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 "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 // Match double null check emitted by Compile::optimize_acmp()
721 if (in(1)->Opcode() == Op_OrL &&
722 in(1)->in(1)->Opcode() == Op_CastP2X &&
723 in(1)->in(2)->Opcode() == Op_CastP2X &&
724 phase->type(in(2))->is_zero_type()) {
725 Node* a = in(1)->in(1)->in(1);
726 Node* b = in(1)->in(2)->in(1);
727 const Type* ta = phase->type(a);
728 const Type* tb = phase->type(b);
729 if (ta->is_zero_type() || tb->is_zero_type()) {
730 // Degraded to a null check, use old acmp
731 return new CmpPNode(a, b);
732 } else if (!TypePtr::NULL_PTR->higher_equal(ta) || !TypePtr::NULL_PTR->higher_equal(tb)) {
733 // One operand is never NULL, emit constant false
734 return new CmpLNode(phase->longcon(0), phase->longcon(1)); // We need to return a new node
735 }
736 }
737 return NULL;
738 }
739
740
741 //=============================================================================
742 // Simplify a CmpL (compare 2 longs ) node, based on local information.
743 // If both inputs are constants, compare them.
744 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
745 const TypeLong *r0 = t1->is_long(); // Handy access
746 const TypeLong *r1 = t2->is_long();
747
748 if( r0->_hi < r1->_lo ) // Range is always low?
749 return TypeInt::CC_LT;
750 else if( r0->_lo > r1->_hi ) // Range is always high?
751 return TypeInt::CC_GT;
752
753 else if( r0->is_con() && r1->is_con() ) { // comparing constants?
754 assert(r0->get_con() == r1->get_con(), "must be equal");
755 return TypeInt::CC_EQ; // Equal results.
756 } else if( r0->_hi == r1->_lo ) // Range is never high?
757 return TypeInt::CC_LE;
758 else if( r0->_lo == r1->_hi ) // Range is never low?
759 return TypeInt::CC_GE;
760 return TypeInt::CC; // else use worst case results
761 }
762
763
764 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information.
765 // If both inputs are constants, compare them.
766 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const {
767 assert(!t1->isa_ptr(), "obsolete usage of CmpUL");
768
769 // comparing two unsigned longs
770 const TypeLong* r0 = t1->is_long(); // Handy access
771 const TypeLong* r1 = t2->is_long();
772
773 // Current installed version
774 // Compare ranges for non-overlap
775 julong lo0 = r0->_lo;
776 julong hi0 = r0->_hi;
777 julong lo1 = r1->_lo;
778 julong hi1 = r1->_hi;
779
780 // If either one has both negative and positive values,
781 // it therefore contains both 0 and -1, and since [0..-1] is the
782 // full unsigned range, the type must act as an unsigned bottom.
783 bool bot0 = ((jlong)(lo0 ^ hi0) < 0);
784 bool bot1 = ((jlong)(lo1 ^ hi1) < 0);
785
786 if (bot0 || bot1) {
787 // All unsigned values are LE -1 and GE 0.
788 if (lo0 == 0 && hi0 == 0) {
789 return TypeInt::CC_LE; // 0 <= bot
790 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) {
791 return TypeInt::CC_GE; // -1 >= bot
792 } else if (lo1 == 0 && hi1 == 0) {
793 return TypeInt::CC_GE; // bot >= 0
794 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) {
795 return TypeInt::CC_LE; // bot <= -1
796 }
797 } else {
798 // We can use ranges of the form [lo..hi] if signs are the same.
799 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
800 // results are reversed, '-' > '+' for unsigned compare
801 if (hi0 < lo1) {
802 return TypeInt::CC_LT; // smaller
803 } else if (lo0 > hi1) {
804 return TypeInt::CC_GT; // greater
805 } else if (hi0 == lo1 && lo0 == hi1) {
806 return TypeInt::CC_EQ; // Equal results
807 } else if (lo0 >= hi1) {
808 return TypeInt::CC_GE;
809 } else if (hi0 <= lo1) {
810 return TypeInt::CC_LE;
811 }
812 }
813
814 return TypeInt::CC; // else use worst case results
815 }
816
817 //=============================================================================
818 //------------------------------sub--------------------------------------------
819 // Simplify an CmpP (compare 2 pointers) node, based on local information.
820 // If both inputs are constants, compare them.
821 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
822 const TypePtr *r0 = t1->is_ptr(); // Handy access
823 const TypePtr *r1 = t2->is_ptr();
824
825 // Undefined inputs makes for an undefined result
826 if( TypePtr::above_centerline(r0->_ptr) ||
827 TypePtr::above_centerline(r1->_ptr) )
828 return Type::TOP;
829
830 if (r0 == r1 && r0->singleton()) {
831 // Equal pointer constants (klasses, nulls, etc.)
