1 /*
2 * Copyright (c) 1997, 2024, 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_BaseCountedLoopEnd()) {
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 case T_OBJECT:
648 case T_ARRAY:
649 case T_ADDRESS:
650 case T_METADATA:
651 return new CmpPNode(in1, in2);
652 case T_NARROWOOP:
653 case T_NARROWKLASS:
654 return new CmpNNode(in1, in2);
655 default:
656 fatal("Not implemented for %s", type2name(bt));
657 }
658 return nullptr;
659 }
660
661 //=============================================================================
662 //------------------------------cmp--------------------------------------------
663 // Simplify a CmpI (compare 2 integers) node, based on local information.
664 // If both inputs are constants, compare them.
665 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
666 const TypeInt *r0 = t1->is_int(); // Handy access
667 const TypeInt *r1 = t2->is_int();
668
669 if( r0->_hi < r1->_lo ) // Range is always low?
670 return TypeInt::CC_LT;
671 else if( r0->_lo > r1->_hi ) // Range is always high?
672 return TypeInt::CC_GT;
673
674 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
675 assert(r0->get_con() == r1->get_con(), "must be equal");
676 return TypeInt::CC_EQ; // Equal results.
677 } else if( r0->_hi == r1->_lo ) // Range is never high?
678 return TypeInt::CC_LE;
679 else if( r0->_lo == r1->_hi ) // Range is never low?
680 return TypeInt::CC_GE;
681 return TypeInt::CC; // else use worst case results
682 }
683
684 const Type* CmpINode::Value(PhaseGVN* phase) const {
685 Node* in1 = in(1);
686 Node* in2 = in(2);
687 // If this test is the zero trip guard for a main or post loop, check whether, with the opaque node removed, the test
688 // would constant fold so the loop is never entered. If so return the type of the test without the opaque node removed:
689 // make the loop unreachable.
690 // The reason for this is that the iv phi captures the bounds of the loop and if the loop becomes unreachable, it can
691 // become top. In that case, the loop must be removed.
692 // This is safe because:
693 // - as optimizations proceed, the range of iterations executed by the main loop narrows. If no iterations remain, then
694 // we're done with optimizations for that loop.
695 // - the post loop is initially not reachable but as long as there's a main loop, the zero trip guard for the post
696 // 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
697 // loop is removed, there's no need to preserve the zero trip guard for the post loop anymore.
698 if (in1 != nullptr && in2 != nullptr) {
699 uint input = 0;
700 Node* cmp = nullptr;
701 BoolTest::mask test;
702 if (in1->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in1) != Type::TOP) {
703 cmp = new CmpINode(in1->in(1), in2);
704 test = ((OpaqueZeroTripGuardNode*)in1)->_loop_entered_mask;
705 }
706 if (in2->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in2) != Type::TOP) {
707 assert(cmp == nullptr, "A cmp with 2 OpaqueZeroTripGuard inputs");
708 cmp = new CmpINode(in1, in2->in(1));
709 test = ((OpaqueZeroTripGuardNode*)in2)->_loop_entered_mask;
710 }
711 if (cmp != nullptr) {
712 const Type* cmp_t = cmp->Value(phase);
713 const Type* t = BoolTest(test).cc2logical(cmp_t);
714 cmp->destruct(phase);
715 if (t == TypeInt::ZERO) {
716 return cmp_t;
717 }
718 }
719 }
720
721 return SubNode::Value(phase);
722 }
723
724
725 // Simplify a CmpU (compare 2 integers) node, based on local information.
726 // If both inputs are constants, compare them.
727 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
728 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
729
730 // comparing two unsigned ints
731 const TypeInt *r0 = t1->is_int(); // Handy access
732 const TypeInt *r1 = t2->is_int();
733
734 // Current installed version
735 // Compare ranges for non-overlap
736 juint lo0 = r0->_lo;
737 juint hi0 = r0->_hi;
738 juint lo1 = r1->_lo;
739 juint hi1 = r1->_hi;
740
741 // If either one has both negative and positive values,
742 // it therefore contains both 0 and -1, and since [0..-1] is the
743 // full unsigned range, the type must act as an unsigned bottom.
744 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
745 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
746
747 if (bot0 || bot1) {
748 // All unsigned values are LE -1 and GE 0.
749 if (lo0 == 0 && hi0 == 0) {
750 return TypeInt::CC_LE; // 0 <= bot
751 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
752 return TypeInt::CC_GE; // -1 >= bot
753 } else if (lo1 == 0 && hi1 == 0) {
754 return TypeInt::CC_GE; // bot >= 0
755 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
756 return TypeInt::CC_LE; // bot <= -1
757 }
758 } else {
759 // We can use ranges of the form [lo..hi] if signs are the same.
760 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
761 // results are reversed, '-' > '+' for unsigned compare
762 if (hi0 < lo1) {
763 return TypeInt::CC_LT; // smaller
764 } else if (lo0 > hi1) {
765 return TypeInt::CC_GT; // greater
766 } else if (hi0 == lo1 && lo0 == hi1) {
767 return TypeInt::CC_EQ; // Equal results
768 } else if (lo0 >= hi1) {
769 return TypeInt::CC_GE;
770 } else if (hi0 <= lo1) {
771 // Check for special case in Hashtable::get. (See below.)
772 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
773 return TypeInt::CC_LT;
774 return TypeInt::CC_LE;
775 }
776 }
777 // Check for special case in Hashtable::get - the hash index is
778 // mod'ed to the table size so the following range check is useless.
779 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
780 // to be positive.
781 // (This is a gross hack, since the sub method never
782 // looks at the structure of the node in any other case.)
783 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
784 return TypeInt::CC_LT;
785 return TypeInt::CC; // else use worst case results
786 }
787
788 const Type* CmpUNode::Value(PhaseGVN* phase) const {
789 const Type* t = SubNode::Value_common(phase);
790 if (t != nullptr) {
791 return t;
792 }
793 const Node* in1 = in(1);
794 const Node* in2 = in(2);
795 const Type* t1 = phase->type(in1);
796 const Type* t2 = phase->type(in2);
797 assert(t1->isa_int(), "CmpU has only Int type inputs");
798 if (t2 == TypeInt::INT) { // Compare to bottom?
799 return bottom_type();
800 }
801
802 const Type* t_sub = sub(t1, t2); // compare based on immediate inputs
803
804 uint in1_op = in1->Opcode();
805 if (in1_op == Op_AddI || in1_op == Op_SubI) {
806 // The problem rise when result of AddI(SubI) may overflow
807 // signed integer value. Let say the input type is
808 // [256, maxint] then +128 will create 2 ranges due to
809 // overflow: [minint, minint+127] and [384, maxint].
810 // But C2 type system keep only 1 type range and as result
811 // it use general [minint, maxint] for this case which we
812 // can't optimize.
813 //
814 // Make 2 separate type ranges based on types of AddI(SubI) inputs
815 // and compare results of their compare. If results are the same
816 // CmpU node can be optimized.
