text: /* Modula-3: modified */
  
  /* Default target hook functions.
     Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010
     Free Software Foundation, Inc.
  
  This file is part of GCC.
  
  GCC 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.
  
  GCC 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 GCC; see the file COPYING3.  If not see
  <http://www.gnu.org/licenses/>.  */
  
  /* The migration of target macros to target hooks works as follows:
  
     1. Create a target hook that uses the existing target macros to
        implement the same functionality.
  
     2. Convert all the MI files to use the hook instead of the macro.
  
     3. Repeat for a majority of the remaining target macros.  This will
        take some time.
  
     4. Tell target maintainers to start migrating.
  
     5. Eventually convert the backends to override the hook instead of
        defining the macros.  This will take some time too.
  
     6. TBD when, poison the macros.  Unmigrated targets will break at
        this point.
  
     Note that we expect steps 1-3 to be done by the people that
     understand what the MI does with each macro, and step 5 to be done
     by the target maintainers for their respective targets.
  
     Note that steps 1 and 2 don't have to be done together, but no
     target can override the new hook until step 2 is complete for it.
  
     Once the macros are poisoned, we will revert to the old migration
     rules - migrate the macro, callers, and targets all at once.  This
     comment can thus be removed at that point.  */
  
  #include "config.h"
  #include "system.h"
  #include "coretypes.h"
  #include "tm.h"
  #include "machmode.h"
  #include "rtl.h"
  #include "tree.h"
  #include "expr.h"
  #include "output.h"
  #include "toplev.h"
  #include "function.h"
  #include "target.h"
  #include "tm_p.h"
  #include "target-def.h"
  #include "ggc.h"
  #include "hard-reg-set.h"
  #include "reload.h"
  #include "optabs.h"
  #include "recog.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  bool
  default_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
  			      rtx addr ATTRIBUTE_UNUSED,
  			      bool strict ATTRIBUTE_UNUSED)
  {
  #ifdef GO_IF_LEGITIMATE_ADDRESS
    /* Defer to the old implementation using a goto.  */
    if (strict)
      return strict_memory_address_p (mode, addr);
    else
      return memory_address_p (mode, addr);
  #else
    gcc_unreachable ();
    return 0;
  #endif
  }
  
  void
  default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  {
  #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
    ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  #endif
  }
  
  int
  default_unspec_may_trap_p (const_rtx x, unsigned flags)
  {
    int i;
  
    if (GET_CODE (x) == UNSPEC_VOLATILE
        /* Any floating arithmetic may trap.  */
        || (SCALAR_FLOAT_MODE_P (GET_MODE (x))
  	  && flag_trapping_math))
      return 1;
  
    for (i = 0; i < XVECLEN (x, 0); ++i)
      {
        if (may_trap_p_1 (XVECEXP (x, 0, i), flags))
  	return 1;
      }
  
    return 0;
  }
  
  enum machine_mode
  default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED,
  			       enum machine_mode mode,
  			       int *punsignedp ATTRIBUTE_UNUSED,
  			       const_tree funtype ATTRIBUTE_UNUSED,
  			       int for_return ATTRIBUTE_UNUSED)
  {
    if (for_return == 2)
      return promote_mode (type, mode, punsignedp);
    return mode;
  }
  
  enum machine_mode
  default_promote_function_mode_always_promote (const_tree type,
  					      enum machine_mode mode,
  					      int *punsignedp,
  					      const_tree funtype ATTRIBUTE_UNUSED,
  					      int for_return ATTRIBUTE_UNUSED)
  {
    return promote_mode (type, mode, punsignedp);
  }
  
  
  enum machine_mode
  default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
  {
    if (m1 == m2)
      return m1;
    return VOIDmode;
  }
  
  bool
  default_return_in_memory (const_tree type,
  			  const_tree fntype ATTRIBUTE_UNUSED)
  {
    return (TYPE_MODE (type) == BLKmode);
  }
  
  rtx
  default_legitimize_address (rtx x, rtx orig_x ATTRIBUTE_UNUSED,
  			    enum machine_mode mode ATTRIBUTE_UNUSED)
  {
    return x;
  }
  
  rtx
  default_expand_builtin_saveregs (void)
  {
    error ("__builtin_saveregs not supported by this target");
    return const0_rtx;
  }
  
  void
  default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
  				enum machine_mode mode ATTRIBUTE_UNUSED,
  				tree type ATTRIBUTE_UNUSED,
  				int *pretend_arg_size ATTRIBUTE_UNUSED,
  				int second_time ATTRIBUTE_UNUSED)
  {
  }
  
