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1.1 root 1: /* Generate code from machine description to recognize rtl as insns.
2: Copyright (C) 1987, 1988, 1992, 1993 Free Software Foundation, Inc.
3:
4: This file is part of GNU CC.
5:
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)
9: any later version.
10:
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.
15:
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. */
19:
20:
21: /* This program is used to produce insn-recog.c, which contains
22: a function called `recog' plus its subroutines.
23: These functions contain a decision tree
24: that recognizes whether an rtx, the argument given to recog,
25: is a valid instruction.
26:
27: recog returns -1 if the rtx is not valid.
28: If the rtx is valid, recog returns a nonnegative number
29: which is the insn code number for the pattern that matched.
30: This is the same as the order in the machine description of the
31: entry that matched. This number can be used as an index into various
32: insn_* tables, such as insn_template, insn_outfun, and insn_n_operands
33: (found in insn-output.c).
34:
35: The third argument to recog is an optional pointer to an int.
36: If present, recog will accept a pattern if it matches except for
37: missing CLOBBER expressions at the end. In that case, the value
38: pointed to by the optional pointer will be set to the number of
39: CLOBBERs that need to be added (it should be initialized to zero by
40: the caller). If it is set nonzero, the caller should allocate a
41: PARALLEL of the appropriate size, copy the initial entries, and call
42: add_clobbers (found in insn-emit.c) to fill in the CLOBBERs.
43:
44: This program also generates the function `split_insns',
45: which returns 0 if the rtl could not be split, or
46: it returns the split rtl in a SEQUENCE. */
47:
48: #include <stdio.h>
49: #include "hconfig.h"
50: #include "rtl.h"
51: #include "obstack.h"
52:
53: static struct obstack obstack;
54: struct obstack *rtl_obstack = &obstack;
55:
56: #define obstack_chunk_alloc xmalloc
57: #define obstack_chunk_free free
58:
59: extern void free ();
60: extern rtx read_rtx ();
61:
62: /* Data structure for a listhead of decision trees. The alternatives
63: to a node are kept in a doublely-linked list so we can easily add nodes
64: to the proper place when merging. */
65:
66: struct decision_head { struct decision *first, *last; };
67:
68: /* Data structure for decision tree for recognizing
69: legitimate instructions. */
70:
71: struct decision
72: {
73: int number; /* Node number, used for labels */
74: char *position; /* String denoting position in pattern */
75: RTX_CODE code; /* Code to test for or UNKNOWN to suppress */
76: char ignore_code; /* If non-zero, need not test code */
77: char ignore_mode; /* If non-zero, need not test mode */
78: int veclen; /* Length of vector, if nonzero */
79: enum machine_mode mode; /* Machine mode of node */
80: char enforce_mode; /* If non-zero, test `mode' */
81: char retest_code, retest_mode; /* See write_tree_1 */
82: int test_elt_zero_int; /* Nonzero if should test XINT (rtl, 0) */
83: int elt_zero_int; /* Required value for XINT (rtl, 0) */
84: int test_elt_one_int; /* Nonzero if should test XINT (rtl, 1) */
85: int elt_one_int; /* Required value for XINT (rtl, 1) */
86: int test_elt_zero_wide; /* Nonzero if should test XWINT (rtl, 0) */
87: HOST_WIDE_INT elt_zero_wide; /* Required value for XWINT (rtl, 0) */
88: char *tests; /* If nonzero predicate to call */
89: int pred; /* `preds' index of predicate or -1 */
90: char *c_test; /* Additional test to perform */
91: struct decision_head success; /* Nodes to test on success */
92: int insn_code_number; /* Insn number matched, if success */
93: int num_clobbers_to_add; /* Number of CLOBBERs to be added to pattern */
94: struct decision *next; /* Node to test on failure */
95: struct decision *prev; /* Node whose failure tests us */
96: struct decision *afterward; /* Node to test on success, but failure of
97: successor nodes */
98: int opno; /* Operand number, if >= 0 */
99: int dupno; /* Number of operand to compare against */
100: int label_needed; /* Nonzero if label needed when writing tree */
101: int subroutine_number; /* Number of subroutine this node starts */
102: };
103:
104: #define SUBROUTINE_THRESHOLD 50
105:
106: static int next_subroutine_number;
107:
108: /* We can write two types of subroutines: One for insn recognition and
109: one to split insns. This defines which type is being written. */
110:
111: enum routine_type {RECOG, SPLIT};
112:
113: /* Next available node number for tree nodes. */
114:
115: static int next_number;
116:
117: /* Next number to use as an insn_code. */
118:
119: static int next_insn_code;
120:
121: /* Similar, but counts all expressions in the MD file; used for
122: error messages. */
123:
124: static int next_index;
125:
126: /* Record the highest depth we ever have so we know how many variables to
127: allocate in each subroutine we make. */
128:
129: static int max_depth;
130:
131: /* This table contains a list of the rtl codes that can possibly match a
132: predicate defined in recog.c. The function `not_both_true' uses it to
133: deduce that there are no expressions that can be matches by certain pairs
134: of tree nodes. Also, if a predicate can match only one code, we can
135: hardwire that code into the node testing the predicate. */
136:
137: static struct pred_table
138: {
139: char *name;
140: RTX_CODE codes[NUM_RTX_CODE];
141: } preds[]
142: = {{"general_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
143: LABEL_REF, SUBREG, REG, MEM}},
144: #ifdef PREDICATE_CODES
145: PREDICATE_CODES
146: #endif
147: {"address_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
148: LABEL_REF, SUBREG, REG, MEM, PLUS, MINUS, MULT}},
149: {"register_operand", {SUBREG, REG}},
150: {"scratch_operand", {SCRATCH, REG}},
151: {"immediate_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
152: LABEL_REF}},
153: {"const_int_operand", {CONST_INT}},
154: {"const_double_operand", {CONST_INT, CONST_DOUBLE}},
155: {"nonimmediate_operand", {SUBREG, REG, MEM}},
156: {"nonmemory_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
157: LABEL_REF, SUBREG, REG}},
158: {"push_operand", {MEM}},
159: {"memory_operand", {SUBREG, MEM}},
160: {"indirect_operand", {SUBREG, MEM}},
161: {"comparison_operator", {EQ, NE, LE, LT, GE, GT, LEU, LTU, GEU, GTU}},
162: {"mode_independent_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
163: LABEL_REF, SUBREG, REG, MEM}}};
164:
165: #define NUM_KNOWN_PREDS (sizeof preds / sizeof preds[0])
166:
167: static struct decision_head make_insn_sequence PROTO((rtx, enum routine_type));
168: static struct decision *add_to_sequence PROTO((rtx, struct decision_head *,
169: char *));
170: static int not_both_true PROTO((struct decision *, struct decision *,
171: int));
172: static int position_merit PROTO((struct decision *, enum machine_mode,
173: enum rtx_code));
174: static struct decision_head merge_trees PROTO((struct decision_head,
175: struct decision_head));
176: static int break_out_subroutines PROTO((struct decision_head,
177: enum routine_type, int));
178: static void write_subroutine PROTO((struct decision *, enum routine_type));
179: static void write_tree_1 PROTO((struct decision *, char *,
180: struct decision *, enum routine_type));
181: static void print_code PROTO((enum rtx_code));
182: static int same_codes PROTO((struct decision *, enum rtx_code));
183: static void clear_codes PROTO((struct decision *));
184: static int same_modes PROTO((struct decision *, enum machine_mode));
185: static void clear_modes PROTO((struct decision *));
186: static void write_tree PROTO((struct decision *, char *,
187: struct decision *, int,
188: enum routine_type));
189: static void change_state PROTO((char *, char *, int));
190: static char *copystr PROTO((char *));
191: static void mybzero PROTO((char *, unsigned));
192: static void mybcopy PROTO((char *, char *, unsigned));
193: static char *concat PROTO((char *, char *));
194: static void fatal PROTO((char *));
195: char *xrealloc PROTO((char *, unsigned));
196: char *xmalloc PROTO((unsigned));
197: void fancy_abort PROTO((void));
198:
199: /* Construct and return a sequence of decisions
200: that will recognize INSN.
