1 /* 2 * Copyright (c) 1997, 2012, 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 "memory/allocation.inline.hpp" 27 #include "opto/addnode.hpp" 28 #include "opto/castnode.hpp" 29 #include "opto/cfgnode.hpp" 30 #include "opto/connode.hpp" 31 #include "opto/machnode.hpp" 32 #include "opto/mulnode.hpp" 33 #include "opto/phaseX.hpp" 34 #include "opto/subnode.hpp" 35 36 // Portions of code courtesy of Clifford Click 37 38 // Classic Add functionality. This covers all the usual 'add' behaviors for 39 // an algebraic ring. Add-integer, add-float, add-double, and binary-or are 40 // all inherited from this class. The various identity values are supplied 41 // by virtual functions. 42 43 44 //============================================================================= 45 //------------------------------hash------------------------------------------- 46 // Hash function over AddNodes. Needs to be commutative; i.e., I swap 47 // (commute) inputs to AddNodes willy-nilly so the hash function must return 48 // the same value in the presence of edge swapping. 49 uint AddNode::hash() const { 50 return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode(); 51 } 52 53 //------------------------------Identity--------------------------------------- 54 // If either input is a constant 0, return the other input. 55 Node *AddNode::Identity( PhaseTransform *phase ) { 56 const Type *zero = add_id(); // The additive identity 57 if( phase->type( in(1) )->higher_equal( zero ) ) return in(2); 58 if( phase->type( in(2) )->higher_equal( zero ) ) return in(1); 59 return this; 60 } 61 62 //------------------------------commute---------------------------------------- 63 // Commute operands to move loads and constants to the right. 64 static bool commute( Node *add, int con_left, int con_right ) { 65 Node *in1 = add->in(1); 66 Node *in2 = add->in(2); 67 68 // Convert "1+x" into "x+1". 69 // Right is a constant; leave it 70 if( con_right ) return false; 71 // Left is a constant; move it right. 72 if( con_left ) { 73 add->swap_edges(1, 2); 74 return true; 75 } 76 77 // Convert "Load+x" into "x+Load". 78 // Now check for loads 79 if (in2->is_Load()) { 80 if (!in1->is_Load()) { 81 // already x+Load to return 82 return false; 83 } 84 // both are loads, so fall through to sort inputs by idx 85 } else if( in1->is_Load() ) { 86 // Left is a Load and Right is not; move it right. 87 add->swap_edges(1, 2); 88 return true; 89 } 90 91 PhiNode *phi; 92 // Check for tight loop increments: Loop-phi of Add of loop-phi 93 if( in1->is_Phi() && (phi = in1->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add) 94 return false; 95 if( in2->is_Phi() && (phi = in2->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add){ 96 add->swap_edges(1, 2); 97 return true; 98 } 99 100 // Otherwise, sort inputs (commutativity) to help value numbering. 101 if( in1->_idx > in2->_idx ) { 102 add->swap_edges(1, 2); 103 return true; 104 } 105 return false; 106 } 107 108 //------------------------------Idealize--------------------------------------- 109 // If we get here, we assume we are associative! 110 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) { 111 const Type *t1 = phase->type( in(1) ); 112 const Type *t2 = phase->type( in(2) ); 113 int con_left = t1->singleton(); 114 int con_right = t2->singleton(); 115 116 // Check for commutative operation desired 117 if( commute(this,con_left,con_right) ) return this; 118 119 AddNode *progress = NULL; // Progress flag 120 121 // Convert "(x+1)+2" into "x+(1+2)". If the right input is a 122 // constant, and the left input is an add of a constant, flatten the 123 // expression tree. 124 Node *add1 = in(1); 125 Node *add2 = in(2); 126 int add1_op = add1->Opcode(); 127 int this_op = Opcode(); 128 if( con_right && t2 != Type::TOP && // Right input is a constant? 