832 return TypeInt::CC_EQ;
833 }
834
835 // Optimize old acmp with value type operands
836 if ((r0->is_valuetypeptr()|| r1->is_valuetypeptr()) &&
837 (!TypePtr::NULL_PTR->higher_equal(r0) || !TypePtr::NULL_PTR->higher_equal(r1))) {
838 // One operand is a value type and one operand is never null, fold to constant false
839 return TypeInt::CC_GT;
840 }
841
842 // See if it is 2 unrelated classes.
843 const TypeOopPtr* p0 = r0->isa_oopptr();
844 const TypeOopPtr* p1 = r1->isa_oopptr();
845 if (p0 && p1) {
846 Node* in1 = in(1)->uncast();
847 Node* in2 = in(2)->uncast();
848 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
849 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
850 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
851 return TypeInt::CC_GT; // different pointers
852 }
853 ciKlass* klass0 = p0->klass();
854 bool xklass0 = p0->klass_is_exact();
855 ciKlass* klass1 = p1->klass();
856 bool xklass1 = p1->klass_is_exact();
857 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
858 if (klass0 && klass1 &&
859 kps != 1 && // both or neither are klass pointers
860 klass0->is_loaded() && !klass0->is_interface() && // do not trust interfaces
861 klass1->is_loaded() && !klass1->is_interface() &&
862 (!klass0->is_obj_array_klass() ||
863 !klass0->as_obj_array_klass()->base_element_klass()->is_interface()) &&
864 (!klass1->is_obj_array_klass() ||
865 !klass1->as_obj_array_klass()->base_element_klass()->is_interface())) {
866 bool unrelated_classes = false;
867 // See if neither subclasses the other, or if the class on top
868 // is precise. In either of these cases, the compare is known
869 // to fail if at least one of the pointers is provably not null.
870 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
871 // Do nothing; we know nothing for imprecise types
872 } else if (klass0->is_subtype_of(klass1)) {
873 // If klass1's type is PRECISE, then classes are unrelated.
874 unrelated_classes = xklass1;
875 } else if (klass1->is_subtype_of(klass0)) {
876 // If klass0's type is PRECISE, then classes are unrelated.
877 unrelated_classes = xklass0;
878 } else { // Neither subtypes the other
879 unrelated_classes = true;
880 }
881 if (unrelated_classes) {
882 // The oops classes are known to be unrelated. If the joined PTRs of
883 // two oops is not Null and not Bottom, then we are sure that one
884 // of the two oops is non-null, and the comparison will always fail.
885 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
886 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
887 return TypeInt::CC_GT;
888 }
889 }
890 }
891 }
892
893 // Known constants can be compared exactly
894 // Null can be distinguished from any NotNull pointers
895 // Unknown inputs makes an unknown result
896 if( r0->singleton() ) {
897 intptr_t bits0 = r0->get_con();
898 if( r1->singleton() )
899 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
900 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
901 } else if( r1->singleton() ) {
902 intptr_t bits1 = r1->get_con();
903 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
904 } else
905 return TypeInt::CC;
906 }
907
908 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
909 // Return the klass node for (indirect load from OopHandle)
910 // LoadP(LoadP(AddP(foo:Klass, #java_mirror)))
911 // or NULL if not matching.
912 if (n->Opcode() != Op_LoadP) return NULL;
913
914 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
915 if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
916
917 Node* adr = n->in(MemNode::Address);
918 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
919 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return NULL;
920 adr = adr->in(MemNode::Address);
921
922 intptr_t off = 0;
923 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
924 if (k == NULL) return NULL;
925 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
926 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return NULL;
927
928 // We've found the klass node of a Java mirror load.
929 return k;
930 }
931
932 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
933 // for ConP(Foo.class) return ConP(Foo.klass)
934 // otherwise return NULL
935 if (!n->is_Con()) return NULL;
936
937 const TypeInstPtr* tp = phase->type(n)->isa_instptr();
938 if (!tp) return NULL;
939
940 ciType* mirror_type = tp->java_mirror_type();
941 // TypeInstPtr::java_mirror_type() returns non-NULL for compile-
942 // time Class constants only.
943 if (!mirror_type) return NULL;
944
945 // x.getClass() == int.class can never be true (for all primitive types)
946 // Return a ConP(NULL) node for this case.
947 if (mirror_type->is_classless()) {
948 return phase->makecon(TypePtr::NULL_PTR);
949 }
950
951 // return the ConP(Foo.klass)
952 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
953 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass()));
954 }
955
956 //------------------------------Ideal------------------------------------------
957 // Normalize comparisons between Java mirror loads to compare the klass instead.
