1 /*
2 * Copyright (c) 1997, 2018, 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 "compiler/compileLog.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shared/c2/barrierSetC2.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "opto/addnode.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/cfgnode.hpp"
33 #include "opto/loopnode.hpp"
34 #include "opto/matcher.hpp"
35 #include "opto/movenode.hpp"
36 #include "opto/mulnode.hpp"
37 #include "opto/opcodes.hpp"
38 #include "opto/phaseX.hpp"
39 #include "opto/subnode.hpp"
40 #include "runtime/sharedRuntime.hpp"
41
42 // Portions of code courtesy of Clifford Click
43
44 // Optimization - Graph Style
45
46 #include "math.h"
47
48 //=============================================================================
49 //------------------------------Identity---------------------------------------
50 // If right input is a constant 0, return the left input.
51 Node* SubNode::Identity(PhaseGVN* phase) {
52 assert(in(1) != this, "Must already have called Value");
53 assert(in(2) != this, "Must already have called Value");
54
55 // Remove double negation
56 const Type *zero = add_id();
57 if( phase->type( in(1) )->higher_equal( zero ) &&
58 in(2)->Opcode() == Opcode() &&
59 phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
60 return in(2)->in(2);
61 }
62
63 // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
64 if( in(1)->Opcode() == Op_AddI ) {
65 if( phase->eqv(in(1)->in(2),in(2)) )
66 return in(1)->in(1);
67 if (phase->eqv(in(1)->in(1),in(2)))
68 return in(1)->in(2);
69
70 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying
71 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes
72 // are originally used, although the optimizer sometimes jiggers things).
73 // This folding through an O2 removes a loop-exit use of a loop-varying
74 // value and generally lowers register pressure in and around the loop.
75 if( in(1)->in(2)->Opcode() == Op_Opaque2 &&
76 phase->eqv(in(1)->in(2)->in(1),in(2)) )
77 return in(1)->in(1);
78 }
79
80 return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
81 }
82
83 //------------------------------Value------------------------------------------
84 // A subtract node differences it's two inputs.
85 const Type* SubNode::Value_common(PhaseTransform *phase) const {
86 const Node* in1 = in(1);
87 const Node* in2 = in(2);
88 // Either input is TOP ==> the result is TOP
89 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
90 if( t1 == Type::TOP ) return Type::TOP;
91 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
92 if( t2 == Type::TOP ) return Type::TOP;
93
94 // Not correct for SubFnode and AddFNode (must check for infinity)
95 // Equal? Subtract is zero
96 if (in1->eqv_uncast(in2)) return add_id();
97
98 // Either input is BOTTOM ==> the result is the local BOTTOM
99 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
100 return bottom_type();
101
102 return NULL;
103 }
104
105 const Type* SubNode::Value(PhaseGVN* phase) const {
106 const Type* t = Value_common(phase);
107 if (t != NULL) {
108 return t;
109 }
110 const Type* t1 = phase->type(in(1));
111 const Type* t2 = phase->type(in(2));
112 return sub(t1,t2); // Local flavor of type subtraction
113
114 }
115
116 //=============================================================================
117 //------------------------------Helper function--------------------------------
118
119 static bool is_cloop_increment(Node* inc) {
120 precond(inc->Opcode() == Op_AddI || inc->Opcode() == Op_AddL);
121
122 if (!inc->in(1)->is_Phi()) {
123 return false;
124 }
125 const PhiNode* phi = inc->in(1)->as_Phi();
126
127 if (phi->is_copy() || !phi->region()->is_CountedLoop()) {
128 return false;
129 }
130
131 return inc == phi->region()->as_CountedLoop()->incr();
132 }
133
134 // Given the expression '(x + C) - v', or
135 // 'v - (x + C)', we examine nodes '+' and 'v':
136 //
137 // 1. Do not convert if '+' is a counted-loop increment, because the '-' is
138 // loop invariant and converting extends the live-range of 'x' to overlap
139 // with the '+', forcing another register to be used in the loop.
140 //
141 // 2. Do not convert if 'v' is a counted-loop induction variable, because
142 // 'x' might be invariant.
143 //
144 static bool ok_to_convert(Node* inc, Node* var) {
145 return !(is_cloop_increment(inc) || var->is_cloop_ind_var());
146 }
147
148 //------------------------------Ideal------------------------------------------
149 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
150 Node *in1 = in(1);
151 Node *in2 = in(2);
152 uint op1 = in1->Opcode();
153 uint op2 = in2->Opcode();
154
155 #ifdef ASSERT
156 // Check for dead loop
157 if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
158 ( ( op1 == Op_AddI || op1 == Op_SubI ) &&
159 ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
160 phase->eqv( in1->in(1), in1 ) || phase->eqv( in1->in(2), in1 ) ) ) )
161 assert(false, "dead loop in SubINode::Ideal");
162 #endif
163
164 const Type *t2 = phase->type( in2 );
165 if( t2 == Type::TOP ) return NULL;
166 // Convert "x-c0" into "x+ -c0".
167 if( t2->base() == Type::Int ){ // Might be bottom or top...
168 const TypeInt *i = t2->is_int();
169 if( i->is_con() )
170 return new AddINode(in1, phase->intcon(-i->get_con()));
171 }
172
173 // Convert "(x+c0) - y" into (x-y) + c0"
174 // Do not collapse (x+c0)-y if "+" is a loop increment or
175 // if "y" is a loop induction variable.
176 if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
177 const Type *tadd = phase->type( in1->in(2) );
178 if( tadd->singleton() && tadd != Type::TOP ) {
179 Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 ));
180 return new AddINode( sub2, in1->in(2) );
181 }
182 }
183
184
185 // Convert "x - (y+c0)" into "(x-y) - c0"
186 // Need the same check as in above optimization but reversed.
187 if (op2 == Op_AddI && ok_to_convert(in2, in1)) {
188 Node* in21 = in2->in(1);
189 Node* in22 = in2->in(2);
190 const TypeInt* tcon = phase->type(in22)->isa_int();
191 if (tcon != NULL && tcon->is_con()) {
192 Node* sub2 = phase->transform( new SubINode(in1, in21) );
193 Node* neg_c0 = phase->intcon(- tcon->get_con());
194 return new AddINode(sub2, neg_c0);
195 }
196 }
197
198 const Type *t1 = phase->type( in1 );
199 if( t1 == Type::TOP ) return NULL;
200
201 #ifdef ASSERT
202 // Check for dead loop
203 if( ( op2 == Op_AddI || op2 == Op_SubI ) &&
204 ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
205 phase->eqv( in2->in(1), in2 ) || phase->eqv( in2->in(2), in2 ) ) )
206 assert(false, "dead loop in SubINode::Ideal");
207 #endif
208
209 // Convert "x - (x+y)" into "-y"
210 if( op2 == Op_AddI &&
211 phase->eqv( in1, in2->in(1) ) )
212 return new SubINode( phase->intcon(0),in2->in(2));
213 // Convert "(x-y) - x" into "-y"
214 if( op1 == Op_SubI &&
215 phase->eqv( in1->in(1), in2 ) )
216 return new SubINode( phase->intcon(0),in1->in(2));
217 // Convert "x - (y+x)" into "-y"
218 if( op2 == Op_AddI &&
219 phase->eqv( in1, in2->in(2) ) )
220 return new SubINode( phase->intcon(0),in2->in(1));
221
222 // Convert "0 - (x-y)" into "y-x"
223 if( t1 == TypeInt::ZERO && op2 == Op_SubI )
224 return new SubINode( in2->in(2), in2->in(1) );
225
226 // Convert "0 - (x+con)" into "-con-x"
227 jint con;
228 if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
229 (con = in2->in(2)->find_int_con(0)) != 0 )
230 return new SubINode( phase->intcon(-con), in2->in(1) );
231
232 // Convert "(X+A) - (X+B)" into "A - B"
233 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
234 return new SubINode( in1->in(2), in2->in(2) );
235
236 // Convert "(A+X) - (B+X)" into "A - B"
237 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
238 return new SubINode( in1->in(1), in2->in(1) );
239
240 // Convert "(A+X) - (X+B)" into "A - B"
241 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
242 return new SubINode( in1->in(1), in2->in(2) );
243
244 // Convert "(X+A) - (B+X)" into "A - B"
245 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
246 return new SubINode( in1->in(2), in2->in(1) );
247
248 // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
249 // nicer to optimize than subtract.
