1/* Process machine description and calculate constant conditions.
2   Copyright (C) 2001, 2002, 2003, 2004, 2005 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
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 2, or (at your option)
9   any later version.
10
11   GCC is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License 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
18   the Free Software Foundation, 51 Franklin Street, Fifth Floor,
19   Boston, MA 02110-1301, USA.  */
20
21/* In a machine description, all of the insn patterns - define_insn,
22   define_expand, define_split, define_peephole, define_peephole2 -
23   contain an optional C expression which makes the final decision
24   about whether or not this pattern is usable.  That expression may
25   turn out to be always false when the compiler is built.  If it is,
26   most of the programs that generate code from the machine
27   description can simply ignore the entire pattern.  */
28
29#include "bconfig.h"
30#include "system.h"
31#include "coretypes.h"
32#include "tm.h"
33#include "rtl.h"
34#include "errors.h"
35#include "hashtab.h"
36#include "gensupport.h"
37
38/* so we can include except.h in the generated file.  */
39static int saw_eh_return;
40
41static void write_header	(void);
42static void write_conditions	(void);
43static int write_one_condition	(void **, void *);
44
45/* Generate the header for insn-conditions.c.  */
46
47static void
48write_header (void)
49{
50  puts ("\
51/* Generated automatically by the program `genconditions' from the target\n\
52   machine description file.  */\n\
53\n\
54#include \"bconfig.h\"\n\
55#include \"system.h\"\n\
56\n\
57/* It is necessary, but not entirely safe, to include the headers below\n\
58   in a generator program.  As a defensive measure, don't do so when the\n\
59   table isn't going to have anything in it.  */\n\
60#if GCC_VERSION >= 3001\n\
61\n\
62/* Do not allow checking to confuse the issue.  */\n\
63#undef ENABLE_CHECKING\n\
64#undef ENABLE_TREE_CHECKING\n\
65#undef ENABLE_RTL_CHECKING\n\
66#undef ENABLE_RTL_FLAG_CHECKING\n\
67#undef ENABLE_GC_CHECKING\n\
68#undef ENABLE_GC_ALWAYS_COLLECT\n\
69\n\
70#include \"coretypes.h\"\n\
71#include \"tm.h\"\n\
72#include \"insn-constants.h\"\n\
73#include \"rtl.h\"\n\
74#include \"tm_p.h\"\n\
75#include \"function.h\"\n\
76\n\
77/* Fake - insn-config.h doesn't exist yet.  */\n\
78#define MAX_RECOG_OPERANDS 10\n\
79#define MAX_DUP_OPERANDS 10\n\
80#define MAX_INSNS_PER_SPLIT 5\n\
81\n\
82#include \"regs.h\"\n\
83#include \"recog.h\"\n\
84#include \"real.h\"\n\
85#include \"output.h\"\n\
86#include \"flags.h\"\n\
87#include \"hard-reg-set.h\"\n\
88#include \"resource.h\"\n\
89#include \"toplev.h\"\n\
90#include \"reload.h\"\n\
91#include \"tm-constrs.h\"\n");
92
93  if (saw_eh_return)
94    puts ("#define HAVE_eh_return 1");
95  puts ("#include \"except.h\"\n");
96
97  puts ("\
98/* Dummy external declarations.  */\n\
99extern rtx insn;\n\
100extern rtx ins1;\n\
101extern rtx operands[];\n\
102\n\
103#endif /* gcc >= 3.0.1 */\n");
104}
105
106/* Write out one entry in the conditions table, using the data pointed
107   to by SLOT.  Each entry looks like this:
108
109   { "! optimize_size && ! TARGET_READ_MODIFY_WRITE",
110     __builtin_constant_p (! optimize_size && ! TARGET_READ_MODIFY_WRITE)
111     ? (int) (! optimize_size && ! TARGET_READ_MODIFY_WRITE)
112     : -1) },  */
113
114static int
115write_one_condition (void **slot, void * ARG_UNUSED (dummy))
116{
117  const struct c_test *test = * (const struct c_test **) slot;
118  const char *p;
119
120  print_rtx_ptr_loc (test->expr);
121  fputs ("  { \"", stdout);
122  for (p = test->expr; *p; p++)
123    {
124      switch (*p)
125	{
126	case '\n': fputs ("\\n\\", stdout); break;