129 add1_op == this_op ) { // Left input is an Add? 130 131 // Type of left _in right input 132 const Type *t12 = phase->type( add1->in(2) ); 133 if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant? 134 // Check for rare case of closed data cycle which can happen inside 135 // unreachable loops. In these cases the computation is undefined. 136 #ifdef ASSERT 137 Node *add11 = add1->in(1); 138 int add11_op = add11->Opcode(); 139 if( (add1 == add1->in(1)) 140 || (add11_op == this_op && add11->in(1) == add1) ) { 141 assert(false, "dead loop in AddNode::Ideal"); 142 } 143 #endif 144 // The Add of the flattened expression 145 Node *x1 = add1->in(1); 146 Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 )); 147 PhaseIterGVN *igvn = phase->is_IterGVN(); 148 if( igvn ) { 149 set_req_X(2,x2,igvn); 150 set_req_X(1,x1,igvn); 151 } else { 152 set_req(2,x2); 153 set_req(1,x1); 154 } 155 progress = this; // Made progress 156 add1 = in(1); 157 add1_op = add1->Opcode(); 158 } 159 } 160 161 // Convert "(x+1)+y" into "(x+y)+1". Push constants down the expression tree. 162 if( add1_op == this_op && !con_right ) { 163 Node *a12 = add1->in(2); 164 const Type *t12 = phase->type( a12 ); 165 if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) && 166 !(add1->in(1)->is_Phi() && add1->in(1)->as_Phi()->is_tripcount()) ) { 167 assert(add1->in(1) != this, "dead loop in AddNode::Ideal"); 168 add2 = add1->clone(); 169 add2->set_req(2, in(2)); 170 add2 = phase->transform(add2); 171 set_req(1, add2); 172 set_req(2, a12); 173 progress = this; 174 add2 = a12; 175 } 176 } 177 178 // Convert "x+(y+1)" into "(x+y)+1". Push constants down the expression tree. 179 int add2_op = add2->Opcode(); 180 if( add2_op == this_op && !con_left ) { 181 Node *a22 = add2->in(2); 182 const Type *t22 = phase->type( a22 ); 183 if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) && 184 !(add2->in(1)->is_Phi() && add2->in(1)->as_Phi()->is_tripcount()) ) { 185 assert(add2->in(1) != this, "dead loop in AddNode::Ideal"); 186 Node *addx = add2->clone(); 187 addx->set_req(1, in(1)); 188 addx->set_req(2, add2->in(1)); 189 addx = phase->transform(addx); 190 set_req(1, addx); 191 set_req(2, a22); 192 progress = this; 193 PhaseIterGVN *igvn = phase->is_IterGVN(); 194 if (add2->outcnt() == 0 && igvn) { 195 // add disconnected. 196 igvn->_worklist.push(add2); 197 } 198 } 199 } 200 201 return progress; 202 } 203 204 //------------------------------Value----------------------------------------- 205 // An add node sums it's two _in. If one input is an RSD, we must mixin 206 // the other input's symbols. 207 const Type *AddNode::Value( PhaseTransform *phase ) const { 208 // Either input is TOP ==> the result is TOP 209 const Type *t1 = phase->type( in(1) ); 210 const Type *t2 = phase->type( in(2) ); 211 if( t1 == Type::TOP ) return Type::TOP; 212 if( t2 == Type::TOP ) return Type::TOP; 213 214 // Either input is BOTTOM ==> the result is the local BOTTOM 215 const Type *bot = bottom_type(); 216 if( (t1 == bot) || (t2 == bot) || 217 (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) ) 218 return bot; 219 220 // Check for an addition involving the additive identity 221 const Type *tadd = add_of_identity( t1, t2 ); 222 if( tadd ) return tadd; 223 224 return add_ring(t1,t2); // Local flavor of type addition 225 } 226 227 //------------------------------add_identity----------------------------------- 228 // Check for addition of the identity 229 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const { 230 const Type *zero = add_id(); // The additive identity 231 if( t1->higher_equal( zero ) ) return t2; 232 