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/loopnode.hpp"
34 #include "opto/matcher.hpp"
35 #include "opto/movenode.hpp"
36 #include "opto/mulnode.hpp"
37 #include "opto/opcodes.hpp"
38 #include "opto/phaseX.hpp"
39 #include "opto/subnode.hpp"
40 #include "runtime/sharedRuntime.hpp"
41
42 // Portions of code courtesy of Clifford Click
43
44 // Optimization - Graph Style
45
46 #include "math.h"
47
48 //=============================================================================
49 //------------------------------Identity---------------------------------------
50 // If right input is a constant 0, return the left input.
51 Node* SubNode::Identity(PhaseGVN* phase) {
52 assert(in(1) != this, "Must already have called Value");
53 assert(in(2) != this, "Must already have called Value");
54
55 // Remove double negation
56 const Type *zero = add_id();
57 if( phase->type( in(1) )->higher_equal( zero ) &&
58 in(2)->Opcode() == Opcode() &&
59 phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
60 return in(2)->in(2);
61 }
62
63 // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
64 if (in(1)->Opcode() == Op_AddI || in(1)->Opcode() == Op_AddL) {
65 if (in(1)->in(2) == in(2)) {
66 return in(1)->in(1);
67 }
68 if (in(1)->in(1) == in(2)) {
69 return in(1)->in(2);
70 }
71
72 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying
73 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes
74 // are originally used, although the optimizer sometimes jiggers things).
75 // This folding through an O2 removes a loop-exit use of a loop-varying
76 // value and generally lowers register pressure in and around the loop.
77 if (in(1)->in(2)->Opcode() == Op_Opaque2 && in(1)->in(2)->in(1) == in(2)) {
78 return in(1)->in(1);
79 }
80 }
81
82 return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
83 }
84
85 //------------------------------Value------------------------------------------
86 // A subtract node differences it's two inputs.
87 const Type* SubNode::Value_common(PhaseTransform *phase) const {
88 const Node* in1 = in(1);
89 const Node* in2 = in(2);
90 // Either input is TOP ==> the result is TOP
91 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
92 if( t1 == Type::TOP ) return Type::TOP;
93 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
94 if( t2 == Type::TOP ) return Type::TOP;
95
96 // Not correct for SubFnode and AddFNode (must check for infinity)
97 // Equal? Subtract is zero
98 if (in1->eqv_uncast(in2)) return add_id();
99
100 // Either input is BOTTOM ==> the result is the local BOTTOM
101 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
102 return bottom_type();
103
104 return NULL;
105 }
106
107 const Type* SubNode::Value(PhaseGVN* phase) const {
108 const Type* t = Value_common(phase);
109 if (t != NULL) {
110 return t;
111 }
112 const Type* t1 = phase->type(in(1));
113 const Type* t2 = phase->type(in(2));
114 return sub(t1,t2); // Local flavor of type subtraction
115
116 }
117
118 SubNode* SubNode::make(Node* in1, Node* in2, BasicType bt) {
119 switch (bt) {
120 case T_INT:
121 return new SubINode(in1, in2);
122 case T_LONG:
123 return new SubLNode(in1, in2);
124 default:
125 fatal("Not implemented for %s", type2name(bt));
126 }
127 return NULL;
128 }
129
130 //=============================================================================
131 //------------------------------Helper function--------------------------------
132
133 static bool is_cloop_increment(Node* inc) {
134 precond(inc->Opcode() == Op_AddI || inc->Opcode() == Op_AddL);
135
136 if (!inc->in(1)->is_Phi()) {
137 return false;
138 }
139 const PhiNode* phi = inc->in(1)->as_Phi();
140
141 if (!phi->region()->is_CountedLoop()) {
142 return false;
143 }
144
145 return inc == phi->region()->as_CountedLoop()->incr();
146 }
147
148 // Given the expression '(x + C) - v', or
149 // 'v - (x + C)', we examine nodes '+' and 'v':
150 //
151 // 1. Do not convert if '+' is a counted-loop increment, because the '-' is
152 // loop invariant and converting extends the live-range of 'x' to overlap
153 // with the '+', forcing another register to be used in the loop.
154 //
155 // 2. Do not convert if 'v' is a counted-loop induction variable, because
156 // 'x' might be invariant.
157 //
158 static bool ok_to_convert(Node* inc, Node* var) {
159 return !(is_cloop_increment(inc) || var->is_cloop_ind_var());
160 }
161
162 //------------------------------Ideal------------------------------------------
163 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
164 Node *in1 = in(1);
165 Node *in2 = in(2);
166 uint op1 = in1->Opcode();
167 uint op2 = in2->Opcode();
168
169 #ifdef ASSERT
170 // Check for dead loop
171 if ((in1 == this) || (in2 == this) ||
172 ((op1 == Op_AddI || op1 == Op_SubI) &&
173 ((in1->in(1) == this) || (in1->in(2) == this) ||
174 (in1->in(1) == in1) || (in1->in(2) == in1)))) {
175 assert(false, "dead loop in SubINode::Ideal");
176 }
177 #endif
178
179 const Type *t2 = phase->type( in2 );
180 if( t2 == Type::TOP ) return NULL;
181 // Convert "x-c0" into "x+ -c0".
182 if( t2->base() == Type::Int ){ // Might be bottom or top...
183 const TypeInt *i = t2->is_int();
184 if( i->is_con() )
185 return new AddINode(in1, phase->intcon(-i->get_con()));
186 }
187
188 // Convert "(x+c0) - y" into (x-y) + c0"
189 // Do not collapse (x+c0)-y if "+" is a loop increment or
190 // if "y" is a loop induction variable.
191 if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
192 const Type *tadd = phase->type( in1->in(2) );
193 if( tadd->singleton() && tadd != Type::TOP ) {
194 Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 ));
195 return new AddINode( sub2, in1->in(2) );
196 }
197 }
198
199 // Convert "x - (y+c0)" into "(x-y) - c0" AND
200 // Convert "c1 - (y+c0)" into "(c1-c0) - y"
201 // Need the same check as in above optimization but reversed.
202 if (op2 == Op_AddI
203 && ok_to_convert(in2, in1)
204 && in2->in(2)->Opcode() == Op_ConI) {
205 jint c0 = phase->type(in2->in(2))->isa_int()->get_con();
206 Node* in21 = in2->in(1);
207 if (in1->Opcode() == Op_ConI) {
208 // Match c1
209 jint c1 = phase->type(in1)->isa_int()->get_con();
210 Node* sub2 = phase->intcon(java_subtract(c1, c0));
211 return new SubINode(sub2, in21);
212 } else {
213 // Match x
214 Node* sub2 = phase->transform(new SubINode(in1, in21));
215 Node* neg_c0 = phase->intcon(-c0);
216 return new AddINode(sub2, neg_c0);
217 }
218 }
219
220 const Type *t1 = phase->type( in1 );
221 if( t1 == Type::TOP ) return NULL;
222
223 #ifdef ASSERT
224 // Check for dead loop
225 if ((op2 == Op_AddI || op2 == Op_SubI) &&
226 ((in2->in(1) == this) || (in2->in(2) == this) ||
227 (in2->in(1) == in2) || (in2->in(2) == in2))) {
228 assert(false, "dead loop in SubINode::Ideal");
229 }
230 #endif
231
232 // Convert "x - (x+y)" into "-y"
233 if (op2 == Op_AddI && in1 == in2->in(1)) {
234 return new SubINode(phase->intcon(0), in2->in(2));
235 }
236 // Convert "(x-y) - x" into "-y"
237 if (op1 == Op_SubI && in1->in(1) == in2) {
238 return new SubINode(phase->intcon(0), in1->in(2));
239 }
240 // Convert "x - (y+x)" into "-y"
241 if (op2 == Op_AddI && in1 == in2->in(2)) {
242 return new SubINode(phase->intcon(0), in2->in(1));
243 }
244
245 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity().
246 if (t1 == TypeInt::ZERO && op2 == Op_SubI && phase->type(in2->in(1)) != TypeInt::ZERO) {
247 return new SubINode(in2->in(2), in2->in(1));
248 }
249
250 // Convert "0 - (x+con)" into "-con-x"
251 jint con;
252 if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
253 (con = in2->in(2)->find_int_con(0)) != 0 )
254 return new SubINode( phase->intcon(-con), in2->in(1) );
255
256 // Convert "(X+A) - (X+B)" into "A - B"
257 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
258 return new SubINode( in1->in(2), in2->in(2) );
259
260 // Convert "(A+X) - (B+X)" into "A - B"
261 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
262 return new SubINode( in1->in(1), in2->in(1) );
263
264 // Convert "(A+X) - (X+B)" into "A - B"
265 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
266 return new SubINode( in1->in(1), in2->in(2) );
267
268 // Convert "(X+A) - (B+X)" into "A - B"
269 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
270 return new SubINode( in1->in(2), in2->in(1) );
271
272 // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
273 // nicer to optimize than subtract.
