gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987, 91, 97-99, 2000 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 #include "errors.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 /* flags to determine output of machine description dependent #define's.  */
  36 static int max_recog_operands;  /* Largest operand number seen.  */
  37 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  38 static int max_clobbers_per_insn;
  39 static int have_cc0_flag;
  40 static int have_cmove_flag;
  41 static int have_cond_arith_flag;
  42 static int have_lo_sum_flag;
  43 static int have_peephole_flag;
  44 static int have_peephole2_flag;
  45
  46 /* Maximum number of insns seen in a split.  */
  47 static int max_insns_per_split = 1;
  48
  49 static int clobbers_seen_this_insn;
  50 static int dup_operands_seen_this_insn;
  51
  52 static void walk_insn_part PARAMS ((rtx, int, int));
  53 static void gen_insn PARAMS ((rtx));
  54 static void gen_expand PARAMS ((rtx));
  55 static void gen_split PARAMS ((rtx));
  56 static void gen_peephole PARAMS ((rtx));
  57
  58 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  59    be used to recognize, rather than just generate an insn.
  60
  61    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  62    of a SET whose destination is not (pc).  */
  63
  64 static void
  65 walk_insn_part (part, recog_p, non_pc_set_src)
  66      rtx part;
  67      int recog_p;
  68      int non_pc_set_src;
  69 {
  70   register int i, j;
  71   register RTX_CODE code;
  72   register const char *format_ptr;
  73
  74   if (part == 0)
  75     return;
  76
  77   code = GET_CODE (part);
  78   switch (code)
  79     {
  80     case CLOBBER:
  81       clobbers_seen_this_insn++;
  82       break;
  83
  84     case MATCH_OPERAND:
  85       if (XINT (part, 0) > max_recog_operands)
  86         max_recog_operands = XINT (part, 0);
  87       return;
  88
  89     case MATCH_OP_DUP:
  90     case MATCH_PAR_DUP:
  91       ++dup_operands_seen_this_insn;
  92     case MATCH_SCRATCH:
  93     case MATCH_PARALLEL:
  94     case MATCH_OPERATOR:
  95       if (XINT (part, 0) > max_recog_operands)
  96         max_recog_operands = XINT (part, 0);
  97       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  98          MATCH_PARALLEL.  */
  99       break;
 100
 101     case LABEL_REF:
 102       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 103         break;
 104       return;
 105
 106     case MATCH_DUP:
 107       ++dup_operands_seen_this_insn;
 108       if (XINT (part, 0) > max_recog_operands)
 109         max_recog_operands = XINT (part, 0);
 110       return;
 111
 112     case CC0:
 113       if (recog_p)
 114         have_cc0_flag = 1;
 115       return;
 116
 117     case LO_SUM:
 118       if (recog_p)
 119         have_lo_sum_flag = 1;
 120       return;
 121
 122     case SET:
 123       walk_insn_part (SET_DEST (part), 0, recog_p);
 124       walk_insn_part (SET_SRC (part), recog_p,
 125                       GET_CODE (SET_DEST (part)) != PC);
 126       return;
 127
 128     case IF_THEN_ELSE:
 129       /* Only consider this machine as having a conditional move if the
 130          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 131          we have some specific IF_THEN_ELSE construct (like the doz
 132          instruction on the RS/6000) that can't be used in the general
 133          context we want it for.  If the first operand is an arithmetic
 134          operation and the second is a MATCH_OPERNAND, show we have
 135          conditional arithmetic.  */
 136
 137       if (recog_p && non_pc_set_src
 138           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 139           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 140         have_cmove_flag = 1;
 141       else if (recog_p && non_pc_set_src
 142                && (GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == '1'
 143                    || GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == '2'
 144                    || GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == 'c')
 145                && GET_CODE (XEXP (XEXP (part, 1), 0)) == MATCH_OPERAND
 146                && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 147         have_cond_arith_flag = 1;
 148       break;
 149
 150     case REG: case CONST_INT: case SYMBOL_REF:
 151     case PC:
 152       return;
 153
 154     default:
 155       break;
 156     }
 157
 158   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 159
 160   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 161     switch (*format_ptr++)
 162       {
 163       case 'e':
 164       case 'u':
 165         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 166         break;
 167       case 'E':
 168         if (XVEC (part, i) != NULL)
 169           for (j = 0; j < XVECLEN (part, i); j++)
 170             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 171         break;
 172       }
 173 }
 174
 175 static void
 176 gen_insn (insn)
 177      rtx insn;
 178 {
 179   int i;
 180
 181   /* Walk the insn pattern to gather the #define's status.  */
 182   clobbers_seen_this_insn = 0;
 183   dup_operands_seen_this_insn = 0;
 184   if (XVEC (insn, 1) != 0)
 185     for (i = 0; i < XVECLEN (insn, 1); i++)
