Mon, 01 Dec 2014 22:27:00 +0100
8054478: C2: Incorrectly compiled char[] array access crashes JVM
Summary: dead backbranch in main loop results in erroneous array access
Reviewed-by: kvn, iveresov
1 /*
2 * Copyright (c) 1997, 2013, 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.
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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.
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23 */
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "opto/addnode.hpp"
28 #include "opto/compile.hpp"
29 #include "opto/connode.hpp"
30 #include "opto/machnode.hpp"
31 #include "opto/matcher.hpp"
32 #include "opto/memnode.hpp"
33 #include "opto/phaseX.hpp"
34 #include "opto/subnode.hpp"
35 #include "runtime/sharedRuntime.hpp"
37 // Optimization - Graph Style
39 //=============================================================================
40 //------------------------------hash-------------------------------------------
41 uint ConNode::hash() const {
42 return (uintptr_t)in(TypeFunc::Control) + _type->hash();
43 }
45 //------------------------------make-------------------------------------------
46 ConNode *ConNode::make( Compile* C, const Type *t ) {
47 switch( t->basic_type() ) {
48 case T_INT: return new (C) ConINode( t->is_int() );
49 case T_LONG: return new (C) ConLNode( t->is_long() );
50 case T_FLOAT: return new (C) ConFNode( t->is_float_constant() );
51 case T_DOUBLE: return new (C) ConDNode( t->is_double_constant() );
52 case T_VOID: return new (C) ConNode ( Type::TOP );
53 case T_OBJECT: return new (C) ConPNode( t->is_ptr() );
54 case T_ARRAY: return new (C) ConPNode( t->is_aryptr() );
55 case T_ADDRESS: return new (C) ConPNode( t->is_ptr() );
56 case T_NARROWOOP: return new (C) ConNNode( t->is_narrowoop() );
57 case T_NARROWKLASS: return new (C) ConNKlassNode( t->is_narrowklass() );
58 case T_METADATA: return new (C) ConPNode( t->is_ptr() );
59 // Expected cases: TypePtr::NULL_PTR, any is_rawptr()
60 // Also seen: AnyPtr(TopPTR *+top); from command line:
61 // r -XX:+PrintOpto -XX:CIStart=285 -XX:+CompileTheWorld -XX:CompileTheWorldStartAt=660
62 // %%%% Stop using TypePtr::NULL_PTR to represent nulls: use either TypeRawPtr::NULL_PTR
63 // or else TypeOopPtr::NULL_PTR. Then set Type::_basic_type[AnyPtr] = T_ILLEGAL
64 }
65 ShouldNotReachHere();
66 return NULL;
67 }
69 //=============================================================================
70 /*
71 The major change is for CMoveP and StrComp. They have related but slightly
72 different problems. They both take in TWO oops which are both null-checked
73 independently before the using Node. After CCP removes the CastPP's they need
74 to pick up the guarding test edge - in this case TWO control edges. I tried
75 various solutions, all have problems:
77 (1) Do nothing. This leads to a bug where we hoist a Load from a CMoveP or a
78 StrComp above a guarding null check. I've seen both cases in normal -Xcomp
79 testing.
81 (2) Plug the control edge from 1 of the 2 oops in. Apparent problem here is
82 to figure out which test post-dominates. The real problem is that it doesn't
83 matter which one you pick. After you pick up, the dominating-test elider in
84 IGVN can remove the test and allow you to hoist up to the dominating test on
85 the chosen oop bypassing the test on the not-chosen oop. Seen in testing.
86 Oops.
88 (3) Leave the CastPP's in. This makes the graph more accurate in some sense;
89 we get to keep around the knowledge that an oop is not-null after some test.
90 Alas, the CastPP's interfere with GVN (some values are the regular oop, some
91 are the CastPP of the oop, all merge at Phi's which cannot collapse, etc).
92 This cost us 10% on SpecJVM, even when I removed some of the more trivial
93 cases in the optimizer. Removing more useless Phi's started allowing Loads to
94 illegally float above null checks. I gave up on this approach.
96 (4) Add BOTH control edges to both tests. Alas, too much code knows that
97 control edges are in slot-zero ONLY. Many quick asserts fail; no way to do
98 this one. Note that I really want to allow the CMoveP to float and add both
99 control edges to the dependent Load op - meaning I can select early but I
100 cannot Load until I pass both tests.
102 (5) Do not hoist CMoveP and StrComp. To this end I added the v-call
103 depends_only_on_test(). No obvious performance loss on Spec, but we are
104 clearly conservative on CMoveP (also so on StrComp but that's unlikely to
105 matter ever).
107 */
110 //------------------------------Ideal------------------------------------------
111 // Return a node which is more "ideal" than the current node.
112 // Move constants to the right.
113 Node *CMoveNode::Ideal(PhaseGVN *phase, bool can_reshape) {
114 if( in(0) && remove_dead_region(phase, can_reshape) ) return this;
115 // Don't bother trying to transform a dead node
116 if( in(0) && in(0)->is_top() ) return NULL;
117 assert( !phase->eqv(in(Condition), this) &&
118 !phase->eqv(in(IfFalse), this) &&
119 !phase->eqv(in(IfTrue), this), "dead loop in CMoveNode::Ideal" );
120 if( phase->type(in(Condition)) == Type::TOP )
121 return NULL; // return NULL when Condition is dead
123 if( in(IfFalse)->is_Con() && !in(IfTrue)->is_Con() ) {
124 if( in(Condition)->is_Bool() ) {
125 BoolNode* b = in(Condition)->as_Bool();
126 BoolNode* b2 = b->negate(phase);
127 return make( phase->C, in(Control), phase->transform(b2), in(IfTrue), in(IfFalse), _type );
128 }
129 }
130 return NULL;
131 }
133 //------------------------------is_cmove_id------------------------------------
134 // Helper function to check for CMOVE identity. Shared with PhiNode::Identity
135 Node *CMoveNode::is_cmove_id( PhaseTransform *phase, Node *cmp, Node *t, Node *f, BoolNode *b ) {
136 // Check for Cmp'ing and CMove'ing same values
137 if( (phase->eqv(cmp->in(1),f) &&
138 phase->eqv(cmp->in(2),t)) ||
139 // Swapped Cmp is OK
140 (phase->eqv(cmp->in(2),f) &&
141 phase->eqv(cmp->in(1),t)) ) {
142 // Give up this identity check for floating points because it may choose incorrect
143 // value around 0.0 and -0.0
144 if ( cmp->Opcode()==Op_CmpF || cmp->Opcode()==Op_CmpD )
145 return NULL;
146 // Check for "(t==f)?t:f;" and replace with "f"
147 if( b->_test._test == BoolTest::eq )
148 return f;
149 // Allow the inverted case as well
150 // Check for "(t!=f)?t:f;" and replace with "t"
151 if( b->_test._test == BoolTest::ne )
152 return t;
153 }
154 return NULL;
155 }
157 //------------------------------Identity---------------------------------------
158 // Conditional-move is an identity if both inputs are the same, or the test
159 // true or false.
160 Node *CMoveNode::Identity( PhaseTransform *phase ) {
161 if( phase->eqv(in(IfFalse),in(IfTrue)) ) // C-moving identical inputs?
162 return in(IfFalse); // Then it doesn't matter
163 if( phase->type(in(Condition)) == TypeInt::ZERO )
164 return in(IfFalse); // Always pick left(false) input
165 if( phase->type(in(Condition)) == TypeInt::ONE )
166 return in(IfTrue); // Always pick right(true) input
168 // Check for CMove'ing a constant after comparing against the constant.
169 // Happens all the time now, since if we compare equality vs a constant in
170 // the parser, we "know" the variable is constant on one path and we force
171 // it. Thus code like "if( x==0 ) {/*EMPTY*/}" ends up inserting a
172 // conditional move: "x = (x==0)?0:x;". Yucko. This fix is slightly more
173 // general in that we don't need constants.
