1 /*
2 * Copyright (c) 1997, 2021, 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 (in(1)->in(2) == in(2)) {
66 return in(1)->in(1);
67 }
68 if (in(1)->in(1) == in(2)) {
69 return in(1)->in(2);
70 }
71
72 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying
73 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes
74 // are originally used, although the optimizer sometimes jiggers things).
75 // This folding through an O2 removes a loop-exit use of a loop-varying
76 // value and generally lowers register pressure in and around the loop.
77 if (in(1)->in(2)->Opcode() == Op_Opaque2 && in(1)->in(2)->in(1) == in(2)) {
78 return in(1)->in(1);
79 }
80 }
81
82 return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
83 }
84
85 //------------------------------Value------------------------------------------
86 // A subtract node differences it's two inputs.
87 const Type* SubNode::Value_common(PhaseTransform *phase) const {
88 const Node* in1 = in(1);
89 const Node* in2 = in(2);
90 // Either input is TOP ==> the result is TOP
91 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
92 if( t1 == Type::TOP ) return Type::TOP;
93 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
94 if( t2 == Type::TOP ) return Type::TOP;
95
96 // Not correct for SubFnode and AddFNode (must check for infinity)
97 // Equal? Subtract is zero
98 if (in1->eqv_uncast(in2)) return add_id();
99
100 // Either input is BOTTOM ==> the result is the local BOTTOM
101 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
102 return bottom_type();
103
104 return NULL;
105 }
106
107 const Type* SubNode::Value(PhaseGVN* phase) const {
108 const Type* t = Value_common(phase);
109 if (t != NULL) {
110 return t;
111 }
112 const Type* t1 = phase->type(in(1));
113 const Type* t2 = phase->type(in(2));
114 return sub(t1,t2); // Local flavor of type subtraction
115
116 }
117
118 SubNode* SubNode::make(Node* in1, Node* in2, BasicType bt) {
119 switch (bt) {
120 case T_INT:
121 return new SubINode(in1, in2);
122 case T_LONG:
123 return new SubLNode(in1, in2);
124 default:
125 fatal("Not implemented for %s", type2name(bt));
126 }
127 return NULL;
128 }
129
130 //=============================================================================
131 //------------------------------Helper function--------------------------------
132
133 static bool is_cloop_increment(Node* inc) {
134 precond(inc->Opcode() == Op_AddI || inc->Opcode() == Op_AddL);
135
136 if (!inc->in(1)->is_Phi()) {
137 return false;
138 }
139 const PhiNode* phi = inc->in(1)->as_Phi();
140
141 if (!phi->region()->is_CountedLoop()) {
142 return false;
143 }
144
145 return inc == phi->region()->as_CountedLoop()->incr();
146 }
147
148 // Given the expression '(x + C) - v', or
149 // 'v - (x + C)', we examine nodes '+' and 'v':
150 //
151 // 1. Do not convert if '+' is a counted-loop increment, because the '-' is
152 // loop invariant and converting extends the live-range of 'x' to overlap
153 // with the '+', forcing another register to be used in the loop.
154 //
155 // 2. Do not convert if 'v' is a counted-loop induction variable, because
156 // 'x' might be invariant.
157 //
158 static bool ok_to_convert(Node* inc, Node* var) {
159 return !(is_cloop_increment(inc) || var->is_cloop_ind_var());
160 }
161
162 //------------------------------Ideal------------------------------------------
163 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
164 Node *in1 = in(1);
165 Node *in2 = in(2);
166 uint op1 = in1->Opcode();
167 uint op2 = in2->Opcode();
168
169 #ifdef ASSERT
170 // Check for dead loop
171 if ((in1 == this) || (in2 == this) ||
172 ((op1 == Op_AddI || op1 == Op_SubI) &&
173 ((in1->in(1) == this) || (in1->in(2) == this) ||
174 (in1->in(1) == in1) || (in1->in(2) == in1)))) {
175 assert(false, "dead loop in SubINode::Ideal");
176 }
177 #endif
178
179 const Type *t2 = phase->type( in2 );
180 if( t2 == Type::TOP ) return NULL;
181 // Convert "x-c0" into "x+ -c0".
182 if( t2->base() == Type::Int ){ // Might be bottom or top...
183 const TypeInt *i = t2->is_int();
184 if( i->is_con() )
185 return new AddINode(in1, phase->intcon(-i->get_con()));
186 }
187
188 // Convert "(x+c0) - y" into (x-y) + c0"
189 // Do not collapse (x+c0)-y if "+" is a loop increment or
190 // if "y" is a loop induction variable.
191 if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
192 const Type *tadd = phase->type( in1->in(2) );
193 if( tadd->singleton() && tadd != Type::TOP ) {
194 Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 ));
195 return new AddINode( sub2, in1->in(2) );
196 }
197 }
198
199
200 // Convert "x - (y+c0)" into "(x-y) - c0"
201 // Need the same check as in above optimization but reversed.
202 if (op2 == Op_AddI && ok_to_convert(in2, in1)) {
203 Node* in21 = in2->in(1);
204 Node* in22 = in2->in(2);
205 const TypeInt* tcon = phase->type(in22)->isa_int();
206 if (tcon != NULL && tcon->is_con()) {
207 Node* sub2 = phase->transform( new SubINode(in1, in21) );
208 Node* neg_c0 = phase->intcon(- tcon->get_con());
209 return new AddINode(sub2, neg_c0);
210 }
211 }
212
213 const Type *t1 = phase->type( in1 );
214 if( t1 == Type::TOP ) return NULL;
215
216 #ifdef ASSERT
217 // Check for dead loop
218 if ((op2 == Op_AddI || op2 == Op_SubI) &&
219 ((in2->in(1) == this) || (in2->in(2) == this) ||
220 (in2->in(1) == in2) || (in2->in(2) == in2))) {
221 assert(false, "dead loop in SubINode::Ideal");
222 }
223 #endif
224
225 // Convert "x - (x+y)" into "-y"
226 if (op2 == Op_AddI && in1 == in2->in(1)) {
227 return new SubINode(phase->intcon(0), in2->in(2));
228 }
229 // Convert "(x-y) - x" into "-y"
230 if (op1 == Op_SubI && in1->in(1) == in2) {
231 return new SubINode(phase->intcon(0), in1->in(2));
232 }
233 // Convert "x - (y+x)" into "-y"
234 if (op2 == Op_AddI && in1 == in2->in(2)) {
235 return new SubINode(phase->intcon(0), in2->in(1));
236 }
237
238 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity().
239 if (t1 == TypeInt::ZERO && op2 == Op_SubI && phase->type(in2->in(1)) != TypeInt::ZERO) {
240 return new SubINode(in2->in(2), in2->in(1));
241 }
242
243 // Convert "0 - (x+con)" into "-con-x"
244 jint con;
245 if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
246 (con = in2->in(2)->find_int_con(0)) != 0 )
247 return new SubINode( phase->intcon(-con), in2->in(1) );
248
249 // Convert "(X+A) - (X+B)" into "A - B"
250 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
251 return new SubINode( in1->in(2), in2->in(2) );
252
253 // Convert "(A+X) - (B+X)" into "A - B"
254 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
255 return new SubINode( in1->in(1), in2->in(1) );
256
257 // Convert "(A+X) - (X+B)" into "A - B"
258 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
259 return new SubINode( in1->in(1), in2->in(2) );
260
261 // Convert "(X+A) - (B+X)" into "A - B"
262 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
263 return new SubINode( in1->in(2), in2->in(1) );
264
265 // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
266 // nicer to optimize than subtract.
