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1.1 root 1: /* Generate code from machine description to recognize rtl as insns.
2: Copyright (C) 1987, 1988, 1992 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>
1.1.1.3 ! root 49: #include "hconfig.h"
1.1 root 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 ();
1.1.1.2 root 60: extern rtx read_rtx ();
1.1 root 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) */
1.1.1.3 ! root 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) */
1.1 root 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_operation", {EQ, NE, LE, LT, GE, LT, 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 int try_merge_1 ();
168: static int no_same_mode ();
169: static int same_codes ();
170: static int same_modes ();
171: char *xmalloc ();
172: static struct decision *add_to_sequence ();
173: static struct decision_head merge_trees ();
174: static struct decision *try_merge_2 ();
175: static void write_subroutine ();
176: static void print_code ();
177: static void clear_codes ();
178: static void clear_modes ();
179: static void change_state ();
180: static void write_tree ();
181: static char *copystr ();
182: static char *concat ();
183: static void fatal ();
184: void fancy_abort ();
185: static void mybzero ();
186: static void mybcopy ();
187:
188: /* Construct and return a sequence of decisions
189: that will recognize INSN.
190:
191: TYPE says what type of routine we are recognizing (RECOG or SPLIT). */
192:
193: static struct decision_head
194: make_insn_sequence (insn, type)
195: rtx insn;
196: enum routine_type type;
197: {
198: rtx x;
199: char *c_test = XSTR (insn, type == RECOG ? 2 : 1);
200: struct decision *last;
201: struct decision_head head;
202:
203: if (XVECLEN (insn, type == RECOG) == 1)
204: x = XVECEXP (insn, type == RECOG, 0);
205: else
206: {
207: x = rtx_alloc (PARALLEL);
208: XVEC (x, 0) = XVEC (insn, type == RECOG);
209: PUT_MODE (x, VOIDmode);
210: }
211:
212: last = add_to_sequence (x, &head, "");
213:
214: if (c_test[0])
215: last->c_test = c_test;
216: last->insn_code_number = next_insn_code;
217: last->num_clobbers_to_add = 0;
218:
219: /* If this is not a DEFINE_SPLIT and X is a PARALLEL, see if it ends with a
220: group of CLOBBERs of (hard) registers or MATCH_SCRATCHes. If so, set up
221: to recognize the pattern without these CLOBBERs. */
222:
223: if (type == RECOG && GET_CODE (x) == PARALLEL)
224: {
225: int i;
226:
227: for (i = XVECLEN (x, 0); i > 0; i--)
228: if (GET_CODE (XVECEXP (x, 0, i - 1)) != CLOBBER
229: || (GET_CODE (XEXP (XVECEXP (x, 0, i - 1), 0)) != REG
230: && GET_CODE (XEXP (XVECEXP (x, 0, i - 1), 0)) != MATCH_SCRATCH))
231: break;
232:
233: if (i != XVECLEN (x, 0))
234: {
235: rtx new;
236: struct decision_head clobber_head;
237:
238: if (i == 1)
239: new = XVECEXP (x, 0, 0);
240: else
241: {
242: int j;
243:
244: new = rtx_alloc (PARALLEL);
245: XVEC (new, 0) = rtvec_alloc (i);
246: for (j = i - 1; j >= 0; j--)
247: XVECEXP (new, 0, j) = XVECEXP (x, 0, j);
248: }
249:
250: last = add_to_sequence (new, &clobber_head, "");
251:
252: if (c_test[0])
253: last->c_test = c_test;
254: last->insn_code_number = next_insn_code;
255: last->num_clobbers_to_add = XVECLEN (x, 0) - i;
256:
257: head = merge_trees (head, clobber_head);
258: }
259: }
260:
261: next_insn_code++;
262:
263: if (type == SPLIT)
264: /* Define the subroutine we will call below and emit in genemit. */
265: printf ("extern rtx gen_split_%d ();\n", last->insn_code_number);
266:
267: return head;
268: }
269:
270: /* Create a chain of nodes to verify that an rtl expression matches
271: PATTERN.
272:
273: LAST is a pointer to the listhead in the previous node in the chain (or
274: in the calling function, for the first node).
275:
276: POSITION is the string representing the current position in the insn.
277:
278: A pointer to the final node in the chain is returned. */
279:
280: static struct decision *
281: add_to_sequence (pattern, last, position)
282: rtx pattern;
283: struct decision_head *last;
284: char *position;
285: {
286: register RTX_CODE code;
287: register struct decision *new
288: = (struct decision *) xmalloc (sizeof (struct decision));
289: struct decision *this;
290: char *newpos;
291: register char *fmt;
292: register int i;
293: int depth = strlen (position);
294: int len;
295:
296: if (depth > max_depth)
297: max_depth = depth;
298:
299: new->number = next_number++;
300: new->position = copystr (position);
301: new->ignore_code = 0;
302: new->ignore_mode = 0;
303: new->enforce_mode = 1;
304: new->retest_code = new->retest_mode = 0;
305: new->veclen = 0;
306: new->test_elt_zero_int = 0;
307: new->test_elt_one_int = 0;
1.1.1.3 ! root 308: new->test_elt_zero_wide = 0;
1.1 root 309: new->elt_zero_int = 0;
310: new->elt_one_int = 0;
1.1.1.3 ! root 311: new->elt_zero_wide = 0;
1.1 root 312: new->tests = 0;
313: new->pred = -1;
314: new->c_test = 0;
315: new->success.first = new->success.last = 0;
316: new->insn_code_number = -1;
317: new->num_clobbers_to_add = 0;
318: new->next = 0;
319: new->prev = 0;
320: new->afterward = 0;
321: new->opno = -1;
322: new->dupno = -1;
323: new->label_needed = 0;
324: new->subroutine_number = 0;
325:
326: this = new;
327:
328: last->first = last->last = new;
329:
330: newpos = (char *) alloca (depth + 2);
331: strcpy (newpos, position);
332: newpos[depth + 1] = 0;
333:
334: restart:
335:
336: new->mode = GET_MODE (pattern);
337: new->code = code = GET_CODE (pattern);
338:
339: switch (code)
340: {
341: case MATCH_OPERAND:
342: case MATCH_SCRATCH:
343: case MATCH_OPERATOR:
344: case MATCH_PARALLEL:
345: new->opno = XINT (pattern, 0);
346: new->code = (code == MATCH_PARALLEL ? PARALLEL : UNKNOWN);
347: new->enforce_mode = 0;
348:
349: if (code == MATCH_SCRATCH)
350: new->tests = "scratch_operand";
351: else
352: new->tests = XSTR (pattern, 1);
353:
354: if (*new->tests == 0)
355: new->tests = 0;
356:
357: /* See if we know about this predicate and save its number. If we do,
358: and it only accepts one code, note that fact. The predicate
359: `const_int_operand' only tests for a CONST_INT, so if we do so we
360: can avoid calling it at all.
