1 /*
2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shared/c2/barrierSetC2.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "opto/addnode.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/cfgnode.hpp"
33 #include "opto/inlinetypenode.hpp"
34 #include "opto/loopnode.hpp"
35 #include "opto/matcher.hpp"
36 #include "opto/movenode.hpp"
37 #include "opto/mulnode.hpp"
38 #include "opto/opaquenode.hpp"
39 #include "opto/opcodes.hpp"
40 #include "opto/phaseX.hpp"
41 #include "opto/subnode.hpp"
42 #include "runtime/sharedRuntime.hpp"
43 #include "utilities/reverse_bits.hpp"
44
45 // Portions of code courtesy of Clifford Click
46
47 // Optimization - Graph Style
48
49 #include "math.h"
50
51 //=============================================================================
52 //------------------------------Identity---------------------------------------
53 // If right input is a constant 0, return the left input.
54 Node* SubNode::Identity(PhaseGVN* phase) {
55 assert(in(1) != this, "Must already have called Value");
56 assert(in(2) != this, "Must already have called Value");
57
58 // Remove double negation
59 const Type *zero = add_id();
60 if( phase->type( in(1) )->higher_equal( zero ) &&
61 in(2)->Opcode() == Opcode() &&
62 phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
63 return in(2)->in(2);
64 }
65
66 // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
67 if (in(1)->Opcode() == Op_AddI || in(1)->Opcode() == Op_AddL) {
68 if (in(1)->in(2) == in(2)) {
69 return in(1)->in(1);
70 }
71 if (in(1)->in(1) == in(2)) {
72 return in(1)->in(2);
73 }
74 }
75
76 return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
77 }
78
79 //------------------------------Value------------------------------------------
80 // A subtract node differences it's two inputs.
81 const Type* SubNode::Value_common(PhaseValues* phase) const {
82 const Node* in1 = in(1);
83 const Node* in2 = in(2);
84 // Either input is TOP ==> the result is TOP
85 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
86 if( t1 == Type::TOP ) return Type::TOP;
87 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
88 if( t2 == Type::TOP ) return Type::TOP;
89
90 // Not correct for SubFnode and AddFNode (must check for infinity)
91 // Equal? Subtract is zero
92 if (in1->eqv_uncast(in2)) return add_id();
93
94 // Either input is BOTTOM ==> the result is the local BOTTOM
95 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
96 return bottom_type();
97
98 return nullptr;
99 }
100
101 const Type* SubNode::Value(PhaseGVN* phase) const {
102 const Type* t = Value_common(phase);
103 if (t != nullptr) {
104 return t;
105 }
106 const Type* t1 = phase->type(in(1));
107 const Type* t2 = phase->type(in(2));
108 return sub(t1,t2); // Local flavor of type subtraction
109
110 }
111
112 SubNode* SubNode::make(Node* in1, Node* in2, BasicType bt) {
113 switch (bt) {
114 case T_INT:
115 return new SubINode(in1, in2);
116 case T_LONG:
117 return new SubLNode(in1, in2);
118 default:
119 fatal("Not implemented for %s", type2name(bt));
120 }
121 return nullptr;
122 }
123
124 //=============================================================================
125 //------------------------------Helper function--------------------------------
126
127 static bool is_cloop_increment(Node* inc) {
128 precond(inc->Opcode() == Op_AddI || inc->Opcode() == Op_AddL);
129
130 if (!inc->in(1)->is_Phi()) {
131 return false;
132 }
133 const PhiNode* phi = inc->in(1)->as_Phi();
134
135 if (!phi->region()->is_CountedLoop()) {
136 return false;
137 }
138
139 return inc == phi->region()->as_CountedLoop()->incr();
140 }
141
142 // Given the expression '(x + C) - v', or
143 // 'v - (x + C)', we examine nodes '+' and 'v':
144 //
145 // 1. Do not convert if '+' is a counted-loop increment, because the '-' is
146 // loop invariant and converting extends the live-range of 'x' to overlap
147 // with the '+', forcing another register to be used in the loop.
148 //
149 // 2. Do not convert if 'v' is a counted-loop induction variable, because
150 // 'x' might be invariant.
151 //
152 static bool ok_to_convert(Node* inc, Node* var) {
153 return !(is_cloop_increment(inc) || var->is_cloop_ind_var());
154 }
155
156 static bool is_cloop_condition(BoolNode* bol) {
157 for (DUIterator_Fast imax, i = bol->fast_outs(imax); i < imax; i++) {
158 Node* out = bol->fast_out(i);
159 if (out->is_CountedLoopEnd()) {
160 return true;
161 }
162 }
163 return false;
164 }
165
166 //------------------------------Ideal------------------------------------------
167 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
168 Node *in1 = in(1);
169 Node *in2 = in(2);
170 uint op1 = in1->Opcode();
171 uint op2 = in2->Opcode();
172
173 #ifdef ASSERT
174 // Check for dead loop
175 if ((in1 == this) || (in2 == this) ||
176 ((op1 == Op_AddI || op1 == Op_SubI) &&
177 ((in1->in(1) == this) || (in1->in(2) == this) ||
178 (in1->in(1) == in1) || (in1->in(2) == in1)))) {
179 assert(false, "dead loop in SubINode::Ideal");
180 }
181 #endif
182
183 const Type *t2 = phase->type( in2 );
184 if( t2 == Type::TOP ) return nullptr;
185 // Convert "x-c0" into "x+ -c0".
186 if( t2->base() == Type::Int ){ // Might be bottom or top...
187 const TypeInt *i = t2->is_int();
188 if( i->is_con() )
189 return new AddINode(in1, phase->intcon(java_negate(i->get_con())));
190 }
191
192 // Convert "(x+c0) - y" into (x-y) + c0"
193 // Do not collapse (x+c0)-y if "+" is a loop increment or
194 // if "y" is a loop induction variable.
195 if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
196 const Type *tadd = phase->type( in1->in(2) );
197 if( tadd->singleton() && tadd != Type::TOP ) {
198 Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 ));
199 return new AddINode( sub2, in1->in(2) );
200 }
201 }
202
203 // Convert "x - (y+c0)" into "(x-y) - c0" AND
204 // Convert "c1 - (y+c0)" into "(c1-c0) - y"
205 // Need the same check as in above optimization but reversed.
206 if (op2 == Op_AddI
207 && ok_to_convert(in2, in1)
208 && in2->in(2)->Opcode() == Op_ConI) {
209 jint c0 = phase->type(in2->in(2))->isa_int()->get_con();
210 Node* in21 = in2->in(1);
211 if (in1->Opcode() == Op_ConI) {
212 // Match c1
213 jint c1 = phase->type(in1)->isa_int()->get_con();
214 Node* sub2 = phase->intcon(java_subtract(c1, c0));
215 return new SubINode(sub2, in21);
216 } else {
217 // Match x
218 Node* sub2 = phase->transform(new SubINode(in1, in21));
219 Node* neg_c0 = phase->intcon(java_negate(c0));
220 return new AddINode(sub2, neg_c0);
221 }
222 }
223
224 const Type *t1 = phase->type( in1 );
225 if( t1 == Type::TOP ) return nullptr;
226
227 #ifdef ASSERT
228 // Check for dead loop
229 if ((op2 == Op_AddI || op2 == Op_SubI) &&
230 ((in2->in(1) == this) || (in2->in(2) == this) ||
231 (in2->in(1) == in2) || (in2->in(2) == in2))) {
232 assert(false, "dead loop in SubINode::Ideal");
233 }
234 #endif
235
236 // Convert "x - (x+y)" into "-y"
237 if (op2 == Op_AddI && in1 == in2->in(1)) {
238 return new SubINode(phase->intcon(0), in2->in(2));
239 }
240 // Convert "(x-y) - x" into "-y"
241 if (op1 == Op_SubI && in1->in(1) == in2) {
242 return new SubINode(phase->intcon(0), in1->in(2));
243 }
244 // Convert "x - (y+x)" into "-y"
245 if (op2 == Op_AddI && in1 == in2->in(2)) {
246 return new SubINode(phase->intcon(0), in2->in(1));
247 }
248
249 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity().
250 if (t1 == TypeInt::ZERO && op2 == Op_SubI && phase->type(in2->in(1)) != TypeInt::ZERO) {
251 return new SubINode(in2->in(2), in2->in(1));
252 }
253
254 // Convert "0 - (x+con)" into "-con-x"
255 jint con;
256 if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
257 (con = in2->in(2)->find_int_con(0)) != 0 )
258 return new SubINode( phase->intcon(-con), in2->in(1) );
259
260 // Convert "(X+A) - (X+B)" into "A - B"
261 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
262 return new SubINode( in1->in(2), in2->in(2) );
263
264 // Convert "(A+X) - (B+X)" into "A - B"
265 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
266 return new SubINode( in1->in(1), in2->in(1) );
267
268 // Convert "(A+X) - (X+B)" into "A - B"
269 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
270 return new SubINode( in1->in(1), in2->in(2) );
271
272 // Convert "(X+A) - (B+X)" into "A - B"
273 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
274 return new SubINode( in1->in(2), in2->in(1) );
275
276 // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
277 // nicer to optimize than subtract.