817 const Node* in11 = in1->in(1);
818 const Node* in12 = in1->in(2);
819 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
820 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
821 // Skip cases when input types are top or bottom.
822 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
823 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
824 const TypeInt *r0 = t11->is_int();
825 const TypeInt *r1 = t12->is_int();
826 jlong lo_r0 = r0->_lo;
827 jlong hi_r0 = r0->_hi;
828 jlong lo_r1 = r1->_lo;
829 jlong hi_r1 = r1->_hi;
830 if (in1_op == Op_SubI) {
831 jlong tmp = hi_r1;
832 hi_r1 = -lo_r1;
833 lo_r1 = -tmp;
834 // Note, for substructing [minint,x] type range
835 // long arithmetic provides correct overflow answer.
836 // The confusion come from the fact that in 32-bit
837 // -minint == minint but in 64-bit -minint == maxint+1.
838 }
839 jlong lo_long = lo_r0 + lo_r1;
840 jlong hi_long = hi_r0 + hi_r1;
841 int lo_tr1 = min_jint;
842 int hi_tr1 = (int)hi_long;
843 int lo_tr2 = (int)lo_long;
844 int hi_tr2 = max_jint;
845 bool underflow = lo_long != (jlong)lo_tr2;
846 bool overflow = hi_long != (jlong)hi_tr1;
847 // Use sub(t1, t2) when there is no overflow (one type range)
848 // or when both overflow and underflow (too complex).
849 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
850 // Overflow only on one boundary, compare 2 separate type ranges.
851 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
852 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
853 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
854 const TypeInt* cmp1 = sub(tr1, t2)->is_int();
855 const TypeInt* cmp2 = sub(tr2, t2)->is_int();
856 // Compute union, so that cmp handles all possible results from the two cases
857 const Type* t_cmp = cmp1->meet(cmp2);
858 // Pick narrowest type, based on overflow computation and on immediate inputs
859 return t_sub->filter(t_cmp);
860 }
861 }
862 }
863
864 return t_sub;
865 }
866
867 bool CmpUNode::is_index_range_check() const {
868 // Check for the "(X ModI Y) CmpU Y" shape
869 return (in(1)->Opcode() == Op_ModI &&
870 in(1)->in(2)->eqv_uncast(in(2)));
871 }
872
873 //------------------------------Idealize---------------------------------------
874 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
875 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
876 switch (in(1)->Opcode()) {
877 case Op_CmpU3: // Collapse a CmpU3/CmpI into a CmpU
878 return new CmpUNode(in(1)->in(1),in(1)->in(2));
879 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
880 return new CmpLNode(in(1)->in(1),in(1)->in(2));
881 case Op_CmpUL3: // Collapse a CmpUL3/CmpI into a CmpUL
882 return new CmpULNode(in(1)->in(1),in(1)->in(2));
883 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
884 return new CmpFNode(in(1)->in(1),in(1)->in(2));
885 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
886 return new CmpDNode(in(1)->in(1),in(1)->in(2));
887 //case Op_SubI:
888 // If (x - y) cannot overflow, then ((x - y) <?> 0)
889 // can be turned into (x <?> y).
890 // This is handled (with more general cases) by Ideal_sub_algebra.
891 }
892 }
893 return nullptr; // No change
894 }
895
896 //------------------------------Ideal------------------------------------------
897 Node* CmpLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
898 Node* a = nullptr;
899 Node* b = nullptr;
900 if (is_double_null_check(phase, a, b) && (phase->type(a)->is_zero_type() || phase->type(b)->is_zero_type())) {
901 // Degraded to a simple null check, use old acmp
902 return new CmpPNode(a, b);
903 }
904 const TypeLong *t2 = phase->type(in(2))->isa_long();
905 if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) {
906 const jlong con = t2->get_con();
907 if (con >= min_jint && con <= max_jint) {
908 return new CmpINode(in(1)->in(1), phase->intcon((jint)con));
909 }
910 }
911 return nullptr;
912 }
913
914 // Match double null check emitted by Compile::optimize_acmp()
915 bool CmpLNode::is_double_null_check(PhaseGVN* phase, Node*& a, Node*& b) const {
916 if (in(1)->Opcode() == Op_OrL &&
917 in(1)->in(1)->Opcode() == Op_CastP2X &&
918 in(1)->in(2)->Opcode() == Op_CastP2X &&
919 in(2)->bottom_type()->is_zero_type()) {
920 assert(EnableValhalla, "unexpected double null check");
921 a = in(1)->in(1)->in(1);
922 b = in(1)->in(2)->in(1);
923 return true;
924 }
925 return false;
926 }
927
928 //------------------------------Value------------------------------------------
929 const Type* CmpLNode::Value(PhaseGVN* phase) const {
930 Node* a = nullptr;
931 Node* b = nullptr;
932 if (is_double_null_check(phase, a, b) && (!phase->type(a)->maybe_null() || !phase->type(b)->maybe_null())) {
933 // One operand is never nullptr, emit constant false
934 return TypeInt::CC_GT;
935 }
936 return SubNode::Value(phase);
937 }
938
939 //=============================================================================
940 // Simplify a CmpL (compare 2 longs ) node, based on local information.
941 // If both inputs are constants, compare them.
942 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
943 const TypeLong *r0 = t1->is_long(); // Handy access
944 const TypeLong *r1 = t2->is_long();
945
946 if( r0->_hi < r1->_lo ) // Range is always low?
947 return TypeInt::CC_LT;
948 else if( r0->_lo > r1->_hi ) // Range is always high?
949 return TypeInt::CC_GT;
950
951 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
952 assert(r0->get_con() == r1->get_con(), "must be equal");
953 return TypeInt::CC_EQ; // Equal results.
954 } else if( r0->_hi == r1->_lo ) // Range is never high?
955 return TypeInt::CC_LE;
956 else if( r0->_lo == r1->_hi ) // Range is never low?
957 return TypeInt::CC_GE;
958 return TypeInt::CC; // else use worst case results
959 }
960
961
962 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
963 // If both inputs are constants, compare them.
964 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
965 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
966
967 // comparing two unsigned longs
968 const TypeLong* r0 = t1->is_long(); // Handy access
969 const TypeLong* r1 = t2->is_long();
970
971 // Current installed version
972 // Compare ranges for non-overlap
973 julong lo0 = r0->_lo;
974 julong hi0 = r0->_hi;
975 julong lo1 = r1->_lo;
976 julong hi1 = r1->_hi;
977
978 // If either one has both negative and positive values,
979 // it therefore contains both 0 and -1, and since [0..-1] is the
980 // full unsigned range, the type must act as an unsigned bottom.
981 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
982 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
983
984 if (bot0 || bot1) {
985 // All unsigned values are LE -1 and GE 0.
986 if (lo0 == 0 && hi0 == 0) {
987 return TypeInt::CC_LE; // 0 <= bot
988 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
989 return TypeInt::CC_GE; // -1 >= bot
990 } else if (lo1 == 0 && hi1 == 0) {
991 return TypeInt::CC_GE; // bot >= 0
992 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
993 return TypeInt::CC_LE; // bot <= -1
994 }
995 } else {
996 // We can use ranges of the form [lo..hi] if signs are the same.