274 if( op2 == Op_SubI && in2->outcnt() == 1) {
275 Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) );
276 return new SubINode( add1, in2->in(1) );
277 }
278
279 // Associative
280 if (op1 == Op_MulI && op2 == Op_MulI) {
281 Node* sub_in1 = NULL;
282 Node* sub_in2 = NULL;
283 Node* mul_in = NULL;
284
285 if (in1->in(1) == in2->in(1)) {
286 // Convert "a*b-a*c into a*(b-c)
287 sub_in1 = in1->in(2);
288 sub_in2 = in2->in(2);
289 mul_in = in1->in(1);
290 } else if (in1->in(2) == in2->in(1)) {
291 // Convert a*b-b*c into b*(a-c)
292 sub_in1 = in1->in(1);
293 sub_in2 = in2->in(2);
294 mul_in = in1->in(2);
295 } else if (in1->in(2) == in2->in(2)) {
296 // Convert a*c-b*c into (a-b)*c
297 sub_in1 = in1->in(1);
298 sub_in2 = in2->in(1);
299 mul_in = in1->in(2);
300 } else if (in1->in(1) == in2->in(2)) {
301 // Convert a*b-c*a into a*(b-c)
302 sub_in1 = in1->in(2);
303 sub_in2 = in2->in(1);
304 mul_in = in1->in(1);
305 }
306
307 if (mul_in != NULL) {
308 Node* sub = phase->transform(new SubINode(sub_in1, sub_in2));
309 return new MulINode(mul_in, sub);
310 }
311 }
312
313 // Convert "0-(A>>31)" into "(A>>>31)"
314 if ( op2 == Op_RShiftI ) {
315 Node *in21 = in2->in(1);
316 Node *in22 = in2->in(2);
317 const TypeInt *zero = phase->type(in1)->isa_int();
318 const TypeInt *t21 = phase->type(in21)->isa_int();
319 const TypeInt *t22 = phase->type(in22)->isa_int();
320 if ( t21 && t22 && zero == TypeInt::ZERO && t22->is_con(31) ) {
321 return new URShiftINode(in21, in22);
322 }
323 }
324
325 return NULL;
326 }
327
328 //------------------------------sub--------------------------------------------
329 // A subtract node differences it's two inputs.
330 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
331 const TypeInt *r0 = t1->is_int(); // Handy access
332 const TypeInt *r1 = t2->is_int();
333 int32_t lo = java_subtract(r0->_lo, r1->_hi);
334 int32_t hi = java_subtract(r0->_hi, r1->_lo);
335
336 // We next check for 32-bit overflow.
337 // If that happens, we just assume all integers are possible.
338 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
339 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
340 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
341 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
342 return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
343 else // Overflow; assume all integers
344 return TypeInt::INT;
345 }
346
347 //=============================================================================
348 //------------------------------Ideal------------------------------------------
349 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
350 Node *in1 = in(1);
351 Node *in2 = in(2);
352 uint op1 = in1->Opcode();
353 uint op2 = in2->Opcode();
354
355 #ifdef ASSERT
356 // Check for dead loop
357 if ((in1 == this) || (in2 == this) ||
358 ((op1 == Op_AddL || op1 == Op_SubL) &&
359 ((in1->in(1) == this) || (in1->in(2) == this) ||
360 (in1->in(1) == in1) || (in1->in(2) == in1)))) {
361 assert(false, "dead loop in SubLNode::Ideal");
362 }
363 #endif
364
365 if( phase->type( in2 ) == Type::TOP ) return NULL;
366 const TypeLong *i = phase->type( in2 )->isa_long();
367 // Convert "x-c0" into "x+ -c0".
368 if( i && // Might be bottom or top...
369 i->is_con() )
370 return new AddLNode(in1, phase->longcon(-i->get_con()));
371
372 // Convert "(x+c0) - y" into (x-y) + c0"
373 // Do not collapse (x+c0)-y if "+" is a loop increment or
374 // if "y" is a loop induction variable.
375 if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
376 Node *in11 = in1->in(1);
377 const Type *tadd = phase->type( in1->in(2) );
378 if( tadd->singleton() && tadd != Type::TOP ) {
379 Node *sub2 = phase->transform( new SubLNode( in11, in2 ));
380 return new AddLNode( sub2, in1->in(2) );
381 }
382 }
383
384 // Convert "x - (y+c0)" into "(x-y) - c0" AND
385 // Convert "c1 - (y+c0)" into "(c1-c0) - y"
386 // Need the same check as in above optimization but reversed.
387 if (op2 == Op_AddL
388 && ok_to_convert(in2, in1)
389 && in2->in(2)->Opcode() == Op_ConL) {
390 jlong c0 = phase->type(in2->in(2))->isa_long()->get_con();
391 Node* in21 = in2->in(1);
392 if (in1->Opcode() == Op_ConL) {
393 // Match c1
394 jlong c1 = phase->type(in1)->isa_long()->get_con();
395 Node* sub2 = phase->longcon(java_subtract(c1, c0));
396 return new SubLNode(sub2, in21);
397 } else {
398 Node* sub2 = phase->transform(new SubLNode(in1, in21));
399 Node* neg_c0 = phase->longcon(-c0);
400 return new AddLNode(sub2, neg_c0);
401 }
402 }
403
404 const Type *t1 = phase->type( in1 );
405 if( t1 == Type::TOP ) return NULL;
406
407 #ifdef ASSERT
408 // Check for dead loop
409 if ((op2 == Op_AddL || op2 == Op_SubL) &&
410 ((in2->in(1) == this) || (in2->in(2) == this) ||
411 (in2->in(1) == in2) || (in2->in(2) == in2))) {
412 assert(false, "dead loop in SubLNode::Ideal");
413 }
414 #endif
415
416 // Convert "x - (x+y)" into "-y"
417 if (op2 == Op_AddL && in1 == in2->in(1)) {
418 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(2));
419 }
420 // Convert "(x-y) - x" into "-y"
421 if (op1 == Op_SubL && in1->in(1) == in2) {
422 return new SubLNode(phase->makecon(TypeLong::ZERO), in1->in(2));
423 }
424 // Convert "x - (y+x)" into "-y"
425 if (op2 == Op_AddL && in1 == in2->in(2)) {
426 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(1));
427 }
428
429 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity.
430 if (t1 == TypeLong::ZERO && op2 == Op_SubL && phase->type(in2->in(1)) != TypeLong::ZERO) {
431 return new SubLNode(in2->in(2), in2->in(1));
432 }
433
434 // Convert "(X+A) - (X+B)" into "A - B"
435 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
436 return new SubLNode( in1->in(2), in2->in(2) );
437
438 // Convert "(A+X) - (B+X)" into "A - B"
439 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
440 return new SubLNode( in1->in(1), in2->in(1) );
441
442 // Convert "(A+X) - (X+B)" into "A - B"
443 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(1) )
444 return new SubLNode( in1->in(1), in2->in(2) );
445
446 // Convert "(X+A) - (B+X)" into "A - B"
447 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(2) )
448 return new SubLNode( in1->in(2), in2->in(1) );
449
450 // Convert "A-(B-C)" into (A+C)-B"
451 if( op2 == Op_SubL && in2->outcnt() == 1) {
452 Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) );
453 return new SubLNode( add1, in2->in(1) );
454 }
455
456 // Associative
457 if (op1 == Op_MulL && op2 == Op_MulL) {
458 Node* sub_in1 = NULL;
459 Node* sub_in2 = NULL;
460 Node* mul_in = NULL;
461
462 if (in1->in(1) == in2->in(1)) {
463 // Convert "a*b-a*c into a*(b+c)
464 sub_in1 = in1->in(2);
465 sub_in2 = in2->in(2);
466 mul_in = in1->in(1);
467 } else if (in1->in(2) == in2->in(1)) {
468 // Convert a*b-b*c into b*(a-c)
469 sub_in1 = in1->in(1);
470 sub_in2 = in2->in(2);
471 mul_in = in1->in(2);
472 } else if (in1->in(2) == in2->in(2)) {
473 // Convert a*c-b*c into (a-b)*c
474 sub_in1 = in1->in(1);
475 sub_in2 = in2->in(1);
476 mul_in = in1->in(2);
477 } else if (in1->in(1) == in2->in(2)) {
478 // Convert a*b-c*a into a*(b-c)
479 sub_in1 = in1->in(2);
480 sub_in2 = in2->in(1);
481 mul_in = in1->in(1);
482 }
483
484 if (mul_in != NULL) {
485 Node* sub = phase->transform(new SubLNode(sub_in1, sub_in2));
486 return new MulLNode(mul_in, sub);
487 }
488 }
489
490 // Convert "0L-(A>>63)" into "(A>>>63)"
491 if ( op2 == Op_RShiftL ) {
492 Node *in21 = in2->in(1);
493 Node *in22 = in2->in(2);
494 const TypeLong *zero = phase->type(in1)->isa_long();
495 const TypeLong *t21 = phase->type(in21)->isa_long();
496 const TypeInt *t22 = phase->type(in22)->isa_int();
497 if ( t21 && t22 && zero == TypeLong::ZERO && t22->is_con(63) ) {
498 return new URShiftLNode(in21, in22);
499 }
500 }
501
502 return NULL;
503 }
504
505 //------------------------------sub--------------------------------------------
506 // A subtract node differences it's two inputs.
