--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/target.h	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,1108 @@
+/* Data structure definitions for a generic GCC target.
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+   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 *);
+
+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;
+
+struct gcc_target
+{
+  /* Functions that output assembler for the target.  */
+  struct asm_out
+  {
+    /* Opening and closing parentheses for asm expression grouping.  */
+    const char *open_paren, *close_paren;
+
+    /* Assembler instructions for creating various kinds of integer object.  */
+    const char *byte_op;
+    struct asm_int_op
+    {
+      const char *hi;
+      const char *si;
+      const char *di;
+      const char *ti;
+    } aligned_op, unaligned_op;
+
+    /* Try to output the assembler code for an integer object whose
+       value is given by X.  SIZE is the size of the object in bytes and
+       ALIGNED_P indicates whether it is aligned.  Return true if
+       successful.  Only handles cases for which BYTE_OP, ALIGNED_OP
+       and UNALIGNED_OP are NULL.  */
+    bool (* integer) (rtx x, unsigned int size, int aligned_p);
+
+    /* Output code that will globalize a label.  */
+    void (* globalize_label) (FILE *, const char *);
+
+    /* Output code that will globalize a declaration.  */
+    void (* globalize_decl_name) (FILE *, tree);
+
+    /* Output code that will emit a label for unwind info, if this
+       target requires such labels.  Second argument is the decl the
+       unwind info is associated with, third is a boolean: true if
+       this is for exception handling, fourth is a boolean: true if
+       this is only a placeholder for an omitted FDE.  */
+    void (* unwind_label) (FILE *, tree, int, int);
+
+    /* Output code that will emit a label to divide up the exception
+       table.  */
+    void (* except_table_label) (FILE *);
+
+    /* Emit any directives required to unwind this instruction.  */
+    void (* unwind_emit) (FILE *, rtx);
+
+    /* Output an internal label.  */
+    void (* internal_label) (FILE *, const char *, unsigned long);
+
+    /* Emit a ttype table reference to a typeinfo object.  */
+    bool (* ttype) (rtx);
+
+    /* Emit an assembler directive to set visibility for the symbol
+       associated with the tree decl.  */
+    void (* visibility) (tree, int);
+
+    /* Output the assembler code for entry to a function.  */
+    void (* function_prologue) (FILE *, HOST_WIDE_INT);
+
+    /* Output the assembler code for end of prologue.  */
+    void (* function_end_prologue) (FILE *);
+
+    /* Output the assembler code for start of epilogue.  */
+    void (* function_begin_epilogue) (FILE *);
+
+    /* Output the assembler code for function exit.  */
+    void (* function_epilogue) (FILE *, HOST_WIDE_INT);
+
+    /* Initialize target-specific sections.  */
+    void (* init_sections) (void);
+
+    /* Tell assembler to change to section NAME with attributes FLAGS.
+       If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with
+       which this section is associated.  */
+    void (* named_section) (const char *name, unsigned int flags, tree decl);
+
+    /* Return a mask describing how relocations should be treated when
+       selecting sections.  Bit 1 should be set if global relocations
+       should be placed in a read-write section; bit 0 should be set if
+       local relocations should be placed in a read-write section.  */
+    int (*reloc_rw_mask) (void);
+
+    /* Return a section for EXP.  It may be a DECL or a constant.  RELOC
+       is nonzero if runtime relocations must be applied; bit 1 will be
+       set if the runtime relocations require non-local name resolution.
+       ALIGN is the required alignment of the data.  */
+    section *(* select_section) (tree, int, unsigned HOST_WIDE_INT);
+
+    /* Return a section for X.  MODE is X's mode and ALIGN is its
+       alignment in bits.  */
+    section *(* select_rtx_section) (enum machine_mode, rtx,
+				     unsigned HOST_WIDE_INT);
+
+    /* Select a unique section name for DECL.  RELOC is the same as
+       for SELECT_SECTION.  */
+    void (* unique_section) (tree, int);
+
+    /* Return the readonly data section associated with function DECL.  */
+    section *(* function_rodata_section) (tree);
+
+    /* Output a constructor for a symbol with a given priority.  */
+    void (* constructor) (rtx, int);
+
+    /* Output a destructor for a symbol with a given priority.  */
+    void (* destructor) (rtx, int);
+
+    /* Output the assembler code for a thunk function.  THUNK_DECL is the
+       declaration for the thunk function itself, FUNCTION is the decl for
+       the target function.  DELTA is an immediate constant offset to be
+       added to THIS.  If VCALL_OFFSET is nonzero, the word at
+       *(*this + vcall_offset) should be added to THIS.  */
+    void (* output_mi_thunk) (FILE *file, tree thunk_decl,
+			      HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset,
+			      tree function_decl);
+
+    /* Determine whether output_mi_thunk would succeed.  */
+    /* ??? Ideally, this hook would not exist, and success or failure
+       would be returned from output_mi_thunk directly.  But there's
+       too much undo-able setup involved in invoking output_mi_thunk.
