gcc/genconfig.c

   1 /* Generate from machine description:
   2
   3    - some #define configuration flags.
   4    Copyright (C) 1987, 1991 Free Software Foundation, Inc.
   5
   6 This file is part of GNU CC.
   7
   8 GNU CC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 GNU CC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU CC; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  21
  22
  23 #include <stdio.h>
  24 #include "config.h"
  25 #include "rtl.h"
  26 #include "obstack.h"
  27
  28 static struct obstack obstack;
  29 struct obstack *rtl_obstack = &obstack;
  30
  31 #define obstack_chunk_alloc xmalloc
  32 #define obstack_chunk_free free
  33
  34 extern void free ();
  35 extern rtx read_rtx ();
  36
  37 /* flags to determine output of machine description dependent #define's.  */
  38 static int max_recog_operands;  /* Largest operand number seen.  */
  39 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  40 static int max_clobbers_per_insn;
  41 static int register_constraint_flag;
  42 static int have_cc0_flag;
  43 static int have_lo_sum_flag;
  44
  45 /* Maximum number of insns seen in a split.  */
  46 static int max_insns_per_split = 1;
  47
  48 static int clobbers_seen_this_insn;
  49 static int dup_operands_seen_this_insn;
  50
  51 char *xmalloc ();
  52 static void fatal ();
  53 void fancy_abort ();
  54
  55 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  56    be used to recognize, rather than just generate an insn.  */
  57
  58 static void
  59 walk_insn_part (part, recog_p)
  60      rtx part;
  61 {
  62   register int i, j;
  63   register RTX_CODE code;
  64   register char *format_ptr;
  65
  66   if (part == 0)
  67     return;
  68
  69   code = GET_CODE (part);
  70   switch (code)
  71     {
  72     case CLOBBER:
  73       clobbers_seen_this_insn++;
  74       break;
  75
  76     case MATCH_OPERAND:
  77       if (XINT (part, 0) > max_recog_operands)
  78         max_recog_operands = XINT (part, 0);
  79       if (XSTR (part, 2) && *XSTR (part, 2))
  80         register_constraint_flag = 1;
  81       return;
  82
  83     case MATCH_OP_DUP:
  84       ++dup_operands_seen_this_insn;
  85     case MATCH_SCRATCH:
  86     case MATCH_PARALLEL:
  87     case MATCH_OPERATOR:
  88       if (XINT (part, 0) > max_recog_operands)
  89         max_recog_operands = XINT (part, 0);
  90       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  91          MATCH_PARALLEL.  */
  92       break;
  93
  94     case LABEL_REF:
  95       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
  96         break;
  97       return;
  98
  99     case MATCH_DUP:
 100       ++dup_operands_seen_this_insn;
 101       if (XINT (part, 0) > max_recog_operands)
 102         max_recog_operands = XINT (part, 0);
 103       return;
 104
 105     case CC0:
 106       if (recog_p)
 107         have_cc0_flag = 1;
 108       return;
 109
 110     case LO_SUM:
 111       if (recog_p)
 112         have_lo_sum_flag = 1;
 113       return;
 114
 115     case REG: case CONST_INT: case SYMBOL_REF:
 116     case PC:
 117       return;
 118     }
 119
 120   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 121
 122   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 123     switch (*format_ptr++)
 124       {
 125       case 'e':
 126       case 'u':
 127         walk_insn_part (XEXP (part, i), recog_p);
 128         break;
 129       case 'E':
 130         if (XVEC (part, i) != NULL)
 131           for (j = 0; j < XVECLEN (part, i); j++)
 132             walk_insn_part (XVECEXP (part, i, j), recog_p);
 133         break;
 134       }
 135 }
 136
 137 static void
 138 gen_insn (insn)
 139      rtx insn;
 140 {
 141   int i;
 142
 143   /* Walk the insn pattern to gather the #define's status.  */
 144   clobbers_seen_this_insn = 0;
 145   dup_operands_seen_this_insn = 0;
 146   if (XVEC (insn, 1) != 0)
 147     for (i = 0; i < XVECLEN (insn, 1); i++)
 148       walk_insn_part (XVECEXP (insn, 1, i), 1);
 149
 150   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 151     max_clobbers_per_insn = clobbers_seen_this_insn;
 152   if (dup_operands_seen_this_insn > max_dup_operands)
 153     max_dup_operands = dup_operands_seen_this_insn;
 154 }
 155
 156 /* Similar but scan a define_expand.  */
 157
 158 static void
 159 gen_expand (insn)
 160      rtx insn;
 161 {
 162   int i;
 163
 164   /* Walk the insn pattern to gather the #define's status.  */
 165