997 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
998 // results are reversed, '-' > '+' for unsigned compare
999 if (hi0 < lo1) {
1000 return TypeInt::CC_LT; // smaller
1001 } else if (lo0 > hi1) {
1002 return TypeInt::CC_GT; // greater
1003 } else if (hi0 == lo1 && lo0 == hi1) {
1004 return TypeInt::CC_EQ; // Equal results
1005 } else if (lo0 >= hi1) {
1006 return TypeInt::CC_GE;
1007 } else if (hi0 <= lo1) {
1008 return TypeInt::CC_LE;
1009 }
1010 }
1011
1012 return TypeInt::CC; // else use worst case results
1013 }
1014
1015 //=============================================================================
1016 //------------------------------sub--------------------------------------------
1017 // Simplify an CmpP (compare 2 pointers) node, based on local information.
1018 // If both inputs are constants, compare them.
1019 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
1020 const TypePtr *r0 = t1->is_ptr(); // Handy access
1021 const TypePtr *r1 = t2->is_ptr();
1022
1023 // Undefined inputs makes for an undefined result
1024 if( TypePtr::above_centerline(r0->_ptr) ||
1025 TypePtr::above_centerline(r1->_ptr) )
1026 return Type::TOP;
1027
1028 if (r0 == r1 && r0->singleton()) {
1029 // Equal pointer constants (klasses, nulls, etc.)
1030 return TypeInt::CC_EQ;
1031 }
1032
1033 // See if it is 2 unrelated classes.
1034 const TypeOopPtr* p0 = r0->isa_oopptr();
1035 const TypeOopPtr* p1 = r1->isa_oopptr();
1036 const TypeKlassPtr* k0 = r0->isa_klassptr();
1037 const TypeKlassPtr* k1 = r1->isa_klassptr();
1038 if ((p0 && p1) || (k0 && k1)) {
1039 if (p0 && p1) {
1040 Node* in1 = in(1)->uncast();
1041 Node* in2 = in(2)->uncast();
1042 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1);
1043 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2);
1044 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, nullptr)) {
1045 return TypeInt::CC_GT; // different pointers
1046 }
1047 }
1048 bool xklass0 = p0 ? p0->klass_is_exact() : k0->klass_is_exact();
1049 bool xklass1 = p1 ? p1->klass_is_exact() : k1->klass_is_exact();
1050 bool unrelated_classes = false;
1051
1052 if ((p0 && p0->is_same_java_type_as(p1)) ||
1053 (k0 && k0->is_same_java_type_as(k1))) {
1054 } else if ((p0 && !p1->maybe_java_subtype_of(p0) && !p0->maybe_java_subtype_of(p1)) ||
1055 (k0 && !k1->maybe_java_subtype_of(k0) && !k0->maybe_java_subtype_of(k1))) {
1056 unrelated_classes = true;
1057 } else if ((p0 && !p1->maybe_java_subtype_of(p0)) ||
1058 (k0 && !k1->maybe_java_subtype_of(k0))) {
1059 unrelated_classes = xklass1;
1060 } else if ((p0 && !p0->maybe_java_subtype_of(p1)) ||
1061 (k0 && !k0->maybe_java_subtype_of(k1))) {
1062 unrelated_classes = xklass0;
1063 }
1064 if (!unrelated_classes) {
1065 // Handle inline type arrays
1066 if ((r0->flat_in_array() && r1->not_flat_in_array()) ||
1067 (r1->flat_in_array() && r0->not_flat_in_array())) {
1068 // One type is in flat arrays but the other type is not. Must be unrelated.
1069 unrelated_classes = true;
1070 } else if ((r0->is_not_flat() && r1->is_flat()) ||
1071 (r1->is_not_flat() && r0->is_flat())) {
1072 // One type is a non-flat array and the other type is a flat array. Must be unrelated.
1073 unrelated_classes = true;
1074 } else if ((r0->is_not_null_free() && r1->is_null_free()) ||
1075 (r1->is_not_null_free() && r0->is_null_free())) {
1076 // One type is a nullable array and the other type is a null-free array. Must be unrelated.
1077 unrelated_classes = true;
1078 }
1079 }
1080 if (unrelated_classes) {
1081 // The oops classes are known to be unrelated. If the joined PTRs of
1082 // two oops is not Null and not Bottom, then we are sure that one
1083 // of the two oops is non-null, and the comparison will always fail.
1084 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1085 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1086 return TypeInt::CC_GT;
1087 }
1088 }
1089 }
1090
1091 // Known constants can be compared exactly
1092 // Null can be distinguished from any NotNull pointers
1093 // Unknown inputs makes an unknown result
1094 if( r0->singleton() ) {
1095 intptr_t bits0 = r0->get_con();
1096 if( r1->singleton() )
1097 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1098 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1099 } else if( r1->singleton() ) {
1100 intptr_t bits1 = r1->get_con();
1101 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1102 } else
1103 return TypeInt::CC;
1104 }
1105
1106 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1107 // Return the klass node for (indirect load from OopHandle)
1108 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1109 // or null if not matching.
1110 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1111 n = bs->step_over_gc_barrier(n);
1112
1113 if (n->Opcode() != Op_LoadP) return nullptr;
1114
1115 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1116 if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr;
1117
1118 Node* adr = n->in(MemNode::Address);
1119 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1120 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr;
1121 adr = adr->in(MemNode::Address);
1122
1123 intptr_t off = 0;
1124 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1125 if (k == nullptr) return nullptr;
1126 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1127 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr;
1128
1129 // We've found the klass node of a Java mirror load.
1130 return k;
1131 }
1132
1133 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
1134 // for ConP(Foo.class) return ConP(Foo.klass)
1135 // otherwise return null
1136 if (!n->is_Con()) return nullptr;
1137
1138 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1139 if (!tp) return nullptr;
1140
1141 ciType* mirror_type = tp->java_mirror_type();
1142 // TypeInstPtr::java_mirror_type() returns non-null for compile-
1143 // time Class constants only.
1144 if (!mirror_type) return nullptr;
1145
1146 // x.getClass() == int.class can never be true (for all primitive types)
1147 // Return a ConP(null) node for this case.
1148 if (mirror_type->is_classless()) {
1149 return phase->makecon(TypePtr::NULL_PTR);
1150 }
1151
1152 // return the ConP(Foo.klass)
1153 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
1154 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass(), Type::trust_interfaces));
1155 }
1156
1157 //------------------------------Ideal------------------------------------------
1158 // Normalize comparisons between Java mirror loads to compare the klass instead.
1159 //
1160 // Also check for the case of comparing an unknown klass loaded from the primary
1161 // super-type array vs a known klass with no subtypes. This amounts to
1162 // checking to see an unknown klass subtypes a known klass with no subtypes;
1163 // this only happens on an exact match. We can shorten this test by 1 load.
