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 n = bs->step_over_gc_barrier(n); 929 930 if (n->Opcode() != Op_LoadP) return NULL; 931 932 const TypeInstPtr* tp = phase->type(n)->isa_instptr(); 933 if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL; 934 935 Node* adr = n->in(MemNode::Address); 936 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier. 937 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return NULL; 938 adr = adr->in(MemNode::Address); 939 940 intptr_t off = 0; 941 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off); 942 if (k == NULL) return NULL; 943 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr(); 944 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return NULL; 945 946 // We've found the klass node of a Java mirror load. 947 return k; 948 } 949 950 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) { 951 // for ConP(Foo.class) return ConP(Foo.klass) 952 // otherwise return NULL 953 if (!n->is_Con()) return NULL; 954 955 const TypeInstPtr* tp = phase->type(n)->isa_instptr(); 956 if (!tp) return NULL; 957 958 ciType* mirror_type = tp->java_mirror_type(); 959 // TypeInstPtr::java_mirror_type() returns non-NULL for compile- 960 // time Class constants only. 961 if (!mirror_type) return NULL; 962 963 // x.getClass() == int.class can never be true (for all primitive types) 964 // Return a ConP(NULL) node for this case. 965 if (mirror_type->is_classless()) { 966 return phase->makecon(TypePtr::NULL_PTR); 967 } 968 969 // return the ConP(Foo.klass) 970 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*"); 971 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass())); 972 } 973 974 //------------------------------Ideal------------------------------------------ 975 // Normalize comparisons between Java mirror loads to compare the klass instead. 976 // 977 // Also check for the case of comparing an unknown klass loaded from the primary 978 // super-type array vs a known klass with no subtypes. This amounts to 979 // checking to see an unknown klass subtypes a known klass with no subtypes; 980 // this only happens on an exact match. We can shorten this test by 1 load. 981 Node* CmpPNode::Ideal(PhaseGVN *phase, bool can_reshape) { 982 Node* pert = has_perturbed_operand(); 983 if (pert != NULL) { 984 // Optimize new acmp 985 Node* a = pert->in(AddPNode::Base); // unperturbed a 986 Node* b = in(2); 987 Node* cmp = phase->C->optimize_acmp(phase, a, b); 988 if (cmp != NULL) { 989 return cmp; 990 } 991 } 992 993 // Normalize comparisons between Java mirrors into comparisons of the low- 994 // level klass, where a dependent load could be shortened. 995 // 996 // The new pattern has a nice effect of matching the same pattern used in the 997 // fast path of instanceof/checkcast/Class.isInstance(), which allows 998 // redundant exact type check be optimized away by GVN. 999 // For example, in 1000 // if (x.getClass() == Foo.class) { 1001 // Foo foo = (Foo) x; 1002 // // ... use a ... 1003 // } 1004 // a CmpPNode could be shared between if_acmpne and checkcast 1005 { 1006 Node* k1 = isa_java_mirror_load(phase, in(1)); 1007 Node* k2 = isa_java_mirror_load(phase, in(2)); 1008 Node* conk2 = isa_const_java_mirror(phase, in(2)); 1009 1010 if (k1 && (k2 || conk2)) { 1011 Node* lhs = k1; 1012 Node* rhs = (k2 != NULL) ? k2 : conk2; 1013 PhaseIterGVN* igvn = phase->is_IterGVN(); 1014 if (igvn != NULL) { 1015 set_req_X(1, lhs, igvn); 1016 set_req_X(2, rhs, igvn); 1017 } else { 1018 set_req(1, lhs); 1019 set_req(2, rhs); 1020 } 1021 return this; 1022 } 1023 } 1024 1025 // Constant pointer on right? 1026 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr(); 1027 if (t2 == NULL || !t2->klass_is_exact()) 1028 return NULL; 1029 // Get the constant klass we are comparing to. 1030 ciKlass* superklass = t2->klass(); 1031 1032 // Now check for LoadKlass on left. 1033 Node* ldk1 = in(1); 1034 if (ldk1->is_DecodeNKlass()) { 1035 ldk1 = ldk1->in(1); 1036 if (ldk1->Opcode() != Op_LoadNKlass ) 1037 return NULL; 1038 } else if (ldk1->Opcode() != Op_LoadKlass ) 1039 return NULL; 1040 // Take apart the address of the LoadKlass: 1041 Node* adr1 = ldk1->in(MemNode::Address); 1042 intptr_t con2 = 0; 1043 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2); 1044 if (ldk2 == NULL) 1045 return NULL; 1046 if (con2 == oopDesc::klass_offset_in_bytes()) { 1047 // We are inspecting an object's concrete class. 