1 /* Generate code from machine description to perform peephole optimizations.
2 Copyright (C) 1987, 1989, 1992, 1997, 1998 Free Software Foundation, Inc.
4 This file is part of GNU CC.
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)
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.
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. */
27 static struct obstack obstack;
28 struct obstack *rtl_obstack = &obstack;
30 #define obstack_chunk_alloc xmalloc
31 #define obstack_chunk_free free
33 /* While tree-walking an instruction pattern, we keep a chain
34 of these `struct link's to record how to get down to the
35 current position. In each one, POS is the operand number,
36 and if the operand is a vector VEC is the element number.
37 VEC is -1 if the operand is not a vector. */
46 char *xmalloc PROTO((unsigned));
47 static void match_rtx PROTO((rtx, struct link *, int));
49 void fancy_abort PROTO((void));
53 /* Number of operands used in current peephole definition. */
55 static int n_operands;
57 /* Peephole optimizations get insn codes just like insn patterns.
58 Count them so we know the code of the define_peephole we are handling. */
60 static int insn_code_number = 0;
62 static void print_path PROTO((struct link *));
63 static void print_code PROTO((RTX_CODE));
69 int ninsns = XVECLEN (peep, 0);
74 printf (" insn = ins1;\n");
76 printf (" want_jump = 0;\n");
79 for (i = 0; i < ninsns; i++)
83 printf (" do { insn = NEXT_INSN (insn);\n");
84 printf (" if (insn == 0) goto L%d; }\n",
86 printf (" while (GET_CODE (insn) == NOTE\n");
87 printf ("\t || (GET_CODE (insn) == INSN\n");
88 printf ("\t && (GET_CODE (PATTERN (insn)) == USE\n");
89 printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n");
91 printf (" if (GET_CODE (insn) == CODE_LABEL\n\
92 || GET_CODE (insn) == BARRIER)\n goto L%d;\n",
97 printf (" if (GET_CODE (insn) == JUMP_INSN)\n");
98 printf (" want_jump = JUMP_LABEL (insn);\n");
101 printf (" pat = PATTERN (insn);\n");
103 /* Walk the insn's pattern, remembering at all times the path
104 down to the walking point. */
106 match_rtx (XVECEXP (peep, 0, i), NULL_PTR, insn_code_number);
109 /* We get this far if the pattern matches.
110 Now test the extra condition. */
112 if (XSTR (peep, 1) && XSTR (peep, 1)[0])
113 printf (" if (! (%s)) goto L%d;\n",
114 XSTR (peep, 1), insn_code_number);
116 /* If that matches, construct new pattern and put it in the first insn.
117 This new pattern will never be matched.
118 It exists only so that insn-extract can get the operands back.
119 So use a simple regular form: a PARALLEL containing a vector
120 of all the operands. */
122 printf (" PATTERN (ins1) = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands);
125 printf (" if (want_jump && GET_CODE (ins1) != JUMP_INSN)\n");
127 printf (" rtx insn2 = emit_jump_insn_before (PATTERN (ins1), ins1);\n");
128 printf (" delete_insn (ins1);\n");
129 printf (" ins1 = ins2;\n");
133 /* Record this define_peephole's insn code in the insn,
134 as if it had been recognized to match this. */
135 printf (" INSN_CODE (ins1) = %d;\n",
138 /* Delete the remaining insns. */
140 printf (" delete_for_peephole (NEXT_INSN (ins1), insn);\n");
142 /* See reload1.c for insertion of NOTE which guarantees that this
144 printf (" return NEXT_INSN (insn);\n");
146 printf (" L%d:\n\n", insn_code_number);
150 match_rtx (x, path, fail_label)
155 register RTX_CODE code;
170 if (XINT (x, 0) > max_opno)
171 max_opno = XINT (x, 0);
172 if (XINT (x, 0) >= n_operands)
173 n_operands = 1 + XINT (x, 0);
179 printf (" operands[%d] = x;\n", XINT (x, 0));
180 if (XSTR (x, 1) && XSTR (x, 1)[0])
181 printf (" if (! %s (x, %smode)) goto L%d;\n",
182 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
191 printf (" if (!rtx_equal_p (operands[%d], x)) goto L%d;\n",
192 XINT (x, 0), fail_label);
200 printf (" if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0));
201 printf (" || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n",
202 XINT (x, 0), fail_label);
203 printf (" operands[%d] = x;\n", XINT (x, 0));
206 for (i = 0; i < XVECLEN (x, 1); i++)
209 match_rtx (XVECEXP (x, 1, i), &link, fail_label);
214 if (XINT (x, 0) > max_opno)
215 max_opno = XINT (x, 0);
216 if (XINT (x, 0) >= n_operands)
217 n_operands = 1 + XINT (x, 0);
223 printf (" operands[%d] = x;\n", XINT (x, 0));
