1 /*
2 * Copyright (c) 1997, 2025, 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.
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23 */
24
25 #include "compiler/compileLog.hpp"
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "opto/addnode.hpp"
30 #include "opto/callnode.hpp"
31 #include "opto/cfgnode.hpp"
32 #include "opto/loopnode.hpp"
33 #include "opto/matcher.hpp"
34 #include "opto/movenode.hpp"
35 #include "opto/mulnode.hpp"
36 #include "opto/opaquenode.hpp"
37 #include "opto/opcodes.hpp"
38 #include "opto/phaseX.hpp"
39 #include "opto/subnode.hpp"
40 #include "runtime/sharedRuntime.hpp"
41 #include "utilities/reverse_bits.hpp"
42
43 // Portions of code courtesy of Clifford Click
44
45 // Optimization - Graph Style
46
47 #include "math.h"
48
49 //=============================================================================
50 //------------------------------Identity---------------------------------------
51 // If right input is a constant 0, return the left input.
52 Node* SubNode::Identity(PhaseGVN* phase) {
53 assert(in(1) != this, "Must already have called Value");
54 assert(in(2) != this, "Must already have called Value");
55
56 const Type* zero = add_id();
57
58 // Remove double negation if it is not a floating point number since negation
59 // is not the same as subtraction for floating point numbers
60 // (cf. JLS § 15.15.4). `0-(0-(-0.0))` must be equal to positive 0.0 according to
61 // JLS § 15.8.2, but would result in -0.0 if this folding would be applied.
62 if (phase->type(in(1))->higher_equal(zero) &&
63 in(2)->Opcode() == Opcode() &&
64 phase->type(in(2)->in(1))->higher_equal(zero) &&
65 !phase->type(in(2)->in(2))->is_floatingpoint()) {
66 return in(2)->in(2);
67 }
68
69 // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
70 if (in(1)->Opcode() == Op_AddI || in(1)->Opcode() == Op_AddL) {
71 if (in(1)->in(2) == in(2)) {
72 return in(1)->in(1);
73 }
74 if (in(1)->in(1) == in(2)) {
75 return in(1)->in(2);
76 }
77 }
78
79 return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
80 }
81
82 //------------------------------Value------------------------------------------
83 // A subtract node differences it's two inputs.
84 const Type* SubNode::Value_common(PhaseValues* phase) const {
85 const Node* in1 = in(1);
86 const Node* in2 = in(2);
87 // Either input is TOP ==> the result is TOP
88 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
89 if( t1 == Type::TOP ) return Type::TOP;
90 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
91 if( t2 == Type::TOP ) return Type::TOP;
92
93 // Not correct for SubFnode and AddFNode (must check for infinity)
94 // Equal? Subtract is zero
95 if (in1->eqv_uncast(in2)) return add_id();
96
97 // Either input is BOTTOM ==> the result is the local BOTTOM
98 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
99 return bottom_type();
100
101 return nullptr;
102 }
103
104 const Type* SubNode::Value(PhaseGVN* phase) const {
105 const Type* t = Value_common(phase);
106 if (t != nullptr) {
107 return t;
108 }
109 const Type* t1 = phase->type(in(1));
110 const Type* t2 = phase->type(in(2));
111 return sub(t1,t2); // Local flavor of type subtraction
112
113 }
114
115 SubNode* SubNode::make(Node* in1, Node* in2, BasicType bt) {
116 switch (bt) {
117 case T_INT:
118 return new SubINode(in1, in2);
119 case T_LONG:
120 return new SubLNode(in1, in2);
121 default:
122 fatal("Not implemented for %s", type2name(bt));
123 }
124 return nullptr;
125 }
126
127 //=============================================================================
128 //------------------------------Helper function--------------------------------
129
130 static bool is_cloop_increment(Node* inc) {
131 precond(inc->Opcode() == Op_AddI || inc->Opcode() == Op_AddL);
132
133 if (!inc->in(1)->is_Phi()) {
134 return false;
135 }
136 const PhiNode* phi = inc->in(1)->as_Phi();
137
138 if (!phi->region()->is_CountedLoop()) {
139 return false;
140 }
141
142 return inc == phi->region()->as_CountedLoop()->incr();
143 }
144
145 // Given the expression '(x + C) - v', or
146 // 'v - (x + C)', we examine nodes '+' and 'v':
147 //
148 // 1. Do not convert if '+' is a counted-loop increment, because the '-' is
149 // loop invariant and converting extends the live-range of 'x' to overlap
150 // with the '+', forcing another register to be used in the loop.
151 //
152 // 2. Do not convert if 'v' is a counted-loop induction variable, because
153 // 'x' might be invariant.
154 //
155 static bool ok_to_convert(Node* inc, Node* var) {
156 return !(is_cloop_increment(inc) || var->is_cloop_ind_var());
157 }
158
159 static bool is_cloop_condition(BoolNode* bol) {
160 for (DUIterator_Fast imax, i = bol->fast_outs(imax); i < imax; i++) {
161 Node* out = bol->fast_out(i);
162 if (out->is_BaseCountedLoopEnd()) {
163 return true;
164 }
165 }
166 return false;
167 }
168
169 //------------------------------Ideal------------------------------------------
170 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
171 Node *in1 = in(1);
172 Node *in2 = in(2);
173 uint op1 = in1->Opcode();
174 uint op2 = in2->Opcode();
175
176 #ifdef ASSERT
177 // Check for dead loop
178 if ((in1 == this) || (in2 == this) ||
179 ((op1 == Op_AddI || op1 == Op_SubI) &&
180 ((in1->in(1) == this) || (in1->in(2) == this) ||
181 (in1->in(1) == in1) || (in1->in(2) == in1)))) {
182 assert(false, "dead loop in SubINode::Ideal");
183 }
184 #endif
185
186 const Type *t2 = phase->type( in2 );
187 if( t2 == Type::TOP ) return nullptr;
188 // Convert "x-c0" into "x+ -c0".
189 if( t2->base() == Type::Int ){ // Might be bottom or top...
190 const TypeInt *i = t2->is_int();
191 if( i->is_con() )
192 return new AddINode(in1, phase->intcon(java_negate(i->get_con())));
193 }
194
195 // Convert "(x+c0) - y" into (x-y) + c0"
196 // Do not collapse (x+c0)-y if "+" is a loop increment or
197 // if "y" is a loop induction variable.
198 if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
199 const Type *tadd = phase->type( in1->in(2) );
200 if( tadd->singleton() && tadd != Type::TOP ) {
201 Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 ));
202 return new AddINode( sub2, in1->in(2) );
203 }
204 }
205
206 // Convert "x - (y+c0)" into "(x-y) - c0" AND
207 // Convert "c1 - (y+c0)" into "(c1-c0) - y"
208 // Need the same check as in above optimization but reversed.
209 if (op2 == Op_AddI
210 && ok_to_convert(in2, in1)
211 && in2->in(2)->Opcode() == Op_ConI) {
212 jint c0 = phase->type(in2->in(2))->isa_int()->get_con();
213 Node* in21 = in2->in(1);
214 if (in1->Opcode() == Op_ConI) {
215 // Match c1
216 jint c1 = phase->type(in1)->isa_int()->get_con();
217 Node* sub2 = phase->intcon(java_subtract(c1, c0));
218 return new SubINode(sub2, in21);
219 } else {
220 // Match x
221 Node* sub2 = phase->transform(new SubINode(in1, in21));
222 Node* neg_c0 = phase->intcon(java_negate(c0));
223 return new AddINode(sub2, neg_c0);
224 }
225 }
226
227 const Type *t1 = phase->type( in1 );
228 if( t1 == Type::TOP ) return nullptr;
229
230 #ifdef ASSERT
231 // Check for dead loop
232 if ((op2 == Op_AddI || op2 == Op_SubI) &&
233 ((in2->in(1) == this) || (in2->in(2) == this) ||
234 (in2->in(1) == in2) || (in2->in(2) == in2))) {
235 assert(false, "dead loop in SubINode::Ideal");
236 }
237 #endif
238
239 // Convert "x - (x+y)" into "-y"
240 if (op2 == Op_AddI && in1 == in2->in(1)) {
241 return new SubINode(phase->intcon(0), in2->in(2));
242 }
243 // Convert "(x-y) - x" into "-y"
244 if (op1 == Op_SubI && in1->in(1) == in2) {
245 return new SubINode(phase->intcon(0), in1->in(2));
246 }
247 // Convert "x - (y+x)" into "-y"
248 if (op2 == Op_AddI && in1 == in2->in(2)) {
249 return new SubINode(phase->intcon(0), in2->in(1));
250 }
251
252 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity().
253 if (t1 == TypeInt::ZERO && op2 == Op_SubI && phase->type(in2->in(1)) != TypeInt::ZERO) {
254 return new SubINode(in2->in(2), in2->in(1));
255 }
256
257 // Convert "0 - (x+con)" into "-con-x"
258 jint con;
259 if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
260 (con = in2->in(2)->find_int_con(0)) != 0 )
261 return new SubINode( phase->intcon(-con), in2->in(1) );
262
263 // Convert "(X+A) - (X+B)" into "A - B"
264 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
265 return new SubINode( in1->in(2), in2->in(2) );
266
267 // Convert "(A+X) - (B+X)" into "A - B"
268 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
269 return new SubINode( in1->in(1), in2->in(1) );
270
271 // Convert "(A+X) - (X+B)" into "A - B"
272 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
273 return new SubINode( in1->in(1), in2->in(2) );
274
275 // Convert "(X+A) - (B+X)" into "A - B"
276 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
277 return new SubINode( in1->in(2), in2->in(1) );
278
279 // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
280 // nicer to optimize than subtract.
