gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987-2018 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     case CLOBBER_HIGH:
  76       clobbers_seen_this_insn++;
  77       break;
  78
  79     case MATCH_OPERAND:
  80       if (XINT (part, 0) > max_recog_operands)
  81         max_recog_operands = XINT (part, 0);
  82       return;
  83
  84     case MATCH_OP_DUP:
  85     case MATCH_PAR_DUP:
  86       ++dup_operands_seen_this_insn;
  87       /* FALLTHRU */
  88     case MATCH_SCRATCH:
  89     case MATCH_PARALLEL:
  90     case MATCH_OPERATOR:
  91       if (XINT (part, 0) > max_recog_operands)
  92         max_recog_operands = XINT (part, 0);
  93       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  94          MATCH_PARALLEL.  */
  95       break;
  96
  97     case LABEL_REF:
  98       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND
  99           || GET_CODE (XEXP (part, 0)) == MATCH_DUP)
 100         break;
 101       return;
 102
 103     case MATCH_DUP:
 104       ++dup_operands_seen_this_insn;
 105       if (XINT (part, 0) > max_recog_operands)
 106         max_recog_operands = XINT (part, 0);
 107       return;
 108
 109     case CC0:
 110       if (recog_p)
 111         have_cc0_flag = 1;
 112       return;
 113
 114     case LO_SUM:
 115       if (recog_p)
 116         have_lo_sum_flag = 1;
 117       return;
 118
 119     case ROTATE:
 120       if (recog_p)
 121         have_rotate_flag = 1;
 122       return;
 123
 124     case ROTATERT:
 125       if (recog_p)
 126         have_rotatert_flag = 1;
 127       return;
 128
 129     case SET:
 130       walk_insn_part (SET_DEST (part), 0, recog_p);
 131       walk_insn_part (SET_SRC (part), recog_p,
 132                       GET_CODE (SET_DEST (part)) != PC);
 133       return;
 134
 135     case IF_THEN_ELSE:
 136       /* Only consider this machine as having a conditional move if the
 137          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 138          we have some specific IF_THEN_ELSE construct (like the doz
 139          instruction on the RS/6000) that can't be used in the general
 140          context we want it for.  */
 141
 142       if (recog_p && non_pc_set_src
 143           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 144           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 145         have_cmove_flag = 1;
 146       break;
 147
 148     case COND_EXEC:
 149       if (recog_p)
 150         have_cond_exec_flag = 1;
 151       break;
 152
 153     case REG: case CONST_INT: case SYMBOL_REF:
 154     case PC:
 155       return;
 156
 157     default:
 158       break;
 159     }
 160
 161   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 162
 163   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 164     switch (*format_ptr++)
 165       {
 166       case 'e':
 167       case 'u':
 168         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 169         break;
 170       case 'E':
 171         if (XVEC (part, i) != NULL)
 172           for (j = 0; j < XVECLEN (part, i); j++)
 173             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 174         break;
 175       }
 176 }
 177
 178 static void
 179 gen_insn (md_rtx_info *info)
 180 {
 181   int i;
 182
 183   /* Walk the insn pattern to gather the #define's status.  */
 184   rtx insn = info->def;
 185   clobbers_seen_this_insn = 0;
 186   dup_operands_seen_this_insn = 0;
 187   if (XVEC (insn, 1) != 0)
 188     for (i = 0; i < XVECLEN (insn, 1); i++)
 189       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 190
 191   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 192     max_clobbers_per_insn = clobbers_seen_this_insn;
 193   if (dup_operands_seen_this_insn > max_dup_operands)
 194     max_dup_operands = dup_operands_seen_this_insn;
 195 }
 196
 197 /* Similar but scan a define_expand.  */
 198
 199 static void
 200 gen_expand (md_rtx_info *info)
 201 {
 202   int i;
 203
 204   /* Walk the insn pattern to gather the #define's status.  */
 205
 206   /* Note that we don't bother recording the number of MATCH_DUPs
 207      that occur in a gen_expand, because only reload cares about that.  */
 208   rtx insn = info->def;
 209   if (XVEC (insn, 1) != 0)
 210     for (i = 0; i < XVECLEN (insn, 1); i++)
 211       {
 212         /* Compute the maximum SETs and CLOBBERS
 213            in any one of the sub-insns;
 214            don't sum across all of them.  */
 215         clobbers_seen_this_insn = 0;
 216
 217         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 218
 219         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 220           max_clobbers_per_insn = clobbers_seen_this_insn;
 221       }
 222 }
 223
 224 /* Similar but scan a define_split.  */
 225
 226 static void
 227 gen_split (md_rtx_info *info)
 228 {
 229   int i;
 230
 231   /* Look through the patterns that are matched
