1 /*
2 * Copyright (c) 1997, 2017, 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 "memory/allocation.inline.hpp"
28 #include "opto/addnode.hpp"
29 #include "opto/callnode.hpp"
30 #include "opto/cfgnode.hpp"
31 #include "opto/loopnode.hpp"
32 #include "opto/matcher.hpp"
33 #include "opto/movenode.hpp"
34 #include "opto/mulnode.hpp"
35 #include "opto/opcodes.hpp"
36 #include "opto/phaseX.hpp"
37 #include "opto/subnode.hpp"
38 #include "runtime/sharedRuntime.hpp"
39
40 // Portions of code courtesy of Clifford Click
41
42 // Optimization - Graph Style
43
44 #include "math.h"
45
46 //=============================================================================
47 //------------------------------Identity---------------------------------------
48 // If right input is a constant 0, return the left input.
49 Node* SubNode::Identity(PhaseGVN* phase) {
50 assert(in(1) != this, "Must already have called Value");
51 assert(in(2) != this, "Must already have called Value");
52
53 // Remove double negation
54 const Type *zero = add_id();
55 if( phase->type( in(1) )->higher_equal( zero ) &&
56 in(2)->Opcode() == Opcode() &&
57 phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
58 return in(2)->in(2);
59 }
60
61 // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
62 if( in(1)->Opcode() == Op_AddI ) {
63 if( phase->eqv(in(1)->in(2),in(2)) )
64 return in(1)->in(1);
65 if (phase->eqv(in(1)->in(1),in(2)))
66 return in(1)->in(2);
67
68 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying
69 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes
70 // are originally used, although the optimizer sometimes jiggers things).
71 // This folding through an O2 removes a loop-exit use of a loop-varying
72 // value and generally lowers register pressure in and around the loop.
73 if( in(1)->in(2)->Opcode() == Op_Opaque2 &&
74 phase->eqv(in(1)->in(2)->in(1),in(2)) )
75 return in(1)->in(1);
76 }
77
78 return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
79 }
80
81 //------------------------------Value------------------------------------------
82 // A subtract node differences it's two inputs.
83 const Type* SubNode::Value_common(PhaseTransform *phase) const {
84 const Node* in1 = in(1);
85 const Node* in2 = in(2);
86 // Either input is TOP ==> the result is TOP
87 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
88 if( t1 == Type::TOP ) return Type::TOP;
89 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
90 if( t2 == Type::TOP ) return Type::TOP;
91
92 // Not correct for SubFnode and AddFNode (must check for infinity)
93 // Equal? Subtract is zero
94 if (in1->eqv_uncast(in2)) return add_id();
95
96 // Either input is BOTTOM ==> the result is the local BOTTOM
97 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
98 return bottom_type();
99
100 return NULL;
101 }
102
103 const Type* SubNode::Value(PhaseGVN* phase) const {
104 const Type* t = Value_common(phase);
105 if (t != NULL) {
106 return t;
107 }
108 const Type* t1 = phase->type(in(1));
109 const Type* t2 = phase->type(in(2));
110 return sub(t1,t2); // Local flavor of type subtraction
111
112 }
113
114 //=============================================================================
115
116 //------------------------------Helper function--------------------------------
117 static bool ok_to_convert(Node* inc, Node* iv) {
118 // Do not collapse (x+c0)-y if "+" is a loop increment, because the
119 // "-" is loop invariant and collapsing extends the live-range of "x"
120 // to overlap with the "+", forcing another register to be used in
121 // the loop.
122 // This test will be clearer with '&&' (apply DeMorgan's rule)
123 // but I like the early cutouts that happen here.
124 const PhiNode *phi;
125 if( ( !inc->in(1)->is_Phi() ||
126 !(phi=inc->in(1)->as_Phi()) ||
127 phi->is_copy() ||
128 !phi->region()->is_CountedLoop() ||
129 inc != phi->region()->as_CountedLoop()->incr() )
130 &&
131 // Do not collapse (x+c0)-iv if "iv" is a loop induction variable,
132 // because "x" maybe invariant.
133 ( !iv->is_loop_iv() )
134 ) {
135 return true;
136 } else {
137 return false;
138 }
139 }
140 //------------------------------Ideal------------------------------------------
141 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
142 Node *in1 = in(1);
143 Node *in2 = in(2);
144 uint op1 = in1->Opcode();
145 uint op2 = in2->Opcode();
146
147 #ifdef ASSERT
148 // Check for dead loop
149 if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
150 ( ( op1 == Op_AddI || op1 == Op_SubI ) &&
151 ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
152 phase->eqv( in1->in(1), in1 ) || phase->eqv( in1->in(2), in1 ) ) ) )
153 assert(false, "dead loop in SubINode::Ideal");
154 #endif
155
156 const Type *t2 = phase->type( in2 );
157 if( t2 == Type::TOP ) return NULL;
158 // Convert "x-c0" into "x+ -c0".
159 if( t2->base() == Type::Int ){ // Might be bottom or top...
160 const TypeInt *i = t2->is_int();
161 if( i->is_con() )
162 return new AddINode(in1, phase->intcon(-i->get_con()));
163 }
164
165 // Convert "(x+c0) - y" into (x-y) + c0"
166 // Do not collapse (x+c0)-y if "+" is a loop increment or
167 // if "y" is a loop induction variable.
168 if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
169 const Type *tadd = phase->type( in1->in(2) );
170 if( tadd->singleton() && tadd != Type::TOP ) {
171 Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 ));
172 return new AddINode( sub2, in1->in(2) );
173 }
174 }
175
176
177 // Convert "x - (y+c0)" into "(x-y) - c0"
178 // Need the same check as in above optimization but reversed.
179 if (op2 == Op_AddI && ok_to_convert(in2, in1)) {
180 Node* in21 = in2->in(1);
181 Node* in22 = in2->in(2);
182 const TypeInt* tcon = phase->type(in22)->isa_int();
183 if (tcon != NULL && tcon->is_con()) {
184 Node* sub2 = phase->transform( new SubINode(in1, in21) );
185 Node* neg_c0 = phase->intcon(- tcon->get_con());
186 return new AddINode(sub2, neg_c0);
187 }
188 }
189
190 const Type *t1 = phase->type( in1 );
191 if( t1 == Type::TOP ) return NULL;
192
193 #ifdef ASSERT
194 // Check for dead loop
195 if( ( op2 == Op_AddI || op2 == Op_SubI ) &&
196 ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
197 phase->eqv( in2->in(1), in2 ) || phase->eqv( in2->in(2), in2 ) ) )
198 assert(false, "dead loop in SubINode::Ideal");
199 #endif
200
201 // Convert "x - (x+y)" into "-y"
202 if( op2 == Op_AddI &&
203 phase->eqv( in1, in2->in(1) ) )
204 return new SubINode( phase->intcon(0),in2->in(2));
205 // Convert "(x-y) - x" into "-y"
206 if( op1 == Op_SubI &&
207 phase->eqv( in1->in(1), in2 ) )
208 return new SubINode( phase->intcon(0),in1->in(2));
209 // Convert "x - (y+x)" into "-y"
210 if( op2 == Op_AddI &&
211 phase->eqv( in1, in2->in(2) ) )
212 return new SubINode( phase->intcon(0),in2->in(1));
213
214 // Convert "0 - (x-y)" into "y-x"
215 if( t1 == TypeInt::ZERO && op2 == Op_SubI )
216 return new SubINode( in2->in(2), in2->in(1) );
217
218 // Convert "0 - (x+con)" into "-con-x"
219 jint con;
220 if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
221 (con = in2->in(2)->find_int_con(0)) != 0 )
222 return new SubINode( phase->intcon(-con), in2->in(1) );
223
224 // Convert "(X+A) - (X+B)" into "A - B"
225 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
226 return new SubINode( in1->in(2), in2->in(2) );
227
228 // Convert "(A+X) - (B+X)" into "A - B"
229 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
230 return new SubINode( in1->in(1), in2->in(1) );
231
232 // Convert "(A+X) - (X+B)" into "A - B"
233 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
234 return new SubINode( in1->in(1), in2->in(2) );
235
236 // Convert "(X+A) - (B+X)" into "A - B"
237 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
238 return new SubINode( in1->in(2), in2->in(1) );
239
240 // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
241 // nicer to optimize than subtract.
