1 /* 2 * Copyright (c) 1997, 2025, 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 "compiler/compileLog.hpp" 26 #include "gc/shared/barrierSet.hpp" 27 #include "gc/shared/c2/barrierSetC2.hpp" 28 #include "memory/allocation.inline.hpp" 29 #include "opto/addnode.hpp" 30 #include "opto/callnode.hpp" 31 #include "opto/cfgnode.hpp" 32 #include "opto/loopnode.hpp" 33 #include "opto/matcher.hpp" 34 #include "opto/movenode.hpp" 35 #include "opto/mulnode.hpp" 36 #include "opto/opaquenode.hpp" 37 #include "opto/opcodes.hpp" 38 #include "opto/phaseX.hpp" 39 #include "opto/subnode.hpp" 40 #include "runtime/sharedRuntime.hpp" 41 #include "utilities/reverse_bits.hpp" 42 43 // Portions of code courtesy of Clifford Click 44 45 // Optimization - Graph Style 46 47 #include "math.h" 48 49 //============================================================================= 50 //------------------------------Identity--------------------------------------- 51 // If right input is a constant 0, return the left input. 52 Node* SubNode::Identity(PhaseGVN* phase) { 53 assert(in(1) != this, "Must already have called Value"); 54 assert(in(2) != this, "Must already have called Value"); 55 56 // Remove double negation 57 const Type *zero = add_id(); 58 if( phase->type( in(1) )->higher_equal( zero ) && 59 in(2)->Opcode() == Opcode() && 60 phase->type( in(2)->in(1) )->higher_equal( zero ) ) { 61 return in(2)->in(2); 62 } 63 64 // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y 65 if (in(1)->Opcode() == Op_AddI || in(1)->Opcode() == Op_AddL) { 66 if (in(1)->in(2) == in(2)) { 67 return in(1)->in(1); 68 } 69 if (in(1)->in(1) == in(2)) { 70 return in(1)->in(2); 71 } 72 } 73 74 return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this; 75 } 76 77 //------------------------------Value------------------------------------------ 78 // A subtract node differences it's two inputs. 79 const Type* SubNode::Value_common(PhaseValues* phase) const { 80 const Node* in1 = in(1); 81 const Node* in2 = in(2); 82 // Either input is TOP ==> the result is TOP 83 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1); 84 if( t1 == Type::TOP ) return Type::TOP; 85 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2); 86 if( t2 == Type::TOP ) return Type::TOP; 87 88 // Not correct for SubFnode and AddFNode (must check for infinity) 89 // Equal? Subtract is zero 90 if (in1->eqv_uncast(in2)) return add_id(); 91 92 // Either input is BOTTOM ==> the result is the local BOTTOM 93 if( t1 == Type::BOTTOM || t2 == Type::BOTTOM ) 94 return bottom_type(); 95 96 return nullptr; 97 } 98 99 const Type* SubNode::Value(PhaseGVN* phase) const { 100 const Type* t = Value_common(phase); 101 if (t != nullptr) { 102 return t; 103 } 104 const Type* t1 = phase->type(in(1)); 105 const Type* t2 = phase->type(in(2)); 106 return sub(t1,t2); // Local flavor of type subtraction 107 108 } 109 110 SubNode* SubNode::make(Node* in1, Node* in2, BasicType bt) { 111 switch (bt) { 112 case T_INT: 113 return new SubINode(in1, in2); 114 case T_LONG: 115 return new SubLNode(in1, in2); 116 default: 117 fatal("Not implemented for %s", type2name(bt)); 118 } 119 return nullptr; 120 } 121 122 //============================================================================= 123 //------------------------------Helper function-------------------------------- 124 125 static bool is_cloop_increment(Node* inc) { 126 precond(inc->Opcode() == Op_AddI || inc->Opcode() == Op_AddL); 127 128 if (!inc->in(1)->is_Phi()) { 129 return false; 130 } 131 const PhiNode* phi = inc->in(1)->as_Phi(); 132 133 if (!phi->region()->is_CountedLoop()) { 134 return false; 135 } 136 137 return inc == phi->region()->as_CountedLoop()->incr(); 138 } 139 140 // Given the expression '(x + C) - v', or 141 // 'v - (x + C)', we examine nodes '+' and 'v': 142 // 143 // 1. Do not convert if '+' is a counted-loop increment, because the '-' is 144 // loop invariant and converting extends the live-range of 'x' to overlap 145 // with the '+', forcing another register to be used in the loop. 146 // 147 // 2. Do not convert if 'v' is a counted-loop induction variable, because 148 // 'x' might be invariant. 149 // 150 static bool ok_to_convert(Node* inc, Node* var) { 151 return !(is_cloop_increment(inc) || var->is_cloop_ind_var()); 152 } 153 154 static bool is_cloop_condition(BoolNode* bol) { 155 for (DUIterator_Fast imax, i = bol->fast_outs(imax); i < imax; i++) { 156 Node* out = bol->fast_out(i); 157 if (out->is_BaseCountedLoopEnd()) { 158 return true; 159 } 160 } 161 return false; 162 } 163 164 //------------------------------Ideal------------------------------------------ 165 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){ 166 Node *in1 = in(1); 167 Node *in2 = in(2); 168 uint op1 = in1->Opcode(); 169 uint op2 = in2->Opcode(); 170 171 #ifdef ASSERT 172 // Check for dead loop 173 if ((in1 == this) || (in2 == this) || 174 ((op1 == Op_AddI || op1 == Op_SubI) && 175 ((in1->in(1) == this) || (in1->in(2) == this) || 176 (in1->in(1) == in1) || (in1->in(2) == in1)))) { 177 assert(false, "dead loop in SubINode::Ideal"); 178 } 179 #endif 180 181 const Type *t2 = phase->type( in2 ); 182 if( t2 == Type::TOP ) return nullptr; 183 // Convert "x-c0" into "x+ -c0". 184 if( t2->base() == Type::Int ){ // Might be bottom or top... 185 const TypeInt *i = t2->is_int(); 186 if( i->is_con() ) 187 return new AddINode(in1, phase->intcon(java_negate(i->get_con()))); 188 } 189 190 // Convert "(x+c0) - y" into (x-y) + c0" 191 // Do not collapse (x+c0)-y if "+" is a loop increment or 192 // if "y" is a loop induction variable. 193 if( op1 == Op_AddI && ok_to_convert(in1, in2) ) { 194 const Type *tadd = phase->type( in1->in(2) ); 195 if( tadd->singleton() && tadd != Type::TOP ) { 196 Node *sub2 = phase->transform( new SubINode( in1->in(1), in2 )); 197 return new AddINode( sub2, in1->in(2) ); 198 } 199 } 200 201 // Convert "x - (y+c0)" into "(x-y) - c0" AND 202 // Convert "c1 - (y+c0)" into "(c1-c0) - y" 203 // Need the same check as in above optimization but reversed. 204 if (op2 == Op_AddI 205 && ok_to_convert(in2, in1) 206 && in2->in(2)->Opcode() == Op_ConI) { 207 jint c0 = phase->type(in2->in(2))->isa_int()->get_con(); 208 Node* in21 = in2->in(1); 209 if (in1->Opcode() == Op_ConI) { 210 // Match c1 211 jint c1 = phase->type(in1)->isa_int()->get_con(); 212 Node* sub2 = phase->intcon(java_subtract(c1, c0)); 213 return new SubINode(sub2, in21); 214 } else { 215 // Match x 216 Node* sub2 = phase->transform(new SubINode(in1, in21)); 217 Node* neg_c0 = phase->intcon(java_negate(c0)); 218 return new AddINode(sub2, neg_c0); 219 } 220 } 221 222 const Type *t1 = phase->type( in1 ); 223 if( t1 == Type::TOP ) return nullptr; 224 225 #ifdef ASSERT 226 // Check for dead loop 227 if ((op2 == Op_AddI || op2 == Op_SubI) && 228 ((in2->in(1) == this) || (in2->in(2) == this) || 229 (in2->in(1) == in2) || (in2->in(2) == in2))) { 230 assert(false, "dead loop in SubINode::Ideal"); 231 } 232 #endif 233 234 // Convert "x - (x+y)" into "-y" 235 if (op2 == Op_AddI && in1 == in2->in(1)) { 236 return new SubINode(phase->intcon(0), in2->in(2)); 237 } 238 // Convert "(x-y) - x" into "-y" 239 if (op1 == Op_SubI && in1->in(1) == in2) { 240 return new SubINode(phase->intcon(0), in1->in(2)); 241 } 242 // Convert "x - (y+x)" into "-y" 243 if (op2 == Op_AddI && in1 == in2->in(2)) { 244 return new SubINode(phase->intcon(0), in2->in(1)); 245 } 246 247 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity(). 248 if (t1 == TypeInt::ZERO && op2 == Op_SubI && phase->type(in2->in(1)) != TypeInt::ZERO) { 249 return new SubINode(in2->in(2), in2->in(1)); 250 } 251 252 // Convert "0 - (x+con)" into "-con-x" 253 jint con; 254 if( t1 == TypeInt::ZERO && op2 == Op_AddI && 255 (con = in2->in(2)->find_int_con(0)) != 0 ) 256 return new SubINode( phase->intcon(-con), in2->in(1) ); 257 258 // Convert "(X+A) - (X+B)" into "A - B" 259 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) ) 260 return new SubINode( in1->in(2), in2->in(2) ); 261 262 // Convert "(A+X) - (B+X)" into "A - B" 263 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) ) 264 return new SubINode( in1->in(1), in2->in(1) ); 265 266 // Convert "(A+X) - (X+B)" into "A - B" 267 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) ) 268 return new SubINode( in1->in(1), in2->in(2) ); 269 270 // Convert "(X+A) - (B+X)" into "A - B" 271 if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) ) 272 return new SubINode( in1->in(2), in2->in(1) ); 273 274 // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally 275 // nicer to optimize than subtract. 276 if( op2 == Op_SubI && in2->outcnt() == 1) { 277 Node *add1 = phase->transform( new AddINode( in1, in2->in(2) ) ); 278 return new SubINode( add1, in2->in(1) ); 279 } 280 281 // Associative 282 if (op1 == Op_MulI && op2 == Op_MulI) { 283 Node* sub_in1 = nullptr; 284 Node* sub_in2 = nullptr; 285 Node* mul_in = nullptr; 286 287 if (in1->in(1) == in2->in(1)) { 288 // Convert "a*b-a*c into a*(b-c) 289 sub_in1 = in1->in(2); 290 sub_in2 = in2->in(2); 291 mul_in = in1->in(1); 292 } else if (in1->in(2) == in2->in(1)) { 293 // Convert a*b-b*c into b*(a-c) 294 sub_in1 = in1->in(1); 295 sub_in2 = in2->in(2); 296 mul_in = in1->in(2); 297 } else if (in1->in(2) == in2->in(2)) { 298 // Convert a*c-b*c into (a-b)*c 299 sub_in1 = in1->in(1); 300 sub_in2 = in2->in(1); 301 mul_in = in1->in(2); 302 } else if (in1->in(1) == in2->in(2)) { 303 // Convert a*b-c*a into a*(b-c) 304 sub_in1 = in1->in(2); 305 sub_in2 = in2->in(1); 306 mul_in = in1->in(1); 307 } 308 309 if (mul_in != nullptr) { 310 Node* sub = phase->transform(new SubINode(sub_in1, sub_in2)); 311 return new MulINode(mul_in, sub); 312 } 313 } 314 315 // Convert "0-(A>>31)" into "(A>>>31)" 316 if ( op2 == Op_RShiftI ) { 317 Node *in21 = in2->in(1); 318 Node *in22 = in2->in(2); 319 const TypeInt *zero = phase->type(in1)->isa_int(); 320 const TypeInt *t21 = phase->type(in21)->isa_int(); 321 const TypeInt *t22 = phase->type(in22)->isa_int(); 322 if ( t21 && t22 && zero == TypeInt::ZERO && t22->is_con(31) ) { 323 return new URShiftINode(in21, in22); 324 } 325 } 326 327 return nullptr; 328 } 329 330 //------------------------------sub-------------------------------------------- 331 // A subtract node differences it's two inputs. 