  /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE.  */
  
  rtx
  default_builtin_setjmp_frame_value (void)
  {
    return virtual_stack_vars_rtx;
  }
  
  /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false.  */
  
  bool
  hook_bool_CUMULATIVE_ARGS_false (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
  {
    return false;
  }
  
  bool
  default_pretend_outgoing_varargs_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
  {
    return (targetm.calls.setup_incoming_varargs
  	  != default_setup_incoming_varargs);
  }
  
  enum machine_mode
  default_eh_return_filter_mode (void)
  {
    return targetm.unwind_word_mode ();
  }
  
  enum machine_mode
  default_libgcc_cmp_return_mode (void)
  {
    return word_mode;
  }
  
  enum machine_mode
  default_libgcc_shift_count_mode (void)
  {
    return word_mode;
  }
  
  enum machine_mode
  default_unwind_word_mode (void)
  {
    return word_mode;
  }
  
  /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK.  */
  
  unsigned HOST_WIDE_INT
  default_shift_truncation_mask (enum machine_mode mode)
  {
    return SHIFT_COUNT_TRUNCATED ? GET_MODE_BITSIZE (mode) - 1 : 0;
  }
  
  /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL.  */
  
  unsigned int
  default_min_divisions_for_recip_mul (enum machine_mode mode ATTRIBUTE_UNUSED)
  {
    return have_insn_for (DIV, mode) ? 3 : 2;
  }
  
  /* The default implementation of TARGET_MODE_REP_EXTENDED.  */
  
  int
  default_mode_rep_extended (enum machine_mode mode ATTRIBUTE_UNUSED,
  			   enum machine_mode mode_rep ATTRIBUTE_UNUSED)
  {
    return UNKNOWN;
  }
  
  /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
  
  bool
  hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
  {
    return true;
  }
  
  /* Return machine mode for non-standard suffix
     or VOIDmode if non-standard suffixes are unsupported.  */
  enum machine_mode
  default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED)
  {
    return VOIDmode;
  }
  
  /* The generic C++ ABI specifies this is a 64-bit value.  */
  tree
  default_cxx_guard_type (void)
  {
    return long_long_integer_type_node;
  }
  
  
  /* Returns the size of the cookie to use when allocating an array
     whose elements have the indicated TYPE.  Assumes that it is already
     known that a cookie is needed.  */
  
  tree
  default_cxx_get_cookie_size (tree type)
  {
    tree cookie_size;
  
    /* We need to allocate an additional max (sizeof (size_t), alignof
       (true_type)) bytes.  */
    tree sizetype_size;
    tree type_align;
  
    sizetype_size = size_in_bytes (sizetype);
    type_align = size_int (TYPE_ALIGN_UNIT (type));
    if (INT_CST_LT_UNSIGNED (type_align, sizetype_size))
      cookie_size = sizetype_size;
    else
      cookie_size = type_align;
  
    return cookie_size;
  }
  
  /* Return true if a parameter must be passed by reference.  This version
     of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK.  */
  
  bool
  hook_pass_by_reference_must_pass_in_stack (CUMULATIVE_ARGS *c ATTRIBUTE_UNUSED,
  	enum machine_mode mode ATTRIBUTE_UNUSED, const_tree type ATTRIBUTE_UNUSED,
  	bool named_arg ATTRIBUTE_UNUSED)
  {
    return targetm.calls.must_pass_in_stack (mode, type);
  }
  
  /* Return true if a parameter follows callee copies conventions.  This
     version of the hook is true for all named arguments.  */
  
  bool
  hook_callee_copies_named (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
  			  enum machine_mode mode ATTRIBUTE_UNUSED,
  			  const_tree type ATTRIBUTE_UNUSED, bool named)
  {
    return named;
  }
  
  /* Emit any directives required to unwind this instruction.  */
  
  void
  default_unwind_emit (FILE * stream ATTRIBUTE_UNUSED,
  		     rtx insn ATTRIBUTE_UNUSED)
  {
    /* Should never happen.  */
    gcc_unreachable ();
  }
  
  /* 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.
  