+       Could be fixed by making output_mi_thunk emit rtl instead of
+       text to the output file.  */
+    bool (* can_output_mi_thunk) (const_tree thunk_decl, HOST_WIDE_INT delta,
+				  HOST_WIDE_INT vcall_offset,
+				  const_tree function_decl);
+
+    /* Output any boilerplate text needed at the beginning of a
+       translation unit.  */
+    void (*file_start) (void);
+
+    /* Output any boilerplate text needed at the end of a
+       translation unit.  */
+    void (*file_end) (void);
+
+    /* Output an assembler pseudo-op to declare a library function name
+       external.  */
+    void (*external_libcall) (rtx);
+
+    /* Output an assembler directive to mark decl live. This instructs
+	linker to not dead code strip this symbol.  */
+    void (*mark_decl_preserved) (const char *);
+
+    /* Output a record of the command line switches that have been passed.  */
+    print_switch_fn_type record_gcc_switches;
+    /* The name of the section that the example ELF implementation of
+       record_gcc_switches will use to store the information.  Target
+       specific versions of record_gcc_switches may or may not use
+       this information.  */
+    const char * record_gcc_switches_section;
+
+    /* Output the definition of a section anchor.  */
+    void (*output_anchor) (rtx);
+
+    /* Output a DTP-relative reference to a TLS symbol.  */
+    void (*output_dwarf_dtprel) (FILE *file, int size, rtx x);
+
+  } asm_out;
+
+  /* Functions relating to instruction scheduling.  */
+  struct sched
+  {
+    /* Given the current cost, COST, of an insn, INSN, calculate and
+       return a new cost based on its relationship to DEP_INSN through
+       the dependence LINK.  The default is to make no adjustment.  */
+    int (* adjust_cost) (rtx insn, rtx link, rtx dep_insn, int cost);
+
+    /* Adjust the priority of an insn as you see fit.  Returns the new
+       priority.  */
+    int (* adjust_priority) (rtx, int);
+
+    /* Function which returns the maximum number of insns that can be
+       scheduled in the same machine cycle.  This must be constant
+       over an entire compilation.  The default is 1.  */
+    int (* issue_rate) (void);
+
+    /* Calculate how much this insn affects how many more insns we
+       can emit this cycle.  Default is they all cost the same.  */
+    int (* variable_issue) (FILE *, int, rtx, int);
+
+    /* Initialize machine-dependent scheduling code.  */
+    void (* md_init) (FILE *, int, int);
+
+    /* Finalize machine-dependent scheduling code.  */
+    void (* md_finish) (FILE *, int);
+
+    /* Initialize machine-dependent function wide scheduling code.  */
+    void (* md_init_global) (FILE *, int, int);
+
+    /* Finalize machine-dependent function wide scheduling code.  */
+    void (* md_finish_global) (FILE *, int);
+
+    /* Reorder insns in a machine-dependent fashion, in two different
+       places.  Default does nothing.  */
+    int (* reorder) (FILE *, int, rtx *, int *, int);
+    int (* reorder2) (FILE *, int, rtx *, int *, int);
+
+    /* The following member value is a pointer to a function called
+       after evaluation forward dependencies of insns in chain given
+       by two parameter values (head and tail correspondingly).  */
+    void (* dependencies_evaluation_hook) (rtx, rtx);
+
+    /* The values of the following four members are pointers to
+       functions used to simplify the automaton descriptions.
+       dfa_pre_cycle_insn and dfa_post_cycle_insn give functions
+       returning insns which are used to change the pipeline hazard
+       recognizer state when the new simulated processor cycle
+       correspondingly starts and finishes.  The function defined by
+       init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used
+       to initialize the corresponding insns.  The default values of
+       the members result in not changing the automaton state when
+       the new simulated processor cycle correspondingly starts and
+       finishes.  */
+    void (* init_dfa_pre_cycle_insn) (void);
+    rtx (* dfa_pre_cycle_insn) (void);
+    void (* init_dfa_post_cycle_insn) (void);
+    rtx (* dfa_post_cycle_insn) (void);
+
+    /* The values of the following two members are pointers to
+       functions used to simplify the automaton descriptions.
+       dfa_pre_advance_cycle and dfa_post_advance_cycle are getting called
+       immediately before and after cycle is advanced.  */
+    void (* dfa_pre_advance_cycle) (void);
+    void (* dfa_post_advance_cycle) (void);
+
+    /* The following member value is a pointer to a function returning value
+       which defines how many insns in queue `ready' will we try for
+       multi-pass scheduling.  If the member value is nonzero and the
+       function returns positive value, the DFA based scheduler will make
+       multi-pass scheduling for the first cycle.  In other words, we will
+       try to choose ready insn which permits to start maximum number of
+       insns on the same cycle.  */
+    int (* first_cycle_multipass_dfa_lookahead) (void);
+
+    /* The following member value is pointer to a function controlling
+       what insns from the ready insn queue will be considered for the
+       multipass insn scheduling.  If the hook returns zero for insn
+       passed as the parameter, the insn will be not chosen to be
+       issued.  */
+    int (* first_cycle_multipass_dfa_lookahead_guard) (rtx);
+
+    /* The following member value is pointer to a function called by
+       the insn scheduler before issuing insn passed as the third
+       parameter on given cycle.  If the hook returns nonzero, the
+       insn is not issued on given processors cycle.  Instead of that,
+       the processor cycle is advanced.  If the value passed through
+       the last parameter is zero, the insn ready queue is not sorted
+       on the new cycle start as usually.  The first parameter passes
