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));
48 void fancy_abort PROTO((void));
52 /* Number of operands used in current peephole definition. */
54 static int n_operands;
56 /* Peephole optimizations get insn codes just like insn patterns.
57 Count them so we know the code of the define_peephole we are handling. */
59 static int insn_code_number = 0;
61 static void gen_peephole PROTO((rtx));
62 static void match_rtx PROTO((rtx, struct link *, int));
63 static void print_path PROTO((struct link *));
64 static void print_code PROTO((RTX_CODE));
70 int ninsns = XVECLEN (peep, 0);
75 printf (" insn = ins1;\n");
77 printf (" want_jump = 0;\n");
80 for (i = 0; i < ninsns; i++)
84 printf (" do { insn = NEXT_INSN (insn);\n");
85 printf (" if (insn == 0) goto L%d; }\n",
87 printf (" while (GET_CODE (insn) == NOTE\n");
88 printf ("\t || (GET_CODE (insn) == INSN\n");
89 printf ("\t && (GET_CODE (PATTERN (insn)) == USE\n");
90 printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n");
92 printf (" if (GET_CODE (insn) == CODE_LABEL\n\
93 || GET_CODE (insn) == BARRIER)\n goto L%d;\n",
98 printf (" if (GET_CODE (insn) == JUMP_INSN)\n");
99 printf (" want_jump = JUMP_LABEL (insn);\n");
102 printf (" pat = PATTERN (insn);\n");
104 /* Walk the insn's pattern, remembering at all times the path
105 down to the walking point. */
107 match_rtx (XVECEXP (peep, 0, i), NULL_PTR, insn_code_number);
110 /* We get this far if the pattern matches.
111 Now test the extra condition. */
113 if (XSTR (peep, 1) && XSTR (peep, 1)[0])
114 printf (" if (! (%s)) goto L%d;\n",
115 XSTR (peep, 1), insn_code_number);
117 /* If that matches, construct new pattern and put it in the first insn.
118 This new pattern will never be matched.
119 It exists only so that insn-extract can get the operands back.
120 So use a simple regular form: a PARALLEL containing a vector
121 of all the operands. */
123 printf (" PATTERN (ins1) = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands);
126 printf (" if (want_jump && GET_CODE (ins1) != JUMP_INSN)\n");
128 printf (" rtx insn2 = emit_jump_insn_before (PATTERN (ins1), ins1);\n");
129 printf (" delete_insn (ins1);\n");
130 printf (" ins1 = ins2;\n");
134 /* Record this define_peephole's insn code in the insn,
135 as if it had been recognized to match this. */
136 printf (" INSN_CODE (ins1) = %d;\n",
139 /* Delete the remaining insns. */
141 printf (" delete_for_peephole (NEXT_INSN (ins1), insn);\n");
143 /* See reload1.c for insertion of NOTE which guarantees that this
145 printf (" return NEXT_INSN (insn);\n");
147 printf (" L%d:\n\n", insn_code_number);
151 match_rtx (x, path, fail_label)
156 register RTX_CODE code;
171 if (XINT (x, 0) > max_opno)
172 max_opno = XINT (x, 0);
173 if (XINT (x, 0) >= n_operands)
174 n_operands = 1 + XINT (x, 0);
180 printf (" operands[%d] = x;\n", XINT (x, 0));
181 if (XSTR (x, 1) && XSTR (x, 1)[0])
182 printf (" if (! %s (x, %smode)) goto L%d;\n",
183 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
192 printf (" if (!rtx_equal_p (operands[%d], x)) goto L%d;\n",
193 XINT (x, 0), fail_label);
201 printf (" if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0));
202 printf (" || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n",
203 XINT (x, 0), fail_label);
204 printf (" operands[%d] = x;\n", XINT (x, 0));
207 for (i = 0; i < XVECLEN (x, 1); i++)
210 match_rtx (XVECEXP (x, 1, i), &link, fail_label);
215 if (XINT (x, 0) > max_opno)
216 max_opno = XINT (x, 0);
217 if (XINT (x, 0) >= n_operands)
218 n_operands = 1 + XINT (x, 0);
224 printf (" operands[%d] = x;\n", XINT (x, 0));
225 if (XSTR (x, 1) && XSTR (x, 1)[0])
226 printf (" if (! %s (x, %smode)) goto L%d;\n",
227 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
230 for (i = 0; i < XVECLEN (x, 2); i++)
233 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
238 if (XINT (x, 0) > max_opno)
239 max_opno = XINT (x, 0);
240 if (XINT (x, 0) >= n_operands)
