1 /* Generate code from machine description to recognize rtl as insns.
2 Copyright (C) 1987, 88, 92, 93, 94, 95, 97, 98 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This program is used to produce insn-recog.c, which contains
23 a function called `recog' plus its subroutines.
24 These functions contain a decision tree
25 that recognizes whether an rtx, the argument given to recog,
26 is a valid instruction.
28 recog returns -1 if the rtx is not valid.
29 If the rtx is valid, recog returns a nonnegative number
30 which is the insn code number for the pattern that matched.
31 This is the same as the order in the machine description of the
32 entry that matched. This number can be used as an index into various
33 insn_* tables, such as insn_template, insn_outfun, and insn_n_operands
34 (found in insn-output.c).
36 The third argument to recog is an optional pointer to an int.
37 If present, recog will accept a pattern if it matches except for
38 missing CLOBBER expressions at the end. In that case, the value
39 pointed to by the optional pointer will be set to the number of
40 CLOBBERs that need to be added (it should be initialized to zero by
41 the caller). If it is set nonzero, the caller should allocate a
42 PARALLEL of the appropriate size, copy the initial entries, and call
43 add_clobbers (found in insn-emit.c) to fill in the CLOBBERs.
45 This program also generates the function `split_insns',
46 which returns 0 if the rtl could not be split, or
47 it returns the split rtl in a SEQUENCE. */
54 static struct obstack obstack;
55 struct obstack *rtl_obstack = &obstack;
57 #define obstack_chunk_alloc xmalloc
58 #define obstack_chunk_free free
60 /* Define this so we can link with print-rtl.o to get debug_rtx function. */
61 char **insn_name_ptr = 0;
63 /* Data structure for a listhead of decision trees. The alternatives
64 to a node are kept in a doublely-linked list so we can easily add nodes
65 to the proper place when merging. */
67 struct decision_head { struct decision *first, *last; };
69 /* Data structure for decision tree for recognizing
70 legitimate instructions. */
74 int number; /* Node number, used for labels */
75 char *position; /* String denoting position in pattern */
76 RTX_CODE code; /* Code to test for or UNKNOWN to suppress */
77 char ignore_code; /* If non-zero, need not test code */
78 char ignore_mode; /* If non-zero, need not test mode */
79 int veclen; /* Length of vector, if nonzero */
80 enum machine_mode mode; /* Machine mode of node */
81 char enforce_mode; /* If non-zero, test `mode' */
82 char retest_code, retest_mode; /* See write_tree_1 */
83 int test_elt_zero_int; /* Nonzero if should test XINT (rtl, 0) */
84 int elt_zero_int; /* Required value for XINT (rtl, 0) */
85 int test_elt_one_int; /* Nonzero if should test XINT (rtl, 1) */
86 int elt_one_int; /* Required value for XINT (rtl, 1) */
87 int test_elt_zero_wide; /* Nonzero if should test XWINT (rtl, 0) */
88 HOST_WIDE_INT elt_zero_wide; /* Required value for XWINT (rtl, 0) */
89 const char *tests; /* If nonzero predicate to call */
90 int pred; /* `preds' index of predicate or -1 */
91 char *c_test; /* Additional test to perform */
92 struct decision_head success; /* Nodes to test on success */
93 int insn_code_number; /* Insn number matched, if success */
94 int num_clobbers_to_add; /* Number of CLOBBERs to be added to pattern */
95 struct decision *next; /* Node to test on failure */
96 struct decision *prev; /* Node whose failure tests us */
97 struct decision *afterward; /* Node to test on success, but failure of
99 int opno; /* Operand number, if >= 0 */
100 int dupno; /* Number of operand to compare against */
101 int label_needed; /* Nonzero if label needed when writing tree */
102 int subroutine_number; /* Number of subroutine this node starts */
105 #define SUBROUTINE_THRESHOLD 50
107 static int next_subroutine_number;
109 /* We can write two types of subroutines: One for insn recognition and
110 one to split insns. This defines which type is being written. */
112 enum routine_type {RECOG, SPLIT};
114 /* Next available node number for tree nodes. */
116 static int next_number;
118 /* Next number to use as an insn_code. */
120 static int next_insn_code;
122 /* Similar, but counts all expressions in the MD file; used for
125 static int next_index;
127 /* Record the highest depth we ever have so we know how many variables to
128 allocate in each subroutine we make. */
130 static int max_depth;
132 /* This table contains a list of the rtl codes that can possibly match a
133 predicate defined in recog.c. The function `not_both_true' uses it to
134 deduce that there are no expressions that can be matches by certain pairs
135 of tree nodes. Also, if a predicate can match only one code, we can
136 hardwire that code into the node testing the predicate. */
138 static struct pred_table
141 RTX_CODE codes[NUM_RTX_CODE];
143 = {{"general_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
144 LABEL_REF, SUBREG, REG, MEM}},
145 #ifdef PREDICATE_CODES
148 {"address_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
149 LABEL_REF, SUBREG, REG, MEM, PLUS, MINUS, MULT}},
150 {"register_operand", {SUBREG, REG}},
151 {"scratch_operand", {SCRATCH, REG}},
152 {"immediate_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
154 {"const_int_operand", {CONST_INT}},
155 {"const_double_operand", {CONST_INT, CONST_DOUBLE}},
156 {"nonimmediate_operand", {SUBREG, REG, MEM}},
157 {"nonmemory_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
158 LABEL_REF, SUBREG, REG}},
159 {"push_operand", {MEM}},
160 {"memory_operand", {SUBREG, MEM}},
161 {"indirect_operand", {SUBREG, MEM}},
162 {"comparison_operator", {EQ, NE, LE, LT, GE, GT, LEU, LTU, GEU, GTU}},
163 {"mode_independent_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
164 LABEL_REF, SUBREG, REG, MEM}}};
166 #define NUM_KNOWN_PREDS (sizeof preds / sizeof preds[0])
168 static struct decision_head make_insn_sequence PROTO((rtx, enum routine_type));
169 static struct decision *add_to_sequence PROTO((rtx, struct decision_head *,
171 static int not_both_true PROTO((struct decision *, struct decision *,
173 static int position_merit PROTO((struct decision *, enum machine_mode,
175 static struct decision_head merge_trees PROTO((struct decision_head,
176 struct decision_head));
177 static int break_out_subroutines PROTO((struct decision_head,
178 enum routine_type, int));
179 static void write_subroutine PROTO((struct decision *, enum routine_type));
180 static void write_tree_1 PROTO((struct decision *, const char *,
181 struct decision *, enum routine_type));
182 static void print_code PROTO((enum rtx_code));
183 static int same_codes PROTO((struct decision *, enum rtx_code));
184 static void clear_codes PROTO((struct decision *));
185 static int same_modes PROTO((struct decision *, enum machine_mode));
186 static void clear_modes PROTO((struct decision *));
187 static void write_tree PROTO((struct decision *, const char *,
188 struct decision *, int,
190 static void change_state PROTO((const char *, const char *, int));
191 static char *copystr PROTO((const char *));
192 static void mybzero PROTO((char *, unsigned));
193 static void mybcopy PROTO((char *, char *, unsigned));
194 static void fatal PVPROTO((const char *, ...))
