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, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23
  24 #include <stdio.h>
  25 #include "hconfig.h"
  26 #include "rtl.h"
  27 #include "obstack.h"
  28
  29 static struct obstack obstack;
  30 struct obstack *rtl_obstack = &obstack;
  31
  32 #define obstack_chunk_alloc xmalloc
  33 #define obstack_chunk_free free
  34
  35 extern void free ();
  36 extern rtx read_rtx ();
  37
  38 /* flags to determine output of machine description dependent #define's.  */
  39 static int max_recog_operands;  /* Largest operand number seen.  */
  40 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  41 static int max_clobbers_per_insn;
  42 static int register_constraint_flag;
  43 static int have_cc0_flag;
  44 static int have_cmove_flag;
  45 static int have_lo_sum_flag;
  46
  47 /* Maximum number of insns seen in a split.  */
  48 static int max_insns_per_split = 1;
  49
  50 static int clobbers_seen_this_insn;
  51 static int dup_operands_seen_this_insn;
  52
  53 char *xmalloc ();
  54 static void fatal ();
  55 void fancy_abort ();
  56
  57 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  58    be used to recognize, rather than just generate an insn.
  59
  60    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  61    of a SET whose destination is not (pc).  */
  62
  63 static void
  64 walk_insn_part (part, recog_p, non_pc_set_src)
  65      rtx part;
  66      int recog_p;
  67      int non_pc_set_src;
  68 {
  69   register int i, j;
  70   register RTX_CODE code;
  71   register char *format_ptr;
  72
  73   if (part == 0)
  74     return;
  75
  76   code = GET_CODE (part);
  77   switch (code)
  78     {
  79     case CLOBBER:
  80       clobbers_seen_this_insn++;
  81       break;
  82
  83     case MATCH_OPERAND:
  84       if (XINT (part, 0) > max_recog_operands)
  85         max_recog_operands = XINT (part, 0);
  86       if (XSTR (part, 2) && *XSTR (part, 2))
  87         register_constraint_flag = 1;
  88       return;
  89
  90     case MATCH_OP_DUP:
  91     case MATCH_PAR_DUP:
  92       ++dup_operands_seen_this_insn;
  93     case MATCH_SCRATCH:
  94     case MATCH_PARALLEL:
  95     case MATCH_OPERATOR:
  96       if (XINT (part, 0) > max_recog_operands)
  97         max_recog_operands = XINT (part, 0);
  98       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  99          MATCH_PARALLEL.  */
 100       break;
 101
 102     case LABEL_REF:
 103       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 104         break;
 105       return;
 106
 107     case MATCH_DUP:
 108       ++dup_operands_seen_this_insn;
 109       if (XINT (part, 0) > max_recog_operands)
 110         max_recog_operands = XINT (part, 0);
 111       return;
 112
 113     case CC0:
 114       if (recog_p)
 115         have_cc0_flag = 1;
 116       return;
 117
 118     case LO_SUM:
 119       if (recog_p)
 120         have_lo_sum_flag = 1;
 121       return;
 122
 123     case SET:
 124       walk_insn_part (SET_DEST (part), 0, recog_p);
 125       walk_insn_part (SET_SRC (part), recog_p,
 126                       GET_CODE (SET_DEST (part)) != PC);
 127       return;
 128
 129     case IF_THEN_ELSE:
 130       /* Only consider this machine as having a conditional move if the
 131          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 132          we have some specific IF_THEN_ELSE construct (like the doz
 133          instruction on the RS/6000) that can't be used in the general
 134          context we want it for.  */
 135
 136       if (recog_p && non_pc_set_src
 137           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 138           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 139         have_cmove_flag = 1;
 140       break;
 141
 142     case REG: case CONST_INT: case SYMBOL_REF:
 143     case PC:
 144       return;
 145     }
 146
 147   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 148
 149   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 150     switch (*format_ptr++)
 151       {
 152       case 'e':
 153       case 'u':
 154         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 155         break;
 156       case 'E':
 157         if (XVEC (part, i) != NULL)
 158           for (j = 0; j < XVECLEN (part, i); j++)
 159             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 160         break;
 161       }
 162 }
 163
 164 static void
 165 gen_insn (insn)
 166      rtx insn;
 167 {
 168   int i;
 169
 170   /* Walk the insn pattern to gather the #define's status.  */
 171   clobbers_seen_this_insn = 0;
 172   dup_operands_seen_this_insn = 0;
 173   if (XVEC (insn, 1) != 0)
 174     for (i = 0; i < XVECLEN (insn, 1); i++)
 175       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 176
 177   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 178     max_clobbers_per_insn = clobbers_seen_this_insn;
