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 //------------------------------Ideal------------------------------------------
556 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
557 const Type *t2 = phase->type( in(2) );
558 // Convert "x-c0" into "x+ -c0".
559 if( t2->base() == Type::FloatCon ) { // Might be bottom or top...
560 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
561 }
562
563 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
564 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
565 //if( phase->type(in(1)) == TypeF::ZERO )
566 //return new (phase->C, 2) NegFNode(in(2));
567
568 return nullptr;
569 }
570
571 //------------------------------sub--------------------------------------------
572 // A subtract node differences its two inputs.
573 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
574 // no folding if one of operands is infinity or NaN, do not do constant folding
575 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
576 return TypeF::make( t1->getf() - t2->getf() );
577 }
578 else if( g_isnan(t1->getf()) ) {
579 return t1;
580 }
581 else if( g_isnan(t2->getf()) ) {
582 return t2;
583 }
584 else {
585 return Type::FLOAT;
586 }
587 }
588
589 //=============================================================================
590 //------------------------------Ideal------------------------------------------
591 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
592 const Type *t2 = phase->type( in(2) );
593 // Convert "x-c0" into "x+ -c0".
594 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
595 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
596 }
597
598 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
599 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
600 //if( phase->type(in(1)) == TypeD::ZERO )
601 //return new (phase->C, 2) NegDNode(in(2));
602
603 return nullptr;
604 }
605
606 //------------------------------sub--------------------------------------------
607 // A subtract node differences its two inputs.
608 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
609 // no folding if one of operands is infinity or NaN, do not do constant folding
610 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
611 return TypeD::make( t1->getd() - t2->getd() );
612 }
613 else if( g_isnan(t1->getd()) ) {
614 return t1;
615 }
616 else if( g_isnan(t2->getd()) ) {
617 return t2;
618 }
619 else {
620 return Type::DOUBLE;
621 }
622 }
623
624 //=============================================================================
625 //------------------------------Idealize---------------------------------------
626 // Unlike SubNodes, compare must still flatten return value to the
627 // range -1, 0, 1.
628 // And optimizations like those for (X + Y) - X fail if overflow happens.
629 Node* CmpNode::Identity(PhaseGVN* phase) {
630 return this;
631 }
632
633 CmpNode *CmpNode::make(Node *in1, Node *in2, BasicType bt, bool unsigned_comp) {
634 switch (bt) {
635 case T_INT:
636 if (unsigned_comp) {
637 return new CmpUNode(in1, in2);
638 }
639 return new CmpINode(in1, in2);
640 case T_LONG:
641 if (unsigned_comp) {
642 return new CmpULNode(in1, in2);
643 }
644 return new CmpLNode(in1, in2);
645 case T_OBJECT:
646 case T_ARRAY:
647 case T_ADDRESS:
648 case T_METADATA:
649 return new CmpPNode(in1, in2);
650 case T_NARROWOOP:
651 case T_NARROWKLASS:
652 return new CmpNNode(in1, in2);
653 default:
654 fatal("Not implemented for %s", type2name(bt));
655 }
656 return nullptr;
657 }
658
659 //=============================================================================
660 //------------------------------cmp--------------------------------------------
661 // Simplify a CmpI (compare 2 integers) node, based on local information.
662 // If both inputs are constants, compare them.
663 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
664 const TypeInt *r0 = t1->is_int(); // Handy access
665 const TypeInt *r1 = t2->is_int();
666
667 if( r0->_hi < r1->_lo ) // Range is always low?
668 return TypeInt::CC_LT;
669 else if( r0->_lo > r1->_hi ) // Range is always high?
670 return TypeInt::CC_GT;
671
672 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
673 assert(r0->get_con() == r1->get_con(), "must be equal");
674 return TypeInt::CC_EQ; // Equal results.
675 } else if( r0->_hi == r1->_lo ) // Range is never high?
676 return TypeInt::CC_LE;
677 else if( r0->_lo == r1->_hi ) // Range is never low?
678 return TypeInt::CC_GE;
679 return TypeInt::CC; // else use worst case results
680 }
681
682 const Type* CmpINode::Value(PhaseGVN* phase) const {
683 Node* in1 = in(1);
684 Node* in2 = in(2);
685 // If this test is the zero trip guard for a main or post loop, check whether, with the opaque node removed, the test
686 // would constant fold so the loop is never entered. If so return the type of the test without the opaque node removed:
687 // make the loop unreachable.
688 // The reason for this is that the iv phi captures the bounds of the loop and if the loop becomes unreachable, it can
689 // become top. In that case, the loop must be removed.
690 // This is safe because:
691 // - as optimizations proceed, the range of iterations executed by the main loop narrows. If no iterations remain, then
692 // we're done with optimizations for that loop.
693 // - the post loop is initially not reachable but as long as there's a main loop, the zero trip guard for the post
694 // 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
695 // loop is removed, there's no need to preserve the zero trip guard for the post loop anymore.
696 if (in1 != nullptr && in2 != nullptr) {
697 uint input = 0;
698 Node* cmp = nullptr;
699 BoolTest::mask test;
700 if (in1->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in1) != Type::TOP) {
701 cmp = new CmpINode(in1->in(1), in2);
702 test = ((OpaqueZeroTripGuardNode*)in1)->_loop_entered_mask;
703 }
704 if (in2->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in2) != Type::TOP) {
705 assert(cmp == nullptr, "A cmp with 2 OpaqueZeroTripGuard inputs");
706 cmp = new CmpINode(in1, in2->in(1));
707 test = ((OpaqueZeroTripGuardNode*)in2)->_loop_entered_mask;
708 }
709 if (cmp != nullptr) {
710 const Type* cmp_t = cmp->Value(phase);
711 const Type* t = BoolTest(test).cc2logical(cmp_t);
712 cmp->destruct(phase);
713 if (t == TypeInt::ZERO) {
714 return cmp_t;
715 }
716 }
717 }
718
719 return SubNode::Value(phase);
720 }
721
722
723 // Simplify a CmpU (compare 2 integers) node, based on local information.
724 // If both inputs are constants, compare them.
725 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
726 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
727
728 // comparing two unsigned ints
729 const TypeInt *r0 = t1->is_int(); // Handy access
730 const TypeInt *r1 = t2->is_int();
731
732 // Current installed version
733 // Compare ranges for non-overlap
734 juint lo0 = r0->_lo;
735 juint hi0 = r0->_hi;
736 juint lo1 = r1->_lo;
737 juint hi1 = r1->_hi;
738
739 // If either one has both negative and positive values,
740 // it therefore contains both 0 and -1, and since [0..-1] is the
741 // full unsigned range, the type must act as an unsigned bottom.
742 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
743 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
744
745 if (bot0 || bot1) {
746 // All unsigned values are LE -1 and GE 0.
747 if (lo0 == 0 && hi0 == 0) {
748 return TypeInt::CC_LE; // 0 <= bot
749 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
750 return TypeInt::CC_GE; // -1 >= bot
751 } else if (lo1 == 0 && hi1 == 0) {
752 return TypeInt::CC_GE; // bot >= 0
753 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
754 return TypeInt::CC_LE; // bot <= -1
755 }
756 } else {
757 // We can use ranges of the form [lo..hi] if signs are the same.