332 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const { 333 const TypeInt *r0 = t1->is_int(); // Handy access 334 const TypeInt *r1 = t2->is_int(); 335 int32_t lo = java_subtract(r0->_lo, r1->_hi); 336 int32_t hi = java_subtract(r0->_hi, r1->_lo); 337 338 // We next check for 32-bit overflow. 339 // If that happens, we just assume all integers are possible. 340 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR 341 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND 342 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR 343 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs 344 return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen)); 345 else // Overflow; assume all integers 346 return TypeInt::INT; 347 } 348 349 //============================================================================= 350 //------------------------------Ideal------------------------------------------ 351 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) { 352 Node *in1 = in(1); 353 Node *in2 = in(2); 354 uint op1 = in1->Opcode(); 355 uint op2 = in2->Opcode(); 356 357 #ifdef ASSERT 358 // Check for dead loop 359 if ((in1 == this) || (in2 == this) || 360 ((op1 == Op_AddL || op1 == Op_SubL) && 361 ((in1->in(1) == this) || (in1->in(2) == this) || 362 (in1->in(1) == in1) || (in1->in(2) == in1)))) { 363 assert(false, "dead loop in SubLNode::Ideal"); 364 } 365 #endif 366 367 if( phase->type( in2 ) == Type::TOP ) return nullptr; 368 const TypeLong *i = phase->type( in2 )->isa_long(); 369 // Convert "x-c0" into "x+ -c0". 370 if( i && // Might be bottom or top... 371 i->is_con() ) 372 return new AddLNode(in1, phase->longcon(java_negate(i->get_con()))); 373 374 // Convert "(x+c0) - y" into (x-y) + c0" 375 // Do not collapse (x+c0)-y if "+" is a loop increment or 376 // if "y" is a loop induction variable. 377 if( op1 == Op_AddL && ok_to_convert(in1, in2) ) { 378 Node *in11 = in1->in(1); 379 const Type *tadd = phase->type( in1->in(2) ); 380 if( tadd->singleton() && tadd != Type::TOP ) { 381 Node *sub2 = phase->transform( new SubLNode( in11, in2 )); 382 return new AddLNode( sub2, in1->in(2) ); 383 } 384 } 385 386 // Convert "x - (y+c0)" into "(x-y) - c0" AND 387 // Convert "c1 - (y+c0)" into "(c1-c0) - y" 388 // Need the same check as in above optimization but reversed. 389 if (op2 == Op_AddL 390 && ok_to_convert(in2, in1) 391 && in2->in(2)->Opcode() == Op_ConL) { 392 jlong c0 = phase->type(in2->in(2))->isa_long()->get_con(); 393 Node* in21 = in2->in(1); 394 if (in1->Opcode() == Op_ConL) { 395 // Match c1 396 jlong c1 = phase->type(in1)->isa_long()->get_con(); 397 Node* sub2 = phase->longcon(java_subtract(c1, c0)); 398 return new SubLNode(sub2, in21); 399 } else { 400 Node* sub2 = phase->transform(new SubLNode(in1, in21)); 401 Node* neg_c0 = phase->longcon(-c0); 402 return new AddLNode(sub2, neg_c0); 403 } 404 } 405 406 const Type *t1 = phase->type( in1 ); 407 if( t1 == Type::TOP ) return nullptr; 408 409 #ifdef ASSERT 410 // Check for dead loop 411 if ((op2 == Op_AddL || op2 == Op_SubL) && 412 ((in2->in(1) == this) || (in2->in(2) == this) || 413 (in2->in(1) == in2) || (in2->in(2) == in2))) { 414 assert(false, "dead loop in SubLNode::Ideal"); 415 } 416 #endif 417 418 // Convert "x - (x+y)" into "-y" 419 if (op2 == Op_AddL && in1 == in2->in(1)) { 420 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(2)); 421 } 422 // Convert "(x-y) - x" into "-y" 423 if (op1 == Op_SubL && in1->in(1) == in2) { 424 return new SubLNode(phase->makecon(TypeLong::ZERO), in1->in(2)); 425 } 426 // Convert "x - (y+x)" into "-y" 427 if (op2 == Op_AddL && in1 == in2->in(2)) { 428 return new SubLNode(phase->makecon(TypeLong::ZERO), in2->in(1)); 429 } 430 431 // Convert "0 - (x-y)" into "y-x", leave the double negation "-(-y)" to SubNode::Identity. 432 if (t1 == TypeLong::ZERO && op2 == Op_SubL && phase->type(in2->in(1)) != TypeLong::ZERO) { 433 return new SubLNode(in2->in(2), in2->in(1)); 434 } 435 436 // Convert "(X+A) - (X+B)" into "A - B" 437 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) ) 438 return new SubLNode( in1->in(2), in2->in(2) ); 439 440 // Convert "(A+X) - (B+X)" into "A - B" 441 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) ) 442 return new SubLNode( in1->in(1), in2->in(1) ); 443 444 // Convert "(A+X) - (X+B)" into "A - B" 445 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(1) ) 446 return new SubLNode( in1->in(1), in2->in(2) ); 447 448 // Convert "(X+A) - (B+X)" into "A - B" 449 if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(2) ) 450 return new SubLNode( in1->in(2), in2->in(1) ); 451 452 // Convert "A-(B-C)" into (A+C)-B" 453 if( op2 == Op_SubL && in2->outcnt() == 1) { 454 Node *add1 = phase->transform( new AddLNode( in1, in2->in(2) ) ); 455 return new SubLNode( add1, in2->in(1) ); 456 } 457 458 // Associative 459 if (op1 == Op_MulL && op2 == Op_MulL) { 460 Node* sub_in1 = nullptr; 461 Node* sub_in2 = nullptr; 462 Node* mul_in = nullptr; 463 464 if (in1->in(1) == in2->in(1)) { 465 // Convert "a*b-a*c into a*(b+c) 466 sub_in1 = in1->in(2); 467 sub_in2 = in2->in(2); 468 mul_in = in1->in(1); 469 } else if (in1->in(2) == in2->in(1)) { 470 // Convert a*b-b*c into b*(a-c) 471 sub_in1 = in1->in(1); 472 sub_in2 = in2->in(2); 473 mul_in = in1->in(2); 474 } else if (in1->in(2) == in2->in(2)) { 475 // Convert a*c-b*c into (a-b)*c 476 sub_in1 = in1->in(1); 477 sub_in2 = in2->in(1); 478 mul_in = in1->in(2); 479 } else if (in1->in(1) == in2->in(2)) { 480 // Convert a*b-c*a into a*(b-c) 481 sub_in1 = in1->in(2); 482 sub_in2 = in2->in(1); 483 mul_in = in1->in(1); 484 } 485 486 if (mul_in != nullptr) { 487 Node* sub = phase->transform(new SubLNode(sub_in1, sub_in2)); 488 return new MulLNode(mul_in, sub); 489 } 490 } 491 492 // Convert "0L-(A>>63)" into "(A>>>63)" 493 if ( op2 == Op_RShiftL ) { 494 Node *in21 = in2->in(1); 495 Node *in22 = in2->in(2); 496 const TypeLong *zero = phase->type(in1)->isa_long(); 497 const TypeLong *t21 = phase->type(in21)->isa_long(); 498 const TypeInt *t22 = phase->type(in22)->isa_int(); 499 if ( t21 && t22 && zero == TypeLong::ZERO && t22->is_con(63) ) { 500 return new URShiftLNode(in21, in22); 501 } 502 } 503 504 return nullptr; 505 } 506 507 //------------------------------sub-------------------------------------------- 508 // A subtract node differences it's two inputs. 509 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const { 510 const TypeLong *r0 = t1->is_long(); // Handy access 511 const TypeLong *r1 = t2->is_long(); 512 jlong lo = java_subtract(r0->_lo, r1->_hi); 513 jlong hi = java_subtract(r0->_hi, r1->_lo); 514 515 // We next check for 32-bit overflow. 516 // If that happens, we just assume all integers are possible. 517 if( (((r0->_lo ^ r1->_hi) >= 0) || // lo ends have same signs OR 518 ((r0->_lo ^ lo) >= 0)) && // lo results have same signs AND 519 (((r0->_hi ^ r1->_lo) >= 0) || // hi ends have same signs OR 520 ((r0->_hi ^ hi) >= 0)) ) // hi results have same signs 521 return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen)); 522 else // Overflow; assume all integers 523 return TypeLong::LONG; 524 } 525 526 //============================================================================= 527 //------------------------------Value------------------------------------------ 528 // A subtract node differences its two inputs. 529 const Type* SubFPNode::Value(PhaseGVN* phase) const { 530 const Node* in1 = in(1); 531 const Node* in2 = in(2); 532 // Either input is TOP ==> the result is TOP 533 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1); 534 if( t1 == Type::TOP ) return Type::TOP; 535 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2); 536 if( t2 == Type::TOP ) return Type::TOP; 537 538 // if both operands are infinity of same sign, the result is NaN; do 539 // not replace with zero 540 if (t1->is_finite() && t2->is_finite() && in1 == in2) { 541 return add_id(); 542 } 543 544 // Either input is BOTTOM ==> the result is the local BOTTOM 545 const Type *bot = bottom_type(); 546 if( (t1 == bot) || (t2 == bot) || 547 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 548 return bot; 549 550 return sub(t1,t2); // Local flavor of type subtraction 551 } 552 553 554 //============================================================================= 555 //------------------------------Ideal------------------------------------------ 556 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) { 557 const Type *t2 = phase->type( in(2) ); 558 // Convert "x-c0" into "x+ -c0". 559 if( t2->base() == Type::FloatCon ) { // Might be bottom or top... 560 // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) ); 561 } 562 563 // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes 564 // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0. 565 //if( phase->type(in(1)) == TypeF::ZERO ) 566 //return new (phase->C, 2) NegFNode(in(2)); 567 568 return nullptr; 569 } 570 571 //------------------------------sub-------------------------------------------- 572 // A subtract node differences its two inputs. 573 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const { 574 // no folding if one of operands is infinity or NaN, do not do constant folding 575 if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) { 576 return TypeF::make( t1->getf() - t2->getf() ); 577 } 578 else if( g_isnan(t1->getf()) ) { 579 return t1; 580 } 581 else if( g_isnan(t2->getf()) ) { 582 return t2; 583 } 584 else { 585 return Type::FLOAT; 586 } 587 } 588 589 //============================================================================= 590 //------------------------------Ideal------------------------------------------ 591 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){ 592 const Type *t2 = phase->type( in(2) ); 593 // Convert "x-c0" into "x+ -c0". 