1 /* Gimple decl, type, and expression support functions.
2
3 Copyright (C) 2007-2020 Free Software Foundation, Inc.
4 Contributed by Aldy Hernandez <aldyh@redhat.com>
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "backend.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "stringpool.h"
29 #include "gimple-ssa.h"
30 #include "fold-const.h"
31 #include "tree-eh.h"
32 #include "gimplify.h"
33 #include "stor-layout.h"
34 #include "demangle.h"
35 #include "hash-set.h"
36 #include "rtl.h"
37 #include "tree-pass.h"
38 #include "stringpool.h"
39 #include "attribs.h"
40 #include "target.h"
41
42 /* ----- Type related ----- */
43
44 /* Return true if the conversion from INNER_TYPE to OUTER_TYPE is a
45 useless type conversion, otherwise return false.
46
47 This function implicitly defines the middle-end type system. With
48 the notion of 'a < b' meaning that useless_type_conversion_p (a, b)
49 holds and 'a > b' meaning that useless_type_conversion_p (b, a) holds,
50 the following invariants shall be fulfilled:
51
52 1) useless_type_conversion_p is transitive.
53 If a < b and b < c then a < c.
54
55 2) useless_type_conversion_p is not symmetric.
56 From a < b does not follow a > b.
57
58 3) Types define the available set of operations applicable to values.
59 A type conversion is useless if the operations for the target type
60 is a subset of the operations for the source type. For example
61 casts to void* are useless, casts from void* are not (void* can't
62 be dereferenced or offsetted, but copied, hence its set of operations
63 is a strict subset of that of all other data pointer types). Casts
64 to const T* are useless (can't be written to), casts from const T*
65 to T* are not. */
66
67 bool
useless_type_conversion_p(tree outer_type,tree inner_type)68 useless_type_conversion_p (tree outer_type, tree inner_type)
69 {
70 /* Do the following before stripping toplevel qualifiers. */
71 if (POINTER_TYPE_P (inner_type)
72 && POINTER_TYPE_P (outer_type))
73 {
74 /* Do not lose casts between pointers to different address spaces. */
75 if (TYPE_ADDR_SPACE (TREE_TYPE (outer_type))
76 != TYPE_ADDR_SPACE (TREE_TYPE (inner_type)))
77 return false;
78 /* Do not lose casts to function pointer types. */
79 if ((TREE_CODE (TREE_TYPE (outer_type)) == FUNCTION_TYPE
80 || TREE_CODE (TREE_TYPE (outer_type)) == METHOD_TYPE)
81 && !(TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE
82 || TREE_CODE (TREE_TYPE (inner_type)) == METHOD_TYPE))
83 return false;
84 }
85
86 /* From now on qualifiers on value types do not matter. */
87 inner_type = TYPE_MAIN_VARIANT (inner_type);
88 outer_type = TYPE_MAIN_VARIANT (outer_type);
89
90 if (inner_type == outer_type)
91 return true;
92
93 /* Changes in machine mode are never useless conversions because the RTL
94 middle-end expects explicit conversions between modes. */
95 if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type))
96 return false;
97
98 /* If both the inner and outer types are integral types, then the
99 conversion is not necessary if they have the same mode and
100 signedness and precision, and both or neither are boolean. */
101 if (INTEGRAL_TYPE_P (inner_type)
102 && INTEGRAL_TYPE_P (outer_type))
103 {
104 /* Preserve changes in signedness or precision. */
105 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
106 || TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
107 return false;
108
109 /* Preserve conversions to/from BOOLEAN_TYPE if types are not
110 of precision one. */
111 if (((TREE_CODE (inner_type) == BOOLEAN_TYPE)
112 != (TREE_CODE (outer_type) == BOOLEAN_TYPE))
113 && TYPE_PRECISION (outer_type) != 1)
114 return false;
115
116 /* We don't need to preserve changes in the types minimum or
117 maximum value in general as these do not generate code
118 unless the types precisions are different. */
119 return true;
120 }
121
122 /* Scalar floating point types with the same mode are compatible. */
123 else if (SCALAR_FLOAT_TYPE_P (inner_type)
