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 /* Assembler instructions for creating various kinds of integer object.  */
 104
 105 struct asm_int_op
 106 {
 107   const char *hi;
 108   const char *si;
 109   const char *di;
 110   const char *ti;
 111 };
 112
 113 /* Types of costs for vectorizer cost model.  */
 114 enum vect_cost_for_stmt
 115 {
 116   scalar_stmt,
 117   scalar_load,
 118   scalar_store,
 119   vector_stmt,
 120   vector_load,
 121   unaligned_load,
 122   unaligned_store,
 123   vector_store,
 124   vec_to_scalar,
 125   scalar_to_vec,
 126   cond_branch_not_taken,
 127   cond_branch_taken,
 128   vec_perm
 129 };
 130
 131 /* The target structure.  This holds all the backend hooks.  */
 132 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 133 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 134 #define DEFHOOK_UNDOC DEFHOOK
 135 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 136
 137 #include "target.def"
 138
 139 extern struct gcc_target targetm;
 140
 141 /* Each target can provide their own.  */
 142 extern struct gcc_targetcm targetcm;
 143
 144 #endif /* GCC_TARGET_H */