281 if( op2 == Op_SubI && in2->outcnt() == 1) {
282 Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) );
283 return new SubINode( add1, in2->in(1) );
284 }
285
286 // Associative
287 if (op1 == Op_MulI && op2 == Op_MulI) {
288 Node* sub_in1 = nullptr;
289 Node* sub_in2 = nullptr;
290 Node* mul_in = nullptr;
291
292 if (in1->in(1) == in2->in(1)) {
293 // Convert "a*b-a*c into a*(b-c)
294 sub_in1 = in1->in(2);
295 sub_in2 = in2->in(2);
296 mul_in = in1->in(1);
297 } else if (in1->in(2) == in2->in(1)) {
298 // Convert a*b-b*c into b*(a-c)
299 sub_in1 = in1->in(1);
300 sub_in2 = in2->in(2);
301 mul_in = in1->in(2);
302 } else if (in1->in(2) == in2->in(2)) {
303 // Convert a*c-b*c into (a-b)*c
304 sub_in1 = in1->in(1);
305 sub_in2 = in2->in(1);
306 mul_in = in1->in(2);
307 } else if (in1->in(1) == in2->in(2)) {
308 // Convert a*b-c*a into a*(b-c)
309 sub_in1 = in1->in(2);
310 sub_in2 = in2->in(1);
311 mul_in = in1->in(1);
312 }
313
314 if (mul_in != nullptr) {
315 Node* sub = phase->transform(new SubINode(sub_in1, sub_in2));
316 return new MulINode(mul_in, sub);
317 }
318 }
319
320 // Convert "0-(A>>31)" into "(A>>>31)"
321 if ( op2 == Op_RShiftI ) {
322 Node *in21 = in2->in(1);
323 Node *in22 = in2->in(2);
324 const TypeInt *zero = phase->type(in1)->isa_int();
325 const TypeInt *t21 = phase->type(in21)->isa_int();
326 const TypeInt *t22 = phase->type(in22)->isa_int();
327 if ( t21 && t22 && zero == TypeInt::ZERO && t22->is_con(31) ) {
328 return new URShiftINode(in21, in22);
329 }
330 }
331
332 return nullptr;
333 }
334
335 //------------------------------sub--------------------------------------------
336 // A subtract node differences it's two inputs.
337 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
338 const TypeInt *r0 = t1->is_int(); // Handy access
339 const TypeInt *r1 = t2->is_int();
340 int32_t lo = java_subtract(r0->_lo, r1->_hi);
341 int32_t hi = java_subtract(r0->_hi, r1->_lo);
342
343 // We next check for 32-bit overflow.
344 // If that happens, we just assume all integers are possible.
345 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
346 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
347 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
348 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
349 return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
350 else // Overflow; assume all integers
351 return TypeInt::INT;
352 }
353
354 //=============================================================================
355 //------------------------------Ideal------------------------------------------
356 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
357 Node *in1 = in(1);
358 Node *in2 = in(2);
359 uint op1 = in1->Opcode();
360 uint op2 = in2->Opcode();
361
362 #ifdef ASSERT
363 // Check for dead loop
364 if ((in1 == this) || (in2 == this) ||
365 ((op1 == Op_AddL || op1 == Op_SubL) &&
366 ((in1->in(1) == this) || (in1->in(2) == this) ||
367 (in1->in(1) == in1) || (in1->in(2) == in1)))) {
368 assert(false, "dead loop in SubLNode::Ideal");
369 }
370 #endif
371
372 if( phase->type( in2 ) == Type::TOP ) return nullptr;
373 const TypeLong *i = phase->type( in2 )->isa_long();
374 // Convert "x-c0" into "x+ -c0".
375 if( i && // Might be bottom or top...
376 i->is_con() )
377 return new AddLNode(in1, phase->longcon(java_negate(i->get_con())));
378
379 // Convert "(x+c0) - y" into (x-y) + c0"
380 // Do not collapse (x+c0)-y if "+" is a loop increment or
381 // if "y" is a loop induction variable.
382 if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
383 Node *in11 = in1->in(1);
384 const Type *tadd = phase->type( in1->in(2) );
385 if( tadd->singleton() && tadd != Type::TOP ) {
386 Node *sub2 = phase->transform( new SubLNode( in11, in2 ));
387 return new AddLNode( sub2, in1->in(2) );
388 }
389 }
390
391 // Convert "x - (y+c0)" into "(x-y) - c0" AND
392 // Convert "c1 - (y+c0)" into "(c1-c0) - y"
393 // Need the same check as in above optimization but reversed.
394 if (op2 == Op_AddL
395 && ok_to_convert(in2, in1)
396 && in2->in(2)->Opcode() == Op_ConL) {
397 jlong c0 = phase->type(in2->in(2))->isa_long()->get_con();
398 Node* in21 = in2->in(1);
399 if (in1->Opcode() == Op_ConL) {
400 // Match c1
401 jlong c1 = phase->type(in1)->isa_long()->get_con();
402 Node* sub2 = phase->longcon(java_subtract(c1, c0));
403 return new SubLNode(sub2, in21);
404 } else {
405 Node* sub2 = phase->transform(new SubLNode(in1, in21));
406 Node* neg_c0 = phase->longcon(java_negate(c0));
407 return new AddLNode(sub2, neg_c0);
408 }
409 }
410
411 const Type *t1 = phase->type( in1 );
412 if( t1 == Type::TOP ) return nullptr;
413
414 #ifdef ASSERT
415 // Check for dead loop
416 if ((op2 == Op_AddL || op2 == Op_SubL) &&
417 ((in2->in(1) == this) || (in2->in(2) == this) ||
418 (in2->in(1) == in2) || (in2->in(2) == in2))) {
419 assert(false, "dead loop in SubLNode::Ideal");
420 }
421 #endif
422
423 // Convert "x - (x+y)" into "-y"
424 if (op2 == Op_AddL && in1 == in2->in(1)) {
425 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(2));
426 }
427 // Convert "(x-y) - x" into "-y"
428 if (op1 == Op_SubL && in1->in(1) == in2) {
429 return new SubLNode(phase->makecon(TypeLong::ZERO), in1->in(2));
430 }
431 // Convert "x - (y+x)" into "-y"
432 if (op2 == Op_AddL && in1 == in2->in(2)) {
433 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(1));
434 }
435
436 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity.
437 if (t1 == TypeLong::ZERO && op2 == Op_SubL && phase->type(in2->in(1)) != TypeLong::ZERO) {
438 return new SubLNode(in2->in(2), in2->in(1));
439 }
440
441 // Convert "(X+A) - (X+B)" into "A - B"
442 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
443 return new SubLNode( in1->in(2), in2->in(2) );
444
445 // Convert "(A+X) - (B+X)" into "A - B"
446 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
447 return new SubLNode( in1->in(1), in2->in(1) );
448
449 // Convert "(A+X) - (X+B)" into "A - B"
450 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(1) )
451 return new SubLNode( in1->in(1), in2->in(2) );
452
453 // Convert "(X+A) - (B+X)" into "A - B"
454 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(2) )
455 return new SubLNode( in1->in(2), in2->in(1) );
456
457 // Convert "A-(B-C)" into (A+C)-B"
458 if( op2 == Op_SubL && in2->outcnt() == 1) {
459 Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) );
460 return new SubLNode( add1, in2->in(1) );
461 }
462
463 // Associative
464 if (op1 == Op_MulL && op2 == Op_MulL) {
465 Node* sub_in1 = nullptr;
466 Node* sub_in2 = nullptr;
467 Node* mul_in = nullptr;
468
469 if (in1->in(1) == in2->in(1)) {
470 // Convert "a*b-a*c into a*(b+c)
471 sub_in1 = in1->in(2);
472 sub_in2 = in2->in(2);
473 mul_in = in1->in(1);
474 } else if (in1->in(2) == in2->in(1)) {
475 // Convert a*b-b*c into b*(a-c)
476 sub_in1 = in1->in(1);
477 sub_in2 = in2->in(2);
478 mul_in = in1->in(2);
479 } else if (in1->in(2) == in2->in(2)) {
480 // Convert a*c-b*c into (a-b)*c
481 sub_in1 = in1->in(1);
482 sub_in2 = in2->in(1);
483 mul_in = in1->in(2);
484 } else if (in1->in(1) == in2->in(2)) {
485 // Convert a*b-c*a into a*(b-c)
486 sub_in1 = in1->in(2);
487 sub_in2 = in2->in(1);
488 mul_in = in1->in(1);
489 }
490
491 if (mul_in != nullptr) {
492 Node* sub = phase->transform(new SubLNode(sub_in1, sub_in2));
493 return new MulLNode(mul_in, sub);
494 }
495 }
496
497 // Convert "0L-(A>>63)" into "(A>>>63)"
498 if ( op2 == Op_RShiftL ) {
499 Node *in21 = in2->in(1);
500 Node *in22 = in2->in(2);
501 const TypeLong *zero = phase->type(in1)->isa_long();
502 const TypeLong *t21 = phase->type(in21)->isa_long();
503 const TypeInt *t22 = phase->type(in22)->isa_int();
504 if ( t21 && t22 && zero == TypeLong::ZERO && t22->is_con(63) ) {
505 return new URShiftLNode(in21, in22);
506 }
507 }
508
509 return nullptr;
510 }
511
512 //------------------------------sub--------------------------------------------
513 // A subtract node differences it's two inputs.
514 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
515 const TypeLong *r0 = t1->is_long(); // Handy access
516 const TypeLong *r1 = t2->is_long();
517 jlong lo = java_subtract(r0->_lo, r1->_hi);
518 jlong hi = java_subtract(r0->_hi, r1->_lo);
519
520 // We next check for 32-bit overflow.
521 // If that happens, we just assume all integers are possible.
522 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
523 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
524 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
525 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
526 return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
527 else // Overflow; assume all integers
528 return TypeLong::LONG;
529 }
530
531 //=============================================================================
532 //------------------------------Value------------------------------------------
533 // A subtract node differences its two inputs.
534 const Type* SubFPNode::Value(PhaseGVN* phase) const {
535 const Node* in1 = in(1);
536 const Node* in2 = in(2);
537 // Either input is TOP ==> the result is TOP
538 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
539 if( t1 == Type::TOP ) return Type::TOP;
540 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
541 if( t2 == Type::TOP ) return Type::TOP;
542
543 // if both operands are infinity of same sign, the result is NaN; do
544 // not replace with zero
545 if (t1->is_finite() && t2->is_finite() && in1 == in2) {
546 return add_id();
547 }
548
549 // Either input is BOTTOM ==> the result is the local BOTTOM
550 const Type *bot = bottom_type();
551 if( (t1 == bot) || (t2 == bot) ||
552 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
553 return bot;
554
555 return sub(t1,t2); // Local flavor of type subtraction
556 }
557
558
559 //=============================================================================
560 //------------------------------sub--------------------------------------------
561 // A subtract node differences its two inputs.
