1 /*
2 * Copyright (c) 2014, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "opto/addnode.hpp"
27 #include "opto/callnode.hpp"
28 #include "opto/castnode.hpp"
29 #include "opto/connode.hpp"
30 #include "opto/graphKit.hpp"
31 #include "opto/inlinetypenode.hpp"
32 #include "opto/matcher.hpp"
33 #include "opto/phaseX.hpp"
34 #include "opto/rootnode.hpp"
35 #include "opto/subnode.hpp"
36 #include "opto/type.hpp"
37 #include "castnode.hpp"
38 #include "utilities/checkedCast.hpp"
39
40 //=============================================================================
41 // If input is already higher or equal to cast type, then this is an identity.
42 Node* ConstraintCastNode::Identity(PhaseGVN* phase) {
43 if (_dependency == UnconditionalDependency) {
44 return this;
45 }
46 Node* dom = dominating_cast(phase, phase);
47 if (dom != nullptr) {
48 return dom;
49 }
50 return higher_equal_types(phase, in(1)) ? in(1) : this;
51 }
52
53 //------------------------------Value------------------------------------------
54 // Take 'join' of input and cast-up type
55 const Type* ConstraintCastNode::Value(PhaseGVN* phase) const {
56 if (in(0) && phase->type(in(0)) == Type::TOP) return Type::TOP;
57
58 const Type* in_type = phase->type(in(1));
59 const Type* ft = in_type->filter_speculative(_type);
60
61 // Check if both _type and in_type had a speculative type, but for the just
62 // computed ft the speculative type was dropped.
63 if (ft->speculative() == nullptr &&
64 _type->speculative() != nullptr &&
65 in_type->speculative() != nullptr) {
66 // Speculative type may have disagreed between cast and input, and was
67 // dropped in filtering. Recompute so that ft can take speculative type
68 // of in_type. If we did not do it now, a subsequent ::Value call would
69 // do it, and violate idempotence of ::Value.
70 ft = in_type->filter_speculative(ft);
71 }
72
73 #ifdef ASSERT
74 // Previous versions of this function had some special case logic,
75 // which is no longer necessary. Make sure of the required effects.
76 switch (Opcode()) {
77 case Op_CastII:
78 {
79 if (in_type == Type::TOP) {
80 assert(ft == Type::TOP, "special case #1");
81 }
82 const Type* rt = in_type->join_speculative(_type);
83 if (rt->empty()) {
84 assert(ft == Type::TOP, "special case #2");
85 }
86 break;
87 }
88 case Op_CastPP:
89 if (in_type == TypePtr::NULL_PTR &&
90 _type->isa_ptr() && _type->is_ptr()->_ptr == TypePtr::NotNull) {
91 assert(ft == Type::TOP, "special case #3");
92 break;
93 }
94 }
95 #endif //ASSERT
96
97 return ft;
98 }
99
100 //------------------------------Ideal------------------------------------------
101 // Return a node which is more "ideal" than the current node. Strip out
102 // control copies
103 Node *ConstraintCastNode::Ideal(PhaseGVN *phase, bool can_reshape) {
104 if (in(0) && remove_dead_region(phase, can_reshape)) {
105 return this;
106 }
107
108 // Push cast through InlineTypeNode
109 InlineTypeNode* vt = in(1)->isa_InlineType();
110 if (vt != nullptr && phase->type(vt)->filter_speculative(_type) != Type::TOP) {
111 // TODO 8325106 Can we avoid cloning?
112 Node* cast = clone();
113 cast->set_req(1, vt->get_oop());
114 vt = vt->clone()->as_InlineType();
115 if (!_type->maybe_null()) {
116 vt->as_InlineType()->set_is_init(*phase);
117 }
118 vt->set_oop(*phase, phase->transform(cast));
119 return vt;
120 }
121
122 return nullptr;
123 }
124
125 uint ConstraintCastNode::hash() const {
126 return TypeNode::hash() + (int)_dependency + (_extra_types != nullptr ? _extra_types->hash() : 0);
127 }
128
129 bool ConstraintCastNode::cmp(const Node &n) const {
130 if (!TypeNode::cmp(n)) {
131 return false;
132 }
133 ConstraintCastNode& cast = (ConstraintCastNode&) n;
134 if (cast._dependency != _dependency) {
135 return false;
136 }
137 if (_extra_types == nullptr || cast._extra_types == nullptr) {
138 return _extra_types == cast._extra_types;
139 }
140 return _extra_types->eq(cast._extra_types);
141 }
142
143 uint ConstraintCastNode::size_of() const {
144 return sizeof(*this);
145 }
146
147 Node* ConstraintCastNode::make_cast_for_basic_type(Node* c, Node* n, const Type* t, DependencyType dependency, BasicType bt) {
148 switch(bt) {
149 case T_INT:
150 return new CastIINode(c, n, t, dependency);
151 case T_LONG:
152 return new CastLLNode(c, n, t, dependency);
153 default:
154 fatal("Bad basic type %s", type2name(bt));
155 }
156 return nullptr;
157 }
158
159 TypeNode* ConstraintCastNode::dominating_cast(PhaseGVN* gvn, PhaseTransform* pt) const {
160 if (_dependency == UnconditionalDependency) {
161 return nullptr;
162 }
163 Node* val = in(1);
164 Node* ctl = in(0);
165 int opc = Opcode();
166 if (ctl == nullptr) {
167 return nullptr;
168 }
169 // Range check CastIIs may all end up under a single range check and
170 // in that case only the narrower CastII would be kept by the code
171 // below which would be incorrect.
