1 /*
2 * Copyright (c) 1997, 2018, 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 ) {
65 if( phase->eqv(in(1)->in(2),in(2)) )
66 return in(1)->in(1);
67 if (phase->eqv(in(1)->in(1),in(2)))
68 return in(1)->in(2);
69
70 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying
71 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes
72 // are originally used, although the optimizer sometimes jiggers things).
73 // This folding through an O2 removes a loop-exit use of a loop-varying
74 // value and generally lowers register pressure in and around the loop.
75 if( in(1)->in(2)->Opcode() == Op_Opaque2 &&
76 phase->eqv(in(1)->in(2)->in(1),in(2)) )
77 return in(1)->in(1);
78 }
79
80 return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
81 }
82
83 //------------------------------Value------------------------------------------
84 // A subtract node differences it's two inputs.
85 const Type* SubNode::Value_common(PhaseTransform *phase) const {
86 const Node* in1 = in(1);
87 const Node* in2 = in(2);
88 // Either input is TOP ==> the result is TOP
89 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
90 if( t1 == Type::TOP ) return Type::TOP;
91 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
92 if( t2 == Type::TOP ) return Type::TOP;
93
94 // Not correct for SubFnode and AddFNode (must check for infinity)
95 // Equal? Subtract is zero
96 if (in1->eqv_uncast(in2)) return add_id();
97
98 // Either input is BOTTOM ==> the result is the local BOTTOM
99 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
100 return bottom_type();
101
102 return NULL;
103 }
104
105 const Type* SubNode::Value(PhaseGVN* phase) const {
106 const Type* t = Value_common(phase);
107 if (t != NULL) {
108 return t;
109 }
110 const Type* t1 = phase->type(in(1));
111 const Type* t2 = phase->type(in(2));
112 return sub(t1,t2); // Local flavor of type subtraction
113
114 }
115
116 //=============================================================================
117
118 //------------------------------Helper function--------------------------------
119 static bool ok_to_convert(Node* inc, Node* iv) {
120 // Do not collapse (x+c0)-y if "+" is a loop increment, because the
121 // "-" is loop invariant and collapsing extends the live-range of "x"
122 // to overlap with the "+", forcing another register to be used in
123 // the loop.
124 // This test will be clearer with '&&' (apply DeMorgan's rule)
125 // but I like the early cutouts that happen here.
126 const PhiNode *phi;
127 if( ( !inc->in(1)->is_Phi() ||
128 !(phi=inc->in(1)->as_Phi()) ||
129 phi->is_copy() ||
130 !phi->region()->is_CountedLoop() ||
131 inc != phi->region()->as_CountedLoop()->incr() )
132 &&
133 // Do not collapse (x+c0)-iv if "iv" is a loop induction variable,
134 // because "x" maybe invariant.
135 ( !iv->is_loop_iv() )
136 ) {
137 return true;
138 } else {
139 return false;
140 }
141 }
142 //------------------------------Ideal------------------------------------------
143 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
144 Node *in1 = in(1);
145 Node *in2 = in(2);
146 uint op1 = in1->Opcode();
147 uint op2 = in2->Opcode();
148
149 #ifdef ASSERT
150 // Check for dead loop
151 if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
152 ( ( op1 == Op_AddI || op1 == Op_SubI ) &&
153 ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
154 phase->eqv( in1->in(1), in1 ) || phase->eqv( in1->in(2), in1 ) ) ) )
155 assert(false, "dead loop in SubINode::Ideal");
156 #endif
157
158 const Type *t2 = phase->type( in2 );
159 if( t2 == Type::TOP ) return NULL;
160 // Convert "x-c0" into "x+ -c0".
161 if( t2->base() == Type::Int ){ // Might be bottom or top...
162 const TypeInt *i = t2->is_int();
163 if( i->is_con() )
164 return new AddINode(in1, phase->intcon(-i->get_con()));
165 }
166
167 // Convert "(x+c0) - y" into (x-y) + c0"
168 // Do not collapse (x+c0)-y if "+" is a loop increment or
169 // if "y" is a loop induction variable.
170 if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
171 const Type *tadd = phase->type( in1->in(2) );
172 if( tadd->singleton() && tadd != Type::TOP ) {
173 Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 ));
174 return new AddINode( sub2, in1->in(2) );
175 }
176 }
177
178
179 // Convert "x - (y+c0)" into "(x-y) - c0"
180 // Need the same check as in above optimization but reversed.
181 if (op2 == Op_AddI && ok_to_convert(in2, in1)) {
182 Node* in21 = in2->in(1);
183 Node* in22 = in2->in(2);
184 const TypeInt* tcon = phase->type(in22)->isa_int();
185 if (tcon != NULL && tcon->is_con()) {
186 Node* sub2 = phase->transform( new SubINode(in1, in21) );
187 Node* neg_c0 = phase->intcon(- tcon->get_con());
188 return new AddINode(sub2, neg_c0);
189 }
190 }
191
192 const Type *t1 = phase->type( in1 );
193 if( t1 == Type::TOP ) return NULL;
194
195 #ifdef ASSERT
196 // Check for dead loop
197 if( ( op2 == Op_AddI || op2 == Op_SubI ) &&
198 ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
199 phase->eqv( in2->in(1), in2 ) || phase->eqv( in2->in(2), in2 ) ) )
200 assert(false, "dead loop in SubINode::Ideal");
201 #endif
202
203 // Convert "x - (x+y)" into "-y"
204 if( op2 == Op_AddI &&
205 phase->eqv( in1, in2->in(1) ) )
206 return new SubINode( phase->intcon(0),in2->in(2));
207 // Convert "(x-y) - x" into "-y"
208 if( op1 == Op_SubI &&
209 phase->eqv( in1->in(1), in2 ) )
210 return new SubINode( phase->intcon(0),in1->in(2));
211 // Convert "x - (y+x)" into "-y"
212 if( op2 == Op_AddI &&
213 phase->eqv( in1, in2->in(2) ) )
214 return new SubINode( phase->intcon(0),in2->in(1));
215
216 // Convert "0 - (x-y)" into "y-x"
217 if( t1 == TypeInt::ZERO && op2 == Op_SubI )
218 return new SubINode( in2->in(2), in2->in(1) );
219
220 // Convert "0 - (x+con)" into "-con-x"
221 jint con;
222 if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
223 (con = in2->in(2)->find_int_con(0)) != 0 )
224 return new SubINode( phase->intcon(-con), in2->in(1) );
225
226 // Convert "(X+A) - (X+B)" into "A - B"
227 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
228 return new SubINode( in1->in(2), in2->in(2) );
229
230 // Convert "(A+X) - (B+X)" into "A - B"
231 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
232 return new SubINode( in1->in(1), in2->in(1) );
233
234 // Convert "(A+X) - (X+B)" into "A - B"
235 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
236 return new SubINode( in1->in(1), in2->in(2) );
237
238 // Convert "(X+A) - (B+X)" into "A - B"
239 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
240 return new SubINode( in1->in(2), in2->in(1) );
241
242 // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
243 // nicer to optimize than subtract.
244 if( op2 == Op_SubI && in2->outcnt() == 1) {
245 Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) );
246 return new SubINode( add1, in2->in(1) );
247 }
248
249 return NULL;
250 }
251
252 //------------------------------sub--------------------------------------------
253 // A subtract node differences it's two inputs.
254 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
255 const TypeInt *r0 = t1->is_int(); // Handy access
256 const TypeInt *r1 = t2->is_int();
257 int32_t lo = java_subtract(r0->_lo, r1->_hi);
258 int32_t hi = java_subtract(r0->_hi, r1->_lo);
259
260 // We next check for 32-bit overflow.