if( t2->higher_equal( zero ) ) return t1; 233 234 return NULL; 235 } 236 237 238 //============================================================================= 239 //------------------------------Idealize--------------------------------------- 240 Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) { 241 Node* in1 = in(1); 242 Node* in2 = in(2); 243 int op1 = in1->Opcode(); 244 int op2 = in2->Opcode(); 245 // Fold (con1-x)+con2 into (con1+con2)-x 246 if ( op1 == Op_AddI && op2 == Op_SubI ) { 247 // Swap edges to try optimizations below 248 in1 = in2; 249 in2 = in(1); 250 op1 = op2; 251 op2 = in2->Opcode(); 252 } 253 if( op1 == Op_SubI ) { 254 const Type *t_sub1 = phase->type( in1->in(1) ); 255 const Type *t_2 = phase->type( in2 ); 256 if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP ) 257 return new SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ), in1->in(2) ); 258 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)" 259 if( op2 == Op_SubI ) { 260 // Check for dead cycle: d = (a-b)+(c-d) 261 assert( in1->in(2) != this && in2->in(2) != this, 262 "dead loop in AddINode::Ideal" ); 263 Node *sub = new SubINode(NULL, NULL); 264 sub->init_req(1, phase->transform(new AddINode(in1->in(1), in2->in(1) ) )); 265 sub->init_req(2, phase->transform(new AddINode(in1->in(2), in2->in(2) ) )); 266 return sub; 267 } 268 // Convert "(a-b)+(b+c)" into "(a+c)" 269 if( op2 == Op_AddI && in1->in(2) == in2->in(1) ) { 270 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal"); 271 return new AddINode(in1->in(1), in2->in(2)); 272 } 273 // Convert "(a-b)+(c+b)" into "(a+c)" 274 if( op2 == Op_AddI && in1->in(2) == in2->in(2) ) { 275 assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal"); 276 return new AddINode(in1->in(1), in2->in(1)); 277 } 278 // Convert "(a-b)+(b-c)" into "(a-c)" 279 if( op2 == Op_SubI && in1->in(2) == in2->in(1) ) { 280 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal"); 281 return new SubINode(in1->in(1), in2->in(2)); 282 } 283 // Convert "(a-b)+(c-a)" into "(c-b)" 284 if( op2 == Op_SubI && in1->in(1) == in2->in(2) ) { 285 assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddINode::Ideal"); 286 return new SubINode(in2->in(1), in1->in(2)); 287 } 288 } 289 290 // Convert "x+(0-y)" into "(x-y)" 291 if( op2 == Op_SubI && phase->type(in2->in(1)) == TypeInt::ZERO ) 292 return new SubINode(in1, in2->in(2) ); 293 294 // Convert "(0-y)+x" into "(x-y)" 295 if( op1 == Op_SubI && phase->type(in1->in(1)) == TypeInt::ZERO ) 296 return new SubINode( in2, in1->in(2) ); 297 298 // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y. 299 // Helps with array allocation math constant folding 300 // See 4790063: 301 // Unrestricted transformation is unsafe for some runtime values of 'x' 302 // ( x == 0, z == 1, y == -1 ) fails 303 // ( x == -5, z == 1, y == 1 ) fails 304 // Transform works for small z and small negative y when the addition 305 // (x + (y << z)) does not cross zero. 306 // Implement support for negative y and (x >= -(y << z)) 307 // Have not observed cases where type information exists to support 308 // positive y and (x <= -(y << z)) 309 if( op1 == Op_URShiftI && op2 == Op_ConI && 310 in1->in(2)->Opcode() == Op_ConI ) { 311 jint z = phase->type( in1->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter 312 jint y = phase->type( in2 )->is_int()->get_con(); 313 314 if( z < 5 && -5 < y && y < 0 ) { 315 const Type *t_in11 = phase->type(in1->in(1)); 316 if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) { 317 Node *a = phase->transform( new AddINode( in1->in(1), phase->intcon(y<<z) ) ); 318 return new URShiftINode( a, in1->in(2) ); 319 } 320 } 321 } 322 323 return AddNode::Ideal(phase, can_reshape); 324 } 325 326 327 //------------------------------Identity--------------------------------------- 328 // Fold (x-y)+y OR y+(x-y) into x 329 Node *AddINode::Identity( PhaseTransform *phase ) { 330 if( in(1)->Opcode() == Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) { 331 return in(1)->in(1); 332 } 333 else if( in(2)->Opcode() == Op_SubI && phase->eqv(in(2)->in(2),in(1)) ) { 334 return in(2)->in(1); 335 } 336 return AddNode::Identity(phase); 337 } 338 339 340 //------------------------------add_ring--------------------------------------- 341 // Supplied function returns the sum of the inputs. Guaranteed never 342 // to be passed a TOP or BOTTOM type, these are filtered out by 343 // pre-check. 344 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const { 345 const TypeInt *r0 = t0->is_int(); // Handy access 346 const TypeInt *r1 = t1->is_int(); 347 int lo = r0->_lo + r1->_lo; 348 int hi = r0->_hi + r1->_hi; 349 if( !(r0->is_con() && r1->is_con()) ) { 350 // Not both constants, compute approximate result 351 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) { 352 lo = min_jint; hi = max_jint; // Underflow on the low side 353 } 354 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) { 355 lo = min_jint; hi = max_jint; // Overflow on the high side 356 } 357 if( lo > hi ) { // Handle overflow 358 lo = min_jint; hi = max_jint; 359 } 360 } else { 361 // both constants, compute precise result using 'lo' and 'hi' 362 // Semantics define overflow and underflow for integer addition 363 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0 364 } 365 return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) ); 366 } 367 368 369 //============================================================================= 370 //------------------------------Idealize--------------------------------------- 371 Node *AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) { 372 Node* in1 = in(1); 373 Node* in2 = in(2); 374 int op1 = in1->Opcode(); 375 int op2 = in2->Opcode(); 376 // Fold (con1-x)+con2 into (con1+con2)-x 377 if ( op1 == Op_AddL && op2 == Op_SubL ) { 378 // Swap edges to try optimizations below 379 in1 = in2; 380 in2 = in(1); 381 op1 = op2; 382 op2 = in2->Opcode(); 383 } 384 // Fold (con1-x)+con2 into (con1+con2)-x 385 if( op1 == Op_SubL ) { 386 const Type *t_sub1 = phase->type( in1->in(1) ); 387 const Type *t_2 = phase->type( in2 ); 388 if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP ) 389 return new SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ), in1->in(2) ); 390 // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)" 391 if( op2 == Op_SubL ) { 392 // Check for dead cycle: d = (a-b)+(c-d) 393 assert( in1->in(2) != this && in2->in(2) != this, 394 "dead loop in AddLNode::Ideal" ); 395 Node *sub = new SubLNode(NULL, NULL); 396 sub->init_req(1, phase->transform(new AddLNode(in1->in(1), in2->in(1) ) )); 397 sub->init_req(2, phase->transform(new AddLNode(in1->in(2), in2->in(2) ) )); 398 return sub; 399 } 400 // Convert "(a-b)+(b+c)" into "(a+c)" 401 if( op2 == Op_AddL && in1->in(2) == in2->in(1) ) { 402 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal"); 403 return new AddLNode(in1->in(1), in2->in(2)); 404 } 405 // Convert "(a-b)+(c+b)" into "(a+c)" 406 if( op2 == Op_AddL && in1->in(2) == in2->in(2) ) { 407 assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal"); 408 return new AddLNode(in1->in(1), in2->in(1)); 409 } 410 // Convert "(a-b)+(b-c)" into "(a-c)" 411 if( op2 == Op_SubL && in1->in(2) == in2->in(1) ) { 412 assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal"); 413 return new SubLNode(in1->in(1), in2->in(2)); 414 } 415 // Convert "(a-b)+(c-a)" into "(c-b)" 416 if( op2 == Op_SubL && in1->in(1) == in1->in(2) ) { 417 assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal"); 418 return new SubLNode(in2->in(1), in1->in(2)); 419 } 420 } 421 422 // Convert "x+(0-y)" into "(x-y)" 423 if( op2 == Op_SubL && phase->type(in2->in(1)) == TypeLong::ZERO ) 424 return new SubLNode( in1, in2->in(2) ); 425 426 // Convert "(0-y)+x" into "(x-y)" 427 if( op1 == Op_SubL && phase->type(in1->in(1)) == TypeInt::ZERO ) 428 return new SubLNode( in2, in1->in(2) ); 429 430 // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)" 431 // into "(X<<1)+Y" and let shift-folding happen. 