195 ATTRIBUTE_PRINTF_1 ATTRIBUTE_NORETURN;
196 void fancy_abort PROTO((void)) ATTRIBUTE_NORETURN;
198 /* Construct and return a sequence of decisions
199 that will recognize INSN.
201 TYPE says what type of routine we are recognizing (RECOG or SPLIT). */
203 static struct decision_head
204 make_insn_sequence (insn, type)
206 enum routine_type type;
209 char *c_test = XSTR (insn, type == RECOG ? 2 : 1);
210 struct decision *last;
211 struct decision_head head;
213 if (XVECLEN (insn, type == RECOG) == 1)
214 x = XVECEXP (insn, type == RECOG, 0);
217 x = rtx_alloc (PARALLEL);
218 XVEC (x, 0) = XVEC (insn, type == RECOG);
219 PUT_MODE (x, VOIDmode);
222 last = add_to_sequence (x, &head, "");
225 last->c_test = c_test;
226 last->insn_code_number = next_insn_code;
227 last->num_clobbers_to_add = 0;
229 /* If this is not a DEFINE_SPLIT and X is a PARALLEL, see if it ends with a
230 group of CLOBBERs of (hard) registers or MATCH_SCRATCHes. If so, set up
231 to recognize the pattern without these CLOBBERs. */
233 if (type == RECOG && GET_CODE (x) == PARALLEL)
237 for (i = XVECLEN (x, 0); i > 0; i--)
238 if (GET_CODE (XVECEXP (x, 0, i - 1)) != CLOBBER
239 || (GET_CODE (XEXP (XVECEXP (x, 0, i - 1), 0)) != REG
240 && GET_CODE (XEXP (XVECEXP (x, 0, i - 1), 0)) != MATCH_SCRATCH))
243 if (i != XVECLEN (x, 0))
246 struct decision_head clobber_head;
249 new = XVECEXP (x, 0, 0);
254 new = rtx_alloc (PARALLEL);
255 XVEC (new, 0) = rtvec_alloc (i);
256 for (j = i - 1; j >= 0; j--)
257 XVECEXP (new, 0, j) = XVECEXP (x, 0, j);
260 last = add_to_sequence (new, &clobber_head, "");
263 last->c_test = c_test;
264 last->insn_code_number = next_insn_code;
265 last->num_clobbers_to_add = XVECLEN (x, 0) - i;
267 head = merge_trees (head, clobber_head);
274 /* Define the subroutine we will call below and emit in genemit. */
275 printf ("extern rtx gen_split_%d ();\n", last->insn_code_number);
280 /* Create a chain of nodes to verify that an rtl expression matches
283 LAST is a pointer to the listhead in the previous node in the chain (or
284 in the calling function, for the first node).
286 POSITION is the string representing the current position in the insn.
288 A pointer to the final node in the chain is returned. */
290 static struct decision *
291 add_to_sequence (pattern, last, position)
293 struct decision_head *last;
294 const char *position;
296 register RTX_CODE code;
297 register struct decision *new
298 = (struct decision *) xmalloc (sizeof (struct decision));
299 struct decision *this;
303 int depth = strlen (position);
306 if (depth > max_depth)
309 new->number = next_number++;
310 new->position = copystr (position);
311 new->ignore_code = 0;
312 new->ignore_mode = 0;
313 new->enforce_mode = 1;
314 new->retest_code = new->retest_mode = 0;
316 new->test_elt_zero_int = 0;
317 new->test_elt_one_int = 0;
318 new->test_elt_zero_wide = 0;
319 new->elt_zero_int = 0;
320 new->elt_one_int = 0;
321 new->elt_zero_wide = 0;
325 new->success.first = new->success.last = 0;
326 new->insn_code_number = -1;
327 new->num_clobbers_to_add = 0;
333 new->label_needed = 0;
334 new->subroutine_number = 0;
338 last->first = last->last = new;
340 newpos = (char *) alloca (depth + 2);
341 strcpy (newpos, position);
342 newpos[depth + 1] = 0;
346 new->mode = GET_MODE (pattern);
347 new->code = code = GET_CODE (pattern);
356 new->opno = XINT (pattern, 0);
357 new->code = (code == MATCH_PARALLEL ? PARALLEL : UNKNOWN);
358 new->enforce_mode = 0;
360 if (code == MATCH_SCRATCH)
361 new->tests = "scratch_operand";
363 new->tests = XSTR (pattern, 1);
365 if (*new->tests == 0)
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.