     By default we guess this means that any C type is supported.  If
     we can't map the mode back to a type that would be available in C,
     then reject it.  Special case, here, is the double-word arithmetic
     supported by optabs.c.  */
  
  bool
  default_scalar_mode_supported_p (enum machine_mode mode)
  {
    int precision = GET_MODE_PRECISION (mode);
  
    switch (GET_MODE_CLASS (mode))
      {
      case MODE_PARTIAL_INT:
      case MODE_INT:
        if (precision == CHAR_TYPE_SIZE)
  	return true;
        if (precision == SHORT_TYPE_SIZE)
  	return true;
        if (precision == INT_TYPE_SIZE)
  	return true;
        if (precision == LONG_TYPE_SIZE)
  	return true;
        if (precision == LONG_LONG_TYPE_SIZE)
  	return true;
        if (precision == 2 * BITS_PER_WORD)
  	return true;
        return false;
  
      case MODE_FLOAT:
        if (precision == FLOAT_TYPE_SIZE)
  	return true;
        if (precision == DOUBLE_TYPE_SIZE)
  	return true;
        if (precision == LONG_DOUBLE_TYPE_SIZE)
  	return true;
        return false;
  
      case MODE_DECIMAL_FLOAT:
      case MODE_FRACT:
      case MODE_UFRACT:
      case MODE_ACCUM:
      case MODE_UACCUM:
        return false;
  
      default:
        gcc_unreachable ();
      }
  }
  
  /* True if the target supports decimal floating point.  */
  
  bool
  default_decimal_float_supported_p (void)
  {
    return ENABLE_DECIMAL_FLOAT;
  }
  
  /* True if the target supports fixed-point arithmetic.  */
  
  bool
  default_fixed_point_supported_p (void)
  {
    return ENABLE_FIXED_POINT;
  }
  
  /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
     an error message.
  
     This function checks whether a given INSN is valid within a low-overhead
     loop.  If INSN is invalid it returns the reason for that, otherwise it
     returns NULL. A called function may clobber any special registers required
     for low-overhead looping. Additionally, some targets (eg, PPC) use the count
     register for branch on table instructions. We reject the doloop pattern in
     these cases.  */
  
  const char *
  default_invalid_within_doloop (const_rtx insn)
  {
    if (CALL_P (insn))
      return "Function call in loop.";
  
    if (JUMP_TABLE_DATA_P (insn))
      return "Computed branch in the loop.";
  
    return NULL;
  }
  
  /* Mapping of builtin functions to vectorized variants.  */
  
  tree
  default_builtin_vectorized_function (tree fndecl ATTRIBUTE_UNUSED,
  				     tree type_out ATTRIBUTE_UNUSED,
  				     tree type_in ATTRIBUTE_UNUSED)
  {
    return NULL_TREE;
  }
  
  /* Vectorized conversion.  */
  
  tree
  default_builtin_vectorized_conversion (unsigned int code ATTRIBUTE_UNUSED,
  				       tree type ATTRIBUTE_UNUSED)
  {
    return NULL_TREE;
  }
  
  /* Reciprocal.  */
  
  tree
  default_builtin_reciprocal (unsigned int fn ATTRIBUTE_UNUSED,
  			    bool md_fn ATTRIBUTE_UNUSED,
  			    bool sqrt ATTRIBUTE_UNUSED)
  {
    return NULL_TREE;
  }
  
  bool
  hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false (
  	CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
  	enum machine_mode mode ATTRIBUTE_UNUSED,
  	const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
  {
    return false;
  }
  
  bool
  hook_bool_CUMULATIVE_ARGS_mode_tree_bool_true (
  	CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
  	enum machine_mode mode ATTRIBUTE_UNUSED,
  	const_tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
  {
    return true;
  }
  
  int
  hook_int_CUMULATIVE_ARGS_mode_tree_bool_0 (
  	CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
  	enum machine_mode mode ATTRIBUTE_UNUSED,
  	tree type ATTRIBUTE_UNUSED, bool named ATTRIBUTE_UNUSED)
  {
    return 0;
  }
  
  void
  hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED)
  {
  }
  
  const char *
  hook_invalid_arg_for_unprototyped_fn (
  	const_tree typelist ATTRIBUTE_UNUSED,
  	const_tree funcdecl ATTRIBUTE_UNUSED,
  	const_tree val ATTRIBUTE_UNUSED)
  {
    return NULL;
  }
  
