gcc/genattr.c

   1 /* Generate attribute information (insn-attr.h) from machine description.
   2    Copyright (C) 1991-2014 Free Software Foundation, Inc.
   3    Contributed by Richard Kenner (kenner@vlsi1.ultra.nyu.edu)
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21
  22 #include "bconfig.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "rtl.h"
  27 #include "errors.h"
  28 #include "read-md.h"
  29 #include "gensupport.h"
  30
  31
  32 static void gen_attr (rtx);
  33
  34 static vec<rtx> const_attrs, reservations;
  35
  36
  37 static void
  38 gen_attr (rtx attr)
  39 {
  40   const char *p;
  41   int is_const = GET_CODE (XEXP (attr, 2)) == CONST;
  42
  43   if (is_const)
  44     const_attrs.safe_push (attr);
  45
  46   printf ("#define HAVE_ATTR_%s 1\n", XSTR (attr, 0));
  47
  48   /* If numeric attribute, don't need to write an enum.  */
  49   if (GET_CODE (attr) == DEFINE_ENUM_ATTR)
  50     printf ("extern enum %s get_attr_%s (%s);\n\n",
  51             XSTR (attr, 1), XSTR (attr, 0), (is_const ? "void" : "rtx"));
  52   else
  53     {
  54       p = XSTR (attr, 1);
  55       if (*p == '\0')
  56         printf ("extern int get_attr_%s (%s);\n", XSTR (attr, 0),
  57                 (is_const ? "void" : "rtx"));
  58       else
  59         printf ("extern enum attr_%s get_attr_%s (%s);\n\n",
  60                 XSTR (attr, 0), XSTR (attr, 0), (is_const ? "void" : "rtx"));
  61     }
  62
  63   /* If `length' attribute, write additional function definitions and define
  64      variables used by `insn_current_length'.  */
  65   if (! strcmp (XSTR (attr, 0), "length"))
  66     {
  67       puts ("\
  68 extern void shorten_branches (rtx);\n\
  69 extern int insn_default_length (rtx);\n\
  70 extern int insn_min_length (rtx);\n\
  71 extern int insn_variable_length_p (rtx);\n\
  72 extern int insn_current_length (rtx);\n\n\
  73 #include \"insn-addr.h\"\n");
  74     }
  75 }
  76
  77 /* Check that attribute NAME is used in define_insn_reservation condition
  78    EXP.  Return true if it is.  */
  79 static bool
  80 check_tune_attr (const char *name, rtx exp)
  81 {
  82   switch (GET_CODE (exp))
  83     {
  84     case AND:
  85       if (check_tune_attr (name, XEXP (exp, 0)))
  86         return true;
  87       return check_tune_attr (name, XEXP (exp, 1));
  88
  89     case IOR:
  90       return (check_tune_attr (name, XEXP (exp, 0))
  91               && check_tune_attr (name, XEXP (exp, 1)));
  92
  93     case EQ_ATTR:
  94       return strcmp (XSTR (exp, 0), name) == 0;
  95
  96     default:
  97       return false;
  98     }
  99 }
 100
 101 /* Try to find a const attribute (usually cpu or tune) that is used
 102    in all define_insn_reservation conditions.  */
 103 static bool
 104 find_tune_attr (rtx exp)
 105 {
 106   unsigned int i;
 107   rtx attr;
 108
 109   switch (GET_CODE (exp))
 110     {
 111     case AND:
 112     case IOR:
 113       if (find_tune_attr (XEXP (exp, 0)))
 114         return true;
 115       return find_tune_attr (XEXP (exp, 1));
 116
 117     case EQ_ATTR:
 118       if (strcmp (XSTR (exp, 0), "alternative") == 0)
 119         return false;
 120
 121       FOR_EACH_VEC_ELT (const_attrs, i, attr)
 122         if (strcmp (XSTR (attr, 0), XSTR (exp, 0)) == 0)
 123           {
 124             unsigned int j;
 125             rtx resv;
 126
 127             FOR_EACH_VEC_ELT (reservations, j, resv)
 128               if (! check_tune_attr (XSTR (attr, 0), XEXP (resv, 2)))
 129                 return false;
 130             return true;
 131           }
 132       return false;
 133
 134     default:
 135       return false;
 136     }
 137 }
 138
 139 int
 140 main (int argc, char **argv)
 141 {
 142   rtx desc;
 143   int have_delay = 0;
 144   int have_annul_true = 0;
 145   int have_annul_false = 0;
 146   int num_insn_reservations = 0;
