gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987-2020 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 /* flags to determine output of machine description dependent #define's.  */
  32 static int max_recog_operands;  /* Largest operand number seen.  */
  33 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  34 static int max_clobbers_per_insn;
  35 static int have_cc0_flag;
  36 static int have_cmove_flag;
  37 static int have_cond_exec_flag;
  38 static int have_lo_sum_flag;
  39 static int have_rotate_flag;
  40 static int have_rotatert_flag;
  41 static int have_peephole_flag;
  42 static int have_peephole2_flag;
  43
  44 /* Maximum number of insns seen in a split.  */
  45 static int max_insns_per_split = 1;
  46
  47 /* Maximum number of input insns for peephole2.  */
  48 static int max_insns_per_peep2;
  49
  50 static int clobbers_seen_this_insn;
  51 static int dup_operands_seen_this_insn;
  52
  53 static void walk_insn_part (rtx, int, int);
  54
  55 /* RECOG_P will be nonzero if this pattern was seen in a context where it will
  56    be used to recognize, rather than just generate an insn.
  57
  58    NON_PC_SET_SRC will be nonzero if this pattern was seen in a SET_SRC
  59    of a SET whose destination is not (pc).  */
  60
  61 static void
  62 walk_insn_part (rtx part, int recog_p, int non_pc_set_src)
  63 {
  64   int i, j;
  65   RTX_CODE code;
  66   const char *format_ptr;
  67
  68   if (part == 0)
  69     return;
  70
  71   code = GET_CODE (part);
  72   switch (code)
  73     {
  74     case CLOBBER:
  75       clobbers_seen_this_insn++;
  76       break;
  77
  78     case MATCH_OPERAND:
  79       if (XINT (part, 0) > max_recog_operands)
  80         max_recog_operands = XINT (part, 0);
  81       return;
  82
  83     case MATCH_OP_DUP:
  84     case MATCH_PAR_DUP:
  85       ++dup_operands_seen_this_insn;
  86       /* FALLTHRU */
  87     case MATCH_SCRATCH:
  88     case MATCH_PARALLEL:
  89     case MATCH_OPERATOR:
  90       if (XINT (part, 0) > max_recog_operands)
  91         max_recog_operands = XINT (part, 0);
  92       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  93          MATCH_PARALLEL.  */
  94       break;
  95
  96     case LABEL_REF:
  97       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND
  98           || GET_CODE (XEXP (part, 0)) == MATCH_DUP)
  99         break;
 100       return;
 101
 102     case MATCH_DUP:
 103       ++dup_operands_seen_this_insn;
 104       if (XINT (part, 0) > max_recog_operands)
 105         max_recog_operands = XINT (part, 0);
 106       return;
 107
 108     case CC0:
 109       if (recog_p)
 110         have_cc0_flag = 1;
 111       return;
 112
 113     case LO_SUM:
 114       if (recog_p)
 115         have_lo_sum_flag = 1;
 116       return;
 117
 118     case ROTATE:
 119       if (recog_p)
 120         have_rotate_flag = 1;
 121       return;
 122
 123     case ROTATERT:
 124       if (recog_p)
 125         have_rotatert_flag = 1;
 126       return;
 127
 128     case SET:
 129       walk_insn_part (SET_DEST (part), 0, recog_p);
 130       walk_insn_part (SET_SRC (part), recog_p,
 131                       GET_CODE (SET_DEST (part)) != PC);
 132       return;
 133
 134     case IF_THEN_ELSE:
 135       /* Only consider this machine as having a conditional move if the
 136          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 137          we have some specific IF_THEN_ELSE construct (like the doz
 138          instruction on the RS/6000) that can't be used in the general
 139          context we want it for.  */
 140
 141       if (recog_p && non_pc_set_src
 142           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 143           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 144         have_cmove_flag = 1;