+       file for debugging output.  The second one passes the scheduler
+       verbose level of the debugging output.  The forth and the fifth
+       parameter values are correspondingly processor cycle on which
+       the previous insn has been issued and the current processor
+       cycle.  */
+    int (* dfa_new_cycle) (FILE *, int, rtx, int, int, int *);
+
+    /* The following member value is a pointer to a function called by the
+       insn scheduler.  It should return true if there exists a dependence
+       which is considered costly by the target, between the insn
+       DEP_PRO (&_DEP), and the insn DEP_CON (&_DEP).  The first parameter is
+       the dep that represents the dependence between the two insns.  The
+       second argument is the cost of the dependence as estimated by
+       the scheduler.  The last argument is the distance in cycles
+       between the already scheduled insn (first parameter) and the
+       second insn (second parameter).  */
+    bool (* is_costly_dependence) (struct _dep *_dep, int, int);
+
+    /* Given the current cost, COST, of an insn, INSN, calculate and
+       return a new cost based on its relationship to DEP_INSN through the
+       dependence of type DEP_TYPE.  The default is to make no adjustment.  */
+    int (* adjust_cost_2) (rtx insn, int, rtx dep_insn, int cost, int dw);
+
+    /* The following member value is a pointer to a function called
+       by the insn scheduler. This hook is called to notify the backend
+       that new instructions were emitted.  */
+    void (* h_i_d_extended) (void);
+
+    /* Next 5 functions are for multi-point scheduling.  */
+
+    /* Allocate memory for scheduler context.  */
+    void *(* alloc_sched_context) (void);
+
+    /* Fills the context from the local machine scheduler context.  */
+    void (* init_sched_context) (void *, bool);
+
+    /* Sets local machine scheduler context to a saved value.  */
+    void (* set_sched_context) (void *);
+
+    /* Clears a scheduler context so it becomes like after init.  */
+    void (* clear_sched_context) (void *);
+
+    /* Frees the scheduler context.  */
+    void (* free_sched_context) (void *);
+
+    /* The following member value is a pointer to a function called
+       by the insn scheduler.
+       The first parameter is an instruction, the second parameter is the type
+       of the requested speculation, and the third parameter is a pointer to the
+       speculative pattern of the corresponding type (set if return value == 1).
+       It should return
+       -1, if there is no pattern, that will satisfy the requested speculation
+       type,
+       0, if current pattern satisfies the requested speculation type,
+       1, if pattern of the instruction should be changed to the newly
+       generated one.  */
+    int (* speculate_insn) (rtx, int, rtx *);
+
+    /* The following member value is a pointer to a function called
+       by the insn scheduler.  It should return true if the check instruction
+       passed as the parameter needs a recovery block.  */
+    bool (* needs_block_p) (int);
+
+    /* The following member value is a pointer to a function called
+       by the insn scheduler.  It should return a pattern for the check
+       instruction.
+       The first parameter is a speculative instruction, the second parameter
+       is the label of the corresponding recovery block (or null, if it is a
+       simple check).  If the mutation of the check is requested (e.g. from
+       ld.c to chk.a), the third parameter is true - in this case the first
+       parameter is the previous check.  */
+    rtx (* gen_spec_check) (rtx, rtx, int);
+
+    /* The following member value is a pointer to a function controlling
+       what insns from the ready insn queue will be considered for the
+       multipass insn scheduling.  If the hook returns zero for the insn
+       passed as the parameter, the insn will not be chosen to be
+       issued.  This hook is used to discard speculative instructions,
+       that stand at the first position of the ready list.  */
+    bool (* first_cycle_multipass_dfa_lookahead_guard_spec) (const_rtx);
+
+    /* The following member value is a pointer to a function that provides
+       information about the speculation capabilities of the target.
+       The parameter is a pointer to spec_info variable.  */
+    void (* set_sched_flags) (struct spec_info_def *);
+
+    /* Return speculation types of the instruction passed as the parameter.  */
+    int (* get_insn_spec_ds) (rtx);
+
+    /* Return speculation types that are checked for the instruction passed as
+       the parameter.  */
+    int (* get_insn_checked_ds) (rtx);
+
+    /* Return bool if rtx scanning should just skip current layer and
+       advance to the inner rtxes.  */
+    bool (* skip_rtx_p) (const_rtx);
+
+    /* The following member value is a pointer to a function that provides
+       information about the target resource-based lower bound which is
+       used by the swing modulo scheduler.  The parameter is a pointer
+       to ddg variable.  */
+    int (* sms_res_mii) (struct ddg *);
+  } sched;
+
+  /* Functions relating to vectorization.  */
+  struct vectorize
+  {
+    /* The following member value is a pointer to a function called
+       by the vectorizer, and return the decl of the target builtin
+       function.  */
+    tree (* builtin_mask_for_load) (void);
+
+    /* Returns a code for builtin that realizes vectorized version of
+       function, or NULL_TREE if not available.  */
+    tree (* builtin_vectorized_function) (unsigned, tree, tree);
+
+    /* Returns a code for builtin that realizes vectorized version of
+       conversion, or NULL_TREE if not available.  */
+    tree (* builtin_conversion) (unsigned, tree);
+
+    /* Target builtin that implements vector widening multiplication.