 179   if (dup_operands_seen_this_insn > max_dup_operands)
 180     max_dup_operands = dup_operands_seen_this_insn;
 181 }
 182
 183 /* Similar but scan a define_expand.  */
 184
 185 static void
 186 gen_expand (insn)
 187      rtx insn;
 188 {
 189   int i;
 190
 191   /* Walk the insn pattern to gather the #define's status.  */
 192
 193   /* Note that we don't bother recording the number of MATCH_DUPs
 194      that occur in a gen_expand, because only reload cares about that.  */
 195   if (XVEC (insn, 1) != 0)
 196     for (i = 0; i < XVECLEN (insn, 1); i++)
 197       {
 198         /* Compute the maximum SETs and CLOBBERS
 199            in any one of the sub-insns;
 200            don't sum across all of them.  */
 201         clobbers_seen_this_insn = 0;
 202
 203         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 204
 205         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 206           max_clobbers_per_insn = clobbers_seen_this_insn;
 207       }
 208 }
 209
 210 /* Similar but scan a define_split.  */
 211
 212 static void
 213 gen_split (split)
 214      rtx split;
 215 {
 216   int i;
 217
 218   /* Look through the patterns that are matched
 219      to compute the maximum operand number.  */
 220   for (i = 0; i < XVECLEN (split, 0); i++)
 221     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 222   /* Look at the number of insns this insn could split into.  */
 223   if (XVECLEN (split, 2) > max_insns_per_split)
 224     max_insns_per_split = XVECLEN (split, 2);
 225 }
 226
 227 static void
 228 gen_peephole (peep)
 229      rtx peep;
 230 {
 231   int i;
 232
 233   /* Look through the patterns that are matched
 234      to compute the maximum operand number.  */
 235   for (i = 0; i < XVECLEN (peep, 0); i++)
 236     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 237 }
 238 \f
 239 char *
 240 xmalloc (size)
 241      unsigned size;
 242 {
 243   register char *val = (char *) malloc (size);
 244
 245   if (val == 0)
 246     fatal ("virtual memory exhausted");
 247
 248   return val;
 249 }
 250
 251 char *
 252 xrealloc (ptr, size)
 253      char *ptr;
 254      unsigned size;
 255 {
 256   char *result = (char *) realloc (ptr, size);
 257   if (!result)
 258     fatal ("virtual memory exhausted");
 259   return result;
 260 }
 261
 262 static void
 263 fatal (s, a1, a2)
 264      char *s;
 265 {
 266   fprintf (stderr, "genconfig: ");
 267   fprintf (stderr, s, a1, a2);
 268   fprintf (stderr, "\n");
 269   exit (FATAL_EXIT_CODE);
 270 }
 271
 272 /* More 'friendly' abort that prints the line and file.
 273    config.h can #define abort fancy_abort if you like that sort of thing.  */
 274
 275 void
 276 fancy_abort ()
 277 {
 278   fatal ("Internal gcc abort.");
 279 }
 280 \f
 281 int
 282 main (argc, argv)
 283      int argc;
 284      char **argv;
 285 {
 286   rtx desc;
 287   FILE *infile;
 288   register int c;
 289
 290   obstack_init (rtl_obstack);
 291
 292   if (argc <= 1)
 293     fatal ("No input file name.");
 294
 295   infile = fopen (argv[1], "r");
 296   if (infile == 0)
 297     {
 298       perror (argv[1]);
 299       exit (FATAL_EXIT_CODE);
 300     }
 301
 302   init_rtl ();
 303
 304   printf ("/* Generated automatically by the program `genconfig'\n\
 305 from the machine description file `md'.  */\n\n");
 306
 307   /* Allow at least 10 operands for the sake of asm constructs.  */
 308   max_recog_operands = 9;  /* We will add 1 later.  */
 309   max_dup_operands = 1;
 310
 311   /* Read the machine description.  */
 312
 313   while (1)
 314     {
 315       c = read_skip_spaces (infile);
 316       if (c == EOF)
 317         break;
 318       ungetc (c, infile);
 319
 320       desc = read_rtx (infile);
 321       if (GET_CODE (desc) == DEFINE_INSN)
 322         gen_insn (desc);
 323       if (GET_CODE (desc) == DEFINE_EXPAND)
 324         gen_expand (desc);
 325       if (GET_CODE (desc) == DEFINE_SPLIT)
 326         gen_split (desc);
 327       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 328         gen_peephole (desc);
 329     }
 330
 331   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 332
 333   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 334
 335   /* This is conditionally defined, in case the user writes code which emits
 336      more splits than we can readily see (and knows s/he does it).  */
 337   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 338           max_insns_per_split);
 339
 340   if (register_constraint_flag)
 341     printf ("#define REGISTER_CONSTRAINTS\n");
 342
 343   if (have_cc0_flag)
 344     printf ("#define HAVE_cc0\n");
 345
 346   if (have_cmove_flag)
 347     printf ("#define HAVE_conditional_move\n");
 348
 349   if (have_lo_sum_flag)
 350     printf ("#define HAVE_lo_sum\n");
 351
 352   fflush (stdout);
 353   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 354   /* NOTREACHED */
 355   return 0;
 356 }