758 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
759 // results are reversed, '-' > '+' for unsigned compare
760 if (hi0 < lo1) {
761 return TypeInt::CC_LT; // smaller
762 } else if (lo0 > hi1) {
763 return TypeInt::CC_GT; // greater
764 } else if (hi0 == lo1 && lo0 == hi1) {
765 return TypeInt::CC_EQ; // Equal results
766 } else if (lo0 >= hi1) {
767 return TypeInt::CC_GE;
768 } else if (hi0 <= lo1) {
769 // Check for special case in Hashtable::get. (See below.)
770 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
771 return TypeInt::CC_LT;
772 return TypeInt::CC_LE;
773 }
774 }
775 // Check for special case in Hashtable::get - the hash index is
776 // mod'ed to the table size so the following range check is useless.
777 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
778 // to be positive.
779 // (This is a gross hack, since the sub method never
780 // looks at the structure of the node in any other case.)
781 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
782 return TypeInt::CC_LT;
783 return TypeInt::CC; // else use worst case results
784 }
785
786 const Type* CmpUNode::Value(PhaseGVN* phase) const {
787 const Type* t = SubNode::Value_common(phase);
788 if (t != nullptr) {
789 return t;
790 }
791 const Node* in1 = in(1);
792 const Node* in2 = in(2);
793 const Type* t1 = phase->type(in1);
794 const Type* t2 = phase->type(in2);
795 assert(t1->isa_int(), "CmpU has only Int type inputs");
796 if (t2 == TypeInt::INT) { // Compare to bottom?
797 return bottom_type();
798 }
799
800 const Type* t_sub = sub(t1, t2); // compare based on immediate inputs
801
802 uint in1_op = in1->Opcode();
803 if (in1_op == Op_AddI || in1_op == Op_SubI) {
804 // The problem rise when result of AddI(SubI) may overflow
805 // signed integer value. Let say the input type is
806 // [256, maxint] then +128 will create 2 ranges due to
807 // overflow: [minint, minint+127] and [384, maxint].
808 // But C2 type system keep only 1 type range and as result
809 // it use general [minint, maxint] for this case which we
810 // can't optimize.
811 //
812 // Make 2 separate type ranges based on types of AddI(SubI) inputs
813 // and compare results of their compare. If results are the same
814 // CmpU node can be optimized.
815 const Node* in11 = in1->in(1);
816 const Node* in12 = in1->in(2);
817 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
818 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
819 // Skip cases when input types are top or bottom.
820 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
821 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
822 const TypeInt *r0 = t11->is_int();
823 const TypeInt *r1 = t12->is_int();
824 jlong lo_r0 = r0->_lo;
825 jlong hi_r0 = r0->_hi;
826 jlong lo_r1 = r1->_lo;
827 jlong hi_r1 = r1->_hi;
828 if (in1_op == Op_SubI) {
829 jlong tmp = hi_r1;
830 hi_r1 = -lo_r1;
831 lo_r1 = -tmp;
832 // Note, for substructing [minint,x] type range
833 // long arithmetic provides correct overflow answer.
834 // The confusion come from the fact that in 32-bit
835 // -minint == minint but in 64-bit -minint == maxint+1.
836 }
837 jlong lo_long = lo_r0 + lo_r1;
838 jlong hi_long = hi_r0 + hi_r1;
839 int lo_tr1 = min_jint;
840 int hi_tr1 = (int)hi_long;
841 int lo_tr2 = (int)lo_long;
842 int hi_tr2 = max_jint;
843 bool underflow = lo_long != (jlong)lo_tr2;
844 bool overflow = hi_long != (jlong)hi_tr1;
845 // Use sub(t1, t2) when there is no overflow (one type range)
846 // or when both overflow and underflow (too complex).
847 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
848 // Overflow only on one boundary, compare 2 separate type ranges.
849 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
850 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
851 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
852 const TypeInt* cmp1 = sub(tr1, t2)->is_int();
853 const TypeInt* cmp2 = sub(tr2, t2)->is_int();
854 // Compute union, so that cmp handles all possible results from the two cases
855 const Type* t_cmp = cmp1->meet(cmp2);
856 // Pick narrowest type, based on overflow computation and on immediate inputs
857 return t_sub->filter(t_cmp);
858 }
859 }
860 }
861
862 return t_sub;
863 }
864
865 bool CmpUNode::is_index_range_check() const {
866 // Check for the "(X ModI Y) CmpU Y" shape
867 return (in(1)->Opcode() == Op_ModI &&
868 in(1)->in(2)->eqv_uncast(in(2)));
869 }
870
871 //------------------------------Idealize---------------------------------------
872 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
873 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
874 switch (in(1)->Opcode()) {
875 case Op_CmpU3: // Collapse a CmpU3/CmpI into a CmpU
876 return new CmpUNode(in(1)->in(1),in(1)->in(2));
877 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
878 return new CmpLNode(in(1)->in(1),in(1)->in(2));
879 case Op_CmpUL3: // Collapse a CmpUL3/CmpI into a CmpUL
880 return new CmpULNode(in(1)->in(1),in(1)->in(2));
881 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
882 return new CmpFNode(in(1)->in(1),in(1)->in(2));
883 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
884 return new CmpDNode(in(1)->in(1),in(1)->in(2));
885 //case Op_SubI:
886 // If (x - y) cannot overflow, then ((x - y) <?> 0)
887 // can be turned into (x <?> y).
888 // This is handled (with more general cases) by Ideal_sub_algebra.
889 }
890 }
891 return nullptr; // No change
892 }
893
894 Node *CmpLNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
895 const TypeLong *t2 = phase->type(in(2))->isa_long();
896 if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) {
897 const jlong con = t2->get_con();
898 if (con >= min_jint && con <= max_jint) {
899 return new CmpINode(in(1)->in(1), phase->intcon((jint)con));
900 }
901 }
902 return nullptr;
903 }
904
905 //=============================================================================
906 // Simplify a CmpL (compare 2 longs ) node, based on local information.
907 // If both inputs are constants, compare them.
908 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
909 const TypeLong *r0 = t1->is_long(); // Handy access
910 const TypeLong *r1 = t2->is_long();
911
912 if( r0->_hi < r1->_lo ) // Range is always low?
913 return TypeInt::CC_LT;
914 else if( r0->_lo > r1->_hi ) // Range is always high?
915 return TypeInt::CC_GT;
916
917 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
918 assert(r0->get_con() == r1->get_con(), "must be equal");
919 return TypeInt::CC_EQ; // Equal results.
920 } else if( r0->_hi == r1->_lo ) // Range is never high?
921 return TypeInt::CC_LE;
922 else if( r0->_lo == r1->_hi ) // Range is never low?
923 return TypeInt::CC_GE;
924 return TypeInt::CC; // else use worst case results
925 }
926
927
928 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
929 // If both inputs are constants, compare them.
