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