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 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
*, 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
*, char *,
188 struct decision
*, int,
190 static void change_state
PROTO((char *, char *, int));
191 static char *copystr
PROTO((char *));
192 static void mybzero
PROTO((char *, unsigned));
193 static void mybcopy
PROTO((char *, char *, unsigned));
194 static void fatal
PVPROTO((char *, ...))
195 ATTRIBUTE_PRINTF_1 ATTRIBUTE_NORETURN
;
196 char *xrealloc
PROTO((char *, unsigned));
197 char *xmalloc
PROTO((unsigned));
198 void fancy_abort
PROTO((void)) ATTRIBUTE_NORETURN
;
200 /* Construct and return a sequence of decisions
201 that will recognize INSN.
203 TYPE says what type of routine we are recognizing (RECOG or SPLIT). */
205 static struct decision_head
206 make_insn_sequence (insn
, type
)
208 enum routine_type type
;
211 char *c_test
= XSTR (insn
, type
== RECOG
? 2 : 1);
212 struct decision
*last
;
213 struct decision_head head
;
215 if (XVECLEN (insn
, type
== RECOG
) == 1)
216 x
= XVECEXP (insn
, type
== RECOG
, 0);
219 x
= rtx_alloc (PARALLEL
);
220 XVEC (x
, 0) = XVEC (insn
, type
== RECOG
);
221 PUT_MODE (x
, VOIDmode
);
224 last
= add_to_sequence (x
, &head
, "");
227 last
->c_test
= c_test
;
228 last
->insn_code_number
= next_insn_code
;
229 last
->num_clobbers_to_add
= 0;
231 /* If this is not a DEFINE_SPLIT and X is a PARALLEL, see if it ends with a
232 group of CLOBBERs of (hard) registers or MATCH_SCRATCHes. If so, set up
233 to recognize the pattern without these CLOBBERs. */
235 if (type
== RECOG
&& GET_CODE (x
) == PARALLEL
)
239 for (i
= XVECLEN (x
, 0); i
> 0; i
--)
240 if (GET_CODE (XVECEXP (x
, 0, i
- 1)) != CLOBBER
241 || (GET_CODE (XEXP (XVECEXP (x
, 0, i
- 1), 0)) != REG
242 && GET_CODE (XEXP (XVECEXP (x
, 0, i
- 1), 0)) != MATCH_SCRATCH
))
245 if (i
!= XVECLEN (x
, 0))
248 struct decision_head clobber_head
;
251 new = XVECEXP (x
, 0, 0);
256 new = rtx_alloc (PARALLEL
);
257 XVEC (new, 0) = rtvec_alloc (i
);
258 for (j
= i
- 1; j
>= 0; j
--)
259 XVECEXP (new, 0, j
) = XVECEXP (x
, 0, j
);
262 last
= add_to_sequence (new, &clobber_head
, "");
265 last
->c_test
= c_test
;
266 last
->insn_code_number
= next_insn_code
;
267 last
->num_clobbers_to_add
= XVECLEN (x
, 0) - i
;
269 head
= merge_trees (head
, clobber_head
);
276 /* Define the subroutine we will call below and emit in genemit. */
277 printf ("extern rtx gen_split_%d ();\n", last
->insn_code_number
);
282 /* Create a chain of nodes to verify that an rtl expression matches
285 LAST is a pointer to the listhead in the previous node in the chain (or
286 in the calling function, for the first node).
288 POSITION is the string representing the current position in the insn.
290 A pointer to the final node in the chain is returned. */
292 static struct decision
*
293 add_to_sequence (pattern
, last
, position
)
295 struct decision_head
*last
;
298 register RTX_CODE code
;
299 register struct decision
*new
300 = (struct decision
*) xmalloc (sizeof (struct decision
));
301 struct decision
*this;
305 int depth
= strlen (position
);
308 if (depth
> max_depth
)
311 new->number
= next_number
++;
312 new->position
= copystr (position
);
313 new->ignore_code
= 0;
314 new->ignore_mode
= 0;
315 new->enforce_mode
= 1;
316 new->retest_code
= new->retest_mode
= 0;
318 new->test_elt_zero_int
= 0;
319 new->test_elt_one_int
= 0;
320 new->test_elt_zero_wide
= 0;
321 new->elt_zero_int
= 0;
322 new->elt_one_int
= 0;
323 new->elt_zero_wide
= 0;
327 new->success
.first
= new->success
.last
= 0;
328 new->insn_code_number
= -1;
329 new->num_clobbers_to_add
= 0;
335 new->label_needed
= 0;
336 new->subroutine_number
= 0;
340 last
->first
= last
->last
= new;
342 newpos
= (char *) alloca (depth
+ 2);
343 strcpy (newpos
, position
);
344 newpos
[depth
+ 1] = 0;
348 new->mode
= GET_MODE (pattern
);
349 new->code
= code
= GET_CODE (pattern
);
358 new->opno
= XINT (pattern
, 0);
359 new->code
= (code
== MATCH_PARALLEL
? PARALLEL
: UNKNOWN
);
360 new->enforce_mode
= 0;
362 if (code
== MATCH_SCRATCH
)
363 new->tests
= "scratch_operand";
365 new->tests
= XSTR (pattern
, 1);
367 if (*new->tests
== 0)
370 /* See if we know about this predicate and save its number. If we do,
371 and it only accepts one code, note that fact. The predicate
372 `const_int_operand' only tests for a CONST_INT, so if we do so we
373 can avoid calling it at all.