 186       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 187
 188   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 189     max_clobbers_per_insn = clobbers_seen_this_insn;
 190   if (dup_operands_seen_this_insn > max_dup_operands)
 191     max_dup_operands = dup_operands_seen_this_insn;
 192 }
 193
 194 /* Similar but scan a define_expand.  */
 195
 196 static void
 197 gen_expand (insn)
 198      rtx insn;
 199 {
 200   int i;
 201
 202   /* Walk the insn pattern to gather the #define's status.  */
 203
 204   /* Note that we don't bother recording the number of MATCH_DUPs
 205      that occur in a gen_expand, because only reload cares about that.  */
 206   if (XVEC (insn, 1) != 0)
 207     for (i = 0; i < XVECLEN (insn, 1); i++)
 208       {
 209         /* Compute the maximum SETs and CLOBBERS
 210            in any one of the sub-insns;
 211            don't sum across all of them.  */
 212         clobbers_seen_this_insn = 0;
 213
 214         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 215
 216         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 217           max_clobbers_per_insn = clobbers_seen_this_insn;
 218       }
 219 }
 220
 221 /* Similar but scan a define_split.  */
 222
 223 static void
 224 gen_split (split)
 225      rtx split;
 226 {
 227   int i;
 228
 229   /* Look through the patterns that are matched
 230      to compute the maximum operand number.  */
 231   for (i = 0; i < XVECLEN (split, 0); i++)
 232     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 233   /* Look at the number of insns this insn could split into.  */
 234   if (XVECLEN (split, 2) > max_insns_per_split)
 235     max_insns_per_split = XVECLEN (split, 2);
 236 }
 237
 238 static void
 239 gen_peephole (peep)
 240      rtx peep;
 241 {
 242   int i;
 243
 244   /* Look through the patterns that are matched
 245      to compute the maximum operand number.  */
 246   for (i = 0; i < XVECLEN (peep, 0); i++)
 247     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 248 }
 249 \f
 250 PTR
 251 xmalloc (size)
 252   size_t size;
 253 {
 254   register PTR val = (PTR) malloc (size);
 255
 256   if (val == 0)
 257     fatal ("virtual memory exhausted");
 258
 259   return val;
 260 }
 261
 262 PTR
 263 xrealloc (old, size)
 264   PTR old;
 265   size_t size;
 266 {
 267   register PTR ptr;
 268   if (old)
 269     ptr = (PTR) realloc (old, size);
 270   else
 271     ptr = (PTR) malloc (size);
 272   if (!ptr)
 273     fatal ("virtual memory exhausted");
 274   return ptr;
 275 }
 276
 277 extern int main PARAMS ((int, char **));
 278
 279 int
 280 main (argc, argv)
 281      int argc;
 282      char **argv;
 283 {
 284   rtx desc;
 285   FILE *infile;
 286   register int c;
 287
 288   progname = "genconfig";
 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       return (FATAL_EXIT_CODE);
 299     }
 300   read_rtx_filename = argv[1];
 301
 302   printf ("/* Generated automatically by the program `genconfig'\n\
 303 from the machine description file `md'.  */\n\n");
 304
 305   /* Allow at least 10 operands for the sake of asm constructs.  */
 306   max_recog_operands = 9;  /* We will add 1 later.  */
 307   max_dup_operands = 1;
 308
 309   /* Read the machine description.  */
 310
 311   while (1)
 312     {
 313       c = read_skip_spaces (infile);
 314       if (c == EOF)
 315         break;
 316       ungetc (c, infile);
 317
 318       desc = read_rtx (infile);
 319       if (GET_CODE (desc) == DEFINE_INSN)
 320         gen_insn (desc);
 321       if (GET_CODE (desc) == DEFINE_EXPAND)
 322         gen_expand (desc);
 323       if (GET_CODE (desc) == DEFINE_SPLIT)
 324         gen_split (desc);
 325       if (GET_CODE (desc) == DEFINE_PEEPHOLE2)
 326         {
 327           have_peephole2_flag = 1;
 328           gen_split (desc);
 329         }
 330       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 331         {
 332           have_peephole_flag = 1;
 333           gen_peephole (desc);
 334         }
 335     }
 336
 337   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 338
 339   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 340
 341   /* This is conditionally defined, in case the user writes code which emits
 342      more splits than we can readily see (and knows s/he does it).  */
 343   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 344           max_insns_per_split);
 345
 346   if (have_cc0_flag)
 347     printf ("#define HAVE_cc0\n");
 348
 349   if (have_cmove_flag)
 350     printf ("#define HAVE_conditional_move\n");
 351
 352 #if 0
 353   /* Disabled.  See the discussion in jump.c.  */
 354   if (have_cond_arith_flag)
 355     printf ("#define HAVE_conditional_arithmetic\n");
 356 #endif
 357
 358   if (have_lo_sum_flag)
 359     printf ("#define HAVE_lo_sum\n");
 360
 361   if (have_peephole_flag)
 362     printf ("#define HAVE_peephole\n");
 363
 364   if (have_peephole2_flag)
 365     printf ("#define HAVE_peephole2\n");
 366
 367   fflush (stdout);
 368   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 369 }
 370
 371 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
 372 const char *
 373 get_insn_name (code)
 374      int code ATTRIBUTE_UNUSED;
 375 {
 376   return NULL;
 377 }