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