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git.ipfire.org Git - thirdparty/gcc.git/blob - gcc/genconditions.c
1 /* Process machine description and calculate constant conditions.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 This file is part of GCC.
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)
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.
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, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
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. */
31 #include "coretypes.h"
36 #include "gensupport.h"
38 /* so we can include except.h in the generated file. */
39 static int saw_eh_return
;
41 static htab_t condition_table
;
43 static void add_condition (const char *);
44 static void write_header (void);
45 static void write_conditions (void);
46 static int write_one_condition (void **, void *);
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. */
53 add_condition (const char *expr
)
60 test
= XNEW (struct c_test
);
63 *(htab_find_slot (condition_table
, test
, INSERT
)) = test
;
66 /* Generate the header for insn-conditions.c. */
72 /* Generated automatically by the program `genconditions' from the target\n\
73 machine description file. */\n\
75 #include \"bconfig.h\"\n\
76 #include \"insn-constants.h\"\n");
79 /* Do not allow checking to confuse the issue. */\n\
80 #undef ENABLE_CHECKING\n\
81 #undef ENABLE_TREE_CHECKING\n\
82 #undef ENABLE_RTL_CHECKING\n\
83 #undef ENABLE_RTL_FLAG_CHECKING\n\
84 #undef ENABLE_GC_CHECKING\n\
85 #undef ENABLE_GC_ALWAYS_COLLECT\n");
88 #include \"system.h\"\n\
89 #if GCC_VERSION < 3001\n\
90 #include \"dummy-conditions.c\"\n\
92 #include \"coretypes.h\"\n\
95 #include \"tm_p.h\"\n\
96 #include \"function.h\"\n");
99 /* Fake - insn-config.h doesn't exist yet. */\n\
100 #define MAX_RECOG_OPERANDS 10\n\
101 #define MAX_DUP_OPERANDS 10\n\
102 #define MAX_INSNS_PER_SPLIT 5\n");
105 #include \"regs.h\"\n\
106 #include \"recog.h\"\n\
107 #include \"real.h\"\n\
108 #include \"output.h\"\n\
109 #include \"flags.h\"\n\
110 #include \"hard-reg-set.h\"\n\
111 #include \"resource.h\"\n\
112 #include \"toplev.h\"\n\
113 #include \"reload.h\"\n\
114 #include \"gensupport.h\"\n");
117 puts ("#define HAVE_eh_return 1");
118 puts ("#include \"except.h\"\n");
121 /* Dummy external declarations. */\n\
124 extern rtx operands[];\n");
127 /* If we don't have __builtin_constant_p, or it's not acceptable in\n\
128 array initializers, fall back (by using dummy-conditions.c above)\n\
129 to assuming that all conditions potentially vary at run time. It\n\
130 works in 3.0.1 and later; 3.0 only when not optimizing. */\n\
131 #define MAYBE_EVAL(expr) (__builtin_constant_p(expr) ? (int) (expr) : -1)\n");
134 /* Write out one entry in the conditions table, using the data pointed
135 to by SLOT. Each entry looks like this:
136 { "! optimize_size && ! TARGET_READ_MODIFY_WRITE",
137 MAYBE_EVAL (! optimize_size && ! TARGET_READ_MODIFY_WRITE) }, */
140 write_one_condition (void **slot
, void * ARG_UNUSED (dummy
))
142 const struct c_test
*test
= * (const struct c_test
**) slot
;
145 fputs (" { \"", stdout
);
146 for (p
= test
->expr
; *p
; p
++)
149 fputs ("\\n\\\n", stdout
);
151 fputs ("\\\"", stdout
);
156 printf ("\",\n MAYBE_EVAL (%s) },\n", test
->expr
);
160 /* Write out the complete conditions table, its size, and a flag
161 indicating that gensupport.c can now do insn elision. */
163 write_conditions (void)
166 /* This table lists each condition found in the machine description.\n\
167 Each condition is mapped to its truth value (0 or 1), or -1 if that\n\
168 cannot be calculated at compile time. */\n\
170 const struct c_test insn_conditions[] = {");
172 htab_traverse (condition_table
, write_one_condition
, 0);
176 printf ("const size_t n_insn_conditions = %lu;\n",
177 (unsigned long) htab_elements (condition_table
));
178 puts ("const int insn_elision_unavailable = 0;\n#endif");
182 main (int argc
, char **argv
)
185 int pattern_lineno
; /* not used */
188 progname
= "genconditions";
190 if (init_md_reader_args (argc
, argv
) != SUCCESS_EXIT_CODE
)
191 return (FATAL_EXIT_CODE
);
193 condition_table
= htab_create (1000, hash_c_test
, cmp_c_test
, NULL
);
195 /* Read the machine description. */
199 desc
= read_md_rtx (&pattern_lineno
, &code
);
203 /* N.B. define_insn_and_split, define_cond_exec are handled
204 entirely within read_md_rtx; we never see them. */
205 switch (GET_CODE (desc
))
212 add_condition (XSTR (desc
, 2));
213 /* except.h needs to know whether there is an eh_return
214 pattern in the machine description. */
215 if (!strcmp (XSTR (desc
, 0), "eh_return"))
220 case DEFINE_PEEPHOLE
:
221 case DEFINE_PEEPHOLE2
:
222 add_condition (XSTR (desc
, 1));
231 return (ferror (stdout
) != 0 ? FATAL_EXIT_CODE
: SUCCESS_EXIT_CODE
);