201:
202: TYPE says what type of routine we are recognizing (RECOG or SPLIT). */
203:
204: static struct decision_head
205: make_insn_sequence (insn, type)
206: rtx insn;
207: enum routine_type type;
208: {
209: rtx x;
210: char *c_test = XSTR (insn, type == RECOG ? 2 : 1);
211: struct decision *last;
212: struct decision_head head;
213:
214: if (XVECLEN (insn, type == RECOG) == 1)
215: x = XVECEXP (insn, type == RECOG, 0);
216: else
217: {
218: x = rtx_alloc (PARALLEL);
219: XVEC (x, 0) = XVEC (insn, type == RECOG);
220: PUT_MODE (x, VOIDmode);
221: }
222:
223: last = add_to_sequence (x, &head, "");
224:
225: if (c_test[0])
226: last->c_test = c_test;
227: last->insn_code_number = next_insn_code;
228: last->num_clobbers_to_add = 0;
229:
230: /* If this is not a DEFINE_SPLIT and X is a PARALLEL, see if it ends with a
231: group of CLOBBERs of (hard) registers or MATCH_SCRATCHes. If so, set up
232: to recognize the pattern without these CLOBBERs. */
233:
234: if (type == RECOG && GET_CODE (x) == PARALLEL)
235: {
236: int i;
237:
238: for (i = XVECLEN (x, 0); i > 0; i--)
239: if (GET_CODE (XVECEXP (x, 0, i - 1)) != CLOBBER
240: || (GET_CODE (XEXP (XVECEXP (x, 0, i - 1), 0)) != REG
241: && GET_CODE (XEXP (XVECEXP (x, 0, i - 1), 0)) != MATCH_SCRATCH))
242: break;
243:
244: if (i != XVECLEN (x, 0))
245: {
246: rtx new;
247: struct decision_head clobber_head;
248:
249: if (i == 1)
250: new = XVECEXP (x, 0, 0);
251: else
252: {
253: int j;
254:
255: new = rtx_alloc (PARALLEL);
256: XVEC (new, 0) = rtvec_alloc (i);
257: for (j = i - 1; j >= 0; j--)
258: XVECEXP (new, 0, j) = XVECEXP (x, 0, j);
259: }
260:
261: last = add_to_sequence (new, &clobber_head, "");
262:
263: if (c_test[0])
264: last->c_test = c_test;
265: last->insn_code_number = next_insn_code;
266: last->num_clobbers_to_add = XVECLEN (x, 0) - i;
267:
268: head = merge_trees (head, clobber_head);
269: }
270: }
271:
272: next_insn_code++;
273:
274: if (type == SPLIT)
275: /* Define the subroutine we will call below and emit in genemit. */
276: printf ("extern rtx gen_split_%d ();\n", last->insn_code_number);
277:
278: return head;
279: }
280:
281: /* Create a chain of nodes to verify that an rtl expression matches
282: PATTERN.
283:
284: LAST is a pointer to the listhead in the previous node in the chain (or
285: in the calling function, for the first node).
286:
287: POSITION is the string representing the current position in the insn.
288:
289: A pointer to the final node in the chain is returned. */
290:
291: static struct decision *
292: add_to_sequence (pattern, last, position)
293: rtx pattern;
294: struct decision_head *last;
295: char *position;
296: {
297: register RTX_CODE code;
298: register struct decision *new
299: = (struct decision *) xmalloc (sizeof (struct decision));
300: struct decision *this;
301: char *newpos;
302: register char *fmt;
303: register int i;
304: int depth = strlen (position);
305: int len;
306:
307: if (depth > max_depth)
308: max_depth = depth;
309:
310: new->number = next_number++;
311: new->position = copystr (position);
312: new->ignore_code = 0;
313: new->ignore_mode = 0;
314: new->enforce_mode = 1;
315: new->retest_code = new->retest_mode = 0;
316: new->veclen = 0;
317: new->test_elt_zero_int = 0;
318: new->test_elt_one_int = 0;
319: new->test_elt_zero_wide = 0;
320: new->elt_zero_int = 0;
321: new->elt_one_int = 0;
322: new->elt_zero_wide = 0;
323: new->tests = 0;
324: new->pred = -1;
325: new->c_test = 0;
326: new->success.first = new->success.last = 0;
327: new->insn_code_number = -1;
328: new->num_clobbers_to_add = 0;
329: new->next = 0;
330: new->prev = 0;
331: new->afterward = 0;
332: new->opno = -1;
333: new->dupno = -1;
334: new->label_needed = 0;
335: new->subroutine_number = 0;
336:
337: this = new;
338:
339: last->first = last->last = new;
340:
341: newpos = (char *) alloca (depth + 2);
342: strcpy (newpos, position);
343: newpos[depth + 1] = 0;
344:
345: restart:
346:
347: new->mode = GET_MODE (pattern);
348: new->code = code = GET_CODE (pattern);
349:
350: switch (code)
351: {
352: case MATCH_OPERAND:
353: case MATCH_SCRATCH:
354: case MATCH_OPERATOR:
355: case MATCH_PARALLEL:
356: new->opno = XINT (pattern, 0);
357: new->code = (code == MATCH_PARALLEL ? PARALLEL : UNKNOWN);
358: new->enforce_mode = 0;
359:
360: if (code == MATCH_SCRATCH)
361: new->tests = "scratch_operand";
362: else
363: new->tests = XSTR (pattern, 1);
364:
365: if (*new->tests == 0)
366: new->tests = 0;
367:
368: /* See if we know about this predicate and save its number. If we do,
369: and it only accepts one code, note that fact. The predicate
370: `const_int_operand' only tests for a CONST_INT, so if we do so we
371: can avoid calling it at all.