375 Finally, if we know that the predicate does not allow CONST_INT, we
376 know that the only way the predicate can match is if the modes match
377 (here we use the kludge of relying on the fact that "address_operand"
378 accepts CONST_INT; otherwise, it would have to be a special case),
379 so we can test the mode (but we need not). This fact should
380 considerably simplify the generated code. */
384 for (i
= 0; i
< NUM_KNOWN_PREDS
; i
++)
385 if (! strcmp (preds
[i
].name
, new->tests
))
388 int allows_const_int
= 0;
392 if (preds
[i
].codes
[1] == 0 && new->code
== UNKNOWN
)
394 new->code
= preds
[i
].codes
[0];
395 if (! strcmp ("const_int_operand", new->tests
))
396 new->tests
= 0, new->pred
= -1;
399 for (j
= 0; j
< NUM_RTX_CODE
&& preds
[i
].codes
[j
] != 0; j
++)
400 if (preds
[i
].codes
[j
] == CONST_INT
)
401 allows_const_int
= 1;
403 if (! allows_const_int
)
404 new->enforce_mode
= new->ignore_mode
= 1;
409 #ifdef PREDICATE_CODES
410 /* If the port has a list of the predicates it uses but omits
412 if (i
== NUM_KNOWN_PREDS
)
413 fprintf (stderr
, "Warning: `%s' not in PREDICATE_CODES\n",
418 if (code
== MATCH_OPERATOR
|| code
== MATCH_PARALLEL
)
420 for (i
= 0; i
< (size_t) XVECLEN (pattern
, 2); i
++)
422 newpos
[depth
] = i
+ (code
== MATCH_OPERATOR
? '0': 'a');
423 new = add_to_sequence (XVECEXP (pattern
, 2, i
),
424 &new->success
, newpos
);
431 new->opno
= XINT (pattern
, 0);
432 new->dupno
= XINT (pattern
, 0);
435 for (i
= 0; i
< (size_t) XVECLEN (pattern
, 1); i
++)
437 newpos
[depth
] = i
+ '0';
438 new = add_to_sequence (XVECEXP (pattern
, 1, i
),
439 &new->success
, newpos
);
445 new->dupno
= XINT (pattern
, 0);
447 new->enforce_mode
= 0;
451 pattern
= XEXP (pattern
, 0);
455 /* The operands of a SET must have the same mode unless one is VOIDmode. */
456 if (GET_MODE (SET_SRC (pattern
)) != VOIDmode
457 && GET_MODE (SET_DEST (pattern
)) != VOIDmode
458 && GET_MODE (SET_SRC (pattern
)) != GET_MODE (SET_DEST (pattern
))
459 /* The mode of an ADDRESS_OPERAND is the mode of the memory reference,
460 not the mode of the address. */
461 && ! (GET_CODE (SET_SRC (pattern
)) == MATCH_OPERAND
462 && ! strcmp (XSTR (SET_SRC (pattern
), 1), "address_operand")))
464 print_rtl (stderr
, pattern
);
465 fputc ('\n', stderr
);
466 fatal ("mode mismatch in SET");
469 new = add_to_sequence (SET_DEST (pattern
), &new->success
, newpos
);
470 this->success
.first
->enforce_mode
= 1;
472 new = add_to_sequence (SET_SRC (pattern
), &new->success
, newpos
);
474 /* If set are setting CC0 from anything other than a COMPARE, we
475 must enforce the mode so that we do not produce ambiguous insns. */
476 if (GET_CODE (SET_DEST (pattern
)) == CC0
477 && GET_CODE (SET_SRC (pattern
)) != COMPARE
)
478 this->success
.first
->enforce_mode
= 1;
483 case STRICT_LOW_PART
:
485 new = add_to_sequence (XEXP (pattern
, 0), &new->success
, newpos
);
486 this->success
.first
->enforce_mode
= 1;
490 this->test_elt_one_int
= 1;
491 this->elt_one_int
= XINT (pattern
, 1);
493 new = add_to_sequence (XEXP (pattern
, 0), &new->success
, newpos
);
494 this->success
.first
->enforce_mode
= 1;
500 new = add_to_sequence (XEXP (pattern
, 0), &new->success
, newpos
);
501 this->success
.first
->enforce_mode
= 1;
503 new = add_to_sequence (XEXP (pattern
, 1), &new->success
, newpos
);
505 new = add_to_sequence (XEXP (pattern
, 2), &new->success
, newpos
);
508 case EQ
: case NE
: case LE
: case LT
: case GE
: case GT
:
509 case LEU
: case LTU
: case GEU
: case GTU
:
510 /* If the first operand is (cc0), we don't have to do anything
512 if (GET_CODE (XEXP (pattern
, 0)) == CC0
)
515 /* ... fall through ... */
518 /* Enforce the mode on the first operand to avoid ambiguous insns. */
520 new = add_to_sequence (XEXP (pattern
, 0), &new->success
, newpos
);
521 this->success
.first
->enforce_mode
= 1;
523 new = add_to_sequence (XEXP (pattern
, 1), &new->success
, newpos
);
530 fmt
= GET_RTX_FORMAT (code
);
531 len
= GET_RTX_LENGTH (code
);
532 for (i
= 0; i
< (size_t) len
; i
++)
534 newpos
[depth
] = '0' + i
;
535 if (fmt
[i
] == 'e' || fmt
[i
] == 'u')
536 new = add_to_sequence (XEXP (pattern
, i
), &new->success
, newpos
);
537 else if (fmt
[i
] == 'i' && i
== 0)
539 this->test_elt_zero_int
= 1;
540 this->elt_zero_int
= XINT (pattern
, i
);
542 else if (fmt
[i
] == 'i' && i
== 1)
544 this->test_elt_one_int
= 1;
545 this->elt_one_int
= XINT (pattern
, i
);
547 else if (fmt
[i
] == 'w' && i
== 0)
549 this->test_elt_zero_wide
= 1;
550 this->elt_zero_wide
= XWINT (pattern
, i
);
552 else if (fmt
[i
] == 'E')
555 /* We do not handle a vector appearing as other than
556 the first item, just because nothing uses them
557 and by handling only the special case
558 we can use one element in newpos for either
559 the item number of a subexpression
560 or the element number in a vector. */
563 this->veclen
= XVECLEN (pattern
, i
);
564 for (j
= 0; j
< XVECLEN (pattern
, i
); j
++)
566 newpos
[depth
] = 'a' + j
;
567 new = add_to_sequence (XVECEXP (pattern
, i
, j
),
568 &new->success
, newpos
);
571 else if (fmt
[i
] != '0')
577 /* Return 1 if we can prove that there is no RTL that can match both
578 D1 and D2. Otherwise, return 0 (it may be that there is an RTL that
579 can match both or just that we couldn't prove there wasn't such an RTL).