278 if( op2 == Op_SubI && in2->outcnt() == 1) {
279 Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) );
280 return new SubINode( add1, in2->in(1) );
281 }
282
283 // Associative
284 if (op1 == Op_MulI && op2 == Op_MulI) {
285 Node* sub_in1 = nullptr;
286 Node* sub_in2 = nullptr;
287 Node* mul_in = nullptr;
288
289 if (in1->in(1) == in2->in(1)) {
290 // Convert "a*b-a*c into a*(b-c)
291 sub_in1 = in1->in(2);
292 sub_in2 = in2->in(2);
293 mul_in = in1->in(1);
294 } else if (in1->in(2) == in2->in(1)) {
295 // Convert a*b-b*c into b*(a-c)
296 sub_in1 = in1->in(1);
297 sub_in2 = in2->in(2);
298 mul_in = in1->in(2);
299 } else if (in1->in(2) == in2->in(2)) {
300 // Convert a*c-b*c into (a-b)*c
301 sub_in1 = in1->in(1);
302 sub_in2 = in2->in(1);
303 mul_in = in1->in(2);
304 } else if (in1->in(1) == in2->in(2)) {
305 // Convert a*b-c*a into a*(b-c)
306 sub_in1 = in1->in(2);
307 sub_in2 = in2->in(1);
308 mul_in = in1->in(1);
309 }
310
311 if (mul_in != nullptr) {
312 Node* sub = phase->transform(new SubINode(sub_in1, sub_in2));
313 return new MulINode(mul_in, sub);
314 }
315 }
316
317 // Convert "0-(A>>31)" into "(A>>>31)"
318 if ( op2 == Op_RShiftI ) {
319 Node *in21 = in2->in(1);
320 Node *in22 = in2->in(2);
321 const TypeInt *zero = phase->type(in1)->isa_int();
322 const TypeInt *t21 = phase->type(in21)->isa_int();
323 const TypeInt *t22 = phase->type(in22)->isa_int();
324 if ( t21 && t22 && zero == TypeInt::ZERO && t22->is_con(31) ) {
325 return new URShiftINode(in21, in22);
326 }
327 }
328
329 return nullptr;
330 }
331
332 //------------------------------sub--------------------------------------------
333 // A subtract node differences it's two inputs.
334 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
335 const TypeInt *r0 = t1->is_int(); // Handy access
336 const TypeInt *r1 = t2->is_int();
337 int32_t lo = java_subtract(r0->_lo, r1->_hi);
338 int32_t hi = java_subtract(r0->_hi, r1->_lo);
339
340 // We next check for 32-bit overflow.
341 // If that happens, we just assume all integers are possible.
342 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
343 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
344 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
345 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
346 return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
347 else // Overflow; assume all integers
348 return TypeInt::INT;
349 }
350
351 //=============================================================================
352 //------------------------------Ideal------------------------------------------
353 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
354 Node *in1 = in(1);
355 Node *in2 = in(2);
356 uint op1 = in1->Opcode();
357 uint op2 = in2->Opcode();
358
359 #ifdef ASSERT
360 // Check for dead loop
361 if ((in1 == this) || (in2 == this) ||
362 ((op1 == Op_AddL || op1 == Op_SubL) &&
363 ((in1->in(1) == this) || (in1->in(2) == this) ||
364 (in1->in(1) == in1) || (in1->in(2) == in1)))) {
365 assert(false, "dead loop in SubLNode::Ideal");
366 }
367 #endif
368
369 if( phase->type( in2 ) == Type::TOP ) return nullptr;
370 const TypeLong *i = phase->type( in2 )->isa_long();
371 // Convert "x-c0" into "x+ -c0".
372 if( i && // Might be bottom or top...
373 i->is_con() )
374 return new AddLNode(in1, phase->longcon(java_negate(i->get_con())));
375
376 // Convert "(x+c0) - y" into (x-y) + c0"
377 // Do not collapse (x+c0)-y if "+" is a loop increment or
378 // if "y" is a loop induction variable.
379 if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
380 Node *in11 = in1->in(1);
381 const Type *tadd = phase->type( in1->in(2) );
382 if( tadd->singleton() && tadd != Type::TOP ) {
383 Node *sub2 = phase->transform( new SubLNode( in11, in2 ));
384 return new AddLNode( sub2, in1->in(2) );
385 }
386 }
387
388 // Convert "x - (y+c0)" into "(x-y) - c0" AND
389 // Convert "c1 - (y+c0)" into "(c1-c0) - y"
390 // Need the same check as in above optimization but reversed.
391 if (op2 == Op_AddL
392 && ok_to_convert(in2, in1)
393 && in2->in(2)->Opcode() == Op_ConL) {
394 jlong c0 = phase->type(in2->in(2))->isa_long()->get_con();
395 Node* in21 = in2->in(1);
396 if (in1->Opcode() == Op_ConL) {
397 // Match c1
398 jlong c1 = phase->type(in1)->isa_long()->get_con();
399 Node* sub2 = phase->longcon(java_subtract(c1, c0));
400 return new SubLNode(sub2, in21);
401 } else {
402 Node* sub2 = phase->transform(new SubLNode(in1, in21));
403 Node* neg_c0 = phase->longcon(-c0);
404 return new AddLNode(sub2, neg_c0);
405 }
406 }
407
408 const Type *t1 = phase->type( in1 );
409 if( t1 == Type::TOP ) return nullptr;
410
411 #ifdef ASSERT
412 // Check for dead loop
413 if ((op2 == Op_AddL || op2 == Op_SubL) &&
414 ((in2->in(1) == this) || (in2->in(2) == this) ||
415 (in2->in(1) == in2) || (in2->in(2) == in2))) {
416 assert(false, "dead loop in SubLNode::Ideal");
417 }
418 #endif
419
420 // Convert "x - (x+y)" into "-y"
421 if (op2 == Op_AddL && in1 == in2->in(1)) {
422 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(2));
423 }
424 // Convert "(x-y) - x" into "-y"
425 if (op1 == Op_SubL && in1->in(1) == in2) {
426 return new SubLNode(phase->makecon(TypeLong::ZERO), in1->in(2));
427 }
428 // Convert "x - (y+x)" into "-y"
429 if (op2 == Op_AddL && in1 == in2->in(2)) {
430 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(1));
431 }
432
433 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity.
434 if (t1 == TypeLong::ZERO && op2 == Op_SubL && phase->type(in2->in(1)) != TypeLong::ZERO) {
435 return new SubLNode(in2->in(2), in2->in(1));
436 }
437
438 // Convert "(X+A) - (X+B)" into "A - B"
439 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
440 return new SubLNode( in1->in(2), in2->in(2) );
441
442 // Convert "(A+X) - (B+X)" into "A - B"
443 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
444 return new SubLNode( in1->in(1), in2->in(1) );
445
446 // Convert "(A+X) - (X+B)" into "A - B"
447 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(1) )
448 return new SubLNode( in1->in(1), in2->in(2) );
449
450 // Convert "(X+A) - (B+X)" into "A - B"
451 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(2) )
452 return new SubLNode( in1->in(2), in2->in(1) );
453
454 // Convert "A-(B-C)" into (A+C)-B"
455 if( op2 == Op_SubL && in2->outcnt() == 1) {
456 Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) );
457 return new SubLNode( add1, in2->in(1) );
458 }
459
460 // Associative
461 if (op1 == Op_MulL && op2 == Op_MulL) {
462 Node* sub_in1 = nullptr;
463 Node* sub_in2 = nullptr;
464 Node* mul_in = nullptr;
465
466 if (in1->in(1) == in2->in(1)) {
467 // Convert "a*b-a*c into a*(b+c)
468 sub_in1 = in1->in(2);
469 sub_in2 = in2->in(2);
470 mul_in = in1->in(1);
471 } else if (in1->in(2) == in2->in(1)) {
472 // Convert a*b-b*c into b*(a-c)
473 sub_in1 = in1->in(1);
474 sub_in2 = in2->in(2);
475 mul_in = in1->in(2);
476 } else if (in1->in(2) == in2->in(2)) {
477 // Convert a*c-b*c into (a-b)*c
478 sub_in1 = in1->in(1);
479 sub_in2 = in2->in(1);
480 mul_in = in1->in(2);
481 } else if (in1->in(1) == in2->in(2)) {
482 // Convert a*b-c*a into a*(b-c)
483 sub_in1 = in1->in(2);
484 sub_in2 = in2->in(1);
485 mul_in = in1->in(1);
486 }
487
488 if (mul_in != nullptr) {
489 Node* sub = phase->transform(new SubLNode(sub_in1, sub_in2));
490 return new MulLNode(mul_in, sub);
491 }
492 }
493
494 // Convert "0L-(A>>63)" into "(A>>>63)"
495 if ( op2 == Op_RShiftL ) {
496 Node *in21 = in2->in(1);
497 Node *in22 = in2->in(2);
498 const TypeLong *zero = phase->type(in1)->isa_long();
499 const TypeLong *t21 = phase->type(in21)->isa_long();
500 const TypeInt *t22 = phase->type(in22)->isa_int();
501 if ( t21 && t22 && zero == TypeLong::ZERO && t22->is_con(63) ) {
502 return new URShiftLNode(in21, in22);
503 }
504 }
505
506 return nullptr;
507 }
508
509 //------------------------------sub--------------------------------------------
510 // A subtract node differences it's two inputs.
511 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
512 const TypeLong *r0 = t1->is_long(); // Handy access
513 const TypeLong *r1 = t2->is_long();
514 jlong lo = java_subtract(r0->_lo, r1->_hi);
515 jlong hi = java_subtract(r0->_hi, r1->_lo);
516
517 // We next check for 32-bit overflow.
518 // If that happens, we just assume all integers are possible.
519 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
520 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
521 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
522 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
523 return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
524 else // Overflow; assume all integers
525 return TypeLong::LONG;
526 }
527
528 //=============================================================================
529 //------------------------------Value------------------------------------------
530 // A subtract node differences its two inputs.