124 && SCALAR_FLOAT_TYPE_P (outer_type))
125 return true;
126
127 /* Fixed point types with the same mode are compatible. */
128 else if (FIXED_POINT_TYPE_P (inner_type)
129 && FIXED_POINT_TYPE_P (outer_type))
130 return TYPE_SATURATING (inner_type) == TYPE_SATURATING (outer_type);
131
132 /* We need to take special care recursing to pointed-to types. */
133 else if (POINTER_TYPE_P (inner_type)
134 && POINTER_TYPE_P (outer_type))
135 {
136 /* We do not care for const qualification of the pointed-to types
137 as const qualification has no semantic value to the middle-end. */
138
139 /* Otherwise pointers/references are equivalent. */
140 return true;
141 }
142
143 /* Recurse for complex types. */
144 else if (TREE_CODE (inner_type) == COMPLEX_TYPE
145 && TREE_CODE (outer_type) == COMPLEX_TYPE)
146 return useless_type_conversion_p (TREE_TYPE (outer_type),
147 TREE_TYPE (inner_type));
148
149 /* Recurse for vector types with the same number of subparts. */
150 else if (TREE_CODE (inner_type) == VECTOR_TYPE
151 && TREE_CODE (outer_type) == VECTOR_TYPE)
152 return (known_eq (TYPE_VECTOR_SUBPARTS (inner_type),
153 TYPE_VECTOR_SUBPARTS (outer_type))
154 && useless_type_conversion_p (TREE_TYPE (outer_type),
155 TREE_TYPE (inner_type))
156 && targetm.compatible_vector_types_p (inner_type, outer_type));
157
158 else if (TREE_CODE (inner_type) == ARRAY_TYPE
159 && TREE_CODE (outer_type) == ARRAY_TYPE)
160 {
161 /* Preserve various attributes. */
162 if (TYPE_REVERSE_STORAGE_ORDER (inner_type)
163 != TYPE_REVERSE_STORAGE_ORDER (outer_type))
164 return false;
165 if (TYPE_STRING_FLAG (inner_type) != TYPE_STRING_FLAG (outer_type))
166 return false;
167
168 /* Conversions from array types with unknown extent to
169 array types with known extent are not useless. */
170 if (!TYPE_DOMAIN (inner_type) && TYPE_DOMAIN (outer_type))
171 return false;
172
173 /* Nor are conversions from array types with non-constant size to
174 array types with constant size or to different size. */
175 if (TYPE_SIZE (outer_type)
176 && TREE_CODE (TYPE_SIZE (outer_type)) == INTEGER_CST
177 && (!TYPE_SIZE (inner_type)
178 || TREE_CODE (TYPE_SIZE (inner_type)) != INTEGER_CST
179 || !tree_int_cst_equal (TYPE_SIZE (outer_type),
180 TYPE_SIZE (inner_type))))
181 return false;
182
183 /* Check conversions between arrays with partially known extents.
184 If the array min/max values are constant they have to match.
185 Otherwise allow conversions to unknown and variable extents.
186 In particular this declares conversions that may change the
187 mode to BLKmode as useless. */
188 if (TYPE_DOMAIN (inner_type)
189 && TYPE_DOMAIN (outer_type)
190 && TYPE_DOMAIN (inner_type) != TYPE_DOMAIN (outer_type))
191 {
192 tree inner_min = TYPE_MIN_VALUE (TYPE_DOMAIN (inner_type));
193 tree outer_min = TYPE_MIN_VALUE (TYPE_DOMAIN (outer_type));
194 tree inner_max = TYPE_MAX_VALUE (TYPE_DOMAIN (inner_type));
195 tree outer_max = TYPE_MAX_VALUE (TYPE_DOMAIN (outer_type));
196
197 /* After gimplification a variable min/max value carries no
198 additional information compared to a NULL value. All that
199 matters has been lowered to be part of the IL. */
200 if (inner_min && TREE_CODE (inner_min) != INTEGER_CST)
201 inner_min = NULL_TREE;
202 if (outer_min && TREE_CODE (outer_min) != INTEGER_CST)
203 outer_min = NULL_TREE;
204 if (inner_max && TREE_CODE (inner_max) != INTEGER_CST)
205 inner_max = NULL_TREE;
206 if (outer_max && TREE_CODE (outer_max) != INTEGER_CST)
207 outer_max = NULL_TREE;
208
209 /* Conversions NULL / variable <- cst are useless, but not
210 the other way around. */
211 if (outer_min
212 && (!inner_min
213 || !tree_int_cst_equal (inner_min, outer_min)))
214 return false;
215 if (outer_max
216 && (!inner_max
217 || !tree_int_cst_equal (inner_max, outer_max)))
218 return false;
219 }
220
221 /* Recurse on the element check. */
222 return useless_type_conversion_p (TREE_TYPE (outer_type),
223 TREE_TYPE (inner_type));
224 }
225