172 if (is_CastII() && as_CastII()->has_range_check()) {
173 return nullptr;
174 }
175 if (type()->isa_rawptr() && (gvn->type_or_null(val) == nullptr || gvn->type(val)->isa_oopptr())) {
176 return nullptr;
177 }
178 for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) {
179 Node* u = val->fast_out(i);
180 if (u != this &&
181 u->outcnt() > 0 &&
182 u->Opcode() == opc &&
183 u->in(0) != nullptr &&
184 higher_equal_types(gvn, u)) {
185 if (pt->is_dominator(u->in(0), ctl)) {
186 return u->as_Type();
187 }
188 if (is_CheckCastPP() && u->in(1)->is_Proj() && u->in(1)->in(0)->is_Allocate() &&
189 u->in(0)->is_Proj() && u->in(0)->in(0)->is_Initialize() &&
190 u->in(1)->in(0)->as_Allocate()->initialization() == u->in(0)->in(0)) {
191 // CheckCastPP following an allocation always dominates all
192 // use of the allocation result
193 return u->as_Type();
194 }
195 }
196 }
197 return nullptr;
198 }
199
200 bool ConstraintCastNode::higher_equal_types(PhaseGVN* phase, const Node* other) const {
201 const Type* t = phase->type(other);
202 if (!t->higher_equal_speculative(type())) {
203 return false;
204 }
205 if (_extra_types != nullptr) {
206 for (uint i = 0; i < _extra_types->cnt(); ++i) {
207 if (!t->higher_equal_speculative(_extra_types->field_at(i))) {
208 return false;
209 }
210 }
211 }
212 return true;
213 }
214
215 #ifndef PRODUCT
216 void ConstraintCastNode::dump_spec(outputStream *st) const {
217 TypeNode::dump_spec(st);
218 if (_extra_types != nullptr) {
219 st->print(" extra types: ");
220 _extra_types->dump_on(st);
221 }
222 if (_dependency != RegularDependency) {
223 st->print(" %s dependency", _dependency == StrongDependency ? "strong" : "unconditional");
224 }
225 }
226 #endif
227
228 const Type* CastIINode::Value(PhaseGVN* phase) const {
229 const Type *res = ConstraintCastNode::Value(phase);
230 if (res == Type::TOP) {
231 return Type::TOP;
232 }
233 assert(res->isa_int(), "res must be int");
234
235 // Similar to ConvI2LNode::Value() for the same reasons
236 // see if we can remove type assertion after loop opts
237 // But here we have to pay extra attention:
238 // Do not narrow the type of range check dependent CastIINodes to
239 // avoid corruption of the graph if a CastII is replaced by TOP but
240 // the corresponding range check is not removed.