562 const Type* SubHFNode::sub(const Type* t1, const Type* t2) const {
563 // Half precision floating point subtraction follows the rules of IEEE 754
564 // applicable to other floating point types.
565 if (t1->isa_half_float_constant() != nullptr &&
566 t2->isa_half_float_constant() != nullptr) {
567 return TypeH::make(t1->getf() - t2->getf());
568 } else {
569 return Type::HALF_FLOAT;
570 }
571 }
572
573 //------------------------------Ideal------------------------------------------
574 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
575 const Type *t2 = phase->type( in(2) );
576 // Convert "x-c0" into "x+ -c0".
577 if( t2->base() == Type::FloatCon ) { // Might be bottom or top...
578 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
579 }
580
581 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
582 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
583 //if( phase->type(in(1)) == TypeF::ZERO )
584 //return new (phase->C, 2) NegFNode(in(2));
585
586 return nullptr;
587 }
588
589 //------------------------------sub--------------------------------------------
590 // A subtract node differences its two inputs.
591 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
592 // no folding if one of operands is infinity or NaN, do not do constant folding
593 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
594 return TypeF::make( t1->getf() - t2->getf() );
595 }
596 else if( g_isnan(t1->getf()) ) {
597 return t1;
598 }
599 else if( g_isnan(t2->getf()) ) {
600 return t2;
601 }
602 else {
603 return Type::FLOAT;
604 }
605 }
606
607 //=============================================================================
608 //------------------------------Ideal------------------------------------------
609 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
610 const Type *t2 = phase->type( in(2) );
611 // Convert "x-c0" into "x+ -c0".
612 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
613 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
614 }
615
616 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
617 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
618 //if( phase->type(in(1)) == TypeD::ZERO )
619 //return new (phase->C, 2) NegDNode(in(2));
620
621 return nullptr;
622 }
623
624 //------------------------------sub--------------------------------------------
625 // A subtract node differences its two inputs.
626 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
627 // no folding if one of operands is infinity or NaN, do not do constant folding
628 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
629 return TypeD::make( t1->getd() - t2->getd() );
630 }
631 else if( g_isnan(t1->getd()) ) {
632 return t1;
633 }
634 else if( g_isnan(t2->getd()) ) {
635 return t2;
636 }
637 else {
638 return Type::DOUBLE;
639 }
640 }
641
642 //=============================================================================
643 //------------------------------Idealize---------------------------------------
644 // Unlike SubNodes, compare must still flatten return value to the
645 // range -1, 0, 1.
646 // And optimizations like those for (X + Y) - X fail if overflow happens.
647 Node* CmpNode::Identity(PhaseGVN* phase) {
648 return this;
649 }
650
651 CmpNode *CmpNode::make(Node *in1, Node *in2, BasicType bt, bool unsigned_comp) {
652 switch (bt) {
653 case T_INT:
654 if (unsigned_comp) {
655 return new CmpUNode(in1, in2);
656 }
657 return new CmpINode(in1, in2);
658 case T_LONG:
659 if (unsigned_comp) {
660 return new CmpULNode(in1, in2);
661 }
662 return new CmpLNode(in1, in2);
663 case T_OBJECT:
664 case T_ARRAY:
665 case T_ADDRESS:
666 case T_METADATA:
667 return new CmpPNode(in1, in2);
668 case T_NARROWOOP:
669 case T_NARROWKLASS:
670 return new CmpNNode(in1, in2);
671 default:
672 fatal("Not implemented for %s", type2name(bt));
673 }
674 return nullptr;
675 }
676
677 //=============================================================================
678 //------------------------------cmp--------------------------------------------
679 // Simplify a CmpI (compare 2 integers) node, based on local information.
680 // If both inputs are constants, compare them.
681 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
682 const TypeInt *r0 = t1->is_int(); // Handy access
683 const TypeInt *r1 = t2->is_int();
684
685 if( r0->_hi < r1->_lo ) // Range is always low?
686 return TypeInt::CC_LT;
687 else if( r0->_lo > r1->_hi ) // Range is always high?
688 return TypeInt::CC_GT;
689
690 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
691 assert(r0->get_con() == r1->get_con(), "must be equal");
692 return TypeInt::CC_EQ; // Equal results.
693 } else if( r0->_hi == r1->_lo ) // Range is never high?
694 return TypeInt::CC_LE;
695 else if( r0->_lo == r1->_hi ) // Range is never low?
696 return TypeInt::CC_GE;
697
698 const Type* joined = r0->join(r1);
699 if (joined == Type::TOP) {
700 return TypeInt::CC_NE;
701 }
702 return TypeInt::CC; // else use worst case results
703 }
704
705 const Type* CmpINode::Value(PhaseGVN* phase) const {
706 Node* in1 = in(1);
707 Node* in2 = in(2);
708 // If this test is the zero trip guard for a main or post loop, check whether, with the opaque node removed, the test
709 // would constant fold so the loop is never entered. If so return the type of the test without the opaque node removed:
710 // make the loop unreachable.
711 // The reason for this is that the iv phi captures the bounds of the loop and if the loop becomes unreachable, it can
712 // become top. In that case, the loop must be removed.
713 // This is safe because:
714 // - as optimizations proceed, the range of iterations executed by the main loop narrows. If no iterations remain, then
715 // we're done with optimizations for that loop.
716 // - the post loop is initially not reachable but as long as there's a main loop, the zero trip guard for the post
717 // loop takes a phi that merges the pre and main loop's iv and can't constant fold the zero trip guard. Once, the main
718 // loop is removed, there's no need to preserve the zero trip guard for the post loop anymore.
719 if (in1 != nullptr && in2 != nullptr) {
720 uint input = 0;
721 Node* cmp = nullptr;
722 BoolTest::mask test;
723 if (in1->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in1) != Type::TOP) {
724 cmp = new CmpINode(in1->in(1), in2);
725 test = ((OpaqueZeroTripGuardNode*)in1)->_loop_entered_mask;
726 }
727 if (in2->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in2) != Type::TOP) {
728 assert(cmp == nullptr, "A cmp with 2 OpaqueZeroTripGuard inputs");
729 cmp = new CmpINode(in1, in2->in(1));
730 test = ((OpaqueZeroTripGuardNode*)in2)->_loop_entered_mask;
731 }
732 if (cmp != nullptr) {
733 const Type* cmp_t = cmp->Value(phase);
734 const Type* t = BoolTest(test).cc2logical(cmp_t);
735 cmp->destruct(phase);
736 if (t == TypeInt::ZERO) {
737 return cmp_t;
738 }
739 }
740 }
741
742 return SubNode::Value(phase);
743 }
744
745
746 // Simplify a CmpU (compare 2 integers) node, based on local information.
747 // If both inputs are constants, compare them.
748 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
749 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
750
751 // comparing two unsigned ints
752 const TypeInt *r0 = t1->is_int(); // Handy access
753 const TypeInt *r1 = t2->is_int();
754
755 // Current installed version
756 // Compare ranges for non-overlap
757 juint lo0 = r0->_lo;
758 juint hi0 = r0->_hi;
759 juint lo1 = r1->_lo;
760 juint hi1 = r1->_hi;
761
762 // If either one has both negative and positive values,
763 // it therefore contains both 0 and -1, and since [0..-1] is the
764 // full unsigned range, the type must act as an unsigned bottom.
765 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
766 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
767
768 if (bot0 || bot1) {
769 // All unsigned values are LE -1 and GE 0.
770 if (lo0 == 0 && hi0 == 0) {
771 return TypeInt::CC_LE; // 0 <= bot
772 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
773 return TypeInt::CC_GE; // -1 >= bot
774 } else if (lo1 == 0 && hi1 == 0) {
775 return TypeInt::CC_GE; // bot >= 0
776 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
777 return TypeInt::CC_LE; // bot <= -1
778 }
779 } else {
780 // We can use ranges of the form [lo..hi] if signs are the same.
781 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
782 // results are reversed, '-' > '+' for unsigned compare
783 if (hi0 < lo1) {
784 return TypeInt::CC_LT; // smaller
785 } else if (lo0 > hi1) {
786 return TypeInt::CC_GT; // greater
787 } else if (hi0 == lo1 && lo0 == hi1) {
788 return TypeInt::CC_EQ; // Equal results
789 } else if (lo0 >= hi1) {
790 return TypeInt::CC_GE;
791 } else if (hi0 <= lo1) {
792 // Check for special case in Hashtable::get. (See below.)
793 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
794 return TypeInt::CC_LT;
795 return TypeInt::CC_LE;
796 }
797 }
798 // Check for special case in Hashtable::get - the hash index is
799 // mod'ed to the table size so the following range check is useless.
800 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
801 // to be positive.
802 // (This is a gross hack, since the sub method never
803 // looks at the structure of the node in any other case.)
804 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
805 return TypeInt::CC_LT;
806
807 const Type* joined = r0->join(r1);
808 if (joined == Type::TOP) {
809 return TypeInt::CC_NE;
810 }
811
812 return TypeInt::CC; // else use worst case results
813 }
814
815 const Type* CmpUNode::Value(PhaseGVN* phase) const {
816 const Type* t = SubNode::Value_common(phase);
817 if (t != nullptr) {
818 return t;
819 }
820 const Node* in1 = in(1);
821 const Node* in2 = in(2);
822 const Type* t1 = phase->type(in1);
823 const Type* t2 = phase->type(in2);
824 assert(t1->isa_int(), "CmpU has only Int type inputs");
825 if (t2 == TypeInt::INT) { // Compare to bottom?
826 return bottom_type();
827 }
828
829 const Type* t_sub = sub(t1, t2); // compare based on immediate inputs
830
831 uint in1_op = in1->Opcode();
832 if (in1_op == Op_AddI || in1_op == Op_SubI) {
833 // The problem rise when result of AddI(SubI) may overflow
834 // signed integer value. Let say the input type is
835 // [256, maxint] then +128 will create 2 ranges due to
836 // overflow: [minint, minint+127] and [384, maxint].