372:
373: Finally, if we know that the predicate does not allow CONST_INT, we
374: know that the only way the predicate can match is if the modes match
375: (here we use the kluge of relying on the fact that "address_operand"
376: accepts CONST_INT; otherwise, it would have to be a special case),
377: so we can test the mode (but we need not). This fact should
378: considerably simplify the generated code. */
379:
380: if (new->tests)
381: {
382: for (i = 0; i < NUM_KNOWN_PREDS; i++)
383: if (! strcmp (preds[i].name, new->tests))
384: {
385: int j;
386: int allows_const_int = 0;
387:
388: new->pred = i;
389:
390: if (preds[i].codes[1] == 0 && new->code == UNKNOWN)
391: {
392: new->code = preds[i].codes[0];
393: if (! strcmp ("const_int_operand", new->tests))
394: new->tests = 0, new->pred = -1;
395: }
396:
397: for (j = 0; j < NUM_RTX_CODE && preds[i].codes[j] != 0; j++)
398: if (preds[i].codes[j] == CONST_INT)
399: allows_const_int = 1;
400:
401: if (! allows_const_int)
402: new->enforce_mode = new->ignore_mode= 1;
403:
404: break;
405: }
406:
407: #ifdef PREDICATE_CODES
408: /* If the port has a list of the predicates it uses but omits
409: one, warn. */
410: if (i == NUM_KNOWN_PREDS)
411: fprintf (stderr, "Warning: `%s' not in PREDICATE_CODES\n",
412: new->tests);
413: #endif
414: }
415:
416: if (code == MATCH_OPERATOR || code == MATCH_PARALLEL)
417: {
418: for (i = 0; i < XVECLEN (pattern, 2); i++)
419: {
420: newpos[depth] = i + (code == MATCH_OPERATOR ? '0': 'a');
421: new = add_to_sequence (XVECEXP (pattern, 2, i),
422: &new->success, newpos);
423: }
424: }
425:
426: return new;
427:
428: case MATCH_OP_DUP:
429: new->opno = XINT (pattern, 0);
430: new->dupno = XINT (pattern, 0);
431: new->code = UNKNOWN;
432: new->tests = 0;
433: for (i = 0; i < XVECLEN (pattern, 1); i++)
434: {
435: newpos[depth] = i + '0';
436: new = add_to_sequence (XVECEXP (pattern, 1, i),
437: &new->success, newpos);
438: }
439: return new;
440:
441: case MATCH_DUP:
442: case MATCH_PAR_DUP:
443: new->dupno = XINT (pattern, 0);
444: new->code = UNKNOWN;
445: new->enforce_mode = 0;
446: return new;
447:
448: case ADDRESS:
449: pattern = XEXP (pattern, 0);
450: goto restart;
451:
452: case SET:
453: newpos[depth] = '0';
454: new = add_to_sequence (SET_DEST (pattern), &new->success, newpos);
455: this->success.first->enforce_mode = 1;
456: newpos[depth] = '1';
457: new = add_to_sequence (SET_SRC (pattern), &new->success, newpos);
458:
459: /* If set are setting CC0 from anything other than a COMPARE, we
460: must enforce the mode so that we do not produce ambiguous insns. */
461: if (GET_CODE (SET_DEST (pattern)) == CC0
462: && GET_CODE (SET_SRC (pattern)) != COMPARE)
463: this->success.first->enforce_mode = 1;
464: return new;
465:
466: case SIGN_EXTEND:
467: case ZERO_EXTEND:
468: case STRICT_LOW_PART:
469: newpos[depth] = '0';
470: new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
471: this->success.first->enforce_mode = 1;
472: return new;
473:
474: case SUBREG:
475: this->test_elt_one_int = 1;
476: this->elt_one_int = XINT (pattern, 1);
477: newpos[depth] = '0';
478: new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
479: this->success.first->enforce_mode = 1;
480: return new;
481:
482: case ZERO_EXTRACT:
483: case SIGN_EXTRACT:
484: newpos[depth] = '0';
485: new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
486: this->success.first->enforce_mode = 1;
487: newpos[depth] = '1';
488: new = add_to_sequence (XEXP (pattern, 1), &new->success, newpos);
489: newpos[depth] = '2';
490: new = add_to_sequence (XEXP (pattern, 2), &new->success, newpos);
491: return new;
492:
493: case EQ: case NE: case LE: case LT: case GE: case GT:
494: case LEU: case LTU: case GEU: case GTU:
495: /* If the first operand is (cc0), we don't have to do anything
496: special. */
497: if (GET_CODE (XEXP (pattern, 0)) == CC0)
498: break;
499:
500: /* ... fall through ... */
501:
502: case COMPARE:
503: /* Enforce the mode on the first operand to avoid ambiguous insns. */
504: newpos[depth] = '0';
505: new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
506: this->success.first->enforce_mode = 1;
507: newpos[depth] = '1';
508: new = add_to_sequence (XEXP (pattern, 1), &new->success, newpos);
509: return new;
510: }
511:
512: fmt = GET_RTX_FORMAT (code);
513: len = GET_RTX_LENGTH (code);
514: for (i = 0; i < len; i++)
515: {
516: newpos[depth] = '0' + i;
517: if (fmt[i] == 'e' || fmt[i] == 'u')
518: new = add_to_sequence (XEXP (pattern, i), &new->success, newpos);
519: else if (fmt[i] == 'i' && i == 0)
520: {
521: this->test_elt_zero_int = 1;
522: this->elt_zero_int = XINT (pattern, i);
523: }
524: else if (fmt[i] == 'i' && i == 1)
525: {
526: this->test_elt_one_int = 1;
527: this->elt_one_int = XINT (pattern, i);
528: }
529: else if (fmt[i] == 'w' && i == 0)
530: {
531: this->test_elt_zero_wide = 1;
532: this->elt_zero_wide = XWINT (pattern, i);
533: }
534: else if (fmt[i] == 'E')
535: {
536: register int j;
537: /* We do not handle a vector appearing as other than
538: the first item, just because nothing uses them
539: and by handling only the special case
540: we can use one element in newpos for either
541: the item number of a subexpression
542: or the element number in a vector. */
543: if (i != 0)
544: abort ();
545: this->veclen = XVECLEN (pattern, i);
546: for (j = 0; j < XVECLEN (pattern, i); j++)
547: {
548: newpos[depth] = 'a' + j;
549: new = add_to_sequence (XVECEXP (pattern, i, j),
550: &new->success, newpos);
551: }
552: }
553: else if (fmt[i] != '0')
554: abort ();
555: }
556: return new;
557: }
558:
559: /* Return 1 if we can prove that there is no RTL that can match both
560: D1 and D2. Otherwise, return 0 (it may be that there is an RTL that
561: can match both or just that we couldn't prove there wasn't such an RTL).
562:
563: TOPLEVEL is non-zero if we are to only look at the top level and not
564: recursively descend. */
565:
566: static int
567: not_both_true (d1, d2, toplevel)
568: struct decision *d1, *d2;
569: int toplevel;
570: {
571: struct decision *p1, *p2;
572:
573: /* If they are both to test modes and the modes are different, they aren't
574: both true. Similarly for codes, integer elements, and vector lengths. */
575:
576: if ((d1->enforce_mode && d2->enforce_mode
577: && d1->mode != VOIDmode && d2->mode != VOIDmode && d1->mode != d2->mode)
578: || (d1->code != UNKNOWN && d2->code != UNKNOWN && d1->code != d2->code)
579: || (d1->test_elt_zero_int && d2->test_elt_zero_int
580: && d1->elt_zero_int != d2->elt_zero_int)
581: || (d1->test_elt_one_int && d2->test_elt_one_int
582: && d1->elt_one_int != d2->elt_one_int)
583: || (d1->test_elt_zero_wide && d2->test_elt_zero_wide
584: && d1->elt_zero_wide != d2->elt_zero_wide)
585: || (d1->veclen && d2->veclen && d1->veclen != d2->veclen))
586: return 1;
587:
588: /* If either is a wild-card MATCH_OPERAND without a predicate, it can match
589: absolutely anything, so we can't say that no intersection is possible.
590: This case is detected by having a zero TESTS field with a code of
591: UNKNOWN. */
592:
593: if ((d1->tests == 0 && d1->code == UNKNOWN)
594: || (d2->tests == 0 && d2->code == UNKNOWN))
595: return 0;
596:
597: /* If either has a predicate that we know something about, set things up so
598: that D1 is the one that always has a known predicate. Then see if they
599: have any codes in common. */
600:
601: if (d1->pred >= 0 || d2->pred >= 0)
602: {
603: int i, j;
604:
605: if (d2->pred >= 0)
606: p1 = d1, d1 = d2, d2 = p1;
607:
608: /* If D2 tests an explicit code, see if it is in the list of valid codes
609: for D1's predicate. */
610: if (d2->code != UNKNOWN)
611: {
612: for (i = 0; i < NUM_RTX_CODE && preds[d1->pred].codes[i] != 0; i++)
613: if (preds[d1->pred].codes[i] == d2->code)
614: break;
615:
616: if (preds[d1->pred].codes[i] == 0)
617: return 1;
618: }
619:
620: /* Otherwise see if the predicates have any codes in common. */
621:
622: else if (d2->pred >= 0)
623: {
624: for (i = 0; i < NUM_RTX_CODE && preds[d1->pred].codes[i] != 0; i++)
625: {
626: for (j = 0; j < NUM_RTX_CODE; j++)
627: if (preds[d2->pred].codes[j] == 0
628: || preds[d2->pred].codes[j] == preds[d1->pred].codes[i])
629: break;
630:
631: if (preds[d2->pred].codes[j] != 0)
632: break;
633: }
634:
635: if (preds[d1->pred].codes[i] == 0)
636: return 1;
637: }
638: }
639:
640: /* If we got here, we can't prove that D1 and D2 cannot both be true.