241 if (!_range_check_dependency) {
242 res = widen_type(phase, res, T_INT);
243 }
244
245 return res;
246 }
247
248 static Node* find_or_make_integer_cast(PhaseIterGVN* igvn, Node* parent, Node* control, const TypeInteger* type, ConstraintCastNode::DependencyType dependency, BasicType bt) {
249 Node* n = ConstraintCastNode::make_cast_for_basic_type(control, parent, type, dependency, bt);
250 Node* existing = igvn->hash_find_insert(n);
251 if (existing != nullptr) {
252 n->destruct(igvn);
253 return existing;
254 }
255 return igvn->register_new_node_with_optimizer(n);
256 }
257
258 Node *CastIINode::Ideal(PhaseGVN *phase, bool can_reshape) {
259 Node* progress = ConstraintCastNode::Ideal(phase, can_reshape);
260 if (progress != nullptr) {
261 return progress;
262 }
263 if (can_reshape && !_range_check_dependency && !phase->C->post_loop_opts_phase()) {
264 // makes sure we run ::Value to potentially remove type assertion after loop opts
265 phase->C->record_for_post_loop_opts_igvn(this);
266 }
267 if (!_range_check_dependency) {
268 return optimize_integer_cast(phase, T_INT);
269 }
270 return nullptr;
271 }
272
273 Node* CastIINode::Identity(PhaseGVN* phase) {
274 Node* progress = ConstraintCastNode::Identity(phase);
275 if (progress != this) {
276 return progress;
277 }
278 if (_range_check_dependency) {
279 if (phase->C->post_loop_opts_phase()) {
280 return this->in(1);
281 } else {
282 phase->C->record_for_post_loop_opts_igvn(this);
283 }
284 }
285 return this;
286 }
287
288 bool CastIINode::cmp(const Node &n) const {
289 return ConstraintCastNode::cmp(n) && ((CastIINode&)n)._range_check_dependency == _range_check_dependency;
290 }
291
292 uint CastIINode::size_of() const {
293 return sizeof(*this);
294 }
295
296 #ifndef PRODUCT
297 void CastIINode::dump_spec(outputStream* st) const {
298 ConstraintCastNode::dump_spec(st);
299 if (_range_check_dependency) {
300 st->print(" range check dependency");
301 }
302 }
303 #endif
304
305 CastIINode* CastIINode::pin_array_access_node() const {
306 assert(_dependency == RegularDependency, "already pinned");
307 if (has_range_check()) {
308 return new CastIINode(in(0), in(1), bottom_type(), StrongDependency, has_range_check());
309 }
310 return nullptr;
311 }
312
313
314 const Type* CastLLNode::Value(PhaseGVN* phase) const {
315 const Type* res = ConstraintCastNode::Value(phase);
316 if (res == Type::TOP) {
317 return Type::TOP;
318 }
319 assert(res->isa_long(), "res must be long");
320
321 return widen_type(phase, res, T_LONG);
322 }
323
324 Node* CastLLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
325 Node* progress = ConstraintCastNode::Ideal(phase, can_reshape);
326 if (progress != nullptr) {
327 return progress;
328 }
329 if (!phase->C->post_loop_opts_phase()) {
330 // makes sure we run ::Value to potentially remove type assertion after loop opts
331 phase->C->record_for_post_loop_opts_igvn(this);
332 }
333 // transform (CastLL (ConvI2L ..)) into (ConvI2L (CastII ..)) if the type of the CastLL is narrower than the type of
334 // the ConvI2L.
335 Node* in1 = in(1);
336 if (in1 != nullptr && in1->Opcode() == Op_ConvI2L) {
337 const Type* t = Value(phase);
338 const Type* t_in = phase->type(in1);
339 if (t != Type::TOP && t_in != Type::TOP) {
340 const TypeLong* tl = t->is_long();
341 const TypeLong* t_in_l = t_in->is_long();
342 assert(tl->_lo >= t_in_l->_lo && tl->_hi <= t_in_l->_hi, "CastLL type should be narrower than or equal to the type of its input");
343 assert((tl != t_in_l) == (tl->_lo > t_in_l->_lo || tl->_hi < t_in_l->_hi), "if type differs then this nodes's type must be narrower");
344 if (tl != t_in_l) {
345 const TypeInt* ti = TypeInt::make(checked_cast<jint>(tl->_lo), checked_cast<jint>(tl->_hi), tl->_widen);
346 Node* castii = phase->transform(new CastIINode(in(0), in1->in(1), ti));
347 Node* convi2l = in1->clone();
348 convi2l->set_req(1, castii);
349 return convi2l;
350 }
351 }
352 }
353 return optimize_integer_cast(phase, T_LONG);
354 }
355
356 //=============================================================================
357 //------------------------------Identity---------------------------------------
358 // If input is already higher or equal to cast type, then this is an identity.