174 if( in(Condition)->is_Bool() ) {
175 BoolNode *b = in(Condition)->as_Bool();
176 Node *cmp = b->in(1);
177 if( cmp->is_Cmp() ) {
178 Node *id = is_cmove_id( phase, cmp, in(IfTrue), in(IfFalse), b );
179 if( id ) return id;
180 }
181 }
183 return this;
184 }
186 //------------------------------Value------------------------------------------
187 // Result is the meet of inputs
188 const Type *CMoveNode::Value( PhaseTransform *phase ) const {
189 if( phase->type(in(Condition)) == Type::TOP )
190 return Type::TOP;
191 return phase->type(in(IfFalse))->meet_speculative(phase->type(in(IfTrue)));
192 }
194 //------------------------------make-------------------------------------------
195 // Make a correctly-flavored CMove. Since _type is directly determined
196 // from the inputs we do not need to specify it here.
197 CMoveNode *CMoveNode::make( Compile *C, Node *c, Node *bol, Node *left, Node *right, const Type *t ) {
198 switch( t->basic_type() ) {
199 case T_INT: return new (C) CMoveINode( bol, left, right, t->is_int() );
200 case T_FLOAT: return new (C) CMoveFNode( bol, left, right, t );
201 case T_DOUBLE: return new (C) CMoveDNode( bol, left, right, t );
202 case T_LONG: return new (C) CMoveLNode( bol, left, right, t->is_long() );
203 case T_OBJECT: return new (C) CMovePNode( c, bol, left, right, t->is_oopptr() );
204 case T_ADDRESS: return new (C) CMovePNode( c, bol, left, right, t->is_ptr() );
205 case T_NARROWOOP: return new (C) CMoveNNode( c, bol, left, right, t );
206 default:
207 ShouldNotReachHere();
208 return NULL;
209 }
210 }
212 //=============================================================================
213 //------------------------------Ideal------------------------------------------
214 // Return a node which is more "ideal" than the current node.
215 // Check for conversions to boolean
216 Node *CMoveINode::Ideal(PhaseGVN *phase, bool can_reshape) {
217 // Try generic ideal's first
218 Node *x = CMoveNode::Ideal(phase, can_reshape);
219 if( x ) return x;
221 // If zero is on the left (false-case, no-move-case) it must mean another
222 // constant is on the right (otherwise the shared CMove::Ideal code would
223 // have moved the constant to the right). This situation is bad for Intel
224 // and a don't-care for Sparc. It's bad for Intel because the zero has to
225 // be manifested in a register with a XOR which kills flags, which are live
226 // on input to the CMoveI, leading to a situation which causes excessive
227 // spilling on Intel. For Sparc, if the zero in on the left the Sparc will
228 // zero a register via G0 and conditionally-move the other constant. If the
229 // zero is on the right, the Sparc will load the first constant with a
230 // 13-bit set-lo and conditionally move G0. See bug 4677505.
231 if( phase->type(in(IfFalse)) == TypeInt::ZERO && !(phase->type(in(IfTrue)) == TypeInt::ZERO) ) {
232 if( in(Condition)->is_Bool() ) {
233 BoolNode* b = in(Condition)->as_Bool();
234 BoolNode* b2 = b->negate(phase);
235 return make( phase->C, in(Control), phase->transform(b2), in(IfTrue), in(IfFalse), _type );
236 }
237 }
239 // Now check for booleans
240 int flip = 0;
242 // Check for picking from zero/one
243 if( phase->type(in(IfFalse)) == TypeInt::ZERO && phase->type(in(IfTrue)) == TypeInt::ONE ) {
244 flip = 1 - flip;
245 } else if( phase->type(in(IfFalse)) == TypeInt::ONE && phase->type(in(IfTrue)) == TypeInt::ZERO ) {
246 } else return NULL;
248 // Check for eq/ne test
249 if( !in(1)->is_Bool() ) return NULL;
250 BoolNode *bol = in(1)->as_Bool();
251 if( bol->_test._test == BoolTest::eq ) {
252 } else if( bol->_test._test == BoolTest::ne ) {
253 flip = 1-flip;
254 } else return NULL;
256 // Check for vs 0 or 1
257 if( !bol->in(1)->is_Cmp() ) return NULL;
258 const CmpNode *cmp = bol->in(1)->as_Cmp();
259 if( phase->type(cmp->in(2)) == TypeInt::ZERO ) {
260 } else if( phase->type(cmp->in(2)) == TypeInt::ONE ) {
261 // Allow cmp-vs-1 if the other input is bounded by 0-1
262 if( phase->type(cmp->in(1)) != TypeInt::BOOL )
263 return NULL;
264 flip = 1 - flip;
265 } else return NULL;
267 // Convert to a bool (flipped)
268 // Build int->bool conversion
269 #ifndef PRODUCT
270 if( PrintOpto ) tty->print_cr("CMOV to I2B");
271 #endif
272 Node *n = new (phase->C) Conv2BNode( cmp->in(1) );
273 if( flip )
274 n = new (phase->C) XorINode( phase->transform(n), phase->intcon(1) );
276 return n;
277 }
279 //=============================================================================
280 //------------------------------Ideal------------------------------------------
281 // Return a node which is more "ideal" than the current node.
282 // Check for absolute value
283 Node *CMoveFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
284 // Try generic ideal's first
285 Node *x = CMoveNode::Ideal(phase, can_reshape);
286 if( x ) return x;
288 int cmp_zero_idx = 0; // Index of compare input where to look for zero
289 int phi_x_idx = 0; // Index of phi input where to find naked x
291 // Find the Bool
292 if( !in(1)->is_Bool() ) return NULL;
293 BoolNode *bol = in(1)->as_Bool();
294 // Check bool sense
295 switch( bol->_test._test ) {
296 case BoolTest::lt: cmp_zero_idx = 1; phi_x_idx = IfTrue; break;
297 case BoolTest::le: cmp_zero_idx = 2; phi_x_idx = IfFalse; break;
298 case BoolTest::gt: cmp_zero_idx = 2; phi_x_idx = IfTrue; break;
299 case BoolTest::ge: cmp_zero_idx = 1; phi_x_idx = IfFalse; break;
300 default: return NULL; break;
301 }
303 // Find zero input of CmpF; the other input is being abs'd
304 Node *cmpf = bol->in(1);
305 if( cmpf->Opcode() != Op_CmpF ) return NULL;
306 Node *X = NULL;
307 bool flip = false;
308 if( phase->type(cmpf->in(cmp_zero_idx)) == TypeF::ZERO ) {
309 X = cmpf->in(3 - cmp_zero_idx);
310 } else if (phase->type(cmpf->in(3 - cmp_zero_idx)) == TypeF::ZERO) {
311 // The test is inverted, we should invert the result...
312 X = cmpf->in(cmp_zero_idx);
313 flip = true;
314 } else {
315 return NULL;
316 }
318 // If X is found on the appropriate phi input, find the subtract on the other
319 if( X != in(phi_x_idx) ) return NULL;
320 int phi_sub_idx = phi_x_idx == IfTrue ? IfFalse : IfTrue;
321 Node *sub = in(phi_sub_idx);
323 // Allow only SubF(0,X) and fail out for all others; NegF is not OK
324 if( sub->Opcode() != Op_SubF ||
325 sub->in(2) != X ||
326 phase->type(sub->in(1)) != TypeF::ZERO ) return NULL;
328 Node *abs = new (phase->C) AbsFNode( X );
329 if( flip )
330 abs = new (phase->C) SubFNode(sub->in(1), phase->transform(abs));
332 return abs;
333 }
335 //=============================================================================
336 //------------------------------Ideal------------------------------------------
337 // Return a node which is more "ideal" than the current node.