250 if( op2 == Op_SubI && in2->outcnt() == 1) {
251 Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) );
252 return new SubINode( add1, in2->in(1) );
253 }
254
255 return NULL;
256 }
257
258 //------------------------------sub--------------------------------------------
259 // A subtract node differences it's two inputs.
260 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
261 const TypeInt *r0 = t1->is_int(); // Handy access
262 const TypeInt *r1 = t2->is_int();
263 int32_t lo = java_subtract(r0->_lo, r1->_hi);
264 int32_t hi = java_subtract(r0->_hi, r1->_lo);
265
266 // We next check for 32-bit overflow.
267 // If that happens, we just assume all integers are possible.
268 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
269 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
270 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
271 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
272 return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
273 else // Overflow; assume all integers
274 return TypeInt::INT;
275 }
276
277 //=============================================================================
278 //------------------------------Ideal------------------------------------------
279 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
280 Node *in1 = in(1);
281 Node *in2 = in(2);
282 uint op1 = in1->Opcode();
283 uint op2 = in2->Opcode();
284
285 #ifdef ASSERT
286 // Check for dead loop
287 if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
288 ( ( op1 == Op_AddL || op1 == Op_SubL ) &&
289 ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
290 phase->eqv( in1->in(1), in1 ) || phase->eqv( in1->in(2), in1 ) ) ) )
291 assert(false, "dead loop in SubLNode::Ideal");
292 #endif
293
294 if( phase->type( in2 ) == Type::TOP ) return NULL;
295 const TypeLong *i = phase->type( in2 )->isa_long();
296 // Convert "x-c0" into "x+ -c0".
297 if( i && // Might be bottom or top...
298 i->is_con() )
299 return new AddLNode(in1, phase->longcon(-i->get_con()));
300
301 // Convert "(x+c0) - y" into (x-y) + c0"
302 // Do not collapse (x+c0)-y if "+" is a loop increment or
303 // if "y" is a loop induction variable.
304 if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
305 Node *in11 = in1->in(1);
306 const Type *tadd = phase->type( in1->in(2) );
307 if( tadd->singleton() && tadd != Type::TOP ) {
308 Node *sub2 = phase->transform( new SubLNode( in11, in2 ));
309 return new AddLNode( sub2, in1->in(2) );
310 }
311 }
312
313 // Convert "x - (y+c0)" into "(x-y) - c0"
314 // Need the same check as in above optimization but reversed.
315 if (op2 == Op_AddL && ok_to_convert(in2, in1)) {
316 Node* in21 = in2->in(1);
317 Node* in22 = in2->in(2);
318 const TypeLong* tcon = phase->type(in22)->isa_long();
319 if (tcon != NULL && tcon->is_con()) {
320 Node* sub2 = phase->transform( new SubLNode(in1, in21) );
321 Node* neg_c0 = phase->longcon(- tcon->get_con());
322 return new AddLNode(sub2, neg_c0);
323 }
324 }
325
326 const Type *t1 = phase->type( in1 );
327 if( t1 == Type::TOP ) return NULL;
328
329 #ifdef ASSERT
330 // Check for dead loop
331 if( ( op2 == Op_AddL || op2 == Op_SubL ) &&
332 ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
333 phase->eqv( in2->in(1), in2 ) || phase->eqv( in2->in(2), in2 ) ) )
334 assert(false, "dead loop in SubLNode::Ideal");
335 #endif
336
337 // Convert "x - (x+y)" into "-y"
338 if( op2 == Op_AddL &&
339 phase->eqv( in1, in2->in(1) ) )
340 return new SubLNode( phase->makecon(TypeLong::ZERO), in2->in(2));
341 // Convert "x - (y+x)" into "-y"
342 if( op2 == Op_AddL &&
343 phase->eqv( in1, in2->in(2) ) )
344 return new SubLNode( phase->makecon(TypeLong::ZERO),in2->in(1));
345
346 // Convert "0 - (x-y)" into "y-x"
347 if( phase->type( in1 ) == TypeLong::ZERO && op2 == Op_SubL )
348 return new SubLNode( in2->in(2), in2->in(1) );
349
350 // Convert "(X+A) - (X+B)" into "A - B"
351 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
352 return new SubLNode( in1->in(2), in2->in(2) );
353
354 // Convert "(A+X) - (B+X)" into "A - B"
355 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
356 return new SubLNode( in1->in(1), in2->in(1) );
357
358 // Convert "A-(B-C)" into (A+C)-B"
359 if( op2 == Op_SubL && in2->outcnt() == 1) {
360 Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) );
361 return new SubLNode( add1, in2->in(1) );
362 }
363
364 return NULL;
365 }
366
367 //------------------------------sub--------------------------------------------
368 // A subtract node differences it's two inputs.
369 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
370 const TypeLong *r0 = t1->is_long(); // Handy access
371 const TypeLong *r1 = t2->is_long();
372 jlong lo = java_subtract(r0->_lo, r1->_hi);
373 jlong hi = java_subtract(r0->_hi, r1->_lo);
374
375 // We next check for 32-bit overflow.
376 // If that happens, we just assume all integers are possible.
377 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
378 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
379 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
380 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
381 return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
382 else // Overflow; assume all integers
383 return TypeLong::LONG;
384 }
385
386 //=============================================================================
387 //------------------------------Value------------------------------------------
388 // A subtract node differences its two inputs.
389 const Type* SubFPNode::Value(PhaseGVN* phase) const {
390 const Node* in1 = in(1);
391 const Node* in2 = in(2);
392 // Either input is TOP ==> the result is TOP
393 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
394 if( t1 == Type::TOP ) return Type::TOP;
395 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
396 if( t2 == Type::TOP ) return Type::TOP;
397
398 // if both operands are infinity of same sign, the result is NaN; do
399 // not replace with zero
400 if( (t1->is_finite() && t2->is_finite()) ) {
401 if( phase->eqv(in1, in2) ) return add_id();
402 }
403
404 // Either input is BOTTOM ==> the result is the local BOTTOM
405 const Type *bot = bottom_type();
406 if( (t1 == bot) || (t2 == bot) ||
407 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
408 return bot;
409
410 return sub(t1,t2); // Local flavor of type subtraction
411 }
412
413
414 //=============================================================================
415 //------------------------------Ideal------------------------------------------
416 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
417 const Type *t2 = phase->type( in(2) );
418 // Convert "x-c0" into "x+ -c0".
419 if( t2->base() == Type::FloatCon ) { // Might be bottom or top...
420 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
421 }
422
423 // Not associative because of boundary conditions (infinity)
424 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
425 // Convert "x - (x+y)" into "-y"
426 if( in(2)->is_Add() &&
427 phase->eqv(in(1),in(2)->in(1) ) )
428 return new SubFNode( phase->makecon(TypeF::ZERO),in(2)->in(2));
429 }
430
431 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
432 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
433 //if( phase->type(in(1)) == TypeF::ZERO )
434 //return new (phase->C, 2) NegFNode(in(2));
435
436 return NULL;
437 }
438
439 //------------------------------sub--------------------------------------------
440 // A subtract node differences its two inputs.