242 if( op2 == Op_SubI && in2->outcnt() == 1) {
243 Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) );
244 return new SubINode( add1, in2->in(1) );
245 }
246
247 return NULL;
248 }
249
250 //------------------------------sub--------------------------------------------
251 // A subtract node differences it's two inputs.
252 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
253 const TypeInt *r0 = t1->is_int(); // Handy access
254 const TypeInt *r1 = t2->is_int();
255 int32_t lo = java_subtract(r0->_lo, r1->_hi);
256 int32_t hi = java_subtract(r0->_hi, r1->_lo);
257
258 // We next check for 32-bit overflow.
259 // If that happens, we just assume all integers are possible.
260 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
261 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
262 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
263 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
264 return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
265 else // Overflow; assume all integers
266 return TypeInt::INT;
267 }
268
269 //=============================================================================
270 //------------------------------Ideal------------------------------------------
271 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
272 Node *in1 = in(1);
273 Node *in2 = in(2);
274 uint op1 = in1->Opcode();
275 uint op2 = in2->Opcode();
276
277 #ifdef ASSERT
278 // Check for dead loop
279 if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
280 ( ( op1 == Op_AddL || op1 == Op_SubL ) &&
281 ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
282 phase->eqv( in1->in(1), in1 ) || phase->eqv( in1->in(2), in1 ) ) ) )
283 assert(false, "dead loop in SubLNode::Ideal");
284 #endif
285
286 if( phase->type( in2 ) == Type::TOP ) return NULL;
287 const TypeLong *i = phase->type( in2 )->isa_long();
288 // Convert "x-c0" into "x+ -c0".
289 if( i && // Might be bottom or top...
290 i->is_con() )
291 return new AddLNode(in1, phase->longcon(-i->get_con()));
292
293 // Convert "(x+c0) - y" into (x-y) + c0"
294 // Do not collapse (x+c0)-y if "+" is a loop increment or
295 // if "y" is a loop induction variable.
296 if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
297 Node *in11 = in1->in(1);
298 const Type *tadd = phase->type( in1->in(2) );
299 if( tadd->singleton() && tadd != Type::TOP ) {
300 Node *sub2 = phase->transform( new SubLNode( in11, in2 ));
301 return new AddLNode( sub2, in1->in(2) );
302 }
303 }
304
305 // Convert "x - (y+c0)" into "(x-y) - c0"
306 // Need the same check as in above optimization but reversed.
307 if (op2 == Op_AddL && ok_to_convert(in2, in1)) {
308 Node* in21 = in2->in(1);
309 Node* in22 = in2->in(2);
310 const TypeLong* tcon = phase->type(in22)->isa_long();
311 if (tcon != NULL && tcon->is_con()) {
312 Node* sub2 = phase->transform( new SubLNode(in1, in21) );
313 Node* neg_c0 = phase->longcon(- tcon->get_con());
314 return new AddLNode(sub2, neg_c0);
315 }
316 }
317
318 const Type *t1 = phase->type( in1 );
319 if( t1 == Type::TOP ) return NULL;
320
321 #ifdef ASSERT
322 // Check for dead loop
323 if( ( op2 == Op_AddL || op2 == Op_SubL ) &&
324 ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
325 phase->eqv( in2->in(1), in2 ) || phase->eqv( in2->in(2), in2 ) ) )
326 assert(false, "dead loop in SubLNode::Ideal");
327 #endif
328
329 // Convert "x - (x+y)" into "-y"
330 if( op2 == Op_AddL &&
331 phase->eqv( in1, in2->in(1) ) )
332 return new SubLNode( phase->makecon(TypeLong::ZERO), in2->in(2));
333 // Convert "x - (y+x)" into "-y"
334 if( op2 == Op_AddL &&
335 phase->eqv( in1, in2->in(2) ) )
336 return new SubLNode( phase->makecon(TypeLong::ZERO),in2->in(1));
337
338 // Convert "0 - (x-y)" into "y-x"
339 if( phase->type( in1 ) == TypeLong::ZERO && op2 == Op_SubL )
340 return new SubLNode( in2->in(2), in2->in(1) );
341
342 // Convert "(X+A) - (X+B)" into "A - B"
343 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
344 return new SubLNode( in1->in(2), in2->in(2) );
345
346 // Convert "(A+X) - (B+X)" into "A - B"
347 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
348 return new SubLNode( in1->in(1), in2->in(1) );
349
350 // Convert "A-(B-C)" into (A+C)-B"
351 if( op2 == Op_SubL && in2->outcnt() == 1) {
352 Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) );
353 return new SubLNode( add1, in2->in(1) );
354 }
355
356 return NULL;
357 }
358
359 //------------------------------sub--------------------------------------------
360 // A subtract node differences it's two inputs.
361 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
362 const TypeLong *r0 = t1->is_long(); // Handy access
363 const TypeLong *r1 = t2->is_long();
364 jlong lo = java_subtract(r0->_lo, r1->_hi);
365 jlong hi = java_subtract(r0->_hi, r1->_lo);
366
367 // We next check for 32-bit overflow.
368 // If that happens, we just assume all integers are possible.
369 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
370 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
371 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
372 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
373 return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
374 else // Overflow; assume all integers
375 return TypeLong::LONG;
376 }
377
378 //=============================================================================
379 //------------------------------Value------------------------------------------
380 // A subtract node differences its two inputs.
381 const Type* SubFPNode::Value(PhaseGVN* phase) const {
382 const Node* in1 = in(1);
383 const Node* in2 = in(2);
384 // Either input is TOP ==> the result is TOP
385 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
386 if( t1 == Type::TOP ) return Type::TOP;
387 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
388 if( t2 == Type::TOP ) return Type::TOP;
389
390 // if both operands are infinity of same sign, the result is NaN; do
391 // not replace with zero
392 if( (t1->is_finite() && t2->is_finite()) ) {
393 if( phase->eqv(in1, in2) ) return add_id();
394 }
395
396 // Either input is BOTTOM ==> the result is the local BOTTOM
397 const Type *bot = bottom_type();
398 if( (t1 == bot) || (t2 == bot) ||
399 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
400 return bot;
401
402 return sub(t1,t2); // Local flavor of type subtraction
403 }
404
405
406 //=============================================================================
407 //------------------------------Ideal------------------------------------------
408 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
409 const Type *t2 = phase->type( in(2) );
410 // Convert "x-c0" into "x+ -c0".
411 if( t2->base() == Type::FloatCon ) { // Might be bottom or top...
412 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
413 }
414
415 // Not associative because of boundary conditions (infinity)
416 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
417 // Convert "x - (x+y)" into "-y"
418 if( in(2)->is_Add() &&
419 phase->eqv(in(1),in(2)->in(1) ) )
420 return new SubFNode( phase->makecon(TypeF::ZERO),in(2)->in(2));
421 }
422
423 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
424 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
425 //if( phase->type(in(1)) == TypeF::ZERO )
426 //return new (phase->C, 2) NegFNode(in(2));
427
428 return NULL;
429 }
430
431 //------------------------------sub--------------------------------------------
432 // A subtract node differences its two inputs.