226 else if ((TREE_CODE (inner_type) == FUNCTION_TYPE
227 || TREE_CODE (inner_type) == METHOD_TYPE)
228 && TREE_CODE (inner_type) == TREE_CODE (outer_type))
229 {
230 tree outer_parm, inner_parm;
231
232 /* If the return types are not compatible bail out. */
233 if (!useless_type_conversion_p (TREE_TYPE (outer_type),
234 TREE_TYPE (inner_type)))
235 return false;
236
237 /* Method types should belong to a compatible base class. */
238 if (TREE_CODE (inner_type) == METHOD_TYPE
239 && !useless_type_conversion_p (TYPE_METHOD_BASETYPE (outer_type),
240 TYPE_METHOD_BASETYPE (inner_type)))
241 return false;
242
243 /* A conversion to an unprototyped argument list is ok. */
244 if (!prototype_p (outer_type))
245 return true;
246
247 /* If the unqualified argument types are compatible the conversion
248 is useless. */
249 if (TYPE_ARG_TYPES (outer_type) == TYPE_ARG_TYPES (inner_type))
250 return true;
251
252 for (outer_parm = TYPE_ARG_TYPES (outer_type),
253 inner_parm = TYPE_ARG_TYPES (inner_type);
254 outer_parm && inner_parm;
255 outer_parm = TREE_CHAIN (outer_parm),
256 inner_parm = TREE_CHAIN (inner_parm))
257 if (!useless_type_conversion_p
258 (TYPE_MAIN_VARIANT (TREE_VALUE (outer_parm)),
259 TYPE_MAIN_VARIANT (TREE_VALUE (inner_parm))))
260 return false;
261
262 /* If there is a mismatch in the number of arguments the functions
263 are not compatible. */
264 if (outer_parm || inner_parm)
265 return false;
266
267 /* Defer to the target if necessary. */
268 if (TYPE_ATTRIBUTES (inner_type) || TYPE_ATTRIBUTES (outer_type))
269 return comp_type_attributes (outer_type, inner_type) != 0;
270
271 return true;
272 }
273
274 /* For aggregates we rely on TYPE_CANONICAL exclusively and require
275 explicit conversions for types involving to be structurally
276 compared types. */
277 else if (AGGREGATE_TYPE_P (inner_type)
278 && TREE_CODE (inner_type) == TREE_CODE (outer_type))
279 return TYPE_CANONICAL (inner_type)
280 && TYPE_CANONICAL (inner_type) == TYPE_CANONICAL (outer_type);
281
282 else if (TREE_CODE (inner_type) == OFFSET_TYPE
283 && TREE_CODE (outer_type) == OFFSET_TYPE)
284 return useless_type_conversion_p (TREE_TYPE (outer_type),
285 TREE_TYPE (inner_type))
286 && useless_type_conversion_p
287 (TYPE_OFFSET_BASETYPE (outer_type),
288 TYPE_OFFSET_BASETYPE (inner_type));
289
290 return false;
291 }
292
293
294 /* ----- Decl related ----- */
295
296 /* Set sequence SEQ to be the GIMPLE body for function FN. */
297
298 void
gimple_set_body(tree fndecl,gimple_seq seq)299 gimple_set_body (tree fndecl, gimple_seq seq)
300 {
301 struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
302 if (fn == NULL)
303 {
304 /* If FNDECL still does not have a function structure associated
305 with it, then it does not make sense for it to receive a
306 GIMPLE body. */
307 gcc_assert (seq == NULL);
308 }
309 else
310 fn->gimple_body = seq;
311 }
312
313
314 /* Return the body of GIMPLE statements for function FN. After the
315 CFG pass, the function body doesn't exist anymore because it has
316 been split up into basic blocks. In this case, it returns
317 NULL. */
318
319 gimple_seq
gimple_body(tree fndecl)320 gimple_body (tree fndecl)
321 {
322 struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
323 return fn ? fn->gimple_body : NULL;
324 }
325
326 /* Return true when FNDECL has Gimple body either in unlowered
327 or CFG form. */
328 bool
gimple_has_body_p(tree fndecl)329 gimple_has_body_p (tree fndecl)
330 {
331 struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
332 return (gimple_body (fndecl) || (fn && fn->cfg && !(fn->curr_properties & PROP_rtl)));
333 }
334
335 /* Return a printable name for symbol DECL. */
336
337 const char *
gimple_decl_printable_name(tree decl,int verbosity)338 gimple_decl_printable_name (tree decl, int verbosity)
339 {
340 if (!DECL_NAME (decl))
341 return NULL;
342
343 if (HAS_DECL_ASSEMBLER_NAME_P (decl) && DECL_ASSEMBLER_NAME_SET_P (decl))
344 {
345 int dmgl_opts = DMGL_NO_OPTS;
346
347 if (verbosity >= 2)