+       builtin_mul_widen_eve computes the element-by-element products 
+       for the even elements, and builtin_mul_widen_odd computes the
+       element-by-element products for the odd elements.  */
+    tree (* builtin_mul_widen_even) (tree);
+    tree (* builtin_mul_widen_odd) (tree);
+
+    /* Returns the cost to be added to the overheads involved with
+       executing the vectorized version of a loop.  */
+    int (*builtin_vectorization_cost) (bool);
+
+    /* Return true if vector alignment is reachable (by peeling N
+       iterations) for the given type.  */
+    bool (* vector_alignment_reachable) (const_tree, bool);
+
+    /* Target builtin that implements vector permute.  */
+    tree (* builtin_vec_perm) (tree, tree*);
+} vectorize;
+
+  /* The initial value of target_flags.  */
+  int default_target_flags;
+
+  /* Handle target switch CODE (an OPT_* value).  ARG is the argument
+     passed to the switch; it is NULL if no argument was.  VALUE is the
+     value of ARG if CODE specifies a UInteger option, otherwise it is
+     1 if the positive form of the switch was used and 0 if the negative
+     form was.  Return true if the switch was valid.  */
+  bool (* handle_option) (size_t code, const char *arg, int value);
+
+  /* Display extra, target specific information in response to a
+     --target-help switch.  */
+  void (* target_help) (void);
+
+  /* Return machine mode for filter value.  */
+  enum machine_mode (* eh_return_filter_mode) (void);
+
+  /* Return machine mode for libgcc expanded cmp instructions.  */
+  enum machine_mode (* libgcc_cmp_return_mode) (void);
+
+  /* Return machine mode for libgcc expanded shift instructions.  */
+  enum machine_mode (* libgcc_shift_count_mode) (void);
+
+  /* Return machine mode to be used for _Unwind_Word type.  */
+  enum machine_mode (* unwind_word_mode) (void);
+
+  /* Given two decls, merge their attributes and return the result.  */
+  tree (* merge_decl_attributes) (tree, tree);
+
+  /* Given two types, merge their attributes and return the result.  */
+  tree (* merge_type_attributes) (tree, tree);
+
+  /* Table of machine attributes and functions to handle them.
+     Ignored if NULL.  */
+  const struct attribute_spec *attribute_table;
+
+  /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
+     one if they are compatible and two if they are nearly compatible
+     (which causes a warning to be generated).  */
+  int (* comp_type_attributes) (const_tree type1, const_tree type2);
+
+  /* Assign default attributes to the newly defined TYPE.  */
+  void (* set_default_type_attributes) (tree type);
+
+  /* Insert attributes on the newly created DECL.  */
+  void (* insert_attributes) (tree decl, tree *attributes);
+
+  /* Return true if FNDECL (which has at least one machine attribute)
+     can be inlined despite its machine attributes, false otherwise.  */
+  bool (* function_attribute_inlinable_p) (const_tree fndecl);
+
+  /* Return true if bitfields in RECORD_TYPE should follow the
+     Microsoft Visual C++ bitfield layout rules.  */
+  bool (* ms_bitfield_layout_p) (const_tree record_type);
+
+  /* True if the target supports decimal floating point.  */
+  bool (* decimal_float_supported_p) (void);
+
+  /* True if the target supports fixed-point.  */
+  bool (* fixed_point_supported_p) (void);
+
+  /* Return true if anonymous bitfields affect structure alignment.  */
+  bool (* align_anon_bitfield) (void);
+
+  /* Return true if volatile bitfields should use the narrowest type possible.
+     Return false if they should use the container type.  */
+  bool (* narrow_volatile_bitfield) (void);
+
+  /* Set up target-specific built-in functions.  */
+  void (* init_builtins) (void);
+
+  /* Expand a target-specific builtin.  */
+  rtx (* expand_builtin) (tree exp, rtx target, rtx subtarget,
+			  enum machine_mode mode, int ignore);
+
+  /* Select a replacement for a target-specific builtin.  This is done
+     *before* regular type checking, and so allows the target to implement
+     a crude form of function overloading.  The result is a complete
+     expression that implements the operation.  */
+  tree (*resolve_overloaded_builtin) (tree decl, tree params);
+
+  /* Fold a target-specific builtin.  */
+  tree (* fold_builtin) (tree fndecl, tree arglist, bool ignore);
+
+  /* Returns a code for a target-specific builtin that implements
+     reciprocal of the function, or NULL_TREE if not available.  */
+  tree (* builtin_reciprocal) (unsigned, bool, bool);
+
+  /* For a vendor-specific TYPE, return a pointer to a statically-allocated
+     string containing the C++ mangling for TYPE.  In all other cases, return
+     NULL.  */
+  const char * (* mangle_type) (const_tree type);
+
+  /* Make any adjustments to libfunc names needed for this target.  */
+  void (* init_libfuncs) (void);
+
+  /* Given a decl, a section name, and whether the decl initializer
+     has relocs, choose attributes for the section.  */
+  /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION.  */
+  unsigned int (* section_type_flags) (tree, const char *, int);
+
+  /* True if new jumps cannot be created, to replace existing ones or
+     not, at the current point in the compilation.  */
+  bool (* cannot_modify_jumps_p) (void);
+
+  /* Return a register class for which branch target register
+     optimizations should be applied.  */
+  int (* branch_target_register_class) (void);
+
+  /* Return true if branch target register optimizations should include
+     callee-saved registers that are not already live during the current
+     function.  AFTER_PE_GEN is true if prologues and epilogues have
+     already been generated.  */
+  bool (* branch_target_register_callee_saved) (bool after_pe_gen);
+
+  /* True if the constant X cannot be placed in the constant pool.  */
+  bool (* cannot_force_const_mem) (rtx);
+
+  /* True if the insn X cannot be duplicated.  */
+  bool (* cannot_copy_insn_p) (rtx);
+
+  /* True if X is considered to be commutative.  */
+  bool (* commutative_p) (const_rtx, int);
+
+  /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS.  */
+  rtx (* delegitimize_address) (rtx);
+
+  /* True if the given constant can be put into an object_block.  */
+  bool (* use_blocks_for_constant_p) (enum machine_mode, const_rtx);
+
+  /* The minimum and maximum byte offsets for anchored addresses.  */
+  HOST_WIDE_INT min_anchor_offset;
+  HOST_WIDE_INT max_anchor_offset;
+
+  /* True if section anchors can be used to access the given symbol.  */
+  bool (* use_anchors_for_symbol_p) (const_rtx);
+
+  /* True if it is OK to do sibling call optimization for the specified
+     call expression EXP.  DECL will be the called function, or NULL if
+     this is an indirect call.  */
+  bool (*function_ok_for_sibcall) (tree decl, tree exp);
+
+  /* Establish appropriate back-end context for processing the function
+     FNDECL.  The argument might be NULL to indicate processing at top
+     level, outside of any function scope.  */
+  void (*set_current_function) (tree fndecl);
+
+  /* True if EXP should be placed in a "small data" section.  */
+  bool (* in_small_data_p) (const_tree);
+
+  /* True if EXP names an object for which name resolution must resolve
+     to the current executable or shared library.  */
+  bool (* binds_local_p) (const_tree);
+
+  /* Modify and return the identifier of a DECL's external name,
+     originally identified by ID, as required by the target,
+    (eg, append @nn to windows32 stdcall function names).