267 if( op2 == Op_SubI && in2->outcnt() == 1) {
268 Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) );
269 return new SubINode( add1, in2->in(1) );
270 }
271
272 // Associative
273 if (op1 == Op_MulI && op2 == Op_MulI) {
274 Node* sub_in1 = NULL;
275 Node* sub_in2 = NULL;
276 Node* mul_in = NULL;
277
278 if (in1->in(1) == in2->in(1)) {
279 // Convert "a*b-a*c into a*(b-c)
280 sub_in1 = in1->in(2);
281 sub_in2 = in2->in(2);
282 mul_in = in1->in(1);
283 } else if (in1->in(2) == in2->in(1)) {
284 // Convert a*b-b*c into b*(a-c)
285 sub_in1 = in1->in(1);
286 sub_in2 = in2->in(2);
287 mul_in = in1->in(2);
288 } else if (in1->in(2) == in2->in(2)) {
289 // Convert a*c-b*c into (a-b)*c
290 sub_in1 = in1->in(1);
291 sub_in2 = in2->in(1);
292 mul_in = in1->in(2);
293 } else if (in1->in(1) == in2->in(2)) {
294 // Convert a*b-c*a into a*(b-c)
295 sub_in1 = in1->in(2);
296 sub_in2 = in2->in(1);
297 mul_in = in1->in(1);
298 }
299
300 if (mul_in != NULL) {
301 Node* sub = phase->transform(new SubINode(sub_in1, sub_in2));
302 return new MulINode(mul_in, sub);
303 }
304 }
305
306 // Convert "0-(A>>31)" into "(A>>>31)"
307 if ( op2 == Op_RShiftI ) {
308 Node *in21 = in2->in(1);
309 Node *in22 = in2->in(2);
310 const TypeInt *zero = phase->type(in1)->isa_int();
311 const TypeInt *t21 = phase->type(in21)->isa_int();
312 const TypeInt *t22 = phase->type(in22)->isa_int();
313 if ( t21 && t22 && zero == TypeInt::ZERO && t22->is_con(31) ) {
314 return new URShiftINode(in21, in22);
315 }
316 }
317
318 return NULL;
319 }
320
321 //------------------------------sub--------------------------------------------
322 // A subtract node differences it's two inputs.
323 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
324 const TypeInt *r0 = t1->is_int(); // Handy access
325 const TypeInt *r1 = t2->is_int();
326 int32_t lo = java_subtract(r0->_lo, r1->_hi);
327 int32_t hi = java_subtract(r0->_hi, r1->_lo);
328
329 // We next check for 32-bit overflow.
330 // If that happens, we just assume all integers are possible.
331 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
332 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
333 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
334 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
335 return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
336 else // Overflow; assume all integers
337 return TypeInt::INT;
338 }
339
340 //=============================================================================
341 //------------------------------Ideal------------------------------------------
342 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
343 Node *in1 = in(1);
344 Node *in2 = in(2);
345 uint op1 = in1->Opcode();
346 uint op2 = in2->Opcode();
347
348 #ifdef ASSERT
349 // Check for dead loop
350 if ((in1 == this) || (in2 == this) ||
351 ((op1 == Op_AddL || op1 == Op_SubL) &&
352 ((in1->in(1) == this) || (in1->in(2) == this) ||
353 (in1->in(1) == in1) || (in1->in(2) == in1)))) {
354 assert(false, "dead loop in SubLNode::Ideal");
355 }
356 #endif
357
358 if( phase->type( in2 ) == Type::TOP ) return NULL;
359 const TypeLong *i = phase->type( in2 )->isa_long();
360 // Convert "x-c0" into "x+ -c0".
361 if( i && // Might be bottom or top...
362 i->is_con() )
363 return new AddLNode(in1, phase->longcon(-i->get_con()));
364
365 // Convert "(x+c0) - y" into (x-y) + c0"
366 // Do not collapse (x+c0)-y if "+" is a loop increment or
367 // if "y" is a loop induction variable.
368 if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
369 Node *in11 = in1->in(1);
370 const Type *tadd = phase->type( in1->in(2) );
371 if( tadd->singleton() && tadd != Type::TOP ) {
372 Node *sub2 = phase->transform( new SubLNode( in11, in2 ));
373 return new AddLNode( sub2, in1->in(2) );
374 }
375 }
376
377 // Convert "x - (y+c0)" into "(x-y) - c0"
378 // Need the same check as in above optimization but reversed.
379 if (op2 == Op_AddL && ok_to_convert(in2, in1)) {
380 Node* in21 = in2->in(1);
381 Node* in22 = in2->in(2);
382 const TypeLong* tcon = phase->type(in22)->isa_long();
383 if (tcon != NULL && tcon->is_con()) {
384 Node* sub2 = phase->transform( new SubLNode(in1, in21) );
385 Node* neg_c0 = phase->longcon(- tcon->get_con());
386 return new AddLNode(sub2, neg_c0);
387 }
388 }
389
390 const Type *t1 = phase->type( in1 );
391 if( t1 == Type::TOP ) return NULL;
392
393 #ifdef ASSERT
394 // Check for dead loop
395 if ((op2 == Op_AddL || op2 == Op_SubL) &&
396 ((in2->in(1) == this) || (in2->in(2) == this) ||
397 (in2->in(1) == in2) || (in2->in(2) == in2))) {
398 assert(false, "dead loop in SubLNode::Ideal");
399 }
400 #endif
401
402 // Convert "x - (x+y)" into "-y"
403 if (op2 == Op_AddL && in1 == in2->in(1)) {
404 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(2));
405 }
406 // Convert "x - (y+x)" into "-y"
407 if (op2 == Op_AddL && in1 == in2->in(2)) {
408 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(1));
409 }
410
411 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity.
412 if (t1 == TypeLong::ZERO && op2 == Op_SubL && phase->type(in2->in(1)) != TypeLong::ZERO) {
413 return new SubLNode(in2->in(2), in2->in(1));
414 }
415
416 // Convert "(X+A) - (X+B)" into "A - B"
417 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
418 return new SubLNode( in1->in(2), in2->in(2) );
419
420 // Convert "(A+X) - (B+X)" into "A - B"
421 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
422 return new SubLNode( in1->in(1), in2->in(1) );
423
424 // Convert "A-(B-C)" into (A+C)-B"
425 if( op2 == Op_SubL && in2->outcnt() == 1) {
426 Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) );
427 return new SubLNode( add1, in2->in(1) );
428 }
429
430 // Associative
431 if (op1 == Op_MulL && op2 == Op_MulL) {
432 Node* sub_in1 = NULL;
433 Node* sub_in2 = NULL;
434 Node* mul_in = NULL;
435
436 if (in1->in(1) == in2->in(1)) {
437 // Convert "a*b-a*c into a*(b+c)
438 sub_in1 = in1->in(2);
439 sub_in2 = in2->in(2);
440 mul_in = in1->in(1);
441 } else if (in1->in(2) == in2->in(1)) {
442 // Convert a*b-b*c into b*(a-c)
443 sub_in1 = in1->in(1);
444 sub_in2 = in2->in(2);
445 mul_in = in1->in(2);
446 } else if (in1->in(2) == in2->in(2)) {
447 // Convert a*c-b*c into (a-b)*c
448 sub_in1 = in1->in(1);
449 sub_in2 = in2->in(1);
450 mul_in = in1->in(2);
451 } else if (in1->in(1) == in2->in(2)) {
452 // Convert a*b-c*a into a*(b-c)
453 sub_in1 = in1->in(2);
454 sub_in2 = in2->in(1);
455 mul_in = in1->in(1);
456 }
457
458 if (mul_in != NULL) {
459 Node* sub = phase->transform(new SubLNode(sub_in1, sub_in2));
460 return new MulLNode(mul_in, sub);
461 }
462 }
463
464 // Convert "0L-(A>>63)" into "(A>>>63)"
465 if ( op2 == Op_RShiftL ) {
466 Node *in21 = in2->in(1);
467 Node *in22 = in2->in(2);
468 const TypeLong *zero = phase->type(in1)->isa_long();
469 const TypeLong *t21 = phase->type(in21)->isa_long();
470 const TypeInt *t22 = phase->type(in22)->isa_int();
471 if ( t21 && t22 && zero == TypeLong::ZERO && t22->is_con(63) ) {
472 return new URShiftLNode(in21, in22);
473 }
474 }
475
476 return NULL;
477 }
478
479 //------------------------------sub--------------------------------------------
480 // A subtract node differences it's two inputs.
