1 /*
2 * Copyright (c) 2014, 2025, 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 "opto/addnode.hpp"
26 #include "opto/callnode.hpp"
27 #include "opto/castnode.hpp"
28 #include "opto/connode.hpp"
29 #include "opto/matcher.hpp"
30 #include "opto/phaseX.hpp"
31 #include "opto/subnode.hpp"
32 #include "opto/type.hpp"
33 #include "castnode.hpp"
34 #include "utilities/checkedCast.hpp"
35
36 //=============================================================================
37 // If input is already higher or equal to cast type, then this is an identity.
38 Node* ConstraintCastNode::Identity(PhaseGVN* phase) {
39 if (_dependency == UnconditionalDependency) {
40 return this;
41 }
42 Node* dom = dominating_cast(phase, phase);
43 if (dom != nullptr) {
44 return dom;
45 }
46 return higher_equal_types(phase, in(1)) ? in(1) : this;
47 }
48
49 //------------------------------Value------------------------------------------
50 // Take 'join' of input and cast-up type
51 const Type* ConstraintCastNode::Value(PhaseGVN* phase) const {
52 if (in(0) && phase->type(in(0)) == Type::TOP) return Type::TOP;
53
54 const Type* in_type = phase->type(in(1));
55 const Type* ft = in_type->filter_speculative(_type);
56
57 // Check if both _type and in_type had a speculative type, but for the just
58 // computed ft the speculative type was dropped.
59 if (ft->speculative() == nullptr &&
60 _type->speculative() != nullptr &&
61 in_type->speculative() != nullptr) {
62 // Speculative type may have disagreed between cast and input, and was
63 // dropped in filtering. Recompute so that ft can take speculative type
64 // of in_type. If we did not do it now, a subsequent ::Value call would
65 // do it, and violate idempotence of ::Value.
66 ft = in_type->filter_speculative(ft);
67 }
68
69 #ifdef ASSERT
70 // Previous versions of this function had some special case logic,
71 // which is no longer necessary. Make sure of the required effects.
72 switch (Opcode()) {
73 case Op_CastII:
74 {
75 if (in_type == Type::TOP) {
76 assert(ft == Type::TOP, "special case #1");
77 }
78 const Type* rt = in_type->join_speculative(_type);
79 if (rt->empty()) {
80 assert(ft == Type::TOP, "special case #2");
81 }
82 break;
83 }
84 case Op_CastPP:
85 if (in_type == TypePtr::NULL_PTR &&
86 _type->isa_ptr() && _type->is_ptr()->_ptr == TypePtr::NotNull) {
87 assert(ft == Type::TOP, "special case #3");
88 break;
89 }
90 }
91 #endif //ASSERT
92
93 return ft;
94 }
95
96 //------------------------------Ideal------------------------------------------
97 // Return a node which is more "ideal" than the current node. Strip out
98 // control copies
99 Node* ConstraintCastNode::Ideal(PhaseGVN* phase, bool can_reshape) {
100 if (in(0) != nullptr && remove_dead_region(phase, can_reshape)) {
101 return this;
102 }
103 if (in(1) != nullptr && phase->type(in(1)) != Type::TOP) {
104 return TypeNode::Ideal(phase, can_reshape);
105 }
106 return nullptr;
107 }
108
109 uint ConstraintCastNode::hash() const {
110 return TypeNode::hash() + (int)_dependency + (_extra_types != nullptr ? _extra_types->hash() : 0);
111 }
112
113 bool ConstraintCastNode::cmp(const Node &n) const {
114 if (!TypeNode::cmp(n)) {
115 return false;
116 }
117 ConstraintCastNode& cast = (ConstraintCastNode&) n;
118 if (cast._dependency != _dependency) {
119 return false;
120 }
121 if (_extra_types == nullptr || cast._extra_types == nullptr) {
122 return _extra_types == cast._extra_types;
123 }
124 return _extra_types->eq(cast._extra_types);
125 }
126
127 uint ConstraintCastNode::size_of() const {
128 return sizeof(*this);
129 }
130
131 Node* ConstraintCastNode::make_cast_for_basic_type(Node* c, Node* n, const Type* t, DependencyType dependency, BasicType bt) {
132 switch(bt) {
133 case T_INT:
134 return new CastIINode(c, n, t, dependency);
135 case T_LONG:
136 return new CastLLNode(c, n, t, dependency);
137 default:
138 fatal("Bad basic type %s", type2name(bt));
139 }
140 return nullptr;
141 }
142
143 TypeNode* ConstraintCastNode::dominating_cast(PhaseGVN* gvn, PhaseTransform* pt) const {
144 if (_dependency == UnconditionalDependency) {
145 return nullptr;
146 }
147 Node* val = in(1);
148 Node* ctl = in(0);
149 int opc = Opcode();
150 if (ctl == nullptr) {
151 return nullptr;
152 }
153 // Range check CastIIs may all end up under a single range check and
154 // in that case only the narrower CastII would be kept by the code
155 // below which would be incorrect.