+     The default is to return ID without modification. */
+   tree (* mangle_decl_assembler_name) (tree decl, tree  id);
+
+  /* Do something target-specific to record properties of the DECL into
+     the associated SYMBOL_REF.  */
+  void (* encode_section_info) (tree, rtx, int);
+
+  /* Undo the effects of encode_section_info on the symbol string.  */
+  const char * (* strip_name_encoding) (const char *);
+
+  /* If shift optabs for MODE are known to always truncate the shift count,
+     return the mask that they apply.  Return 0 otherwise.  */
+  unsigned HOST_WIDE_INT (* shift_truncation_mask) (enum machine_mode mode);
+
+  /* Return the number of divisions in the given MODE that should be present,
+     so that it is profitable to turn the division into a multiplication by
+     the reciprocal.  */
+  unsigned int (* min_divisions_for_recip_mul) (enum machine_mode mode);
+
+  /* If the representation of integral MODE is such that values are
+     always sign-extended to a wider mode MODE_REP then return
+     SIGN_EXTEND.  Return UNKNOWN otherwise.  */
+  /* Note that the return type ought to be RTX_CODE, but that's not
+     necessarily defined at this point.  */
+  int (* mode_rep_extended) (enum machine_mode mode,
+			     enum machine_mode mode_rep);
+
+  /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))).  */
+  bool (* valid_pointer_mode) (enum machine_mode mode);
+
+  /* True if MODE is valid for the target.  By "valid", we mean able to
+     be manipulated in non-trivial ways.  In particular, this means all
+     the arithmetic is supported.  */
+  bool (* scalar_mode_supported_p) (enum machine_mode mode);
+
+  /* Similarly for vector modes.  "Supported" here is less strict.  At
+     least some operations are supported; need to check optabs or builtins
+     for further details.  */
+  bool (* vector_mode_supported_p) (enum machine_mode mode);
+
+  /* True if a vector is opaque.  */
+  bool (* vector_opaque_p) (const_tree);
+
+  /* Compute a (partial) cost for rtx X.  Return true if the complete
+     cost has been computed, and false if subexpressions should be
+     scanned.  In either case, *TOTAL contains the cost result.  */
+  /* Note that CODE and OUTER_CODE ought to be RTX_CODE, but that's
+     not necessarily defined at this point.  */
+  bool (* rtx_costs) (rtx x, int code, int outer_code, int *total, bool speed);
+
+  /* Compute the cost of X, used as an address.  Never called with
+     invalid addresses.  */
+  int (* address_cost) (rtx x, bool speed);
+
+  /* Return where to allocate pseudo for a given hard register initial
+     value.  */
+  rtx (* allocate_initial_value) (rtx x);
+
+  /* Return nonzero if evaluating UNSPEC[_VOLATILE] X might cause a trap.
+     FLAGS has the same meaning as in rtlanal.c: may_trap_p_1.  */
+  int (* unspec_may_trap_p) (const_rtx x, unsigned flags);
+
+  /* Given a register, this hook should return a parallel of registers
+     to represent where to find the register pieces.  Define this hook
+     if the register and its mode are represented in Dwarf in
+     non-contiguous locations, or if the register should be
+     represented in more than one register in Dwarf.  Otherwise, this
+     hook should return NULL_RTX.  */
+  rtx (* dwarf_register_span) (rtx);
+
+  /* If expand_builtin_init_dwarf_reg_sizes needs to fill in table
+     entries not corresponding directly to registers below
+     FIRST_PSEUDO_REGISTER, this hook should generate the necessary
+     code, given the address of the table.  */
+  void (* init_dwarf_reg_sizes_extra) (tree);
+
+  /* Fetch the fixed register(s) which hold condition codes, for
+     targets where it makes sense to look for duplicate assignments to
+     the condition codes.  This should return true if there is such a
+     register, false otherwise.  The arguments should be set to the
+     fixed register numbers.  Up to two condition code registers are
+     supported.  If there is only one for this target, the int pointed
+     at by the second argument should be set to -1.  */
+  bool (* fixed_condition_code_regs) (unsigned int *, unsigned int *);
+
+  /* If two condition code modes are compatible, return a condition
+     code mode which is compatible with both, such that a comparison
+     done in the returned mode will work for both of the original
+     modes.  If the condition code modes are not compatible, return
+     VOIDmode.  */
+  enum machine_mode (* cc_modes_compatible) (enum machine_mode,
+					     enum machine_mode);
+
+  /* Do machine-dependent code transformations.  Called just before
+     delayed-branch scheduling.  */
+  void (* machine_dependent_reorg) (void);
+
+  /* Create the __builtin_va_list type.  */
+  tree (* build_builtin_va_list) (void);
+
+  /* Get the cfun/fndecl calling abi __builtin_va_list type.  */
+  tree (* fn_abi_va_list) (tree);
+
+  /* Get the __builtin_va_list type dependent on input type.  */
+  tree (* canonical_va_list_type) (tree);
+
+  /* Expand the __builtin_va_start builtin.  */
+  void (* expand_builtin_va_start) (tree valist, rtx nextarg);
+
+  /* Gimplifies a VA_ARG_EXPR.  */
+  tree (* gimplify_va_arg_expr) (tree valist, tree type, gimple_seq *pre_p,
+				 gimple_seq *post_p);
+
+  /* Validity-checking routines for PCH files, target-specific.
