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 #include "gensupport.h"
  30
  31 static struct obstack obstack;
  32 struct obstack *rtl_obstack = &obstack;
  33
  34 #define obstack_chunk_alloc xmalloc
  35 #define obstack_chunk_free free
  36
  37 /* flags to determine output of machine description dependent #define's.  */
  38 static int max_recog_operands;  /* Largest operand number seen.  */
  39 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  40 static int max_clobbers_per_insn;
  41 static int have_cc0_flag;
  42 static int have_cmove_flag;
  43 static int have_cond_exec_flag;
  44 static int have_lo_sum_flag;
  45 static int have_peephole_flag;
  46 static int have_peephole2_flag;
  47
  48 /* Maximum number of insns seen in a split.  */
  49 static int max_insns_per_split = 1;
  50
  51 static int clobbers_seen_this_insn;
  52 static int dup_operands_seen_this_insn;
  53
  54 static void walk_insn_part PARAMS ((rtx, int, int));
  55 static void gen_insn PARAMS ((rtx));
  56 static void gen_expand PARAMS ((rtx));
  57 static void gen_split PARAMS ((rtx));
  58 static void gen_peephole PARAMS ((rtx));
  59
  60 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  61    be used to recognize, rather than just generate an insn.
  62
  63    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  64    of a SET whose destination is not (pc).  */
  65
  66 static void
  67 walk_insn_part (part, recog_p, non_pc_set_src)
  68      rtx part;
  69      int recog_p;
  70      int non_pc_set_src;
  71 {
  72   register int i, j;
  73   register RTX_CODE code;
  74   register const char *format_ptr;
  75
  76   if (part == 0)
  77     return;
  78
  79   code = GET_CODE (part);
  80   switch (code)
  81     {
  82     case CLOBBER:
  83       clobbers_seen_this_insn++;
  84       break;
  85
  86     case MATCH_OPERAND:
  87       if (XINT (part, 0) > max_recog_operands)
  88         max_recog_operands = XINT (part, 0);
  89       return;
  90
  91     case MATCH_OP_DUP:
  92     case MATCH_PAR_DUP:
  93       ++dup_operands_seen_this_insn;
  94     case MATCH_SCRATCH:
  95     case MATCH_PARALLEL:
  96     case MATCH_OPERATOR:
  97       if (XINT (part, 0) > max_recog_operands)
  98         max_recog_operands = XINT (part, 0);
  99       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
 100          MATCH_PARALLEL.  */
 101       break;
 102
 103     case LABEL_REF:
 104       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 105         break;
 106       return;
 107
 108     case MATCH_DUP:
 109       ++dup_operands_seen_this_insn;
 110       if (XINT (part, 0) > max_recog_operands)
 111         max_recog_operands = XINT (part, 0);
 112       return;
 113
 114     case CC0:
 115       if (recog_p)
 116         have_cc0_flag = 1;
 117       return;
 118
 119     case LO_SUM:
 120       if (recog_p)
 121         have_lo_sum_flag = 1;
 122       return;
 123
 124     case SET:
 125       walk_insn_part (SET_DEST (part), 0, recog_p);
 126       walk_insn_part (SET_SRC (part), recog_p,
 127                       GET_CODE (SET_DEST (part)) != PC);
 128       return;
 129
 130     case IF_THEN_ELSE:
 131       /* Only consider this machine as having a conditional move if the
 132          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 133          we have some specific IF_THEN_ELSE construct (like the doz
 134          instruction on the RS/6000) that can't be used in the general
 135          context we want it for.  */
 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       break;
 142
 143     case COND_EXEC:
 144       if (recog_p)
 145         have_cond_exec_flag = 1;
 146       break;
 147
 148     case REG: case CONST_INT: case SYMBOL_REF:
 149     case PC:
 150       return;
 151
 152     default:
 153       break;
 154     }
 155
 156   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 157
 158   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 159     switch (*format_ptr++)
 160       {
 161       case 'e':
 162       case 'u':
 163         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 164         break;
 165       case 'E':
 166         if (XVEC (part, i) != NULL)
 167           for (j = 0; j < XVECLEN (part, i); j++)
 168             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 169         break;
 170       }
 171 }
 172
 173 static void
 174 gen_insn (insn)
 175      rtx insn;
 176 {
 177   int i;
 178
 179   /* Walk the insn pattern to gather the #define's status.  */
 180   clobbers_seen_this_insn = 0;
 181   dup_operands_seen_this_insn = 0;
 182   if (XVEC (insn, 1) != 0)
 183     for (i = 0; i < XVECLEN (insn, 1); i++)
 184       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 185
 186   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 187     max_clobbers_per_insn = clobbers_seen_this_insn;
 188   if (dup_operands_seen_this_insn > max_dup_operands)