1048 // Short-circuit the check if the query is abstract. 1049 if (superklass->is_interface() || 1050 superklass->is_abstract()) { 1051 // Make it come out always false: 1052 this->set_req(2, phase->makecon(TypePtr::NULL_PTR)); 1053 return this; 1054 } 1055 } 1056 1057 // Check for a LoadKlass from primary supertype array. 1058 // Any nested loadklass from loadklass+con must be from the p.s. array. 1059 if (ldk2->is_DecodeNKlass()) { 1060 // Keep ldk2 as DecodeN since it could be used in CmpP below. 1061 if (ldk2->in(1)->Opcode() != Op_LoadNKlass ) 1062 return NULL; 1063 } else if (ldk2->Opcode() != Op_LoadKlass) 1064 return NULL; 1065 1066 // Verify that we understand the situation 1067 if (con2 != (intptr_t) superklass->super_check_offset()) 1068 return NULL; // Might be element-klass loading from array klass 1069 1070 // If 'superklass' has no subklasses and is not an interface, then we are 1071 // assured that the only input which will pass the type check is 1072 // 'superklass' itself. 1073 // 1074 // We could be more liberal here, and allow the optimization on interfaces 1075 // which have a single implementor. This would require us to increase the 1076 // expressiveness of the add_dependency() mechanism. 1077 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now. 1078 1079 // Object arrays must have their base element have no subtypes 1080 while (superklass->is_obj_array_klass()) { 1081 ciType* elem = superklass->as_obj_array_klass()->element_type(); 1082 superklass = elem->as_klass(); 1083 } 1084 if (superklass->is_instance_klass()) { 1085 ciInstanceKlass* ik = superklass->as_instance_klass(); 1086 if (ik->has_subklass() || ik->is_interface()) return NULL; 1087 // Add a dependency if there is a chance that a subclass will be added later. 1088 if (!ik->is_final()) { 1089 phase->C->dependencies()->assert_leaf_type(ik); 1090 } 1091 } 1092 1093 // Bypass the dependent load, and compare directly 1094 this->set_req(1,ldk2); 1095 1096 return this; 1097 } 1098 1099 // Checks if one operand is perturbed and returns it 1100 Node* CmpPNode::has_perturbed_operand() const { 1101 // We always perturbe the first operand 1102 AddPNode* addP = in(1)->isa_AddP(); 1103 if (addP != NULL) { 1104 Node* base = addP->in(AddPNode::Base); 1105 if (base->is_top()) { 1106 // RawPtr comparison 1107 return NULL; 1108 } 1109 assert(EnableValhalla && UsePointerPerturbation, "unexpected perturbed oop"); 1110 return in(1); 1111 } 1112 return NULL; 1113 } 1114 1115 //============================================================================= 1116 //------------------------------sub-------------------------------------------- 1117 // Simplify an CmpN (compare 2 pointers) node, based on local information. 1118 // If both inputs are constants, compare them. 1119 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const { 1120 const TypePtr *r0 = t1->make_ptr(); // Handy access 1121 const TypePtr *r1 = t2->make_ptr(); 1122 1123 // Undefined inputs makes for an undefined result 1124 if ((r0 == NULL) || (r1 == NULL) || 1125 TypePtr::above_centerline(r0->_ptr) || 1126 TypePtr::above_centerline(r1->_ptr)) { 1127 return Type::TOP; 1128 } 1129 if (r0 == r1 && r0->singleton()) { 1130 // Equal pointer constants (klasses, nulls, etc.) 1131 return TypeInt::CC_EQ; 1132 } 1133 1134 // See if it is 2 unrelated classes. 1135 const TypeOopPtr* p0 = r0->isa_oopptr(); 1136 const TypeOopPtr* p1 = r1->isa_oopptr(); 1137 if (p0 && p1) { 1138 ciKlass* klass0 = p0->klass(); 1139 bool xklass0 = p0->klass_is_exact(); 1140 ciKlass* klass1 = p1->klass(); 1141 bool xklass1 = p1->klass_is_exact(); 1142 int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0); 1143 if (klass0 && klass1 && 1144 kps != 1 && // both or neither are klass pointers 1145 !klass0->is_interface() && // do not trust interfaces 1146 !klass1->is_interface()) { 1147 bool unrelated_classes = false; 1148 // See if neither subclasses the other, or if the class on top 1149 // is precise. In either of these cases, the compare is known 1150 // to fail if at least one of the pointers is provably not null. 1151 if (klass0->equals(klass1)) { // if types are unequal but klasses are equal 1152 // Do nothing; we know nothing for imprecise types 1153 } else if (klass0->is_subtype_of(klass1)) { 1154 // If klass1's type is PRECISE, then classes are unrelated. 