531 const Type* SubFPNode::Value(PhaseGVN* phase) const {
532 const Node* in1 = in(1);
533 const Node* in2 = in(2);
534 // Either input is TOP ==> the result is TOP
535 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
536 if( t1 == Type::TOP ) return Type::TOP;
537 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
538 if( t2 == Type::TOP ) return Type::TOP;
539
540 // if both operands are infinity of same sign, the result is NaN; do
541 // not replace with zero
542 if (t1->is_finite() && t2->is_finite() && in1 == in2) {
543 return add_id();
544 }
545
546 // Either input is BOTTOM ==> the result is the local BOTTOM
547 const Type *bot = bottom_type();
548 if( (t1 == bot) || (t2 == bot) ||
549 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
550 return bot;
551
552 return sub(t1,t2); // Local flavor of type subtraction
553 }
554
555
556 //=============================================================================
557 //------------------------------Ideal------------------------------------------
558 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
559 const Type *t2 = phase->type( in(2) );
560 // Convert "x-c0" into "x+ -c0".
561 if( t2->base() == Type::FloatCon ) { // Might be bottom or top...
562 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
563 }
564
565 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
566 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
567 //if( phase->type(in(1)) == TypeF::ZERO )
568 //return new (phase->C, 2) NegFNode(in(2));
569
570 return nullptr;
571 }
572
573 //------------------------------sub--------------------------------------------
574 // A subtract node differences its two inputs.
575 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
576 // no folding if one of operands is infinity or NaN, do not do constant folding
577 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
578 return TypeF::make( t1->getf() - t2->getf() );
579 }
580 else if( g_isnan(t1->getf()) ) {
581 return t1;
582 }
583 else if( g_isnan(t2->getf()) ) {
584 return t2;
585 }
586 else {
587 return Type::FLOAT;
588 }
589 }
590
591 //=============================================================================
592 //------------------------------Ideal------------------------------------------
593 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
594 const Type *t2 = phase->type( in(2) );
595 // Convert "x-c0" into "x+ -c0".
596 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
597 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
598 }
599
600 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
601 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
602 //if( phase->type(in(1)) == TypeD::ZERO )
603 //return new (phase->C, 2) NegDNode(in(2));
604
605 return nullptr;
606 }
607
608 //------------------------------sub--------------------------------------------
609 // A subtract node differences its two inputs.
610 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
611 // no folding if one of operands is infinity or NaN, do not do constant folding
612 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
613 return TypeD::make( t1->getd() - t2->getd() );
614 }
615 else if( g_isnan(t1->getd()) ) {
616 return t1;
617 }
618 else if( g_isnan(t2->getd()) ) {
619 return t2;
620 }
621 else {
622 return Type::DOUBLE;
623 }
624 }
625
626 //=============================================================================
627 //------------------------------Idealize---------------------------------------
628 // Unlike SubNodes, compare must still flatten return value to the
629 // range -1, 0, 1.
630 // And optimizations like those for (X + Y) - X fail if overflow happens.
631 Node* CmpNode::Identity(PhaseGVN* phase) {
632 return this;
633 }
634
635 CmpNode *CmpNode::make(Node *in1, Node *in2, BasicType bt, bool unsigned_comp) {
636 switch (bt) {
637 case T_INT:
638 if (unsigned_comp) {
639 return new CmpUNode(in1, in2);
640 }
641 return new CmpINode(in1, in2);
642 case T_LONG:
643 if (unsigned_comp) {
644 return new CmpULNode(in1, in2);
645 }
646 return new CmpLNode(in1, in2);
647 default:
648 fatal("Not implemented for %s", type2name(bt));
649 }
650 return nullptr;
651 }
652
653 //=============================================================================
654 //------------------------------cmp--------------------------------------------
655 // Simplify a CmpI (compare 2 integers) node, based on local information.
656 // If both inputs are constants, compare them.
657 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
658 const TypeInt *r0 = t1->is_int(); // Handy access
659 const TypeInt *r1 = t2->is_int();
660
661 if( r0->_hi < r1->_lo ) // Range is always low?
662 return TypeInt::CC_LT;
663 else if( r0->_lo > r1->_hi ) // Range is always high?
664 return TypeInt::CC_GT;
665
666 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
667 assert(r0->get_con() == r1->get_con(), "must be equal");
668 return TypeInt::CC_EQ; // Equal results.
669 } else if( r0->_hi == r1->_lo ) // Range is never high?
670 return TypeInt::CC_LE;
671 else if( r0->_lo == r1->_hi ) // Range is never low?
672 return TypeInt::CC_GE;
673 return TypeInt::CC; // else use worst case results
674 }
675
676 const Type* CmpINode::Value(PhaseGVN* phase) const {
677 Node* in1 = in(1);
678 Node* in2 = in(2);
679 // If this test is the zero trip guard for a main or post loop, check whether, with the opaque node removed, the test
680 // would constant fold so the loop is never entered. If so return the type of the test without the opaque node removed:
681 // make the loop unreachable.
682 // The reason for this is that the iv phi captures the bounds of the loop and if the loop becomes unreachable, it can
683 // become top. In that case, the loop must be removed.
684 // This is safe because:
685 // - as optimizations proceed, the range of iterations executed by the main loop narrows. If no iterations remain, then
686 // we're done with optimizations for that loop.
687 // - the post loop is initially not reachable but as long as there's a main loop, the zero trip guard for the post
688 // 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
689 // loop is removed, there's no need to preserve the zero trip guard for the post loop anymore.
690 if (in1 != nullptr && in2 != nullptr) {
691 uint input = 0;
692 Node* cmp = nullptr;
693 BoolTest::mask test;
694 if (in1->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in1) != Type::TOP) {
695 cmp = new CmpINode(in1->in(1), in2);
696 test = ((OpaqueZeroTripGuardNode*)in1)->_loop_entered_mask;
697 }
698 if (in2->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in2) != Type::TOP) {
699 assert(cmp == nullptr, "A cmp with 2 OpaqueZeroTripGuard inputs");
700 cmp = new CmpINode(in1, in2->in(1));
701 test = ((OpaqueZeroTripGuardNode*)in2)->_loop_entered_mask;
702 }
703 if (cmp != nullptr) {
704 const Type* cmp_t = cmp->Value(phase);
705 const Type* t = BoolTest(test).cc2logical(cmp_t);
706 cmp->destruct(phase);
707 if (t == TypeInt::ZERO) {
708 return cmp_t;
709 }
710 }
711 }
712
713 return SubNode::Value(phase);
714 }
715
716
717 // Simplify a CmpU (compare 2 integers) node, based on local information.
718 // If both inputs are constants, compare them.
719 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
720 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
721
722 // comparing two unsigned ints
723 const TypeInt *r0 = t1->is_int(); // Handy access
724 const TypeInt *r1 = t2->is_int();
725
726 // Current installed version
727 // Compare ranges for non-overlap
728 juint lo0 = r0->_lo;
729 juint hi0 = r0->_hi;
730 juint lo1 = r1->_lo;
731 juint hi1 = r1->_hi;
732
733 // If either one has both negative and positive values,
734 // it therefore contains both 0 and -1, and since [0..-1] is the
735 // full unsigned range, the type must act as an unsigned bottom.
736 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
737 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
738
739 if (bot0 || bot1) {
740 // All unsigned values are LE -1 and GE 0.
741 if (lo0 == 0 && hi0 == 0) {
742 return TypeInt::CC_LE; // 0 <= bot
743 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
744 return TypeInt::CC_GE; // -1 >= bot
745 } else if (lo1 == 0 && hi1 == 0) {
746 return TypeInt::CC_GE; // bot >= 0
747 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
748 return TypeInt::CC_LE; // bot <= -1
749 }
750 } else {
751 // We can use ranges of the form [lo..hi] if signs are the same.
752 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
753 // results are reversed, '-' > '+' for unsigned compare
754 if (hi0 < lo1) {
755 return TypeInt::CC_LT; // smaller
756 } else if (lo0 > hi1) {
757 return TypeInt::CC_GT; // greater
758 } else if (hi0 == lo1 && lo0 == hi1) {
759 return TypeInt::CC_EQ; // Equal results
760 } else if (lo0 >= hi1) {
761 return TypeInt::CC_GE;
762 } else if (hi0 <= lo1) {
763 // Check for special case in Hashtable::get. (See below.)
764 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
765 return TypeInt::CC_LT;
766 return TypeInt::CC_LE;
767 }
768 }
769 // Check for special case in Hashtable::get - the hash index is
770 // mod'ed to the table size so the following range check is useless.
771 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
772 // to be positive.
773 // (This is a gross hack, since the sub method never
774 // looks at the structure of the node in any other case.)
775 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
776 return TypeInt::CC_LT;
777 return TypeInt::CC; // else use worst case results
778 }
779
780 const Type* CmpUNode::Value(PhaseGVN* phase) const {
781 const Type* t = SubNode::Value_common(phase);
782 if (t != nullptr) {
783 return t;
784 }
785 const Node* in1 = in(1);
786 const Node* in2 = in(2);
787 const Type* t1 = phase->type(in1);
788 const Type* t2 = phase->type(in2);
789 assert(t1->isa_int(), "CmpU has only Int type inputs");
790 if (t2 == TypeInt::INT) { // Compare to bottom?
791 return bottom_type();
792 }
793
794 const Type* t_sub = sub(t1, t2); // compare based on immediate inputs
795
796 uint in1_op = in1->Opcode();
797 if (in1_op == Op_AddI || in1_op == Op_SubI) {
798 // The problem rise when result of AddI(SubI) may overflow
799 // signed integer value. Let say the input type is
800 // [256, maxint] then +128 will create 2 ranges due to
801 // overflow: [minint, minint+127] and [384, maxint].
802 // But C2 type system keep only 1 type range and as result
803 // it use general [minint, maxint] for this case which we
804 // can't optimize.
