targhooks.c revision 132718 
1/* Default target hook functions.
2   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 2, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING.  If not, write to the Free
18Software Foundation, 59 Temple Place - Suite 330, Boston, MA
1902111-1307, 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
65void
66default_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
73enum machine_mode
74default_cc_modes_compatible (enum machine_mode m1, enum machine_mode m2)
75{
76  if (m1 == m2)
77    return m1;
78  return VOIDmode;
79}
80
81bool
82default_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
91bool
92default_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
101bool
102default_promote_prototypes (tree fntype ATTRIBUTE_UNUSED)
103{
104  if (PROMOTE_PROTOTYPES)
105    return true;
106  else
107    return false;
108}
109
110rtx
111default_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
145bool
146default_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
156rtx
157default_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
167void
168default_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
179bool
180default_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
189bool
190default_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
201bool
202hook_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
209bool
210hook_bool_machine_mode_true (enum machine_mode a ATTRIBUTE_UNUSED)
211{
212  return true;
213}
214