gcc/genattr.c

   1 /* Generate attribute information (insn-attr.h) from machine description.
   2    Copyright (C) 1991, 1994, 1996, 1998, 1999, 2000, 2003, 2004, 2007, 2008,
   3    2010, 2011  Free Software Foundation, Inc.
   4    Contributed by Richard Kenner (kenner@vlsi1.ultra.nyu.edu)
   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 "read-md.h"
  30 #include "gensupport.h"
  31
  32
  33 static void gen_attr (rtx);
  34
  35 static VEC (rtx, heap) *const_attrs, *reservations;
  36
  37
  38 static void
  39 gen_attr (rtx attr)
  40 {
  41   const char *p;
  42   int is_const = GET_CODE (XEXP (attr, 2)) == CONST;
  43
  44   if (is_const)
  45     VEC_safe_push (rtx, heap, const_attrs, attr);
  46
  47   printf ("#define HAVE_ATTR_%s\n", XSTR (attr, 0));
  48
  49   /* If numeric attribute, don't need to write an enum.  */
  50   if (GET_CODE (attr) == DEFINE_ENUM_ATTR)
  51     printf ("extern enum %s get_attr_%s (%s);\n\n",
  52             XSTR (attr, 1), XSTR (attr, 0), (is_const ? "void" : "rtx"));
  53   else
  54     {
  55       p = XSTR (attr, 1);
  56       if (*p == '\0')
  57         printf ("extern int get_attr_%s (%s);\n", XSTR (attr, 0),
  58                 (is_const ? "void" : "rtx"));
  59       else
  60         printf ("extern enum attr_%s get_attr_%s (%s);\n\n",
  61                 XSTR (attr, 0), XSTR (attr, 0), (is_const ? "void" : "rtx"));
  62     }
  63
  64   /* If `length' attribute, write additional function definitions and define
  65      variables used by `insn_current_length'.  */
  66   if (! strcmp (XSTR (attr, 0), "length"))
  67     {
  68       puts ("\
  69 extern void shorten_branches (rtx);\n\
  70 extern int insn_default_length (rtx);\n\
  71 extern int insn_min_length (rtx);\n\
  72 extern int insn_variable_length_p (rtx);\n\
  73 extern int insn_current_length (rtx);\n\n\
  74 #include \"insn-addr.h\"\n");
  75     }
  76 }
  77
  78 /* Check that attribute NAME is used in define_insn_reservation condition
  79    EXP.  Return true if it is.  */
  80 static bool
  81 check_tune_attr (const char *name, rtx exp)
  82 {
  83   switch (GET_CODE (exp))
  84     {
  85     case AND:
  86       if (check_tune_attr (name, XEXP (exp, 0)))
  87         return true;
  88       return check_tune_attr (name, XEXP (exp, 1));
  89
  90     case IOR:
  91       return (check_tune_attr (name, XEXP (exp, 0))
  92               && check_tune_attr (name, XEXP (exp, 1)));
  93
  94     case EQ_ATTR:
  95       return strcmp (XSTR (exp, 0), name) == 0;
  96
  97     default:
  98       return false;
  99     }
 100 }
 101
 102 /* Try to find a const attribute (usually cpu or tune) that is used
 103    in all define_insn_reservation conditions.  */
 104 static bool
 105 find_tune_attr (rtx exp)
 106 {
 107   unsigned int i;
 108   rtx attr;
 109
 110   switch (GET_CODE (exp))
 111     {
 112     case AND:
 113     case IOR:
 114       if (find_tune_attr (XEXP (exp, 0)))
 115         return true;
 116       return find_tune_attr (XEXP (exp, 1));
 117
 118     case EQ_ATTR:
 119       if (strcmp (XSTR (exp, 0), "alternative") == 0)
 120         return false;
 121
 122       FOR_EACH_VEC_ELT (rtx, const_attrs, i, attr)
 123         if (strcmp (XSTR (attr, 0), XSTR (exp, 0)) == 0)
 124           {
 125             unsigned int j;
 126             rtx resv;
 127
 128             FOR_EACH_VEC_ELT (rtx, reservations, j, resv)
 129               if (! check_tune_attr (XSTR (attr, 0), XEXP (resv, 2)))
 130                 return false;
 131             return true;
 132           }
 133       return false;
 134
 135     default:
 136       return false;
 137     }
 138 }
 139
 140 int
 141 main (int argc, char **argv)
 142 {