805 //
806 // Make 2 separate type ranges based on types of AddI(SubI) inputs
807 // and compare results of their compare. If results are the same
808 // CmpU node can be optimized.
809 const Node* in11 = in1->in(1);
810 const Node* in12 = in1->in(2);
811 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
812 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
813 // Skip cases when input types are top or bottom.
814 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
815 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
816 const TypeInt *r0 = t11->is_int();
817 const TypeInt *r1 = t12->is_int();
818 jlong lo_r0 = r0->_lo;
819 jlong hi_r0 = r0->_hi;
820 jlong lo_r1 = r1->_lo;
821 jlong hi_r1 = r1->_hi;
822 if (in1_op == Op_SubI) {
823 jlong tmp = hi_r1;
824 hi_r1 = -lo_r1;
825 lo_r1 = -tmp;
826 // Note, for substructing [minint,x] type range
827 // long arithmetic provides correct overflow answer.
828 // The confusion come from the fact that in 32-bit
829 // -minint == minint but in 64-bit -minint == maxint+1.
830 }
831 jlong lo_long = lo_r0 + lo_r1;
832 jlong hi_long = hi_r0 + hi_r1;
833 int lo_tr1 = min_jint;
834 int hi_tr1 = (int)hi_long;
835 int lo_tr2 = (int)lo_long;
836 int hi_tr2 = max_jint;
837 bool underflow = lo_long != (jlong)lo_tr2;
838 bool overflow = hi_long != (jlong)hi_tr1;
839 // Use sub(t1, t2) when there is no overflow (one type range)
840 // or when both overflow and underflow (too complex).
841 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
842 // Overflow only on one boundary, compare 2 separate type ranges.
843 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
844 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
845 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
846 const TypeInt* cmp1 = sub(tr1, t2)->is_int();
847 const TypeInt* cmp2 = sub(tr2, t2)->is_int();
848 // Compute union, so that cmp handles all possible results from the two cases
849 const Type* t_cmp = cmp1->meet(cmp2);
850 // Pick narrowest type, based on overflow computation and on immediate inputs
851 return t_sub->filter(t_cmp);
852 }
853 }
854 }
855
856 return t_sub;
857 }
858
859 bool CmpUNode::is_index_range_check() const {
860 // Check for the "(X ModI Y) CmpU Y" shape
861 return (in(1)->Opcode() == Op_ModI &&
862 in(1)->in(2)->eqv_uncast(in(2)));
863 }
864
865 //------------------------------Idealize---------------------------------------
866 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
867 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
868 switch (in(1)->Opcode()) {
869 case Op_CmpU3: // Collapse a CmpU3/CmpI into a CmpU
870 return new CmpUNode(in(1)->in(1),in(1)->in(2));
871 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
872 return new CmpLNode(in(1)->in(1),in(1)->in(2));
873 case Op_CmpUL3: // Collapse a CmpUL3/CmpI into a CmpUL
874 return new CmpULNode(in(1)->in(1),in(1)->in(2));
875 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
876 return new CmpFNode(in(1)->in(1),in(1)->in(2));
877 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
878 return new CmpDNode(in(1)->in(1),in(1)->in(2));
879 //case Op_SubI:
880 // If (x - y) cannot overflow, then ((x - y) <?> 0)
881 // can be turned into (x <?> y).
882 // This is handled (with more general cases) by Ideal_sub_algebra.
883 }
884 }
885 return nullptr; // No change
886 }
887
888 //------------------------------Ideal------------------------------------------
889 Node* CmpLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
890 Node* a = nullptr;
891 Node* b = nullptr;
892 if (is_double_null_check(phase, a, b) && (phase->type(a)->is_zero_type() || phase->type(b)->is_zero_type())) {
893 // Degraded to a simple null check, use old acmp
894 return new CmpPNode(a, b);
895 }
896 const TypeLong *t2 = phase->type(in(2))->isa_long();
897 if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) {
898 const jlong con = t2->get_con();
899 if (con >= min_jint && con <= max_jint) {
900 return new CmpINode(in(1)->in(1), phase->intcon((jint)con));
901 }
902 }
903 return nullptr;
904 }
905
906 // Match double null check emitted by Compile::optimize_acmp()
907 bool CmpLNode::is_double_null_check(PhaseGVN* phase, Node*& a, Node*& b) const {
908 if (in(1)->Opcode() == Op_OrL &&
909 in(1)->in(1)->Opcode() == Op_CastP2X &&
910 in(1)->in(2)->Opcode() == Op_CastP2X &&
911 in(2)->bottom_type()->is_zero_type()) {
912 assert(EnableValhalla, "unexpected double null check");
913 a = in(1)->in(1)->in(1);
914 b = in(1)->in(2)->in(1);
915 return true;
916 }
917 return false;
918 }
919
920 //------------------------------Value------------------------------------------
921 const Type* CmpLNode::Value(PhaseGVN* phase) const {
922 Node* a = nullptr;
923 Node* b = nullptr;
924 if (is_double_null_check(phase, a, b) && (!phase->type(a)->maybe_null() || !phase->type(b)->maybe_null())) {
925 // One operand is never nullptr, emit constant false
926 return TypeInt::CC_GT;
927 }
928 return SubNode::Value(phase);
929 }
930
931 //=============================================================================
932 // Simplify a CmpL (compare 2 longs ) node, based on local information.
933 // If both inputs are constants, compare them.
934 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
935 const TypeLong *r0 = t1->is_long(); // Handy access
936 const TypeLong *r1 = t2->is_long();
937
938 if( r0->_hi < r1->_lo ) // Range is always low?
939 return TypeInt::CC_LT;
940 else if( r0->_lo > r1->_hi ) // Range is always high?
941 return TypeInt::CC_GT;
942
943 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
944 assert(r0->get_con() == r1->get_con(), "must be equal");
945 return TypeInt::CC_EQ; // Equal results.
946 } else if( r0->_hi == r1->_lo ) // Range is never high?
947 return TypeInt::CC_LE;
948 else if( r0->_lo == r1->_hi ) // Range is never low?
949 return TypeInt::CC_GE;
950 return TypeInt::CC; // else use worst case results
951 }
952
953
954 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
955 // If both inputs are constants, compare them.
956 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
957 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
958
959 // comparing two unsigned longs
960 const TypeLong* r0 = t1->is_long(); // Handy access
961 const TypeLong* r1 = t2->is_long();
962
963 // Current installed version
964 // Compare ranges for non-overlap
965 julong lo0 = r0->_lo;
966 julong hi0 = r0->_hi;
967 julong lo1 = r1->_lo;
968 julong hi1 = r1->_hi;
969
970 // If either one has both negative and positive values,
971 // it therefore contains both 0 and -1, and since [0..-1] is the
972 // full unsigned range, the type must act as an unsigned bottom.
973 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
974 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
975
976 if (bot0 || bot1) {
977 // All unsigned values are LE -1 and GE 0.
978 if (lo0 == 0 && hi0 == 0) {
979 return TypeInt::CC_LE; // 0 <= bot
980 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
981 return TypeInt::CC_GE; // -1 >= bot
982 } else if (lo1 == 0 && hi1 == 0) {
983 return TypeInt::CC_GE; // bot >= 0
984 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
985 return TypeInt::CC_LE; // bot <= -1
986 }
987 } else {
988 // We can use ranges of the form [lo..hi] if signs are the same.
989 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
990 // results are reversed, '-' > '+' for unsigned compare
991 if (hi0 < lo1) {
992 return TypeInt::CC_LT; // smaller
993 } else if (lo0 > hi1) {
994 return TypeInt::CC_GT; // greater
995 } else if (hi0 == lo1 && lo0 == hi1) {
996 return TypeInt::CC_EQ; // Equal results
997 } else if (lo0 >= hi1) {
998 return TypeInt::CC_GE;
999 } else if (hi0 <= lo1) {
1000 return TypeInt::CC_LE;
1001 }
1002 }
1003
1004 return TypeInt::CC; // else use worst case results
1005 }
1006
1007 //=============================================================================
1008 //------------------------------sub--------------------------------------------
1009 // Simplify an CmpP (compare 2 pointers) node, based on local information.
1010 // If both inputs are constants, compare them.
1011 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
1012 const TypePtr *r0 = t1->is_ptr(); // Handy access
1013 const TypePtr *r1 = t2->is_ptr();
1014
1015 // Undefined inputs makes for an undefined result
1016 if( TypePtr::above_centerline(r0->_ptr) ||
1017 TypePtr::above_centerline(r1->_ptr) )
1018 return Type::TOP;
1019
1020 if (r0 == r1 && r0->singleton()) {
1021 // Equal pointer constants (klasses, nulls, etc.)
1022 return TypeInt::CC_EQ;
1023 }
1024
1025 // See if it is 2 unrelated classes.
