1 /* Process machine description and calculate constant conditions.
2 Copyright (C) 2001-2018 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 3, 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 COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 /* In a machine description, all of the insn patterns - define_insn,
21 define_expand, define_split, define_peephole, define_peephole2 -
22 contain an optional C expression which makes the final decision
23 about whether or not this pattern is usable. That expression may
24 turn out to be always false when the compiler is built. If it is,
25 most of the programs that generate code from the machine
26 description can simply ignore the entire pattern. */
27
28 #include "bconfig.h"
29 #include "system.h"
30 #include "coretypes.h"
31 #include "tm.h"
32 #include "rtl.h"
33 #include "errors.h"
34 #include "read-md.h"
35 #include "gensupport.h"
36
37 /* so we can include except.h in the generated file. */
38 static int saw_eh_return;
39
40 static void write_header (void);
41 static void write_conditions (void);
42 static int write_one_condition (void **, void *);
43
44 /* Generate the header for insn-conditions.c. */
45
46 static void
write_header(void)47 write_header (void)
48 {
49 puts ("\
50 /* Generated automatically by the program `genconditions' from the target\n\
51 machine description file. */\n\
52 \n\
53 #define IN_TARGET_CODE 1\n\
54 #include \"bconfig.h\"\n\
55 #define INCLUDE_STRING\n\
56 #include \"system.h\"\n\
57 \n\
58 /* It is necessary, but not entirely safe, to include the headers below\n\
59 in a generator program. As a defensive measure, don't do so when the\n\
60 table isn't going to have anything in it. */\n\
61 #if GCC_VERSION >= 3001\n\
62 \n\
63 /* Do not allow checking to confuse the issue. */\n\
64 #undef CHECKING_P\n\
65 #define CHECKING_P 0\n\
66 #undef ENABLE_TREE_CHECKING\n\
67 #undef ENABLE_RTL_CHECKING\n\
68 #undef ENABLE_RTL_FLAG_CHECKING\n\
69 #undef ENABLE_GC_CHECKING\n\
70 #undef ENABLE_GC_ALWAYS_COLLECT\n\
71 #define USE_ENUM_MODES\n\
72 \n\
73 #include \"coretypes.h\"\n\
74 #include \"tm.h\"\n\
75 #include \"insn-constants.h\"\n\
76 #include \"rtl.h\"\n\
77 #include \"memmodel.h\"\n\
78 #include \"tm_p.h\"\n\
79 #include \"hard-reg-set.h\"\n\
80 #include \"function.h\"\n\
81 #include \"emit-rtl.h\"\n\
82 \n\
83 /* Fake - insn-config.h doesn't exist yet. */\n\
84 #define MAX_RECOG_OPERANDS 10\n\
85 #define MAX_DUP_OPERANDS 10\n\
86 #define MAX_INSNS_PER_SPLIT 5\n\
87 \n\
88 #include \"regs.h\"\n\
89 #include \"recog.h\"\n\
90 #include \"output.h\"\n\
91 #include \"flags.h\"\n\
92 #include \"hard-reg-set.h\"\n\
93 #include \"predict.h\"\n\
94 #include \"basic-block.h\"\n\
95 #include \"bitmap.h\"\n\
96 #include \"df.h\"\n\
97 #include \"resource.h\"\n\
98 #include \"diagnostic-core.h\"\n\
99 #include \"reload.h\"\n\
100 #include \"tm-constrs.h\"\n");
101
102 if (saw_eh_return)
103 puts ("#define HAVE_eh_return 1");
104 puts ("#include \"except.h\"\n");
105
106 puts ("\
107 /* Dummy external declarations. */\n\
108 extern rtx_insn *insn;\n\
109 extern rtx ins1;\n\
110 extern rtx operands[];\n\
111 \n\
112 #endif /* gcc >= 3.0.1 */\n");
113 }
114
115 /* Write out one entry in the conditions table, using the data pointed
116 to by SLOT. Each entry looks like this:
117
118 { "! optimize_size && ! TARGET_READ_MODIFY_WRITE",
119 __builtin_constant_p (! optimize_size && ! TARGET_READ_MODIFY_WRITE)
120 ? (int) (! optimize_size && ! TARGET_READ_MODIFY_WRITE)
121 : -1) }, */
122
123 static int
write_one_condition(void ** slot,void * ARG_UNUSED (dummy))124 write_one_condition (void **slot, void * ARG_UNUSED (dummy))