507 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
508 const TypeLong *r0 = t1->is_long(); // Handy access
509 const TypeLong *r1 = t2->is_long();
510 jlong lo = java_subtract(r0->_lo, r1->_hi);
511 jlong hi = java_subtract(r0->_hi, r1->_lo);
512
513 // We next check for 32-bit overflow.
514 // If that happens, we just assume all integers are possible.
515 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
516 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
517 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
518 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
519 return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
520 else // Overflow; assume all integers
521 return TypeLong::LONG;
522 }
523
524 //=============================================================================
525 //------------------------------Value------------------------------------------
526 // A subtract node differences its two inputs.
527 const Type* SubFPNode::Value(PhaseGVN* phase) const {
528 const Node* in1 = in(1);
529 const Node* in2 = in(2);
530 // Either input is TOP ==> the result is TOP
531 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
532 if( t1 == Type::TOP ) return Type::TOP;
533 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
534 if( t2 == Type::TOP ) return Type::TOP;
535
536 // if both operands are infinity of same sign, the result is NaN; do
537 // not replace with zero
538 if (t1->is_finite() && t2->is_finite() && in1 == in2) {
539 return add_id();
540 }
541
542 // Either input is BOTTOM ==> the result is the local BOTTOM
543 const Type *bot = bottom_type();
544 if( (t1 == bot) || (t2 == bot) ||
545 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
546 return bot;
547
548 return sub(t1,t2); // Local flavor of type subtraction
549 }
550
551
552 //=============================================================================
553 //------------------------------Ideal------------------------------------------
554 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
555 const Type *t2 = phase->type( in(2) );
556 // Convert "x-c0" into "x+ -c0".
557 if( t2->base() == Type::FloatCon ) { // Might be bottom or top...
558 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
559 }
560
561 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
562 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
563 //if( phase->type(in(1)) == TypeF::ZERO )
564 //return new (phase->C, 2) NegFNode(in(2));
565
566 return NULL;
567 }
568
569 //------------------------------sub--------------------------------------------
570 // A subtract node differences its two inputs.
571 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
572 // no folding if one of operands is infinity or NaN, do not do constant folding
573 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
574 return TypeF::make( t1->getf() - t2->getf() );
575 }
576 else if( g_isnan(t1->getf()) ) {
577 return t1;
578 }
579 else if( g_isnan(t2->getf()) ) {
580 return t2;
581 }
582 else {
583 return Type::FLOAT;
584 }
585 }
586
587 //=============================================================================
588 //------------------------------Ideal------------------------------------------
589 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
590 const Type *t2 = phase->type( in(2) );
591 // Convert "x-c0" into "x+ -c0".
592 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
593 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
594 }
595
596 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
597 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
598 //if( phase->type(in(1)) == TypeD::ZERO )
599 //return new (phase->C, 2) NegDNode(in(2));
600
601 return NULL;
602 }
603
604 //------------------------------sub--------------------------------------------
605 // A subtract node differences its two inputs.
606 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
607 // no folding if one of operands is infinity or NaN, do not do constant folding
608 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
609 return TypeD::make( t1->getd() - t2->getd() );
610 }
611 else if( g_isnan(t1->getd()) ) {
612 return t1;
613 }
614 else if( g_isnan(t2->getd()) ) {
615 return t2;
616 }
617 else {
618 return Type::DOUBLE;
619 }
620 }
621
622 //=============================================================================
623 //------------------------------Idealize---------------------------------------
624 // Unlike SubNodes, compare must still flatten return value to the
625 // range -1, 0, 1.
626 // And optimizations like those for (X + Y) - X fail if overflow happens.
627 Node* CmpNode::Identity(PhaseGVN* phase) {
628 return this;
629 }
630
631 #ifndef PRODUCT
632 //----------------------------related------------------------------------------
633 // Related nodes of comparison nodes include all data inputs (until hitting a
634 // control boundary) as well as all outputs until and including control nodes
635 // as well as their projections. In compact mode, data inputs till depth 1 and
636 // all outputs till depth 1 are considered.
637 void CmpNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
638 if (compact) {
639 this->collect_nodes(in_rel, 1, false, true);
640 this->collect_nodes(out_rel, -1, false, false);
641 } else {
642 this->collect_nodes_in_all_data(in_rel, false);
643 this->collect_nodes_out_all_ctrl_boundary(out_rel);
644 // Now, find all control nodes in out_rel, and include their projections
645 // and projection targets (if any) in the result.
646 GrowableArray<Node*> proj(Compile::current()->unique());
647 for (GrowableArrayIterator<Node*> it = out_rel->begin(); it != out_rel->end(); ++it) {
648 Node* n = *it;
649 if (n->is_CFG() && !n->is_Proj()) {
650 // Assume projections and projection targets are found at levels 1 and 2.
651 n->collect_nodes(&proj, -2, false, false);
652 for (GrowableArrayIterator<Node*> p = proj.begin(); p != proj.end(); ++p) {
653 out_rel->append_if_missing(*p);
654 }
655 proj.clear();
656 }
657 }
658 }
659 }
660
661 #endif
662
663 CmpNode *CmpNode::make(Node *in1, Node *in2, BasicType bt, bool unsigned_comp) {
664 switch (bt) {
665 case T_INT:
666 if (unsigned_comp) {
667 return new CmpUNode(in1, in2);
668 }
669 return new CmpINode(in1, in2);
670 case T_LONG:
671 if (unsigned_comp) {
672 return new CmpULNode(in1, in2);
673 }
674 return new CmpLNode(in1, in2);
675 default:
676 fatal("Not implemented for %s", type2name(bt));
677 }
678 return NULL;
679 }
680
681 //=============================================================================
682 //------------------------------cmp--------------------------------------------
683 // Simplify a CmpI (compare 2 integers) node, based on local information.
684 // If both inputs are constants, compare them.
685 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
686 const TypeInt *r0 = t1->is_int(); // Handy access
687 const TypeInt *r1 = t2->is_int();
688
689 if( r0->_hi < r1->_lo ) // Range is always low?
690 return TypeInt::CC_LT;
691 else if( r0->_lo > r1->_hi ) // Range is always high?
692 return TypeInt::CC_GT;
693
694 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
695 assert(r0->get_con() == r1->get_con(), "must be equal");
696 return TypeInt::CC_EQ; // Equal results.
697 } else if( r0->_hi == r1->_lo ) // Range is never high?
698 return TypeInt::CC_LE;
699 else if( r0->_lo == r1->_hi ) // Range is never low?
700 return TypeInt::CC_GE;
701 return TypeInt::CC; // else use worst case results
702 }
703
704 // Simplify a CmpU (compare 2 integers) node, based on local information.
705 // If both inputs are constants, compare them.
706 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
707 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
708
709 // comparing two unsigned ints
710 const TypeInt *r0 = t1->is_int(); // Handy access
711 const TypeInt *r1 = t2->is_int();
712
713 // Current installed version
714 // Compare ranges for non-overlap
715 juint lo0 = r0->_lo;
716 juint hi0 = r0->_hi;
717 juint lo1 = r1->_lo;
718 juint hi1 = r1->_hi;
719
720 // If either one has both negative and positive values,
721 // it therefore contains both 0 and -1, and since [0..-1] is the
722 // full unsigned range, the type must act as an unsigned bottom.
723 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
724 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
725
726 if (bot0 || bot1) {
727 // All unsigned values are LE -1 and GE 0.
728 if (lo0 == 0 && hi0 == 0) {
729 return TypeInt::CC_LE; // 0 <= bot
730 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
731 return TypeInt::CC_GE; // -1 >= bot
732 } else if (lo1 == 0 && hi1 == 0) {
733 return TypeInt::CC_GE; // bot >= 0
734 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
735 return TypeInt::CC_LE; // bot <= -1
736 }
737 } else {
738 // We can use ranges of the form [lo..hi] if signs are the same.
739 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
740 // results are reversed, '-' > '+' for unsigned compare
741 if (hi0 < lo1) {
742 return TypeInt::CC_LT; // smaller
743 } else if (lo0 > hi1) {
744 return TypeInt::CC_GT; // greater
745 } else if (hi0 == lo1 && lo0 == hi1) {
746 return TypeInt::CC_EQ; // Equal results
747 } else if (lo0 >= hi1) {
748 return TypeInt::CC_GE;
749 } else if (hi0 <= lo1) {
750 // Check for special case in Hashtable::get. (See below.)