348 {
349 dmgl_opts = DMGL_VERBOSE
350 | DMGL_ANSI
351 | DMGL_GNU_V3
352 | DMGL_RET_POSTFIX;
353 if (TREE_CODE (decl) == FUNCTION_DECL)
354 dmgl_opts |= DMGL_PARAMS;
355 }
356
357 const char *mangled_str
358 = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME_RAW (decl));
359 const char *str = cplus_demangle_v3 (mangled_str, dmgl_opts);
360 return str ? str : mangled_str;
361 }
362
363 return IDENTIFIER_POINTER (DECL_NAME (decl));
364 }
365
366
367 /* Create a new VAR_DECL and copy information from VAR to it. */
368
369 tree
copy_var_decl(tree var,tree name,tree type)370 copy_var_decl (tree var, tree name, tree type)
371 {
372 tree copy = build_decl (DECL_SOURCE_LOCATION (var), VAR_DECL, name, type);
373
374 TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (var);
375 TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (var);
376 DECL_GIMPLE_REG_P (copy) = DECL_GIMPLE_REG_P (var);
377 DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (var);
378 DECL_IGNORED_P (copy) = DECL_IGNORED_P (var);
379 DECL_CONTEXT (copy) = DECL_CONTEXT (var);
380 TREE_NO_WARNING (copy) = TREE_NO_WARNING (var);
381 TREE_USED (copy) = 1;
382 DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
383 DECL_ATTRIBUTES (copy) = DECL_ATTRIBUTES (var);
384 if (DECL_USER_ALIGN (var))
385 {
386 SET_DECL_ALIGN (copy, DECL_ALIGN (var));
387 DECL_USER_ALIGN (copy) = 1;
388 }
389
390 return copy;
391 }
392
393 /* Strip off a legitimate source ending from the input string NAME of
394 length LEN. Rather than having to know the names used by all of
395 our front ends, we strip off an ending of a period followed by
396 up to four characters. (like ".cpp".) */
397
398 static inline void
remove_suffix(char * name,int len)399 remove_suffix (char *name, int len)
400 {
401 int i;
402
403 for (i = 2; i < 7 && len > i; i++)
404 {
405 if (name[len - i] == '.')
406 {
407 name[len - i] = '\0';
408 break;
409 }
410 }
411 }
412
413 /* Create a new temporary name with PREFIX. Return an identifier. */
414
415 static GTY(()) unsigned int tmp_var_id_num;
416
417 tree
create_tmp_var_name(const char * prefix)418 create_tmp_var_name (const char *prefix)
419 {
420 char *tmp_name;
421
422 if (prefix)
423 {
424 char *preftmp = ASTRDUP (prefix);
425
426 remove_suffix (preftmp, strlen (preftmp));
427 clean_symbol_name (preftmp);
428
429 prefix = preftmp;
430 }
431
432 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
433 return get_identifier (tmp_name);
434 }
435
436 /* Create a new temporary variable declaration of type TYPE.
437 Do NOT push it into the current binding. */
438
439 tree
create_tmp_var_raw(tree type,const char * prefix)440 create_tmp_var_raw (tree type, const char *prefix)
441 {
442 tree tmp_var;
443
444 tmp_var = build_decl (input_location,
445 VAR_DECL, prefix ? create_tmp_var_name (prefix) : NULL,
446 type);
447
448 /* The variable was declared by the compiler. */
449 DECL_ARTIFICIAL (tmp_var) = 1;
450 /* And we don't want debug info for it. */
451 DECL_IGNORED_P (tmp_var) = 1;
452 /* And we don't want even the fancy names of those printed in
453 -fdump-final-insns= dumps. */
454 DECL_NAMELESS (tmp_var) = 1;
455
456 /* Make the variable writable. */
457 TREE_READONLY (tmp_var) = 0;
458
459 DECL_EXTERNAL (tmp_var) = 0;
460 TREE_STATIC (tmp_var) = 0;
461 TREE_USED (tmp_var) = 1;
462
463 return tmp_var;
464 }
465
466 /* Create a new temporary variable declaration of type TYPE. DO push the
467 variable into the current binding. Further, assume that this is called
468 only from gimplification or optimization, at which point the creation of
469 certain types are bugs. */
470
471 tree
create_tmp_var(tree type,const char * prefix)472 create_tmp_var (tree type, const char *prefix)
473 {
474 tree tmp_var;
475
476 /* We don't allow types that are addressable (meaning we can't make copies),
477 or incomplete. We also used to reject every variable size objects here,
478 but now support those for which a constant upper bound can be obtained.