261 // If that happens, we just assume all integers are possible.
262 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
263 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
264 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
265 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
266 return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
267 else // Overflow; assume all integers
268 return TypeInt::INT;
269 }
270
271 //=============================================================================
272 //------------------------------Ideal------------------------------------------
273 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
274 Node *in1 = in(1);
275 Node *in2 = in(2);
276 uint op1 = in1->Opcode();
277 uint op2 = in2->Opcode();
278
279 #ifdef ASSERT
280 // Check for dead loop
281 if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
282 ( ( op1 == Op_AddL || op1 == Op_SubL ) &&
283 ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
284 phase->eqv( in1->in(1), in1 ) || phase->eqv( in1->in(2), in1 ) ) ) )
285 assert(false, "dead loop in SubLNode::Ideal");
286 #endif
287
288 if( phase->type( in2 ) == Type::TOP ) return NULL;
289 const TypeLong *i = phase->type( in2 )->isa_long();
290 // Convert "x-c0" into "x+ -c0".
291 if( i && // Might be bottom or top...
292 i->is_con() )
293 return new AddLNode(in1, phase->longcon(-i->get_con()));
294
295 // Convert "(x+c0) - y" into (x-y) + c0"
296 // Do not collapse (x+c0)-y if "+" is a loop increment or
297 // if "y" is a loop induction variable.
298 if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
299 Node *in11 = in1->in(1);
300 const Type *tadd = phase->type( in1->in(2) );
301 if( tadd->singleton() && tadd != Type::TOP ) {
302 Node *sub2 = phase->transform( new SubLNode( in11, in2 ));
303 return new AddLNode( sub2, in1->in(2) );
304 }
305 }
306
307 // Convert "x - (y+c0)" into "(x-y) - c0"
308 // Need the same check as in above optimization but reversed.
309 if (op2 == Op_AddL && ok_to_convert(in2, in1)) {
310 Node* in21 = in2->in(1);
311 Node* in22 = in2->in(2);
312 const TypeLong* tcon = phase->type(in22)->isa_long();
313 if (tcon != NULL && tcon->is_con()) {
314 Node* sub2 = phase->transform( new SubLNode(in1, in21) );
315 Node* neg_c0 = phase->longcon(- tcon->get_con());
316 return new AddLNode(sub2, neg_c0);
317 }
318 }
319
320 const Type *t1 = phase->type( in1 );
321 if( t1 == Type::TOP ) return NULL;
322
323 #ifdef ASSERT
324 // Check for dead loop
325 if( ( op2 == Op_AddL || op2 == Op_SubL ) &&
326 ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
327 phase->eqv( in2->in(1), in2 ) || phase->eqv( in2->in(2), in2 ) ) )
328 assert(false, "dead loop in SubLNode::Ideal");
329 #endif
330
331 // Convert "x - (x+y)" into "-y"
332 if( op2 == Op_AddL &&
333 phase->eqv( in1, in2->in(1) ) )
334 return new SubLNode( phase->makecon(TypeLong::ZERO), in2->in(2));
335 // Convert "x - (y+x)" into "-y"
336 if( op2 == Op_AddL &&
337 phase->eqv( in1, in2->in(2) ) )
338 return new SubLNode( phase->makecon(TypeLong::ZERO),in2->in(1));
339
340 // Convert "0 - (x-y)" into "y-x"
341 if( phase->type( in1 ) == TypeLong::ZERO && op2 == Op_SubL )
342 return new SubLNode( in2->in(2), in2->in(1) );
343
344 // Convert "(X+A) - (X+B)" into "A - B"
345 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
346 return new SubLNode( in1->in(2), in2->in(2) );
347
348 // Convert "(A+X) - (B+X)" into "A - B"
349 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
350 return new SubLNode( in1->in(1), in2->in(1) );
351
352 // Convert "A-(B-C)" into (A+C)-B"
353 if( op2 == Op_SubL && in2->outcnt() == 1) {
354 Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) );
355 return new SubLNode( add1, in2->in(1) );
356 }
357
358 return NULL;
359 }
360
361 //------------------------------sub--------------------------------------------
362 // A subtract node differences it's two inputs.
363 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
364 const TypeLong *r0 = t1->is_long(); // Handy access
365 const TypeLong *r1 = t2->is_long();
366 jlong lo = java_subtract(r0->_lo, r1->_hi);
367 jlong hi = java_subtract(r0->_hi, r1->_lo);
368
369 // We next check for 32-bit overflow.
370 // If that happens, we just assume all integers are possible.
371 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR
372 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND
373 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR
374 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs
375 return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
376 else // Overflow; assume all integers
377 return TypeLong::LONG;
378 }
379
380 //=============================================================================
381 //------------------------------Value------------------------------------------
382 // A subtract node differences its two inputs.
383 const Type* SubFPNode::Value(PhaseGVN* phase) const {
384 const Node* in1 = in(1);
385 const Node* in2 = in(2);
386 // Either input is TOP ==> the result is TOP
387 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
388 if( t1 == Type::TOP ) return Type::TOP;
389 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
390 if( t2 == Type::TOP ) return Type::TOP;
391
392 // if both operands are infinity of same sign, the result is NaN; do
393 // not replace with zero
394 if( (t1->is_finite() && t2->is_finite()) ) {
395 if( phase->eqv(in1, in2) ) return add_id();
396 }
397
398 // Either input is BOTTOM ==> the result is the local BOTTOM
399 const Type *bot = bottom_type();
400 if( (t1 == bot) || (t2 == bot) ||
401 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
402 return bot;
403
404 return sub(t1,t2); // Local flavor of type subtraction
405 }
406
407
408 //=============================================================================
409 //------------------------------Ideal------------------------------------------
410 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
411 const Type *t2 = phase->type( in(2) );
412 // Convert "x-c0" into "x+ -c0".
413 if( t2->base() == Type::FloatCon ) { // Might be bottom or top...
414 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
415 }
416
417 // Not associative because of boundary conditions (infinity)
418 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
419 // Convert "x - (x+y)" into "-y"
420 if( in(2)->is_Add() &&
421 phase->eqv(in(1),in(2)->in(1) ) )
422 return new SubFNode( phase->makecon(TypeF::ZERO),in(2)->in(2));
423 }
424
425 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
426 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
427 //if( phase->type(in(1)) == TypeF::ZERO )
428 //return new (phase->C, 2) NegFNode(in(2));
429
430 return NULL;
431 }
432
433 //------------------------------sub--------------------------------------------
434 // A subtract node differences its two inputs.
435 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
436 // no folding if one of operands is infinity or NaN, do not do constant folding
437 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
438 return TypeF::make( t1->getf() - t2->getf() );
439 }
440 else if( g_isnan(t1->getf()) ) {
441 return t1;
442 }
443 else if( g_isnan(t2->getf()) ) {
444 return t2;
445 }
446 else {
447 return Type::FLOAT;
448 }
449 }
450
451 //=============================================================================
452 //------------------------------Ideal------------------------------------------
453 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
454 const Type *t2 = phase->type( in(2) );
455 // Convert "x-c0" into "x+ -c0".
456 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
457 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
458 }
459
460 // Not associative because of boundary conditions (infinity)
461 if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
462 // Convert "x - (x+y)" into "-y"
463 if( in(2)->is_Add() &&
464 phase->eqv(in(1),in(2)->in(1) ) )
465 return new SubDNode( phase->makecon(TypeD::ZERO),in(2)->in(2));
466 }
467
468 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
469 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
470 //if( phase->type(in(1)) == TypeD::ZERO )
471 //return new (phase->C, 2) NegDNode(in(2));
472
473 return NULL;
474 }
475
476 //------------------------------sub--------------------------------------------
477 // A subtract node differences its two inputs.