338 // Check for absolute value
339 Node *CMoveDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
340 // Try generic ideal's first
341 Node *x = CMoveNode::Ideal(phase, can_reshape);
342 if( x ) return x;
344 int cmp_zero_idx = 0; // Index of compare input where to look for zero
345 int phi_x_idx = 0; // Index of phi input where to find naked x
347 // Find the Bool
348 if( !in(1)->is_Bool() ) return NULL;
349 BoolNode *bol = in(1)->as_Bool();
350 // Check bool sense
351 switch( bol->_test._test ) {
352 case BoolTest::lt: cmp_zero_idx = 1; phi_x_idx = IfTrue; break;
353 case BoolTest::le: cmp_zero_idx = 2; phi_x_idx = IfFalse; break;
354 case BoolTest::gt: cmp_zero_idx = 2; phi_x_idx = IfTrue; break;
355 case BoolTest::ge: cmp_zero_idx = 1; phi_x_idx = IfFalse; break;
356 default: return NULL; break;
357 }
359 // Find zero input of CmpD; the other input is being abs'd
360 Node *cmpd = bol->in(1);
361 if( cmpd->Opcode() != Op_CmpD ) return NULL;
362 Node *X = NULL;
363 bool flip = false;
364 if( phase->type(cmpd->in(cmp_zero_idx)) == TypeD::ZERO ) {
365 X = cmpd->in(3 - cmp_zero_idx);
366 } else if (phase->type(cmpd->in(3 - cmp_zero_idx)) == TypeD::ZERO) {
367 // The test is inverted, we should invert the result...
368 X = cmpd->in(cmp_zero_idx);
369 flip = true;
370 } else {
371 return NULL;
372 }
374 // If X is found on the appropriate phi input, find the subtract on the other
375 if( X != in(phi_x_idx) ) return NULL;
376 int phi_sub_idx = phi_x_idx == IfTrue ? IfFalse : IfTrue;
377 Node *sub = in(phi_sub_idx);
379 // Allow only SubD(0,X) and fail out for all others; NegD is not OK
380 if( sub->Opcode() != Op_SubD ||
381 sub->in(2) != X ||
382 phase->type(sub->in(1)) != TypeD::ZERO ) return NULL;
384 Node *abs = new (phase->C) AbsDNode( X );
385 if( flip )
386 abs = new (phase->C) SubDNode(sub->in(1), phase->transform(abs));
388 return abs;
389 }
392 //=============================================================================
393 // If input is already higher or equal to cast type, then this is an identity.
394 Node *ConstraintCastNode::Identity( PhaseTransform *phase ) {
395 return phase->type(in(1))->higher_equal_speculative(_type) ? in(1) : this;
396 }
398 //------------------------------Value------------------------------------------
399 // Take 'join' of input and cast-up type
400 const Type *ConstraintCastNode::Value( PhaseTransform *phase ) const {
401 if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;
402 const Type* ft = phase->type(in(1))->filter_speculative(_type);
404 #ifdef ASSERT
405 // Previous versions of this function had some special case logic,
406 // which is no longer necessary. Make sure of the required effects.
407 switch (Opcode()) {
408 case Op_CastII:
409 {
410 const Type* t1 = phase->type(in(1));
411 if( t1 == Type::TOP ) assert(ft == Type::TOP, "special case #1");
412 const Type* rt = t1->join_speculative(_type);
413 if (rt->empty()) assert(ft == Type::TOP, "special case #2");
414 break;
415 }
416 case Op_CastPP:
417 if (phase->type(in(1)) == TypePtr::NULL_PTR &&
418 _type->isa_ptr() && _type->is_ptr()->_ptr == TypePtr::NotNull)
419 assert(ft == Type::TOP, "special case #3");
420 break;
421 }
422 #endif //ASSERT
424 return ft;
425 }
427 //------------------------------Ideal------------------------------------------
428 // Return a node which is more "ideal" than the current node. Strip out
429 // control copies
430 Node *ConstraintCastNode::Ideal(PhaseGVN *phase, bool can_reshape){
431 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;
432 }
434 //------------------------------Ideal_DU_postCCP-------------------------------
435 // Throw away cast after constant propagation
436 Node *ConstraintCastNode::Ideal_DU_postCCP( PhaseCCP *ccp ) {
437 const Type *t = ccp->type(in(1));
438 ccp->hash_delete(this);
439 set_type(t); // Turn into ID function
440 ccp->hash_insert(this);
441 return this;
442 }
444 uint CastIINode::size_of() const {
445 return sizeof(*this);
446 }
448 uint CastIINode::cmp(const Node &n) const {
449 return TypeNode::cmp(n) && ((CastIINode&)n)._carry_dependency == _carry_dependency;
450 }
452 Node *CastIINode::Identity(PhaseTransform *phase) {
453 if (_carry_dependency) {
454 return this;
455 }
456 return ConstraintCastNode::Identity(phase);
457 }
459 const Type *CastIINode::Value(PhaseTransform *phase) const {
460 const Type *res = ConstraintCastNode::Value(phase);
462 // Try to improve the type of the CastII if we recognize a CmpI/If
463 // pattern.
464 if (_carry_dependency) {
465 if (in(0) != NULL && (in(0)->is_IfFalse() || in(0)->is_IfTrue())) {
466 Node* proj = in(0);
467 if (proj->in(0)->in(1)->is_Bool()) {
468 Node* b = proj->in(0)->in(1);
469 if (b->in(1)->Opcode() == Op_CmpI) {
470 Node* cmp = b->in(1);
471 if (cmp->in(1) == in(1) && phase->type(cmp->in(2))->isa_int()) {
472 const TypeInt* in2_t = phase->type(cmp->in(2))->is_int();
473 const Type* t = TypeInt::INT;
474 BoolTest test = b->as_Bool()->_test;
475 if (proj->is_IfFalse()) {
476 test = test.negate();
477 }
478 BoolTest::mask m = test._test;
479 jlong lo_long = min_jint;
480 jlong hi_long = max_jint;
481 if (m == BoolTest::le || m == BoolTest::lt) {
482 hi_long = in2_t->_hi;
483 if (m == BoolTest::lt) {
484 hi_long -= 1;
485 }
486 } else if (m == BoolTest::ge || m == BoolTest::gt) {
487 lo_long = in2_t->_lo;
488 if (m == BoolTest::gt) {
489 lo_long += 1;
490 }
491 } else if (m == BoolTest::eq) {
492 lo_long = in2_t->_lo;
493 hi_long = in2_t->_hi;
494 } else if (m == BoolTest::ne) {
495 // can't do any better
496 } else {
497 stringStream ss;
498 test.dump_on(&ss);
499 fatal(err_msg_res("unexpected comparison %s", ss.as_string()));
500 }
501 int lo_int = (int)lo_long;
502 int hi_int = (int)hi_long;
504 if (lo_long != (jlong)lo_int) {
505 lo_int = min_jint;
506 }
507 if (hi_long != (jlong)hi_int) {
508 hi_int = max_jint;
509 }
511 t = TypeInt::make(lo_int, hi_int, Type::WidenMax);
513 res = res->filter_speculative(t);
515 return res;
516 }
517 }
518 }
519 }
520 }
521 return res;
522 }
524 Node *CastIINode::Ideal_DU_postCCP(PhaseCCP *ccp) {
525 if (_carry_dependency) {
526 return NULL;
527 }
528 return ConstraintCastNode::Ideal_DU_postCCP(ccp);
529 }
531 #ifndef PRODUCT
532 void CastIINode::dump_spec(outputStream *st) const {
533 TypeNode::dump_spec(st);
534 if (_carry_dependency) {
535 st->print(" carry dependency");
536 }
537 }
538 #endif
540 //=============================================================================
542 //------------------------------Ideal_DU_postCCP-------------------------------
543 // If not converting int->oop, throw away cast after constant propagation
544 Node *CastPPNode::Ideal_DU_postCCP( PhaseCCP *ccp ) {
545 const Type *t = ccp->type(in(1));
546 if (!t->isa_oop_ptr() || ((in(1)->is_DecodeN()) && Matcher::gen_narrow_oop_implicit_null_checks())) {
547 return NULL; // do not transform raw pointers or narrow oops
548 }
549 return ConstraintCastNode::Ideal_DU_postCCP(ccp);
550 }
554 //=============================================================================
555 //------------------------------Identity---------------------------------------
556 // If input is already higher or equal to cast type, then this is an identity.
557 Node *CheckCastPPNode::Identity( PhaseTransform *phase ) {
558 // Toned down to rescue meeting at a Phi 3 different oops all implementing
559 // the same interface. CompileTheWorld starting at 502, kd12rc1.zip.