359 Node* CheckCastPPNode::Identity(PhaseGVN* phase) {
360 if (in(1)->is_InlineType() && _type->isa_instptr() && phase->type(in(1))->inline_klass()->is_subtype_of(_type->is_instptr()->instance_klass())) {
361 return in(1);
362 }
363 return ConstraintCastNode::Identity(phase);
364 }
365
366 //------------------------------Value------------------------------------------
367 // Take 'join' of input and cast-up type, unless working with an Interface
368 const Type* CheckCastPPNode::Value(PhaseGVN* phase) const {
369 if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;
370
371 const Type *inn = phase->type(in(1));
372 if( inn == Type::TOP ) return Type::TOP; // No information yet
373
374 if (inn->isa_oopptr() && _type->isa_oopptr()) {
375 return ConstraintCastNode::Value(phase);
376 }
377
378 const TypePtr *in_type = inn->isa_ptr();
379 const TypePtr *my_type = _type->isa_ptr();
380 const Type *result = _type;
381 if (in_type != nullptr && my_type != nullptr) {
382 // TODO 8302672
383 if (!StressReflectiveCode && my_type->isa_aryptr() && in_type->isa_aryptr()) {
384 // Propagate array properties (not flat/null-free)
385 // Don't do this when StressReflectiveCode is enabled because it might lead to
386 // a dying data path while the corresponding flat/null-free check is not folded.
387 my_type = my_type->is_aryptr()->update_properties(in_type->is_aryptr());
388 if (my_type == nullptr) {
389 return Type::TOP; // Inconsistent properties
390 }
391 }
392 TypePtr::PTR in_ptr = in_type->ptr();
393 if (in_ptr == TypePtr::Null) {
394 result = in_type;
395 } else if (in_ptr != TypePtr::Constant) {
396 result = my_type->cast_to_ptr_type(my_type->join_ptr(in_ptr));
397 }
398 }
399
400 return result;
401 }
402
403 //=============================================================================
404 //------------------------------Value------------------------------------------
405 const Type* CastX2PNode::Value(PhaseGVN* phase) const {
406 const Type* t = phase->type(in(1));
407 if (t == Type::TOP) return Type::TOP;
408 if (t->base() == Type_X && t->singleton()) {
409 uintptr_t bits = (uintptr_t) t->is_intptr_t()->get_con();
410 if (bits == 0) return TypePtr::NULL_PTR;
411 return TypeRawPtr::make((address) bits);
412 }
413 return CastX2PNode::bottom_type();
414 }
415
416 //------------------------------Idealize---------------------------------------
417 static inline bool fits_in_int(const Type* t, bool but_not_min_int = false) {
418 if (t == Type::TOP) return false;
419 const TypeX* tl = t->is_intptr_t();
420 jint lo = min_jint;
421 jint hi = max_jint;
422 if (but_not_min_int) ++lo; // caller wants to negate the value w/o overflow
423 return (tl->_lo >= lo) && (tl->_hi <= hi);
424 }
425
426 static inline Node* addP_of_X2P(PhaseGVN *phase,
427 Node* base,
428 Node* dispX,
429 bool negate = false) {
430 if (negate) {
431 dispX = phase->transform(new SubXNode(phase->MakeConX(0), dispX));
432 }
433 return new AddPNode(phase->C->top(),
434 phase->transform(new CastX2PNode(base)),
435 dispX);
436 }
437
438 Node *CastX2PNode::Ideal(PhaseGVN *phase, bool can_reshape) {
439 // convert CastX2P(AddX(x, y)) to AddP(CastX2P(x), y) if y fits in an int
440 int op = in(1)->Opcode();
441 Node* x;
442 Node* y;
443 switch (op) {
444 case Op_SubX:
445 x = in(1)->in(1);
446 // Avoid ideal transformations ping-pong between this and AddP for raw pointers.