478 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
479 // no folding if one of operands is infinity or NaN, do not do constant folding
480 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
481 return TypeD::make( t1->getd() - t2->getd() );
482 }
483 else if( g_isnan(t1->getd()) ) {
484 return t1;
485 }
486 else if( g_isnan(t2->getd()) ) {
487 return t2;
488 }
489 else {
490 return Type::DOUBLE;
491 }
492 }
493
494 //=============================================================================
495 //------------------------------Idealize---------------------------------------
496 // Unlike SubNodes, compare must still flatten return value to the
497 // range -1, 0, 1.
498 // And optimizations like those for (X + Y) - X fail if overflow happens.
499 Node* CmpNode::Identity(PhaseGVN* phase) {
500 return this;
501 }
502
503 #ifndef PRODUCT
504 //----------------------------related------------------------------------------
505 // Related nodes of comparison nodes include all data inputs (until hitting a
506 // control boundary) as well as all outputs until and including control nodes
507 // as well as their projections. In compact mode, data inputs till depth 1 and
508 // all outputs till depth 1 are considered.
509 void CmpNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
510 if (compact) {
511 this->collect_nodes(in_rel, 1, false, true);
512 this->collect_nodes(out_rel, -1, false, false);
513 } else {
514 this->collect_nodes_in_all_data(in_rel, false);
515 this->collect_nodes_out_all_ctrl_boundary(out_rel);
516 // Now, find all control nodes in out_rel, and include their projections
517 // and projection targets (if any) in the result.
518 GrowableArray<Node*> proj(Compile::current()->unique());
519 for (GrowableArrayIterator<Node*> it = out_rel->begin(); it != out_rel->end(); ++it) {
520 Node* n = *it;
521 if (n->is_CFG() && !n->is_Proj()) {
522 // Assume projections and projection targets are found at levels 1 and 2.
523 n->collect_nodes(&proj, -2, false, false);
524 for (GrowableArrayIterator<Node*> p = proj.begin(); p != proj.end(); ++p) {
525 out_rel->append_if_missing(*p);
526 }
527 proj.clear();
528 }
529 }
530 }
531 }
532 #endif
533
534 //=============================================================================
535 //------------------------------cmp--------------------------------------------
536 // Simplify a CmpI (compare 2 integers) node, based on local information.
537 // If both inputs are constants, compare them.
538 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
539 const TypeInt *r0 = t1->is_int(); // Handy access
540 const TypeInt *r1 = t2->is_int();
541
542 if( r0->_hi < r1->_lo ) // Range is always low?
543 return TypeInt::CC_LT;
544 else if( r0->_lo > r1->_hi ) // Range is always high?
545 return TypeInt::CC_GT;
546
547 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
548 assert(r0->get_con() == r1->get_con(), "must be equal");
549 return TypeInt::CC_EQ; // Equal results.
550 } else if( r0->_hi == r1->_lo ) // Range is never high?
551 return TypeInt::CC_LE;
552 else if( r0->_lo == r1->_hi ) // Range is never low?
553 return TypeInt::CC_GE;
554 return TypeInt::CC; // else use worst case results
555 }
556
557 // Simplify a CmpU (compare 2 integers) node, based on local information.
558 // If both inputs are constants, compare them.
559 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
560 assert(!t1->isa_ptr(), "obsolete usage of CmpU");
561
562 // comparing two unsigned ints
563 const TypeInt *r0 = t1->is_int(); // Handy access
564 const TypeInt *r1 = t2->is_int();
565
566 // Current installed version
567 // Compare ranges for non-overlap
568 juint lo0 = r0->_lo;
569 juint hi0 = r0->_hi;
570 juint lo1 = r1->_lo;
571 juint hi1 = r1->_hi;
572
573 // If either one has both negative and positive values,
574 // it therefore contains both 0 and -1, and since [0..-1] is the
575 // full unsigned range, the type must act as an unsigned bottom.
576 bool bot0 = ((jint)(lo0 ^ hi0) < 0);
577 bool bot1 = ((jint)(lo1 ^ hi1) < 0);
578
579 if (bot0 || bot1) {
580 // All unsigned values are LE -1 and GE 0.
581 if (lo0 == 0 && hi0 == 0) {
582 return TypeInt::CC_LE; // 0 <= bot
583 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) {
584 return TypeInt::CC_GE; // -1 >= bot
585 } else if (lo1 == 0 && hi1 == 0) {
586 return TypeInt::CC_GE; // bot >= 0
587 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) {
588 return TypeInt::CC_LE; // bot <= -1
589 }
590 } else {
591 // We can use ranges of the form [lo..hi] if signs are the same.
592 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
593 // results are reversed, '-' > '+' for unsigned compare
594 if (hi0 < lo1) {
595 return TypeInt::CC_LT; // smaller
596 } else if (lo0 > hi1) {
597 return TypeInt::CC_GT; // greater
598 } else if (hi0 == lo1 && lo0 == hi1) {
599 return TypeInt::CC_EQ; // Equal results
600 } else if (lo0 >= hi1) {
601 return TypeInt::CC_GE;
602 } else if (hi0 <= lo1) {
603 // Check for special case in Hashtable::get. (See below.)
604 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
605 return TypeInt::CC_LT;
606 return TypeInt::CC_LE;
607 }
608 }
609 // Check for special case in Hashtable::get - the hash index is
610 // mod'ed to the table size so the following range check is useless.
611 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
612 // to be positive.
613 // (This is a gross hack, since the sub method never
614 // looks at the structure of the node in any other case.)
615 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
616 return TypeInt::CC_LT;
617 return TypeInt::CC; // else use worst case results
618 }
619
620 const Type* CmpUNode::Value(PhaseGVN* phase) const {
621 const Type* t = SubNode::Value_common(phase);
622 if (t != NULL) {
623 return t;
624 }
625 const Node* in1 = in(1);
626 const Node* in2 = in(2);
627 const Type* t1 = phase->type(in1);
628 const Type* t2 = phase->type(in2);
629 assert(t1->isa_int(), "CmpU has only Int type inputs");
630 if (t2 == TypeInt::INT) { // Compare to bottom?
631 return bottom_type();
632 }
633 uint in1_op = in1->Opcode();
634 if (in1_op == Op_AddI || in1_op == Op_SubI) {
635 // The problem rise when result of AddI(SubI) may overflow
636 // signed integer value. Let say the input type is
637 // [256, maxint] then +128 will create 2 ranges due to
638 // overflow: [minint, minint+127] and [384, maxint].
639 // But C2 type system keep only 1 type range and as result
640 // it use general [minint, maxint] for this case which we
641 // can't optimize.
642 //
643 // Make 2 separate type ranges based on types of AddI(SubI) inputs
644 // and compare results of their compare. If results are the same
645 // CmpU node can be optimized.
646 const Node* in11 = in1->in(1);
647 const Node* in12 = in1->in(2);
648 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
649 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
650 // Skip cases when input types are top or bottom.
651 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
652 (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
653 const TypeInt *r0 = t11->is_int();
654 const TypeInt *r1 = t12->is_int();
655 jlong lo_r0 = r0->_lo;
656 jlong hi_r0 = r0->_hi;
657 jlong lo_r1 = r1->_lo;
658 jlong hi_r1 = r1->_hi;
659 if (in1_op == Op_SubI) {
660 jlong tmp = hi_r1;
661 hi_r1 = -lo_r1;
662 lo_r1 = -tmp;
663 // Note, for substructing [minint,x] type range
664 // long arithmetic provides correct overflow answer.
