1 /* Process machine description and calculate constant conditions.
2 Copyright (C) 2001, 2002 Free Software Foundation, Inc.
3
4 This file is part of GNU CC.
5
6 GNU CC 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 GNU CC 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 GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, 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 "hconfig.h"
30 #include "system.h"
31 #include "rtl.h"
32 #include "errors.h"
33 #include "hashtab.h"
34 #include "gensupport.h"
35
36 /* so we can include except.h in the generated file */
37 static int saw_eh_return;
38
39 static htab_t condition_table;
40
41 static void add_condition PARAMS ((const char *));
42 static void write_header PARAMS ((void));
43 static void write_conditions PARAMS ((void));
44 static int write_one_condition PARAMS ((PTR *, PTR));
45
46 extern int main PARAMS ((int, char **));
47
48 /* Record the C test expression EXPR in the condition_table.
49 Duplicates clobber previous entries, which leaks memory, but
50 we don't care for this application. */
51
52 static void
add_condition(expr)53 add_condition (expr)
54 const char *expr;
55 {
56 struct c_test *test;
57
58 if (expr[0] == 0)
59 return;
60
61 test = (struct c_test *) xmalloc (sizeof (struct c_test));
62 test->expr = expr;
63
64 *(htab_find_slot (condition_table, test, INSERT)) = test;
65 }
66
67 /* Generate the header for insn-conditions.c. */
68
69 static void
write_header()70 write_header ()
71 {
72 puts ("\
73 /* Generated automatically by the program `genconditions' from the target\n\
74 machine description file. */\n\
75 \n\
76 #include \"hconfig.h\"\n\
77 #include \"insn-constants.h\"\n");
78
79 puts ("\
80 /* Do not allow checking to confuse the issue. */\n\
81 #undef ENABLE_CHECKING\n\
82 #undef ENABLE_TREE_CHECKING\n\
83 #undef ENABLE_RTL_CHECKING\n\
84 #undef ENABLE_RTL_FLAG_CHECKING\n\
85 #undef ENABLE_GC_CHECKING\n\
86 #undef ENABLE_GC_ALWAYS_COLLECT\n");
87
88 puts ("\
89 #include \"system.h\"\n\
90 #include \"rtl.h\"\n\
91 #include \"tm_p.h\"\n\
92 #include \"function.h\"\n");
93
94 puts ("\
95 /* Fake - insn-config.h doesn't exist yet. */\n\
96 #define MAX_RECOG_OPERANDS 10\n\
97 #define MAX_DUP_OPERANDS 10\n\
98 #define MAX_INSNS_PER_SPLIT 5\n");
99
100 puts ("\
101 #include \"regs.h\"\n\
102 #include \"recog.h\"\n\
103 #include \"real.h\"\n\
104 #include \"output.h\"\n\
105 #include \"flags.h\"\n\
106 #include \"hard-reg-set.h\"\n\
107 #include \"resource.h\"\n\
108 #include \"toplev.h\"\n\
109 #include \"reload.h\"\n\
110 #include \"gensupport.h\"\n");
111
112 if (saw_eh_return)
113 puts ("#define HAVE_eh_return 1");
114 puts ("#include \"except.h\"\n");
115
116 puts ("\
117 /* Dummy external declarations. */\n\
118 extern rtx insn;\n\
119 extern rtx ins1;\n\
120 extern rtx operands[];\n\
121 extern int next_insn_tests_no_inequality PARAMS ((rtx));\n");
122
123 puts ("\
124 /* If we don't have __builtin_constant_p, or it's not acceptable in\n\
125 array initializers, fall back to assuming that all conditions\n\
126 potentially vary at run time. It works in 3.0.1 and later; 3.0\n\
127 only when not optimizing. */\n\
128 #if (GCC_VERSION >= 3001) || ((GCC_VERSION == 3000) && !__OPTIMIZE__)\n\
129 # define MAYBE_EVAL(expr) (__builtin_constant_p(expr) ? (int) (expr) : -1)\n\
130 #else\n\
131 # define MAYBE_EVAL(expr) -1\n\
132 #endif\n");
133 }
134
135 /* Write out one entry in the conditions table, using the data pointed
136 to by SLOT. Each entry looks like this:
137 { "! optimize_size && ! TARGET_READ_MODIFY_WRITE",
138 MAYBE_EVAL (! optimize_size && ! TARGET_READ_MODIFY_WRITE) }, */
139
140 static int
write_one_condition(slot,dummy)141 write_one_condition (slot, dummy)
142 PTR *slot;
143 PTR dummy ATTRIBUTE_UNUSED;
144 {
145 const struct c_test *test = * (const struct c_test **) slot;
146 const char *p;
147
148 fputs (" { \"", stdout);
149 for (p = test->expr; *p; p++)
150 {
151 if (*p == '\n')
152 fputs ("\\n\\\n", stdout);
153 else if (*p == '"')
154 fputs ("\\\"", stdout);
155 else
156 putchar (*p);
157 }
158
159 printf ("\",\n MAYBE_EVAL (%s) },\n", test->expr);
160 return 1;
161 }
162
163 /* Write out the complete conditions table, its size, and a flag
164 indicating that gensupport.c can now do insn elision. */
165 static void
write_conditions()166 write_conditions ()
167 {
168 puts ("\
169 /* This table lists each condition found in the machine description.\n\
170 Each condition is mapped to its truth value (0 or 1), or -1 if that\n\
171 cannot be calculated at compile time. */\n\
172 \n\
173 const struct c_test insn_conditions[] = {");
174
175 htab_traverse (condition_table, write_one_condition, 0);
176
177 puts ("};\n");
178
179 printf ("const size_t n_insn_conditions = %lu;\n",
180 (unsigned long) htab_elements (condition_table));
181 puts ("const int insn_elision_unavailable = 0;");
182 }
183
184 int
main(argc,argv)185 main (argc, argv)
186 int argc;
187 char **argv;
188 {
189 rtx desc;
190 int pattern_lineno; /* not used */
191 int code;
192
193 progname = "genconditions";
194
195 if (argc <= 1)
196 fatal ("No input file name.");
197
198 if (init_md_reader (argv[1]) != SUCCESS_EXIT_CODE)
199 return (FATAL_EXIT_CODE);
200
201 condition_table = htab_create (1000, hash_c_test, cmp_c_test, NULL);
202
203 /* Read the machine description. */
204
205 while (1)
206 {
207 desc = read_md_rtx (&pattern_lineno, &code);
208 if (desc == NULL)
209 break;
210
211 /* N.B. define_insn_and_split, define_cond_exec are handled
212 entirely within read_md_rtx; we never see them. */
213 switch (GET_CODE (desc))
214 {
215 default:
216 break;
217
218 case DEFINE_INSN:
219 case DEFINE_EXPAND:
220 add_condition (XSTR (desc, 2));
221 /* except.h needs to know whether there is an eh_return
222 pattern in the machine description. */
223 if (!strcmp (XSTR (desc, 0), "eh_return"))
224 saw_eh_return = 1;
225 break;
226
227 case DEFINE_SPLIT:
228 case DEFINE_PEEPHOLE:
229 case DEFINE_PEEPHOLE2:
230 add_condition (XSTR (desc, 1));
231 break;
232 }
233 }
234
235 write_header ();
236 write_conditions ();
237
238 fflush (stdout);
239 return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
240 }
241