447 if (phase->find_intptr_t_con(x, -1) == 0)
448 break;
449 y = in(1)->in(2);
450 if (fits_in_int(phase->type(y), true)) {
451 return addP_of_X2P(phase, x, y, true);
452 }
453 break;
454 case Op_AddX:
455 x = in(1)->in(1);
456 y = in(1)->in(2);
457 if (fits_in_int(phase->type(y))) {
458 return addP_of_X2P(phase, x, y);
459 }
460 if (fits_in_int(phase->type(x))) {
461 return addP_of_X2P(phase, y, x);
462 }
463 break;
464 }
465 return nullptr;
466 }
467
468 //------------------------------Identity---------------------------------------
469 Node* CastX2PNode::Identity(PhaseGVN* phase) {
470 if (in(1)->Opcode() == Op_CastP2X) return in(1)->in(1);
471 return this;
472 }
473
474 //=============================================================================
475 //------------------------------Value------------------------------------------
476 const Type* CastP2XNode::Value(PhaseGVN* phase) const {
477 const Type* t = phase->type(in(1));
478 if (t == Type::TOP) return Type::TOP;
479 if (t->base() == Type::RawPtr && t->singleton()) {
480 uintptr_t bits = (uintptr_t) t->is_rawptr()->get_con();
481 return TypeX::make(bits);
482 }
483
484 if (t->is_zero_type() || !t->maybe_null()) {
485 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
486 Node* u = fast_out(i);
487 if (u->Opcode() == Op_OrL) {
488 for (DUIterator_Fast jmax, j = u->fast_outs(jmax); j < jmax; j++) {
489 Node* cmp = u->fast_out(j);
490 if (cmp->Opcode() == Op_CmpL) {
491 // Give CmpL a chance to get optimized
492 phase->record_for_igvn(cmp);
493 }
494 }
495 }
496 }
497 }
498
499 return CastP2XNode::bottom_type();
500 }
501
502 Node *CastP2XNode::Ideal(PhaseGVN *phase, bool can_reshape) {
503 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : nullptr;
504 }
505
506 //------------------------------Identity---------------------------------------
507 Node* CastP2XNode::Identity(PhaseGVN* phase) {
508 if (in(1)->Opcode() == Op_CastX2P) return in(1)->in(1);
509 return this;
510 }
511
512 Node* ConstraintCastNode::make_cast_for_type(Node* c, Node* in, const Type* type, DependencyType dependency,
513 const TypeTuple* types) {
514 if (type->isa_int()) {
515 return new CastIINode(c, in, type, dependency, false, types);
516 } else if (type->isa_long()) {
517 return new CastLLNode(c, in, type, dependency, types);
518 } else if (type->isa_float()) {
519 return new CastFFNode(c, in, type, dependency, types);
520 } else if (type->isa_double()) {
521 return new CastDDNode(c, in, type, dependency, types);
522 } else if (type->isa_vect()) {
523 return new CastVVNode(c, in, type, dependency, types);
524 } else if (type->isa_ptr()) {
525 return new CastPPNode(c, in, type, dependency, types);
526 }
527 fatal("unreachable. Invalid cast type.");
528 return nullptr;
529 }
530
531 Node* ConstraintCastNode::optimize_integer_cast(PhaseGVN* phase, BasicType bt) {
532 PhaseIterGVN *igvn = phase->is_IterGVN();
533 const TypeInteger* this_type = this->type()->is_integer(bt);
534 Node* z = in(1);
535 const TypeInteger* rx = nullptr;
536 const TypeInteger* ry = nullptr;
537 // Similar to ConvI2LNode::Ideal() for the same reasons
538 if (Compile::push_thru_add(phase, z, this_type, rx, ry, bt, bt)) {
539 if (igvn == nullptr) {
540 // Postpone this optimization to iterative GVN, where we can handle deep
541 // AddI chains without an exponential number of recursive Ideal() calls.
542 phase->record_for_igvn(this);
543 return nullptr;
544 }
545 int op = z->Opcode();
546 Node* x = z->in(1);
547 Node* y = z->in(2);
548
549 Node* cx = find_or_make_integer_cast(igvn, x, in(0), rx, _dependency, bt);
550 Node* cy = find_or_make_integer_cast(igvn, y, in(0), ry, _dependency, bt);
551 if (op == Op_Add(bt)) {
552 return AddNode::make(cx, cy, bt);
553 } else {
554 assert(op == Op_Sub(bt), "");
555 return SubNode::make(cx, cy, bt);
556 }
557 return nullptr;
558 }
559 return nullptr;
560 }
561
562 const Type* ConstraintCastNode::widen_type(const PhaseGVN* phase, const Type* res, BasicType bt) const {
563 if (!phase->C->post_loop_opts_phase()) {
564 return res;
565 }
566 const TypeInteger* this_type = res->is_integer(bt);
567 const TypeInteger* in_type = phase->type(in(1))->isa_integer(bt);
568 if (in_type != nullptr &&
569 (in_type->lo_as_long() != this_type->lo_as_long() ||
570 in_type->hi_as_long() != this_type->hi_as_long())) {
571 jlong lo1 = this_type->lo_as_long();
572 jlong hi1 = this_type->hi_as_long();
573 int w1 = this_type->_widen;
574 if (lo1 >= 0) {
575 // Keep a range assertion of >=0.
576 lo1 = 0; hi1 = max_signed_integer(bt);
577 } else if (hi1 < 0) {
578 // Keep a range assertion of <0.
579 lo1 = min_signed_integer(bt); hi1 = -1;
580 } else {
581 lo1 = min_signed_integer(bt); hi1 = max_signed_integer(bt);
582 }
583 return TypeInteger::make(MAX2(in_type->lo_as_long(), lo1),
584 MIN2(in_type->hi_as_long(), hi1),
585 MAX2((int)in_type->_widen, w1), bt);
586 }
587 return res;
588 }