665 // The confusion come from the fact that in 32-bit
666 // -minint == minint but in 64-bit -minint == maxint+1.
667 }
668 jlong lo_long = lo_r0 + lo_r1;
669 jlong hi_long = hi_r0 + hi_r1;
670 int lo_tr1 = min_jint;
671 int hi_tr1 = (int)hi_long;
672 int lo_tr2 = (int)lo_long;
673 int hi_tr2 = max_jint;
674 bool underflow = lo_long != (jlong)lo_tr2;
675 bool overflow = hi_long != (jlong)hi_tr1;
676 // Use sub(t1, t2) when there is no overflow (one type range)
677 // or when both overflow and underflow (too complex).
678 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
679 // Overflow only on one boundary, compare 2 separate type ranges.
680 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
681 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
682 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
683 const Type* cmp1 = sub(tr1, t2);
684 const Type* cmp2 = sub(tr2, t2);
685 if (cmp1 == cmp2) {
686 return cmp1; // Hit!
687 }
688 }
689 }
690 }
691
692 return sub(t1, t2); // Local flavor of type subtraction
693 }
694
695 bool CmpUNode::is_index_range_check() const {
696 // Check for the "(X ModI Y) CmpU Y" shape
697 return (in(1)->Opcode() == Op_ModI &&
698 in(1)->in(2)->eqv_uncast(in(2)));
699 }
700
701 //------------------------------Idealize---------------------------------------
702 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
703 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
704 switch (in(1)->Opcode()) {
705 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL
706 return new CmpLNode(in(1)->in(1),in(1)->in(2));
707 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF
708 return new CmpFNode(in(1)->in(1),in(1)->in(2));
709 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD
710 return new CmpDNode(in(1)->in(1),in(1)->in(2));
711 //case Op_SubI:
712 // If (x - y) cannot overflow, then ((x - y) <?> 0)
713 // can be turned into (x <?> y).
714 // This is handled (with more general cases) by Ideal_sub_algebra.
715 }
716 }
717 return NULL; // No change
718 }
719
720 //------------------------------Ideal------------------------------------------
721 Node* CmpLNode::Ideal(PhaseGVN* phase, bool can_reshape) {
722 Node* a = NULL;
723 Node* b = NULL;
724 if (is_double_null_check(phase, a, b) && (phase->type(a)->is_zero_type() || phase->type(b)->is_zero_type())) {
725 // Degraded to a simple null check, use old acmp
726 return new CmpPNode(a, b);
727 }
728 return NULL;
729 }
730
731 // Match double null check emitted by Compile::optimize_acmp()
732 bool CmpLNode::is_double_null_check(PhaseGVN* phase, Node*& a, Node*& b) const {
733 if (in(1)->Opcode() == Op_OrL &&
734 in(1)->in(1)->Opcode() == Op_CastP2X &&
735 in(1)->in(2)->Opcode() == Op_CastP2X &&
736 in(2)->bottom_type()->is_zero_type()) {
737 assert(EnableValhalla, "unexpected double null check");
738 a = in(1)->in(1)->in(1);
739 b = in(1)->in(2)->in(1);
740 return true;
741 }
742 return false;
743 }
744
745 //------------------------------Value------------------------------------------
746 const Type* CmpLNode::Value(PhaseGVN* phase) const {
747 Node* a = NULL;
748 Node* b = NULL;
749 if (is_double_null_check(phase, a, b) && (!phase->type(a)->maybe_null() || !phase->type(b)->maybe_null())) {
750 // One operand is never NULL, emit constant false
751 return TypeInt::CC_GT;
752 }
753 return SubNode::Value(phase);
754 }
755
756 //=============================================================================
757 // Simplify a CmpL (compare 2 longs ) node, based on local information.
758 // If both inputs are constants, compare them.
759 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
760 const TypeLong *r0 = t1->is_long(); // Handy access
761 const TypeLong *r1 = t2->is_long();
762
763 if( r0->_hi < r1->_lo ) // Range is always low?
764 return TypeInt::CC_LT;
765 else if( r0->_lo > r1->_hi ) // Range is always high?
766 return TypeInt::CC_GT;
767
768 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
769 assert(r0->get_con() == r1->get_con(), "must be equal");
770 return TypeInt::CC_EQ; // Equal results.
771 } else if( r0->_hi == r1->_lo ) // Range is never high?
772 return TypeInt::CC_LE;
773 else if( r0->_lo == r1->_hi ) // Range is never low?
774 return TypeInt::CC_GE;
775 return TypeInt::CC; // else use worst case results
776 }
777
778
779 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
780 // If both inputs are constants, compare them.
781 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
782 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
783
784 // comparing two unsigned longs
785 const TypeLong* r0 = t1->is_long(); // Handy access
786 const TypeLong* r1 = t2->is_long();
787
788 // Current installed version
789 // Compare ranges for non-overlap
790 julong lo0 = r0->_lo;
791 julong hi0 = r0->_hi;
792 julong lo1 = r1->_lo;
793 julong hi1 = r1->_hi;
794
795 // If either one has both negative and positive values,
796 // it therefore contains both 0 and -1, and since [0..-1] is the
797 // full unsigned range, the type must act as an unsigned bottom.
798 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
799 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
800
801 if (bot0 || bot1) {
802 // All unsigned values are LE -1 and GE 0.
803 if (lo0 == 0 && hi0 == 0) {
804 return TypeInt::CC_LE; // 0 <= bot
805 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
806 return TypeInt::CC_GE; // -1 >= bot
807 } else if (lo1 == 0 && hi1 == 0) {
808 return TypeInt::CC_GE; // bot >= 0
809 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
810 return TypeInt::CC_LE; // bot <= -1
811 }
812 } else {
813 // We can use ranges of the form [lo..hi] if signs are the same.
814 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
815 // results are reversed, '-' > '+' for unsigned compare
816 if (hi0 < lo1) {
817 return TypeInt::CC_LT; // smaller
818 } else if (lo0 > hi1) {
819 return TypeInt::CC_GT; // greater
820 } else if (hi0 == lo1 && lo0 == hi1) {
821 return TypeInt::CC_EQ; // Equal results
822 } else if (lo0 >= hi1) {
823 return TypeInt::CC_GE;
824 } else if (hi0 <= lo1) {
825 return TypeInt::CC_LE;
826 }
827 }
828
829 return TypeInt::CC; // else use worst case results
830 }
831
832 //=============================================================================
833 //------------------------------sub--------------------------------------------
834 // Simplify an CmpP (compare 2 pointers) node, based on local information.
835 // If both inputs are constants, compare them.
836 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
837 if (t1->isa_valuetype() || t2->isa_valuetype() ||
838 ((t1->is_valuetypeptr() || t2->is_valuetypeptr()) &&
839 (!t1->maybe_null() || !t2->maybe_null()))) {
840 // One operand is a value type and one operand is never null, fold to constant false
841 return TypeInt::CC_GT;
842 }
843
844 const TypePtr *r0 = t1->is_ptr(); // Handy access
845 const TypePtr *r1 = t2->is_ptr();
846
847 // Undefined inputs makes for an undefined result
848 if( TypePtr::above_centerline(r0->_ptr) ||
849 TypePtr::above_centerline(r1->_ptr) )
850 return Type::TOP;
851
852 if (r0 == r1 && r0->singleton()) {
853 // Equal pointer constants (klasses, nulls, etc.)