641: If we are only to check the top level, return 0. Otherwise, see if
642: we can prove that all choices in both successors are mutually
643: exclusive. If either does not have any successors, we can't prove
644: they can't both be true. */
645:
646: if (toplevel || d1->success.first == 0 || d2->success.first == 0)
647: return 0;
648:
649: for (p1 = d1->success.first; p1; p1 = p1->next)
650: for (p2 = d2->success.first; p2; p2 = p2->next)
651: if (! not_both_true (p1, p2, 0))
652: return 0;
653:
654: return 1;
655: }
656:
657: /* Assuming that we can reorder all the alternatives at a specific point in
658: the tree (see discussion in merge_trees), we would prefer an ordering of
659: nodes where groups of consecutive nodes test the same mode and, within each
660: mode, groups of nodes test the same code. With this order, we can
661: construct nested switch statements, the inner one to test the code and
662: the outer one to test the mode.
663:
664: We would like to list nodes testing for specific codes before those
665: that test predicates to avoid unnecessary function calls. Similarly,
666: tests for specific modes should precede nodes that allow any mode.
667:
668: This function returns the merit (with 0 being the best) of inserting
669: a test involving the specified MODE and CODE after node P. If P is
670: zero, we are to determine the merit of inserting the test at the front
671: of the list. */
672:
673: static int
674: position_merit (p, mode, code)
675: struct decision *p;
676: enum machine_mode mode;
677: enum rtx_code code;
678: {
679: enum machine_mode p_mode;
680:
681: /* The only time the front of the list is anything other than the worst
682: position is if we are testing a mode that isn't VOIDmode. */
683: if (p == 0)
684: return mode == VOIDmode ? 3 : 2;
685:
686: p_mode = p->enforce_mode ? p->mode : VOIDmode;
687:
688: /* The best case is if the codes and modes both match. */
689: if (p_mode == mode && p->code== code)
690: return 0;
691:
692: /* If the codes don't match, the next best case is if the modes match.
693: In that case, the best position for this node depends on whether
694: we are testing for a specific code or not. If we are, the best place
695: is after some other test for an explicit code and our mode or after
696: the last test in the previous mode if every test in our mode is for
697: an unknown code.
698:
699: If we are testing for UNKNOWN, then the next best case is at the end of
700: our mode. */
701:
702: if ((code != UNKNOWN
703: && ((p_mode == mode && p->code != UNKNOWN)
704: || (p_mode != mode && p->next
705: && (p->next->enforce_mode ? p->next->mode : VOIDmode) == mode
706: && (p->next->code == UNKNOWN))))
707: || (code == UNKNOWN && p_mode == mode
708: && (p->next == 0
709: || (p->next->enforce_mode ? p->next->mode : VOIDmode) != mode)))
710: return 1;
711:
712: /* The third best case occurs when nothing is testing MODE. If MODE
713: is not VOIDmode, then the third best case is after something of any
714: mode that is not VOIDmode. If we are testing VOIDmode, the third best
715: place is the end of the list. */
716:
717: if (p_mode != mode
718: && ((mode != VOIDmode && p_mode != VOIDmode)
719: || (mode == VOIDmode && p->next == 0)))
720: return 2;
721:
722: /* Otherwise, we have the worst case. */
723: return 3;
724: }
725:
726: /* Merge two decision tree listheads OLDH and ADDH,
727: modifying OLDH destructively, and return the merged tree. */
728:
729: static struct decision_head
730: merge_trees (oldh, addh)
731: register struct decision_head oldh, addh;
732: {
733: struct decision *add, *next;
734:
735: if (oldh.first == 0)
736: return addh;
737:
738: if (addh.first == 0)
739: return oldh;
740:
741: /* If we are adding things at different positions, something is wrong. */
742: if (strcmp (oldh.first->position, addh.first->position))
743: abort ();
744:
745: for (add = addh.first; add; add = next)
746: {
747: enum machine_mode add_mode = add->enforce_mode ? add->mode : VOIDmode;
748: struct decision *best_position = 0;
749: int best_merit = 4;
750: struct decision *old;
751:
752: next = add->next;
753:
754: /* The semantics of pattern matching state that the tests are done in
755: the order given in the MD file so that if an insn matches two
756: patterns, the first one will be used. However, in practice, most,
757: if not all, patterns are unambiguous so that their order is
758: independent. In that case, we can merge identical tests and
759: group all similar modes and codes together.
760:
761: Scan starting from the end of OLDH until we reach a point
762: where we reach the head of the list or where we pass a pattern
763: that could also be true if NEW is true. If we find an identical
764: pattern, we can merge them. Also, record the last node that tests
765: the same code and mode and the last one that tests just the same mode.
766:
767: If we have no match, place NEW after the closest match we found. */
768:
769: for (old = oldh.last; old; old = old->prev)
770: {
771: int our_merit;
772:
773: /* If we don't have anything to test except an additional test,
774: do not consider the two nodes equal. If we did, the test below
775: would cause an infinite recursion. */
776: if (old->tests == 0 && old->test_elt_zero_int == 0
777: && old->test_elt_one_int == 0 && old->veclen == 0
778: && old->test_elt_zero_wide == 0
779: && old->dupno == -1 && old->mode == VOIDmode
780: && old->code == UNKNOWN
781: && (old->c_test != 0 || add->c_test != 0))
782: ;
783:
784: else if ((old->tests == add->tests
785: || (old->pred >= 0 && old->pred == add->pred)
786: || (old->tests && add->tests
787: && !strcmp (old->tests, add->tests)))
788: && old->test_elt_zero_int == add->test_elt_zero_int
789: && old->elt_zero_int == add->elt_zero_int
790: && old->test_elt_one_int == add->test_elt_one_int
791: && old->elt_one_int == add->elt_one_int
792: && old->test_elt_zero_wide == add->test_elt_zero_wide
793: && old->elt_zero_wide == add->elt_zero_wide
794: && old->veclen == add->veclen
795: && old->dupno == add->dupno
796: && old->opno == add->opno
797: && old->code == add->code
798: && old->enforce_mode == add->enforce_mode
799: && old->mode == add->mode)
800: {
801: /* If the additional test is not the same, split both nodes
802: into nodes that just contain all things tested before the
803: additional test and nodes that contain the additional test
804: and actions when it is true. This optimization is important
805: because of the case where we have almost identical patterns
806: with different tests on target flags. */
807:
808: if (old->c_test != add->c_test
809: && ! (old->c_test && add->c_test
810: && !strcmp (old->c_test, add->c_test)))
811: {
812: if (old->insn_code_number >= 0 || old->opno >= 0)
813: {
814: struct decision *split
815: = (struct decision *) xmalloc (sizeof (struct decision));
816:
817: mybcopy ((char *) old, (char *) split,
818: sizeof (struct decision));
819:
820: old->success.first = old->success.last = split;
821: old->c_test = 0;
822: old->opno = -1;
823: old->insn_code_number = -1;
824: old->num_clobbers_to_add = 0;
825:
826: split->number = next_number++;
827: split->next = split->prev = 0;
828: split->mode = VOIDmode;
829: split->code = UNKNOWN;
830: split->veclen = 0;
831: split->test_elt_zero_int = 0;
832: split->test_elt_one_int = 0;
833: split->test_elt_zero_wide = 0;
834: split->tests = 0;
835: split->pred = -1;
836: split->dupno = -1;
837: }
838:
839: if (add->insn_code_number >= 0 || add->opno >= 0)
840: {
841: struct decision *split
842: = (struct decision *) xmalloc (sizeof (struct decision));
843:
844: mybcopy ((char *) add, (char *) split,
845: sizeof (struct decision));
846:
847: add->success.first = add->success.last = split;
848: add->c_test = 0;
849: add->opno = -1;
850: add->insn_code_number = -1;
851: add->num_clobbers_to_add = 0;
852:
853: split->number = next_number++;
854: split->next = split->prev = 0;
855: split->mode = VOIDmode;
856: split->code = UNKNOWN;
857: split->veclen = 0;
858: split->test_elt_zero_int = 0;
859: split->test_elt_one_int = 0;
860: split->test_elt_zero_wide = 0;
861: split->tests = 0;
862: split->pred = -1;
863: split->dupno = -1;
864: }
865: }
866:
867: if (old->insn_code_number >= 0 && add->insn_code_number >= 0)
868: {
869: /* If one node is for a normal insn and the second is
870: for the base insn with clobbers stripped off, the
871: second node should be ignored. */
872:
873: if (old->num_clobbers_to_add == 0
874: && add->num_clobbers_to_add > 0)
875: /* Nothing to do here. */
876: ;
877: else if (old->num_clobbers_to_add > 0
878: && add->num_clobbers_to_add == 0)
879: {
880: /* In this case, replace OLD with ADD. */
881: old->insn_code_number = add->insn_code_number;
882: old->num_clobbers_to_add = 0;
883: }
884: else
885: fatal ("Two actions at one point in tree");
886: }
887:
888: if (old->insn_code_number == -1)
889: old->insn_code_number = add->insn_code_number;
890: old->success = merge_trees (old->success, add->success);
891: add = 0;
892: break;
893: }
894:
895: /* Unless we have already found the best possible insert point,
896: see if this position is better. If so, record it. */
897:
898: if (best_merit != 0
899: && ((our_merit = position_merit (old, add_mode, add->code))
900: < best_merit))
901: best_merit = our_merit, best_position = old;
902:
903: if (! not_both_true (old, add, 0))
904: break;
905: }
906:
907: /* If ADD was duplicate, we are done. */
908: if (add == 0)
909: continue;
910:
911: /* Otherwise, find the best place to insert ADD. Normally this is
912: BEST_POSITION. However, if we went all the way to the top of
913: the list, it might be better to insert at the top. */
914:
915: if (best_position == 0)
916: abort ();
917:
918: if (old == 0
919: && position_merit (NULL_PTR, add_mode, add->code) < best_merit)
920: {
921: add->prev = 0;
922: add->next = oldh.first;
923: oldh.first->prev = add;
924: oldh.first = add;
925: }
926:
927: else
928: {
929: add->prev = best_position;
930: add->next = best_position->next;
931: best_position->next = add;
932: if (best_position == oldh.last)
933: oldh.last = add;
934: else
935: add->next->prev = add;
936: }
937: }
938:
939: return oldh;
940: }
941:
942: /* Count the number of subnodes of HEAD. If the number is high enough,
943: make the first node in HEAD start a separate subroutine in the C code
944: that is generated.