127	case '\\':
128	case '\"': putchar ('\\'); break;
129	default: break;
130	}
131      putchar (*p);
132    }
133
134  fputs ("\",\n    __builtin_constant_p ", stdout);
135  print_c_condition (test->expr);
136  fputs ("\n    ? (int) ", stdout);
137  print_c_condition (test->expr);
138  fputs ("\n    : -1 },\n", stdout);
139  return 1;
140}
141
142/* Write out the complete conditions table, its size, and a flag
143   indicating that gensupport.c can now do insn elision.  */
144static void
145write_conditions (void)
146{
147  puts ("\
148/* Structure definition duplicated from gensupport.h rather than\n\
149   drag in that file and its dependencies.  */\n\
150struct c_test\n\
151{\n\
152  const char *expr;\n\
153  int value;\n\
154};\n\
155\n\
156/* This table lists each condition found in the machine description.\n\
157   Each condition is mapped to its truth value (0 or 1), or -1 if that\n\
158   cannot be calculated at compile time.\n\
159   If we don't have __builtin_constant_p, or it's not acceptable in array\n\
160   initializers, fall back to assuming that all conditions potentially\n\
161   vary at run time.  It works in 3.0.1 and later; 3.0 only when not\n\
162   optimizing.  */\n\
163\n\
164#if GCC_VERSION >= 3001\n\
165static const struct c_test insn_conditions[] = {\n");
166
167  traverse_c_tests (write_one_condition, 0);
168
169  puts ("\n};\n#endif /* gcc >= 3.0.1 */\n");
170}
171
172/* Emit code which will convert the C-format table to a
173   (define_conditions) form, which the MD reader can understand.
174   The result will be added to the set of files scanned by
175   'downstream' generators.  */
176static void
177write_writer (void)
178{
179  puts ("int\n"
180	"main(void)\n"
181	"{\n"
182	"  unsigned int i;\n"
183        "  const char *p;\n"
184        "  puts (\"(define_conditions [\");\n"
185	"#if GCC_VERSION >= 3001\n"
186	"  for (i = 0; i < ARRAY_SIZE (insn_conditions); i++)\n"
187	"    {\n"
188	"      printf (\"  (%d \\\"\", insn_conditions[i].value);\n"
189	"      for (p = insn_conditions[i].expr; *p; p++)\n"
190	"        {\n"
191	"          switch (*p)\n"
192	"	     {\n"
193	"	     case '\\\\':\n"
194	"	     case '\\\"': putchar ('\\\\'); break;\n"
195	"	     default: break;\n"
196	"	     }\n"
197	"          putchar (*p);\n"
198	"        }\n"
199        "      puts (\"\\\")\");\n"
200        "    }\n"
201	"#endif /* gcc >= 3.0.1 */\n"
202	"  puts (\"])\");\n"
203        "  fflush (stdout);\n"
204        "return ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE;\n"
205	"}");
206}
207
208int
209main (int argc, char **argv)
210{
211  rtx desc;
212  int pattern_lineno; /* not used */
213  int code;
214
215  progname = "genconditions";
216
217  if (init_md_reader_args (argc, argv) != SUCCESS_EXIT_CODE)
218    return (FATAL_EXIT_CODE);
219
220  /* Read the machine description.  */
221  while (1)
222    {
223      desc = read_md_rtx (&pattern_lineno, &code);
224      if (desc == NULL)
225	break;
226
227      /* N.B. define_insn_and_split, define_cond_exec are handled
228	 entirely within read_md_rtx; we never see them.  */
229      switch (GET_CODE (desc))
230	{
231	default:
232	  break;
233
234	case DEFINE_INSN:
235	case DEFINE_EXPAND:
236	  add_c_test (XSTR (desc, 2), -1);
237	  /* except.h needs to know whether there is an eh_return
238	     pattern in the machine description.  */
239	  if (!strcmp (XSTR (desc, 0), "eh_return"))
240	    saw_eh_return = 1;
241	  break;
242
243	case DEFINE_SPLIT:
244	case DEFINE_PEEPHOLE:
245	case DEFINE_PEEPHOLE2:
246	  add_c_test (XSTR (desc, 1), -1);
247	  break;
248	}
249    }
250
251  write_header ();
252  write_conditions ();
253  write_writer ();
254
255  fflush (stdout);
256  return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
257}
258