");
 364   printf ("#include \"tm_p.h\"\n");
 365   printf ("#include \"regs.h\"\n");
 366   printf ("#include \"output.h\"\n");
 367   printf ("#include \"recog.h\"\n");
 368   printf ("#include \"except.h\"\n");
 369   printf ("#include \"function.h\"\n");
 370   printf ("#include \"diagnostic-core.h\"\n");
 371   printf ("#include \"flags.h\"\n");
 372   printf ("#include \"tm-constrs.h\"\n\n");
 373
 374   printf ("#ifdef HAVE_peephole\n");
 375   printf ("extern rtx peep_operand[];\n\n");
 376   printf ("#define operands peep_operand\n\n");
 377
 378   printf ("rtx\npeephole (rtx ins1)\n{\n");
 379   printf ("  rtx insn ATTRIBUTE_UNUSED, x ATTRIBUTE_UNUSED, pat ATTRIBUTE_UNUSED;\n\n");
 380
 381   /* Early out: no peepholes for insns followed by barriers.  */
 382   printf ("  if (NEXT_INSN (ins1)\n");
 383   printf ("      && BARRIER_P (NEXT_INSN (ins1)))\n");
 384   printf ("    return 0;\n\n");
 385
 386   /* Read the machine description.  */
 387
 388   while (1)
 389     {
 390       int line_no;
 391       int insn_code_number;
 392
 393       desc = read_md_rtx (&line_no, &insn_code_number);
 394       if (desc == NULL)
 395         break;
 396
 397       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 398         gen_peephole (desc, insn_code_number);
 399     }
 400
 401   printf ("  return 0;\n}\n\n");
 402
 403   if (max_opno == -1)
 404     max_opno = 1;
 405
 406   printf ("rtx peep_operand[%d];\n", max_opno + 1);
 407   printf ("#endif\n");
 408
 409   fflush (stdout);
 410   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 411 }