441 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
442 // no folding if one of operands is infinity or NaN, do not do constant folding
443 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
444 return TypeF::make( t1->getf() - t2->getf() );
445 }
446 else if( g_isnan(t1->getf()) ) {
447 return t1;
448 }
449 else if( g_isnan(t2->getf()) ) {
450 return t2;
451 }
452 else {
453 return Type::FLOAT;
454 }
455 }
456
457 //=============================================================================
458 //------------------------------Ideal------------------------------------------
459 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
460 const Type *t2 = phase->type( in(2) );
461 // Convert "x-c0" into "x+ -c0".
462 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
463 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
464 }
465
466 // Not associative because of boundary conditions (infinity)
467 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
468 // Convert "x - (x+y)" into "-y"
469 if( in(2)->is_Add() &&
470 phase->eqv(in(1),in(2)->in(1) ) )
471 return new SubDNode( phase->makecon(TypeD::ZERO),in(2)->in(2));
472 }
473
474 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
475 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
476 //if( phase->type(in(1)) == TypeD::ZERO )
477 //return new (phase->C, 2) NegDNode(in(2));
478
479 return NULL;
480 }
481
482 //------------------------------sub--------------------------------------------
483 // A subtract node differences its two inputs.
484 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
485 // no folding if one of operands is infinity or NaN, do not do constant folding
486 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
487 return TypeD::make( t1->getd() - t2->getd() );
488 }
489 else if( g_isnan(t1->getd()) ) {
490 return t1;
491 }
492 else if( g_isnan(t2->getd()) ) {
493 return t2;
494 }
495 else {
496 return Type::DOUBLE;
497 }
498 }
499
500 //=============================================================================
501 //------------------------------Idealize---------------------------------------
502 // Unlike SubNodes, compare must still flatten return value to the
503 // range -1, 0, 1.
504 // And optimizations like those for (X + Y) - X fail if overflow happens.
505 Node* CmpNode::Identity(PhaseGVN* phase) {
506 return this;
507 }
508
509 #ifndef PRODUCT
510 //----------------------------related------------------------------------------
511 // Related nodes of comparison nodes include all data inputs (until hitting a
512 // control boundary) as well as all outputs until and including control nodes
513 // as well as their projections. In compact mode, data inputs till depth 1 and
514 // all outputs till depth 1 are considered.
515 void CmpNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
516 if (compact) {
517 this->collect_nodes(in_rel, 1, false, true);
518 this->collect_nodes(out_rel, -1, false, false);
519 } else {
520 this->collect_nodes_in_all_data(in_rel, false);
521 this->collect_nodes_out_all_ctrl_boundary(out_rel);
522 // Now, find all control nodes in out_rel, and include their projections
523 // and projection targets (if any) in the result.
524 GrowableArray<Node*> proj(Compile::current()->unique());
525 for (GrowableArrayIterator<Node*> it = out_rel->begin(); it != out_rel->end(); ++it) {
526 Node* n = *it;
527 if (n->is_CFG() && !n->is_Proj()) {
528 // Assume projections and projection targets are found at levels 1 and 2.
529 n->collect_nodes(&proj, -2, false, false);
530 for (GrowableArrayIterator<Node*> p = proj.begin(); p != proj.end(); ++p) {
531 out_rel->append_if_missing(*p);
532 }
533 proj.clear();
534 }
535 }
536 }
537 }
538 #endif
539
540 //=============================================================================
541 //------------------------------cmp--------------------------------------------
542 // Simplify a CmpI (compare 2 integers) node, based on local information.
543 // If both inputs are constants, compare them.
544 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
545 const TypeInt *r0 = t1->is_int(); // Handy access
546 const TypeInt *r1 = t2->is_int();
547
548 if( r0->_hi < r1->_lo ) // Range is always low?
549 return TypeInt::CC_LT;
550 else if( r0->_lo > r1->_hi ) // Range is always high?
551 return TypeInt::CC_GT;
552
553 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
554 assert(r0->get_con() == r1->get_con(), "must be equal");
555 return TypeInt::CC_EQ; // Equal results.
556 } else if( r0->_hi == r1->_lo ) // Range is never high?
557 return TypeInt::CC_LE;
558 else if( r0->_lo == r1->_hi ) // Range is never low?
559 return TypeInt::CC_GE;
560 return TypeInt::CC; // else use worst case results
561 }
562
563 // Simplify a CmpU (compare 2 integers) node, based on local information.
564 // If both inputs are constants, compare them.
565 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
566 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
567
568 // comparing two unsigned ints
569 const TypeInt *r0 = t1->is_int(); // Handy access
570 const TypeInt *r1 = t2->is_int();
571
572 // Current installed version
573 // Compare ranges for non-overlap
574 juint lo0 = r0->_lo;
575 juint hi0 = r0->_hi;
576 juint lo1 = r1->_lo;
577 juint hi1 = r1->_hi;
578
579 // If either one has both negative and positive values,
580 // it therefore contains both 0 and -1, and since [0..-1] is the
581 // full unsigned range, the type must act as an unsigned bottom.
582 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
583 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
584
585 if (bot0 || bot1) {
586 // All unsigned values are LE -1 and GE 0.
587 if (lo0 == 0 && hi0 == 0) {
588 return TypeInt::CC_LE; // 0 <= bot
589 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
590 return TypeInt::CC_GE; // -1 >= bot
591 } else if (lo1 == 0 && hi1 == 0) {
592 return TypeInt::CC_GE; // bot >= 0
593 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
594 return TypeInt::CC_LE; // bot <= -1
595 }
596 } else {
597 // We can use ranges of the form [lo..hi] if signs are the same.
598 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
599 // results are reversed, '-' > '+' for unsigned compare
600 if (hi0 < lo1) {
601 return TypeInt::CC_LT; // smaller
602 } else if (lo0 > hi1) {
603 return TypeInt::CC_GT; // greater
604 } else if (hi0 == lo1 && lo0 == hi1) {
605 return TypeInt::CC_EQ; // Equal results
606 } else if (lo0 >= hi1) {
607 return TypeInt::CC_GE;
608 } else if (hi0 <= lo1) {
609 // Check for special case in Hashtable::get. (See below.)
610 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
611 return TypeInt::CC_LT;
612 return TypeInt::CC_LE;
613 }
614 }
615 // Check for special case in Hashtable::get - the hash index is
616 // mod'ed to the table size so the following range check is useless.
617 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
618 // to be positive.
619 // (This is a gross hack, since the sub method never
620 // looks at the structure of the node in any other case.)
621 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
622 return TypeInt::CC_LT;
623 return TypeInt::CC; // else use worst case results
624 }
625
626 const Type* CmpUNode::Value(PhaseGVN* phase) const {
627 const Type* t = SubNode::Value_common(phase);
628 if (t != NULL) {
629 return t;
630 }
631 const Node* in1 = in(1);
632 const Node* in2 = in(2);
633 const Type* t1 = phase->type(in1);
634 const Type* t2 = phase->type(in2);
635 assert(t1->isa_int(), "CmpU has only Int type inputs");
636 if (t2 == TypeInt::INT) { // Compare to bottom?
637 return bottom_type();
638 }
639 uint in1_op = in1->Opcode();
640 if (in1_op == Op_AddI || in1_op == Op_SubI) {
641 // The problem rise when result of AddI(SubI) may overflow
642 // signed integer value. Let say the input type is
643 // [256, maxint] then +128 will create 2 ranges due to
644 // overflow: [minint, minint+127] and [384, maxint].
645 // But C2 type system keep only 1 type range and as result
646 // it use general [minint, maxint] for this case which we
647 // can't optimize.