 147   int i;
 148
 149   progname = "genattr";
 150
 151   if (!init_rtx_reader_args (argc, argv))
 152     return (FATAL_EXIT_CODE);
 153
 154   puts ("/* Generated automatically by the program `genattr'");
 155   puts ("   from the machine description file `md'.  */\n");
 156   puts ("#ifndef GCC_INSN_ATTR_H");
 157   puts ("#define GCC_INSN_ATTR_H\n");
 158
 159   puts ("#include \"insn-attr-common.h\"\n");
 160
 161   /* Read the machine description.  */
 162
 163   while (1)
 164     {
 165       int line_no, insn_code_number;
 166
 167       desc = read_md_rtx (&line_no, &insn_code_number);
 168       if (desc == NULL)
 169         break;
 170
 171       if (GET_CODE (desc) == DEFINE_ATTR
 172           || GET_CODE (desc) == DEFINE_ENUM_ATTR)
 173         gen_attr (desc);
 174
 175       else if (GET_CODE (desc) == DEFINE_DELAY)
 176         {
 177           if (! have_delay)
 178             {
 179               printf ("extern int num_delay_slots (rtx);\n");
 180               printf ("extern int eligible_for_delay (rtx, int, rtx, int);\n\n");
 181               printf ("extern int const_num_delay_slots (rtx);\n\n");
 182               have_delay = 1;
 183             }
 184
 185           for (i = 0; i < XVECLEN (desc, 1); i += 3)
 186             {
 187               if (XVECEXP (desc, 1, i + 1) && ! have_annul_true)
 188                 {
 189                   printf ("#define ANNUL_IFTRUE_SLOTS\n");
 190                   printf ("extern int eligible_for_annul_true (rtx, int, rtx, int);\n");
 191                   have_annul_true = 1;
 192                 }
 193
 194               if (XVECEXP (desc, 1, i + 2) && ! have_annul_false)
 195                 {
 196                   printf ("#define ANNUL_IFFALSE_SLOTS\n");
 197                   printf ("extern int eligible_for_annul_false (rtx, int, rtx, int);\n");
 198                   have_annul_false = 1;
 199                 }
 200             }
 201         }
 202
 203       else if (GET_CODE (desc) == DEFINE_INSN_RESERVATION)
 204         {
 205           num_insn_reservations++;
 206           reservations.safe_push (desc);
 207         }
 208     }
 209
 210   if (num_insn_reservations > 0)
 211     {
 212       bool has_tune_attr
 213         = find_tune_attr (XEXP (reservations[0], 2));
 214       /* Output interface for pipeline hazards recognition based on
 215          DFA (deterministic finite state automata.  */
 216       printf ("\n/* DFA based pipeline interface.  */");
 217       printf ("\n#ifndef AUTOMATON_ALTS\n");
 218       printf ("#define AUTOMATON_ALTS 0\n");
 219       printf ("#endif\n\n");
 220       printf ("\n#ifndef AUTOMATON_STATE_ALTS\n");
 221       printf ("#define AUTOMATON_STATE_ALTS 0\n");
 222       printf ("#endif\n\n");
 223       printf ("#ifndef CPU_UNITS_QUERY\n");
 224       printf ("#define CPU_UNITS_QUERY 0\n");
 225       printf ("#endif\n\n");
 226       /* Interface itself: */
 227       if (has_tune_attr)
 228         {
 229           printf ("/* Initialize fn pointers for internal_dfa_insn_code\n");
 230           printf ("   and insn_default_latency.  */\n");
 231           printf ("extern void init_sched_attrs (void);\n\n");
 232           printf ("/* Internal insn code number used by automata.  */\n");
 233           printf ("extern int (*internal_dfa_insn_code) (rtx);\n\n");
 234           printf ("/* Insn latency time defined in define_insn_reservation. */\n");
 235           printf ("extern int (*insn_default_latency) (rtx);\n\n");
 236         }
 237       else
 238         {
 239           printf ("#define init_sched_attrs() do { } while (0)\n\n");
 240           printf ("/* Internal insn code number used by automata.  */\n");
 241           printf ("extern int internal_dfa_insn_code (rtx);\n\n");
 242           printf ("/* Insn latency time defined in define_insn_reservation. */\n");