 145       break;
 146
 147     case COND_EXEC:
 148       if (recog_p)
 149         have_cond_exec_flag = 1;
 150       break;
 151
 152     case REG: case CONST_INT: case SYMBOL_REF:
 153     case PC:
 154       return;
 155
 156     default:
 157       break;
 158     }
 159
 160   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 161
 162   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 163     switch (*format_ptr++)
 164       {
 165       case 'e':
 166       case 'u':
 167         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 168         break;
 169       case 'E':
 170         if (XVEC (part, i) != NULL)
 171           for (j = 0; j < XVECLEN (part, i); j++)
 172             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 173         break;
 174       }
 175 }
 176
 177 static void
 178 gen_insn (md_rtx_info *info)
 179 {
 180   int i;
 181
 182   /* Walk the insn pattern to gather the #define's status.  */
 183   rtx insn = info->def;
 184   clobbers_seen_this_insn = 0;
 185   dup_operands_seen_this_insn = 0;
 186   if (XVEC (insn, 1) != 0)
 187     for (i = 0; i < XVECLEN (insn, 1); i++)
 188       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 189
 190   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 191     max_clobbers_per_insn = clobbers_seen_this_insn;
 192   if (dup_operands_seen_this_insn > max_dup_operands)
 193     max_dup_operands = dup_operands_seen_this_insn;
 194 }
 195
 196 /* Similar but scan a define_expand.  */
 197
 198 static void
 199 gen_expand (md_rtx_info *info)
 200 {
 201   int i;
 202
 203   /* Walk the insn pattern to gather the #define's status.  */
 204
 205   /* Note that we don't bother recording the number of MATCH_DUPs
 206      that occur in a gen_expand, because only reload cares about that.  */
 207   rtx insn = info->def;
 208   if (XVEC (insn, 1) != 0)
 209     for (i = 0; i < XVECLEN (insn, 1); i++)
 210       {
 211         /* Compute the maximum SETs and CLOBBERS
 212            in any one of the sub-insns;
 213            don't sum across all of them.  */
 214         clobbers_seen_this_insn = 0;
 215
 216         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 217
 218         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 219           max_clobbers_per_insn = clobbers_seen_this_insn;
 220       }
 221 }
 222
 223 /* Similar but scan a define_split.  */
 224
 225 static void
 226 gen_split (md_rtx_info *info)
 227 {
 228   int i;
 229
 230   /* Look through the patterns that are matched
 231      to compute the maximum operand number.  */
 232   rtx split = info->def;
 233   for (i = 0; i < XVECLEN (split, 0); i++)
 234     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 235   /* Look at the number of insns this insn could split into.  */
 236   if (XVECLEN (split, 2) > max_insns_per_split)
 237     max_insns_per_split = XVECLEN (split, 2);
 238 }
 239
 240 static void
 241 gen_peephole (md_rtx_info *info)
 242 {
 243   int i;
 244
 245   /* Look through the patterns that are matched
 246      to compute the maximum operand number.  */
 247   rtx peep = info->def;
 248   for (i = 0; i < XVECLEN (peep, 0); i++)
 249     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 250 }
 251
 252 static void
 253 gen_peephole2 (md_rtx_info *info)
 254 {
 255   int i, n;
 256
 257   /* Look through the patterns that are matched
 258      to compute the maximum operand number.  */
 259   rtx peep = info->def;
 260   for (i = XVECLEN (peep, 0) - 1; i >= 0; --i)
 261     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 262
 263   /* Look at the number of insns this insn can be matched from.  */
 264   for (i = XVECLEN (peep, 0) - 1, n = 0; i >= 0; --i)