958 //
959 // Also check for the case of comparing an unknown klass loaded from the primary
960 // super-type array vs a known klass with no subtypes. This amounts to
961 // checking to see an unknown klass subtypes a known klass with no subtypes;
962 // this only happens on an exact match. We can shorten this test by 1 load.
963 Node* CmpPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
964 Node* pert = has_perturbed_operand();
965 if (pert != NULL) {
966 // Optimize new acmp
967 Node* a = pert->in(AddPNode::Base); // unperturbed a
968 Node* b = in(2);
969 Node* cmp = phase->C->optimize_acmp(phase, a, b);
970 if (cmp != NULL) {
971 return cmp;
972 }
973 if ( TypePtr::NULL_PTR->higher_equal(phase->type(a)) &&
974 !TypePtr::NULL_PTR->higher_equal(phase->type(b))) {
975 // Operand 'b' is never null, swap operands to avoid null check
976 Node* is_value = phase->C->load_is_value_bit(phase, b);
977 set_req(1, phase->transform(new AddPNode(b, b, is_value)));
978 set_req(2, a);
979 return this;
980 }
981 }
982
983 // Normalize comparisons between Java mirrors into comparisons of the low-
984 // level klass, where a dependent load could be shortened.
985 //
986 // The new pattern has a nice effect of matching the same pattern used in the
987 // fast path of instanceof/checkcast/Class.isInstance(), which allows
988 // redundant exact type check be optimized away by GVN.
989 // For example, in
990 // if (x.getClass() == Foo.class) {
991 // Foo foo = (Foo) x;
992 // // ... use a ...
993 // }
994 // a CmpPNode could be shared between if_acmpne and checkcast
995 {
996 Node* k1 = isa_java_mirror_load(phase, in(1));
997 Node* k2 = isa_java_mirror_load(phase, in(2));
998 Node* conk2 = isa_const_java_mirror(phase, in(2));
999
1000 if (k1 && (k2 || conk2)) {
1001 Node* lhs = k1;
1002 Node* rhs = (k2 != NULL) ? k2 : conk2;
1003 this->set_req(1, lhs);
1004 this->set_req(2, rhs);
1005 return this;
1006 }
1007 }
1008
1009 // Constant pointer on right?
1010 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
1011 if (t2 == NULL || !t2->klass_is_exact())
1012 return NULL;
1013 // Get the constant klass we are comparing to.
1014 ciKlass* superklass = t2->klass();
1015
1016 // Now check for LoadKlass on left.
1017 Node* ldk1 = in(1);
1018 if (ldk1->is_DecodeNKlass()) {
1019 ldk1 = ldk1->in(1);
1020 if (ldk1->Opcode() != Op_LoadNKlass )
1021 return NULL;
1022 } else if (ldk1->Opcode() != Op_LoadKlass )
1023 return NULL;
1024 // Take apart the address of the LoadKlass:
1025 Node* adr1 = ldk1->in(MemNode::Address);
1026 intptr_t con2 = 0;
1027 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
1028 if (ldk2 == NULL)
1029 return NULL;
1030 if (con2 == oopDesc::klass_offset_in_bytes()) {
1031 // We are inspecting an object's concrete class.
1032 // Short-circuit the check if the query is abstract.
1033 if (superklass->is_interface() ||
1034 superklass->is_abstract()) {
1035 // Make it come out always false:
1036 this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
1037 return this;
1038 }
1039 }
1040
1041 // Check for a LoadKlass from primary supertype array.
1042 // Any nested loadklass from loadklass+con must be from the p.s. array.
1043 if (ldk2->is_DecodeNKlass()) {
1044 // Keep ldk2 as DecodeN since it could be used in CmpP below.
1045 if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
1046 return NULL;
1047 } else if (ldk2->Opcode() != Op_LoadKlass)
1048 return NULL;
1049
1050 // Verify that we understand the situation
1051 if (con2 != (intptr_t) superklass->super_check_offset())
1052 return NULL; // Might be element-klass loading from array klass
1053
1054 // If 'superklass' has no subklasses and is not an interface, then we are
1055 // assured that the only input which will pass the type check is
1056 // 'superklass' itself.
1057 //
1058 // We could be more liberal here, and allow the optimization on interfaces
1059 // which have a single implementor. This would require us to increase the
1060 // expressiveness of the add_dependency() mechanism.
1061 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now.
1062
1063 // Object arrays must have their base element have no subtypes
1064 while (superklass->is_obj_array_klass()) {
1065 ciType* elem = superklass->as_obj_array_klass()->element_type();
1066 superklass = elem->as_klass();
1067 }
1068 if (superklass->is_instance_klass()) {
1069 ciInstanceKlass* ik = superklass->as_instance_klass();
1070 if (ik->has_subklass() || ik->is_interface()) return NULL;
1071 // Add a dependency if there is a chance that a subclass will be added later.
