1 /* Generate code from machine description to perform peephole optimizations.
2 Copyright (C) 1987, 1989, 1992, 1997, 1998,
3 1999, 2000, 2003, 2004 Free Software Foundation, Inc.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
20 02110-1301, USA. */
21
22
23 #include "bconfig.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
27 #include "rtl.h"
28 #include "errors.h"
29 #include "gensupport.h"
30
31
32 /* While tree-walking an instruction pattern, we keep a chain
33 of these `struct link's to record how to get down to the
34 current position. In each one, POS is the operand number,
35 and if the operand is a vector VEC is the element number.
36 VEC is -1 if the operand is not a vector. */
37
38 struct link
39 {
40 struct link *next;
41 int pos;
42 int vecelt;
43 };
44
45 static int max_opno;
46
47 /* Number of operands used in current peephole definition. */
48
49 static int n_operands;
50
51 /* Peephole optimizations get insn codes just like insn patterns.
52 Count them so we know the code of the define_peephole we are handling. */
53
54 static int insn_code_number = 0;
55
56 static void gen_peephole (rtx);
57 static void match_rtx (rtx, struct link *, int);
58 static void print_path (struct link *);
59 static void print_code (RTX_CODE);
60
61 static void
gen_peephole(rtx peep)62 gen_peephole (rtx peep)
63 {
64 int ninsns = XVECLEN (peep, 0);
65 int i;
66
67 n_operands = 0;
68
69 printf (" insn = ins1;\n");
70
71 for (i = 0; i < ninsns; i++)
72 {
73 if (i > 0)
74 {
75 printf (" do { insn = NEXT_INSN (insn);\n");
76 printf (" if (insn == 0) goto L%d; }\n",
77 insn_code_number);
78 printf (" while (NOTE_P (insn)\n");
79 printf ("\t || (NONJUMP_INSN_P (insn)\n");
80 printf ("\t && (GET_CODE (PATTERN (insn)) == USE\n");
81 printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n");
82
83 printf (" if (LABEL_P (insn)\n\
84 || BARRIER_P (insn))\n goto L%d;\n",
85 insn_code_number);
86 }
87
88 printf (" pat = PATTERN (insn);\n");
89
90 /* Walk the insn's pattern, remembering at all times the path
91 down to the walking point. */
92
93 match_rtx (XVECEXP (peep, 0, i), NULL, insn_code_number);
94 }
95
96 /* We get this far if the pattern matches.
97 Now test the extra condition. */
98
99 if (XSTR (peep, 1) && XSTR (peep, 1)[0])
100 printf (" if (! (%s)) goto L%d;\n",
101 XSTR (peep, 1), insn_code_number);
102
103 /* If that matches, construct new pattern and put it in the first insn.
104 This new pattern will never be matched.
105 It exists only so that insn-extract can get the operands back.
106 So use a simple regular form: a PARALLEL containing a vector
107 of all the operands. */
108
109 printf (" PATTERN (ins1) = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands);
110
111 /* Record this define_peephole's insn code in the insn,
112 as if it had been recognized to match this. */
113 printf (" INSN_CODE (ins1) = %d;\n",
114 insn_code_number);
115
116 /* Delete the remaining insns. */
117 if (ninsns > 1)
118 printf (" delete_for_peephole (NEXT_INSN (ins1), insn);\n");
119
120 /* See reload1.c for insertion of NOTE which guarantees that this
121 cannot be zero. */
122 printf (" return NEXT_INSN (insn);\n");
123
124 printf (" L%d:\n\n", insn_code_number);
125 }
126
127 static void
match_rtx(rtx x,struct link * path,int fail_label)128 match_rtx (rtx x, struct link *path, int fail_label)
129 {
130 RTX_CODE code;
131 int i;
132 int len;
133 const char *fmt;
134 struct link link;
135
136 if (x == 0)
137 return;
138
139
140 code = GET_CODE (x);
141
142 switch (code)
143 {
144 case MATCH_OPERAND:
145 if (XINT (x, 0) > max_opno)
146 max_opno = XINT (x, 0);
147 if (XINT (x, 0) >= n_operands)
