1 /*
2 * Copyright (c) 1997, 2026, 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 const TypeInt* r0 = t1->is_int();
750 const TypeInt* r1 = t2->is_int();
751
752 // Check for special case in Hashtable::get - the hash index is
753 // mod'ed to the table size so the following range check is useless.
754 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
755 // to be positive.
756 // (This is a gross hack, since the sub method never
757 // looks at the structure of the node in any other case.)
758 if (r0->_lo >= 0 && r1->_lo >= 0 && is_index_range_check()) {
759 return TypeInt::CC_LT;
760 }
761
762 if (r0->_uhi < r1->_ulo) {
763 return TypeInt::CC_LT;
764 } else if (r0->_ulo > r1->_uhi) {
765 return TypeInt::CC_GT;
766 } else if (r0->is_con() && r1->is_con()) {
767 // Since r0->_ulo == r0->_uhi == r0->get_con(), we only reach here if the constants are equal
768 assert(r0->get_con() == r1->get_con(), "must reach a previous branch otherwise");
769 return TypeInt::CC_EQ;
770 } else if (r0->_uhi == r1->_ulo) {
771 return TypeInt::CC_LE;
772 } else if (r0->_ulo == r1->_uhi) {
773 return TypeInt::CC_GE;
774 }
775
776 const Type* joined = r0->join(r1);
777 if (joined == Type::TOP) {
778 return TypeInt::CC_NE;
779 }
780
781 return TypeInt::CC;
782 }
783
784 const Type* CmpUNode::Value(PhaseGVN* phase) const {
785 const Type* t = SubNode::Value_common(phase);
786 if (t != nullptr) {
787 return t;
788 }
789 const Node* in1 = in(1);
790 const Node* in2 = in(2);
791 const Type* t1 = phase->type(in1);
792 const Type* t2 = phase->type(in2);
793 assert(t1->isa_int(), "CmpU has only Int type inputs");
794 if (t2 == TypeInt::INT) { // Compare to bottom?
795 return bottom_type();
796 }
797
798 const Type* t_sub = sub(t1, t2); // compare based on immediate inputs
799
800 uint in1_op = in1->Opcode();
801 if (in1_op == Op_AddI || in1_op == Op_SubI) {
802 // The problem rise when result of AddI(SubI) may overflow
803 // signed integer value. Let say the input type is
804 // [256, maxint] then +128 will create 2 ranges due to
805 // overflow: [minint, minint+127] and [384, maxint].
806 // But C2 type system keep only 1 type range and as result
807 // it use general [minint, maxint] for this case which we
808 // can't optimize.
809 //
810 // Make 2 separate type ranges based on types of AddI(SubI) inputs
811 // and compare results of their compare. If results are the same
812 // CmpU node can be optimized.
813 const Node* in11 = in1->in(1);
814 const Node* in12 = in1->in(2);
815 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
816 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
817 // Skip cases when input types are top or bottom.
818 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
819 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
820 const TypeInt *r0 = t11->is_int();
821 const TypeInt *r1 = t12->is_int();
822 jlong lo_r0 = r0->_lo;
823 jlong hi_r0 = r0->_hi;
824 jlong lo_r1 = r1->_lo;
825 jlong hi_r1 = r1->_hi;
826 if (in1_op == Op_SubI) {
827 jlong tmp = hi_r1;
828 hi_r1 = -lo_r1;
829 lo_r1 = -tmp;
830 // Note, for substructing [minint,x] type range
831 // long arithmetic provides correct overflow answer.
832 // The confusion come from the fact that in 32-bit
833 // -minint == minint but in 64-bit -minint == maxint+1.
834 }
835 jlong lo_long = lo_r0 + lo_r1;
836 jlong hi_long = hi_r0 + hi_r1;
837 int lo_tr1 = min_jint;
838 int hi_tr1 = (int)hi_long;
839 int lo_tr2 = (int)lo_long;
840 int hi_tr2 = max_jint;
841 bool underflow = lo_long != (jlong)lo_tr2;
842 bool overflow = hi_long != (jlong)hi_tr1;
843 // Use sub(t1, t2) when there is no overflow (one type range)
844 // or when both overflow and underflow (too complex).
845 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
846 // Overflow only on one boundary, compare 2 separate type ranges.
847 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
848 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
849 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
850 const TypeInt* cmp1 = sub(tr1, t2)->is_int();
851 const TypeInt* cmp2 = sub(tr2, t2)->is_int();
852 // Compute union, so that cmp handles all possible results from the two cases
853 const Type* t_cmp = cmp1->meet(cmp2);
854 // Pick narrowest type, based on overflow computation and on immediate inputs
855 return t_sub->filter(t_cmp);
856 }
857 }
858 }
859
860 return t_sub;
861 }
862
863 bool CmpUNode::is_index_range_check() const {
864 // Check for the "(X ModI Y) CmpU Y" shape
865 return (in(1)->Opcode() == Op_ModI &&
866 in(1)->in(2)->eqv_uncast(in(2)));
867 }
868
869 //------------------------------Idealize---------------------------------------
870 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
871 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
872 switch (in(1)->Opcode()) {
873 case Op_CmpU3: // Collapse a CmpU3/CmpI into a CmpU
874 return new CmpUNode(in(1)->in(1),in(1)->in(2));
875 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
876 return new CmpLNode(in(1)->in(1),in(1)->in(2));
877 case Op_CmpUL3: // Collapse a CmpUL3/CmpI into a CmpUL
878 return new CmpULNode(in(1)->in(1),in(1)->in(2));
879 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
880 return new CmpFNode(in(1)->in(1),in(1)->in(2));
881 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
882 return new CmpDNode(in(1)->in(1),in(1)->in(2));
883 //case Op_SubI:
884 // If (x - y) cannot overflow, then ((x - y) <?> 0)
885 // can be turned into (x <?> y).
886 // This is handled (with more general cases) by Ideal_sub_algebra.
887 }
888 }
889 return nullptr; // No change
890 }
891
892 Node *CmpLNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
893 const TypeLong *t2 = phase->type(in(2))->isa_long();
894 if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) {
895 const jlong con = t2->get_con();
896 if (con >= min_jint && con <= max_jint) {
897 return new CmpINode(in(1)->in(1), phase->intcon((jint)con));
898 }
899 }
900 return nullptr;
901 }
902
903 //=============================================================================
904 // Simplify a CmpL (compare 2 longs ) node, based on local information.
905 // If both inputs are constants, compare them.
906 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
907 const TypeLong *r0 = t1->is_long(); // Handy access
908 const TypeLong *r1 = t2->is_long();
909
910 if( r0->_hi < r1->_lo ) // Range is always low?