751 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
752 return TypeInt::CC_LT;
753 return TypeInt::CC_LE;
754 }
755 }
756 // Check for special case in Hashtable::get - the hash index is
757 // mod'ed to the table size so the following range check is useless.
758 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
759 // to be positive.
760 // (This is a gross hack, since the sub method never
761 // looks at the structure of the node in any other case.)
762 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
763 return TypeInt::CC_LT;
764 return TypeInt::CC; // else use worst case results
765 }
766
767 const Type* CmpUNode::Value(PhaseGVN* phase) const {
768 const Type* t = SubNode::Value_common(phase);
769 if (t != NULL) {
770 return t;
771 }
772 const Node* in1 = in(1);
773 const Node* in2 = in(2);
774 const Type* t1 = phase->type(in1);
775 const Type* t2 = phase->type(in2);
776 assert(t1->isa_int(), "CmpU has only Int type inputs");
777 if (t2 == TypeInt::INT) { // Compare to bottom?
778 return bottom_type();
779 }
780 uint in1_op = in1->Opcode();
781 if (in1_op == Op_AddI || in1_op == Op_SubI) {
782 // The problem rise when result of AddI(SubI) may overflow
783 // signed integer value. Let say the input type is
784 // [256, maxint] then +128 will create 2 ranges due to
785 // overflow: [minint, minint+127] and [384, maxint].
786 // But C2 type system keep only 1 type range and as result
787 // it use general [minint, maxint] for this case which we
788 // can't optimize.
789 //
790 // Make 2 separate type ranges based on types of AddI(SubI) inputs
791 // and compare results of their compare. If results are the same
792 // CmpU node can be optimized.
793 const Node* in11 = in1->in(1);
794 const Node* in12 = in1->in(2);
795 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
796 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
797 // Skip cases when input types are top or bottom.
798 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
799 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
800 const TypeInt *r0 = t11->is_int();
801 const TypeInt *r1 = t12->is_int();
802 jlong lo_r0 = r0->_lo;
803 jlong hi_r0 = r0->_hi;
804 jlong lo_r1 = r1->_lo;
805 jlong hi_r1 = r1->_hi;
806 if (in1_op == Op_SubI) {
807 jlong tmp = hi_r1;
808 hi_r1 = -lo_r1;
809 lo_r1 = -tmp;
810 // Note, for substructing [minint,x] type range
811 // long arithmetic provides correct overflow answer.
812 // The confusion come from the fact that in 32-bit
813 // -minint == minint but in 64-bit -minint == maxint+1.
814 }
815 jlong lo_long = lo_r0 + lo_r1;
816 jlong hi_long = hi_r0 + hi_r1;
817 int lo_tr1 = min_jint;
818 int hi_tr1 = (int)hi_long;
819 int lo_tr2 = (int)lo_long;
820 int hi_tr2 = max_jint;
821 bool underflow = lo_long != (jlong)lo_tr2;
822 bool overflow = hi_long != (jlong)hi_tr1;
823 // Use sub(t1, t2) when there is no overflow (one type range)
824 // or when both overflow and underflow (too complex).
825 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
826 // Overflow only on one boundary, compare 2 separate type ranges.
827 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
828 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
829 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
830 const Type* cmp1 = sub(tr1, t2);
831 const Type* cmp2 = sub(tr2, t2);
832 if (cmp1 == cmp2) {
833 return cmp1; // Hit!
834 }
835 }
836 }
837 }
838
839 return sub(t1, t2); // Local flavor of type subtraction
840 }
841
842 bool CmpUNode::is_index_range_check() const {
843 // Check for the "(X ModI Y) CmpU Y" shape
844 return (in(1)->Opcode() == Op_ModI &&
845 in(1)->in(2)->eqv_uncast(in(2)));
846 }
847
848 //------------------------------Idealize---------------------------------------
849 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
850 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
851 switch (in(1)->Opcode()) {
852 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
853 return new CmpLNode(in(1)->in(1),in(1)->in(2));
854 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
855 return new CmpFNode(in(1)->in(1),in(1)->in(2));
856 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
857 return new CmpDNode(in(1)->in(1),in(1)->in(2));
858 //case Op_SubI:
859 // If (x - y) cannot overflow, then ((x - y) <?> 0)
860 // can be turned into (x <?> y).
861 // This is handled (with more general cases) by Ideal_sub_algebra.
862 }
863 }
864 return NULL; // No change
865 }
866
867 Node *CmpLNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
868 const TypeLong *t2 = phase->type(in(2))->isa_long();
869 if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) {
870 const jlong con = t2->get_con();
871 if (con >= min_jint && con <= max_jint) {
872 return new CmpINode(in(1)->in(1), phase->intcon((jint)con));
873 }
874 }
875 return NULL;
876 }
877
878 //=============================================================================
879 // Simplify a CmpL (compare 2 longs ) node, based on local information.
880 // If both inputs are constants, compare them.
881 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
882 const TypeLong *r0 = t1->is_long(); // Handy access
883 const TypeLong *r1 = t2->is_long();
884
885 if( r0->_hi < r1->_lo ) // Range is always low?
886 return TypeInt::CC_LT;
887 else if( r0->_lo > r1->_hi ) // Range is always high?
888 return TypeInt::CC_GT;
889
890 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
891 assert(r0->get_con() == r1->get_con(), "must be equal");
892 return TypeInt::CC_EQ; // Equal results.
893 } else if( r0->_hi == r1->_lo ) // Range is never high?
894 return TypeInt::CC_LE;
895 else if( r0->_lo == r1->_hi ) // Range is never low?
896 return TypeInt::CC_GE;
897 return TypeInt::CC; // else use worst case results
898 }
899
900
901 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
902 // If both inputs are constants, compare them.
903 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
904 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
905
906 // comparing two unsigned longs
907 const TypeLong* r0 = t1->is_long(); // Handy access
908 const TypeLong* r1 = t2->is_long();
909
910 // Current installed version
911 // Compare ranges for non-overlap
912 julong lo0 = r0->_lo;
913 julong hi0 = r0->_hi;
914 julong lo1 = r1->_lo;
915 julong hi1 = r1->_hi;
916
917 // If either one has both negative and positive values,
918 // it therefore contains both 0 and -1, and since [0..-1] is the
919 // full unsigned range, the type must act as an unsigned bottom.
920 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
921 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
922
923 if (bot0 || bot1) {
924 // All unsigned values are LE -1 and GE 0.
925 if (lo0 == 0 && hi0 == 0) {
926 return TypeInt::CC_LE; // 0 <= bot
927 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
928 return TypeInt::CC_GE; // -1 >= bot
929 } else if (lo1 == 0 && hi1 == 0) {
930 return TypeInt::CC_GE; // bot >= 0
931 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
932 return TypeInt::CC_LE; // bot <= -1
933 }
934 } else {
935 // We can use ranges of the form [lo..hi] if signs are the same.
936 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
937 // results are reversed, '-' > '+' for unsigned compare
938 if (hi0 < lo1) {
939 return TypeInt::CC_LT; // smaller
940 } else if (lo0 > hi1) {
941 return TypeInt::CC_GT; // greater
942 } else if (hi0 == lo1 && lo0 == hi1) {
943 return TypeInt::CC_EQ; // Equal results
944 } else if (lo0 >= hi1) {
945 return TypeInt::CC_GE;
946 } else if (hi0 <= lo1) {
947 return TypeInt::CC_LE;
948 }
949 }
950
951 return TypeInt::CC; // else use worst case results
952 }
953
954 //=============================================================================
955 //------------------------------sub--------------------------------------------
956 // Simplify an CmpP (compare 2 pointers) node, based on local information.
957 // If both inputs are constants, compare them.
958 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
959 const TypePtr *r0 = t1->is_ptr(); // Handy access
960 const TypePtr *r1 = t2->is_ptr();
961
962 // Undefined inputs makes for an undefined result
963 if( TypePtr::above_centerline(r0->_ptr) ||
964 TypePtr::above_centerline(r1->_ptr) )
965 return Type::TOP;
966
967 if (r0 == r1 && r0->singleton()) {
968 // Equal pointer constants (klasses, nulls, etc.)
969 return TypeInt::CC_EQ;
970 }
971
972 // See if it is 2 unrelated classes.