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 kludge 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. */
382 for (i = 0; i < NUM_KNOWN_PREDS; i++)
383 if (! strcmp (preds[i].name, new->tests))
386 int allows_const_int = 0;
390 if (preds[i].codes[1] == 0 && new->code == UNKNOWN)
392 new->code = preds[i].codes[0];
393 if (! strcmp ("const_int_operand", new->tests))
394 new->tests = 0, new->pred = -1;
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;
401 if (! allows_const_int)
402 new->enforce_mode = new->ignore_mode= 1;
407 #ifdef PREDICATE_CODES
408 /* If the port has a list of the predicates it uses but omits
410 if (i == NUM_KNOWN_PREDS)
411 fprintf (stderr, "Warning: `%s' not in PREDICATE_CODES\n",
416 if (code == MATCH_OPERATOR || code == MATCH_PARALLEL)
418 for (i = 0; i < (size_t) XVECLEN (pattern, 2); i++)
420 newpos[depth] = i + (code == MATCH_OPERATOR ? '0': 'a');
421 new = add_to_sequence (XVECEXP (pattern, 2, i),
422 &new->success, newpos);
429 new->opno = XINT (pattern, 0);
430 new->dupno = XINT (pattern, 0);
433 for (i = 0; i < (size_t) XVECLEN (pattern, 1); i++)
435 newpos[depth] = i + '0';
436 new = add_to_sequence (XVECEXP (pattern, 1, i),
437 &new->success, newpos);
443 new->dupno = XINT (pattern, 0);
445 new->enforce_mode = 0;
449 pattern = XEXP (pattern, 0);
453 /* The operands of a SET must have the same mode unless one is VOIDmode. */
454 if (GET_MODE (SET_SRC (pattern)) != VOIDmode
455 && GET_MODE (SET_DEST (pattern)) != VOIDmode
456 && GET_MODE (SET_SRC (pattern)) != GET_MODE (SET_DEST (pattern))
457 /* The mode of an ADDRESS_OPERAND is the mode of the memory reference,
458 not the mode of the address. */
459 && ! (GET_CODE (SET_SRC (pattern)) == MATCH_OPERAND
460 && ! strcmp (XSTR (SET_SRC (pattern), 1), "address_operand")))
462 print_rtl (stderr, pattern);
463 fputc ('\n', stderr);
464 fatal ("mode mismatch in SET");
467 new = add_to_sequence (SET_DEST (pattern), &new->success, newpos);
468 this->success.first->enforce_mode = 1;
470 new = add_to_sequence (SET_SRC (pattern), &new->success, newpos);
472 /* If set are setting CC0 from anything other than a COMPARE, we
473 must enforce the mode so that we do not produce ambiguous insns. */
474 if (GET_CODE (SET_DEST (pattern)) == CC0
475 && GET_CODE (SET_SRC (pattern)) != COMPARE)
476 this->success.first->enforce_mode = 1;
481 case STRICT_LOW_PART:
483 new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
484 this->success.first->enforce_mode = 1;
488 this->test_elt_one_int = 1;
489 this->elt_one_int = XINT (pattern, 1);
491 new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
492 this->success.first->enforce_mode = 1;
498 new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
499 this->success.first->enforce_mode = 1;
501 new = add_to_sequence (XEXP (pattern, 1), &new->success, newpos);
503 new = add_to_sequence (XEXP (pattern, 2), &new->success, newpos);
506 case EQ: case NE: case LE: case LT: case GE: case GT:
507 case LEU: case LTU: case GEU: case GTU:
508 /* If the first operand is (cc0), we don't have to do anything
510 if (GET_CODE (XEXP (pattern, 0)) == CC0)
513 /* ... fall through ... */
516 /* Enforce the mode on the first operand to avoid ambiguous insns. */
518 new = add_to_sequence (XEXP (pattern, 0), &new->success, newpos);
519 this->success.first->enforce_mode = 1;
521 new = add_to_sequence (XEXP (pattern, 1), &new->success, newpos);
528 fmt = GET_RTX_FORMAT (code);
529 len = GET_RTX_LENGTH (code);
530 for (i = 0; i < (size_t) len; i++)
532 newpos[depth] = '0' + i;
533 if (fmt[i] == 'e' || fmt[i] == 'u')
534 new = add_to_sequence (XEXP (pattern, i), &new->success, newpos);
535 else if (fmt[i] == 'i' && i == 0)
537 this->test_elt_zero_int = 1;
538 this->elt_zero_int = XINT (pattern, i);
540 else if (fmt[i] == 'i' && i == 1)
542 this->test_elt_one_int = 1;
543 this->elt_one_int = XINT (pattern, i);
545 else if (fmt[i] == 'w' && i == 0)
547 this->test_elt_zero_wide = 1;
548 this->elt_zero_wide = XWINT (pattern, i);
550 else if (fmt[i] == 'E')
553 /* We do not handle a vector appearing as other than
554 the first item, just because nothing uses them
555 and by handling only the special case
556 we can use one element in newpos for either
557 the item number of a subexpression
558 or the element number in a vector. */
561 this->veclen = XVECLEN (pattern, i);
562 for (j = 0; j < XVECLEN (pattern, i); j++)
564 newpos[depth] = 'a' + j;
565 new = add_to_sequence (XVECEXP (pattern, i, j),
566 &new->success, newpos);
569 else if (fmt[i] != '0')
575 /* Return 1 if we can prove that there is no RTL that can match both
576 D1 and D2. Otherwise, return 0 (it may be that there is an RTL that
577 can match both or just that we couldn't prove there wasn't such an RTL).
579 TOPLEVEL is non-zero if we are to only look at the top level and not
580 recursively descend. */
583 not_both_true (d1, d2, toplevel)
584 struct decision *d1, *d2;
587 struct decision *p1, *p2;
589 /* If they are both to test modes and the modes are different, they aren't
590 both true. Similarly for codes, integer elements, and vector lengths. */
592 if ((d1->enforce_mode && d2->enforce_mode
593 && d1->mode != VOIDmode && d2->mode != VOIDmode && d1->mode != d2->mode)
594 || (d1->code != UNKNOWN && d2->code != UNKNOWN && d1->code != d2->code)
595 || (d1->test_elt_zero_int && d2->test_elt_zero_int
596 && d1->elt_zero_int != d2->elt_zero_int)
597 || (d1->test_elt_one_int && d2->test_elt_one_int
598 && d1->elt_one_int != d2->elt_one_int)
599 || (d1->test_elt_zero_wide && d2->test_elt_zero_wide
600 && d1->elt_zero_wide != d2->elt_zero_wide)
601 || (d1->veclen && d2->veclen && d1->veclen != d2->veclen))
604 /* If either is a wild-card MATCH_OPERAND without a predicate, it can match
605 absolutely anything, so we can't say that no intersection is possible.
606 This case is detected by having a zero TESTS field with a code of
609 if ((d1->tests == 0 && d1->code == UNKNOWN)
610 || (d2->tests == 0 && d2->code == UNKNOWN))
613 /* If either has a predicate that we know something about, set things up so
614 that D1 is the one that always has a known predicate. Then see if they
615 have any codes in common. */
617 if (d1->pred >= 0 || d2->pred >= 0)
622 p1 = d1, d1 = d2, d2 = p1;
624 /* If D2 tests an explicit code, see if it is in the list of valid codes
625 for D1's predicate. */
626 if (d2->code != UNKNOWN)
628 for (i = 0; i < NUM_RTX_CODE && preds[d1->pred].codes[i] != 0; i++)
629 if (preds[d1->pred].codes[i] == d2->code)
632 if (preds[d1->pred].codes[i] == 0)
636 /* Otherwise see if the predicates have any codes in common. */
638 else if (d2->pred >= 0)
640 for (i = 0; i < NUM_RTX_CODE && preds[d1->pred].codes[i] != 0; i++)
642 for (j = 0; j < NUM_RTX_CODE; j++)
643 if (preds[d2->pred].codes[j] == 0
644 || preds[d2->pred].codes[j] == preds[d1->pred].codes[i])
647 if (preds[d2->pred].codes[j] != 0)
651 if (preds[d1->pred].codes[i] == 0)
656 /* If we got here, we can't prove that D1 and D2 cannot both be true.
