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_INCOMING_REGNUM
 112       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_INCOMING_REGNUM);
 113 #else
 114 #ifdef STRUCT_VALUE
 115       rv = STRUCT_VALUE;
 116 #else
 117 #ifndef STRUCT_VALUE_REGNUM
 118       abort();
 119 #else
 120       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 121 #endif
 122 #endif
 123 #endif
 124 #endif
 125     }
 126   else
 127     {
 128 #ifdef STRUCT_VALUE
 129       rv = STRUCT_VALUE;
 130 #else
 131 #ifndef STRUCT_VALUE_REGNUM
 132       abort();
 133 #else
 134       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 135 #endif
 136 #endif
 137     }
 138   return rv;
 139 }
 140
 141 bool
 142 default_return_in_memory (tree type,
 143                           tree fntype ATTRIBUTE_UNUSED)
 144 {
 145 #ifndef RETURN_IN_MEMORY
 146   return (TYPE_MODE (type) == BLKmode);
 147 #else
 148   return RETURN_IN_MEMORY (type);
 149 #endif
 150 }
 151
 152 rtx
 153 default_expand_builtin_saveregs (void)
 154 {
 155 #ifdef EXPAND_BUILTIN_SAVEREGS
 156   return EXPAND_BUILTIN_SAVEREGS ();
 157 #else
 158   error ("__builtin_saveregs not supported by this target");
 159   return const0_rtx;
 160 #endif
 161 }
 162
 163 void
 164 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 165                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 166                                 tree type ATTRIBUTE_UNUSED,
 167                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 168                                 int second_time ATTRIBUTE_UNUSED)
 169 {
 170 #ifdef SETUP_INCOMING_VARARGS
 171   SETUP_INCOMING_VARARGS ((*ca), mode, type, (*pretend_arg_size), second_time);
 172 #endif
 173 }
 174
 175 bool
 176 default_strict_argument_naming (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 177 {
 178 #ifdef STRICT_ARGUMENT_NAMING
 179   return STRICT_ARGUMENT_NAMING;
 180 #else
 181   return 0;
 182 #endif
 183 }
 184
 185 bool
 186 default_pretend_outgoing_varargs_named(CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 187 {
 188 #ifdef PRETEND_OUTGOING_VARARGS_NAMED
 189   return PRETEND_OUTGOING_VARARGS_NAMED;
 190 #else
 191 #ifdef SETUP_INCOMING_VARARGS
 192   return 1;
 193 #else
 194   return (targetm.calls.setup_incoming_varargs != default_setup_incoming_varargs);
 195 #endif
 196 #endif
 197 }
 198
 199 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true.  */
 200 bool
 201 hook_bool_CUMULATIVE_ARGS_true (CUMULATIVE_ARGS * a ATTRIBUTE_UNUSED)
 202 {
 203   return true;
 204 }