1026 const TypeOopPtr* p0 = r0->isa_oopptr();
1027 const TypeOopPtr* p1 = r1->isa_oopptr();
1028 const TypeKlassPtr* k0 = r0->isa_klassptr();
1029 const TypeKlassPtr* k1 = r1->isa_klassptr();
1030 if ((p0 && p1) || (k0 && k1)) {
1031 if (p0 && p1) {
1032 Node* in1 = in(1)->uncast();
1033 Node* in2 = in(2)->uncast();
1034 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1);
1035 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2);
1036 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, nullptr)) {
1037 return TypeInt::CC_GT; // different pointers
1038 }
1039 }
1040 bool xklass0 = p0 ? p0->klass_is_exact() : k0->klass_is_exact();
1041 bool xklass1 = p1 ? p1->klass_is_exact() : k1->klass_is_exact();
1042 bool unrelated_classes = false;
1043
1044 if ((p0 && p0->is_same_java_type_as(p1)) ||
1045 (k0 && k0->is_same_java_type_as(k1))) {
1046 } else if ((p0 && !p1->maybe_java_subtype_of(p0) && !p0->maybe_java_subtype_of(p1)) ||
1047 (k0 && !k1->maybe_java_subtype_of(k0) && !k0->maybe_java_subtype_of(k1))) {
1048 unrelated_classes = true;
1049 } else if ((p0 && !p1->maybe_java_subtype_of(p0)) ||
1050 (k0 && !k1->maybe_java_subtype_of(k0))) {
1051 unrelated_classes = xklass1;
1052 } else if ((p0 && !p0->maybe_java_subtype_of(p1)) ||
1053 (k0 && !k0->maybe_java_subtype_of(k1))) {
1054 unrelated_classes = xklass0;
1055 }
1056 if (!unrelated_classes) {
1057 // Handle inline type arrays
1058 if ((r0->flat_in_array() && r1->not_flat_in_array()) ||
1059 (r1->flat_in_array() && r0->not_flat_in_array())) {
1060 // One type is in flat arrays but the other type is not. Must be unrelated.
1061 unrelated_classes = true;
1062 } else if ((r0->is_not_flat() && r1->is_flat()) ||
1063 (r1->is_not_flat() && r0->is_flat())) {
1064 // One type is a non-flat array and the other type is a flat array. Must be unrelated.
1065 unrelated_classes = true;
1066 } else if ((r0->is_not_null_free() && r1->is_null_free()) ||
1067 (r1->is_not_null_free() && r0->is_null_free())) {
1068 // One type is a nullable array and the other type is a null-free array. Must be unrelated.
1069 unrelated_classes = true;
1070 }
1071 }
1072 if (unrelated_classes) {
1073 // The oops classes are known to be unrelated. If the joined PTRs of
1074 // two oops is not Null and not Bottom, then we are sure that one
1075 // of the two oops is non-null, and the comparison will always fail.
1076 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1077 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1078 return TypeInt::CC_GT;
1079 }
1080 }
1081 }
1082
1083 // Known constants can be compared exactly
1084 // Null can be distinguished from any NotNull pointers
1085 // Unknown inputs makes an unknown result
1086 if( r0->singleton() ) {
1087 intptr_t bits0 = r0->get_con();
1088 if( r1->singleton() )
1089 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1090 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1091 } else if( r1->singleton() ) {
1092 intptr_t bits1 = r1->get_con();
1093 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1094 } else
1095 return TypeInt::CC;
1096 }
1097
1098 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1099 // Return the klass node for (indirect load from OopHandle)
1100 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1101 // or null if not matching.
1102 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1103 n = bs->step_over_gc_barrier(n);
1104
1105 if (n->Opcode() != Op_LoadP) return nullptr;
1106
1107 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1108 if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr;
1109
1110 Node* adr = n->in(MemNode::Address);
1111 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1112 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr;
1113 adr = adr->in(MemNode::Address);
1114
1115 intptr_t off = 0;
1116 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1117 if (k == nullptr) return nullptr;
1118 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1119 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr;
1120
1121 // We've found the klass node of a Java mirror load.
1122 return k;
1123 }
1124
1125 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
1126 // for ConP(Foo.class) return ConP(Foo.klass)
1127 // otherwise return null
1128 if (!n->is_Con()) return nullptr;
1129
1130 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1131 if (!tp) return nullptr;
1132
1133 ciType* mirror_type = tp->java_mirror_type();
1134 // TypeInstPtr::java_mirror_type() returns non-null for compile-
1135 // time Class constants only.
1136 if (!mirror_type) return nullptr;
1137
1138 // x.getClass() == int.class can never be true (for all primitive types)
1139 // Return a ConP(null) node for this case.
1140 if (mirror_type->is_classless()) {
1141 return phase->makecon(TypePtr::NULL_PTR);
1142 }
1143
1144 // return the ConP(Foo.klass)
1145 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
1146 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass(), Type::trust_interfaces));
1147 }
1148
1149 //------------------------------Ideal------------------------------------------
1150 // Normalize comparisons between Java mirror loads to compare the klass instead.
1151 //
1152 // Also check for the case of comparing an unknown klass loaded from the primary
1153 // super-type array vs a known klass with no subtypes. This amounts to
1154 // checking to see an unknown klass subtypes a known klass with no subtypes;
1155 // this only happens on an exact match. We can shorten this test by 1 load.
1156 Node* CmpPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1157 // TODO 8284443 in(1) could be cast?
1158 if (in(1)->is_InlineType() && phase->type(in(2))->is_zero_type()) {
1159 // Null checking a scalarized but nullable inline type. Check the IsInit
1160 // input instead of the oop input to avoid keeping buffer allocations alive.
1161 return new CmpINode(in(1)->as_InlineType()->get_is_init(), phase->intcon(0));
1162 }
1163
1164 // Normalize comparisons between Java mirrors into comparisons of the low-
1165 // level klass, where a dependent load could be shortened.
1166 //
1167 // The new pattern has a nice effect of matching the same pattern used in the
1168 // fast path of instanceof/checkcast/Class.isInstance(), which allows
1169 // redundant exact type check be optimized away by GVN.
1170 // For example, in
1171 // if (x.getClass() == Foo.class) {
1172 // Foo foo = (Foo) x;
1173 // // ... use a ...
1174 // }
1175 // a CmpPNode could be shared between if_acmpne and checkcast
1176 {
1177 Node* k1 = isa_java_mirror_load(phase, in(1));
1178 Node* k2 = isa_java_mirror_load(phase, in(2));
1179 Node* conk2 = isa_const_java_mirror(phase, in(2));
1180
1181 if (k1 && (k2 || conk2)) {
1182 Node* lhs = k1;
1183 Node* rhs = (k2 != nullptr) ? k2 : conk2;
1184 set_req_X(1, lhs, phase);
1185 set_req_X(2, rhs, phase);
1186 return this;
1187 }
1188 }
1189
1190 // Constant pointer on right?
1191 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1192 if (t2 == nullptr || !t2->klass_is_exact())
1193 return nullptr;
1194 // Get the constant klass we are comparing to.
1195 ciKlass* superklass = t2->exact_klass();
1196
1197 // Now check for LoadKlass on left.
1198 Node* ldk1 = in(1);
1199 if (ldk1->is_DecodeNKlass()) {
1200 ldk1 = ldk1->in(1);
1201 if (ldk1->Opcode() != Op_LoadNKlass )
1202 return nullptr;
1203 } else if (ldk1->Opcode() != Op_LoadKlass )
1204 return nullptr;
1205 // Take apart the address of the LoadKlass:
1206 Node* adr1 = ldk1->in(MemNode::Address);
1207 intptr_t con2 = 0;
1208 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1209 if (ldk2 == nullptr)
1210 return nullptr;
1211 if (con2 == oopDesc::klass_offset_in_bytes()) {
1212 // We are inspecting an object's concrete class.
1213 // Short-circuit the check if the query is abstract.
1214 if (superklass->is_interface() ||
1215 superklass->is_abstract()) {
1216 // Make it come out always false:
1217 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1218 return this;
1219 }
1220 }
1221
1222 // Check for a LoadKlass from primary supertype array.
1223 // Any nested loadklass from loadklass+con must be from the p.s. array.
1224 if (ldk2->is_DecodeNKlass()) {
1225 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1226 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1227 return nullptr;
1228 } else if (ldk2->Opcode() != Op_LoadKlass)
1229 return nullptr;
1230
1231 // Verify that we understand the situation
1232 if (con2 != (intptr_t) superklass->super_check_offset())
1233 return nullptr; // Might be element-klass loading from array klass
1234
1235 // TODO 8325106 Fix comment
1236 // Do not fold the subtype check to an array klass pointer comparison for [V? arrays.
1237 // [QMyValue is a subtype of [LMyValue but the klass for [QMyValue is not equal to
1238 // the klass for [LMyValue. Do not bypass the klass load from the primary supertype array.
1239 if (superklass->is_obj_array_klass() && !superklass->as_array_klass()->is_elem_null_free() &&
1240 superklass->as_array_klass()->element_klass()->is_inlinetype()) {
1241 return nullptr;
1242 }
1243
1244 // If 'superklass' has no subklasses and is not an interface, then we are
1245 // assured that the only input which will pass the type check is
1246 // 'superklass' itself.
1247 //
1248 // We could be more liberal here, and allow the optimization on interfaces
1249 // which have a single implementor. This would require us to increase the
1250 // expressiveness of the add_dependency() mechanism.
1251 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1252
1253 // Object arrays must have their base element have no subtypes
1254 while (superklass->is_obj_array_klass()) {
1255 ciType* elem = superklass->as_obj_array_klass()->element_type();
1256 superklass = elem->as_klass();
1257 }
1258 if (superklass->is_instance_klass()) {
1259 ciInstanceKlass* ik = superklass->as_instance_klass();
1260 if (ik->has_subklass() || ik->is_interface()) return nullptr;
1261 // Add a dependency if there is a chance that a subclass will be added later.
1262 if (!ik->is_final()) {
1263 phase->C->dependencies()->assert_leaf_type(ik);
1264 }
1265 }
1266
1267 // Bypass the dependent load, and compare directly
1268 this->set_req_X(1, ldk2, phase);
1269
1270 return this;
1271 }
1272
1273 //=============================================================================
1274 //------------------------------sub--------------------------------------------
1275 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1276 // If both inputs are constants, compare them.
1277 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1278 ShouldNotReachHere();
1279 return bottom_type();
1280 }
1281
1282 //------------------------------Ideal------------------------------------------
1283 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1284 return nullptr;
1285 }
1286
1287 //=============================================================================
1288 //------------------------------Value------------------------------------------
1289 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1290 // If both inputs are constants, compare them.