125 {
126 const struct c_test *test = * (const struct c_test **) slot;
127 const char *p;
128
129 rtx_reader_ptr->print_md_ptr_loc (test->expr);
130 fputs (" { \"", stdout);
131 for (p = test->expr; *p; p++)
132 {
133 switch (*p)
134 {
135 case '\n': fputs ("\\n\\", stdout); break;
136 case '\\':
137 case '\"': putchar ('\\'); break;
138 default: break;
139 }
140 putchar (*p);
141 }
142
143 fputs ("\",\n __builtin_constant_p ", stdout);
144 rtx_reader_ptr->print_c_condition (test->expr);
145 fputs ("\n ? (int) ", stdout);
146 rtx_reader_ptr->print_c_condition (test->expr);
147 fputs ("\n : -1 },\n", stdout);
148 return 1;
149 }
150
151 /* Write out the complete conditions table, its size, and a flag
152 indicating that gensupport.c can now do insn elision. */
153 static void
write_conditions(void)154 write_conditions (void)
155 {
156 puts ("\
157 /* Structure definition duplicated from gensupport.h rather than\n\
158 drag in that file and its dependencies. */\n\
159 struct c_test\n\
160 {\n\
161 const char *expr;\n\
162 int value;\n\
163 };\n\
164 \n\
165 /* This table lists each condition found in the machine description.\n\
166 Each condition is mapped to its truth value (0 or 1), or -1 if that\n\
167 cannot be calculated at compile time.\n\
168 If we don't have __builtin_constant_p, or it's not acceptable in array\n\
169 initializers, fall back to assuming that all conditions potentially\n\
170 vary at run time. It works in 3.0.1 and later; 3.0 only when not\n\
171 optimizing. */\n\
172 \n\
173 #if GCC_VERSION >= 3001\n\
174 static const struct c_test insn_conditions[] = {\n");
175
176 traverse_c_tests (write_one_condition, 0);
177
178 puts ("\n};\n#endif /* gcc >= 3.0.1 */\n");
179 }
180
181 /* Emit code which will convert the C-format table to a
182 (define_conditions) form, which the MD reader can understand.
183 The result will be added to the set of files scanned by
184 'downstream' generators. */
185 static void
write_writer(void)186 write_writer (void)
187 {
188 puts ("int\n"
189 "main(void)\n"
190 "{\n"
191 " unsigned int i;\n"
192 " const char *p;\n"
193 " puts (\"(define_conditions [\");\n"
194 "#if GCC_VERSION >= 3001\n"
195 " for (i = 0; i < ARRAY_SIZE (insn_conditions); i++)\n"
196 " {\n"
197 " printf (\" (%d \\\"\", insn_conditions[i].value);\n"
198 " for (p = insn_conditions[i].expr; *p; p++)\n"
199 " {\n"
200 " switch (*p)\n"
201 " {\n"
202 " case '\\\\':\n"
203 " case '\\\"': putchar ('\\\\'); break;\n"
204 " default: break;\n"
205 " }\n"
206 " putchar (*p);\n"
207 " }\n"
208 " puts (\"\\\")\");\n"
209 " }\n"
210 "#endif /* gcc >= 3.0.1 */\n"
211 " puts (\"])\");\n"
212 " fflush (stdout);\n"
213 "return ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE;\n"
214 "}");
215 }
216
217 int
main(int argc,const char ** argv)218 main (int argc, const char **argv)
219 {
220 progname = "genconditions";
221
222 if (!init_rtx_reader_args (argc, argv))
223 return (FATAL_EXIT_CODE);
224
225 /* Read the machine description. */
226 md_rtx_info info;
227 while (read_md_rtx (&info))
228 {
229 rtx def = info.def;
230 add_c_test (get_c_test (def), -1);
231 switch (GET_CODE (def))
232 {
233 case DEFINE_INSN:
234 case DEFINE_EXPAND:
235 /* except.h needs to know whether there is an eh_return
236 pattern in the machine description. */
237 if (!strcmp (XSTR (def, 0), "eh_return"))
238 saw_eh_return = 1;
239 break;
240
241 default:
242 break;
243 }
244 }
245
246 write_header ();
247 write_conditions ();
248 write_writer ();
249
250 fflush (stdout);
251 return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
252 }
253