560 return (phase->type(in(1)) == phase->type(this)) ? in(1) : this;
561 }
563 //------------------------------Value------------------------------------------
564 // Take 'join' of input and cast-up type, unless working with an Interface
565 const Type *CheckCastPPNode::Value( PhaseTransform *phase ) const {
566 if( in(0) && phase->type(in(0)) == Type::TOP ) return Type::TOP;
568 const Type *inn = phase->type(in(1));
569 if( inn == Type::TOP ) return Type::TOP; // No information yet
571 const TypePtr *in_type = inn->isa_ptr();
572 const TypePtr *my_type = _type->isa_ptr();
573 const Type *result = _type;
574 if( in_type != NULL && my_type != NULL ) {
575 TypePtr::PTR in_ptr = in_type->ptr();
576 if( in_ptr == TypePtr::Null ) {
577 result = in_type;
578 } else if( in_ptr == TypePtr::Constant ) {
579 // Casting a constant oop to an interface?
580 // (i.e., a String to a Comparable?)
581 // Then return the interface.
582 const TypeOopPtr *jptr = my_type->isa_oopptr();
583 assert( jptr, "" );
584 result = (jptr->klass()->is_interface() || !in_type->higher_equal(_type))
585 ? my_type->cast_to_ptr_type( TypePtr::NotNull )
586 : in_type;
587 } else {
588 result = my_type->cast_to_ptr_type( my_type->join_ptr(in_ptr) );
589 }
590 }
591 return result;
593 // JOIN NOT DONE HERE BECAUSE OF INTERFACE ISSUES.
594 // FIX THIS (DO THE JOIN) WHEN UNION TYPES APPEAR!
596 //
597 // Remove this code after overnight run indicates no performance
598 // loss from not performing JOIN at CheckCastPPNode
599 //
600 // const TypeInstPtr *in_oop = in->isa_instptr();
601 // const TypeInstPtr *my_oop = _type->isa_instptr();
602 // // If either input is an 'interface', return destination type
603 // assert (in_oop == NULL || in_oop->klass() != NULL, "");
604 // assert (my_oop == NULL || my_oop->klass() != NULL, "");
605 // if( (in_oop && in_oop->klass()->is_interface())
606 // ||(my_oop && my_oop->klass()->is_interface()) ) {
607 // TypePtr::PTR in_ptr = in->isa_ptr() ? in->is_ptr()->_ptr : TypePtr::BotPTR;
608 // // Preserve cast away nullness for interfaces
609 // if( in_ptr == TypePtr::NotNull && my_oop && my_oop->_ptr == TypePtr::BotPTR ) {
610 // return my_oop->cast_to_ptr_type(TypePtr::NotNull);
611 // }
612 // return _type;
613 // }
614 //
615 // // Neither the input nor the destination type is an interface,
616 //
617 // // history: JOIN used to cause weird corner case bugs
618 // // return (in == TypeOopPtr::NULL_PTR) ? in : _type;
619 // // JOIN picks up NotNull in common instance-of/check-cast idioms, both oops.
620 // // JOIN does not preserve NotNull in other cases, e.g. RawPtr vs InstPtr
621 // const Type *join = in->join(_type);
622 // // Check if join preserved NotNull'ness for pointers
623 // if( join->isa_ptr() && _type->isa_ptr() ) {
624 // TypePtr::PTR join_ptr = join->is_ptr()->_ptr;
625 // TypePtr::PTR type_ptr = _type->is_ptr()->_ptr;
626 // // If there isn't any NotNull'ness to preserve
627 // // OR if join preserved NotNull'ness then return it
628 // if( type_ptr == TypePtr::BotPTR || type_ptr == TypePtr::Null ||
629 // join_ptr == TypePtr::NotNull || join_ptr == TypePtr::Constant ) {
630 // return join;
631 // }
632 // // ELSE return same old type as before
633 // return _type;
634 // }
635 // // Not joining two pointers
636 // return join;
637 }
639 //------------------------------Ideal------------------------------------------
640 // Return a node which is more "ideal" than the current node. Strip out
641 // control copies
642 Node *CheckCastPPNode::Ideal(PhaseGVN *phase, bool can_reshape){
643 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;
644 }
647 Node* DecodeNNode::Identity(PhaseTransform* phase) {
648 const Type *t = phase->type( in(1) );
649 if( t == Type::TOP ) return in(1);
651 if (in(1)->is_EncodeP()) {
652 // (DecodeN (EncodeP p)) -> p
653 return in(1)->in(1);
654 }
655 return this;
656 }
658 const Type *DecodeNNode::Value( PhaseTransform *phase ) const {
659 const Type *t = phase->type( in(1) );
660 if (t == Type::TOP) return Type::TOP;
661 if (t == TypeNarrowOop::NULL_PTR) return TypePtr::NULL_PTR;
663 assert(t->isa_narrowoop(), "only narrowoop here");
664 return t->make_ptr();
665 }
667 Node* EncodePNode::Identity(PhaseTransform* phase) {
668 const Type *t = phase->type( in(1) );
669 if( t == Type::TOP ) return in(1);
671 if (in(1)->is_DecodeN()) {
672 // (EncodeP (DecodeN p)) -> p
673 return in(1)->in(1);
674 }
675 return this;
676 }
678 const Type *EncodePNode::Value( PhaseTransform *phase ) const {
679 const Type *t = phase->type( in(1) );
680 if (t == Type::TOP) return Type::TOP;
681 if (t == TypePtr::NULL_PTR) return TypeNarrowOop::NULL_PTR;
683 assert(t->isa_oop_ptr(), "only oopptr here");
684 return t->make_narrowoop();
685 }
688 Node *EncodeNarrowPtrNode::Ideal_DU_postCCP( PhaseCCP *ccp ) {
689 return MemNode::Ideal_common_DU_postCCP(ccp, this, in(1));
690 }
692 Node* DecodeNKlassNode::Identity(PhaseTransform* phase) {
693 const Type *t = phase->type( in(1) );
694 if( t == Type::TOP ) return in(1);
696 if (in(1)->is_EncodePKlass()) {
697 // (DecodeNKlass (EncodePKlass p)) -> p
698 return in(1)->in(1);
699 }
700 return this;
701 }
703 const Type *DecodeNKlassNode::Value( PhaseTransform *phase ) const {
704 const Type *t = phase->type( in(1) );
705 if (t == Type::TOP) return Type::TOP;
706 assert(t != TypeNarrowKlass::NULL_PTR, "null klass?");
708 assert(t->isa_narrowklass(), "only narrow klass ptr here");
709 return t->make_ptr();
710 }
712 Node* EncodePKlassNode::Identity(PhaseTransform* phase) {
713 const Type *t = phase->type( in(1) );
714 if( t == Type::TOP ) return in(1);
716 if (in(1)->is_DecodeNKlass()) {
717 // (EncodePKlass (DecodeNKlass p)) -> p
718 return in(1)->in(1);
719 }
720 return this;
721 }
723 const Type *EncodePKlassNode::Value( PhaseTransform *phase ) const {
724 const Type *t = phase->type( in(1) );
725 if (t == Type::TOP) return Type::TOP;
726 assert (t != TypePtr::NULL_PTR, "null klass?");
728 assert(UseCompressedClassPointers && t->isa_klassptr(), "only klass ptr here");
729 return t->make_narrowklass();
730 }
733 //=============================================================================
734 //------------------------------Identity---------------------------------------
735 Node *Conv2BNode::Identity( PhaseTransform *phase ) {
736 const Type *t = phase->type( in(1) );
737 if( t == Type::TOP ) return in(1);
738 if( t == TypeInt::ZERO ) return in(1);
739 if( t == TypeInt::ONE ) return in(1);
740 if( t == TypeInt::BOOL ) return in(1);
741 return this;
742 }
744 //------------------------------Value------------------------------------------
745 const Type *Conv2BNode::Value( PhaseTransform *phase ) const {
746 const Type *t = phase->type( in(1) );
747 if( t == Type::TOP ) return Type::TOP;
748 if( t == TypeInt::ZERO ) return TypeInt::ZERO;
749 if( t == TypePtr::NULL_PTR ) return TypeInt::ZERO;
750 const TypePtr *tp = t->isa_ptr();
751 if( tp != NULL ) {
752 if( tp->ptr() == TypePtr::AnyNull ) return Type::TOP;
753 if( tp->ptr() == TypePtr::Constant) return TypeInt::ONE;
754 if (tp->ptr() == TypePtr::NotNull) return TypeInt::ONE;
755 return TypeInt::BOOL;
756 }
757 if (t->base() != Type::Int) return TypeInt::BOOL;
758 const TypeInt *ti = t->is_int();
759 if( ti->_hi < 0 || ti->_lo > 0 ) return TypeInt::ONE;
760 return TypeInt::BOOL;
761 }
764 // The conversions operations are all Alpha sorted. Please keep it that way!