432 if( op2 == Op_AddL && 433 in2->in(1) == in1 && 434 op1 != Op_ConL && 435 0 ) { 436 Node *shift = phase->transform(new LShiftLNode(in1,phase->intcon(1))); 437 return new AddLNode(shift,in2->in(2)); 438 } 439 440 return AddNode::Ideal(phase, can_reshape); 441 } 442 443 444 //------------------------------Identity--------------------------------------- 445 // Fold (x-y)+y OR y+(x-y) into x 446 Node *AddLNode::Identity( PhaseTransform *phase ) { 447 if( in(1)->Opcode() == Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) { 448 return in(1)->in(1); 449 } 450 else if( in(2)->Opcode() == Op_SubL && phase->eqv(in(2)->in(2),in(1)) ) { 451 return in(2)->in(1); 452 } 453 return AddNode::Identity(phase); 454 } 455 456 457 //------------------------------add_ring--------------------------------------- 458 // Supplied function returns the sum of the inputs. Guaranteed never 459 // to be passed a TOP or BOTTOM type, these are filtered out by 460 // pre-check. 461 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const { 462 const TypeLong *r0 = t0->is_long(); // Handy access 463 const TypeLong *r1 = t1->is_long(); 464 jlong lo = r0->_lo + r1->_lo; 465 jlong hi = r0->_hi + r1->_hi; 466 if( !(r0->is_con() && r1->is_con()) ) { 467 // Not both constants, compute approximate result 468 if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) { 469 lo =min_jlong; hi = max_jlong; // Underflow on the low side 470 } 471 if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) { 472 lo = min_jlong; hi = max_jlong; // Overflow on the high side 473 } 474 if( lo > hi ) { // Handle overflow 475 lo = min_jlong; hi = max_jlong; 476 } 477 } else { 478 // both constants, compute precise result using 'lo' and 'hi' 479 // Semantics define overflow and underflow for integer addition 480 // as expected. In particular: 0x80000000 + 0x80000000 --> 0x0 481 } 482 return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) ); 483 } 484 485 486 //============================================================================= 487 //------------------------------add_of_identity-------------------------------- 488 // Check for addition of the identity 489 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const { 490 // x ADD 0 should return x unless 'x' is a -zero 491 // 492 // const Type *zero = add_id(); // The additive identity 493 // jfloat f1 = t1->getf(); 494 // jfloat f2 = t2->getf(); 495 // 496 // if( t1->higher_equal( zero ) ) return t2; 497 // if( t2->higher_equal( zero ) ) return t1; 498 499 return NULL; 500 } 501 502 //------------------------------add_ring--------------------------------------- 503 // Supplied function returns the sum of the inputs. 504 // This also type-checks the inputs for sanity. Guaranteed never to 505 // be passed a TOP or BOTTOM type, these are filtered out by pre-check. 506 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const { 507 // We must be adding 2 float constants. 