973 const TypeOopPtr* oop_p0 = r0->isa_oopptr();
974 const TypeOopPtr* oop_p1 = r1->isa_oopptr();
975 bool both_oop_ptr = oop_p0 && oop_p1;
976
977 if (both_oop_ptr) {
978 Node* in1 = in(1)->uncast();
979 Node* in2 = in(2)->uncast();
980 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
981 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
982 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
983 return TypeInt::CC_GT; // different pointers
984 }
985 }
986
987 const TypeKlassPtr* klass_p0 = r0->isa_klassptr();
988 const TypeKlassPtr* klass_p1 = r1->isa_klassptr();
989
990 if (both_oop_ptr || (klass_p0 && klass_p1)) { // both or neither are klass pointers
991 ciKlass* klass0 = NULL;
992 bool xklass0 = false;
993 ciKlass* klass1 = NULL;
994 bool xklass1 = false;
995
996 if (oop_p0) {
997 klass0 = oop_p0->klass();
998 xklass0 = oop_p0->klass_is_exact();
999 } else {
1000 assert(klass_p0, "must be non-null if oop_p0 is null");
1001 klass0 = klass_p0->klass();
1002 xklass0 = klass_p0->klass_is_exact();
1003 }
1004
1005 if (oop_p1) {
1006 klass1 = oop_p1->klass();
1007 xklass1 = oop_p1->klass_is_exact();
1008 } else {
1009 assert(klass_p1, "must be non-null if oop_p1 is null");
1010 klass1 = klass_p1->klass();
1011 xklass1 = klass_p1->klass_is_exact();
1012 }
1013
1014 if (klass0 && klass1 &&
1015 klass0->is_loaded() && !klass0->is_interface() && // do not trust interfaces
1016 klass1->is_loaded() && !klass1->is_interface() &&
1017 (!klass0->is_obj_array_klass() ||
1018 !klass0->as_obj_array_klass()->base_element_klass()->is_interface()) &&
1019 (!klass1->is_obj_array_klass() ||
1020 !klass1->as_obj_array_klass()->base_element_klass()->is_interface())) {
1021 bool unrelated_classes = false;
1022 // See if neither subclasses the other, or if the class on top
1023 // is precise. In either of these cases, the compare is known
1024 // to fail if at least one of the pointers is provably not null.
1025 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
1026 // Do nothing; we know nothing for imprecise types
1027 } else if (klass0->is_subtype_of(klass1)) {
1028 // If klass1's type is PRECISE, then classes are unrelated.
1029 unrelated_classes = xklass1;
1030 } else if (klass1->is_subtype_of(klass0)) {
1031 // If klass0's type is PRECISE, then classes are unrelated.
1032 unrelated_classes = xklass0;
1033 } else { // Neither subtypes the other
1034 unrelated_classes = true;
1035 }
1036 if (unrelated_classes) {
1037 // The oops classes are known to be unrelated. If the joined PTRs of
1038 // two oops is not Null and not Bottom, then we are sure that one
1039 // of the two oops is non-null, and the comparison will always fail.
1040 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1041 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1042 return TypeInt::CC_GT;
1043 }
1044 }
1045 }
1046 }
1047
1048 // Known constants can be compared exactly
1049 // Null can be distinguished from any NotNull pointers
1050 // Unknown inputs makes an unknown result
1051 if( r0->singleton() ) {
1052 intptr_t bits0 = r0->get_con();
1053 if( r1->singleton() )
1054 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1055 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1056 } else if( r1->singleton() ) {
1057 intptr_t bits1 = r1->get_con();
1058 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1059 } else
1060 return TypeInt::CC;
1061 }
1062
1063 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1064 // Return the klass node for (indirect load from OopHandle)
1065 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1066 // or NULL if not matching.
1067 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1068 n = bs->step_over_gc_barrier(n);
1069
1070 if (n->Opcode() != Op_LoadP) return NULL;
1071
1072 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1073 if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
1074
1075 Node* adr = n->in(MemNode::Address);
1076 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1077 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return NULL;
1078 adr = adr->in(MemNode::Address);
1079
1080 intptr_t off = 0;
1081 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1082 if (k == NULL) return NULL;
1083 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1084 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return NULL;
1085
1086 // We've found the klass node of a Java mirror load.
1087 return k;
1088 }
1089
1090 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
1091 // for ConP(Foo.class) return ConP(Foo.klass)
1092 // otherwise return NULL
1093 if (!n->is_Con()) return NULL;
1094
1095 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1096 if (!tp) return NULL;
1097
1098 ciType* mirror_type = tp->java_mirror_type();
1099 // TypeInstPtr::java_mirror_type() returns non-NULL for compile-
1100 // time Class constants only.
1101 if (!mirror_type) return NULL;
1102
1103 // x.getClass() == int.class can never be true (for all primitive types)
1104 // Return a ConP(NULL) node for this case.
1105 if (mirror_type->is_classless()) {
1106 return phase->makecon(TypePtr::NULL_PTR);
1107 }
1108
1109 // return the ConP(Foo.klass)
1110 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
1111 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass()));
1112 }
1113
1114 //------------------------------Ideal------------------------------------------
1115 // Normalize comparisons between Java mirror loads to compare the klass instead.
1116 //
1117 // Also check for the case of comparing an unknown klass loaded from the primary
1118 // super-type array vs a known klass with no subtypes. This amounts to
1119 // checking to see an unknown klass subtypes a known klass with no subtypes;
1120 // this only happens on an exact match. We can shorten this test by 1 load.
1121 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1122 // Normalize comparisons between Java mirrors into comparisons of the low-
1123 // level klass, where a dependent load could be shortened.
1124 //
1125 // The new pattern has a nice effect of matching the same pattern used in the
1126 // fast path of instanceof/checkcast/Class.isInstance(), which allows
1127 // redundant exact type check be optimized away by GVN.
1128 // For example, in
1129 // if (x.getClass() == Foo.class) {
1130 // Foo foo = (Foo) x;
1131 // // ... use a ...
1132 // }
1133 // a CmpPNode could be shared between if_acmpne and checkcast
1134 {
1135 Node* k1 = isa_java_mirror_load(phase, in(1));
1136 Node* k2 = isa_java_mirror_load(phase, in(2));
1137 Node* conk2 = isa_const_java_mirror(phase, in(2));
1138
1139 if (k1 && (k2 || conk2)) {
1140 Node* lhs = k1;
1141 Node* rhs = (k2 != NULL) ? k2 : conk2;
1142 set_req_X(1, lhs, phase);
1143 set_req_X(2, rhs, phase);
1144 return this;
1145 }
1146 }
1147
1148 // Constant pointer on right?
1149 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1150 if (t2 == NULL || !t2->klass_is_exact())
1151 return NULL;
1152 // Get the constant klass we are comparing to.
1153 ciKlass* superklass = t2->klass();
1154
1155 // Now check for LoadKlass on left.
1156 Node* ldk1 = in(1);
1157 if (ldk1->is_DecodeNKlass()) {
1158 ldk1 = ldk1->in(1);
1159 if (ldk1->Opcode() != Op_LoadNKlass )
1160 return NULL;
1161 } else if (ldk1->Opcode() != Op_LoadKlass )
1162 return NULL;
1163 // Take apart the address of the LoadKlass:
1164 Node* adr1 = ldk1->in(MemNode::Address);
1165 intptr_t con2 = 0;
1166 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1167 if (ldk2 == NULL)
1168 return NULL;
1169 if (con2 == oopDesc::klass_offset_in_bytes()) {
1170 // We are inspecting an object's concrete class.
1171 // Short-circuit the check if the query is abstract.
1172 if (superklass->is_interface() ||
1173 superklass->is_abstract()) {
1174 // Make it come out always false:
1175 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1176 return this;
1177 }
1178 }
1179
1180 // Check for a LoadKlass from primary supertype array.
1181 // Any nested loadklass from loadklass+con must be from the p.s. array.
1182 if (ldk2->is_DecodeNKlass()) {
1183 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1184 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1185 return NULL;
1186 } else if (ldk2->Opcode() != Op_LoadKlass)
1187 return NULL;
1188
1189 // Verify that we understand the situation
1190 if (con2 != (intptr_t) superklass->super_check_offset())
1191 return NULL; // Might be element-klass loading from array klass
1192
1193 // If 'superklass' has no subklasses and is not an interface, then we are
1194 // assured that the only input which will pass the type check is
1195 // 'superklass' itself.
1196 //
1197 // We could be more liberal here, and allow the optimization on interfaces
1198 // which have a single implementor. This would require us to increase the
1199 // expressiveness of the add_dependency() mechanism.
1200 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1201
1202 // Object arrays must have their base element have no subtypes
1203 while (superklass->is_obj_array_klass()) {
1204 ciType* elem = superklass->as_obj_array_klass()->element_type();
1205 superklass = elem->as_klass();
1206 }
1207 if (superklass->is_instance_klass()) {
1208 ciInstanceKlass* ik = superklass->as_instance_klass();
1209 if (ik->has_subklass() || ik->is_interface()) return NULL;
1210 // Add a dependency if there is a chance that a subclass will be added later.
