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 extern rtx read_rtx ();
  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 register_constraint_flag;
  41 static int have_cc0_flag;
  42 static int have_cmove_flag;
  43 static int have_cond_arith_flag;
  44 static int have_lo_sum_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 char *xmalloc ();
  53 #ifdef HAVE_VPRINTF
  54 void fatal PVPROTO((char *, ...));
  55 #else
  56 /* We must not provide any prototype here, even if ANSI C.  */
  57 void fatal PROTO(());
  58 #endif
  59 void fancy_abort ();
  60
  61 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  62    be used to recognize, rather than just generate an insn.
  63
  64    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  65    of a SET whose destination is not (pc).  */
  66
  67 static void
  68 walk_insn_part (part, recog_p, non_pc_set_src)
  69      rtx part;
  70      int recog_p;
  71      int non_pc_set_src;
  72 {
  73   register int i, j;
  74   register RTX_CODE code;
  75   register char *format_ptr;
  76
  77   if (part == 0)
  78     return;
  79
  80   code = GET_CODE (part);
  81   switch (code)
  82     {
  83     case CLOBBER:
  84       clobbers_seen_this_insn++;
  85       break;
  86
  87     case MATCH_OPERAND:
  88       if (XINT (part, 0) > max_recog_operands)
  89         max_recog_operands = XINT (part, 0);
  90       if (XSTR (part, 2) && *XSTR (part, 2))
  91         register_constraint_flag = 1;
  92       return;
  93
  94     case MATCH_OP_DUP:
  95     case MATCH_PAR_DUP:
  96       ++dup_operands_seen_this_insn;
  97     case MATCH_SCRATCH:
  98     case MATCH_PARALLEL:
  99     case MATCH_OPERATOR:
 100       if (XINT (part, 0) > max_recog_operands)
 101         max_recog_operands = XINT (part, 0);
 102       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
 103          MATCH_PARALLEL.  */
 104       break;
 105
 106     case LABEL_REF:
 107       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 108         break;
 109       return;
 110
 111     case MATCH_DUP:
 112       ++dup_operands_seen_this_insn;
 113       if (XINT (part, 0) > max_recog_operands)
 114         max_recog_operands = XINT (part, 0);
 115       return;
 116
 117     case CC0:
 118       if (recog_p)
 119         have_cc0_flag = 1;
 120       return;
 121
 122     case LO_SUM:
 123       if (recog_p)
 124         have_lo_sum_flag = 1;
 125       return;
 126
 127     case SET:
 128       walk_insn_part (SET_DEST (part), 0, recog_p);
 129       walk_insn_part (SET_SRC (part), recog_p,
 130                       GET_CODE (SET_DEST (part)) != PC);
 131       return;
 132
 133     case IF_THEN_ELSE:
 134       /* Only consider this machine as having a conditional move if the
 135          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 136          we have some specific IF_THEN_ELSE construct (like the doz
 137          instruction on the RS/6000) that can't be used in the general
 138          context we want it for.  If the first operand is an arithmetic
 139          operation and the second is a MATCH_OPERNAND, show we have
 140          conditional arithmetic.  */
 141
 142       if (recog_p && non_pc_set_src
 143           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 144           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 145         have_cmove_flag = 1;
 146       else if (recog_p && non_pc_set_src
 147                && (GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == '1'
 148                    || GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == '2'
 149                    || GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == 'c')
 150                && GET_CODE (XEXP (XEXP (part, 1), 0)) == MATCH_OPERAND
 151                && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 152         have_cond_arith_flag = 1;
 153       break;
 154
 155     case REG: case CONST_INT: case SYMBOL_REF:
 156     case PC:
 157       return;
 158
 159     default:
 160       break;
 161     }
 162
 163   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 164
 165   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 166     switch (*format_ptr++)
 167       {
 168       case 'e':
 169       case 'u':
 170         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 171         break;
 172       case 'E':
 173         if (XVEC (part, i) != NULL)
 174           for (j = 0; j < XVECLEN (part, i); j++)
 175             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 176         break;
 177       }
 178 }
 179
 180 static void
 181 gen_insn (insn)
 182      rtx insn;
 183 {
 184   int i;
 185
 186   /* Walk the insn pattern to gather the #define's status.  */
 187   clobbers_seen_this_insn = 0;
 188   dup_operands_seen_this_insn = 0;
 189   if (XVEC (insn, 1) != 0)
 190     for (i = 0; i < XVECLEN (insn, 1); i++)
 191       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 192
 193   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 194     max_clobbers_per_insn = clobbers_seen_this_insn;
 195   if (dup_operands_seen_this_insn > max_dup_operands)
 196     max_dup_operands = dup_operands_seen_this_insn;
 197 }
 198
 199 /* Similar but scan a define_expand.  */
 200
 201 static void
 202 gen_expand (insn)
 203      rtx insn;
