gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
   3    2011, 2012
   4    Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 3, or (at your option) any
   9    later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; see the file COPYING3.  If not see
  18    <http://www.gnu.org/licenses/>.
  19
  20    In other words, you are welcome to use, share and improve this program.
  21    You are forbidden to forbid anyone else to use, share and improve
  22    what you give them.   Help stamp out software-hoarding!  */
  23
  24
  25 /* This file contains a data structure that describes a GCC target.
  26    At present it is incomplete, but in future it should grow to
  27    contain most or all target machine and target O/S specific
  28    information.
  29
  30    This structure has its initializer declared in target-def.h in the
  31    form of large macro TARGET_INITIALIZER that expands to many smaller
  32    macros.
  33
  34    The smaller macros each initialize one component of the structure,
  35    and each has a default.  Each target should have a file that
  36    includes target.h and target-def.h, and overrides any inappropriate
  37    defaults by undefining the relevant macro and defining a suitable
  38    replacement.  That file should then contain the definition of
  39    "targetm" like so:
  40
  41    struct gcc_target targetm = TARGET_INITIALIZER;
  42
  43    Doing things this way allows us to bring together everything that
  44    defines a GCC target.  By supplying a default that is appropriate
  45    to most targets, we can easily add new items without needing to
  46    edit dozens of target configuration files.  It should also allow us
  47    to gradually reduce the amount of conditional compilation that is
  48    scattered throughout GCC.  */
  49
  50 #ifndef GCC_TARGET_H
  51 #define GCC_TARGET_H
  52
  53 #include "insn-modes.h"
  54
  55 #ifdef ENABLE_CHECKING
  56
  57 typedef struct { void *magic; void *p; } cumulative_args_t;
  58
  59 #else /* !ENABLE_CHECKING */
  60
  61 /* When using a GCC build compiler, we could use
  62    __attribute__((transparent_union)) to get cumulative_args_t function
  63    arguments passed like scalars where the ABI would mandate a less
  64    efficient way of argument passing otherwise.  However, that would come
  65    at the cost of less type-safe !ENABLE_CHECKING compilation.  */
  66
  67 typedef union { void *p; } cumulative_args_t;
  68
  69 #endif /* !ENABLE_CHECKING */
  70
  71 /* Types used by the record_gcc_switches() target function.  */
  72 typedef enum
  73 {
  74   SWITCH_TYPE_PASSED,           /* A switch passed on the command line.  */
  75   SWITCH_TYPE_ENABLED,          /* An option that is currently enabled.  */
  76   SWITCH_TYPE_DESCRIPTIVE,      /* Descriptive text, not a switch or option.  */
  77   SWITCH_TYPE_LINE_START,       /* Please emit any necessary text at the start of a line.  */
  78   SWITCH_TYPE_LINE_END          /* Please emit a line terminator.  */
  79 }
  80 print_switch_type;
  81
  82 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
  83
  84 /* An example implementation for ELF targets.  Defined in varasm.c  */
  85 extern int elf_record_gcc_switches (print_switch_type type, const char *);
  86
  87 /* Some places still assume that all pointer or address modes are the
  88    standard Pmode and ptr_mode.  These optimizations become invalid if
  89    the target actually supports multiple different modes.  For now,
  90    we disable such optimizations on such targets, using this function.  */
  91 extern bool target_default_pointer_address_modes_p (void);
  92
  93 struct stdarg_info;
  94 struct spec_info_def;
  95 struct hard_reg_set_container;
  96
  97 /* The struct used by the secondary_reload target hook.  */
  98 typedef struct secondary_reload_info
  99 {
 100   /* icode is actually an enum insn_code, but we don't want to force every
 101      file that includes target.h to include optabs.h .  */
 102   int icode;
 103   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 104                      into account by copy_cost.  */
 105   /* The next two members are for the use of the backward
 106      compatibility hook.  */
 107   struct secondary_reload_info *prev_sri;
 108   int t_icode; /* Actually an enum insn_code - see above.  */
 109 } secondary_reload_info;
 110
 111 /* This is defined in sched-int.h .  */
 112 struct _dep;
 113
 114 /* This is defined in ddg.h .  */
 115 struct ddg;
 116
 117 /* This is defined in cfgloop.h .  */
 118 struct loop;
 119
 120 /* This is defined in tree-ssa-alias.h.  */
 121 struct ao_ref_s;
 122
 123 /* Assembler instructions for creating various kinds of integer object.  */
 124
 125 struct asm_int_op
 126 {
 127   const char *hi;
 128   const char *si;
 129   const char *di;
 130   const char *ti;
 131 };
 132
 133 /* Types of costs for vectorizer cost model.  */
 134 enum vect_cost_for_stmt
 135 {
 136   scalar_stmt,
 137   scalar_load,
 138   scalar_store,
 139   vector_stmt,
 140   vector_load,
 141   unaligned_load,
 142   unaligned_store,
 143   vector_store,
 144   vec_to_scalar,
 145   scalar_to_vec,
 146   cond_branch_not_taken,
 147   cond_branch_taken,
 148   vec_perm,
 149   vec_promote_demote
 150 };
 151
 152 /* The target structure.  This holds all the backend hooks.  */
 153 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 154 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 155 #define DEFHOOK_UNDOC DEFHOOK
 156 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 157
 158 #include "target.def"
 159
 160 extern struct gcc_target targetm;
 161
 162 #ifdef GCC_TM_H
 163
 164 #ifndef CUMULATIVE_ARGS_MAGIC
 165 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 166 #endif
 167
 168 static inline CUMULATIVE_ARGS *
 169 get_cumulative_args (cumulative_args_t arg)
 170 {
 171 #ifdef ENABLE_CHECKING
 172   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 173 #endif /* ENABLE_CHECKING */
 174   return (CUMULATIVE_ARGS *) arg.p;
 175 }
 176
 177 static inline cumulative_args_t
 178 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 179 {
 180   cumulative_args_t ret;
 181
 182 #ifdef ENABLE_CHECKING
 183   ret.magic = CUMULATIVE_ARGS_MAGIC;
 184 #endif /* ENABLE_CHECKING */
 185   ret.p = (void *) arg;
 186   return ret;
 187 }
 188 #endif /* GCC_TM_H */
 189
 190 #endif /* GCC_TARGET_H */