765 //=============================================================================
766 //------------------------------Value------------------------------------------
767 const Type *ConvD2FNode::Value( PhaseTransform *phase ) const {
768 const Type *t = phase->type( in(1) );
769 if( t == Type::TOP ) return Type::TOP;
770 if( t == Type::DOUBLE ) return Type::FLOAT;
771 const TypeD *td = t->is_double_constant();
772 return TypeF::make( (float)td->getd() );
773 }
775 //------------------------------Identity---------------------------------------
776 // Float's can be converted to doubles with no loss of bits. Hence
777 // converting a float to a double and back to a float is a NOP.
778 Node *ConvD2FNode::Identity(PhaseTransform *phase) {
779 return (in(1)->Opcode() == Op_ConvF2D) ? in(1)->in(1) : this;
780 }
782 //=============================================================================
783 //------------------------------Value------------------------------------------
784 const Type *ConvD2INode::Value( PhaseTransform *phase ) const {
785 const Type *t = phase->type( in(1) );
786 if( t == Type::TOP ) return Type::TOP;
787 if( t == Type::DOUBLE ) return TypeInt::INT;
788 const TypeD *td = t->is_double_constant();
789 return TypeInt::make( SharedRuntime::d2i( td->getd() ) );
790 }
792 //------------------------------Ideal------------------------------------------
793 // If converting to an int type, skip any rounding nodes
794 Node *ConvD2INode::Ideal(PhaseGVN *phase, bool can_reshape) {
795 if( in(1)->Opcode() == Op_RoundDouble )
796 set_req(1,in(1)->in(1));
797 return NULL;
798 }
800 //------------------------------Identity---------------------------------------
801 // Int's can be converted to doubles with no loss of bits. Hence
802 // converting an integer to a double and back to an integer is a NOP.
803 Node *ConvD2INode::Identity(PhaseTransform *phase) {
804 return (in(1)->Opcode() == Op_ConvI2D) ? in(1)->in(1) : this;
805 }
807 //=============================================================================
808 //------------------------------Value------------------------------------------
809 const Type *ConvD2LNode::Value( PhaseTransform *phase ) const {
810 const Type *t = phase->type( in(1) );
811 if( t == Type::TOP ) return Type::TOP;
812 if( t == Type::DOUBLE ) return TypeLong::LONG;
813 const TypeD *td = t->is_double_constant();
814 return TypeLong::make( SharedRuntime::d2l( td->getd() ) );
815 }
817 //------------------------------Identity---------------------------------------
818 Node *ConvD2LNode::Identity(PhaseTransform *phase) {
819 // Remove ConvD2L->ConvL2D->ConvD2L sequences.
820 if( in(1) ->Opcode() == Op_ConvL2D &&
821 in(1)->in(1)->Opcode() == Op_ConvD2L )
822 return in(1)->in(1);
823 return this;
824 }
826 //------------------------------Ideal------------------------------------------
827 // If converting to an int type, skip any rounding nodes
828 Node *ConvD2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
829 if( in(1)->Opcode() == Op_RoundDouble )
830 set_req(1,in(1)->in(1));
831 return NULL;
832 }
834 //=============================================================================
835 //------------------------------Value------------------------------------------
836 const Type *ConvF2DNode::Value( PhaseTransform *phase ) const {
837 const Type *t = phase->type( in(1) );
838 if( t == Type::TOP ) return Type::TOP;
839 if( t == Type::FLOAT ) return Type::DOUBLE;
840 const TypeF *tf = t->is_float_constant();
841 return TypeD::make( (double)tf->getf() );
842 }
844 //=============================================================================
845 //------------------------------Value------------------------------------------
846 const Type *ConvF2INode::Value( PhaseTransform *phase ) const {
847 const Type *t = phase->type( in(1) );
848 if( t == Type::TOP ) return Type::TOP;
849 if( t == Type::FLOAT ) return TypeInt::INT;
850 const TypeF *tf = t->is_float_constant();
851 return TypeInt::make( SharedRuntime::f2i( tf->getf() ) );
852 }
854 //------------------------------Identity---------------------------------------
855 Node *ConvF2INode::Identity(PhaseTransform *phase) {
856 // Remove ConvF2I->ConvI2F->ConvF2I sequences.
857 if( in(1) ->Opcode() == Op_ConvI2F &&
858 in(1)->in(1)->Opcode() == Op_ConvF2I )
859 return in(1)->in(1);
860 return this;
861 }
863 //------------------------------Ideal------------------------------------------
864 // If converting to an int type, skip any rounding nodes
865 Node *ConvF2INode::Ideal(PhaseGVN *phase, bool can_reshape) {
866 if( in(1)->Opcode() == Op_RoundFloat )
867 set_req(1,in(1)->in(1));
868 return NULL;
869 }
871 //=============================================================================
872 //------------------------------Value------------------------------------------
873 const Type *ConvF2LNode::Value( PhaseTransform *phase ) const {
874 const Type *t = phase->type( in(1) );
875 if( t == Type::TOP ) return Type::TOP;
876 if( t == Type::FLOAT ) return TypeLong::LONG;
877 const TypeF *tf = t->is_float_constant();
878 return TypeLong::make( SharedRuntime::f2l( tf->getf() ) );
879 }
881 //------------------------------Identity---------------------------------------
882 Node *ConvF2LNode::Identity(PhaseTransform *phase) {
883 // Remove ConvF2L->ConvL2F->ConvF2L sequences.
884 if( in(1) ->Opcode() == Op_ConvL2F &&
885 in(1)->in(1)->Opcode() == Op_ConvF2L )
886 return in(1)->in(1);
887 return this;
888 }
890 //------------------------------Ideal------------------------------------------
891 // If converting to an int type, skip any rounding nodes
892 Node *ConvF2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
893 if( in(1)->Opcode() == Op_RoundFloat )
894 set_req(1,in(1)->in(1));
895 return NULL;
896 }
898 //=============================================================================
899 //------------------------------Value------------------------------------------
900 const Type *ConvI2DNode::Value( PhaseTransform *phase ) const {
901 const Type *t = phase->type( in(1) );
902 if( t == Type::TOP ) return Type::TOP;
903 const TypeInt *ti = t->is_int();
904 if( ti->is_con() ) return TypeD::make( (double)ti->get_con() );
905 return bottom_type();
906 }
908 //=============================================================================
909 //------------------------------Value------------------------------------------
910 const Type *ConvI2FNode::Value( PhaseTransform *phase ) const {
911 const Type *t = phase->type( in(1) );
912 if( t == Type::TOP ) return Type::TOP;
913 const TypeInt *ti = t->is_int();
914 if( ti->is_con() ) return TypeF::make( (float)ti->get_con() );
915 return bottom_type();
916 }
918 //------------------------------Identity---------------------------------------
919 Node *ConvI2FNode::Identity(PhaseTransform *phase) {
920 // Remove ConvI2F->ConvF2I->ConvI2F sequences.
921 if( in(1) ->Opcode() == Op_ConvF2I &&
922 in(1)->in(1)->Opcode() == Op_ConvI2F )
923 return in(1)->in(1);
924 return this;
925 }
927 //=============================================================================
928 //------------------------------Value------------------------------------------
929 const Type *ConvI2LNode::Value( PhaseTransform *phase ) const {
930 const Type *t = phase->type( in(1) );
931 if( t == Type::TOP ) return Type::TOP;
932 const TypeInt *ti = t->is_int();
933 const Type* tl = TypeLong::make(ti->_lo, ti->_hi, ti->_widen);
934 // Join my declared type against my incoming type.