 243           printf ("extern int insn_default_latency (rtx);\n\n");
 244         }
 245       printf ("/* Return nonzero if there is a bypass for given insn\n");
 246       printf ("   which is a data producer.  */\n");
 247       printf ("extern int bypass_p (rtx);\n\n");
 248       printf ("/* Insn latency time on data consumed by the 2nd insn.\n");
 249       printf ("   Use the function if bypass_p returns nonzero for\n");
 250       printf ("   the 1st insn. */\n");
 251       printf ("extern int insn_latency (rtx, rtx);\n\n");
 252       printf ("/* Maximal insn latency time possible of all bypasses for this insn.\n");
 253       printf ("   Use the function if bypass_p returns nonzero for\n");
 254       printf ("   the 1st insn. */\n");
 255       printf ("extern int maximal_insn_latency (rtx);\n\n");
 256       printf ("\n#if AUTOMATON_ALTS\n");
 257       printf ("/* The following function returns number of alternative\n");
 258       printf ("   reservations of given insn.  It may be used for better\n");
 259       printf ("   insns scheduling heuristics. */\n");
 260       printf ("extern int insn_alts (rtx);\n\n");
 261       printf ("#endif\n\n");
 262       printf ("/* Maximal possible number of insns waiting results being\n");
 263       printf ("   produced by insns whose execution is not finished. */\n");
 264       printf ("extern const int max_insn_queue_index;\n\n");
 265       printf ("/* Pointer to data describing current state of DFA.  */\n");
 266       printf ("typedef void *state_t;\n\n");
 267       printf ("/* Size of the data in bytes.  */\n");
 268       printf ("extern int state_size (void);\n\n");
 269       printf ("/* Initiate given DFA state, i.e. Set up the state\n");
 270       printf ("   as all functional units were not reserved.  */\n");
 271       printf ("extern void state_reset (state_t);\n");
 272       printf ("/* The following function returns negative value if given\n");
 273       printf ("   insn can be issued in processor state described by given\n");
 274       printf ("   DFA state.  In this case, the DFA state is changed to\n");
 275       printf ("   reflect the current and future reservations by given\n");
 276       printf ("   insn.  Otherwise the function returns minimal time\n");
 277       printf ("   delay to issue the insn.  This delay may be zero\n");
 278       printf ("   for superscalar or VLIW processors.  If the second\n");
 279       printf ("   parameter is NULL the function changes given DFA state\n");
 280       printf ("   as new processor cycle started.  */\n");
 281       printf ("extern int state_transition (state_t, rtx);\n");
 282       printf ("\n#if AUTOMATON_STATE_ALTS\n");
 283       printf ("/* The following function returns number of possible\n");
 284       printf ("   alternative reservations of given insn in given\n");
 285       printf ("   DFA state.  It may be used for better insns scheduling\n");
 286       printf ("   heuristics.  By default the function is defined if\n");
 287       printf ("   macro AUTOMATON_STATE_ALTS is defined because its\n");
 288       printf ("   implementation may require much memory.  */\n");
 289       printf ("extern int state_alts (state_t, rtx);\n");
 290       printf ("#endif\n\n");
 291       printf ("extern int min_issue_delay (state_t, rtx);\n");
 292       printf ("/* The following function returns nonzero if no one insn\n");
 293       printf ("   can be issued in current DFA state. */\n");
 294       printf ("extern int state_dead_lock_p (state_t);\n");
 295       printf ("/* The function returns minimal delay of issue of the 2nd\n");
 296       printf ("   insn after issuing the 1st insn in given DFA state.\n");
 297       printf ("   The 1st insn should be issued in given state (i.e.\n");
 298       printf ("    state_transition should return negative value for\n");