648 //
649 // Make 2 separate type ranges based on types of AddI(SubI) inputs
650 // and compare results of their compare. If results are the same
651 // CmpU node can be optimized.
652 const Node* in11 = in1->in(1);
653 const Node* in12 = in1->in(2);
654 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
655 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
656 // Skip cases when input types are top or bottom.
657 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
658 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
659 const TypeInt *r0 = t11->is_int();
660 const TypeInt *r1 = t12->is_int();
661 jlong lo_r0 = r0->_lo;
662 jlong hi_r0 = r0->_hi;
663 jlong lo_r1 = r1->_lo;
664 jlong hi_r1 = r1->_hi;
665 if (in1_op == Op_SubI) {
666 jlong tmp = hi_r1;
667 hi_r1 = -lo_r1;
668 lo_r1 = -tmp;
669 // Note, for substructing [minint,x] type range
670 // long arithmetic provides correct overflow answer.
671 // The confusion come from the fact that in 32-bit
672 // -minint == minint but in 64-bit -minint == maxint+1.
673 }
674 jlong lo_long = lo_r0 + lo_r1;
675 jlong hi_long = hi_r0 + hi_r1;
676 int lo_tr1 = min_jint;
677 int hi_tr1 = (int)hi_long;
678 int lo_tr2 = (int)lo_long;
679 int hi_tr2 = max_jint;
680 bool underflow = lo_long != (jlong)lo_tr2;
681 bool overflow = hi_long != (jlong)hi_tr1;
682 // Use sub(t1, t2) when there is no overflow (one type range)
683 // or when both overflow and underflow (too complex).
684 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
685 // Overflow only on one boundary, compare 2 separate type ranges.
686 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
687 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
688 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
689 const Type* cmp1 = sub(tr1, t2);
690 const Type* cmp2 = sub(tr2, t2);
691 if (cmp1 == cmp2) {
692 return cmp1; // Hit!
693 }
694 }
695 }
696 }
697
698 return sub(t1, t2); // Local flavor of type subtraction
699 }
700
701 bool CmpUNode::is_index_range_check() const {
702 // Check for the "(X ModI Y) CmpU Y" shape
703 return (in(1)->Opcode() == Op_ModI &&
704 in(1)->in(2)->eqv_uncast(in(2)));
705 }
706
707 //------------------------------Idealize---------------------------------------
708 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
709 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
710 switch (in(1)->Opcode()) {
711 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
712 return new CmpLNode(in(1)->in(1),in(1)->in(2));
713 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
714 return new CmpFNode(in(1)->in(1),in(1)->in(2));
715 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
716 return new CmpDNode(in(1)->in(1),in(1)->in(2));
717 //case Op_SubI:
718 // If (x - y) cannot overflow, then ((x - y) <?> 0)
719 // can be turned into (x <?> y).
720 // This is handled (with more general cases) by Ideal_sub_algebra.
721 }
722 }
723 return NULL; // No change
724 }
725
726
727 //=============================================================================
728 // Simplify a CmpL (compare 2 longs ) node, based on local information.
729 // If both inputs are constants, compare them.
730 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
731 const TypeLong *r0 = t1->is_long(); // Handy access
732 const TypeLong *r1 = t2->is_long();
733
734 if( r0->_hi < r1->_lo ) // Range is always low?
735 return TypeInt::CC_LT;
736 else if( r0->_lo > r1->_hi ) // Range is always high?
737 return TypeInt::CC_GT;
738
739 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
740 assert(r0->get_con() == r1->get_con(), "must be equal");
741 return TypeInt::CC_EQ; // Equal results.
742 } else if( r0->_hi == r1->_lo ) // Range is never high?
743 return TypeInt::CC_LE;
744 else if( r0->_lo == r1->_hi ) // Range is never low?
745 return TypeInt::CC_GE;
746 return TypeInt::CC; // else use worst case results
747 }
748
749
750 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
751 // If both inputs are constants, compare them.
752 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
753 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
754
755 // comparing two unsigned longs
756 const TypeLong* r0 = t1->is_long(); // Handy access
757 const TypeLong* r1 = t2->is_long();
758
759 // Current installed version
760 // Compare ranges for non-overlap
761 julong lo0 = r0->_lo;
762 julong hi0 = r0->_hi;
763 julong lo1 = r1->_lo;
764 julong hi1 = r1->_hi;
765
766 // If either one has both negative and positive values,
767 // it therefore contains both 0 and -1, and since [0..-1] is the
768 // full unsigned range, the type must act as an unsigned bottom.
769 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
770 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
771
772 if (bot0 || bot1) {
773 // All unsigned values are LE -1 and GE 0.
774 if (lo0 == 0 && hi0 == 0) {
775 return TypeInt::CC_LE; // 0 <= bot
776 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
777 return TypeInt::CC_GE; // -1 >= bot
778 } else if (lo1 == 0 && hi1 == 0) {
779 return TypeInt::CC_GE; // bot >= 0
780 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
781 return TypeInt::CC_LE; // bot <= -1
782 }
783 } else {
784 // We can use ranges of the form [lo..hi] if signs are the same.
785 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
786 // results are reversed, '-' > '+' for unsigned compare
787 if (hi0 < lo1) {
788 return TypeInt::CC_LT; // smaller
789 } else if (lo0 > hi1) {
790 return TypeInt::CC_GT; // greater
791 } else if (hi0 == lo1 && lo0 == hi1) {
792 return TypeInt::CC_EQ; // Equal results
793 } else if (lo0 >= hi1) {
794 return TypeInt::CC_GE;
795 } else if (hi0 <= lo1) {
796 return TypeInt::CC_LE;
797 }
798 }
799
800 return TypeInt::CC; // else use worst case results
801 }
802
803 //=============================================================================
804 //------------------------------sub--------------------------------------------
805 // Simplify an CmpP (compare 2 pointers) node, based on local information.
806 // If both inputs are constants, compare them.
807 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
808 const TypePtr *r0 = t1->is_ptr(); // Handy access
809 const TypePtr *r1 = t2->is_ptr();
810
811 // Undefined inputs makes for an undefined result
812 if( TypePtr::above_centerline(r0->_ptr) ||
813 TypePtr::above_centerline(r1->_ptr) )
814 return Type::TOP;
815
816 if (r0 == r1 && r0->singleton()) {
817 // Equal pointer constants (klasses, nulls, etc.)
818 return TypeInt::CC_EQ;
819 }
820
821 // See if it is 2 unrelated classes.
822 const TypeOopPtr* p0 = r0->isa_oopptr();
823 const TypeOopPtr* p1 = r1->isa_oopptr();
824 if (p0 && p1) {
825 Node* in1 = in(1)->uncast();
826 Node* in2 = in(2)->uncast();
827 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
828 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
829 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
830 return TypeInt::CC_GT; // different pointers
831 }
832 ciKlass* klass0 = p0->klass();
833 bool xklass0 = p0->klass_is_exact();
834 ciKlass* klass1 = p1->klass();
835 bool xklass1 = p1->klass_is_exact();
836 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
837 if (klass0 && klass1 &&
838 kps != 1 && // both or neither are klass pointers
839 klass0->is_loaded() && !klass0->is_interface() && // do not trust interfaces
840 klass1->is_loaded() && !klass1->is_interface() &&
841 (!klass0->is_obj_array_klass() ||
842 !klass0->as_obj_array_klass()->base_element_klass()->is_interface()) &&
843 (!klass1->is_obj_array_klass() ||
844 !klass1->as_obj_array_klass()->base_element_klass()->is_interface())) {
845 bool unrelated_classes = false;
846 // See if neither subclasses the other, or if the class on top
847 // is precise. In either of these cases, the compare is known
848 // to fail if at least one of the pointers is provably not null.