481 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
482 const TypeLong *r0 = t1->is_long(); // Handy access
483 const TypeLong *r1 = t2->is_long();
484 jlong lo = java_subtract(r0->_lo, r1->_hi);
485 jlong hi = java_subtract(r0->_hi, r1->_lo);
486
487 // We next check for 32-bit overflow.
488 // If that happens, we just assume all integers are possible.
489 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
490 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
491 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
492 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
493 return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
494 else // Overflow; assume all integers
495 return TypeLong::LONG;
496 }
497
498 //=============================================================================
499 //------------------------------Value------------------------------------------
500 // A subtract node differences its two inputs.
501 const Type* SubFPNode::Value(PhaseGVN* phase) const {
502 const Node* in1 = in(1);
503 const Node* in2 = in(2);
504 // Either input is TOP ==> the result is TOP
505 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
506 if( t1 == Type::TOP ) return Type::TOP;
507 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
508 if( t2 == Type::TOP ) return Type::TOP;
509
510 // if both operands are infinity of same sign, the result is NaN; do
511 // not replace with zero
512 if (t1->is_finite() && t2->is_finite() && in1 == in2) {
513 return add_id();
514 }
515
516 // Either input is BOTTOM ==> the result is the local BOTTOM
517 const Type *bot = bottom_type();
518 if( (t1 == bot) || (t2 == bot) ||
519 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
520 return bot;
521
522 return sub(t1,t2); // Local flavor of type subtraction
523 }
524
525
526 //=============================================================================
527 //------------------------------Ideal------------------------------------------
528 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
529 const Type *t2 = phase->type( in(2) );
530 // Convert "x-c0" into "x+ -c0".
531 if( t2->base() == Type::FloatCon ) { // Might be bottom or top...
532 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
533 }
534
535 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
536 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
537 //if( phase->type(in(1)) == TypeF::ZERO )
538 //return new (phase->C, 2) NegFNode(in(2));
539
540 return NULL;
541 }
542
543 //------------------------------sub--------------------------------------------
544 // A subtract node differences its two inputs.
545 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
546 // no folding if one of operands is infinity or NaN, do not do constant folding
547 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
548 return TypeF::make( t1->getf() - t2->getf() );
549 }
550 else if( g_isnan(t1->getf()) ) {
551 return t1;
552 }
553 else if( g_isnan(t2->getf()) ) {
554 return t2;
555 }
556 else {
557 return Type::FLOAT;
558 }
559 }
560
561 //=============================================================================
562 //------------------------------Ideal------------------------------------------
563 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
564 const Type *t2 = phase->type( in(2) );
565 // Convert "x-c0" into "x+ -c0".
566 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
567 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
568 }
569
570 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
571 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
572 //if( phase->type(in(1)) == TypeD::ZERO )
573 //return new (phase->C, 2) NegDNode(in(2));
574
575 return NULL;
576 }
577
578 //------------------------------sub--------------------------------------------
579 // A subtract node differences its two inputs.
580 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
581 // no folding if one of operands is infinity or NaN, do not do constant folding
582 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
583 return TypeD::make( t1->getd() - t2->getd() );
584 }
585 else if( g_isnan(t1->getd()) ) {
586 return t1;
587 }
588 else if( g_isnan(t2->getd()) ) {
589 return t2;
590 }
591 else {
592 return Type::DOUBLE;
593 }
594 }
595
596 //=============================================================================
597 //------------------------------Idealize---------------------------------------
598 // Unlike SubNodes, compare must still flatten return value to the
599 // range -1, 0, 1.
600 // And optimizations like those for (X + Y) - X fail if overflow happens.
601 Node* CmpNode::Identity(PhaseGVN* phase) {
602 return this;
603 }
604
605 #ifndef PRODUCT
606 //----------------------------related------------------------------------------
607 // Related nodes of comparison nodes include all data inputs (until hitting a
608 // control boundary) as well as all outputs until and including control nodes
609 // as well as their projections. In compact mode, data inputs till depth 1 and
610 // all outputs till depth 1 are considered.
611 void CmpNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
612 if (compact) {
613 this->collect_nodes(in_rel, 1, false, true);
614 this->collect_nodes(out_rel, -1, false, false);
615 } else {
616 this->collect_nodes_in_all_data(in_rel, false);
617 this->collect_nodes_out_all_ctrl_boundary(out_rel);
618 // Now, find all control nodes in out_rel, and include their projections
619 // and projection targets (if any) in the result.
620 GrowableArray<Node*> proj(Compile::current()->unique());
621 for (GrowableArrayIterator<Node*> it = out_rel->begin(); it != out_rel->end(); ++it) {
622 Node* n = *it;
623 if (n->is_CFG() && !n->is_Proj()) {
624 // Assume projections and projection targets are found at levels 1 and 2.
625 n->collect_nodes(&proj, -2, false, false);
626 for (GrowableArrayIterator<Node*> p = proj.begin(); p != proj.end(); ++p) {
627 out_rel->append_if_missing(*p);
628 }
629 proj.clear();
630 }
631 }
632 }
633 }
634
635 #endif
636
637 CmpNode *CmpNode::make(Node *in1, Node *in2, BasicType bt, bool unsigned_comp) {
638 switch (bt) {
639 case T_INT:
640 if (unsigned_comp) {
641 return new CmpUNode(in1, in2);
642 }
643 return new CmpINode(in1, in2);
644 case T_LONG:
645 if (unsigned_comp) {
646 return new CmpULNode(in1, in2);
647 }
648 return new CmpLNode(in1, in2);
649 default:
650 fatal("Not implemented for %s", type2name(bt));
651 }
652 return NULL;
653 }
654
655 //=============================================================================
656 //------------------------------cmp--------------------------------------------
657 // Simplify a CmpI (compare 2 integers) node, based on local information.
658 // If both inputs are constants, compare them.
659 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
660 const TypeInt *r0 = t1->is_int(); // Handy access
661 const TypeInt *r1 = t2->is_int();
662
663 if( r0->_hi < r1->_lo ) // Range is always low?
664 return TypeInt::CC_LT;
665 else if( r0->_lo > r1->_hi ) // Range is always high?
666 return TypeInt::CC_GT;
667
668 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
669 assert(r0->get_con() == r1->get_con(), "must be equal");
670 return TypeInt::CC_EQ; // Equal results.
671 } else if( r0->_hi == r1->_lo ) // Range is never high?
672 return TypeInt::CC_LE;
673 else if( r0->_lo == r1->_hi ) // Range is never low?
674 return TypeInt::CC_GE;
675 return TypeInt::CC; // else use worst case results
676 }
677
678 // Simplify a CmpU (compare 2 integers) node, based on local information.
679 // If both inputs are constants, compare them.
680 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
681 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
682
683 // comparing two unsigned ints
684 const TypeInt *r0 = t1->is_int(); // Handy access
685 const TypeInt *r1 = t2->is_int();
686
687 // Current installed version
688 // Compare ranges for non-overlap
689 juint lo0 = r0->_lo;
690 juint hi0 = r0->_hi;
691 juint lo1 = r1->_lo;
692 juint hi1 = r1->_hi;
693
694 // If either one has both negative and positive values,
695 // it therefore contains both 0 and -1, and since [0..-1] is the
696 // full unsigned range, the type must act as an unsigned bottom.
697 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
698 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
699
700 if (bot0 || bot1) {
701 // All unsigned values are LE -1 and GE 0.
702 if (lo0 == 0 && hi0 == 0) {
703 return TypeInt::CC_LE; // 0 <= bot
704 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
705 return TypeInt::CC_GE; // -1 >= bot
706 } else if (lo1 == 0 && hi1 == 0) {
707 return TypeInt::CC_GE; // bot >= 0
708 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
709 return TypeInt::CC_LE; // bot <= -1
710 }
711 } else {
712 // We can use ranges of the form [lo..hi] if signs are the same.