 143   rtx desc;
 144   int have_delay = 0;
 145   int have_annul_true = 0;
 146   int have_annul_false = 0;
 147   int num_insn_reservations = 0;
 148   int i;
 149
 150   progname = "genattr";
 151
 152   if (!init_rtx_reader_args (argc, argv))
 153     return (FATAL_EXIT_CODE);
 154
 155   puts ("/* Generated automatically by the program `genattr'");
 156   puts ("   from the machine description file `md'.  */\n");
 157   puts ("#ifndef GCC_INSN_ATTR_H");
 158   puts ("#define GCC_INSN_ATTR_H\n");
 159
 160   puts ("#include \"insn-attr-common.h\"\n");
 161
 162   /* For compatibility, define the attribute `alternative', which is just
 163      a reference to the variable `which_alternative'.  */
 164
 165   puts ("#define HAVE_ATTR_alternative");
 166   puts ("#define get_attr_alternative(insn) which_alternative");
 167
 168   /* Read the machine description.  */
 169
 170   while (1)
 171     {
 172       int line_no, insn_code_number;
 173
 174       desc = read_md_rtx (&line_no, &insn_code_number);
 175       if (desc == NULL)
 176         break;
 177
 178       if (GET_CODE (desc) == DEFINE_ATTR
 179           || GET_CODE (desc) == DEFINE_ENUM_ATTR)
 180         gen_attr (desc);
 181
 182       else if (GET_CODE (desc) == DEFINE_DELAY)
 183         {
 184           if (! have_delay)
 185             {
 186               printf ("extern int num_delay_slots (rtx);\n");
 187               printf ("extern int eligible_for_delay (rtx, int, rtx, int);\n\n");
 188               printf ("extern int const_num_delay_slots (rtx);\n\n");
 189               have_delay = 1;
 190             }
 191
 192           for (i = 0; i < XVECLEN (desc, 1); i += 3)
 193             {
 194               if (XVECEXP (desc, 1, i + 1) && ! have_annul_true)
 195                 {
 196                   printf ("#define ANNUL_IFTRUE_SLOTS\n");
 197                   printf ("extern int eligible_for_annul_true (rtx, int, rtx, int);\n");
 198                   have_annul_true = 1;
 199                 }
 200
 201               if (XVECEXP (desc, 1, i + 2) && ! have_annul_false)
 202                 {
 203                   printf ("#define ANNUL_IFFALSE_SLOTS\n");
 204                   printf ("extern int eligible_for_annul_false (rtx, int, rtx, int);\n");
 205                   have_annul_false = 1;
 206                 }
 207             }
 208         }
 209
 210       else if (GET_CODE (desc) == DEFINE_INSN_RESERVATION)
 211         {
 212           num_insn_reservations++;
 213           VEC_safe_push (rtx, heap, reservations, desc);
 214         }
 215     }
 216
 217   if (num_insn_reservations > 0)
 218     {
 219       bool has_tune_attr
 220         = find_tune_attr (XEXP (VEC_index (rtx, reservations, 0), 2));
 221       /* Output interface for pipeline hazards recognition based on
 222          DFA (deterministic finite state automata.  */
 223       printf ("\n/* DFA based pipeline interface.  */");
 224       printf ("\n#ifndef AUTOMATON_ALTS\n");
 225       printf ("#define AUTOMATON_ALTS 0\n");
 226       printf ("#endif\n\n");
 227       printf ("\n#ifndef AUTOMATON_STATE_ALTS\n");
 228       printf ("#define AUTOMATON_STATE_ALTS 0\n");
 229       printf ("#endif\n\n");
 230       printf ("#ifndef CPU_UNITS_QUERY\n");
 231       printf ("#define CPU_UNITS_QUERY 0\n");
 232       printf ("#endif\n\n");
 233       /* Interface itself: */
 234       if (has_tune_attr)
 235         {
 236           printf ("/* Initialize fn pointers for internal_dfa_insn_code\n");
 237           printf ("   and insn_default_latency.  */\n");
 238           printf ("extern void init_sched_attrs (void);\n\n");
 239           printf ("/* Internal insn code number used by automata.  */\n");
