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