  /* Initialize the stack protection decls.  */
  
  /* Stack protection related decls living in libgcc.  */
  static GTY(()) tree stack_chk_guard_decl;
  
  tree
  default_stack_protect_guard (void)
  {
    tree t = stack_chk_guard_decl;
  
    if (t == NULL)
      {
        t = build_decl (UNKNOWN_LOCATION,
  		      VAR_DECL, get_identifier ("__stack_chk_guard"),
  		      ptr_type_node);
        TREE_STATIC (t) = 1;
        TREE_PUBLIC (t) = 1;
        DECL_EXTERNAL (t) = 1;
        TREE_USED (t) = 1;
        TREE_THIS_VOLATILE (t) = 1;
        DECL_ARTIFICIAL (t) = 1;
        DECL_IGNORED_P (t) = 1;
  
        stack_chk_guard_decl = t;
      }
  
    return t;
  }
  
  static GTY(()) tree stack_chk_fail_decl;
  
  tree
  default_external_stack_protect_fail (void)
  {
    tree t = stack_chk_fail_decl;
  
    if (t == NULL_TREE)
      {
        t = build_function_type_list (void_type_node, NULL_TREE);
        t = build_decl (UNKNOWN_LOCATION,
  		      FUNCTION_DECL, get_identifier ("__stack_chk_fail"), t);
        TREE_STATIC (t) = 1;
        TREE_PUBLIC (t) = 1;
        DECL_EXTERNAL (t) = 1;
        TREE_USED (t) = 1;
        TREE_THIS_VOLATILE (t) = 1;
        TREE_NOTHROW (t) = 1;
        DECL_ARTIFICIAL (t) = 1;
        DECL_IGNORED_P (t) = 1;
        DECL_VISIBILITY (t) = VISIBILITY_DEFAULT;
        DECL_VISIBILITY_SPECIFIED (t) = 1;
  
        stack_chk_fail_decl = t;
      }
  
    return build_call_expr (t, 0);
  }
  
  tree
  default_hidden_stack_protect_fail (void)
  {
  #ifndef HAVE_GAS_HIDDEN
    return default_external_stack_protect_fail ();
  #else
    tree t = stack_chk_fail_decl;
  
    if (!flag_pic)
      return default_external_stack_protect_fail ();
  
    if (t == NULL_TREE)
      {
        t = build_function_type_list (void_type_node, NULL_TREE);
        t = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
  		      get_identifier ("__stack_chk_fail_local"), t);
        TREE_STATIC (t) = 1;
        TREE_PUBLIC (t) = 1;
        DECL_EXTERNAL (t) = 1;
        TREE_USED (t) = 1;
        TREE_THIS_VOLATILE (t) = 1;
        TREE_NOTHROW (t) = 1;
        DECL_ARTIFICIAL (t) = 1;
        DECL_IGNORED_P (t) = 1;
        DECL_VISIBILITY_SPECIFIED (t) = 1;
        DECL_VISIBILITY (t) = VISIBILITY_HIDDEN;
  
        stack_chk_fail_decl = t;
      }
  
    return build_call_expr (t, 0);
  #endif
  }
  
  bool
  hook_bool_const_rtx_commutative_p (const_rtx x,
  				   int outer_code ATTRIBUTE_UNUSED)
  {
    return COMMUTATIVE_P (x);
  }
  
  rtx
  default_function_value (const_tree ret_type ATTRIBUTE_UNUSED,
  			const_tree fn_decl_or_type,
  			bool outgoing ATTRIBUTE_UNUSED)
  {
    /* The old interface doesn't handle receiving the function type.  */
    if (fn_decl_or_type
        && !DECL_P (fn_decl_or_type))
      fn_decl_or_type = NULL;
  