594 if( t2->base() == Type::DoubleCon ) { // Might be bottom or top... 595 // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) ); 596 } 597 598 // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes 599 // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0. 600 //if( phase->type(in(1)) == TypeD::ZERO ) 601 //return new (phase->C, 2) NegDNode(in(2)); 602 603 return nullptr; 604 } 605 606 //------------------------------sub-------------------------------------------- 607 // A subtract node differences its two inputs. 608 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const { 609 // no folding if one of operands is infinity or NaN, do not do constant folding 610 if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) { 611 return TypeD::make( t1->getd() - t2->getd() ); 612 } 613 else if( g_isnan(t1->getd()) ) { 614 return t1; 615 } 616 else if( g_isnan(t2->getd()) ) { 617 return t2; 618 } 619 else { 620 return Type::DOUBLE; 621 } 622 } 623 624 //============================================================================= 625 //------------------------------Idealize--------------------------------------- 626 // Unlike SubNodes, compare must still flatten return value to the 627 // range -1, 0, 1. 628 // And optimizations like those for (X + Y) - X fail if overflow happens. 629 Node* CmpNode::Identity(PhaseGVN* phase) { 630 return this; 631 } 632 633 CmpNode *CmpNode::make(Node *in1, Node *in2, BasicType bt, bool unsigned_comp) { 634 switch (bt) { 635 case T_INT: 636 if (unsigned_comp) { 637 return new CmpUNode(in1, in2); 638 } 639 return new CmpINode(in1, in2); 640 case T_LONG: 641 if (unsigned_comp) { 642 return new CmpULNode(in1, in2); 643 } 644 return new CmpLNode(in1, in2); 645 case T_OBJECT: 646 case T_ARRAY: 647 case T_ADDRESS: 648 case T_METADATA: 649 return new CmpPNode(in1, in2); 650 case T_NARROWOOP: 651 case T_NARROWKLASS: 652 return new CmpNNode(in1, in2); 653 default: 654 fatal("Not implemented for %s", type2name(bt)); 655 } 656 return nullptr; 657 } 658 659 //============================================================================= 660 //------------------------------cmp-------------------------------------------- 661 // Simplify a CmpI (compare 2 integers) node, based on local information. 662 // If both inputs are constants, compare them. 663 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const { 664 const TypeInt *r0 = t1->is_int(); // Handy access 665 const TypeInt *r1 = t2->is_int(); 666 667 if( r0->_hi < r1->_lo ) // Range is always low? 668 return TypeInt::CC_LT; 669 else if( r0->_lo > r1->_hi ) // Range is always high? 670 return TypeInt::CC_GT; 671 672 else if( r0->is_con() && r1->is_con() ) { // comparing constants? 673 assert(r0->get_con() == r1->get_con(), "must be equal"); 674 return TypeInt::CC_EQ; // Equal results. 675 } else if( r0->_hi == r1->_lo ) // Range is never high? 676 return TypeInt::CC_LE; 677 else if( r0->_lo == r1->_hi ) // Range is never low? 678 return TypeInt::CC_GE; 679 return TypeInt::CC; // else use worst case results 680 } 681 682 const Type* CmpINode::Value(PhaseGVN* phase) const { 683 Node* in1 = in(1); 684 Node* in2 = in(2); 685 // If this test is the zero trip guard for a main or post loop, check whether, with the opaque node removed, the test 686 // would constant fold so the loop is never entered. If so return the type of the test without the opaque node removed: 687 // make the loop unreachable. 688 // The reason for this is that the iv phi captures the bounds of the loop and if the loop becomes unreachable, it can 689 // become top. In that case, the loop must be removed. 690 // This is safe because: 691 // - as optimizations proceed, the range of iterations executed by the main loop narrows. If no iterations remain, then 692 // we're done with optimizations for that loop. 693 // - the post loop is initially not reachable but as long as there's a main loop, the zero trip guard for the post 694 // loop takes a phi that merges the pre and main loop's iv and can't constant fold the zero trip guard. Once, the main 695 // loop is removed, there's no need to preserve the zero trip guard for the post loop anymore. 696 if (in1 != nullptr && in2 != nullptr) { 697 uint input = 0; 698 Node* cmp = nullptr; 699 BoolTest::mask test; 700 if (in1->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in1) != Type::TOP) { 701 cmp = new CmpINode(in1->in(1), in2); 702 test = ((OpaqueZeroTripGuardNode*)in1)->_loop_entered_mask; 703 } 704 if (in2->Opcode() == Op_OpaqueZeroTripGuard && phase->type(in2) != Type::TOP) { 705 assert(cmp == nullptr, "A cmp with 2 OpaqueZeroTripGuard inputs"); 706 cmp = new CmpINode(in1, in2->in(1)); 707 test = ((OpaqueZeroTripGuardNode*)in2)->_loop_entered_mask; 708 } 709 if (cmp != nullptr) { 710 const Type* cmp_t = cmp->Value(phase); 711 const Type* t = BoolTest(test).cc2logical(cmp_t); 712 cmp->destruct(phase); 713 if (t == TypeInt::ZERO) { 714 return cmp_t; 715 } 716 } 717 } 718 719 return SubNode::Value(phase); 720 } 721 722 723 // Simplify a CmpU (compare 2 integers) node, based on local information. 724 // If both inputs are constants, compare them. 725 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const { 726 assert(!t1->isa_ptr(), "obsolete usage of CmpU"); 727 728 // comparing two unsigned ints 729 const TypeInt *r0 = t1->is_int(); // Handy access 730 const TypeInt *r1 = t2->is_int(); 731 732 // Current installed version 733 // Compare ranges for non-overlap 734 juint lo0 = r0->_lo; 735 juint hi0 = r0->_hi; 736 juint lo1 = r1->_lo; 737 juint hi1 = r1->_hi; 738 739 // If either one has both negative and positive values, 740 // it therefore contains both 0 and -1, and since [0..-1] is the 741 // full unsigned range, the type must act as an unsigned bottom. 742 bool bot0 = ((jint)(lo0 ^ hi0) < 0); 743 bool bot1 = ((jint)(lo1 ^ hi1) < 0); 744 745 if (bot0 || bot1) { 746 // All unsigned values are LE -1 and GE 0. 747 if (lo0 == 0 && hi0 == 0) { 748 return TypeInt::CC_LE; // 0 <= bot 749 } else if ((jint)lo0 == -1 && (jint)hi0 == -1) { 750 return TypeInt::CC_GE; // -1 >= bot 751 } else if (lo1 == 0 && hi1 == 0) { 752 return TypeInt::CC_GE; // bot >= 0 753 } else if ((jint)lo1 == -1 && (jint)hi1 == -1) { 754 return TypeInt::CC_LE; // bot <= -1 755 } 756 } else { 757 // We can use ranges of the form [lo..hi] if signs are the same. 758 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid"); 759 // results are reversed, '-' > '+' for unsigned compare 760 if (hi0 < lo1) { 761 return TypeInt::CC_LT; // smaller 762 } else if (lo0 > hi1) { 763 return TypeInt::CC_GT; // greater 764 } else if (hi0 == lo1 && lo0 == hi1) { 765 return TypeInt::CC_EQ; // Equal results 766 } else if (lo0 >= hi1) { 767 return TypeInt::CC_GE; 768 } else if (hi0 <= lo1) { 769 // Check for special case in Hashtable::get. (See below.) 770 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check()) 771 return TypeInt::CC_LT; 772 return TypeInt::CC_LE; 773 } 774 } 775 // Check for special case in Hashtable::get - the hash index is 776 // mod'ed to the table size so the following range check is useless. 777 // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have 778 // to be positive. 779 // (This is a gross hack, since the sub method never 780 // looks at the structure of the node in any other case.) 781 if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check()) 782 return TypeInt::CC_LT; 783 return TypeInt::CC; // else use worst case results 784 } 785 786 const Type* CmpUNode::Value(PhaseGVN* phase) const { 787 const Type* t = SubNode::Value_common(phase); 788 if (t != nullptr) { 789 return t; 790 } 791 const Node* in1 = in(1); 792 const Node* in2 = in(2); 793 const Type* t1 = phase->type(in1); 794 const Type* t2 = phase->type(in2); 795 assert(t1->isa_int(), "CmpU has only Int type inputs"); 796 if (t2 == TypeInt::INT) { // Compare to bottom? 797 return bottom_type(); 798 } 799 800 const Type* t_sub = sub(t1, t2); // compare based on immediate inputs 801 802 uint in1_op = in1->Opcode(); 803 if (in1_op == Op_AddI || in1_op == Op_SubI) { 804 // The problem rise when result of AddI(SubI) may overflow 805 // signed integer value. Let say the input type is 806 // [256, maxint] then +128 will create 2 ranges due to 807 // overflow: [minint, minint+127] and [384, maxint]. 808 // But C2 type system keep only 1 type range and as result 809 // it use general [minint, maxint] for this case which we 810 // can't optimize. 811 // 812 // Make 2 separate type ranges based on types of AddI(SubI) inputs 813 // and compare results of their compare. If results are the same 814 // CmpU node can be optimized. 815 const Node* in11 = in1->in(1); 816 const Node* in12 = in1->in(2); 817 const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11); 818 const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12); 819 // Skip cases when input types are top or bottom. 820 if ((t11 != Type::TOP) && (t11 != TypeInt::INT) && 821 (t12 != Type::TOP) && (t12 != TypeInt::INT)) { 822 const TypeInt *r0 = t11->is_int(); 823 const TypeInt *r1 = t12->is_int(); 824 jlong lo_r0 = r0->_lo; 825 jlong hi_r0 = r0->_hi; 826 jlong lo_r1 = r1->_lo; 827 jlong hi_r1 = r1->_hi; 828 if (in1_op == Op_SubI) { 829 jlong tmp = hi_r1; 830 hi_r1 = -lo_r1; 831 lo_r1 = -tmp; 832 // Note, for substructing [minint,x] type range 833 // long arithmetic provides correct overflow answer. 834 // The confusion come from the fact that in 32-bit 835 // -minint == minint but in 64-bit -minint == maxint+1. 