930 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
931 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
932
933 // comparing two unsigned longs
934 const TypeLong* r0 = t1->is_long(); // Handy access
935 const TypeLong* r1 = t2->is_long();
936
937 // Current installed version
938 // Compare ranges for non-overlap
939 julong lo0 = r0->_lo;
940 julong hi0 = r0->_hi;
941 julong lo1 = r1->_lo;
942 julong hi1 = r1->_hi;
943
944 // If either one has both negative and positive values,
945 // it therefore contains both 0 and -1, and since [0..-1] is the
946 // full unsigned range, the type must act as an unsigned bottom.
947 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
948 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
949
950 if (bot0 || bot1) {
951 // All unsigned values are LE -1 and GE 0.
952 if (lo0 == 0 && hi0 == 0) {
953 return TypeInt::CC_LE; // 0 <= bot
954 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
955 return TypeInt::CC_GE; // -1 >= bot
956 } else if (lo1 == 0 && hi1 == 0) {
957 return TypeInt::CC_GE; // bot >= 0
958 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
959 return TypeInt::CC_LE; // bot <= -1
960 }
961 } else {
962 // We can use ranges of the form [lo..hi] if signs are the same.
963 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
964 // results are reversed, '-' > '+' for unsigned compare
965 if (hi0 < lo1) {
966 return TypeInt::CC_LT; // smaller
967 } else if (lo0 > hi1) {
968 return TypeInt::CC_GT; // greater
969 } else if (hi0 == lo1 && lo0 == hi1) {
970 return TypeInt::CC_EQ; // Equal results
971 } else if (lo0 >= hi1) {
972 return TypeInt::CC_GE;
973 } else if (hi0 <= lo1) {
974 return TypeInt::CC_LE;
975 }
976 }
977
978 return TypeInt::CC; // else use worst case results
979 }
980
981 //=============================================================================
982 //------------------------------sub--------------------------------------------
983 // Simplify an CmpP (compare 2 pointers) node, based on local information.
984 // If both inputs are constants, compare them.
985 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
986 const TypePtr *r0 = t1->is_ptr(); // Handy access
987 const TypePtr *r1 = t2->is_ptr();
988
989 // Undefined inputs makes for an undefined result
990 if( TypePtr::above_centerline(r0->_ptr) ||
991 TypePtr::above_centerline(r1->_ptr) )
992 return Type::TOP;
993
994 if (r0 == r1 && r0->singleton()) {
995 // Equal pointer constants (klasses, nulls, etc.)
996 return TypeInt::CC_EQ;
997 }
998
999 // See if it is 2 unrelated classes.
1000 const TypeOopPtr* p0 = r0->isa_oopptr();
1001 const TypeOopPtr* p1 = r1->isa_oopptr();
1002 const TypeKlassPtr* k0 = r0->isa_klassptr();
1003 const TypeKlassPtr* k1 = r1->isa_klassptr();
1004 if ((p0 && p1) || (k0 && k1)) {
1005 if (p0 && p1) {
1006 Node* in1 = in(1)->uncast();
1007 Node* in2 = in(2)->uncast();
1008 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1);
1009 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2);
1010 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, nullptr)) {
1011 return TypeInt::CC_GT; // different pointers
1012 }
1013 }
1014 bool xklass0 = p0 ? p0->klass_is_exact() : k0->klass_is_exact();
1015 bool xklass1 = p1 ? p1->klass_is_exact() : k1->klass_is_exact();
1016 bool unrelated_classes = false;
1017
1018 if ((p0 && p0->is_same_java_type_as(p1)) ||
1019 (k0 && k0->is_same_java_type_as(k1))) {
1020 } else if ((p0 && !p1->maybe_java_subtype_of(p0) && !p0->maybe_java_subtype_of(p1)) ||
1021 (k0 && !k1->maybe_java_subtype_of(k0) && !k0->maybe_java_subtype_of(k1))) {
1022 unrelated_classes = true;
1023 } else if ((p0 && !p1->maybe_java_subtype_of(p0)) ||
1024 (k0 && !k1->maybe_java_subtype_of(k0))) {
1025 unrelated_classes = xklass1;
1026 } else if ((p0 && !p0->maybe_java_subtype_of(p1)) ||
1027 (k0 && !k0->maybe_java_subtype_of(k1))) {
1028 unrelated_classes = xklass0;
1029 }
1030
1031 if (unrelated_classes) {
1032 // The oops classes are known to be unrelated. If the joined PTRs of
1033 // two oops is not Null and not Bottom, then we are sure that one
1034 // of the two oops is non-null, and the comparison will always fail.
1035 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1036 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1037 return TypeInt::CC_GT;
1038 }
1039 }
1040 }
1041
1042 // Known constants can be compared exactly
1043 // Null can be distinguished from any NotNull pointers
1044 // Unknown inputs makes an unknown result
1045 if( r0->singleton() ) {
1046 intptr_t bits0 = r0->get_con();
1047 if( r1->singleton() )
1048 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1049 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1050 } else if( r1->singleton() ) {
1051 intptr_t bits1 = r1->get_con();
1052 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1053 } else
1054 return TypeInt::CC;
1055 }
1056
1057 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1058 // Return the klass node for (indirect load from OopHandle)
1059 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1060 // or null if not matching.
1061 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1062 n = bs->step_over_gc_barrier(n);
1063
1064 if (n->Opcode() != Op_LoadP) return nullptr;
1065
1066 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1067 if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr;
1068
1069 Node* adr = n->in(MemNode::Address);
1070 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1071 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr;
1072 adr = adr->in(MemNode::Address);
1073
1074 intptr_t off = 0;
1075 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1076 if (k == nullptr) return nullptr;
1077 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1078 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr;
1079
1080 // We've found the klass node of a Java mirror load.
1081 return k;
1082 }
1083
1084 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
1085 // for ConP(Foo.class) return ConP(Foo.klass)
1086 // otherwise return null
1087 if (!n->is_Con()) return nullptr;
1088
1089 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1090 if (!tp) return nullptr;
1091
1092 ciType* mirror_type = tp->java_mirror_type();
1093 // TypeInstPtr::java_mirror_type() returns non-null for compile-
1094 // time Class constants only.
1095 if (!mirror_type) return nullptr;
1096
1097 // x.getClass() == int.class can never be true (for all primitive types)
1098 // Return a ConP(null) node for this case.
1099 if (mirror_type->is_classless()) {
1100 return phase->makecon(TypePtr::NULL_PTR);
1101 }
1102
1103 // return the ConP(Foo.klass)
1104 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
1105 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass(), Type::trust_interfaces));
1106 }
1107
1108 //------------------------------Ideal------------------------------------------
1109 // Normalize comparisons between Java mirror loads to compare the klass instead.
1110 //
1111 // Also check for the case of comparing an unknown klass loaded from the primary
1112 // super-type array vs a known klass with no subtypes. This amounts to
1113 // checking to see an unknown klass subtypes a known klass with no subtypes;
1114 // this only happens on an exact match. We can shorten this test by 1 load.
1115 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1116 // Normalize comparisons between Java mirrors into comparisons of the low-
1117 // level klass, where a dependent load could be shortened.
1118 //
1119 // The new pattern has a nice effect of matching the same pattern used in the
1120 // fast path of instanceof/checkcast/Class.isInstance(), which allows
1121 // redundant exact type check be optimized away by GVN.
