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
   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
  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 /* Assembler instructions for creating various kinds of integer object.  */
 123
 124 struct asm_int_op
 125 {
 126   const char *hi;
 127   const char *si;
 128   const char *di;
 129   const char *ti;
 130 };
 131
 132 /* Types of costs for vectorizer cost model.  */
 133 enum vect_cost_for_stmt
 134 {
 135   scalar_stmt,
 136   scalar_load,
 137   scalar_store,
 138   vector_stmt,
 139   vector_load,
 140   unaligned_load,
 141   unaligned_store,
 142   vector_store,
 143   vec_to_scalar,
 144   scalar_to_vec,
 145   cond_branch_not_taken,
 146   cond_branch_taken,
 147   vec_perm
 148 };
 149
 150 /* The target structure.  This holds all the backend hooks.  */
 151 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 152 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 153 #define DEFHOOK_UNDOC DEFHOOK
 154 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 155
 156 #include "target.def"
 157
 158 extern struct gcc_target targetm;
 159
 160 #ifdef GCC_TM_H
 161
 162 #ifndef CUMULATIVE_ARGS_MAGIC
 163 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 164 #endif
 165
 166 static inline CUMULATIVE_ARGS *
 167 get_cumulative_args (cumulative_args_t arg)
 168 {
 169 #ifdef ENABLE_CHECKING
 170   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 171 #endif /* ENABLE_CHECKING */
 172   return (CUMULATIVE_ARGS *) arg.p;
 173 }
 174
 175 static inline cumulative_args_t
 176 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 177 {
 178   cumulative_args_t ret;
 179
 180 #ifdef ENABLE_CHECKING
 181   ret.magic = CUMULATIVE_ARGS_MAGIC;
 182 #endif /* ENABLE_CHECKING */
 183   ret.p = (void *) arg;
 184   return ret;
 185 }
 186 #endif /* GCC_TM_H */
 187
 188 #endif /* GCC_TARGET_H */