945:
946: TYPE gives the type of routine we are writing.
947:
948: INITIAL is non-zero if this is the highest-level node. We never write
949: it out here. */
950:
951: static int
952: break_out_subroutines (head, type, initial)
953: struct decision_head head;
954: enum routine_type type;
955: int initial;
956: {
957: int size = 0;
958: struct decision *node, *sub;
959:
960: for (sub = head.first; sub; sub = sub->next)
961: size += 1 + break_out_subroutines (sub->success, type, 0);
962:
963: if (size > SUBROUTINE_THRESHOLD && ! initial)
964: {
965: head.first->subroutine_number = ++next_subroutine_number;
966: write_subroutine (head.first, type);
967: size = 1;
968: }
969: return size;
970: }
971:
972: /* Write out a subroutine of type TYPE to do comparisons starting at node
973: TREE. */
974:
975: static void
976: write_subroutine (tree, type)
977: struct decision *tree;
978: enum routine_type type;
979: {
980: int i;
981:
982: if (type == SPLIT)
983: printf ("rtx\nsplit");
984: else
985: printf ("int\nrecog");
986:
987: if (tree != 0 && tree->subroutine_number > 0)
988: printf ("_%d", tree->subroutine_number);
989: else if (type == SPLIT)
990: printf ("_insns");
991:
992: printf (" (x0, insn");
993: if (type == RECOG)
994: printf (", pnum_clobbers");
995:
996: printf (")\n");
997: printf (" register rtx x0;\n rtx insn;\n");
998: if (type == RECOG)
999: printf (" int *pnum_clobbers;\n");
1000:
1001: printf ("{\n");
1002: printf (" register rtx *ro = &recog_operand[0];\n");
1003:
1004: printf (" register rtx ");
1005: for (i = 1; i < max_depth; i++)
1006: printf ("x%d, ", i);
1007:
1008: printf ("x%d;\n", max_depth);
1009: printf (" %s tem;\n", type == SPLIT ? "rtx" : "int");
1010: write_tree (tree, "", NULL_PTR, 1, type);
1011: printf (" ret0: return %d;\n}\n\n", type == SPLIT ? 0 : -1);
1012: }
1013:
1014: /* This table is used to indent the recog_* functions when we are inside
1015: conditions or switch statements. We only support small indentations
1016: and always indent at least two spaces. */
1017:
1018: static char *indents[]
1019: = {" ", " ", " ", " ", " ", " ", " ", " ",
1020: "\t", "\t ", "\t ", "\t ", "\t ", "\t ", "\t ",
1021: "\t\t", "\t\t ", "\t\t ", "\t\t ", "\t\t ", "\t\t "};
1022:
1023: /* Write out C code to perform the decisions in TREE for a subroutine of
1024: type TYPE. If all of the choices fail, branch to node AFTERWARD, if
1025: non-zero, otherwise return. PREVPOS is the position of the node that
1026: branched to this test.
1027:
1028: When we merged all alternatives, we tried to set up a convenient order.
1029: Specifically, tests involving the same mode are all grouped together,
1030: followed by a group that does not contain a mode test. Within each group
1031: of the same mode, we also group tests with the same code, followed by a
1032: group that does not test a code.
1033:
1034: Occasionally, we cannot arbitrarily reorder the tests so that multiple
1035: sequence of groups as described above are present.
1036:
1037: We generate two nested switch statements, the outer statement for
1038: testing modes, and the inner switch for testing RTX codes. It is
1039: not worth optimizing cases when only a small number of modes or
1040: codes is tested, since the compiler can do that when compiling the
1041: resulting function. We do check for when every test is the same mode
1042: or code. */
1043:
1044: static void
1045: write_tree_1 (tree, prevpos, afterward, type)
1046: struct decision *tree;
1047: char *prevpos;
1048: struct decision *afterward;
1049: enum routine_type type;
1050: {
1051: register struct decision *p, *p1;
1052: register int depth = tree ? strlen (tree->position) : 0;
1053: enum machine_mode switch_mode = VOIDmode;
1054: RTX_CODE switch_code = UNKNOWN;
1055: int uncond = 0;
1056: char modemap[NUM_MACHINE_MODES];
1057: char codemap[NUM_RTX_CODE];
1058: int indent = 2;
1059: int i;
1060:
1061: /* One tricky area is what is the exact state when we branch to a
1062: node's label. There are two cases where we branch: when looking at
1063: successors to a node, or when a set of tests fails.
1064:
1065: In the former case, we are always branching to the first node in a
1066: decision list and we want all required tests to be performed. We
1067: put the labels for such nodes in front of any switch or test statements.
1068: These branches are done without updating the position to that of the
1069: target node.
1070:
1071: In the latter case, we are branching to a node that is not the first
1072: node in a decision list. We have already checked that it is possible
1073: for both the node we originally tested at this level and the node we
1074: are branching to to be both match some pattern. That means that they
1075: usually will be testing the same mode and code. So it is normally safe
1076: for such labels to be inside switch statements, since the tests done
1077: by virtue of arriving at that label will usually already have been
1078: done. The exception is a branch from a node that does not test a
1079: mode or code to one that does. In such cases, we set the `retest_mode'
1080: or `retest_code' flags. That will ensure that we start a new switch
1081: at that position and put the label before the switch.
1082:
1083: The branches in the latter case must set the position to that of the
1084: target node. */
1085:
1086:
1087: printf ("\n");
1088: if (tree && tree->subroutine_number == 0)
1089: {
1090: printf (" L%d:\n", tree->number);
1091: tree->label_needed = 0;
1092: }
1093:
1094: if (tree)
1095: {
1096: change_state (prevpos, tree->position, 2);
1097: prevpos = tree->position;
1098: }
1099:
1100: for (p = tree; p; p = p->next)
1101: {
1102: enum machine_mode mode = p->enforce_mode ? p->mode : VOIDmode;
1103: int need_bracket;
1104: int wrote_bracket = 0;
1105: int inner_indent;
1106:
1107: if (p->success.first == 0 && p->insn_code_number < 0)
1108: abort ();
1109:
1110: /* Find the next alternative to p that might be true when p is true.