479 The processing for variable sizes is performed in gimple_add_tmp_var,
480 point at which it really matters and possibly reached via paths not going
481 through this function, e.g. after direct calls to create_tmp_var_raw. */
482 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
483
484 tmp_var = create_tmp_var_raw (type, prefix);
485 gimple_add_tmp_var (tmp_var);
486 return tmp_var;
487 }
488
489 /* Create a new temporary variable declaration of type TYPE by calling
490 create_tmp_var and if TYPE is a vector or a complex number, mark the new
491 temporary as gimple register. */
492
493 tree
create_tmp_reg(tree type,const char * prefix)494 create_tmp_reg (tree type, const char *prefix)
495 {
496 tree tmp;
497
498 tmp = create_tmp_var (type, prefix);
499 if (TREE_CODE (type) == COMPLEX_TYPE
500 || TREE_CODE (type) == VECTOR_TYPE)
501 DECL_GIMPLE_REG_P (tmp) = 1;
502
503 return tmp;
504 }
505
506 /* Create a new temporary variable declaration of type TYPE by calling
507 create_tmp_var and if TYPE is a vector or a complex number, mark the new
508 temporary as gimple register. */
509
510 tree
create_tmp_reg_fn(struct function * fn,tree type,const char * prefix)511 create_tmp_reg_fn (struct function *fn, tree type, const char *prefix)
512 {
513 tree tmp;
514
515 tmp = create_tmp_var_raw (type, prefix);
516 gimple_add_tmp_var_fn (fn, tmp);
517 if (TREE_CODE (type) == COMPLEX_TYPE
518 || TREE_CODE (type) == VECTOR_TYPE)
519 DECL_GIMPLE_REG_P (tmp) = 1;
520
521 return tmp;
522 }
523
524
525 /* ----- Expression related ----- */
526
527 /* Extract the operands and code for expression EXPR into *SUBCODE_P,
528 *OP1_P, *OP2_P and *OP3_P respectively. */
529
530 void
extract_ops_from_tree(tree expr,enum tree_code * subcode_p,tree * op1_p,tree * op2_p,tree * op3_p)531 extract_ops_from_tree (tree expr, enum tree_code *subcode_p, tree *op1_p,
532 tree *op2_p, tree *op3_p)
533 {
534 *subcode_p = TREE_CODE (expr);
535 switch (get_gimple_rhs_class (*subcode_p))
536 {
537 case GIMPLE_TERNARY_RHS:
538 {
539 *op1_p = TREE_OPERAND (expr, 0);
540 *op2_p = TREE_OPERAND (expr, 1);
541 *op3_p = TREE_OPERAND (expr, 2);
542 break;
543 }
544 case GIMPLE_BINARY_RHS:
545 {
546 *op1_p = TREE_OPERAND (expr, 0);
547 *op2_p = TREE_OPERAND (expr, 1);
548 *op3_p = NULL_TREE;
549 break;
550 }
551 case GIMPLE_UNARY_RHS:
552 {
553 *op1_p = TREE_OPERAND (expr, 0);
554 *op2_p = NULL_TREE;
555 *op3_p = NULL_TREE;
556 break;
557 }
558 case GIMPLE_SINGLE_RHS:
559 {
560 *op1_p = expr;
561 *op2_p = NULL_TREE;
562 *op3_p = NULL_TREE;
563 break;
564 }
565 default:
566 gcc_unreachable ();
567 }
568 }
569
570 /* Extract operands for a GIMPLE_COND statement out of COND_EXPR tree COND. */
571
572 void
gimple_cond_get_ops_from_tree(tree cond,enum tree_code * code_p,tree * lhs_p,tree * rhs_p)573 gimple_cond_get_ops_from_tree (tree cond, enum tree_code *code_p,
574 tree *lhs_p, tree *rhs_p)
575 {
576 gcc_assert (COMPARISON_CLASS_P (cond)
577 || TREE_CODE (cond) == TRUTH_NOT_EXPR
578 || is_gimple_min_invariant (cond)
579 || SSA_VAR_P (cond));
580 gcc_checking_assert (!tree_could_throw_p (cond));