  #ifdef FUNCTION_OUTGOING_VALUE
    if (outgoing)
      return FUNCTION_OUTGOING_VALUE (ret_type, fn_decl_or_type);
  #endif
  
  #ifdef FUNCTION_VALUE
    return FUNCTION_VALUE (ret_type, fn_decl_or_type);
  #else
    gcc_unreachable ();
    return 0;
  #endif
  }
  
  rtx
  default_libcall_value (enum machine_mode mode ATTRIBUTE_UNUSED,
  		       const_rtx fun ATTRIBUTE_UNUSED)
  {
  #ifdef LIBCALL_VALUE
    return LIBCALL_VALUE (mode);
  #else
    gcc_unreachable ();
    return 0;
  #endif
  }
  
  rtx
  default_internal_arg_pointer (void)
  {
    /* If the reg that the virtual arg pointer will be translated into is
       not a fixed reg or is the stack pointer, make a copy of the virtual
       arg pointer, and address parms via the copy.  The frame pointer is
       considered fixed even though it is not marked as such.  */
    if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
         || ! (fixed_regs[ARG_POINTER_REGNUM]
  	     || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
      return copy_to_reg (virtual_incoming_args_rtx);
    else
      return virtual_incoming_args_rtx;
  }
  
  rtx
  default_static_chain (const_tree fndecl, bool incoming_p)
  {
  #if 0
    if (!DECL_STATIC_CHAIN (fndecl))
      return NULL;
  #else /* For Modula-3 July 2010 */
    if (fndecl && !DECL_STATIC_CHAIN (fndecl))
      return NULL;
  #endif
  
    if (incoming_p)
      {
  #ifdef STATIC_CHAIN_INCOMING_REGNUM
        return gen_rtx_REG (Pmode, STATIC_CHAIN_INCOMING_REGNUM);
  #endif
      }
  
  #ifdef STATIC_CHAIN_REGNUM
    return gen_rtx_REG (Pmode, STATIC_CHAIN_REGNUM);
  #endif
  
    {
      static bool issued_error;
      if (!issued_error)
        {
  	issued_error = true;
  	sorry ("nested functions not supported on this target");
        }
  
      /* It really doesn't matter what we return here, so long at it
         doesn't cause the rest of the compiler to crash.  */
      return gen_rtx_MEM (Pmode, stack_pointer_rtx);
    }
  }
  
  void
  default_trampoline_init (rtx ARG_UNUSED (m_tramp), tree ARG_UNUSED (t_func),
  			 rtx ARG_UNUSED (r_chain))
  {
    sorry ("nested function trampolines not supported on this target");
  }
  
  enum reg_class
  default_branch_target_register_class (void)
  {
    return NO_REGS;
  }
  
  #ifdef IRA_COVER_CLASSES
  const enum reg_class *
  default_ira_cover_classes (void)
  {
    static enum reg_class classes[] = IRA_COVER_CLASSES;
    return classes;
  }
  #endif
  
  enum reg_class
  default_secondary_reload (bool in_p ATTRIBUTE_UNUSED, rtx x ATTRIBUTE_UNUSED,
  			  enum reg_class reload_class ATTRIBUTE_UNUSED,
  			  enum machine_mode reload_mode ATTRIBUTE_UNUSED,
  			  secondary_reload_info *sri)
  {
    enum reg_class rclass = NO_REGS;
  
    if (sri->prev_sri && sri->prev_sri->t_icode != CODE_FOR_nothing)
      {
        sri->icode = sri->prev_sri->t_icode;
        return NO_REGS;
      }
  #ifdef SECONDARY_INPUT_RELOAD_CLASS
    if (in_p)
      rclass = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
  #endif
  #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
    if (! in_p)
      rclass = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
  #endif
    if (rclass != NO_REGS)
      {
        enum insn_code icode = (in_p ? reload_in_optab[(int) reload_mode]
  			      : reload_out_optab[(int) reload_mode]);
  
        if (icode != CODE_FOR_nothing
  	  && insn_data[(int) icode].operand[in_p].predicate
  	  && ! insn_data[(int) icode].operand[in_p].predicate (x, reload_mode))
  	icode = CODE_FOR_nothing;
        else if (icode != CODE_FOR_nothing)
  	{
  	  const char *insn_constraint, *scratch_constraint;
  	  char insn_letter, scratch_letter;
  	  enum reg_class insn_class, scratch_class;
  