148 n_operands = 1 + XINT (x, 0);
149
150 printf (" x = ");
151 print_path (path);
152 printf (";\n");
153
154 printf (" operands[%d] = x;\n", XINT (x, 0));
155 if (XSTR (x, 1) && XSTR (x, 1)[0])
156 printf (" if (! %s (x, %smode)) goto L%d;\n",
157 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
158 return;
159
160 case MATCH_DUP:
161 case MATCH_PAR_DUP:
162 printf (" x = ");
163 print_path (path);
164 printf (";\n");
165
166 printf (" if (!rtx_equal_p (operands[%d], x)) goto L%d;\n",
167 XINT (x, 0), fail_label);
168 return;
169
170 case MATCH_OP_DUP:
171 printf (" x = ");
172 print_path (path);
173 printf (";\n");
174
175 printf (" if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0));
176 printf (" || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n",
177 XINT (x, 0), fail_label);
178 printf (" operands[%d] = x;\n", XINT (x, 0));
179 link.next = path;
180 link.vecelt = -1;
181 for (i = 0; i < XVECLEN (x, 1); i++)
182 {
183 link.pos = i;
184 match_rtx (XVECEXP (x, 1, i), &link, fail_label);
185 }
186 return;
187
188 case MATCH_OPERATOR:
189 if (XINT (x, 0) > max_opno)
190 max_opno = XINT (x, 0);
191 if (XINT (x, 0) >= n_operands)
192 n_operands = 1 + XINT (x, 0);
193
194 printf (" x = ");
195 print_path (path);
196 printf (";\n");
197
198 printf (" operands[%d] = x;\n", XINT (x, 0));
199 if (XSTR (x, 1) && XSTR (x, 1)[0])
200 printf (" if (! %s (x, %smode)) goto L%d;\n",
201 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
202 link.next = path;
203 link.vecelt = -1;
204 for (i = 0; i < XVECLEN (x, 2); i++)
205 {
206 link.pos = i;
207 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
208 }
209 return;
210
211 case MATCH_PARALLEL:
212 if (XINT (x, 0) > max_opno)
213 max_opno = XINT (x, 0);
214 if (XINT (x, 0) >= n_operands)
215 n_operands = 1 + XINT (x, 0);
216
217 printf (" x = ");
218 print_path (path);
219 printf (";\n");
220
221 printf (" if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label);
222 printf (" operands[%d] = x;\n", XINT (x, 0));
223 if (XSTR (x, 1) && XSTR (x, 1)[0])
224 printf (" if (! %s (x, %smode)) goto L%d;\n",
225 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
226 link.next = path;
227 link.pos = 0;
228 for (i = 0; i < XVECLEN (x, 2); i++)
229 {
230 link.vecelt = i;
231 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
232 }
233 return;
234
235 case ADDRESS:
236 match_rtx (XEXP (x, 0), path, fail_label);
237 return;
238
239 default:
240 break;
241 }
242
243 printf (" x = ");
244 print_path (path);
245 printf (";\n");
246
247 printf (" if (GET_CODE (x) != ");
248 print_code (code);
249 printf (") goto L%d;\n", fail_label);
250
251 if (GET_MODE (x) != VOIDmode)
252 {
253 printf (" if (GET_MODE (x) != %smode) goto L%d;\n",
254 GET_MODE_NAME (GET_MODE (x)), fail_label);
255 }
256
257 link.next = path;
258 link.vecelt = -1;
259 fmt = GET_RTX_FORMAT (code);
260 len = GET_RTX_LENGTH (code);
261 for (i = 0; i < len; i++)
262 {
263 link.pos = i;
264 if (fmt[i] == 'e' || fmt[i] == 'u')
265 match_rtx (XEXP (x, i), &link, fail_label);
266 else if (fmt[i] == 'E')
267 {
268 int j;
269 printf (" if (XVECLEN (x, %d) != %d) goto L%d;\n",
270 i, XVECLEN (x, i), fail_label);
271 for (j = 0; j < XVECLEN (x, i); j++)
272 {
273 link.vecelt = j;
274 match_rtx (XVECEXP (x, i, j), &link, fail_label);
275 }
276 }
277 else if (fmt[i] == 'i')
278 {
279 /* Make sure that at run time `x' is the RTX we want to test. */
280 if (i != 0)
281 {
282 printf (" x = ");
283 print_path (path);
284 printf (";\n");
285 }
286
287 printf (" if (XINT (x, %d) != %d) goto L%d;\n",
288 i, XINT (x, i), fail_label);
289 }
290 else if (fmt[i] == 'w')
291 {