433 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
434 // no folding if one of operands is infinity or NaN, do not do constant folding
435 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
436 return TypeF::make( t1->getf() - t2->getf() );
437 }
438 else if( g_isnan(t1->getf()) ) {
439 return t1;
440 }
441 else if( g_isnan(t2->getf()) ) {
442 return t2;
443 }
444 else {
445 return Type::FLOAT;
446 }
447 }
448
449 //=============================================================================
450 //------------------------------Ideal------------------------------------------
451 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
452 const Type *t2 = phase->type( in(2) );
453 // Convert "x-c0" into "x+ -c0".
454 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
455 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
456 }
457
458 // Not associative because of boundary conditions (infinity)
459 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
460 // Convert "x - (x+y)" into "-y"
461 if( in(2)->is_Add() &&
462 phase->eqv(in(1),in(2)->in(1) ) )
463 return new SubDNode( phase->makecon(TypeD::ZERO),in(2)->in(2));
464 }
465
466 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
467 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
468 //if( phase->type(in(1)) == TypeD::ZERO )
469 //return new (phase->C, 2) NegDNode(in(2));
470
471 return NULL;
472 }
473
474 //------------------------------sub--------------------------------------------
475 // A subtract node differences its two inputs.
476 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
477 // no folding if one of operands is infinity or NaN, do not do constant folding
478 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
479 return TypeD::make( t1->getd() - t2->getd() );
480 }
481 else if( g_isnan(t1->getd()) ) {
482 return t1;
483 }
484 else if( g_isnan(t2->getd()) ) {
485 return t2;
486 }
487 else {
488 return Type::DOUBLE;
489 }
490 }
491
492 //=============================================================================
493 //------------------------------Idealize---------------------------------------
494 // Unlike SubNodes, compare must still flatten return value to the
495 // range -1, 0, 1.
496 // And optimizations like those for (X + Y) - X fail if overflow happens.
497 Node* CmpNode::Identity(PhaseGVN* phase) {
498 return this;
499 }
500
501 #ifndef PRODUCT
502 //----------------------------related------------------------------------------
503 // Related nodes of comparison nodes include all data inputs (until hitting a
504 // control boundary) as well as all outputs until and including control nodes
505 // as well as their projections. In compact mode, data inputs till depth 1 and
506 // all outputs till depth 1 are considered.
507 void CmpNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
508 if (compact) {
509 this->collect_nodes(in_rel, 1, false, true);
510 this->collect_nodes(out_rel, -1, false, false);
511 } else {
512 this->collect_nodes_in_all_data(in_rel, false);
513 this->collect_nodes_out_all_ctrl_boundary(out_rel);
514 // Now, find all control nodes in out_rel, and include their projections
515 // and projection targets (if any) in the result.
516 GrowableArray<Node*> proj(Compile::current()->unique());
517 for (GrowableArrayIterator<Node*> it = out_rel->begin(); it != out_rel->end(); ++it) {
518 Node* n = *it;
519 if (n->is_CFG() && !n->is_Proj()) {
520 // Assume projections and projection targets are found at levels 1 and 2.
521 n->collect_nodes(&proj, -2, false, false);
522 for (GrowableArrayIterator<Node*> p = proj.begin(); p != proj.end(); ++p) {
523 out_rel->append_if_missing(*p);
524 }
525 proj.clear();
526 }
527 }
528 }
529 }
530 #endif
531
532 //=============================================================================
533 //------------------------------cmp--------------------------------------------
534 // Simplify a CmpI (compare 2 integers) node, based on local information.
535 // If both inputs are constants, compare them.
536 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
537 const TypeInt *r0 = t1->is_int(); // Handy access
538 const TypeInt *r1 = t2->is_int();
539
540 if( r0->_hi < r1->_lo ) // Range is always low?
541 return TypeInt::CC_LT;
542 else if( r0->_lo > r1->_hi ) // Range is always high?
543 return TypeInt::CC_GT;
544
545 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
546 assert(r0->get_con() == r1->get_con(), "must be equal");
547 return TypeInt::CC_EQ; // Equal results.
548 } else if( r0->_hi == r1->_lo ) // Range is never high?
549 return TypeInt::CC_LE;
550 else if( r0->_lo == r1->_hi ) // Range is never low?
551 return TypeInt::CC_GE;
552 return TypeInt::CC; // else use worst case results
553 }
554
555 // Simplify a CmpU (compare 2 integers) node, based on local information.
556 // If both inputs are constants, compare them.
557 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
558 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
559
560 // comparing two unsigned ints
561 const TypeInt *r0 = t1->is_int(); // Handy access
562 const TypeInt *r1 = t2->is_int();
563
564 // Current installed version
565 // Compare ranges for non-overlap
566 juint lo0 = r0->_lo;
567 juint hi0 = r0->_hi;
568 juint lo1 = r1->_lo;
569 juint hi1 = r1->_hi;
570
571 // If either one has both negative and positive values,
572 // it therefore contains both 0 and -1, and since [0..-1] is the
573 // full unsigned range, the type must act as an unsigned bottom.
574 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
575 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
576
577 if (bot0 || bot1) {
578 // All unsigned values are LE -1 and GE 0.
579 if (lo0 == 0 && hi0 == 0) {
580 return TypeInt::CC_LE; // 0 <= bot
581 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
582 return TypeInt::CC_GE; // -1 >= bot
583 } else if (lo1 == 0 && hi1 == 0) {
584 return TypeInt::CC_GE; // bot >= 0
585 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
586 return TypeInt::CC_LE; // bot <= -1
587 }
588 } else {
589 // We can use ranges of the form [lo..hi] if signs are the same.
590 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
591 // results are reversed, '-' > '+' for unsigned compare
592 if (hi0 < lo1) {
593 return TypeInt::CC_LT; // smaller
594 } else if (lo0 > hi1) {
595 return TypeInt::CC_GT; // greater
596 } else if (hi0 == lo1 && lo0 == hi1) {
597 return TypeInt::CC_EQ; // Equal results
598 } else if (lo0 >= hi1) {
599 return TypeInt::CC_GE;
600 } else if (hi0 <= lo1) {
601 // Check for special case in Hashtable::get. (See below.)
602 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
603 return TypeInt::CC_LT;
604 return TypeInt::CC_LE;
605 }
606 }
607 // Check for special case in Hashtable::get - the hash index is
608 // mod'ed to the table size so the following range check is useless.
609 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
610 // to be positive.
611 // (This is a gross hack, since the sub method never
612 // looks at the structure of the node in any other case.)
613 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
614 return TypeInt::CC_LT;
615 return TypeInt::CC; // else use worst case results
616 }
617
618 const Type* CmpUNode::Value(PhaseGVN* phase) const {
619 const Type* t = SubNode::Value_common(phase);
620 if (t != NULL) {
621 return t;
622 }
623 const Node* in1 = in(1);
624 const Node* in2 = in(2);
625 const Type* t1 = phase->type(in1);
626 const Type* t2 = phase->type(in2);
627 assert(t1->isa_int(), "CmpU has only Int type inputs");
628 if (t2 == TypeInt::INT) { // Compare to bottom?
629 return bottom_type();
630 }
631 uint in1_op = in1->Opcode();
632 if (in1_op == Op_AddI || in1_op == Op_SubI) {
633 // The problem rise when result of AddI(SubI) may overflow
634 // signed integer value. Let say the input type is
635 // [256, maxint] then +128 will create 2 ranges due to
636 // overflow: [minint, minint+127] and [384, maxint].
637 // But C2 type system keep only 1 type range and as result
638 // it use general [minint, maxint] for this case which we
639 // can't optimize.
640 //
641 // Make 2 separate type ranges based on types of AddI(SubI) inputs
642 // and compare results of their compare. If results are the same
643 // CmpU node can be optimized.