837 // But C2 type system keep only 1 type range and as result
838 // it use general [minint, maxint] for this case which we
839 // can't optimize.
840 //
841 // Make 2 separate type ranges based on types of AddI(SubI) inputs
842 // and compare results of their compare. If results are the same
843 // CmpU node can be optimized.
844 const Node* in11 = in1->in(1);
845 const Node* in12 = in1->in(2);
846 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
847 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
848 // Skip cases when input types are top or bottom.
849 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
850 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
851 const TypeInt *r0 = t11->is_int();
852 const TypeInt *r1 = t12->is_int();
853 jlong lo_r0 = r0->_lo;
854 jlong hi_r0 = r0->_hi;
855 jlong lo_r1 = r1->_lo;
856 jlong hi_r1 = r1->_hi;
857 if (in1_op == Op_SubI) {
858 jlong tmp = hi_r1;
859 hi_r1 = -lo_r1;
860 lo_r1 = -tmp;
861 // Note, for substructing [minint,x] type range
862 // long arithmetic provides correct overflow answer.
863 // The confusion come from the fact that in 32-bit
864 // -minint == minint but in 64-bit -minint == maxint+1.
865 }
866 jlong lo_long = lo_r0 + lo_r1;
867 jlong hi_long = hi_r0 + hi_r1;
868 int lo_tr1 = min_jint;
869 int hi_tr1 = (int)hi_long;
870 int lo_tr2 = (int)lo_long;
871 int hi_tr2 = max_jint;
872 bool underflow = lo_long != (jlong)lo_tr2;
873 bool overflow = hi_long != (jlong)hi_tr1;
874 // Use sub(t1, t2) when there is no overflow (one type range)
875 // or when both overflow and underflow (too complex).
876 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
877 // Overflow only on one boundary, compare 2 separate type ranges.
878 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
879 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
880 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
881 const TypeInt* cmp1 = sub(tr1, t2)->is_int();
882 const TypeInt* cmp2 = sub(tr2, t2)->is_int();
883 // Compute union, so that cmp handles all possible results from the two cases
884 const Type* t_cmp = cmp1->meet(cmp2);
885 // Pick narrowest type, based on overflow computation and on immediate inputs
886 return t_sub->filter(t_cmp);
887 }
888 }
889 }
890
891 return t_sub;
892 }
893
894 bool CmpUNode::is_index_range_check() const {
895 // Check for the "(X ModI Y) CmpU Y" shape
896 return (in(1)->Opcode() == Op_ModI &&
897 in(1)->in(2)->eqv_uncast(in(2)));
898 }
899
900 //------------------------------Idealize---------------------------------------
901 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
902 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
903 switch (in(1)->Opcode()) {
904 case Op_CmpU3: // Collapse a CmpU3/CmpI into a CmpU
905 return new CmpUNode(in(1)->in(1),in(1)->in(2));
906 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
907 return new CmpLNode(in(1)->in(1),in(1)->in(2));
908 case Op_CmpUL3: // Collapse a CmpUL3/CmpI into a CmpUL
909 return new CmpULNode(in(1)->in(1),in(1)->in(2));
910 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
911 return new CmpFNode(in(1)->in(1),in(1)->in(2));
912 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
913 return new CmpDNode(in(1)->in(1),in(1)->in(2));
914 //case Op_SubI:
915 // If (x - y) cannot overflow, then ((x - y) <?> 0)
916 // can be turned into (x <?> y).
917 // This is handled (with more general cases) by Ideal_sub_algebra.
918 }
919 }
920 return nullptr; // No change
921 }
922
923 Node *CmpLNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
924 const TypeLong *t2 = phase->type(in(2))->isa_long();
925 if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) {
926 const jlong con = t2->get_con();
927 if (con >= min_jint && con <= max_jint) {
928 return new CmpINode(in(1)->in(1), phase->intcon((jint)con));
929 }
930 }
931 return nullptr;
932 }
933
934 //=============================================================================
935 // Simplify a CmpL (compare 2 longs ) node, based on local information.
936 // If both inputs are constants, compare them.
937 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
938 const TypeLong *r0 = t1->is_long(); // Handy access
939 const TypeLong *r1 = t2->is_long();
940
941 if( r0->_hi < r1->_lo ) // Range is always low?
942 return TypeInt::CC_LT;
943 else if( r0->_lo > r1->_hi ) // Range is always high?
944 return TypeInt::CC_GT;
945
946 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
947 assert(r0->get_con() == r1->get_con(), "must be equal");
948 return TypeInt::CC_EQ; // Equal results.
949 } else if( r0->_hi == r1->_lo ) // Range is never high?
950 return TypeInt::CC_LE;
951 else if( r0->_lo == r1->_hi ) // Range is never low?
952 return TypeInt::CC_GE;
953
954 const Type* joined = r0->join(r1);
955 if (joined == Type::TOP) {
956 return TypeInt::CC_NE;
957 }
958
959 return TypeInt::CC; // else use worst case results
960 }
961
962
963 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
964 // If both inputs are constants, compare them.
965 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
966 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
967
968 // comparing two unsigned longs
969 const TypeLong* r0 = t1->is_long(); // Handy access
970 const TypeLong* r1 = t2->is_long();
971
972 // Current installed version
973 // Compare ranges for non-overlap
974 julong lo0 = r0->_lo;
975 julong hi0 = r0->_hi;
976 julong lo1 = r1->_lo;
977 julong hi1 = r1->_hi;
978
979 // If either one has both negative and positive values,
980 // it therefore contains both 0 and -1, and since [0..-1] is the
981 // full unsigned range, the type must act as an unsigned bottom.
982 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
983 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
984
985 if (bot0 || bot1) {
986 // All unsigned values are LE -1 and GE 0.
987 if (lo0 == 0 && hi0 == 0) {
988 return TypeInt::CC_LE; // 0 <= bot
989 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
990 return TypeInt::CC_GE; // -1 >= bot
991 } else if (lo1 == 0 && hi1 == 0) {
992 return TypeInt::CC_GE; // bot >= 0
993 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
994 return TypeInt::CC_LE; // bot <= -1
995 }
996 } else {
997 // We can use ranges of the form [lo..hi] if signs are the same.
998 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
999 // results are reversed, '-' > '+' for unsigned compare
1000 if (hi0 < lo1) {
1001 return TypeInt::CC_LT; // smaller
1002 } else if (lo0 > hi1) {
1003 return TypeInt::CC_GT; // greater
1004 } else if (hi0 == lo1 && lo0 == hi1) {
1005 return TypeInt::CC_EQ; // Equal results
1006 } else if (lo0 >= hi1) {
1007 return TypeInt::CC_GE;
1008 } else if (hi0 <= lo1) {
1009 return TypeInt::CC_LE;
1010 }
1011 }
1012
1013 const Type* joined = r0->join(r1);
1014 if (joined == Type::TOP) {
1015 return TypeInt::CC_NE;
1016 }
1017
1018 return TypeInt::CC; // else use worst case results
1019 }
1020
1021 //=============================================================================
1022 //------------------------------sub--------------------------------------------
1023 // Simplify an CmpP (compare 2 pointers) node, based on local information.
1024 // If both inputs are constants, compare them.
1025 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
1026 const TypePtr *r0 = t1->is_ptr(); // Handy access
1027 const TypePtr *r1 = t2->is_ptr();
1028
1029 // Undefined inputs makes for an undefined result
1030 if( TypePtr::above_centerline(r0->_ptr) ||
1031 TypePtr::above_centerline(r1->_ptr) )
1032 return Type::TOP;
1033
1034 if (r0 == r1 && r0->singleton()) {
1035 // Equal pointer constants (klasses, nulls, etc.)
1036 return TypeInt::CC_EQ;
1037 }
1038
1039 // See if it is 2 unrelated classes.
1040 const TypeOopPtr* p0 = r0->isa_oopptr();
1041 const TypeOopPtr* p1 = r1->isa_oopptr();
1042 const TypeKlassPtr* k0 = r0->isa_klassptr();
1043 const TypeKlassPtr* k1 = r1->isa_klassptr();
1044 if ((p0 && p1) || (k0 && k1)) {
1045 if (p0 && p1) {
1046 Node* in1 = in(1)->uncast();
1047 Node* in2 = in(2)->uncast();
1048 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1);
1049 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2);
1050 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, nullptr)) {
1051 return TypeInt::CC_GT; // different pointers
1052 }
1053 }
1054 bool xklass0 = p0 ? p0->klass_is_exact() : k0->klass_is_exact();
1055 bool xklass1 = p1 ? p1->klass_is_exact() : k1->klass_is_exact();
1056 bool unrelated_classes = false;
1057
1058 if ((p0 && p0->is_same_java_type_as(p1)) ||
1059 (k0 && k0->is_same_java_type_as(k1))) {
1060 } else if ((p0 && !p1->maybe_java_subtype_of(p0) && !p0->maybe_java_subtype_of(p1)) ||
1061 (k0 && !k1->maybe_java_subtype_of(k0) && !k0->maybe_java_subtype_of(k1))) {
1062 unrelated_classes = true;
1063 } else if ((p0 && !p1->maybe_java_subtype_of(p0)) ||
1064 (k0 && !k1->maybe_java_subtype_of(k0))) {
1065 unrelated_classes = xklass1;
1066 } else if ((p0 && !p0->maybe_java_subtype_of(p1)) ||
1067 (k0 && !k0->maybe_java_subtype_of(k1))) {
1068 unrelated_classes = xklass0;
1069 }
1070
1071 if (unrelated_classes) {
1072 // The oops classes are known to be unrelated. If the joined PTRs of
1073 // two oops is not Null and not Bottom, then we are sure that one
1074 // of the two oops is non-null, and the comparison will always fail.