581 TOPLEVEL is non-zero if we are to only look at the top level and not
582 recursively descend. */
585 not_both_true (d1
, d2
, toplevel
)
586 struct decision
*d1
, *d2
;
589 struct decision
*p1
, *p2
;
591 /* If they are both to test modes and the modes are different, they aren't
592 both true. Similarly for codes, integer elements, and vector lengths. */
594 if ((d1
->enforce_mode
&& d2
->enforce_mode
595 && d1
->mode
!= VOIDmode
&& d2
->mode
!= VOIDmode
&& d1
->mode
!= d2
->mode
)
596 || (d1
->code
!= UNKNOWN
&& d2
->code
!= UNKNOWN
&& d1
->code
!= d2
->code
)
597 || (d1
->test_elt_zero_int
&& d2
->test_elt_zero_int
598 && d1
->elt_zero_int
!= d2
->elt_zero_int
)
599 || (d1
->test_elt_one_int
&& d2
->test_elt_one_int
600 && d1
->elt_one_int
!= d2
->elt_one_int
)
601 || (d1
->test_elt_zero_wide
&& d2
->test_elt_zero_wide
602 && d1
->elt_zero_wide
!= d2
->elt_zero_wide
)
603 || (d1
->veclen
&& d2
->veclen
&& d1
->veclen
!= d2
->veclen
))
606 /* If either is a wild-card MATCH_OPERAND without a predicate, it can match
607 absolutely anything, so we can't say that no intersection is possible.
608 This case is detected by having a zero TESTS field with a code of
611 if ((d1
->tests
== 0 && d1
->code
== UNKNOWN
)
612 || (d2
->tests
== 0 && d2
->code
== UNKNOWN
))
615 /* If either has a predicate that we know something about, set things up so
616 that D1 is the one that always has a known predicate. Then see if they
617 have any codes in common. */
619 if (d1
->pred
>= 0 || d2
->pred
>= 0)
624 p1
= d1
, d1
= d2
, d2
= p1
;
626 /* If D2 tests an explicit code, see if it is in the list of valid codes
627 for D1's predicate. */
628 if (d2
->code
!= UNKNOWN
)
630 for (i
= 0; i
< NUM_RTX_CODE
&& preds
[d1
->pred
].codes
[i
] != 0; i
++)
631 if (preds
[d1
->pred
].codes
[i
] == d2
->code
)
634 if (preds
[d1
->pred
].codes
[i
] == 0)
638 /* Otherwise see if the predicates have any codes in common. */
640 else if (d2
->pred
>= 0)
642 for (i
= 0; i
< NUM_RTX_CODE
&& preds
[d1
->pred
].codes
[i
] != 0; i
++)
644 for (j
= 0; j
< NUM_RTX_CODE
; j
++)
645 if (preds
[d2
->pred
].codes
[j
] == 0
646 || preds
[d2
->pred
].codes
[j
] == preds
[d1
->pred
].codes
[i
])
649 if (preds
[d2
->pred
].codes
[j
] != 0)
653 if (preds
[d1
->pred
].codes
[i
] == 0)
658 /* If we got here, we can't prove that D1 and D2 cannot both be true.
659 If we are only to check the top level, return 0. Otherwise, see if
660 we can prove that all choices in both successors are mutually
661 exclusive. If either does not have any successors, we can't prove
662 they can't both be true. */
664 if (toplevel
|| d1
->success
.first
== 0 || d2
->success
.first
== 0)
667 for (p1
= d1
->success
.first
; p1
; p1
= p1
->next
)
668 for (p2
= d2
->success
.first
; p2
; p2
= p2
->next
)
669 if (! not_both_true (p1
, p2
, 0))
675 /* Assuming that we can reorder all the alternatives at a specific point in
676 the tree (see discussion in merge_trees), we would prefer an ordering of
677 nodes where groups of consecutive nodes test the same mode and, within each
678 mode, groups of nodes test the same code. With this order, we can
679 construct nested switch statements, the inner one to test the code and
680 the outer one to test the mode.
682 We would like to list nodes testing for specific codes before those
683 that test predicates to avoid unnecessary function calls. Similarly,
684 tests for specific modes should precede nodes that allow any mode.
686 This function returns the merit (with 0 being the best) of inserting
687 a test involving the specified MODE and CODE after node P. If P is
688 zero, we are to determine the merit of inserting the test at the front
692 position_merit (p
, mode
, code
)
694 enum machine_mode mode
;
697 enum machine_mode p_mode
;
699 /* The only time the front of the list is anything other than the worst
700 position is if we are testing a mode that isn't VOIDmode. */
702 return mode
== VOIDmode
? 3 : 2;
704 p_mode
= p
->enforce_mode
? p
->mode
: VOIDmode
;
706 /* The best case is if the codes and modes both match. */
707 if (p_mode
== mode
&& p
->code
== code
)
710 /* If the codes don't match, the next best case is if the modes match.
711 In that case, the best position for this node depends on whether
712 we are testing for a specific code or not. If we are, the best place
713 is after some other test for an explicit code and our mode or after
714 the last test in the previous mode if every test in our mode is for
717 If we are testing for UNKNOWN, then the next best case is at the end of
721 && ((p_mode
== mode
&& p
->code
!= UNKNOWN
)
722 || (p_mode
!= mode
&& p
->next
723 && (p
->next
->enforce_mode
? p
->next
->mode
: VOIDmode
) == mode
724 && (p
->next
->code
== UNKNOWN
))))
725 || (code
== UNKNOWN
&& p_mode
== mode
727 || (p
->next
->enforce_mode
? p
->next
->mode
: VOIDmode
) != mode
)))
730 /* The third best case occurs when nothing is testing MODE. If MODE
731 is not VOIDmode, then the third best case is after something of any
732 mode that is not VOIDmode. If we are testing VOIDmode, the third best
733 place is the end of the list. */
736 && ((mode
!= VOIDmode
&& p_mode
!= VOIDmode
)
737 || (mode
== VOIDmode
&& p
->next
== 0)))
740 /* Otherwise, we have the worst case. */
744 /* Merge two decision tree listheads OLDH and ADDH,
745 modifying OLDH destructively, and return the merged tree. */
747 static struct decision_head
748 merge_trees (oldh
, addh
)
749 register struct decision_head oldh
, addh
;
751 struct decision
*add
, *next
;
759 /* If we are adding things at different positions, something is wrong. */
760 if (strcmp (oldh
.first
->position
, addh
.first
->position
))
763 for (add
= addh
.first
; add
; add
= next
)
765 enum machine_mode add_mode
= add
->enforce_mode
? add
->mode
: VOIDmode
;
766 struct decision
*best_position
= 0;
768 struct decision
*old
;
772 /* The semantics of pattern matching state that the tests are done in
773 the order given in the MD file so that if an insn matches two
774 patterns, the first one will be used. However, in practice, most,
775 if not all, patterns are unambiguous so that their order is
776 independent. In that case, we can merge identical tests and
777 group all similar modes and codes together.