644 const Node* in11 = in1->in(1);
645 const Node* in12 = in1->in(2);
646 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
647 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
648 // Skip cases when input types are top or bottom.
649 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
650 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
651 const TypeInt *r0 = t11->is_int();
652 const TypeInt *r1 = t12->is_int();
653 jlong lo_r0 = r0->_lo;
654 jlong hi_r0 = r0->_hi;
655 jlong lo_r1 = r1->_lo;
656 jlong hi_r1 = r1->_hi;
657 if (in1_op == Op_SubI) {
658 jlong tmp = hi_r1;
659 hi_r1 = -lo_r1;
660 lo_r1 = -tmp;
661 // Note, for substructing [minint,x] type range
662 // long arithmetic provides correct overflow answer.
663 // The confusion come from the fact that in 32-bit
664 // -minint == minint but in 64-bit -minint == maxint+1.
665 }
666 jlong lo_long = lo_r0 + lo_r1;
667 jlong hi_long = hi_r0 + hi_r1;
668 int lo_tr1 = min_jint;
669 int hi_tr1 = (int)hi_long;
670 int lo_tr2 = (int)lo_long;
671 int hi_tr2 = max_jint;
672 bool underflow = lo_long != (jlong)lo_tr2;
673 bool overflow = hi_long != (jlong)hi_tr1;
674 // Use sub(t1, t2) when there is no overflow (one type range)
675 // or when both overflow and underflow (too complex).
676 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
677 // Overflow only on one boundary, compare 2 separate type ranges.
678 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
679 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
680 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
681 const Type* cmp1 = sub(tr1, t2);
682 const Type* cmp2 = sub(tr2, t2);
683 if (cmp1 == cmp2) {
684 return cmp1; // Hit!
685 }
686 }
687 }
688 }
689
690 return sub(t1, t2); // Local flavor of type subtraction
691 }
692
693 bool CmpUNode::is_index_range_check() const {
694 // Check for the "(X ModI Y) CmpU Y" shape
695 return (in(1)->Opcode() == Op_ModI &&
696 in(1)->in(2)->eqv_uncast(in(2)));
697 }
698
699 //------------------------------Idealize---------------------------------------
700 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
701 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
702 switch (in(1)->Opcode()) {
703 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
704 return new CmpLNode(in(1)->in(1),in(1)->in(2));
705 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
706 return new CmpFNode(in(1)->in(1),in(1)->in(2));
707 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
708 return new CmpDNode(in(1)->in(1),in(1)->in(2));
709 //case Op_SubI:
710 // If (x - y) cannot overflow, then ((x - y) <?> 0)
711 // can be turned into (x <?> y).
712 // This is handled (with more general cases) by Ideal_sub_algebra.
713 }
714 }
715 return NULL; // No change
716 }
717
718 //------------------------------Ideal------------------------------------------
719 Node* CmpLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
720 if (in(1)->Opcode() == Op_OrL && in(1)->in(1)->Opcode() == Op_CastP2X && in(1)->in(2)->Opcode() == Op_CastP2X) {
721 Node* a = in(1)->in(1)->in(1);
722 Node* b = in(1)->in(2)->in(1);
723 const Type* ta = phase->type(a);
724 const Type* tb = phase->type(b);
725 if (ta->is_zero_type() || tb->is_zero_type()) {
726 if (Verbose) tty->print_cr("\n# NULL CHECK (CmpLNode::Ideal)");
727 return new CmpPNode(a, b);
728 } else if (!TypePtr::NULL_PTR->higher_equal(ta) || !TypePtr::NULL_PTR->higher_equal(tb)) {
729 // One operand is never NULL, emit constant false
730 if (Verbose) tty->print_cr("\n# CONSTANT FALSE (CmpLNode::Ideal)");
731 set_req(1, phase->longcon(0));
732 set_req(2, phase->longcon(1));
733 return this;
734 }
735 }
736 return NULL;
737 }
738
739
740 //=============================================================================
741 // Simplify a CmpL (compare 2 longs ) node, based on local information.
742 // If both inputs are constants, compare them.
743 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
744 const TypeLong *r0 = t1->is_long(); // Handy access
745 const TypeLong *r1 = t2->is_long();
746
747 if( r0->_hi < r1->_lo ) // Range is always low?
748 return TypeInt::CC_LT;
749 else if( r0->_lo > r1->_hi ) // Range is always high?
750 return TypeInt::CC_GT;
751
752 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
753 assert(r0->get_con() == r1->get_con(), "must be equal");
754 return TypeInt::CC_EQ; // Equal results.
755 } else if( r0->_hi == r1->_lo ) // Range is never high?
756 return TypeInt::CC_LE;
757 else if( r0->_lo == r1->_hi ) // Range is never low?
758 return TypeInt::CC_GE;
759 return TypeInt::CC; // else use worst case results
760 }
761
762
763 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
764 // If both inputs are constants, compare them.
765 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
766 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
767
768 // comparing two unsigned longs
769 const TypeLong* r0 = t1->is_long(); // Handy access
770 const TypeLong* r1 = t2->is_long();
771
772 // Current installed version
773 // Compare ranges for non-overlap
774 julong lo0 = r0->_lo;
775 julong hi0 = r0->_hi;
776 julong lo1 = r1->_lo;
777 julong hi1 = r1->_hi;
778
779 // If either one has both negative and positive values,
780 // it therefore contains both 0 and -1, and since [0..-1] is the
781 // full unsigned range, the type must act as an unsigned bottom.
782 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
783 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
784
785 if (bot0 || bot1) {
786 // All unsigned values are LE -1 and GE 0.
787 if (lo0 == 0 && hi0 == 0) {
788 return TypeInt::CC_LE; // 0 <= bot
789 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
790 return TypeInt::CC_GE; // -1 >= bot
791 } else if (lo1 == 0 && hi1 == 0) {
792 return TypeInt::CC_GE; // bot >= 0
793 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
794 return TypeInt::CC_LE; // bot <= -1
795 }
796 } else {
797 // We can use ranges of the form [lo..hi] if signs are the same.
798 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
799 // results are reversed, '-' > '+' for unsigned compare
800 if (hi0 < lo1) {
801 return TypeInt::CC_LT; // smaller
802 } else if (lo0 > hi1) {
803 return TypeInt::CC_GT; // greater
804 } else if (hi0 == lo1 && lo0 == hi1) {
805 return TypeInt::CC_EQ; // Equal results
806 } else if (lo0 >= hi1) {
807 return TypeInt::CC_GE;
808 } else if (hi0 <= lo1) {
809 return TypeInt::CC_LE;
810 }
811 }
812
813 return TypeInt::CC; // else use worst case results
814 }
815
816 //=============================================================================
817 //------------------------------sub--------------------------------------------
818 // Simplify an CmpP (compare 2 pointers) node, based on local information.
819 // If both inputs are constants, compare them.
820 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
821 const TypePtr *r0 = t1->is_ptr(); // Handy access
822 const TypePtr *r1 = t2->is_ptr();
823
824 // Undefined inputs makes for an undefined result
825 if( TypePtr::above_centerline(r0->_ptr) ||
826 TypePtr::above_centerline(r1->_ptr) )
827 return Type::TOP;
828
829 if (r0 == r1 && r0->singleton()) {
830 // Equal pointer constants (klasses, nulls, etc.)
831 return TypeInt::CC_EQ;
832 }
833
834 // See if it is 2 unrelated classes.