1075 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1076 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1077 return TypeInt::CC_GT;
1078 }
1079 }
1080 }
1081
1082 // Known constants can be compared exactly
1083 // Null can be distinguished from any NotNull pointers
1084 // Unknown inputs makes an unknown result
1085 if( r0->singleton() ) {
1086 intptr_t bits0 = r0->get_con();
1087 if( r1->singleton() )
1088 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1089 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1090 } else if( r1->singleton() ) {
1091 intptr_t bits1 = r1->get_con();
1092 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1093 } else
1094 return TypeInt::CC;
1095 }
1096
1097 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1098 // Return the klass node for (indirect load from OopHandle)
1099 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1100 // or null if not matching.
1101 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1102 n = bs->step_over_gc_barrier(n);
1103
1104 if (n->Opcode() != Op_LoadP) return nullptr;
1105
1106 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1107 if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr;
1108
1109 Node* adr = n->in(MemNode::Address);
1110 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1111 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr;
1112 adr = adr->in(MemNode::Address);
1113
1114 intptr_t off = 0;
1115 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1116 if (k == nullptr) return nullptr;
1117 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1118 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr;
1119
1120 // We've found the klass node of a Java mirror load.
1121 return k;
1122 }
1123
1124 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
1125 // for ConP(Foo.class) return ConP(Foo.klass)
1126 // otherwise return null
1127 if (!n->is_Con()) return nullptr;
1128
1129 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1130 if (!tp) return nullptr;
1131
1132 ciType* mirror_type = tp->java_mirror_type();
1133 // TypeInstPtr::java_mirror_type() returns non-null for compile-
1134 // time Class constants only.
1135 if (!mirror_type) return nullptr;
1136
1137 // x.getClass() == int.class can never be true (for all primitive types)
1138 // Return a ConP(null) node for this case.
1139 if (mirror_type->is_classless()) {
1140 return phase->makecon(TypePtr::NULL_PTR);
1141 }
1142
1143 // return the ConP(Foo.klass)
1144 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
1145 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass(), Type::trust_interfaces));
1146 }
1147
1148 //------------------------------Ideal------------------------------------------
1149 // Normalize comparisons between Java mirror loads to compare the klass instead.
1150 //
1151 // Also check for the case of comparing an unknown klass loaded from the primary
1152 // super-type array vs a known klass with no subtypes. This amounts to
1153 // checking to see an unknown klass subtypes a known klass with no subtypes;
1154 // this only happens on an exact match. We can shorten this test by 1 load.
1155 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1156 // Normalize comparisons between Java mirrors into comparisons of the low-
1157 // level klass, where a dependent load could be shortened.
1158 //
1159 // The new pattern has a nice effect of matching the same pattern used in the
1160 // fast path of instanceof/checkcast/Class.isInstance(), which allows
1161 // redundant exact type check be optimized away by GVN.
1162 // For example, in
1163 // if (x.getClass() == Foo.class) {
1164 // Foo foo = (Foo) x;
1165 // // ... use a ...
1166 // }
1167 // a CmpPNode could be shared between if_acmpne and checkcast
1168 {
1169 Node* k1 = isa_java_mirror_load(phase, in(1));
1170 Node* k2 = isa_java_mirror_load(phase, in(2));
1171 Node* conk2 = isa_const_java_mirror(phase, in(2));
1172
1173 if (k1 && (k2 || conk2)) {
1174 Node* lhs = k1;
1175 Node* rhs = (k2 != nullptr) ? k2 : conk2;
1176 set_req_X(1, lhs, phase);
1177 set_req_X(2, rhs, phase);
1178 return this;
1179 }
1180 }
1181
1182 // Constant pointer on right?
1183 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1184 if (t2 == nullptr || !t2->klass_is_exact())
1185 return nullptr;
1186 // Get the constant klass we are comparing to.
1187 ciKlass* superklass = t2->exact_klass();
1188
1189 // Now check for LoadKlass on left.
1190 Node* ldk1 = in(1);
1191 if (ldk1->is_DecodeNKlass()) {
1192 ldk1 = ldk1->in(1);
1193 if (ldk1->Opcode() != Op_LoadNKlass )
1194 return nullptr;
1195 } else if (ldk1->Opcode() != Op_LoadKlass )
1196 return nullptr;
1197 // Take apart the address of the LoadKlass:
1198 Node* adr1 = ldk1->in(MemNode::Address);
1199 intptr_t con2 = 0;
1200 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1201 if (ldk2 == nullptr)
1202 return nullptr;
1203 if (con2 == oopDesc::klass_offset_in_bytes()) {
1204 // We are inspecting an object's concrete class.
1205 // Short-circuit the check if the query is abstract.
1206 if (superklass->is_interface() ||
1207 superklass->is_abstract()) {
1208 // Make it come out always false:
1209 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1210 return this;
1211 }
1212 }
1213
1214 // Check for a LoadKlass from primary supertype array.
1215 // Any nested loadklass from loadklass+con must be from the p.s. array.
1216 if (ldk2->is_DecodeNKlass()) {
1217 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1218 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1219 return nullptr;
1220 } else if (ldk2->Opcode() != Op_LoadKlass)
1221 return nullptr;
1222
1223 // Verify that we understand the situation
1224 if (con2 != (intptr_t) superklass->super_check_offset())
1225 return nullptr; // Might be element-klass loading from array klass
1226
1227 // If 'superklass' has no subklasses and is not an interface, then we are
1228 // assured that the only input which will pass the type check is
1229 // 'superklass' itself.
1230 //
1231 // We could be more liberal here, and allow the optimization on interfaces
1232 // which have a single implementor. This would require us to increase the
1233 // expressiveness of the add_dependency() mechanism.
1234 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1235
1236 // Object arrays must have their base element have no subtypes
1237 while (superklass->is_obj_array_klass()) {
1238 ciType* elem = superklass->as_obj_array_klass()->element_type();
1239 superklass = elem->as_klass();
1240 }
1241 if (superklass->is_instance_klass()) {
1242 ciInstanceKlass* ik = superklass->as_instance_klass();
1243 if (ik->has_subklass() || ik->is_interface()) return nullptr;
1244 // Add a dependency if there is a chance that a subclass will be added later.
1245 if (!ik->is_final()) {
1246 phase->C->dependencies()->assert_leaf_type(ik);
1247 }
1248 }
1249
1250 // Bypass the dependent load, and compare directly
1251 this->set_req_X(1, ldk2, phase);
1252
1253 return this;
1254 }
1255
1256 //=============================================================================
1257 //------------------------------sub--------------------------------------------
1258 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1259 // If both inputs are constants, compare them.
1260 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1261 ShouldNotReachHere();
1262 return bottom_type();
1263 }
1264
1265 //------------------------------Ideal------------------------------------------
1266 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1267 return nullptr;
1268 }
1269
1270 //=============================================================================
1271 //------------------------------Value------------------------------------------
1272 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1273 // If both inputs are constants, compare them.
1274 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1275 const Node* in1 = in(1);
1276 const Node* in2 = in(2);
1277 // Either input is TOP ==> the result is TOP
1278 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1279 if( t1 == Type::TOP ) return Type::TOP;
1280 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1281 if( t2 == Type::TOP ) return Type::TOP;
1282
1283 // Not constants? Don't know squat - even if they are the same
1284 // value! If they are NaN's they compare to LT instead of EQ.
1285 const TypeF *tf1 = t1->isa_float_constant();
1286 const TypeF *tf2 = t2->isa_float_constant();
1287 if( !tf1 || !tf2 ) return TypeInt::CC;
1288
1289 // This implements the Java bytecode fcmpl, so unordered returns -1.
1290 if( tf1->is_nan() || tf2->is_nan() )
1291 return TypeInt::CC_LT;
1292
1293 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1294 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1295 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1296 return TypeInt::CC_EQ;
1297 }
1298
1299
1300 //=============================================================================
1301 //------------------------------Value------------------------------------------
1302 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1303 // If both inputs are constants, compare them.
1304 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1305 const Node* in1 = in(1);
1306 const Node* in2 = in(2);
1307 // Either input is TOP ==> the result is TOP
1308 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1309 if( t1 == Type::TOP ) return Type::TOP;
1310 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1311 if( t2 == Type::TOP ) return Type::TOP;
1312
1313 // Not constants? Don't know squat - even if they are the same
1314 // value! If they are NaN's they compare to LT instead of EQ.
1315 const TypeD *td1 = t1->isa_double_constant();
1316 const TypeD *td2 = t2->isa_double_constant();
1317 if( !td1 || !td2 ) return TypeInt::CC;
1318
1319 // This implements the Java bytecode dcmpl, so unordered returns -1.
1320 if( td1->is_nan() || td2->is_nan() )
1321 return TypeInt::CC_LT;
1322
1323 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1324 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1325 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1326 return TypeInt::CC_EQ;
1327 }
1328
1329 //------------------------------Ideal------------------------------------------
1330 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1331 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1332 // Change (CMPD (F2D (float)) (ConD value))
1333 // To (CMPF (float) (ConF value))
1334 // Valid when 'value' does not lose precision as a float.
1335 // Benefits: eliminates conversion, does not require 24-bit mode
1336
1337 // NaNs prevent commuting operands. This transform works regardless of the
1338 // order of ConD and ConvF2D inputs by preserving the original order.
1339 int idx_f2d = 1; // ConvF2D on left side?