292 /* Make sure that at run time `x' is the RTX we want to test. */
293 if (i != 0)
294 {
295 printf (" x = ");
296 print_path (path);
297 printf (";\n");
298 }
299
300 printf (" if (XWINT (x, %d) != ", i);
301 printf (HOST_WIDE_INT_PRINT_DEC, XWINT (x, i));
302 printf (") goto L%d;\n", fail_label);
303 }
304 else if (fmt[i] == 's')
305 {
306 /* Make sure that at run time `x' is the RTX we want to test. */
307 if (i != 0)
308 {
309 printf (" x = ");
310 print_path (path);
311 printf (";\n");
312 }
313
314 printf (" if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n",
315 i, XSTR (x, i), fail_label);
316 }
317 }
318 }
319
320 /* Given a PATH, representing a path down the instruction's
321 pattern from the root to a certain point, output code to
322 evaluate to the rtx at that point. */
323
324 static void
print_path(struct link * path)325 print_path (struct link *path)
326 {
327 if (path == 0)
328 printf ("pat");
329 else if (path->vecelt >= 0)
330 {
331 printf ("XVECEXP (");
332 print_path (path->next);
333 printf (", %d, %d)", path->pos, path->vecelt);
334 }
335 else
336 {
337 printf ("XEXP (");
338 print_path (path->next);
339 printf (", %d)", path->pos);
340 }
341 }
342
343 static void
print_code(RTX_CODE code)344 print_code (RTX_CODE code)
345 {
346 const char *p1;
347 for (p1 = GET_RTX_NAME (code); *p1; p1++)
348 putchar (TOUPPER(*p1));
349 }
350
351 extern int main (int, char **);
352
353 int
main(int argc,char ** argv)354 main (int argc, char **argv)
355 {
356 rtx desc;
357
358 max_opno = -1;
359
360 progname = "genpeep";
361
362 if (init_md_reader_args (argc, argv) != SUCCESS_EXIT_CODE)
363 return (FATAL_EXIT_CODE);
364
365 printf ("/* Generated automatically by the program `genpeep'\n\
366 from the machine description file `md'. */\n\n");
367
368 printf ("#include \"config.h\"\n");
369 printf ("#include \"system.h\"\n");
370 printf ("#include \"coretypes.h\"\n");
371 printf ("#include \"tm.h\"\n");
372 printf ("#include \"insn-config.h\"\n");
373 printf ("#include \"rtl.h\"\n");
374 printf ("#include \"tm_p.h\"\n");
375 printf ("#include \"regs.h\"\n");
376 printf ("#include \"output.h\"\n");
377 printf ("#include \"real.h\"\n");
378 printf ("#include \"recog.h\"\n");
379 printf ("#include \"except.h\"\n");
380 printf ("#include \"function.h\"\n");
381 printf ("#include \"toplev.h\"\n");
382 printf ("#include \"flags.h\"\n");
383 printf ("#include \"tm-constrs.h\"\n\n");
384
385 printf ("#ifdef HAVE_peephole\n");
386 printf ("extern rtx peep_operand[];\n\n");
387 printf ("#define operands peep_operand\n\n");
388
389 printf ("rtx\npeephole (rtx ins1)\n{\n");
390 printf (" rtx insn ATTRIBUTE_UNUSED, x ATTRIBUTE_UNUSED, pat ATTRIBUTE_UNUSED;\n\n");
391
392 /* Early out: no peepholes for insns followed by barriers. */
393 printf (" if (NEXT_INSN (ins1)\n");
394 printf (" && BARRIER_P (NEXT_INSN (ins1)))\n");
395 printf (" return 0;\n\n");
396
397 /* Read the machine description. */
398
399 while (1)
400 {
401 int line_no, rtx_number = 0;
402
403 desc = read_md_rtx (&line_no, &rtx_number);
404 if (desc == NULL)
405 break;
406
407 if (GET_CODE (desc) == DEFINE_PEEPHOLE)
408 {
409 gen_peephole (desc);
410 insn_code_number++;
411 }
412 if (GET_CODE (desc) == DEFINE_INSN
413 || GET_CODE (desc) == DEFINE_EXPAND
414 || GET_CODE (desc) == DEFINE_SPLIT
415 || GET_CODE (desc) == DEFINE_PEEPHOLE2)
416 {
417 insn_code_number++;
418 }
419 }
420
421 printf (" return 0;\n}\n\n");
422
423 if (max_opno == -1)
424 max_opno = 1;
425
426 printf ("rtx peep_operand[%d];\n", max_opno + 1);
427 printf ("#endif\n");
428
429 fflush (stdout);
430 return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
431 }
432