657 If we are only to check the top level, return 0. Otherwise, see if
658 we can prove that all choices in both successors are mutually
659 exclusive. If either does not have any successors, we can't prove
660 they can't both be true. */
662 if (toplevel || d1->success.first == 0 || d2->success.first == 0)
665 for (p1 = d1->success.first; p1; p1 = p1->next)
666 for (p2 = d2->success.first; p2; p2 = p2->next)
667 if (! not_both_true (p1, p2, 0))
673 /* Assuming that we can reorder all the alternatives at a specific point in
674 the tree (see discussion in merge_trees), we would prefer an ordering of
675 nodes where groups of consecutive nodes test the same mode and, within each
676 mode, groups of nodes test the same code. With this order, we can
677 construct nested switch statements, the inner one to test the code and
678 the outer one to test the mode.
680 We would like to list nodes testing for specific codes before those
681 that test predicates to avoid unnecessary function calls. Similarly,
682 tests for specific modes should precede nodes that allow any mode.
684 This function returns the merit (with 0 being the best) of inserting
685 a test involving the specified MODE and CODE after node P. If P is
686 zero, we are to determine the merit of inserting the test at the front
690 position_merit (p, mode, code)
692 enum machine_mode mode;
695 enum machine_mode p_mode;
697 /* The only time the front of the list is anything other than the worst
698 position is if we are testing a mode that isn't VOIDmode. */
700 return mode == VOIDmode ? 3 : 2;
702 p_mode = p->enforce_mode ? p->mode : VOIDmode;
704 /* The best case is if the codes and modes both match. */
705 if (p_mode == mode && p->code== code)
708 /* If the codes don't match, the next best case is if the modes match.
709 In that case, the best position for this node depends on whether
710 we are testing for a specific code or not. If we are, the best place
711 is after some other test for an explicit code and our mode or after
712 the last test in the previous mode if every test in our mode is for
715 If we are testing for UNKNOWN, then the next best case is at the end of
719 && ((p_mode == mode && p->code != UNKNOWN)
720 || (p_mode != mode && p->next
721 && (p->next->enforce_mode ? p->next->mode : VOIDmode) == mode
722 && (p->next->code == UNKNOWN))))
723 || (code == UNKNOWN && p_mode == mode
725 || (p->next->enforce_mode ? p->next->mode : VOIDmode) != mode)))
728 /* The third best case occurs when nothing is testing MODE. If MODE
729 is not VOIDmode, then the third best case is after something of any
730 mode that is not VOIDmode. If we are testing VOIDmode, the third best
731 place is the end of the list. */
734 && ((mode != VOIDmode && p_mode != VOIDmode)
735 || (mode == VOIDmode && p->next == 0)))
738 /* Otherwise, we have the worst case. */
742 /* Merge two decision tree listheads OLDH and ADDH,
743 modifying OLDH destructively, and return the merged tree. */
745 static struct decision_head
746 merge_trees (oldh, addh)
747 register struct decision_head oldh, addh;
749 struct decision *add, *next;
757 /* If we are adding things at different positions, something is wrong. */
758 if (strcmp (oldh.first->position, addh.first->position))
761 for (add = addh.first; add; add = next)
763 enum machine_mode add_mode = add->enforce_mode ? add->mode : VOIDmode;
764 struct decision *best_position = 0;
766 struct decision *old;
770 /* The semantics of pattern matching state that the tests are done in
771 the order given in the MD file so that if an insn matches two
772 patterns, the first one will be used. However, in practice, most,
773 if not all, patterns are unambiguous so that their order is
774 independent. In that case, we can merge identical tests and
775 group all similar modes and codes together.
777 Scan starting from the end of OLDH until we reach a point
778 where we reach the head of the list or where we pass a pattern
779 that could also be true if NEW is true. If we find an identical
780 pattern, we can merge them. Also, record the last node that tests
781 the same code and mode and the last one that tests just the same mode.
783 If we have no match, place NEW after the closest match we found. */
785 for (old = oldh.last; old; old = old->prev)
789 /* If we don't have anything to test except an additional test,
790 do not consider the two nodes equal. If we did, the test below
791 would cause an infinite recursion. */
792 if (old->tests == 0 && old->test_elt_zero_int == 0
793 && old->test_elt_one_int == 0 && old->veclen == 0
794 && old->test_elt_zero_wide == 0
795 && old->dupno == -1 && old->mode == VOIDmode
796 && old->code == UNKNOWN
797 && (old->c_test != 0 || add->c_test != 0))
800 else if ((old->tests == add->tests
801 || (old->pred >= 0 && old->pred == add->pred)
802 || (old->tests && add->tests
803 && !strcmp (old->tests, add->tests)))
804 && old->test_elt_zero_int == add->test_elt_zero_int
805 && old->elt_zero_int == add->elt_zero_int
806 && old->test_elt_one_int == add->test_elt_one_int
807 && old->elt_one_int == add->elt_one_int
808 && old->test_elt_zero_wide == add->test_elt_zero_wide
809 && old->elt_zero_wide == add->elt_zero_wide
810 && old->veclen == add->veclen
811 && old->dupno == add->dupno
812 && old->opno == add->opno
813 && old->code == add->code
814 && old->enforce_mode == add->enforce_mode
815 && old->mode == add->mode)
817 /* If the additional test is not the same, split both nodes
818 into nodes that just contain all things tested before the
819 additional test and nodes that contain the additional test
820 and actions when it is true. This optimization is important
821 because of the case where we have almost identical patterns
822 with different tests on target flags. */
824 if (old->c_test != add->c_test
825 && ! (old->c_test && add->c_test
826 && !strcmp (old->c_test, add->c_test)))
828 if (old->insn_code_number >= 0 || old->opno >= 0)
830 struct decision *split
831 = (struct decision *) xmalloc (sizeof (struct decision));
833 mybcopy ((char *) old, (char *) split,
834 sizeof (struct decision));
836 old->success.first = old->success.last = split;