779 Scan starting from the end of OLDH until we reach a point
780 where we reach the head of the list or where we pass a pattern
781 that could also be true if NEW is true. If we find an identical
782 pattern, we can merge them. Also, record the last node that tests
783 the same code and mode and the last one that tests just the same mode.
785 If we have no match, place NEW after the closest match we found. */
787 for (old
= oldh
.last
; old
; old
= old
->prev
)
791 /* If we don't have anything to test except an additional test,
792 do not consider the two nodes equal. If we did, the test below
793 would cause an infinite recursion. */
794 if (old
->tests
== 0 && old
->test_elt_zero_int
== 0
795 && old
->test_elt_one_int
== 0 && old
->veclen
== 0
796 && old
->test_elt_zero_wide
== 0
797 && old
->dupno
== -1 && old
->mode
== VOIDmode
798 && old
->code
== UNKNOWN
799 && (old
->c_test
!= 0 || add
->c_test
!= 0))
802 else if ((old
->tests
== add
->tests
803 || (old
->pred
>= 0 && old
->pred
== add
->pred
)
804 || (old
->tests
&& add
->tests
805 && !strcmp (old
->tests
, add
->tests
)))
806 && old
->test_elt_zero_int
== add
->test_elt_zero_int
807 && old
->elt_zero_int
== add
->elt_zero_int
808 && old
->test_elt_one_int
== add
->test_elt_one_int
809 && old
->elt_one_int
== add
->elt_one_int
810 && old
->test_elt_zero_wide
== add
->test_elt_zero_wide
811 && old
->elt_zero_wide
== add
->elt_zero_wide
812 && old
->veclen
== add
->veclen
813 && old
->dupno
== add
->dupno
814 && old
->opno
== add
->opno
815 && old
->code
== add
->code
816 && old
->enforce_mode
== add
->enforce_mode
817 && old
->mode
== add
->mode
)
819 /* If the additional test is not the same, split both nodes
820 into nodes that just contain all things tested before the
821 additional test and nodes that contain the additional test
822 and actions when it is true. This optimization is important
823 because of the case where we have almost identical patterns
824 with different tests on target flags. */
826 if (old
->c_test
!= add
->c_test
827 && ! (old
->c_test
&& add
->c_test
828 && !strcmp (old
->c_test
, add
->c_test
)))
830 if (old
->insn_code_number
>= 0 || old
->opno
>= 0)
832 struct decision
*split
833 = (struct decision
*) xmalloc (sizeof (struct decision
));
835 mybcopy ((char *) old
, (char *) split
,
836 sizeof (struct decision
));
838 old
->success
.first
= old
->success
.last
= split
;
841 old
->insn_code_number
= -1;
842 old
->num_clobbers_to_add
= 0;
844 split
->number
= next_number
++;
845 split
->next
= split
->prev
= 0;
846 split
->mode
= VOIDmode
;
847 split
->code
= UNKNOWN
;
849 split
->test_elt_zero_int
= 0;
850 split
->test_elt_one_int
= 0;
851 split
->test_elt_zero_wide
= 0;
857 if (add
->insn_code_number
>= 0 || add
->opno
>= 0)
859 struct decision
*split
860 = (struct decision
*) xmalloc (sizeof (struct decision
));
862 mybcopy ((char *) add
, (char *) split
,
863 sizeof (struct decision
));
865 add
->success
.first
= add
->success
.last
= split
;
868 add
->insn_code_number
= -1;
869 add
->num_clobbers_to_add
= 0;
871 split
->number
= next_number
++;
872 split
->next
= split
->prev
= 0;
873 split
->mode
= VOIDmode
;
874 split
->code
= UNKNOWN
;
876 split
->test_elt_zero_int
= 0;
877 split
->test_elt_one_int
= 0;
878 split
->test_elt_zero_wide
= 0;
885 if (old
->insn_code_number
>= 0 && add
->insn_code_number
>= 0)
887 /* If one node is for a normal insn and the second is
888 for the base insn with clobbers stripped off, the
889 second node should be ignored. */
891 if (old
->num_clobbers_to_add
== 0
892 && add
->num_clobbers_to_add
> 0)
893 /* Nothing to do here. */
895 else if (old
->num_clobbers_to_add
> 0
896 && add
->num_clobbers_to_add
== 0)
898 /* In this case, replace OLD with ADD. */
899 old
->insn_code_number
= add
->insn_code_number
;
900 old
->num_clobbers_to_add
= 0;
903 fatal ("Two actions at one point in tree");
906 if (old
->insn_code_number
== -1)
907 old
->insn_code_number
= add
->insn_code_number
;
908 old
->success
= merge_trees (old
->success
, add
->success
);
913 /* Unless we have already found the best possible insert point,
914 see if this position is better. If so, record it. */
917 && ((our_merit
= position_merit (old
, add_mode
, add
->code
))
919 best_merit
= our_merit
, best_position
= old
;
921 if (! not_both_true (old
, add
, 0))
925 /* If ADD was duplicate, we are done. */
929 /* Otherwise, find the best place to insert ADD. Normally this is
930 BEST_POSITION. However, if we went all the way to the top of
931 the list, it might be better to insert at the top. */
933 if (best_position
== 0)
937 && position_merit (NULL_PTR
, add_mode
, add
->code
) < best_merit
)
940 add
->next
= oldh
.first
;
941 oldh
.first
->prev
= add
;
947 add
->prev
= best_position
;
948 add
->next
= best_position
->next
;
949 best_position
->next
= add
;
950 if (best_position
== oldh
.last
)
953 add
->next
->prev
= add
;