911 return TypeInt::CC_LT;
912 else if( r0->_lo > r1->_hi ) // Range is always high?
913 return TypeInt::CC_GT;
914
915 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
916 assert(r0->get_con() == r1->get_con(), "must be equal");
917 return TypeInt::CC_EQ; // Equal results.
918 } else if( r0->_hi == r1->_lo ) // Range is never high?
919 return TypeInt::CC_LE;
920 else if( r0->_lo == r1->_hi ) // Range is never low?
921 return TypeInt::CC_GE;
922
923 const Type* joined = r0->join(r1);
924 if (joined == Type::TOP) {
925 return TypeInt::CC_NE;
926 }
927
928 return TypeInt::CC; // else use worst case results
929 }
930
931
932 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
933 // If both inputs are constants, compare them.
934 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
935 const TypeLong* r0 = t1->is_long();
936 const TypeLong* r1 = t2->is_long();
937
938 if (r0->_uhi < r1->_ulo) {
939 return TypeInt::CC_LT;
940 } else if (r0->_ulo > r1->_uhi) {
941 return TypeInt::CC_GT;
942 } else if (r0->is_con() && r1->is_con()) {
943 // Since r0->_ulo == r0->_uhi == r0->get_con(), we only reach here if the constants are equal
944 assert(r0->get_con() == r1->get_con(), "must reach a previous branch otherwise");
945 return TypeInt::CC_EQ;
946 } else if (r0->_uhi == r1->_ulo) {
947 return TypeInt::CC_LE;
948 } else if (r0->_ulo == r1->_uhi) {
949 return TypeInt::CC_GE;
950 }
951
952 const Type* joined = r0->join(r1);
953 if (joined == Type::TOP) {
954 return TypeInt::CC_NE;
955 }
956
957 return TypeInt::CC;
958 }
959
960 //=============================================================================
961 //------------------------------sub--------------------------------------------
962 // Simplify an CmpP (compare 2 pointers) node, based on local information.
963 // If both inputs are constants, compare them.
964 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
965 const TypePtr *r0 = t1->is_ptr(); // Handy access
966 const TypePtr *r1 = t2->is_ptr();
967
968 // Undefined inputs makes for an undefined result
969 if( TypePtr::above_centerline(r0->_ptr) ||
970 TypePtr::above_centerline(r1->_ptr) )
971 return Type::TOP;
972
973 if (r0 == r1 && r0->singleton()) {
974 // Equal pointer constants (klasses, nulls, etc.)
975 return TypeInt::CC_EQ;
976 }
977
978 // See if it is 2 unrelated classes.
979 const TypeOopPtr* p0 = r0->isa_oopptr();
980 const TypeOopPtr* p1 = r1->isa_oopptr();
981 const TypeKlassPtr* k0 = r0->isa_klassptr();
982 const TypeKlassPtr* k1 = r1->isa_klassptr();
983 if ((p0 && p1) || (k0 && k1)) {
984 bool xklass0 = p0 ? p0->klass_is_exact() : k0->klass_is_exact();
985 bool xklass1 = p1 ? p1->klass_is_exact() : k1->klass_is_exact();
986 bool unrelated_classes = false;
987
988 if ((p0 && p0->is_same_java_type_as(p1)) ||
989 (k0 && k0->is_same_java_type_as(k1))) {
990 } else if ((p0 && !p1->maybe_java_subtype_of(p0) && !p0->maybe_java_subtype_of(p1)) ||
991 (k0 && !k1->maybe_java_subtype_of(k0) && !k0->maybe_java_subtype_of(k1))) {
992 unrelated_classes = true;
993 } else if ((p0 && !p1->maybe_java_subtype_of(p0)) ||
994 (k0 && !k1->maybe_java_subtype_of(k0))) {
995 unrelated_classes = xklass1;
996 } else if ((p0 && !p0->maybe_java_subtype_of(p1)) ||
997 (k0 && !k0->maybe_java_subtype_of(k1))) {
998 unrelated_classes = xklass0;
999 }
1000
1001 if (unrelated_classes) {
1002 // The oops classes are known to be unrelated. If the joined PTRs of
1003 // two oops is not Null and not Bottom, then we are sure that one
1004 // of the two oops is non-null, and the comparison will always fail.
1005 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1006 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1007 return TypeInt::CC_GT;
1008 }
1009 }
1010 }
1011
1012 // Known constants can be compared exactly
1013 // Null can be distinguished from any NotNull pointers
1014 // Unknown inputs makes an unknown result
1015 if( r0->singleton() ) {
1016 intptr_t bits0 = r0->get_con();
1017 if( r1->singleton() )
1018 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1019 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1020 } else if( r1->singleton() ) {
1021 intptr_t bits1 = r1->get_con();
1022 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1023 } else
1024 return TypeInt::CC;
1025 }
1026
1027 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1028 // Return the klass node for (indirect load from OopHandle)
1029 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1030 // or null if not matching.
1031 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1032 n = bs->step_over_gc_barrier(n);
1033
1034 if (n->Opcode() != Op_LoadP) return nullptr;
1035
1036 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1037 if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr;
1038
1039 Node* adr = n->in(MemNode::Address);
1040 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1041 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr;
1042 adr = adr->in(MemNode::Address);
1043
1044 intptr_t off = 0;
1045 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1046 if (k == nullptr) return nullptr;
1047 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1048 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr;
1049
1050 // We've found the klass node of a Java mirror load.
1051 return k;
1052 }
1053
1054 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
1055 // for ConP(Foo.class) return ConP(Foo.klass)
1056 // otherwise return null
1057 if (!n->is_Con()) return nullptr;
1058
1059 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1060 if (!tp) return nullptr;
1061
1062 ciType* mirror_type = tp->java_mirror_type();
1063 // TypeInstPtr::java_mirror_type() returns non-null for compile-
1064 // time Class constants only.
1065 if (!mirror_type) return nullptr;
1066
1067 // x.getClass() == int.class can never be true (for all primitive types)
1068 // Return a ConP(null) node for this case.
1069 if (mirror_type->is_classless()) {
1070 return phase->makecon(TypePtr::NULL_PTR);
1071 }
1072
1073 // return the ConP(Foo.klass)
1074 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
1075 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass(), Type::trust_interfaces));
1076 }
1077
1078 //------------------------------Ideal------------------------------------------
1079 // Normalize comparisons between Java mirror loads to compare the klass instead.