1122 // For example, in
1123 // if (x.getClass() == Foo.class) {
1124 // Foo foo = (Foo) x;
1125 // // ... use a ...
1126 // }
1127 // a CmpPNode could be shared between if_acmpne and checkcast
1128 {
1129 Node* k1 = isa_java_mirror_load(phase, in(1));
1130 Node* k2 = isa_java_mirror_load(phase, in(2));
1131 Node* conk2 = isa_const_java_mirror(phase, in(2));
1132
1133 if (k1 && (k2 || conk2)) {
1134 Node* lhs = k1;
1135 Node* rhs = (k2 != nullptr) ? k2 : conk2;
1136 set_req_X(1, lhs, phase);
1137 set_req_X(2, rhs, phase);
1138 return this;
1139 }
1140 }
1141
1142 // Constant pointer on right?
1143 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1144 if (t2 == nullptr || !t2->klass_is_exact())
1145 return nullptr;
1146 // Get the constant klass we are comparing to.
1147 ciKlass* superklass = t2->exact_klass();
1148
1149 // Now check for LoadKlass on left.
1150 Node* ldk1 = in(1);
1151 if (ldk1->is_DecodeNKlass()) {
1152 ldk1 = ldk1->in(1);
1153 if (ldk1->Opcode() != Op_LoadNKlass )
1154 return nullptr;
1155 } else if (ldk1->Opcode() != Op_LoadKlass )
1156 return nullptr;
1157 // Take apart the address of the LoadKlass:
1158 Node* adr1 = ldk1->in(MemNode::Address);
1159 intptr_t con2 = 0;
1160 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1161 if (ldk2 == nullptr)
1162 return nullptr;
1163 if (con2 == Type::klass_offset()) {
1164 // We are inspecting an object's concrete class.
1165 // Short-circuit the check if the query is abstract.
1166 if (superklass->is_interface() ||
1167 superklass->is_abstract()) {
1168 // Make it come out always false:
1169 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1170 return this;
1171 }
1172 }
1173
1174 // Check for a LoadKlass from primary supertype array.
1175 // Any nested loadklass from loadklass+con must be from the p.s. array.
1176 if (ldk2->is_DecodeNKlass()) {
1177 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1178 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1179 return nullptr;
1180 } else if (ldk2->Opcode() != Op_LoadKlass)
1181 return nullptr;
1182
1183 // Verify that we understand the situation
1184 if (con2 != (intptr_t) superklass->super_check_offset())
1185 return nullptr; // Might be element-klass loading from array klass
1186
1187 // If 'superklass' has no subklasses and is not an interface, then we are
1188 // assured that the only input which will pass the type check is
1189 // 'superklass' itself.
1190 //
1191 // We could be more liberal here, and allow the optimization on interfaces
1192 // which have a single implementor. This would require us to increase the
1193 // expressiveness of the add_dependency() mechanism.
1194 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1195
1196 // Object arrays must have their base element have no subtypes
1197 while (superklass->is_obj_array_klass()) {
1198 ciType* elem = superklass->as_obj_array_klass()->element_type();
1199 superklass = elem->as_klass();
1200 }
1201 if (superklass->is_instance_klass()) {
1202 ciInstanceKlass* ik = superklass->as_instance_klass();
1203 if (ik->has_subklass() || ik->is_interface()) return nullptr;
1204 // Add a dependency if there is a chance that a subclass will be added later.
1205 if (!ik->is_final()) {
1206 phase->C->dependencies()->assert_leaf_type(ik);
1207 }
1208 }
1209
1210 // Bypass the dependent load, and compare directly
1211 this->set_req_X(1, ldk2, phase);
1212
1213 return this;
1214 }
1215
1216 //=============================================================================
1217 //------------------------------sub--------------------------------------------
1218 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1219 // If both inputs are constants, compare them.
1220 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1221 ShouldNotReachHere();
1222 return bottom_type();
1223 }
1224
1225 //------------------------------Ideal------------------------------------------
1226 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1227 return nullptr;
1228 }
1229
1230 //=============================================================================
1231 //------------------------------Value------------------------------------------
1232 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1233 // If both inputs are constants, compare them.
1234 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1235 const Node* in1 = in(1);
1236 const Node* in2 = in(2);
1237 // Either input is TOP ==> the result is TOP
1238 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1239 if( t1 == Type::TOP ) return Type::TOP;
1240 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1241 if( t2 == Type::TOP ) return Type::TOP;
1242
1243 // Not constants? Don't know squat - even if they are the same
1244 // value! If they are NaN's they compare to LT instead of EQ.
1245 const TypeF *tf1 = t1->isa_float_constant();
1246 const TypeF *tf2 = t2->isa_float_constant();
1247 if( !tf1 || !tf2 ) return TypeInt::CC;
1248
1249 // This implements the Java bytecode fcmpl, so unordered returns -1.
1250 if( tf1->is_nan() || tf2->is_nan() )
1251 return TypeInt::CC_LT;
1252
1253 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1254 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1255 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1256 return TypeInt::CC_EQ;
1257 }
1258
1259
1260 //=============================================================================
1261 //------------------------------Value------------------------------------------
1262 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1263 // If both inputs are constants, compare them.
1264 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1265 const Node* in1 = in(1);
1266 const Node* in2 = in(2);
1267 // Either input is TOP ==> the result is TOP
1268 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1269 if( t1 == Type::TOP ) return Type::TOP;
1270 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1271 if( t2 == Type::TOP ) return Type::TOP;
1272
1273 // Not constants? Don't know squat - even if they are the same
1274 // value! If they are NaN's they compare to LT instead of EQ.
1275 const TypeD *td1 = t1->isa_double_constant();
1276 const TypeD *td2 = t2->isa_double_constant();
1277 if( !td1 || !td2 ) return TypeInt::CC;
1278
1279 // This implements the Java bytecode dcmpl, so unordered returns -1.
1280 if( td1->is_nan() || td2->is_nan() )
1281 return TypeInt::CC_LT;
1282
1283 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1284 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1285 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1286 return TypeInt::CC_EQ;
1287 }
1288
1289 //------------------------------Ideal------------------------------------------
1290 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1291 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1292 // Change (CMPD (F2D (float)) (ConD value))
1293 // To (CMPF (float) (ConF value))
1294 // Valid when 'value' does not lose precision as a float.
1295 // Benefits: eliminates conversion, does not require 24-bit mode
1296
1297 // NaNs prevent commuting operands. This transform works regardless of the
1298 // order of ConD and ConvF2D inputs by preserving the original order.
1299 int idx_f2d = 1; // ConvF2D on left side?