 204 {
 205   int i;
 206
 207   /* Walk the insn pattern to gather the #define's status.  */
 208
 209   /* Note that we don't bother recording the number of MATCH_DUPs
 210      that occur in a gen_expand, because only reload cares about that.  */
 211   if (XVEC (insn, 1) != 0)
 212     for (i = 0; i < XVECLEN (insn, 1); i++)
 213       {
 214         /* Compute the maximum SETs and CLOBBERS
 215            in any one of the sub-insns;
 216            don't sum across all of them.  */
 217         clobbers_seen_this_insn = 0;
 218
 219         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 220
 221         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 222           max_clobbers_per_insn = clobbers_seen_this_insn;
 223       }
 224 }
 225
 226 /* Similar but scan a define_split.  */
 227
 228 static void
 229 gen_split (split)
 230      rtx split;
 231 {
 232   int i;
 233
 234   /* Look through the patterns that are matched
 235      to compute the maximum operand number.  */
 236   for (i = 0; i < XVECLEN (split, 0); i++)
 237     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 238   /* Look at the number of insns this insn could split into.  */
 239   if (XVECLEN (split, 2) > max_insns_per_split)
 240     max_insns_per_split = XVECLEN (split, 2);
 241 }
 242
 243 static void
 244 gen_peephole (peep)
 245      rtx peep;
 246 {
 247   int i;
 248
 249   /* Look through the patterns that are matched
 250      to compute the maximum operand number.  */
 251   for (i = 0; i < XVECLEN (peep, 0); i++)
 252     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 253 }
 254 \f
 255 char *
 256 xmalloc (size)
 257      unsigned size;
 258 {
 259   register char *val = (char *) malloc (size);
 260
 261   if (val == 0)
 262     fatal ("virtual memory exhausted");
 263
 264   return val;
 265 }
 266
 267 char *
 268 xrealloc (ptr, size)
 269      char *ptr;
 270      unsigned size;
 271 {
 272   char *result = (char *) realloc (ptr, size);
 273   if (!result)
 274     fatal ("virtual memory exhausted");
 275   return result;
 276 }
 277
 278 #ifdef HAVE_VPRINTF
 279 void
 280 fatal VPROTO((char *s, ...))
 281 {
 282 #ifndef ANSI_PROTOTYPES
 283   char *s;
 284 #endif
 285   va_list ap;
 286
 287   VA_START (ap, s);
 288
 289 #ifndef ANSI_PROTOTYPES
 290   s = va_arg (ap, char *);
 291 #endif
 292
 293   fprintf (stderr, "genconfig: ");
 294   vfprintf (stderr, s, ap);
 295   va_end (ap);
 296   fprintf (stderr, "\n");
 297   exit (FATAL_EXIT_CODE);
 298 }
 299 #else /* not HAVE_VPRINTF */
 300
 301 void
 302 fatal (s, a1, a2)
 303      char *s;
 304 {
 305   fprintf (stderr, "genconfig: ");
 306   fprintf (stderr, s, a1, a2);
 307   fprintf (stderr, "\n");
 308   exit (FATAL_EXIT_CODE);
 309 }
 310 #endif /* not HAVE_VPRINTF */
 311
 312 /* More 'friendly' abort that prints the line and file.
 313    config.h can #define abort fancy_abort if you like that sort of thing.  */
 314
 315 void
 316 fancy_abort ()
 317 {
 318   fatal ("Internal gcc abort.");
 319 }
 320 \f
 321 int
 322 main (argc, argv)
 323      int argc;
 324      char **argv;
 325 {
 326   rtx desc;
 327   FILE *infile;
 328   register int c;
 329
 330   obstack_init (rtl_obstack);
 331
 332   if (argc <= 1)
 333     fatal ("No input file name.");
 334
 335   infile = fopen (argv[1], "r");
 336   if (infile == 0)
 337     {
 338       perror (argv[1]);
 339       exit (FATAL_EXIT_CODE);
 340     }
 341
 342   init_rtl ();
 343
 344   printf ("/* Generated automatically by the program `genconfig'\n\
 345 from the machine description file `md'.  */\n\n");
 346
 347   /* Allow at least 10 operands for the sake of asm constructs.  */
 348   max_recog_operands = 9;  /* We will add 1 later.  */
 349   max_dup_operands = 1;
 350
 351   /* Read the machine description.  */
 352
 353   while (1)
 354     {
 355       c = read_skip_spaces (infile);
 356       if (c == EOF)
 357         break;
 358       ungetc (c, infile);
 359
 360       desc = read_rtx (infile);
 361       if (GET_CODE (desc) == DEFINE_INSN)
 362         gen_insn (desc);
 363       if (GET_CODE (desc) == DEFINE_EXPAND)
 364         gen_expand (desc);
 365       if (GET_CODE (desc) == DEFINE_SPLIT)
 366         gen_split (desc);
 367       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 368         gen_peephole (desc);
 369     }
 370
 371   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 372
 373   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 374
 375   /* This is conditionally defined, in case the user writes code which emits
 376      more splits than we can readily see (and knows s/he does it).  */
 377   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 378           max_insns_per_split);
 379
 380   if (register_constraint_flag)
 381     printf ("#define REGISTER_CONSTRAINTS\n");
 382
 383   if (have_cc0_flag)
 384     printf ("#define HAVE_cc0\n");
 385
 386   if (have_cmove_flag)
 387     printf ("#define HAVE_conditional_move\n");
 388
 389   if (have_cond_arith_flag)
 390     printf ("#define HAVE_conditional_arithmetic\n");
 391
 392   if (have_lo_sum_flag)
 393     printf ("#define HAVE_lo_sum\n");
 394
 395   fflush (stdout);
 396   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 397   /* NOTREACHED */
 398   return 0;
 399 }