+     get_pch_validity returns a pointer to the data to be stored,
+     and stores the size in its argument.  pch_valid_p gets the same
+     information back and returns NULL if the PCH is valid,
+     or an error message if not.
+  */
+  void * (* get_pch_validity) (size_t *);
+  const char * (* pch_valid_p) (const void *, size_t);
+
+  /* If nonnull, this function checks whether a PCH file with the
+     given set of target flags can be used.  It returns NULL if so,
+     otherwise it returns an error message.  */
+  const char *(*check_pch_target_flags) (int);
+
+  /* True if the compiler should give an enum type only as many
+     bytes as it takes to represent the range of possible values of
+     that type.  */
+  bool (* default_short_enums) (void);
+
+  /* This target hook returns an rtx that is used to store the address
+     of the current frame into the built-in setjmp buffer.  */
+  rtx (* builtin_setjmp_frame_value) (void);
+
+  /* This target hook should add STRING_CST trees for any hard regs
+     the port wishes to automatically clobber for an asm.  */
+  tree (* md_asm_clobbers) (tree, tree, tree);
+
+  /* This target hook allows the backend to specify a calling convention
+     in the debug information.  This function actually returns an
+     enum dwarf_calling_convention, but because of forward declarations
+     and not wanting to include dwarf2.h everywhere target.h is included
+     the function is being declared as an int.  */
+  int (* dwarf_calling_convention) (const_tree);
+
+  /* This target hook allows the backend to emit frame-related insns that
+     contain UNSPECs or UNSPEC_VOLATILEs.  The call frame debugging info
+     engine will invoke it on insns of the form
+       (set (reg) (unspec [...] UNSPEC_INDEX))
+     and
+       (set (reg) (unspec_volatile [...] UNSPECV_INDEX))
+     to let the backend emit the call frame instructions.  */
+  void (* dwarf_handle_frame_unspec) (const char *, rtx, int);
+
+  /* Perform architecture specific checking of statements gimplified
+     from VA_ARG_EXPR.  STMT is the statement.  Returns true if the statement
+     doesn't need to be checked for va_list references.  */
+  bool (* stdarg_optimize_hook) (struct stdarg_info *ai, const_gimple stmt);
+
+  /* This target hook allows the operating system to override the DECL
+     that represents the external variable that contains the stack
+     protection guard variable.  The type of this DECL is ptr_type_node.  */
+  tree (* stack_protect_guard) (void);
+
+  /* This target hook allows the operating system to override the CALL_EXPR
+     that is invoked when a check vs the guard variable fails.  */
+  tree (* stack_protect_fail) (void);
+
+  /* Returns NULL if target supports the insn within a doloop block,
+     otherwise it returns an error message.  */
+  const char * (*invalid_within_doloop) (const_rtx);
+
+  /* DECL is a variable or function with __attribute__((dllimport))
+     specified.  Use this hook if the target needs to add extra validation
+     checks to  handle_dll_attribute ().  */
+  bool (* valid_dllimport_attribute_p) (const_tree decl);
+
+  /* Functions relating to calls - argument passing, returns, etc.  */
+  struct calls {
+    bool (*promote_function_args) (const_tree fntype);
+    bool (*promote_function_return) (const_tree fntype);
+    bool (*promote_prototypes) (const_tree fntype);
+    rtx (*struct_value_rtx) (tree fndecl, int incoming);
+    bool (*return_in_memory) (const_tree type, const_tree fndecl);
+    bool (*return_in_msb) (const_tree type);
+
+    /* Return true if a parameter must be passed by reference.  TYPE may
+       be null if this is a libcall.  CA may be null if this query is
+       from __builtin_va_arg.  */
+    bool (*pass_by_reference) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
+			       const_tree type, bool named_arg);
+
+    rtx (*expand_builtin_saveregs) (void);
+    /* Returns pretend_argument_size.  */
+    void (*setup_incoming_varargs) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
+				    tree type, int *pretend_arg_size,
+				    int second_time);
+    bool (*strict_argument_naming) (CUMULATIVE_ARGS *ca);
+    /* Returns true if we should use
+       targetm.calls.setup_incoming_varargs() and/or
+       targetm.calls.strict_argument_naming().  */
+    bool (*pretend_outgoing_varargs_named) (CUMULATIVE_ARGS *ca);
+
+    /* Given a complex type T, return true if a parameter of type T
+       should be passed as two scalars.  */
+    bool (* split_complex_arg) (const_tree type);
+
+    /* Return true if type T, mode MODE, may not be passed in registers,
+       but must be passed on the stack.  */
+    /* ??? This predicate should be applied strictly after pass-by-reference.