1164 Node* CmpPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1165 // TODO 8284443 in(1) could be cast?
1166 if (in(1)->is_InlineType() && phase->type(in(2))->is_zero_type()) {
1167 // Null checking a scalarized but nullable inline type. Check the IsInit
1168 // input instead of the oop input to avoid keeping buffer allocations alive.
1169 return new CmpINode(in(1)->as_InlineType()->get_is_init(), phase->intcon(0));
1170 }
1171
1172 // Normalize comparisons between Java mirrors into comparisons of the low-
1173 // level klass, where a dependent load could be shortened.
1174 //
1175 // The new pattern has a nice effect of matching the same pattern used in the
1176 // fast path of instanceof/checkcast/Class.isInstance(), which allows
1177 // redundant exact type check be optimized away by GVN.
1178 // For example, in
1179 // if (x.getClass() == Foo.class) {
1180 // Foo foo = (Foo) x;
1181 // // ... use a ...
1182 // }
1183 // a CmpPNode could be shared between if_acmpne and checkcast
1184 {
1185 Node* k1 = isa_java_mirror_load(phase, in(1));
1186 Node* k2 = isa_java_mirror_load(phase, in(2));
1187 Node* conk2 = isa_const_java_mirror(phase, in(2));
1188
1189 if (k1 && (k2 || conk2)) {
1190 Node* lhs = k1;
1191 Node* rhs = (k2 != nullptr) ? k2 : conk2;
1192 set_req_X(1, lhs, phase);
1193 set_req_X(2, rhs, phase);
1194 return this;
1195 }
1196 }
1197
1198 // Constant pointer on right?
1199 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1200 if (t2 == nullptr || !t2->klass_is_exact())
1201 return nullptr;
1202 // Get the constant klass we are comparing to.
1203 ciKlass* superklass = t2->exact_klass();
1204
1205 // Now check for LoadKlass on left.
1206 Node* ldk1 = in(1);
1207 if (ldk1->is_DecodeNKlass()) {
1208 ldk1 = ldk1->in(1);
1209 if (ldk1->Opcode() != Op_LoadNKlass )
1210 return nullptr;
1211 } else if (ldk1->Opcode() != Op_LoadKlass )
1212 return nullptr;
1213 // Take apart the address of the LoadKlass:
1214 Node* adr1 = ldk1->in(MemNode::Address);
1215 intptr_t con2 = 0;
1216 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1217 if (ldk2 == nullptr)
1218 return nullptr;
1219 if (con2 == oopDesc::klass_offset_in_bytes()) {
1220 // We are inspecting an object's concrete class.
1221 // Short-circuit the check if the query is abstract.
1222 if (superklass->is_interface() ||
1223 superklass->is_abstract()) {
1224 // Make it come out always false:
1225 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1226 return this;
1227 }
1228 }
1229
1230 // Check for a LoadKlass from primary supertype array.
1231 // Any nested loadklass from loadklass+con must be from the p.s. array.
1232 if (ldk2->is_DecodeNKlass()) {
1233 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1234 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1235 return nullptr;
1236 } else if (ldk2->Opcode() != Op_LoadKlass)
1237 return nullptr;
1238
1239 // Verify that we understand the situation
1240 if (con2 != (intptr_t) superklass->super_check_offset())
1241 return nullptr; // Might be element-klass loading from array klass
1242
1243 // Do not fold the subtype check to an array klass pointer comparison for null-able inline type arrays
1244 // because null-free [LMyValue <: null-able [LMyValue but the klasses are different. Perform a full test.
1245 if (superklass->is_obj_array_klass() && !superklass->as_array_klass()->is_elem_null_free() &&
1246 superklass->as_array_klass()->element_klass()->is_inlinetype()) {
1247 return nullptr;
1248 }
1249
1250 // If 'superklass' has no subklasses and is not an interface, then we are
1251 // assured that the only input which will pass the type check is
1252 // 'superklass' itself.
1253 //
1254 // We could be more liberal here, and allow the optimization on interfaces
1255 // which have a single implementor. This would require us to increase the
1256 // expressiveness of the add_dependency() mechanism.
1257 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1258
1259 // Object arrays must have their base element have no subtypes
1260 while (superklass->is_obj_array_klass()) {
1261 ciType* elem = superklass->as_obj_array_klass()->element_type();
1262 superklass = elem->as_klass();
1263 }
1264 if (superklass->is_instance_klass()) {
1265 ciInstanceKlass* ik = superklass->as_instance_klass();
1266 if (ik->has_subklass() || ik->is_interface()) return nullptr;
1267 // Add a dependency if there is a chance that a subclass will be added later.
1268 if (!ik->is_final()) {
1269 phase->C->dependencies()->assert_leaf_type(ik);
1270 }
1271 }
1272
1273 // Bypass the dependent load, and compare directly
1274 this->set_req_X(1, ldk2, phase);
1275
1276 return this;
1277 }
1278
1279 //=============================================================================
1280 //------------------------------sub--------------------------------------------
1281 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1282 // If both inputs are constants, compare them.
1283 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1284 ShouldNotReachHere();
1285 return bottom_type();
1286 }
1287
1288 //------------------------------Ideal------------------------------------------
1289 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1290 return nullptr;
1291 }
1292
1293 //=============================================================================
1294 //------------------------------Value------------------------------------------
1295 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1296 // If both inputs are constants, compare them.
1297 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1298 const Node* in1 = in(1);
1299 const Node* in2 = in(2);
1300 // Either input is TOP ==> the result is TOP
1301 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1302 if( t1 == Type::TOP ) return Type::TOP;
1303 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1304 if( t2 == Type::TOP ) return Type::TOP;
1305
1306 // Not constants? Don't know squat - even if they are the same
1307 // value! If they are NaN's they compare to LT instead of EQ.
1308 const TypeF *tf1 = t1->isa_float_constant();
1309 const TypeF *tf2 = t2->isa_float_constant();
1310 if( !tf1 || !tf2 ) return TypeInt::CC;
1311
1312 // This implements the Java bytecode fcmpl, so unordered returns -1.
1313 if( tf1->is_nan() || tf2->is_nan() )
1314 return TypeInt::CC_LT;
1315
1316 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1317 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1318 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1319 return TypeInt::CC_EQ;
1320 }
1321
1322
1323 //=============================================================================
1324 //------------------------------Value------------------------------------------
1325 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1326 // If both inputs are constants, compare them.
1327 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1328 const Node* in1 = in(1);
1329 const Node* in2 = in(2);
1330 // Either input is TOP ==> the result is TOP
1331 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1332 if( t1 == Type::TOP ) return Type::TOP;
1333 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1334 if( t2 == Type::TOP ) return Type::TOP;
1335
1336 // Not constants? Don't know squat - even if they are the same
1337 // value! If they are NaN's they compare to LT instead of EQ.
1338 const TypeD *td1 = t1->isa_double_constant();
1339 const TypeD *td2 = t2->isa_double_constant();
1340 if( !td1 || !td2 ) return TypeInt::CC;
1341
1342 // This implements the Java bytecode dcmpl, so unordered returns -1.
