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