1291 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1292 const Node* in1 = in(1);
1293 const Node* in2 = in(2);
1294 // Either input is TOP ==> the result is TOP
1295 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1296 if( t1 == Type::TOP ) return Type::TOP;
1297 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1298 if( t2 == Type::TOP ) return Type::TOP;
1299
1300 // Not constants? Don't know squat - even if they are the same
1301 // value! If they are NaN's they compare to LT instead of EQ.
1302 const TypeF *tf1 = t1->isa_float_constant();
1303 const TypeF *tf2 = t2->isa_float_constant();
1304 if( !tf1 || !tf2 ) return TypeInt::CC;
1305
1306 // This implements the Java bytecode fcmpl, so unordered returns -1.
1307 if( tf1->is_nan() || tf2->is_nan() )
1308 return TypeInt::CC_LT;
1309
1310 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1311 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1312 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1313 return TypeInt::CC_EQ;
1314 }
1315
1316
1317 //=============================================================================
1318 //------------------------------Value------------------------------------------
1319 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1320 // If both inputs are constants, compare them.
1321 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1322 const Node* in1 = in(1);
1323 const Node* in2 = in(2);
1324 // Either input is TOP ==> the result is TOP
1325 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1326 if( t1 == Type::TOP ) return Type::TOP;
1327 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1328 if( t2 == Type::TOP ) return Type::TOP;
1329
1330 // Not constants? Don't know squat - even if they are the same
1331 // value! If they are NaN's they compare to LT instead of EQ.
1332 const TypeD *td1 = t1->isa_double_constant();
1333 const TypeD *td2 = t2->isa_double_constant();
1334 if( !td1 || !td2 ) return TypeInt::CC;
1335
1336 // This implements the Java bytecode dcmpl, so unordered returns -1.
1337 if( td1->is_nan() || td2->is_nan() )
1338 return TypeInt::CC_LT;
1339
1340 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1341 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1342 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1343 return TypeInt::CC_EQ;
1344 }
1345
1346 //------------------------------Ideal------------------------------------------
1347 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1348 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1349 // Change (CMPD (F2D (float)) (ConD value))
1350 // To (CMPF (float) (ConF value))
1351 // Valid when 'value' does not lose precision as a float.
1352 // Benefits: eliminates conversion, does not require 24-bit mode
1353
1354 // NaNs prevent commuting operands. This transform works regardless of the
1355 // order of ConD and ConvF2D inputs by preserving the original order.
1356 int idx_f2d = 1; // ConvF2D on left side?
1357 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1358 idx_f2d = 2; // No, swap to check for reversed args
1359 int idx_con = 3-idx_f2d; // Check for the constant on other input
1360
1361 if( ConvertCmpD2CmpF &&
1362 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1363 in(idx_con)->Opcode() == Op_ConD ) {
1364 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1365 double t2_value_as_double = t2->_d;
1366 float t2_value_as_float = (float)t2_value_as_double;
1367 if( t2_value_as_double == (double)t2_value_as_float ) {
1368 // Test value can be represented as a float
1369 // Eliminate the conversion to double and create new comparison
1370 Node *new_in1 = in(idx_f2d)->in(1);
1371 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1372 if( idx_f2d != 1 ) { // Must flip args to match original order
1373 Node *tmp = new_in1;
1374 new_in1 = new_in2;
1375 new_in2 = tmp;
1376 }
1377 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1378 ? new CmpF3Node( new_in1, new_in2 )
1379 : new CmpFNode ( new_in1, new_in2 ) ;
1380 return new_cmp; // Changed to CmpFNode
1381 }
1382 // Testing value required the precision of a double
1383 }
1384 return nullptr; // No change
1385 }
1386
1387 //=============================================================================
1388 //------------------------------Value------------------------------------------
1389 const Type* FlatArrayCheckNode::Value(PhaseGVN* phase) const {
1390 bool all_not_flat = true;
1391 for (uint i = ArrayOrKlass; i < req(); ++i) {
1392 const Type* t = phase->type(in(i));
1393 if (t == Type::TOP) {
1394 return Type::TOP;
1395 }
1396 if (t->is_ptr()->is_flat()) {
1397 // One of the input arrays is flat, check always passes
1398 return TypeInt::CC_EQ;
1399 } else if (!t->is_ptr()->is_not_flat()) {
1400 // One of the input arrays might be flat
1401 all_not_flat = false;
1402 }
1403 }
1404 if (all_not_flat) {
1405 // None of the input arrays can be flat, check always fails
1406 return TypeInt::CC_GT;
1407 }
1408 return TypeInt::CC;
1409 }
1410
1411 //------------------------------Ideal------------------------------------------
1412 Node* FlatArrayCheckNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1413 bool changed = false;
1414 // Remove inputs that are known to be non-flat
1415 for (uint i = ArrayOrKlass; i < req(); ++i) {
1416 const Type* t = phase->type(in(i));
1417 if (t->isa_ptr() && t->is_ptr()->is_not_flat()) {
1418 del_req(i--);
1419 changed = true;
1420 }
1421 }
1422 return changed ? this : nullptr;
1423 }
1424
1425 //=============================================================================
1426 //------------------------------cc2logical-------------------------------------
1427 // Convert a condition code type to a logical type
1428 const Type *BoolTest::cc2logical( const Type *CC ) const {
1429 if( CC == Type::TOP ) return Type::TOP;
1430 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1431 const TypeInt *ti = CC->is_int();
1432 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1433 // Match low order 2 bits
1434 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1435 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1436 return TypeInt::make(tmp); // Boolean result
1437 }
1438
1439 if( CC == TypeInt::CC_GE ) {
1440 if( _test == ge ) return TypeInt::ONE;
1441 if( _test == lt ) return TypeInt::ZERO;
1442 }
1443 if( CC == TypeInt::CC_LE ) {
1444 if( _test == le ) return TypeInt::ONE;
1445 if( _test == gt ) return TypeInt::ZERO;
1446 }
1447
1448 return TypeInt::BOOL;
1449 }
1450
1451 //------------------------------dump_spec-------------------------------------
1452 // Print special per-node info
1453 void BoolTest::dump_on(outputStream *st) const {
1454 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1455 st->print("%s", msg[_test]);
1456 }
1457
1458 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1459 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1460 BoolTest::mask BoolTest::merge(BoolTest other) const {
1461 const mask res[illegal+1][illegal+1] = {
1462 // eq, gt, of, lt, ne, le, nof, ge, never, illegal
1463 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq
1464 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt
1465 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of
1466 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt
1467 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne
1468 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le
1469 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof
1470 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge
1471 {never, never, never, never, never, never, never, never, never, illegal}, // never
1472 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1473 return res[_test][other._test];
1474 }
1475
1476 //=============================================================================
1477 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1478 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1479
1480 //------------------------------operator==-------------------------------------
1481 bool BoolNode::cmp( const Node &n ) const {
1482 const BoolNode *b = (const BoolNode *)&n; // Cast up
1483 return (_test._test == b->_test._test);
1484 }
1485
1486 //-------------------------------make_predicate--------------------------------
1487 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1488 if (test_value->is_Con()) return test_value;
1489 if (test_value->is_Bool()) return test_value;
1490 if (test_value->is_CMove() &&
1491 test_value->in(CMoveNode::Condition)->is_Bool()) {
1492 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1493 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1494 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1495 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1496 return bol;
1497 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1498 return phase->transform( bol->negate(phase) );
1499 }
1500 // Else fall through. The CMove gets in the way of the test.
1501 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1502 }
1503 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1504 cmp = phase->transform(cmp);
1505 Node* bol = new BoolNode(cmp, BoolTest::ne);
1506 return phase->transform(bol);
1507 }
1508
1509 //--------------------------------as_int_value---------------------------------
1510 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1511 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1512 Node* cmov = CMoveNode::make(nullptr, this,
1513 phase->intcon(0), phase->intcon(1),
1514 TypeInt::BOOL);
1515 return phase->transform(cmov);
1516 }
1517
1518 //----------------------------------negate-------------------------------------
1519 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1520 return new BoolNode(in(1), _test.negate());
1521 }
1522
1523 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1524 // overflows and we can prove that C is not in the two resulting ranges.
1525 // This optimization is similar to the one performed by CmpUNode::Value().
1526 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1527 int cmp1_op, const TypeInt* cmp2_type) {
1528 // Only optimize eq/ne integer comparison of add/sub
1529 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1530 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1531 // Skip cases were inputs of add/sub are not integers or of bottom type
1532 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1533 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1534 if ((r0 != nullptr) && (r0 != TypeInt::INT) &&
1535 (r1 != nullptr) && (r1 != TypeInt::INT) &&
1536 (cmp2_type != TypeInt::INT)) {
1537 // Compute exact (long) type range of add/sub result
1538 jlong lo_long = r0->_lo;
1539 jlong hi_long = r0->_hi;
1540 if (cmp1_op == Op_AddI) {
1541 lo_long += r1->_lo;
1542 hi_long += r1->_hi;
1543 } else {
1544 lo_long -= r1->_hi;
1545 hi_long -= r1->_lo;
1546 }
1547 // Check for over-/underflow by casting to integer
1548 int lo_int = (int)lo_long;
1549 int hi_int = (int)hi_long;
1550 bool underflow = lo_long != (jlong)lo_int;
1551 bool overflow = hi_long != (jlong)hi_int;
1552 if ((underflow != overflow) && (hi_int < lo_int)) {
1553 // Overflow on one boundary, compute resulting type ranges:
1554 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1555 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1556 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1557 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1558 // Compare second input of cmp to both type ranges
1559 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1560 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1561 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1562 // The result of the add/sub will never equal cmp2. Replace BoolNode
1563 // by false (0) if it tests for equality and by true (1) otherwise.