1080 //
1081 // Also check for the case of comparing an unknown klass loaded from the primary
1082 // super-type array vs a known klass with no subtypes. This amounts to
1083 // checking to see an unknown klass subtypes a known klass with no subtypes;
1084 // this only happens on an exact match. We can shorten this test by 1 load.
1085 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1086 // Normalize comparisons between Java mirrors into comparisons of the low-
1087 // level klass, where a dependent load could be shortened.
1088 //
1089 // The new pattern has a nice effect of matching the same pattern used in the
1090 // fast path of instanceof/checkcast/Class.isInstance(), which allows
1091 // redundant exact type check be optimized away by GVN.
1092 // For example, in
1093 // if (x.getClass() == Foo.class) {
1094 // Foo foo = (Foo) x;
1095 // // ... use a ...
1096 // }
1097 // a CmpPNode could be shared between if_acmpne and checkcast
1098 {
1099 Node* k1 = isa_java_mirror_load(phase, in(1));
1100 Node* k2 = isa_java_mirror_load(phase, in(2));
1101 Node* conk2 = isa_const_java_mirror(phase, in(2));
1102
1103 if (k1 && (k2 || conk2)) {
1104 Node* lhs = k1;
1105 Node* rhs = (k2 != nullptr) ? k2 : conk2;
1106 set_req_X(1, lhs, phase);
1107 set_req_X(2, rhs, phase);
1108 return this;
1109 }
1110 }
1111
1112 // Constant pointer on right?
1113 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1114 if (t2 == nullptr || !t2->klass_is_exact())
1115 return nullptr;
1116 // Get the constant klass we are comparing to.
1117 ciKlass* superklass = t2->exact_klass();
1118
1119 // Now check for LoadKlass on left.
1120 Node* ldk1 = in(1);
1121 if (ldk1->is_DecodeNKlass()) {
1122 ldk1 = ldk1->in(1);
1123 if (ldk1->Opcode() != Op_LoadNKlass )
1124 return nullptr;
1125 } else if (ldk1->Opcode() != Op_LoadKlass )
1126 return nullptr;
1127 // Take apart the address of the LoadKlass:
1128 Node* adr1 = ldk1->in(MemNode::Address);
1129 intptr_t con2 = 0;
1130 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1131 if (ldk2 == nullptr)
1132 return nullptr;
1133 if (con2 == oopDesc::klass_offset_in_bytes()) {
1134 // We are inspecting an object's concrete class.
1135 // Short-circuit the check if the query is abstract.
1136 if (superklass->is_interface() ||
1137 superklass->is_abstract()) {
1138 // Make it come out always false:
1139 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1140 return this;
1141 }
1142 }
1143
1144 // Check for a LoadKlass from primary supertype array.
1145 // Any nested loadklass from loadklass+con must be from the p.s. array.
1146 if (ldk2->is_DecodeNKlass()) {
1147 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1148 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1149 return nullptr;
1150 } else if (ldk2->Opcode() != Op_LoadKlass)
1151 return nullptr;
1152
1153 // Verify that we understand the situation
1154 if (con2 != (intptr_t) superklass->super_check_offset())
1155 return nullptr; // Might be element-klass loading from array klass
1156
1157 // If 'superklass' has no subklasses and is not an interface, then we are
1158 // assured that the only input which will pass the type check is
1159 // 'superklass' itself.
1160 //
1161 // We could be more liberal here, and allow the optimization on interfaces
1162 // which have a single implementor. This would require us to increase the
1163 // expressiveness of the add_dependency() mechanism.
1164 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1165
1166 // Object arrays must have their base element have no subtypes
1167 while (superklass->is_obj_array_klass()) {
1168 ciType* elem = superklass->as_obj_array_klass()->element_type();
1169 superklass = elem->as_klass();
1170 }
1171 if (superklass->is_instance_klass()) {
1172 ciInstanceKlass* ik = superklass->as_instance_klass();
1173 if (ik->has_subklass() || ik->is_interface()) return nullptr;
1174 // Add a dependency if there is a chance that a subclass will be added later.
1175 if (!ik->is_final()) {
1176 phase->C->dependencies()->assert_leaf_type(ik);
1177 }
1178 }
1179
1180 // Bypass the dependent load, and compare directly
1181 this->set_req_X(1, ldk2, phase);
1182
1183 return this;
1184 }
1185
1186 const Type* CmpPNode::Value(PhaseGVN* phase) const {
1187 const Type* res = CmpNode::Value(phase);
1188 if (res == TypeInt::CC) {
1189 const TypeOopPtr* p0 = phase->type(in(1))->isa_oopptr();
1190 const TypeOopPtr* p1 = phase->type(in(2))->isa_oopptr();
1191 if (p0 != nullptr && p1 != nullptr) {
1192 Node* in1 = in(1)->uncast();
1193 Node* in2 = in(2)->uncast();
1194 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1);
1195 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2);
1196 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, phase)) {
1197 return TypeInt::CC_GT; // different pointers
1198 }
1199 }
1200 }
1201 return res;
1202 }
1203
1204 //=============================================================================
1205 //------------------------------sub--------------------------------------------
1206 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1207 // If both inputs are constants, compare them.
1208 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1209 ShouldNotReachHere();
1210 return bottom_type();
1211 }
1212
1213 //------------------------------Ideal------------------------------------------
1214 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1215 return nullptr;
1216 }
1217
1218 //=============================================================================
1219 //------------------------------Value------------------------------------------
1220 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1221 // If both inputs are constants, compare them.
1222 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1223 const Node* in1 = in(1);
1224 const Node* in2 = in(2);
1225 // Either input is TOP ==> the result is TOP
1226 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1227 if( t1 == Type::TOP ) return Type::TOP;
1228 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1229 if( t2 == Type::TOP ) return Type::TOP;
1230
1231 // Not constants? Don't know squat - even if they are the same
1232 // value! If they are NaN's they compare to LT instead of EQ.
1233 const TypeF *tf1 = t1->isa_float_constant();
1234 const TypeF *tf2 = t2->isa_float_constant();
1235 if( !tf1 || !tf2 ) return TypeInt::CC;
1236
1237 // This implements the Java bytecode fcmpl, so unordered returns -1.
1238 if( tf1->is_nan() || tf2->is_nan() )
1239 return TypeInt::CC_LT;
1240
1241 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1242 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1243 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1244 return TypeInt::CC_EQ;
1245 }
1246
1247
1248 //=============================================================================
1249 //------------------------------Value------------------------------------------
1250 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1251 // If both inputs are constants, compare them.