713 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
714 // results are reversed, '-' > '+' for unsigned compare
715 if (hi0 < lo1) {
716 return TypeInt::CC_LT; // smaller
717 } else if (lo0 > hi1) {
718 return TypeInt::CC_GT; // greater
719 } else if (hi0 == lo1 && lo0 == hi1) {
720 return TypeInt::CC_EQ; // Equal results
721 } else if (lo0 >= hi1) {
722 return TypeInt::CC_GE;
723 } else if (hi0 <= lo1) {
724 // Check for special case in Hashtable::get. (See below.)
725 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
726 return TypeInt::CC_LT;
727 return TypeInt::CC_LE;
728 }
729 }
730 // Check for special case in Hashtable::get - the hash index is
731 // mod'ed to the table size so the following range check is useless.
732 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
733 // to be positive.
734 // (This is a gross hack, since the sub method never
735 // looks at the structure of the node in any other case.)
736 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
737 return TypeInt::CC_LT;
738 return TypeInt::CC; // else use worst case results
739 }
740
741 const Type* CmpUNode::Value(PhaseGVN* phase) const {
742 const Type* t = SubNode::Value_common(phase);
743 if (t != NULL) {
744 return t;
745 }
746 const Node* in1 = in(1);
747 const Node* in2 = in(2);
748 const Type* t1 = phase->type(in1);
749 const Type* t2 = phase->type(in2);
750 assert(t1->isa_int(), "CmpU has only Int type inputs");
751 if (t2 == TypeInt::INT) { // Compare to bottom?
752 return bottom_type();
753 }
754 uint in1_op = in1->Opcode();
755 if (in1_op == Op_AddI || in1_op == Op_SubI) {
756 // The problem rise when result of AddI(SubI) may overflow
757 // signed integer value. Let say the input type is
758 // [256, maxint] then +128 will create 2 ranges due to
759 // overflow: [minint, minint+127] and [384, maxint].
760 // But C2 type system keep only 1 type range and as result
761 // it use general [minint, maxint] for this case which we
762 // can't optimize.
763 //
764 // Make 2 separate type ranges based on types of AddI(SubI) inputs
765 // and compare results of their compare. If results are the same
766 // CmpU node can be optimized.
767 const Node* in11 = in1->in(1);
768 const Node* in12 = in1->in(2);
769 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
770 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
771 // Skip cases when input types are top or bottom.
772 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
773 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
774 const TypeInt *r0 = t11->is_int();
775 const TypeInt *r1 = t12->is_int();
776 jlong lo_r0 = r0->_lo;
777 jlong hi_r0 = r0->_hi;
778 jlong lo_r1 = r1->_lo;
779 jlong hi_r1 = r1->_hi;
780 if (in1_op == Op_SubI) {
781 jlong tmp = hi_r1;
782 hi_r1 = -lo_r1;
783 lo_r1 = -tmp;
784 // Note, for substructing [minint,x] type range
785 // long arithmetic provides correct overflow answer.
786 // The confusion come from the fact that in 32-bit
787 // -minint == minint but in 64-bit -minint == maxint+1.
788 }
789 jlong lo_long = lo_r0 + lo_r1;
790 jlong hi_long = hi_r0 + hi_r1;
791 int lo_tr1 = min_jint;
792 int hi_tr1 = (int)hi_long;
793 int lo_tr2 = (int)lo_long;
794 int hi_tr2 = max_jint;
795 bool underflow = lo_long != (jlong)lo_tr2;
796 bool overflow = hi_long != (jlong)hi_tr1;
797 // Use sub(t1, t2) when there is no overflow (one type range)
798 // or when both overflow and underflow (too complex).
799 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
800 // Overflow only on one boundary, compare 2 separate type ranges.
801 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
802 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
803 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
804 const Type* cmp1 = sub(tr1, t2);
805 const Type* cmp2 = sub(tr2, t2);
806 if (cmp1 == cmp2) {
807 return cmp1; // Hit!
808 }
809 }
810 }
811 }
812
813 return sub(t1, t2); // Local flavor of type subtraction
814 }
815
816 bool CmpUNode::is_index_range_check() const {
817 // Check for the "(X ModI Y) CmpU Y" shape
818 return (in(1)->Opcode() == Op_ModI &&
819 in(1)->in(2)->eqv_uncast(in(2)));
820 }
821
822 //------------------------------Idealize---------------------------------------
823 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
824 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
825 switch (in(1)->Opcode()) {
826 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
827 return new CmpLNode(in(1)->in(1),in(1)->in(2));
828 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
829 return new CmpFNode(in(1)->in(1),in(1)->in(2));
830 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
831 return new CmpDNode(in(1)->in(1),in(1)->in(2));
832 //case Op_SubI:
833 // If (x - y) cannot overflow, then ((x - y) <?> 0)
834 // can be turned into (x <?> y).
835 // This is handled (with more general cases) by Ideal_sub_algebra.
836 }
837 }
838 return NULL; // No change
839 }
840
841 Node *CmpLNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
842 const TypeLong *t2 = phase->type(in(2))->isa_long();
843 if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) {
844 const jlong con = t2->get_con();
845 if (con >= min_jint && con <= max_jint) {
846 return new CmpINode(in(1)->in(1), phase->intcon((jint)con));
847 }
848 }
849 return NULL;
850 }
851
852 //=============================================================================
853 // Simplify a CmpL (compare 2 longs ) node, based on local information.
854 // If both inputs are constants, compare them.
855 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
856 const TypeLong *r0 = t1->is_long(); // Handy access
857 const TypeLong *r1 = t2->is_long();
858
859 if( r0->_hi < r1->_lo ) // Range is always low?
860 return TypeInt::CC_LT;
861 else if( r0->_lo > r1->_hi ) // Range is always high?
862 return TypeInt::CC_GT;
863
864 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
865 assert(r0->get_con() == r1->get_con(), "must be equal");
866 return TypeInt::CC_EQ; // Equal results.
867 } else if( r0->_hi == r1->_lo ) // Range is never high?
868 return TypeInt::CC_LE;
869 else if( r0->_lo == r1->_hi ) // Range is never low?
870 return TypeInt::CC_GE;
871 return TypeInt::CC; // else use worst case results
872 }
873
874
875 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
876 // If both inputs are constants, compare them.
877 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
878 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
879
880 // comparing two unsigned longs
881 const TypeLong* r0 = t1->is_long(); // Handy access
882 const TypeLong* r1 = t2->is_long();
883
884 // Current installed version
885 // Compare ranges for non-overlap
886 julong lo0 = r0->_lo;
887 julong hi0 = r0->_hi;
888 julong lo1 = r1->_lo;
889 julong hi1 = r1->_hi;
890
891 // If either one has both negative and positive values,
892 // it therefore contains both 0 and -1, and since [0..-1] is the
893 // full unsigned range, the type must act as an unsigned bottom.
894 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
895 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
896
897 if (bot0 || bot1) {
898 // All unsigned values are LE -1 and GE 0.
899 if (lo0 == 0 && hi0 == 0) {
900 return TypeInt::CC_LE; // 0 <= bot
901 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
902 return TypeInt::CC_GE; // -1 >= bot
903 } else if (lo1 == 0 && hi1 == 0) {
904 return TypeInt::CC_GE; // bot >= 0
905 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
906 return TypeInt::CC_LE; // bot <= -1
907 }
908 } else {
909 // We can use ranges of the form [lo..hi] if signs are the same.
910 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
911 // results are reversed, '-' > '+' for unsigned compare
912 if (hi0 < lo1) {
913 return TypeInt::CC_LT; // smaller
914 } else if (lo0 > hi1) {
915 return TypeInt::CC_GT; // greater
916 } else if (hi0 == lo1 && lo0 == hi1) {
917 return TypeInt::CC_EQ; // Equal results
918 } else if (lo0 >= hi1) {
919 return TypeInt::CC_GE;
920 } else if (hi0 <= lo1) {
921 return TypeInt::CC_LE;
922 }
923 }
924
925 return TypeInt::CC; // else use worst case results
926 }
927
928 //=============================================================================
929 //------------------------------sub--------------------------------------------
930 // Simplify an CmpP (compare 2 pointers) node, based on local information.