1340 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1341 idx_f2d = 2; // No, swap to check for reversed args
1342 int idx_con = 3-idx_f2d; // Check for the constant on other input
1343
1344 if( ConvertCmpD2CmpF &&
1345 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1346 in(idx_con)->Opcode() == Op_ConD ) {
1347 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1348 double t2_value_as_double = t2->_d;
1349 float t2_value_as_float = (float)t2_value_as_double;
1350 if( t2_value_as_double == (double)t2_value_as_float ) {
1351 // Test value can be represented as a float
1352 // Eliminate the conversion to double and create new comparison
1353 Node *new_in1 = in(idx_f2d)->in(1);
1354 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1355 if( idx_f2d != 1 ) { // Must flip args to match original order
1356 Node *tmp = new_in1;
1357 new_in1 = new_in2;
1358 new_in2 = tmp;
1359 }
1360 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1361 ? new CmpF3Node( new_in1, new_in2 )
1362 : new CmpFNode ( new_in1, new_in2 ) ;
1363 return new_cmp; // Changed to CmpFNode
1364 }
1365 // Testing value required the precision of a double
1366 }
1367 return nullptr; // No change
1368 }
1369
1370
1371 //=============================================================================
1372 //------------------------------cc2logical-------------------------------------
1373 // Convert a condition code type to a logical type
1374 const Type *BoolTest::cc2logical( const Type *CC ) const {
1375 if( CC == Type::TOP ) return Type::TOP;
1376 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1377 const TypeInt *ti = CC->is_int();
1378 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1379 // Match low order 2 bits
1380 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1381 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1382 return TypeInt::make(tmp); // Boolean result
1383 }
1384
1385 if( CC == TypeInt::CC_GE ) {
1386 if( _test == ge ) return TypeInt::ONE;
1387 if( _test == lt ) return TypeInt::ZERO;
1388 }
1389 if( CC == TypeInt::CC_LE ) {
1390 if( _test == le ) return TypeInt::ONE;
1391 if( _test == gt ) return TypeInt::ZERO;
1392 }
1393 if( CC == TypeInt::CC_NE ) {
1394 if( _test == ne ) return TypeInt::ONE;
1395 if( _test == eq ) return TypeInt::ZERO;
1396 }
1397
1398 return TypeInt::BOOL;
1399 }
1400
1401 BoolTest::mask BoolTest::unsigned_mask(BoolTest::mask btm) {
1402 switch(btm) {
1403 case eq:
1404 case ne:
1405 return btm;
1406 case lt:
1407 case le:
1408 case gt:
1409 case ge:
1410 return mask(btm | unsigned_compare);
1411 default:
1412 ShouldNotReachHere();
1413 }
1414 }
1415
1416 //------------------------------dump_spec-------------------------------------
1417 // Print special per-node info
1418 void BoolTest::dump_on(outputStream *st) const {
1419 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1420 st->print("%s", msg[_test]);
1421 }
1422
1423 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1424 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1425 BoolTest::mask BoolTest::merge(BoolTest other) const {
1426 const mask res[illegal+1][illegal+1] = {
1427 // eq, gt, of, lt, ne, le, nof, ge, never, illegal
1428 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq
1429 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt
1430 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of
1431 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt
1432 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne
1433 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le
1434 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof
1435 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge
1436 {never, never, never, never, never, never, never, never, never, illegal}, // never
1437 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1438 return res[_test][other._test];
1439 }
1440
1441 //=============================================================================
1442 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1443 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1444
1445 //------------------------------operator==-------------------------------------
1446 bool BoolNode::cmp( const Node &n ) const {
1447 const BoolNode *b = (const BoolNode *)&n; // Cast up
1448 return (_test._test == b->_test._test);
1449 }
1450
1451 //-------------------------------make_predicate--------------------------------
1452 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1453 if (test_value->is_Con()) return test_value;
1454 if (test_value->is_Bool()) return test_value;
1455 if (test_value->is_CMove() &&
1456 test_value->in(CMoveNode::Condition)->is_Bool()) {
1457 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1458 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1459 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1460 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1461 return bol;
1462 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1463 return phase->transform( bol->negate(phase) );
1464 }
1465 // Else fall through. The CMove gets in the way of the test.
1466 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1467 }
1468 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1469 cmp = phase->transform(cmp);
1470 Node* bol = new BoolNode(cmp, BoolTest::ne);
1471 return phase->transform(bol);
1472 }
1473
1474 //--------------------------------as_int_value---------------------------------
1475 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1476 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1477 Node* cmov = CMoveNode::make(this, phase->intcon(0), phase->intcon(1), TypeInt::BOOL);
1478 return phase->transform(cmov);
1479 }
1480
1481 //----------------------------------negate-------------------------------------
1482 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1483 return new BoolNode(in(1), _test.negate());
1484 }
1485
1486 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1487 // overflows and we can prove that C is not in the two resulting ranges.
1488 // This optimization is similar to the one performed by CmpUNode::Value().
1489 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1490 int cmp1_op, const TypeInt* cmp2_type) {
1491 // Only optimize eq/ne integer comparison of add/sub
1492 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1493 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1494 // Skip cases were inputs of add/sub are not integers or of bottom type
1495 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1496 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1497 if ((r0 != nullptr) && (r0 != TypeInt::INT) &&
1498 (r1 != nullptr) && (r1 != TypeInt::INT) &&
1499 (cmp2_type != TypeInt::INT)) {
1500 // Compute exact (long) type range of add/sub result
1501 jlong lo_long = r0->_lo;
1502 jlong hi_long = r0->_hi;
1503 if (cmp1_op == Op_AddI) {
1504 lo_long += r1->_lo;
1505 hi_long += r1->_hi;
1506 } else {
1507 lo_long -= r1->_hi;
1508 hi_long -= r1->_lo;
1509 }
1510 // Check for over-/underflow by casting to integer
1511 int lo_int = (int)lo_long;
1512 int hi_int = (int)hi_long;
1513 bool underflow = lo_long != (jlong)lo_int;
1514 bool overflow = hi_long != (jlong)hi_int;
1515 if ((underflow != overflow) && (hi_int < lo_int)) {
1516 // Overflow on one boundary, compute resulting type ranges:
1517 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1518 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1519 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1520 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1521 // Compare second input of cmp to both type ranges
1522 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1523 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1524 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1525 // The result of the add/sub will never equal cmp2. Replace BoolNode
1526 // by false (0) if it tests for equality and by true (1) otherwise.
1527 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1528 }
1529 }
1530 }
1531 }
1532 return nullptr;
1533 }
1534
1535 static bool is_counted_loop_cmp(Node *cmp) {
1536 Node *n = cmp->in(1)->in(1);
1537 return n != nullptr &&
1538 n->is_Phi() &&
1539 n->in(0) != nullptr &&
1540 n->in(0)->is_CountedLoop() &&
1541 n->in(0)->as_CountedLoop()->phi() == n;
1542 }
1543
1544 //------------------------------Ideal------------------------------------------
1545 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1546 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1547 // This moves the constant to the right. Helps value-numbering.
1548 Node *cmp = in(1);
1549 if( !cmp->is_Sub() ) return nullptr;
1550 int cop = cmp->Opcode();
1551 if( cop == Op_FastLock || cop == Op_FastUnlock ||
1552 cmp->is_SubTypeCheck() || cop == Op_VectorTest ) {
1553 return nullptr;
1554 }
1555 Node *cmp1 = cmp->in(1);
1556 Node *cmp2 = cmp->in(2);
1557 if( !cmp1 ) return nullptr;
1558
1559 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1560 return nullptr;
1561 }
1562
1563 const int cmp1_op = cmp1->Opcode();
1564 const int cmp2_op = cmp2->Opcode();
1565
1566 // Constant on left?
1567 Node *con = cmp1;
1568 // Move constants to the right of compare's to canonicalize.
1569 // Do not muck with Opaque1 nodes, as this indicates a loop
1570 // guard that cannot change shape.
1571 if (con->is_Con() && !cmp2->is_Con() && cmp2_op != Op_OpaqueZeroTripGuard &&
1572 // Because of NaN's, CmpD and CmpF are not commutative
1573 cop != Op_CmpD && cop != Op_CmpF &&
1574 // Protect against swapping inputs to a compare when it is used by a
1575 // counted loop exit, which requires maintaining the loop-limit as in(2)
1576 !is_counted_loop_exit_test() ) {
1577 // Ok, commute the constant to the right of the cmp node.
1578 // Clone the Node, getting a new Node of the same class
1579 cmp = cmp->clone();
1580 // Swap inputs to the clone
1581 cmp->swap_edges(1, 2);
1582 cmp = phase->transform( cmp );
1583 return new BoolNode( cmp, _test.commute() );
1584 }
1585
1586 // Change "bool eq/ne (cmp (cmove (bool tst (cmp2)) 1 0) 0)" into "bool tst/~tst (cmp2)"
1587 if (cop == Op_CmpI &&
1588 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1589 cmp1_op == Op_CMoveI && cmp2->find_int_con(1) == 0) {
1590 // 0 should be on the true branch
1591 if (cmp1->in(CMoveNode::Condition)->is_Bool() &&
1592 cmp1->in(CMoveNode::IfTrue)->find_int_con(1) == 0 &&
1593 cmp1->in(CMoveNode::IfFalse)->find_int_con(0) != 0) {
1594 BoolNode* target = cmp1->in(CMoveNode::Condition)->as_Bool();
1595 return new BoolNode(target->in(1),
1596 (_test._test == BoolTest::eq) ? target->_test._test :
1597 target->_test.negate());
1598 }
1599 }
1600
1601 // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1602 if (cop == Op_CmpI &&
1603 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1604 cmp1_op == Op_AndI && cmp2_op == Op_ConI &&
1605 cmp1->in(2)->Opcode() == Op_ConI) {
1606 const TypeInt *t12 = phase->type(cmp2)->isa_int();
1607 const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int();
1608 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1609 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1610 Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1611 return new BoolNode(ncmp, _test.negate());
1612 }
1613 }
1614
1615 // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1616 if (cop == Op_CmpL &&
1617 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1618 cmp1_op == Op_AndL && cmp2_op == Op_ConL &&
1619 cmp1->in(2)->Opcode() == Op_ConL) {
1620 const TypeLong *t12 = phase->type(cmp2)->isa_long();
1621 const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long();
1622 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1623 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1624 Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0)));
1625 return new BoolNode(ncmp, _test.negate());
1626 }
1627 }
1628
1629 // Change "cmp (add X min_jint) (add Y min_jint)" into "cmpu X Y"
1630 // and "cmp (add X min_jint) c" into "cmpu X (c + min_jint)"
1631 if (cop == Op_CmpI &&
1632 cmp1_op == Op_AddI &&
1633 phase->type(cmp1->in(2)) == TypeInt::MIN &&
1634 !is_cloop_condition(this)) {
1635 if (cmp2_op == Op_ConI) {
1636 Node* ncmp2 = phase->intcon(java_add(cmp2->get_int(), min_jint));
1637 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), ncmp2));
1638 return new BoolNode(ncmp, _test._test);
1639 } else if (cmp2_op == Op_AddI &&
1640 phase->type(cmp2->in(2)) == TypeInt::MIN &&
1641 !is_cloop_condition(this)) {
1642 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), cmp2->in(1)));
1643 return new BoolNode(ncmp, _test._test);
1644 }
1645 }
1646
1647 // Change "cmp (add X min_jlong) (add Y min_jlong)" into "cmpu X Y"
1648 // and "cmp (add X min_jlong) c" into "cmpu X (c + min_jlong)"
1649 if (cop == Op_CmpL &&
1650 cmp1_op == Op_AddL &&
1651 phase->type(cmp1->in(2)) == TypeLong::MIN &&
1652 !is_cloop_condition(this)) {
1653 if (cmp2_op == Op_ConL) {
1654 Node* ncmp2 = phase->longcon(java_add(cmp2->get_long(), min_jlong));
1655 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), ncmp2));
1656 return new BoolNode(ncmp, _test._test);
1657 } else if (cmp2_op == Op_AddL &&
1658 phase->type(cmp2->in(2)) == TypeLong::MIN &&
1659 !is_cloop_condition(this)) {
1660 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), cmp2->in(1)));
1661 return new BoolNode(ncmp, _test._test);
1662 }
1663 }
1664
1665 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1666 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1667 // test instead.