1300 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1301 idx_f2d = 2; // No, swap to check for reversed args
1302 int idx_con = 3-idx_f2d; // Check for the constant on other input
1303
1304 if( ConvertCmpD2CmpF &&
1305 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1306 in(idx_con)->Opcode() == Op_ConD ) {
1307 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1308 double t2_value_as_double = t2->_d;
1309 float t2_value_as_float = (float)t2_value_as_double;
1310 if( t2_value_as_double == (double)t2_value_as_float ) {
1311 // Test value can be represented as a float
1312 // Eliminate the conversion to double and create new comparison
1313 Node *new_in1 = in(idx_f2d)->in(1);
1314 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1315 if( idx_f2d != 1 ) { // Must flip args to match original order
1316 Node *tmp = new_in1;
1317 new_in1 = new_in2;
1318 new_in2 = tmp;
1319 }
1320 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1321 ? new CmpF3Node( new_in1, new_in2 )
1322 : new CmpFNode ( new_in1, new_in2 ) ;
1323 return new_cmp; // Changed to CmpFNode
1324 }
1325 // Testing value required the precision of a double
1326 }
1327 return nullptr; // No change
1328 }
1329
1330
1331 //=============================================================================
1332 //------------------------------cc2logical-------------------------------------
1333 // Convert a condition code type to a logical type
1334 const Type *BoolTest::cc2logical( const Type *CC ) const {
1335 if( CC == Type::TOP ) return Type::TOP;
1336 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1337 const TypeInt *ti = CC->is_int();
1338 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1339 // Match low order 2 bits
1340 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1341 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1342 return TypeInt::make(tmp); // Boolean result
1343 }
1344
1345 if( CC == TypeInt::CC_GE ) {
1346 if( _test == ge ) return TypeInt::ONE;
1347 if( _test == lt ) return TypeInt::ZERO;
1348 }
1349 if( CC == TypeInt::CC_LE ) {
1350 if( _test == le ) return TypeInt::ONE;
1351 if( _test == gt ) return TypeInt::ZERO;
1352 }
1353
1354 return TypeInt::BOOL;
1355 }
1356
1357 //------------------------------dump_spec-------------------------------------
1358 // Print special per-node info
1359 void BoolTest::dump_on(outputStream *st) const {
1360 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1361 st->print("%s", msg[_test]);
1362 }
1363
1364 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1365 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1366 BoolTest::mask BoolTest::merge(BoolTest other) const {
1367 const mask res[illegal+1][illegal+1] = {
1368 // eq, gt, of, lt, ne, le, nof, ge, never, illegal
1369 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq
1370 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt
1371 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of
1372 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt
1373 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne
1374 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le
1375 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof
1376 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge
1377 {never, never, never, never, never, never, never, never, never, illegal}, // never
1378 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1379 return res[_test][other._test];
1380 }
1381
1382 //=============================================================================
1383 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1384 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1385
1386 //------------------------------operator==-------------------------------------
1387 bool BoolNode::cmp( const Node &n ) const {
1388 const BoolNode *b = (const BoolNode *)&n; // Cast up
1389 return (_test._test == b->_test._test);
1390 }
1391
1392 //-------------------------------make_predicate--------------------------------
1393 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1394 if (test_value->is_Con()) return test_value;
1395 if (test_value->is_Bool()) return test_value;
1396 if (test_value->is_CMove() &&
1397 test_value->in(CMoveNode::Condition)->is_Bool()) {
1398 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1399 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1400 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1401 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1402 return bol;
1403 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1404 return phase->transform( bol->negate(phase) );
1405 }
1406 // Else fall through. The CMove gets in the way of the test.
1407 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1408 }
1409 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1410 cmp = phase->transform(cmp);
1411 Node* bol = new BoolNode(cmp, BoolTest::ne);
1412 return phase->transform(bol);
1413 }
1414
1415 //--------------------------------as_int_value---------------------------------
1416 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1417 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1418 Node* cmov = CMoveNode::make(this, phase->intcon(0), phase->intcon(1), TypeInt::BOOL);
1419 return phase->transform(cmov);
1420 }
1421
1422 //----------------------------------negate-------------------------------------
1423 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1424 return new BoolNode(in(1), _test.negate());
1425 }
1426
1427 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1428 // overflows and we can prove that C is not in the two resulting ranges.
1429 // This optimization is similar to the one performed by CmpUNode::Value().
1430 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1431 int cmp1_op, const TypeInt* cmp2_type) {
1432 // Only optimize eq/ne integer comparison of add/sub
1433 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1434 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1435 // Skip cases were inputs of add/sub are not integers or of bottom type
1436 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1437 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1438 if ((r0 != nullptr) && (r0 != TypeInt::INT) &&
1439 (r1 != nullptr) && (r1 != TypeInt::INT) &&
1440 (cmp2_type != TypeInt::INT)) {
1441 // Compute exact (long) type range of add/sub result
1442 jlong lo_long = r0->_lo;
1443 jlong hi_long = r0->_hi;
1444 if (cmp1_op == Op_AddI) {
1445 lo_long += r1->_lo;
1446 hi_long += r1->_hi;
1447 } else {
1448 lo_long -= r1->_hi;
1449 hi_long -= r1->_lo;
1450 }
1451 // Check for over-/underflow by casting to integer
1452 int lo_int = (int)lo_long;
1453 int hi_int = (int)hi_long;
1454 bool underflow = lo_long != (jlong)lo_int;
1455 bool overflow = hi_long != (jlong)hi_int;
1456 if ((underflow != overflow) && (hi_int < lo_int)) {
1457 // Overflow on one boundary, compute resulting type ranges:
1458 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1459 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1460 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1461 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1462 // Compare second input of cmp to both type ranges
1463 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1464 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1465 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1466 // The result of the add/sub will never equal cmp2. Replace BoolNode
1467 // by false (0) if it tests for equality and by true (1) otherwise.
1468 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1469 }
1470 }
1471 }
1472 }
1473 return nullptr;
1474 }
1475
1476 static bool is_counted_loop_cmp(Node *cmp) {
1477 Node *n = cmp->in(1)->in(1);
1478 return n != nullptr &&
1479 n->is_Phi() &&
1480 n->in(0) != nullptr &&
1481 n->in(0)->is_CountedLoop() &&
1482 n->in(0)->as_CountedLoop()->phi() == n;
1483 }
1484
1485 //------------------------------Ideal------------------------------------------
1486 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1487 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1488 // This moves the constant to the right. Helps value-numbering.
1489 Node *cmp = in(1);
1490 if( !cmp->is_Sub() ) return nullptr;
1491 int cop = cmp->Opcode();
1492 if( cop == Op_FastLock || cop == Op_FastUnlock ||
1493 cmp->is_SubTypeCheck() || cop == Op_VectorTest ) {
1494 return nullptr;
1495 }
1496 Node *cmp1 = cmp->in(1);
1497 Node *cmp2 = cmp->in(2);
1498 if( !cmp1 ) return nullptr;
1499
1500 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1501 return nullptr;
1502 }
1503
1504 const int cmp1_op = cmp1->Opcode();
1505 const int cmp2_op = cmp2->Opcode();
1506
1507 // Constant on left?
1508 Node *con = cmp1;
1509 // Move constants to the right of compare's to canonicalize.
1510 // Do not muck with Opaque1 nodes, as this indicates a loop
1511 // guard that cannot change shape.
1512 if (con->is_Con() && !cmp2->is_Con() && cmp2_op != Op_OpaqueZeroTripGuard &&
1513 // Because of NaN's, CmpD and CmpF are not commutative
1514 cop != Op_CmpD && cop != Op_CmpF &&
1515 // Protect against swapping inputs to a compare when it is used by a
1516 // counted loop exit, which requires maintaining the loop-limit as in(2)
1517 !is_counted_loop_exit_test() ) {
1518 // Ok, commute the constant to the right of the cmp node.