 240           printf ("extern int (*internal_dfa_insn_code) (rtx);\n\n");
 241           printf ("/* Insn latency time defined in define_insn_reservation. */\n");
 242           printf ("extern int (*insn_default_latency) (rtx);\n\n");
 243         }
 244       else
 245         {
 246           printf ("#define init_sched_attrs() do { } while (0)\n\n");
 247           printf ("/* Internal insn code number used by automata.  */\n");
 248           printf ("extern int internal_dfa_insn_code (rtx);\n\n");
 249           printf ("/* Insn latency time defined in define_insn_reservation. */\n");
 250           printf ("extern int insn_default_latency (rtx);\n\n");
 251         }
 252       printf ("/* Return nonzero if there is a bypass for given insn\n");
 253       printf ("   which is a data producer.  */\n");
 254       printf ("extern int bypass_p (rtx);\n\n");
 255       printf ("/* Insn latency time on data consumed by the 2nd insn.\n");
 256       printf ("   Use the function if bypass_p returns nonzero for\n");
 257       printf ("   the 1st insn. */\n");
 258       printf ("extern int insn_latency (rtx, rtx);\n\n");
 259       printf ("/* Maximal insn latency time possible of all bypasses for this insn.\n");
 260       printf ("   Use the function if bypass_p returns nonzero for\n");
 261       printf ("   the 1st insn. */\n");
 262       printf ("extern int maximal_insn_latency (rtx);\n\n");
 263       printf ("\n#if AUTOMATON_ALTS\n");
 264       printf ("/* The following function returns number of alternative\n");
 265       printf ("   reservations of given insn.  It may be used for better\n");
 266       printf ("   insns scheduling heuristics. */\n");
 267       printf ("extern int insn_alts (rtx);\n\n");
 268       printf ("#endif\n\n");
 269       printf ("/* Maximal possible number of insns waiting results being\n");
 270       printf ("   produced by insns whose execution is not finished. */\n");
 271       printf ("extern const int max_insn_queue_index;\n\n");
 272       printf ("/* Pointer to data describing current state of DFA.  */\n");
 273       printf ("typedef void *state_t;\n\n");
 274       printf ("/* Size of the data in bytes.  */\n");
 275       printf ("extern int state_size (void);\n\n");
 276       printf ("/* Initiate given DFA state, i.e. Set up the state\n");
 277       printf ("   as all functional units were not reserved.  */\n");
 278       printf ("extern void state_reset (state_t);\n");
 279       printf ("/* The following function returns negative value if given\n");
 280       printf ("   insn can be issued in processor state described by given\n");
 281       printf ("   DFA state.  In this case, the DFA state is changed to\n");
 282       printf ("   reflect the current and future reservations by given\n");
 283       printf ("   insn.  Otherwise the function returns minimal time\n");
 284       printf ("   delay to issue the insn.  This delay may be zero\n");
 285       printf ("   for superscalar or VLIW processors.  If the second\n");
 286       printf ("   parameter is NULL the function changes given DFA state\n");
 287       printf ("   as new processor cycle started.  */\n");
 288       printf ("extern int state_transition (state_t, rtx);\n");
 289       printf ("\n#if AUTOMATON_STATE_ALTS\n");
 290       printf ("/* The following function returns number of possible\n");
 291       printf ("   alternative reservations of given insn in given\n");
 292       printf ("   DFA state.  It may be used for better insns scheduling\n");
 293       printf ("   heuristics.  By default the function is defined if\n");
 294       printf ("   macro AUTOMATON_STATE_ALTS is defined because its\n");
