gcc/gcc/target.h

/* Data structure definitions for a generic GCC target.
   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
   Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 3, or (at your option) any
   later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; see the file COPYING3.  If not see
   <http://www.gnu.org/licenses/>.

   In other words, you are welcome to use, share and improve this program.
   You are forbidden to forbid anyone else to use, share and improve
   what you give them.   Help stamp out software-hoarding!  */


/* This file contains a data structure that describes a GCC target.
   At present it is incomplete, but in future it should grow to
   contain most or all target machine and target O/S specific
   information.

   This structure has its initializer declared in target-def.h in the
   form of large macro TARGET_INITIALIZER that expands to many smaller
   macros.

   The smaller macros each initialize one component of the structure,
   and each has a default.  Each target should have a file that
   includes target.h and target-def.h, and overrides any inappropriate
   defaults by undefining the relevant macro and defining a suitable
   replacement.  That file should then contain the definition of
   "targetm" like so:

   struct gcc_target targetm = TARGET_INITIALIZER;

   Doing things this way allows us to bring together everything that
   defines a GCC target.  By supplying a default that is appropriate
   to most targets, we can easily add new items without needing to
   edit dozens of target configuration files.  It should also allow us
   to gradually reduce the amount of conditional compilation that is
   scattered throughout GCC.  */

#ifndef GCC_TARGET_H
#define GCC_TARGET_H

#include "tm.h"
#include "insn-modes.h"

/* Types used by the record_gcc_switches() target function.  */
typedef enum
{
  SWITCH_TYPE_PASSED,		/* A switch passed on the command line.  */
  SWITCH_TYPE_ENABLED,		/* An option that is currently enabled.  */
  SWITCH_TYPE_DESCRIPTIVE,	/* Descriptive text, not a switch or option.  */
  SWITCH_TYPE_LINE_START,	/* Please emit any necessary text at the start of a line.  */
  SWITCH_TYPE_LINE_END		/* Please emit a line terminator.  */
}
print_switch_type;

typedef int (* print_switch_fn_type) (print_switch_type, const char *);

/* An example implementation for ELF targets.  Defined in varasm.c  */
extern int elf_record_gcc_switches (print_switch_type type, const char *);

/* Some places still assume that all pointer or address modes are the
   standard Pmode and ptr_mode.  These optimizations become invalid if
   the target actually supports multiple different modes.  For now,
   we disable such optimizations on such targets, using this function.  */
extern bool target_default_pointer_address_modes_p (void);

struct stdarg_info;
struct spec_info_def;

/* The struct used by the secondary_reload target hook.  */
typedef struct secondary_reload_info
{
  /* icode is actually an enum insn_code, but we don't want to force every
     file that includes target.h to include optabs.h .  */
  int icode;
  int extra_cost; /* Cost for using (a) scratch register(s) to be taken
		     into account by copy_cost.  */
  /* The next two members are for the use of the backward
     compatibility hook.  */
  struct secondary_reload_info *prev_sri;
  int t_icode; /* Actually an enum insn_code - see above.  */
} secondary_reload_info;

/* This is defined in sched-int.h .  */
struct _dep;

/* This is defined in ddg.h .  */
struct ddg;

/* This is defined in cfgloop.h .  */
struct loop;

/* Assembler instructions for creating various kinds of integer object.  */

struct asm_int_op
{
  const char *hi;
  const char *si;
  const char *di;
  const char *ti;
};

/* Types of costs for vectorizer cost model.  */
enum vect_cost_for_stmt
{
  scalar_stmt,
  scalar_load,
  scalar_store,
  vector_stmt,
  vector_load,
  unaligned_load,
  unaligned_store,
  vector_store,
  vec_to_scalar,
  scalar_to_vec,
  cond_branch_not_taken,
  cond_branch_taken,
  vec_perm
};

/* Sets of optimization levels at which an option may be enabled by
   default_options_optimization.  */
enum opt_levels
{
  OPT_LEVELS_NONE, /* No levels (mark end of array).  */
  OPT_LEVELS_ALL, /* All levels (used by targets to disable options
		     enabled in target-independent code).  */
  OPT_LEVELS_0_ONLY, /* -O0 only.  */
  OPT_LEVELS_1_PLUS, /* -O1 and above, including -Os.  */
  OPT_LEVELS_1_PLUS_SPEED_ONLY, /* -O1 and above, but not -Os.  */
  OPT_LEVELS_2_PLUS, /* -O2 and above, including -Os.  */
  OPT_LEVELS_2_PLUS_SPEED_ONLY, /* -O2 and above, but not -Os.  */
  OPT_LEVELS_3_PLUS, /* -O3 and above.  */
  OPT_LEVELS_3_PLUS_AND_SIZE, /* -O3 and above and -Os.  */
  OPT_LEVELS_SIZE, /* -Os only.  */
  OPT_LEVELS_FAST /* -Ofast only.  */
};

/* Description of options to enable by default at given levels.  */
struct default_options
{
  /* The levels at which to enable the option.  */
  enum opt_levels levels;

  /* The option index and argument or enabled/disabled sense of the
     option, as passed to handle_generated_option.  If ARG is NULL and
     the option allows a negative form, the option is considered to be
     passed in negative form when the optimization level is not one of
     those in LEVELS (in order to handle changes to the optimization
     level with the "optimize" attribute).  */
  size_t opt_index;
  const char *arg;
  int value;
};

/* The target structure.  This holds all the backend hooks.  */
#define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
#define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
#define DEFHOOK_UNDOC DEFHOOK
#define HOOKSTRUCT(FRAGMENT) FRAGMENT

#include "target.def"

extern struct gcc_target targetm;

/* Each target can provide their own.  */
extern struct gcc_targetcm targetcm;

#endif /* GCC_TARGET_H */