960 /* Count the number of subnodes of HEAD. If the number is high enough,
961 make the first node in HEAD start a separate subroutine in the C code
964 TYPE gives the type of routine we are writing.
966 INITIAL is non-zero if this is the highest-level node. We never write
970 break_out_subroutines (head
, type
, initial
)
971 struct decision_head head
;
972 enum routine_type type
;
976 struct decision
*sub
;
978 for (sub
= head
.first
; sub
; sub
= sub
->next
)
979 size
+= 1 + break_out_subroutines (sub
->success
, type
, 0);
981 if (size
> SUBROUTINE_THRESHOLD
&& ! initial
)
983 head
.first
->subroutine_number
= ++next_subroutine_number
;
984 write_subroutine (head
.first
, type
);
990 /* Write out a subroutine of type TYPE to do comparisons starting at node
994 write_subroutine (tree
, type
)
995 struct decision
*tree
;
996 enum routine_type type
;
1001 printf ("rtx\nsplit");
1003 printf ("int\nrecog");
1005 if (tree
!= 0 && tree
->subroutine_number
> 0)
1006 printf ("_%d", tree
->subroutine_number
);
1007 else if (type
== SPLIT
)
1010 printf (" (x0, insn");
1012 printf (", pnum_clobbers");
1015 printf (" register rtx x0;\n rtx insn ATTRIBUTE_UNUSED;\n");
1017 printf (" int *pnum_clobbers ATTRIBUTE_UNUSED;\n");
1020 printf (" register rtx *ro = &recog_operand[0];\n");
1022 printf (" register rtx ");
1023 for (i
= 1; i
< max_depth
; i
++)
1024 printf ("x%d ATTRIBUTE_UNUSED, ", i
);
1026 printf ("x%d ATTRIBUTE_UNUSED;\n", max_depth
);
1027 printf (" %s tem ATTRIBUTE_UNUSED;\n", type
== SPLIT
? "rtx" : "int");
1028 write_tree (tree
, "", NULL_PTR
, 1, type
);
1029 printf (" ret0: return %d;\n}\n\n", type
== SPLIT
? 0 : -1);
1032 /* This table is used to indent the recog_* functions when we are inside
1033 conditions or switch statements. We only support small indentations
1034 and always indent at least two spaces. */
1036 static char *indents
[]
1037 = {" ", " ", " ", " ", " ", " ", " ", " ",
1038 "\t", "\t ", "\t ", "\t ", "\t ", "\t ", "\t ",
1039 "\t\t", "\t\t ", "\t\t ", "\t\t ", "\t\t ", "\t\t "};
1041 /* Write out C code to perform the decisions in TREE for a subroutine of
1042 type TYPE. If all of the choices fail, branch to node AFTERWARD, if
1043 non-zero, otherwise return. PREVPOS is the position of the node that
1044 branched to this test.
1046 When we merged all alternatives, we tried to set up a convenient order.
1047 Specifically, tests involving the same mode are all grouped together,
1048 followed by a group that does not contain a mode test. Within each group
1049 of the same mode, we also group tests with the same code, followed by a
1050 group that does not test a code.
1052 Occasionally, we cannot arbitrarily reorder the tests so that multiple
1053 sequence of groups as described above are present.
1055 We generate two nested switch statements, the outer statement for
1056 testing modes, and the inner switch for testing RTX codes. It is
1057 not worth optimizing cases when only a small number of modes or
1058 codes is tested, since the compiler can do that when compiling the
1059 resulting function. We do check for when every test is the same mode
1063 write_tree_1 (tree
, prevpos
, afterward
, type
)
1064 struct decision
*tree
;
1066 struct decision
*afterward
;
1067 enum routine_type type
;
1069 register struct decision
*p
, *p1
;
1070 register int depth
= tree
? strlen (tree
->position
) : 0;
1071 enum machine_mode switch_mode
= VOIDmode
;
1072 RTX_CODE switch_code
= UNKNOWN
;
1074 char modemap
[NUM_MACHINE_MODES
];
1075 char codemap
[NUM_RTX_CODE
];
1079 /* One tricky area is what is the exact state when we branch to a
1080 node's label. There are two cases where we branch: when looking at
1081 successors to a node, or when a set of tests fails.
1083 In the former case, we are always branching to the first node in a
1084 decision list and we want all required tests to be performed. We
1085 put the labels for such nodes in front of any switch or test statements.
1086 These branches are done without updating the position to that of the
1089 In the latter case, we are branching to a node that is not the first
1090 node in a decision list. We have already checked that it is possible
1091 for both the node we originally tested at this level and the node we
1092 are branching to to both match some pattern. That means that they
1093 usually will be testing the same mode and code. So it is normally safe
1094 for such labels to be inside switch statements, since the tests done
1095 by virtue of arriving at that label will usually already have been
1096 done. The exception is a branch from a node that does not test a
1097 mode or code to one that does. In such cases, we set the `retest_mode'
1098 or `retest_code' flags. That will ensure that we start a new switch
1099 at that position and put the label before the switch.
1101 The branches in the latter case must set the position to that of the
1106 if (tree
&& tree
->subroutine_number
== 0)
1108 printf (" L%d:\n", tree
->number
);
1109 tree
->label_needed
= 0;
1114 change_state (prevpos
, tree
->position
, 2);
1115 prevpos
= tree
->position
;
1118 for (p
= tree
; p
; p
= p
->next
)
1120 enum machine_mode mode
= p
->enforce_mode
? p
->mode
: VOIDmode
;
1122 int wrote_bracket
= 0;
1125 if (p
->success
.first
== 0 && p
->insn_code_number
< 0)
1128 /* Find the next alternative to p that might be true when p is true.