1343 if( td1->is_nan() || td2->is_nan() )
1344 return TypeInt::CC_LT;
1345
1346 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1347 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1348 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1349 return TypeInt::CC_EQ;
1350 }
1351
1352 //------------------------------Ideal------------------------------------------
1353 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1354 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1355 // Change (CMPD (F2D (float)) (ConD value))
1356 // To (CMPF (float) (ConF value))
1357 // Valid when 'value' does not lose precision as a float.
1358 // Benefits: eliminates conversion, does not require 24-bit mode
1359
1360 // NaNs prevent commuting operands. This transform works regardless of the
1361 // order of ConD and ConvF2D inputs by preserving the original order.
1362 int idx_f2d = 1; // ConvF2D on left side?
1363 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1364 idx_f2d = 2; // No, swap to check for reversed args
1365 int idx_con = 3-idx_f2d; // Check for the constant on other input
1366
1367 if( ConvertCmpD2CmpF &&
1368 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1369 in(idx_con)->Opcode() == Op_ConD ) {
1370 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1371 double t2_value_as_double = t2->_d;
1372 float t2_value_as_float = (float)t2_value_as_double;
1373 if( t2_value_as_double == (double)t2_value_as_float ) {
1374 // Test value can be represented as a float
1375 // Eliminate the conversion to double and create new comparison
1376 Node *new_in1 = in(idx_f2d)->in(1);
1377 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1378 if( idx_f2d != 1 ) { // Must flip args to match original order
1379 Node *tmp = new_in1;
1380 new_in1 = new_in2;
1381 new_in2 = tmp;
1382 }
1383 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1384 ? new CmpF3Node( new_in1, new_in2 )
1385 : new CmpFNode ( new_in1, new_in2 ) ;
1386 return new_cmp; // Changed to CmpFNode
1387 }
1388 // Testing value required the precision of a double
1389 }
1390 return nullptr; // No change
1391 }
1392
1393 //=============================================================================
1394 //------------------------------Value------------------------------------------
1395 const Type* FlatArrayCheckNode::Value(PhaseGVN* phase) const {
1396 bool all_not_flat = true;
1397 for (uint i = ArrayOrKlass; i < req(); ++i) {
1398 const Type* t = phase->type(in(i));
1399 if (t == Type::TOP) {
1400 return Type::TOP;
1401 }
1402 if (t->is_ptr()->is_flat()) {
1403 // One of the input arrays is flat, check always passes
1404 return TypeInt::CC_EQ;
1405 } else if (!t->is_ptr()->is_not_flat()) {
1406 // One of the input arrays might be flat
1407 all_not_flat = false;
1408 }
1409 }
1410 if (all_not_flat) {
1411 // None of the input arrays can be flat, check always fails
1412 return TypeInt::CC_GT;
1413 }
1414 return TypeInt::CC;
1415 }
1416
1417 //------------------------------Ideal------------------------------------------
1418 Node* FlatArrayCheckNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1419 bool changed = false;
1420 // Remove inputs that are known to be non-flat
1421 for (uint i = ArrayOrKlass; i < req(); ++i) {
1422 const Type* t = phase->type(in(i));
1423 if (t->isa_ptr() && t->is_ptr()->is_not_flat()) {
1424 del_req(i--);
1425 changed = true;
1426 }
1427 }
1428 return changed ? this : nullptr;
1429 }
1430
1431 //=============================================================================
1432 //------------------------------cc2logical-------------------------------------
1433 // Convert a condition code type to a logical type
1434 const Type *BoolTest::cc2logical( const Type *CC ) const {
1435 if( CC == Type::TOP ) return Type::TOP;
1436 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1437 const TypeInt *ti = CC->is_int();
1438 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1439 // Match low order 2 bits
1440 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1441 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1442 return TypeInt::make(tmp); // Boolean result
1443 }
1444
1445 if( CC == TypeInt::CC_GE ) {
1446 if( _test == ge ) return TypeInt::ONE;
1447 if( _test == lt ) return TypeInt::ZERO;
1448 }
1449 if( CC == TypeInt::CC_LE ) {
1450 if( _test == le ) return TypeInt::ONE;
1451 if( _test == gt ) return TypeInt::ZERO;
1452 }
1453
1454 return TypeInt::BOOL;
1455 }
1456
1457 //------------------------------dump_spec-------------------------------------
1458 // Print special per-node info
1459 void BoolTest::dump_on(outputStream *st) const {
1460 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1461 st->print("%s", msg[_test]);
1462 }
1463
1464 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1465 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1466 BoolTest::mask BoolTest::merge(BoolTest other) const {
1467 const mask res[illegal+1][illegal+1] = {
1468 // eq, gt, of, lt, ne, le, nof, ge, never, illegal
1469 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq
1470 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt
1471 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of
1472 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt
1473 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne
1474 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le
1475 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof
1476 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge
1477 {never, never, never, never, never, never, never, never, never, illegal}, // never
1478 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1479 return res[_test][other._test];
1480 }
1481
1482 //=============================================================================
1483 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1484 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1485
1486 //------------------------------operator==-------------------------------------
1487 bool BoolNode::cmp( const Node &n ) const {
1488 const BoolNode *b = (const BoolNode *)&n; // Cast up
1489 return (_test._test == b->_test._test);
1490 }
1491
1492 //-------------------------------make_predicate--------------------------------
1493 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1494 if (test_value->is_Con()) return test_value;
1495 if (test_value->is_Bool()) return test_value;
1496 if (test_value->is_CMove() &&
1497 test_value->in(CMoveNode::Condition)->is_Bool()) {
1498 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1499 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1500 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1501 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1502 return bol;
1503 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1504 return phase->transform( bol->negate(phase) );
1505 }
1506 // Else fall through. The CMove gets in the way of the test.
1507 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1508 }
1509 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1510 cmp = phase->transform(cmp);
1511 Node* bol = new BoolNode(cmp, BoolTest::ne);
1512 return phase->transform(bol);
1513 }
1514
1515 //--------------------------------as_int_value---------------------------------
1516 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1517 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1518 Node* cmov = CMoveNode::make(nullptr, this,
1519 phase->intcon(0), phase->intcon(1),
1520 TypeInt::BOOL);
1521 return phase->transform(cmov);
1522 }
1523
1524 //----------------------------------negate-------------------------------------
1525 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1526 return new BoolNode(in(1), _test.negate());
1527 }
1528
1529 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1530 // overflows and we can prove that C is not in the two resulting ranges.
1531 // This optimization is similar to the one performed by CmpUNode::Value().