854 return TypeInt::CC_EQ;
855 }
856
857 // See if it is 2 unrelated classes.
858 const TypeOopPtr* p0 = r0->isa_oopptr();
859 const TypeOopPtr* p1 = r1->isa_oopptr();
860 if (p0 && p1) {
861 Node* in1 = in(1)->uncast();
862 Node* in2 = in(2)->uncast();
863 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
864 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
865 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
866 return TypeInt::CC_GT; // different pointers
867 }
868 ciKlass* klass0 = p0->klass();
869 bool xklass0 = p0->klass_is_exact();
870 ciKlass* klass1 = p1->klass();
871 bool xklass1 = p1->klass_is_exact();
872 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
873 if (klass0 && klass1 &&
874 kps != 1 && // both or neither are klass pointers
875 klass0->is_loaded() && !klass0->is_interface() && // do not trust interfaces
876 klass1->is_loaded() && !klass1->is_interface() &&
877 (!klass0->is_obj_array_klass() ||
878 !klass0->as_obj_array_klass()->base_element_klass()->is_interface()) &&
879 (!klass1->is_obj_array_klass() ||
880 !klass1->as_obj_array_klass()->base_element_klass()->is_interface())) {
881 bool unrelated_classes = false;
882 // See if neither subclasses the other, or if the class on top
883 // is precise. In either of these cases, the compare is known
884 // to fail if at least one of the pointers is provably not null.
885 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
886 // Do nothing; we know nothing for imprecise types
887 } else if (klass0->is_subtype_of(klass1)) {
888 // If klass1's type is PRECISE, then classes are unrelated.
889 unrelated_classes = xklass1;
890 } else if (klass1->is_subtype_of(klass0)) {
891 // If klass0's type is PRECISE, then classes are unrelated.
892 unrelated_classes = xklass0;
893 } else { // Neither subtypes the other
894 unrelated_classes = true;
895 }
896 if (unrelated_classes) {
897 // The oops classes are known to be unrelated. If the joined PTRs of
898 // two oops is not Null and not Bottom, then we are sure that one
899 // of the two oops is non-null, and the comparison will always fail.
900 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
901 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
902 return TypeInt::CC_GT;
903 }
904 }
905 }
906 }
907
908 // Known constants can be compared exactly
909 // Null can be distinguished from any NotNull pointers
910 // Unknown inputs makes an unknown result
911 if( r0->singleton() ) {
912 intptr_t bits0 = r0->get_con();
913 if( r1->singleton() )
914 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
915 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
916 } else if( r1->singleton() ) {
917 intptr_t bits1 = r1->get_con();
918 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
919 } else
920 return TypeInt::CC;
921 }
922
923 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
924 // Return the klass node for (indirect load from OopHandle)
925 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
926 // or NULL if not matching.
927 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
928 if (bs->is_gc_barrier_node(n)) {
929 n = bs->step_over_gc_barrier(n);
930 }
931
932 if (n->Opcode() != Op_LoadP) return NULL;
933
934 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
935 if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
936
937 Node* adr = n->in(MemNode::Address);
938 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
939 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return NULL;
940 adr = adr->in(MemNode::Address);
941
942 intptr_t off = 0;
943 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
944 if (k == NULL) return NULL;
945 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
946 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return NULL;
947
948 // We've found the klass node of a Java mirror load.
949 return k;
950 }
951
952 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
953 // for ConP(Foo.class) return ConP(Foo.klass)
954 // otherwise return NULL
955 if (!n->is_Con()) return NULL;
956
957 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
958 if (!tp) return NULL;
959
960 ciType* mirror_type = tp->java_mirror_type();
961 // TypeInstPtr::java_mirror_type() returns non-NULL for compile-
962 // time Class constants only.
963 if (!mirror_type) return NULL;
964
965 // x.getClass() == int.class can never be true (for all primitive types)
966 // Return a ConP(NULL) node for this case.
967 if (mirror_type->is_classless()) {
968 return phase->makecon(TypePtr::NULL_PTR);
969 }
970
971 // return the ConP(Foo.klass)
972 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
973 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass()));
974 }
975
976 //------------------------------Ideal------------------------------------------
977 // Normalize comparisons between Java mirror loads to compare the klass instead.
978 //
979 // Also check for the case of comparing an unknown klass loaded from the primary
980 // super-type array vs a known klass with no subtypes. This amounts to
981 // checking to see an unknown klass subtypes a known klass with no subtypes;
982 // this only happens on an exact match. We can shorten this test by 1 load.
983 Node* CmpPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
984 Node* pert = has_perturbed_operand();
985 if (pert != NULL) {
986 // Optimize new acmp
987 Node* a = pert->in(AddPNode::Base); // unperturbed a
988 Node* b = in(2);
989 Node* cmp = phase->C->optimize_acmp(phase, a, b);
990 if (cmp != NULL) {
991 return cmp;
992 }
993 }
994
995 // Normalize comparisons between Java mirrors into comparisons of the low-
996 // level klass, where a dependent load could be shortened.
997 //
998 // The new pattern has a nice effect of matching the same pattern used in the
999 // fast path of instanceof/checkcast/Class.isInstance(), which allows
1000 // redundant exact type check be optimized away by GVN.
1001 // For example, in
1002 // if (x.getClass() == Foo.class) {
1003 // Foo foo = (Foo) x;
1004 // // ... use a ...
1005 // }
1006 // a CmpPNode could be shared between if_acmpne and checkcast
1007 {
1008 Node* k1 = isa_java_mirror_load(phase, in(1));
1009 Node* k2 = isa_java_mirror_load(phase, in(2));
1010 Node* conk2 = isa_const_java_mirror(phase, in(2));
1011
1012 if (k1 && (k2 || conk2)) {
1013 Node* lhs = k1;
1014 Node* rhs = (k2 != NULL) ? k2 : conk2;
1015 this->set_req(1, lhs);
1016 this->set_req(2, rhs);
1017 return this;
1018 }
1019 }
1020
1021 // Constant pointer on right?
1022 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1023 if (t2 == NULL || !t2->klass_is_exact())
1024 return NULL;
1025 // Get the constant klass we are comparing to.
1026 ciKlass* superklass = t2->klass();
1027
1028 // Now check for LoadKlass on left.
1029 Node* ldk1 = in(1);
1030 if (ldk1->is_DecodeNKlass()) {
1031 ldk1 = ldk1->in(1);
1032 if (ldk1->Opcode() != Op_LoadNKlass )
1033 return NULL;
1034 } else if (ldk1->Opcode() != Op_LoadKlass )
1035 return NULL;
1036 // Take apart the address of the LoadKlass:
1037 Node* adr1 = ldk1->in(MemNode::Address);
1038 intptr_t con2 = 0;
1039 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1040 if (ldk2 == NULL)
1041 return NULL;
1042 if (con2 == oopDesc::klass_offset_in_bytes()) {
1043 // We are inspecting an object's concrete class.
1044 // Short-circuit the check if the query is abstract.
1045 if (superklass->is_interface() ||
1046 superklass->is_abstract()) {
1047 // Make it come out always false:
1048 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1049 return this;
1050 }
1051 }
1052
1053 // Check for a LoadKlass from primary supertype array.
1054 // Any nested loadklass from loadklass+con must be from the p.s. array.
1055 if (ldk2->is_DecodeNKlass()) {
1056 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1057 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1058 return NULL;
1059 } else if (ldk2->Opcode() != Op_LoadKlass)
1060 return NULL;
1061
1062 // Verify that we understand the situation
1063 if (con2 != (intptr_t) superklass->super_check_offset())
1064 return NULL; // Might be element-klass loading from array klass
1065
1066 // If 'superklass' has no subklasses and is not an interface, then we are
1067 // assured that the only input which will pass the type check is
1068 // 'superklass' itself.