1072 if (!ik->is_final()) {
1073 phase->C->dependencies()->assert_leaf_type(ik);
1074 }
1075 }
1076
1077 // Bypass the dependent load, and compare directly
1078 this->set_req(1,ldk2);
1079
1080 return this;
1081 }
1082
1083 // Checks if one operand is perturbed and returns it
1084 Node* CmpPNode::has_perturbed_operand() const {
1085 // We always perturbe the first operand
1086 AddPNode* addP = in(1)->isa_AddP();
1087 if (addP != NULL) {
1088 Node* base = addP->in(AddPNode::Base);
1089 if (base->is_top()) {
1090 // RawPtr comparison
1091 return NULL;
1092 }
1093 assert(EnableValhalla, "unexpected perturbed oop");
1094 return in(1);
1095 }
1096 return NULL;
1097 }
1098
1099 //=============================================================================
1100 //------------------------------sub--------------------------------------------
1101 // Simplify an CmpN (compare 2 pointers) node, based on local information.
1102 // If both inputs are constants, compare them.
1103 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
1104 const TypePtr *r0 = t1->make_ptr(); // Handy access
1105 const TypePtr *r1 = t2->make_ptr();
1106
1107 // Undefined inputs makes for an undefined result
1108 if ((r0 == NULL) || (r1 == NULL) ||
1109 TypePtr::above_centerline(r0->_ptr) ||
1110 TypePtr::above_centerline(r1->_ptr)) {
1111 return Type::TOP;
1112 }
1113 if (r0 == r1 && r0->singleton()) {
1114 // Equal pointer constants (klasses, nulls, etc.)
1115 return TypeInt::CC_EQ;
1116 }
1117
1118 // See if it is 2 unrelated classes.
1119 const TypeOopPtr* p0 = r0->isa_oopptr();
1120 const TypeOopPtr* p1 = r1->isa_oopptr();
1121 if (p0 && p1) {
1122 ciKlass* klass0 = p0->klass();
1123 bool xklass0 = p0->klass_is_exact();
1124 ciKlass* klass1 = p1->klass();
1125 bool xklass1 = p1->klass_is_exact();
1126 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
1127 if (klass0 && klass1 &&
1128 kps != 1 && // both or neither are klass pointers
1129 !klass0->is_interface() && // do not trust interfaces
1130 !klass1->is_interface()) {
1131 bool unrelated_classes = false;
1132 // See if neither subclasses the other, or if the class on top
1133 // is precise. In either of these cases, the compare is known
1134 // to fail if at least one of the pointers is provably not null.
1135 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
1136 // Do nothing; we know nothing for imprecise types
1137 } else if (klass0->is_subtype_of(klass1)) {
1138 // If klass1's type is PRECISE, then classes are unrelated.
1139 unrelated_classes = xklass1;
1140 } else if (klass1->is_subtype_of(klass0)) {
1141 // If klass0's type is PRECISE, then classes are unrelated.
1142 unrelated_classes = xklass0;
1143 } else { // Neither subtypes the other
1144 unrelated_classes = true;
1145 }
1146 if (unrelated_classes) {
1147 // The oops classes are known to be unrelated. If the joined PTRs of
1148 // two oops is not Null and not Bottom, then we are sure that one
1149 // of the two oops is non-null, and the comparison will always fail.
1150 TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
1151 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
1152 return TypeInt::CC_GT;
1153 }
1154 }
1155 }
1156 }
1157
1158 // Known constants can be compared exactly
1159 // Null can be distinguished from any NotNull pointers
1160 // Unknown inputs makes an unknown result
1161 if( r0->singleton() ) {
1162 intptr_t bits0 = r0->get_con();
1163 if( r1->singleton() )
1164 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1165 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1166 } else if( r1->singleton() ) {
1167 intptr_t bits1 = r1->get_con();
1168 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1169 } else
1170 return TypeInt::CC;
1171 }
1172
1173 //------------------------------Ideal------------------------------------------
1174 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
1175 return NULL;
1176 }
1177
1178 //=============================================================================
1179 //------------------------------Value------------------------------------------
1180 // Simplify an CmpF (compare 2 floats ) node, based on local information.
1181 // If both inputs are constants, compare them.
1182 const Type* CmpFNode::Value(PhaseGVN* phase) const {
1183 const Node* in1 = in(1);
1184 const Node* in2 = in(2);
1185 // Either input is TOP ==> the result is TOP
1186 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1187 if( t1 == Type::TOP ) return Type::TOP;
1188 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1189 if( t2 == Type::TOP ) return Type::TOP;
1190
1191 // Not constants? Don't know squat - even if they are the same
1192 // value! If they are NaN's they compare to LT instead of EQ.