  	  gcc_assert (insn_data[(int) icode].n_operands == 3);
  	  insn_constraint = insn_data[(int) icode].operand[!in_p].constraint;
  	  if (!*insn_constraint)
  	    insn_class = ALL_REGS;
  	  else
  	    {
  	      if (in_p)
  		{
  		  gcc_assert (*insn_constraint == '=');
  		  insn_constraint++;
  		}
  	      insn_letter = *insn_constraint;
  	      insn_class
  		= (insn_letter == 'r' ? GENERAL_REGS
  		   : REG_CLASS_FROM_CONSTRAINT ((unsigned char) insn_letter,
  						insn_constraint));
  	      gcc_assert (insn_class != NO_REGS);
  	    }
  
  	  scratch_constraint = insn_data[(int) icode].operand[2].constraint;
  	  /* The scratch register's constraint must start with "=&",
  	     except for an input reload, where only "=" is necessary,
  	     and where it might be beneficial to re-use registers from
  	     the input.  */
  	  gcc_assert (scratch_constraint[0] == '='
  		      && (in_p || scratch_constraint[1] == '&'));
  	  scratch_constraint++;
  	  if (*scratch_constraint == '&')
  	    scratch_constraint++;
  	  scratch_letter = *scratch_constraint;
  	  scratch_class
  	    = (scratch_letter == 'r' ? GENERAL_REGS
  	       : REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
  					    scratch_constraint));
  
  	  if (reg_class_subset_p (reload_class, insn_class))
  	    {
  	      gcc_assert (scratch_class == rclass);
  	      rclass = NO_REGS;
  	    }
  	  else
  	    rclass = insn_class;
  
          }
        if (rclass == NO_REGS)
  	sri->icode = icode;
        else
  	sri->t_icode = icode;
      }
    return rclass;
  }
  
  bool
  default_handle_c_option (size_t code ATTRIBUTE_UNUSED,
  			 const char *arg ATTRIBUTE_UNUSED,
  			 int value ATTRIBUTE_UNUSED)
  {
    return false;
  }
  
  /* By default, if flag_pic is true, then neither local nor global relocs
     should be placed in readonly memory.  */
  
  int
  default_reloc_rw_mask (void)
  {
    return flag_pic ? 3 : 0;
  }
  
  /* By default, do no modification. */
  tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
  					 tree id)
  {
     return id;
  }
  
  bool
  default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
  {
    if (is_packed)
      return false;
  
    /* Assuming that types whose size is > pointer-size are not guaranteed to be
       naturally aligned.  */
    if (tree_int_cst_compare (TYPE_SIZE (type), bitsize_int (POINTER_SIZE)) > 0)
      return false;
  
    /* Assuming that types whose size is <= pointer-size
       are naturally aligned.  */
    return true;
  }
  
  /* By default, assume that a target supports any factor of misalignment
     memory access if it supports movmisalign patten.
     is_packed is true if the memory access is defined in a packed struct.  */
  bool
  default_builtin_support_vector_misalignment (enum machine_mode mode,
  					     const_tree type
  					     ATTRIBUTE_UNUSED,
  					     int misalignment
  					     ATTRIBUTE_UNUSED,
  					     bool is_packed
  					     ATTRIBUTE_UNUSED)
  {
    if (optab_handler (movmisalign_optab, mode)->insn_code != CODE_FOR_nothing)
      return true;
    return false;
  }
  
  /* Determine whether or not a pointer mode is valid. Assume defaults
     of ptr_mode or Pmode - can be overridden.  */
  bool
  default_valid_pointer_mode (enum machine_mode mode)
  {
    return (mode == ptr_mode || mode == Pmode);
  }
  
  /* Return the mode for a pointer to a given ADDRSPACE, defaulting to ptr_mode
     for the generic address space only.  */
  
  enum machine_mode
  default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
  {
    gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
    return ptr_mode;
  }
  
  /* Return the mode for an address in a given ADDRSPACE, defaulting to Pmode
     for the generic address space only.  */
  
  enum machine_mode
  default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED)
  {
    gcc_assert (ADDR_SPACE_GENERIC_P (addrspace));
    return Pmode;
  }
  