361:
362: Finally, if we know that the predicate does not allow CONST_INT, we
363: know that the only way the predicate can match is if the modes match
364: (here we use the kluge of relying on the fact that "address_operand"
365: accepts CONST_INT; otherwise, it would have to be a special case),
366: so we can test the mode (but we need not). This fact should
367: considerably simplify the generated code. */
368:
369: if (new->tests)
370: for (i = 0; i < NUM_KNOWN_PREDS; i++)
371: if (! strcmp (preds[i].name, new->tests))
372: {
373: int j;
374: int allows_const_int = 0;
375:
376: new->pred = i;
377:
378: if (preds[i].codes[1] == 0 && new->code == UNKNOWN)
379: {
380: new->code = preds[i].codes[0];
381: if (! strcmp ("const_int_operand", new->tests))
382: new->tests = 0, new->pred = -1;
383: }
384:
385: for (j = 0; j < NUM_RTX_CODE && preds[i].codes[j] != 0; j++)
386: if (preds[i].codes[j] == CONST_INT)
387: allows_const_int = 1;
388:
389: if (! allows_const_int)
390: new->enforce_mode = new->ignore_mode= 1;
391:
392: break;
393: }
394:
395: if (code == MATCH_OPERATOR || code == MATCH_PARALLEL)
396: {
397: for (i = 0; i < XVECLEN (pattern, 2); i++)
398: {
399: newpos[depth] = i + (code == MATCH_OPERATOR ? '0': 'a');
400: new = add_to_sequence (XVECEXP (pattern, 2, i),
401: &new->success, newpos);
402: }
403: }
404:
405: return new;
406:
407: case MATCH_OP_DUP:
408: new->opno = XINT (pattern, 0);
409: new->dupno = XINT (pattern, 0);
410: new->code = UNKNOWN;
411: new->tests = 0;
412: for (i = 0; i < XVECLEN (pattern, 1); i++)
413: {
414: newpos[depth] = i + '0';
415: new = add_to_sequence (XVECEXP (pattern, 1, i),
416: &new->success, newpos);
417: }
418: return new;
419:
420: case MATCH_DUP:
1.1.1.3 ! root 421: case MATCH_PAR_DUP:
1.1 root 422: new->dupno = XINT (pattern, 0);
423: new->code = UNKNOWN;
424: new->enforce_mode = 0;
425: return new;
426:
427: case ADDRESS:
428: pattern = XEXP (pattern, 0);
429: goto restart;
430:
431: case SET:
432: newpos[depth] = '0';
433: new = add_to_sequence (SET_DEST (pattern), &new->success, newpos);
434: this->success.first->enforce_mode = 1;
435: newpos[depth] = '1';
436: new = add_to_sequence (SET_SRC (pattern), &new->success, newpos);
437:
438: /* If set are setting CC0 from anything other than a COMPARE, we
439: must enforce the mode so that we do not produce ambiguous insns. */
440: if (GET_CODE (SET_DEST (pattern)) == CC0
441: && GET_CODE (SET_SRC (pattern)) != COMPARE)
442: this->success.first->enforce_mode = 1;
443: return new;
444:
445: case SIGN_EXTEND:
446: case ZERO_EXTEND:
447: case STRICT_LOW_PART:
448: newpos[depth] = '0';
449: new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
450: this->success.first->enforce_mode = 1;
451: return new;
452:
453: case SUBREG:
454: this->test_elt_one_int = 1;
455: this->elt_one_int = XINT (pattern, 1);
456: newpos[depth] = '0';
457: new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
458: this->success.first->enforce_mode = 1;
459: return new;
460:
461: case ZERO_EXTRACT:
462: case SIGN_EXTRACT:
463: newpos[depth] = '0';
464: new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
465: this->success.first->enforce_mode = 1;
466: newpos[depth] = '1';
467: new = add_to_sequence (XEXP (pattern, 1), &new->success, newpos);
468: newpos[depth] = '2';
469: new = add_to_sequence (XEXP (pattern, 2), &new->success, newpos);
470: return new;
471:
472: case EQ: case NE: case LE: case LT: case GE: case GT:
473: case LEU: case LTU: case GEU: case GTU:
474: /* If the first operand is (cc0), we don't have to do anything
475: special. */
476: if (GET_CODE (XEXP (pattern, 0)) == CC0)
477: break;
478:
479: /* ... fall through ... */
480:
481: case COMPARE:
482: /* Enforce the mode on the first operand to avoid ambiguous insns. */
483: newpos[depth] = '0';
484: new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
485: this->success.first->enforce_mode = 1;
486: newpos[depth] = '1';
487: new = add_to_sequence (XEXP (pattern, 1), &new->success, newpos);
488: return new;
489: }
490:
491: fmt = GET_RTX_FORMAT (code);
492: len = GET_RTX_LENGTH (code);
493: for (i = 0; i < len; i++)
494: {
495: newpos[depth] = '0' + i;
496: if (fmt[i] == 'e' || fmt[i] == 'u')
497: new = add_to_sequence (XEXP (pattern, i), &new->success, newpos);
498: else if (fmt[i] == 'i' && i == 0)
499: {
500: this->test_elt_zero_int = 1;
501: this->elt_zero_int = XINT (pattern, i);
502: }
503: else if (fmt[i] == 'i' && i == 1)
504: {
505: this->test_elt_one_int = 1;
506: this->elt_one_int = XINT (pattern, i);
507: }
1.1.1.3 ! root 508: else if (fmt[i] == 'w' && i == 0)
! 509: {
! 510: this->test_elt_zero_wide = 1;
! 511: this->elt_zero_wide = XWINT (pattern, i);
! 512: }
1.1 root 513: else if (fmt[i] == 'E')
514: {
515: register int j;
516: /* We do not handle a vector appearing as other than
517: the first item, just because nothing uses them
518: and by handling only the special case
519: we can use one element in newpos for either
520: the item number of a subexpression
521: or the element number in a vector. */
522: if (i != 0)
523: abort ();
524: this->veclen = XVECLEN (pattern, i);
525: for (j = 0; j < XVECLEN (pattern, i); j++)
526: {
527: newpos[depth] = 'a' + j;
528: new = add_to_sequence (XVECEXP (pattern, i, j),
529: &new->success, newpos);
530: }
531: }
532: else if (fmt[i] != '0')
533: abort ();
534: }
535: return new;
536: }
537:
538: /* Return 1 if we can prove that there is no RTL that can match both
539: D1 and D2. Otherwise, return 0 (it may be that there is an RTL that
540: can match both or just that we couldn't prove there wasn't such an RTL).
541:
542: TOPLEVEL is non-zero if we are to only look at the top level and not
543: recursively descend. */
544:
545: static int
546: not_both_true (d1, d2, toplevel)
547: struct decision *d1, *d2;
548: int toplevel;
549: {
550: struct decision *p1, *p2;
551:
552: /* If they are both to test modes and the modes are different, they aren't
553: both true. Similarly for codes, integer elements, and vector lengths. */
554:
555: if ((d1->enforce_mode && d2->enforce_mode
556: && d1->mode != VOIDmode && d2->mode != VOIDmode && d1->mode != d2->mode)
557: || (d1->code != UNKNOWN && d2->code != UNKNOWN && d1->code != d2->code)
558: || (d1->test_elt_zero_int && d2->test_elt_zero_int
559: && d1->elt_zero_int != d2->elt_zero_int)
560: || (d1->test_elt_one_int && d2->test_elt_one_int
561: && d1->elt_one_int != d2->elt_one_int)
1.1.1.3 ! root 562: || (d1->test_elt_zero_wide && d2->test_elt_zero_wide
! 563: && d1->elt_zero_wide != d2->elt_zero_wide)
1.1 root 564: || (d1->veclen && d2->veclen && d1->veclen != d2->veclen))
565: return 1;
566:
567: /* If either is a wild-card MATCH_OPERAND without a predicate, it can match
568: absolutely anything, so we can't say that no intersection is possible.