+       Need audit to verify that this is the case.  */
+    bool (* must_pass_in_stack) (enum machine_mode mode, const_tree t);
+
+    /* Return true if type TYPE, mode MODE, which is passed by reference,
+       should have the object copy generated by the callee rather than
+       the caller.  It is never called for TYPE requiring constructors.  */
+    bool (* callee_copies) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
+			    const_tree type, bool named);
+
+    /* Return zero for arguments passed entirely on the stack or entirely
+       in registers.  If passed in both, return the number of bytes passed
+       in registers; the balance is therefore passed on the stack.  */
+    int (* arg_partial_bytes) (CUMULATIVE_ARGS *ca, enum machine_mode mode,
+			       tree type, bool named);
+
+    /* Return the diagnostic message string if function without a prototype
+       is not allowed for this 'val' argument; NULL otherwise. */
+    const char *(*invalid_arg_for_unprototyped_fn) (const_tree typelist,
+					     	    const_tree funcdecl,
+						    const_tree val);
+
+    /* Return an rtx for the return value location of the function
+       specified by FN_DECL_OR_TYPE with a return type of RET_TYPE.  */
+    rtx (*function_value) (const_tree ret_type, const_tree fn_decl_or_type,
+			   bool outgoing);
+
+    /* Return an rtx for the argument pointer incoming to the
+       current function.  */
+    rtx (*internal_arg_pointer) (void);
+
+    /* Update the current function stack boundary if needed.  */
+    void (*update_stack_boundary) (void);
+
+    /* Handle stack alignment and return an rtx for Dynamic Realign
+       Argument Pointer if necessary.  */
+    rtx (*get_drap_rtx) (void);
+
+    /* Return true if all function parameters should be spilled to the
+       stack.  */
+    bool (*allocate_stack_slots_for_args) (void);
+    
+  } calls;
+
+  /* Return the diagnostic message string if conversion from FROMTYPE
+     to TOTYPE is not allowed, NULL otherwise.  */
+  const char *(*invalid_conversion) (const_tree fromtype, const_tree totype);
+
+  /* Return the diagnostic message string if the unary operation OP is
+     not permitted on TYPE, NULL otherwise.  */
+  const char *(*invalid_unary_op) (int op, const_tree type);
+
+  /* Return the diagnostic message string if the binary operation OP
+     is not permitted on TYPE1 and TYPE2, NULL otherwise.  */
+  const char *(*invalid_binary_op) (int op, const_tree type1, const_tree type2);
+
+  /* Return the array of IRA cover classes for the current target.  */
+  const enum reg_class *(*ira_cover_classes) (void);
+
+  /* Return the class for a secondary reload, and fill in extra information.  */
+  enum reg_class (*secondary_reload) (bool, rtx, enum reg_class,
+				      enum machine_mode,
+				      struct secondary_reload_info *);
+
+  /* This target hook allows the backend to perform additional
+     processing while initializing for variable expansion.  */
+  void (* expand_to_rtl_hook) (void);
+
+  /* This target hook allows the backend to perform additional
+     instantiations on rtx that are not actually in insns yet,
+     but will be later.  */
+  void (* instantiate_decls) (void);
+
+  /* Return true if is OK to use a hard register REGNO as scratch register
+     in peephole2.  */
+  bool (* hard_regno_scratch_ok) (unsigned int regno);
+
+  /* Functions specific to the C family of frontends.  */
+  struct c {
+    /* Return machine mode for non-standard suffix
+       or VOIDmode if non-standard suffixes are unsupported.  */
+    enum machine_mode (*mode_for_suffix) (char);
+  } c;
+
+  /* Functions specific to the C++ frontend.  */
+  struct cxx {
+    /* Return the integer type used for guard variables.  */
+    tree (*guard_type) (void);
+    /* Return true if only the low bit of the guard should be tested.  */
+    bool (*guard_mask_bit) (void);
+    /* Returns the size of the array cookie for an array of type.  */
+    tree (*get_cookie_size) (tree);
+    /* Returns true if the element size should be stored in the
+       array cookie.  */
+    bool (*cookie_has_size) (void);
+    /* Allows backends to perform additional processing when
+       deciding if a class should be exported or imported.  */
+    int (*import_export_class) (tree, int);
+    /* Returns true if constructors and destructors return "this".  */
+    bool (*cdtor_returns_this) (void);
+    /* Returns true if the key method for a class can be an inline
+       function, so long as it is not declared inline in the class
+       itself.  Returning true is the behavior required by the Itanium
+       C++ ABI.  */
+    bool (*key_method_may_be_inline) (void);
+    /* DECL is a virtual table, virtual table table, typeinfo object,
+       or other similar implicit class data object that will be
+       emitted with external linkage in this translation unit.  No ELF
+       visibility has been explicitly specified.  If the target needs
+       to specify a visibility other than that of the containing class,
+       use this hook to set DECL_VISIBILITY and
+       DECL_VISIBILITY_SPECIFIED.  */
+    void (*determine_class_data_visibility) (tree decl);
+    /* Returns true (the default) if virtual tables and other
+       similar implicit class data objects are always COMDAT if they
+       have external linkage.  If this hook returns false, then
+       class data for classes whose virtual table will be emitted in
+       only one translation unit will not be COMDAT.  */