508 return TypeF::make( t0->getf() + t1->getf() ); 509 } 510 511 //------------------------------Ideal------------------------------------------ 512 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) { 513 if( IdealizedNumerics && !phase->C->method()->is_strict() ) { 514 return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms 515 } 516 517 // Floating point additions are not associative because of boundary conditions (infinity) 518 return commute(this, 519 phase->type( in(1) )->singleton(), 520 phase->type( in(2) )->singleton() ) ? this : NULL; 521 } 522 523 524 //============================================================================= 525 //------------------------------add_of_identity-------------------------------- 526 // Check for addition of the identity 527 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const { 528 // x ADD 0 should return x unless 'x' is a -zero 529 // 530 // const Type *zero = add_id(); // The additive identity 531 // jfloat f1 = t1->getf(); 532 // jfloat f2 = t2->getf(); 533 // 534 // if( t1->higher_equal( zero ) ) return t2; 535 // if( t2->higher_equal( zero ) ) return t1; 536 537 return NULL; 538 } 539 //------------------------------add_ring--------------------------------------- 540 // Supplied function returns the sum of the inputs. 541 // This also type-checks the inputs for sanity. Guaranteed never to 542 // be passed a TOP or BOTTOM type, these are filtered out by pre-check. 543 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const { 544 // We must be adding 2 double constants. 545 return TypeD::make( t0->getd() + t1->getd() ); 546 } 547 548 //------------------------------Ideal------------------------------------------ 549 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) { 550 if( IdealizedNumerics && !phase->C->method()->is_strict() ) { 551 return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms 552 } 553 554 // Floating point additions are not associative because of boundary conditions (infinity) 555 return commute(this, 556 phase->type( in(1) )->singleton(), 557 phase->type( in(2) )->singleton() ) ? this : NULL; 558 } 559 560 561 //============================================================================= 562 //------------------------------Identity--------------------------------------- 563 // If one input is a constant 0, return the other input. 564 Node *AddPNode::Identity( PhaseTransform *phase ) { 565 return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this; 566 } 567 568 //------------------------------Idealize--------------------------------------- 569 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) { 570 // Bail out if dead inputs 571 if( phase->type( in(Address) ) == Type::TOP ) return NULL; 572 573 // If the left input is an add of a constant, flatten the expression tree. 574 const Node *n = in(Address); 575 if (n->is_AddP() && n->in(Base) == in(Base)) { 576 const AddPNode *addp = n->as_AddP(); // Left input is an AddP 577 assert( !addp->in(Address)->is_AddP() || 578 addp->in(Address)->as_AddP() != addp, 579 "dead loop in AddPNode::Ideal" ); 580 // Type of left input's right input 581 const Type *t = phase->type( addp->in(Offset) ); 582 if( t == Type::TOP ) return NULL; 583 const TypeX *t12 = t->is_intptr_t(); 584 if( t12->is_con() ) { // Left input is an add of a constant? 585 // If the right input is a constant, combine constants 586 const Type *temp_t2 = phase->type( in(Offset) ); 587 if( temp_t2 == Type::TOP ) return NULL; 588 const TypeX *t2 = temp_t2->is_intptr_t(); 589 Node* address; 590 Node* offset; 591 if( t2->is_con() ) { 592 // The Add of the flattened expression 593 address = addp->in(Address); 594 offset = phase->MakeConX(t2->get_con() + t12->get_con()); 595 } else { 596 // Else move the constant to the right. ((A+con)+B) into ((A+B)+con) 597 address = phase->transform(new AddPNode(in(Base),addp->in(Address),in(Offset))); 598 offset = addp->in(Offset); 599 } 600 PhaseIterGVN *igvn = phase->is_IterGVN(); 601 if( igvn ) { 602 set_req_X(Address,address,igvn); 603 set_req_X(Offset,offset,igvn); 604 } else { 605 set_req(Address,address); 606 set_req(Offset,offset); 607 } 608 return this; 609 } 610 } 611 612 // Raw pointers? 