581
582 extract_ops_from_tree (cond, code_p, lhs_p, rhs_p);
583
584 /* Canonicalize conditionals of the form 'if (!VAL)'. */
585 if (*code_p == TRUTH_NOT_EXPR)
586 {
587 *code_p = EQ_EXPR;
588 gcc_assert (*lhs_p && *rhs_p == NULL_TREE);
589 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
590 }
591 /* Canonicalize conditionals of the form 'if (VAL)' */
592 else if (TREE_CODE_CLASS (*code_p) != tcc_comparison)
593 {
594 *code_p = NE_EXPR;
595 gcc_assert (*lhs_p && *rhs_p == NULL_TREE);
596 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
597 }
598 }
599
600 /* Return true if T is a valid LHS for a GIMPLE assignment expression. */
601
602 bool
is_gimple_lvalue(tree t)603 is_gimple_lvalue (tree t)
604 {
605 return (is_gimple_addressable (t)
606 || TREE_CODE (t) == WITH_SIZE_EXPR
607 /* These are complex lvalues, but don't have addresses, so they
608 go here. */
609 || TREE_CODE (t) == BIT_FIELD_REF);
610 }
611
612 /* Helper for is_gimple_condexpr and is_gimple_condexpr_for_cond. */
613
614 static bool
is_gimple_condexpr_1(tree t,bool allow_traps)615 is_gimple_condexpr_1 (tree t, bool allow_traps)
616 {
617 return (is_gimple_val (t) || (COMPARISON_CLASS_P (t)
618 && (allow_traps || !tree_could_throw_p (t))
619 && is_gimple_val (TREE_OPERAND (t, 0))
620 && is_gimple_val (TREE_OPERAND (t, 1))));
621 }
622
623 /* Return true if T is a GIMPLE condition. */
624
625 bool
is_gimple_condexpr(tree t)626 is_gimple_condexpr (tree t)
627 {
628 return is_gimple_condexpr_1 (t, true);
629 }
630
631 /* Like is_gimple_condexpr, but does not allow T to trap. */
632
633 bool
is_gimple_condexpr_for_cond(tree t)634 is_gimple_condexpr_for_cond (tree t)
635 {
636 return is_gimple_condexpr_1 (t, false);
637 }
638
639 /* Return true if T is a gimple address. */
640
641 bool
is_gimple_address(const_tree t)642 is_gimple_address (const_tree t)
643 {
644 tree op;
645
646 if (TREE_CODE (t) != ADDR_EXPR)
647 return false;
648
649 op = TREE_OPERAND (t, 0);
650 while (handled_component_p (op))
651 {
652 if ((TREE_CODE (op) == ARRAY_REF
653 || TREE_CODE (op) == ARRAY_RANGE_REF)
654 && !is_gimple_val (TREE_OPERAND (op, 1)))
655 return false;
656
657 op = TREE_OPERAND (op, 0);
658 }
659
660 if (CONSTANT_CLASS_P (op)
661 || TREE_CODE (op) == TARGET_MEM_REF
662 || TREE_CODE (op) == MEM_REF)
663 return true;
664
665 switch (TREE_CODE (op))
666 {
667 case PARM_DECL:
668 case RESULT_DECL:
669 case LABEL_DECL:
670 case FUNCTION_DECL:
671 case VAR_DECL:
672 case CONST_DECL:
673 return true;
674
675 default:
676 return false;
677 }
678 }
679
680 /* Return true if T is a gimple invariant address. */
681
682 bool
is_gimple_invariant_address(const_tree t)683 is_gimple_invariant_address (const_tree t)
684 {
685 const_tree op;
686
687 if (TREE_CODE (t) != ADDR_EXPR)
688 return false;
689
690 op = strip_invariant_refs (TREE_OPERAND (t, 0));
691 if (!op)
692 return false;
693
694 if (TREE_CODE (op) == MEM_REF)
695 {
696 const_tree op0 = TREE_OPERAND (op, 0);
697 return (TREE_CODE (op0) == ADDR_EXPR
698 && (CONSTANT_CLASS_P (TREE_OPERAND (op0, 0))
699 || decl_address_invariant_p (TREE_OPERAND (op0, 0))));