836 } 837 jlong lo_long = lo_r0 + lo_r1; 838 jlong hi_long = hi_r0 + hi_r1; 839 int lo_tr1 = min_jint; 840 int hi_tr1 = (int)hi_long; 841 int lo_tr2 = (int)lo_long; 842 int hi_tr2 = max_jint; 843 bool underflow = lo_long != (jlong)lo_tr2; 844 bool overflow = hi_long != (jlong)hi_tr1; 845 // Use sub(t1, t2) when there is no overflow (one type range) 846 // or when both overflow and underflow (too complex). 847 if ((underflow != overflow) && (hi_tr1 < lo_tr2)) { 848 // Overflow only on one boundary, compare 2 separate type ranges. 849 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here 850 const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w); 851 const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w); 852 const TypeInt* cmp1 = sub(tr1, t2)->is_int(); 853 const TypeInt* cmp2 = sub(tr2, t2)->is_int(); 854 // Compute union, so that cmp handles all possible results from the two cases 855 const Type* t_cmp = cmp1->meet(cmp2); 856 // Pick narrowest type, based on overflow computation and on immediate inputs 857 return t_sub->filter(t_cmp); 858 } 859 } 860 } 861 862 return t_sub; 863 } 864 865 bool CmpUNode::is_index_range_check() const { 866 // Check for the "(X ModI Y) CmpU Y" shape 867 return (in(1)->Opcode() == Op_ModI && 868 in(1)->in(2)->eqv_uncast(in(2))); 869 } 870 871 //------------------------------Idealize--------------------------------------- 872 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) { 873 if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) { 874 switch (in(1)->Opcode()) { 875 case Op_CmpU3: // Collapse a CmpU3/CmpI into a CmpU 876 return new CmpUNode(in(1)->in(1),in(1)->in(2)); 877 case Op_CmpL3: // Collapse a CmpL3/CmpI into a CmpL 878 return new CmpLNode(in(1)->in(1),in(1)->in(2)); 879 case Op_CmpUL3: // Collapse a CmpUL3/CmpI into a CmpUL 880 return new CmpULNode(in(1)->in(1),in(1)->in(2)); 881 case Op_CmpF3: // Collapse a CmpF3/CmpI into a CmpF 882 return new CmpFNode(in(1)->in(1),in(1)->in(2)); 883 case Op_CmpD3: // Collapse a CmpD3/CmpI into a CmpD 884 return new CmpDNode(in(1)->in(1),in(1)->in(2)); 885 //case Op_SubI: 886 // If (x - y) cannot overflow, then ((x - y) <?> 0) 887 // can be turned into (x <?> y). 888 // This is handled (with more general cases) by Ideal_sub_algebra. 889 } 890 } 891 return nullptr; // No change 892 } 893 894 Node *CmpLNode::Ideal( PhaseGVN *phase, bool can_reshape ) { 895 const TypeLong *t2 = phase->type(in(2))->isa_long(); 896 if (Opcode() == Op_CmpL && in(1)->Opcode() == Op_ConvI2L && t2 && t2->is_con()) { 897 const jlong con = t2->get_con(); 898 if (con >= min_jint && con <= max_jint) { 899 return new CmpINode(in(1)->in(1), phase->intcon((jint)con)); 900 } 901 } 902 return nullptr; 903 } 904 905 //============================================================================= 906 // Simplify a CmpL (compare 2 longs ) node, based on local information. 907 // If both inputs are constants, compare them. 908 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const { 909 const TypeLong *r0 = t1->is_long(); // Handy access 910 const TypeLong *r1 = t2->is_long(); 911 912 if( r0->_hi < r1->_lo ) // Range is always low? 913 return TypeInt::CC_LT; 914 else if( r0->_lo > r1->_hi ) // Range is always high? 915 return TypeInt::CC_GT; 916 917 else if( r0->is_con() && r1->is_con() ) { // comparing constants? 918 assert(r0->get_con() == r1->get_con(), "must be equal"); 919 return TypeInt::CC_EQ; // Equal results. 920 } else if( r0->_hi == r1->_lo ) // Range is never high? 921 return TypeInt::CC_LE; 922 else if( r0->_lo == r1->_hi ) // Range is never low? 923 return TypeInt::CC_GE; 924 return TypeInt::CC; // else use worst case results 925 } 926 927 928 // Simplify a CmpUL (compare 2 unsigned longs) node, based on local information. 929 // If both inputs are constants, compare them. 930 const Type* CmpULNode::sub(const Type* t1, const Type* t2) const { 931 assert(!t1->isa_ptr(), "obsolete usage of CmpUL"); 932 933 // comparing two unsigned longs 934 const TypeLong* r0 = t1->is_long(); // Handy access 935 const TypeLong* r1 = t2->is_long(); 936 937 // Current installed version 938 // Compare ranges for non-overlap 939 julong lo0 = r0->_lo; 940 julong hi0 = r0->_hi; 941 julong lo1 = r1->_lo; 942 julong hi1 = r1->_hi; 943 944 // If either one has both negative and positive values, 945 // it therefore contains both 0 and -1, and since [0..-1] is the 946 // full unsigned range, the type must act as an unsigned bottom. 947 bool bot0 = ((jlong)(lo0 ^ hi0) < 0); 948 bool bot1 = ((jlong)(lo1 ^ hi1) < 0); 949 950 if (bot0 || bot1) { 951 // All unsigned values are LE -1 and GE 0. 952 if (lo0 == 0 && hi0 == 0) { 953 return TypeInt::CC_LE; // 0 <= bot 954 } else if ((jlong)lo0 == -1 && (jlong)hi0 == -1) { 955 return TypeInt::CC_GE; // -1 >= bot 956 } else if (lo1 == 0 && hi1 == 0) { 957 return TypeInt::CC_GE; // bot >= 0 958 } else if ((jlong)lo1 == -1 && (jlong)hi1 == -1) { 959 return TypeInt::CC_LE; // bot <= -1 960 } 961 } else { 962 // We can use ranges of the form [lo..hi] if signs are the same. 963 assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid"); 964 // results are reversed, '-' > '+' for unsigned compare 965 if (hi0 < lo1) { 966 return TypeInt::CC_LT; // smaller 967 } else if (lo0 > hi1) { 968 return TypeInt::CC_GT; // greater 969 } else if (hi0 == lo1 && lo0 == hi1) { 970 return TypeInt::CC_EQ; // Equal results 971 } else if (lo0 >= hi1) { 972 return TypeInt::CC_GE; 973 } else if (hi0 <= lo1) { 974 return TypeInt::CC_LE; 975 } 976 } 977 978 return TypeInt::CC; // else use worst case results 979 } 980 981 //============================================================================= 982 //------------------------------sub-------------------------------------------- 983 // Simplify an CmpP (compare 2 pointers) node, based on local information. 984 // If both inputs are constants, compare them. 985 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const { 986 const TypePtr *r0 = t1->is_ptr(); // Handy access 987 const TypePtr *r1 = t2->is_ptr(); 988 989 // Undefined inputs makes for an undefined result 990 if( TypePtr::above_centerline(r0->_ptr) || 991 TypePtr::above_centerline(r1->_ptr) ) 992 return Type::TOP; 993 994 if (r0 == r1 && r0->singleton()) { 995 // Equal pointer constants (klasses, nulls, etc.) 996 return TypeInt::CC_EQ; 997 } 998 999 // See if it is 2 unrelated classes. 1000 const TypeOopPtr* p0 = r0->isa_oopptr(); 1001 const TypeOopPtr* p1 = r1->isa_oopptr(); 1002 const TypeKlassPtr* k0 = r0->isa_klassptr(); 1003 const TypeKlassPtr* k1 = r1->isa_klassptr(); 1004 if ((p0 && p1) || (k0 && k1)) { 1005 if (p0 && p1) { 1006 Node* in1 = in(1)->uncast(); 1007 Node* in2 = in(2)->uncast(); 1008 AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1); 1009 AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2); 1010 if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, nullptr)) { 1011 return TypeInt::CC_GT; // different pointers 1012 } 1013 } 1014 bool xklass0 = p0 ? p0->klass_is_exact() : k0->klass_is_exact(); 1015 bool xklass1 = p1 ? p1->klass_is_exact() : k1->klass_is_exact(); 1016 bool unrelated_classes = false; 1017 1018 if ((p0 && p0->is_same_java_type_as(p1)) || 1019 (k0 && k0->is_same_java_type_as(k1))) { 1020 } else if ((p0 && !p1->maybe_java_subtype_of(p0) && !p0->maybe_java_subtype_of(p1)) || 1021 (k0 && !k1->maybe_java_subtype_of(k0) && !k0->maybe_java_subtype_of(k1))) { 1022 unrelated_classes = true; 1023 } else if ((p0 && !p1->maybe_java_subtype_of(p0)) || 1024 (k0 && !k1->maybe_java_subtype_of(k0))) { 1025 unrelated_classes = xklass1; 1026 } else if ((p0 && !p0->maybe_java_subtype_of(p1)) || 1027 (k0 && !k0->maybe_java_subtype_of(k1))) { 1028 unrelated_classes = xklass0; 1029 } 1030 1031 if (unrelated_classes) { 1032 // The oops classes are known to be unrelated. If the joined PTRs of 1033 // two oops is not Null and not Bottom, then we are sure that one 1034 // of the two oops is non-null, and the comparison will always fail. 1035 TypePtr::PTR jp = r0->join_ptr(r1->_ptr); 1036 if (jp != TypePtr::Null && jp != TypePtr::BotPTR) { 1037 return TypeInt::CC_GT; 1038 } 1039 } 1040 } 1041 1042 // Known constants can be compared exactly 1043 // Null can be distinguished from any NotNull pointers 1044 // Unknown inputs makes an unknown result 1045 if( r0->singleton() ) { 1046 intptr_t bits0 = r0->get_con(); 1047 if( r1->singleton() ) 1048 return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT; 1049 return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC; 1050 } else if( r1->singleton() ) { 1051 intptr_t bits1 = r1->get_con(); 1052 return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC; 1053 } else 1054 return TypeInt::CC; 1055 } 1056 1057 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) { 1058 // Return the klass node for (indirect load from OopHandle) 1059 // LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror)))) 1060 // or null if not matching. 