835 const TypeOopPtr* p0 = r0->isa_oopptr();
836 const TypeOopPtr* p1 = r1->isa_oopptr();
837 if (p0 && p1) {
838 Node* in1 = in(1)->uncast();
839 Node* in2 = in(2)->uncast();
840 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
841 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
842 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
843 return TypeInt::CC_GT; // different pointers
844 }
845 ciKlass* klass0 = p0->klass();
846 bool xklass0 = p0->klass_is_exact();
847 ciKlass* klass1 = p1->klass();
848 bool xklass1 = p1->klass_is_exact();
849 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
850 if (klass0 && klass1 &&
851 kps != 1 && // both or neither are klass pointers
852 klass0->is_loaded() && !klass0->is_interface() && // do not trust interfaces
853 klass1->is_loaded() && !klass1->is_interface() &&
854 (!klass0->is_obj_array_klass() ||
855 !klass0->as_obj_array_klass()->base_element_klass()->is_interface()) &&
856 (!klass1->is_obj_array_klass() ||
857 !klass1->as_obj_array_klass()->base_element_klass()->is_interface())) {
858 bool unrelated_classes = false;
859 // See if neither subclasses the other, or if the class on top
860 // is precise. In either of these cases, the compare is known
861 // to fail if at least one of the pointers is provably not null.
862 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
863 // Do nothing; we know nothing for imprecise types
864 } else if (klass0->is_subtype_of(klass1)) {
865 // If klass1's type is PRECISE, then classes are unrelated.
866 unrelated_classes = xklass1;
867 } else if (klass1->is_subtype_of(klass0)) {
868 // If klass0's type is PRECISE, then classes are unrelated.
869 unrelated_classes = xklass0;
870 } else { // Neither subtypes the other
871 unrelated_classes = true;
872 }
873 if (unrelated_classes) {
874 // The oops classes are known to be unrelated. If the joined PTRs of
875 // two oops is not Null and not Bottom, then we are sure that one
876 // of the two oops is non-null, and the comparison will always fail.
877 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
878 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
879 return TypeInt::CC_GT;
880 }
881 }
882 }
883 }
884
885 // Known constants can be compared exactly
886 // Null can be distinguished from any NotNull pointers
887 // Unknown inputs makes an unknown result
888 if( r0->singleton() ) {
889 intptr_t bits0 = r0->get_con();
890 if( r1->singleton() )
891 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
892 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
893 } else if( r1->singleton() ) {
894 intptr_t bits1 = r1->get_con();
895 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
896 } else
897 return TypeInt::CC;
898 }
899
900 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
901 // Return the klass node for (indirect load from OopHandle)
902 // LoadP(LoadP(AddP(foo:Klass, #java_mirror)))
903 // or NULL if not matching.
904 if (n->Opcode() != Op_LoadP) return NULL;
905
906 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
907 if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
908
909 Node* adr = n->in(MemNode::Address);
910 // First load from OopHandle
911 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return NULL;
912 adr = adr->in(MemNode::Address);
913
914 intptr_t off = 0;
915 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
916 if (k == NULL) return NULL;
917 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
918 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return NULL;
919
920 // We've found the klass node of a Java mirror load.
921 return k;
922 }
923
924 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
925 // for ConP(Foo.class) return ConP(Foo.klass)
926 // otherwise return NULL
927 if (!n->is_Con()) return NULL;
928
929 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
930 if (!tp) return NULL;
931
932 ciType* mirror_type = tp->java_mirror_type();
933 // TypeInstPtr::java_mirror_type() returns non-NULL for compile-
934 // time Class constants only.
935 if (!mirror_type) return NULL;
936
937 // x.getClass() == int.class can never be true (for all primitive types)
938 // Return a ConP(NULL) node for this case.
939 if (mirror_type->is_classless()) {
940 return phase->makecon(TypePtr::NULL_PTR);
941 }
942
943 // return the ConP(Foo.klass)
944 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
945 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass()));
946 }
947
948 //------------------------------Ideal------------------------------------------
949 // Normalize comparisons between Java mirror loads to compare the klass instead.
950 //
951 // Also check for the case of comparing an unknown klass loaded from the primary
952 // super-type array vs a known klass with no subtypes. This amounts to
953 // checking to see an unknown klass subtypes a known klass with no subtypes;
954 // this only happens on an exact match. We can shorten this test by 1 load.
955 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
956 Node* pert = has_perturbed_operand();
957 if (pert != NULL) {
958 // Optimize new acmp
959 Node* a = pert->in(AddPNode::Base); // unperturbed a
960 Node* b = in(2);
961 Node* cmp = phase->C->optimize_acmp(phase, a, b);
962 if (cmp != NULL) {
963 return cmp;
964 }
965 if ( TypePtr::NULL_PTR->higher_equal(phase->type(a)) &&
966 !TypePtr::NULL_PTR->higher_equal(phase->type(b))) {
967 // Operand 'b' is never null, swap operands to avoid null check
968 Node* is_value = phase->C->load_is_value_bit(phase, b);
969 set_req(1, phase->transform(new AddPNode(b, b, is_value)));
970 set_req(2, a);
971 return this;
972 }
973 } else {
974 // Optimize old acmp with value type operands
975 const TypeInstPtr* ta = phase->type(in(1))->isa_instptr();
976 const TypeInstPtr* tb = phase->type(in(2))->isa_instptr();
977 if (((ta != NULL && ta->is_loaded() && ta->is_value_based()) || (tb != NULL && tb->is_loaded() && tb->is_value_based())) &&
978 (!TypePtr::NULL_PTR->higher_equal(phase->type(in(1))) || !TypePtr::NULL_PTR->higher_equal(phase->type(in(2))))) {
979 // One operand is a value type and one operand is never null, fold to constant false
980 if (Verbose) tty->print_cr("\n# CONSTANT FALSE");
981 return new CmpINode(phase->intcon(0), phase->intcon(1));
982 }
983 }
984
985 // Normalize comparisons between Java mirrors into comparisons of the low-
986 // level klass, where a dependent load could be shortened.
987 //
988 // The new pattern has a nice effect of matching the same pattern used in the
989 // fast path of instanceof/checkcast/Class.isInstance(), which allows
990 // redundant exact type check be optimized away by GVN.
991 // For example, in
992 // if (x.getClass() == Foo.class) {
993 // Foo foo = (Foo) x;
994 // // ... use a ...
995 // }
996 // a CmpPNode could be shared between if_acmpne and checkcast
997 {
998 Node* k1 = isa_java_mirror_load(phase, in(1));
999 Node* k2 = isa_java_mirror_load(phase, in(2));
1000 Node* conk2 = isa_const_java_mirror(phase, in(2));
1001
1002 if (k1 && (k2 || conk2)) {
1003 Node* lhs = k1;
1004 Node* rhs = (k2 != NULL) ? k2 : conk2;
1005 this->set_req(1, lhs);
1006 this->set_req(2, rhs);
1007 return this;
1008 }
1009 }
1010
1011 // Constant pointer on right?
1012 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1013 if (t2 == NULL || !t2->klass_is_exact())
1014 return NULL;
1015 // Get the constant klass we are comparing to.
1016 ciKlass* superklass = t2->klass();
1017
1018 // Now check for LoadKlass on left.
1019 Node* ldk1 = in(1);
1020 if (ldk1->is_DecodeNKlass()) {
1021 ldk1 = ldk1->in(1);
1022 if (ldk1->Opcode() != Op_LoadNKlass )
1023 return NULL;
1024 } else if (ldk1->Opcode() != Op_LoadKlass )
1025 return NULL;
1026 // Take apart the address of the LoadKlass:
1027 Node* adr1 = ldk1->in(MemNode::Address);
1028 intptr_t con2 = 0;
1029 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1030 if (ldk2 == NULL)
1031 return NULL;
1032 if (con2 == oopDesc::klass_offset_in_bytes()) {
1033 // We are inspecting an object's concrete class.
1034 // Short-circuit the check if the query is abstract.