613 if( in(Base)->bottom_type() == Type::TOP ) { 614 // If this is a NULL+long form (from unsafe accesses), switch to a rawptr. 615 if (phase->type(in(Address)) == TypePtr::NULL_PTR) { 616 Node* offset = in(Offset); 617 return new CastX2PNode(offset); 618 } 619 } 620 621 // If the right is an add of a constant, push the offset down. 622 // Convert: (ptr + (offset+con)) into (ptr+offset)+con. 623 // The idea is to merge array_base+scaled_index groups together, 624 // and only have different constant offsets from the same base. 625 const Node *add = in(Offset); 626 if( add->Opcode() == Op_AddX && add->in(1) != add ) { 627 const Type *t22 = phase->type( add->in(2) ); 628 if( t22->singleton() && (t22 != Type::TOP) ) { // Right input is an add of a constant? 629 set_req(Address, phase->transform(new AddPNode(in(Base),in(Address),add->in(1)))); 630 set_req(Offset, add->in(2)); 631 PhaseIterGVN *igvn = phase->is_IterGVN(); 632 if (add->outcnt() == 0 && igvn) { 633 // add disconnected. 634 igvn->_worklist.push((Node*)add); 635 } 636 return this; // Made progress 637 } 638 } 639 640 return NULL; // No progress 641 } 642 643 //------------------------------bottom_type------------------------------------ 644 // Bottom-type is the pointer-type with unknown offset. 645 const Type *AddPNode::bottom_type() const { 646 if (in(Address) == NULL) return TypePtr::BOTTOM; 647 const TypePtr *tp = in(Address)->bottom_type()->isa_ptr(); 648 if( !tp ) return Type::TOP; // TOP input means TOP output 649 assert( in(Offset)->Opcode() != Op_ConP, "" ); 650 const Type *t = in(Offset)->bottom_type(); 651 if( t == Type::TOP ) 652 return tp->add_offset(Type::OffsetTop); 653 const TypeX *tx = t->is_intptr_t(); 654 intptr_t txoffset = Type::OffsetBot; 655 if (tx->is_con()) { // Left input is an add of a constant? 656 txoffset = tx->get_con(); 657 } 658 return tp->add_offset(txoffset); 659 } 660 661 //------------------------------Value------------------------------------------ 662 const Type *AddPNode::Value( PhaseTransform *phase ) const { 663 // Either input is TOP ==> the result is TOP 664 const Type *t1 = phase->type( in(Address) ); 665 const Type *t2 = phase->type( in(Offset) ); 666 if( t1 == Type::TOP ) return Type::TOP; 667 if( t2 == Type::TOP ) return Type::TOP; 668 669 // Left input is a pointer 670 const TypePtr *p1 = t1->isa_ptr(); 671 // Right input is an int 672 const TypeX *p2 = t2->is_intptr_t(); 673 // Add 'em 674 intptr_t p2offset = Type::OffsetBot; 675 if (p2->is_con()) { // Left input is an add of a constant? 676 p2offset = p2->get_con(); 677 } 678 return p1->add_offset(p2offset); 679 } 680 681 //------------------------Ideal_base_and_offset-------------------------------- 682 // Split an oop pointer into a base and offset. 683 // (The offset might be Type::OffsetBot in the case of an array.) 684 // Return the base, or NULL if failure. 685 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseTransform* phase, 686 // second return value: 687 intptr_t& offset) { 688 if (ptr->is_AddP()) { 689 Node* base = ptr->in(AddPNode::Base); 690 Node* addr = ptr->in(AddPNode::Address); 691 Node* offs = ptr->in(AddPNode::Offset); 692 if (base == addr || base->is_top()) { 693 offset = phase->find_intptr_t_con(offs, Type::OffsetBot); 694 if (offset != Type::OffsetBot) { 695 return addr; 696 } 697 } 698 } 699 offset = Type::OffsetBot; 700 return NULL; 701 } 702 703 //------------------------------unpack_offsets---------------------------------- 704 // Collect the AddP offset values into the elements array, giving up 705 // if there are more than length. 