1193 const TypeF *tf1 = t1->isa_float_constant();
1194 const TypeF *tf2 = t2->isa_float_constant();
1195 if( !tf1 || !tf2 ) return TypeInt::CC;
1196
1197 // This implements the Java bytecode fcmpl, so unordered returns -1.
1198 if( tf1->is_nan() || tf2->is_nan() )
1199 return TypeInt::CC_LT;
1200
1201 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
1202 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
1203 assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
1204 return TypeInt::CC_EQ;
1205 }
1206
1207
1208 //=============================================================================
1209 //------------------------------Value------------------------------------------
1210 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
1211 // If both inputs are constants, compare them.
1212 const Type* CmpDNode::Value(PhaseGVN* phase) const {
1213 const Node* in1 = in(1);
1214 const Node* in2 = in(2);
1215 // Either input is TOP ==> the result is TOP
1216 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
1217 if( t1 == Type::TOP ) return Type::TOP;
1218 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
1219 if( t2 == Type::TOP ) return Type::TOP;
1220
1221 // Not constants? Don't know squat - even if they are the same
1222 // value! If they are NaN's they compare to LT instead of EQ.
1223 const TypeD *td1 = t1->isa_double_constant();
1224 const TypeD *td2 = t2->isa_double_constant();
1225 if( !td1 || !td2 ) return TypeInt::CC;
1226
1227 // This implements the Java bytecode dcmpl, so unordered returns -1.
1228 if( td1->is_nan() || td2->is_nan() )
1229 return TypeInt::CC_LT;
1230
1231 if( td1->_d < td2->_d ) return TypeInt::CC_LT;
1232 if( td1->_d > td2->_d ) return TypeInt::CC_GT;
1233 assert( td1->_d == td2->_d, "do not understand FP behavior" );
1234 return TypeInt::CC_EQ;
1235 }
1236
1237 //------------------------------Ideal------------------------------------------
1238 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
1239 // Check if we can change this to a CmpF and remove a ConvD2F operation.
1240 // Change (CMPD (F2D (float)) (ConD value))
1241 // To (CMPF (float) (ConF value))
1242 // Valid when 'value' does not lose precision as a float.
1243 // Benefits: eliminates conversion, does not require 24-bit mode
1244
1245 // NaNs prevent commuting operands. This transform works regardless of the
1246 // order of ConD and ConvF2D inputs by preserving the original order.
1247 int idx_f2d = 1; // ConvF2D on left side?
1248 if( in(idx_f2d)->Opcode() != Op_ConvF2D )
1249 idx_f2d = 2; // No, swap to check for reversed args
1250 int idx_con = 3-idx_f2d; // Check for the constant on other input
1251
1252 if( ConvertCmpD2CmpF &&
1253 in(idx_f2d)->Opcode() == Op_ConvF2D &&
1254 in(idx_con)->Opcode() == Op_ConD ) {
1255 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
1256 double t2_value_as_double = t2->_d;
1257 float t2_value_as_float = (float)t2_value_as_double;
1258 if( t2_value_as_double == (double)t2_value_as_float ) {
1259 // Test value can be represented as a float
1260 // Eliminate the conversion to double and create new comparison
1261 Node *new_in1 = in(idx_f2d)->in(1);
1262 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
1263 if( idx_f2d != 1 ) { // Must flip args to match original order
1264 Node *tmp = new_in1;
1265 new_in1 = new_in2;
1266 new_in2 = tmp;
1267 }
1268 CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
1269 ? new CmpF3Node( new_in1, new_in2 )
1270 : new CmpFNode ( new_in1, new_in2 ) ;
1271 return new_cmp; // Changed to CmpFNode
1272 }
1273 // Testing value required the precision of a double
1274 }
1275 return NULL; // No change
1276 }
1277
1278
1279 //=============================================================================
1280 //------------------------------cc2logical-------------------------------------
1281 // Convert a condition code type to a logical type
1282 const Type *BoolTest::cc2logical( const Type *CC ) const {
1283 if( CC == Type::TOP ) return Type::TOP;
1284 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
1285 const TypeInt *ti = CC->is_int();
1286 if( ti->is_con() ) { // Only 1 kind of condition codes set?