849 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
850 // Do nothing; we know nothing for imprecise types
851 } else if (klass0->is_subtype_of(klass1)) {
852 // If klass1's type is PRECISE, then classes are unrelated.
853 unrelated_classes = xklass1;
854 } else if (klass1->is_subtype_of(klass0)) {
855 // If klass0's type is PRECISE, then classes are unrelated.
856 unrelated_classes = xklass0;
857 } else { // Neither subtypes the other
858 unrelated_classes = true;
859 }
860 if (unrelated_classes) {
861 // The oops classes are known to be unrelated. If the joined PTRs of
862 // two oops is not Null and not Bottom, then we are sure that one
863 // of the two oops is non-null, and the comparison will always fail.
864 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
865 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
866 return TypeInt::CC_GT;
867 }
868 }
869 }
870 }
871
872 // Known constants can be compared exactly
873 // Null can be distinguished from any NotNull pointers
874 // Unknown inputs makes an unknown result
875 if( r0->singleton() ) {
876 intptr_t bits0 = r0->get_con();
877 if( r1->singleton() )
878 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
879 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
880 } else if( r1->singleton() ) {
881 intptr_t bits1 = r1->get_con();
882 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
883 } else
884 return TypeInt::CC;
885 }
886
887 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
888 // Return the klass node for (indirect load from OopHandle)
889 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
890 // or NULL if not matching.
891 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
892 n = bs->step_over_gc_barrier(n);
893
894 if (n->Opcode() != Op_LoadP) return NULL;
895
896 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
897 if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
898
899 Node* adr = n->in(MemNode::Address);
900 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
901 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return NULL;
902 adr = adr->in(MemNode::Address);
903
904 intptr_t off = 0;
905 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
906 if (k == NULL) return NULL;
907 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
908 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return NULL;
909
910 // We've found the klass node of a Java mirror load.
911 return k;
912 }
913
914 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
915 // for ConP(Foo.class) return ConP(Foo.klass)
916 // otherwise return NULL
917 if (!n->is_Con()) return NULL;
918
919 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
920 if (!tp) return NULL;
921
922 ciType* mirror_type = tp->java_mirror_type();
923 // TypeInstPtr::java_mirror_type() returns non-NULL for compile-
924 // time Class constants only.
925 if (!mirror_type) return NULL;
926
927 // x.getClass() == int.class can never be true (for all primitive types)
928 // Return a ConP(NULL) node for this case.
929 if (mirror_type->is_classless()) {
930 return phase->makecon(TypePtr::NULL_PTR);
931 }
932
933 // return the ConP(Foo.klass)
934 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
935 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass()));
936 }
937
938 //------------------------------Ideal------------------------------------------
939 // Normalize comparisons between Java mirror loads to compare the klass instead.
940 //
941 // Also check for the case of comparing an unknown klass loaded from the primary
942 // super-type array vs a known klass with no subtypes. This amounts to
943 // checking to see an unknown klass subtypes a known klass with no subtypes;
944 // this only happens on an exact match. We can shorten this test by 1 load.
945 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
946 // Normalize comparisons between Java mirrors into comparisons of the low-
947 // level klass, where a dependent load could be shortened.
948 //
949 // The new pattern has a nice effect of matching the same pattern used in the
950 // fast path of instanceof/checkcast/Class.isInstance(), which allows
951 // redundant exact type check be optimized away by GVN.
952 // For example, in
953 // if (x.getClass() == Foo.class) {
954 // Foo foo = (Foo) x;
955 // // ... use a ...
956 // }
957 // a CmpPNode could be shared between if_acmpne and checkcast
958 {
959 Node* k1 = isa_java_mirror_load(phase, in(1));
960 Node* k2 = isa_java_mirror_load(phase, in(2));
961 Node* conk2 = isa_const_java_mirror(phase, in(2));
962
963 if (k1 && (k2 || conk2)) {
964 Node* lhs = k1;
965 Node* rhs = (k2 != NULL) ? k2 : conk2;
966 PhaseIterGVN* igvn = phase->is_IterGVN();
967 if (igvn != NULL) {
968 set_req_X(1, lhs, igvn);
969 set_req_X(2, rhs, igvn);
970 } else {
971 set_req(1, lhs);
972 set_req(2, rhs);
973 }
974 return this;
975 }
976 }
977
978 // Constant pointer on right?
979 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
980 if (t2 == NULL || !t2->klass_is_exact())
981 return NULL;
982 // Get the constant klass we are comparing to.
983 ciKlass* superklass = t2->klass();
984
985 // Now check for LoadKlass on left.
986 Node* ldk1 = in(1);
987 if (ldk1->is_DecodeNKlass()) {
988 ldk1 = ldk1->in(1);
989 if (ldk1->Opcode() != Op_LoadNKlass )
990 return NULL;
991 } else if (ldk1->Opcode() != Op_LoadKlass )
992 return NULL;
993 // Take apart the address of the LoadKlass:
994 Node* adr1 = ldk1->in(MemNode::Address);
995 intptr_t con2 = 0;
996 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
997 if (ldk2 == NULL)
998 return NULL;
999 if (con2 == oopDesc::klass_offset_in_bytes()) {
1000 // We are inspecting an object's concrete class.
1001 // Short-circuit the check if the query is abstract.
1002 if (superklass->is_interface() ||
1003 superklass->is_abstract()) {
1004 // Make it come out always false:
1005 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1006 return this;
1007 }
1008 }
1009
1010 // Check for a LoadKlass from primary supertype array.
1011 // Any nested loadklass from loadklass+con must be from the p.s. array.
1012 if (ldk2->is_DecodeNKlass()) {
1013 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1014 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1015 return NULL;
1016 } else if (ldk2->Opcode() != Op_LoadKlass)
1017 return NULL;
1018
1019 // Verify that we understand the situation
1020 if (con2 != (intptr_t) superklass->super_check_offset())
1021 return NULL; // Might be element-klass loading from array klass
1022
1023 // If 'superklass' has no subklasses and is not an interface, then we are
1024 // assured that the only input which will pass the type check is
1025 // 'superklass' itself.
1026 //
1027 // We could be more liberal here, and allow the optimization on interfaces
1028 // which have a single implementor. This would require us to increase the
1029 // expressiveness of the add_dependency() mechanism.
1030 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1031
1032 // Object arrays must have their base element have no subtypes
1033 while (superklass->is_obj_array_klass()) {
1034 ciType* elem = superklass->as_obj_array_klass()->element_type();
1035 superklass = elem->as_klass();
1036 }
1037 if (superklass->is_instance_klass()) {
1038 ciInstanceKlass* ik = superklass->as_instance_klass();
1039 if (ik->has_subklass() || ik->is_interface()) return NULL;
1040 // Add a dependency if there is a chance that a subclass will be added later.
1041 if (!ik->is_final()) {
1042 phase->C->dependencies()->assert_leaf_type(ik);
1043 }
1044 }
1045
1046 // Bypass the dependent load, and compare directly
1047 this->set_req(1,ldk2);
1048
1049 return this;
1050 }
1051
1052 //=============================================================================
1053 //------------------------------sub--------------------------------------------
1054 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1055 // If both inputs are constants, compare them.
1056 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1057 const TypePtr *r0 = t1->make_ptr(); // Handy access
1058 const TypePtr *r1 = t2->make_ptr();
1059
1060 // Undefined inputs makes for an undefined result
1061 if ((r0 == NULL) || (r1 == NULL) ||
1062 TypePtr::above_centerline(r0->_ptr) ||
1063 TypePtr::above_centerline(r1->_ptr)) {
1064 return Type::TOP;
1065 }
1066 if (r0 == r1 && r0->singleton()) {
1067 // Equal pointer constants (klasses, nulls, etc.)