935 tl = tl->filter(_type);
936 return tl;
937 }
939 #ifdef _LP64
940 static inline bool long_ranges_overlap(jlong lo1, jlong hi1,
941 jlong lo2, jlong hi2) {
942 // Two ranges overlap iff one range's low point falls in the other range.
943 return (lo2 <= lo1 && lo1 <= hi2) || (lo1 <= lo2 && lo2 <= hi1);
944 }
945 #endif
947 //------------------------------Ideal------------------------------------------
948 Node *ConvI2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
949 const TypeLong* this_type = this->type()->is_long();
950 Node* this_changed = NULL;
952 // If _major_progress, then more loop optimizations follow. Do NOT
953 // remove this node's type assertion until no more loop ops can happen.
954 // The progress bit is set in the major loop optimizations THEN comes the
955 // call to IterGVN and any chance of hitting this code. Cf. Opaque1Node.
956 if (can_reshape && !phase->C->major_progress()) {
957 const TypeInt* in_type = phase->type(in(1))->isa_int();
958 if (in_type != NULL && this_type != NULL &&
959 (in_type->_lo != this_type->_lo ||
960 in_type->_hi != this_type->_hi)) {
961 // Although this WORSENS the type, it increases GVN opportunities,
962 // because I2L nodes with the same input will common up, regardless
963 // of slightly differing type assertions. Such slight differences
964 // arise routinely as a result of loop unrolling, so this is a
965 // post-unrolling graph cleanup. Choose a type which depends only
966 // on my input. (Exception: Keep a range assertion of >=0 or <0.)
967 jlong lo1 = this_type->_lo;
968 jlong hi1 = this_type->_hi;
969 int w1 = this_type->_widen;
970 if (lo1 != (jint)lo1 ||
971 hi1 != (jint)hi1 ||
972 lo1 > hi1) {
973 // Overflow leads to wraparound, wraparound leads to range saturation.
974 lo1 = min_jint; hi1 = max_jint;
975 } else if (lo1 >= 0) {
976 // Keep a range assertion of >=0.
977 lo1 = 0; hi1 = max_jint;
978 } else if (hi1 < 0) {
979 // Keep a range assertion of <0.
980 lo1 = min_jint; hi1 = -1;
981 } else {
982 lo1 = min_jint; hi1 = max_jint;
983 }
984 const TypeLong* wtype = TypeLong::make(MAX2((jlong)in_type->_lo, lo1),
985 MIN2((jlong)in_type->_hi, hi1),
986 MAX2((int)in_type->_widen, w1));
987 if (wtype != type()) {
988 set_type(wtype);
989 // Note: this_type still has old type value, for the logic below.
990 this_changed = this;
991 }
992 }
993 }
995 #ifdef _LP64
996 // Convert ConvI2L(AddI(x, y)) to AddL(ConvI2L(x), ConvI2L(y)) ,
997 // but only if x and y have subranges that cannot cause 32-bit overflow,
998 // under the assumption that x+y is in my own subrange this->type().
1000 // This assumption is based on a constraint (i.e., type assertion)
1001 // established in Parse::array_addressing or perhaps elsewhere.
1002 // This constraint has been adjoined to the "natural" type of
1003 // the incoming argument in(0). We know (because of runtime
1004 // checks) - that the result value I2L(x+y) is in the joined range.
1005 // Hence we can restrict the incoming terms (x, y) to values such
1006 // that their sum also lands in that range.
1008 // This optimization is useful only on 64-bit systems, where we hope
1009 // the addition will end up subsumed in an addressing mode.
1010 // It is necessary to do this when optimizing an unrolled array
1011 // copy loop such as x[i++] = y[i++].
1013 // On 32-bit systems, it's better to perform as much 32-bit math as
1014 // possible before the I2L conversion, because 32-bit math is cheaper.
1015 // There's no common reason to "leak" a constant offset through the I2L.
1016 // Addressing arithmetic will not absorb it as part of a 64-bit AddL.
1018 Node* z = in(1);
1019 int op = z->Opcode();
1020 if (op == Op_AddI || op == Op_SubI) {
1021 Node* x = z->in(1);
1022 Node* y = z->in(2);
1023 assert (x != z && y != z, "dead loop in ConvI2LNode::Ideal");
1024 if (phase->type(x) == Type::TOP) return this_changed;
1025 if (phase->type(y) == Type::TOP) return this_changed;
1026 const TypeInt* tx = phase->type(x)->is_int();
1027 const TypeInt* ty = phase->type(y)->is_int();
1028 const TypeLong* tz = this_type;
1029 jlong xlo = tx->_lo;
1030 jlong xhi = tx->_hi;
1031 jlong ylo = ty->_lo;
1032 jlong yhi = ty->_hi;
1033 jlong zlo = tz->_lo;
1034 jlong zhi = tz->_hi;
1035 jlong vbit = CONST64(1) << BitsPerInt;
1036 int widen = MAX2(tx->_widen, ty->_widen);
1037 if (op == Op_SubI) {
1038 jlong ylo0 = ylo;
1039 ylo = -yhi;
1040 yhi = -ylo0;
1041 }
1042 // See if x+y can cause positive overflow into z+2**32
1043 if (long_ranges_overlap(xlo+ylo, xhi+yhi, zlo+vbit, zhi+vbit)) {
1044 return this_changed;
1045 }
1046 // See if x+y can cause negative overflow into z-2**32
1047 if (long_ranges_overlap(xlo+ylo, xhi+yhi, zlo-vbit, zhi-vbit)) {
1048 return this_changed;
1049 }
1050 // Now it's always safe to assume x+y does not overflow.
1051 // This is true even if some pairs x,y might cause overflow, as long
1052 // as that overflow value cannot fall into [zlo,zhi].
1054 // Confident that the arithmetic is "as if infinite precision",
1055 // we can now use z's range to put constraints on those of x and y.
1056 // The "natural" range of x [xlo,xhi] can perhaps be narrowed to a
1057 // more "restricted" range by intersecting [xlo,xhi] with the
1058 // range obtained by subtracting y's range from the asserted range
1059 // of the I2L conversion. Here's the interval arithmetic algebra:
1060 // x == z-y == [zlo,zhi]-[ylo,yhi] == [zlo,zhi]+[-yhi,-ylo]
1061 // => x in [zlo-yhi, zhi-ylo]
1062 // => x in [zlo-yhi, zhi-ylo] INTERSECT [xlo,xhi]
1063 // => x in [xlo MAX zlo-yhi, xhi MIN zhi-ylo]
1064 jlong rxlo = MAX2(xlo, zlo - yhi);
1065 jlong rxhi = MIN2(xhi, zhi - ylo);
1066 // And similarly, x changing place with y:
1067 jlong rylo = MAX2(ylo, zlo - xhi);
1068 jlong ryhi = MIN2(yhi, zhi - xlo);
1069 if (rxlo > rxhi || rylo > ryhi) {
1070 return this_changed; // x or y is dying; don't mess w/ it
1071 }
1072 if (op == Op_SubI) {
1073 jlong rylo0 = rylo;
1074 rylo = -ryhi;
1075 ryhi = -rylo0;
1076 }
1078 Node* cx = phase->transform( new (phase->C) ConvI2LNode(x, TypeLong::make(rxlo, rxhi, widen)) );
1079 Node* cy = phase->transform( new (phase->C) ConvI2LNode(y, TypeLong::make(rylo, ryhi, widen)) );
1080 switch (op) {
1081 case Op_AddI: return new (phase->C) AddLNode(cx, cy);
1082 case Op_SubI: return new (phase->C) SubLNode(cx, cy);
1083 default: ShouldNotReachHere();
1084 }
1085 }
1086 #endif //_LP64
1088 return this_changed;
1089 }
1091 //=============================================================================
1092 //------------------------------Value------------------------------------------
1093 const Type *ConvL2DNode::Value( PhaseTransform *phase ) const {
1094 const Type *t = phase->type( in(1) );
1095 if( t == Type::TOP ) return Type::TOP;
1096 const TypeLong *tl = t->is_long();
1097 if( tl->is_con() ) return TypeD::make( (double)tl->get_con() );
1098 return bottom_type();
1099 }
1101 //=============================================================================
1102 //------------------------------Value------------------------------------------
1103 const Type *ConvL2FNode::Value( PhaseTransform *phase ) const {
1104 const Type *t = phase->type( in(1) );
1105 if( t == Type::TOP ) return Type::TOP;
1106 const TypeLong *tl = t->is_long();
1107 if( tl->is_con() ) return TypeF::make( (float)tl->get_con() );
1108 return bottom_type();
1109 }
1111 //=============================================================================
1112 //----------------------------Identity-----------------------------------------
1113 Node *ConvL2INode::Identity( PhaseTransform *phase ) {
1114 // Convert L2I(I2L(x)) => x
1115 if (in(1)->Opcode() == Op_ConvI2L) return in(1)->in(1);
1116 return this;
1117 }
1119 //------------------------------Value------------------------------------------
1120 const Type *ConvL2INode::Value( PhaseTransform *phase ) const {
1121 const Type *t = phase->type( in(1) );
1122 if( t == Type::TOP ) return Type::TOP;
1123 const TypeLong *tl = t->is_long();
1124 if (tl->is_con())
1125 // Easy case.
