1 /*
2 * Copyright (c) 2014, 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
35 //=============================================================================
36 // If input is already higher or equal to cast type, then this is an identity.
37 Node* ConstraintCastNode::Identity(PhaseGVN* phase) {
38 Node* dom = dominating_cast(phase, phase);
39 if (dom != NULL) {
40 return dom;
41 }
42 if (_carry_dependency) {
43 return this;
44 }
45 return phase->type(in(1))->higher_equal_speculative(_type) ? in(1) : this;
46 }
47
48 //------------------------------Value------------------------------------------
49 // Take 'join' of input and cast-up type
50 const Type* ConstraintCastNode::Value(PhaseGVN* phase) const {
51 if (in(0) && phase->type(in(0)) == Type::TOP) return Type::TOP;
52 const Type* ft = phase->type(in(1))->filter_speculative(_type);
53
54 #ifdef ASSERT
55 // Previous versions of this function had some special case logic,
56 // which is no longer necessary. Make sure of the required effects.
57 switch (Opcode()) {
58 case Op_CastII:
59 {
60 const Type* t1 = phase->type(in(1));
61 if( t1 == Type::TOP ) assert(ft == Type::TOP, "special case #1");
62 const Type* rt = t1->join_speculative(_type);
63 if (rt->empty()) assert(ft == Type::TOP, "special case #2");
64 break;
65 }
66 case Op_CastPP:
67 if (phase->type(in(1)) == TypePtr::NULL_PTR &&
68 _type->isa_ptr() && _type->is_ptr()->_ptr == TypePtr::NotNull)
69 assert(ft == Type::TOP, "special case #3");
70 break;
71 }
72 #endif //ASSERT
73
74 return ft;
75 }
76
77 //------------------------------Ideal------------------------------------------
78 // Return a node which is more "ideal" than the current node. Strip out
79 // control copies
80 Node *ConstraintCastNode::Ideal(PhaseGVN *phase, bool can_reshape) {
81 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;
82 }
83
84 bool ConstraintCastNode::cmp(const Node &n) const {
85 return TypeNode::cmp(n) && ((ConstraintCastNode&)n)._carry_dependency == _carry_dependency;
86 }
87
88 uint ConstraintCastNode::size_of() const {
89 return sizeof(*this);
90 }
91
92 Node* ConstraintCastNode::make_cast(int opcode, Node* c, Node *n, const Type *t, bool carry_dependency) {
93 switch(opcode) {
94 case Op_CastII: {
95 Node* cast = new CastIINode(n, t, carry_dependency);
96 cast->set_req(0, c);
97 return cast;
98 }
99 case Op_CastPP: {
100 Node* cast = new CastPPNode(n, t, carry_dependency);
101 cast->set_req(0, c);
102 return cast;
103 }
104 case Op_CheckCastPP: return new CheckCastPPNode(c, n, t, carry_dependency);
105 default:
106 fatal("Bad opcode %d", opcode);
107 }
108 return NULL;
109 }
110
111 TypeNode* ConstraintCastNode::dominating_cast(PhaseGVN* gvn, PhaseTransform* pt) const {
112 Node* val = in(1);
113 Node* ctl = in(0);
114 int opc = Opcode();
115 if (ctl == NULL) {
116 return NULL;
117 }
118 // Range check CastIIs may all end up under a single range check and
119 // in that case only the narrower CastII would be kept by the code
120 // below which would be incorrect.
121 if (is_CastII() && as_CastII()->has_range_check()) {
122 return NULL;
123 }
124 if (type()->isa_rawptr() && (gvn->type_or_null(val) == NULL || gvn->type(val)->isa_oopptr())) {
125 return NULL;
126 }
127 for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) {
128 Node* u = val->fast_out(i);
129 if (u != this &&
130 u->outcnt() > 0 &&
131 u->Opcode() == opc &&
132 u->in(0) != NULL &&
133 u->bottom_type()->higher_equal(type())) {
134 if (pt->is_dominator(u->in(0), ctl)) {
135 return u->as_Type();
136 }
137 if (is_CheckCastPP() && u->in(1)->is_Proj() && u->in(1)->in(0)->is_Allocate() &&
138 u->in(0)->is_Proj() && u->in(0)->in(0)->is_Initialize() &&
139 u->in(1)->in(0)->as_Allocate()->initialization() == u->in(0)->in(0)) {
140 // CheckCastPP following an allocation always dominates all
141 // use of the allocation result
142 return u->as_Type();
143 }
144 }
145 }
146 return NULL;
147 }
148
149 #ifndef PRODUCT
150 void ConstraintCastNode::dump_spec(outputStream *st) const {
151 TypeNode::dump_spec(st);
152 if (_carry_dependency) {
153 st->print(" carry dependency");
154 }
155 }
156 #endif
157
158 const Type* CastIINode::Value(PhaseGVN* phase) const {
159 const Type *res = ConstraintCastNode::Value(phase);
160
161 // Try to improve the type of the CastII if we recognize a CmpI/If
162 // pattern.