1155 unrelated_classes = xklass1; 1156 } else if (klass1->is_subtype_of(klass0)) { 1157 // If klass0's type is PRECISE, then classes are unrelated. 1158 unrelated_classes = xklass0; 1159 } else { // Neither subtypes the other 1160 unrelated_classes = true; 1161 } 1162 if (unrelated_classes) { 1163 // The oops classes are known to be unrelated. If the joined PTRs of 1164 // two oops is not Null and not Bottom, then we are sure that one 1165 // of the two oops is non-null, and the comparison will always fail. 1166 TypePtr::PTR jp = r0->join_ptr(r1->_ptr); 1167 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) { 1168 return TypeInt::CC_GT; 1169 } 1170 } 1171 } 1172 } 1173 1174 // Known constants can be compared exactly 1175 // Null can be distinguished from any NotNull pointers 1176 // Unknown inputs makes an unknown result 1177 if( r0->singleton() ) { 1178 intptr_t bits0 = r0->get_con(); 1179 if( r1->singleton() ) 1180 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT; 1181 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC; 1182 } else if( r1->singleton() ) { 1183 intptr_t bits1 = r1->get_con(); 1184 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC; 1185 } else 1186 return TypeInt::CC; 1187 } 1188 1189 //------------------------------Ideal------------------------------------------ 1190 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) { 1191 return NULL; 1192 } 1193 1194 //============================================================================= 1195 //------------------------------Value------------------------------------------ 1196 // Simplify an CmpF (compare 2 floats ) node, based on local information. 1197 // If both inputs are constants, compare them. 1198 const Type* CmpFNode::Value(PhaseGVN* phase) const { 1199 const Node* in1 = in(1); 1200 const Node* in2 = in(2); 1201 // Either input is TOP ==> the result is TOP 1202 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1); 1203 if( t1 == Type::TOP ) return Type::TOP; 1204 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2); 1205 if( t2 == Type::TOP ) return Type::TOP; 1206 1207 // Not constants? Don't know squat - even if they are the same 1208 // value! If they are NaN's they compare to LT instead of EQ. 1209 const TypeF *tf1 = t1->isa_float_constant(); 1210 const TypeF *tf2 = t2->isa_float_constant(); 1211 if( !tf1 || !tf2 ) return TypeInt::CC; 1212 1213 // This implements the Java bytecode fcmpl, so unordered returns -1. 1214 if( tf1->is_nan() || tf2->is_nan() ) 1215 return TypeInt::CC_LT; 1216 1217 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT; 1218 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT; 1219 assert( tf1->_f == tf2->_f, "do not understand FP behavior" ); 1220 return TypeInt::CC_EQ; 1221 } 1222 1223 1224 //============================================================================= 1225 //------------------------------Value------------------------------------------ 1226 // Simplify an CmpD (compare 2 doubles ) node, based on local information. 1227 // If both inputs are constants, compare them. 1228 const Type* CmpDNode::Value(PhaseGVN* phase) const { 1229 const Node* in1 = in(1); 1230 const Node* in2 = in(2); 1231 // Either input is TOP ==> the result is TOP 1232 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1); 1233 if( t1 == Type::TOP ) return Type::TOP; 1234 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2); 1235 if( t2 == Type::TOP ) return Type::TOP; 1236 1237 // Not constants? Don't know squat - even if they are the same 1238 // value! If they are NaN's they compare to LT instead of EQ. 1239 const TypeD *td1 = t1->isa_double_constant(); 1240 const TypeD *td2 = t2->isa_double_constant(); 1241 if( !td1 || !td2 ) return TypeInt::CC; 1242 1243 // This implements the Java bytecode dcmpl, so unordered returns -1. 1244 if( td1->is_nan() || td2->is_nan() ) 1245 return TypeInt::CC_LT; 1246 1247 if( td1->_d < td2->_d ) return TypeInt::CC_LT; 1248 if( td1->_d > td2->_d ) return TypeInt::CC_GT; 1249 assert( td1->_d == td2->_d, "do not understand FP behavior" ); 1250 return TypeInt::CC_EQ; 1251 } 1252 1253 //------------------------------Ideal------------------------------------------ 1254 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){ 1255 // Check if we can change this to a CmpF and remove a ConvD2F operation. 