1 /* Generate code from machine description to perform peephole optimizations.
2 Copyright (C) 1987, 1989, 1992 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
26 static struct obstack obstack;
27 struct obstack *rtl_obstack = &obstack;
29 #define obstack_chunk_alloc xmalloc
30 #define obstack_chunk_free free
33 extern rtx read_rtx ();
35 /* While tree-walking an instruction pattern, we keep a chain
36 of these `struct link's to record how to get down to the
37 current position. In each one, POS is the operand number,
38 and if the operand is a vector VEC is the element number.
39 VEC is -1 if the operand is not a vector. */
49 static void match_rtx ();
50 static void gen_exp ();
56 /* Number of operands used in current peephole definition. */
58 static int n_operands;
60 /* Peephole optimizations get insn codes just like insn patterns.
61 Count them so we know the code of the define_peephole we are handling. */
63 static int insn_code_number = 0;
65 static void print_path ();
66 static void print_code ();
72 int ninsns = XVECLEN (peep, 0);
77 printf (" insn = ins1;\n");
79 printf (" want_jump = 0;\n");
82 for (i = 0; i < ninsns; i++)
86 printf (" do { insn = NEXT_INSN (insn);\n");
87 printf (" if (insn == 0) goto L%d; }\n",
89 printf (" while (GET_CODE (insn) == NOTE\n");
90 printf ("\t || (GET_CODE (insn) == INSN\n");
91 printf ("\t && (GET_CODE (PATTERN (insn)) == USE\n");
92 printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n");
94 printf (" if (GET_CODE (insn) == CODE_LABEL\n\
95 || GET_CODE (insn) == BARRIER)\n goto L%d;\n",
100 printf (" if (GET_CODE (insn) == JUMP_INSN)\n");
101 printf (" want_jump = JUMP_LABEL (insn);\n");
104 printf (" pat = PATTERN (insn);\n");
106 /* Walk the insn's pattern, remembering at all times the path
107 down to the walking point. */
109 match_rtx (XVECEXP (peep, 0, i), NULL_PTR, insn_code_number);
112 /* We get this far if the pattern matches.
113 Now test the extra condition. */
115 if (XSTR (peep, 1) && XSTR (peep, 1)[0])
116 printf (" if (! (%s)) goto L%d;\n",
117 XSTR (peep, 1), insn_code_number);
119 /* If that matches, construct new pattern and put it in the first insn.
120 This new pattern will never be matched.
121 It exists only so that insn-extract can get the operands back.
122 So use a simple regular form: a PARALLEL containing a vector
123 of all the operands. */
125 printf (" PATTERN (ins1) = gen_rtx (PARALLEL, VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands);
128 printf (" if (want_jump && GET_CODE (ins1) != JUMP_INSN)\n");
130 printf (" rtx insn2 = emit_jump_insn_before (PATTERN (ins1), ins1);\n");
131 printf (" delete_insn (ins1);\n");
132 printf (" ins1 = ins2;\n");
136 /* Record this define_peephole's insn code in the insn,
137 as if it had been recognized to match this. */
138 printf (" INSN_CODE (ins1) = %d;\n",
141 /* Delete the remaining insns. */
143 printf (" delete_for_peephole (NEXT_INSN (ins1), insn);\n");
145 /* See reload1.c for insertion of NOTE which guarantees that this
147 printf (" return NEXT_INSN (insn);\n");
149 printf (" L%d:\n\n", insn_code_number);
153 match_rtx (x, path, fail_label)
158 register RTX_CODE code;
173 if (XINT (x, 0) > max_opno)
174 max_opno = XINT (x, 0);
175 if (XINT (x, 0) >= n_operands)
176 n_operands = 1 + XINT (x, 0);
182 printf (" operands[%d] = x;\n", XINT (x, 0));
183 if (XSTR (x, 1) && XSTR (x, 1)[0])
184 printf (" if (! %s (x, %smode)) goto L%d;\n",
185 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
193 printf (" if (!rtx_equal_p (operands[%d], x)) goto L%d;\n",
194 XINT (x, 0), fail_label);
202 printf (" if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0));
203 printf (" || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n",
204 XINT (x, 0), fail_label);
205 printf (" operands[%d] = x;\n", XINT (x, 0));
208 for (i = 0; i < XVECLEN (x, 1); i++)
211 match_rtx (XVECEXP (x, 1, i), &link, fail_label);
216 if (XINT (x, 0) > max_opno)
217 max_opno = XINT (x, 0);
218 if (XINT (x, 0) >= n_operands)
219 n_operands = 1 + XINT (x, 0);
225 printf (" operands[%d] = x;\n", XINT (x, 0));
226 if (XSTR (x, 1) && XSTR (x, 1)[0])
