gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987, 1991, 1997, 1998 Free Software Foundation, Inc.
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22
  23 #include <stdio.h>
  24 #include "hconfig.h"
  25 #include "rtl.h"
  26 #include "obstack.h"
  27
  28 #ifdef HAVE_STDLIB_H
  29 #include <stdlib.h>
  30 #endif
  31
  32 static struct obstack obstack;
  33 struct obstack *rtl_obstack = &obstack;
  34
  35 #define obstack_chunk_alloc xmalloc
  36 #define obstack_chunk_free free
  37
  38 #ifdef NEED_DECLARATION_FREE
  39 extern void free ();
  40 #endif
  41 extern rtx read_rtx ();
  42
  43 /* flags to determine output of machine description dependent #define's.  */
  44 static int max_recog_operands;  /* Largest operand number seen.  */
  45 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  46 static int max_clobbers_per_insn;
  47 static int register_constraint_flag;
  48 static int have_cc0_flag;
  49 static int have_cmove_flag;
  50 static int have_lo_sum_flag;
  51
  52 /* Maximum number of insns seen in a split.  */
  53 static int max_insns_per_split = 1;
  54
  55 static int clobbers_seen_this_insn;
  56 static int dup_operands_seen_this_insn;
  57
  58 char *xmalloc ();
  59 static void fatal ();
  60 void fancy_abort ();
  61
  62 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  63    be used to recognize, rather than just generate an insn.
  64
  65    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  66    of a SET whose destination is not (pc).  */
  67
  68 static void
  69 walk_insn_part (part, recog_p, non_pc_set_src)
  70      rtx part;
  71      int recog_p;
  72      int non_pc_set_src;
  73 {
  74   register int i, j;
  75   register RTX_CODE code;
  76   register char *format_ptr;
  77
  78   if (part == 0)
  79     return;
  80
  81   code = GET_CODE (part);
  82   switch (code)
  83     {
  84     case CLOBBER:
  85       clobbers_seen_this_insn++;
  86       break;
  87
  88     case MATCH_OPERAND:
  89       if (XINT (part, 0) > max_recog_operands)
  90         max_recog_operands = XINT (part, 0);
  91       if (XSTR (part, 2) && *XSTR (part, 2))
  92         register_constraint_flag = 1;
  93       return;
  94
  95     case MATCH_OP_DUP:
  96     case MATCH_PAR_DUP:
  97       ++dup_operands_seen_this_insn;
  98     case MATCH_SCRATCH:
  99     case MATCH_PARALLEL:
 100     case MATCH_OPERATOR:
 101       if (XINT (part, 0) > max_recog_operands)
 102         max_recog_operands = XINT (part, 0);
 103       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
 104          MATCH_PARALLEL.  */
 105       break;
 106
 107     case LABEL_REF:
 108       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 109         break;
 110       return;
 111
 112     case MATCH_DUP:
 113       ++dup_operands_seen_this_insn;
 114       if (XINT (part, 0) > max_recog_operands)
 115         max_recog_operands = XINT (part, 0);
 116       return;
 117
 118     case CC0:
 119       if (recog_p)
 120         have_cc0_flag = 1;
 121       return;
 122
 123     case LO_SUM:
 124       if (recog_p)
 125         have_lo_sum_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 REG: case CONST_INT: case SYMBOL_REF:
 148     case PC:
 149       return;
 150
 151     default:
 152       break;
 153     }
 154
 155   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 156
 157   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 158     switch (*format_ptr++)
 159       {
 160       case 'e':
 161       case 'u':
 162         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 163         break;
 164       case 'E':
 165         if (XVEC (part, i) != NULL)
 166           for (j = 0; j < XVECLEN (part, i); j++)
 167             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 168         break;
 169       }
 170 }
 171
 172 static void
 173 gen_insn (insn)
 174      rtx insn;
 175 {
 176   int i;
 177
 178   /* Walk the insn pattern to gather the #define's status.  */
 179   clobbers_seen_this_insn = 0;
 180   dup_operands_seen_this_insn = 0;
 181   if (XVEC (insn, 1) != 0)
 182     for (i = 0; i < XVECLEN (insn, 1); i++)
 183       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 184
 185   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 186     max_clobbers_per_insn = clobbers_seen_this_insn;
 187   if (dup_operands_seen_this_insn > max_dup_operands)
 188     max_dup_operands = dup_operands_seen_this_insn;
 189 }
 190
 191 /* Similar but scan a define_expand.  */
 192
 193 static void
 194 gen_expand (insn)
 195      rtx insn;
 196 {
 197   int i;
 198
 199   /* Walk the insn pattern to gather the #define's status.  */