1256 // Change (CMPD (F2D (float)) (ConD value)) 1257 // To (CMPF (float) (ConF value)) 1258 // Valid when 'value' does not lose precision as a float. 1259 // Benefits: eliminates conversion, does not require 24-bit mode 1260 1261 // NaNs prevent commuting operands. This transform works regardless of the 1262 // order of ConD and ConvF2D inputs by preserving the original order. 1263 int idx_f2d = 1; // ConvF2D on left side? 1264 if( in(idx_f2d)->Opcode() != Op_ConvF2D ) 1265 idx_f2d = 2; // No, swap to check for reversed args 1266 int idx_con = 3-idx_f2d; // Check for the constant on other input 1267 1268 if( ConvertCmpD2CmpF && 1269 in(idx_f2d)->Opcode() == Op_ConvF2D && 1270 in(idx_con)->Opcode() == Op_ConD ) { 1271 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant(); 1272 double t2_value_as_double = t2->_d; 1273 float t2_value_as_float = (float)t2_value_as_double; 1274 if( t2_value_as_double == (double)t2_value_as_float ) { 1275 // Test value can be represented as a float 1276 // Eliminate the conversion to double and create new comparison 1277 Node *new_in1 = in(idx_f2d)->in(1); 1278 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) ); 1279 if( idx_f2d != 1 ) { // Must flip args to match original order 1280 Node *tmp = new_in1; 1281 new_in1 = new_in2; 1282 new_in2 = tmp; 1283 } 1284 CmpFNode *new_cmp = (Opcode() == Op_CmpD3) 1285 ? new CmpF3Node( new_in1, new_in2 ) 1286 : new CmpFNode ( new_in1, new_in2 ) ; 1287 return new_cmp; // Changed to CmpFNode 1288 } 1289 // Testing value required the precision of a double 1290 } 1291 return NULL; // No change 1292 } 1293 1294 1295 //============================================================================= 1296 //------------------------------cc2logical------------------------------------- 1297 // Convert a condition code type to a logical type 1298 const Type *BoolTest::cc2logical( const Type *CC ) const { 1299 if( CC == Type::TOP ) return Type::TOP; 1300 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse 1301 const TypeInt *ti = CC->is_int(); 1302 if( ti->is_con() ) { // Only 1 kind of condition codes set? 1303 // Match low order 2 bits 1304 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0; 1305 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result 1306 return TypeInt::make(tmp); // Boolean result 1307 } 1308 1309 if( CC == TypeInt::CC_GE ) { 1310 if( _test == ge ) return TypeInt::ONE; 1311 if( _test == lt ) return TypeInt::ZERO; 1312 } 1313 if( CC == TypeInt::CC_LE ) { 1314 if( _test == le ) return TypeInt::ONE; 1315 if( _test == gt ) return TypeInt::ZERO; 1316 } 1317 1318 return TypeInt::BOOL; 1319 } 1320 1321 //------------------------------dump_spec------------------------------------- 1322 // Print special per-node info 1323 void BoolTest::dump_on(outputStream *st) const { 1324 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"}; 1325 st->print("%s", msg[_test]); 1326 } 1327 1328 // Returns the logical AND of two tests (or 'never' if both tests can never be true). 1329 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'. 1330 BoolTest::mask BoolTest::merge(BoolTest other) const { 1331 const mask res[illegal+1][illegal+1] = { 1332 // eq, gt, of, lt, ne, le, nof, ge, never, illegal 1333 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq 1334 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt 1335 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of 1336 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt 1337 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne 1338 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le 1339 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof 1340 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge 1341 {never, never, never, never, never, never, never, never, never, illegal}, // never 1342 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal 1343 return res[_test][other._test]; 1344 } 1345 1346 //============================================================================= 1347 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); } 1348 uint BoolNode::size_of() const { return sizeof(BoolNode); } 1349 1350 //------------------------------operator==------------------------------------- 1351 uint BoolNode::cmp( const Node &n ) const { 1352 const BoolNode *b = (const BoolNode *)&n; // Cast up 1353 return (_test._test == b->_test._test); 1354 } 1355 1356 //-------------------------------make_predicate-------------------------------- 1357 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) { 1358 if (test_value->is_Con()) return test_value; 1359 if (test_value->is_Bool()) return test_value; 1360 if (test_value->is_CMove() && 1361 test_value->in(CMoveNode::Condition)->is_Bool()) { 1362 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool(); 1363 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse)); 1364 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue)); 1365 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) { 1366 return bol; 1367 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) { 1368 return phase->transform( bol->negate(phase) ); 1369 } 1370 // Else fall through. The CMove gets in the way of the test. 1371 // It should be the case that make_predicate(bol->as_int_value()) == bol. 1372 } 1373 Node* cmp = new CmpINode(test_value, phase->intcon(0)); 1374 cmp = phase->transform(cmp); 1375 Node* bol = new BoolNode(cmp, BoolTest::ne); 1376 return phase->transform(bol); 1377 } 1378 1379 //--------------------------------as_int_value--------------------------------- 1380 Node* BoolNode::as_int_value(PhaseGVN* phase) { 1381 // Inverse to make_predicate. The CMove probably boils down to a Conv2B. 1382 Node* cmov = CMoveNode::make(NULL, this, 1383 phase->intcon(0), phase->intcon(1), 1384 TypeInt::BOOL); 1385 return phase->transform(cmov); 1386 } 1387 1388 //----------------------------------negate------------------------------------- 1389 BoolNode* BoolNode::negate(PhaseGVN* phase) { 1390 return new BoolNode(in(1), _test.negate()); 1391 } 1392 1393 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub 1394 // overflows and we can prove that C is not in the two resulting ranges. 1395 // This optimization is similar to the one performed by CmpUNode::Value(). 1396 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op, 1397 int cmp1_op, const TypeInt* cmp2_type) { 1398 // Only optimize eq/ne integer comparison of add/sub 1399 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1400 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) { 1401 // Skip cases were inputs of add/sub are not integers or of bottom type 1402 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int(); 1403 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int(); 1404 if ((r0 != NULL) && (r0 != TypeInt::INT) && 1405 (r1 != NULL) && (r1 != TypeInt::INT) && 1406 (cmp2_type != TypeInt::INT)) { 1407 // Compute exact (long) type range of add/sub result 1408 jlong lo_long = r0->_lo; 1409 jlong hi_long = r0->_hi; 1410 if (cmp1_op == Op_AddI) { 1411 lo_long += r1->_lo; 1412 hi_long += r1->_hi; 1413 } else { 1414 lo_long -= r1->_hi; 1415 hi_long -= r1->_lo; 1416 } 1417 // Check for over-/underflow by casting to integer 1418 int lo_int = (int)lo_long; 1419 int hi_int = (int)hi_long; 1420 bool underflow = lo_long != (jlong)lo_int; 1421 bool overflow = hi_long != (jlong)hi_int; 1422 if ((underflow != overflow) && (hi_int < lo_int)) { 1423 // Overflow on one boundary, compute resulting type ranges: 1424 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT] 1425 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here 1426 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w); 1427 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w); 1428 // Compare second input of cmp to both type ranges 1429 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type); 1430 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type); 1431 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) { 1432 // The result of the add/sub will never equal cmp2. Replace BoolNode 1433 // by false (0) if it tests for equality and by true (1) otherwise. 1434 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1); 1435 } 1436 } 1437 } 1438 } 1439 return NULL; 1440 } 1441 1442 static bool is_counted_loop_cmp(Node *cmp) { 1443 Node *n = cmp->in(1)->in(1); 1444 return n != NULL && 1445 n->is_Phi() && 1446 n->in(0) != NULL && 1447 n->in(0)->is_CountedLoop() && 1448 n->in(0)->as_CountedLoop()->phi() == n; 1449 } 1450 1451 //------------------------------Ideal------------------------------------------ 1452 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) { 1453 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)". 