224 if (XSTR (x, 1) && XSTR (x, 1)[0])
225 printf (" if (! %s (x, %smode)) goto L%d;\n",
226 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
229 for (i = 0; i < XVECLEN (x, 2); i++)
232 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
237 if (XINT (x, 0) > max_opno)
238 max_opno = XINT (x, 0);
239 if (XINT (x, 0) >= n_operands)
240 n_operands = 1 + XINT (x, 0);
246 printf (" if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label);
247 printf (" operands[%d] = x;\n", XINT (x, 0));
248 if (XSTR (x, 1) && XSTR (x, 1)[0])
249 printf (" if (! %s (x, %smode)) goto L%d;\n",
250 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
253 for (i = 0; i < XVECLEN (x, 2); i++)
256 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
261 match_rtx (XEXP (x, 0), path, fail_label);
272 printf (" if (GET_CODE (x) != ");
274 printf (") goto L%d;\n", fail_label);
276 if (GET_MODE (x) != VOIDmode)
278 printf (" if (GET_MODE (x) != %smode) goto L%d;\n",
279 GET_MODE_NAME (GET_MODE (x)), fail_label);
284 fmt = GET_RTX_FORMAT (code);
285 len = GET_RTX_LENGTH (code);
286 for (i = 0; i < len; i++)
289 if (fmt[i] == 'e' || fmt[i] == 'u')
290 match_rtx (XEXP (x, i), &link, fail_label);
291 else if (fmt[i] == 'E')
294 printf (" if (XVECLEN (x, %d) != %d) goto L%d;\n",
295 i, XVECLEN (x, i), fail_label);
296 for (j = 0; j < XVECLEN (x, i); j++)
299 match_rtx (XVECEXP (x, i, j), &link, fail_label);
302 else if (fmt[i] == 'i')
304 /* Make sure that at run time `x' is the RTX we want to test. */
312 printf (" if (XINT (x, %d) != %d) goto L%d;\n",
313 i, XINT (x, i), fail_label);
315 else if (fmt[i] == 'w')
317 /* Make sure that at run time `x' is the RTX we want to test. */
325 printf (" if (XWINT (x, %d) != ", i);
326 printf (HOST_WIDE_INT_PRINT_DEC, XWINT (x, i));
327 printf (") goto L%d;\n", fail_label);
329 else if (fmt[i] == 's')
331 /* Make sure that at run time `x' is the RTX we want to test. */
339 printf (" if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n",
340 i, XSTR (x, i), fail_label);
345 /* Given a PATH, representing a path down the instruction's
346 pattern from the root to a certain point, output code to
347 evaluate to the rtx at that point. */
355 else if (path->vecelt >= 0)
357 printf ("XVECEXP (");
358 print_path (path->next);
359 printf (", %d, %d)", path->pos, path->vecelt);
364 print_path (path->next);
365 printf (", %d)", path->pos);
374 for (p1 = GET_RTX_NAME (code); *p1; p1++)
376 if (*p1 >= 'a' && *p1 <= 'z')
377 putchar (*p1 + 'A' - 'a');
387 register char *val = (char *) malloc (size);
390 fatal ("virtual memory exhausted");
399 char *result = (char *) realloc (ptr, size);
401 fatal ("virtual memory exhausted");
409 fprintf (stderr, "genpeep: ");
410 fprintf (stderr, s, a1, a2);
411 fprintf (stderr, "\n");
412 exit (FATAL_EXIT_CODE);
415 /* More 'friendly' abort that prints the line and file.
416 config.h can #define abort fancy_abort if you like that sort of thing. */
421 fatal ("Internal gcc abort.");
435 obstack_init (rtl_obstack);
438 fatal ("No input file name.");
440 infile = fopen (argv[1], "r");
444 exit (FATAL_EXIT_CODE);
449 printf ("/* Generated automatically by the program `genpeep'\n\
450 from the machine description file `md'. */\n\n");
452 printf ("#include \"config.h\"\n");
453 printf ("#include <stdio.h>\n");
454 printf ("#include \"rtl.h\"\n");
455 printf ("#include \"regs.h\"\n");
456 printf ("#include \"output.h\"\n");
457 printf ("#include \"real.h\"\n");
458 printf ("#include \"except.h\"\n\n");
460 printf ("extern rtx peep_operand[];\n\n");
461 printf ("#define operands peep_operand\n\n");
463 printf ("rtx\npeephole (ins1)\n rtx ins1;\n{\n");
464 printf (" rtx insn, x, pat;\n\n");
466 /* Early out: no peepholes for insns followed by barriers. */
467 printf (" if (NEXT_INSN (ins1)\n");
468 printf (" && GET_CODE (NEXT_INSN (ins1)) == BARRIER)\n");
469 printf (" return 0;\n\n");
471 /* Read the machine description. */
475 c = read_skip_spaces (infile);
480 desc = read_rtx (infile);
481 if (GET_CODE (desc) == DEFINE_PEEPHOLE)
486 if (GET_CODE (desc) == DEFINE_INSN
487 || GET_CODE (desc) == DEFINE_EXPAND
488 || GET_CODE (desc) == DEFINE_SPLIT)
494 printf (" return 0;\n}\n\n");
499 printf ("rtx peep_operand[%d];\n", max_opno + 1);
502 exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);