156 if (is_CastII() && as_CastII()->has_range_check()) {
157 return nullptr;
158 }
159 if (type()->isa_rawptr() && (gvn->type_or_null(val) == nullptr || gvn->type(val)->isa_oopptr())) {
160 return nullptr;
161 }
162 for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) {
163 Node* u = val->fast_out(i);
164 if (u != this &&
165 u->outcnt() > 0 &&
166 u->Opcode() == opc &&
167 u->in(0) != nullptr &&
168 higher_equal_types(gvn, u)) {
169 if (pt->is_dominator(u->in(0), ctl)) {
170 return u->as_Type();
171 }
172 if (is_CheckCastPP() && u->in(1)->is_Proj() && u->in(1)->in(0)->is_Allocate() &&
173 u->in(0)->is_Proj() && u->in(0)->in(0)->is_Initialize() &&
174 u->in(1)->in(0)->as_Allocate()->initialization() == u->in(0)->in(0)) {
175 // CheckCastPP following an allocation always dominates all
176 // use of the allocation result
177 return u->as_Type();
178 }
179 }
180 }
181 return nullptr;
182 }
183
184 bool ConstraintCastNode::higher_equal_types(PhaseGVN* phase, const Node* other) const {
185 const Type* t = phase->type(other);
186 if (!t->higher_equal_speculative(type())) {
187 return false;
188 }
189 if (_extra_types != nullptr) {
190 for (uint i = 0; i < _extra_types->cnt(); ++i) {
191 if (!t->higher_equal_speculative(_extra_types->field_at(i))) {
192 return false;
193 }
194 }
195 }
196 return true;
197 }
198
199 #ifndef PRODUCT
200 void ConstraintCastNode::dump_spec(outputStream *st) const {
201 TypeNode::dump_spec(st);
202 if (_extra_types != nullptr) {
203 st->print(" extra types: ");
204 _extra_types->dump_on(st);
205 }
206 if (_dependency != RegularDependency) {
207 st->print(" %s dependency", _dependency == StrongDependency ? "strong" : "unconditional");
208 }
209 }
210 #endif
211
212 const Type* CastIINode::Value(PhaseGVN* phase) const {
213 const Type *res = ConstraintCastNode::Value(phase);
214 if (res == Type::TOP) {
215 return Type::TOP;
216 }
217 assert(res->isa_int(), "res must be int");
218
219 // Similar to ConvI2LNode::Value() for the same reasons
220 // see if we can remove type assertion after loop opts
221 res = widen_type(phase, res, T_INT);
222
223 return res;
224 }
225
226 Node* ConstraintCastNode::find_or_make_integer_cast(PhaseIterGVN* igvn, Node* parent, const TypeInteger* type) const {
227 Node* n = clone();
228 n->set_req(1, parent);
229 n->as_ConstraintCast()->set_type(type);
230 Node* existing = igvn->hash_find_insert(n);
231 if (existing != nullptr) {
232 n->destruct(igvn);
233 return existing;
234 }
235 return igvn->register_new_node_with_optimizer(n);
236 }
237
238 Node *CastIINode::Ideal(PhaseGVN *phase, bool can_reshape) {
239 Node* progress = ConstraintCastNode::Ideal(phase, can_reshape);
240 if (progress != nullptr) {
241 return progress;
242 }
243 if (can_reshape && !phase->C->post_loop_opts_phase()) {
244 // makes sure we run ::Value to potentially remove type assertion after loop opts
245 phase->C->record_for_post_loop_opts_igvn(this);
246 }
247 if (!_range_check_dependency || phase->C->post_loop_opts_phase()) {