1454 // This moves the constant to the right. Helps value-numbering. 1455 Node *cmp = in(1); 1456 if( !cmp->is_Sub() ) return NULL; 1457 int cop = cmp->Opcode(); 1458 if( cop == Op_FastLock || cop == Op_FastUnlock) return NULL; 1459 Node *cmp1 = cmp->in(1); 1460 Node *cmp2 = cmp->in(2); 1461 if( !cmp1 ) return NULL; 1462 1463 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) { 1464 return NULL; 1465 } 1466 1467 // Constant on left? 1468 Node *con = cmp1; 1469 uint op2 = cmp2->Opcode(); 1470 // Move constants to the right of compare's to canonicalize. 1471 // Do not muck with Opaque1 nodes, as this indicates a loop 1472 // guard that cannot change shape. 1473 if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 && 1474 // Because of NaN's, CmpD and CmpF are not commutative 1475 cop != Op_CmpD && cop != Op_CmpF && 1476 // Protect against swapping inputs to a compare when it is used by a 1477 // counted loop exit, which requires maintaining the loop-limit as in(2) 1478 !is_counted_loop_exit_test() ) { 1479 // Ok, commute the constant to the right of the cmp node. 1480 // Clone the Node, getting a new Node of the same class 1481 cmp = cmp->clone(); 1482 // Swap inputs to the clone 1483 cmp->swap_edges(1, 2); 1484 cmp = phase->transform( cmp ); 1485 return new BoolNode( cmp, _test.commute() ); 1486 } 1487 1488 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)". 1489 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the 1490 // test instead. 1491 int cmp1_op = cmp1->Opcode(); 1492 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int(); 1493 if (cmp2_type == NULL) return NULL; 1494 Node* j_xor = cmp1; 1495 if( cmp2_type == TypeInt::ZERO && 1496 cmp1_op == Op_XorI && 1497 j_xor->in(1) != j_xor && // An xor of itself is dead 1498 phase->type( j_xor->in(1) ) == TypeInt::BOOL && 1499 phase->type( j_xor->in(2) ) == TypeInt::ONE && 1500 (_test._test == BoolTest::eq || 1501 _test._test == BoolTest::ne) ) { 1502 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2)); 1503 return new BoolNode( ncmp, _test.negate() ); 1504 } 1505 1506 // Change ((x & m) u<= m) or ((m & x) u<= m) to always true 1507 // Same with ((x & m) u< m+1) and ((m & x) u< m+1) 1508 if (cop == Op_CmpU && 1509 cmp1_op == Op_AndI) { 1510 Node* bound = NULL; 1511 if (_test._test == BoolTest::le) { 1512 bound = cmp2; 1513 } else if (_test._test == BoolTest::lt && 1514 cmp2->Opcode() == Op_AddI && 1515 cmp2->in(2)->find_int_con(0) == 1) { 1516 bound = cmp2->in(1); 1517 } 1518 if (cmp1->in(2) == bound || cmp1->in(1) == bound) { 1519 return ConINode::make(1); 1520 } 1521 } 1522 1523 // Change ((x & (m - 1)) u< m) into (m > 0) 1524 // This is the off-by-one variant of the above 1525 if (cop == Op_CmpU && 1526 _test._test == BoolTest::lt && 1527 cmp1_op == Op_AndI) { 1528 Node* l = cmp1->in(1); 1529 Node* r = cmp1->in(2); 1530 for (int repeat = 0; repeat < 2; repeat++) { 1531 bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 && 1532 r->in(1) == cmp2; 1533 if (match) { 1534 // arraylength known to be non-negative, so a (arraylength != 0) is sufficient, 1535 // but to be compatible with the array range check pattern, use (arraylength u> 0) 1536 Node* ncmp = cmp2->Opcode() == Op_LoadRange 1537 ? phase->transform(new CmpUNode(cmp2, phase->intcon(0))) 1538 : phase->transform(new CmpINode(cmp2, phase->intcon(0))); 1539 return new BoolNode(ncmp, BoolTest::gt); 1540 } else { 1541 // commute and try again 1542 l = cmp1->in(2); 1543 r = cmp1->in(1); 1544 } 1545 } 1546 } 1547 1548 // Change x u< 1 or x u<= 0 to x == 0 1549 if (cop == Op_CmpU && 1550 cmp1_op != Op_LoadRange && 1551 ((_test._test == BoolTest::lt && 1552 cmp2->find_int_con(-1) == 1) || 1553 (_test._test == BoolTest::le && 1554 cmp2->find_int_con(-1) == 0))) { 1555 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0))); 1556 return new BoolNode(ncmp, BoolTest::eq); 1557 } 1558 1559 // Change (arraylength <= 0) or (arraylength == 0) 1560 // into (arraylength u<= 0) 1561 // Also change (arraylength != 0) into (arraylength u> 0) 1562 // The latter version matches the code pattern generated for 1563 // array range checks, which will more likely be optimized later. 