emit-rtl.c (global_rtl): Update comment.
[gcc.git] / gcc / gengenrtl.c
1 /* Generate code to allocate RTL structures.
2 Copyright (C) 1997, 1998, 1999, 2000 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 it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 2, or (at your option) any later
9 version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 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 the Free
18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
19 02111-1307, USA. */
20
21
22 #include "hconfig.h"
23 #include "system.h"
24
25 #define NO_GENRTL_H
26 #include "rtl.h"
27 #undef abort
28
29 #include "real.h"
30
31 struct rtx_definition
32 {
33 const char *const enumname, *const name, *const format;
34 };
35
36 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS) { STRINGX(ENUM), NAME, FORMAT },
37
38 static const struct rtx_definition defs[] =
39 {
40 #include "rtl.def" /* rtl expressions are documented here */
41 };
42
43 static const char *formats[NUM_RTX_CODE];
44
45 static const char *type_from_format PARAMS ((int));
46 static const char *accessor_from_format PARAMS ((int));
47 static int special_format PARAMS ((const char *));
48 static int special_rtx PARAMS ((int));
49 static void find_formats PARAMS ((void));
50 static void gendecl PARAMS ((const char *));
51 static void genmacro PARAMS ((int));
52 static void gendef PARAMS ((const char *));
53 static void genlegend PARAMS ((void));
54 static void genheader PARAMS ((void));
55 static void gencode PARAMS ((void));
56 \f
57 /* Decode a format letter into a C type string. */
58
59 static const char *
60 type_from_format (c)
61 int c;
62 {
63 switch (c)
64 {
65 case 'i':
66 return "int ";
67
68 case 'w':
69 return "HOST_WIDE_INT ";
70
71 case 's':
72 return "const char *";
73
74 case 'e': case 'u':
75 return "rtx ";
76
77 case 'E':
78 return "rtvec ";
79 case 'b':
80 return "struct bitmap_head_def *"; /* bitmap - typedef not available */
81 case 't':
82 return "union tree_node *"; /* tree - typedef not available */
83 default:
84 abort ();
85 }
86 }
87
88 /* Decode a format letter into the proper accessor function. */
89
90 static const char *
91 accessor_from_format (c)
92 int c;
93 {
94 switch (c)
95 {
96 case 'i':
97 return "XINT";
98
99 case 'w':
100 return "XWINT";
101
102 case 's':
103 return "XSTR";
104
105 case 'e': case 'u':
106 return "XEXP";
107
108 case 'E':
109 return "XVEC";
110
111 case 'b':
112 return "XBITMAP";
113
114 case 't':
115 return "XTREE";
116
117 default:
118 abort ();
119 }
120 }
121
122 /* Return nonzero if we should ignore FMT, an RTL format, when making
123 the list of formats we write routines to create. */
124
125 static int
126 special_format (fmt)
127 const char *fmt;
128 {
129 return (strchr (fmt, '*') != 0
130 || strchr (fmt, 'V') != 0
131 || strchr (fmt, 'S') != 0
132 || strchr (fmt, 'n') != 0);
133 }
134
135 /* Return nonzero if the RTL code given by index IDX is one that we should
136 generate a gen_rtx_raw_FOO macro for, not gen_rtx_FOO (because gen_rtx_FOO
137 is a wrapper in emit-rtl.c). */
138
139 static int
140 special_rtx (idx)
141 int idx;
142 {
143 return (strcmp (defs[idx].enumname, "CONST_INT") == 0
144 || strcmp (defs[idx].enumname, "REG") == 0
145 || strcmp (defs[idx].enumname, "SUBREG") == 0
146 || strcmp (defs[idx].enumname, "MEM") == 0);
147 }
148
149 /* Return nonzero if the RTL code given by index IDX is one that we should
150 generate no macro for at all (because gen_rtx_FOO is never used or
151 cannot have the obvious interface). */
152
153 static int
154 excluded_rtx (idx)
155 int idx;
156 {
157 return (strcmp (defs[idx].enumname, "CONST_DOUBLE") == 0);
158 }
159
160 /* Place a list of all format specifiers we use into the array FORMAT. */
161
162 static void
163 find_formats ()
164 {
165 int i;
166
167 for (i = 0; i < NUM_RTX_CODE; i++)
168 {
169 const char **f;
170
171 if (special_format (defs[i].format))
172 continue;
173
174 for (f = formats; *f; f++)
175 if (! strcmp (*f, defs[i].format))
176 break;
177
178 if (*f == 0)
179 *f = defs[i].format;
180 }
181 }
182
183 /* Write the declarations for the routine to allocate RTL with FORMAT. */
184
185 static void
186 gendecl (format)
187 const char *format;
188 {
189 const char *p;
190 int i, pos;
191
192 printf ("extern rtx gen_rtx_fmt_%s\tPARAMS ((RTX_CODE, ", format);
193 printf ("enum machine_mode mode");
194