569: This case is detected by having a zero TESTS field with a code of
570: UNKNOWN. */
571:
572: if ((d1->tests == 0 && d1->code == UNKNOWN)
573: || (d2->tests == 0 && d2->code == UNKNOWN))
574: return 0;
575:
576: /* If either has a predicate that we know something about, set things up so
577: that D1 is the one that always has a known predicate. Then see if they
578: have any codes in common. */
579:
580: if (d1->pred >= 0 || d2->pred >= 0)
581: {
582: int i, j;
583:
584: if (d2->pred >= 0)
585: p1 = d1, d1 = d2, d2 = p1;
586:
587: /* If D2 tests an explicit code, see if it is in the list of valid codes
588: for D1's predicate. */
589: if (d2->code != UNKNOWN)
590: {
1.1.1.3 ! root 591: for (i = 0; i < NUM_RTX_CODE && preds[d1->pred].codes[i] != 0; i++)
1.1 root 592: if (preds[d1->pred].codes[i] == d2->code)
593: break;
594:
595: if (preds[d1->pred].codes[i] == 0)
596: return 1;
597: }
598:
599: /* Otherwise see if the predicates have any codes in common. */
600:
601: else if (d2->pred >= 0)
602: {
1.1.1.3 ! root 603: for (i = 0; i < NUM_RTX_CODE && preds[d1->pred].codes[i] != 0; i++)
1.1 root 604: {
605: for (j = 0; j < NUM_RTX_CODE; j++)
606: if (preds[d2->pred].codes[j] == 0
607: || preds[d2->pred].codes[j] == preds[d1->pred].codes[i])
608: break;
609:
610: if (preds[d2->pred].codes[j] != 0)
611: break;
612: }
613:
614: if (preds[d1->pred].codes[i] == 0)
615: return 1;
616: }
617: }
618:
619: /* If we got here, we can't prove that D1 and D2 cannot both be true.
620: If we are only to check the top level, return 0. Otherwise, see if
621: we can prove that all choices in both successors are mutually
622: exclusive. If either does not have any successors, we can't prove
623: they can't both be true. */
624:
625: if (toplevel || d1->success.first == 0 || d2->success.first == 0)
626: return 0;
627:
628: for (p1 = d1->success.first; p1; p1 = p1->next)
629: for (p2 = d2->success.first; p2; p2 = p2->next)
630: if (! not_both_true (p1, p2, 0))
631: return 0;
632:
633: return 1;
634: }
635:
636: /* Assuming that we can reorder all the alternatives at a specific point in
637: the tree (see discussion in merge_trees), we would prefer an ordering of
638: nodes where groups of consecutive nodes test the same mode and, within each
639: mode, groups of nodes test the same code. With this order, we can
640: construct nested switch statements, the inner one to test the code and
641: the outer one to test the mode.
642:
643: We would like to list nodes testing for specific codes before those
644: that test predicates to avoid unnecessary function calls. Similarly,
1.1.1.2 root 645: tests for specific modes should precede nodes that allow any mode.
1.1 root 646:
647: This function returns the merit (with 0 being the best) of inserting
648: a test involving the specified MODE and CODE after node P. If P is
649: zero, we are to determine the merit of inserting the test at the front
650: of the list. */
651:
652: static int
653: position_merit (p, mode, code)
654: struct decision *p;
655: enum machine_mode mode;
656: RTX_CODE code;
657: {
658: enum machine_mode p_mode;
659:
660: /* The only time the front of the list is anything other than the worst
661: position is if we are testing a mode that isn't VOIDmode. */
662: if (p == 0)
663: return mode == VOIDmode ? 3 : 2;
664:
665: p_mode = p->enforce_mode ? p->mode : VOIDmode;
666:
667: /* The best case is if the codes and modes both match. */
668: if (p_mode == mode && p->code== code)
669: return 0;
670:
671: /* If the codes don't match, the next best case is if the modes match.
672: In that case, the best position for this node depends on whether
673: we are testing for a specific code or not. If we are, the best place
674: is after some other test for an explicit code and our mode or after
675: the last test in the previous mode if every test in our mode is for
676: an unknown code.
677:
678: If we are testing for UNKNOWN, then the next best case is at the end of
679: our mode. */
680:
681: if ((code != UNKNOWN
682: && ((p_mode == mode && p->code != UNKNOWN)
683: || (p_mode != mode && p->next
684: && (p->next->enforce_mode ? p->next->mode : VOIDmode) == mode
685: && (p->next->code == UNKNOWN))))
686: || (code == UNKNOWN && p_mode == mode
687: && (p->next == 0
688: || (p->next->enforce_mode ? p->next->mode : VOIDmode) != mode)))
689: return 1;
690:
691: /* The third best case occurs when nothing is testing MODE. If MODE
692: is not VOIDmode, then the third best case is after something of any
693: mode that is not VOIDmode. If we are testing VOIDmode, the third best
694: place is the end of the list. */
695:
696: if (p_mode != mode
697: && ((mode != VOIDmode && p_mode != VOIDmode)
698: || (mode == VOIDmode && p->next == 0)))
699: return 2;
700:
701: /* Otherwise, we have the worst case. */
702: return 3;
703: }
704:
705: /* Merge two decision tree listheads OLDH and ADDH,
706: modifying OLDH destructively, and return the merged tree. */
707:
708: static struct decision_head
709: merge_trees (oldh, addh)
710: register struct decision_head oldh, addh;
711: {
712: struct decision *add, *next;
713:
714: if (oldh.first == 0)
715: return addh;
716:
717: if (addh.first == 0)
718: return oldh;
719:
720: /* If we are adding things at different positions, something is wrong. */
721: if (strcmp (oldh.first->position, addh.first->position))
722: abort ();
723:
724: for (add = addh.first; add; add = next)
725: {
726: enum machine_mode add_mode = add->enforce_mode ? add->mode : VOIDmode;
727: struct decision *best_position = 0;
728: int best_merit = 4;
729: struct decision *old;
730:
731: next = add->next;
732:
733: /* The semantics of pattern matching state that the tests are done in
734: the order given in the MD file so that if an insn matches two
735: patterns, the first one will be used. However, in practice, most,
736: if not all, patterns are unambiguous so that their order is
737: independent. In that case, we can merge identical tests and
738: group all similar modes and codes together.
739:
740: Scan starting from the end of OLDH until we reach a point
741: where we reach the head of the list or where we pass a pattern
742: that could also be true if NEW is true. If we find an identical
743: pattern, we can merge them. Also, record the last node that tests
744: the same code and mode and the last one that tests just the same mode.