1068 return TypeInt::CC_EQ;
1069 }
1070
1071 // See if it is 2 unrelated classes.
1072 const TypeOopPtr* p0 = r0->isa_oopptr();
1073 const TypeOopPtr* p1 = r1->isa_oopptr();
1074 if (p0 && p1) {
1075 ciKlass* klass0 = p0->klass();
1076 bool xklass0 = p0->klass_is_exact();
1077 ciKlass* klass1 = p1->klass();
1078 bool xklass1 = p1->klass_is_exact();
1079 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
1080 if (klass0 && klass1 &&
1081 kps != 1 && // both or neither are klass pointers
1082 !klass0->is_interface() && // do not trust interfaces
1083 !klass1->is_interface()) {
1084 bool unrelated_classes = false;
1085 // See if neither subclasses the other, or if the class on top
1086 // is precise. In either of these cases, the compare is known
1087 // to fail if at least one of the pointers is provably not null.
1088 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
1089 // Do nothing; we know nothing for imprecise types
1090 } else if (klass0->is_subtype_of(klass1)) {
1091 // If klass1's type is PRECISE, then classes are unrelated.
1092 unrelated_classes = xklass1;
1093 } else if (klass1->is_subtype_of(klass0)) {
1094 // If klass0's type is PRECISE, then classes are unrelated.
1095 unrelated_classes = xklass0;
1096 } else { // Neither subtypes the other
1097 unrelated_classes = true;
1098 }
1099 if (unrelated_classes) {
1100 // The oops classes are known to be unrelated. If the joined PTRs of
1101 // two oops is not Null and not Bottom, then we are sure that one
1102 // of the two oops is non-null, and the comparison will always fail.
1103 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1104 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1105 return TypeInt::CC_GT;
1106 }
1107 }
1108 }
1109 }
1110
1111 // Known constants can be compared exactly
1112 // Null can be distinguished from any NotNull pointers
1113 // Unknown inputs makes an unknown result
1114 if( r0->singleton() ) {
1115 intptr_t bits0 = r0->get_con();
1116 if( r1->singleton() )
1117 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1118 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1119 } else if( r1->singleton() ) {
1120 intptr_t bits1 = r1->get_con();
1121 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1122 } else
1123 return TypeInt::CC;
1124 }
1125
1126 //------------------------------Ideal------------------------------------------
1127 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1128 return NULL;
1129 }
1130
1131 //=============================================================================
1132 //------------------------------Value------------------------------------------
1133 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1134 // If both inputs are constants, compare them.
1135 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1136 const Node* in1 = in(1);
1137 const Node* in2 = in(2);
1138 // Either input is TOP ==> the result is TOP
1139 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1140 if( t1 == Type::TOP ) return Type::TOP;
1141 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1142 if( t2 == Type::TOP ) return Type::TOP;
1143
1144 // Not constants? Don't know squat - even if they are the same
1145 // value! If they are NaN's they compare to LT instead of EQ.
1146 const TypeF *tf1 = t1->isa_float_constant();
1147 const TypeF *tf2 = t2->isa_float_constant();
1148 if( !tf1 || !tf2 ) return TypeInt::CC;
1149
1150 // This implements the Java bytecode fcmpl, so unordered returns -1.
1151 if( tf1->is_nan() || tf2->is_nan() )
1152 return TypeInt::CC_LT;
1153
1154 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1155 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1156 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1157 return TypeInt::CC_EQ;
1158 }
1159
1160
1161 //=============================================================================
1162 //------------------------------Value------------------------------------------
1163 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1164 // If both inputs are constants, compare them.
1165 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1166 const Node* in1 = in(1);
1167 const Node* in2 = in(2);
1168 // Either input is TOP ==> the result is TOP
1169 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1170 if( t1 == Type::TOP ) return Type::TOP;
1171 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1172 if( t2 == Type::TOP ) return Type::TOP;
1173
1174 // Not constants? Don't know squat - even if they are the same
1175 // value! If they are NaN's they compare to LT instead of EQ.
1176 const TypeD *td1 = t1->isa_double_constant();
1177 const TypeD *td2 = t2->isa_double_constant();
1178 if( !td1 || !td2 ) return TypeInt::CC;
1179
1180 // This implements the Java bytecode dcmpl, so unordered returns -1.
1181 if( td1->is_nan() || td2->is_nan() )
1182 return TypeInt::CC_LT;
1183
1184 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1185 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1186 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1187 return TypeInt::CC_EQ;
1188 }
1189
1190 //------------------------------Ideal------------------------------------------
1191 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1192 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1193 // Change (CMPD (F2D (float)) (ConD value))
1194 // To (CMPF (float) (ConF value))
1195 // Valid when 'value' does not lose precision as a float.
1196 // Benefits: eliminates conversion, does not require 24-bit mode
1197
1198 // NaNs prevent commuting operands. This transform works regardless of the
1199 // order of ConD and ConvF2D inputs by preserving the original order.
1200 int idx_f2d = 1; // ConvF2D on left side?
1201 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1202 idx_f2d = 2; // No, swap to check for reversed args
1203 int idx_con = 3-idx_f2d; // Check for the constant on other input
1204
1205 if( ConvertCmpD2CmpF &&
1206 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1207 in(idx_con)->Opcode() == Op_ConD ) {
1208 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1209 double t2_value_as_double = t2->_d;
1210 float t2_value_as_float = (float)t2_value_as_double;
1211 if( t2_value_as_double == (double)t2_value_as_float ) {
1212 // Test value can be represented as a float
1213 // Eliminate the conversion to double and create new comparison
1214 Node *new_in1 = in(idx_f2d)->in(1);
1215 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1216 if( idx_f2d != 1 ) { // Must flip args to match original order
1217 Node *tmp = new_in1;
1218 new_in1 = new_in2;
1219 new_in2 = tmp;
1220 }
1221 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1222 ? new CmpF3Node( new_in1, new_in2 )
1223 : new CmpFNode ( new_in1, new_in2 ) ;
1224 return new_cmp; // Changed to CmpFNode
1225 }
1226 // Testing value required the precision of a double
1227 }
1228 return NULL; // No change
1229 }
1230
1231
1232 //=============================================================================
1233 //------------------------------cc2logical-------------------------------------
1234 // Convert a condition code type to a logical type
1235 const Type *BoolTest::cc2logical( const Type *CC ) const {
1236 if( CC == Type::TOP ) return Type::TOP;
1237 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1238 const TypeInt *ti = CC->is_int();
1239 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1240 // Match low order 2 bits
1241 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1242 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1243 return TypeInt::make(tmp); // Boolean result
1244 }
1245
1246 if( CC == TypeInt::CC_GE ) {
1247 if( _test == ge ) return TypeInt::ONE;
1248 if( _test == lt ) return TypeInt::ZERO;
1249 }
1250 if( CC == TypeInt::CC_LE ) {
1251 if( _test == le ) return TypeInt::ONE;
1252 if( _test == gt ) return TypeInt::ZERO;
1253 }
1254
1255 return TypeInt::BOOL;
1256 }
1257
1258 //------------------------------dump_spec-------------------------------------
1259 // Print special per-node info
1260 void BoolTest::dump_on(outputStream *st) const {
1261 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1262 st->print("%s", msg[_test]);
1263 }
1264
1265 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1266 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1267 BoolTest::mask BoolTest::merge(BoolTest other) const {
1268 const mask res[illegal+1][illegal+1] = {
1269 // eq, gt, of, lt, ne, le, nof, ge, never, illegal
1270 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq
1271 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt
1272 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of
1273 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt
1274 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne
1275 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le
1276 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof
1277 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge
1278 {never, never, never, never, never, never, never, never, never, illegal}, // never
1279 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1280 return res[_test][other._test];
1281 }
1282
1283 //=============================================================================
1284 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1285 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1286
1287 //------------------------------operator==-------------------------------------
1288 bool BoolNode::cmp( const Node &n ) const {
1289 const BoolNode *b = (const BoolNode *)&n; // Cast up
1290 return (_test._test == b->_test._test);
1291 }
1292
1293 //-------------------------------make_predicate--------------------------------
1294 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1295 if (test_value->is_Con()) return test_value;
1296 if (test_value->is_Bool()) return test_value;
1297 if (test_value->is_CMove() &&
1298 test_value->in(CMoveNode::Condition)->is_Bool()) {
1299 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1300 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1301 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1302 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1303 return bol;
1304 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1305 return phase->transform( bol->negate(phase) );
1306 }
1307 // Else fall through. The CMove gets in the way of the test.