931 // If both inputs are constants, compare them.
932 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
933 const TypePtr *r0 = t1->is_ptr(); // Handy access
934 const TypePtr *r1 = t2->is_ptr();
935
936 // Undefined inputs makes for an undefined result
937 if( TypePtr::above_centerline(r0->_ptr) ||
938 TypePtr::above_centerline(r1->_ptr) )
939 return Type::TOP;
940
941 if (r0 == r1 && r0->singleton()) {
942 // Equal pointer constants (klasses, nulls, etc.)
943 return TypeInt::CC_EQ;
944 }
945
946 // See if it is 2 unrelated classes.
947 const TypeOopPtr* oop_p0 = r0->isa_oopptr();
948 const TypeOopPtr* oop_p1 = r1->isa_oopptr();
949 bool both_oop_ptr = oop_p0 && oop_p1;
950
951 if (both_oop_ptr) {
952 Node* in1 = in(1)->uncast();
953 Node* in2 = in(2)->uncast();
954 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
955 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
956 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
957 return TypeInt::CC_GT; // different pointers
958 }
959 }
960
961 const TypeKlassPtr* klass_p0 = r0->isa_klassptr();
962 const TypeKlassPtr* klass_p1 = r1->isa_klassptr();
963
964 if (both_oop_ptr || (klass_p0 && klass_p1)) { // both or neither are klass pointers
965 ciKlass* klass0 = NULL;
966 bool xklass0 = false;
967 ciKlass* klass1 = NULL;
968 bool xklass1 = false;
969
970 if (oop_p0) {
971 klass0 = oop_p0->klass();
972 xklass0 = oop_p0->klass_is_exact();
973 } else {
974 assert(klass_p0, "must be non-null if oop_p0 is null");
975 klass0 = klass_p0->klass();
976 xklass0 = klass_p0->klass_is_exact();
977 }
978
979 if (oop_p1) {
980 klass1 = oop_p1->klass();
981 xklass1 = oop_p1->klass_is_exact();
982 } else {
983 assert(klass_p1, "must be non-null if oop_p1 is null");
984 klass1 = klass_p1->klass();
985 xklass1 = klass_p1->klass_is_exact();
986 }
987
988 if (klass0 && klass1 &&
989 klass0->is_loaded() && !klass0->is_interface() && // do not trust interfaces
990 klass1->is_loaded() && !klass1->is_interface() &&
991 (!klass0->is_obj_array_klass() ||
992 !klass0->as_obj_array_klass()->base_element_klass()->is_interface()) &&
993 (!klass1->is_obj_array_klass() ||
994 !klass1->as_obj_array_klass()->base_element_klass()->is_interface())) {
995 bool unrelated_classes = false;
996 // See if neither subclasses the other, or if the class on top
997 // is precise. In either of these cases, the compare is known
998 // to fail if at least one of the pointers is provably not null.
999 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
1000 // Do nothing; we know nothing for imprecise types
1001 } else if (klass0->is_subtype_of(klass1)) {
1002 // If klass1's type is PRECISE, then classes are unrelated.
1003 unrelated_classes = xklass1;
1004 } else if (klass1->is_subtype_of(klass0)) {
1005 // If klass0's type is PRECISE, then classes are unrelated.
1006 unrelated_classes = xklass0;
1007 } else { // Neither subtypes the other
1008 unrelated_classes = true;
1009 }
1010 if (unrelated_classes) {
1011 // The oops classes are known to be unrelated. If the joined PTRs of
1012 // two oops is not Null and not Bottom, then we are sure that one
1013 // of the two oops is non-null, and the comparison will always fail.
1014 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1015 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1016 return TypeInt::CC_GT;
1017 }
1018 }
1019 }
1020 }
1021
1022 // Known constants can be compared exactly
1023 // Null can be distinguished from any NotNull pointers
1024 // Unknown inputs makes an unknown result
1025 if( r0->singleton() ) {
1026 intptr_t bits0 = r0->get_con();
1027 if( r1->singleton() )
1028 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1029 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1030 } else if( r1->singleton() ) {
1031 intptr_t bits1 = r1->get_con();
1032 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1033 } else
1034 return TypeInt::CC;
1035 }
1036
1037 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1038 // Return the klass node for (indirect load from OopHandle)
1039 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1040 // or NULL if not matching.
1041 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1042 n = bs->step_over_gc_barrier(n);
1043
1044 if (n->Opcode() != Op_LoadP) return NULL;
1045
1046 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1047 if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
1048
1049 Node* adr = n->in(MemNode::Address);
1050 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1051 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return NULL;
1052 adr = adr->in(MemNode::Address);
1053
1054 intptr_t off = 0;
1055 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1056 if (k == NULL) return NULL;
1057 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1058 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return NULL;
1059
1060 // We've found the klass node of a Java mirror load.
1061 return k;
1062 }
1063
1064 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
1065 // for ConP(Foo.class) return ConP(Foo.klass)
1066 // otherwise return NULL
1067 if (!n->is_Con()) return NULL;
1068
1069 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1070 if (!tp) return NULL;
1071
1072 ciType* mirror_type = tp->java_mirror_type();
1073 // TypeInstPtr::java_mirror_type() returns non-NULL for compile-
1074 // time Class constants only.
1075 if (!mirror_type) return NULL;
1076
1077 // x.getClass() == int.class can never be true (for all primitive types)
1078 // Return a ConP(NULL) node for this case.
1079 if (mirror_type->is_classless()) {
1080 return phase->makecon(TypePtr::NULL_PTR);
1081 }
1082
1083 // return the ConP(Foo.klass)
1084 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
1085 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass()));
1086 }
1087
1088 //------------------------------Ideal------------------------------------------
1089 // Normalize comparisons between Java mirror loads to compare the klass instead.
1090 //
1091 // Also check for the case of comparing an unknown klass loaded from the primary
1092 // super-type array vs a known klass with no subtypes. This amounts to
1093 // checking to see an unknown klass subtypes a known klass with no subtypes;
1094 // this only happens on an exact match. We can shorten this test by 1 load.
1095 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1096 // Normalize comparisons between Java mirrors into comparisons of the low-
1097 // level klass, where a dependent load could be shortened.
1098 //
1099 // The new pattern has a nice effect of matching the same pattern used in the
1100 // fast path of instanceof/checkcast/Class.isInstance(), which allows
1101 // redundant exact type check be optimized away by GVN.
1102 // For example, in
1103 // if (x.getClass() == Foo.class) {
1104 // Foo foo = (Foo) x;
1105 // // ... use a ...
1106 // }
1107 // a CmpPNode could be shared between if_acmpne and checkcast
1108 {
1109 Node* k1 = isa_java_mirror_load(phase, in(1));
1110 Node* k2 = isa_java_mirror_load(phase, in(2));
1111 Node* conk2 = isa_const_java_mirror(phase, in(2));
1112
1113 if (k1 && (k2 || conk2)) {
1114 Node* lhs = k1;
1115 Node* rhs = (k2 != NULL) ? k2 : conk2;
1116 set_req_X(1, lhs, phase);
1117 set_req_X(2, rhs, phase);
1118 return this;
1119 }
1120 }
1121
1122 // Constant pointer on right?
1123 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1124 if (t2 == NULL || !t2->klass_is_exact())
1125 return NULL;
1126 // Get the constant klass we are comparing to.
1127 ciKlass* superklass = t2->klass();
1128
1129 // Now check for LoadKlass on left.
1130 Node* ldk1 = in(1);
1131 if (ldk1->is_DecodeNKlass()) {
1132 ldk1 = ldk1->in(1);
1133 if (ldk1->Opcode() != Op_LoadNKlass )
1134 return NULL;
1135 } else if (ldk1->Opcode() != Op_LoadKlass )
1136 return NULL;
1137 // Take apart the address of the LoadKlass:
1138 Node* adr1 = ldk1->in(MemNode::Address);
1139 intptr_t con2 = 0;
1140 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1141 if (ldk2 == NULL)
1142 return NULL;
1143 if (con2 == oopDesc::klass_offset_in_bytes()) {
1144 // We are inspecting an object's concrete class.
