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