 189     max_dup_operands = dup_operands_seen_this_insn;
 190 }
 191
 192 /* Similar but scan a define_expand.  */
 193
 194 static void
 195 gen_expand (insn)
 196      rtx insn;
 197 {
 198   int i;
 199
 200   /* Walk the insn pattern to gather the #define's status.  */
 201
 202   /* Note that we don't bother recording the number of MATCH_DUPs
 203      that occur in a gen_expand, because only reload cares about that.  */
 204   if (XVEC (insn, 1) != 0)
 205     for (i = 0; i < XVECLEN (insn, 1); i++)
 206       {
 207         /* Compute the maximum SETs and CLOBBERS
 208            in any one of the sub-insns;
 209            don't sum across all of them.  */
 210         clobbers_seen_this_insn = 0;
 211
 212         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 213
 214         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 215           max_clobbers_per_insn = clobbers_seen_this_insn;
 216       }
 217 }
 218
 219 /* Similar but scan a define_split.  */
 220
 221 static void
 222 gen_split (split)
 223      rtx split;
 224 {
 225   int i;
 226
 227   /* Look through the patterns that are matched
 228      to compute the maximum operand number.  */
 229   for (i = 0; i < XVECLEN (split, 0); i++)
 230     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 231   /* Look at the number of insns this insn could split into.  */
 232   if (XVECLEN (split, 2) > max_insns_per_split)
 233     max_insns_per_split = XVECLEN (split, 2);
 234 }
 235
 236 static void
 237 gen_peephole (peep)
 238      rtx peep;
 239 {
 240   int i;
 241
 242   /* Look through the patterns that are matched
 243      to compute the maximum operand number.  */
 244   for (i = 0; i < XVECLEN (peep, 0); i++)
 245     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 246 }
 247 \f
 248 PTR
 249 xmalloc (size)
 250   size_t size;
 251 {
 252   register PTR val = (PTR) malloc (size);
 253
 254   if (val == 0)
 255     fatal ("virtual memory exhausted");
 256
 257   return val;
 258 }
 259
 260 PTR
 261 xrealloc (old, size)
 262   PTR old;
 263   size_t size;
 264 {
 265   register PTR ptr;
 266   if (old)
 267     ptr = (PTR) realloc (old, size);
 268   else
 269     ptr = (PTR) malloc (size);
 270   if (!ptr)
 271     fatal ("virtual memory exhausted");
 272   return ptr;
 273 }
 274
 275 extern int main PARAMS ((int, char **));
 276
 277 int
 278 main (argc, argv)
 279      int argc;
 280      char **argv;
 281 {
 282   rtx desc;
 283
 284   progname = "genconfig";
 285   obstack_init (rtl_obstack);
 286
 287   if (argc <= 1)
 288     fatal ("No input file name.");
 289
 290   if (init_md_reader (argv[1]) != SUCCESS_EXIT_CODE)
 291     return (FATAL_EXIT_CODE);
 292
 293   printf ("/* Generated automatically by the program `genconfig'\n\
 294 from the machine description file `md'.  */\n\n");
 295
 296   /* Allow at least 10 operands for the sake of asm constructs.  */
 297   max_recog_operands = 9;  /* We will add 1 later.  */
 298   max_dup_operands = 1;
 299
 300   /* Read the machine description.  */
 301
 302   while (1)
 303     {
 304       int line_no, insn_code_number = 0;
 305
 306       desc = read_md_rtx (&line_no, &insn_code_number);
 307       if (desc == NULL)
 308         break;
 309
 310       switch (GET_CODE (desc))
 311         {
 312           case DEFINE_INSN:
 313             gen_insn (desc);
 314             break;
 315
 316           case DEFINE_EXPAND:
 317             gen_expand (desc);
 318             break;
 319
 320           case DEFINE_SPLIT:
 321             gen_split (desc);
 322             break;
 323
 324           case DEFINE_PEEPHOLE2:
 325             have_peephole2_flag = 1;
 326             gen_split (desc);
 327             break;
 328
 329           case DEFINE_PEEPHOLE:
 330             have_peephole_flag = 1;
 331             gen_peephole (desc);
 332             break;
 333
 334           default:
 335             break;
 336         }
 337     }
 338
 339   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 340
 341   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 342
 343   /* This is conditionally defined, in case the user writes code which emits
 344      more splits than we can readily see (and knows s/he does it).  */
 345   printf ("#ifndef MAX_INSNS_PER_SPLIT\n");
 346   printf ("#define MAX_INSNS_PER_SPLIT %d\n", max_insns_per_split);
 347   printf ("#endif\n");
 348
 349   if (have_cc0_flag)
 350     printf ("#define HAVE_cc0 1\n");
 351
 352   if (have_cmove_flag)
 353     printf ("#define HAVE_conditional_move 1\n");
 354
 355   if (have_cond_exec_flag)
 356     printf ("#define HAVE_conditional_execution 1\n");
 357
 358   if (have_lo_sum_flag)
 359     printf ("#define HAVE_lo_sum 1\n");
 360
 361   if (have_peephole_flag)
 362     printf ("#define HAVE_peephole 1\n");
 363
 364   if (have_peephole2_flag)
 365     printf ("#define HAVE_peephole2 1\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 }