+    bool (*class_data_always_comdat) (void);
+    /* Returns true (the default) if the RTTI for the basic types,
+       which is always defined in the C++ runtime, should be COMDAT;
+       false if it should not be COMDAT.  */
+    bool (*library_rtti_comdat) (void);
+    /* Returns true if __aeabi_atexit should be used to register static
+       destructors.  */
+    bool (*use_aeabi_atexit) (void);
+    /* Returns true if target may use atexit in the same manner as
+    __cxa_atexit  to register static destructors.  */
+    bool (*use_atexit_for_cxa_atexit) (void);
+    /* TYPE is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that
+       has just been defined.  Use this hook to make adjustments to the
+       class  (eg, tweak visibility or perform any other required
+       target modifications).  */
+    void (*adjust_class_at_definition) (tree type);
+  } cxx;
+
+  /* Functions and data for emulated TLS support.  */
+  struct emutls {
+    /* Name of the address and common functions.  */
+    const char *get_address;
+    const char *register_common;
+
+    /* Prefixes for proxy variable and template.  */
+    const char *var_section;
+    const char *tmpl_section;
+
+    /* Prefixes for proxy variable and template.  */
+    const char *var_prefix;
+    const char *tmpl_prefix;
+    
+    /* Function to generate field definitions of the proxy variable.  */
+    tree (*var_fields) (tree, tree *);
+
+    /* Function to initialize a proxy variable.  */
+    tree (*var_init) (tree, tree, tree);
+
+    /* Whether we are allowed to alter the usual alignment of the
+       proxy variable.  */
+    bool var_align_fixed;
+
+    /* Whether we can emit debug information for TLS vars.  */
+    bool debug_form_tls_address;
+  } emutls;  
+
+  struct target_option_hooks {
+    /* Function to validate the attribute((option(...))) strings or NULL.  If
+       the option is validated, it is assumed that DECL_FUNCTION_SPECIFIC will
+       be filled in in the function decl node.  */
+    bool (*valid_attribute_p) (tree, tree, tree, int);
+
+    /* Function to save any extra target state in the target options
+       structure.  */
+    void (*save) (struct cl_target_option *);
+
+    /* Function to restore any extra target state from the target options
+       structure.  */
+    void (*restore) (struct cl_target_option *);
+
+    /* Function to print any extra target state from the target options
+       structure.  */
+    void (*print) (FILE *, int, struct cl_target_option *);
+
+    /* Function to parse arguments to be validated for #pragma option, and to
+       change the state if the options are valid.  If the first argument is
+       NULL, the second argument specifies the default options to use.  Return
+       true if the options are valid, and set the current state.  */
+    bool (*pragma_parse) (tree, tree);
+
+    /* Function to determine if one function can inline another function.  */
+    bool (*can_inline_p) (tree, tree);
+  } target_option;
+
+  /* For targets that need to mark extra registers as live on entry to
+     the function, they should define this target hook and set their
+     bits in the bitmap passed in. */  
+  void (*live_on_entry) (bitmap); 
+
+  /* True if unwinding tables should be generated by default.  */
+  bool unwind_tables_default;
+
+  /* Leave the boolean fields at the end.  */
+
+  /* True if arbitrary sections are supported.  */
+  bool have_named_sections;
+
+  /* True if we can create zeroed data by switching to a BSS section
+     and then using ASM_OUTPUT_SKIP to allocate the space.  */
+  bool have_switchable_bss_sections;
+
+  /* True if "native" constructors and destructors are supported,
+     false if we're using collect2 for the job.  */
+  bool have_ctors_dtors;
+
+  /* True if thread-local storage is supported.  */
+  bool have_tls;
+
+  /* True if a small readonly data section is supported.  */
+  bool have_srodata_section;
+
+  /* True if EH frame info sections should be zero-terminated.  */
+  bool terminate_dw2_eh_frame_info;
+
+  /* True if #NO_APP should be emitted at the beginning of
+     assembly output.  */
+  bool file_start_app_off;
+
+  /* True if output_file_directive should be called for main_input_filename
+     at the beginning of assembly output.  */
+  bool file_start_file_directive;
+
+  /* True if #pragma redefine_extname is to be supported.  */
+  bool handle_pragma_redefine_extname;
+
+  /* True if #pragma extern_prefix is to be supported.  */
+  bool handle_pragma_extern_prefix;
+
+  /* True if the target is allowed to reorder memory accesses unless
+     synchronization is explicitly requested.  */
+  bool relaxed_ordering;
+
+  /* Returns true if we should generate exception tables for use with the
+     ARM EABI.  The effects the encoding of function exception specifications.
+   */
+  bool arm_eabi_unwinder;
+
+  /* Leave the boolean fields at the end.  */
+};
+
+extern struct gcc_target targetm;
+
+struct gcc_targetcm {
+  /* Handle target switch CODE (an OPT_* value).  ARG is the argument
+     passed to the switch; it is NULL if no argument was.  VALUE is the
+     value of ARG if CODE specifies a UInteger option, otherwise it is
+     1 if the positive form of the switch was used and 0 if the negative
+     form was.  Return true if the switch was valid.  */
+  bool (*handle_c_option) (size_t code, const char *arg, int value);
+};
+
+/* Each target can provide their own.  */
+extern struct gcc_targetcm targetcm;
+
+#endif /* GCC_TARGET_H */