1061 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 1062 n = bs->step_over_gc_barrier(n); 1063 1064 if (n->Opcode() != Op_LoadP) return nullptr; 1065 1066 const TypeInstPtr* tp = phase->type(n)->isa_instptr(); 1067 if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr; 1068 1069 Node* adr = n->in(MemNode::Address); 1070 // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier. 1071 if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr; 1072 adr = adr->in(MemNode::Address); 1073 1074 intptr_t off = 0; 1075 Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off); 1076 if (k == nullptr) return nullptr; 1077 const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr(); 1078 if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr; 1079 1080 // We've found the klass node of a Java mirror load. 1081 return k; 1082 } 1083 1084 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) { 1085 // for ConP(Foo.class) return ConP(Foo.klass) 1086 // otherwise return null 1087 if (!n->is_Con()) return nullptr; 1088 1089 const TypeInstPtr* tp = phase->type(n)->isa_instptr(); 1090 if (!tp) return nullptr; 1091 1092 ciType* mirror_type = tp->java_mirror_type(); 1093 // TypeInstPtr::java_mirror_type() returns non-null for compile- 1094 // time Class constants only. 1095 if (!mirror_type) return nullptr; 1096 1097 // x.getClass() == int.class can never be true (for all primitive types) 1098 // Return a ConP(null) node for this case. 1099 if (mirror_type->is_classless()) { 1100 return phase->makecon(TypePtr::NULL_PTR); 1101 } 1102 1103 // return the ConP(Foo.klass) 1104 assert(mirror_type->is_klass(), "mirror_type should represent a Klass*"); 1105 return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass(), Type::trust_interfaces)); 1106 } 1107 1108 //------------------------------Ideal------------------------------------------ 1109 // Normalize comparisons between Java mirror loads to compare the klass instead. 1110 // 1111 // Also check for the case of comparing an unknown klass loaded from the primary 1112 // super-type array vs a known klass with no subtypes. This amounts to 1113 // checking to see an unknown klass subtypes a known klass with no subtypes; 1114 // this only happens on an exact match. We can shorten this test by 1 load. 1115 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) { 1116 // Normalize comparisons between Java mirrors into comparisons of the low- 1117 // level klass, where a dependent load could be shortened. 1118 // 1119 // The new pattern has a nice effect of matching the same pattern used in the 1120 // fast path of instanceof/checkcast/Class.isInstance(), which allows 1121 // redundant exact type check be optimized away by GVN. 1122 // For example, in 1123 // if (x.getClass() == Foo.class) { 1124 // Foo foo = (Foo) x; 1125 // // ... use a ... 1126 // } 1127 // a CmpPNode could be shared between if_acmpne and checkcast 1128 { 1129 Node* k1 = isa_java_mirror_load(phase, in(1)); 1130 Node* k2 = isa_java_mirror_load(phase, in(2)); 1131 Node* conk2 = isa_const_java_mirror(phase, in(2)); 1132 1133 if (k1 && (k2 || conk2)) { 1134 Node* lhs = k1; 1135 Node* rhs = (k2 != nullptr) ? k2 : conk2; 1136 set_req_X(1, lhs, phase); 1137 set_req_X(2, rhs, phase); 1138 return this; 1139 } 1140 } 1141 1142 // Constant pointer on right? 1143 const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr(); 1144 if (t2 == nullptr || !t2->klass_is_exact()) 1145 return nullptr; 1146 // Get the constant klass we are comparing to. 1147 ciKlass* superklass = t2->exact_klass(); 1148 1149 // Now check for LoadKlass on left. 1150 Node* ldk1 = in(1); 1151 if (ldk1->is_DecodeNKlass()) { 1152 ldk1 = ldk1->in(1); 1153 if (ldk1->Opcode() != Op_LoadNKlass ) 1154 return nullptr; 1155 } else if (ldk1->Opcode() != Op_LoadKlass ) 1156 return nullptr; 1157 // Take apart the address of the LoadKlass: 1158 Node* adr1 = ldk1->in(MemNode::Address); 1159 intptr_t con2 = 0; 1160 Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2); 1161 if (ldk2 == nullptr) 1162 return nullptr; 1163 if (con2 == oopDesc::klass_offset_in_bytes()) { 1164 // We are inspecting an object's concrete class. 1165 // Short-circuit the check if the query is abstract. 1166 if (superklass->is_interface() || 1167 superklass->is_abstract()) { 1168 // Make it come out always false: 1169 this->set_req(2, phase->makecon(TypePtr::NULL_PTR)); 1170 return this; 1171 } 1172 } 1173 1174 // Check for a LoadKlass from primary supertype array. 1175 // Any nested loadklass from loadklass+con must be from the p.s. array. 1176 if (ldk2->is_DecodeNKlass()) { 1177 // Keep ldk2 as DecodeN since it could be used in CmpP below. 1178 if (ldk2->in(1)->Opcode() != Op_LoadNKlass ) 1179 return nullptr; 1180 } else if (ldk2->Opcode() != Op_LoadKlass) 1181 return nullptr; 1182 1183 // Verify that we understand the situation 1184 if (con2 != (intptr_t) superklass->super_check_offset()) 1185 return nullptr; // Might be element-klass loading from array klass 1186 1187 // If 'superklass' has no subklasses and is not an interface, then we are 1188 // assured that the only input which will pass the type check is 1189 // 'superklass' itself. 1190 // 1191 // We could be more liberal here, and allow the optimization on interfaces 1192 // which have a single implementor. This would require us to increase the 1193 // expressiveness of the add_dependency() mechanism. 1194 // %%% Do this after we fix TypeOopPtr: Deps are expressive enough now. 1195 1196 // Object arrays must have their base element have no subtypes 1197 while (superklass->is_obj_array_klass()) { 1198 ciType* elem = superklass->as_obj_array_klass()->element_type(); 1199 superklass = elem->as_klass(); 1200 } 1201 if (superklass->is_instance_klass()) { 1202 ciInstanceKlass* ik = superklass->as_instance_klass(); 1203 if (ik->has_subklass() || ik->is_interface()) return nullptr; 1204 // Add a dependency if there is a chance that a subclass will be added later. 1205 if (!ik->is_final()) { 1206 phase->C->dependencies()->assert_leaf_type(ik); 1207 } 1208 } 1209 1210 // Bypass the dependent load, and compare directly 1211 this->set_req_X(1, ldk2, phase); 1212 1213 return this; 1214 } 1215 1216 //============================================================================= 1217 //------------------------------sub-------------------------------------------- 1218 // Simplify an CmpN (compare 2 pointers) node, based on local information. 1219 // If both inputs are constants, compare them. 1220 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const { 1221 ShouldNotReachHere(); 1222 return bottom_type(); 1223 } 1224 1225 //------------------------------Ideal------------------------------------------ 1226 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) { 1227 return nullptr; 1228 } 1229 1230 //============================================================================= 1231 //------------------------------Value------------------------------------------ 1232 // Simplify an CmpF (compare 2 floats ) node, based on local information. 1233 // If both inputs are constants, compare them. 1234 const Type* CmpFNode::Value(PhaseGVN* phase) const { 1235 const Node* in1 = in(1); 1236 const Node* in2 = in(2); 1237 // Either input is TOP ==> the result is TOP 1238 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1); 1239 if( t1 == Type::TOP ) return Type::TOP; 1240 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2); 1241 if( t2 == Type::TOP ) return Type::TOP; 1242 1243 // Not constants? Don't know squat - even if they are the same 1244 // value! If they are NaN's they compare to LT instead of EQ. 1245 const TypeF *tf1 = t1->isa_float_constant(); 1246 const TypeF *tf2 = t2->isa_float_constant(); 1247 if( !tf1 || !tf2 ) return TypeInt::CC; 1248 1249 // This implements the Java bytecode fcmpl, so unordered returns -1. 1250 if( tf1->is_nan() || tf2->is_nan() ) 1251 return TypeInt::CC_LT; 1252 1253 if( tf1->_f < tf2->_f ) return TypeInt::CC_LT; 1254 if( tf1->_f > tf2->_f ) return TypeInt::CC_GT; 1255 assert( tf1->_f == tf2->_f, "do not understand FP behavior" ); 1256 return TypeInt::CC_EQ; 1257 } 1258 1259 1260 //============================================================================= 1261 //------------------------------Value------------------------------------------ 1262 // Simplify an CmpD (compare 2 doubles ) node, based on local information. 1263 // If both inputs are constants, compare them. 1264 const Type* CmpDNode::Value(PhaseGVN* phase) const { 1265 const Node* in1 = in(1); 1266 const Node* in2 = in(2); 1267 // Either input is TOP ==> the result is TOP 1268 const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1); 1269 if( t1 == Type::TOP ) return Type::TOP; 1270 const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2); 1271 if( t2 == Type::TOP ) return Type::TOP; 1272 1273 // Not constants? Don't know squat - even if they are the same 1274 // value! If they are NaN's they compare to LT instead of EQ. 1275 const TypeD *td1 = t1->isa_double_constant(); 1276 const TypeD *td2 = t2->isa_double_constant(); 1277 if( !td1 || !td2 ) return TypeInt::CC; 1278 1279 // This implements the Java bytecode dcmpl, so unordered returns -1. 1280 if( td1->is_nan() || td2->is_nan() ) 1281 return TypeInt::CC_LT; 1282 1283 if( td1->_d < td2->_d ) return TypeInt::CC_LT; 1284 if( td1->_d > td2->_d ) return TypeInt::CC_GT; 1285 assert( td1->_d == td2->_d, "do not understand FP behavior" ); 1286 return TypeInt::CC_EQ; 1287 } 1288 1289 //------------------------------Ideal------------------------------------------ 1290 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){ 1291 // Check if we can change this to a CmpF and remove a ConvD2F operation. 1292 // Change (CMPD (F2D (float)) (ConD value)) 1293 // To (CMPF (float) (ConF value)) 1294 // Valid when 'value' does not lose precision as a float. 1295 // Benefits: eliminates conversion, does not require 24-bit mode 1296 1297 // NaNs prevent commuting operands. This transform works regardless of the 1298 // order of ConD and ConvF2D inputs by preserving the original order. 