1564 if (cop == Op_CmpI && 1565 cmp1_op == Op_LoadRange && 1566 cmp2->find_int_con(-1) == 0) { 1567 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) { 1568 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2)); 1569 return new BoolNode(ncmp, BoolTest::le); 1570 } else if (_test._test == BoolTest::ne) { 1571 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2)); 1572 return new BoolNode(ncmp, BoolTest::gt); 1573 } 1574 } 1575 1576 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)". 1577 // This is a standard idiom for branching on a boolean value. 1578 Node *c2b = cmp1; 1579 if( cmp2_type == TypeInt::ZERO && 1580 cmp1_op == Op_Conv2B && 1581 (_test._test == BoolTest::eq || 1582 _test._test == BoolTest::ne) ) { 1583 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int() 1584 ? (Node*)new CmpINode(c2b->in(1),cmp2) 1585 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR)) 1586 ); 1587 return new BoolNode( ncmp, _test._test ); 1588 } 1589 1590 // Comparing a SubI against a zero is equal to comparing the SubI 1591 // arguments directly. This only works for eq and ne comparisons 1592 // due to possible integer overflow. 1593 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1594 (cop == Op_CmpI) && 1595 (cmp1_op == Op_SubI) && 1596 ( cmp2_type == TypeInt::ZERO ) ) { 1597 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2))); 1598 return new BoolNode( ncmp, _test._test ); 1599 } 1600 1601 // Same as above but with and AddI of a constant 1602 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1603 cop == Op_CmpI && 1604 cmp1_op == Op_AddI && 1605 cmp1->in(2) != NULL && 1606 phase->type(cmp1->in(2))->isa_int() && 1607 phase->type(cmp1->in(2))->is_int()->is_con() && 1608 cmp2_type == TypeInt::ZERO && 1609 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape 1610 ) { 1611 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int(); 1612 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi))); 1613 return new BoolNode( ncmp, _test._test ); 1614 } 1615 1616 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)" 1617 // since zero check of conditional negation of an integer is equal to 1618 // zero check of the integer directly. 1619 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1620 (cop == Op_CmpI) && 1621 (cmp2_type == TypeInt::ZERO) && 1622 (cmp1_op == Op_Phi)) { 1623 // There should be a diamond phi with true path at index 1 or 2 1624 PhiNode *phi = cmp1->as_Phi(); 1625 int idx_true = phi->is_diamond_phi(); 1626 if (idx_true != 0) { 1627 // True input is in(idx_true) while false input is in(3 - idx_true) 1628 Node *tin = phi->in(idx_true); 1629 Node *fin = phi->in(3 - idx_true); 1630 if ((tin->Opcode() == Op_SubI) && 1631 (phase->type(tin->in(1)) == TypeInt::ZERO) && 1632 (tin->in(2) == fin)) { 1633 // Found conditional negation at true path, create a new CmpINode without that 1634 Node *ncmp = phase->transform(new CmpINode(fin, cmp2)); 1635 return new BoolNode(ncmp, _test._test); 1636 } 1637 if ((fin->Opcode() == Op_SubI) && 1638 (phase->type(fin->in(1)) == TypeInt::ZERO) && 1639 (fin->in(2) == tin)) { 1640 // Found conditional negation at false path, create a new CmpINode without that 1641 Node *ncmp = phase->transform(new CmpINode(tin, cmp2)); 1642 return new BoolNode(ncmp, _test._test); 1643 } 1644 } 1645 } 1646 1647 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the 1648 // most general case because negating 0x80000000 does nothing. Needed for 1649 // the CmpF3/SubI/CmpI idiom. 1650 if( cop == Op_CmpI && 1651 cmp1_op == Op_SubI && 1652 cmp2_type == TypeInt::ZERO && 1653 phase->type( cmp1->in(1) ) == TypeInt::ZERO && 1654 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) { 1655 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2)); 1656 return new BoolNode( ncmp, _test.commute() ); 1657 } 1658 1659 // Try to optimize signed integer comparison 1660 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type); 1661 1662 // The transformation below is not valid for either signed or unsigned 1663 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE. 1664 // This transformation can be resurrected when we are able to 1665 // make inferences about the range of values being subtracted from 1666 // (or added to) relative to the wraparound point. 1667 // 1668 // // Remove +/-1's if possible. 