1129 Test that one next if p's successors fail. */
1131 for (p1
= p
->next
; p1
&& not_both_true (p
, p1
, 1); p1
= p1
->next
)
1137 if (mode
== VOIDmode
&& p1
->enforce_mode
&& p1
->mode
!= VOIDmode
)
1138 p1
->retest_mode
= 1;
1139 if (p
->code
== UNKNOWN
&& p1
->code
!= UNKNOWN
)
1140 p1
->retest_code
= 1;
1141 p1
->label_needed
= 1;
1144 /* If we have a different code or mode than the last node and
1145 are in a switch on codes, we must either end the switch or
1146 go to another case. We must also end the switch if this
1147 node needs a label and to retest either the mode or code. */
1149 if (switch_code
!= UNKNOWN
1150 && (switch_code
!= p
->code
|| switch_mode
!= mode
1151 || (p
->label_needed
&& (p
->retest_mode
|| p
->retest_code
))))
1153 enum rtx_code code
= p
->code
;
1155 /* If P is testing a predicate that we know about and we haven't
1156 seen any of the codes that are valid for the predicate, we
1157 can write a series of "case" statement, one for each possible
1158 code. Since we are already in a switch, these redundant tests
1159 are very cheap and will reduce the number of predicate called. */
1163 for (i
= 0; i
< NUM_RTX_CODE
&& preds
[p
->pred
].codes
[i
] != 0; i
++)
1164 if (codemap
[(int) preds
[p
->pred
].codes
[i
]])
1167 if (preds
[p
->pred
].codes
[i
] == 0)
1168 code
= MATCH_OPERAND
;
1171 if (code
== UNKNOWN
|| codemap
[(int) code
]
1172 || switch_mode
!= mode
1173 || (p
->label_needed
&& (p
->retest_mode
|| p
->retest_code
)))
1175 printf ("%s}\n", indents
[indent
- 2]);
1176 switch_code
= UNKNOWN
;
1182 printf ("%sbreak;\n", indents
[indent
]);
1184 if (code
== MATCH_OPERAND
)
1186 for (i
= 0; i
< NUM_RTX_CODE
&& preds
[p
->pred
].codes
[i
] != 0; i
++)
1188 printf ("%scase ", indents
[indent
- 2]);
1189 print_code (preds
[p
->pred
].codes
[i
]);
1191 codemap
[(int) preds
[p
->pred
].codes
[i
]] = 1;
1196 printf ("%scase ", indents
[indent
- 2]);
1199 codemap
[(int) p
->code
] = 1;
1208 /* If we were previously in a switch on modes and now have a different
1209 mode, end at least the case, and maybe end the switch if we are
1210 not testing a mode or testing a mode whose case we already saw. */
1212 if (switch_mode
!= VOIDmode
1213 && (switch_mode
!= mode
|| (p
->label_needed
&& p
->retest_mode
)))
1215 if (mode
== VOIDmode
|| modemap
[(int) mode
]
1216 || (p
->label_needed
&& p
->retest_mode
))
1218 printf ("%s}\n", indents
[indent
- 2]);
1219 switch_mode
= VOIDmode
;
1225 printf (" break;\n");
1226 printf (" case %smode:\n", GET_MODE_NAME (mode
));
1228 modemap
[(int) mode
] = 1;
1234 /* If we are about to write dead code, something went wrong. */
1235 if (! p
->label_needed
&& uncond
)
1238 /* If we need a label and we will want to retest the mode or code at
1239 that label, write the label now. We have already ensured that
1240 things will be valid for the test. */
1242 if (p
->label_needed
&& (p
->retest_mode
|| p
->retest_code
))
1244 printf ("%sL%d:\n", indents
[indent
- 2], p
->number
);
1245 p
->label_needed
= 0;
1250 /* If we are not in any switches, see if we can shortcut things
1251 by checking for identical modes and codes. */
1253 if (switch_mode
== VOIDmode
&& switch_code
== UNKNOWN
)
1255 /* If p and its alternatives all want the same mode,
1256 reject all others at once, first, then ignore the mode. */
1258 if (mode
!= VOIDmode
&& p
->next
&& same_modes (p
, mode
))
1260 printf (" if (GET_MODE (x%d) != %smode)\n",
1261 depth
, GET_MODE_NAME (p
->mode
));
1265 change_state (p
->position
, afterward
->position
, 6);
1266 printf (" goto L%d;\n }\n", afterward
->number
);
1269 printf (" goto ret0;\n");
1274 /* If p and its alternatives all want the same code,
1275 reject all others at once, first, then ignore the code. */
1277 if (p
->code
!= UNKNOWN
&& p
->next
&& same_codes (p
, p
->code
))
1279 printf (" if (GET_CODE (x%d) != ", depth
);
1280 print_code (p
->code
);
1285 change_state (p
->position
, afterward
->position
, indent
+ 4);
1286 printf (" goto L%d;\n }\n", afterward
->number
);
1289 printf (" goto ret0;\n");
1294 /* If we are not in a mode switch and we are testing for a specific
1295 mode, start a mode switch unless we have just one node or the next
1296 node is not testing a mode (we have already tested for the case of
1297 more than one mode, but all of the same mode). */
1299 if (switch_mode
== VOIDmode
&& mode
!= VOIDmode
&& p
->next
!= 0
1300 && p
->next
->enforce_mode
&& p
->next
->mode
!= VOIDmode
)
1302 mybzero (modemap
, sizeof modemap
);
1303 printf ("%sswitch (GET_MODE (x%d))\n", indents
[indent
], depth
);
1304 printf ("%s{\n", indents
[indent
+ 2]);
1306 printf ("%sdefault:\n%sbreak;\n", indents
[indent
- 2],
1308 printf ("%scase %smode:\n", indents
[indent
- 2],
1309 GET_MODE_NAME (mode
));
1310 modemap
[(int) mode
] = 1;
1314 /* Similarly for testing codes. */
1316 if (switch_code
== UNKNOWN
&& p
->code
!= UNKNOWN
&& ! p
->ignore_code
1317 && p
->next
!= 0 && p
->next
->code
!= UNKNOWN
)
1319 mybzero (codemap
, sizeof codemap
);
1320 printf ("%sswitch (GET_CODE (x%d))\n", indents
[indent
], depth
);
1321 printf ("%s{\n", indents
[indent
+ 2]);
1323 printf ("%sdefault:\n%sbreak;\n", indents
[indent
- 2],
1325 printf ("%scase ", indents
[indent
- 2]);
1326 print_code (p
->code
);
1328 codemap
[(int) p
->code
] = 1;
1329 switch_code
= p
->code
;
1332 /* Now that most mode and code tests have been done, we can write out
1333 a label for an inner node, if we haven't already. */
1334 if (p
->label_needed
)
1335 printf ("%sL%d:\n", indents
[indent
- 2], p
->number
);
1337 inner_indent
= indent
;
1339 /* The only way we can have to do a mode or code test here is if
1340 this node needs such a test but is the only node to be tested.