1299 int idx_f2d = 1; // ConvF2D on left side? 1300 if( in(idx_f2d)->Opcode() != Op_ConvF2D ) 1301 idx_f2d = 2; // No, swap to check for reversed args 1302 int idx_con = 3-idx_f2d; // Check for the constant on other input 1303 1304 if( ConvertCmpD2CmpF && 1305 in(idx_f2d)->Opcode() == Op_ConvF2D && 1306 in(idx_con)->Opcode() == Op_ConD ) { 1307 const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant(); 1308 double t2_value_as_double = t2->_d; 1309 float t2_value_as_float = (float)t2_value_as_double; 1310 if( t2_value_as_double == (double)t2_value_as_float ) { 1311 // Test value can be represented as a float 1312 // Eliminate the conversion to double and create new comparison 1313 Node *new_in1 = in(idx_f2d)->in(1); 1314 Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) ); 1315 if( idx_f2d != 1 ) { // Must flip args to match original order 1316 Node *tmp = new_in1; 1317 new_in1 = new_in2; 1318 new_in2 = tmp; 1319 } 1320 CmpFNode *new_cmp = (Opcode() == Op_CmpD3) 1321 ? new CmpF3Node( new_in1, new_in2 ) 1322 : new CmpFNode ( new_in1, new_in2 ) ; 1323 return new_cmp; // Changed to CmpFNode 1324 } 1325 // Testing value required the precision of a double 1326 } 1327 return nullptr; // No change 1328 } 1329 1330 1331 //============================================================================= 1332 //------------------------------cc2logical------------------------------------- 1333 // Convert a condition code type to a logical type 1334 const Type *BoolTest::cc2logical( const Type *CC ) const { 1335 if( CC == Type::TOP ) return Type::TOP; 1336 if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse 1337 const TypeInt *ti = CC->is_int(); 1338 if( ti->is_con() ) { // Only 1 kind of condition codes set? 1339 // Match low order 2 bits 1340 int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0; 1341 if( _test & 4 ) tmp = 1-tmp; // Optionally complement result 1342 return TypeInt::make(tmp); // Boolean result 1343 } 1344 1345 if( CC == TypeInt::CC_GE ) { 1346 if( _test == ge ) return TypeInt::ONE; 1347 if( _test == lt ) return TypeInt::ZERO; 1348 } 1349 if( CC == TypeInt::CC_LE ) { 1350 if( _test == le ) return TypeInt::ONE; 1351 if( _test == gt ) return TypeInt::ZERO; 1352 } 1353 1354 return TypeInt::BOOL; 1355 } 1356 1357 //------------------------------dump_spec------------------------------------- 1358 // Print special per-node info 1359 void BoolTest::dump_on(outputStream *st) const { 1360 const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"}; 1361 st->print("%s", msg[_test]); 1362 } 1363 1364 // Returns the logical AND of two tests (or 'never' if both tests can never be true). 1365 // For example, a test for 'le' followed by a test for 'lt' is equivalent with 'lt'. 1366 BoolTest::mask BoolTest::merge(BoolTest other) const { 1367 const mask res[illegal+1][illegal+1] = { 1368 // eq, gt, of, lt, ne, le, nof, ge, never, illegal 1369 {eq, never, illegal, never, never, eq, illegal, eq, never, illegal}, // eq 1370 {never, gt, illegal, never, gt, never, illegal, gt, never, illegal}, // gt 1371 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // of 1372 {never, never, illegal, lt, lt, lt, illegal, never, never, illegal}, // lt 1373 {never, gt, illegal, lt, ne, lt, illegal, gt, never, illegal}, // ne 1374 {eq, never, illegal, lt, lt, le, illegal, eq, never, illegal}, // le 1375 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, never, illegal}, // nof 1376 {eq, gt, illegal, never, gt, eq, illegal, ge, never, illegal}, // ge 1377 {never, never, never, never, never, never, never, never, never, illegal}, // never 1378 {illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal, illegal}}; // illegal 1379 return res[_test][other._test]; 1380 } 1381 1382 //============================================================================= 1383 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); } 1384 uint BoolNode::size_of() const { return sizeof(BoolNode); } 1385 1386 //------------------------------operator==------------------------------------- 1387 bool BoolNode::cmp( const Node &n ) const { 1388 const BoolNode *b = (const BoolNode *)&n; // Cast up 1389 return (_test._test == b->_test._test); 1390 } 1391 1392 //-------------------------------make_predicate-------------------------------- 1393 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) { 1394 if (test_value->is_Con()) return test_value; 1395 if (test_value->is_Bool()) return test_value; 1396 if (test_value->is_CMove() && 1397 test_value->in(CMoveNode::Condition)->is_Bool()) { 1398 BoolNode* bol = test_value->in(CMoveNode::Condition)->as_Bool(); 1399 const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse)); 1400 const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue)); 1401 if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) { 1402 return bol; 1403 } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) { 1404 return phase->transform( bol->negate(phase) ); 1405 } 1406 // Else fall through. The CMove gets in the way of the test. 1407 // It should be the case that make_predicate(bol->as_int_value()) == bol. 1408 } 1409 Node* cmp = new CmpINode(test_value, phase->intcon(0)); 1410 cmp = phase->transform(cmp); 1411 Node* bol = new BoolNode(cmp, BoolTest::ne); 1412 return phase->transform(bol); 1413 } 1414 1415 //--------------------------------as_int_value--------------------------------- 1416 Node* BoolNode::as_int_value(PhaseGVN* phase) { 1417 // Inverse to make_predicate. The CMove probably boils down to a Conv2B. 1418 Node* cmov = CMoveNode::make(this, phase->intcon(0), phase->intcon(1), TypeInt::BOOL); 1419 return phase->transform(cmov); 1420 } 1421 1422 //----------------------------------negate------------------------------------- 1423 BoolNode* BoolNode::negate(PhaseGVN* phase) { 1424 return new BoolNode(in(1), _test.negate()); 1425 } 1426 1427 // Change "bool eq/ne (cmp (add/sub A B) C)" into false/true if add/sub 1428 // overflows and we can prove that C is not in the two resulting ranges. 1429 // This optimization is similar to the one performed by CmpUNode::Value(). 1430 Node* BoolNode::fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op, 1431 int cmp1_op, const TypeInt* cmp2_type) { 1432 // Only optimize eq/ne integer comparison of add/sub 1433 if((_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1434 (cmp_op == Op_CmpI) && (cmp1_op == Op_AddI || cmp1_op == Op_SubI)) { 1435 // Skip cases were inputs of add/sub are not integers or of bottom type 1436 const TypeInt* r0 = phase->type(cmp1->in(1))->isa_int(); 1437 const TypeInt* r1 = phase->type(cmp1->in(2))->isa_int(); 1438 if ((r0 != nullptr) && (r0 != TypeInt::INT) && 1439 (r1 != nullptr) && (r1 != TypeInt::INT) && 1440 (cmp2_type != TypeInt::INT)) { 1441 // Compute exact (long) type range of add/sub result 1442 jlong lo_long = r0->_lo; 1443 jlong hi_long = r0->_hi; 1444 if (cmp1_op == Op_AddI) { 1445 lo_long += r1->_lo; 1446 hi_long += r1->_hi; 1447 } else { 1448 lo_long -= r1->_hi; 1449 hi_long -= r1->_lo; 1450 } 1451 // Check for over-/underflow by casting to integer 1452 int lo_int = (int)lo_long; 1453 int hi_int = (int)hi_long; 1454 bool underflow = lo_long != (jlong)lo_int; 1455 bool overflow = hi_long != (jlong)hi_int; 1456 if ((underflow != overflow) && (hi_int < lo_int)) { 1457 // Overflow on one boundary, compute resulting type ranges: 1458 // tr1 [MIN_INT, hi_int] and tr2 [lo_int, MAX_INT] 1459 int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here 1460 const TypeInt* tr1 = TypeInt::make(min_jint, hi_int, w); 1461 const TypeInt* tr2 = TypeInt::make(lo_int, max_jint, w); 1462 // Compare second input of cmp to both type ranges 1463 const Type* sub_tr1 = cmp->sub(tr1, cmp2_type); 1464 const Type* sub_tr2 = cmp->sub(tr2, cmp2_type); 1465 if (sub_tr1 == TypeInt::CC_LT && sub_tr2 == TypeInt::CC_GT) { 1466 // The result of the add/sub will never equal cmp2. Replace BoolNode 1467 // by false (0) if it tests for equality and by true (1) otherwise. 1468 return ConINode::make((_test._test == BoolTest::eq) ? 0 : 1); 1469 } 1470 } 1471 } 1472 } 1473 return nullptr; 1474 } 1475 1476 static bool is_counted_loop_cmp(Node *cmp) { 1477 Node *n = cmp->in(1)->in(1); 1478 return n != nullptr && 1479 n->is_Phi() && 1480 n->in(0) != nullptr && 1481 n->in(0)->is_CountedLoop() && 1482 n->in(0)->as_CountedLoop()->phi() == n; 1483 } 1484 1485 //------------------------------Ideal------------------------------------------ 1486 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) { 1487 // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)". 1488 // This moves the constant to the right. Helps value-numbering. 1489 Node *cmp = in(1); 1490 if( !cmp->is_Sub() ) return nullptr; 1491 int cop = cmp->Opcode(); 1492 if( cop == Op_FastLock || cop == Op_FastUnlock || 1493 cmp->is_SubTypeCheck() || cop == Op_VectorTest ) { 1494 return nullptr; 1495 } 1496 Node *cmp1 = cmp->in(1); 1497 Node *cmp2 = cmp->in(2); 1498 if( !cmp1 ) return nullptr; 1499 1500 if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) { 1501 return nullptr; 1502 } 1503 1504 const int cmp1_op = cmp1->Opcode(); 1505 const int cmp2_op = cmp2->Opcode(); 1506 1507 // Constant on left? 1508 Node *con = cmp1; 1509 // Move constants to the right of compare's to canonicalize. 1510 // Do not muck with Opaque1 nodes, as this indicates a loop 1511 // guard that cannot change shape. 1512 if (con->is_Con() && !cmp2->is_Con() && cmp2_op != Op_OpaqueZeroTripGuard && 1513 // Because of NaN's, CmpD and CmpF are not commutative 1514 cop != Op_CmpD && cop != Op_CmpF && 1515 // Protect against swapping inputs to a compare when it is used by a 1516 // counted loop exit, which requires maintaining the loop-limit as in(2) 1517 !is_counted_loop_exit_test() ) { 1518 // Ok, commute the constant to the right of the cmp node. 1519 // Clone the Node, getting a new Node of the same class 1520 cmp = cmp->clone(); 1521 // Swap inputs to the clone 1522 cmp->swap_edges(1, 2); 1523 cmp = phase->transform( cmp ); 1524 return new BoolNode( cmp, _test.commute() ); 1525 } 1526 1527 // Change "bool eq/ne (cmp (cmove (bool tst (cmp2)) 1 0) 0)" into "bool tst/~tst (cmp2)" 1528 if (cop == Op_CmpI && 1529 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1530 cmp1_op == Op_CMoveI && cmp2->find_int_con(1) == 0) { 1531 // 0 should be on the true branch 1532 if (cmp1->in(CMoveNode::Condition)->is_Bool() && 1533 cmp1->in(CMoveNode::IfTrue)->find_int_con(1) == 0 && 1534 cmp1->in(CMoveNode::IfFalse)->find_int_con(0) != 0) { 1535 BoolNode* target = cmp1->in(CMoveNode::Condition)->as_Bool(); 1536 return new BoolNode(target->in(1), 1537 (_test._test == BoolTest::eq) ? target->_test._test : 1538 target->_test.negate()); 1539 } 1540 } 1541 1542 // Change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)". 