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
  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 bool
  74 default_promote_function_args (tree fntype ATTRIBUTE_UNUSED)
  75 {
  76 #ifdef PROMOTE_FUNCTION_ARGS
  77   return true;
  78 #else
  79   return false;
  80 #endif
  81 }
  82
  83 bool
  84 default_promote_function_return (tree fntype ATTRIBUTE_UNUSED)
  85 {
  86 #ifdef PROMOTE_FUNCTION_RETURN
  87   return true;
  88 #else
  89   return false;
  90 #endif
  91 }
  92
  93 bool
  94 default_promote_prototypes (tree fntype ATTRIBUTE_UNUSED)
  95 {
  96   if (PROMOTE_PROTOTYPES)
  97     return true;
  98   else
  99     return false;
 100 }
 101
 102 rtx
 103 default_struct_value_rtx (tree fntype ATTRIBUTE_UNUSED, int incoming)
 104 {
 105   rtx rv = 0;
 106   if (incoming)
 107     {
 108 #ifdef STRUCT_VALUE_INCOMING
 109       rv = STRUCT_VALUE_INCOMING;
 110 #else
 111 #ifdef STRUCT_VALUE
 112       rv = STRUCT_VALUE;
 113 #else
 114 #ifndef STRUCT_VALUE_REGNUM
 115       abort();
 116 #else
 117       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 118 #endif
 119 #endif
 120 #endif
 121     }
 122   else
 123     {
 124 #ifdef STRUCT_VALUE
 125       rv = STRUCT_VALUE;
 126 #else
 127 #ifndef STRUCT_VALUE_REGNUM
 128       abort();
 129 #else
 130       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 131 #endif
 132 #endif
 133     }
 134   return rv;
 135 }
 136
 137 bool
 138 default_return_in_memory (tree type,
 139                           tree fntype ATTRIBUTE_UNUSED)
 140 {
 141 #ifndef RETURN_IN_MEMORY
 142   return (TYPE_MODE (type) == BLKmode);
 143 #else
 144   return RETURN_IN_MEMORY (type);
 145 #endif
 146 }
 147
 148 rtx
 149 default_expand_builtin_saveregs (void)
 150 {
 151 #ifdef EXPAND_BUILTIN_SAVEREGS
 152   return EXPAND_BUILTIN_SAVEREGS ();
 153 #else
 154   error ("__builtin_saveregs not supported by this target");
 155   return const0_rtx;
 156 #endif
 157 }
 158
 159 void
 160 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 161                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 162                                 tree type ATTRIBUTE_UNUSED,
 163                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 164                                 int second_time ATTRIBUTE_UNUSED)
 165 {
 166 #ifdef SETUP_INCOMING_VARARGS
 167   SETUP_INCOMING_VARARGS ((*ca), mode, type, (*pretend_arg_size), second_time);
 168 #endif
 169 }
 170
 171 bool
 172 default_strict_argument_naming (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 173 {
 174 #ifdef STRICT_ARGUMENT_NAMING
 175   return STRICT_ARGUMENT_NAMING;
 176 #else
 177   return 0;
 178 #endif
 179 }
 180
 181 bool
 182 default_pretend_outgoing_varargs_named(CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 183 {
 184 #ifdef SETUP_INCOMING_VARARGS
 185   return 1;
 186 #else
 187   return (targetm.calls.setup_incoming_varargs != default_setup_incoming_varargs);
 188 #endif
 189 }
 190
 191 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 192
 193 bool
 194 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
 195 {
 196   return true;
 197 }
 198
 199 /* Generic hook that takes a machine mode and returns true.  */
 200
 201 bool
 202 hook_bool_machine_mode_true (enum machine_mode a ATTRIBUTE_UNUSED)
 203 {
 204   return true;
 205 }