1252 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1253 const Node* in1 = in(1);
1254 const Node* in2 = in(2);
1255 // Either input is TOP ==> the result is TOP
1256 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1257 if( t1 == Type::TOP ) return Type::TOP;
1258 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1259 if( t2 == Type::TOP ) return Type::TOP;
1260
1261 // Not constants? Don't know squat - even if they are the same
1262 // value! If they are NaN's they compare to LT instead of EQ.
1263 const TypeD *td1 = t1->isa_double_constant();
1264 const TypeD *td2 = t2->isa_double_constant();
1265 if( !td1 || !td2 ) return TypeInt::CC;
1266
1267 // This implements the Java bytecode dcmpl, so unordered returns -1.
1268 if( td1->is_nan() || td2->is_nan() )
1269 return TypeInt::CC_LT;
1270
1271 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1272 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1273 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1274 return TypeInt::CC_EQ;
1275 }
1276
1277 //------------------------------Ideal------------------------------------------
1278 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1279 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1280 // Change (CMPD (F2D (float)) (ConD value))
1281 // To (CMPF (float) (ConF value))
1282 // Valid when 'value' does not lose precision as a float.
1283 // Benefits: eliminates conversion, does not require 24-bit mode
1284
1285 // NaNs prevent commuting operands. This transform works regardless of the
1286 // order of ConD and ConvF2D inputs by preserving the original order.
1287 int idx_f2d = 1; // ConvF2D on left side?
1288 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1289 idx_f2d = 2; // No, swap to check for reversed args
1290 int idx_con = 3-idx_f2d; // Check for the constant on other input
1291
1292 if( ConvertCmpD2CmpF &&
1293 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1294 in(idx_con)->Opcode() == Op_ConD ) {
1295 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1296 double t2_value_as_double = t2->_d;
1297 float t2_value_as_float = (float)t2_value_as_double;
1298 if( t2_value_as_double == (double)t2_value_as_float ) {
1299 // Test value can be represented as a float
1300 // Eliminate the conversion to double and create new comparison
1301 Node *new_in1 = in(idx_f2d)->in(1);
1302 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1303 if( idx_f2d != 1 ) { // Must flip args to match original order
1304 Node *tmp = new_in1;
1305 new_in1 = new_in2;
1306 new_in2 = tmp;
1307 }
1308 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1309 ? new CmpF3Node( new_in1, new_in2 )
1310 : new CmpFNode ( new_in1, new_in2 ) ;
1311 return new_cmp; // Changed to CmpFNode
1312 }
1313 // Testing value required the precision of a double
1314 }
1315 return nullptr; // No change
1316 }
1317
1318
1319 //=============================================================================
1320 //------------------------------cc2logical-------------------------------------
1321 // Convert a condition code type to a logical type
1322 const Type *BoolTest::cc2logical( const Type *CC ) const {
1323 if( CC == Type::TOP ) return Type::TOP;
1324 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1325 const TypeInt *ti = CC->is_int();
1326 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1327 // Match low order 2 bits
1328 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1329 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1330 return TypeInt::make(tmp); // Boolean result
1331 }
1332
1333 if( CC == TypeInt::CC_GE ) {
1334 if( _test == ge ) return TypeInt::ONE;
1335 if( _test == lt ) return TypeInt::ZERO;
1336 }
1337 if( CC == TypeInt::CC_LE ) {
1338 if( _test == le ) return TypeInt::ONE;
1339 if( _test == gt ) return TypeInt::ZERO;
1340 }
1341 if( CC == TypeInt::CC_NE ) {
1342 if( _test == ne ) return TypeInt::ONE;
1343 if( _test == eq ) return TypeInt::ZERO;
1344 }
1345
1346 return TypeInt::BOOL;
1347 }
1348
1349 BoolTest::mask BoolTest::unsigned_mask(BoolTest::mask btm) {
1350 switch(btm) {
1351 case eq:
1352 case ne:
1353 return btm;
1354 case lt:
1355 case le:
1356 case gt:
1357 case ge:
1358 return mask(btm | unsigned_compare);
1359 default:
1360 ShouldNotReachHere();
1361 }
1362 }
1363
1364 //------------------------------dump_spec-------------------------------------
1365 // Print special per-node info
1366 void BoolTest::dump_on(outputStream *st) const {
1367 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1368 st->print("%s", msg[_test]);
1369 }
1370
1371 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1372 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1373 BoolTest::mask BoolTest::merge(BoolTest other) const {
1374 const mask res[illegal+1][illegal+1] = {
1375 // eq, gt, of, lt, ne, le, nof, ge, never, illegal
1376 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq
1377 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt
1378 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of
1379 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt
1380 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne
1381 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le
1382 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof
1383 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge
1384 {never, never, never, never, never, never, never, never, never, illegal}, // never
1385 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1386 return res[_test][other._test];
1387 }
1388
1389 //=============================================================================
1390 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1391 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1392
1393 //------------------------------operator==-------------------------------------
1394 bool BoolNode::cmp( const Node &n ) const {
1395 const BoolNode *b = (const BoolNode *)&n; // Cast up
1396 return (_test._test == b->_test._test);
1397 }
1398
1399 //-------------------------------make_predicate--------------------------------
1400 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1401 if (test_value->is_Con()) return test_value;
1402 if (test_value->is_Bool()) return test_value;
1403 if (test_value->is_CMove() &&
1404 test_value->in(CMoveNode::Condition)->is_Bool()) {
1405 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1406 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1407 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1408 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1409 return bol;
1410 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1411 return phase->transform( bol->negate(phase) );
1412 }
1413 // Else fall through. The CMove gets in the way of the test.
1414 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1415 }
1416 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1417 cmp = phase->transform(cmp);
1418 Node* bol = new BoolNode(cmp, BoolTest::ne);
1419 return phase->transform(bol);
1420 }
1421
1422 //--------------------------------as_int_value---------------------------------
1423 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1424 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1425 Node* cmov = CMoveNode::make(this, phase->intcon(0), phase->intcon(1), TypeInt::BOOL);
1426 return phase->transform(cmov);
1427 }
1428
1429 //----------------------------------negate-------------------------------------
1430 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1431 return new BoolNode(in(1), _test.negate());
1432 }
1433
1434 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1435 // overflows and we can prove that C is not in the two resulting ranges.
1436 // This optimization is similar to the one performed by CmpUNode::Value().