1211 if (!ik->is_final()) {
1212 phase->C->dependencies()->assert_leaf_type(ik);
1213 }
1214 }
1215
1216 // Bypass the dependent load, and compare directly
1217 this->set_req(1,ldk2);
1218
1219 return this;
1220 }
1221
1222 //=============================================================================
1223 //------------------------------sub--------------------------------------------
1224 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1225 // If both inputs are constants, compare them.
1226 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1227 ShouldNotReachHere();
1228 return bottom_type();
1229 }
1230
1231 //------------------------------Ideal------------------------------------------
1232 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1233 return NULL;
1234 }
1235
1236 //=============================================================================
1237 //------------------------------Value------------------------------------------
1238 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1239 // If both inputs are constants, compare them.
1240 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1241 const Node* in1 = in(1);
1242 const Node* in2 = in(2);
1243 // Either input is TOP ==> the result is TOP
1244 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1245 if( t1 == Type::TOP ) return Type::TOP;
1246 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1247 if( t2 == Type::TOP ) return Type::TOP;
1248
1249 // Not constants? Don't know squat - even if they are the same
1250 // value! If they are NaN's they compare to LT instead of EQ.
1251 const TypeF *tf1 = t1->isa_float_constant();
1252 const TypeF *tf2 = t2->isa_float_constant();
1253 if( !tf1 || !tf2 ) return TypeInt::CC;
1254
1255 // This implements the Java bytecode fcmpl, so unordered returns -1.
1256 if( tf1->is_nan() || tf2->is_nan() )
1257 return TypeInt::CC_LT;
1258
1259 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1260 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1261 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1262 return TypeInt::CC_EQ;
1263 }
1264
1265
1266 //=============================================================================
1267 //------------------------------Value------------------------------------------
1268 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1269 // If both inputs are constants, compare them.
1270 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1271 const Node* in1 = in(1);
1272 const Node* in2 = in(2);
1273 // Either input is TOP ==> the result is TOP
1274 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1275 if( t1 == Type::TOP ) return Type::TOP;
1276 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1277 if( t2 == Type::TOP ) return Type::TOP;
1278
1279 // Not constants? Don't know squat - even if they are the same
1280 // value! If they are NaN's they compare to LT instead of EQ.
1281 const TypeD *td1 = t1->isa_double_constant();
1282 const TypeD *td2 = t2->isa_double_constant();
1283 if( !td1 || !td2 ) return TypeInt::CC;
1284
1285 // This implements the Java bytecode dcmpl, so unordered returns -1.
1286 if( td1->is_nan() || td2->is_nan() )
1287 return TypeInt::CC_LT;
1288
1289 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1290 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1291 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1292 return TypeInt::CC_EQ;
1293 }
1294
1295 //------------------------------Ideal------------------------------------------
1296 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1297 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1298 // Change (CMPD (F2D (float)) (ConD value))
1299 // To (CMPF (float) (ConF value))
1300 // Valid when 'value' does not lose precision as a float.
1301 // Benefits: eliminates conversion, does not require 24-bit mode
1302
1303 // NaNs prevent commuting operands. This transform works regardless of the
1304 // order of ConD and ConvF2D inputs by preserving the original order.
1305 int idx_f2d = 1; // ConvF2D on left side?
1306 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1307 idx_f2d = 2; // No, swap to check for reversed args
1308 int idx_con = 3-idx_f2d; // Check for the constant on other input
1309
1310 if( ConvertCmpD2CmpF &&
1311 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1312 in(idx_con)->Opcode() == Op_ConD ) {
1313 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1314 double t2_value_as_double = t2->_d;
1315 float t2_value_as_float = (float)t2_value_as_double;
1316 if( t2_value_as_double == (double)t2_value_as_float ) {
1317 // Test value can be represented as a float
1318 // Eliminate the conversion to double and create new comparison
1319 Node *new_in1 = in(idx_f2d)->in(1);
1320 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1321 if( idx_f2d != 1 ) { // Must flip args to match original order
1322 Node *tmp = new_in1;
1323 new_in1 = new_in2;
1324 new_in2 = tmp;
1325 }
1326 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1327 ? new CmpF3Node( new_in1, new_in2 )
1328 : new CmpFNode ( new_in1, new_in2 ) ;
1329 return new_cmp; // Changed to CmpFNode
1330 }
1331 // Testing value required the precision of a double
1332 }
1333 return NULL; // No change
1334 }
1335
1336
1337 //=============================================================================
1338 //------------------------------cc2logical-------------------------------------
1339 // Convert a condition code type to a logical type
1340 const Type *BoolTest::cc2logical( const Type *CC ) const {
1341 if( CC == Type::TOP ) return Type::TOP;
1342 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1343 const TypeInt *ti = CC->is_int();
1344 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1345 // Match low order 2 bits
1346 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1347 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1348 return TypeInt::make(tmp); // Boolean result
1349 }
1350
1351 if( CC == TypeInt::CC_GE ) {
1352 if( _test == ge ) return TypeInt::ONE;
1353 if( _test == lt ) return TypeInt::ZERO;
1354 }
1355 if( CC == TypeInt::CC_LE ) {
1356 if( _test == le ) return TypeInt::ONE;
1357 if( _test == gt ) return TypeInt::ZERO;
1358 }
1359
1360 return TypeInt::BOOL;
1361 }
1362
1363 //------------------------------dump_spec-------------------------------------
1364 // Print special per-node info
1365 void BoolTest::dump_on(outputStream *st) const {
1366 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1367 st->print("%s", msg[_test]);
1368 }
1369
1370 // Returns the logical AND of two tests (or 'never' if both tests can never be true).
1371 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'.
1372 BoolTest::mask BoolTest::merge(BoolTest other) const {
1373 const mask res[illegal+1][illegal+1] = {
1374 // eq, gt, of, lt, ne, le, nof, ge, never, illegal
1375 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq
1376 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt
1377 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of
1378 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt
1379 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne
1380 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le
1381 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof
1382 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge
1383 {never, never, never, never, never, never, never, never, never, illegal}, // never
1384 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal
1385 return res[_test][other._test];
1386 }
1387
1388 //=============================================================================
1389 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1390 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1391
1392 //------------------------------operator==-------------------------------------
1393 bool BoolNode::cmp( const Node &n ) const {
1394 const BoolNode *b = (const BoolNode *)&n; // Cast up
1395 return (_test._test == b->_test._test);
1396 }
1397
1398 //-------------------------------make_predicate--------------------------------
1399 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1400 if (test_value->is_Con()) return test_value;
1401 if (test_value->is_Bool()) return test_value;
1402 if (test_value->is_CMove() &&
1403 test_value->in(CMoveNode::Condition)->is_Bool()) {
1404 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1405 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1406 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1407 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1408 return bol;
1409 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1410 return phase->transform( bol->negate(phase) );
1411 }
1412 // Else fall through. The CMove gets in the way of the test.
1413 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1414 }
1415 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1416 cmp = phase->transform(cmp);
1417 Node* bol = new BoolNode(cmp, BoolTest::ne);
1418 return phase->transform(bol);
1419 }
1420
1421 //--------------------------------as_int_value---------------------------------
1422 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1423 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1424 Node* cmov = CMoveNode::make(NULL, this,
1425 phase->intcon(0), phase->intcon(1),
1426 TypeInt::BOOL);
1427 return phase->transform(cmov);
1428 }
1429
1430 //----------------------------------negate-------------------------------------
1431 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1432 return new BoolNode(in(1), _test.negate());
1433 }
1434
1435 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1436 // overflows and we can prove that C is not in the two resulting ranges.
1437 // This optimization is similar to the one performed by CmpUNode::Value().
1438 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1439 int cmp1_op, const TypeInt* cmp2_type) {
1440 // Only optimize eq/ne integer comparison of add/sub
1441 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1442 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1443 // Skip cases were inputs of add/sub are not integers or of bottom type
1444 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1445 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1446 if ((r0 != NULL) && (r0 != TypeInt::INT) &&
1447 (r1 != NULL) && (r1 != TypeInt::INT) &&
1448 (cmp2_type != TypeInt::INT)) {
1449 // Compute exact (long) type range of add/sub result
1450 jlong lo_long = r0->_lo;
1451 jlong hi_long = r0->_hi;
1452 if (cmp1_op == Op_AddI) {
1453 lo_long += r1->_lo;
1454 hi_long += r1->_hi;
1455 } else {
1456 lo_long -= r1->_hi;
1457 hi_long -= r1->_lo;
1458 }
1459 // Check for over-/underflow by casting to integer
1460 int lo_int = (int)lo_long;
1461 int hi_int = (int)hi_long;
1462 bool underflow = lo_long != (jlong)lo_int;
1463 bool overflow = hi_long != (jlong)hi_int;
1464 if ((underflow != overflow) && (hi_int < lo_int)) {
1465 // Overflow on one boundary, compute resulting type ranges:
1466 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1467 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1468 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1469 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1470 // Compare second input of cmp to both type ranges
1471 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1472 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1473 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1474 // The result of the add/sub will never equal cmp2. Replace BoolNode
1475 // by false (0) if it tests for equality and by true (1) otherwise.