248 return optimize_integer_cast(phase, T_INT);
249 }
250 phase->C->record_for_post_loop_opts_igvn(this);
251 return nullptr;
252 }
253
254 Node* CastIINode::Identity(PhaseGVN* phase) {
255 Node* progress = ConstraintCastNode::Identity(phase);
256 if (progress != this) {
257 return progress;
258 }
259 return this;
260 }
261
262 bool CastIINode::cmp(const Node &n) const {
263 return ConstraintCastNode::cmp(n) && ((CastIINode&)n)._range_check_dependency == _range_check_dependency;
264 }
265
266 uint CastIINode::size_of() const {
267 return sizeof(*this);
268 }
269
270 #ifndef PRODUCT
271 void CastIINode::dump_spec(outputStream* st) const {
272 ConstraintCastNode::dump_spec(st);
273 if (_range_check_dependency) {
274 st->print(" range check dependency");
275 }
276 }
277 #endif
278
279 CastIINode* CastIINode::pin_array_access_node() const {
280 assert(_dependency == RegularDependency, "already pinned");
281 if (has_range_check()) {
282 return new CastIINode(in(0), in(1), bottom_type(), StrongDependency, has_range_check());
283 }
284 return nullptr;
285 }
286
287 void CastIINode::remove_range_check_cast(Compile* C) {
288 if (has_range_check()) {
289 // Range check CastII nodes feed into an address computation subgraph. Remove them to let that subgraph float freely.
290 // For memory access or integer divisions nodes that depend on the cast, record the dependency on the cast's control
291 // as a precedence edge, so they can't float above the cast in case that cast's narrowed type helped eliminate a
292 // range check or a null divisor check.
293 assert(in(0) != nullptr, "All RangeCheck CastII must have a control dependency");
294 ResourceMark rm;
295 Unique_Node_List wq;
296 wq.push(this);
297 for (uint next = 0; next < wq.size(); ++next) {
298 Node* m = wq.at(next);
299 for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
300 Node* use = m->fast_out(i);
301 if (use->is_Mem() || use->is_div_or_mod(T_INT) || use->is_div_or_mod(T_LONG)) {
302 use->ensure_control_or_add_prec(in(0));
303 } else if (!use->is_CFG() && !use->is_Phi()) {
304 wq.push(use);
305 }
306 }
307 }
308 subsume_by(in(1), C);
309 if (outcnt() == 0) {
310 disconnect_inputs(C);
311 }
312 }
313 }
314
315
316 const Type* CastLLNode::Value(PhaseGVN* phase) const {
317 const Type* res = ConstraintCastNode::Value(phase);
318 if (res == Type::TOP) {
319 return Type::TOP;
320 }
321 assert(res->isa_long(), "res must be long");
322
323 return widen_type(phase, res, T_LONG);
324 }
325
326 Node* CastLLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
327 Node* progress = ConstraintCastNode::Ideal(phase, can_reshape);
328 if (progress != nullptr) {
329 return progress;
330 }
331 if (!phase->C->post_loop_opts_phase()) {
332 // makes sure we run ::Value to potentially remove type assertion after loop opts
333 phase->C->record_for_post_loop_opts_igvn(this);
334 }
335 // transform (CastLL (ConvI2L ..)) into (ConvI2L (CastII ..)) if the type of the CastLL is narrower than the type of
336 // the ConvI2L.