839 old->insn_code_number = -1;
840 old->num_clobbers_to_add = 0;
842 split->number = next_number++;
843 split->next = split->prev = 0;
844 split->mode = VOIDmode;
845 split->code = UNKNOWN;
847 split->test_elt_zero_int = 0;
848 split->test_elt_one_int = 0;
849 split->test_elt_zero_wide = 0;
855 if (add->insn_code_number >= 0 || add->opno >= 0)
857 struct decision *split
858 = (struct decision *) xmalloc (sizeof (struct decision));
860 mybcopy ((char *) add, (char *) split,
861 sizeof (struct decision));
863 add->success.first = add->success.last = split;
866 add->insn_code_number = -1;
867 add->num_clobbers_to_add = 0;
869 split->number = next_number++;
870 split->next = split->prev = 0;
871 split->mode = VOIDmode;
872 split->code = UNKNOWN;
874 split->test_elt_zero_int = 0;
875 split->test_elt_one_int = 0;
876 split->test_elt_zero_wide = 0;
883 if (old->insn_code_number >= 0 && add->insn_code_number >= 0)
885 /* If one node is for a normal insn and the second is
886 for the base insn with clobbers stripped off, the
887 second node should be ignored. */
889 if (old->num_clobbers_to_add == 0
890 && add->num_clobbers_to_add > 0)
891 /* Nothing to do here. */
893 else if (old->num_clobbers_to_add > 0
894 && add->num_clobbers_to_add == 0)
896 /* In this case, replace OLD with ADD. */
897 old->insn_code_number = add->insn_code_number;
898 old->num_clobbers_to_add = 0;
901 fatal ("Two actions at one point in tree");
904 if (old->insn_code_number == -1)
905 old->insn_code_number = add->insn_code_number;
906 old->success = merge_trees (old->success, add->success);
911 /* Unless we have already found the best possible insert point,
912 see if this position is better. If so, record it. */
915 && ((our_merit = position_merit (old, add_mode, add->code))
917 best_merit = our_merit, best_position = old;
919 if (! not_both_true (old, add, 0))
923 /* If ADD was duplicate, we are done. */
927 /* Otherwise, find the best place to insert ADD. Normally this is
928 BEST_POSITION. However, if we went all the way to the top of
929 the list, it might be better to insert at the top. */
931 if (best_position == 0)
935 && position_merit (NULL_PTR, add_mode, add->code) < best_merit)
938 add->next = oldh.first;
939 oldh.first->prev = add;
945 add->prev = best_position;
946 add->next = best_position->next;
947 best_position->next = add;
948 if (best_position == oldh.last)
951 add->next->prev = add;
958 /* Count the number of subnodes of HEAD. If the number is high enough,
959 make the first node in HEAD start a separate subroutine in the C code
962 TYPE gives the type of routine we are writing.
964 INITIAL is non-zero if this is the highest-level node. We never write
968 break_out_subroutines (head, type, initial)
969 struct decision_head head;
970 enum routine_type type;
974 struct decision *sub;
976 for (sub = head.first; sub; sub = sub->next)
977 size += 1 + break_out_subroutines (sub->success, type, 0);
979 if (size > SUBROUTINE_THRESHOLD && ! initial)
981 head.first->subroutine_number = ++next_subroutine_number;
982 write_subroutine (head.first, type);
988 /* Write out a subroutine of type TYPE to do comparisons starting at node
992 write_subroutine (tree, type)
993 struct decision *tree;
994 enum routine_type type;
999 printf ("rtx\nsplit");
1001 printf ("int\nrecog");
1003 if (tree != 0 && tree->subroutine_number > 0)
1004 printf ("_%d", tree->subroutine_number);
1005 else if (type == SPLIT)
1008 printf (" (x0, insn");
1010 printf (", pnum_clobbers");
1013 printf (" register rtx x0;\n rtx insn ATTRIBUTE_UNUSED;\n");
1015 printf (" int *pnum_clobbers ATTRIBUTE_UNUSED;\n");
1018 printf (" register rtx *ro = &recog_operand[0];\n");
1020 printf (" register rtx ");
1021 for (i = 1; i < max_depth; i++)
1022 printf ("x%d ATTRIBUTE_UNUSED, ", i);
1024 printf ("x%d ATTRIBUTE_UNUSED;\n", max_depth);
1025 printf (" %s tem ATTRIBUTE_UNUSED;\n", type == SPLIT ? "rtx" : "int");
1026 write_tree (tree, "", NULL_PTR, 1, type);
1027 printf (" ret0: return %d;\n}\n\n", type == SPLIT ? 0 : -1);
1030 /* This table is used to indent the recog_* functions when we are inside
1031 conditions or switch statements. We only support small indentations
1032 and always indent at least two spaces. */
1034 static const char *indents[]
1035 = {" ", " ", " ", " ", " ", " ", " ", " ",
1036 "\t", "\t ", "\t ", "\t ", "\t ", "\t ", "\t ",
1037 "\t\t", "\t\t ", "\t\t ", "\t\t ", "\t\t ", "\t\t "};
1039 /* Write out C code to perform the decisions in TREE for a subroutine of
1040 type TYPE. If all of the choices fail, branch to node AFTERWARD, if
1041 non-zero, otherwise return. PREVPOS is the position of the node that
1042 branched to this test.
1044 When we merged all alternatives, we tried to set up a convenient order.
1045 Specifically, tests involving the same mode are all grouped together,
1046 followed by a group that does not contain a mode test. Within each group
1047 of the same mode, we also group tests with the same code, followed by a
1048 group that does not test a code.
1050 Occasionally, we cannot arbitrarily reorder the tests so that multiple
1051 sequence of groups as described above are present.
1053 We generate two nested switch statements, the outer statement for
1054 testing modes, and the inner switch for testing RTX codes. It is
1055 not worth optimizing cases when only a small number of modes or
1056 codes is tested, since the compiler can do that when compiling the
1057 resulting function. We do check for when every test is the same mode
1061 write_tree_1 (tree, prevpos, afterward, type)
1062 struct decision *tree;
1063 const char *prevpos;
1064 struct decision *afterward;
1065 enum routine_type type;
1067 register struct decision *p, *p1;
1068 register int depth = tree ? strlen (tree->position) : 0;
1069 enum machine_mode switch_mode = VOIDmode;
1070 RTX_CODE switch_code = UNKNOWN;
1072 char modemap[NUM_MACHINE_MODES];
1073 char codemap[NUM_RTX_CODE];
1077 /* One tricky area is what is the exact state when we branch to a
1078 node's label. There are two cases where we branch: when looking at
1079 successors to a node, or when a set of tests fails.