1476 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1477 }
1478 }
1479 }
1480 }
1481 return NULL;
1482 }
1483
1484 static bool is_counted_loop_cmp(Node *cmp) {
1485 Node *n = cmp->in(1)->in(1);
1486 return n != NULL &&
1487 n->is_Phi() &&
1488 n->in(0) != NULL &&
1489 n->in(0)->is_CountedLoop() &&
1490 n->in(0)->as_CountedLoop()->phi() == n;
1491 }
1492
1493 //------------------------------Ideal------------------------------------------
1494 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1495 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1496 // This moves the constant to the right. Helps value-numbering.
1497 Node *cmp = in(1);
1498 if( !cmp->is_Sub() ) return NULL;
1499 int cop = cmp->Opcode();
1500 if( cop == Op_FastLock || cop == Op_FastUnlock || cmp->is_SubTypeCheck()) return NULL;
1501 Node *cmp1 = cmp->in(1);
1502 Node *cmp2 = cmp->in(2);
1503 if( !cmp1 ) return NULL;
1504
1505 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1506 return NULL;
1507 }
1508
1509 const int cmp1_op = cmp1->Opcode();
1510 const int cmp2_op = cmp2->Opcode();
1511
1512 // Constant on left?
1513 Node *con = cmp1;
1514 // Move constants to the right of compare's to canonicalize.
1515 // Do not muck with Opaque1 nodes, as this indicates a loop
1516 // guard that cannot change shape.
1517 if( con->is_Con() && !cmp2->is_Con() && cmp2_op != Op_Opaque1 &&
1518 // Because of NaN's, CmpD and CmpF are not commutative
1519 cop != Op_CmpD && cop != Op_CmpF &&
1520 // Protect against swapping inputs to a compare when it is used by a
1521 // counted loop exit, which requires maintaining the loop-limit as in(2)
1522 !is_counted_loop_exit_test() ) {
1523 // Ok, commute the constant to the right of the cmp node.
1524 // Clone the Node, getting a new Node of the same class
1525 cmp = cmp->clone();
1526 // Swap inputs to the clone
1527 cmp->swap_edges(1, 2);
1528 cmp = phase->transform( cmp );
1529 return new BoolNode( cmp, _test.commute() );
1530 }
1531
1532 // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1533 if (cop == Op_CmpI &&
1534 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1535 cmp1_op == Op_AndI && cmp2_op == Op_ConI &&
1536 cmp1->in(2)->Opcode() == Op_ConI) {
1537 const TypeInt *t12 = phase->type(cmp2)->isa_int();
1538 const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int();
1539 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1540 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1541 Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1542 return new BoolNode(ncmp, _test.negate());
1543 }
1544 }
1545
1546 // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)".
1547 if (cop == Op_CmpL &&
1548 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1549 cmp1_op == Op_AndL && cmp2_op == Op_ConL &&
1550 cmp1->in(2)->Opcode() == Op_ConL) {
1551 const TypeLong *t12 = phase->type(cmp2)->isa_long();
1552 const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long();
1553 if (t12 && t12->is_con() && t112 && t112->is_con() &&
1554 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) {
1555 Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0)));
1556 return new BoolNode(ncmp, _test.negate());
1557 }
1558 }
1559
1560 // Change "cmp (add X min_jint) (add Y min_jint)" into "cmpu X Y"
1561 // and "cmp (add X min_jint) c" into "cmpu X (c + min_jint)"
1562 if (cop == Op_CmpI &&
1563 cmp1_op == Op_AddI &&
1564 phase->type(cmp1->in(2)) == TypeInt::MIN) {
1565 if (cmp2_op == Op_ConI) {
1566 Node* ncmp2 = phase->intcon(java_add(cmp2->get_int(), min_jint));
1567 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), ncmp2));
1568 return new BoolNode(ncmp, _test._test);
1569 } else if (cmp2_op == Op_AddI &&
1570 phase->type(cmp2->in(2)) == TypeInt::MIN) {
1571 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), cmp2->in(1)));
1572 return new BoolNode(ncmp, _test._test);
1573 }
1574 }
1575
1576 // Change "cmp (add X min_jlong) (add Y min_jlong)" into "cmpu X Y"
1577 // and "cmp (add X min_jlong) c" into "cmpu X (c + min_jlong)"
1578 if (cop == Op_CmpL &&
1579 cmp1_op == Op_AddL &&
1580 phase->type(cmp1->in(2)) == TypeLong::MIN) {
1581 if (cmp2_op == Op_ConL) {
1582 Node* ncmp2 = phase->longcon(java_add(cmp2->get_long(), min_jlong));
1583 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), ncmp2));
1584 return new BoolNode(ncmp, _test._test);
1585 } else if (cmp2_op == Op_AddL &&
1586 phase->type(cmp2->in(2)) == TypeLong::MIN) {
1587 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), cmp2->in(1)));
1588 return new BoolNode(ncmp, _test._test);
1589 }
1590 }
1591
1592 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1593 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1594 // test instead.
1595 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1596 if (cmp2_type == NULL) return NULL;
1597 Node* j_xor = cmp1;
1598 if( cmp2_type == TypeInt::ZERO &&
1599 cmp1_op == Op_XorI &&
1600 j_xor->in(1) != j_xor && // An xor of itself is dead
1601 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1602 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1603 (_test._test == BoolTest::eq ||
1604 _test._test == BoolTest::ne) ) {
1605 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1606 return new BoolNode( ncmp, _test.negate() );
1607 }
1608
1609 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1610 // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1611 if (cop == Op_CmpU &&
1612 cmp1_op == Op_AndI) {
1613 Node* bound = NULL;
1614 if (_test._test == BoolTest::le) {
1615 bound = cmp2;
1616 } else if (_test._test == BoolTest::lt &&
1617 cmp2->Opcode() == Op_AddI &&
1618 cmp2->in(2)->find_int_con(0) == 1) {
1619 bound = cmp2->in(1);
1620 }
1621 if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1622 return ConINode::make(1);
1623 }
1624 }
1625
1626 // Change ((x & (m - 1)) u< m) into (m > 0)
1627 // This is the off-by-one variant of the above
1628 if (cop == Op_CmpU &&
1629 _test._test == BoolTest::lt &&
1630 cmp1_op == Op_AndI) {
1631 Node* l = cmp1->in(1);
1632 Node* r = cmp1->in(2);
1633 for (int repeat = 0; repeat < 2; repeat++) {
1634 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1635 r->in(1) == cmp2;
1636 if (match) {
1637 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1638 // but to be compatible with the array range check pattern, use (arraylength u> 0)
1639 Node* ncmp = cmp2->Opcode() == Op_LoadRange
1640 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1641 : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1642 return new BoolNode(ncmp, BoolTest::gt);
1643 } else {
1644 // commute and try again
1645 l = cmp1->in(2);
1646 r = cmp1->in(1);
1647 }
1648 }
1649 }
1650
1651 // Change x u< 1 or x u<= 0 to x == 0
1652 if (cop == Op_CmpU &&
1653 cmp1_op != Op_LoadRange &&
1654 ((_test._test == BoolTest::lt &&
1655 cmp2->find_int_con(-1) == 1) ||
1656 (_test._test == BoolTest::le &&
1657 cmp2->find_int_con(-1) == 0))) {
1658 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0)));
1659 return new BoolNode(ncmp, BoolTest::eq);
1660 }
1661
1662 // Change (arraylength <= 0) or (arraylength == 0)
1663 // into (arraylength u<= 0)
1664 // Also change (arraylength != 0) into (arraylength u> 0)
1665 // The latter version matches the code pattern generated for
1666 // array range checks, which will more likely be optimized later.
1667 if (cop == Op_CmpI &&
1668 cmp1_op == Op_LoadRange &&
1669 cmp2->find_int_con(-1) == 0) {
1670 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1671 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1672 return new BoolNode(ncmp, BoolTest::le);
1673 } else if (_test._test == BoolTest::ne) {
1674 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1675 return new BoolNode(ncmp, BoolTest::gt);
1676 }
1677 }
1678
1679 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1680 // This is a standard idiom for branching on a boolean value.
1681 Node *c2b = cmp1;
1682 if( cmp2_type == TypeInt::ZERO &&
1683 cmp1_op == Op_Conv2B &&
1684 (_test._test == BoolTest::eq ||
1685 _test._test == BoolTest::ne) ) {
1686 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1687 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1688 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1689 );
1690 return new BoolNode( ncmp, _test._test );
1691 }
1692
1693 // Comparing a SubI against a zero is equal to comparing the SubI
1694 // arguments directly. This only works for eq and ne comparisons
1695 // due to possible integer overflow.