1543 if (cop == Op_CmpI && 1544 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1545 cmp1_op == Op_AndI && cmp2_op == Op_ConI && 1546 cmp1->in(2)->Opcode() == Op_ConI) { 1547 const TypeInt *t12 = phase->type(cmp2)->isa_int(); 1548 const TypeInt *t112 = phase->type(cmp1->in(2))->isa_int(); 1549 if (t12 && t12->is_con() && t112 && t112->is_con() && 1550 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) { 1551 Node *ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0))); 1552 return new BoolNode(ncmp, _test.negate()); 1553 } 1554 } 1555 1556 // Same for long type: change "bool eq/ne (cmp (and X 16) 16)" into "bool ne/eq (cmp (and X 16) 0)". 1557 if (cop == Op_CmpL && 1558 (_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1559 cmp1_op == Op_AndL && cmp2_op == Op_ConL && 1560 cmp1->in(2)->Opcode() == Op_ConL) { 1561 const TypeLong *t12 = phase->type(cmp2)->isa_long(); 1562 const TypeLong *t112 = phase->type(cmp1->in(2))->isa_long(); 1563 if (t12 && t12->is_con() && t112 && t112->is_con() && 1564 t12->get_con() == t112->get_con() && is_power_of_2(t12->get_con())) { 1565 Node *ncmp = phase->transform(new CmpLNode(cmp1, phase->longcon(0))); 1566 return new BoolNode(ncmp, _test.negate()); 1567 } 1568 } 1569 1570 // Change "cmp (add X min_jint) (add Y min_jint)" into "cmpu X Y" 1571 // and "cmp (add X min_jint) c" into "cmpu X (c + min_jint)" 1572 if (cop == Op_CmpI && 1573 cmp1_op == Op_AddI && 1574 phase->type(cmp1->in(2)) == TypeInt::MIN && 1575 !is_cloop_condition(this)) { 1576 if (cmp2_op == Op_ConI) { 1577 Node* ncmp2 = phase->intcon(java_add(cmp2->get_int(), min_jint)); 1578 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), ncmp2)); 1579 return new BoolNode(ncmp, _test._test); 1580 } else if (cmp2_op == Op_AddI && 1581 phase->type(cmp2->in(2)) == TypeInt::MIN && 1582 !is_cloop_condition(this)) { 1583 Node* ncmp = phase->transform(new CmpUNode(cmp1->in(1), cmp2->in(1))); 1584 return new BoolNode(ncmp, _test._test); 1585 } 1586 } 1587 1588 // Change "cmp (add X min_jlong) (add Y min_jlong)" into "cmpu X Y" 1589 // and "cmp (add X min_jlong) c" into "cmpu X (c + min_jlong)" 1590 if (cop == Op_CmpL && 1591 cmp1_op == Op_AddL && 1592 phase->type(cmp1->in(2)) == TypeLong::MIN && 1593 !is_cloop_condition(this)) { 1594 if (cmp2_op == Op_ConL) { 1595 Node* ncmp2 = phase->longcon(java_add(cmp2->get_long(), min_jlong)); 1596 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), ncmp2)); 1597 return new BoolNode(ncmp, _test._test); 1598 } else if (cmp2_op == Op_AddL && 1599 phase->type(cmp2->in(2)) == TypeLong::MIN && 1600 !is_cloop_condition(this)) { 1601 Node* ncmp = phase->transform(new CmpULNode(cmp1->in(1), cmp2->in(1))); 1602 return new BoolNode(ncmp, _test._test); 1603 } 1604 } 1605 1606 // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)". 1607 // The XOR-1 is an idiom used to flip the sense of a bool. We flip the 1608 // test instead. 1609 const TypeInt* cmp2_type = phase->type(cmp2)->isa_int(); 1610 if (cmp2_type == nullptr) return nullptr; 1611 Node* j_xor = cmp1; 1612 if( cmp2_type == TypeInt::ZERO && 1613 cmp1_op == Op_XorI && 1614 j_xor->in(1) != j_xor && // An xor of itself is dead 1615 phase->type( j_xor->in(1) ) == TypeInt::BOOL && 1616 phase->type( j_xor->in(2) ) == TypeInt::ONE && 1617 (_test._test == BoolTest::eq || 1618 _test._test == BoolTest::ne) ) { 1619 Node *ncmp = phase->transform(new CmpINode(j_xor->in(1),cmp2)); 1620 return new BoolNode( ncmp, _test.negate() ); 1621 } 1622 1623 // Transform: "((x & (m - 1)) <u m)" or "(((m - 1) & x) <u m)" into "(m >u 0)" 1624 // This is case [CMPU_MASK] which is further described at the method comment of BoolNode::Value_cmpu_and_mask(). 1625 if (cop == Op_CmpU && _test._test == BoolTest::lt && cmp1_op == Op_AndI) { 1626 Node* m = cmp2; // RHS: m 1627 for (int add_idx = 1; add_idx <= 2; add_idx++) { // LHS: "(m + (-1)) & x" or "x & (m + (-1))"? 1628 Node* maybe_m_minus_1 = cmp1->in(add_idx); 1629 if (maybe_m_minus_1->Opcode() == Op_AddI && 1630 maybe_m_minus_1->in(2)->find_int_con(0) == -1 && 1631 maybe_m_minus_1->in(1) == m) { 1632 Node* m_cmpu_0 = phase->transform(new CmpUNode(m, phase->intcon(0))); 1633 return new BoolNode(m_cmpu_0, BoolTest::gt); 1634 } 1635 } 1636 } 1637 1638 // Change x u< 1 or x u<= 0 to x == 0 1639 // and x u> 0 or u>= 1 to x != 0 1640 if (cop == Op_CmpU && 1641 cmp1_op != Op_LoadRange && 1642 (((_test._test == BoolTest::lt || _test._test == BoolTest::ge) && 1643 cmp2->find_int_con(-1) == 1) || 1644 ((_test._test == BoolTest::le || _test._test == BoolTest::gt) && 1645 cmp2->find_int_con(-1) == 0))) { 1646 Node* ncmp = phase->transform(new CmpINode(cmp1, phase->intcon(0))); 1647 return new BoolNode(ncmp, _test.is_less() ? BoolTest::eq : BoolTest::ne); 1648 } 1649 1650 // Change (arraylength <= 0) or (arraylength == 0) 1651 // into (arraylength u<= 0) 1652 // Also change (arraylength != 0) into (arraylength u> 0) 1653 // The latter version matches the code pattern generated for 1654 // array range checks, which will more likely be optimized later. 1655 if (cop == Op_CmpI && 1656 cmp1_op == Op_LoadRange && 1657 cmp2->find_int_con(-1) == 0) { 1658 if (_test._test == BoolTest::le || _test._test == BoolTest::eq) { 1659 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2)); 1660 return new BoolNode(ncmp, BoolTest::le); 1661 } else if (_test._test == BoolTest::ne) { 1662 Node* ncmp = phase->transform(new CmpUNode(cmp1, cmp2)); 1663 return new BoolNode(ncmp, BoolTest::gt); 1664 } 1665 } 1666 1667 // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)". 1668 // This is a standard idiom for branching on a boolean value. 1669 Node *c2b = cmp1; 1670 if( cmp2_type == TypeInt::ZERO && 1671 cmp1_op == Op_Conv2B && 1672 (_test._test == BoolTest::eq || 1673 _test._test == BoolTest::ne) ) { 1674 Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int() 1675 ? (Node*)new CmpINode(c2b->in(1),cmp2) 1676 : (Node*)new CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR)) 1677 ); 1678 return new BoolNode( ncmp, _test._test ); 1679 } 1680 1681 // Comparing a SubI against a zero is equal to comparing the SubI 1682 // arguments directly. This only works for eq and ne comparisons 1683 // due to possible integer overflow. 1684 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1685 (cop == Op_CmpI) && 1686 (cmp1_op == Op_SubI) && 1687 ( cmp2_type == TypeInt::ZERO ) ) { 1688 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),cmp1->in(2))); 1689 return new BoolNode( ncmp, _test._test ); 1690 } 1691 1692 // Same as above but with and AddI of a constant 1693 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1694 cop == Op_CmpI && 1695 cmp1_op == Op_AddI && 1696 cmp1->in(2) != nullptr && 1697 phase->type(cmp1->in(2))->isa_int() && 1698 phase->type(cmp1->in(2))->is_int()->is_con() && 1699 cmp2_type == TypeInt::ZERO && 1700 !is_counted_loop_cmp(cmp) // modifying the exit test of a counted loop messes the counted loop shape 1701 ) { 1702 const TypeInt* cmp1_in2 = phase->type(cmp1->in(2))->is_int(); 1703 Node *ncmp = phase->transform( new CmpINode(cmp1->in(1),phase->intcon(-cmp1_in2->_hi))); 1704 return new BoolNode( ncmp, _test._test ); 1705 } 1706 1707 // Change "bool eq/ne (cmp (phi (X -X) 0))" into "bool eq/ne (cmp X 0)" 1708 // since zero check of conditional negation of an integer is equal to 1709 // zero check of the integer directly. 1710 if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) && 1711 (cop == Op_CmpI) && 1712 (cmp2_type == TypeInt::ZERO) && 1713 (cmp1_op == Op_Phi)) { 1714 // There should be a diamond phi with true path at index 1 or 2 1715 PhiNode *phi = cmp1->as_Phi(); 1716 int idx_true = phi->is_diamond_phi(); 1717 if (idx_true != 0) { 1718 // True input is in(idx_true) while false input is in(3 - idx_true) 1719 Node *tin = phi->in(idx_true); 1720 Node *fin = phi->in(3 - idx_true); 1721 if ((tin->Opcode() == Op_SubI) && 1722 (phase->type(tin->in(1)) == TypeInt::ZERO) && 1723 (tin->in(2) == fin)) { 1724 // Found conditional negation at true path, create a new CmpINode without that 1725 Node *ncmp = phase->transform(new CmpINode(fin, cmp2)); 1726 return new BoolNode(ncmp, _test._test); 1727 } 1728 if ((fin->Opcode() == Op_SubI) && 1729 (phase->type(fin->in(1)) == TypeInt::ZERO) && 1730 (fin->in(2) == tin)) { 1731 // Found conditional negation at false path, create a new CmpINode without that 1732 Node *ncmp = phase->transform(new CmpINode(tin, cmp2)); 1733 return new BoolNode(ncmp, _test._test); 1734 } 1735 } 1736 } 1737 1738 // Change (-A vs 0) into (A vs 0) by commuting the test. Disallow in the 1739 // most general case because negating 0x80000000 does nothing. Needed for 1740 // the CmpF3/SubI/CmpI idiom. 1741 if( cop == Op_CmpI && 1742 cmp1_op == Op_SubI && 1743 cmp2_type == TypeInt::ZERO && 1744 phase->type( cmp1->in(1) ) == TypeInt::ZERO && 1745 phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) { 1746 Node *ncmp = phase->transform( new CmpINode(cmp1->in(2),cmp2)); 1747 return new BoolNode( ncmp, _test.commute() ); 1748 } 1749 1750 // Try to optimize signed integer comparison 1751 return fold_cmpI(phase, cmp->as_Sub(), cmp1, cop, cmp1_op, cmp2_type); 1752 1753 // The transformation below is not valid for either signed or unsigned 1754 // comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE. 1755 // This transformation can be resurrected when we are able to 1756 // make inferences about the range of values being subtracted from 1757 // (or added to) relative to the wraparound point. 1758 // 1759 // // Remove +/-1's if possible. 