1035 if (superklass->is_interface() ||
1036 superklass->is_abstract()) {
1037 // Make it come out always false:
1038 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1039 return this;
1040 }
1041 }
1042
1043 // Check for a LoadKlass from primary supertype array.
1044 // Any nested loadklass from loadklass+con must be from the p.s. array.
1045 if (ldk2->is_DecodeNKlass()) {
1046 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1047 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1048 return NULL;
1049 } else if (ldk2->Opcode() != Op_LoadKlass)
1050 return NULL;
1051
1052 // Verify that we understand the situation
1053 if (con2 != (intptr_t) superklass->super_check_offset())
1054 return NULL; // Might be element-klass loading from array klass
1055
1056 // If 'superklass' has no subklasses and is not an interface, then we are
1057 // assured that the only input which will pass the type check is
1058 // 'superklass' itself.
1059 //
1060 // We could be more liberal here, and allow the optimization on interfaces
1061 // which have a single implementor. This would require us to increase the
1062 // expressiveness of the add_dependency() mechanism.
1063 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1064
1065 // Object arrays must have their base element have no subtypes
1066 while (superklass->is_obj_array_klass()) {
1067 ciType* elem = superklass->as_obj_array_klass()->element_type();
1068 superklass = elem->as_klass();
1069 }
1070 if (superklass->is_instance_klass()) {
1071 ciInstanceKlass* ik = superklass->as_instance_klass();
1072 if (ik->has_subklass() || ik->is_interface()) return NULL;
1073 // Add a dependency if there is a chance that a subclass will be added later.
1074 if (!ik->is_final()) {
1075 phase->C->dependencies()->assert_leaf_type(ik);
1076 }
1077 }
1078
1079 // Bypass the dependent load, and compare directly
1080 this->set_req(1,ldk2);
1081
1082 return this;
1083 }
1084
1085 // Checks if one operand is perturbed and returns it
1086 Node* CmpPNode::has_perturbed_operand() const {
1087 // We always perturbe the first operand
1088 AddPNode* addP = in(1)->isa_AddP();
1089 if (addP != NULL) {
1090 Node* base = addP->in(AddPNode::Base);
1091 if (base->is_top()) {
1092 // RawPtr comparison
1093 return NULL;
1094 }
1095 assert(UseNewAcmp, "unexpected perturbed oop");
1096 return in(1);
1097 }
1098 return NULL;
1099 }
1100
1101 //=============================================================================
1102 //------------------------------sub--------------------------------------------
1103 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1104 // If both inputs are constants, compare them.
1105 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1106 const TypePtr *r0 = t1->make_ptr(); // Handy access
1107 const TypePtr *r1 = t2->make_ptr();
1108
1109 // Undefined inputs makes for an undefined result
1110 if ((r0 == NULL) || (r1 == NULL) ||
1111 TypePtr::above_centerline(r0->_ptr) ||
1112 TypePtr::above_centerline(r1->_ptr)) {
1113 return Type::TOP;
1114 }
1115 if (r0 == r1 && r0->singleton()) {
1116 // Equal pointer constants (klasses, nulls, etc.)
1117 return TypeInt::CC_EQ;
1118 }
1119
1120 // See if it is 2 unrelated classes.
1121 const TypeOopPtr* p0 = r0->isa_oopptr();
1122 const TypeOopPtr* p1 = r1->isa_oopptr();
1123 if (p0 && p1) {
1124 ciKlass* klass0 = p0->klass();
1125 bool xklass0 = p0->klass_is_exact();
1126 ciKlass* klass1 = p1->klass();
1127 bool xklass1 = p1->klass_is_exact();
1128 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
1129 if (klass0 && klass1 &&
1130 kps != 1 && // both or neither are klass pointers
1131 !klass0->is_interface() && // do not trust interfaces
1132 !klass1->is_interface()) {
1133 bool unrelated_classes = false;
1134 // See if neither subclasses the other, or if the class on top
1135 // is precise. In either of these cases, the compare is known
1136 // to fail if at least one of the pointers is provably not null.
1137 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
1138 // Do nothing; we know nothing for imprecise types
1139 } else if (klass0->is_subtype_of(klass1)) {
1140 // If klass1's type is PRECISE, then classes are unrelated.
1141 unrelated_classes = xklass1;
1142 } else if (klass1->is_subtype_of(klass0)) {
1143 // If klass0's type is PRECISE, then classes are unrelated.
1144 unrelated_classes = xklass0;
1145 } else { // Neither subtypes the other
1146 unrelated_classes = true;
1147 }
1148 if (unrelated_classes) {
1149 // The oops classes are known to be unrelated. If the joined PTRs of
1150 // two oops is not Null and not Bottom, then we are sure that one
1151 // of the two oops is non-null, and the comparison will always fail.
1152 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1153 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1154 return TypeInt::CC_GT;
1155 }
1156 }
1157 }
1158 }
1159
1160 // Known constants can be compared exactly
1161 // Null can be distinguished from any NotNull pointers
1162 // Unknown inputs makes an unknown result
1163 if( r0->singleton() ) {
1164 intptr_t bits0 = r0->get_con();
1165 if( r1->singleton() )
1166 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1167 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1168 } else if( r1->singleton() ) {
1169 intptr_t bits1 = r1->get_con();
1170 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1171 } else
1172 return TypeInt::CC;
1173 }
1174
1175 //------------------------------Ideal------------------------------------------
1176 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1177 return NULL;
1178 }
1179
1180 //=============================================================================
1181 //------------------------------Value------------------------------------------
1182 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1183 // If both inputs are constants, compare them.
1184 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1185 const Node* in1 = in(1);
1186 const Node* in2 = in(2);
1187 // Either input is TOP ==> the result is TOP
1188 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1189 if( t1 == Type::TOP ) return Type::TOP;
1190 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1191 if( t2 == Type::TOP ) return Type::TOP;
1192
1193 // Not constants? Don't know squat - even if they are the same
1194 // value! If they are NaN's they compare to LT instead of EQ.
1195 const TypeF *tf1 = t1->isa_float_constant();
1196 const TypeF *tf2 = t2->isa_float_constant();
1197 if( !tf1 || !tf2 ) return TypeInt::CC;
1198
1199 // This implements the Java bytecode fcmpl, so unordered returns -1.
1200 if( tf1->is_nan() || tf2->is_nan() )
1201 return TypeInt::CC_LT;
1202
1203 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1204 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1205 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1206 return TypeInt::CC_EQ;
1207 }
1208
1209
1210 //=============================================================================
1211 //------------------------------Value------------------------------------------
1212 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1213 // If both inputs are constants, compare them.
1214 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1215 const Node* in1 = in(1);
1216 const Node* in2 = in(2);
1217 // Either input is TOP ==> the result is TOP
1218 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1219 if( t1 == Type::TOP ) return Type::TOP;
1220 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1221 if( t2 == Type::TOP ) return Type::TOP;
1222
1223 // Not constants? Don't know squat - even if they are the same
1224 // value! If they are NaN's they compare to LT instead of EQ.
1225 const TypeD *td1 = t1->isa_double_constant();
1226 const TypeD *td2 = t2->isa_double_constant();
1227 if( !td1 || !td2 ) return TypeInt::CC;
1228
1229 // This implements the Java bytecode dcmpl, so unordered returns -1.
1230 if( td1->is_nan() || td2->is_nan() )
1231 return TypeInt::CC_LT;
1232
1233 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1234 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1235 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1236 return TypeInt::CC_EQ;
1237 }
1238
1239 //------------------------------Ideal------------------------------------------
1240 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1241 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1242 // Change (CMPD (F2D (float)) (ConD value))
1243 // To (CMPF (float) (ConF value))
1244 // Valid when 'value' does not lose precision as a float.