1532 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1533 int cmp1_op, const TypeInt* cmp2_type) {
1534 // Only optimize eq/ne integer comparison of add/sub
1535 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1536 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1537 // Skip cases were inputs of add/sub are not integers or of bottom type
1538 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1539 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1540 if ((r0 != nullptr) && (r0 != TypeInt::INT) &&
1541 (r1 != nullptr) && (r1 != TypeInt::INT) &&
1542 (cmp2_type != TypeInt::INT)) {
1543 // Compute exact (long) type range of add/sub result
1544 jlong lo_long = r0->_lo;
1545 jlong hi_long = r0->_hi;
1546 if (cmp1_op == Op_AddI) {
1547 lo_long += r1->_lo;
1548 hi_long += r1->_hi;
1549 } else {
1550 lo_long -= r1->_hi;
1551 hi_long -= r1->_lo;
1552 }
1553 // Check for over-/underflow by casting to integer
1554 int lo_int = (int)lo_long;
1555 int hi_int = (int)hi_long;
1556 bool underflow = lo_long != (jlong)lo_int;
1557 bool overflow = hi_long != (jlong)hi_int;
1558 if ((underflow != overflow) && (hi_int < lo_int)) {
1559 // Overflow on one boundary, compute resulting type ranges:
1560 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1561 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1562 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1563 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1564 // Compare second input of cmp to both type ranges
1565 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1566 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1567 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1568 // The result of the add/sub will never equal cmp2. Replace BoolNode
1569 // by false (0) if it tests for equality and by true (1) otherwise.
1570 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1571 }
1572 }
1573 }
1574 }
1575 return nullptr;
1576 }
1577
1578 static bool is_counted_loop_cmp(Node *cmp) {
1579 Node *n = cmp->in(1)->in(1);
1580 return n != nullptr &&
1581 n->is_Phi() &&
1582 n->in(0) != nullptr &&
1583 n->in(0)->is_CountedLoop() &&
1584 n->in(0)->as_CountedLoop()->phi() == n;
1585 }
1586
1587 //------------------------------Ideal------------------------------------------
1588 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1589 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1590 // This moves the constant to the right. Helps value-numbering.
1591 Node *cmp = in(1);
1592 if( !cmp->is_Sub() ) return nullptr;
1593 int cop = cmp->Opcode();
1594 if( cop == Op_FastLock || cop == Op_FastUnlock ||
1595 cmp->is_SubTypeCheck() || cop == Op_VectorTest ) {
1596 return nullptr;
1597 }
1598 Node *cmp1 = cmp->in(1);
1599 Node *cmp2 = cmp->in(2);
1600 if( !cmp1 ) return nullptr;
1601
1602 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1603 return nullptr;
1604 }
1605
1606 const int cmp1_op = cmp1->Opcode();
1607 const int cmp2_op = cmp2->Opcode();
1608
1609 // Constant on left?
1610 Node *con = cmp1;
1611 // Move constants to the right of compare's to canonicalize.
1612 // Do not muck with Opaque1 nodes, as this indicates a loop
1613 // guard that cannot change shape.
1614 if (con->is_Con() && !cmp2->is_Con() && cmp2_op != Op_OpaqueZeroTripGuard &&
1615 // Because of NaN's, CmpD and CmpF are not commutative
1616 cop != Op_CmpD && cop != Op_CmpF &&
1617 // Protect against swapping inputs to a compare when it is used by a
1618 // counted loop exit, which requires maintaining the loop-limit as in(2)
1619 !is_counted_loop_exit_test() ) {
1620 // Ok, commute the constant to the right of the cmp node.
1621 // Clone the Node, getting a new Node of the same class
1622 cmp = cmp->clone();
1623 // Swap inputs to the clone
1624 cmp->swap_edges(1, 2);
1625 cmp = phase->transform( cmp );
1626 return new BoolNode( cmp, _test.commute() );
1627 }
1628
1629 // Change "bool eq/ne (cmp (cmove (bool tst (cmp2)) 1 0) 0)" into "bool tst/~tst (cmp2)"
1630 if (cop == Op_CmpI &&
1631 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1632 cmp1_op == Op_CMoveI && cmp2->find_int_con(1) == 0) {
1633 // 0 should be on the true branch
1634 if (cmp1->in(CMoveNode::Condition)->is_Bool() &&
1635 cmp1->in(CMoveNode::IfTrue)->find_int_con(1) == 0 &&
1636 cmp1->in(CMoveNode::IfFalse)->find_int_con(0) != 0) {
1637 BoolNode* target = cmp1->in(CMoveNode::Condition)->as_Bool();
1638 return new BoolNode(target->in(1),
1639 (_test._test == BoolTest::eq) ? target->_test._test :
1640 target->_test.negate());
1641 }
1642 }
1643
1644 // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1645 if (cop == Op_CmpI &&
1646 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1647 cmp1_op == Op_AndI && cmp2_op == Op_ConI &&
1648 cmp1->in(2)->Opcode() == Op_ConI) {
1649 const TypeInt *t12 = phase->type(cmp2)->isa_int();
1650 const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int();
1651 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1652 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1653 Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1654 return new BoolNode(ncmp, _test.negate());
1655 }
1656 }
1657
1658 // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1659 if (cop == Op_CmpL &&
1660 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1661 cmp1_op == Op_AndL && cmp2_op == Op_ConL &&
1662 cmp1->in(2)->Opcode() == Op_ConL) {
1663 const TypeLong *t12 = phase->type(cmp2)->isa_long();
1664 const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long();
1665 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1666 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1667 Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0)));
1668 return new BoolNode(ncmp, _test.negate());
1669 }
1670 }
1671
1672 // Change "cmp (add X min_jint) (add Y min_jint)" into "cmpu X Y"
1673 // and "cmp (add X min_jint) c" into "cmpu X (c + min_jint)"
1674 if (cop == Op_CmpI &&
1675 cmp1_op == Op_AddI &&
1676 phase->type(cmp1->in(2)) == TypeInt::MIN &&
1677 !is_cloop_condition(this)) {
1678 if (cmp2_op == Op_ConI) {
1679 Node* ncmp2 = phase->intcon(java_add(cmp2->get_int(), min_jint));
1680 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), ncmp2));
1681 return new BoolNode(ncmp, _test._test);
1682 } else if (cmp2_op == Op_AddI &&
1683 phase->type(cmp2->in(2)) == TypeInt::MIN &&
1684 !is_cloop_condition(this)) {
1685 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), cmp2->in(1)));
1686 return new BoolNode(ncmp, _test._test);
1687 }
1688 }
1689
1690 // Change "cmp (add X min_jlong) (add Y min_jlong)" into "cmpu X Y"
1691 // and "cmp (add X min_jlong) c" into "cmpu X (c + min_jlong)"
1692 if (cop == Op_CmpL &&
1693 cmp1_op == Op_AddL &&
1694 phase->type(cmp1->in(2)) == TypeLong::MIN &&
1695 !is_cloop_condition(this)) {
1696 if (cmp2_op == Op_ConL) {
1697 Node* ncmp2 = phase->longcon(java_add(cmp2->get_long(), min_jlong));
1698 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), ncmp2));
1699 return new BoolNode(ncmp, _test._test);
1700 } else if (cmp2_op == Op_AddL &&
1701 phase->type(cmp2->in(2)) == TypeLong::MIN &&
1702 !is_cloop_condition(this)) {
1703 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), cmp2->in(1)));
1704 return new BoolNode(ncmp, _test._test);
1705 }
1706 }
1707
1708 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1709 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1710 // test instead.