1519 // Clone the Node, getting a new Node of the same class
1520 cmp = cmp->clone();
1521 // Swap inputs to the clone
1522 cmp->swap_edges(1, 2);
1523 cmp = phase->transform( cmp );
1524 return new BoolNode( cmp, _test.commute() );
1525 }
1526
1527 // Change "bool eq/ne (cmp (cmove (bool tst (cmp2)) 1 0) 0)" into "bool tst/~tst (cmp2)"
1528 if (cop == Op_CmpI &&
1529 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1530 cmp1_op == Op_CMoveI && cmp2->find_int_con(1) == 0) {
1531 // 0 should be on the true branch
1532 if (cmp1->in(CMoveNode::Condition)->is_Bool() &&
1533 cmp1->in(CMoveNode::IfTrue)->find_int_con(1) == 0 &&
1534 cmp1->in(CMoveNode::IfFalse)->find_int_con(0) != 0) {
1535 BoolNode* target = cmp1->in(CMoveNode::Condition)->as_Bool();
1536 return new BoolNode(target->in(1),
1537 (_test._test == BoolTest::eq) ? target->_test._test :
1538 target->_test.negate());
1539 }
1540 }
1541
1542 // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1543 if (cop == Op_CmpI &&
1544 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1545 cmp1_op == Op_AndI && cmp2_op == Op_ConI &&
1546 cmp1->in(2)->Opcode() == Op_ConI) {
1547 const TypeInt *t12 = phase->type(cmp2)->isa_int();
1548 const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int();
1549 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1550 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1551 Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1552 return new BoolNode(ncmp, _test.negate());
1553 }
1554 }
1555
1556 // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1557 if (cop == Op_CmpL &&
1558 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1559 cmp1_op == Op_AndL && cmp2_op == Op_ConL &&
1560 cmp1->in(2)->Opcode() == Op_ConL) {
1561 const TypeLong *t12 = phase->type(cmp2)->isa_long();
1562 const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long();
1563 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1564 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1565 Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0)));
1566 return new BoolNode(ncmp, _test.negate());
1567 }
1568 }
1569
1570 // Change "cmp (add X min_jint) (add Y min_jint)" into "cmpu X Y"
1571 // and "cmp (add X min_jint) c" into "cmpu X (c + min_jint)"
1572 if (cop == Op_CmpI &&
1573 cmp1_op == Op_AddI &&
1574 phase->type(cmp1->in(2)) == TypeInt::MIN &&
1575 !is_cloop_condition(this)) {
1576 if (cmp2_op == Op_ConI) {
1577 Node* ncmp2 = phase->intcon(java_add(cmp2->get_int(), min_jint));
1578 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), ncmp2));
1579 return new BoolNode(ncmp, _test._test);
1580 } else if (cmp2_op == Op_AddI &&
1581 phase->type(cmp2->in(2)) == TypeInt::MIN &&
1582 !is_cloop_condition(this)) {
1583 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), cmp2->in(1)));
1584 return new BoolNode(ncmp, _test._test);
1585 }
1586 }
1587
1588 // Change "cmp (add X min_jlong) (add Y min_jlong)" into "cmpu X Y"
1589 // and "cmp (add X min_jlong) c" into "cmpu X (c + min_jlong)"
1590 if (cop == Op_CmpL &&
1591 cmp1_op == Op_AddL &&
1592 phase->type(cmp1->in(2)) == TypeLong::MIN &&
1593 !is_cloop_condition(this)) {
1594 if (cmp2_op == Op_ConL) {
1595 Node* ncmp2 = phase->longcon(java_add(cmp2->get_long(), min_jlong));
1596 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), ncmp2));
1597 return new BoolNode(ncmp, _test._test);
1598 } else if (cmp2_op == Op_AddL &&
1599 phase->type(cmp2->in(2)) == TypeLong::MIN &&
1600 !is_cloop_condition(this)) {
1601 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), cmp2->in(1)));
1602 return new BoolNode(ncmp, _test._test);
1603 }
1604 }
1605
1606 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1607 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1608 // test instead.
1609 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1610 if (cmp2_type == nullptr) return nullptr;
1611 Node* j_xor = cmp1;
1612 if( cmp2_type == TypeInt::ZERO &&
1613 cmp1_op == Op_XorI &&
1614 j_xor->in(1) != j_xor && // An xor of itself is dead
1615 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1616 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1617 (_test._test == BoolTest::eq ||
1618 _test._test == BoolTest::ne) ) {
1619 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1620 return new BoolNode( ncmp, _test.negate() );
1621 }
1622
1623 // Transform: "((x & (m - 1)) <u m)" or "(((m - 1) & x) <u m)" into "(m >u 0)"
1624 // This is case [CMPU_MASK] which is further described at the method comment of BoolNode::Value_cmpu_and_mask().
1625 if (cop == Op_CmpU && _test._test == BoolTest::lt && cmp1_op == Op_AndI) {
1626 Node* m = cmp2; // RHS: m
1627 for (int add_idx = 1; add_idx <= 2; add_idx++) { // LHS: "(m + (-1)) & x" or "x & (m + (-1))"?
1628 Node* maybe_m_minus_1 = cmp1->in(add_idx);
1629 if (maybe_m_minus_1->Opcode() == Op_AddI &&
1630 maybe_m_minus_1->in(2)->find_int_con(0) == -1 &&
1631 maybe_m_minus_1->in(1) == m) {
1632 Node* m_cmpu_0 = phase->transform(new CmpUNode(m, phase->intcon(0)));
1633 return new BoolNode(m_cmpu_0, BoolTest::gt);
1634 }
1635 }
1636 }
1637
1638 // Change x u< 1 or x u<= 0 to x == 0
1639 // and x u> 0 or u>= 1 to x != 0
1640 if (cop == Op_CmpU &&
1641 cmp1_op != Op_LoadRange &&
1642 (((_test._test == BoolTest::lt || _test._test == BoolTest::ge) &&
1643 cmp2->find_int_con(-1) == 1) ||
1644 ((_test._test == BoolTest::le || _test._test == BoolTest::gt) &&
1645 cmp2->find_int_con(-1) == 0))) {
1646 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1647 return new BoolNode(ncmp, _test.is_less() ? BoolTest::eq : BoolTest::ne);
1648 }
1649
1650 // Change (arraylength <= 0) or (arraylength == 0)
1651 // into (arraylength u<= 0)
1652 // Also change (arraylength != 0) into (arraylength u> 0)
1653 // The latter version matches the code pattern generated for
1654 // array range checks, which will more likely be optimized later.
1655 if (cop == Op_CmpI &&
1656 cmp1_op == Op_LoadRange &&
1657 cmp2->find_int_con(-1) == 0) {
1658 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1659 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1660 return new BoolNode(ncmp, BoolTest::le);
1661 } else if (_test._test == BoolTest::ne) {
1662 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1663 return new BoolNode(ncmp, BoolTest::gt);
1664 }
1665 }
1666
1667 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1668 // This is a standard idiom for branching on a boolean value.