1245 // Benefits: eliminates conversion, does not require 24-bit mode
1246
1247 // NaNs prevent commuting operands. This transform works regardless of the
1248 // order of ConD and ConvF2D inputs by preserving the original order.
1249 int idx_f2d = 1; // ConvF2D on left side?
1250 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1251 idx_f2d = 2; // No, swap to check for reversed args
1252 int idx_con = 3-idx_f2d; // Check for the constant on other input
1253
1254 if( ConvertCmpD2CmpF &&
1255 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1256 in(idx_con)->Opcode() == Op_ConD ) {
1257 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1258 double t2_value_as_double = t2->_d;
1259 float t2_value_as_float = (float)t2_value_as_double;
1260 if( t2_value_as_double == (double)t2_value_as_float ) {
1261 // Test value can be represented as a float
1262 // Eliminate the conversion to double and create new comparison
1263 Node *new_in1 = in(idx_f2d)->in(1);
1264 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1265 if( idx_f2d != 1 ) { // Must flip args to match original order
1266 Node *tmp = new_in1;
1267 new_in1 = new_in2;
1268 new_in2 = tmp;
1269 }
1270 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1271 ? new CmpF3Node( new_in1, new_in2 )
1272 : new CmpFNode ( new_in1, new_in2 ) ;
1273 return new_cmp; // Changed to CmpFNode
1274 }
1275 // Testing value required the precision of a double
1276 }
1277 return NULL; // No change
1278 }
1279
1280
1281 //=============================================================================
1282 //------------------------------cc2logical-------------------------------------
1283 // Convert a condition code type to a logical type
1284 const Type *BoolTest::cc2logical( const Type *CC ) const {
1285 if( CC == Type::TOP ) return Type::TOP;
1286 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1287 const TypeInt *ti = CC->is_int();
1288 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1289 // Match low order 2 bits
1290 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1291 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1292 return TypeInt::make(tmp); // Boolean result
1293 }
1294
1295 if( CC == TypeInt::CC_GE ) {
1296 if( _test == ge ) return TypeInt::ONE;
1297 if( _test == lt ) return TypeInt::ZERO;
1298 }
1299 if( CC == TypeInt::CC_LE ) {
1300 if( _test == le ) return TypeInt::ONE;
1301 if( _test == gt ) return TypeInt::ZERO;
1302 }
1303
1304 return TypeInt::BOOL;
1305 }
1306
1307 //------------------------------dump_spec-------------------------------------
1308 // Print special per-node info
1309 void BoolTest::dump_on(outputStream *st) const {
1310 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1311 st->print("%s", msg[_test]);
1312 }
1313
1314 //=============================================================================
1315 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1316 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1317
1318 //------------------------------operator==-------------------------------------
1319 uint BoolNode::cmp( const Node &n ) const {
1320 const BoolNode *b = (const BoolNode *)&n; // Cast up
1321 return (_test._test == b->_test._test);
1322 }
1323
1324 //-------------------------------make_predicate--------------------------------
1325 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1326 if (test_value->is_Con()) return test_value;
1327 if (test_value->is_Bool()) return test_value;
1328 if (test_value->is_CMove() &&
1329 test_value->in(CMoveNode::Condition)->is_Bool()) {
1330 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1331 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1332 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1333 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1334 return bol;
1335 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1336 return phase->transform( bol->negate(phase) );
1337 }
1338 // Else fall through. The CMove gets in the way of the test.
1339 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1340 }
1341 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1342 cmp = phase->transform(cmp);
1343 Node* bol = new BoolNode(cmp, BoolTest::ne);
1344 return phase->transform(bol);
1345 }
1346
1347 //--------------------------------as_int_value---------------------------------
1348 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1349 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1350 Node* cmov = CMoveNode::make(NULL, this,
1351 phase->intcon(0), phase->intcon(1),
1352 TypeInt::BOOL);
1353 return phase->transform(cmov);
1354 }
1355
1356 //----------------------------------negate-------------------------------------
1357 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1358 return new BoolNode(in(1), _test.negate());
1359 }
1360
1361 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1362 // overflows and we can prove that C is not in the two resulting ranges.
1363 // This optimization is similar to the one performed by CmpUNode::Value().
1364 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1365 int cmp1_op, const TypeInt* cmp2_type) {
1366 // Only optimize eq/ne integer comparison of add/sub
1367 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1368 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1369 // Skip cases were inputs of add/sub are not integers or of bottom type
1370 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1371 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1372 if ((r0 != NULL) && (r0 != TypeInt::INT) &&
1373 (r1 != NULL) && (r1 != TypeInt::INT) &&
1374 (cmp2_type != TypeInt::INT)) {
1375 // Compute exact (long) type range of add/sub result
1376 jlong lo_long = r0->_lo;
1377 jlong hi_long = r0->_hi;
1378 if (cmp1_op == Op_AddI) {
1379 lo_long += r1->_lo;
1380 hi_long += r1->_hi;
1381 } else {
1382 lo_long -= r1->_hi;
1383 hi_long -= r1->_lo;
1384 }
1385 // Check for over-/underflow by casting to integer
1386 int lo_int = (int)lo_long;
1387 int hi_int = (int)hi_long;
1388 bool underflow = lo_long != (jlong)lo_int;
1389 bool overflow = hi_long != (jlong)hi_int;
1390 if ((underflow != overflow) && (hi_int < lo_int)) {
1391 // Overflow on one boundary, compute resulting type ranges:
1392 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1393 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1394 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1395 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1396 // Compare second input of cmp to both type ranges
1397 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1398 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1399 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1400 // The result of the add/sub will never equal cmp2. Replace BoolNode
1401 // by false (0) if it tests for equality and by true (1) otherwise.
1402 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1403 }
1404 }
1405 }
1406 }
1407 return NULL;
1408 }
1409
1410 //------------------------------Ideal------------------------------------------
1411 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1412 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1413 // This moves the constant to the right. Helps value-numbering.
1414 Node *cmp = in(1);
1415 if( !cmp->is_Sub() ) return NULL;
1416 int cop = cmp->Opcode();
1417 if( cop == Op_FastLock || cop == Op_FastUnlock) return NULL;
1418 Node *cmp1 = cmp->in(1);
1419 Node *cmp2 = cmp->in(2);
1420 if( !cmp1 ) return NULL;
1421
1422 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1423 return NULL;
1424 }
1425
1426 // Constant on left?
1427 Node *con = cmp1;
1428 uint op2 = cmp2->Opcode();
1429 // Move constants to the right of compare's to canonicalize.
1430 // Do not muck with Opaque1 nodes, as this indicates a loop
1431 // guard that cannot change shape.
1432 if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 &&
1433 // Because of NaN's, CmpD and CmpF are not commutative
1434 cop != Op_CmpD && cop != Op_CmpF &&
1435 // Protect against swapping inputs to a compare when it is used by a
1436 // counted loop exit, which requires maintaining the loop-limit as in(2)
1437 !is_counted_loop_exit_test() ) {
1438 // Ok, commute the constant to the right of the cmp node.
1439 // Clone the Node, getting a new Node of the same class
1440 cmp = cmp->clone();
1441 // Swap inputs to the clone
1442 cmp->swap_edges(1, 2);
1443 cmp = phase->transform( cmp );
1444 return new BoolNode( cmp, _test.commute() );
1445 }
1446
1447 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1448 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1449 // test instead.