1668 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1669 if (cmp2_type == nullptr) return nullptr;
1670 Node* j_xor = cmp1;
1671 if( cmp2_type == TypeInt::ZERO &&
1672 cmp1_op == Op_XorI &&
1673 j_xor->in(1) != j_xor && // An xor of itself is dead
1674 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1675 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1676 (_test._test == BoolTest::eq ||
1677 _test._test == BoolTest::ne) ) {
1678 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1679 return new BoolNode( ncmp, _test.negate() );
1680 }
1681
1682 // Transform: "((x & (m - 1)) <u m)" or "(((m - 1) & x) <u m)" into "(m >u 0)"
1683 // This is case [CMPU_MASK] which is further described at the method comment of BoolNode::Value_cmpu_and_mask().
1684 if (cop == Op_CmpU && _test._test == BoolTest::lt && cmp1_op == Op_AndI) {
1685 Node* m = cmp2; // RHS: m
1686 for (int add_idx = 1; add_idx <= 2; add_idx++) { // LHS: "(m + (-1)) & x" or "x & (m + (-1))"?
1687 Node* maybe_m_minus_1 = cmp1->in(add_idx);
1688 if (maybe_m_minus_1->Opcode() == Op_AddI &&
1689 maybe_m_minus_1->in(2)->find_int_con(0) == -1 &&
1690 maybe_m_minus_1->in(1) == m) {
1691 Node* m_cmpu_0 = phase->transform(new CmpUNode(m, phase->intcon(0)));
1692 return new BoolNode(m_cmpu_0, BoolTest::gt);
1693 }
1694 }
1695 }
1696
1697 // Change x u< 1 or x u<= 0 to x == 0
1698 // and x u> 0 or u>= 1 to x != 0
1699 if (cop == Op_CmpU &&
1700 cmp1_op != Op_LoadRange &&
1701 (((_test._test == BoolTest::lt || _test._test == BoolTest::ge) &&
1702 cmp2->find_int_con(-1) == 1) ||
1703 ((_test._test == BoolTest::le || _test._test == BoolTest::gt) &&
1704 cmp2->find_int_con(-1) == 0))) {
1705 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1706 return new BoolNode(ncmp, _test.is_less() ? BoolTest::eq : BoolTest::ne);
1707 }
1708
1709 // Change (arraylength <= 0) or (arraylength == 0)
1710 // into (arraylength u<= 0)
1711 // Also change (arraylength != 0) into (arraylength u> 0)
1712 // The latter version matches the code pattern generated for
1713 // array range checks, which will more likely be optimized later.
1714 if (cop == Op_CmpI &&
1715 cmp1_op == Op_LoadRange &&
1716 cmp2->find_int_con(-1) == 0) {
1717 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1718 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1719 return new BoolNode(ncmp, BoolTest::le);
1720 } else if (_test._test == BoolTest::ne) {
1721 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1722 return new BoolNode(ncmp, BoolTest::gt);
1723 }
1724 }
1725
1726 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1727 // This is a standard idiom for branching on a boolean value.
1728 Node *c2b = cmp1;
1729 if( cmp2_type == TypeInt::ZERO &&
1730 cmp1_op == Op_Conv2B &&
1731 (_test._test == BoolTest::eq ||
1732 _test._test == BoolTest::ne) ) {
1733 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1734 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1735 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1736 );
1737 return new BoolNode( ncmp, _test._test );
1738 }
1739
1740 // Comparing a SubI against a zero is equal to comparing the SubI
1741 // arguments directly. This only works for eq and ne comparisons
1742 // due to possible integer overflow.
1743 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1744 (cop == Op_CmpI) &&
1745 (cmp1_op == Op_SubI) &&
1746 ( cmp2_type == TypeInt::ZERO ) ) {
1747 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1748 return new BoolNode( ncmp, _test._test );
1749 }
1750
1751 // Same as above but with and AddI of a constant
1752 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1753 cop == Op_CmpI &&
1754 cmp1_op == Op_AddI &&
1755 cmp1->in(2) != nullptr &&
1756 phase->type(cmp1->in(2))->isa_int() &&
1757 phase->type(cmp1->in(2))->is_int()->is_con() &&
1758 cmp2_type == TypeInt::ZERO &&
1759 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1760 ) {
1761 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1762 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1763 return new BoolNode( ncmp, _test._test );
1764 }
1765
1766 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1767 // since zero check of conditional negation of an integer is equal to
1768 // zero check of the integer directly.
1769 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1770 (cop == Op_CmpI) &&
1771 (cmp2_type == TypeInt::ZERO) &&
1772 (cmp1_op == Op_Phi)) {
1773 // There should be a diamond phi with true path at index 1 or 2
1774 PhiNode *phi = cmp1->as_Phi();
1775 int idx_true = phi->is_diamond_phi();
1776 if (idx_true != 0) {
1777 // True input is in(idx_true) while false input is in(3 - idx_true)
1778 Node *tin = phi->in(idx_true);
1779 Node *fin = phi->in(3 - idx_true);
1780 if ((tin->Opcode() == Op_SubI) &&
1781 (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1782 (tin->in(2) == fin)) {
1783 // Found conditional negation at true path, create a new CmpINode without that
1784 Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1785 return new BoolNode(ncmp, _test._test);
1786 }
1787 if ((fin->Opcode() == Op_SubI) &&
1788 (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1789 (fin->in(2) == tin)) {
1790 // Found conditional negation at false path, create a new CmpINode without that
1791 Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1792 return new BoolNode(ncmp, _test._test);
1793 }
1794 }
1795 }
1796
1797 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1798 // most general case because negating 0x80000000 does nothing. Needed for
1799 // the CmpF3/SubI/CmpI idiom.
1800 if( cop == Op_CmpI &&
1801 cmp1_op == Op_SubI &&
1802 cmp2_type == TypeInt::ZERO &&
1803 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1804 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1805 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1806 return new BoolNode( ncmp, _test.commute() );
1807 }
1808
1809 // Try to optimize signed integer comparison
1810 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1811
1812 // The transformation below is not valid for either signed or unsigned
1813 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1814 // This transformation can be resurrected when we are able to
1815 // make inferences about the range of values being subtracted from
1816 // (or added to) relative to the wraparound point.
1817 //
1818 // // Remove +/-1's if possible.
1819 // // "X <= Y-1" becomes "X < Y"
1820 // // "X+1 <= Y" becomes "X < Y"
1821 // // "X < Y+1" becomes "X <= Y"
1822 // // "X-1 < Y" becomes "X <= Y"
1823 // // Do not this to compares off of the counted-loop-end. These guys are
1824 // // checking the trip counter and they want to use the post-incremented
1825 // // counter. If they use the PRE-incremented counter, then the counter has
1826 // // to be incremented in a private block on a loop backedge.
1827 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1828 // return nullptr;
1829 // #ifndef PRODUCT
1830 // // Do not do this in a wash GVN pass during verification.
1831 // // Gets triggered by too many simple optimizations to be bothered with
1832 // // re-trying it again and again.
1833 // if( !phase->allow_progress() ) return nullptr;
1834 // #endif
1835 // // Not valid for unsigned compare because of corner cases in involving zero.
1836 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1837 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1838 // // "0 <=u Y" is always true).
1839 // if( cmp->Opcode() == Op_CmpU ) return nullptr;
1840 // int cmp2_op = cmp2->Opcode();
1841 // if( _test._test == BoolTest::le ) {
1842 // if( cmp1_op == Op_AddI &&
1843 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1844 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1845 // else if( cmp2_op == Op_AddI &&
1846 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1847 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1848 // } else if( _test._test == BoolTest::lt ) {
1849 // if( cmp1_op == Op_AddI &&
1850 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1851 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1852 // else if( cmp2_op == Op_AddI &&
1853 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1854 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1855 // }
1856 }
1857
1858 // We use the following Lemmas/insights for the following two transformations (1) and (2):
1859 // x & y <=u y, for any x and y (Lemma 1, masking always results in a smaller unsigned number)
1860 // y <u y + 1 is always true if y != -1 (Lemma 2, (uint)(-1 + 1) == (uint)(UINT_MAX + 1) which overflows)
1861 // y <u 0 is always false for any y (Lemma 3, 0 == UINT_MIN and nothing can be smaller than that)
1862 //
1863 // (1a) Always: Change ((x & m) <=u m ) or ((m & x) <=u m ) to always true (true by Lemma 1)
1864 // (1b) If m != -1: Change ((x & m) <u m + 1) or ((m & x) <u m + 1) to always true:
1865 // x & m <=u m is always true // (Lemma 1)
1866 // x & m <=u m <u m + 1 is always true // (Lemma 2: m <u m + 1, if m != -1)
1867 //
1868 // A counter example for (1b), if we allowed m == -1:
1869 // (x & m) <u m + 1
1870 // (x & -1) <u 0
1871 // x <u 0
1872 // which is false for any x (Lemma 3)
1873 //
1874 // (2) Change ((x & (m - 1)) <u m) or (((m - 1) & x) <u m) to (m >u 0)
1875 // This is the off-by-one variant of the above.