1437 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1438 int cmp1_op, const TypeInt* cmp2_type) {
1439 // Only optimize eq/ne integer comparison of add/sub
1440 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1441 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1442 // Skip cases were inputs of add/sub are not integers or of bottom type
1443 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1444 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1445 if ((r0 != nullptr) && (r0 != TypeInt::INT) &&
1446 (r1 != nullptr) && (r1 != TypeInt::INT) &&
1447 (cmp2_type != TypeInt::INT)) {
1448 // Compute exact (long) type range of add/sub result
1449 jlong lo_long = r0->_lo;
1450 jlong hi_long = r0->_hi;
1451 if (cmp1_op == Op_AddI) {
1452 lo_long += r1->_lo;
1453 hi_long += r1->_hi;
1454 } else {
1455 lo_long -= r1->_hi;
1456 hi_long -= r1->_lo;
1457 }
1458 // Check for over-/underflow by casting to integer
1459 int lo_int = (int)lo_long;
1460 int hi_int = (int)hi_long;
1461 bool underflow = lo_long != (jlong)lo_int;
1462 bool overflow = hi_long != (jlong)hi_int;
1463 if ((underflow != overflow) && (hi_int < lo_int)) {
1464 // Overflow on one boundary, compute resulting type ranges:
1465 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1466 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1467 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1468 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1469 // Compare second input of cmp to both type ranges
1470 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1471 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1472 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1473 // The result of the add/sub will never equal cmp2. Replace BoolNode
1474 // by false (0) if it tests for equality and by true (1) otherwise.
1475 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1476 }
1477 }
1478 }
1479 }
1480 return nullptr;
1481 }
1482
1483 static bool is_counted_loop_cmp(Node *cmp) {
1484 Node *n = cmp->in(1)->in(1);
1485 return n != nullptr &&
1486 n->is_Phi() &&
1487 n->in(0) != nullptr &&
1488 n->in(0)->is_CountedLoop() &&
1489 n->in(0)->as_CountedLoop()->phi() == n;
1490 }
1491
1492 //------------------------------Ideal------------------------------------------
1493 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1494 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1495 // This moves the constant to the right. Helps value-numbering.
1496 Node *cmp = in(1);
1497 if( !cmp->is_Sub() ) return nullptr;
1498 int cop = cmp->Opcode();
1499 if( cop == Op_FastLock || cop == Op_FastUnlock ||
1500 cmp->is_SubTypeCheck() || cop == Op_VectorTest ) {
1501 return nullptr;
1502 }
1503 Node *cmp1 = cmp->in(1);
1504 Node *cmp2 = cmp->in(2);
1505 if( !cmp1 ) return nullptr;
1506
1507 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1508 return nullptr;
1509 }
1510
1511 const int cmp1_op = cmp1->Opcode();
1512 const int cmp2_op = cmp2->Opcode();
1513
1514 // Constant on left?
1515 Node *con = cmp1;
1516 // Move constants to the right of compare's to canonicalize.
1517 // Do not muck with Opaque1 nodes, as this indicates a loop
1518 // guard that cannot change shape.
1519 if (con->is_Con() && !cmp2->is_Con() && cmp2_op != Op_OpaqueZeroTripGuard &&
1520 // Because of NaN's, CmpD and CmpF are not commutative
1521 cop != Op_CmpD && cop != Op_CmpF &&
1522 // Protect against swapping inputs to a compare when it is used by a
1523 // counted loop exit, which requires maintaining the loop-limit as in(2)
1524 !is_counted_loop_exit_test() ) {
1525 // Ok, commute the constant to the right of the cmp node.
1526 // Clone the Node, getting a new Node of the same class
1527 cmp = cmp->clone();
1528 // Swap inputs to the clone
1529 cmp->swap_edges(1, 2);
1530 cmp = phase->transform( cmp );
1531 return new BoolNode( cmp, _test.commute() );
1532 }
1533
1534 // Change "bool eq/ne (cmp (cmove (bool tst (cmp2)) 1 0) 0)" into "bool tst/~tst (cmp2)"
1535 if (cop == Op_CmpI &&
1536 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1537 cmp1_op == Op_CMoveI && cmp2->find_int_con(1) == 0) {
1538 // 0 should be on the true branch
1539 if (cmp1->in(CMoveNode::Condition)->is_Bool() &&
1540 cmp1->in(CMoveNode::IfTrue)->find_int_con(1) == 0 &&
1541 cmp1->in(CMoveNode::IfFalse)->find_int_con(0) != 0) {
1542 BoolNode* target = cmp1->in(CMoveNode::Condition)->as_Bool();
1543 return new BoolNode(target->in(1),
1544 (_test._test == BoolTest::eq) ? target->_test._test :
1545 target->_test.negate());
1546 }
1547 }
1548
1549 // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1550 if (cop == Op_CmpI &&
1551 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1552 cmp1_op == Op_AndI && cmp2_op == Op_ConI &&
1553 cmp1->in(2)->Opcode() == Op_ConI) {
1554 const TypeInt *t12 = phase->type(cmp2)->isa_int();
1555 const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int();
1556 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1557 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1558 Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1559 return new BoolNode(ncmp, _test.negate());
1560 }
1561 }
1562
1563 // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1564 if (cop == Op_CmpL &&
1565 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1566 cmp1_op == Op_AndL && cmp2_op == Op_ConL &&
1567 cmp1->in(2)->Opcode() == Op_ConL) {
1568 const TypeLong *t12 = phase->type(cmp2)->isa_long();
1569 const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long();
1570 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1571 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1572 Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0)));
1573 return new BoolNode(ncmp, _test.negate());
1574 }
1575 }
1576
1577 // Change "cmp (add X min_jint) (add Y min_jint)" into "cmpu X Y"
1578 // and "cmp (add X min_jint) c" into "cmpu X (c + min_jint)"
1579 if (cop == Op_CmpI &&
1580 cmp1_op == Op_AddI &&
1581 phase->type(cmp1->in(2)) == TypeInt::MIN &&
1582 !is_cloop_condition(this)) {
1583 if (cmp2_op == Op_ConI) {
1584 Node* ncmp2 = phase->intcon(java_add(cmp2->get_int(), min_jint));
1585 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), ncmp2));
1586 return new BoolNode(ncmp, _test._test);
1587 } else if (cmp2_op == Op_AddI &&
1588 phase->type(cmp2->in(2)) == TypeInt::MIN &&
1589 !is_cloop_condition(this)) {
1590 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), cmp2->in(1)));
1591 return new BoolNode(ncmp, _test._test);
1592 }
1593 }
1594
1595 // Change "cmp (add X min_jlong) (add Y min_jlong)" into "cmpu X Y"
1596 // and "cmp (add X min_jlong) c" into "cmpu X (c + min_jlong)"
1597 if (cop == Op_CmpL &&
1598 cmp1_op == Op_AddL &&
1599 phase->type(cmp1->in(2)) == TypeLong::MIN &&
1600 !is_cloop_condition(this)) {
1601 if (cmp2_op == Op_ConL) {
1602 Node* ncmp2 = phase->longcon(java_add(cmp2->get_long(), min_jlong));
1603 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), ncmp2));
1604 return new BoolNode(ncmp, _test._test);
1605 } else if (cmp2_op == Op_AddL &&
1606 phase->type(cmp2->in(2)) == TypeLong::MIN &&
1607 !is_cloop_condition(this)) {
1608 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), cmp2->in(1)));
1609 return new BoolNode(ncmp, _test._test);
1610 }
1611 }
1612
1613 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1614 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1615 // test instead.
