gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001-2013 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify it
   5    under the terms of the GNU General Public License as published by the
   6    Free Software Foundation; either version 3, or (at your option) any
   7    later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; see the file COPYING3.  If not see
  16    <http://www.gnu.org/licenses/>.
  17
  18    In other words, you are welcome to use, share and improve this program.
  19    You are forbidden to forbid anyone else to use, share and improve
  20    what you give them.   Help stamp out software-hoarding!  */
  21
  22
  23 /* This file contains a data structure that describes a GCC target.
  24    At present it is incomplete, but in future it should grow to
  25    contain most or all target machine and target O/S specific
  26    information.
  27
  28    This structure has its initializer declared in target-def.h in the
  29    form of large macro TARGET_INITIALIZER that expands to many smaller
  30    macros.
  31
  32    The smaller macros each initialize one component of the structure,
  33    and each has a default.  Each target should have a file that
  34    includes target.h and target-def.h, and overrides any inappropriate
  35    defaults by undefining the relevant macro and defining a suitable
  36    replacement.  That file should then contain the definition of
  37    "targetm" like so:
  38
  39    struct gcc_target targetm = TARGET_INITIALIZER;
  40
  41    Doing things this way allows us to bring together everything that
  42    defines a GCC target.  By supplying a default that is appropriate
  43    to most targets, we can easily add new items without needing to
  44    edit dozens of target configuration files.  It should also allow us
  45    to gradually reduce the amount of conditional compilation that is
  46    scattered throughout GCC.  */
  47
  48 #ifndef GCC_TARGET_H
  49 #define GCC_TARGET_H
  50
  51 #include "insn-modes.h"
  52 #include "insn-codes.h"
  53
  54 #ifdef ENABLE_CHECKING
  55
  56 typedef struct { void *magic; void *p; } cumulative_args_t;
  57
  58 #else /* !ENABLE_CHECKING */
  59
  60 /* When using a GCC build compiler, we could use
  61    __attribute__((transparent_union)) to get cumulative_args_t function
  62    arguments passed like scalars where the ABI would mandate a less
  63    efficient way of argument passing otherwise.  However, that would come
  64    at the cost of less type-safe !ENABLE_CHECKING compilation.  */
  65
  66 typedef union { void *p; } cumulative_args_t;
  67
  68 #endif /* !ENABLE_CHECKING */
  69
  70 /* Types used by the record_gcc_switches() target function.  */
  71 typedef enum
  72 {
  73   SWITCH_TYPE_PASSED,           /* A switch passed on the command line.  */
  74   SWITCH_TYPE_ENABLED,          /* An option that is currently enabled.  */
  75   SWITCH_TYPE_DESCRIPTIVE,      /* Descriptive text, not a switch or option.  */
  76   SWITCH_TYPE_LINE_START,       /* Please emit any necessary text at the start of a line.  */
  77   SWITCH_TYPE_LINE_END          /* Please emit a line terminator.  */
  78 }
  79 print_switch_type;
  80
  81 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
  82
  83 /* An example implementation for ELF targets.  Defined in varasm.c  */
  84 extern int elf_record_gcc_switches (print_switch_type type, const char *);
  85
  86 /* Some places still assume that all pointer or address modes are the
  87    standard Pmode and ptr_mode.  These optimizations become invalid if
  88    the target actually supports multiple different modes.  For now,
  89    we disable such optimizations on such targets, using this function.  */
  90 extern bool target_default_pointer_address_modes_p (void);
  91
  92 struct stdarg_info;
  93 struct spec_info_def;
  94 struct hard_reg_set_container;
  95
  96 /* The struct used by the secondary_reload target hook.  */
  97 typedef struct secondary_reload_info
  98 {
  99   /* icode is actually an enum insn_code, but we don't want to force every
 100      file that includes target.h to include optabs.h .  */
 101   int icode;
 102   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 103                      into account by copy_cost.  */
 104   /* The next two members are for the use of the backward
 105      compatibility hook.  */
 106   struct secondary_reload_info *prev_sri;
 107   int t_icode; /* Actually an enum insn_code - see above.  */
 108 } secondary_reload_info;
 109
 110 /* This is defined in sched-int.h .  */
 111 struct _dep;
 112
 113 /* This is defined in ddg.h .  */
 114 struct ddg;
 115
 116 /* This is defined in cfgloop.h .  */
 117 struct loop;
 118
 119 /* This is defined in tree-ssa-alias.h.  */
 120 struct ao_ref_s;
 121
 122 /* This is defined in tree-vectorizer.h.  */
 123 struct _stmt_vec_info;
 124
 125 /* These are defined in tree-vect-stmts.c.  */
 126 extern tree stmt_vectype (struct _stmt_vec_info *);
 127 extern bool stmt_in_inner_loop_p (struct _stmt_vec_info *);
 128
 129 /* Assembler instructions for creating various kinds of integer object.  */
 130
 131 struct asm_int_op
 132 {
 133   const char *hi;
 134   const char *si;
 135   const char *di;
 136   const char *ti;
 137 };
 138
 139 /* Types of costs for vectorizer cost model.  */
 140 enum vect_cost_for_stmt
 141 {
 142   scalar_stmt,
 143   scalar_load,
 144   scalar_store,
 145   vector_stmt,
 146   vector_load,
 147   unaligned_load,
 148   unaligned_store,
 149   vector_store,
 150   vec_to_scalar,
 151   scalar_to_vec,
 152   cond_branch_not_taken,
 153   cond_branch_taken,
 154   vec_perm,
 155   vec_promote_demote,
 156   vec_construct
 157 };
 158
 159 /* Separate locations for which the vectorizer cost model should
 160    track costs.  */
 161 enum vect_cost_model_location {
 162   vect_prologue = 0,
 163   vect_body = 1,
 164   vect_epilogue = 2
 165 };
 166
 167 /* The target structure.  This holds all the backend hooks.  */
 168 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 169 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 170 #define DEFHOOK_UNDOC DEFHOOK
 171 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 172
 173 #include "target.def"
 174
 175 extern struct gcc_target targetm;
 176
 177 #ifdef GCC_TM_H
 178
 179 #ifndef CUMULATIVE_ARGS_MAGIC
 180 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 181 #endif
 182
 183 static inline CUMULATIVE_ARGS *
 184 get_cumulative_args (cumulative_args_t arg)
 185 {
 186 #ifdef ENABLE_CHECKING
 187   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 188 #endif /* ENABLE_CHECKING */
 189   return (CUMULATIVE_ARGS *) arg.p;
 190 }
 191
 192 static inline cumulative_args_t
 193 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 194 {
 195   cumulative_args_t ret;
 196
 197 #ifdef ENABLE_CHECKING
 198   ret.magic = CUMULATIVE_ARGS_MAGIC;
 199 #endif /* ENABLE_CHECKING */
 200   ret.p = (void *) arg;
 201   return ret;
 202 }
 203 #endif /* GCC_TM_H */
 204
 205 #endif /* GCC_TARGET_H */