1341 In that case, we won't have started a switch. Note that this is
1342 the only way the switch and test modes can disagree. */
1344 if ((mode
!= switch_mode
&& ! p
->ignore_mode
)
1345 || (p
->code
!= switch_code
&& p
->code
!= UNKNOWN
&& ! p
->ignore_code
)
1346 || p
->test_elt_zero_int
|| p
->test_elt_one_int
1347 || p
->test_elt_zero_wide
|| p
->veclen
1348 || p
->dupno
>= 0 || p
->tests
|| p
->num_clobbers_to_add
)
1350 printf ("%sif (", indents
[indent
]);
1352 if (mode
!= switch_mode
&& ! p
->ignore_mode
)
1353 printf ("GET_MODE (x%d) == %smode && ",
1354 depth
, GET_MODE_NAME (mode
));
1355 if (p
->code
!= switch_code
&& p
->code
!= UNKNOWN
&& ! p
->ignore_code
)
1357 printf ("GET_CODE (x%d) == ", depth
);
1358 print_code (p
->code
);
1362 if (p
->test_elt_zero_int
)
1363 printf ("XINT (x%d, 0) == %d && ", depth
, p
->elt_zero_int
);
1364 if (p
->test_elt_one_int
)
1365 printf ("XINT (x%d, 1) == %d && ", depth
, p
->elt_one_int
);
1366 if (p
->test_elt_zero_wide
)
1368 /* Set offset to 1 iff the number might get propagated to
1369 unsigned long by ANSI C rules, else 0.
1370 Prospective hosts are required to have at least 32 bit
1371 ints, and integer constants in machine descriptions
1372 must fit in 32 bit, thus it suffices to check only
1374 HOST_WIDE_INT offset
= p
->elt_zero_wide
== -2147483647 - 1;
1375 printf ("XWINT (x%d, 0) == ", depth
);
1376 printf (HOST_WIDE_INT_PRINT_DEC
, p
->elt_zero_wide
+ offset
);
1377 printf ("%s && ", offset
? "-1" : "");
1380 printf ("XVECLEN (x%d, 0) == %d && ", depth
, p
->veclen
);
1382 printf ("rtx_equal_p (x%d, ro[%d]) && ", depth
, p
->dupno
);
1383 if (p
->num_clobbers_to_add
)
1384 printf ("pnum_clobbers != 0 && ");
1386 printf ("%s (x%d, %smode)", p
->tests
, depth
,
1387 GET_MODE_NAME (p
->mode
));
1397 need_bracket
= ! uncond
;
1403 printf ("%s{\n", indents
[inner_indent
]);
1409 printf ("%sro[%d] = x%d;\n", indents
[inner_indent
], p
->opno
, depth
);
1414 printf ("%sif (%s)\n", indents
[inner_indent
], p
->c_test
);
1420 if (p
->insn_code_number
>= 0)
1423 printf ("%sreturn gen_split_%d (operands);\n",
1424 indents
[inner_indent
], p
->insn_code_number
);
1427 if (p
->num_clobbers_to_add
)
1431 printf ("%s{\n", indents
[inner_indent
]);
1435 printf ("%s*pnum_clobbers = %d;\n",
1436 indents
[inner_indent
], p
->num_clobbers_to_add
);
1437 printf ("%sreturn %d;\n",
1438 indents
[inner_indent
], p
->insn_code_number
);
1443 printf ("%s}\n", indents
[inner_indent
]);
1447 printf ("%sreturn %d;\n",
1448 indents
[inner_indent
], p
->insn_code_number
);
1452 printf ("%sgoto L%d;\n", indents
[inner_indent
],
1453 p
->success
.first
->number
);
1456 printf ("%s}\n", indents
[inner_indent
- 2]);
1459 /* We have now tested all alternatives. End any switches we have open
1460 and branch to the alternative node unless we know that we can't fall
1461 through to the branch. */
1463 if (switch_code
!= UNKNOWN
)
1465 printf ("%s}\n", indents
[indent
- 2]);
1470 if (switch_mode
!= VOIDmode
)
1472 printf ("%s}\n", indents
[indent
- 2]);
1485 change_state (prevpos
, afterward
->position
, 2);
1486 printf (" goto L%d;\n", afterward
->number
);
1489 printf (" goto ret0;\n");
1497 for (p1
= GET_RTX_NAME (code
); *p1
; p1
++)
1499 if (*p1
>= 'a' && *p1
<= 'z')
1500 putchar (*p1
+ 'A' - 'a');
1507 same_codes (p
, code
)
1508 register struct decision
*p
;
1509 register enum rtx_code code
;
1511 for (; p
; p
= p
->next
)
1512 if (p
->code
!= code
)
1520 register struct decision
*p
;
1522 for (; p
; p
= p
->next
)
1527 same_modes (p
, mode
)
1528 register struct decision
*p
;
1529 register enum machine_mode mode
;
1531 for (; p
; p
= p
->next
)
1532 if ((p
->enforce_mode
? p
->mode
: VOIDmode
) != mode
)
1540 register struct decision
*p
;
1542 for (; p
; p
= p
->next
)
1543 p
->enforce_mode
= 0;
1546 /* Write out the decision tree starting at TREE for a subroutine of type TYPE.
1548 PREVPOS is the position at the node that branched to this node.
1550 INITIAL is nonzero if this is the first node we are writing in a subroutine.
1552 If all nodes are false, branch to the node AFTERWARD. */
1555 write_tree (tree
, prevpos
, afterward
, initial
, type
)
1556 struct decision
*tree
;
1558 struct decision
*afterward
;
1560 enum routine_type type
;
1562 register struct decision
*p
;
1563 char *name_prefix
= (type
== SPLIT
? "split" : "recog");
1564 char *call_suffix
= (type
== SPLIT
? "" : ", pnum_clobbers");
1566 if (! initial
&& tree
->subroutine_number
> 0)
1568 printf (" L%d:\n", tree
->number
);
1572 printf (" tem = %s_%d (x0, insn%s);\n",
1573 name_prefix
, tree
->subroutine_number
, call_suffix
);
1575 printf (" if (tem != 0) return tem;\n");
1577 printf (" if (tem >= 0) return tem;\n");
1578 change_state (tree
->position
, afterward
->position
, 2);
1579 printf (" goto L%d;\n", afterward
->number
);
1582 printf (" return %s_%d (x0, insn%s);\n",
1583 name_prefix
, tree
->subroutine_number
, call_suffix
);
1587 write_tree_1 (tree
, prevpos
, afterward
, type
);
1589 for (p
= tree
; p
; p
= p
->next
)
1590 if (p
->success
.first
)
1591 write_tree (p
->success
.first
, p
->position
,
1592 p
->afterward
? p
->afterward
: afterward
, 0, type
);
1596 /* Assuming that the state of argument is denoted by OLDPOS, take whatever
1597 actions are necessary to move to NEWPOS.