 166   /* Note that we don't bother recording the number of MATCH_DUPs
 167      that occur in a gen_expand, because only reload cares about that.  */
 168   if (XVEC (insn, 1) != 0)
 169     for (i = 0; i < XVECLEN (insn, 1); i++)
 170       {
 171         /* Compute the maximum SETs and CLOBBERS
 172            in any one of the sub-insns;
 173            don't sum across all of them.  */
 174         clobbers_seen_this_insn = 0;
 175
 176         walk_insn_part (XVECEXP (insn, 1, i), 0);
 177
 178         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 179           max_clobbers_per_insn = clobbers_seen_this_insn;
 180       }
 181 }
 182
 183 /* Similar but scan a define_split.  */
 184
 185 static void
 186 gen_split (split)
 187      rtx split;
 188 {
 189   int i;
 190
 191   /* Look through the patterns that are matched
 192      to compute the maximum operand number.  */
 193   for (i = 0; i < XVECLEN (split, 0); i++)
 194     walk_insn_part (XVECEXP (split, 0, i), 1);
 195   /* Look at the number of insns this insn could split into.  */
 196   if (XVECLEN (split, 2) > max_insns_per_split)
 197     max_insns_per_split = XVECLEN (split, 2);
 198 }
 199
 200 static void
 201 gen_peephole (peep)
 202      rtx peep;
 203 {
 204   int i;
 205
 206   /* Look through the patterns that are matched
 207      to compute the maximum operand number.  */
 208   for (i = 0; i < XVECLEN (peep, 0); i++)
 209     walk_insn_part (XVECEXP (peep, 0, i), 1);
 210 }
 211 \f
 212 char *
 213 xmalloc (size)
 214      unsigned size;
 215 {
 216   register char *val = (char *) malloc (size);
 217
 218   if (val == 0)
 219     fatal ("virtual memory exhausted");
 220
 221   return val;
 222 }
 223
 224 char *
 225 xrealloc (ptr, size)
 226      char *ptr;
 227      unsigned size;
 228 {
 229   char *result = (char *) realloc (ptr, size);
 230   if (!result)
 231     fatal ("virtual memory exhausted");
 232   return result;
 233 }
 234
 235 static void
 236 fatal (s, a1, a2)
 237      char *s;
 238 {
 239   fprintf (stderr, "genconfig: ");
 240   fprintf (stderr, s, a1, a2);
 241   fprintf (stderr, "\n");
 242   exit (FATAL_EXIT_CODE);
 243 }
 244
 245 /* More 'friendly' abort that prints the line and file.
 246    config.h can #define abort fancy_abort if you like that sort of thing.  */
 247
 248 void
 249 fancy_abort ()
 250 {
 251   fatal ("Internal gcc abort.");
 252 }
 253 \f
 254 int
 255 main (argc, argv)
 256      int argc;
 257      char **argv;
 258 {
 259   rtx desc;
 260   FILE *infile;
 261   register int c;
 262
 263   obstack_init (rtl_obstack);
 264
 265   if (argc <= 1)
 266     fatal ("No input file name.");
 267
 268   infile = fopen (argv[1], "r");
 269   if (infile == 0)
 270     {
 271       perror (argv[1]);
 272       exit (FATAL_EXIT_CODE);
 273     }
 274
 275   init_rtl ();
 276
 277   printf ("/* Generated automatically by the program `genconfig'\n\
 278 from the machine description file `md'.  */\n\n");
 279
 280   /* Allow at least 10 operands for the sake of asm constructs.  */
 281   max_recog_operands = 9;  /* We will add 1 later.  */
 282   max_dup_operands = 1;
 283
 284   /* Read the machine description.  */
 285
 286   while (1)
 287     {
 288       c = read_skip_spaces (infile);
 289       if (c == EOF)
 290         break;
 291       ungetc (c, infile);
 292
 293       desc = read_rtx (infile);
 294       if (GET_CODE (desc) == DEFINE_INSN)
 295         gen_insn (desc);
 296       if (GET_CODE (desc) == DEFINE_EXPAND)
 297         gen_expand (desc);
 298       if (GET_CODE (desc) == DEFINE_SPLIT)
 299         gen_split (desc);
 300       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 301         gen_peephole (desc);
 302     }
 303
 304   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 305
 306   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 307
 308   /* This is conditionally defined, in case the user writes code which emits
 309      more splits than we can readily see (and knows s/he does it).  */
 310   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 311           max_insns_per_split);
 312
 313   if (register_constraint_flag)
 314     printf ("#define REGISTER_CONSTRAINTS\n");
 315
 316   if (have_cc0_flag)
 317     printf ("#define HAVE_cc0\n");
 318
 319   if (have_lo_sum_flag)
 320     printf ("#define HAVE_lo_sum\n");
 321
 322   fflush (stdout);
 323   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 324   /* NOTREACHED */
 325   return 0;
 326 }