1111: Test that one next if p's successors fail. */
1112:
1113: for (p1 = p->next; p1 && not_both_true (p, p1, 1); p1 = p1->next)
1114: ;
1115: p->afterward = p1;
1116:
1117: if (p1)
1118: {
1119: if (mode == VOIDmode && p1->enforce_mode && p1->mode != VOIDmode)
1120: p1->retest_mode = 1;
1121: if (p->code == UNKNOWN && p1->code != UNKNOWN)
1122: p1->retest_code = 1;
1123: p1->label_needed = 1;
1124: }
1125:
1126: /* If we have a different code or mode than the last node and
1127: are in a switch on codes, we must either end the switch or
1128: go to another case. We must also end the switch if this
1129: node needs a label and to retest either the mode or code. */
1130:
1131: if (switch_code != UNKNOWN
1132: && (switch_code != p->code || switch_mode != mode
1133: || (p->label_needed && (p->retest_mode || p->retest_code))))
1134: {
1135: enum rtx_code code = p->code;
1136:
1137: /* If P is testing a predicate that we know about and we haven't
1138: seen any of the codes that are valid for the predicate, we
1139: can write a series of "case" statement, one for each possible
1140: code. Since we are already in a switch, these redundant tests
1141: are very cheap and will reduce the number of predicate called. */
1142:
1143: if (p->pred >= 0)
1144: {
1145: for (i = 0; i < NUM_RTX_CODE && preds[p->pred].codes[i] != 0; i++)
1146: if (codemap[(int) preds[p->pred].codes[i]])
1147: break;
1148:
1149: if (preds[p->pred].codes[i] == 0)
1150: code = MATCH_OPERAND;
1151: }
1152:
1153: if (code == UNKNOWN || codemap[(int) code]
1154: || switch_mode != mode
1155: || (p->label_needed && (p->retest_mode || p->retest_code)))
1156: {
1157: printf ("%s}\n", indents[indent - 2]);
1158: switch_code = UNKNOWN;
1159: indent -= 4;
1160: }
1161: else
1162: {
1163: if (! uncond)
1164: printf ("%sbreak;\n", indents[indent]);
1165:
1166: if (code == MATCH_OPERAND)
1167: {
1168: for (i = 0; i < NUM_RTX_CODE && preds[p->pred].codes[i] != 0; i++)
1169: {
1170: printf ("%scase ", indents[indent - 2]);
1171: print_code (preds[p->pred].codes[i]);
1172: printf (":\n");
1173: codemap[(int) preds[p->pred].codes[i]] = 1;
1174: }
1175: }
1176: else
1177: {
1178: printf ("%scase ", indents[indent - 2]);
1179: print_code (code);
1180: printf (":\n");
1181: codemap[(int) p->code] = 1;
1182: }
1183:
1184: switch_code = code;
1185: }
1186:
1187: uncond = 0;
1188: }
1189:
1190: /* If we were previously in a switch on modes and now have a different
1191: mode, end at least the case, and maybe end the switch if we are
1192: not testing a mode or testing a mode whose case we already saw. */
1193:
1194: if (switch_mode != VOIDmode
1195: && (switch_mode != mode || (p->label_needed && p->retest_mode)))
1196: {
1197: if (mode == VOIDmode || modemap[(int) mode]
1198: || (p->label_needed && p->retest_mode))
1199: {
1200: printf ("%s}\n", indents[indent - 2]);
1201: switch_mode = VOIDmode;
1202: indent -= 4;
1203: }
1204: else
1205: {
1206: if (! uncond)
1207: printf (" break;\n");
1208: printf (" case %smode:\n", GET_MODE_NAME (mode));
1209: switch_mode = mode;
1210: modemap[(int) mode] = 1;
1211: }
1212:
1213: uncond = 0;
1214: }
1215:
1216: /* If we are about to write dead code, something went wrong. */
1217: if (! p->label_needed && uncond)
1218: abort ();
1219:
1220: /* If we need a label and we will want to retest the mode or code at
1221: that label, write the label now. We have already ensured that
1222: things will be valid for the test. */
1223:
1224: if (p->label_needed && (p->retest_mode || p->retest_code))
1225: {
1226: printf ("%sL%d:\n", indents[indent - 2], p->number);
1227: p->label_needed = 0;
1228: }
1229:
1230: uncond = 0;
1231:
1232: /* If we are not in any switches, see if we can shortcut things
1233: by checking for identical modes and codes. */
1234:
1235: if (switch_mode == VOIDmode && switch_code == UNKNOWN)
1236: {
1237: /* If p and its alternatives all want the same mode,
1238: reject all others at once, first, then ignore the mode. */
1239:
1240: if (mode != VOIDmode && p->next && same_modes (p, mode))
1241: {
1242: printf (" if (GET_MODE (x%d) != %smode)\n",
1243: depth, GET_MODE_NAME (p->mode));
1244: if (afterward)
1245: {
1246: printf (" {\n");
1247: change_state (p->position, afterward->position, 6);
1248: printf (" goto L%d;\n }\n", afterward->number);
1249: }
1250: else
1251: printf (" goto ret0;\n");
1252: clear_modes (p);
1253: mode = VOIDmode;
1254: }
1255:
1256: /* If p and its alternatives all want the same code,
1257: reject all others at once, first, then ignore the code. */
1258:
1259: if (p->code != UNKNOWN && p->next && same_codes (p, p->code))
1260: {
1261: printf (" if (GET_CODE (x%d) != ", depth);
1262: print_code (p->code);
1263: printf (")\n");
1264: if (afterward)
1265: {
1266: printf (" {\n");
1267: change_state (p->position, afterward->position, indent + 4);
1268: printf (" goto L%d;\n }\n", afterward->number);
1269: }
1270: else
1271: printf (" goto ret0;\n");
1272: clear_codes (p);
1273: }
1274: }
1275:
1276: /* If we are not in a mode switch and we are testing for a specific
1277: mode, start a mode switch unless we have just one node or the next
1278: node is not testing a mode (we have already tested for the case of
1279: more than one mode, but all of the same mode). */
1280:
1281: if (switch_mode == VOIDmode && mode != VOIDmode && p->next != 0
1282: && p->next->enforce_mode && p->next->mode != VOIDmode)
1283: {
1284: mybzero (modemap, sizeof modemap);
1285: printf ("%sswitch (GET_MODE (x%d))\n", indents[indent], depth);
1286: printf ("%s{\n", indents[indent + 2]);
1287: indent += 4;
1288: printf ("%scase %smode:\n", indents[indent - 2],
1289: GET_MODE_NAME (mode));
1290: modemap[(int) mode] = 1;
1291: switch_mode = mode;
1292: }
1293:
1294: /* Similarly for testing codes. */
1295:
1296: if (switch_code == UNKNOWN && p->code != UNKNOWN && ! p->ignore_code
1297: && p->next != 0 && p->next->code != UNKNOWN)
1298: {
1299: mybzero (codemap, sizeof codemap);
1300: printf ("%sswitch (GET_CODE (x%d))\n", indents[indent], depth);
1301: printf ("%s{\n", indents[indent + 2]);
1302: indent += 4;
1303: printf ("%scase ", indents[indent - 2]);
1304: print_code (p->code);
1305: printf (":\n");
1306: codemap[(int) p->code] = 1;
1307: switch_code = p->code;
1308: }
1309:
1310: /* Now that most mode and code tests have been done, we can write out
1311: a label for an inner node, if we haven't already. */
1312: if (p->label_needed)
1313: printf ("%sL%d:\n", indents[indent - 2], p->number);
1314:
1315: inner_indent = indent;
1316:
1317: /* The only way we can have to do a mode or code test here is if
1318: this node needs such a test but is the only node to be tested.