1669 Node *c2b = cmp1;
1670 if( cmp2_type == TypeInt::ZERO &&
1671 cmp1_op == Op_Conv2B &&
1672 (_test._test == BoolTest::eq ||
1673 _test._test == BoolTest::ne) ) {
1674 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1675 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1676 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1677 );
1678 return new BoolNode( ncmp, _test._test );
1679 }
1680
1681 // Comparing a SubI against a zero is equal to comparing the SubI
1682 // arguments directly. This only works for eq and ne comparisons
1683 // due to possible integer overflow.
1684 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1685 (cop == Op_CmpI) &&
1686 (cmp1_op == Op_SubI) &&
1687 ( cmp2_type == TypeInt::ZERO ) ) {
1688 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1689 return new BoolNode( ncmp, _test._test );
1690 }
1691
1692 // Same as above but with and AddI of a constant
1693 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1694 cop == Op_CmpI &&
1695 cmp1_op == Op_AddI &&
1696 cmp1->in(2) != nullptr &&
1697 phase->type(cmp1->in(2))->isa_int() &&
1698 phase->type(cmp1->in(2))->is_int()->is_con() &&
1699 cmp2_type == TypeInt::ZERO &&
1700 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1701 ) {
1702 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1703 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1704 return new BoolNode( ncmp, _test._test );
1705 }
1706
1707 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1708 // since zero check of conditional negation of an integer is equal to
1709 // zero check of the integer directly.
1710 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1711 (cop == Op_CmpI) &&
1712 (cmp2_type == TypeInt::ZERO) &&
1713 (cmp1_op == Op_Phi)) {
1714 // There should be a diamond phi with true path at index 1 or 2
1715 PhiNode *phi = cmp1->as_Phi();
1716 int idx_true = phi->is_diamond_phi();
1717 if (idx_true != 0) {
1718 // True input is in(idx_true) while false input is in(3 - idx_true)
1719 Node *tin = phi->in(idx_true);
1720 Node *fin = phi->in(3 - idx_true);
1721 if ((tin->Opcode() == Op_SubI) &&
1722 (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1723 (tin->in(2) == fin)) {
1724 // Found conditional negation at true path, create a new CmpINode without that
1725 Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1726 return new BoolNode(ncmp, _test._test);
1727 }
1728 if ((fin->Opcode() == Op_SubI) &&
1729 (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1730 (fin->in(2) == tin)) {
1731 // Found conditional negation at false path, create a new CmpINode without that
1732 Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1733 return new BoolNode(ncmp, _test._test);
1734 }
1735 }
1736 }
1737
1738 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1739 // most general case because negating 0x80000000 does nothing. Needed for
1740 // the CmpF3/SubI/CmpI idiom.
1741 if( cop == Op_CmpI &&
1742 cmp1_op == Op_SubI &&
1743 cmp2_type == TypeInt::ZERO &&
1744 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1745 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1746 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1747 return new BoolNode( ncmp, _test.commute() );
1748 }
1749
1750 // Try to optimize signed integer comparison
1751 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1752
1753 // The transformation below is not valid for either signed or unsigned
1754 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1755 // This transformation can be resurrected when we are able to
1756 // make inferences about the range of values being subtracted from
1757 // (or added to) relative to the wraparound point.
1758 //
1759 // // Remove +/-1's if possible.
1760 // // "X <= Y-1" becomes "X < Y"
1761 // // "X+1 <= Y" becomes "X < Y"
1762 // // "X < Y+1" becomes "X <= Y"
1763 // // "X-1 < Y" becomes "X <= Y"
1764 // // Do not this to compares off of the counted-loop-end. These guys are
1765 // // checking the trip counter and they want to use the post-incremented
1766 // // counter. If they use the PRE-incremented counter, then the counter has
1767 // // to be incremented in a private block on a loop backedge.
1768 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1769 // return nullptr;
1770 // #ifndef PRODUCT
1771 // // Do not do this in a wash GVN pass during verification.
1772 // // Gets triggered by too many simple optimizations to be bothered with
1773 // // re-trying it again and again.
1774 // if( !phase->allow_progress() ) return nullptr;
1775 // #endif
1776 // // Not valid for unsigned compare because of corner cases in involving zero.
1777 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1778 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1779 // // "0 <=u Y" is always true).
1780 // if( cmp->Opcode() == Op_CmpU ) return nullptr;
1781 // int cmp2_op = cmp2->Opcode();
1782 // if( _test._test == BoolTest::le ) {
1783 // if( cmp1_op == Op_AddI &&
1784 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1785 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1786 // else if( cmp2_op == Op_AddI &&
1787 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1788 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1789 // } else if( _test._test == BoolTest::lt ) {
1790 // if( cmp1_op == Op_AddI &&
1791 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1792 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1793 // else if( cmp2_op == Op_AddI &&
1794 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1795 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1796 // }
1797 }
1798
1799 // We use the following Lemmas/insights for the following two transformations (1) and (2):
1800 // x & y <=u y, for any x and y (Lemma 1, masking always results in a smaller unsigned number)
1801 // y <u y + 1 is always true if y != -1 (Lemma 2, (uint)(-1 + 1) == (uint)(UINT_MAX + 1) which overflows)
1802 // y <u 0 is always false for any y (Lemma 3, 0 == UINT_MIN and nothing can be smaller than that)
1803 //
1804 // (1a) Always: Change ((x & m) <=u m ) or ((m & x) <=u m ) to always true (true by Lemma 1)
1805 // (1b) If m != -1: Change ((x & m) <u m + 1) or ((m & x) <u m + 1) to always true:
1806 // x & m <=u m is always true // (Lemma 1)
1807 // x & m <=u m <u m + 1 is always true // (Lemma 2: m <u m + 1, if m != -1)
1808 //
1809 // A counter example for (1b), if we allowed m == -1:
1810 // (x & m) <u m + 1
1811 // (x & -1) <u 0
1812 // x <u 0
1813 // which is false for any x (Lemma 3)
1814 //
1815 // (2) Change ((x & (m - 1)) <u m) or (((m - 1) & x) <u m) to (m >u 0)
1816 // This is the off-by-one variant of the above.
1817 //
1818 // We now prove that this replacement is correct. This is the same as proving
1819 // "m >u 0" if and only if "x & (m - 1) <u m", i.e. "m >u 0 <=> x & (m - 1) <u m"
1820 //
1821 // We use (Lemma 1) and (Lemma 3) from above.
1822 //
1823 // Case "x & (m - 1) <u m => m >u 0":
1824 // We prove this by contradiction:
1825 // Assume m <=u 0 which is equivalent to m == 0:
1826 // and thus
1827 // x & (m - 1) <u m = 0 // m == 0
1828 // y <u 0 // y = x & (m - 1)
1829 // by Lemma 3, this is always false, i.e. a contradiction to our assumption.
1830 //
1831 // Case "m >u 0 => x & (m - 1) <u m":
1832 // x & (m - 1) <=u (m - 1) // (Lemma 1)
1833 // x & (m - 1) <=u (m - 1) <u m // Using assumption m >u 0, no underflow of "m - 1"
1834 //
1835 //
1836 // Note that the signed version of "m > 0":
1837 // m > 0 <=> x & (m - 1) <u m
1838 // does not hold:
1839 // Assume m == -1 and x == -1:
1840 // x & (m - 1) <u m
1841 // -1 & -2 <u -1
1842 // -2 <u -1
1843 // UINT_MAX - 1 <u UINT_MAX // Signed to unsigned numbers
1844 // which is true while
1845 // m > 0
1846 // is false which is a contradiction.