1126 return TypeInt::make((jint)tl->get_con());
1127 return bottom_type();
1128 }
1130 //------------------------------Ideal------------------------------------------
1131 // Return a node which is more "ideal" than the current node.
1132 // Blow off prior masking to int
1133 Node *ConvL2INode::Ideal(PhaseGVN *phase, bool can_reshape) {
1134 Node *andl = in(1);
1135 uint andl_op = andl->Opcode();
1136 if( andl_op == Op_AndL ) {
1137 // Blow off prior masking to int
1138 if( phase->type(andl->in(2)) == TypeLong::make( 0xFFFFFFFF ) ) {
1139 set_req(1,andl->in(1));
1140 return this;
1141 }
1142 }
1144 // Swap with a prior add: convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1145 // This replaces an 'AddL' with an 'AddI'.
1146 if( andl_op == Op_AddL ) {
1147 // Don't do this for nodes which have more than one user since
1148 // we'll end up computing the long add anyway.
1149 if (andl->outcnt() > 1) return NULL;
1151 Node* x = andl->in(1);
1152 Node* y = andl->in(2);
1153 assert( x != andl && y != andl, "dead loop in ConvL2INode::Ideal" );
1154 if (phase->type(x) == Type::TOP) return NULL;
1155 if (phase->type(y) == Type::TOP) return NULL;
1156 Node *add1 = phase->transform(new (phase->C) ConvL2INode(x));
1157 Node *add2 = phase->transform(new (phase->C) ConvL2INode(y));
1158 return new (phase->C) AddINode(add1,add2);
1159 }
1161 // Disable optimization: LoadL->ConvL2I ==> LoadI.
1162 // It causes problems (sizes of Load and Store nodes do not match)
1163 // in objects initialization code and Escape Analysis.
1164 return NULL;
1165 }
1167 //=============================================================================
1168 //------------------------------Value------------------------------------------
1169 const Type *CastX2PNode::Value( PhaseTransform *phase ) const {
1170 const Type* t = phase->type(in(1));
1171 if (t == Type::TOP) return Type::TOP;
1172 if (t->base() == Type_X && t->singleton()) {
1173 uintptr_t bits = (uintptr_t) t->is_intptr_t()->get_con();
1174 if (bits == 0) return TypePtr::NULL_PTR;
1175 return TypeRawPtr::make((address) bits);
1176 }
1177 return CastX2PNode::bottom_type();
1178 }
1180 //------------------------------Idealize---------------------------------------
1181 static inline bool fits_in_int(const Type* t, bool but_not_min_int = false) {
1182 if (t == Type::TOP) return false;
1183 const TypeX* tl = t->is_intptr_t();
1184 jint lo = min_jint;
1185 jint hi = max_jint;
1186 if (but_not_min_int) ++lo; // caller wants to negate the value w/o overflow
1187 return (tl->_lo >= lo) && (tl->_hi <= hi);
1188 }
1190 static inline Node* addP_of_X2P(PhaseGVN *phase,
1191 Node* base,
1192 Node* dispX,
1193 bool negate = false) {
1194 if (negate) {
1195 dispX = new (phase->C) SubXNode(phase->MakeConX(0), phase->transform(dispX));
1196 }
1197 return new (phase->C) AddPNode(phase->C->top(),
1198 phase->transform(new (phase->C) CastX2PNode(base)),
1199 phase->transform(dispX));
1200 }
1202 Node *CastX2PNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1203 // convert CastX2P(AddX(x, y)) to AddP(CastX2P(x), y) if y fits in an int
1204 int op = in(1)->Opcode();
1205 Node* x;
1206 Node* y;
1207 switch (op) {
1208 case Op_SubX:
1209 x = in(1)->in(1);
1210 // Avoid ideal transformations ping-pong between this and AddP for raw pointers.
1211 if (phase->find_intptr_t_con(x, -1) == 0)
1212 break;
1213 y = in(1)->in(2);
1214 if (fits_in_int(phase->type(y), true)) {
1215 return addP_of_X2P(phase, x, y, true);
1216 }
1217 break;
1218 case Op_AddX:
1219 x = in(1)->in(1);
1220 y = in(1)->in(2);
1221 if (fits_in_int(phase->type(y))) {
1222 return addP_of_X2P(phase, x, y);
1223 }
1224 if (fits_in_int(phase->type(x))) {
1225 return addP_of_X2P(phase, y, x);
1226 }
1227 break;
1228 }
1229 return NULL;
1230 }
1232 //------------------------------Identity---------------------------------------
1233 Node *CastX2PNode::Identity( PhaseTransform *phase ) {
1234 if (in(1)->Opcode() == Op_CastP2X) return in(1)->in(1);
1235 return this;
1236 }
1238 //=============================================================================
1239 //------------------------------Value------------------------------------------
1240 const Type *CastP2XNode::Value( PhaseTransform *phase ) const {
1241 const Type* t = phase->type(in(1));
1242 if (t == Type::TOP) return Type::TOP;
1243 if (t->base() == Type::RawPtr && t->singleton()) {
1244 uintptr_t bits = (uintptr_t) t->is_rawptr()->get_con();
1245 return TypeX::make(bits);
1246 }
1247 return CastP2XNode::bottom_type();
1248 }
1250 Node *CastP2XNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1251 return (in(0) && remove_dead_region(phase, can_reshape)) ? this : NULL;
1252 }
1254 //------------------------------Identity---------------------------------------
1255 Node *CastP2XNode::Identity( PhaseTransform *phase ) {
1256 if (in(1)->Opcode() == Op_CastX2P) return in(1)->in(1);
1257 return this;
1258 }
1261 //=============================================================================
1262 //------------------------------Identity---------------------------------------
1263 // Remove redundant roundings
1264 Node *RoundFloatNode::Identity( PhaseTransform *phase ) {
1265 assert(Matcher::strict_fp_requires_explicit_rounding, "should only generate for Intel");
1266 // Do not round constants
1267 if (phase->type(in(1))->base() == Type::FloatCon) return in(1);
1268 int op = in(1)->Opcode();
1269 // Redundant rounding
1270 if( op == Op_RoundFloat ) return in(1);
1271 // Already rounded
1272 if( op == Op_Parm ) return in(1);
1273 if( op == Op_LoadF ) return in(1);
1274 return this;
1275 }
1277 //------------------------------Value------------------------------------------
1278 const Type *RoundFloatNode::Value( PhaseTransform *phase ) const {
1279 return phase->type( in(1) );
1280 }
1282 //=============================================================================
1283 //------------------------------Identity---------------------------------------
1284 // Remove redundant roundings. Incoming arguments are already rounded.