745:
746: If we have no match, place NEW after the closest match we found. */
747:
748: for (old = oldh.last; old; old = old->prev)
749: {
750: int our_merit;
751:
752: /* If we don't have anything to test except an additional test,
753: do not consider the two nodes equal. If we did, the test below
754: would cause an infinite recursion. */
755: if (old->tests == 0 && old->test_elt_zero_int == 0
756: && old->test_elt_one_int == 0 && old->veclen == 0
1.1.1.3 ! root 757: && old->test_elt_zero_wide == 0
1.1 root 758: && old->dupno == -1 && old->mode == VOIDmode
759: && old->code == UNKNOWN
760: && (old->c_test != 0 || add->c_test != 0))
761: ;
762:
763: else if ((old->tests == add->tests
764: || (old->pred >= 0 && old->pred == add->pred)
765: || (old->tests && add->tests
766: && !strcmp (old->tests, add->tests)))
1.1.1.3 ! root 767: && old->test_elt_zero_int == add->test_elt_zero_int
! 768: && old->elt_zero_int == add->elt_zero_int
! 769: && old->test_elt_one_int == add->test_elt_one_int
! 770: && old->elt_one_int == add->elt_one_int
! 771: && old->test_elt_zero_wide == add->test_elt_zero_wide
! 772: && old->elt_zero_wide == add->elt_zero_wide
! 773: && old->veclen == add->veclen
! 774: && old->dupno == add->dupno
! 775: && old->opno == add->opno
! 776: && old->code == add->code
! 777: && old->enforce_mode == add->enforce_mode
! 778: && old->mode == add->mode)
1.1 root 779: {
780: /* If the additional test is not the same, split both nodes
781: into nodes that just contain all things tested before the
782: additional test and nodes that contain the additional test
783: and actions when it is true. This optimization is important
784: because of the case where we have almost identical patterns
785: with different tests on target flags. */
786:
787: if (old->c_test != add->c_test
788: && ! (old->c_test && add->c_test
789: && !strcmp (old->c_test, add->c_test)))
790: {
791: if (old->insn_code_number >= 0 || old->opno >= 0)
792: {
793: struct decision *split
794: = (struct decision *) xmalloc (sizeof (struct decision));
795:
796: mybcopy (old, split, sizeof (struct decision));
797:
798: old->success.first = old->success.last = split;
799: old->c_test = 0;
800: old->opno = -1;
801: old->insn_code_number = -1;
802: old->num_clobbers_to_add = 0;
803:
804: split->number = next_number++;
805: split->next = split->prev = 0;
806: split->mode = VOIDmode;
807: split->code = UNKNOWN;
808: split->veclen = 0;
809: split->test_elt_zero_int = 0;
810: split->test_elt_one_int = 0;
1.1.1.3 ! root 811: split->test_elt_zero_wide = 0;
1.1 root 812: split->tests = 0;
813: split->pred = -1;
1.1.1.3 ! root 814: split->dupno = -1;
1.1 root 815: }
816:
817: if (add->insn_code_number >= 0 || add->opno >= 0)
818: {
819: struct decision *split
820: = (struct decision *) xmalloc (sizeof (struct decision));
821:
822: mybcopy (add, split, sizeof (struct decision));
823:
824: add->success.first = add->success.last = split;
825: add->c_test = 0;
826: add->opno = -1;
827: add->insn_code_number = -1;
828: add->num_clobbers_to_add = 0;
829:
830: split->number = next_number++;
831: split->next = split->prev = 0;
832: split->mode = VOIDmode;
833: split->code = UNKNOWN;
834: split->veclen = 0;
835: split->test_elt_zero_int = 0;
836: split->test_elt_one_int = 0;
1.1.1.3 ! root 837: split->test_elt_zero_wide = 0;
1.1 root 838: split->tests = 0;
839: split->pred = -1;
1.1.1.3 ! root 840: split->dupno = -1;
1.1 root 841: }
842: }
843:
844: if (old->insn_code_number >= 0 && add->insn_code_number >= 0)
845: {
846: /* If one node is for a normal insn and the second is
847: for the base insn with clobbers stripped off, the
848: second node should be ignored. */
849:
850: if (old->num_clobbers_to_add == 0
851: && add->num_clobbers_to_add > 0)
852: /* Nothing to do here. */
853: ;
854: else if (old->num_clobbers_to_add > 0
855: && add->num_clobbers_to_add == 0)
856: {
857: /* In this case, replace OLD with ADD. */
858: old->insn_code_number = add->insn_code_number;
859: old->num_clobbers_to_add = 0;
860: }
861: else
862: fatal ("Two actions at one point in tree");
863: }
864:
865: if (old->insn_code_number == -1)
866: old->insn_code_number = add->insn_code_number;
867: old->success = merge_trees (old->success, add->success);
868: add = 0;
869: break;
870: }
871:
872: /* Unless we have already found the best possible insert point,
873: see if this position is better. If so, record it. */
874:
875: if (best_merit != 0
876: && ((our_merit = position_merit (old, add_mode, add->code))
877: < best_merit))
878: best_merit = our_merit, best_position = old;
879:
880: if (! not_both_true (old, add, 0))
881: break;
882: }
883:
884: /* If ADD was duplicate, we are done. */
885: if (add == 0)
886: continue;
887:
888: /* Otherwise, find the best place to insert ADD. Normally this is
889: BEST_POSITION. However, if we went all the way to the top of
890: the list, it might be better to insert at the top. */
891:
892: if (best_position == 0)
893: abort ();
894:
1.1.1.3 ! root 895: if (old == 0
! 896: && position_merit (NULL_PTR, add_mode, add->code) < best_merit)
1.1 root 897: {
898: add->prev = 0;
899: add->next = oldh.first;
900: oldh.first->prev = add;
901: oldh.first = add;
902: }
903:
904: else
905: {
906: add->prev = best_position;
907: add->next = best_position->next;
908: best_position->next = add;
909: if (best_position == oldh.last)
910: oldh.last = add;
911: else
912: add->next->prev = add;
913: }
914: }
915:
916: return oldh;
917: }
918:
919: /* Count the number of subnodes of HEAD. If the number is high enough,
920: make the first node in HEAD start a separate subroutine in the C code
921: that is generated.
922:
923: TYPE gives the type of routine we are writing.