195 /* Write each parameter that is needed and start a new line when the line
196 would overflow. */
197 for (p = format, i = 0, pos = 75; *p != 0; p++)
198 if (*p != '0')
199 {
200 int ourlen = strlen (type_from_format (*p)) + 6 + (i > 9);
201
202 printf (",");
203 if (pos + ourlen > 76)
204 printf ("\n\t\t\t\t "), pos = 39;
205
206 printf (" %sarg%d", type_from_format (*p), i++);
207 pos += ourlen;
208 }
209
210 printf ("));\n");
211 }
212
213 /* Generate macros to generate RTL of code IDX using the functions we
214 write. */
215
216 static void
217 genmacro (idx)
218 int idx;
219 {
220 const char *p;
221 int i;
222
223 /* We write a macro that defines gen_rtx_RTLCODE to be an equivalent to
224 gen_rtx_fmt_FORMAT where FORMAT is the RTX_FORMAT of RTLCODE. */
225
226 if (excluded_rtx (idx))
227 /* Don't define a macro for this code. */
228 return;
229
230 printf ("#define gen_rtx_%s%s(MODE",
231 special_rtx (idx) ? "raw_" : "", defs[idx].enumname);
232
233 for (p = defs[idx].format, i = 0; *p != 0; p++)
234 if (*p != '0')
235 printf (", ARG%d", i++);
236
237 printf (") \\\n gen_rtx_fmt_%s (%s, (MODE)",
238 defs[idx].format, defs[idx].enumname);
239
240 for (p = defs[idx].format, i = 0; *p != 0; p++)
241 if (*p != '0')
242 printf (", (ARG%d)", i++);
243
244 puts (")");
245 }
246
247 /* Generate the code for the function to generate RTL whose
248 format is FORMAT. */
249
250 static void
251 gendef (format)
252 const char *format;
253 {
254 const char *p;
255 int i, j;
256
257 /* Start by writing the definition of the function name and the types
258 of the arguments. */
259
260 printf ("rtx\ngen_rtx_fmt_%s (code, mode", format);
261 for (p = format, i = 0; *p != 0; p++)
262 if (*p != '0')
263 printf (", arg%d", i++);
264
265 puts (")\n RTX_CODE code;\n enum machine_mode mode;");
266 for (p = format, i = 0; *p != 0; p++)
267 if (*p != '0')
268 printf (" %sarg%d;\n", type_from_format (*p), i++);
269
270 /* Now write out the body of the function itself, which allocates
271 the memory and initializes it. */
272 puts ("{");
273 puts (" rtx rt;");
274 printf (" rt = ggc_alloc_rtx (%d);\n", (int) strlen (format));
275
276 puts (" memset (rt, 0, sizeof (struct rtx_def) - sizeof (rtunion));\n");
277 puts (" PUT_CODE (rt, code);");
278 puts (" PUT_MODE (rt, mode);");
279
280 for (p = format, i = j = 0; *p ; ++p, ++i)
281 if (*p != '0')
282 printf (" %s (rt, %d) = arg%d;\n", accessor_from_format (*p), i, j++);
283 else
284 printf (" X0EXP (rt, %d) = NULL_RTX;\n", i);
285
286 puts ("\n return rt;\n}\n");
287 }
288
289 /* Generate the documentation header for files we write. */
290
291 static void
292 genlegend ()
293 {
294 puts ("/* Generated automatically by gengenrtl from rtl.def. */\n");
295 }
296
297 /* Generate the text of the header file we make, genrtl.h. */
298
299 static void
300 genheader ()
301 {
302 int i;
303 const char **fmt;
304
305 puts ("#ifndef GCC_GENRTL_H");
306 puts ("#define GCC_GENRTL_H\n");
307
308 for (fmt = formats; *fmt; ++fmt)
309 gendecl (*fmt);
310
311 putchar ('\n');
312
313 for (i = 0; i < NUM_RTX_CODE; i++)
314 if (! special_format (defs[i].format))
315 genmacro (i);
316
317 puts ("\n#endif /* GCC_GENRTL_H */");
318 }
319
320 /* Generate the text of the code file we write, genrtl.c. */
321
322 static void
323 gencode ()
324 {
325 const char **fmt;
326
327 puts ("#include \"config.h\"");
328 puts ("#include \"system.h\"");
329 puts ("#include \"obstack.h\"");
330 puts ("#include \"rtl.h\"");
331 puts ("#include \"ggc.h\"\n");
332 puts ("extern struct obstack *rtl_obstack;\n");
333 puts ("#define obstack_alloc_rtx(n) \\");
334 puts (" ((rtx) obstack_alloc (rtl_obstack, \\");
335 puts (" sizeof (struct rtx_def) \\");
336 puts (" + ((n) - 1) * sizeof (rtunion)))\n");
337
338 for (fmt = formats; *fmt != 0; fmt++)
339 gendef (*fmt);
340 }
341
342 /* This is the main program. We accept only one argument, "-h", which
343 says we are writing the genrtl.h file. Otherwise we are writing the
344 genrtl.c file. */
345 extern int main PARAMS ((int, char **));
346
347 int
348 main (argc, argv)
349 int argc;
350 char **argv;
351 {
352 find_formats ();
353 genlegend ();
354
355 if (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'h')
356 genheader ();
357 else
358 gencode ();
359
360 if (ferror (stdout) || fflush (stdout) || fclose (stdout))
361 return FATAL_EXIT_CODE;
362
363 return SUCCESS_EXIT_CODE;
364 }