1711 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1712 if (cmp2_type == nullptr) return nullptr;
1713 Node* j_xor = cmp1;
1714 if( cmp2_type == TypeInt::ZERO &&
1715 cmp1_op == Op_XorI &&
1716 j_xor->in(1) != j_xor && // An xor of itself is dead
1717 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1718 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1719 (_test._test == BoolTest::eq ||
1720 _test._test == BoolTest::ne) ) {
1721 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1722 return new BoolNode( ncmp, _test.negate() );
1723 }
1724
1725 // Change ((x & (m - 1)) u< m) into (m > 0)
1726 // This is the off-by-one variant of ((x & m) u<= m)
1727 if (cop == Op_CmpU &&
1728 _test._test == BoolTest::lt &&
1729 cmp1_op == Op_AndI) {
1730 Node* l = cmp1->in(1);
1731 Node* r = cmp1->in(2);
1732 for (int repeat = 0; repeat < 2; repeat++) {
1733 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1734 r->in(1) == cmp2;
1735 if (match) {
1736 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1737 // but to be compatible with the array range check pattern, use (arraylength u> 0)
1738 Node* ncmp = cmp2->Opcode() == Op_LoadRange
1739 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1740 : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1741 return new BoolNode(ncmp, BoolTest::gt);
1742 } else {
1743 // commute and try again
1744 l = cmp1->in(2);
1745 r = cmp1->in(1);
1746 }
1747 }
1748 }
1749
1750 // Change x u< 1 or x u<= 0 to x == 0
1751 // and x u> 0 or u>= 1 to x != 0
1752 if (cop == Op_CmpU &&
1753 cmp1_op != Op_LoadRange &&
1754 (((_test._test == BoolTest::lt || _test._test == BoolTest::ge) &&
1755 cmp2->find_int_con(-1) == 1) ||
1756 ((_test._test == BoolTest::le || _test._test == BoolTest::gt) &&
1757 cmp2->find_int_con(-1) == 0))) {
1758 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1759 return new BoolNode(ncmp, _test.is_less() ? BoolTest::eq : BoolTest::ne);
1760 }
1761
1762 // Change (arraylength <= 0) or (arraylength == 0)
1763 // into (arraylength u<= 0)
1764 // Also change (arraylength != 0) into (arraylength u> 0)
1765 // The latter version matches the code pattern generated for
1766 // array range checks, which will more likely be optimized later.
1767 if (cop == Op_CmpI &&
1768 cmp1_op == Op_LoadRange &&
1769 cmp2->find_int_con(-1) == 0) {
1770 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1771 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1772 return new BoolNode(ncmp, BoolTest::le);
1773 } else if (_test._test == BoolTest::ne) {
1774 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1775 return new BoolNode(ncmp, BoolTest::gt);
1776 }
1777 }
1778
1779 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1780 // This is a standard idiom for branching on a boolean value.
1781 Node *c2b = cmp1;
1782 if( cmp2_type == TypeInt::ZERO &&
1783 cmp1_op == Op_Conv2B &&
1784 (_test._test == BoolTest::eq ||
1785 _test._test == BoolTest::ne) ) {
1786 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1787 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1788 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1789 );
1790 return new BoolNode( ncmp, _test._test );
1791 }
1792
1793 // Comparing a SubI against a zero is equal to comparing the SubI
1794 // arguments directly. This only works for eq and ne comparisons
1795 // due to possible integer overflow.
1796 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1797 (cop == Op_CmpI) &&
1798 (cmp1_op == Op_SubI) &&
1799 ( cmp2_type == TypeInt::ZERO ) ) {
1800 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1801 return new BoolNode( ncmp, _test._test );
1802 }
1803
1804 // Same as above but with and AddI of a constant
1805 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1806 cop == Op_CmpI &&
1807 cmp1_op == Op_AddI &&
1808 cmp1->in(2) != nullptr &&
1809 phase->type(cmp1->in(2))->isa_int() &&
1810 phase->type(cmp1->in(2))->is_int()->is_con() &&
1811 cmp2_type == TypeInt::ZERO &&
1812 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1813 ) {
1814 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1815 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1816 return new BoolNode( ncmp, _test._test );
1817 }
1818
1819 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1820 // since zero check of conditional negation of an integer is equal to
1821 // zero check of the integer directly.
1822 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1823 (cop == Op_CmpI) &&
1824 (cmp2_type == TypeInt::ZERO) &&
1825 (cmp1_op == Op_Phi)) {
1826 // There should be a diamond phi with true path at index 1 or 2
1827 PhiNode *phi = cmp1->as_Phi();
1828 int idx_true = phi->is_diamond_phi();
1829 if (idx_true != 0) {
1830 // True input is in(idx_true) while false input is in(3 - idx_true)
1831 Node *tin = phi->in(idx_true);
1832 Node *fin = phi->in(3 - idx_true);
1833 if ((tin->Opcode() == Op_SubI) &&
1834 (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1835 (tin->in(2) == fin)) {
1836 // Found conditional negation at true path, create a new CmpINode without that
1837 Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1838 return new BoolNode(ncmp, _test._test);
1839 }
1840 if ((fin->Opcode() == Op_SubI) &&
1841 (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1842 (fin->in(2) == tin)) {
1843 // Found conditional negation at false path, create a new CmpINode without that
1844 Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1845 return new BoolNode(ncmp, _test._test);
1846 }
1847 }
1848 }
1849
1850 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1851 // most general case because negating 0x80000000 does nothing. Needed for
1852 // the CmpF3/SubI/CmpI idiom.
1853 if( cop == Op_CmpI &&
1854 cmp1_op == Op_SubI &&
1855 cmp2_type == TypeInt::ZERO &&
1856 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1857 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1858 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1859 return new BoolNode( ncmp, _test.commute() );
1860 }
1861
1862 // Try to optimize signed integer comparison
1863 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1864
1865 // The transformation below is not valid for either signed or unsigned
1866 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1867 // This transformation can be resurrected when we are able to
1868 // make inferences about the range of values being subtracted from
1869 // (or added to) relative to the wraparound point.
1870 //
1871 // // Remove +/-1's if possible.
1872 // // "X <= Y-1" becomes "X < Y"
1873 // // "X+1 <= Y" becomes "X < Y"
1874 // // "X < Y+1" becomes "X <= Y"
1875 // // "X-1 < Y" becomes "X <= Y"
1876 // // Do not this to compares off of the counted-loop-end. These guys are
1877 // // checking the trip counter and they want to use the post-incremented
1878 // // counter. If they use the PRE-incremented counter, then the counter has
1879 // // to be incremented in a private block on a loop backedge.
1880 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1881 // return nullptr;
1882 // #ifndef PRODUCT
1883 // // Do not do this in a wash GVN pass during verification.
1884 // // Gets triggered by too many simple optimizations to be bothered with
1885 // // re-trying it again and again.