337 Node* in1 = in(1);
338 if (in1 != nullptr && in1->Opcode() == Op_ConvI2L) {
339 const Type* t = Value(phase);
340 const Type* t_in = phase->type(in1);
341 if (t != Type::TOP && t_in != Type::TOP) {
342 const TypeLong* tl = t->is_long();
343 const TypeLong* t_in_l = t_in->is_long();
344 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");
345 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");
346 if (tl != t_in_l) {
347 const TypeInt* ti = TypeInt::make(checked_cast<jint>(tl->_lo), checked_cast<jint>(tl->_hi), tl->_widen);
348 Node* castii = phase->transform(new CastIINode(in(0), in1->in(1), ti));
349 Node* convi2l = in1->clone();
350 convi2l->set_req(1, castii);
351 return convi2l;
352 }
353 }
354 }
355 return optimize_integer_cast(phase, T_LONG);
356 }
357
358 //------------------------------Value------------------------------------------
359 // Take 'join' of input and cast-up type, unless working with an Interface
360 const Type* CheckCastPPNode::Value(PhaseGVN* phase) const {
361 if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;
362
363 const Type *inn = phase->type(in(1));
364 if( inn == Type::TOP ) return Type::TOP; // No information yet
365
366 if (inn->isa_oopptr() && _type->isa_oopptr()) {
367 return ConstraintCastNode::Value(phase);
368 }
369
370 const TypePtr *in_type = inn->isa_ptr();
371 const TypePtr *my_type = _type->isa_ptr();
372 const Type *result = _type;
373 if (in_type != nullptr && my_type != nullptr) {
374 TypePtr::PTR in_ptr = in_type->ptr();
375 if (in_ptr == TypePtr::Null) {
376 result = in_type;
377 } else if (in_ptr != TypePtr::Constant) {
378 result = my_type->cast_to_ptr_type(my_type->join_ptr(in_ptr));
379 }
380 }
381
382 return result;
383 }
384
385 //=============================================================================
386 //------------------------------Value------------------------------------------
387 const Type* CastX2PNode::Value(PhaseGVN* phase) const {
388 const Type* t = phase->type(in(1));
389 if (t == Type::TOP) return Type::TOP;
390 if (t->base() == Type_X && t->singleton()) {
391 uintptr_t bits = (uintptr_t) t->is_intptr_t()->get_con();
392 if (bits == 0) return TypePtr::NULL_PTR;
393 return TypeRawPtr::make((address) bits);
394 }
395 return CastX2PNode::bottom_type();
396 }
397
398 //------------------------------Idealize---------------------------------------
399 static inline bool fits_in_int(const Type* t, bool but_not_min_int = false) {
400 if (t == Type::TOP) return false;
401 const TypeX* tl = t->is_intptr_t();
402 jint lo = min_jint;
403 jint hi = max_jint;
404 if (but_not_min_int) ++lo; // caller wants to negate the value w/o overflow
405 return (tl->_lo >= lo) && (tl->_hi <= hi);
406 }
407
408 static inline Node* addP_of_X2P(PhaseGVN *phase,
409 Node* base,
410 Node* dispX,
411 bool negate = false) {
412 if (negate) {
413 dispX = phase->transform(new SubXNode(phase->MakeConX(0), dispX));
414 }
415 return new AddPNode(phase->C->top(),
416 phase->transform(new CastX2PNode(base)),
417 dispX);
418 }
419
420 Node *CastX2PNode::Ideal(PhaseGVN *phase, bool can_reshape) {
421 // convert CastX2P(AddX(x, y)) to AddP(CastX2P(x), y) if y fits in an int
422 int op = in(1)->Opcode();
423 Node* x;
424 Node* y;
425 switch (op) {
426 case Op_SubX:
427 x = in(1)->in(1);
428 // Avoid ideal transformations ping-pong between this and AddP for raw pointers.