1081 In the former case, we are always branching to the first node in a
1082 decision list and we want all required tests to be performed. We
1083 put the labels for such nodes in front of any switch or test statements.
1084 These branches are done without updating the position to that of the
1087 In the latter case, we are branching to a node that is not the first
1088 node in a decision list. We have already checked that it is possible
1089 for both the node we originally tested at this level and the node we
1090 are branching to to both match some pattern. That means that they
1091 usually will be testing the same mode and code. So it is normally safe
1092 for such labels to be inside switch statements, since the tests done
1093 by virtue of arriving at that label will usually already have been
1094 done. The exception is a branch from a node that does not test a
1095 mode or code to one that does. In such cases, we set the `retest_mode'
1096 or `retest_code' flags. That will ensure that we start a new switch
1097 at that position and put the label before the switch.
1099 The branches in the latter case must set the position to that of the
1104 if (tree && tree->subroutine_number == 0)
1106 printf (" L%d:\n", tree->number);
1107 tree->label_needed = 0;
1112 change_state (prevpos, tree->position, 2);
1113 prevpos = tree->position;
1116 for (p = tree; p; p = p->next)
1118 enum machine_mode mode = p->enforce_mode ? p->mode : VOIDmode;
1120 int wrote_bracket = 0;
1123 if (p->success.first == 0 && p->insn_code_number < 0)
1126 /* Find the next alternative to p that might be true when p is true.
1127 Test that one next if p's successors fail. */
1129 for (p1 = p->next; p1 && not_both_true (p, p1, 1); p1 = p1->next)
1135 if (mode == VOIDmode && p1->enforce_mode && p1->mode != VOIDmode)
1136 p1->retest_mode = 1;
1137 if (p->code == UNKNOWN && p1->code != UNKNOWN)
1138 p1->retest_code = 1;
1139 p1->label_needed = 1;
1142 /* If we have a different code or mode than the last node and
1143 are in a switch on codes, we must either end the switch or
1144 go to another case. We must also end the switch if this
1145 node needs a label and to retest either the mode or code. */
1147 if (switch_code != UNKNOWN
1148 && (switch_code != p->code || switch_mode != mode
1149 || (p->label_needed && (p->retest_mode || p->retest_code))))
1151 enum rtx_code code = p->code;
1153 /* If P is testing a predicate that we know about and we haven't
1154 seen any of the codes that are valid for the predicate, we
1155 can write a series of "case" statement, one for each possible
1156 code. Since we are already in a switch, these redundant tests
1157 are very cheap and will reduce the number of predicate called. */
1161 for (i = 0; i < NUM_RTX_CODE && preds[p->pred].codes[i] != 0; i++)
1162 if (codemap[(int) preds[p->pred].codes[i]])
1165 if (preds[p->pred].codes[i] == 0)
1166 code = MATCH_OPERAND;
1169 if (code == UNKNOWN || codemap[(int) code]
1170 || switch_mode != mode
1171 || (p->label_needed && (p->retest_mode || p->retest_code)))
1173 printf ("%s}\n", indents[indent - 2]);
1174 switch_code = UNKNOWN;
1180 printf ("%sbreak;\n", indents[indent]);
1182 if (code == MATCH_OPERAND)
1184 for (i = 0; i < NUM_RTX_CODE && preds[p->pred].codes[i] != 0; i++)
1186 printf ("%scase ", indents[indent - 2]);
1187 print_code (preds[p->pred].codes[i]);
1189 codemap[(int) preds[p->pred].codes[i]] = 1;
1194 printf ("%scase ", indents[indent - 2]);
1197 codemap[(int) p->code] = 1;
1206 /* If we were previously in a switch on modes and now have a different
1207 mode, end at least the case, and maybe end the switch if we are
1208 not testing a mode or testing a mode whose case we already saw. */
1210 if (switch_mode != VOIDmode
1211 && (switch_mode != mode || (p->label_needed && p->retest_mode)))
1213 if (mode == VOIDmode || modemap[(int) mode]
1214 || (p->label_needed && p->retest_mode))
1216 printf ("%s}\n", indents[indent - 2]);
1217 switch_mode = VOIDmode;
1223 printf (" break;\n");
1224 printf (" case %smode:\n", GET_MODE_NAME (mode));
1226 modemap[(int) mode] = 1;
1232 /* If we are about to write dead code, something went wrong. */
1233 if (! p->label_needed && uncond)
1236 /* If we need a label and we will want to retest the mode or code at
1237 that label, write the label now. We have already ensured that
1238 things will be valid for the test. */
1240 if (p->label_needed && (p->retest_mode || p->retest_code))
1242 printf ("%sL%d:\n", indents[indent - 2], p->number);
1243 p->label_needed = 0;
1248 /* If we are not in any switches, see if we can shortcut things
1249 by checking for identical modes and codes. */
1251 if (switch_mode == VOIDmode && switch_code == UNKNOWN)
1253 /* If p and its alternatives all want the same mode,
1254 reject all others at once, first, then ignore the mode. */
1256 if (mode != VOIDmode && p->next && same_modes (p, mode))
1258 printf (" if (GET_MODE (x%d) != %smode)\n",
1259 depth, GET_MODE_NAME (p->mode));
1263 change_state (p->position, afterward->position, 6);
1264 printf (" goto L%d;\n }\n", afterward->number);
1267 printf (" goto ret0;\n");
1272 /* If p and its alternatives all want the same code,
1273 reject all others at once, first, then ignore the code. */
1275 if (p->code != UNKNOWN && p->next && same_codes (p, p->code))
1277 printf (" if (GET_CODE (x%d) != ", depth);
1278 print_code (p->code);
1283 change_state (p->position, afterward->position, indent + 4);
1284 printf (" goto L%d;\n }\n", afterward->number);
1287 printf (" goto ret0;\n");
1292 /* If we are not in a mode switch and we are testing for a specific
1293 mode, start a mode switch unless we have just one node or the next
1294 node is not testing a mode (we have already tested for the case of
1295 more than one mode, but all of the same mode). */
1297 if (switch_mode == VOIDmode && mode != VOIDmode && p->next != 0
1298 && p->next->enforce_mode && p->next->mode != VOIDmode)
1300 mybzero (modemap, sizeof modemap);
1301 printf ("%sswitch (GET_MODE (x%d))\n", indents[indent], depth);
1302 printf ("%s{\n", indents[indent + 2]);
1304 printf ("%sdefault:\n%sbreak;\n", indents[indent - 2],
1306 printf ("%scase %smode:\n", indents[indent - 2],
1307 GET_MODE_NAME (mode));
1308 modemap[(int) mode] = 1;
1312 /* Similarly for testing codes. */
1314 if (switch_code == UNKNOWN && p->code != UNKNOWN && ! p->ignore_code
1315 && p->next != 0 && p->next->code != UNKNOWN)
1317 mybzero (codemap, sizeof codemap);
1318 printf ("%sswitch (GET_CODE (x%d))\n", indents[indent], depth);
1319 printf ("%s{\n", indents[indent + 2]);
1321 printf ("%sdefault:\n%sbreak;\n", indents[indent - 2],
1323 printf ("%scase ", indents[indent - 2]);
1324 print_code (p->code);
1326 codemap[(int) p->code] = 1;
1327 switch_code = p->code;
1330 /* Now that most mode and code tests have been done, we can write out
1331 a label for an inner node, if we haven't already. */
1332 if (p->label_needed)
1333 printf ("%sL%d:\n", indents[indent - 2], p->number);
1335 inner_indent = indent;
1337 /* The only way we can have to do a mode or code test here is if
1338 this node needs such a test but is the only node to be tested.