227 printf (" if (! %s (x, %smode)) goto L%d;\n",
228 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
231 for (i = 0; i < XVECLEN (x, 2); i++)
234 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
239 if (XINT (x, 0) > max_opno)
240 max_opno = XINT (x, 0);
241 if (XINT (x, 0) >= n_operands)
242 n_operands = 1 + XINT (x, 0);
248 printf (" if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label);
249 printf (" operands[%d] = x;\n", XINT (x, 0));
250 if (XSTR (x, 1) && XSTR (x, 1)[0])
251 printf (" if (! %s (x, %smode)) goto L%d;\n",
252 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label);
255 for (i = 0; i < XVECLEN (x, 2); i++)
258 match_rtx (XVECEXP (x, 2, i), &link, fail_label);
263 match_rtx (XEXP (x, 0), path, fail_label);
271 printf (" if (GET_CODE (x) != ");
273 printf (") goto L%d;\n", fail_label);
275 if (GET_MODE (x) != VOIDmode)
277 printf (" if (GET_MODE (x) != %smode) goto L%d;\n",
278 GET_MODE_NAME (GET_MODE (x)), fail_label);
283 fmt = GET_RTX_FORMAT (code);
284 len = GET_RTX_LENGTH (code);
285 for (i = 0; i < len; i++)
288 if (fmt[i] == 'e' || fmt[i] == 'u')
289 match_rtx (XEXP (x, i), &link, fail_label);
290 else if (fmt[i] == 'E')
293 printf (" if (XVECLEN (x, %d) != %d) goto L%d;\n",
294 i, XVECLEN (x, i), fail_label);
295 for (j = 0; j < XVECLEN (x, i); j++)
298 match_rtx (XVECEXP (x, i, j), &link, fail_label);
301 else if (fmt[i] == 'i')
303 /* Make sure that at run time `x' is the RTX we want to test. */
311 printf (" if (XINT (x, %d) != %d) goto L%d;\n",
312 i, XINT (x, i), fail_label);
314 else if (fmt[i] == 'w')
316 /* Make sure that at run time `x' is the RTX we want to test. */
324 printf (" if (XWINT (x, %d) != %d) goto L%d;\n",
325 i, XWINT (x, i), fail_label);
327 else if (fmt[i] == 's')
329 /* Make sure that at run time `x' is the RTX we want to test. */
337 printf (" if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n",
338 i, XSTR (x, i), fail_label);
343 /* Given a PATH, representing a path down the instruction's
344 pattern from the root to a certain point, output code to
345 evaluate to the rtx at that point. */
353 else if (path->vecelt >= 0)
355 printf ("XVECEXP (");
356 print_path (path->next);
357 printf (", %d, %d)", path->pos, path->vecelt);
362 print_path (path->next);
363 printf (", %d)", path->pos);
372 for (p1 = GET_RTX_NAME (code); *p1; p1++)
374 if (*p1 >= 'a' && *p1 <= 'z')
375 putchar (*p1 + 'A' - 'a');
385 register char *val = (char *) malloc (size);
388 fatal ("virtual memory exhausted");
397 char *result = (char *) realloc (ptr, size);
399 fatal ("virtual memory exhausted");
407 fprintf (stderr, "genpeep: ");
408 fprintf (stderr, s, a1, a2);
409 fprintf (stderr, "\n");
410 exit (FATAL_EXIT_CODE);
413 /* More 'friendly' abort that prints the line and file.
414 config.h can #define abort fancy_abort if you like that sort of thing. */
419 fatal ("Internal gcc abort.");
433 obstack_init (rtl_obstack);
436 fatal ("No input file name.");
438 infile = fopen (argv[1], "r");
442 exit (FATAL_EXIT_CODE);
447 printf ("/* Generated automatically by the program `genpeep'\n\
448 from the machine description file `md'. */\n\n");
450 printf ("#include \"config.h\"\n");
451 printf ("#include \"rtl.h\"\n");
452 printf ("#include \"regs.h\"\n");
453 printf ("#include \"output.h\"\n");
454 printf ("#include \"real.h\"\n\n");
456 printf ("extern rtx peep_operand[];\n\n");
457 printf ("#define operands peep_operand\n\n");
459 printf ("rtx\npeephole (ins1)\n rtx ins1;\n{\n");
460 printf (" rtx insn, x, pat;\n");
461 printf (" int i;\n\n");
463 /* Early out: no peepholes for insns followed by barriers. */
464 printf (" if (NEXT_INSN (ins1)\n");
465 printf (" && GET_CODE (NEXT_INSN (ins1)) == BARRIER)\n");
466 printf (" return 0;\n\n");
468 /* Read the machine description. */
472 c = read_skip_spaces (infile);
477 desc = read_rtx (infile);
478 if (GET_CODE (desc) == DEFINE_PEEPHOLE)
483 if (GET_CODE (desc) == DEFINE_INSN
484 || GET_CODE (desc) == DEFINE_EXPAND
485 || GET_CODE (desc) == DEFINE_SPLIT)
491 printf (" return 0;\n}\n\n");
496 printf ("rtx peep_operand[%d];\n", max_opno + 1);
499 exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);