 295       printf ("   implementation may require much memory.  */\n");
 296       printf ("extern int state_alts (state_t, rtx);\n");
 297       printf ("#endif\n\n");
 298       printf ("extern int min_issue_delay (state_t, rtx);\n");
 299       printf ("/* The following function returns nonzero if no one insn\n");
 300       printf ("   can be issued in current DFA state. */\n");
 301       printf ("extern int state_dead_lock_p (state_t);\n");
 302       printf ("/* The function returns minimal delay of issue of the 2nd\n");
 303       printf ("   insn after issuing the 1st insn in given DFA state.\n");
 304       printf ("   The 1st insn should be issued in given state (i.e.\n");
 305       printf ("    state_transition should return negative value for\n");
 306       printf ("    the insn and the state).  Data dependencies between\n");
 307       printf ("    the insns are ignored by the function.  */\n");
 308       printf
 309         ("extern int min_insn_conflict_delay (state_t, rtx, rtx);\n");
 310       printf ("/* The following function outputs reservations for given\n");
 311       printf ("   insn as they are described in the corresponding\n");
 312       printf ("   define_insn_reservation.  */\n");
 313       printf ("extern void print_reservation (FILE *, rtx);\n");
 314       printf ("\n#if CPU_UNITS_QUERY\n");
 315       printf ("/* The following function returns code of functional unit\n");
 316       printf ("   with given name (see define_cpu_unit). */\n");
 317       printf ("extern int get_cpu_unit_code (const char *);\n");
 318       printf ("/* The following function returns nonzero if functional\n");
 319       printf ("   unit with given code is currently reserved in given\n");
 320       printf ("   DFA state.  */\n");
 321       printf ("extern int cpu_unit_reservation_p (state_t, int);\n");
 322       printf ("#endif\n\n");
 323       printf ("/* The following function returns true if insn\n");
 324       printf ("   has a dfa reservation.  */\n");
 325       printf ("extern bool insn_has_dfa_reservation_p (rtx);\n\n");
 326       printf ("/* Clean insn code cache.  It should be called if there\n");
 327       printf ("   is a chance that condition value in a\n");
 328       printf ("   define_insn_reservation will be changed after\n");
 329       printf ("   last call of dfa_start.  */\n");
 330       printf ("extern void dfa_clean_insn_cache (void);\n\n");
 331       printf ("extern void dfa_clear_single_insn_cache (rtx);\n\n");
 332       printf ("/* Initiate and finish work with DFA.  They should be\n");
 333       printf ("   called as the first and the last interface\n");
 334       printf ("   functions.  */\n");
 335       printf ("extern void dfa_start (void);\n");
 336       printf ("extern void dfa_finish (void);\n");
 337     }
 338   else
 339     {
 340       /* Otherwise we do no scheduling, but we need these typedefs
 341          in order to avoid uglifying other code with more ifdefs.  */
 342       printf ("typedef void *state_t;\n\n");
 343     }
 344
 345   /* Output flag masks for use by reorg.
 346
 347      Flags are used to hold branch direction and prediction information
 348      for use by eligible_for_...  */
 349   printf("\n#define ATTR_FLAG_forward\t0x1\n");
 350   printf("#define ATTR_FLAG_backward\t0x2\n");
 351   printf("#define ATTR_FLAG_likely\t0x4\n");
 352   printf("#define ATTR_FLAG_very_likely\t0x8\n");
 353   printf("#define ATTR_FLAG_unlikely\t0x10\n");
 354   printf("#define ATTR_FLAG_very_unlikely\t0x20\n");
 355
 356   puts("\n#endif /* GCC_INSN_ATTR_H */");
 357
 358   if (ferror (stdout) || fflush (stdout) || fclose (stdout))
 359     return FATAL_EXIT_CODE;
 360
 361   return SUCCESS_EXIT_CODE;
 362 }