1145 // Short-circuit the check if the query is abstract.
1146 if (superklass->is_interface() ||
1147 superklass->is_abstract()) {
1148 // Make it come out always false:
1149 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1150 return this;
1151 }
1152 }
1153
1154 // Check for a LoadKlass from primary supertype array.
1155 // Any nested loadklass from loadklass+con must be from the p.s. array.
1156 if (ldk2->is_DecodeNKlass()) {
1157 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1158 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1159 return NULL;
1160 } else if (ldk2->Opcode() != Op_LoadKlass)
1161 return NULL;
1162
1163 // Verify that we understand the situation
1164 if (con2 != (intptr_t) superklass->super_check_offset())
1165 return NULL; // Might be element-klass loading from array klass
1166
1167 // If 'superklass' has no subklasses and is not an interface, then we are
1168 // assured that the only input which will pass the type check is
1169 // 'superklass' itself.
1170 //
1171 // We could be more liberal here, and allow the optimization on interfaces
1172 // which have a single implementor. This would require us to increase the
1173 // expressiveness of the add_dependency() mechanism.
1174 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1175
1176 // Object arrays must have their base element have no subtypes
1177 while (superklass->is_obj_array_klass()) {
1178 ciType* elem = superklass->as_obj_array_klass()->element_type();
1179 superklass = elem->as_klass();
1180 }
1181 if (superklass->is_instance_klass()) {
1182 ciInstanceKlass* ik = superklass->as_instance_klass();
1183 if (ik->has_subklass() || ik->is_interface()) return NULL;
1184 // Add a dependency if there is a chance that a subclass will be added later.
1185 if (!ik->is_final()) {
1186 phase->C->dependencies()->assert_leaf_type(ik);
1187 }
1188 }
1189
1190 // Bypass the dependent load, and compare directly
1191 this->set_req(1,ldk2);
1192
1193 return this;
1194 }
1195
1196 //=============================================================================
1197 //------------------------------sub--------------------------------------------
1198 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1199 // If both inputs are constants, compare them.
1200 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1201 ShouldNotReachHere();
1202 return bottom_type();
1203 }
1204
1205 //------------------------------Ideal------------------------------------------
1206 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1207 return NULL;
1208 }
1209
1210 //=============================================================================
1211 //------------------------------Value------------------------------------------
1212 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1213 // If both inputs are constants, compare them.
1214 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1215 const Node* in1 = in(1);
1216 const Node* in2 = in(2);
1217 // Either input is TOP ==> the result is TOP
1218 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1219 if( t1 == Type::TOP ) return Type::TOP;
1220 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1221 if( t2 == Type::TOP ) return Type::TOP;
1222
1223 // Not constants? Don't know squat - even if they are the same
1224 // value! If they are NaN's they compare to LT instead of EQ.
1225 const TypeF *tf1 = t1->isa_float_constant();
1226 const TypeF *tf2 = t2->isa_float_constant();
1227 if( !tf1 || !tf2 ) return TypeInt::CC;
1228
1229 // This implements the Java bytecode fcmpl, so unordered returns -1.
1230 if( tf1->is_nan() || tf2->is_nan() )
1231 return TypeInt::CC_LT;
1232
1233 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1234 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1235 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1236 return TypeInt::CC_EQ;
1237 }
1238
1239
1240 //=============================================================================
1241 //------------------------------Value------------------------------------------
1242 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1243 // If both inputs are constants, compare them.
1244 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1245 const Node* in1 = in(1);
1246 const Node* in2 = in(2);
1247 // Either input is TOP ==> the result is TOP
1248 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1249 if( t1 == Type::TOP ) return Type::TOP;
1250 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1251 if( t2 == Type::TOP ) return Type::TOP;
1252
1253 // Not constants? Don't know squat - even if they are the same
1254 // value! If they are NaN's they compare to LT instead of EQ.
1255 const TypeD *td1 = t1->isa_double_constant();
1256 const TypeD *td2 = t2->isa_double_constant();
1257 if( !td1 || !td2 ) return TypeInt::CC;
1258
1259 // This implements the Java bytecode dcmpl, so unordered returns -1.
1260 if( td1->is_nan() || td2->is_nan() )
1261 return TypeInt::CC_LT;
1262
1263 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1264 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1265 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1266 return TypeInt::CC_EQ;
1267 }
1268
1269 //------------------------------Ideal------------------------------------------
1270 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1271 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1272 // Change (CMPD (F2D (float)) (ConD value))
1273 // To (CMPF (float) (ConF value))
1274 // Valid when 'value' does not lose precision as a float.
1275 // Benefits: eliminates conversion, does not require 24-bit mode
1276
1277 // NaNs prevent commuting operands. This transform works regardless of the
1278 // order of ConD and ConvF2D inputs by preserving the original order.
1279 int idx_f2d = 1; // ConvF2D on left side?
1280 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1281 idx_f2d = 2; // No, swap to check for reversed args
1282 int idx_con = 3-idx_f2d; // Check for the constant on other input
1283
1284 if( ConvertCmpD2CmpF &&
1285 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1286 in(idx_con)->Opcode() == Op_ConD ) {
1287 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1288 double t2_value_as_double = t2->_d;
1289 float t2_value_as_float = (float)t2_value_as_double;
1290 if( t2_value_as_double == (double)t2_value_as_float ) {
1291 // Test value can be represented as a float
1292 // Eliminate the conversion to double and create new comparison
1293 Node *new_in1 = in(idx_f2d)->in(1);
1294 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1295 if( idx_f2d != 1 ) { // Must flip args to match original order
1296 Node *tmp = new_in1;
1297 new_in1 = new_in2;
1298 new_in2 = tmp;
1299 }
1300 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1301 ? new CmpF3Node( new_in1, new_in2 )
1302 : new CmpFNode ( new_in1, new_in2 ) ;
1303 return new_cmp; // Changed to CmpFNode
1304 }
1305 // Testing value required the precision of a double
1306 }
1307 return NULL; // No change
1308 }
1309
1310
1311 //=============================================================================
1312 //------------------------------cc2logical-------------------------------------
1313 // Convert a condition code type to a logical type
1314 const Type *BoolTest::cc2logical( const Type *CC ) const {
1315 if( CC == Type::TOP ) return Type::TOP;
1316 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1317 const TypeInt *ti = CC->is_int();
1318 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1319 // Match low order 2 bits
1320 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1321 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1322 return TypeInt::make(tmp); // Boolean result
1323 }
1324
1325 if( CC == TypeInt::CC_GE ) {
1326 if( _test == ge ) return TypeInt::ONE;
1327 if( _test == lt ) return TypeInt::ZERO;
1328 }
1329 if( CC == TypeInt::CC_LE ) {
1330 if( _test == le ) return TypeInt::ONE;
1331 if( _test == gt ) return TypeInt::ZERO;
1332 }
1333
1334 return TypeInt::BOOL;
1335 }
1336
1337 //------------------------------dump_spec-------------------------------------
1338 // Print special per-node info
1339 void BoolTest::dump_on(outputStream *st) const {
1340 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1341 st->print("%s", msg[_test]);
1342 }
1343
1344 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1345 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1346 BoolTest::mask BoolTest::merge(BoolTest other) const {
1347 const mask res[illegal+1][illegal+1] = {
1348 // eq, gt, of, lt, ne, le, nof, ge, never, illegal
1349 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq
1350 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt
1351 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of
1352 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt
1353 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne
1354 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le
1355 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof
1356 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge
1357 {never, never, never, never, never, never, never, never, never, illegal}, // never
1358 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1359 return res[_test][other._test];
1360 }
1361
1362 //=============================================================================
1363 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1364 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1365
1366 //------------------------------operator==-------------------------------------
1367 bool BoolNode::cmp( const Node &n ) const {
1368 const BoolNode *b = (const BoolNode *)&n; // Cast up
1369 return (_test._test == b->_test._test);
1370 }
1371
1372 //-------------------------------make_predicate--------------------------------
1373 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1374 if (test_value->is_Con()) return test_value;
1375 if (test_value->is_Bool()) return test_value;
1376 if (test_value->is_CMove() &&
1377 test_value->in(CMoveNode::Condition)->is_Bool()) {
1378 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1379 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1380 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1381 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1382 return bol;
1383 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1384 return phase->transform( bol->negate(phase) );
1385 }
1386 // Else fall through. The CMove gets in the way of the test.