924:
925: INITIAL is non-zero if this is the highest-level node. We never write
926: it out here. */
927:
928: static int
929: break_out_subroutines (head, type, initial)
930: struct decision_head head;
931: enum routine_type type;
932: int initial;
933: {
934: int size = 0;
935: struct decision *node, *sub;
936:
937: for (sub = head.first; sub; sub = sub->next)
938: size += 1 + break_out_subroutines (sub->success, type, 0);
939:
940: if (size > SUBROUTINE_THRESHOLD && ! initial)
941: {
942: head.first->subroutine_number = ++next_subroutine_number;
943: write_subroutine (head.first, type);
944: size = 1;
945: }
946: return size;
947: }
948:
949: /* Write out a subroutine of type TYPE to do comparisons starting at node
950: TREE. */
951:
952: static void
953: write_subroutine (tree, type)
954: struct decision *tree;
955: enum routine_type type;
956: {
957: int i;
958:
959: if (type == SPLIT)
960: printf ("rtx\nsplit");
961: else
962: printf ("int\nrecog");
963:
964: if (tree != 0 && tree->subroutine_number > 0)
965: printf ("_%d", tree->subroutine_number);
966: else if (type == SPLIT)
967: printf ("_insns");
968:
969: printf (" (x0, insn");
970: if (type == RECOG)
971: printf (", pnum_clobbers");
972:
973: printf (")\n");
974: printf (" register rtx x0;\n rtx insn;\n");
975: if (type == RECOG)
976: printf (" int *pnum_clobbers;\n");
977:
978: printf ("{\n");
979: printf (" register rtx *ro = &recog_operand[0];\n");
980:
981: printf (" register rtx ");
982: for (i = 1; i < max_depth; i++)
983: printf ("x%d, ", i);
984:
985: printf ("x%d;\n", max_depth);
986: printf (" %s tem;\n", type == SPLIT ? "rtx" : "int");
1.1.1.3 ! root 987: write_tree (tree, "", NULL_PTR, 1, type);
1.1 root 988: printf (" ret0: return %d;\n}\n\n", type == SPLIT ? 0 : -1);
989: }
990:
991: /* This table is used to indent the recog_* functions when we are inside
992: conditions or switch statements. We only support small indentations
993: and always indent at least two spaces. */
994:
995: static char *indents[]
996: = {" ", " ", " ", " ", " ", " ", " ", " ",
997: "\t", "\t ", "\t ", "\t ", "\t ", "\t ", "\t ",
998: "\t\t", "\t\t ", "\t\t ", "\t\t ", "\t\t ", "\t\t "};
999:
1000: /* Write out C code to perform the decisions in TREE for a subroutine of
1001: type TYPE. If all of the choices fail, branch to node AFTERWARD, if
1002: non-zero, otherwise return. PREVPOS is the position of the node that
1003: branched to this test.
1004:
1005: When we merged all alternatives, we tried to set up a convenient order.
1006: Specifically, tests involving the same mode are all grouped together,
1007: followed by a group that does not contain a mode test. Within each group
1008: of the same mode, we also group tests with the same code, followed by a
1009: group that does not test a code.
1010:
1.1.1.2 root 1011: Occasionally, we cannot arbitrarily reorder the tests so that multiple
1.1 root 1012: sequence of groups as described above are present.
1013:
1014: We generate two nested switch statements, the outer statement for
1015: testing modes, and the inner switch for testing RTX codes. It is
1016: not worth optimizing cases when only a small number of modes or
1017: codes is tested, since the compiler can do that when compiling the
1018: resulting function. We do check for when every test is the same mode
1019: or code. */
1020:
1021: void
1022: write_tree_1 (tree, prevpos, afterward, type)
1023: struct decision *tree;
1024: char *prevpos;
1025: struct decision *afterward;
1026: enum routine_type type;
1027: {
1028: register struct decision *p, *p1;
1029: register int depth = tree ? strlen (tree->position) : 0;
1030: enum machine_mode switch_mode = VOIDmode;
1031: RTX_CODE switch_code = UNKNOWN;
1032: int uncond = 0;
1033: char modemap[NUM_MACHINE_MODES];
1034: char codemap[NUM_RTX_CODE];
1035: int indent = 2;
1036: int i;
1037:
1038: /* One tricky area is what is the exact state when we branch to a
1039: node's label. There are two cases where we branch: when looking at
1040: successors to a node, or when a set of tests fails.
1041:
1042: In the former case, we are always branching to the first node in a
1043: decision list and we want all required tests to be performed. We
1044: put the labels for such nodes in front of any switch or test statements.
1045: These branches are done without updating the position to that of the
1046: target node.
1047:
1048: In the latter case, we are branching to a node that is not the first
1049: node in a decision list. We have already checked that it is possible
1050: for both the node we originally tested at this level and the node we
1051: are branching to to be both match some pattern. That means that they
1052: usually will be testing the same mode and code. So it is normally safe
1053: for such labels to be inside switch statements, since the tests done
1054: by virtue of arriving at that label will usually already have been
1055: done. The exception is a branch from a node that does not test a
1056: mode or code to one that does. In such cases, we set the `retest_mode'
1057: or `retest_code' flags. That will ensure that we start a new switch
1058: at that position and put the label before the switch.
1059:
1060: The branches in the latter case must set the position to that of the
1061: target node. */
1062:
1063:
1064: printf ("\n");
1065: if (tree && tree->subroutine_number == 0)
1066: {
1067: printf (" L%d:\n", tree->number);
1068: tree->label_needed = 0;
1069: }
1070:
1071: if (tree)
1072: {
1073: change_state (prevpos, tree->position, 2);
1074: prevpos = tree->position;
1075: }
1076:
1077: for (p = tree; p; p = p->next)
1078: {
1079: enum machine_mode mode = p->enforce_mode ? p->mode : VOIDmode;
1080: int need_bracket;
1081: int wrote_bracket = 0;
1082: int inner_indent;
1083:
1084: if (p->success.first == 0 && p->insn_code_number < 0)
1085: abort ();
1086:
1087: /* Find the next alternative to p that might be true when p is true.
1088: Test that one next if p's successors fail. */
1089:
1090: for (p1 = p->next; p1 && not_both_true (p, p1, 1); p1 = p1->next)
1091: ;
1092: p->afterward = p1;
1093:
1094: if (p1)
1095: {
1096: if (mode == VOIDmode && p1->enforce_mode && p1->mode != VOIDmode)
1097: p1->retest_mode = 1;
1098: if (p->code == UNKNOWN && p1->code != UNKNOWN)
1099: p1->retest_code = 1;
1100: p1->label_needed = 1;