1760 // // "X <= Y-1" becomes "X < Y" 1761 // // "X+1 <= Y" becomes "X < Y" 1762 // // "X < Y+1" becomes "X <= Y" 1763 // // "X-1 < Y" becomes "X <= Y" 1764 // // Do not this to compares off of the counted-loop-end. These guys are 1765 // // checking the trip counter and they want to use the post-incremented 1766 // // counter. If they use the PRE-incremented counter, then the counter has 1767 // // to be incremented in a private block on a loop backedge. 1768 // if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd ) 1769 // return nullptr; 1770 // #ifndef PRODUCT 1771 // // Do not do this in a wash GVN pass during verification. 1772 // // Gets triggered by too many simple optimizations to be bothered with 1773 // // re-trying it again and again. 1774 // if( !phase->allow_progress() ) return nullptr; 1775 // #endif 1776 // // Not valid for unsigned compare because of corner cases in involving zero. 1777 // // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an 1778 // // exception in case X is 0 (because 0-1 turns into 4billion unsigned but 1779 // // "0 <=u Y" is always true). 1780 // if( cmp->Opcode() == Op_CmpU ) return nullptr; 1781 // int cmp2_op = cmp2->Opcode(); 1782 // if( _test._test == BoolTest::le ) { 1783 // if( cmp1_op == Op_AddI && 1784 // phase->type( cmp1->in(2) ) == TypeInt::ONE ) 1785 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt ); 1786 // else if( cmp2_op == Op_AddI && 1787 // phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 ) 1788 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt ); 1789 // } else if( _test._test == BoolTest::lt ) { 1790 // if( cmp1_op == Op_AddI && 1791 // phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 ) 1792 // return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le ); 1793 // else if( cmp2_op == Op_AddI && 1794 // phase->type( cmp2->in(2) ) == TypeInt::ONE ) 1795 // return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le ); 1796 // } 1797 } 1798 1799 // We use the following Lemmas/insights for the following two transformations (1) and (2): 1800 // x & y <=u y, for any x and y (Lemma 1, masking always results in a smaller unsigned number) 1801 // y <u y + 1 is always true if y != -1 (Lemma 2, (uint)(-1 + 1) == (uint)(UINT_MAX + 1) which overflows) 1802 // y <u 0 is always false for any y (Lemma 3, 0 == UINT_MIN and nothing can be smaller than that) 1803 // 1804 // (1a) Always: Change ((x & m) <=u m ) or ((m & x) <=u m ) to always true (true by Lemma 1) 1805 // (1b) If m != -1: Change ((x & m) <u m + 1) or ((m & x) <u m + 1) to always true: 1806 // x & m <=u m is always true // (Lemma 1) 1807 // x & m <=u m <u m + 1 is always true // (Lemma 2: m <u m + 1, if m != -1) 1808 // 1809 // A counter example for (1b), if we allowed m == -1: 1810 // (x & m) <u m + 1 1811 // (x & -1) <u 0 1812 // x <u 0 1813 // which is false for any x (Lemma 3) 1814 // 1815 // (2) Change ((x & (m - 1)) <u m) or (((m - 1) & x) <u m) to (m >u 0) 1816 // This is the off-by-one variant of the above. 1817 // 1818 // We now prove that this replacement is correct. This is the same as proving 1819 // "m >u 0" if and only if "x & (m - 1) <u m", i.e. "m >u 0 <=> x & (m - 1) <u m" 1820 // 1821 // We use (Lemma 1) and (Lemma 3) from above. 1822 // 1823 // Case "x & (m - 1) <u m => m >u 0": 1824 // We prove this by contradiction: 1825 // Assume m <=u 0 which is equivalent to m == 0: 1826 // and thus 1827 // x & (m - 1) <u m = 0 // m == 0 1828 // y <u 0 // y = x & (m - 1) 1829 // by Lemma 3, this is always false, i.e. a contradiction to our assumption. 1830 // 1831 // Case "m >u 0 => x & (m - 1) <u m": 1832 // x & (m - 1) <=u (m - 1) // (Lemma 1) 1833 // x & (m - 1) <=u (m - 1) <u m // Using assumption m >u 0, no underflow of "m - 1" 1834 // 1835 // 1836 // Note that the signed version of "m > 0": 1837 // m > 0 <=> x & (m - 1) <u m 1838 // does not hold: 1839 // Assume m == -1 and x == -1: 1840 // x & (m - 1) <u m 1841 // -1 & -2 <u -1 1842 // -2 <u -1 1843 // UINT_MAX - 1 <u UINT_MAX // Signed to unsigned numbers 1844 // which is true while 1845 // m > 0 1846 // is false which is a contradiction. 1847 // 1848 // (1a) and (1b) is covered by this method since we can directly return a true value as type while (2) is covered 1849 // in BoolNode::Ideal since we create a new non-constant node (see [CMPU_MASK]). 1850 const Type* BoolNode::Value_cmpu_and_mask(PhaseValues* phase) const { 1851 Node* cmp = in(1); 1852 if (cmp != nullptr && cmp->Opcode() == Op_CmpU) { 1853 Node* cmp1 = cmp->in(1); 1854 Node* cmp2 = cmp->in(2); 1855 1856 if (cmp1->Opcode() == Op_AndI) { 1857 Node* m = nullptr; 1858 if (_test._test == BoolTest::le) { 1859 // (1a) "((x & m) <=u m)", cmp2 = m 1860 m = cmp2; 1861 } else if (_test._test == BoolTest::lt && cmp2->Opcode() == Op_AddI && cmp2->in(2)->find_int_con(0) == 1) { 1862 // (1b) "(x & m) <u m + 1" and "(m & x) <u m + 1", cmp2 = m + 1 1863 Node* rhs_m = cmp2->in(1); 1864 const TypeInt* rhs_m_type = phase->type(rhs_m)->isa_int(); 1865 if (rhs_m_type->_lo > -1 || rhs_m_type->_hi < -1) { 1866 // Exclude any case where m == -1 is possible. 1867 m = rhs_m; 1868 } 1869 } 1870 1871 if (cmp1->in(2) == m || cmp1->in(1) == m) { 1872 return TypeInt::ONE; 1873 } 1874 } 1875 } 1876 1877 return nullptr; 1878 } 1879 1880 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node, 1881 // based on local information. If the input is constant, do it. 1882 const Type* BoolNode::Value(PhaseGVN* phase) const { 1883 const Type* t = Value_cmpu_and_mask(phase); 1884 if (t != nullptr) { 1885 return t; 1886 } 1887 1888 return _test.cc2logical( phase->type( in(1) ) ); 1889 } 1890 1891 #ifndef PRODUCT 1892 //------------------------------dump_spec-------------------------------------- 1893 // Dump special per-node info 1894 void BoolNode::dump_spec(outputStream *st) const { 1895 st->print("["); 1896 _test.dump_on(st); 1897 st->print("]"); 1898 } 1899 #endif 1900 1901 //----------------------is_counted_loop_exit_test------------------------------ 1902 // Returns true if node is used by a counted loop node. 1903 bool BoolNode::is_counted_loop_exit_test() { 1904 for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) { 1905 Node* use = fast_out(i); 1906 if (use->is_CountedLoopEnd()) { 1907 return true; 1908 } 1909 } 1910 return false; 1911 } 1912 1913 //============================================================================= 1914 //------------------------------Value------------------------------------------ 1915 const Type* AbsNode::Value(PhaseGVN* phase) const { 1916 const Type* t1 = phase->type(in(1)); 1917 if (t1 == Type::TOP) return Type::TOP; 1918 1919 switch (t1->base()) { 1920 case Type::Int: { 1921 const TypeInt* ti = t1->is_int(); 1922 if (ti->is_con()) { 1923 return TypeInt::make(uabs(ti->get_con())); 1924 } 1925 break; 1926 } 1927 case Type::Long: { 1928 const TypeLong* tl = t1->is_long(); 1929 if (tl->is_con()) { 1930 return TypeLong::make(uabs(tl->get_con())); 1931 } 1932 break; 1933 } 1934 case Type::FloatCon: 1935 return TypeF::make(abs(t1->getf())); 1936 case Type::DoubleCon: 1937 return TypeD::make(abs(t1->getd())); 1938 default: 1939 break; 1940 } 1941 1942 return bottom_type(); 1943 } 1944 1945 //------------------------------Identity---------------------------------------- 1946 Node* AbsNode::Identity(PhaseGVN* phase) { 1947 Node* in1 = in(1); 1948 // No need to do abs for non-negative values 1949 if (phase->type(in1)->higher_equal(TypeInt::POS) || 1950 phase->type(in1)->higher_equal(TypeLong::POS)) { 1951 return in1; 1952 } 1953 // Convert "abs(abs(x))" into "abs(x)" 1954 if (in1->Opcode() == Opcode()) { 1955 return in1; 1956 } 1957 return this; 1958 } 1959 1960 //------------------------------Ideal------------------------------------------ 1961 Node* AbsNode::Ideal(PhaseGVN* phase, bool can_reshape) { 1962 Node* in1 = in(1); 1963 // Convert "abs(0-x)" into "abs(x)" 1964 if (in1->is_Sub() && phase->type(in1->in(1))->is_zero_type()) { 1965 set_req_X(1, in1->in(2), phase); 1966 return this; 1967 } 1968 return nullptr; 1969 } 1970 1971 //============================================================================= 1972 //------------------------------Value------------------------------------------ 1973 // Compute sqrt 1974 const Type* SqrtDNode::Value(PhaseGVN* phase) const { 1975 const Type *t1 = phase->type( in(1) ); 1976 if( t1 == Type::TOP ) return Type::TOP; 1977 if( t1->base() != Type::DoubleCon ) return Type::DOUBLE; 1978 double d = t1->getd(); 1979 if( d < 0.0 ) return Type::DOUBLE; 1980 return TypeD::make( sqrt( d ) ); 1981 } 1982 1983 const Type* SqrtFNode::Value(PhaseGVN* phase) const { 1984 const Type *t1 = phase->type( in(1) ); 1985 if( t1 == Type::TOP ) return Type::TOP; 1986 if( t1->base() != Type::FloatCon ) return Type::FLOAT; 1987 float f = t1->getf(); 1988 if( f < 0.0f ) return Type::FLOAT; 1989 return TypeF::make( (float)sqrt( (double)f ) ); 1990 } 1991 1992 const Type* ReverseINode::Value(PhaseGVN* phase) const { 1993 const Type *t1 = phase->type( in(1) ); 1994 if (t1 == Type::TOP) { 1995 return Type::TOP; 1996 } 1997 const TypeInt* t1int = t1->isa_int(); 1998 if (t1int && t1int->is_con()) { 1999 jint res = reverse_bits(t1int->get_con()); 2000 return TypeInt::make(res); 2001 } 2002 return bottom_type(); 2003 } 2004 2005 const Type* ReverseLNode::Value(PhaseGVN* phase) const { 2006 const Type *t1 = phase->type( in(1) ); 2007 if (t1 == Type::TOP) { 2008 return Type::TOP; 2009 } 2010 const TypeLong* t1long = t1->isa_long(); 2011 if (t1long && t1long->is_con()) { 2012 jlong res = reverse_bits(t1long->get_con()); 2013 return TypeLong::make(res); 2014 } 2015 return bottom_type(); 2016 } 2017 2018 Node* ReverseINode::Identity(PhaseGVN* phase) { 2019 if (in(1)->Opcode() == Op_ReverseI) { 2020 return in(1)->in(1); 2021 } 2022 return this; 2023 } 2024 2025 Node* ReverseLNode::Identity(PhaseGVN* phase) { 2026 if (in(1)->Opcode() == Op_ReverseL) { 2027 return in(1)->in(1); 2028 } 2029 return this; 2030 }