 265     if (GET_CODE (XVECEXP (peep, 0, i)) != MATCH_DUP
 266         && GET_CODE (XVECEXP (peep, 0, i)) != MATCH_SCRATCH)
 267       n++;
 268   if (n > max_insns_per_peep2)
 269     max_insns_per_peep2 = n;
 270 }
 271
 272 int
 273 main (int argc, const char **argv)
 274 {
 275   progname = "genconfig";
 276
 277   if (!init_rtx_reader_args (argc, argv))
 278     return (FATAL_EXIT_CODE);
 279
 280   puts ("/* Generated automatically by the program `genconfig'");
 281   puts ("   from the machine description file `md'.  */\n");
 282   puts ("#ifndef GCC_INSN_CONFIG_H");
 283   puts ("#define GCC_INSN_CONFIG_H\n");
 284
 285   /* Allow at least 30 operands for the sake of asm constructs.  */
 286   /* ??? We *really* ought to reorganize things such that there
 287      is no fixed upper bound.  */
 288   max_recog_operands = 29;  /* We will add 1 later.  */
 289   max_dup_operands = 1;
 290
 291   /* Read the machine description.  */
 292
 293   md_rtx_info info;
 294   while (read_md_rtx (&info))
 295     switch (GET_CODE (info.def))
 296       {
 297       case DEFINE_INSN:
 298         gen_insn (&info);
 299         break;
 300
 301       case DEFINE_EXPAND:
 302         gen_expand (&info);
 303         break;
 304
 305       case DEFINE_SPLIT:
 306         gen_split (&info);
 307         break;
 308
 309       case DEFINE_PEEPHOLE2:
 310         have_peephole2_flag = 1;
 311         gen_peephole2 (&info);
 312         break;
 313
 314       case DEFINE_PEEPHOLE:
 315         have_peephole_flag = 1;
 316         gen_peephole (&info);
 317         break;
 318
 319       default:
 320         break;
 321       }
 322
 323   printf ("#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 324   printf ("#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 325
 326   /* This is conditionally defined, in case the user writes code which emits
 327      more splits than we can readily see (and knows s/he does it).  */
 328   printf ("#ifndef MAX_INSNS_PER_SPLIT\n");
 329   printf ("#define MAX_INSNS_PER_SPLIT %d\n", max_insns_per_split);
 330   printf ("#endif\n");
 331
 332   if (have_cc0_flag)
 333     {
 334       printf ("#define HAVE_cc0 1\n");
 335       printf ("#define CC0_P(X) ((X) == cc0_rtx)\n");
 336     }
 337   else
 338     {
 339       /* We output CC0_P this way to make sure that X is declared
 340          somewhere.  */
 341       printf ("#define HAVE_cc0 0\n");
 342       printf ("#define CC0_P(X) ((X) ? 0 : 0)\n");
 343     }
 344
 345   if (have_cmove_flag)
 346     printf ("#define HAVE_conditional_move 1\n");
 347   else
 348     printf ("#define HAVE_conditional_move 0\n");
 349
 350   if (have_cond_exec_flag)
 351     printf ("#define HAVE_conditional_execution 1\n");
 352   else
 353     printf ("#define HAVE_conditional_execution 0\n");
 354
 355   if (have_lo_sum_flag)
 356     printf ("#define HAVE_lo_sum 1\n");
 357   else
 358     printf ("#define HAVE_lo_sum 0\n");
 359
 360   if (have_rotate_flag)
 361     printf ("#define HAVE_rotate 1\n");
 362
 363   if (have_rotatert_flag)
 364     printf ("#define HAVE_rotatert 1\n");
 365
 366   if (have_peephole_flag)
 367     printf ("#define HAVE_peephole 1\n");
 368   else
 369     printf ("#define HAVE_peephole 0\n");
 370
 371   if (have_peephole2_flag)
 372     {
 373       printf ("#define HAVE_peephole2 1\n");
 374       printf ("#define MAX_INSNS_PER_PEEP2 %d\n", max_insns_per_peep2);
 375     }
 376   else
 377     {
 378       printf ("#define HAVE_peephole2 0\n");
 379       printf ("#define MAX_INSNS_PER_PEEP2 0\n");
 380     }
 381
 382   puts ("\n#endif /* GCC_INSN_CONFIG_H */");
 383
 384   if (ferror (stdout) || fflush (stdout) || fclose (stdout))
 385     return FATAL_EXIT_CODE;
 386
 387   return SUCCESS_EXIT_CODE;
 388 }