1616 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1617 if (cmp2_type == nullptr) return nullptr;
1618 Node* j_xor = cmp1;
1619 if( cmp2_type == TypeInt::ZERO &&
1620 cmp1_op == Op_XorI &&
1621 j_xor->in(1) != j_xor && // An xor of itself is dead
1622 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1623 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1624 (_test._test == BoolTest::eq ||
1625 _test._test == BoolTest::ne) ) {
1626 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1627 return new BoolNode( ncmp, _test.negate() );
1628 }
1629
1630 // Transform: "((x & (m - 1)) <u m)" or "(((m - 1) & x) <u m)" into "(m >u 0)"
1631 // This is case [CMPU_MASK] which is further described at the method comment of BoolNode::Value_cmpu_and_mask().
1632 if (cop == Op_CmpU && _test._test == BoolTest::lt && cmp1_op == Op_AndI) {
1633 Node* m = cmp2; // RHS: m
1634 for (int add_idx = 1; add_idx <= 2; add_idx++) { // LHS: "(m + (-1)) & x" or "x & (m + (-1))"?
1635 Node* maybe_m_minus_1 = cmp1->in(add_idx);
1636 if (maybe_m_minus_1->Opcode() == Op_AddI &&
1637 maybe_m_minus_1->in(2)->find_int_con(0) == -1 &&
1638 maybe_m_minus_1->in(1) == m) {
1639 Node* m_cmpu_0 = phase->transform(new CmpUNode(m, phase->intcon(0)));
1640 return new BoolNode(m_cmpu_0, BoolTest::gt);
1641 }
1642 }
1643 }
1644
1645 // Change x u< 1 or x u<= 0 to x == 0
1646 // and x u> 0 or u>= 1 to x != 0
1647 if (cop == Op_CmpU &&
1648 cmp1_op != Op_LoadRange &&
1649 (((_test._test == BoolTest::lt || _test._test == BoolTest::ge) &&
1650 cmp2->find_int_con(-1) == 1) ||
1651 ((_test._test == BoolTest::le || _test._test == BoolTest::gt) &&
1652 cmp2->find_int_con(-1) == 0))) {
1653 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1654 return new BoolNode(ncmp, _test.is_less() ? BoolTest::eq : BoolTest::ne);
1655 }
1656
1657 // Change (arraylength <= 0) or (arraylength == 0)
1658 // into (arraylength u<= 0)
1659 // Also change (arraylength != 0) into (arraylength u> 0)
1660 // The latter version matches the code pattern generated for
1661 // array range checks, which will more likely be optimized later.
1662 if (cop == Op_CmpI &&
1663 cmp1_op == Op_LoadRange &&
1664 cmp2->find_int_con(-1) == 0) {
1665 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1666 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1667 return new BoolNode(ncmp, BoolTest::le);
1668 } else if (_test._test == BoolTest::ne) {
1669 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1670 return new BoolNode(ncmp, BoolTest::gt);
1671 }
1672 }
1673
1674 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1675 // This is a standard idiom for branching on a boolean value.
1676 Node *c2b = cmp1;
1677 if( cmp2_type == TypeInt::ZERO &&
1678 cmp1_op == Op_Conv2B &&
1679 (_test._test == BoolTest::eq ||
1680 _test._test == BoolTest::ne) ) {
1681 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1682 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1683 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1684 );
1685 return new BoolNode( ncmp, _test._test );
1686 }
1687
1688 // Comparing a SubI against a zero is equal to comparing the SubI
1689 // arguments directly. This only works for eq and ne comparisons
1690 // due to possible integer overflow.
1691 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1692 (cop == Op_CmpI) &&
1693 (cmp1_op == Op_SubI) &&
1694 ( cmp2_type == TypeInt::ZERO ) ) {
1695 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1696 return new BoolNode( ncmp, _test._test );
1697 }
1698
1699 // Same as above but with and AddI of a constant
1700 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1701 cop == Op_CmpI &&
1702 cmp1_op == Op_AddI &&
1703 cmp1->in(2) != nullptr &&
1704 phase->type(cmp1->in(2))->isa_int() &&
1705 phase->type(cmp1->in(2))->is_int()->is_con() &&
1706 cmp2_type == TypeInt::ZERO &&
1707 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1708 ) {
1709 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1710 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1711 return new BoolNode( ncmp, _test._test );
1712 }
1713
1714 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1715 // since zero check of conditional negation of an integer is equal to
1716 // zero check of the integer directly.
1717 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1718 (cop == Op_CmpI) &&
1719 (cmp2_type == TypeInt::ZERO) &&
1720 (cmp1_op == Op_Phi)) {
1721 // There should be a diamond phi with true path at index 1 or 2
1722 PhiNode *phi = cmp1->as_Phi();
1723 int idx_true = phi->is_diamond_phi();
1724 if (idx_true != 0) {
1725 // True input is in(idx_true) while false input is in(3 - idx_true)
1726 Node *tin = phi->in(idx_true);
1727 Node *fin = phi->in(3 - idx_true);
1728 if ((tin->Opcode() == Op_SubI) &&
1729 (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1730 (tin->in(2) == fin)) {
1731 // Found conditional negation at true path, create a new CmpINode without that
1732 Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1733 return new BoolNode(ncmp, _test._test);
1734 }
1735 if ((fin->Opcode() == Op_SubI) &&
1736 (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1737 (fin->in(2) == tin)) {
1738 // Found conditional negation at false path, create a new CmpINode without that
1739 Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1740 return new BoolNode(ncmp, _test._test);
1741 }
1742 }
1743 }
1744
1745 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1746 // most general case because negating 0x80000000 does nothing. Needed for
1747 // the CmpF3/SubI/CmpI idiom.
1748 if( cop == Op_CmpI &&
1749 cmp1_op == Op_SubI &&
1750 cmp2_type == TypeInt::ZERO &&
1751 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1752 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1753 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1754 return new BoolNode( ncmp, _test.commute() );
1755 }
1756
1757 // Try to optimize signed integer comparison
1758 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1759
1760 // The transformation below is not valid for either signed or unsigned
1761 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1762 // This transformation can be resurrected when we are able to
1763 // make inferences about the range of values being subtracted from
1764 // (or added to) relative to the wraparound point.