1287 // Match low order 2 bits
1288 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
1289 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result
1290 return TypeInt::make(tmp); // Boolean result
1291 }
1292
1293 if( CC == TypeInt::CC_GE ) {
1294 if( _test == ge ) return TypeInt::ONE;
1295 if( _test == lt ) return TypeInt::ZERO;
1296 }
1297 if( CC == TypeInt::CC_LE ) {
1298 if( _test == le ) return TypeInt::ONE;
1299 if( _test == gt ) return TypeInt::ZERO;
1300 }
1301
1302 return TypeInt::BOOL;
1303 }
1304
1305 //------------------------------dump_spec-------------------------------------
1306 // Print special per-node info
1307 void BoolTest::dump_on(outputStream *st) const {
1308 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
1309 st->print("%s", msg[_test]);
1310 }
1311
1312 //=============================================================================
1313 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1314 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1315
1316 //------------------------------operator==-------------------------------------
1317 uint BoolNode::cmp( const Node &n ) const {
1318 const BoolNode *b = (const BoolNode *)&n; // Cast up
1319 return (_test._test == b->_test._test);
1320 }
1321
1322 //-------------------------------make_predicate--------------------------------
1323 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1324 if (test_value->is_Con()) return test_value;
1325 if (test_value->is_Bool()) return test_value;
1326 if (test_value->is_CMove() &&
1327 test_value->in(CMoveNode::Condition)->is_Bool()) {
1328 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool();
1329 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1330 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1331 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1332 return bol;
1333 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1334 return phase->transform( bol->negate(phase) );
1335 }
1336 // Else fall through. The CMove gets in the way of the test.
1337 // It should be the case that make_predicate(bol->as_int_value()) == bol.
1338 }
1339 Node* cmp = new CmpINode(test_value, phase->intcon(0));
1340 cmp = phase->transform(cmp);
1341 Node* bol = new BoolNode(cmp, BoolTest::ne);
1342 return phase->transform(bol);
1343 }
1344
1345 //--------------------------------as_int_value---------------------------------
1346 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1347 // Inverse to make_predicate. The CMove probably boils down to a Conv2B.
1348 Node* cmov = CMoveNode::make(NULL, this,
1349 phase->intcon(0), phase->intcon(1),
1350 TypeInt::BOOL);
1351 return phase->transform(cmov);
1352 }
1353
1354 //----------------------------------negate-------------------------------------
1355 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1356 return new BoolNode(in(1), _test.negate());
1357 }
1358
1359 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub
1360 // overflows and we can prove that C is not in the two resulting ranges.
1361 // This optimization is similar to the one performed by CmpUNode::Value().
1362 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
1363 int cmp1_op, const TypeInt* cmp2_type) {
1364 // Only optimize eq/ne integer comparison of add/sub
1365 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1366 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) {
1367 // Skip cases were inputs of add/sub are not integers or of bottom type
1368 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int();
1369 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int();
1370 if ((r0 != NULL) && (r0 != TypeInt::INT) &&
1371 (r1 != NULL) && (r1 != TypeInt::INT) &&
1372 (cmp2_type != TypeInt::INT)) {
1373 // Compute exact (long) type range of add/sub result
1374 jlong lo_long = r0->_lo;
1375 jlong hi_long = r0->_hi;
1376 if (cmp1_op == Op_AddI) {
1377 lo_long += r1->_lo;
1378 hi_long += r1->_hi;
1379 } else {
1380 lo_long -= r1->_hi;
1381 hi_long -= r1->_lo;
1382 }
1383 // Check for over-/underflow by casting to integer
1384 int lo_int = (int)lo_long;
1385 int hi_int = (int)hi_long;
1386 bool underflow = lo_long != (jlong)lo_int;
1387 bool overflow = hi_long != (jlong)hi_int;
1388 if ((underflow != overflow) && (hi_int < lo_int)) {
1389 // Overflow on one boundary, compute resulting type ranges:
1390 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT]
1391 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
1392 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w);
1393 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w);
1394 // Compare second input of cmp to both type ranges
1395 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type);
1396 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type);
1397 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) {
1398 // The result of the add/sub will never equal cmp2. Replace BoolNode
1399 // by false (0) if it tests for equality and by true (1) otherwise.
1400 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1);
1401 }
1402 }
1403 }
1404 }
1405 return NULL;
1406 }
1407
1408 //------------------------------Ideal------------------------------------------
1409 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1410 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1411 // This moves the constant to the right. Helps value-numbering.
1412 Node *cmp = in(1);
1413 if( !cmp->is_Sub() ) return NULL;
1414 int cop = cmp->Opcode();
1415 if( cop == Op_FastLock || cop == Op_FastUnlock) return NULL;
1416 Node *cmp1 = cmp->in(1);
1417 Node *cmp2 = cmp->in(2);
1418 if( !cmp1 ) return NULL;
1419
1420 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
1421 return NULL;
1422 }
1423
1424 // Constant on left?
1425 Node *con = cmp1;
1426 uint op2 = cmp2->Opcode();
1427 // Move constants to the right of compare's to canonicalize.
1428 // Do not muck with Opaque1 nodes, as this indicates a loop
1429 // guard that cannot change shape.
