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 "toplev.h"
  59 #include "function.h"
  60 #include "target.h"
  61 #include "tm_p.h"
  62 #include "target-def.h"
  63
  64 bool
  65 default_promote_function_args (fntype)
  66      tree fntype ATTRIBUTE_UNUSED;
  67 {
  68 #ifdef PROMOTE_FUNCTION_ARGS
  69   return true;
  70 #else
  71   return false;
  72 #endif
  73 }
  74
  75 bool
  76 default_promote_function_return (fntype)
  77      tree fntype ATTRIBUTE_UNUSED;
  78 {
  79 #ifdef PROMOTE_FUNCTION_RETURN
  80   return true;
  81 #else
  82   return false;
  83 #endif
  84 }
  85
  86 bool
  87 default_promote_prototypes (fntype)
  88      tree fntype ATTRIBUTE_UNUSED;
  89 {
  90   if (PROMOTE_PROTOTYPES)
  91     return true;
  92   else
  93     return false;
  94 }
  95
  96 rtx
  97 default_struct_value_rtx (tree fntype ATTRIBUTE_UNUSED, int incoming)
  98 {
  99   rtx rv = 0;
 100   if (incoming)
 101     {
 102 #ifdef STRUCT_VALUE_INCOMING
 103       rv = STRUCT_VALUE_INCOMING;
 104 #else
 105 #ifdef STRUCT_VALUE_INCOMING_REGNUM
 106       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_INCOMING_REGNUM);
 107 #else
 108 #ifdef STRUCT_VALUE
 109       rv = STRUCT_VALUE;
 110 #else
 111 #ifndef STRUCT_VALUE_REGNUM
 112       abort();
 113 #else
 114       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 115 #endif
 116 #endif
 117 #endif
 118 #endif
 119     }
 120   else
 121     {
 122 #ifdef STRUCT_VALUE
 123       rv = STRUCT_VALUE;
 124 #else
 125 #ifndef STRUCT_VALUE_REGNUM
 126       abort();
 127 #else
 128       rv = gen_rtx_REG (Pmode, STRUCT_VALUE_REGNUM);
 129 #endif
 130 #endif
 131     }
 132   return rv;
 133 }
 134
 135 bool
 136 default_return_in_memory (tree type,
 137                           tree fntype ATTRIBUTE_UNUSED)
 138 {
 139 #ifndef RETURN_IN_MEMORY
 140   return (TYPE_MODE (type) == BLKmode);
 141 #else
 142   return RETURN_IN_MEMORY (type);
 143 #endif
 144 }
 145
 146 rtx
 147 default_expand_builtin_saveregs (void)
 148 {
 149 #ifdef EXPAND_BUILTIN_SAVEREGS
 150   return EXPAND_BUILTIN_SAVEREGS ();
 151 #else
 152   error ("__builtin_saveregs not supported by this target");
 153   return const0_rtx;
 154 #endif
 155 }
 156
 157 void
 158 default_setup_incoming_varargs (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED,
 159                                 enum machine_mode mode ATTRIBUTE_UNUSED,
 160                                 tree type ATTRIBUTE_UNUSED,
 161                                 int *pretend_arg_size ATTRIBUTE_UNUSED,
 162                                 int second_time ATTRIBUTE_UNUSED)
 163 {
 164 #ifdef SETUP_INCOMING_VARARGS
 165   SETUP_INCOMING_VARARGS ((*ca), mode, type, (*pretend_arg_size), second_time);
 166 #endif
 167 }
 168
 169 bool
 170 default_strict_argument_naming (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 171 {
 172 #ifdef STRICT_ARGUMENT_NAMING
 173   return STRICT_ARGUMENT_NAMING;
 174 #else
 175   return 0;
 176 #endif
 177 }
 178
 179 bool
 180 default_pretend_outgoing_varargs_named(CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
 181 {
 182 #ifdef PRETEND_OUTGOING_VARARGS_NAMED
 183   return PRETEND_OUTGOING_VARARGS_NAMED;
 184 #else
 185 #ifdef SETUP_INCOMING_VARARGS
 186   return 1;
 187 #else
 188   return (targetm.calls.setup_incoming_varargs != default_setup_incoming_varargs);
 189 #endif
 190 #endif
 191 }