1 /* Generate code from machine description to perform peephole optimizations.
2 Copyright (C) 1987-2018 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 it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, 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 COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20
21 #include "bconfig.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "tm.h"
25 #include "rtl.h"
26 #include "errors.h"
27 #include "gensupport.h"
28
29
30 /* While tree-walking an instruction pattern, we keep a chain
31 of these `struct link's to record how to get down to the
32 current position. In each one, POS is the operand number,
33 and if the operand is a vector VEC is the element number.
34 VEC is -1 if the operand is not a vector. */
35
36 struct link
37 {
38 struct link *next;
39 int pos;
40 int vecelt;
41 };
42
43 static int max_opno;
44
45 /* Number of operands used in current peephole definition. */
46
47 static int n_operands;
48
49 static void match_rtx (rtx, struct link *, int);
50 static void print_path (struct link *);
51 static void print_code (RTX_CODE);
52
53 static void
gen_peephole(md_rtx_info * info)54 gen_peephole (md_rtx_info *info)
55 {
56 rtx peep = info->def;
57 int ninsns = XVECLEN (peep, 0);
58 int i;
59
60 n_operands = 0;
61
62 printf (" insn = ins1;\n");
63
64 for (i = 0; i < ninsns; i++)
65 {
66 if (i > 0)
67 {
68 printf (" do { insn = NEXT_INSN (insn);\n");
69 printf (" if (insn == 0) goto L%d; }\n", info->index);
70 printf (" while (NOTE_P (insn)\n");
71 printf ("\t || (NONJUMP_INSN_P (insn)\n");
72 printf ("\t && (GET_CODE (PATTERN (insn)) == USE\n");
73 printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n");
74
75 printf (" if (LABEL_P (insn)\n\
76 || BARRIER_P (insn))\n goto L%d;\n", info->index);
77 }
78
79 printf (" pat = PATTERN (insn);\n");
80
81 /* Walk the insn's pattern, remembering at all times the path
82 down to the walking point. */
83
84 match_rtx (XVECEXP (peep, 0, i), NULL, info->index);
85 }
86
87 /* We get this far if the pattern matches.
88 Now test the extra condition. */
89
90 if (XSTR (peep, 1) && XSTR (peep, 1)[0])
91 printf (" if (! (%s)) goto L%d;\n",
92 XSTR (peep, 1), info->index);
93
94 /* If that matches, construct new pattern and put it in the first insn.
95 This new pattern will never be matched.
96 It exists only so that insn-extract can get the operands back.
97 So use a simple regular form: a PARALLEL containing a vector
98 of all the operands. */
99
100 printf (" PATTERN (ins1) = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands);
101
102 /* Record this define_peephole's insn code in the insn,
103 as if it had been recognized to match this. */
104 printf (" INSN_CODE (ins1) = %d;\n", info->index);
105
106 /* Delete the remaining insns. */
107 if (ninsns > 1)
108 printf (" delete_for_peephole (NEXT_INSN (ins1), insn);\n");
109
110 /* See reload1.c for insertion of NOTE which guarantees that this
111 cannot be zero. */
112 printf (" return NEXT_INSN (insn);\n");
113
114 printf (" L%d:\n\n", info->index);
115 }
116
117 static void
match_rtx(rtx x,struct link * path,int fail_label)118 match_rtx (rtx x, struct link *path, int fail_label)
119 {
120 RTX_CODE code;
121 int i;
122 int len;
123 const char *fmt;
124 struct link link;
125
126 if (x == 0)
127 return;
128
129
130 code = GET_CODE (x);
131
132 switch (code)
133 {
134 case MATCH_OPERAND:
135 if (XINT (x, 0) > max_opno)
136 max_opno = XINT (x, 0);
137 if (XINT (x, 0) >= n_operands)
138 n_operands = 1 + XINT (x, 0);
139
140 printf (" x = ");
141 print_path (path);
142 printf (";\n");
143