1319: In that case, we won't have started a switch. Note that this is
1320: the only way the switch and test modes can disagree. */
1321:
1322: if ((mode != switch_mode && ! p->ignore_mode)
1323: || (p->code != switch_code && p->code != UNKNOWN && ! p->ignore_code)
1324: || p->test_elt_zero_int || p->test_elt_one_int
1325: || p->test_elt_zero_wide || p->veclen
1326: || p->dupno >= 0 || p->tests || p->num_clobbers_to_add)
1327: {
1328: printf ("%sif (", indents[indent]);
1329:
1330: if (mode != switch_mode && ! p->ignore_mode)
1331: printf ("GET_MODE (x%d) == %smode && ",
1332: depth, GET_MODE_NAME (mode));
1333: if (p->code != switch_code && p->code != UNKNOWN && ! p->ignore_code)
1334: {
1335: printf ("GET_CODE (x%d) == ", depth);
1336: print_code (p->code);
1337: printf (" && ");
1338: }
1339:
1340: if (p->test_elt_zero_int)
1341: printf ("XINT (x%d, 0) == %d && ", depth, p->elt_zero_int);
1342: if (p->test_elt_one_int)
1343: printf ("XINT (x%d, 1) == %d && ", depth, p->elt_one_int);
1344: if (p->test_elt_zero_wide)
1345: printf (
1346: #if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_INT
1347: "XWINT (x%d, 0) == %d && ",
1348: #else
1349: "XWINT (x%d, 0) == %ld && ",
1350: #endif
1351: depth, p->elt_zero_wide);
1352: if (p->veclen)
1353: printf ("XVECLEN (x%d, 0) == %d && ", depth, p->veclen);
1354: if (p->dupno >= 0)
1355: printf ("rtx_equal_p (x%d, ro[%d]) && ", depth, p->dupno);
1356: if (p->num_clobbers_to_add)
1357: printf ("pnum_clobbers != 0 && ");
1358: if (p->tests)
1359: printf ("%s (x%d, %smode)", p->tests, depth,
1360: GET_MODE_NAME (p->mode));
1361: else
1362: printf ("1");
1363:
1364: printf (")\n");
1365: inner_indent += 2;
1366: }
1367: else
1368: uncond = 1;
1369:
1370: need_bracket = ! uncond;
1371:
1372: if (p->opno >= 0)
1373: {
1374: if (need_bracket)
1375: {
1376: printf ("%s{\n", indents[inner_indent]);
1377: inner_indent += 2;
1378: wrote_bracket = 1;
1379: need_bracket = 0;
1380: }
1381:
1382: printf ("%sro[%d] = x%d;\n", indents[inner_indent], p->opno, depth);
1383: }
1384:
1385: if (p->c_test)
1386: {
1387: printf ("%sif (%s)\n", indents[inner_indent], p->c_test);
1388: inner_indent += 2;
1389: uncond = 0;
1390: need_bracket = 1;
1391: }
1392:
1393: if (p->insn_code_number >= 0)
1394: {
1395: if (type == SPLIT)
1396: printf ("%sreturn gen_split_%d (operands);\n",
1397: indents[inner_indent], p->insn_code_number);
1398: else
1399: {
1400: if (p->num_clobbers_to_add)
1401: {
1402: if (need_bracket)
1403: {
1404: printf ("%s{\n", indents[inner_indent]);
1405: inner_indent += 2;
1406: }
1407:
1408: printf ("%s*pnum_clobbers = %d;\n",
1409: indents[inner_indent], p->num_clobbers_to_add);
1410: printf ("%sreturn %d;\n",
1411: indents[inner_indent], p->insn_code_number);
1412:
1413: if (need_bracket)
1414: {
1415: inner_indent -= 2;
1416: printf ("%s}\n", indents[inner_indent]);
1417: }
1418: }
1419: else
1420: printf ("%sreturn %d;\n",
1421: indents[inner_indent], p->insn_code_number);
1422: }
1423: }
1424: else
1425: printf ("%sgoto L%d;\n", indents[inner_indent],
1426: p->success.first->number);
1427:
1428: if (wrote_bracket)
1429: printf ("%s}\n", indents[inner_indent - 2]);
1430: }
1431:
1432: /* We have now tested all alternatives. End any switches we have open
1433: and branch to the alternative node unless we know that we can't fall
1434: through to the branch. */
1435:
1436: if (switch_code != UNKNOWN)
1437: {
1438: printf ("%s}\n", indents[indent - 2]);
1439: indent -= 4;
1440: uncond = 0;
1441: }
1442:
1443: if (switch_mode != VOIDmode)
1444: {
1445: printf ("%s}\n", indents[indent - 2]);
1446: indent -= 4;
1447: uncond = 0;
1448: }
1449:
1450: if (indent != 2)
1451: abort ();
1452:
1453: if (uncond)
1454: return;
1455:
1456: if (afterward)
1457: {
1458: change_state (prevpos, afterward->position, 2);
1459: printf (" goto L%d;\n", afterward->number);
1460: }
1461: else
1462: printf (" goto ret0;\n");
1463: }
1464:
1465: static void
1466: print_code (code)
1467: enum rtx_code code;
1468: {
1469: register char *p1;
1470: for (p1 = GET_RTX_NAME (code); *p1; p1++)
1471: {
1472: if (*p1 >= 'a' && *p1 <= 'z')
1473: putchar (*p1 + 'A' - 'a');
1474: else
1475: putchar (*p1);
1476: }
1477: }
1478:
1479: static int
1480: same_codes (p, code)
1481: register struct decision *p;
1482: register enum rtx_code code;
1483: {
1484: for (; p; p = p->next)
1485: if (p->code != code)
1486: return 0;
1487:
1488: return 1;
1489: }
1490:
1491: static void
1492: clear_codes (p)
1493: register struct decision *p;
1494: {
1495: for (; p; p = p->next)
1496: p->ignore_code = 1;
1497: }
1498:
1499: static int
1500: same_modes (p, mode)
1501: register struct decision *p;
1502: register enum machine_mode mode;
1503: {
1504: for (; p; p = p->next)
1505: if ((p->enforce_mode ? p->mode : VOIDmode) != mode)
1506: return 0;
1507:
1508: return 1;
1509: }
1510:
1511: static void
1512: clear_modes (p)
1513: register struct decision *p;
1514: {
1515: for (; p; p = p->next)
1516: p->enforce_mode = 0;
1517: }
1518:
1519: /* Write out the decision tree starting at TREE for a subroutine of type TYPE.
1520:
1521: PREVPOS is the position at the node that branched to this node.
1522:
1523: INITIAL is nonzero if this is the first node we are writing in a subroutine.
1524:
1525: If all nodes are false, branch to the node AFTERWARD. */
1526:
1527: static void
1528: write_tree (tree, prevpos, afterward, initial, type)
1529: struct decision *tree;
1530: char *prevpos;
1531: struct decision *afterward;
1532: int initial;
1533: enum routine_type type;
1534: {
1535: register struct decision *p;
1536: char *name_prefix = (type == SPLIT ? "split" : "recog");
1537: char *call_suffix = (type == SPLIT ? "" : ", pnum_clobbers");
1538:
1539: if (! initial && tree->subroutine_number > 0)
1540: {
1541: printf (" L%d:\n", tree->number);
1542:
1543: if (afterward)
1544: {
1545: printf (" tem = %s_%d (x0, insn%s);\n",
1546: name_prefix, tree->subroutine_number, call_suffix);
1547: if (type == SPLIT)
1548: printf (" if (tem != 0) return tem;\n");
1549: else
1550: printf (" if (tem >= 0) return tem;\n");
1551: change_state (tree->position, afterward->position, 2);
1552: printf (" goto L%d;\n", afterward->number);
1553: }
1554: else
1555: printf (" return %s_%d (x0, insn%s);\n",
1556: name_prefix, tree->subroutine_number, call_suffix);
1557: return;
1558: }
1559:
1560: write_tree_1 (tree, prevpos, afterward, type);
1561:
1562: for (p = tree; p; p = p->next)
1563: if (p->success.first)
1564: write_tree (p->success.first, p->position,
1565: p->afterward ? p->afterward : afterward, 0, type);
1566: }
1567:
1568:
1569: /* Assuming that the state of argument is denoted by OLDPOS, take whatever
1570: actions are necessary to move to NEWPOS.