1101: }
1102:
1103: /* If we have a different code or mode than the last node and
1104: are in a switch on codes, we must either end the switch or
1105: go to another case. We must also end the switch if this
1106: node needs a label and to retest either the mode or code. */
1107:
1108: if (switch_code != UNKNOWN
1109: && (switch_code != p->code || switch_mode != mode
1110: || (p->label_needed && (p->retest_mode || p->retest_code))))
1111: {
1112: enum rtx_code code = p->code;
1113:
1114: /* If P is testing a predicate that we know about and we haven't
1115: seen any of the codes that are valid for the predicate, we
1116: can write a series of "case" statement, one for each possible
1117: code. Since we are already in a switch, these redundant tests
1118: are very cheap and will reduce the number of predicate called. */
1119:
1120: if (p->pred >= 0)
1121: {
1.1.1.3 ! root 1122: for (i = 0; i < NUM_RTX_CODE && preds[p->pred].codes[i] != 0; i++)
1.1 root 1123: if (codemap[(int) preds[p->pred].codes[i]])
1124: break;
1125:
1126: if (preds[p->pred].codes[i] == 0)
1127: code = MATCH_OPERAND;
1128: }
1129:
1130: if (code == UNKNOWN || codemap[(int) code]
1131: || switch_mode != mode
1132: || (p->label_needed && (p->retest_mode || p->retest_code)))
1133: {
1134: printf ("%s}\n", indents[indent - 2]);
1135: switch_code = UNKNOWN;
1136: indent -= 4;
1137: }
1138: else
1139: {
1140: if (! uncond)
1141: printf ("%sbreak;\n", indents[indent]);
1142:
1143: if (code == MATCH_OPERAND)
1144: {
1.1.1.3 ! root 1145: for (i = 0; i < NUM_RTX_CODE && preds[p->pred].codes[i] != 0; i++)
1.1 root 1146: {
1147: printf ("%scase ", indents[indent - 2]);
1148: print_code (preds[p->pred].codes[i]);
1149: printf (":\n");
1150: codemap[(int) preds[p->pred].codes[i]] = 1;
1151: }
1152: }
1153: else
1154: {
1155: printf ("%scase ", indents[indent - 2]);
1156: print_code (code);
1157: printf (":\n");
1158: codemap[(int) p->code] = 1;
1159: }
1160:
1161: switch_code = code;
1162: }
1163:
1164: uncond = 0;
1165: }
1166:
1167: /* If we were previously in a switch on modes and now have a different
1168: mode, end at least the case, and maybe end the switch if we are
1169: not testing a mode or testing a mode whose case we already saw. */
1170:
1171: if (switch_mode != VOIDmode
1172: && (switch_mode != mode || (p->label_needed && p->retest_mode)))
1173: {
1174: if (mode == VOIDmode || modemap[(int) mode]
1175: || (p->label_needed && p->retest_mode))
1176: {
1177: printf ("%s}\n", indents[indent - 2]);
1178: switch_mode = VOIDmode;
1179: indent -= 4;
1180: }
1181: else
1182: {
1183: if (! uncond)
1184: printf (" break;\n");
1185: printf (" case %smode:\n", GET_MODE_NAME (mode));
1186: switch_mode = mode;
1187: modemap[(int) mode] = 1;
1188: }
1189:
1190: uncond = 0;
1191: }
1192:
1193: /* If we are about to write dead code, something went wrong. */
1194: if (! p->label_needed && uncond)
1195: abort ();
1196:
1197: /* If we need a label and we will want to retest the mode or code at
1198: that label, write the label now. We have already ensured that
1199: things will be valid for the test. */
1200:
1201: if (p->label_needed && (p->retest_mode || p->retest_code))
1202: {
1203: printf ("%sL%d:\n", indents[indent - 2], p->number);
1204: p->label_needed = 0;
1205: }
1206:
1207: uncond = 0;
1208:
1209: /* If we are not in any switches, see if we can shortcut things
1210: by checking for identical modes and codes. */
1211:
1212: if (switch_mode == VOIDmode && switch_code == UNKNOWN)
1213: {
1214: /* If p and its alternatives all want the same mode,
1215: reject all others at once, first, then ignore the mode. */
1216:
1217: if (mode != VOIDmode && p->next && same_modes (p, mode))
1218: {
1219: printf (" if (GET_MODE (x%d) != %smode)\n",
1220: depth, GET_MODE_NAME (p->mode));
1221: if (afterward)
1222: {
1223: printf (" {\n");
1224: change_state (p->position, afterward->position, 6);
1225: printf (" goto L%d;\n }\n", afterward->number);
1226: }
1227: else
1228: printf (" goto ret0;\n");
1229: clear_modes (p);
1230: mode = VOIDmode;
1231: }
1232:
1233: /* If p and its alternatives all want the same code,
1234: reject all others at once, first, then ignore the code. */
1235:
1236: if (p->code != UNKNOWN && p->next && same_codes (p, p->code))
1237: {
1238: printf (" if (GET_CODE (x%d) != ", depth);
1239: print_code (p->code);
1240: printf (")\n");
1241: if (afterward)
1242: {
1243: printf (" {\n");
1244: change_state (p->position, afterward->position, indent + 4);
1245: printf (" goto L%d;\n }\n", afterward->number);
1246: }
1247: else
1248: printf (" goto ret0;\n");
1249: clear_codes (p);
1250: }
1251: }
1252:
1253: /* If we are not in a mode switch and we are testing for a specific
1254: mode, start a mode switch unless we have just one node or the next
1255: node is not testing a mode (we have already tested for the case of
1256: more than one mode, but all of the same mode). */
1257:
1258: if (switch_mode == VOIDmode && mode != VOIDmode && p->next != 0
1259: && p->next->enforce_mode && p->next->mode != VOIDmode)
1260: {
1261: mybzero (modemap, sizeof modemap);
1262: printf ("%sswitch (GET_MODE (x%d))\n", indents[indent], depth);
1263: printf ("%s{\n", indents[indent + 2]);
1264: indent += 4;
1265: printf ("%scase %smode:\n", indents[indent - 2],
1266: GET_MODE_NAME (mode));
1267: modemap[(int) mode] = 1;
1268: switch_mode = mode;
1269: }
1270:
1271: /* Similarly for testing codes. */
1272:
1273: if (switch_code == UNKNOWN && p->code != UNKNOWN && ! p->ignore_code
1274: && p->next != 0 && p->next->code != UNKNOWN)
1275: {
1276: mybzero (codemap, sizeof codemap);
1277: printf ("%sswitch (GET_CODE (x%d))\n", indents[indent], depth);
1278: printf ("%s{\n", indents[indent + 2]);
1279: indent += 4;
1280: printf ("%scase ", indents[indent - 2]);
1281: print_code (p->code);
1282: printf (":\n");
1283: codemap[(int) p->code] = 1;
1284: switch_code = p->code;
1285: }
1286:
1287: /* Now that most mode and code tests have been done, we can write out
1288: a label for an inner node, if we haven't already. */
1289: if (p->label_needed)
1290: printf ("%sL%d:\n", indents[indent - 2], p->number);
1291:
1292: inner_indent = indent;
1293:
1294: /* The only way we can have to do a mode or code test here is if
1295: this node needs such a test but is the only node to be tested.