1765 //
1766 // // Remove +/-1's if possible.
1767 // // "X <= Y-1" becomes "X < Y"
1768 // // "X+1 <= Y" becomes "X < Y"
1769 // // "X < Y+1" becomes "X <= Y"
1770 // // "X-1 < Y" becomes "X <= Y"
1771 // // Do not this to compares off of the counted-loop-end. These guys are
1772 // // checking the trip counter and they want to use the post-incremented
1773 // // counter. If they use the PRE-incremented counter, then the counter has
1774 // // to be incremented in a private block on a loop backedge.
1775 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1776 // return nullptr;
1777 // #ifndef PRODUCT
1778 // // Do not do this in a wash GVN pass during verification.
1779 // // Gets triggered by too many simple optimizations to be bothered with
1780 // // re-trying it again and again.
1781 // if( !phase->allow_progress() ) return nullptr;
1782 // #endif
1783 // // Not valid for unsigned compare because of corner cases in involving zero.
1784 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1785 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1786 // // "0 <=u Y" is always true).
1787 // if( cmp->Opcode() == Op_CmpU ) return nullptr;
1788 // int cmp2_op = cmp2->Opcode();
1789 // if( _test._test == BoolTest::le ) {
1790 // if( cmp1_op == Op_AddI &&
1791 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1792 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1793 // else if( cmp2_op == Op_AddI &&
1794 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1795 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1796 // } else if( _test._test == BoolTest::lt ) {
1797 // if( cmp1_op == Op_AddI &&
1798 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1799 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1800 // else if( cmp2_op == Op_AddI &&
1801 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1802 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1803 // }
1804 }
1805
1806 // We use the following Lemmas/insights for the following two transformations (1) and (2):
1807 // x & y <=u y, for any x and y (Lemma 1, masking always results in a smaller unsigned number)
1808 // y <u y + 1 is always true if y != -1 (Lemma 2, (uint)(-1 + 1) == (uint)(UINT_MAX + 1) which overflows)
1809 // y <u 0 is always false for any y (Lemma 3, 0 == UINT_MIN and nothing can be smaller than that)
1810 //
1811 // (1a) Always: Change ((x & m) <=u m ) or ((m & x) <=u m ) to always true (true by Lemma 1)
1812 // (1b) If m != -1: Change ((x & m) <u m + 1) or ((m & x) <u m + 1) to always true:
1813 // x & m <=u m is always true // (Lemma 1)
1814 // x & m <=u m <u m + 1 is always true // (Lemma 2: m <u m + 1, if m != -1)
1815 //
1816 // A counter example for (1b), if we allowed m == -1:
1817 // (x & m) <u m + 1
1818 // (x & -1) <u 0
1819 // x <u 0
1820 // which is false for any x (Lemma 3)
1821 //
1822 // (2) Change ((x & (m - 1)) <u m) or (((m - 1) & x) <u m) to (m >u 0)
1823 // This is the off-by-one variant of the above.
1824 //
1825 // We now prove that this replacement is correct. This is the same as proving
1826 // "m >u 0" if and only if "x & (m - 1) <u m", i.e. "m >u 0 <=> x & (m - 1) <u m"
1827 //
1828 // We use (Lemma 1) and (Lemma 3) from above.
1829 //
1830 // Case "x & (m - 1) <u m => m >u 0":
1831 // We prove this by contradiction:
1832 // Assume m <=u 0 which is equivalent to m == 0:
1833 // and thus
1834 // x & (m - 1) <u m = 0 // m == 0
1835 // y <u 0 // y = x & (m - 1)
1836 // by Lemma 3, this is always false, i.e. a contradiction to our assumption.
1837 //
1838 // Case "m >u 0 => x & (m - 1) <u m":
1839 // x & (m - 1) <=u (m - 1) // (Lemma 1)
1840 // x & (m - 1) <=u (m - 1) <u m // Using assumption m >u 0, no underflow of "m - 1"
1841 //
1842 //
1843 // Note that the signed version of "m > 0":
1844 // m > 0 <=> x & (m - 1) <u m
1845 // does not hold:
1846 // Assume m == -1 and x == -1:
1847 // x & (m - 1) <u m
1848 // -1 & -2 <u -1
1849 // -2 <u -1
1850 // UINT_MAX - 1 <u UINT_MAX // Signed to unsigned numbers
1851 // which is true while
1852 // m > 0
1853 // is false which is a contradiction.
1854 //
1855 // (1a) and (1b) is covered by this method since we can directly return a true value as type while (2) is covered
1856 // in BoolNode::Ideal since we create a new non-constant node (see [CMPU_MASK]).
1857 const Type* BoolNode::Value_cmpu_and_mask(PhaseValues* phase) const {
1858 Node* cmp = in(1);
1859 if (cmp != nullptr && cmp->Opcode() == Op_CmpU) {
1860 Node* cmp1 = cmp->in(1);
1861 Node* cmp2 = cmp->in(2);
1862
1863 if (cmp1->Opcode() == Op_AndI) {
1864 Node* m = nullptr;
1865 if (_test._test == BoolTest::le) {
1866 // (1a) "((x & m) <=u m)", cmp2 = m
1867 m = cmp2;
1868 } else if (_test._test == BoolTest::lt && cmp2->Opcode() == Op_AddI && cmp2->in(2)->find_int_con(0) == 1) {
1869 // (1b) "(x & m) <u m + 1" and "(m & x) <u m + 1", cmp2 = m + 1
1870 Node* rhs_m = cmp2->in(1);
1871 const TypeInt* rhs_m_type = phase->type(rhs_m)->isa_int();
1872 if (rhs_m_type != nullptr && (rhs_m_type->_lo > -1 || rhs_m_type->_hi < -1)) {
1873 // Exclude any case where m == -1 is possible.
1874 m = rhs_m;
1875 }
1876 }
1877
1878 if (cmp1->in(2) == m || cmp1->in(1) == m) {
1879 return TypeInt::ONE;
1880 }
1881 }
1882 }
1883
1884 return nullptr;
1885 }
1886
1887 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1888 // based on local information. If the input is constant, do it.