1387 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1388 }
1389 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1390 cmp = phase->transform(cmp);
1391 Node* bol = new BoolNode(cmp, BoolTest::ne);
1392 return phase->transform(bol);
1393 }
1394
1395 //--------------------------------as_int_value---------------------------------
1396 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1397 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1398 Node* cmov = CMoveNode::make(NULL, this,
1399 phase->intcon(0), phase->intcon(1),
1400 TypeInt::BOOL);
1401 return phase->transform(cmov);
1402 }
1403
1404 //----------------------------------negate-------------------------------------
1405 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1406 return new BoolNode(in(1), _test.negate());
1407 }
1408
1409 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1410 // overflows and we can prove that C is not in the two resulting ranges.
1411 // This optimization is similar to the one performed by CmpUNode::Value().
1412 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1413 int cmp1_op, const TypeInt* cmp2_type) {
1414 // Only optimize eq/ne integer comparison of add/sub
1415 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1416 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1417 // Skip cases were inputs of add/sub are not integers or of bottom type
1418 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1419 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1420 if ((r0 != NULL) && (r0 != TypeInt::INT) &&
1421 (r1 != NULL) && (r1 != TypeInt::INT) &&
1422 (cmp2_type != TypeInt::INT)) {
1423 // Compute exact (long) type range of add/sub result
1424 jlong lo_long = r0->_lo;
1425 jlong hi_long = r0->_hi;
1426 if (cmp1_op == Op_AddI) {
1427 lo_long += r1->_lo;
1428 hi_long += r1->_hi;
1429 } else {
1430 lo_long -= r1->_hi;
1431 hi_long -= r1->_lo;
1432 }
1433 // Check for over-/underflow by casting to integer
1434 int lo_int = (int)lo_long;
1435 int hi_int = (int)hi_long;
1436 bool underflow = lo_long != (jlong)lo_int;
1437 bool overflow = hi_long != (jlong)hi_int;
1438 if ((underflow != overflow) && (hi_int < lo_int)) {
1439 // Overflow on one boundary, compute resulting type ranges:
1440 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1441 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1442 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1443 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1444 // Compare second input of cmp to both type ranges
1445 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1446 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1447 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1448 // The result of the add/sub will never equal cmp2. Replace BoolNode
1449 // by false (0) if it tests for equality and by true (1) otherwise.
1450 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1451 }
1452 }
1453 }
1454 }
1455 return NULL;
1456 }
1457
1458 static bool is_counted_loop_cmp(Node *cmp) {
1459 Node *n = cmp->in(1)->in(1);
1460 return n != NULL &&
1461 n->is_Phi() &&
1462 n->in(0) != NULL &&
1463 n->in(0)->is_CountedLoop() &&
1464 n->in(0)->as_CountedLoop()->phi() == n;
1465 }
1466
1467 //------------------------------Ideal------------------------------------------
1468 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1469 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1470 // This moves the constant to the right. Helps value-numbering.
1471 Node *cmp = in(1);
1472 if( !cmp->is_Sub() ) return NULL;
1473 int cop = cmp->Opcode();
1474 if( cop == Op_FastLock || cop == Op_FastUnlock || cmp->is_SubTypeCheck()) return NULL;
1475 Node *cmp1 = cmp->in(1);
1476 Node *cmp2 = cmp->in(2);
1477 if( !cmp1 ) return NULL;
1478
1479 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1480 return NULL;
1481 }
1482
1483 // Constant on left?
1484 Node *con = cmp1;
1485 uint op2 = cmp2->Opcode();
1486 // Move constants to the right of compare's to canonicalize.
1487 // Do not muck with Opaque1 nodes, as this indicates a loop
1488 // guard that cannot change shape.
1489 if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 &&
1490 // Because of NaN's, CmpD and CmpF are not commutative
1491 cop != Op_CmpD && cop != Op_CmpF &&
1492 // Protect against swapping inputs to a compare when it is used by a
1493 // counted loop exit, which requires maintaining the loop-limit as in(2)
1494 !is_counted_loop_exit_test() ) {
1495 // Ok, commute the constant to the right of the cmp node.
1496 // Clone the Node, getting a new Node of the same class
1497 cmp = cmp->clone();
1498 // Swap inputs to the clone
1499 cmp->swap_edges(1, 2);
1500 cmp = phase->transform( cmp );
1501 return new BoolNode( cmp, _test.commute() );
1502 }
1503
1504 // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1505 if (cop == Op_CmpI &&
1506 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1507 cmp1->Opcode() == Op_AndI && cmp2->Opcode() == Op_ConI &&
1508 cmp1->in(2)->Opcode() == Op_ConI) {
1509 const TypeInt *t12 = phase->type(cmp2)->isa_int();
1510 const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int();
1511 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1512 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1513 Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1514 return new BoolNode(ncmp, _test.negate());
1515 }
1516 }
1517
1518 // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1519 if (cop == Op_CmpL &&
1520 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1521 cmp1->Opcode() == Op_AndL && cmp2->Opcode() == Op_ConL &&
1522 cmp1->in(2)->Opcode() == Op_ConL) {
1523 const TypeLong *t12 = phase->type(cmp2)->isa_long();
1524 const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long();
1525 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1526 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1527 Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0)));
1528 return new BoolNode(ncmp, _test.negate());
1529 }
1530 }
1531
1532 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1533 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1534 // test instead.
1535 int cmp1_op = cmp1->Opcode();
1536 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1537 if (cmp2_type == NULL) return NULL;
1538 Node* j_xor = cmp1;
1539 if( cmp2_type == TypeInt::ZERO &&
1540 cmp1_op == Op_XorI &&
1541 j_xor->in(1) != j_xor && // An xor of itself is dead
1542 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1543 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1544 (_test._test == BoolTest::eq ||
1545 _test._test == BoolTest::ne) ) {
1546 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1547 return new BoolNode( ncmp, _test.negate() );
1548 }
1549
1550 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1551 // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1552 if (cop == Op_CmpU &&
1553 cmp1_op == Op_AndI) {
1554 Node* bound = NULL;
1555 if (_test._test == BoolTest::le) {
1556 bound = cmp2;
1557 } else if (_test._test == BoolTest::lt &&
1558 cmp2->Opcode() == Op_AddI &&
1559 cmp2->in(2)->find_int_con(0) == 1) {
1560 bound = cmp2->in(1);
1561 }
1562 if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1563 return ConINode::make(1);
1564 }
1565 }
1566
1567 // Change ((x & (m - 1)) u< m) into (m > 0)
1568 // This is the off-by-one variant of the above
1569 if (cop == Op_CmpU &&
1570 _test._test == BoolTest::lt &&
1571 cmp1_op == Op_AndI) {
1572 Node* l = cmp1->in(1);
1573 Node* r = cmp1->in(2);
1574 for (int repeat = 0; repeat < 2; repeat++) {
1575 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1576 r->in(1) == cmp2;
1577 if (match) {
1578 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1579 // but to be compatible with the array range check pattern, use (arraylength u> 0)
1580 Node* ncmp = cmp2->Opcode() == Op_LoadRange
1581 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1582 : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1583 return new BoolNode(ncmp, BoolTest::gt);
1584 } else {
1585 // commute and try again
1586 l = cmp1->in(2);
1587 r = cmp1->in(1);
1588 }
1589 }
1590 }
1591
1592 // Change x u< 1 or x u<= 0 to x == 0
1593 if (cop == Op_CmpU &&
1594 cmp1_op != Op_LoadRange &&
1595 ((_test._test == BoolTest::lt &&
1596 cmp2->find_int_con(-1) == 1) ||
1597 (_test._test == BoolTest::le &&
1598 cmp2->find_int_con(-1) == 0))) {
1599 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1600 return new BoolNode(ncmp, BoolTest::eq);
1601 }
1602
1603 // Change (arraylength <= 0) or (arraylength == 0)
1604 // into (arraylength u<= 0)
1605 // Also change (arraylength != 0) into (arraylength u> 0)
1606 // The latter version matches the code pattern generated for
1607 // array range checks, which will more likely be optimized later.