1669 // // "X <= Y-1" becomes "X < Y" 1670 // // "X+1 <= Y" becomes "X < Y" 1671 // // "X < Y+1" becomes "X <= Y" 1672 // // "X-1 < Y" becomes "X <= Y" 1673 // // Do not this to compares off of the counted-loop-end. These guys are 1674 // // checking the trip counter and they want to use the post-incremented 1675 // // counter. If they use the PRE-incremented counter, then the counter has 1676 // // to be incremented in a private block on a loop backedge. 1677 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd ) 1678 // return NULL; 1679 // #ifndef PRODUCT 1680 // // Do not do this in a wash GVN pass during verification. 1681 // // Gets triggered by too many simple optimizations to be bothered with 1682 // // re-trying it again and again. 1683 // if( !phase->allow_progress() ) return NULL; 1684 // #endif 1685 // // Not valid for unsigned compare because of corner cases in involving zero. 1686 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an 1687 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but 1688 // // "0 <=u Y" is always true). 1689 // if( cmp->Opcode() == Op_CmpU ) return NULL; 1690 // int cmp2_op = cmp2->Opcode(); 1691 // if( _test._test == BoolTest::le ) { 1692 // if( cmp1_op == Op_AddI && 1693 // phase->type( cmp1->in(2) ) == TypeInt::ONE ) 1694 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt ); 1695 // else if( cmp2_op == Op_AddI && 1696 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 ) 1697 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt ); 1698 // } else if( _test._test == BoolTest::lt ) { 1699 // if( cmp1_op == Op_AddI && 1700 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 ) 1701 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le ); 1702 // else if( cmp2_op == Op_AddI && 1703 // phase->type( cmp2->in(2) ) == TypeInt::ONE ) 1704 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le ); 1705 // } 1706 } 1707 1708 //------------------------------Value------------------------------------------ 1709 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node, 1710 // based on local information. If the input is constant, do it. 1711 const Type* BoolNode::Value(PhaseGVN* phase) const { 1712 return _test.cc2logical( phase->type( in(1) ) ); 1713 } 1714 1715 #ifndef PRODUCT 1716 //------------------------------dump_spec-------------------------------------- 1717 // Dump special per-node info 1718 void BoolNode::dump_spec(outputStream *st) const { 1719 st->print("["); 1720 _test.dump_on(st); 1721 st->print("]"); 1722 } 1723 1724 //-------------------------------related--------------------------------------- 1725 // A BoolNode's related nodes are all of its data inputs, and all of its 1726 // outputs until control nodes are hit, which are included. In compact 1727 // representation, inputs till level 3 and immediate outputs are included. 1728 void BoolNode::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const { 1729 if (compact) { 1730 this->collect_nodes(in_rel, 3, false, true); 1731 this->collect_nodes(out_rel, -1, false, false); 1732 } else { 1733 this->collect_nodes_in_all_data(in_rel, false); 1734 this->collect_nodes_out_all_ctrl_boundary(out_rel); 1735 } 1736 } 1737 #endif 1738 1739 //----------------------is_counted_loop_exit_test------------------------------ 1740 // Returns true if node is used by a counted loop node. 1741 bool BoolNode::is_counted_loop_exit_test() { 1742 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) { 1743 Node* use = fast_out(i); 1744 if (use->is_CountedLoopEnd()) { 1745 return true; 1746 } 1747 } 1748 return false; 1749 } 1750 1751 //============================================================================= 1752 //------------------------------Value------------------------------------------ 1753 // Compute sqrt 1754 const Type* SqrtDNode::Value(PhaseGVN* phase) const { 1755 const Type *t1 = phase->type( in(1) ); 1756 if( t1 == Type::TOP ) return Type::TOP; 1757 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE; 1758 double d = t1->getd(); 1759 if( d < 0.0 ) return Type::DOUBLE; 1760 return TypeD::make( sqrt( d ) ); 1761 } 1762 1763 const Type* SqrtFNode::Value(PhaseGVN* phase) const { 1764 const Type *t1 = phase->type( in(1) ); 1765 if( t1 == Type::TOP ) return Type::TOP; 1766 if( t1->base() != Type::FloatCon ) return Type::FLOAT; 1767 float f = t1->getf(); 1768 if( f < 0.0f ) return Type::FLOAT; 1769 return TypeF::make( (float)sqrt( (double)f ) ); 1770 }