1696 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1697 (cop == Op_CmpI) &&
1698 (cmp1_op == Op_SubI) &&
1699 ( cmp2_type == TypeInt::ZERO ) ) {
1700 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1701 return new BoolNode( ncmp, _test._test );
1702 }
1703
1704 // Same as above but with and AddI of a constant
1705 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1706 cop == Op_CmpI &&
1707 cmp1_op == Op_AddI &&
1708 cmp1->in(2) != NULL &&
1709 phase->type(cmp1->in(2))->isa_int() &&
1710 phase->type(cmp1->in(2))->is_int()->is_con() &&
1711 cmp2_type == TypeInt::ZERO &&
1712 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape
1713 ) {
1714 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int();
1715 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi)));
1716 return new BoolNode( ncmp, _test._test );
1717 }
1718
1719 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)"
1720 // since zero check of conditional negation of an integer is equal to
1721 // zero check of the integer directly.
1722 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1723 (cop == Op_CmpI) &&
1724 (cmp2_type == TypeInt::ZERO) &&
1725 (cmp1_op == Op_Phi)) {
1726 // There should be a diamond phi with true path at index 1 or 2
1727 PhiNode *phi = cmp1->as_Phi();
1728 int idx_true = phi->is_diamond_phi();
1729 if (idx_true != 0) {
1730 // True input is in(idx_true) while false input is in(3 - idx_true)
1731 Node *tin = phi->in(idx_true);
1732 Node *fin = phi->in(3 - idx_true);
1733 if ((tin->Opcode() == Op_SubI) &&
1734 (phase->type(tin->in(1)) == TypeInt::ZERO) &&
1735 (tin->in(2) == fin)) {
1736 // Found conditional negation at true path, create a new CmpINode without that
1737 Node *ncmp = phase->transform(new CmpINode(fin, cmp2));
1738 return new BoolNode(ncmp, _test._test);
1739 }
1740 if ((fin->Opcode() == Op_SubI) &&
1741 (phase->type(fin->in(1)) == TypeInt::ZERO) &&
1742 (fin->in(2) == tin)) {
1743 // Found conditional negation at false path, create a new CmpINode without that
1744 Node *ncmp = phase->transform(new CmpINode(tin, cmp2));
1745 return new BoolNode(ncmp, _test._test);
1746 }
1747 }
1748 }
1749
1750 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1751 // most general case because negating 0x80000000 does nothing. Needed for
1752 // the CmpF3/SubI/CmpI idiom.
1753 if( cop == Op_CmpI &&
1754 cmp1_op == Op_SubI &&
1755 cmp2_type == TypeInt::ZERO &&
1756 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1757 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1758 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1759 return new BoolNode( ncmp, _test.commute() );
1760 }
1761
1762 // Try to optimize signed integer comparison
1763 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1764
1765 // The transformation below is not valid for either signed or unsigned
1766 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1767 // This transformation can be resurrected when we are able to
1768 // make inferences about the range of values being subtracted from
1769 // (or added to) relative to the wraparound point.
1770 //
1771 // // Remove +/-1's if possible.
1772 // // "X <= Y-1" becomes "X < Y"
1773 // // "X+1 <= Y" becomes "X < Y"
1774 // // "X < Y+1" becomes "X <= Y"
1775 // // "X-1 < Y" becomes "X <= Y"
1776 // // Do not this to compares off of the counted-loop-end. These guys are
1777 // // checking the trip counter and they want to use the post-incremented
1778 // // counter. If they use the PRE-incremented counter, then the counter has
1779 // // to be incremented in a private block on a loop backedge.
1780 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1781 // return NULL;
1782 // #ifndef PRODUCT
1783 // // Do not do this in a wash GVN pass during verification.
1784 // // Gets triggered by too many simple optimizations to be bothered with
1785 // // re-trying it again and again.
1786 // if( !phase->allow_progress() ) return NULL;
1787 // #endif
1788 // // Not valid for unsigned compare because of corner cases in involving zero.
1789 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1790 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1791 // // "0 <=u Y" is always true).
1792 // if( cmp->Opcode() == Op_CmpU ) return NULL;
1793 // int cmp2_op = cmp2->Opcode();
1794 // if( _test._test == BoolTest::le ) {
1795 // if( cmp1_op == Op_AddI &&
1796 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1797 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1798 // else if( cmp2_op == Op_AddI &&
1799 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1800 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1801 // } else if( _test._test == BoolTest::lt ) {
1802 // if( cmp1_op == Op_AddI &&
1803 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1804 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1805 // else if( cmp2_op == Op_AddI &&
1806 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1807 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1808 // }
1809 }
1810
1811 //------------------------------Value------------------------------------------
1812 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1813 // based on local information. If the input is constant, do it.
1814 const Type* BoolNode::Value(PhaseGVN* phase) const {
1815 return _test.cc2logical( phase->type( in(1) ) );
1816 }
1817
1818 #ifndef PRODUCT
1819 //------------------------------dump_spec--------------------------------------
1820 // Dump special per-node info
1821 void BoolNode::dump_spec(outputStream *st) const {
1822 st->print("[");
1823 _test.dump_on(st);
1824 st->print("]");
1825 }
1826
1827 //-------------------------------related---------------------------------------
1828 // A BoolNode's related nodes are all of its data inputs, and all of its
1829 // outputs until control nodes are hit, which are included. In compact
1830 // representation, inputs till level 3 and immediate outputs are included.
1831 void BoolNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1832 if (compact) {
1833 this->collect_nodes(in_rel, 3, false, true);
1834 this->collect_nodes(out_rel, -1, false, false);
1835 } else {
1836 this->collect_nodes_in_all_data(in_rel, false);
1837 this->collect_nodes_out_all_ctrl_boundary(out_rel);
1838 }
1839 }
1840 #endif
1841
1842 //----------------------is_counted_loop_exit_test------------------------------
1843 // Returns true if node is used by a counted loop node.
1844 bool BoolNode::is_counted_loop_exit_test() {
1845 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1846 Node* use = fast_out(i);
1847 if (use->is_CountedLoopEnd()) {
1848 return true;
1849 }
1850 }
1851 return false;
1852 }
1853
1854 //=============================================================================
1855 //------------------------------Value------------------------------------------
1856 const Type* AbsNode::Value(PhaseGVN* phase) const {
1857 const Type* t1 = phase->type(in(1));
1858 if (t1 == Type::TOP) return Type::TOP;
1859
1860 switch (t1->base()) {
1861 case Type::Int: {
1862 const TypeInt* ti = t1->is_int();
1863 if (ti->is_con()) {
1864 return TypeInt::make(uabs(ti->get_con()));
1865 }
1866 break;
1867 }
1868 case Type::Long: {
1869 const TypeLong* tl = t1->is_long();
1870 if (tl->is_con()) {
1871 return TypeLong::make(uabs(tl->get_con()));
1872 }
1873 break;
1874 }
1875 case Type::FloatCon:
1876 return TypeF::make(abs(t1->getf()));
1877 case Type::DoubleCon:
1878 return TypeD::make(abs(t1->getd()));
1879 default:
1880 break;
1881 }
1882
1883 return bottom_type();
1884 }
1885
1886 //------------------------------Identity----------------------------------------
1887 Node* AbsNode::Identity(PhaseGVN* phase) {
1888 Node* in1 = in(1);
1889 // No need to do abs for non-negative values
1890 if (phase->type(in1)->higher_equal(TypeInt::POS) ||
1891 phase->type(in1)->higher_equal(TypeLong::POS)) {
1892 return in1;
1893 }
1894 // Convert "abs(abs(x))" into "abs(x)"
1895 if (in1->Opcode() == Opcode()) {
1896 return in1;
1897 }
1898 return this;
1899 }
1900
1901 //------------------------------Ideal------------------------------------------
1902 Node* AbsNode::Ideal(PhaseGVN* phase, bool can_reshape) {
1903 Node* in1 = in(1);
1904 // Convert "abs(0-x)" into "abs(x)"
1905 if (in1->is_Sub() && phase->type(in1->in(1))->is_zero_type()) {
1906 set_req_X(1, in1->in(2), phase);
1907 return this;
1908 }
1909 return NULL;
1910 }
1911
1912 //=============================================================================
1913 //------------------------------Value------------------------------------------
1914 // Compute sqrt
1915 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
1916 const Type *t1 = phase->type( in(1) );
1917 if( t1 == Type::TOP ) return Type::TOP;
1918 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1919 double d = t1->getd();
1920 if( d < 0.0 ) return Type::DOUBLE;
1921 return TypeD::make( sqrt( d ) );
1922 }
1923
1924 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
1925 const Type *t1 = phase->type( in(1) );
1926 if( t1 == Type::TOP ) return Type::TOP;
1927 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
1928 float f = t1->getf();
1929 if( f < 0.0f ) return Type::FLOAT;
1930 return TypeF::make( (float)sqrt( (double)f ) );
1931 }