  /* Named address space version of valid_pointer_mode.  */
  
  bool
  default_addr_space_valid_pointer_mode (enum machine_mode mode, addr_space_t as)
  {
    if (!ADDR_SPACE_GENERIC_P (as))
      return (mode == targetm.addr_space.pointer_mode (as)
  	    || mode == targetm.addr_space.address_mode (as));
  
    return targetm.valid_pointer_mode (mode);
  }
  
  /* 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.  */
  
  bool
  target_default_pointer_address_modes_p (void)
  {
    if (targetm.addr_space.address_mode != default_addr_space_address_mode)
      return false;
    if (targetm.addr_space.pointer_mode != default_addr_space_pointer_mode)
      return false;
  
    return true;
  }
  
  /* Named address space version of legitimate_address_p.  */
  
  bool
  default_addr_space_legitimate_address_p (enum machine_mode mode, rtx mem,
  					 bool strict, addr_space_t as)
  {
    if (!ADDR_SPACE_GENERIC_P (as))
      gcc_unreachable ();
  
    return targetm.legitimate_address_p (mode, mem, strict);
  }
  
  /* Named address space version of LEGITIMIZE_ADDRESS.  */
  
  rtx
  default_addr_space_legitimize_address (rtx x, rtx oldx,
  				       enum machine_mode mode, addr_space_t as)
  {
    if (!ADDR_SPACE_GENERIC_P (as))
      return x;
  
    return targetm.legitimize_address (x, oldx, mode);
  }
  
  /* The default hook for determining if one named address space is a subset of
     another and to return which address space to use as the common address
     space.  */
  
  bool
  default_addr_space_subset_p (addr_space_t subset, addr_space_t superset)
  {
    return (subset == superset);
  }
  
  /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
     called for targets with only a generic address space.  */
  
  rtx
  default_addr_space_convert (rtx op ATTRIBUTE_UNUSED,
  			    tree from_type ATTRIBUTE_UNUSED,
  			    tree to_type ATTRIBUTE_UNUSED)
  {
    gcc_unreachable ();
    return 0;
  }
  
  bool
  default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED)
  {
    return true;
  }
  
  bool
  default_target_option_valid_attribute_p (tree ARG_UNUSED (fndecl),
  					 tree ARG_UNUSED (name),
  					 tree ARG_UNUSED (args),
  					 int ARG_UNUSED (flags))
  {
    warning (OPT_Wattributes,
  	   "target attribute is not supported on this machine");
  
    return false;
  }
  
  bool
  default_target_option_pragma_parse (tree ARG_UNUSED (args),
  				    tree ARG_UNUSED (pop_target))
  {
    warning (OPT_Wpragmas,
  	   "#pragma GCC target is not supported for this machine");
  
    return false;
  }
  
  bool
  default_target_can_inline_p (tree caller, tree callee)
  {
    bool ret = false;
    tree callee_opts = DECL_FUNCTION_SPECIFIC_TARGET (callee);
    tree caller_opts = DECL_FUNCTION_SPECIFIC_TARGET (caller);
  
    /* If callee has no option attributes, then it is ok to inline */
    if (!callee_opts)
      ret = true;
  
    /* If caller has no option attributes, but callee does then it is not ok to
       inline */
    else if (!caller_opts)
      ret = false;
  
    /* If both caller and callee have attributes, assume that if the pointer is
       different, the the two functions have different target options since
       build_target_option_node uses a hash table for the options.  */
    else
      ret = (callee_opts == caller_opts);
  
    return ret;
  }
  
  #ifndef HAVE_casesi
  # define HAVE_casesi 0
  #endif
  
  /* If the machine does not have a case insn that compares the bounds,
     this means extra overhead for dispatch tables, which raises the
     threshold for using them.  */
  
  unsigned int default_case_values_threshold (void)
  {
    return (HAVE_casesi ? 4 : 5);
  }
  
  bool
  default_have_conditional_execution (void)
  {
  #ifdef HAVE_conditional_execution
    return HAVE_conditional_execution;
  #else
    return false;
  #endif
  }
  
  #include "gt-targhooks.h"
  
  #ifdef __cplusplus
  } /* extern "C" */
  #endif
  