1571:
1572: INDENT says how many blanks to place at the front of lines. */
1573:
1574: static void
1575: change_state (oldpos, newpos, indent)
1576: char *oldpos;
1577: char *newpos;
1578: int indent;
1579: {
1580: int odepth = strlen (oldpos);
1581: int depth = odepth;
1582: int ndepth = strlen (newpos);
1583:
1584: /* Pop up as many levels as necessary. */
1585:
1586: while (strncmp (oldpos, newpos, depth))
1587: --depth;
1588:
1589: /* Go down to desired level. */
1590:
1591: while (depth < ndepth)
1592: {
1593: if (newpos[depth] >= 'a' && newpos[depth] <= 'z')
1594: printf ("%sx%d = XVECEXP (x%d, 0, %d);\n",
1595: indents[indent], depth + 1, depth, newpos[depth] - 'a');
1596: else
1597: printf ("%sx%d = XEXP (x%d, %c);\n",
1598: indents[indent], depth + 1, depth, newpos[depth]);
1599: ++depth;
1600: }
1601: }
1602:
1603: static char *
1604: copystr (s1)
1605: char *s1;
1606: {
1607: register char *tem;
1608:
1609: if (s1 == 0)
1610: return 0;
1611:
1612: tem = (char *) xmalloc (strlen (s1) + 1);
1613: strcpy (tem, s1);
1614:
1615: return tem;
1616: }
1617:
1618: static void
1619: mybzero (b, length)
1620: register char *b;
1621: register unsigned length;
1622: {
1623: while (length-- > 0)
1624: *b++ = 0;
1625: }
1626:
1627: static void
1628: mybcopy (in, out, length)
1629: register char *in, *out;
1630: register unsigned length;
1631: {
1632: while (length-- > 0)
1633: *out++ = *in++;
1634: }
1635:
1636: static char *
1637: concat (s1, s2)
1638: char *s1, *s2;
1639: {
1640: register char *tem;
1641:
1642: if (s1 == 0)
1643: return s2;
1644: if (s2 == 0)
1645: return s1;
1646:
1647: tem = (char *) xmalloc (strlen (s1) + strlen (s2) + 2);
1648: strcpy (tem, s1);
1649: strcat (tem, " ");
1650: strcat (tem, s2);
1651:
1652: return tem;
1653: }
1654:
1655: char *
1656: xrealloc (ptr, size)
1657: char *ptr;
1658: unsigned size;
1659: {
1660: char *result = (char *) realloc (ptr, size);
1661: if (!result)
1662: fatal ("virtual memory exhausted");
1663: return result;
1664: }
1665:
1666: char *
1667: xmalloc (size)
1668: unsigned size;
1669: {
1670: register char *val = (char *) malloc (size);
1671:
1672: if (val == 0)
1673: fatal ("virtual memory exhausted");
1674: return val;
1675: }
1676:
1677: static void
1678: fatal (s)
1679: char *s;
1680: {
1681: fprintf (stderr, "genrecog: ");
1682: fprintf (stderr, s);
1683: fprintf (stderr, "\n");
1684: fprintf (stderr, "after %d definitions\n", next_index);
1685: exit (FATAL_EXIT_CODE);
1686: }
1687:
1688: /* More 'friendly' abort that prints the line and file.
1689: config.h can #define abort fancy_abort if you like that sort of thing. */
1690:
1691: void
1692: fancy_abort ()
1693: {
1694: fatal ("Internal gcc abort.");
1695: }
1696:
1697: int
1698: main (argc, argv)
1699: int argc;
1700: char **argv;
1701: {
1702: rtx desc;
1703: struct decision_head recog_tree;
1704: struct decision_head split_tree;
1705: FILE *infile;
1706: register int c;
1707:
1708: obstack_init (rtl_obstack);
1709: recog_tree.first = recog_tree.last = split_tree.first = split_tree.last = 0;
1710:
1711: if (argc <= 1)
1712: fatal ("No input file name.");
1713:
1714: infile = fopen (argv[1], "r");
1715: if (infile == 0)
1716: {
1717: perror (argv[1]);
1718: exit (FATAL_EXIT_CODE);
1719: }
1720:
1721: init_rtl ();
1722: next_insn_code = 0;
1723: next_index = 0;
1724:
1725: printf ("/* Generated automatically by the program `genrecog'\n\
1726: from the machine description file `md'. */\n\n");
1727:
1728: printf ("#include \"config.h\"\n");
1729: printf ("#include \"rtl.h\"\n");
1730: printf ("#include \"insn-config.h\"\n");
1731: printf ("#include \"recog.h\"\n");
1732: printf ("#include \"real.h\"\n");
1733: printf ("#include \"output.h\"\n");
1734: printf ("#include \"flags.h\"\n");
1735: printf ("\n");
1736:
1737: /* Read the machine description. */
1738:
1739: while (1)
1740: {
1741: c = read_skip_spaces (infile);
1742: if (c == EOF)
1743: break;
1744: ungetc (c, infile);
1745:
1746: desc = read_rtx (infile);
1747: if (GET_CODE (desc) == DEFINE_INSN)
1748: recog_tree = merge_trees (recog_tree,
1749: make_insn_sequence (desc, RECOG));
1750: else if (GET_CODE (desc) == DEFINE_SPLIT)
1751: split_tree = merge_trees (split_tree,
1752: make_insn_sequence (desc, SPLIT));
1753: if (GET_CODE (desc) == DEFINE_PEEPHOLE
1754: || GET_CODE (desc) == DEFINE_EXPAND)
1755: next_insn_code++;
1756: next_index++;
1757: }
1758:
1759: printf ("\n\
1760: /* `recog' contains a decision tree\n\
1761: that recognizes whether the rtx X0 is a valid instruction.\n\
1762: \n\
1763: recog returns -1 if the rtx is not valid.\n\
1764: If the rtx is valid, recog returns a nonnegative number\n\
1765: which is the insn code number for the pattern that matched.\n");
1766: printf (" This is the same as the order in the machine description of\n\
1767: the entry that matched. This number can be used as an index into\n\
1768: entry that matched. This number can be used as an index into various\n\
1769: insn_* tables, such as insn_templates, insn_outfun, and insn_n_operands\n\
1770: (found in insn-output.c).\n\n");
1771: printf (" The third argument to recog is an optional pointer to an int.\n\
1772: If present, recog will accept a pattern if it matches except for\n\
1773: missing CLOBBER expressions at the end. In that case, the value\n\
1774: pointed to by the optional pointer will be set to the number of\n\
1775: CLOBBERs that need to be added (it should be initialized to zero by\n\
1776: the caller). If it is set nonzero, the caller should allocate a\n\
1777: PARALLEL of the appropriate size, copy the initial entries, and call\n\
1778: add_clobbers (found in insn-emit.c) to fill in the CLOBBERs.");
1779:
1780: if (split_tree.first)
1781: printf ("\n\n The function split_insns returns 0 if the rtl could not\n\
1782: be split or the split rtl in a SEQUENCE if it can be.");
1783:
1784: printf ("*/\n\n");
1785:
1786: printf ("rtx recog_operand[MAX_RECOG_OPERANDS];\n\n");
1787: printf ("rtx *recog_operand_loc[MAX_RECOG_OPERANDS];\n\n");
1788: printf ("rtx *recog_dup_loc[MAX_DUP_OPERANDS];\n\n");
1789: printf ("char recog_dup_num[MAX_DUP_OPERANDS];\n\n");
1790: printf ("#define operands recog_operand\n\n");
1791:
1792: next_subroutine_number = 0;
1793: break_out_subroutines (recog_tree, RECOG, 1);
1794: write_subroutine (recog_tree.first, RECOG);
1795:
1796: next_subroutine_number = 0;
1797: break_out_subroutines (split_tree, SPLIT, 1);
1798: write_subroutine (split_tree.first, SPLIT);
1799:
1800: fflush (stdout);
1801: exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
1802: /* NOTREACHED */
1803: return 0;
1804: }
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