1450 int cmp1_op = cmp1->Opcode();
1451 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1452 if (cmp2_type == NULL) return NULL;
1453 Node* j_xor = cmp1;
1454 if( cmp2_type == TypeInt::ZERO &&
1455 cmp1_op == Op_XorI &&
1456 j_xor->in(1) != j_xor && // An xor of itself is dead
1457 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1458 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1459 (_test._test == BoolTest::eq ||
1460 _test._test == BoolTest::ne) ) {
1461 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1462 return new BoolNode( ncmp, _test.negate() );
1463 }
1464
1465 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1466 // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1467 if (cop == Op_CmpU &&
1468 cmp1->Opcode() == Op_AndI) {
1469 Node* bound = NULL;
1470 if (_test._test == BoolTest::le) {
1471 bound = cmp2;
1472 } else if (_test._test == BoolTest::lt &&
1473 cmp2->Opcode() == Op_AddI &&
1474 cmp2->in(2)->find_int_con(0) == 1) {
1475 bound = cmp2->in(1);
1476 }
1477 if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1478 return ConINode::make(1);
1479 }
1480 }
1481
1482 // Change ((x & (m - 1)) u< m) into (m > 0)
1483 // This is the off-by-one variant of the above
1484 if (cop == Op_CmpU &&
1485 _test._test == BoolTest::lt &&
1486 cmp1->Opcode() == Op_AndI) {
1487 Node* l = cmp1->in(1);
1488 Node* r = cmp1->in(2);
1489 for (int repeat = 0; repeat < 2; repeat++) {
1490 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1491 r->in(1) == cmp2;
1492 if (match) {
1493 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1494 // but to be compatible with the array range check pattern, use (arraylength u> 0)
1495 Node* ncmp = cmp2->Opcode() == Op_LoadRange
1496 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1497 : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1498 return new BoolNode(ncmp, BoolTest::gt);
1499 } else {
1500 // commute and try again
1501 l = cmp1->in(2);
1502 r = cmp1->in(1);
1503 }
1504 }
1505 }
1506
1507 // Change (arraylength <= 0) or (arraylength == 0)
1508 // into (arraylength u<= 0)
1509 // Also change (arraylength != 0) into (arraylength u> 0)
1510 // The latter version matches the code pattern generated for
1511 // array range checks, which will more likely be optimized later.
1512 if (cop == Op_CmpI &&
1513 cmp1->Opcode() == Op_LoadRange &&
1514 cmp2->find_int_con(-1) == 0) {
1515 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1516 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1517 return new BoolNode(ncmp, BoolTest::le);
1518 } else if (_test._test == BoolTest::ne) {
1519 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1520 return new BoolNode(ncmp, BoolTest::gt);
1521 }
1522 }
1523
1524 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1525 // This is a standard idiom for branching on a boolean value.
1526 Node *c2b = cmp1;
1527 if( cmp2_type == TypeInt::ZERO &&
1528 cmp1_op == Op_Conv2B &&
1529 (_test._test == BoolTest::eq ||
1530 _test._test == BoolTest::ne) ) {
1531 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1532 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1533 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1534 );
1535 return new BoolNode( ncmp, _test._test );
1536 }
1537
1538 // Comparing a SubI against a zero is equal to comparing the SubI
1539 // arguments directly. This only works for eq and ne comparisons
1540 // due to possible integer overflow.
1541 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1542 (cop == Op_CmpI) &&
1543 (cmp1->Opcode() == Op_SubI) &&
1544 ( cmp2_type == TypeInt::ZERO ) ) {
1545 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1546 return new BoolNode( ncmp, _test._test );
1547 }
1548
1549 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1550 // most general case because negating 0x80000000 does nothing. Needed for
1551 // the CmpF3/SubI/CmpI idiom.
1552 if( cop == Op_CmpI &&
1553 cmp1->Opcode() == Op_SubI &&
1554 cmp2_type == TypeInt::ZERO &&
1555 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1556 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1557 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1558 return new BoolNode( ncmp, _test.commute() );
1559 }
1560
1561 // Try to optimize signed integer comparison
1562 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1563
1564 // The transformation below is not valid for either signed or unsigned
1565 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1566 // This transformation can be resurrected when we are able to
1567 // make inferences about the range of values being subtracted from
1568 // (or added to) relative to the wraparound point.
1569 //
1570 // // Remove +/-1's if possible.
1571 // // "X <= Y-1" becomes "X < Y"
1572 // // "X+1 <= Y" becomes "X < Y"
1573 // // "X < Y+1" becomes "X <= Y"
1574 // // "X-1 < Y" becomes "X <= Y"
1575 // // Do not this to compares off of the counted-loop-end. These guys are
1576 // // checking the trip counter and they want to use the post-incremented
1577 // // counter. If they use the PRE-incremented counter, then the counter has
1578 // // to be incremented in a private block on a loop backedge.
1579 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1580 // return NULL;
1581 // #ifndef PRODUCT
1582 // // Do not do this in a wash GVN pass during verification.
1583 // // Gets triggered by too many simple optimizations to be bothered with
1584 // // re-trying it again and again.
1585 // if( !phase->allow_progress() ) return NULL;
1586 // #endif
1587 // // Not valid for unsigned compare because of corner cases in involving zero.
1588 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1589 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1590 // // "0 <=u Y" is always true).
1591 // if( cmp->Opcode() == Op_CmpU ) return NULL;
1592 // int cmp2_op = cmp2->Opcode();
1593 // if( _test._test == BoolTest::le ) {
1594 // if( cmp1_op == Op_AddI &&
1595 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1596 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1597 // else if( cmp2_op == Op_AddI &&
1598 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1599 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1600 // } else if( _test._test == BoolTest::lt ) {
1601 // if( cmp1_op == Op_AddI &&
1602 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1603 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1604 // else if( cmp2_op == Op_AddI &&
1605 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1606 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1607 // }
1608 }
1609
1610 //------------------------------Value------------------------------------------
1611 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1612 // based on local information. If the input is constant, do it.
1613 const Type* BoolNode::Value(PhaseGVN* phase) const {
1614 return _test.cc2logical( phase->type( in(1) ) );
1615 }
1616
1617 #ifndef PRODUCT
1618 //------------------------------dump_spec--------------------------------------
1619 // Dump special per-node info
1620 void BoolNode::dump_spec(outputStream *st) const {
1621 st->print("[");
1622 _test.dump_on(st);
1623 st->print("]");
1624 }
1625
1626 //-------------------------------related---------------------------------------
1627 // A BoolNode's related nodes are all of its data inputs, and all of its
1628 // outputs until control nodes are hit, which are included. In compact
1629 // representation, inputs till level 3 and immediate outputs are included.
1630 void BoolNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1631 if (compact) {
1632 this->collect_nodes(in_rel, 3, false, true);
1633 this->collect_nodes(out_rel, -1, false, false);
1634 } else {
1635 this->collect_nodes_in_all_data(in_rel, false);
1636 this->collect_nodes_out_all_ctrl_boundary(out_rel);
1637 }
1638 }
1639 #endif
1640
1641 //----------------------is_counted_loop_exit_test------------------------------
1642 // Returns true if node is used by a counted loop node.
1643 bool BoolNode::is_counted_loop_exit_test() {
1644 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1645 Node* use = fast_out(i);
1646 if (use->is_CountedLoopEnd()) {
1647 return true;
1648 }
1649 }
1650 return false;
1651 }
1652
1653 //=============================================================================
1654 //------------------------------Value------------------------------------------
1655 // Compute sqrt
1656 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
1657 const Type *t1 = phase->type( in(1) );
1658 if( t1 == Type::TOP ) return Type::TOP;
1659 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1660 double d = t1->getd();
1661 if( d < 0.0 ) return Type::DOUBLE;
1662 return TypeD::make( sqrt( d ) );
1663 }
1664
1665 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
1666 const Type *t1 = phase->type( in(1) );
1667 if( t1 == Type::TOP ) return Type::TOP;
1668 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
1669 float f = t1->getf();
1670 if( f < 0.0f ) return Type::FLOAT;
1671 return TypeF::make( (float)sqrt( (double)f ) );
1672 }