429 if (phase->find_intptr_t_con(x, -1) == 0)
430 break;
431 y = in(1)->in(2);
432 if (fits_in_int(phase->type(y), true)) {
433 return addP_of_X2P(phase, x, y, true);
434 }
435 break;
436 case Op_AddX:
437 x = in(1)->in(1);
438 y = in(1)->in(2);
439 if (fits_in_int(phase->type(y))) {
440 return addP_of_X2P(phase, x, y);
441 }
442 if (fits_in_int(phase->type(x))) {
443 return addP_of_X2P(phase, y, x);
444 }
445 break;
446 }
447 return nullptr;
448 }
449
450 //------------------------------Identity---------------------------------------
451 Node* CastX2PNode::Identity(PhaseGVN* phase) {
452 if (in(1)->Opcode() == Op_CastP2X) return in(1)->in(1);
453 return this;
454 }
455
456 //=============================================================================
457 //------------------------------Value------------------------------------------
458 const Type* CastP2XNode::Value(PhaseGVN* phase) const {
459 const Type* t = phase->type(in(1));
460 if (t == Type::TOP) return Type::TOP;
461 if (t->base() == Type::RawPtr && t->singleton()) {
462 uintptr_t bits = (uintptr_t) t->is_rawptr()->get_con();
463 return TypeX::make(bits);
464 }
465 return CastP2XNode::bottom_type();
466 }
467
468 Node *CastP2XNode::Ideal(PhaseGVN *phase, bool can_reshape) {
469 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : nullptr;
470 }
471
472 //------------------------------Identity---------------------------------------
473 Node* CastP2XNode::Identity(PhaseGVN* phase) {
474 if (in(1)->Opcode() == Op_CastX2P) return in(1)->in(1);
475 return this;
476 }
477
478 Node* ConstraintCastNode::make_cast_for_type(Node* c, Node* in, const Type* type, DependencyType dependency,
479 const TypeTuple* types) {
480 if (type->isa_int()) {
481 return new CastIINode(c, in, type, dependency, false, types);
482 } else if (type->isa_long()) {
483 return new CastLLNode(c, in, type, dependency, types);
484 } else if (type->isa_half_float()) {
485 return new CastHHNode(c, in, type, dependency, types);
486 } else if (type->isa_float()) {
487 return new CastFFNode(c, in, type, dependency, types);
488 } else if (type->isa_double()) {
489 return new CastDDNode(c, in, type, dependency, types);
490 } else if (type->isa_vect()) {
491 return new CastVVNode(c, in, type, dependency, types);
492 } else if (type->isa_ptr()) {
493 return new CastPPNode(c, in, type, dependency, types);
494 }
495 fatal("unreachable. Invalid cast type.");
496 return nullptr;
497 }
498
499 Node* ConstraintCastNode::optimize_integer_cast(PhaseGVN* phase, BasicType bt) {
500 PhaseIterGVN *igvn = phase->is_IterGVN();
501 const TypeInteger* this_type = this->type()->is_integer(bt);
502 Node* z = in(1);
503 const TypeInteger* rx = nullptr;
504 const TypeInteger* ry = nullptr;
505 // Similar to ConvI2LNode::Ideal() for the same reasons
506 if (Compile::push_thru_add(phase, z, this_type, rx, ry, bt, bt)) {
507 if (igvn == nullptr) {
508 // Postpone this optimization to iterative GVN, where we can handle deep
509 // AddI chains without an exponential number of recursive Ideal() calls.
510 phase->record_for_igvn(this);
511 return nullptr;
512 }
513 int op = z->Opcode();
514 Node* x = z->in(1);
515 Node* y = z->in(2);
516
517 Node* cx = find_or_make_integer_cast(igvn, x, rx);
518 Node* cy = find_or_make_integer_cast(igvn, y, ry);
519 if (op == Op_Add(bt)) {
520 return AddNode::make(cx, cy, bt);
521 } else {
522 assert(op == Op_Sub(bt), "");
523 return SubNode::make(cx, cy, bt);
524 }
525 return nullptr;
526 }
527 return nullptr;
528 }
529
530 const Type* ConstraintCastNode::widen_type(const PhaseGVN* phase, const Type* res, BasicType bt) const {
531 if (!phase->C->post_loop_opts_phase()) {
532 return res;
533 }
534 const TypeInteger* this_type = res->is_integer(bt);
535 const TypeInteger* in_type = phase->type(in(1))->isa_integer(bt);
536 if (in_type != nullptr &&
537 (in_type->lo_as_long() != this_type->lo_as_long() ||
538 in_type->hi_as_long() != this_type->hi_as_long())) {
539 jlong lo1 = this_type->lo_as_long();
540 jlong hi1 = this_type->hi_as_long();
541 int w1 = this_type->_widen;
542 if (lo1 >= 0) {
543 // Keep a range assertion of >=0.
544 lo1 = 0; hi1 = max_signed_integer(bt);
545 } else if (hi1 < 0) {
546 // Keep a range assertion of <0.
547 lo1 = min_signed_integer(bt); hi1 = -1;
548 } else {
549 lo1 = min_signed_integer(bt); hi1 = max_signed_integer(bt);
550 }
551 return TypeInteger::make(MAX2(in_type->lo_as_long(), lo1),
552 MIN2(in_type->hi_as_long(), hi1),
553 MAX2((int)in_type->_widen, w1), bt);
554 }
555 return res;
556 }