contrib/gcc-3.4/gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003, 2004 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 2, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to the Free
  18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 /* The migration of target macros to target hooks works as follows:
  22
  23    1. Create a target hook that uses the existing target macros to
  24       implement the same functionality.
  25
  26    2. Convert all the MI files to use the hook instead of the macro.
  27
  28    3. Repeat for a majority of the remaining target macros.  This will
  29       take some time.
  30
  31    4. Tell target maintainers to start migrating.
  32
  33    5. Eventually convert the backends to override the hook instead of
  34       defining the macros.  This will take some time too.
  35
  36    6. TBD when, poison the macros.  Unmigrated targets will break at
  37       this point.
  38
  39    Note that we expect steps 1-3 to be done by the people that
  40    understand what the MI does with each macro, and step 5 to be done
  41    by the target maintainers for their respective targets.
  42
  43    Note that steps 1 and 2 don't have to be done together, but no
  44    target can override the new hook until step 2 is complete for it.
  45
  46    Once the macros are poisoned, we will revert to the old migration
  47    rules - migrate the macro, callers, and targets all at once.  This
  48    comment can thus be removed at that point.  */
  49
  50 #include "config.h"
  51 #include "system.h"
  52 #include "coretypes.h"
  53 #include "tm.h"
  54 #include "machmode.h"
  55 #include "rtl.h"
  56 #include "tree.h"
  57 #include "expr.h"
  58 #include "output.h"
  59 #include "toplev.h"
  60 #include "function.h"
  61 #include "target.h"
  62 #include "tm_p.h"
  63 #include "target-def.h"
  64
  65 void
  66 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  67 {
  68 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  69   ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  70 #endif
  71 }
  72
  73 enum machine_mode
  74 default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
  75 {
  76   if (m1 == m2)
  77     return m1;
  78   return VOIDmode;
  79 }
  80
  81 bool
  82 default_promote_function_args (tree fntype ATTRIBUTE_UNUSED)
  83 {
  84 #ifdef PROMOTE_FUNCTION_ARGS
  85   return true;
  86 #else
  87   return false;
  88 #endif
  89 }
  90
  91 bool
  92 default_promote_function_return (tree fntype ATTRIBUTE_UNUSED)
  93 {
  94 #ifdef PROMOTE_FUNCTION_RETURN
  95   return true;
  96 #else
  97   return false;
  98 #endif
  99 }
 100
 101 bool
 102 default_promote_prototypes (tree fntype ATTRIBUTE_UNUSED)
 103 {
 104   if (PROMOTE_PROTOTYPES)
 105     return true;
 106   else
 107     return false;
 108 }
 109
 110 rtx
 111 default_struct_value_rtx (tree fntype ATTRIBUTE_UNUSED, int incoming)
 112 {
 113   rtx rv = 0;
 114   if (incoming)
 115     {
 116 #ifdef STRUCT_VALUE_INCOMING
 117       rv = STRUCT_VALUE_INCOMING;
 118 #else
 119 #ifdef STRUCT_VALUE
 120       rv = STRUCT_VALUE;
 121 #else
 122 #ifndef STRUCT_VALUE_REGNUM
 123       abort();
 124 #else
 125       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 126 #endif
 127 #endif
 128 #endif
 129     }
 130   else
 131     {
 132 #ifdef STRUCT_VALUE
 133       rv = STRUCT_VALUE;
 134 #else
 135 #ifndef STRUCT_VALUE_REGNUM
 136       abort();
 137 #else
 138       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 139 #endif
 140 #endif
 141     }
 142   return rv;
 143 }
 144
 145 bool
 146 default_return_in_memory (tree type,
 147                           tree fntype ATTRIBUTE_UNUSED)
 148 {
 149 #ifndef RETURN_IN_MEMORY
 150   return (TYPE_MODE (type) == BLKmode);
 151 #else
 152   return RETURN_IN_MEMORY (type);
 153 #endif
 154 }
 155
 156 rtx
 157 default_expand_builtin_saveregs (void)
 158 {
 159 #ifdef EXPAND_BUILTIN_SAVEREGS
 160   return EXPAND_BUILTIN_SAVEREGS ();
 161 #else
 162   error ("__builtin_saveregs not supported by this target");
 163   return const0_rtx;
 164 #endif
 165 }
 166
 167 void
 168 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 169                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 170                                 tree type ATTRIBUTE_UNUSED,
 171                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 172                                 int second_time ATTRIBUTE_UNUSED)
 173 {
 174 #ifdef SETUP_INCOMING_VARARGS
 175   SETUP_INCOMING_VARARGS ((*ca), mode, type, (*pretend_arg_size), second_time);
 176 #endif
 177 }
 178
 179 bool
 180 default_strict_argument_naming (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 181 {
 182 #ifdef STRICT_ARGUMENT_NAMING
 183   return STRICT_ARGUMENT_NAMING;
 184 #else
 185   return 0;
 186 #endif
 187 }
 188
 189 bool
 190 default_pretend_outgoing_varargs_named(CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 191 {
 192 #ifdef SETUP_INCOMING_VARARGS
 193   return 1;
 194 #else
 195   return (targetm.calls.setup_incoming_varargs != default_setup_incoming_varargs);
 196 #endif
 197 }
 198
 199 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 200
 201 bool
 202 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
 203 {
 204   return true;
 205 }
 206
 207 /* Generic hook that takes a machine mode and returns true.  */
 208
 209 bool
 210 hook_bool_machine_mode_true (enum machine_mode a ATTRIBUTE_UNUSED)
 211 {
 212   return true;
 213 }