 299       printf ("    the insn and the state).  Data dependencies between\n");
 300       printf ("    the insns are ignored by the function.  */\n");
 301       printf
 302         ("extern int min_insn_conflict_delay (state_t, rtx, rtx);\n");
 303       printf ("/* The following function outputs reservations for given\n");
 304       printf ("   insn as they are described in the corresponding\n");
 305       printf ("   define_insn_reservation.  */\n");
 306       printf ("extern void print_reservation (FILE *, rtx);\n");
 307       printf ("\n#if CPU_UNITS_QUERY\n");
 308       printf ("/* The following function returns code of functional unit\n");
 309       printf ("   with given name (see define_cpu_unit). */\n");
 310       printf ("extern int get_cpu_unit_code (const char *);\n");
 311       printf ("/* The following function returns nonzero if functional\n");
 312       printf ("   unit with given code is currently reserved in given\n");
 313       printf ("   DFA state.  */\n");
 314       printf ("extern int cpu_unit_reservation_p (state_t, int);\n");
 315       printf ("#endif\n\n");
 316       printf ("/* The following function returns true if insn\n");
 317       printf ("   has a dfa reservation.  */\n");
 318       printf ("extern bool insn_has_dfa_reservation_p (rtx);\n\n");
 319       printf ("/* Clean insn code cache.  It should be called if there\n");
 320       printf ("   is a chance that condition value in a\n");
 321       printf ("   define_insn_reservation will be changed after\n");
 322       printf ("   last call of dfa_start.  */\n");
 323       printf ("extern void dfa_clean_insn_cache (void);\n\n");
 324       printf ("extern void dfa_clear_single_insn_cache (rtx);\n\n");
 325       printf ("/* Initiate and finish work with DFA.  They should be\n");
 326       printf ("   called as the first and the last interface\n");
 327       printf ("   functions.  */\n");
 328       printf ("extern void dfa_start (void);\n");
 329       printf ("extern void dfa_finish (void);\n");
 330     }
 331   else
 332     {
 333       /* Otherwise we do no scheduling, but we need these typedefs
 334          in order to avoid uglifying other code with more ifdefs.  */
 335       printf ("typedef void *state_t;\n\n");
 336     }
 337
 338   /* Special-purpose attributes should be tested with if, not #ifdef.  */
 339   const char * const special_attrs[] = { "length", "enabled", 0 };
 340   for (const char * const *p = special_attrs; *p; p++)
 341     {
 342       printf ("#ifndef HAVE_ATTR_%s\n"
 343               "#define HAVE_ATTR_%s 0\n"
 344               "#endif\n", *p, *p);
 345     }
 346   /* We make an exception here to provide stub definitions for
 347      insn_*_length* / get_attr_enabled functions.  */
 348   puts ("#if !HAVE_ATTR_length\n"
 349         "extern int hook_int_rtx_unreachable (rtx);\n"
 350         "#define insn_default_length hook_int_rtx_unreachable\n"
 351         "#define insn_min_length hook_int_rtx_unreachable\n"
 352         "#define insn_variable_length_p hook_int_rtx_unreachable\n"
 353         "#define insn_current_length hook_int_rtx_unreachable\n"
 354         "#include \"insn-addr.h\"\n"
 355         "#endif\n"
 356         "#if !HAVE_ATTR_enabled\n"
 357         "extern int hook_int_rtx_1 (rtx);\n"
 358         "#define get_attr_enabled hook_int_rtx_1\n"
 359         "#endif\n");
 360
 361   /* Output flag masks for use by reorg.
 362
 363      Flags are used to hold branch direction for use by eligible_for_...  */
 364   printf ("\n#define ATTR_FLAG_forward\t0x1\n");
 365   printf ("#define ATTR_FLAG_backward\t0x2\n");
 366
 367   puts ("\n#endif /* GCC_INSN_ATTR_H */");
 368
 369   if (ferror (stdout) || fflush (stdout) || fclose (stdout))
 370     return FATAL_EXIT_CODE;
 371
 372   return SUCCESS_EXIT_CODE;
 373 }