1889 const Type* BoolNode::Value(PhaseGVN* phase) const {
1890 const Type* input_type = phase->type(in(1));
1891 if (input_type == Type::TOP) {
1892 return Type::TOP;
1893 }
1894 const Type* t = Value_cmpu_and_mask(phase);
1895 if (t != nullptr) {
1896 return t;
1897 }
1898
1899 return _test.cc2logical(input_type);
1900 }
1901
1902 #ifndef PRODUCT
1903 //------------------------------dump_spec--------------------------------------
1904 // Dump special per-node info
1905 void BoolNode::dump_spec(outputStream *st) const {
1906 st->print("[");
1907 _test.dump_on(st);
1908 st->print("]");
1909 }
1910 #endif
1911
1912 //----------------------is_counted_loop_exit_test------------------------------
1913 // Returns true if node is used by a counted loop node.
1914 bool BoolNode::is_counted_loop_exit_test() {
1915 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1916 Node* use = fast_out(i);
1917 if (use->is_CountedLoopEnd()) {
1918 return true;
1919 }
1920 }
1921 return false;
1922 }
1923
1924 //=============================================================================
1925 //------------------------------Value------------------------------------------
1926 const Type* AbsNode::Value(PhaseGVN* phase) const {
1927 const Type* t1 = phase->type(in(1));
1928 if (t1 == Type::TOP) return Type::TOP;
1929
1930 switch (t1->base()) {
1931 case Type::Int: {
1932 const TypeInt* ti = t1->is_int();
1933 if (ti->is_con()) {
1934 return TypeInt::make(g_uabs(ti->get_con()));
1935 }
1936 break;
1937 }
1938 case Type::Long: {
1939 const TypeLong* tl = t1->is_long();
1940 if (tl->is_con()) {
1941 return TypeLong::make(g_uabs(tl->get_con()));
1942 }
1943 break;
1944 }
1945 case Type::FloatCon:
1946 return TypeF::make(abs(t1->getf()));
1947 case Type::DoubleCon:
1948 return TypeD::make(abs(t1->getd()));
1949 default:
1950 break;
1951 }
1952
1953 return bottom_type();
1954 }
1955
1956 //------------------------------Identity----------------------------------------
1957 Node* AbsNode::Identity(PhaseGVN* phase) {
1958 Node* in1 = in(1);
1959 // No need to do abs for non-negative values
1960 if (phase->type(in1)->higher_equal(TypeInt::POS) ||
1961 phase->type(in1)->higher_equal(TypeLong::POS)) {
1962 return in1;
1963 }
1964 // Convert "abs(abs(x))" into "abs(x)"
1965 if (in1->Opcode() == Opcode()) {
1966 return in1;
1967 }
1968 return this;
1969 }
1970
1971 //------------------------------Ideal------------------------------------------
1972 Node* AbsNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1973 Node* in1 = in(1);
1974 // Convert "abs(0-x)" into "abs(x)"
1975 if (in1->is_Sub() && phase->type(in1->in(1))->is_zero_type()) {
1976 set_req_X(1, in1->in(2), phase);
1977 return this;
1978 }
1979 return nullptr;
1980 }
1981
1982 //=============================================================================
1983 //------------------------------Value------------------------------------------
1984 // Compute sqrt
1985 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
1986 const Type *t1 = phase->type( in(1) );
1987 if( t1 == Type::TOP ) return Type::TOP;
1988 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1989 double d = t1->getd();
1990 if( d < 0.0 ) return Type::DOUBLE;
1991 return TypeD::make( sqrt( d ) );
1992 }
1993
1994 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
1995 const Type *t1 = phase->type( in(1) );
1996 if( t1 == Type::TOP ) return Type::TOP;
1997 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
1998 float f = t1->getf();
1999 if( f < 0.0f ) return Type::FLOAT;
2000 return TypeF::make( (float)sqrt( (double)f ) );
2001 }
2002
2003 const Type* SqrtHFNode::Value(PhaseGVN* phase) const {
2004 const Type* t1 = phase->type(in(1));
2005 if (t1 == Type::TOP) { return Type::TOP; }
2006 if (t1->base() != Type::HalfFloatCon) { return Type::HALF_FLOAT; }
2007 float f = t1->getf();
2008 if (f < 0.0f) return Type::HALF_FLOAT;
2009 return TypeH::make((float)sqrt((double)f));
2010 }
2011
2012 static const Type* reverse_bytes(int opcode, const Type* con) {
2013 switch (opcode) {
2014 // It is valid in bytecode to load any int and pass it to a method that expects a smaller type (i.e., short, char).
2015 // Let's cast the value to match the Java behavior.
2016 case Op_ReverseBytesS: return TypeInt::make(byteswap(static_cast<jshort>(con->is_int()->get_con())));
2017 case Op_ReverseBytesUS: return TypeInt::make(byteswap(static_cast<jchar>(con->is_int()->get_con())));
2018 case Op_ReverseBytesI: return TypeInt::make(byteswap(con->is_int()->get_con()));
2019 case Op_ReverseBytesL: return TypeLong::make(byteswap(con->is_long()->get_con()));
2020 default: ShouldNotReachHere();
2021 }
2022 }
2023
2024 const Type* ReverseBytesNode::Value(PhaseGVN* phase) const {
2025 const Type* type = phase->type(in(1));
2026 if (type == Type::TOP) {
2027 return Type::TOP;
2028 }
2029 if (type->singleton()) {
2030 return reverse_bytes(Opcode(), type);
2031 }
2032 return bottom_type();
2033 }
2034
2035 const Type* ReverseINode::Value(PhaseGVN* phase) const {
2036 const Type *t1 = phase->type( in(1) );
2037 if (t1 == Type::TOP) {
2038 return Type::TOP;
2039 }
2040 const TypeInt* t1int = t1->isa_int();
2041 if (t1int && t1int->is_con()) {
2042 jint res = reverse_bits(t1int->get_con());
2043 return TypeInt::make(res);
2044 }
2045 return bottom_type();
2046 }
2047
2048 const Type* ReverseLNode::Value(PhaseGVN* phase) const {
2049 const Type *t1 = phase->type( in(1) );
2050 if (t1 == Type::TOP) {
2051 return Type::TOP;
2052 }
2053 const TypeLong* t1long = t1->isa_long();
2054 if (t1long && t1long->is_con()) {
2055 jlong res = reverse_bits(t1long->get_con());
2056 return TypeLong::make(res);
2057 }
2058 return bottom_type();
2059 }
2060
2061 Node* ReverseINode::Identity(PhaseGVN* phase) {
2062 if (in(1)->Opcode() == Op_ReverseI) {
2063 return in(1)->in(1);
2064 }
2065 return this;
2066 }
2067
2068 Node* ReverseLNode::Identity(PhaseGVN* phase) {
2069 if (in(1)->Opcode() == Op_ReverseL) {
2070 return in(1)->in(1);
2071 }
2072 return this;
2073 }