1308 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1309 }
1310 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1311 cmp = phase->transform(cmp);
1312 Node* bol = new BoolNode(cmp, BoolTest::ne);
1313 return phase->transform(bol);
1314 }
1315
1316 //--------------------------------as_int_value---------------------------------
1317 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1318 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1319 Node* cmov = CMoveNode::make(NULL, this,
1320 phase->intcon(0), phase->intcon(1),
1321 TypeInt::BOOL);
1322 return phase->transform(cmov);
1323 }
1324
1325 //----------------------------------negate-------------------------------------
1326 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1327 return new BoolNode(in(1), _test.negate());
1328 }
1329
1330 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1331 // overflows and we can prove that C is not in the two resulting ranges.
1332 // This optimization is similar to the one performed by CmpUNode::Value().
1333 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1334 int cmp1_op, const TypeInt* cmp2_type) {
1335 // Only optimize eq/ne integer comparison of add/sub
1336 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1337 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1338 // Skip cases were inputs of add/sub are not integers or of bottom type
1339 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1340 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1341 if ((r0 != NULL) && (r0 != TypeInt::INT) &&
1342 (r1 != NULL) && (r1 != TypeInt::INT) &&
1343 (cmp2_type != TypeInt::INT)) {
1344 // Compute exact (long) type range of add/sub result
1345 jlong lo_long = r0->_lo;
1346 jlong hi_long = r0->_hi;
1347 if (cmp1_op == Op_AddI) {
1348 lo_long += r1->_lo;
1349 hi_long += r1->_hi;
1350 } else {
1351 lo_long -= r1->_hi;
1352 hi_long -= r1->_lo;
1353 }
1354 // Check for over-/underflow by casting to integer
1355 int lo_int = (int)lo_long;
1356 int hi_int = (int)hi_long;
1357 bool underflow = lo_long != (jlong)lo_int;
1358 bool overflow = hi_long != (jlong)hi_int;
1359 if ((underflow != overflow) && (hi_int < lo_int)) {
1360 // Overflow on one boundary, compute resulting type ranges:
1361 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1362 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1363 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1364 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1365 // Compare second input of cmp to both type ranges
1366 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1367 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1368 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1369 // The result of the add/sub will never equal cmp2. Replace BoolNode
1370 // by false (0) if it tests for equality and by true (1) otherwise.
1371 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1372 }
1373 }
1374 }
1375 }
1376 return NULL;
1377 }
1378
1379 static bool is_counted_loop_cmp(Node *cmp) {
1380 Node *n = cmp->in(1)->in(1);
1381 return n != NULL &&
1382 n->is_Phi() &&
1383 n->in(0) != NULL &&
1384 n->in(0)->is_CountedLoop() &&
1385 n->in(0)->as_CountedLoop()->phi() == n;
1386 }
1387
1388 //------------------------------Ideal------------------------------------------
1389 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1390 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1391 // This moves the constant to the right. Helps value-numbering.
1392 Node *cmp = in(1);
1393 if( !cmp->is_Sub() ) return NULL;
1394 int cop = cmp->Opcode();
1395 if( cop == Op_FastLock || cop == Op_FastUnlock) return NULL;
1396 Node *cmp1 = cmp->in(1);
1397 Node *cmp2 = cmp->in(2);
1398 if( !cmp1 ) return NULL;
1399
1400 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1401 return NULL;
1402 }
1403
1404 // Constant on left?
1405 Node *con = cmp1;
1406 uint op2 = cmp2->Opcode();
1407 // Move constants to the right of compare's to canonicalize.
1408 // Do not muck with Opaque1 nodes, as this indicates a loop
1409 // guard that cannot change shape.
1410 if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 &&
1411 // Because of NaN's, CmpD and CmpF are not commutative
1412 cop != Op_CmpD && cop != Op_CmpF &&
1413 // Protect against swapping inputs to a compare when it is used by a
1414 // counted loop exit, which requires maintaining the loop-limit as in(2)
1415 !is_counted_loop_exit_test() ) {
1416 // Ok, commute the constant to the right of the cmp node.
1417 // Clone the Node, getting a new Node of the same class
1418 cmp = cmp->clone();
1419 // Swap inputs to the clone
1420 cmp->swap_edges(1, 2);
1421 cmp = phase->transform( cmp );
1422 return new BoolNode( cmp, _test.commute() );
1423 }
1424
1425 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1426 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1427 // test instead.
1428 int cmp1_op = cmp1->Opcode();
1429 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1430 if (cmp2_type == NULL) return NULL;
1431 Node* j_xor = cmp1;
1432 if( cmp2_type == TypeInt::ZERO &&
1433 cmp1_op == Op_XorI &&
1434 j_xor->in(1) != j_xor && // An xor of itself is dead
1435 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1436 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1437 (_test._test == BoolTest::eq ||
1438 _test._test == BoolTest::ne) ) {
1439 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1440 return new BoolNode( ncmp, _test.negate() );
1441 }
1442
1443 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1444 // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1445 if (cop == Op_CmpU &&
1446 cmp1_op == Op_AndI) {
1447 Node* bound = NULL;
1448 if (_test._test == BoolTest::le) {
1449 bound = cmp2;
1450 } else if (_test._test == BoolTest::lt &&
1451 cmp2->Opcode() == Op_AddI &&
1452 cmp2->in(2)->find_int_con(0) == 1) {
1453 bound = cmp2->in(1);
1454 }
1455 if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1456 return ConINode::make(1);
1457 }
1458 }
1459
1460 // Change ((x & (m - 1)) u< m) into (m > 0)
1461 // This is the off-by-one variant of the above
1462 if (cop == Op_CmpU &&
1463 _test._test == BoolTest::lt &&
1464 cmp1_op == Op_AndI) {
1465 Node* l = cmp1->in(1);
1466 Node* r = cmp1->in(2);
1467 for (int repeat = 0; repeat < 2; repeat++) {
1468 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1469 r->in(1) == cmp2;
1470 if (match) {
1471 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1472 // but to be compatible with the array range check pattern, use (arraylength u> 0)
1473 Node* ncmp = cmp2->Opcode() == Op_LoadRange
1474 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1475 : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1476 return new BoolNode(ncmp, BoolTest::gt);
1477 } else {
1478 // commute and try again
1479 l = cmp1->in(2);
1480 r = cmp1->in(1);
1481 }
1482 }
1483 }
1484
1485 // Change x u< 1 or x u<= 0 to x == 0
1486 if (cop == Op_CmpU &&
1487 cmp1_op != Op_LoadRange &&
1488 ((_test._test == BoolTest::lt &&
1489 cmp2->find_int_con(-1) == 1) ||
1490 (_test._test == BoolTest::le &&
1491 cmp2->find_int_con(-1) == 0))) {
1492 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1493 return new BoolNode(ncmp, BoolTest::eq);
1494 }
1495
1496 // Change (arraylength <= 0) or (arraylength == 0)
1497 // into (arraylength u<= 0)
1498 // Also change (arraylength != 0) into (arraylength u> 0)
1499 // The latter version matches the code pattern generated for
1500 // array range checks, which will more likely be optimized later.