1296: In that case, we won't have started a switch. Note that this is
1297: the only way the switch and test modes can disagree. */
1298:
1299: if ((mode != switch_mode && ! p->ignore_mode)
1300: || (p->code != switch_code && p->code != UNKNOWN && ! p->ignore_code)
1.1.1.3 ! root 1301: || p->test_elt_zero_int || p->test_elt_one_int
! 1302: || p->test_elt_zero_wide || p->veclen
1.1 root 1303: || p->dupno >= 0 || p->tests || p->num_clobbers_to_add)
1304: {
1305: printf ("%sif (", indents[indent]);
1306:
1307: if (mode != switch_mode && ! p->ignore_mode)
1308: printf ("GET_MODE (x%d) == %smode && ",
1309: depth, GET_MODE_NAME (mode));
1310: if (p->code != switch_code && p->code != UNKNOWN && ! p->ignore_code)
1311: {
1312: printf ("GET_CODE (x%d) == ", depth);
1313: print_code (p->code);
1314: printf (" && ");
1315: }
1316:
1317: if (p->test_elt_zero_int)
1318: printf ("XINT (x%d, 0) == %d && ", depth, p->elt_zero_int);
1319: if (p->test_elt_one_int)
1320: printf ("XINT (x%d, 1) == %d && ", depth, p->elt_one_int);
1.1.1.3 ! root 1321: if (p->test_elt_zero_wide)
! 1322: printf (
! 1323: #if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_INT
! 1324: "XWINT (x%d, 0) == %d && ",
! 1325: #else
! 1326: "XWINT (x%d, 0) == %ld && ",
! 1327: #endif
! 1328: depth, p->elt_zero_wide);
1.1 root 1329: if (p->veclen)
1330: printf ("XVECLEN (x%d, 0) == %d && ", depth, p->veclen);
1331: if (p->dupno >= 0)
1332: printf ("rtx_equal_p (x%d, ro[%d]) && ", depth, p->dupno);
1333: if (p->num_clobbers_to_add)
1334: printf ("pnum_clobbers != 0 && ");
1335: if (p->tests)
1336: printf ("%s (x%d, %smode)", p->tests, depth,
1337: GET_MODE_NAME (p->mode));
1338: else
1339: printf ("1");
1340:
1341: printf (")\n");
1342: inner_indent += 2;
1343: }
1344: else
1345: uncond = 1;
1346:
1347: need_bracket = ! uncond;
1348:
1349: if (p->opno >= 0)
1350: {
1351: if (need_bracket)
1352: {
1353: printf ("%s{\n", indents[inner_indent]);
1354: inner_indent += 2;
1355: wrote_bracket = 1;
1356: need_bracket = 0;
1357: }
1358:
1359: printf ("%sro[%d] = x%d;\n", indents[inner_indent], p->opno, depth);
1360: }
1361:
1362: if (p->c_test)
1363: {
1364: printf ("%sif (%s)\n", indents[inner_indent], p->c_test);
1365: inner_indent += 2;
1366: uncond = 0;
1367: need_bracket = 1;
1368: }
1369:
1370: if (p->insn_code_number >= 0)
1371: {
1372: if (type == SPLIT)
1373: printf ("%sreturn gen_split_%d (operands);\n",
1374: indents[inner_indent], p->insn_code_number);
1375: else
1376: {
1377: if (p->num_clobbers_to_add)
1378: {
1379: if (need_bracket)
1380: {
1381: printf ("%s{\n", indents[inner_indent]);
1382: inner_indent += 2;
1383: }
1384:
1385: printf ("%s*pnum_clobbers = %d;\n",
1386: indents[inner_indent], p->num_clobbers_to_add);
1387: printf ("%sreturn %d;\n",
1388: indents[inner_indent], p->insn_code_number);
1389:
1390: if (need_bracket)
1391: {
1392: inner_indent -= 2;
1393: printf ("%s}\n", indents[inner_indent]);
1394: }
1395: }
1396: else
1397: printf ("%sreturn %d;\n",
1398: indents[inner_indent], p->insn_code_number);
1399: }
1400: }
1401: else
1402: printf ("%sgoto L%d;\n", indents[inner_indent],
1403: p->success.first->number);
1404:
1405: if (wrote_bracket)
1406: printf ("%s}\n", indents[inner_indent - 2]);
1407: }
1408:
1409: /* We have now tested all alternatives. End any switches we have open
1410: and branch to the alternative node unless we know that we can't fall
1411: through to the branch. */
1412:
1413: if (switch_code != UNKNOWN)
1414: {
1415: printf ("%s}\n", indents[indent - 2]);
1416: indent -= 4;
1417: uncond = 0;
1418: }
1419:
1420: if (switch_mode != VOIDmode)
1421: {
1422: printf ("%s}\n", indents[indent - 2]);
1423: indent -= 4;
1424: uncond = 0;
1425: }
1426:
1427: if (indent != 2)
1428: abort ();
1429:
1430: if (uncond)
1431: return;
1432:
1433: if (afterward)
1434: {
1435: change_state (prevpos, afterward->position, 2);
1436: printf (" goto L%d;\n", afterward->number);
1437: }
1438: else
1439: printf (" goto ret0;\n");
1440: }
1441:
1442: static void
1443: print_code (code)
1444: RTX_CODE code;
1445: {
1446: register char *p1;
1447: for (p1 = GET_RTX_NAME (code); *p1; p1++)
1448: {
1449: if (*p1 >= 'a' && *p1 <= 'z')
1450: putchar (*p1 + 'A' - 'a');
1451: else
1452: putchar (*p1);
1453: }
1454: }
1455:
1456: static int
1457: same_codes (p, code)
1458: register struct decision *p;
1459: register RTX_CODE code;
1460: {
1461: for (; p; p = p->next)
1462: if (p->code != code)
1463: return 0;
1464:
1465: return 1;
1466: }
1467:
1468: static void
1469: clear_codes (p)
1470: register struct decision *p;
1471: {
1472: for (; p; p = p->next)
1473: p->ignore_code = 1;
1474: }
1475:
1476: static int
1477: same_modes (p, mode)
1478: register struct decision *p;
1479: register enum machine_mode mode;
1480: {
1481: for (; p; p = p->next)
1482: if ((p->enforce_mode ? p->mode : VOIDmode) != mode)
1483: return 0;
1484:
1485: return 1;
1486: }
1487:
1488: static void
1489: clear_modes (p)
1490: register struct decision *p;
1491: {
1492: for (; p; p = p->next)
1493: p->enforce_mode = 0;
1494: }
1495:
1496: /* Write out the decision tree starting at TREE for a subroutine of type TYPE.
1497:
1498: PREVPOS is the position at the node that branched to this node.
1499:
1500: INITIAL is nonzero if this is the first node we are writing in a subroutine.
1501:
1502: If all nodes are false, branch to the node AFTERWARD. */
1503:
1504: static void
1505: write_tree (tree, prevpos, afterward, initial, type)
1506: struct decision *tree;
1507: char *prevpos;
1508: struct decision *afterward;
1509: int initial;
1510: enum routine_type type;
1511: {
1512: register struct decision *p;
1513: char *name_prefix = (type == SPLIT ? "split" : "recog");
1514: char *call_suffix = (type == SPLIT ? "" : ", pnum_clobbers");
1515:
1516: if (! initial && tree->subroutine_number > 0)
1517: {
1518: printf (" L%d:\n", tree->number);
1519:
1520: if (afterward)
1521: {
1522: printf (" tem = %s_%d (x0, insn%s);\n",
1523: name_prefix, tree->subroutine_number, call_suffix);
1.1.1.3 ! root 1524: if (type == SPLIT)
! 1525: printf (" if (tem != 0) return tem;\n");
! 1526: else
! 1527: printf (" if (tem >= 0) return tem;\n");
1.1 root 1528: change_state (tree->position, afterward->position, 2);
1529: printf (" goto L%d;\n", afterward->number);
1530: }
1531: else
1532: printf (" return %s_%d (x0, insn%s);\n",
1533: name_prefix, tree->subroutine_number, call_suffix);
1534: return;
1535: }
1536:
1537: write_tree_1 (tree, prevpos, afterward, type);
1538:
1539: for (p = tree; p; p = p->next)
1540: if (p->success.first)
1541: write_tree (p->success.first, p->position,
1542: p->afterward ? p->afterward : afterward, 0, type);
1543: }
1544:
1545:
1546: /* Assuming that the state of argument is denoted by OLDPOS, take whatever
1547: actions are necessary to move to NEWPOS.