1339 In that case, we won't have started a switch. Note that this is
1340 the only way the switch and test modes can disagree. */
1342 if ((mode != switch_mode && ! p->ignore_mode)
1343 || (p->code != switch_code && p->code != UNKNOWN && ! p->ignore_code)
1344 || p->test_elt_zero_int || p->test_elt_one_int
1345 || p->test_elt_zero_wide || p->veclen
1346 || p->dupno >= 0 || p->tests || p->num_clobbers_to_add)
1348 printf ("%sif (", indents[indent]);
1350 if (mode != switch_mode && ! p->ignore_mode)
1351 printf ("GET_MODE (x%d) == %smode && ",
1352 depth, GET_MODE_NAME (mode));
1353 if (p->code != switch_code && p->code != UNKNOWN && ! p->ignore_code)
1355 printf ("GET_CODE (x%d) == ", depth);
1356 print_code (p->code);
1360 if (p->test_elt_zero_int)
1361 printf ("XINT (x%d, 0) == %d && ", depth, p->elt_zero_int);
1362 if (p->test_elt_one_int)
1363 printf ("XINT (x%d, 1) == %d && ", depth, p->elt_one_int);
1364 if (p->test_elt_zero_wide)
1366 /* Set offset to 1 iff the number might get propagated to
1367 unsigned long by ANSI C rules, else 0.
1368 Prospective hosts are required to have at least 32 bit
1369 ints, and integer constants in machine descriptions
1370 must fit in 32 bit, thus it suffices to check only
1372 HOST_WIDE_INT offset = p->elt_zero_wide == -2147483647 - 1;
1373 printf ("XWINT (x%d, 0) == ", depth);
1374 printf (HOST_WIDE_INT_PRINT_DEC, p->elt_zero_wide + offset);
1375 printf ("%s && ", offset ? "-1" : "");
1378 printf ("XVECLEN (x%d, 0) == %d && ", depth, p->veclen);
1380 printf ("rtx_equal_p (x%d, ro[%d]) && ", depth, p->dupno);
1381 if (p->num_clobbers_to_add)
1382 printf ("pnum_clobbers != 0 && ");
1384 printf ("%s (x%d, %smode)", p->tests, depth,
1385 GET_MODE_NAME (p->mode));
1395 need_bracket = ! uncond;
1401 printf ("%s{\n", indents[inner_indent]);
1407 printf ("%sro[%d] = x%d;\n", indents[inner_indent], p->opno, depth);
1412 printf ("%sif (%s)\n", indents[inner_indent], p->c_test);
1418 if (p->insn_code_number >= 0)
1421 printf ("%sreturn gen_split_%d (operands);\n",
1422 indents[inner_indent], p->insn_code_number);
1425 if (p->num_clobbers_to_add)
1429 printf ("%s{\n", indents[inner_indent]);
1433 printf ("%s*pnum_clobbers = %d;\n",
1434 indents[inner_indent], p->num_clobbers_to_add);
1435 printf ("%sreturn %d;\n",
1436 indents[inner_indent], p->insn_code_number);
1441 printf ("%s}\n", indents[inner_indent]);
1445 printf ("%sreturn %d;\n",
1446 indents[inner_indent], p->insn_code_number);
1450 printf ("%sgoto L%d;\n", indents[inner_indent],
1451 p->success.first->number);
1454 printf ("%s}\n", indents[inner_indent - 2]);
1457 /* We have now tested all alternatives. End any switches we have open
1458 and branch to the alternative node unless we know that we can't fall
1459 through to the branch. */
1461 if (switch_code != UNKNOWN)
1463 printf ("%s}\n", indents[indent - 2]);
1468 if (switch_mode != VOIDmode)
1470 printf ("%s}\n", indents[indent - 2]);
1483 change_state (prevpos, afterward->position, 2);
1484 printf (" goto L%d;\n", afterward->number);
1487 printf (" goto ret0;\n");
1495 for (p1 = GET_RTX_NAME (code); *p1; p1++)
1497 if (*p1 >= 'a' && *p1 <= 'z')
1498 putchar (*p1 + 'A' - 'a');
1505 same_codes (p, code)
1506 register struct decision *p;
1507 register enum rtx_code code;
1509 for (; p; p = p->next)
1510 if (p->code != code)
1518 register struct decision *p;
1520 for (; p; p = p->next)
1525 same_modes (p, mode)
1526 register struct decision *p;
1527 register enum machine_mode mode;
1529 for (; p; p = p->next)
1530 if ((p->enforce_mode ? p->mode : VOIDmode) != mode)
1538 register struct decision *p;
1540 for (; p; p = p->next)
1541 p->enforce_mode = 0;
1544 /* Write out the decision tree starting at TREE for a subroutine of type TYPE.