1564 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1565 }
1566 }
1567 }
1568 }
1569 return nullptr;
1570 }
1571
1572 static bool is_counted_loop_cmp(Node *cmp) {
1573 Node *n = cmp->in(1)->in(1);
1574 return n != nullptr &&
1575 n->is_Phi() &&
1576 n->in(0) != nullptr &&
1577 n->in(0)->is_CountedLoop() &&
1578 n->in(0)->as_CountedLoop()->phi() == n;
1579 }
1580
1581 //------------------------------Ideal------------------------------------------
1582 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1583 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1584 // This moves the constant to the right. Helps value-numbering.
1585 Node *cmp = in(1);
1586 if( !cmp->is_Sub() ) return nullptr;
1587 int cop = cmp->Opcode();
1588 if( cop == Op_FastLock || cop == Op_FastUnlock ||
1589 cmp->is_SubTypeCheck() || cop == Op_VectorTest ) {
1590 return nullptr;
1591 }
1592 Node *cmp1 = cmp->in(1);
1593 Node *cmp2 = cmp->in(2);
1594 if( !cmp1 ) return nullptr;
1595
1596 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1597 return nullptr;
1598 }
1599
1600 const int cmp1_op = cmp1->Opcode();
1601 const int cmp2_op = cmp2->Opcode();
1602
1603 // Constant on left?
1604 Node *con = cmp1;
1605 // Move constants to the right of compare's to canonicalize.
1606 // Do not muck with Opaque1 nodes, as this indicates a loop
1607 // guard that cannot change shape.
1608 if (con->is_Con() && !cmp2->is_Con() && cmp2_op != Op_OpaqueZeroTripGuard &&
1609 // Because of NaN's, CmpD and CmpF are not commutative
1610 cop != Op_CmpD && cop != Op_CmpF &&
1611 // Protect against swapping inputs to a compare when it is used by a
1612 // counted loop exit, which requires maintaining the loop-limit as in(2)
1613 !is_counted_loop_exit_test() ) {
1614 // Ok, commute the constant to the right of the cmp node.
1615 // Clone the Node, getting a new Node of the same class
1616 cmp = cmp->clone();
1617 // Swap inputs to the clone
1618 cmp->swap_edges(1, 2);
1619 cmp = phase->transform( cmp );
1620 return new BoolNode( cmp, _test.commute() );
1621 }
1622
1623 // Change "bool eq/ne (cmp (cmove (bool tst (cmp2)) 1 0) 0)" into "bool tst/~tst (cmp2)"
1624 if (cop == Op_CmpI &&
1625 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1626 cmp1_op == Op_CMoveI && cmp2->find_int_con(1) == 0) {
1627 // 0 should be on the true branch
1628 if (cmp1->in(CMoveNode::Condition)->is_Bool() &&
1629 cmp1->in(CMoveNode::IfTrue)->find_int_con(1) == 0 &&
1630 cmp1->in(CMoveNode::IfFalse)->find_int_con(0) != 0) {
1631 BoolNode* target = cmp1->in(CMoveNode::Condition)->as_Bool();
1632 return new BoolNode(target->in(1),
1633 (_test._test == BoolTest::eq) ? target->_test._test :
1634 target->_test.negate());
1635 }
1636 }
1637
1638 // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1639 if (cop == Op_CmpI &&
1640 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1641 cmp1_op == Op_AndI && cmp2_op == Op_ConI &&
1642 cmp1->in(2)->Opcode() == Op_ConI) {
1643 const TypeInt *t12 = phase->type(cmp2)->isa_int();
1644 const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int();
1645 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1646 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1647 Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1648 return new BoolNode(ncmp, _test.negate());
1649 }
1650 }
1651
1652 // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1653 if (cop == Op_CmpL &&
1654 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1655 cmp1_op == Op_AndL && cmp2_op == Op_ConL &&
1656 cmp1->in(2)->Opcode() == Op_ConL) {
1657 const TypeLong *t12 = phase->type(cmp2)->isa_long();
1658 const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long();
1659 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1660 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1661 Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0)));
1662 return new BoolNode(ncmp, _test.negate());
1663 }
1664 }
1665
1666 // Change "cmp (add X min_jint) (add Y min_jint)" into "cmpu X Y"
1667 // and "cmp (add X min_jint) c" into "cmpu X (c + min_jint)"
1668 if (cop == Op_CmpI &&
1669 cmp1_op == Op_AddI &&
1670 phase->type(cmp1->in(2)) == TypeInt::MIN &&
1671 !is_cloop_condition(this)) {
1672 if (cmp2_op == Op_ConI) {
1673 Node* ncmp2 = phase->intcon(java_add(cmp2->get_int(), min_jint));
1674 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), ncmp2));
1675 return new BoolNode(ncmp, _test._test);
1676 } else if (cmp2_op == Op_AddI &&
1677 phase->type(cmp2->in(2)) == TypeInt::MIN &&
1678 !is_cloop_condition(this)) {
1679 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), cmp2->in(1)));
1680 return new BoolNode(ncmp, _test._test);
1681 }
1682 }
1683
1684 // Change "cmp (add X min_jlong) (add Y min_jlong)" into "cmpu X Y"
1685 // and "cmp (add X min_jlong) c" into "cmpu X (c + min_jlong)"
1686 if (cop == Op_CmpL &&
1687 cmp1_op == Op_AddL &&
1688 phase->type(cmp1->in(2)) == TypeLong::MIN &&
1689 !is_cloop_condition(this)) {
1690 if (cmp2_op == Op_ConL) {
1691 Node* ncmp2 = phase->longcon(java_add(cmp2->get_long(), min_jlong));
1692 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), ncmp2));
1693 return new BoolNode(ncmp, _test._test);
1694 } else if (cmp2_op == Op_AddL &&
1695 phase->type(cmp2->in(2)) == TypeLong::MIN &&
1696 !is_cloop_condition(this)) {
1697 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), cmp2->in(1)));
1698 return new BoolNode(ncmp, _test._test);
1699 }
1700 }
1701
1702 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1703 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1704 // test instead.
1705 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1706 if (cmp2_type == nullptr) return nullptr;
1707 Node* j_xor = cmp1;
1708 if( cmp2_type == TypeInt::ZERO &&
1709 cmp1_op == Op_XorI &&
1710 j_xor->in(1) != j_xor && // An xor of itself is dead
1711 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1712 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1713 (_test._test == BoolTest::eq ||
1714 _test._test == BoolTest::ne) ) {
1715 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1716 return new BoolNode( ncmp, _test.negate() );
1717 }
1718
1719 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1720 // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1721 if (cop == Op_CmpU &&
1722 cmp1_op == Op_AndI) {
1723 Node* bound = nullptr;
1724 if (_test._test == BoolTest::le) {
1725 bound = cmp2;
1726 } else if (_test._test == BoolTest::lt &&
1727 cmp2->Opcode() == Op_AddI &&
1728 cmp2->in(2)->find_int_con(0) == 1) {
1729 bound = cmp2->in(1);
1730 }
1731 if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1732 return ConINode::make(1);
1733 }
1734 }
1735
1736 // Change ((x & (m - 1)) u< m) into (m > 0)
1737 // This is the off-by-one variant of the above
1738 if (cop == Op_CmpU &&
1739 _test._test == BoolTest::lt &&
1740 cmp1_op == Op_AndI) {
1741 Node* l = cmp1->in(1);
1742 Node* r = cmp1->in(2);
1743 for (int repeat = 0; repeat < 2; repeat++) {
1744 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1745 r->in(1) == cmp2;
1746 if (match) {
1747 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1748 // but to be compatible with the array range check pattern, use (arraylength u> 0)
1749 Node* ncmp = cmp2->Opcode() == Op_LoadRange
1750 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1751 : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1752 return new BoolNode(ncmp, BoolTest::gt);
1753 } else {
1754 // commute and try again
1755 l = cmp1->in(2);
1756 r = cmp1->in(1);
1757 }
1758 }
1759 }
1760
1761 // Change x u< 1 or x u<= 0 to x == 0
1762 // and x u> 0 or u>= 1 to x != 0
1763 if (cop == Op_CmpU &&
1764 cmp1_op != Op_LoadRange &&
1765 (((_test._test == BoolTest::lt || _test._test == BoolTest::ge) &&
1766 cmp2->find_int_con(-1) == 1) ||
1767 ((_test._test == BoolTest::le || _test._test == BoolTest::gt) &&
1768 cmp2->find_int_con(-1) == 0))) {
1769 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1770 return new BoolNode(ncmp, _test.is_less() ? BoolTest::eq : BoolTest::ne);
1771 }
1772
1773 // Change (arraylength <= 0) or (arraylength == 0)
1774 // into (arraylength u<= 0)
1775 // Also change (arraylength != 0) into (arraylength u> 0)
1776 // The latter version matches the code pattern generated for
1777 // array range checks, which will more likely be optimized later.
1778 if (cop == Op_CmpI &&
1779 cmp1_op == Op_LoadRange &&
1780 cmp2->find_int_con(-1) == 0) {
1781 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1782 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1783 return new BoolNode(ncmp, BoolTest::le);
1784 } else if (_test._test == BoolTest::ne) {
1785 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1786 return new BoolNode(ncmp, BoolTest::gt);
1787 }
1788 }
1789
1790 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1791 // This is a standard idiom for branching on a boolean value.
