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