1501 if (cop == Op_CmpI &&
1502 cmp1_op == Op_LoadRange &&
1503 cmp2->find_int_con(-1) == 0) {
1504 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1505 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1506 return new BoolNode(ncmp, BoolTest::le);
1507 } else if (_test._test == BoolTest::ne) {
1508 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1509 return new BoolNode(ncmp, BoolTest::gt);
1510 }
1511 }
1512
1513 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1514 // This is a standard idiom for branching on a boolean value.
1515 Node *c2b = cmp1;
1516 if( cmp2_type == TypeInt::ZERO &&
1517 cmp1_op == Op_Conv2B &&
1518 (_test._test == BoolTest::eq ||
1519 _test._test == BoolTest::ne) ) {
1520 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1521 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1522 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1523 );
1524 return new BoolNode( ncmp, _test._test );
1525 }
1526
1527 // Comparing a SubI against a zero is equal to comparing the SubI
1528 // arguments directly. This only works for eq and ne comparisons
1529 // due to possible integer overflow.
1530 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1531 (cop == Op_CmpI) &&
1532 (cmp1_op == Op_SubI) &&
1533 ( cmp2_type == TypeInt::ZERO ) ) {
1534 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1535 return new BoolNode( ncmp, _test._test );
1536 }
1537
1538 // Same as above but with and AddI of a constant
1539 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1540 cop == Op_CmpI &&
1541 cmp1_op == Op_AddI &&
1542 cmp1->in(2) != NULL &&
1543 phase->type(cmp1->in(2))->isa_int() &&
1544 phase->type(cmp1->in(2))->is_int()->is_con() &&
1545 cmp2_type == TypeInt::ZERO &&
1546 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1547 ) {
1548 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1549 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1550 return new BoolNode( ncmp, _test._test );
1551 }
1552
1553 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1554 // since zero check of conditional negation of an integer is equal to
1555 // zero check of the integer directly.
1556 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1557 (cop == Op_CmpI) &&
1558 (cmp2_type == TypeInt::ZERO) &&
1559 (cmp1_op == Op_Phi)) {
1560 // There should be a diamond phi with true path at index 1 or 2
1561 PhiNode *phi = cmp1->as_Phi();
1562 int idx_true = phi->is_diamond_phi();
1563 if (idx_true != 0) {
1564 // True input is in(idx_true) while false input is in(3 - idx_true)
1565 Node *tin = phi->in(idx_true);
1566 Node *fin = phi->in(3 - idx_true);
1567 if ((tin->Opcode() == Op_SubI) &&
1568 (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1569 (tin->in(2) == fin)) {
1570 // Found conditional negation at true path, create a new CmpINode without that
1571 Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1572 return new BoolNode(ncmp, _test._test);
1573 }
1574 if ((fin->Opcode() == Op_SubI) &&
1575 (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1576 (fin->in(2) == tin)) {
1577 // Found conditional negation at false path, create a new CmpINode without that
1578 Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1579 return new BoolNode(ncmp, _test._test);
1580 }
1581 }
1582 }
1583
1584 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1585 // most general case because negating 0x80000000 does nothing. Needed for
1586 // the CmpF3/SubI/CmpI idiom.
1587 if( cop == Op_CmpI &&
1588 cmp1_op == Op_SubI &&
1589 cmp2_type == TypeInt::ZERO &&
1590 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1591 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1592 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1593 return new BoolNode( ncmp, _test.commute() );
1594 }
1595
1596 // Try to optimize signed integer comparison
1597 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1598
1599 // The transformation below is not valid for either signed or unsigned
1600 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1601 // This transformation can be resurrected when we are able to
1602 // make inferences about the range of values being subtracted from
1603 // (or added to) relative to the wraparound point.
1604 //
1605 // // Remove +/-1's if possible.
1606 // // "X <= Y-1" becomes "X < Y"
1607 // // "X+1 <= Y" becomes "X < Y"
1608 // // "X < Y+1" becomes "X <= Y"
1609 // // "X-1 < Y" becomes "X <= Y"
1610 // // Do not this to compares off of the counted-loop-end. These guys are
1611 // // checking the trip counter and they want to use the post-incremented
1612 // // counter. If they use the PRE-incremented counter, then the counter has
1613 // // to be incremented in a private block on a loop backedge.
1614 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1615 // return NULL;
1616 // #ifndef PRODUCT
1617 // // Do not do this in a wash GVN pass during verification.
1618 // // Gets triggered by too many simple optimizations to be bothered with
1619 // // re-trying it again and again.
1620 // if( !phase->allow_progress() ) return NULL;
1621 // #endif
1622 // // Not valid for unsigned compare because of corner cases in involving zero.
1623 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1624 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1625 // // "0 <=u Y" is always true).
1626 // if( cmp->Opcode() == Op_CmpU ) return NULL;
1627 // int cmp2_op = cmp2->Opcode();
1628 // if( _test._test == BoolTest::le ) {
1629 // if( cmp1_op == Op_AddI &&
1630 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1631 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1632 // else if( cmp2_op == Op_AddI &&
1633 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1634 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1635 // } else if( _test._test == BoolTest::lt ) {
1636 // if( cmp1_op == Op_AddI &&
1637 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1638 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1639 // else if( cmp2_op == Op_AddI &&
1640 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1641 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1642 // }
1643 }
1644
1645 //------------------------------Value------------------------------------------
1646 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1647 // based on local information. If the input is constant, do it.
1648 const Type* BoolNode::Value(PhaseGVN* phase) const {
1649 return _test.cc2logical( phase->type( in(1) ) );
1650 }
1651
1652 #ifndef PRODUCT
1653 //------------------------------dump_spec--------------------------------------
1654 // Dump special per-node info
1655 void BoolNode::dump_spec(outputStream *st) const {
1656 st->print("[");
1657 _test.dump_on(st);
1658 st->print("]");
1659 }
1660
1661 //-------------------------------related---------------------------------------
1662 // A BoolNode's related nodes are all of its data inputs, and all of its
1663 // outputs until control nodes are hit, which are included. In compact
1664 // representation, inputs till level 3 and immediate outputs are included.
1665 void BoolNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1666 if (compact) {
1667 this->collect_nodes(in_rel, 3, false, true);
1668 this->collect_nodes(out_rel, -1, false, false);
1669 } else {
1670 this->collect_nodes_in_all_data(in_rel, false);
1671 this->collect_nodes_out_all_ctrl_boundary(out_rel);
1672 }
1673 }
1674 #endif
1675
1676 //----------------------is_counted_loop_exit_test------------------------------
1677 // Returns true if node is used by a counted loop node.
1678 bool BoolNode::is_counted_loop_exit_test() {
1679 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1680 Node* use = fast_out(i);
1681 if (use->is_CountedLoopEnd()) {
1682 return true;
1683 }
1684 }
1685 return false;
1686 }
1687
1688 //=============================================================================
1689 //------------------------------Value------------------------------------------
1690 // Compute sqrt
1691 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
1692 const Type *t1 = phase->type( in(1) );
1693 if( t1 == Type::TOP ) return Type::TOP;
1694 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1695 double d = t1->getd();
1696 if( d < 0.0 ) return Type::DOUBLE;
1697 return TypeD::make( sqrt( d ) );
1698 }
1699
1700 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
1701 const Type *t1 = phase->type( in(1) );
1702 if( t1 == Type::TOP ) return Type::TOP;
1703 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
1704 float f = t1->getf();
1705 if( f < 0.0f ) return Type::FLOAT;
1706 return TypeF::make( (float)sqrt( (double)f ) );
1707 }