1608 if (cop == Op_CmpI &&
1609 cmp1_op == Op_LoadRange &&
1610 cmp2->find_int_con(-1) == 0) {
1611 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1612 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1613 return new BoolNode(ncmp, BoolTest::le);
1614 } else if (_test._test == BoolTest::ne) {
1615 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1616 return new BoolNode(ncmp, BoolTest::gt);
1617 }
1618 }
1619
1620 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1621 // This is a standard idiom for branching on a boolean value.
1622 Node *c2b = cmp1;
1623 if( cmp2_type == TypeInt::ZERO &&
1624 cmp1_op == Op_Conv2B &&
1625 (_test._test == BoolTest::eq ||
1626 _test._test == BoolTest::ne) ) {
1627 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1628 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1629 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1630 );
1631 return new BoolNode( ncmp, _test._test );
1632 }
1633
1634 // Comparing a SubI against a zero is equal to comparing the SubI
1635 // arguments directly. This only works for eq and ne comparisons
1636 // due to possible integer overflow.
1637 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1638 (cop == Op_CmpI) &&
1639 (cmp1_op == Op_SubI) &&
1640 ( cmp2_type == TypeInt::ZERO ) ) {
1641 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1642 return new BoolNode( ncmp, _test._test );
1643 }
1644
1645 // Same as above but with and AddI of a constant
1646 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1647 cop == Op_CmpI &&
1648 cmp1_op == Op_AddI &&
1649 cmp1->in(2) != NULL &&
1650 phase->type(cmp1->in(2))->isa_int() &&
1651 phase->type(cmp1->in(2))->is_int()->is_con() &&
1652 cmp2_type == TypeInt::ZERO &&
1653 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1654 ) {
1655 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1656 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1657 return new BoolNode( ncmp, _test._test );
1658 }
1659
1660 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1661 // since zero check of conditional negation of an integer is equal to
1662 // zero check of the integer directly.
1663 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1664 (cop == Op_CmpI) &&
1665 (cmp2_type == TypeInt::ZERO) &&
1666 (cmp1_op == Op_Phi)) {
1667 // There should be a diamond phi with true path at index 1 or 2
1668 PhiNode *phi = cmp1->as_Phi();
1669 int idx_true = phi->is_diamond_phi();
1670 if (idx_true != 0) {
1671 // True input is in(idx_true) while false input is in(3 - idx_true)
1672 Node *tin = phi->in(idx_true);
1673 Node *fin = phi->in(3 - idx_true);
1674 if ((tin->Opcode() == Op_SubI) &&
1675 (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1676 (tin->in(2) == fin)) {
1677 // Found conditional negation at true path, create a new CmpINode without that
1678 Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1679 return new BoolNode(ncmp, _test._test);
1680 }
1681 if ((fin->Opcode() == Op_SubI) &&
1682 (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1683 (fin->in(2) == tin)) {
1684 // Found conditional negation at false path, create a new CmpINode without that
1685 Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1686 return new BoolNode(ncmp, _test._test);
1687 }
1688 }
1689 }
1690
1691 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1692 // most general case because negating 0x80000000 does nothing. Needed for
1693 // the CmpF3/SubI/CmpI idiom.
1694 if( cop == Op_CmpI &&
1695 cmp1_op == Op_SubI &&
1696 cmp2_type == TypeInt::ZERO &&
1697 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1698 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1699 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1700 return new BoolNode( ncmp, _test.commute() );
1701 }
1702
1703 // Try to optimize signed integer comparison
1704 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1705
1706 // The transformation below is not valid for either signed or unsigned
1707 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1708 // This transformation can be resurrected when we are able to
1709 // make inferences about the range of values being subtracted from
1710 // (or added to) relative to the wraparound point.
1711 //
1712 // // Remove +/-1's if possible.
1713 // // "X <= Y-1" becomes "X < Y"
1714 // // "X+1 <= Y" becomes "X < Y"
1715 // // "X < Y+1" becomes "X <= Y"
1716 // // "X-1 < Y" becomes "X <= Y"
1717 // // Do not this to compares off of the counted-loop-end. These guys are
1718 // // checking the trip counter and they want to use the post-incremented
1719 // // counter. If they use the PRE-incremented counter, then the counter has
1720 // // to be incremented in a private block on a loop backedge.
1721 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1722 // return NULL;
1723 // #ifndef PRODUCT
1724 // // Do not do this in a wash GVN pass during verification.
1725 // // Gets triggered by too many simple optimizations to be bothered with
1726 // // re-trying it again and again.
1727 // if( !phase->allow_progress() ) return NULL;
1728 // #endif
1729 // // Not valid for unsigned compare because of corner cases in involving zero.
1730 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1731 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1732 // // "0 <=u Y" is always true).
1733 // if( cmp->Opcode() == Op_CmpU ) return NULL;
1734 // int cmp2_op = cmp2->Opcode();
1735 // if( _test._test == BoolTest::le ) {
1736 // if( cmp1_op == Op_AddI &&
1737 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1738 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1739 // else if( cmp2_op == Op_AddI &&
1740 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1741 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1742 // } else if( _test._test == BoolTest::lt ) {
1743 // if( cmp1_op == Op_AddI &&
1744 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1745 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1746 // else if( cmp2_op == Op_AddI &&
1747 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1748 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1749 // }
1750 }
1751
1752 //------------------------------Value------------------------------------------
1753 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1754 // based on local information. If the input is constant, do it.
1755 const Type* BoolNode::Value(PhaseGVN* phase) const {
1756 return _test.cc2logical( phase->type( in(1) ) );
1757 }
1758
1759 #ifndef PRODUCT
1760 //------------------------------dump_spec--------------------------------------
1761 // Dump special per-node info
1762 void BoolNode::dump_spec(outputStream *st) const {
1763 st->print("[");
1764 _test.dump_on(st);
1765 st->print("]");
1766 }
1767
1768 //-------------------------------related---------------------------------------
1769 // A BoolNode's related nodes are all of its data inputs, and all of its
1770 // outputs until control nodes are hit, which are included. In compact
1771 // representation, inputs till level 3 and immediate outputs are included.
1772 void BoolNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1773 if (compact) {
1774 this->collect_nodes(in_rel, 3, false, true);
1775 this->collect_nodes(out_rel, -1, false, false);
1776 } else {
1777 this->collect_nodes_in_all_data(in_rel, false);
1778 this->collect_nodes_out_all_ctrl_boundary(out_rel);
1779 }
1780 }
1781 #endif
1782
1783 //----------------------is_counted_loop_exit_test------------------------------
1784 // Returns true if node is used by a counted loop node.
1785 bool BoolNode::is_counted_loop_exit_test() {
1786 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1787 Node* use = fast_out(i);
1788 if (use->is_CountedLoopEnd()) {
1789 return true;
1790 }
1791 }
1792 return false;
1793 }
1794
1795 //=============================================================================
1796 //------------------------------Value------------------------------------------
1797 // Compute sqrt
1798 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
1799 const Type *t1 = phase->type( in(1) );
1800 if( t1 == Type::TOP ) return Type::TOP;
1801 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1802 double d = t1->getd();
1803 if( d < 0.0 ) return Type::DOUBLE;
1804 return TypeD::make( sqrt( d ) );
1805 }
1806
1807 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
1808 const Type *t1 = phase->type( in(1) );
1809 if( t1 == Type::TOP ) return Type::TOP;
1810 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
1811 float f = t1->getf();
1812 if( f < 0.0f ) return Type::FLOAT;
1813 return TypeF::make( (float)sqrt( (double)f ) );
1814 }