700 }
701
702 return CONSTANT_CLASS_P (op) || decl_address_invariant_p (op);
703 }
704
705 /* Return true if T is a gimple invariant address at IPA level
706 (so addresses of variables on stack are not allowed). */
707
708 bool
is_gimple_ip_invariant_address(const_tree t)709 is_gimple_ip_invariant_address (const_tree t)
710 {
711 const_tree op;
712
713 if (TREE_CODE (t) != ADDR_EXPR)
714 return false;
715
716 op = strip_invariant_refs (TREE_OPERAND (t, 0));
717 if (!op)
718 return false;
719
720 if (TREE_CODE (op) == MEM_REF)
721 {
722 const_tree op0 = TREE_OPERAND (op, 0);
723 return (TREE_CODE (op0) == ADDR_EXPR
724 && (CONSTANT_CLASS_P (TREE_OPERAND (op0, 0))
725 || decl_address_ip_invariant_p (TREE_OPERAND (op0, 0))));
726 }
727
728 return CONSTANT_CLASS_P (op) || decl_address_ip_invariant_p (op);
729 }
730
731 /* Return true if T is a GIMPLE minimal invariant. It's a restricted
732 form of function invariant. */
733
734 bool
is_gimple_min_invariant(const_tree t)735 is_gimple_min_invariant (const_tree t)
736 {
737 if (TREE_CODE (t) == ADDR_EXPR)
738 return is_gimple_invariant_address (t);
739
740 return is_gimple_constant (t);
741 }
742
743 /* Return true if T is a GIMPLE interprocedural invariant. It's a restricted
744 form of gimple minimal invariant. */
745
746 bool
is_gimple_ip_invariant(const_tree t)747 is_gimple_ip_invariant (const_tree t)
748 {
749 if (TREE_CODE (t) == ADDR_EXPR)
750 return is_gimple_ip_invariant_address (t);
751
752 return is_gimple_constant (t);
753 }
754
755 /* Return true if T is a non-aggregate register variable. */
756
757 bool
is_gimple_reg(tree t)758 is_gimple_reg (tree t)
759 {
760 if (virtual_operand_p (t))
761 return false;
762
763 if (TREE_CODE (t) == SSA_NAME)
764 return true;
765
766 if (!is_gimple_variable (t))
767 return false;
768
769 if (!is_gimple_reg_type (TREE_TYPE (t)))
770 return false;
771
772 /* A volatile decl is not acceptable because we can't reuse it as
773 needed. We need to copy it into a temp first. */
774 if (TREE_THIS_VOLATILE (t))
775 return false;
776
777 /* We define "registers" as things that can be renamed as needed,
778 which with our infrastructure does not apply to memory. */
779 if (needs_to_live_in_memory (t))
780 return false;
781
782 /* Hard register variables are an interesting case. For those that
783 are call-clobbered, we don't know where all the calls are, since
784 we don't (want to) take into account which operations will turn
785 into libcalls at the rtl level. For those that are call-saved,
786 we don't currently model the fact that calls may in fact change
787 global hard registers, nor do we examine ASM_CLOBBERS at the tree
788 level, and so miss variable changes that might imply. All around,
789 it seems safest to not do too much optimization with these at the
790 tree level at all. We'll have to rely on the rtl optimizers to
791 clean this up, as there we've got all the appropriate bits exposed. */
792 if (TREE_CODE (t) == VAR_DECL && DECL_HARD_REGISTER (t))
793 return false;
794
795 /* Complex and vector values must have been put into SSA-like form.
