gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987, 1991, 1997, 1998, 1999, 2000, 2003, 2004, 2007, 2010
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22
  23 #include "bconfig.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "tm.h"
  27 #include "rtl.h"
  28 #include "errors.h"
  29 #include "gensupport.h"
  30
  31
  32 /* flags to determine output of machine description dependent #define's.  */
  33 static int max_recog_operands;  /* Largest operand number seen.  */
  34 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  35 static int max_clobbers_per_insn;
  36 static int have_cc0_flag;
  37 static int have_cmove_flag;
  38 static int have_cond_exec_flag;
  39 static int have_lo_sum_flag;
  40 static int have_peephole_flag;
  41 static int have_peephole2_flag;
  42
  43 /* Maximum number of insns seen in a split.  */
  44 static int max_insns_per_split = 1;
  45
  46 /* Maximum number of input insns for peephole2.  */
  47 static int max_insns_per_peep2;
  48
  49 static int clobbers_seen_this_insn;
  50 static int dup_operands_seen_this_insn;
  51
  52 static void walk_insn_part (rtx, int, int);
  53 static void gen_insn (rtx);
  54 static void gen_expand (rtx);
  55 static void gen_split (rtx);
  56 static void gen_peephole (rtx);
  57 static void gen_peephole2 (rtx);
  58
  59 /* RECOG_P will be nonzero 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 nonzero 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 (rtx part, int recog_p, int non_pc_set_src)
  67 {
  68   int i, j;
  69   RTX_CODE code;
  70   const char *format_ptr;
  71
  72   if (part == 0)
  73     return;
  74
  75   code = GET_CODE (part);
  76   switch (code)
  77     {
  78     case CLOBBER:
  79       clobbers_seen_this_insn++;
  80       break;
  81
  82     case MATCH_OPERAND:
  83       if (XINT (part, 0) > max_recog_operands)
  84         max_recog_operands = XINT (part, 0);
  85       return;
  86
  87     case MATCH_OP_DUP:
  88     case MATCH_PAR_DUP:
  89       ++dup_operands_seen_this_insn;
  90     case MATCH_SCRATCH:
  91     case MATCH_PARALLEL:
  92     case MATCH_OPERATOR:
  93       if (XINT (part, 0) > max_recog_operands)
  94         max_recog_operands = XINT (part, 0);
  95       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  96          MATCH_PARALLEL.  */
  97       break;
  98
  99     case LABEL_REF:
 100       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND
 101           || GET_CODE (XEXP (part, 0)) == MATCH_DUP)
 102         break;
 103       return;
 104
 105     case MATCH_DUP:
 106       ++dup_operands_seen_this_insn;
 107       if (XINT (part, 0) > max_recog_operands)
 108         max_recog_operands = XINT (part, 0);
 109       return;
 110
 111     case CC0:
 112       if (recog_p)
 113         have_cc0_flag = 1;
 114       return;
 115
 116     case LO_SUM:
 117       if (recog_p)
 118         have_lo_sum_flag = 1;
 119       return;
 120
 121     case SET:
 122       walk_insn_part (SET_DEST (part), 0, recog_p);
 123       walk_insn_part (SET_SRC (part), recog_p,
 124                       GET_CODE (SET_DEST (part)) != PC);
 125       return;
 126
 127     case IF_THEN_ELSE:
 128       /* Only consider this machine as having a conditional move if the
 129          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 130          we have some specific IF_THEN_ELSE construct (like the doz
 131          instruction on the RS/6000) that can't be used in the general
 132          context we want it for.  */
 133
 134       if (recog_p && non_pc_set_src
 135           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 136           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 137         have_cmove_flag = 1;
 138       break;
 139
 140     case COND_EXEC:
 141       if (recog_p)
 142         have_cond_exec_flag = 1;
 143       break;
 144
 145     case REG: case CONST_INT: case SYMBOL_REF:
 146     case PC:
 147       return;
 148
 149     default:
 150       break;
 151     }
 152
 153   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 154
 155   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 156     switch (*format_ptr++)
 157       {
 158       case 'e':
 159       case 'u':
 160         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 161         break;
 162       case 'E':
 163         if (XVEC (part, i) != NULL)
 164           for (j = 0; j < XVECLEN (part, i); j++)
 165             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 166         break;
 167       }
 168 }
 169
 170 static void
 171 gen_insn (rtx insn)
 172 {
 173   int i;
 174
 175   /* Walk the insn pattern to gather the #define's status.  */
 176   clobbers_seen_this_insn = 0;
 177   dup_operands_seen_this_insn = 0;
 178   if (XVEC (insn, 1) != 0)
 179     for (i = 0; i < XVECLEN (insn, 1); i++)
 180       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 181
 182   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 183     max_clobbers_per_insn = clobbers_seen_this_insn;
 184   if (dup_operands_seen_this_insn > max_dup_operands)
 185     max_dup_operands = dup_operands_seen_this_insn;
 186 }
 187
 188 /* Similar but scan a define_expand.  */
 189
 190 static void
 191 gen_expand (rtx insn)
 192 {
 193   int i;
 194
 195   /* Walk the insn pattern to gather the #define's status.  */