1069 //
1070 // We could be more liberal here, and allow the optimization on interfaces
1071 // which have a single implementor. This would require us to increase the
1072 // expressiveness of the add_dependency() mechanism.
1073 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1074
1075 // Object arrays must have their base element have no subtypes
1076 while (superklass->is_obj_array_klass()) {
1077 ciType* elem = superklass->as_obj_array_klass()->element_type();
1078 superklass = elem->as_klass();
1079 }
1080 if (superklass->is_instance_klass()) {
1081 ciInstanceKlass* ik = superklass->as_instance_klass();
1082 if (ik->has_subklass() || ik->is_interface()) return NULL;
1083 // Add a dependency if there is a chance that a subclass will be added later.
1084 if (!ik->is_final()) {
1085 phase->C->dependencies()->assert_leaf_type(ik);
1086 }
1087 }
1088
1089 // Bypass the dependent load, and compare directly
1090 this->set_req(1,ldk2);
1091
1092 return this;
1093 }
1094
1095 // Checks if one operand is perturbed and returns it
1096 Node* CmpPNode::has_perturbed_operand() const {
1097 // We always perturbe the first operand
1098 AddPNode* addP = in(1)->isa_AddP();
1099 if (addP != NULL) {
1100 Node* base = addP->in(AddPNode::Base);
1101 if (base->is_top()) {
1102 // RawPtr comparison
1103 return NULL;
1104 }
1105 assert(EnableValhalla && UsePointerPerturbation, "unexpected perturbed oop");
1106 return in(1);
1107 }
1108 return NULL;
1109 }
1110
1111 //=============================================================================
1112 //------------------------------sub--------------------------------------------
1113 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1114 // If both inputs are constants, compare them.
1115 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1116 const TypePtr *r0 = t1->make_ptr(); // Handy access
1117 const TypePtr *r1 = t2->make_ptr();
1118
1119 // Undefined inputs makes for an undefined result
1120 if ((r0 == NULL) || (r1 == NULL) ||
1121 TypePtr::above_centerline(r0->_ptr) ||
1122 TypePtr::above_centerline(r1->_ptr)) {
1123 return Type::TOP;
1124 }
1125 if (r0 == r1 && r0->singleton()) {
1126 // Equal pointer constants (klasses, nulls, etc.)
1127 return TypeInt::CC_EQ;
1128 }
1129
1130 // See if it is 2 unrelated classes.
1131 const TypeOopPtr* p0 = r0->isa_oopptr();
1132 const TypeOopPtr* p1 = r1->isa_oopptr();
1133 if (p0 && p1) {
1134 ciKlass* klass0 = p0->klass();
1135 bool xklass0 = p0->klass_is_exact();
1136 ciKlass* klass1 = p1->klass();
1137 bool xklass1 = p1->klass_is_exact();
1138 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
1139 if (klass0 && klass1 &&
1140 kps != 1 && // both or neither are klass pointers
1141 !klass0->is_interface() && // do not trust interfaces
1142 !klass1->is_interface()) {
1143 bool unrelated_classes = false;
1144 // See if neither subclasses the other, or if the class on top
1145 // is precise. In either of these cases, the compare is known
1146 // to fail if at least one of the pointers is provably not null.
1147 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
1148 // Do nothing; we know nothing for imprecise types
1149 } else if (klass0->is_subtype_of(klass1)) {
1150 // If klass1's type is PRECISE, then classes are unrelated.
1151 unrelated_classes = xklass1;
1152 } else if (klass1->is_subtype_of(klass0)) {
1153 // If klass0's type is PRECISE, then classes are unrelated.
1154 unrelated_classes = xklass0;
1155 } else { // Neither subtypes the other
1156 unrelated_classes = true;
1157 }
1158 if (unrelated_classes) {
1159 // The oops classes are known to be unrelated. If the joined PTRs of
1160 // two oops is not Null and not Bottom, then we are sure that one
1161 // of the two oops is non-null, and the comparison will always fail.
1162 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1163 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1164 return TypeInt::CC_GT;
1165 }
1166 }
1167 }
1168 }
1169
1170 // Known constants can be compared exactly
1171 // Null can be distinguished from any NotNull pointers
1172 // Unknown inputs makes an unknown result
1173 if( r0->singleton() ) {
1174 intptr_t bits0 = r0->get_con();
1175 if( r1->singleton() )
1176 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1177 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1178 } else if( r1->singleton() ) {
1179 intptr_t bits1 = r1->get_con();
1180 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1181 } else
1182 return TypeInt::CC;
1183 }
1184
1185 //------------------------------Ideal------------------------------------------
1186 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1187 return NULL;
1188 }
1189
1190 //=============================================================================
1191 //------------------------------Value------------------------------------------
1192 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1193 // If both inputs are constants, compare them.
1194 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1195 const Node* in1 = in(1);
1196 const Node* in2 = in(2);
1197 // Either input is TOP ==> the result is TOP
1198 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1199 if( t1 == Type::TOP ) return Type::TOP;
1200 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1201 if( t2 == Type::TOP ) return Type::TOP;
1202
1203 // Not constants? Don't know squat - even if they are the same
1204 // value! If they are NaN's they compare to LT instead of EQ.
1205 const TypeF *tf1 = t1->isa_float_constant();
1206 const TypeF *tf2 = t2->isa_float_constant();
1207 if( !tf1 || !tf2 ) return TypeInt::CC;
1208
1209 // This implements the Java bytecode fcmpl, so unordered returns -1.
1210 if( tf1->is_nan() || tf2->is_nan() )
1211 return TypeInt::CC_LT;
1212
1213 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1214 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1215 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1216 return TypeInt::CC_EQ;
1217 }
1218
1219
1220 //=============================================================================
1221 //------------------------------Value------------------------------------------
1222 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1223 // If both inputs are constants, compare them.
1224 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1225 const Node* in1 = in(1);
1226 const Node* in2 = in(2);
1227 // Either input is TOP ==> the result is TOP
1228 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1229 if( t1 == Type::TOP ) return Type::TOP;
1230 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1231 if( t2 == Type::TOP ) return Type::TOP;
1232
1233 // Not constants? Don't know squat - even if they are the same
1234 // value! If they are NaN's they compare to LT instead of EQ.
1235 const TypeD *td1 = t1->isa_double_constant();
1236 const TypeD *td2 = t2->isa_double_constant();
1237 if( !td1 || !td2 ) return TypeInt::CC;
1238
1239 // This implements the Java bytecode dcmpl, so unordered returns -1.
1240 if( td1->is_nan() || td2->is_nan() )
1241 return TypeInt::CC_LT;
1242
1243 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1244 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1245 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1246 return TypeInt::CC_EQ;
1247 }
1248
1249 //------------------------------Ideal------------------------------------------
1250 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1251 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1252 // Change (CMPD (F2D (float)) (ConD value))
1253 // To (CMPF (float) (ConF value))
1254 // Valid when 'value' does not lose precision as a float.
1255 // Benefits: eliminates conversion, does not require 24-bit mode
1256
1257 // NaNs prevent commuting operands. This transform works regardless of the
1258 // order of ConD and ConvF2D inputs by preserving the original order.
1259 int idx_f2d = 1; // ConvF2D on left side?