144 printf (" operands[%d] = x;\n", XINT (x, 0));
145 if (XSTR (x, 1) && XSTR (x, 1)[0])
146 printf (" if (! %s (x, %smode)) goto L%d;\n",
147 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
148 return;
149
150 case MATCH_DUP:
151 case MATCH_PAR_DUP:
152 printf (" x = ");
153 print_path (path);
154 printf (";\n");
155
156 printf (" if (!rtx_equal_p (operands[%d], x)) goto L%d;\n",
157 XINT (x, 0), fail_label);
158 return;
159
160 case MATCH_OP_DUP:
161 printf (" x = ");
162 print_path (path);
163 printf (";\n");
164
165 printf (" if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0));
166 printf (" || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n",
167 XINT (x, 0), fail_label);
168 printf (" operands[%d] = x;\n", XINT (x, 0));
169 link.next = path;
170 link.vecelt = -1;
171 for (i = 0; i < XVECLEN (x, 1); i++)
172 {
173 link.pos = i;
174 match_rtx (XVECEXP (x, 1, i), &link, fail_label);
175 }
176 return;
177
178 case MATCH_OPERATOR:
179 if (XINT (x, 0) > max_opno)
180 max_opno = XINT (x, 0);
181 if (XINT (x, 0) >= n_operands)
182 n_operands = 1 + XINT (x, 0);
183
184 printf (" x = ");
185 print_path (path);
186 printf (";\n");
187
188 printf (" operands[%d] = x;\n", XINT (x, 0));
189 if (XSTR (x, 1) && XSTR (x, 1)[0])
190 printf (" if (! %s (x, %smode)) goto L%d;\n",
191 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
192 link.next = path;
193 link.vecelt = -1;
194 for (i = 0; i < XVECLEN (x, 2); i++)
195 {
196 link.pos = i;
197 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
198 }
199 return;
200
201 case MATCH_PARALLEL:
202 if (XINT (x, 0) > max_opno)
203 max_opno = XINT (x, 0);
204 if (XINT (x, 0) >= n_operands)
205 n_operands = 1 + XINT (x, 0);
206
207 printf (" x = ");
208 print_path (path);
209 printf (";\n");
210
211 printf (" if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label);
212 printf (" operands[%d] = x;\n", XINT (x, 0));
213 if (XSTR (x, 1) && XSTR (x, 1)[0])
214 printf (" if (! %s (x, %smode)) goto L%d;\n",
215 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
216 link.next = path;
217 link.pos = 0;
218 for (i = 0; i < XVECLEN (x, 2); i++)
219 {
220 link.vecelt = i;
221 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
222 }
223 return;
224
225 default:
226 break;
227 }
228
229 printf (" x = ");
230 print_path (path);
231 printf (";\n");
232
233 printf (" if (GET_CODE (x) != ");
234 print_code (code);
235 printf (") goto L%d;\n", fail_label);
236
237 if (GET_MODE (x) != VOIDmode)
238 {
239 printf (" if (GET_MODE (x) != %smode) goto L%d;\n",
240 GET_MODE_NAME (GET_MODE (x)), fail_label);
241 }
242
243 link.next = path;
244 link.vecelt = -1;
245 fmt = GET_RTX_FORMAT (code);
246 len = GET_RTX_LENGTH (code);
247 for (i = 0; i < len; i++)
248 {
249 link.pos = i;
250 if (fmt[i] == 'e' || fmt[i] == 'u')
251 match_rtx (XEXP (x, i), &link, fail_label);
252 else if (fmt[i] == 'E')
253 {
254 int j;
255 printf (" if (XVECLEN (x, %d) != %d) goto L%d;\n",
256 i, XVECLEN (x, i), fail_label);
257 for (j = 0; j < XVECLEN (x, i); j++)
258 {
259 link.vecelt = j;
260 match_rtx (XVECEXP (x, i, j), &link, fail_label);
261 }
262 }
263 else if (fmt[i] == 'i')
264 {
265 /* Make sure that at run time `x' is the RTX we want to test. */
266 if (i != 0)
267 {
268 printf (" x = ");
269 print_path (path);
270 printf (";\n");
271 }
272
273 printf (" if (XINT (x, %d) != %d) goto L%d;\n",
274 i, XINT (x, i), fail_label);
275 }
276 else if (fmt[i] == 'r')
277 {
278 gcc_assert (i == 0);
279 printf (" if (REGNO (x) != %d) goto L%d;\n",
280 REGNO (x), fail_label);
281 }
282 else if (fmt[i] == 'w')
283 {
284 /* Make sure that at run time `x' is the RTX we want to test. */
