gcc/targhooks.c

   1 /* Default target hook functions.
   2    Copyright (C) 2003 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 #include "insn-config.h"
  65 #include "recog.h"
  66 #include "ggc.h"
  67
  68 void
  69 default_external_libcall (rtx fun ATTRIBUTE_UNUSED)
  70 {
  71 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
  72   ASM_OUTPUT_EXTERNAL_LIBCALL(asm_out_file, fun);
  73 #endif
  74 }
  75
  76 bool
  77 default_promote_function_args (tree fntype ATTRIBUTE_UNUSED)
  78 {
  79 #ifdef PROMOTE_FUNCTION_ARGS
  80   return true;
  81 #else
  82   return false;
  83 #endif
  84 }
  85
  86 bool
  87 default_promote_function_return (tree fntype ATTRIBUTE_UNUSED)
  88 {
  89 #ifdef PROMOTE_FUNCTION_RETURN
  90   return true;
  91 #else
  92   return false;
  93 #endif
  94 }
  95
  96 bool
  97 default_promote_prototypes (tree fntype ATTRIBUTE_UNUSED)
  98 {
  99   if (PROMOTE_PROTOTYPES)
 100     return true;
 101   else
 102     return false;
 103 }
 104
 105 rtx
 106 default_struct_value_rtx (tree fntype ATTRIBUTE_UNUSED, int incoming)
 107 {
 108   rtx rv = 0;
 109   if (incoming)
 110     {
 111 #ifdef STRUCT_VALUE_INCOMING
 112       rv = STRUCT_VALUE_INCOMING;
 113 #else
 114 #ifdef STRUCT_VALUE_INCOMING_REGNUM
 115       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_INCOMING_REGNUM);
 116 #else
 117 #ifdef STRUCT_VALUE
 118       rv = STRUCT_VALUE;
 119 #else
 120 #ifndef STRUCT_VALUE_REGNUM
 121       abort();
 122 #else
 123       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 124 #endif
 125 #endif
 126 #endif
 127 #endif
 128     }
 129   else
 130     {
 131 #ifdef STRUCT_VALUE
 132       rv = STRUCT_VALUE;
 133 #else
 134 #ifndef STRUCT_VALUE_REGNUM
 135       abort();
 136 #else
 137       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 138 #endif
 139 #endif
 140     }
 141   return rv;
 142 }
 143
 144 bool
 145 default_return_in_memory (tree type,
 146                           tree fntype ATTRIBUTE_UNUSED)
 147 {
 148 #ifndef RETURN_IN_MEMORY
 149   return (TYPE_MODE (type) == BLKmode);
 150 #else
 151   return RETURN_IN_MEMORY (type);
 152 #endif
 153 }
 154
 155 rtx
 156 default_expand_builtin_saveregs (void)
 157 {
 158 #ifdef EXPAND_BUILTIN_SAVEREGS
 159   return EXPAND_BUILTIN_SAVEREGS ();
 160 #else
 161   error ("__builtin_saveregs not supported by this target");
 162   return const0_rtx;
 163 #endif
 164 }
 165
 166 void
 167 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 168                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 169                                 tree type ATTRIBUTE_UNUSED,
 170                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 171                                 int second_time ATTRIBUTE_UNUSED)
 172 {
 173 #ifdef SETUP_INCOMING_VARARGS
 174   SETUP_INCOMING_VARARGS ((*ca), mode, type, (*pretend_arg_size), second_time);
 175 #endif
 176 }
 177
 178 bool
 179 default_strict_argument_naming (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 180 {
 181 #ifdef STRICT_ARGUMENT_NAMING
 182   return STRICT_ARGUMENT_NAMING;
 183 #else
 184   return 0;
 185 #endif
 186 }
 187
 188 bool
 189 default_pretend_outgoing_varargs_named(CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 190 {
 191 #ifdef PRETEND_OUTGOING_VARARGS_NAMED
 192   return PRETEND_OUTGOING_VARARGS_NAMED;
 193 #else
 194 #ifdef SETUP_INCOMING_VARARGS
 195   return 1;
 196 #else
 197   return (targetm.calls.setup_incoming_varargs != default_setup_incoming_varargs);
 198 #endif
 199 #endif
 200 }
 201
 202 /* A SYMBOL_REF for a local symbol.  Used by default_direct_pool_load_p.  */
 203
 204 static GTY(()) rtx pool_symbol;
 205
 206 /* See whether a local symbol is a valid address for MODE.  If so, assume
 207    that constant pool symbols are also valid addresses, otherwise assume
 208    that they aren't.
 209
 210    ??? This is only an approximation.  We can't test constant pool
 211    symbols directly without forcing something into the constant pool.  */
 212
 213 bool
 214 default_direct_pool_load_p (enum machine_mode mode)
 215 {
 216   if (pool_symbol == 0)
 217     {
 218       char label[256];
 219
 220       ASM_GENERATE_INTERNAL_LABEL (label, "LC", 0);
 221       pool_symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
 222       SYMBOL_REF_FLAGS (pool_symbol) = SYMBOL_FLAG_LOCAL;
 223     }
 224   return memory_address_p (mode, pool_symbol);
 225 }
 226
 227 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 228
 229 bool
 230 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
 231 {
 232   return true;
 233 }
 234
 235 /* Generic hook that takes a machine mode and returns true.  */
 236
 237 bool
 238 hook_bool_machine_mode_true (enum machine_mode a ATTRIBUTE_UNUSED)
 239 {
 240   return true;
 241 }
 242
 243 #include "gt-targhooks.h"