1599 INDENT says how many blanks to place at the front of lines. */
1602 change_state (oldpos
, newpos
, indent
)
1607 int odepth
= strlen (oldpos
);
1609 int ndepth
= strlen (newpos
);
1611 /* Pop up as many levels as necessary. */
1613 while (strncmp (oldpos
, newpos
, depth
))
1616 /* Go down to desired level. */
1618 while (depth
< ndepth
)
1620 if (newpos
[depth
] >= 'a' && newpos
[depth
] <= 'z')
1621 printf ("%sx%d = XVECEXP (x%d, 0, %d);\n",
1622 indents
[indent
], depth
+ 1, depth
, newpos
[depth
] - 'a');
1624 printf ("%sx%d = XEXP (x%d, %c);\n",
1625 indents
[indent
], depth
+ 1, depth
, newpos
[depth
]);
1639 tem
= (char *) xmalloc (strlen (s1
) + 1);
1648 register unsigned length
;
1650 while (length
-- > 0)
1655 mybcopy (in
, out
, length
)
1656 register char *in
, *out
;
1657 register unsigned length
;
1659 while (length
-- > 0)
1664 xrealloc (ptr
, size
)
1668 char *result
= (char *) realloc (ptr
, size
);
1670 fatal ("virtual memory exhausted");
1678 register char *val
= (char *) malloc (size
);
1681 fatal ("virtual memory exhausted");
1686 fatal
VPROTO ((char *format
, ...))
1693 VA_START (ap
, format
);
1696 format
= va_arg (ap
, char *);
1699 fprintf (stderr
, "genrecog: ");
1700 vfprintf (stderr
, format
, ap
);
1702 fprintf (stderr
, "\n");
1703 fprintf (stderr
, "after %d definitions\n", next_index
);
1704 exit (FATAL_EXIT_CODE
);
1707 /* More 'friendly' abort that prints the line and file.
1708 config.h can #define abort fancy_abort if you like that sort of thing. */
1713 fatal ("Internal gcc abort.");
1722 struct decision_head recog_tree
;
1723 struct decision_head split_tree
;
1727 obstack_init (rtl_obstack
);
1728 recog_tree
.first
= recog_tree
.last
= split_tree
.first
= split_tree
.last
= 0;
1731 fatal ("No input file name.");
1733 infile
= fopen (argv
[1], "r");
1737 exit (FATAL_EXIT_CODE
);
1744 printf ("/* Generated automatically by the program `genrecog'\n\
1745 from the machine description file `md'. */\n\n");
1747 printf ("#include \"config.h\"\n");
1748 printf ("#include \"system.h\"\n");
1749 printf ("#include \"rtl.h\"\n");
1750 printf ("#include \"insn-config.h\"\n");
1751 printf ("#include \"recog.h\"\n");
1752 printf ("#include \"real.h\"\n");
1753 printf ("#include \"output.h\"\n");
1754 printf ("#include \"flags.h\"\n");
1757 /* Read the machine description. */
1761 c
= read_skip_spaces (infile
);
1766 desc
= read_rtx (infile
);
1767 if (GET_CODE (desc
) == DEFINE_INSN
)
1768 recog_tree
= merge_trees (recog_tree
,
1769 make_insn_sequence (desc
, RECOG
));
1770 else if (GET_CODE (desc
) == DEFINE_SPLIT
)
1771 split_tree
= merge_trees (split_tree
,
1772 make_insn_sequence (desc
, SPLIT
));
1773 if (GET_CODE (desc
) == DEFINE_PEEPHOLE
1774 || GET_CODE (desc
) == DEFINE_EXPAND
)
1780 /* `recog' contains a decision tree\n\
1781 that recognizes whether the rtx X0 is a valid instruction.\n\
1783 recog returns -1 if the rtx is not valid.\n\
1784 If the rtx is valid, recog returns a nonnegative number\n\
1785 which is the insn code number for the pattern that matched.\n");
1786 printf (" This is the same as the order in the machine description of\n\
1787 the entry that matched. This number can be used as an index into various\n\
1788 insn_* tables, such as insn_templates, insn_outfun, and insn_n_operands\n\
1789 (found in insn-output.c).\n\n");
1790 printf (" The third argument to recog is an optional pointer to an int.\n\
1791 If present, recog will accept a pattern if it matches except for\n\
1792 missing CLOBBER expressions at the end. In that case, the value\n\
1793 pointed to by the optional pointer will be set to the number of\n\
1794 CLOBBERs that need to be added (it should be initialized to zero by\n\
1795 the caller). If it is set nonzero, the caller should allocate a\n\
1796 PARALLEL of the appropriate size, copy the initial entries, and call\n\
1797 add_clobbers (found in insn-emit.c) to fill in the CLOBBERs.");
1799 if (split_tree
.first
)
1800 printf ("\n\n The function split_insns returns 0 if the rtl could not\n\
1801 be split or the split rtl in a SEQUENCE if it can be.");
1805 printf ("#define operands recog_operand\n\n");
1807 next_subroutine_number
= 0;
1808 break_out_subroutines (recog_tree
, RECOG
, 1);
1809 write_subroutine (recog_tree
.first
, RECOG
);
1811 next_subroutine_number
= 0;
1812 break_out_subroutines (split_tree
, SPLIT
, 1);
1813 write_subroutine (split_tree
.first
, SPLIT
);
1816 exit (ferror (stdout
) != 0 ? FATAL_EXIT_CODE
: SUCCESS_EXIT_CODE
);