285 if (i != 0)
286 {
287 printf (" x = ");
288 print_path (path);
289 printf (";\n");
290 }
291
292 printf (" if (XWINT (x, %d) != ", i);
293 printf (HOST_WIDE_INT_PRINT_DEC, XWINT (x, i));
294 printf (") goto L%d;\n", fail_label);
295 }
296 else if (fmt[i] == 's')
297 {
298 /* Make sure that at run time `x' is the RTX we want to test. */
299 if (i != 0)
300 {
301 printf (" x = ");
302 print_path (path);
303 printf (";\n");
304 }
305
306 printf (" if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n",
307 i, XSTR (x, i), fail_label);
308 }
309 else if (fmt[i] == 'p')
310 /* Not going to support subregs for legacy define_peeholes. */
311 gcc_unreachable ();
312 }
313 }
314
315 /* Given a PATH, representing a path down the instruction's
316 pattern from the root to a certain point, output code to
317 evaluate to the rtx at that point. */
318
319 static void
print_path(struct link * path)320 print_path (struct link *path)
321 {
322 if (path == 0)
323 printf ("pat");
324 else if (path->vecelt >= 0)
325 {
326 printf ("XVECEXP (");
327 print_path (path->next);
328 printf (", %d, %d)", path->pos, path->vecelt);
329 }
330 else
331 {
332 printf ("XEXP (");
333 print_path (path->next);
334 printf (", %d)", path->pos);
335 }
336 }
337
338 static void
print_code(RTX_CODE code)339 print_code (RTX_CODE code)
340 {
341 const char *p1;
342 for (p1 = GET_RTX_NAME (code); *p1; p1++)
343 putchar (TOUPPER (*p1));
344 }
345
346 extern int main (int, const char **);
347
348 int
main(int argc,const char ** argv)349 main (int argc, const char **argv)
350 {
351 max_opno = -1;
352
353 progname = "genpeep";
354
355 if (!init_rtx_reader_args (argc, argv))
356 return (FATAL_EXIT_CODE);
357
358 printf ("/* Generated automatically by the program `genpeep'\n\
359 from the machine description file `md'. */\n\n");
360
361 printf ("#define IN_TARGET_CODE 1\n");
362 printf ("#include \"config.h\"\n");
363 printf ("#include \"system.h\"\n");
364 printf ("#include \"coretypes.h\"\n");
365 printf ("#include \"backend.h\"\n");
366 printf ("#include \"tree.h\"\n");
367 printf ("#include \"rtl.h\"\n");
368 printf ("#include \"insn-config.h\"\n");
369 printf ("#include \"alias.h\"\n");
370 printf ("#include \"varasm.h\"\n");
371 printf ("#include \"stor-layout.h\"\n");
372 printf ("#include \"calls.h\"\n");
373 printf ("#include \"memmodel.h\"\n");
374 printf ("#include \"tm_p.h\"\n");
375 printf ("#include \"regs.h\"\n");
376 printf ("#include \"output.h\"\n");
377 printf ("#include \"recog.h\"\n");
378 printf ("#include \"except.h\"\n");
379 printf ("#include \"diagnostic-core.h\"\n");
380 printf ("#include \"flags.h\"\n");
381 printf ("#include \"tm-constrs.h\"\n\n");
382
383 printf ("extern rtx peep_operand[];\n\n");
384 printf ("#define operands peep_operand\n\n");
385
386 printf ("rtx_insn *\npeephole (rtx_insn *ins1)\n{\n");
387 printf (" rtx_insn *insn ATTRIBUTE_UNUSED;\n");
388 printf (" rtx x ATTRIBUTE_UNUSED, pat ATTRIBUTE_UNUSED;\n\n");
389
390 /* Early out: no peepholes for insns followed by barriers. */
391 printf (" if (NEXT_INSN (ins1)\n");
392 printf (" && BARRIER_P (NEXT_INSN (ins1)))\n");
393 printf (" return 0;\n\n");
394
395 /* Read the machine description. */
396
397 md_rtx_info info;
398 while (read_md_rtx (&info))
399 switch (GET_CODE (info.def))
400 {
401 case DEFINE_PEEPHOLE:
402 gen_peephole (&info);
403 break;
404
405 default:
406 break;
407 }
408
409 printf (" return 0;\n}\n\n");
410
411 if (max_opno == -1)
412 max_opno = 1;
413
414 printf ("rtx peep_operand[%d];\n", max_opno + 1);
415
416 fflush (stdout);
417 return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
418 }
419