163 if (_carry_dependency) {
164 if (in(0) != NULL && in(0)->in(0) != NULL && in(0)->in(0)->is_If()) {
165 assert(in(0)->is_IfFalse() || in(0)->is_IfTrue(), "should be If proj");
166 Node* proj = in(0);
167 if (proj->in(0)->in(1)->is_Bool()) {
168 Node* b = proj->in(0)->in(1);
169 if (b->in(1)->Opcode() == Op_CmpI) {
170 Node* cmp = b->in(1);
171 if (cmp->in(1) == in(1) && phase->type(cmp->in(2))->isa_int()) {
172 const TypeInt* in2_t = phase->type(cmp->in(2))->is_int();
173 const Type* t = TypeInt::INT;
174 BoolTest test = b->as_Bool()->_test;
175 if (proj->is_IfFalse()) {
176 test = test.negate();
177 }
178 BoolTest::mask m = test._test;
179 jlong lo_long = min_jint;
180 jlong hi_long = max_jint;
181 if (m == BoolTest::le || m == BoolTest::lt) {
182 hi_long = in2_t->_hi;
183 if (m == BoolTest::lt) {
184 hi_long -= 1;
185 }
186 } else if (m == BoolTest::ge || m == BoolTest::gt) {
187 lo_long = in2_t->_lo;
188 if (m == BoolTest::gt) {
189 lo_long += 1;
190 }
191 } else if (m == BoolTest::eq) {
192 lo_long = in2_t->_lo;
193 hi_long = in2_t->_hi;
194 } else if (m == BoolTest::ne) {
195 // can't do any better
196 } else {
197 stringStream ss;
198 test.dump_on(&ss);
199 fatal("unexpected comparison %s", ss.as_string());
200 }
201 int lo_int = (int)lo_long;
202 int hi_int = (int)hi_long;
203
204 if (lo_long != (jlong)lo_int) {
205 lo_int = min_jint;
206 }
207 if (hi_long != (jlong)hi_int) {
208 hi_int = max_jint;
209 }
210
211 t = TypeInt::make(lo_int, hi_int, Type::WidenMax);
212
213 res = res->filter_speculative(t);
214
215 return res;
216 }
217 }
218 }
219 }
220 }
221 return res;
222 }
223
224 Node *CastIINode::Ideal(PhaseGVN *phase, bool can_reshape) {
225 Node* progress = ConstraintCastNode::Ideal(phase, can_reshape);
226 if (progress != NULL) {
227 return progress;
228 }
229
230 // Similar to ConvI2LNode::Ideal() for the same reasons
231 // Do not narrow the type of range check dependent CastIINodes to
232 // avoid corruption of the graph if a CastII is replaced by TOP but
233 // the corresponding range check is not removed.
234 if (can_reshape && !_range_check_dependency && !phase->C->major_progress()) {
235 const TypeInt* this_type = this->type()->is_int();
236 const TypeInt* in_type = phase->type(in(1))->isa_int();
237 if (in_type != NULL && this_type != NULL &&
238 (in_type->_lo != this_type->_lo ||
239 in_type->_hi != this_type->_hi)) {
240 jint lo1 = this_type->_lo;
241 jint hi1 = this_type->_hi;
242 int w1 = this_type->_widen;
243
244 if (lo1 >= 0) {
245 // Keep a range assertion of >=0.
246 lo1 = 0; hi1 = max_jint;
247 } else if (hi1 < 0) {
248 // Keep a range assertion of <0.
249 lo1 = min_jint; hi1 = -1;
250 } else {
251 lo1 = min_jint; hi1 = max_jint;
252 }
253 const TypeInt* wtype = TypeInt::make(MAX2(in_type->_lo, lo1),
254 MIN2(in_type->_hi, hi1),
255 MAX2((int)in_type->_widen, w1));
256 if (wtype != type()) {
257 set_type(wtype);
258 return this;
259 }
260 }
261 }
262 return NULL;
263 }
264
265 bool CastIINode::cmp(const Node &n) const {
266 return ConstraintCastNode::cmp(n) && ((CastIINode&)n)._range_check_dependency == _range_check_dependency;
267 }
268
269 uint CastIINode::size_of() const {
270 return sizeof(*this);
271 }
272
273 #ifndef PRODUCT
274 void CastIINode::dump_spec(outputStream* st) const {
275 ConstraintCastNode::dump_spec(st);
276 if (_range_check_dependency) {
277 st->print(" range check dependency");
278 }
279 }
280 #endif
281
282 //=============================================================================
283 //------------------------------Identity---------------------------------------
284 // If input is already higher or equal to cast type, then this is an identity.