1260 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1261 idx_f2d = 2; // No, swap to check for reversed args
1262 int idx_con = 3-idx_f2d; // Check for the constant on other input
1263
1264 if( ConvertCmpD2CmpF &&
1265 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1266 in(idx_con)->Opcode() == Op_ConD ) {
1267 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1268 double t2_value_as_double = t2->_d;
1269 float t2_value_as_float = (float)t2_value_as_double;
1270 if( t2_value_as_double == (double)t2_value_as_float ) {
1271 // Test value can be represented as a float
1272 // Eliminate the conversion to double and create new comparison
1273 Node *new_in1 = in(idx_f2d)->in(1);
1274 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1275 if( idx_f2d != 1 ) { // Must flip args to match original order
1276 Node *tmp = new_in1;
1277 new_in1 = new_in2;
1278 new_in2 = tmp;
1279 }
1280 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1281 ? new CmpF3Node( new_in1, new_in2 )
1282 : new CmpFNode ( new_in1, new_in2 ) ;
1283 return new_cmp; // Changed to CmpFNode
1284 }
1285 // Testing value required the precision of a double
1286 }
1287 return NULL; // No change
1288 }
1289
1290
1291 //=============================================================================
1292 //------------------------------cc2logical-------------------------------------
1293 // Convert a condition code type to a logical type
1294 const Type *BoolTest::cc2logical( const Type *CC ) const {
1295 if( CC == Type::TOP ) return Type::TOP;
1296 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1297 const TypeInt *ti = CC->is_int();
1298 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1299 // Match low order 2 bits
1300 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1301 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1302 return TypeInt::make(tmp); // Boolean result
1303 }
1304
1305 if( CC == TypeInt::CC_GE ) {
1306 if( _test == ge ) return TypeInt::ONE;
1307 if( _test == lt ) return TypeInt::ZERO;
1308 }
1309 if( CC == TypeInt::CC_LE ) {
1310 if( _test == le ) return TypeInt::ONE;
1311 if( _test == gt ) return TypeInt::ZERO;
1312 }
1313
1314 return TypeInt::BOOL;
1315 }
1316
1317 //------------------------------dump_spec-------------------------------------
1318 // Print special per-node info
1319 void BoolTest::dump_on(outputStream *st) const {
1320 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1321 st->print("%s", msg[_test]);
1322 }
1323
1324 //=============================================================================
1325 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1326 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1327
1328 //------------------------------operator==-------------------------------------
1329 uint BoolNode::cmp( const Node &n ) const {
1330 const BoolNode *b = (const BoolNode *)&n; // Cast up
1331 return (_test._test == b->_test._test);
1332 }
1333
1334 //-------------------------------make_predicate--------------------------------
1335 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1336 if (test_value->is_Con()) return test_value;
1337 if (test_value->is_Bool()) return test_value;
1338 if (test_value->is_CMove() &&
1339 test_value->in(CMoveNode::Condition)->is_Bool()) {
1340 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1341 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1342 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1343 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1344 return bol;
1345 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1346 return phase->transform( bol->negate(phase) );
1347 }
1348 // Else fall through. The CMove gets in the way of the test.
1349 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1350 }
1351 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1352 cmp = phase->transform(cmp);
1353 Node* bol = new BoolNode(cmp, BoolTest::ne);
1354 return phase->transform(bol);
1355 }
1356
1357 //--------------------------------as_int_value---------------------------------
1358 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1359 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1360 Node* cmov = CMoveNode::make(NULL, this,
1361 phase->intcon(0), phase->intcon(1),
1362 TypeInt::BOOL);
1363 return phase->transform(cmov);
1364 }
1365
1366 //----------------------------------negate-------------------------------------
1367 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1368 return new BoolNode(in(1), _test.negate());
1369 }
1370
1371 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1372 // overflows and we can prove that C is not in the two resulting ranges.
1373 // This optimization is similar to the one performed by CmpUNode::Value().
1374 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1375 int cmp1_op, const TypeInt* cmp2_type) {
1376 // Only optimize eq/ne integer comparison of add/sub
1377 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1378 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1379 // Skip cases were inputs of add/sub are not integers or of bottom type
1380 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1381 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1382 if ((r0 != NULL) && (r0 != TypeInt::INT) &&
1383 (r1 != NULL) && (r1 != TypeInt::INT) &&
1384 (cmp2_type != TypeInt::INT)) {
1385 // Compute exact (long) type range of add/sub result
1386 jlong lo_long = r0->_lo;
1387 jlong hi_long = r0->_hi;
1388 if (cmp1_op == Op_AddI) {
1389 lo_long += r1->_lo;
1390 hi_long += r1->_hi;
1391 } else {
1392 lo_long -= r1->_hi;
1393 hi_long -= r1->_lo;
1394 }
1395 // Check for over-/underflow by casting to integer
1396 int lo_int = (int)lo_long;
1397 int hi_int = (int)hi_long;
1398 bool underflow = lo_long != (jlong)lo_int;
1399 bool overflow = hi_long != (jlong)hi_int;
1400 if ((underflow != overflow) && (hi_int < lo_int)) {
1401 // Overflow on one boundary, compute resulting type ranges:
1402 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1403 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1404 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1405 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1406 // Compare second input of cmp to both type ranges
1407 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1408 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1409 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1410 // The result of the add/sub will never equal cmp2. Replace BoolNode
1411 // by false (0) if it tests for equality and by true (1) otherwise.
1412 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1413 }
1414 }
1415 }
1416 }
1417 return NULL;
1418 }
1419
1420 //------------------------------Ideal------------------------------------------
1421 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1422 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1423 // This moves the constant to the right. Helps value-numbering.
1424 Node *cmp = in(1);
1425 if( !cmp->is_Sub() ) return NULL;
1426 int cop = cmp->Opcode();
1427 if( cop == Op_FastLock || cop == Op_FastUnlock) return NULL;
1428 Node *cmp1 = cmp->in(1);
1429 Node *cmp2 = cmp->in(2);
1430 if( !cmp1 ) return NULL;
1431
1432 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1433 return NULL;
1434 }
1435
1436 // Constant on left?
1437 Node *con = cmp1;
1438 uint op2 = cmp2->Opcode();
1439 // Move constants to the right of compare's to canonicalize.
1440 // Do not muck with Opaque1 nodes, as this indicates a loop
1441 // guard that cannot change shape.
1442 if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 &&
1443 // Because of NaN's, CmpD and CmpF are not commutative
1444 cop != Op_CmpD && cop != Op_CmpF &&
1445 // Protect against swapping inputs to a compare when it is used by a
1446 // counted loop exit, which requires maintaining the loop-limit as in(2)
1447 !is_counted_loop_exit_test() ) {
1448 // Ok, commute the constant to the right of the cmp node.
1449 // Clone the Node, getting a new Node of the same class
1450 cmp = cmp->clone();
1451 // Swap inputs to the clone
1452 cmp->swap_edges(1, 2);
1453 cmp = phase->transform( cmp );
1454 return new BoolNode( cmp, _test.commute() );
1455 }
1456
1457 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1458 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1459 // test instead.