1792 Node *c2b = cmp1;
1793 if( cmp2_type == TypeInt::ZERO &&
1794 cmp1_op == Op_Conv2B &&
1795 (_test._test == BoolTest::eq ||
1796 _test._test == BoolTest::ne) ) {
1797 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1798 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1799 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1800 );
1801 return new BoolNode( ncmp, _test._test );
1802 }
1803
1804 // Comparing a SubI against a zero is equal to comparing the SubI
1805 // arguments directly. This only works for eq and ne comparisons
1806 // due to possible integer overflow.
1807 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1808 (cop == Op_CmpI) &&
1809 (cmp1_op == Op_SubI) &&
1810 ( cmp2_type == TypeInt::ZERO ) ) {
1811 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1812 return new BoolNode( ncmp, _test._test );
1813 }
1814
1815 // Same as above but with and AddI of a constant
1816 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1817 cop == Op_CmpI &&
1818 cmp1_op == Op_AddI &&
1819 cmp1->in(2) != nullptr &&
1820 phase->type(cmp1->in(2))->isa_int() &&
1821 phase->type(cmp1->in(2))->is_int()->is_con() &&
1822 cmp2_type == TypeInt::ZERO &&
1823 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1824 ) {
1825 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1826 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1827 return new BoolNode( ncmp, _test._test );
1828 }
1829
1830 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1831 // since zero check of conditional negation of an integer is equal to
1832 // zero check of the integer directly.
1833 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1834 (cop == Op_CmpI) &&
1835 (cmp2_type == TypeInt::ZERO) &&
1836 (cmp1_op == Op_Phi)) {
1837 // There should be a diamond phi with true path at index 1 or 2
1838 PhiNode *phi = cmp1->as_Phi();
1839 int idx_true = phi->is_diamond_phi();
1840 if (idx_true != 0) {
1841 // True input is in(idx_true) while false input is in(3 - idx_true)
1842 Node *tin = phi->in(idx_true);
1843 Node *fin = phi->in(3 - idx_true);
1844 if ((tin->Opcode() == Op_SubI) &&
1845 (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1846 (tin->in(2) == fin)) {
1847 // Found conditional negation at true path, create a new CmpINode without that
1848 Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1849 return new BoolNode(ncmp, _test._test);
1850 }
1851 if ((fin->Opcode() == Op_SubI) &&
1852 (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1853 (fin->in(2) == tin)) {
1854 // Found conditional negation at false path, create a new CmpINode without that
1855 Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1856 return new BoolNode(ncmp, _test._test);
1857 }
1858 }
1859 }
1860
1861 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1862 // most general case because negating 0x80000000 does nothing. Needed for
1863 // the CmpF3/SubI/CmpI idiom.
1864 if( cop == Op_CmpI &&
1865 cmp1_op == Op_SubI &&
1866 cmp2_type == TypeInt::ZERO &&
1867 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1868 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1869 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1870 return new BoolNode( ncmp, _test.commute() );
1871 }
1872
1873 // Try to optimize signed integer comparison
1874 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1875
1876 // The transformation below is not valid for either signed or unsigned
1877 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1878 // This transformation can be resurrected when we are able to
1879 // make inferences about the range of values being subtracted from
1880 // (or added to) relative to the wraparound point.
1881 //
1882 // // Remove +/-1's if possible.
1883 // // "X <= Y-1" becomes "X < Y"
1884 // // "X+1 <= Y" becomes "X < Y"
1885 // // "X < Y+1" becomes "X <= Y"
1886 // // "X-1 < Y" becomes "X <= Y"
1887 // // Do not this to compares off of the counted-loop-end. These guys are
1888 // // checking the trip counter and they want to use the post-incremented
1889 // // counter. If they use the PRE-incremented counter, then the counter has
1890 // // to be incremented in a private block on a loop backedge.
1891 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1892 // return nullptr;
1893 // #ifndef PRODUCT
1894 // // Do not do this in a wash GVN pass during verification.
1895 // // Gets triggered by too many simple optimizations to be bothered with
1896 // // re-trying it again and again.
1897 // if( !phase->allow_progress() ) return nullptr;
1898 // #endif
1899 // // Not valid for unsigned compare because of corner cases in involving zero.
1900 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1901 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1902 // // "0 <=u Y" is always true).
1903 // if( cmp->Opcode() == Op_CmpU ) return nullptr;
1904 // int cmp2_op = cmp2->Opcode();
1905 // if( _test._test == BoolTest::le ) {
1906 // if( cmp1_op == Op_AddI &&
1907 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1908 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1909 // else if( cmp2_op == Op_AddI &&
1910 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1911 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1912 // } else if( _test._test == BoolTest::lt ) {
1913 // if( cmp1_op == Op_AddI &&
1914 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1915 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1916 // else if( cmp2_op == Op_AddI &&
1917 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1918 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1919 // }
1920 }
1921
1922 //------------------------------Value------------------------------------------
1923 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1924 // based on local information. If the input is constant, do it.
1925 const Type* BoolNode::Value(PhaseGVN* phase) const {
1926 return _test.cc2logical( phase->type( in(1) ) );
1927 }
1928
1929 #ifndef PRODUCT
1930 //------------------------------dump_spec--------------------------------------
1931 // Dump special per-node info
1932 void BoolNode::dump_spec(outputStream *st) const {
1933 st->print("[");
1934 _test.dump_on(st);
1935 st->print("]");
1936 }
1937 #endif
1938
1939 //----------------------is_counted_loop_exit_test------------------------------
1940 // Returns true if node is used by a counted loop node.
1941 bool BoolNode::is_counted_loop_exit_test() {
1942 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1943 Node* use = fast_out(i);
1944 if (use->is_CountedLoopEnd()) {
1945 return true;
1946 }
1947 }
1948 return false;
1949 }
1950
1951 //=============================================================================
1952 //------------------------------Value------------------------------------------
1953 const Type* AbsNode::Value(PhaseGVN* phase) const {
1954 const Type* t1 = phase->type(in(1));
1955 if (t1 == Type::TOP) return Type::TOP;
1956
1957 switch (t1->base()) {
1958 case Type::Int: {
1959 const TypeInt* ti = t1->is_int();
1960 if (ti->is_con()) {
1961 return TypeInt::make(uabs(ti->get_con()));
1962 }
1963 break;
1964 }
1965 case Type::Long: {
1966 const TypeLong* tl = t1->is_long();
1967 if (tl->is_con()) {
1968 return TypeLong::make(uabs(tl->get_con()));
1969 }
1970 break;
1971 }
1972 case Type::FloatCon:
1973 return TypeF::make(abs(t1->getf()));
1974 case Type::DoubleCon:
1975 return TypeD::make(abs(t1->getd()));
1976 default:
1977 break;
1978 }
1979
1980 return bottom_type();
1981 }
1982
1983 //------------------------------Identity----------------------------------------
1984 Node* AbsNode::Identity(PhaseGVN* phase) {
1985 Node* in1 = in(1);
1986 // No need to do abs for non-negative values
1987 if (phase->type(in1)->higher_equal(TypeInt::POS) ||
1988 phase->type(in1)->higher_equal(TypeLong::POS)) {
1989 return in1;
1990 }
1991 // Convert "abs(abs(x))" into "abs(x)"
1992 if (in1->Opcode() == Opcode()) {
1993 return in1;
1994 }
1995 return this;
1996 }
1997
1998 //------------------------------Ideal------------------------------------------
1999 Node* AbsNode::Ideal(PhaseGVN* phase, bool can_reshape) {
2000 Node* in1 = in(1);
2001 // Convert "abs(0-x)" into "abs(x)"
2002 if (in1->is_Sub() && phase->type(in1->in(1))->is_zero_type()) {
2003 set_req_X(1, in1->in(2), phase);
2004 return this;
2005 }
2006 return nullptr;
2007 }
2008
2009 //=============================================================================
2010 //------------------------------Value------------------------------------------
2011 // Compute sqrt
2012 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
2013 const Type *t1 = phase->type( in(1) );
2014 if( t1 == Type::TOP ) return Type::TOP;
2015 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
2016 double d = t1->getd();
2017 if( d < 0.0 ) return Type::DOUBLE;
2018 return TypeD::make( sqrt( d ) );
2019 }
2020
2021 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
2022 const Type *t1 = phase->type( in(1) );
2023 if( t1 == Type::TOP ) return Type::TOP;
2024 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
2025 float f = t1->getf();
2026 if( f < 0.0f ) return Type::FLOAT;
2027 return TypeF::make( (float)sqrt( (double)f ) );
2028 }
2029
2030 const Type* ReverseINode::Value(PhaseGVN* phase) const {
2031 const Type *t1 = phase->type( in(1) );
2032 if (t1 == Type::TOP) {
2033 return Type::TOP;
2034 }
2035 const TypeInt* t1int = t1->isa_int();
2036 if (t1int && t1int->is_con()) {
2037 jint res = reverse_bits(t1int->get_con());
2038 return TypeInt::make(res);
2039 }
2040 return bottom_type();
2041 }
2042
2043 const Type* ReverseLNode::Value(PhaseGVN* phase) const {
2044 const Type *t1 = phase->type( in(1) );
2045 if (t1 == Type::TOP) {
2046 return Type::TOP;
2047 }
2048 const TypeLong* t1long = t1->isa_long();
2049 if (t1long && t1long->is_con()) {
2050 jlong res = reverse_bits(t1long->get_con());
2051 return TypeLong::make(res);
2052 }
2053 return bottom_type();
2054 }
2055
2056 Node* ReverseINode::Identity(PhaseGVN* phase) {
2057 if (in(1)->Opcode() == Op_ReverseI) {
2058 return in(1)->in(1);
2059 }
2060 return this;
2061 }
2062
2063 Node* ReverseLNode::Identity(PhaseGVN* phase) {
2064 if (in(1)->Opcode() == Op_ReverseL) {
2065 return in(1)->in(1);
2066 }
2067 return this;
2068 }