1847 //
1848 // (1a) and (1b) is covered by this method since we can directly return a true value as type while (2) is covered
1849 // in BoolNode::Ideal since we create a new non-constant node (see [CMPU_MASK]).
1850 const Type* BoolNode::Value_cmpu_and_mask(PhaseValues* phase) const {
1851 Node* cmp = in(1);
1852 if (cmp != nullptr && cmp->Opcode() == Op_CmpU) {
1853 Node* cmp1 = cmp->in(1);
1854 Node* cmp2 = cmp->in(2);
1855
1856 if (cmp1->Opcode() == Op_AndI) {
1857 Node* m = nullptr;
1858 if (_test._test == BoolTest::le) {
1859 // (1a) "((x & m) <=u m)", cmp2 = m
1860 m = cmp2;
1861 } else if (_test._test == BoolTest::lt && cmp2->Opcode() == Op_AddI && cmp2->in(2)->find_int_con(0) == 1) {
1862 // (1b) "(x & m) <u m + 1" and "(m & x) <u m + 1", cmp2 = m + 1
1863 Node* rhs_m = cmp2->in(1);
1864 const TypeInt* rhs_m_type = phase->type(rhs_m)->isa_int();
1865 if (rhs_m_type->_lo > -1 || rhs_m_type->_hi < -1) {
1866 // Exclude any case where m == -1 is possible.
1867 m = rhs_m;
1868 }
1869 }
1870
1871 if (cmp1->in(2) == m || cmp1->in(1) == m) {
1872 return TypeInt::ONE;
1873 }
1874 }
1875 }
1876
1877 return nullptr;
1878 }
1879
1880 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1881 // based on local information. If the input is constant, do it.
1882 const Type* BoolNode::Value(PhaseGVN* phase) const {
1883 const Type* t = Value_cmpu_and_mask(phase);
1884 if (t != nullptr) {
1885 return t;
1886 }
1887
1888 return _test.cc2logical( phase->type( in(1) ) );
1889 }
1890
1891 #ifndef PRODUCT
1892 //------------------------------dump_spec--------------------------------------
1893 // Dump special per-node info
1894 void BoolNode::dump_spec(outputStream *st) const {
1895 st->print("[");
1896 _test.dump_on(st);
1897 st->print("]");
1898 }
1899 #endif
1900
1901 //----------------------is_counted_loop_exit_test------------------------------
1902 // Returns true if node is used by a counted loop node.
1903 bool BoolNode::is_counted_loop_exit_test() {
1904 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1905 Node* use = fast_out(i);
1906 if (use->is_CountedLoopEnd()) {
1907 return true;
1908 }
1909 }
1910 return false;
1911 }
1912
1913 //=============================================================================
1914 //------------------------------Value------------------------------------------
1915 const Type* AbsNode::Value(PhaseGVN* phase) const {
1916 const Type* t1 = phase->type(in(1));
1917 if (t1 == Type::TOP) return Type::TOP;
1918
1919 switch (t1->base()) {
1920 case Type::Int: {
1921 const TypeInt* ti = t1->is_int();
1922 if (ti->is_con()) {
1923 return TypeInt::make(uabs(ti->get_con()));
1924 }
1925 break;
1926 }
1927 case Type::Long: {
1928 const TypeLong* tl = t1->is_long();
1929 if (tl->is_con()) {
1930 return TypeLong::make(uabs(tl->get_con()));
1931 }
1932 break;
1933 }
1934 case Type::FloatCon:
1935 return TypeF::make(abs(t1->getf()));
1936 case Type::DoubleCon:
1937 return TypeD::make(abs(t1->getd()));
1938 default:
1939 break;
1940 }
1941
1942 return bottom_type();
1943 }
1944
1945 //------------------------------Identity----------------------------------------
1946 Node* AbsNode::Identity(PhaseGVN* phase) {
1947 Node* in1 = in(1);
1948 // No need to do abs for non-negative values
1949 if (phase->type(in1)->higher_equal(TypeInt::POS) ||
1950 phase->type(in1)->higher_equal(TypeLong::POS)) {
1951 return in1;
1952 }
1953 // Convert "abs(abs(x))" into "abs(x)"
1954 if (in1->Opcode() == Opcode()) {
1955 return in1;
1956 }
1957 return this;
1958 }
1959
1960 //------------------------------Ideal------------------------------------------
1961 Node* AbsNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1962 Node* in1 = in(1);
1963 // Convert "abs(0-x)" into "abs(x)"
1964 if (in1->is_Sub() && phase->type(in1->in(1))->is_zero_type()) {
1965 set_req_X(1, in1->in(2), phase);
1966 return this;
1967 }
1968 return nullptr;
1969 }
1970
1971 //=============================================================================
1972 //------------------------------Value------------------------------------------
1973 // Compute sqrt
1974 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
1975 const Type *t1 = phase->type( in(1) );
1976 if( t1 == Type::TOP ) return Type::TOP;
1977 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1978 double d = t1->getd();
1979 if( d < 0.0 ) return Type::DOUBLE;
1980 return TypeD::make( sqrt( d ) );
1981 }
1982
1983 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
1984 const Type *t1 = phase->type( in(1) );
1985 if( t1 == Type::TOP ) return Type::TOP;
1986 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
1987 float f = t1->getf();
1988 if( f < 0.0f ) return Type::FLOAT;
1989 return TypeF::make( (float)sqrt( (double)f ) );
1990 }
1991
1992 const Type* ReverseINode::Value(PhaseGVN* phase) const {
1993 const Type *t1 = phase->type( in(1) );
1994 if (t1 == Type::TOP) {
1995 return Type::TOP;
1996 }
1997 const TypeInt* t1int = t1->isa_int();
1998 if (t1int && t1int->is_con()) {
1999 jint res = reverse_bits(t1int->get_con());
2000 return TypeInt::make(res);
2001 }
2002 return bottom_type();
2003 }
2004
2005 const Type* ReverseLNode::Value(PhaseGVN* phase) const {
2006 const Type *t1 = phase->type( in(1) );
2007 if (t1 == Type::TOP) {
2008 return Type::TOP;
2009 }
2010 const TypeLong* t1long = t1->isa_long();
2011 if (t1long && t1long->is_con()) {
2012 jlong res = reverse_bits(t1long->get_con());
2013 return TypeLong::make(res);
2014 }
2015 return bottom_type();
2016 }
2017
2018 Node* ReverseINode::Identity(PhaseGVN* phase) {
2019 if (in(1)->Opcode() == Op_ReverseI) {
2020 return in(1)->in(1);
2021 }
2022 return this;
2023 }
2024
2025 Node* ReverseLNode::Identity(PhaseGVN* phase) {
2026 if (in(1)->Opcode() == Op_ReverseL) {
2027 return in(1)->in(1);
2028 }
2029 return this;
2030 }