gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987, 1991, 1997, 1998,
   4    1999, 2000 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 "hconfig.h"
  25 #include "system.h"
  26 #include "rtl.h"
  27 #include "obstack.h"
  28 #include "errors.h"
  29
  30 static struct obstack obstack;
  31 struct obstack *rtl_obstack = &obstack;
  32
  33 #define obstack_chunk_alloc xmalloc
  34 #define obstack_chunk_free free
  35
  36 /* flags to determine output of machine description dependent #define's.  */
  37 static int max_recog_operands;  /* Largest operand number seen.  */
  38 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  39 static int max_clobbers_per_insn;
  40 static int have_cc0_flag;
  41 static int have_cmove_flag;
  42 static int have_cond_exec_flag;
  43 static int have_lo_sum_flag;
  44 static int have_peephole_flag;
  45 static int have_peephole2_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 static void walk_insn_part PARAMS ((rtx, int, int));
  54 static void gen_insn PARAMS ((rtx));
  55 static void gen_expand PARAMS ((rtx));
  56 static void gen_split PARAMS ((rtx));
  57 static void gen_peephole PARAMS ((rtx));
  58
  59 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  60    be used to recognize, rather than just generate an insn.
  61
  62    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  63    of a SET whose destination is not (pc).  */
  64
  65 static void
  66 walk_insn_part (part, recog_p, non_pc_set_src)
  67      rtx part;
  68      int recog_p;
  69      int non_pc_set_src;
  70 {
  71   register int i, j;
  72   register RTX_CODE code;
  73   register const char *format_ptr;
  74
  75   if (part == 0)
  76     return;
  77
  78   code = GET_CODE (part);
  79   switch (code)
  80     {
  81     case CLOBBER:
  82       clobbers_seen_this_insn++;
  83       break;
  84
  85     case MATCH_OPERAND:
  86       if (XINT (part, 0) > max_recog_operands)
  87         max_recog_operands = XINT (part, 0);
  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 COND_EXEC:
 143       if (recog_p)
 144         have_cond_exec_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 PTR
 248 xmalloc (size)
 249   size_t size;
 250 {
 251   register PTR val = (PTR) malloc (size);
 252
 253   if (val == 0)
 254     fatal ("virtual memory exhausted");
 255
 256   return val;
 257 }
 258
 259 PTR
 260 xrealloc (old, size)
 261   PTR old;
 262   size_t size;
 263 {
 264   register PTR ptr;
 265   if (old)
 266     ptr = (PTR) realloc (old, size);
 267   else
 268     ptr = (PTR) malloc (size);
 269   if (!ptr)
 270     fatal ("virtual memory exhausted");
 271   return ptr;
 272 }
 273
 274 extern int main PARAMS ((int, char **));
 275
 276 int
 277 main (argc, argv)
 278      int argc;
 279      char **argv;
 280 {
 281   rtx desc;
 282   FILE *infile;
 283   register int c;
 284
 285   progname = "genconfig";
 286   obstack_init (rtl_obstack);
 287
 288   if (argc <= 1)
 289     fatal ("No input file name.");
 290
 291   infile = fopen (argv[1], "r");
 292   if (infile == 0)
 293     {
 294       perror (argv[1]);
 295       return (FATAL_EXIT_CODE);
 296     }
 297   read_rtx_filename = argv[1];
 298
 299   printf ("/* Generated automatically by the program `genconfig'\n\
 300 from the machine description file `md'.  */\n\n");
 301
 302   /* Allow at least 10 operands for the sake of asm constructs.  */
 303   max_recog_operands = 9;  /* We will add 1 later.  */
 304   max_dup_operands = 1;
 305
 306   /* Read the machine description.  */
 307
 308   while (1)
 309     {
 310       c = read_skip_spaces (infile);
 311       if (c == EOF)
 312         break;
 313       ungetc (c, infile);
 314
 315       desc = read_rtx (infile);
 316       if (GET_CODE (desc) == DEFINE_INSN)
 317         gen_insn (desc);
 318       if (GET_CODE (desc) == DEFINE_EXPAND)
 319         gen_expand (desc);
 320       if (GET_CODE (desc) == DEFINE_SPLIT)
 321         gen_split (desc);
 322       if (GET_CODE (desc) == DEFINE_PEEPHOLE2)
 323         {
 324           have_peephole2_flag = 1;
 325           gen_split (desc);
 326         }
 327       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 328         {
 329           have_peephole_flag = 1;
 330           gen_peephole (desc);
 331         }
 332     }
 333
 334   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 335
 336   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 337
 338   /* This is conditionally defined, in case the user writes code which emits
 339      more splits than we can readily see (and knows s/he does it).  */
 340   printf ("#ifndef MAX_INSNS_PER_SPLIT\n");
 341   printf ("#define MAX_INSNS_PER_SPLIT %d\n", max_insns_per_split);
 342   printf ("#endif\n");
 343
 344   if (have_cc0_flag)
 345     printf ("#define HAVE_cc0\n");
 346
 347   if (have_cmove_flag)
 348     printf ("#define HAVE_conditional_move\n");
 349
 350   if (have_cond_exec_flag)
 351     printf ("#define HAVE_conditional_execution\n");
 352
 353   if (have_lo_sum_flag)
 354     printf ("#define HAVE_lo_sum\n");
 355
 356   if (have_peephole_flag)
 357     printf ("#define HAVE_peephole\n");
 358
 359   if (have_peephole2_flag)
 360     printf ("#define HAVE_peephole2\n");
 361
 362   fflush (stdout);
 363   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 364 }
 365
 366 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
 367 const char *
 368 get_insn_name (code)
 369      int code ATTRIBUTE_UNUSED;
 370 {
 371   return NULL;
 372 }