 200
 201   /* Note that we don't bother recording the number of MATCH_DUPs
 202      that occur in a gen_expand, because only reload cares about that.  */
 203   if (XVEC (insn, 1) != 0)
 204     for (i = 0; i < XVECLEN (insn, 1); i++)
 205       {
 206         /* Compute the maximum SETs and CLOBBERS
 207            in any one of the sub-insns;
 208            don't sum across all of them.  */
 209         clobbers_seen_this_insn = 0;
 210
 211         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 212
 213         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 214           max_clobbers_per_insn = clobbers_seen_this_insn;
 215       }
 216 }
 217
 218 /* Similar but scan a define_split.  */
 219
 220 static void
 221 gen_split (split)
 222      rtx split;
 223 {
 224   int i;
 225
 226   /* Look through the patterns that are matched
 227      to compute the maximum operand number.  */
 228   for (i = 0; i < XVECLEN (split, 0); i++)
 229     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 230   /* Look at the number of insns this insn could split into.  */
 231   if (XVECLEN (split, 2) > max_insns_per_split)
 232     max_insns_per_split = XVECLEN (split, 2);
 233 }
 234
 235 static void
 236 gen_peephole (peep)
 237      rtx peep;
 238 {
 239   int i;
 240
 241   /* Look through the patterns that are matched
 242      to compute the maximum operand number.  */
 243   for (i = 0; i < XVECLEN (peep, 0); i++)
 244     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 245 }
 246 \f
 247 char *
 248 xmalloc (size)
 249      unsigned size;
 250 {
 251   register char *val = (char *) malloc (size);
 252
 253   if (val == 0)
 254     fatal ("virtual memory exhausted");
 255
 256   return val;
 257 }
 258
 259 char *
 260 xrealloc (ptr, size)
 261      char *ptr;
 262      unsigned size;
 263 {
 264   char *result = (char *) realloc (ptr, size);
 265   if (!result)
 266     fatal ("virtual memory exhausted");
 267   return result;
 268 }
 269
 270 static void
 271 fatal (s, a1, a2)
 272      char *s;
 273 {
 274   fprintf (stderr, "genconfig: ");
 275   fprintf (stderr, s, a1, a2);
 276   fprintf (stderr, "\n");
 277   exit (FATAL_EXIT_CODE);
 278 }
 279
 280 /* More 'friendly' abort that prints the line and file.
 281    config.h can #define abort fancy_abort if you like that sort of thing.  */
 282
 283 void
 284 fancy_abort ()
 285 {
 286   fatal ("Internal gcc abort.");
 287 }
 288 \f
 289 int
 290 main (argc, argv)
 291      int argc;
 292      char **argv;
 293 {
 294   rtx desc;
 295   FILE *infile;
 296   register int c;
 297
 298   obstack_init (rtl_obstack);
 299
 300   if (argc <= 1)
 301     fatal ("No input file name.");
 302
 303   infile = fopen (argv[1], "r");
 304   if (infile == 0)
 305     {
 306       perror (argv[1]);
 307       exit (FATAL_EXIT_CODE);
 308     }
 309
 310   init_rtl ();
 311
 312   printf ("/* Generated automatically by the program `genconfig'\n\
 313 from the machine description file `md'.  */\n\n");
 314
 315   /* Allow at least 10 operands for the sake of asm constructs.  */
 316   max_recog_operands = 9;  /* We will add 1 later.  */
 317   max_dup_operands = 1;
 318
 319   /* Read the machine description.  */
 320
 321   while (1)
 322     {
 323       c = read_skip_spaces (infile);
 324       if (c == EOF)
 325         break;
 326       ungetc (c, infile);
 327
 328       desc = read_rtx (infile);
 329       if (GET_CODE (desc) == DEFINE_INSN)
 330         gen_insn (desc);
 331       if (GET_CODE (desc) == DEFINE_EXPAND)
 332         gen_expand (desc);
 333       if (GET_CODE (desc) == DEFINE_SPLIT)
 334         gen_split (desc);
 335       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 336         gen_peephole (desc);
 337     }
 338
 339   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 340
 341   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 342
 343   /* This is conditionally defined, in case the user writes code which emits
 344      more splits than we can readily see (and knows s/he does it).  */
 345   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 346           max_insns_per_split);
 347
 348   if (register_constraint_flag)
 349     printf ("#define REGISTER_CONSTRAINTS\n");
 350
 351   if (have_cc0_flag)
 352     printf ("#define HAVE_cc0\n");
 353
 354   if (have_cmove_flag)
 355     printf ("#define HAVE_conditional_move\n");
 356
 357   if (have_lo_sum_flag)
 358     printf ("#define HAVE_lo_sum\n");
 359
 360   fflush (stdout);
 361   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 362   /* NOTREACHED */
 363   return 0;
 364 }