 196
 197   /* Note that we don't bother recording the number of MATCH_DUPs
 198      that occur in a gen_expand, because only reload cares about that.  */
 199   if (XVEC (insn, 1) != 0)
 200     for (i = 0; i < XVECLEN (insn, 1); i++)
 201       {
 202         /* Compute the maximum SETs and CLOBBERS
 203            in any one of the sub-insns;
 204            don't sum across all of them.  */
 205         clobbers_seen_this_insn = 0;
 206
 207         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 208
 209         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 210           max_clobbers_per_insn = clobbers_seen_this_insn;
 211       }
 212 }
 213
 214 /* Similar but scan a define_split.  */
 215
 216 static void
 217 gen_split (rtx split)
 218 {
 219   int i;
 220
 221   /* Look through the patterns that are matched
 222      to compute the maximum operand number.  */
 223   for (i = 0; i < XVECLEN (split, 0); i++)
 224     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 225   /* Look at the number of insns this insn could split into.  */
 226   if (XVECLEN (split, 2) > max_insns_per_split)
 227     max_insns_per_split = XVECLEN (split, 2);
 228 }
 229
 230 static void
 231 gen_peephole (rtx peep)
 232 {
 233   int i;
 234
 235   /* Look through the patterns that are matched
 236      to compute the maximum operand number.  */
 237   for (i = 0; i < XVECLEN (peep, 0); i++)
 238     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 239 }
 240
 241 static void
 242 gen_peephole2 (rtx peep)
 243 {
 244   int i, n;
 245
 246   /* Look through the patterns that are matched
 247      to compute the maximum operand number.  */
 248   for (i = XVECLEN (peep, 0) - 1; i >= 0; --i)
 249     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 250
 251   /* Look at the number of insns this insn can be matched from.  */
 252   for (i = XVECLEN (peep, 0) - 1, n = 0; i >= 0; --i)
 253     if (GET_CODE (XVECEXP (peep, 0, i)) != MATCH_DUP
 254         && GET_CODE (XVECEXP (peep, 0, i)) != MATCH_SCRATCH)
 255       n++;
 256   if (n > max_insns_per_peep2)
 257     max_insns_per_peep2 = n;
 258 }
 259
 260 int
 261 main (int argc, char **argv)
 262 {
 263   rtx desc;
 264
 265   progname = "genconfig";
 266
 267   if (!init_rtx_reader_args (argc, argv))
 268     return (FATAL_EXIT_CODE);
 269
 270   puts ("/* Generated automatically by the program `genconfig'");
 271   puts ("   from the machine description file `md'.  */\n");
 272   puts ("#ifndef GCC_INSN_CONFIG_H");
 273   puts ("#define GCC_INSN_CONFIG_H\n");
 274
 275   /* Allow at least 30 operands for the sake of asm constructs.  */
 276   /* ??? We *really* ought to reorganize things such that there
 277      is no fixed upper bound.  */
 278   max_recog_operands = 29;  /* We will add 1 later.  */
 279   max_dup_operands = 1;
 280
 281   /* Read the machine description.  */
 282
 283   while (1)
 284     {
 285       int line_no, insn_code_number = 0;
 286
 287       desc = read_md_rtx (&line_no, &insn_code_number);
 288       if (desc == NULL)
 289         break;
 290
 291       switch (GET_CODE (desc))
 292         {
 293           case DEFINE_INSN:
 294             gen_insn (desc);
 295             break;
 296
 297           case DEFINE_EXPAND:
 298             gen_expand (desc);
 299             break;
 300
 301           case DEFINE_SPLIT:
 302             gen_split (desc);
 303             break;
 304
 305           case DEFINE_PEEPHOLE2:
 306             have_peephole2_flag = 1;
 307             gen_peephole2 (desc);
 308             break;
 309
 310           case DEFINE_PEEPHOLE:
 311             have_peephole_flag = 1;
 312             gen_peephole (desc);
 313             break;
 314
 315           default:
 316             break;
 317         }
 318     }
 319
 320   printf ("#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 321   printf ("#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 322
 323   /* This is conditionally defined, in case the user writes code which emits
 324      more splits than we can readily see (and knows s/he does it).  */
 325   printf ("#ifndef MAX_INSNS_PER_SPLIT\n");
 326   printf ("#define MAX_INSNS_PER_SPLIT %d\n", max_insns_per_split);
 327   printf ("#endif\n");
 328
 329   if (have_cc0_flag)
 330     {
 331       printf ("#define HAVE_cc0 1\n");
 332       printf ("#define CC0_P(X) ((X) == cc0_rtx)\n");
 333     }
 334   else
 335     {
 336       /* We output CC0_P this way to make sure that X is declared
 337          somewhere.  */
 338       printf ("#define CC0_P(X) ((X) ? 0 : 0)\n");
 339     }
 340
 341   if (have_cmove_flag)
 342     printf ("#define HAVE_conditional_move 1\n");
 343
 344   if (have_cond_exec_flag)
 345     printf ("#define HAVE_conditional_execution 1\n");
 346
 347   if (have_lo_sum_flag)
 348     printf ("#define HAVE_lo_sum 1\n");
 349
 350   if (have_peephole_flag)
 351     printf ("#define HAVE_peephole 1\n");
 352
 353   if (have_peephole2_flag)
 354     {
 355       printf ("#define HAVE_peephole2 1\n");
 356       printf ("#define MAX_INSNS_PER_PEEP2 %d\n", max_insns_per_peep2);
 357     }
 358
 359   puts("\n#endif /* GCC_INSN_CONFIG_H */");
 360
 361   if (ferror (stdout) || fflush (stdout) || fclose (stdout))
 362     return FATAL_EXIT_CODE;
 363
 364   return SUCCESS_EXIT_CODE;
 365 }