 232      to compute the maximum operand number.  */
 233   rtx split = info->def;
 234   for (i = 0; i < XVECLEN (split, 0); i++)
 235     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 236   /* Look at the number of insns this insn could split into.  */
 237   if (XVECLEN (split, 2) > max_insns_per_split)
 238     max_insns_per_split = XVECLEN (split, 2);
 239 }
 240
 241 static void
 242 gen_peephole (md_rtx_info *info)
 243 {
 244   int i;
 245
 246   /* Look through the patterns that are matched
 247      to compute the maximum operand number.  */
 248   rtx peep = info->def;
 249   for (i = 0; i < XVECLEN (peep, 0); i++)
 250     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 251 }
 252
 253 static void
 254 gen_peephole2 (md_rtx_info *info)
 255 {
 256   int i, n;
 257
 258   /* Look through the patterns that are matched
 259      to compute the maximum operand number.  */
 260   rtx peep = info->def;
 261   for (i = XVECLEN (peep, 0) - 1; i >= 0; --i)
 262     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 263
 264   /* Look at the number of insns this insn can be matched from.  */
 265   for (i = XVECLEN (peep, 0) - 1, n = 0; i >= 0; --i)
 266     if (GET_CODE (XVECEXP (peep, 0, i)) != MATCH_DUP
 267         && GET_CODE (XVECEXP (peep, 0, i)) != MATCH_SCRATCH)
 268       n++;
 269   if (n > max_insns_per_peep2)
 270     max_insns_per_peep2 = n;
 271 }
 272
 273 int
 274 main (int argc, const char **argv)
 275 {
 276   progname = "genconfig";
 277
 278   if (!init_rtx_reader_args (argc, argv))
 279     return (FATAL_EXIT_CODE);
 280
 281   puts ("/* Generated automatically by the program `genconfig'");
 282   puts ("   from the machine description file `md'.  */\n");
 283   puts ("#ifndef GCC_INSN_CONFIG_H");
 284   puts ("#define GCC_INSN_CONFIG_H\n");
 285
 286   /* Allow at least 30 operands for the sake of asm constructs.  */
 287   /* ??? We *really* ought to reorganize things such that there
 288      is no fixed upper bound.  */
 289   max_recog_operands = 29;  /* We will add 1 later.  */
 290   max_dup_operands = 1;
 291
 292   /* Read the machine description.  */
 293
 294   md_rtx_info info;
 295   while (read_md_rtx (&info))
 296     switch (GET_CODE (info.def))
 297       {
 298       case DEFINE_INSN:
 299         gen_insn (&info);
 300         break;
 301
 302       case DEFINE_EXPAND:
 303         gen_expand (&info);
 304         break;
 305
 306       case DEFINE_SPLIT:
 307         gen_split (&info);
 308         break;
 309
 310       case DEFINE_PEEPHOLE2:
 311         have_peephole2_flag = 1;
 312         gen_peephole2 (&info);
 313         break;
 314
 315       case DEFINE_PEEPHOLE:
 316         have_peephole_flag = 1;
 317         gen_peephole (&info);
 318         break;
 319
 320       default:
 321         break;
 322       }
 323
 324   printf ("#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 325   printf ("#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 326
 327   /* This is conditionally defined, in case the user writes code which emits
 328      more splits than we can readily see (and knows s/he does it).  */
 329   printf ("#ifndef MAX_INSNS_PER_SPLIT\n");
 330   printf ("#define MAX_INSNS_PER_SPLIT %d\n", max_insns_per_split);
 331   printf ("#endif\n");
 332
 333   if (have_cc0_flag)
 334     {
 335       printf ("#define HAVE_cc0 1\n");
 336       printf ("#define CC0_P(X) ((X) == cc0_rtx)\n");
 337     }
 338   else
 339     {
 340       /* We output CC0_P this way to make sure that X is declared
 341          somewhere.  */
 342       printf ("#define HAVE_cc0 0\n");
 343       printf ("#define CC0_P(X) ((X) ? 0 : 0)\n");
 344     }
 345
 346   if (have_cmove_flag)
 347     printf ("#define HAVE_conditional_move 1\n");
 348   else
 349     printf ("#define HAVE_conditional_move 0\n");
 350
 351   if (have_cond_exec_flag)
 352     printf ("#define HAVE_conditional_execution 1\n");
 353   else
 354     printf ("#define HAVE_conditional_execution 0\n");
 355
 356   if (have_lo_sum_flag)
 357     printf ("#define HAVE_lo_sum 1\n");
 358   else
 359     printf ("#define HAVE_lo_sum 0\n");
 360
 361   if (have_rotate_flag)
 362     printf ("#define HAVE_rotate 1\n");
 363
 364   if (have_rotatert_flag)
 365     printf ("#define HAVE_rotatert 1\n");
 366
 367   if (have_peephole_flag)
 368     printf ("#define HAVE_peephole 1\n");
 369   else
 370     printf ("#define HAVE_peephole 0\n");
 371
 372   if (have_peephole2_flag)
 373     {
 374       printf ("#define HAVE_peephole2 1\n");
 375       printf ("#define MAX_INSNS_PER_PEEP2 %d\n", max_insns_per_peep2);
 376     }
 377   else
 378     {
 379       printf ("#define HAVE_peephole2 0\n");
 380       printf ("#define MAX_INSNS_PER_PEEP2 0\n");
 381     }
 382
 383   puts ("\n#endif /* GCC_INSN_CONFIG_H */");
 384
 385   if (ferror (stdout) || fflush (stdout) || fclose (stdout))
 386     return FATAL_EXIT_CODE;
 387
 388   return SUCCESS_EXIT_CODE;
 389 }