1285 Node *RoundDoubleNode::Identity( PhaseTransform *phase ) {
1286 assert(Matcher::strict_fp_requires_explicit_rounding, "should only generate for Intel");
1287 // Do not round constants
1288 if (phase->type(in(1))->base() == Type::DoubleCon) return in(1);
1289 int op = in(1)->Opcode();
1290 // Redundant rounding
1291 if( op == Op_RoundDouble ) return in(1);
1292 // Already rounded
1293 if( op == Op_Parm ) return in(1);
1294 if( op == Op_LoadD ) return in(1);
1295 if( op == Op_ConvF2D ) return in(1);
1296 if( op == Op_ConvI2D ) return in(1);
1297 return this;
1298 }
1300 //------------------------------Value------------------------------------------
1301 const Type *RoundDoubleNode::Value( PhaseTransform *phase ) const {
1302 return phase->type( in(1) );
1303 }
1306 //=============================================================================
1307 // Do not allow value-numbering
1308 uint Opaque1Node::hash() const { return NO_HASH; }
1309 uint Opaque1Node::cmp( const Node &n ) const {
1310 return (&n == this); // Always fail except on self
1311 }
1313 //------------------------------Identity---------------------------------------
1314 // If _major_progress, then more loop optimizations follow. Do NOT remove
1315 // the opaque Node until no more loop ops can happen. Note the timing of
1316 // _major_progress; it's set in the major loop optimizations THEN comes the
1317 // call to IterGVN and any chance of hitting this code. Hence there's no
1318 // phase-ordering problem with stripping Opaque1 in IGVN followed by some
1319 // more loop optimizations that require it.
1320 Node *Opaque1Node::Identity( PhaseTransform *phase ) {
1321 return phase->C->major_progress() ? this : in(1);
1322 }
1324 //=============================================================================
1325 // A node to prevent unwanted optimizations. Allows constant folding. Stops
1326 // value-numbering, most Ideal calls or Identity functions. This Node is
1327 // specifically designed to prevent the pre-increment value of a loop trip
1328 // counter from being live out of the bottom of the loop (hence causing the
1329 // pre- and post-increment values both being live and thus requiring an extra
1330 // temp register and an extra move). If we "accidentally" optimize through
1331 // this kind of a Node, we'll get slightly pessimal, but correct, code. Thus
1332 // it's OK to be slightly sloppy on optimizations here.
1334 // Do not allow value-numbering
1335 uint Opaque2Node::hash() const { return NO_HASH; }
1336 uint Opaque2Node::cmp( const Node &n ) const {
1337 return (&n == this); // Always fail except on self
1338 }
1341 //------------------------------Value------------------------------------------
1342 const Type *MoveL2DNode::Value( PhaseTransform *phase ) const {
1343 const Type *t = phase->type( in(1) );
1344 if( t == Type::TOP ) return Type::TOP;
1345 const TypeLong *tl = t->is_long();
1346 if( !tl->is_con() ) return bottom_type();
1347 JavaValue v;
1348 v.set_jlong(tl->get_con());
1349 return TypeD::make( v.get_jdouble() );
1350 }
1352 //------------------------------Value------------------------------------------
1353 const Type *MoveI2FNode::Value( PhaseTransform *phase ) const {
1354 const Type *t = phase->type( in(1) );
1355 if( t == Type::TOP ) return Type::TOP;
1356 const TypeInt *ti = t->is_int();
1357 if( !ti->is_con() ) return bottom_type();
1358 JavaValue v;
1359 v.set_jint(ti->get_con());
1360 return TypeF::make( v.get_jfloat() );
1361 }
1363 //------------------------------Value------------------------------------------
1364 const Type *MoveF2INode::Value( PhaseTransform *phase ) const {
1365 const Type *t = phase->type( in(1) );
1366 if( t == Type::TOP ) return Type::TOP;
1367 if( t == Type::FLOAT ) return TypeInt::INT;
1368 const TypeF *tf = t->is_float_constant();
1369 JavaValue v;
1370 v.set_jfloat(tf->getf());
1371 return TypeInt::make( v.get_jint() );
1372 }
1374 //------------------------------Value------------------------------------------
1375 const Type *MoveD2LNode::Value( PhaseTransform *phase ) const {
1376 const Type *t = phase->type( in(1) );
1377 if( t == Type::TOP ) return Type::TOP;
1378 if( t == Type::DOUBLE ) return TypeLong::LONG;
1379 const TypeD *td = t->is_double_constant();
1380 JavaValue v;
1381 v.set_jdouble(td->getd());
1382 return TypeLong::make( v.get_jlong() );
1383 }
1385 //------------------------------Value------------------------------------------
1386 const Type* CountLeadingZerosINode::Value(PhaseTransform* phase) const {
1387 const Type* t = phase->type(in(1));
1388 if (t == Type::TOP) return Type::TOP;
1389 const TypeInt* ti = t->isa_int();
1390 if (ti && ti->is_con()) {
1391 jint i = ti->get_con();
1392 // HD, Figure 5-6
1393 if (i == 0)
1394 return TypeInt::make(BitsPerInt);
1395 int n = 1;
1396 unsigned int x = i;
1397 if (x >> 16 == 0) { n += 16; x <<= 16; }
1398 if (x >> 24 == 0) { n += 8; x <<= 8; }
1399 if (x >> 28 == 0) { n += 4; x <<= 4; }
1400 if (x >> 30 == 0) { n += 2; x <<= 2; }
1401 n -= x >> 31;
1402 return TypeInt::make(n);
1403 }
1404 return TypeInt::INT;
1405 }
1407 //------------------------------Value------------------------------------------
1408 const Type* CountLeadingZerosLNode::Value(PhaseTransform* phase) const {
1409 const Type* t = phase->type(in(1));
1410 if (t == Type::TOP) return Type::TOP;
1411 const TypeLong* tl = t->isa_long();
1412 if (tl && tl->is_con()) {
1413 jlong l = tl->get_con();
1414 // HD, Figure 5-6
1415 if (l == 0)
1416 return TypeInt::make(BitsPerLong);
1417 int n = 1;
1418 unsigned int x = (((julong) l) >> 32);
1419 if (x == 0) { n += 32; x = (int) l; }
1420 if (x >> 16 == 0) { n += 16; x <<= 16; }
1421 if (x >> 24 == 0) { n += 8; x <<= 8; }
1422 if (x >> 28 == 0) { n += 4; x <<= 4; }
1423 if (x >> 30 == 0) { n += 2; x <<= 2; }
1424 n -= x >> 31;
1425 return TypeInt::make(n);
1426 }
1427 return TypeInt::INT;
1428 }
1430 //------------------------------Value------------------------------------------
1431 const Type* CountTrailingZerosINode::Value(PhaseTransform* phase) const {
1432 const Type* t = phase->type(in(1));
1433 if (t == Type::TOP) return Type::TOP;
1434 const TypeInt* ti = t->isa_int();
1435 if (ti && ti->is_con()) {
1436 jint i = ti->get_con();
1437 // HD, Figure 5-14
1438 int y;
1439 if (i == 0)
1440 return TypeInt::make(BitsPerInt);
1441 int n = 31;
1442 y = i << 16; if (y != 0) { n = n - 16; i = y; }
1443 y = i << 8; if (y != 0) { n = n - 8; i = y; }
1444 y = i << 4; if (y != 0) { n = n - 4; i = y; }
1445 y = i << 2; if (y != 0) { n = n - 2; i = y; }
1446 y = i << 1; if (y != 0) { n = n - 1; }
1447 return TypeInt::make(n);
1448 }
1449 return TypeInt::INT;
1450 }
1452 //------------------------------Value------------------------------------------
1453 const Type* CountTrailingZerosLNode::Value(PhaseTransform* phase) const {
1454 const Type* t = phase->type(in(1));
1455 if (t == Type::TOP) return Type::TOP;
1456 const TypeLong* tl = t->isa_long();
1457 if (tl && tl->is_con()) {
1458 jlong l = tl->get_con();
1459 // HD, Figure 5-14
1460 int x, y;
1461 if (l == 0)
1462 return TypeInt::make(BitsPerLong);
1463 int n = 63;
1464 y = (int) l; if (y != 0) { n = n - 32; x = y; } else x = (((julong) l) >> 32);
1465 y = x << 16; if (y != 0) { n = n - 16; x = y; }
1466 y = x << 8; if (y != 0) { n = n - 8; x = y; }
1467 y = x << 4; if (y != 0) { n = n - 4; x = y; }
1468 y = x << 2; if (y != 0) { n = n - 2; x = y; }
1469 y = x << 1; if (y != 0) { n = n - 1; }
1470 return TypeInt::make(n);
1471 }
1472 return TypeInt::INT;
1473 }