1546 PREVPOS is the position at the node that branched to this node.
1548 INITIAL is nonzero if this is the first node we are writing in a subroutine.
1550 If all nodes are false, branch to the node AFTERWARD. */
1553 write_tree (tree, prevpos, afterward, initial, type)
1554 struct decision *tree;
1555 const char *prevpos;
1556 struct decision *afterward;
1558 enum routine_type type;
1560 register struct decision *p;
1561 const char *name_prefix = (type == SPLIT ? "split" : "recog");
1562 const char *call_suffix = (type == SPLIT ? "" : ", pnum_clobbers");
1564 if (! initial && tree->subroutine_number > 0)
1566 printf (" L%d:\n", tree->number);
1570 printf (" tem = %s_%d (x0, insn%s);\n",
1571 name_prefix, tree->subroutine_number, call_suffix);
1573 printf (" if (tem != 0) return tem;\n");
1575 printf (" if (tem >= 0) return tem;\n");
1576 change_state (tree->position, afterward->position, 2);
1577 printf (" goto L%d;\n", afterward->number);
1580 printf (" return %s_%d (x0, insn%s);\n",
1581 name_prefix, tree->subroutine_number, call_suffix);
1585 write_tree_1 (tree, prevpos, afterward, type);
1587 for (p = tree; p; p = p->next)
1588 if (p->success.first)
1589 write_tree (p->success.first, p->position,
1590 p->afterward ? p->afterward : afterward, 0, type);
1594 /* Assuming that the state of argument is denoted by OLDPOS, take whatever
1595 actions are necessary to move to NEWPOS.
1597 INDENT says how many blanks to place at the front of lines. */
1600 change_state (oldpos, newpos, indent)
1605 int odepth = strlen (oldpos);
1607 int ndepth = strlen (newpos);
1609 /* Pop up as many levels as necessary. */
1611 while (strncmp (oldpos, newpos, depth))
1614 /* Go down to desired level. */
1616 while (depth < ndepth)
1618 if (newpos[depth] >= 'a' && newpos[depth] <= 'z')
1619 printf ("%sx%d = XVECEXP (x%d, 0, %d);\n",
1620 indents[indent], depth + 1, depth, newpos[depth] - 'a');
1622 printf ("%sx%d = XEXP (x%d, %c);\n",
1623 indents[indent], depth + 1, depth, newpos[depth]);
1637 tem = (char *) xmalloc (strlen (s1) + 1);
1646 register unsigned length;
1648 while (length-- > 0)
1653 mybcopy (in, out, length)
1654 register char *in, *out;
1655 register unsigned length;
1657 while (length-- > 0)
1662 xrealloc (ptr, size)
1666 register PTR result = (PTR) realloc (ptr, size);
1668 fatal ("virtual memory exhausted");
1676 register PTR val = (PTR) malloc (size);
1679 fatal ("virtual memory exhausted");
1684 fatal VPROTO ((const char *format, ...))
1686 #ifndef ANSI_PROTOTYPES
1691 VA_START (ap, format);
1693 #ifndef ANSI_PROTOTYPES
1694 format = va_arg (ap, const char *);
1697 fprintf (stderr, "genrecog: ");
1698 vfprintf (stderr, format, ap);
1700 fprintf (stderr, "\n");
1701 fprintf (stderr, "after %d definitions\n", next_index);
1702 exit (FATAL_EXIT_CODE);
1705 /* More 'friendly' abort that prints the line and file.
1706 config.h can #define abort fancy_abort if you like that sort of thing. */
1711 fatal ("Internal gcc abort.");
1720 struct decision_head recog_tree;
1721 struct decision_head split_tree;
1725 obstack_init (rtl_obstack);
1726 recog_tree.first = recog_tree.last = split_tree.first = split_tree.last = 0;
1729 fatal ("No input file name.");
1731 infile = fopen (argv[1], "r");
1735 exit (FATAL_EXIT_CODE);
1742 printf ("/* Generated automatically by the program `genrecog'\n\
1743 from the machine description file `md'. */\n\n");
1745 printf ("#include \"config.h\"\n");
1746 printf ("#include \"system.h\"\n");
1747 printf ("#include \"rtl.h\"\n");
1748 printf ("#include \"insn-config.h\"\n");
1749 printf ("#include \"recog.h\"\n");
1750 printf ("#include \"real.h\"\n");
1751 printf ("#include \"output.h\"\n");
1752 printf ("#include \"flags.h\"\n");
1755 /* Read the machine description. */
1759 c = read_skip_spaces (infile);
1764 desc = read_rtx (infile);
1765 if (GET_CODE (desc) == DEFINE_INSN)
1766 recog_tree = merge_trees (recog_tree,
1767 make_insn_sequence (desc, RECOG));
1768 else if (GET_CODE (desc) == DEFINE_SPLIT)
1769 split_tree = merge_trees (split_tree,
1770 make_insn_sequence (desc, SPLIT));
1771 if (GET_CODE (desc) == DEFINE_PEEPHOLE
1772 || GET_CODE (desc) == DEFINE_EXPAND)
1778 /* `recog' contains a decision tree\n\
1779 that recognizes whether the rtx X0 is a valid instruction.\n\
1781 recog returns -1 if the rtx is not valid.\n\
1782 If the rtx is valid, recog returns a nonnegative number\n\
1783 which is the insn code number for the pattern that matched.\n");
1784 printf (" This is the same as the order in the machine description of\n\
1785 the entry that matched. This number can be used as an index into various\n\
1786 insn_* tables, such as insn_templates, insn_outfun, and insn_n_operands\n\
1787 (found in insn-output.c).\n\n");
1788 printf (" The third argument to recog is an optional pointer to an int.\n\
1789 If present, recog will accept a pattern if it matches except for\n\
1790 missing CLOBBER expressions at the end. In that case, the value\n\
1791 pointed to by the optional pointer will be set to the number of\n\
1792 CLOBBERs that need to be added (it should be initialized to zero by\n\
1793 the caller). If it is set nonzero, the caller should allocate a\n\
1794 PARALLEL of the appropriate size, copy the initial entries, and call\n\
1795 add_clobbers (found in insn-emit.c) to fill in the CLOBBERs.");
1797 if (split_tree.first)
1798 printf ("\n\n The function split_insns returns 0 if the rtl could not\n\
1799 be split or the split rtl in a SEQUENCE if it can be.");
1803 printf ("#define operands recog_operand\n\n");
1805 next_subroutine_number = 0;
1806 break_out_subroutines (recog_tree, RECOG, 1);
1807 write_subroutine (recog_tree.first, RECOG);
1809 next_subroutine_number = 0;
1810 break_out_subroutines (split_tree, SPLIT, 1);
1811 write_subroutine (split_tree.first, SPLIT);
1814 exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);