285 Node* CheckCastPPNode::Identity(PhaseGVN* phase) {
286 Node* dom = dominating_cast(phase, phase);
287 if (dom != NULL) {
288 return dom;
289 }
290 if (_carry_dependency) {
291 return this;
292 }
293 // Toned down to rescue meeting at a Phi 3 different oops all implementing
294 // the same interface.
295 return (phase->type(in(1)) == phase->type(this)) ? in(1) : this;
296 }
297
298 //------------------------------Value------------------------------------------
299 // Take 'join' of input and cast-up type, unless working with an Interface
300 const Type* CheckCastPPNode::Value(PhaseGVN* phase) const {
301 if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;
302
303 const Type *inn = phase->type(in(1));
304 if( inn == Type::TOP ) return Type::TOP; // No information yet
305
306 const TypePtr *in_type = inn->isa_ptr();
307 const TypePtr *my_type = _type->isa_ptr();
308 const Type *result = _type;
309 if( in_type != NULL && my_type != NULL ) {
310 TypePtr::PTR in_ptr = in_type->ptr();
311 if (in_ptr == TypePtr::Null) {
312 result = in_type;
313 } else if (in_ptr == TypePtr::Constant) {
314 if (my_type->isa_rawptr()) {
315 result = my_type;
316 } else {
317 const TypeOopPtr *jptr = my_type->isa_oopptr();
318 assert(jptr, "");
319 result = !in_type->higher_equal(_type)
320 ? my_type->cast_to_ptr_type(TypePtr::NotNull)
321 : in_type;
322 }
323 } else {
324 result = my_type->cast_to_ptr_type( my_type->join_ptr(in_ptr) );
325 }
326 }
327
328 // This is the code from TypePtr::xmeet() that prevents us from
329 // having 2 ways to represent the same type. We have to replicate it
330 // here because we don't go through meet/join.
331 if (result->remove_speculative() == result->speculative()) {
332 result = result->remove_speculative();
333 }
334
335 // Same as above: because we don't go through meet/join, remove the
336 // speculative type if we know we won't use it.
337 return result->cleanup_speculative();
338
339 // JOIN NOT DONE HERE BECAUSE OF INTERFACE ISSUES.
340 // FIX THIS (DO THE JOIN) WHEN UNION TYPES APPEAR!
341
342 //
343 // Remove this code after overnight run indicates no performance
344 // loss from not performing JOIN at CheckCastPPNode
345 //
346 // const TypeInstPtr *in_oop = in->isa_instptr();
347 // const TypeInstPtr *my_oop = _type->isa_instptr();
348 // // If either input is an 'interface', return destination type
349 // assert (in_oop == NULL || in_oop->klass() != NULL, "");
350 // assert (my_oop == NULL || my_oop->klass() != NULL, "");
351 // if( (in_oop && in_oop->klass()->is_interface())
352 // ||(my_oop && my_oop->klass()->is_interface()) ) {
353 // TypePtr::PTR in_ptr = in->isa_ptr() ? in->is_ptr()->_ptr : TypePtr::BotPTR;
354 // // Preserve cast away nullness for interfaces
355 // if( in_ptr == TypePtr::NotNull && my_oop && my_oop->_ptr == TypePtr::BotPTR ) {
356 // return my_oop->cast_to_ptr_type(TypePtr::NotNull);
357 // }
358 // return _type;
359 // }
360 //
361 // // Neither the input nor the destination type is an interface,
362 //
363 // // history: JOIN used to cause weird corner case bugs
364 // // return (in == TypeOopPtr::NULL_PTR) ? in : _type;
365 // // JOIN picks up NotNull in common instance-of/check-cast idioms, both oops.
366 // // JOIN does not preserve NotNull in other cases, e.g. RawPtr vs InstPtr
367 // const Type *join = in->join(_type);
368 // // Check if join preserved NotNull'ness for pointers
369 // if( join->isa_ptr() && _type->isa_ptr() ) {
370 // TypePtr::PTR join_ptr = join->is_ptr()->_ptr;
371 // TypePtr::PTR type_ptr = _type->is_ptr()->_ptr;
372 // // If there isn't any NotNull'ness to preserve
373 // // OR if join preserved NotNull'ness then return it
374 // if( type_ptr == TypePtr::BotPTR || type_ptr == TypePtr::Null ||
375 // join_ptr == TypePtr::NotNull || join_ptr == TypePtr::Constant ) {
376 // return join;
377 // }
378 // // ELSE return same old type as before
379 // return _type;
380 // }
381 // // Not joining two pointers
382 // return join;
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 NULL;
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 : NULL;
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 }