1430 if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 &&
1431 // Because of NaN's, CmpD and CmpF are not commutative
1432 cop != Op_CmpD && cop != Op_CmpF &&
1433 // Protect against swapping inputs to a compare when it is used by a
1434 // counted loop exit, which requires maintaining the loop-limit as in(2)
1435 !is_counted_loop_exit_test() ) {
1436 // Ok, commute the constant to the right of the cmp node.
1437 // Clone the Node, getting a new Node of the same class
1438 cmp = cmp->clone();
1439 // Swap inputs to the clone
1440 cmp->swap_edges(1, 2);
1441 cmp = phase->transform( cmp );
1442 return new BoolNode( cmp, _test.commute() );
1443 }
1444
1445 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1446 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the
1447 // test instead.
1448 int cmp1_op = cmp1->Opcode();
1449 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1450 if (cmp2_type == NULL) return NULL;
1451 Node* j_xor = cmp1;
1452 if( cmp2_type == TypeInt::ZERO &&
1453 cmp1_op == Op_XorI &&
1454 j_xor->in(1) != j_xor && // An xor of itself is dead
1455 phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1456 phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1457 (_test._test == BoolTest::eq ||
1458 _test._test == BoolTest::ne) ) {
1459 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2));
1460 return new BoolNode( ncmp, _test.negate() );
1461 }
1462
1463 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true
1464 // Same with ((x & m) u< m+1) and ((m & x) u< m+1)
1465 if (cop == Op_CmpU &&
1466 cmp1->Opcode() == Op_AndI) {
1467 Node* bound = NULL;
1468 if (_test._test == BoolTest::le) {
1469 bound = cmp2;
1470 } else if (_test._test == BoolTest::lt &&
1471 cmp2->Opcode() == Op_AddI &&
1472 cmp2->in(2)->find_int_con(0) == 1) {
1473 bound = cmp2->in(1);
1474 }
1475 if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
1476 return ConINode::make(1);
1477 }
1478 }
1479
1480 // Change ((x & (m - 1)) u< m) into (m > 0)
1481 // This is the off-by-one variant of the above
1482 if (cop == Op_CmpU &&
1483 _test._test == BoolTest::lt &&
1484 cmp1->Opcode() == Op_AndI) {
1485 Node* l = cmp1->in(1);
1486 Node* r = cmp1->in(2);
1487 for (int repeat = 0; repeat < 2; repeat++) {
1488 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
1489 r->in(1) == cmp2;
1490 if (match) {
1491 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
1492 // but to be compatible with the array range check pattern, use (arraylength u> 0)
1493 Node* ncmp = cmp2->Opcode() == Op_LoadRange
1494 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
1495 : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
1496 return new BoolNode(ncmp, BoolTest::gt);
1497 } else {
1498 // commute and try again
1499 l = cmp1->in(2);
1500 r = cmp1->in(1);
1501 }
1502 }
1503 }
1504
1505 // Change (arraylength <= 0) or (arraylength == 0)
1506 // into (arraylength u<= 0)
1507 // Also change (arraylength != 0) into (arraylength u> 0)
1508 // The latter version matches the code pattern generated for
1509 // array range checks, which will more likely be optimized later.
1510 if (cop == Op_CmpI &&
1511 cmp1->Opcode() == Op_LoadRange &&
1512 cmp2->find_int_con(-1) == 0) {
1513 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) {
1514 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1515 return new BoolNode(ncmp, BoolTest::le);
1516 } else if (_test._test == BoolTest::ne) {
1517 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2));
1518 return new BoolNode(ncmp, BoolTest::gt);
1519 }
1520 }
1521
1522 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1523 // This is a standard idiom for branching on a boolean value.
1524 Node *c2b = cmp1;
1525 if( cmp2_type == TypeInt::ZERO &&
1526 cmp1_op == Op_Conv2B &&
1527 (_test._test == BoolTest::eq ||
1528 _test._test == BoolTest::ne) ) {
1529 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1530 ? (Node*)new CmpINode(c2b->in(1),cmp2)
1531 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1532 );
1533 return new BoolNode( ncmp, _test._test );
1534 }
1535
1536 // Comparing a SubI against a zero is equal to comparing the SubI
1537 // arguments directly. This only works for eq and ne comparisons
1538 // due to possible integer overflow.
1539 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1540 (cop == Op_CmpI) &&
1541 (cmp1->Opcode() == Op_SubI) &&
1542 ( cmp2_type == TypeInt::ZERO ) ) {
1543 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2)));
1544 return new BoolNode( ncmp, _test._test );
1545 }
1546
1547 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the
1548 // most general case because negating 0x80000000 does nothing. Needed for
1549 // the CmpF3/SubI/CmpI idiom.