1460 int cmp1_op = cmp1->Opcode();
1461 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1462 if (cmp2_type == NULL) return NULL;
1463 Node* j_xor = cmp1;
1464 if( cmp2_type == TypeInt::ZERO &&
1465 cmp1_op == Op_XorI &&
1466 j_xor->in(1) != j_xor && // An xor of itself is dead
1467 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1468 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1469 (_test._test == BoolTest::eq ||
1470 _test._test == BoolTest::ne) ) {
1471 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1472 return new BoolNode( ncmp, _test.negate() );
1473 }
1474
1475 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1476 // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1477 if (cop == Op_CmpU &&
1478 cmp1->Opcode() == Op_AndI) {
1479 Node* bound = NULL;
1480 if (_test._test == BoolTest::le) {
1481 bound = cmp2;
1482 } else if (_test._test == BoolTest::lt &&
1483 cmp2->Opcode() == Op_AddI &&
1484 cmp2->in(2)->find_int_con(0) == 1) {
1485 bound = cmp2->in(1);
1486 }
1487 if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1488 return ConINode::make(1);
1489 }
1490 }
1491
1492 // Change ((x & (m - 1)) u< m) into (m > 0)
1493 // This is the off-by-one variant of the above
1494 if (cop == Op_CmpU &&
1495 _test._test == BoolTest::lt &&
1496 cmp1->Opcode() == Op_AndI) {
1497 Node* l = cmp1->in(1);
1498 Node* r = cmp1->in(2);
1499 for (int repeat = 0; repeat < 2; repeat++) {
1500 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1501 r->in(1) == cmp2;
1502 if (match) {
1503 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1504 // but to be compatible with the array range check pattern, use (arraylength u> 0)
1505 Node* ncmp = cmp2->Opcode() == Op_LoadRange
1506 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1507 : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1508 return new BoolNode(ncmp, BoolTest::gt);
1509 } else {
1510 // commute and try again
1511 l = cmp1->in(2);
1512 r = cmp1->in(1);
1513 }
1514 }
1515 }
1516
1517 // Change (arraylength <= 0) or (arraylength == 0)
1518 // into (arraylength u<= 0)
1519 // Also change (arraylength != 0) into (arraylength u> 0)
1520 // The latter version matches the code pattern generated for
1521 // array range checks, which will more likely be optimized later.
1522 if (cop == Op_CmpI &&
1523 cmp1->Opcode() == Op_LoadRange &&
1524 cmp2->find_int_con(-1) == 0) {
1525 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1526 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1527 return new BoolNode(ncmp, BoolTest::le);
1528 } else if (_test._test == BoolTest::ne) {
1529 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1530 return new BoolNode(ncmp, BoolTest::gt);
1531 }
1532 }
1533
1534 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1535 // This is a standard idiom for branching on a boolean value.
1536 Node *c2b = cmp1;
1537 if( cmp2_type == TypeInt::ZERO &&
1538 cmp1_op == Op_Conv2B &&
1539 (_test._test == BoolTest::eq ||
1540 _test._test == BoolTest::ne) ) {
1541 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1542 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1543 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1544 );
1545 return new BoolNode( ncmp, _test._test );
1546 }
1547
1548 // Comparing a SubI against a zero is equal to comparing the SubI
1549 // arguments directly. This only works for eq and ne comparisons
1550 // due to possible integer overflow.
1551 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1552 (cop == Op_CmpI) &&
1553 (cmp1->Opcode() == Op_SubI) &&
1554 ( cmp2_type == TypeInt::ZERO ) ) {
1555 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1556 return new BoolNode( ncmp, _test._test );
1557 }
1558
1559 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1560 // most general case because negating 0x80000000 does nothing. Needed for
1561 // the CmpF3/SubI/CmpI idiom.
1562 if( cop == Op_CmpI &&
1563 cmp1->Opcode() == Op_SubI &&
1564 cmp2_type == TypeInt::ZERO &&
1565 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1566 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1567 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1568 return new BoolNode( ncmp, _test.commute() );
1569 }
1570
1571 // Try to optimize signed integer comparison
1572 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1573
1574 // The transformation below is not valid for either signed or unsigned
1575 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1576 // This transformation can be resurrected when we are able to
1577 // make inferences about the range of values being subtracted from
1578 // (or added to) relative to the wraparound point.
1579 //
1580 // // Remove +/-1's if possible.
1581 // // "X <= Y-1" becomes "X < Y"
1582 // // "X+1 <= Y" becomes "X < Y"
1583 // // "X < Y+1" becomes "X <= Y"
1584 // // "X-1 < Y" becomes "X <= Y"
1585 // // Do not this to compares off of the counted-loop-end. These guys are
1586 // // checking the trip counter and they want to use the post-incremented
1587 // // counter. If they use the PRE-incremented counter, then the counter has
1588 // // to be incremented in a private block on a loop backedge.
1589 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1590 // return NULL;
1591 // #ifndef PRODUCT
1592 // // Do not do this in a wash GVN pass during verification.
1593 // // Gets triggered by too many simple optimizations to be bothered with
1594 // // re-trying it again and again.
1595 // if( !phase->allow_progress() ) return NULL;
1596 // #endif
1597 // // Not valid for unsigned compare because of corner cases in involving zero.
1598 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1599 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1600 // // "0 <=u Y" is always true).
1601 // if( cmp->Opcode() == Op_CmpU ) return NULL;
1602 // int cmp2_op = cmp2->Opcode();
1603 // if( _test._test == BoolTest::le ) {
1604 // if( cmp1_op == Op_AddI &&
1605 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1606 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1607 // else if( cmp2_op == Op_AddI &&
1608 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1609 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1610 // } else if( _test._test == BoolTest::lt ) {
1611 // if( cmp1_op == Op_AddI &&
1612 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1613 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1614 // else if( cmp2_op == Op_AddI &&
1615 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1616 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1617 // }
1618 }
1619
1620 //------------------------------Value------------------------------------------
1621 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1622 // based on local information. If the input is constant, do it.
1623 const Type* BoolNode::Value(PhaseGVN* phase) const {
1624 return _test.cc2logical( phase->type( in(1) ) );
1625 }
1626
1627 #ifndef PRODUCT
1628 //------------------------------dump_spec--------------------------------------
1629 // Dump special per-node info
1630 void BoolNode::dump_spec(outputStream *st) const {
1631 st->print("[");
1632 _test.dump_on(st);
1633 st->print("]");
1634 }
1635
1636 //-------------------------------related---------------------------------------
1637 // A BoolNode's related nodes are all of its data inputs, and all of its
1638 // outputs until control nodes are hit, which are included. In compact
1639 // representation, inputs till level 3 and immediate outputs are included.
1640 void BoolNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1641 if (compact) {
1642 this->collect_nodes(in_rel, 3, false, true);
1643 this->collect_nodes(out_rel, -1, false, false);
1644 } else {
1645 this->collect_nodes_in_all_data(in_rel, false);
1646 this->collect_nodes_out_all_ctrl_boundary(out_rel);
1647 }
1648 }
1649 #endif
1650
1651 //----------------------is_counted_loop_exit_test------------------------------
1652 // Returns true if node is used by a counted loop node.
1653 bool BoolNode::is_counted_loop_exit_test() {
1654 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1655 Node* use = fast_out(i);
1656 if (use->is_CountedLoopEnd()) {
1657 return true;
1658 }
1659 }
1660 return false;
1661 }
1662
1663 //=============================================================================
1664 //------------------------------Value------------------------------------------
1665 // Compute sqrt
1666 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
1667 const Type *t1 = phase->type( in(1) );
1668 if( t1 == Type::TOP ) return Type::TOP;
1669 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1670 double d = t1->getd();
1671 if( d < 0.0 ) return Type::DOUBLE;
1672 return TypeD::make( sqrt( d ) );
1673 }
1674
1675 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
1676 const Type *t1 = phase->type( in(1) );
1677 if( t1 == Type::TOP ) return Type::TOP;
1678 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
1679 float f = t1->getf();
1680 if( f < 0.0f ) return Type::FLOAT;
1681 return TypeF::make( (float)sqrt( (double)f ) );
1682 }