796 That is, no assignments to the individual components. */
797 if (TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE
798 || TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
799 return DECL_GIMPLE_REG_P (t);
800
801 return true;
802 }
803
804
805 /* Return true if T is a GIMPLE rvalue, i.e. an identifier or a constant. */
806
807 bool
is_gimple_val(tree t)808 is_gimple_val (tree t)
809 {
810 /* Make loads from volatiles and memory vars explicit. */
811 if (is_gimple_variable (t)
812 && is_gimple_reg_type (TREE_TYPE (t))
813 && !is_gimple_reg (t))
814 return false;
815
816 return (is_gimple_variable (t) || is_gimple_min_invariant (t));
817 }
818
819 /* Similarly, but accept hard registers as inputs to asm statements. */
820
821 bool
is_gimple_asm_val(tree t)822 is_gimple_asm_val (tree t)
823 {
824 if (TREE_CODE (t) == VAR_DECL && DECL_HARD_REGISTER (t))
825 return true;
826
827 return is_gimple_val (t);
828 }
829
830 /* Return true if T is a GIMPLE minimal lvalue. */
831
832 bool
is_gimple_min_lval(tree t)833 is_gimple_min_lval (tree t)
834 {
835 if (!(t = CONST_CAST_TREE (strip_invariant_refs (t))))
836 return false;
837 return (is_gimple_id (t) || TREE_CODE (t) == MEM_REF);
838 }
839
840 /* Return true if T is a valid function operand of a CALL_EXPR. */
841
842 bool
is_gimple_call_addr(tree t)843 is_gimple_call_addr (tree t)
844 {
845 return (TREE_CODE (t) == OBJ_TYPE_REF || is_gimple_val (t));
846 }
847
848 /* Return true if T is a valid address operand of a MEM_REF. */
849
850 bool
is_gimple_mem_ref_addr(tree t)851 is_gimple_mem_ref_addr (tree t)
852 {
853 return (is_gimple_reg (t)
854 || TREE_CODE (t) == INTEGER_CST
855 || (TREE_CODE (t) == ADDR_EXPR
856 && (CONSTANT_CLASS_P (TREE_OPERAND (t, 0))
857 || decl_address_invariant_p (TREE_OPERAND (t, 0)))));
858 }
859
860 /* Hold trees marked addressable during expand. */
861
862 static hash_set<tree> *mark_addressable_queue;
863
864 /* Mark X as addressable or queue it up if called during expand. We
865 don't want to apply it immediately during expand because decls are
866 made addressable at that point due to RTL-only concerns, such as
867 uses of memcpy for block moves, and TREE_ADDRESSABLE changes
868 is_gimple_reg, which might make it seem like a variable that used
869 to be a gimple_reg shouldn't have been an SSA name. So we queue up
870 this flag setting and only apply it when we're done with GIMPLE and
871 only RTL issues matter. */
872
873 static void
mark_addressable_1(tree x)874 mark_addressable_1 (tree x)
875 {
876 if (!currently_expanding_to_rtl)
877 {
878 TREE_ADDRESSABLE (x) = 1;
879 return;
880 }
881
882 if (!mark_addressable_queue)
883 mark_addressable_queue = new hash_set<tree>();
884 mark_addressable_queue->add (x);
885 }
886
887 /* Adaptor for mark_addressable_1 for use in hash_set traversal. */
888
889 bool
890 mark_addressable_2 (tree const &x, void * ATTRIBUTE_UNUSED = NULL)
891 {
892 mark_addressable_1 (x);
893 return false;
894 }
895
896 /* Mark all queued trees as addressable, and empty the queue. To be
897 called right after clearing CURRENTLY_EXPANDING_TO_RTL. */
898
899 void
flush_mark_addressable_queue()900 flush_mark_addressable_queue ()
901 {
902 gcc_assert (!currently_expanding_to_rtl);
903 if (mark_addressable_queue)
904 {
905 mark_addressable_queue->traverse<void*, mark_addressable_2> (NULL);
906 delete mark_addressable_queue;
907 mark_addressable_queue = NULL;
908 }
909 }
910
911 /* Mark X addressable. Unlike the langhook we expect X to be in gimple
912 form and we don't do any syntax checking. */
913
914 void
mark_addressable(tree x)915 mark_addressable (tree x)
916 {
917 while (handled_component_p (x))
918 x = TREE_OPERAND (x, 0);
919 if (TREE_CODE (x) == MEM_REF
920 && TREE_CODE (TREE_OPERAND (x, 0)) == ADDR_EXPR)
921 x = TREE_OPERAND (TREE_OPERAND (x, 0), 0);
922 if (!VAR_P (x)
923 && TREE_CODE (x) != PARM_DECL
924 && TREE_CODE (x) != RESULT_DECL)
925 return;
926 mark_addressable_1 (x);
927
928 /* Also mark the artificial SSA_NAME that points to the partition of X. */
929 if (TREE_CODE (x) == VAR_DECL
930 && !DECL_EXTERNAL (x)
931 && !TREE_STATIC (x)
932 && cfun->gimple_df != NULL
933 && cfun->gimple_df->decls_to_pointers != NULL)
934 {
935 tree *namep = cfun->gimple_df->decls_to_pointers->get (x);
936 if (namep)
937 mark_addressable_1 (*namep);
938 }
939 }
940
941 /* Returns true iff T is a valid RHS for an assignment to a renamed
942 user -- or front-end generated artificial -- variable. */
943
944 bool
is_gimple_reg_rhs(tree t)945 is_gimple_reg_rhs (tree t)
946 {
947 return get_gimple_rhs_class (TREE_CODE (t)) != GIMPLE_INVALID_RHS;
948 }
949
950 #include "gt-gimple-expr.h"
951