1876 //
1877 // We now prove that this replacement is correct. This is the same as proving
1878 // "m >u 0" if and only if "x & (m - 1) <u m", i.e. "m >u 0 <=> x & (m - 1) <u m"
1879 //
1880 // We use (Lemma 1) and (Lemma 3) from above.
1881 //
1882 // Case "x & (m - 1) <u m => m >u 0":
1883 // We prove this by contradiction:
1884 // Assume m <=u 0 which is equivalent to m == 0:
1885 // and thus
1886 // x & (m - 1) <u m = 0 // m == 0
1887 // y <u 0 // y = x & (m - 1)
1888 // by Lemma 3, this is always false, i.e. a contradiction to our assumption.
1889 //
1890 // Case "m >u 0 => x & (m - 1) <u m":
1891 // x & (m - 1) <=u (m - 1) // (Lemma 1)
1892 // x & (m - 1) <=u (m - 1) <u m // Using assumption m >u 0, no underflow of "m - 1"
1893 //
1894 //
1895 // Note that the signed version of "m > 0":
1896 // m > 0 <=> x & (m - 1) <u m
1897 // does not hold:
1898 // Assume m == -1 and x == -1:
1899 // x & (m - 1) <u m
1900 // -1 & -2 <u -1
1901 // -2 <u -1
1902 // UINT_MAX - 1 <u UINT_MAX // Signed to unsigned numbers
1903 // which is true while
1904 // m > 0
1905 // is false which is a contradiction.
1906 //
1907 // (1a) and (1b) is covered by this method since we can directly return a true value as type while (2) is covered
1908 // in BoolNode::Ideal since we create a new non-constant node (see [CMPU_MASK]).
1909 const Type* BoolNode::Value_cmpu_and_mask(PhaseValues* phase) const {
1910 Node* cmp = in(1);
1911 if (cmp != nullptr && cmp->Opcode() == Op_CmpU) {
1912 Node* cmp1 = cmp->in(1);
1913 Node* cmp2 = cmp->in(2);
1914
1915 if (cmp1->Opcode() == Op_AndI) {
1916 Node* m = nullptr;
1917 if (_test._test == BoolTest::le) {
1918 // (1a) "((x & m) <=u m)", cmp2 = m
1919 m = cmp2;
1920 } else if (_test._test == BoolTest::lt && cmp2->Opcode() == Op_AddI && cmp2->in(2)->find_int_con(0) == 1) {
1921 // (1b) "(x & m) <u m + 1" and "(m & x) <u m + 1", cmp2 = m + 1
1922 Node* rhs_m = cmp2->in(1);
1923 const TypeInt* rhs_m_type = phase->type(rhs_m)->isa_int();
1924 if (rhs_m_type != nullptr && (rhs_m_type->_lo > -1 || rhs_m_type->_hi < -1)) {
1925 // Exclude any case where m == -1 is possible.
1926 m = rhs_m;
1927 }
1928 }
1929
1930 if (cmp1->in(2) == m || cmp1->in(1) == m) {
1931 return TypeInt::ONE;
1932 }
1933 }
1934 }
1935
1936 return nullptr;
1937 }
1938
1939 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1940 // based on local information. If the input is constant, do it.
1941 const Type* BoolNode::Value(PhaseGVN* phase) const {
1942 const Type* input_type = phase->type(in(1));
1943 if (input_type == Type::TOP) {
1944 return Type::TOP;
1945 }
1946 const Type* t = Value_cmpu_and_mask(phase);
1947 if (t != nullptr) {
1948 return t;
1949 }
1950
1951 return _test.cc2logical(input_type);
1952 }
1953
1954 #ifndef PRODUCT
1955 //------------------------------dump_spec--------------------------------------
1956 // Dump special per-node info
1957 void BoolNode::dump_spec(outputStream *st) const {
1958 st->print("[");
1959 _test.dump_on(st);
1960 st->print("]");
1961 }
1962 #endif
1963
1964 //----------------------is_counted_loop_exit_test------------------------------
1965 // Returns true if node is used by a counted loop node.
1966 bool BoolNode::is_counted_loop_exit_test() {
1967 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1968 Node* use = fast_out(i);
1969 if (use->is_CountedLoopEnd()) {
1970 return true;
1971 }
1972 }
1973 return false;
1974 }
1975
1976 //=============================================================================
1977 //------------------------------Value------------------------------------------
1978 const Type* AbsNode::Value(PhaseGVN* phase) const {
1979 const Type* t1 = phase->type(in(1));
1980 if (t1 == Type::TOP) return Type::TOP;
1981
1982 switch (t1->base()) {
1983 case Type::Int: {
1984 const TypeInt* ti = t1->is_int();
1985 if (ti->is_con()) {
1986 return TypeInt::make(g_uabs(ti->get_con()));
1987 }
1988 break;
1989 }
1990 case Type::Long: {
1991 const TypeLong* tl = t1->is_long();
1992 if (tl->is_con()) {
1993 return TypeLong::make(g_uabs(tl->get_con()));
1994 }
1995 break;
1996 }
1997 case Type::FloatCon:
1998 return TypeF::make(abs(t1->getf()));
1999 case Type::DoubleCon:
2000 return TypeD::make(abs(t1->getd()));
2001 default:
2002 break;
2003 }
2004
2005 return bottom_type();
2006 }
2007
2008 //------------------------------Identity----------------------------------------
2009 Node* AbsNode::Identity(PhaseGVN* phase) {
2010 Node* in1 = in(1);
2011 // No need to do abs for non-negative values
2012 if (phase->type(in1)->higher_equal(TypeInt::POS) ||
2013 phase->type(in1)->higher_equal(TypeLong::POS)) {
2014 return in1;
2015 }
2016 // Convert "abs(abs(x))" into "abs(x)"
2017 if (in1->Opcode() == Opcode()) {
2018 return in1;
2019 }
2020 return this;
2021 }
2022
2023 //------------------------------Ideal------------------------------------------
2024 Node* AbsNode::Ideal(PhaseGVN* phase, bool can_reshape) {
2025 Node* in1 = in(1);
2026 // Convert "abs(0-x)" into "abs(x)"
2027 if (in1->is_Sub() && phase->type(in1->in(1))->is_zero_type()) {
2028 set_req_X(1, in1->in(2), phase);
2029 return this;
2030 }
2031 return nullptr;
2032 }
2033
2034 //=============================================================================
2035 //------------------------------Value------------------------------------------
2036 // Compute sqrt
2037 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
2038 const Type *t1 = phase->type( in(1) );
2039 if( t1 == Type::TOP ) return Type::TOP;
2040 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
2041 double d = t1->getd();
2042 if( d < 0.0 ) return Type::DOUBLE;
2043 return TypeD::make( sqrt( d ) );
2044 }
2045
2046 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
2047 const Type *t1 = phase->type( in(1) );
2048 if( t1 == Type::TOP ) return Type::TOP;
2049 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
2050 float f = t1->getf();
2051 if( f < 0.0f ) return Type::FLOAT;
2052 return TypeF::make( (float)sqrt( (double)f ) );
2053 }
2054
2055 const Type* SqrtHFNode::Value(PhaseGVN* phase) const {
2056 const Type* t1 = phase->type(in(1));
2057 if (t1 == Type::TOP) { return Type::TOP; }
2058 if (t1->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; }
2059 float f = t1->getf();
2060 if (f < 0.0f) return Type::HALF_FLOAT;
2061 return TypeH::make((float)sqrt((double)f));
2062 }
2063
2064 static const Type* reverse_bytes(int opcode, const Type* con) {
2065 switch (opcode) {
2066 // It is valid in bytecode to load any int and pass it to a method that expects a smaller type (i.e., short, char).
2067 // Let's cast the value to match the Java behavior.
2068 case Op_ReverseBytesS: return TypeInt::make(byteswap(static_cast<jshort>(con->is_int()->get_con())));
2069 case Op_ReverseBytesUS: return TypeInt::make(byteswap(static_cast<jchar>(con->is_int()->get_con())));
2070 case Op_ReverseBytesI: return TypeInt::make(byteswap(con->is_int()->get_con()));
2071 case Op_ReverseBytesL: return TypeLong::make(byteswap(con->is_long()->get_con()));
2072 default: ShouldNotReachHere();
2073 }
2074 }
2075
2076 const Type* ReverseBytesNode::Value(PhaseGVN* phase) const {
2077 const Type* type = phase->type(in(1));
2078 if (type == Type::TOP) {
2079 return Type::TOP;
2080 }
2081 if (type->singleton()) {
2082 return reverse_bytes(Opcode(), type);
2083 }
2084 return bottom_type();
2085 }
2086
2087 const Type* ReverseINode::Value(PhaseGVN* phase) const {
2088 const Type *t1 = phase->type( in(1) );
2089 if (t1 == Type::TOP) {
2090 return Type::TOP;
2091 }
2092 const TypeInt* t1int = t1->isa_int();
2093 if (t1int && t1int->is_con()) {
2094 jint res = reverse_bits(t1int->get_con());
2095 return TypeInt::make(res);
2096 }
2097 return bottom_type();
2098 }
2099
2100 const Type* ReverseLNode::Value(PhaseGVN* phase) const {
2101 const Type *t1 = phase->type( in(1) );
2102 if (t1 == Type::TOP) {
2103 return Type::TOP;
2104 }
2105 const TypeLong* t1long = t1->isa_long();
2106 if (t1long && t1long->is_con()) {
2107 jlong res = reverse_bits(t1long->get_con());
2108 return TypeLong::make(res);
2109 }
2110 return bottom_type();
2111 }
2112
2113 Node* ReverseINode::Identity(PhaseGVN* phase) {
2114 if (in(1)->Opcode() == Op_ReverseI) {
2115 return in(1)->in(1);
2116 }
2117 return this;
2118 }
2119
2120 Node* ReverseLNode::Identity(PhaseGVN* phase) {
2121 if (in(1)->Opcode() == Op_ReverseL) {
2122 return in(1)->in(1);
2123 }
2124 return this;
2125 }