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    Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU General Public License as published by the
   7    Free Software Foundation; either version 3, or (at your option) any
   8    later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; see the file COPYING3.  If not see
  17    <http://www.gnu.org/licenses/>.
  18
  19    In other words, you are welcome to use, share and improve this program.
  20    You are forbidden to forbid anyone else to use, share and improve
  21    what you give them.   Help stamp out software-hoarding!  */
  22
  23
  24 /* This file contains a data structure that describes a GCC target.
  25    At present it is incomplete, but in future it should grow to
  26    contain most or all target machine and target O/S specific
  27    information.
  28
  29    This structure has its initializer declared in target-def.h in the
  30    form of large macro TARGET_INITIALIZER that expands to many smaller
  31    macros.
  32
  33    The smaller macros each initialize one component of the structure,
  34    and each has a default.  Each target should have a file that
  35    includes target.h and target-def.h, and overrides any inappropriate
  36    defaults by undefining the relevant macro and defining a suitable
  37    replacement.  That file should then contain the definition of
  38    "targetm" like so:
  39
  40    struct gcc_target targetm = TARGET_INITIALIZER;
  41
  42    Doing things this way allows us to bring together everything that
  43    defines a GCC target.  By supplying a default that is appropriate
  44    to most targets, we can easily add new items without needing to
  45    edit dozens of target configuration files.  It should also allow us
  46    to gradually reduce the amount of conditional compilation that is
  47    scattered throughout GCC.  */
  48
  49 #ifndef GCC_TARGET_H
  50 #define GCC_TARGET_H
  51
  52 #include "tm.h"
  53 #include "insn-modes.h"
  54
  55 /* Types used by the record_gcc_switches() target function.  */
  56 typedef enum
  57 {
  58   SWITCH_TYPE_PASSED,           /* A switch passed on the command line.  */
  59   SWITCH_TYPE_ENABLED,          /* An option that is currently enabled.  */
  60   SWITCH_TYPE_DESCRIPTIVE,      /* Descriptive text, not a switch or option.  */
  61   SWITCH_TYPE_LINE_START,       /* Please emit any necessary text at the start of a line.  */
  62   SWITCH_TYPE_LINE_END          /* Please emit a line terminator.  */
  63 }
  64 print_switch_type;
  65
  66 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
  67
  68 /* An example implementation for ELF targets.  Defined in varasm.c  */
  69 extern int elf_record_gcc_switches (print_switch_type type, const char *);
  70
  71 /* Some places still assume that all pointer or address modes are the
  72    standard Pmode and ptr_mode.  These optimizations become invalid if
  73    the target actually supports multiple different modes.  For now,
  74    we disable such optimizations on such targets, using this function.  */
  75 extern bool target_default_pointer_address_modes_p (void);
  76
  77 struct stdarg_info;
  78 struct spec_info_def;
  79
  80 /* The struct used by the secondary_reload target hook.  */
  81 typedef struct secondary_reload_info
  82 {
  83   /* icode is actually an enum insn_code, but we don't want to force every
  84      file that includes target.h to include optabs.h .  */
  85   int icode;
  86   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
  87                      into account by copy_cost.  */
  88   /* The next two members are for the use of the backward
  89      compatibility hook.  */
  90   struct secondary_reload_info *prev_sri;
  91   int t_icode; /* Actually an enum insn_code - see above.  */
  92 } secondary_reload_info;
  93
  94 /* This is defined in sched-int.h .  */
  95 struct _dep;
  96
  97 /* This is defined in ddg.h .  */
  98 struct ddg;
  99
 100 /* This is defined in cfgloop.h .  */
 101 struct loop;
 102
 103 /* This is defined in tree-ssa-alias.h.  */
 104 struct ao_ref_s;
 105
 106 /* Assembler instructions for creating various kinds of integer object.  */
 107
 108 struct asm_int_op
 109 {
 110   const char *hi;
 111   const char *si;
 112   const char *di;
 113   const char *ti;
 114 };
 115
 116 /* Types of costs for vectorizer cost model.  */
 117 enum vect_cost_for_stmt
 118 {
 119   scalar_stmt,
 120   scalar_load,
 121   scalar_store,
 122   vector_stmt,
 123   vector_load,
 124   unaligned_load,
 125   unaligned_store,
 126   vector_store,
 127   vec_to_scalar,
 128   scalar_to_vec,
 129   cond_branch_not_taken,
 130   cond_branch_taken,
 131   vec_perm
 132 };
 133
 134 /* Sets of optimization levels at which an option may be enabled by
 135    default_options_optimization.  */
 136 enum opt_levels
 137 {
 138   OPT_LEVELS_NONE, /* No levels (mark end of array).  */
 139   OPT_LEVELS_ALL, /* All levels (used by targets to disable options
 140                      enabled in target-independent code).  */
 141   OPT_LEVELS_0_ONLY, /* -O0 only.  */
 142   OPT_LEVELS_1_PLUS, /* -O1 and above, including -Os.  */
 143   OPT_LEVELS_1_PLUS_SPEED_ONLY, /* -O1 and above, but not -Os.  */
 144   OPT_LEVELS_2_PLUS, /* -O2 and above, including -Os.  */
 145   OPT_LEVELS_2_PLUS_SPEED_ONLY, /* -O2 and above, but not -Os.  */
 146   OPT_LEVELS_3_PLUS, /* -O3 and above.  */
 147   OPT_LEVELS_3_PLUS_AND_SIZE, /* -O3 and above and -Os.  */
 148   OPT_LEVELS_SIZE, /* -Os only.  */
 149   OPT_LEVELS_FAST /* -Ofast only.  */
 150 };
 151
 152 /* Description of options to enable by default at given levels.  */
 153 struct default_options
 154 {
 155   /* The levels at which to enable the option.  */
 156   enum opt_levels levels;
 157
 158   /* The option index and argument or enabled/disabled sense of the
 159      option, as passed to handle_generated_option.  If ARG is NULL and
 160      the option allows a negative form, the option is considered to be
 161      passed in negative form when the optimization level is not one of
 162      those in LEVELS (in order to handle changes to the optimization
 163      level with the "optimize" attribute).  */
 164   size_t opt_index;
 165   const char *arg;
 166   int value;
 167 };
 168
 169 /* The target structure.  This holds all the backend hooks.  */
 170 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 171 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 172 #define DEFHOOK_UNDOC DEFHOOK
 173 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 174
 175 #include "target.def"
 176
 177 extern struct gcc_target targetm;
 178
 179 /* Each target can provide their own.  */
 180 extern struct gcc_targetcm targetcm;
 181
 182 #endif /* GCC_TARGET_H */