1886 // if( !phase->allow_progress() ) return nullptr;
1887 // #endif
1888 // // Not valid for unsigned compare because of corner cases in involving zero.
1889 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1890 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1891 // // "0 <=u Y" is always true).
1892 // if( cmp->Opcode() == Op_CmpU ) return nullptr;
1893 // int cmp2_op = cmp2->Opcode();
1894 // if( _test._test == BoolTest::le ) {
1895 // if( cmp1_op == Op_AddI &&
1896 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1897 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1898 // else if( cmp2_op == Op_AddI &&
1899 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1900 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1901 // } else if( _test._test == BoolTest::lt ) {
1902 // if( cmp1_op == Op_AddI &&
1903 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1904 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1905 // else if( cmp2_op == Op_AddI &&
1906 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1907 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1908 // }
1909 }
1910
1911 //------------------------------Value------------------------------------------
1912 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1913 // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1914 const Type* BoolNode::Value_cmpu_and_mask(PhaseValues* phase) const {
1915 Node* cmp = in(1);
1916 if (cmp != nullptr && cmp->Opcode() == Op_CmpU) {
1917 Node* cmp1 = cmp->in(1);
1918 Node* cmp2 = cmp->in(2);
1919
1920 if (cmp1->Opcode() == Op_AndI) {
1921 Node* bound = nullptr;
1922 if (_test._test == BoolTest::le) {
1923 bound = cmp2;
1924 } else if (_test._test == BoolTest::lt && cmp2->Opcode() == Op_AddI && cmp2->in(2)->find_int_con(0) == 1) {
1925 bound = cmp2->in(1);
1926 }
1927
1928 if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1929 return TypeInt::ONE;
1930 }
1931 }
1932 }
1933
1934 return nullptr;
1935 }
1936
1937 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1938 // based on local information. If the input is constant, do it.
1939 const Type* BoolNode::Value(PhaseGVN* phase) const {
1940 const Type* t = Value_cmpu_and_mask(phase);
1941 if (t != nullptr) {
1942 return t;
1943 }
1944
1945 return _test.cc2logical( phase->type( in(1) ) );
1946 }
1947
1948 #ifndef PRODUCT
1949 //------------------------------dump_spec--------------------------------------
1950 // Dump special per-node info
1951 void BoolNode::dump_spec(outputStream *st) const {
1952 st->print("[");
1953 _test.dump_on(st);
1954 st->print("]");
1955 }
1956 #endif
1957
1958 //----------------------is_counted_loop_exit_test------------------------------
1959 // Returns true if node is used by a counted loop node.
1960 bool BoolNode::is_counted_loop_exit_test() {
1961 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1962 Node* use = fast_out(i);
1963 if (use->is_CountedLoopEnd()) {
1964 return true;
1965 }
1966 }
1967 return false;
1968 }
1969
1970 //=============================================================================
1971 //------------------------------Value------------------------------------------
1972 const Type* AbsNode::Value(PhaseGVN* phase) const {
1973 const Type* t1 = phase->type(in(1));
1974 if (t1 == Type::TOP) return Type::TOP;
1975
1976 switch (t1->base()) {
1977 case Type::Int: {
1978 const TypeInt* ti = t1->is_int();
1979 if (ti->is_con()) {
1980 return TypeInt::make(uabs(ti->get_con()));
1981 }
1982 break;
1983 }
1984 case Type::Long: {
1985 const TypeLong* tl = t1->is_long();
1986 if (tl->is_con()) {
1987 return TypeLong::make(uabs(tl->get_con()));
1988 }
1989 break;
1990 }
1991 case Type::FloatCon:
1992 return TypeF::make(abs(t1->getf()));
1993 case Type::DoubleCon:
1994 return TypeD::make(abs(t1->getd()));
1995 default:
1996 break;
1997 }
1998
1999 return bottom_type();
2000 }
2001
2002 //------------------------------Identity----------------------------------------
2003 Node* AbsNode::Identity(PhaseGVN* phase) {
2004 Node* in1 = in(1);
2005 // No need to do abs for non-negative values
2006 if (phase->type(in1)->higher_equal(TypeInt::POS) ||
2007 phase->type(in1)->higher_equal(TypeLong::POS)) {
2008 return in1;
2009 }
2010 // Convert "abs(abs(x))" into "abs(x)"
2011 if (in1->Opcode() == Opcode()) {
2012 return in1;
2013 }
2014 return this;
2015 }
2016
2017 //------------------------------Ideal------------------------------------------
2018 Node* AbsNode::Ideal(PhaseGVN* phase, bool can_reshape) {
2019 Node* in1 = in(1);
2020 // Convert "abs(0-x)" into "abs(x)"
2021 if (in1->is_Sub() && phase->type(in1->in(1))->is_zero_type()) {
2022 set_req_X(1, in1->in(2), phase);
2023 return this;
2024 }
2025 return nullptr;
2026 }
2027
2028 //=============================================================================
2029 //------------------------------Value------------------------------------------
2030 // Compute sqrt
2031 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
2032 const Type *t1 = phase->type( in(1) );
2033 if( t1 == Type::TOP ) return Type::TOP;
2034 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
2035 double d = t1->getd();
2036 if( d < 0.0 ) return Type::DOUBLE;
2037 return TypeD::make( sqrt( d ) );
2038 }
2039
2040 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
2041 const Type *t1 = phase->type( in(1) );
2042 if( t1 == Type::TOP ) return Type::TOP;
2043 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
2044 float f = t1->getf();
2045 if( f < 0.0f ) return Type::FLOAT;
2046 return TypeF::make( (float)sqrt( (double)f ) );
2047 }
2048
2049 const Type* ReverseINode::Value(PhaseGVN* phase) const {
2050 const Type *t1 = phase->type( in(1) );
2051 if (t1 == Type::TOP) {
2052 return Type::TOP;
2053 }
2054 const TypeInt* t1int = t1->isa_int();
2055 if (t1int && t1int->is_con()) {
2056 jint res = reverse_bits(t1int->get_con());
2057 return TypeInt::make(res);
2058 }
2059 return bottom_type();
2060 }
2061
2062 const Type* ReverseLNode::Value(PhaseGVN* phase) const {
2063 const Type *t1 = phase->type( in(1) );
2064 if (t1 == Type::TOP) {
2065 return Type::TOP;
2066 }
2067 const TypeLong* t1long = t1->isa_long();
2068 if (t1long && t1long->is_con()) {
2069 jlong res = reverse_bits(t1long->get_con());
2070 return TypeLong::make(res);
2071 }
2072 return bottom_type();
2073 }
2074
2075 Node* ReverseINode::Identity(PhaseGVN* phase) {
2076 if (in(1)->Opcode() == Op_ReverseI) {
2077 return in(1)->in(1);
2078 }
2079 return this;
2080 }
2081
2082 Node* ReverseLNode::Identity(PhaseGVN* phase) {
2083 if (in(1)->Opcode() == Op_ReverseL) {
2084 return in(1)->in(1);
2085 }
2086 return this;
2087 }