1550 if( cop == Op_CmpI &&
1551 cmp1->Opcode() == Op_SubI &&
1552 cmp2_type == TypeInt::ZERO &&
1553 phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1554 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1555 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2));
1556 return new BoolNode( ncmp, _test.commute() );
1557 }
1558
1559 // Try to optimize signed integer comparison
1560 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type);
1561
1562 // The transformation below is not valid for either signed or unsigned
1563 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1564 // This transformation can be resurrected when we are able to
1565 // make inferences about the range of values being subtracted from
1566 // (or added to) relative to the wraparound point.
1567 //
1568 // // Remove +/-1's if possible.
1569 // // "X <= Y-1" becomes "X < Y"
1570 // // "X+1 <= Y" becomes "X < Y"
1571 // // "X < Y+1" becomes "X <= Y"
1572 // // "X-1 < Y" becomes "X <= Y"
1573 // // Do not this to compares off of the counted-loop-end. These guys are
1574 // // checking the trip counter and they want to use the post-incremented
1575 // // counter. If they use the PRE-incremented counter, then the counter has
1576 // // to be incremented in a private block on a loop backedge.
1577 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1578 // return NULL;
1579 // #ifndef PRODUCT
1580 // // Do not do this in a wash GVN pass during verification.
1581 // // Gets triggered by too many simple optimizations to be bothered with
1582 // // re-trying it again and again.
1583 // if( !phase->allow_progress() ) return NULL;
1584 // #endif
1585 // // Not valid for unsigned compare because of corner cases in involving zero.
1586 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1587 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1588 // // "0 <=u Y" is always true).
1589 // if( cmp->Opcode() == Op_CmpU ) return NULL;
1590 // int cmp2_op = cmp2->Opcode();
1591 // if( _test._test == BoolTest::le ) {
1592 // if( cmp1_op == Op_AddI &&
1593 // phase->type( cmp1->in(2) ) == TypeInt::ONE )
1594 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1595 // else if( cmp2_op == Op_AddI &&
1596 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1597 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1598 // } else if( _test._test == BoolTest::lt ) {
1599 // if( cmp1_op == Op_AddI &&
1600 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1601 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1602 // else if( cmp2_op == Op_AddI &&
1603 // phase->type( cmp2->in(2) ) == TypeInt::ONE )
1604 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1605 // }
1606 }
1607
1608 //------------------------------Value------------------------------------------
1609 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1610 // based on local information. If the input is constant, do it.
1611 const Type* BoolNode::Value(PhaseGVN* phase) const {
1612 return _test.cc2logical( phase->type( in(1) ) );
1613 }
1614
1615 #ifndef PRODUCT
1616 //------------------------------dump_spec--------------------------------------
1617 // Dump special per-node info
1618 void BoolNode::dump_spec(outputStream *st) const {
1619 st->print("[");
1620 _test.dump_on(st);
1621 st->print("]");
1622 }
1623
1624 //-------------------------------related---------------------------------------
1625 // A BoolNode's related nodes are all of its data inputs, and all of its
1626 // outputs until control nodes are hit, which are included. In compact
1627 // representation, inputs till level 3 and immediate outputs are included.
1628 void BoolNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1629 if (compact) {
1630 this->collect_nodes(in_rel, 3, false, true);
1631 this->collect_nodes(out_rel, -1, false, false);
1632 } else {
1633 this->collect_nodes_in_all_data(in_rel, false);
1634 this->collect_nodes_out_all_ctrl_boundary(out_rel);
1635 }
1636 }
1637 #endif
1638
1639 //----------------------is_counted_loop_exit_test------------------------------
1640 // Returns true if node is used by a counted loop node.
1641 bool BoolNode::is_counted_loop_exit_test() {
1642 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1643 Node* use = fast_out(i);
1644 if (use->is_CountedLoopEnd()) {
1645 return true;
1646 }
1647 }
1648 return false;
1649 }
1650
1651 //=============================================================================
1652 //------------------------------Value------------------------------------------
1653 // Compute sqrt
1654 const Type* SqrtDNode::Value(PhaseGVN* phase) const {
1655 const Type *t1 = phase->type( in(1) );
1656 if( t1 == Type::TOP ) return Type::TOP;
1657 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1658 double d = t1->getd();
1659 if( d < 0.0 ) return Type::DOUBLE;
1660 return TypeD::make( sqrt( d ) );
1661 }
1662
1663 const Type* SqrtFNode::Value(PhaseGVN* phase) const {
1664 const Type *t1 = phase->type( in(1) );
1665 if( t1 == Type::TOP ) return Type::TOP;
1666 if( t1->base() != Type::FloatCon ) return Type::FLOAT;
1667 float f = t1->getf();
1668 if( f < 0.0f ) return Type::FLOAT;
1669 return TypeF::make( (float)sqrt( (double)f ) );
1670 }