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_arith_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.  If the first operand is an arithmetic
 135          operation and the second is a MATCH_OPERNAND, show we have
 136          conditional arithmetic.  */
 137
 138       if (recog_p && non_pc_set_src
 139           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 140           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 141         have_cmove_flag = 1;
 142       else if (recog_p && non_pc_set_src
 143                && (GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == '1'
 144                    || GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == '2'
 145                    || GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == 'c')
 146                && GET_CODE (XEXP (XEXP (part, 1), 0)) == MATCH_OPERAND
 147                && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 148         have_cond_arith_flag = 1;
 149       break;
 150
 151     case REG: case CONST_INT: case SYMBOL_REF:
 152     case PC:
 153       return;
 154
 155     default:
 156       break;
 157     }
 158
 159   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 160
 161   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 162     switch (*format_ptr++)
 163       {
 164       case 'e':
 165       case 'u':
 166         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 167         break;
 168       case 'E':
 169         if (XVEC (part, i) != NULL)
 170           for (j = 0; j < XVECLEN (part, i); j++)
 171             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 172         break;
 173       }
 174 }
 175
 176 static void
 177 gen_insn (insn)
 178      rtx insn;
 179 {
 180   int i;
 181
 182   /* Walk the insn pattern to gather the #define's status.  */
 183   clobbers_seen_this_insn = 0;
 184   dup_operands_seen_this_insn = 0;
 185   if (XVEC (insn, 1) != 0)
 186     for (i = 0; i < XVECLEN (insn, 1); i++)
 187       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 188
 189   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 190     max_clobbers_per_insn = clobbers_seen_this_insn;
 191   if (dup_operands_seen_this_insn > max_dup_operands)
 192     max_dup_operands = dup_operands_seen_this_insn;
 193 }
 194
 195 /* Similar but scan a define_expand.  */
 196
 197 static void
 198 gen_expand (insn)
 199      rtx insn;
 200 {
 201   int i;
 202
 203   /* Walk the insn pattern to gather the #define's status.  */
 204
 205   /* Note that we don't bother recording the number of MATCH_DUPs
 206      that occur in a gen_expand, because only reload cares about that.  */
 207   if (XVEC (insn, 1) != 0)
 208     for (i = 0; i < XVECLEN (insn, 1); i++)
 209       {
 210         /* Compute the maximum SETs and CLOBBERS
 211            in any one of the sub-insns;
 212            don't sum across all of them.  */
 213         clobbers_seen_this_insn = 0;
 214
 215         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 216
 217         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 218           max_clobbers_per_insn = clobbers_seen_this_insn;
 219       }
 220 }
 221
 222 /* Similar but scan a define_split.  */
 223
 224 static void
 225 gen_split (split)
 226      rtx split;
 227 {
 228   int i;
 229
 230   /* Look through the patterns that are matched
 231      to compute the maximum operand number.  */
 232   for (i = 0; i < XVECLEN (split, 0); i++)
 233     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 234   /* Look at the number of insns this insn could split into.  */
 235   if (XVECLEN (split, 2) > max_insns_per_split)
 236     max_insns_per_split = XVECLEN (split, 2);
 237 }
 238
 239 static void
 240 gen_peephole (peep)
 241      rtx peep;
 242 {
 243   int i;
 244
 245   /* Look through the patterns that are matched
 246      to compute the maximum operand number.  */
 247   for (i = 0; i < XVECLEN (peep, 0); i++)
 248     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 249 }
 250 \f
 251 PTR
 252 xmalloc (size)
 253   size_t size;
 254 {
 255   register PTR val = (PTR) malloc (size);
 256
 257   if (val == 0)
 258     fatal ("virtual memory exhausted");
 259
 260   return val;
 261 }
 262
 263 PTR
 264 xrealloc (old, size)
 265   PTR old;
 266   size_t size;
 267 {
 268   register PTR ptr;
 269   if (old)
 270     ptr = (PTR) realloc (old, size);
 271   else
 272     ptr = (PTR) malloc (size);
 273   if (!ptr)
 274     fatal ("virtual memory exhausted");
 275   return ptr;
 276 }
 277
 278 extern int main PARAMS ((int, char **));
 279
 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   progname = "genconfig";
 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       return (FATAL_EXIT_CODE);
 300     }
 301   read_rtx_filename = argv[1];
 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_PEEPHOLE2)
 327         {
 328           have_peephole2_flag = 1;
 329           gen_split (desc);
 330         }
 331       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 332         {
 333           have_peephole_flag = 1;
 334           gen_peephole (desc);
 335         }
 336     }
 337
 338   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 339
 340   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 341
 342   /* This is conditionally defined, in case the user writes code which emits
 343      more splits than we can readily see (and knows s/he does it).  */
 344   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 345           max_insns_per_split);
 346
 347   if (have_cc0_flag)
 348     printf ("#define HAVE_cc0\n");
 349
 350   if (have_cmove_flag)
 351     printf ("#define HAVE_conditional_move\n");
 352
 353 #if 0
 354   /* Disabled.  See the discussion in jump.c.  */
 355   if (have_cond_arith_flag)
 356     printf ("#define HAVE_conditional_arithmetic\n");
 357 #endif
 358
 359   if (have_lo_sum_flag)
 360     printf ("#define HAVE_lo_sum\n");
 361
 362   if (have_peephole_flag)
 363     printf ("#define HAVE_peephole\n");
 364
 365   if (have_peephole2_flag)
 366     printf ("#define HAVE_peephole2\n");
 367
 368   fflush (stdout);
 369   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 370 }
 371
 372 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
 373 const char *
 374 get_insn_name (code)
 375      int code ATTRIBUTE_UNUSED;
 376 {
 377   return NULL;
 378 }