1548:
1549: INDENT says how many blanks to place at the front of lines. */
1550:
1551: static void
1552: change_state (oldpos, newpos, indent)
1553: char *oldpos;
1554: char *newpos;
1555: int indent;
1556: {
1557: int odepth = strlen (oldpos);
1558: int depth = odepth;
1559: int ndepth = strlen (newpos);
1560:
1561: /* Pop up as many levels as necessary. */
1562:
1563: while (strncmp (oldpos, newpos, depth))
1564: --depth;
1565:
1566: /* Go down to desired level. */
1567:
1568: while (depth < ndepth)
1569: {
1570: if (newpos[depth] >= 'a' && newpos[depth] <= 'z')
1571: printf ("%sx%d = XVECEXP (x%d, 0, %d);\n",
1572: indents[indent], depth + 1, depth, newpos[depth] - 'a');
1573: else
1574: printf ("%sx%d = XEXP (x%d, %c);\n",
1575: indents[indent], depth + 1, depth, newpos[depth]);
1576: ++depth;
1577: }
1578: }
1579:
1580: static char *
1581: copystr (s1)
1582: char *s1;
1583: {
1584: register char *tem;
1585:
1586: if (s1 == 0)
1587: return 0;
1588:
1589: tem = (char *) xmalloc (strlen (s1) + 1);
1590: strcpy (tem, s1);
1591:
1592: return tem;
1593: }
1594:
1595: static void
1596: mybzero (b, length)
1597: register char *b;
1598: register unsigned length;
1599: {
1600: while (length-- > 0)
1601: *b++ = 0;
1602: }
1603:
1604: static void
1605: mybcopy (in, out, length)
1606: register char *in, *out;
1607: register unsigned length;
1608: {
1609: while (length-- > 0)
1610: *out++ = *in++;
1611: }
1612:
1613: static char *
1614: concat (s1, s2)
1615: char *s1, *s2;
1616: {
1617: register char *tem;
1618:
1619: if (s1 == 0)
1620: return s2;
1621: if (s2 == 0)
1622: return s1;
1623:
1624: tem = (char *) xmalloc (strlen (s1) + strlen (s2) + 2);
1625: strcpy (tem, s1);
1626: strcat (tem, " ");
1627: strcat (tem, s2);
1628:
1629: return tem;
1630: }
1631:
1632: char *
1633: xrealloc (ptr, size)
1634: char *ptr;
1635: unsigned size;
1636: {
1637: char *result = (char *) realloc (ptr, size);
1638: if (!result)
1639: fatal ("virtual memory exhausted");
1640: return result;
1641: }
1642:
1643: char *
1644: xmalloc (size)
1645: unsigned size;
1646: {
1647: register char *val = (char *) malloc (size);
1648:
1649: if (val == 0)
1650: fatal ("virtual memory exhausted");
1651: return val;
1652: }
1653:
1654: static void
1655: fatal (s, a1, a2)
1656: char *s;
1657: {
1658: fprintf (stderr, "genrecog: ");
1659: fprintf (stderr, s, a1, a2);
1660: fprintf (stderr, "\n");
1661: fprintf (stderr, "after %d definitions\n", next_index);
1662: exit (FATAL_EXIT_CODE);
1663: }
1664:
1665: /* More 'friendly' abort that prints the line and file.
1666: config.h can #define abort fancy_abort if you like that sort of thing. */
1667:
1668: void
1669: fancy_abort ()
1670: {
1671: fatal ("Internal gcc abort.");
1672: }
1673:
1674: int
1675: main (argc, argv)
1676: int argc;
1677: char **argv;
1678: {
1679: rtx desc;
1680: struct decision_head recog_tree;
1681: struct decision_head split_tree;
1682: FILE *infile;
1683: register int c;
1684:
1685: obstack_init (rtl_obstack);
1686: recog_tree.first = recog_tree.last = split_tree.first = split_tree.last = 0;
1687:
1688: if (argc <= 1)
1689: fatal ("No input file name.");
1690:
1691: infile = fopen (argv[1], "r");
1692: if (infile == 0)
1693: {
1694: perror (argv[1]);
1695: exit (FATAL_EXIT_CODE);
1696: }
1697:
1698: init_rtl ();
1699: next_insn_code = 0;
1700: next_index = 0;
1701:
1702: printf ("/* Generated automatically by the program `genrecog'\n\
1703: from the machine description file `md'. */\n\n");
1704:
1705: printf ("#include \"config.h\"\n");
1706: printf ("#include \"rtl.h\"\n");
1707: printf ("#include \"insn-config.h\"\n");
1708: printf ("#include \"recog.h\"\n");
1709: printf ("#include \"real.h\"\n");
1710: printf ("#include \"output.h\"\n");
1711: printf ("#include \"flags.h\"\n");
1712: printf ("\n");
1713:
1714: /* Read the machine description. */
1715:
1716: while (1)
1717: {
1718: c = read_skip_spaces (infile);
1719: if (c == EOF)
1720: break;
1721: ungetc (c, infile);
1722:
1723: desc = read_rtx (infile);
1724: if (GET_CODE (desc) == DEFINE_INSN)
1725: recog_tree = merge_trees (recog_tree,
1726: make_insn_sequence (desc, RECOG));
1727: else if (GET_CODE (desc) == DEFINE_SPLIT)
1728: split_tree = merge_trees (split_tree,
1729: make_insn_sequence (desc, SPLIT));
1730: if (GET_CODE (desc) == DEFINE_PEEPHOLE
1731: || GET_CODE (desc) == DEFINE_EXPAND)
1732: next_insn_code++;
1733: next_index++;
1734: }
1735:
1736: printf ("\n\
1737: /* `recog' contains a decision tree\n\
1738: that recognizes whether the rtx X0 is a valid instruction.\n\
1739: \n\
1740: recog returns -1 if the rtx is not valid.\n\
1741: If the rtx is valid, recog returns a nonnegative number\n\
1742: which is the insn code number for the pattern that matched.\n");
1743: printf (" This is the same as the order in the machine description of\n\
1744: the entry that matched. This number can be used as an index into\n\
1745: entry that matched. This number can be used as an index into various\n\
1746: insn_* tables, such as insn_templates, insn_outfun, and insn_n_operands\n\
1747: (found in insn-output.c).\n\n");
1748: printf (" The third argument to recog is an optional pointer to an int.\n\
1749: If present, recog will accept a pattern if it matches except for\n\
1750: missing CLOBBER expressions at the end. In that case, the value\n\
1751: pointed to by the optional pointer will be set to the number of\n\
1752: CLOBBERs that need to be added (it should be initialized to zero by\n\
1753: the caller). If it is set nonzero, the caller should allocate a\n\
1754: PARALLEL of the appropriate size, copy the initial entries, and call\n\
1755: add_clobbers (found in insn-emit.c) to fill in the CLOBBERs.");
1756:
1757: if (split_tree.first)
1758: printf ("\n\n The function split_insns returns 0 if the rtl could not\n\
1759: be split or the split rtl in a SEQUENCE if it can be.");
1760:
1761: printf ("*/\n\n");
1762:
1763: printf ("rtx recog_operand[MAX_RECOG_OPERANDS];\n\n");
1764: printf ("rtx *recog_operand_loc[MAX_RECOG_OPERANDS];\n\n");
1765: printf ("rtx *recog_dup_loc[MAX_DUP_OPERANDS];\n\n");
1766: printf ("char recog_dup_num[MAX_DUP_OPERANDS];\n\n");
1767: printf ("#define operands recog_operand\n\n");
1768:
1769: next_subroutine_number = 0;
1770: break_out_subroutines (recog_tree, RECOG, 1);
1771: write_subroutine (recog_tree.first, RECOG);
1772:
1773: next_subroutine_number = 0;
1774: break_out_subroutines (split_tree, SPLIT, 1);
1775: write_subroutine (split_tree.first, SPLIT);
1776:
1777: fflush (stdout);
1778: exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
1779: /* NOTREACHED */
1780: return 0;
1781: }
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