241 n_operands = 1 + XINT (x, 0);
247 printf (" if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label);
248 printf (" operands[%d] = x;\n", XINT (x, 0));
249 if (XSTR (x, 1) && XSTR (x, 1)[0])
250 printf (" if (! %s (x, %smode)) goto L%d;\n",
251 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
254 for (i = 0; i < XVECLEN (x, 2); i++)
257 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
262 match_rtx (XEXP (x, 0), path, fail_label);
273 printf (" if (GET_CODE (x) != ");
275 printf (") goto L%d;\n", fail_label);
277 if (GET_MODE (x) != VOIDmode)
279 printf (" if (GET_MODE (x) != %smode) goto L%d;\n",
280 GET_MODE_NAME (GET_MODE (x)), fail_label);
285 fmt = GET_RTX_FORMAT (code);
286 len = GET_RTX_LENGTH (code);
287 for (i = 0; i < len; i++)
290 if (fmt[i] == 'e' || fmt[i] == 'u')
291 match_rtx (XEXP (x, i), &link, fail_label);
292 else if (fmt[i] == 'E')
295 printf (" if (XVECLEN (x, %d) != %d) goto L%d;\n",
296 i, XVECLEN (x, i), fail_label);
297 for (j = 0; j < XVECLEN (x, i); j++)
300 match_rtx (XVECEXP (x, i, j), &link, fail_label);
303 else if (fmt[i] == 'i')
305 /* Make sure that at run time `x' is the RTX we want to test. */
313 printf (" if (XINT (x, %d) != %d) goto L%d;\n",
314 i, XINT (x, i), fail_label);
316 else if (fmt[i] == 'w')
318 /* Make sure that at run time `x' is the RTX we want to test. */
326 printf (" if (XWINT (x, %d) != ", i);
327 printf (HOST_WIDE_INT_PRINT_DEC, XWINT (x, i));
328 printf (") goto L%d;\n", fail_label);
330 else if (fmt[i] == 's')
332 /* Make sure that at run time `x' is the RTX we want to test. */
340 printf (" if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n",
341 i, XSTR (x, i), fail_label);
346 /* Given a PATH, representing a path down the instruction's
347 pattern from the root to a certain point, output code to
348 evaluate to the rtx at that point. */
356 else if (path->vecelt >= 0)
358 printf ("XVECEXP (");
359 print_path (path->next);
360 printf (", %d, %d)", path->pos, path->vecelt);
365 print_path (path->next);
366 printf (", %d)", path->pos);
375 for (p1 = GET_RTX_NAME (code); *p1; p1++)
377 if (*p1 >= 'a' && *p1 <= 'z')
378 putchar (*p1 + 'A' - 'a');
388 register char *val = (char *) malloc (size);
391 fatal ("virtual memory exhausted");
400 char *result = (char *) realloc (ptr, size);
402 fatal ("virtual memory exhausted");
410 fprintf (stderr, "genpeep: ");
411 fprintf (stderr, s, a1, a2);
412 fprintf (stderr, "\n");
413 exit (FATAL_EXIT_CODE);
416 /* More 'friendly' abort that prints the line and file.
417 config.h can #define abort fancy_abort if you like that sort of thing. */
422 fatal ("Internal gcc abort.");
436 obstack_init (rtl_obstack);
439 fatal ("No input file name.");
441 infile = fopen (argv[1], "r");
445 exit (FATAL_EXIT_CODE);
450 printf ("/* Generated automatically by the program `genpeep'\n\
451 from the machine description file `md'. */\n\n");
453 printf ("#include \"config.h\"\n");
454 printf ("#include \"system.h\"\n");
455 printf ("#include \"rtl.h\"\n");
456 printf ("#include \"regs.h\"\n");
457 printf ("#include \"output.h\"\n");
458 printf ("#include \"real.h\"\n");
459 printf ("#include \"except.h\"\n\n");
461 printf ("extern rtx peep_operand[];\n\n");
462 printf ("#define operands peep_operand\n\n");
464 printf ("rtx\npeephole (ins1)\n rtx ins1;\n{\n");
465 printf (" rtx insn, x, pat;\n\n");
467 /* Early out: no peepholes for insns followed by barriers. */
468 printf (" if (NEXT_INSN (ins1)\n");
469 printf (" && GET_CODE (NEXT_INSN (ins1)) == BARRIER)\n");
470 printf (" return 0;\n\n");
472 /* Read the machine description. */
476 c = read_skip_spaces (infile);
481 desc = read_rtx (infile);
482 if (GET_CODE (desc) == DEFINE_PEEPHOLE)
487 if (GET_CODE (desc) == DEFINE_INSN
488 || GET_CODE (desc) == DEFINE_EXPAND
489 || GET_CODE (desc) == DEFINE_SPLIT)
495 printf (" return 0;\n}\n\n");
500 printf ("rtx peep_operand[%d];\n", max_opno + 1);
503 exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);