706 int AddPNode::unpack_offsets(Node* elements[], int length) { 707 int count = 0; 708 Node* addr = this; 709 Node* base = addr->in(AddPNode::Base); 710 while (addr->is_AddP()) { 711 if (addr->in(AddPNode::Base) != base) { 712 // give up 713 return -1; 714 } 715 elements[count++] = addr->in(AddPNode::Offset); 716 if (count == length) { 717 // give up 718 return -1; 719 } 720 addr = addr->in(AddPNode::Address); 721 } 722 if (addr != base) { 723 return -1; 724 } 725 return count; 726 } 727 728 //------------------------------match_edge------------------------------------- 729 // Do we Match on this edge index or not? Do not match base pointer edge 730 uint AddPNode::match_edge(uint idx) const { 731 return idx > Base; 732 } 733 734 //============================================================================= 735 //------------------------------Identity--------------------------------------- 736 Node *OrINode::Identity( PhaseTransform *phase ) { 737 // x | x => x 738 if (phase->eqv(in(1), in(2))) { 739 return in(1); 740 } 741 742 return AddNode::Identity(phase); 743 } 744 745 //------------------------------add_ring--------------------------------------- 746 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For 747 // the logical operations the ring's ADD is really a logical OR function. 748 // This also type-checks the inputs for sanity. Guaranteed never to 749 // be passed a TOP or BOTTOM type, these are filtered out by pre-check. 750 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const { 751 const TypeInt *r0 = t0->is_int(); // Handy access 752 const TypeInt *r1 = t1->is_int(); 753 754 // If both args are bool, can figure out better types 755 if ( r0 == TypeInt::BOOL ) { 756 if ( r1 == TypeInt::ONE) { 757 return TypeInt::ONE; 758 } else if ( r1 == TypeInt::BOOL ) { 759 return TypeInt::BOOL; 760 } 761 } else if ( r0 == TypeInt::ONE ) { 762 if ( r1 == TypeInt::BOOL ) { 763 return TypeInt::ONE; 764 } 765 } 766 767 // If either input is not a constant, just return all integers. 768 if( !r0->is_con() || !r1->is_con() ) 769 return TypeInt::INT; // Any integer, but still no symbols. 770 771 // Otherwise just OR them bits. 772 return TypeInt::make( r0->get_con() | r1->get_con() ); 773 } 774 775 //============================================================================= 776 //------------------------------Identity--------------------------------------- 777 Node *OrLNode::Identity( PhaseTransform *phase ) { 778 // x | x => x 779 if (phase->eqv(in(1), in(2))) { 780 return in(1); 781 } 782 783 return AddNode::Identity(phase); 784 } 785 786 //------------------------------add_ring--------------------------------------- 787 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const { 788 const TypeLong *r0 = t0->is_long(); // Handy access 789 const TypeLong *r1 = t1->is_long(); 790 791 // If either input is not a constant, just return all integers. 792 if( !r0->is_con() || !r1->is_con() ) 793 return TypeLong::LONG; // Any integer, but still no symbols. 794 795 // Otherwise just OR them bits. 796 return TypeLong::make( r0->get_con() | r1->get_con() ); 797 } 798 799 //============================================================================= 800 //------------------------------add_ring--------------------------------------- 801 // Supplied function returns the sum of the inputs IN THE CURRENT RING. For 802 // the logical operations the ring's ADD is really a logical OR function. 803 // This also type-checks the inputs for sanity. Guaranteed never to 804 // be passed a TOP or BOTTOM type, these are filtered out by pre-check. 805 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const { 806 const TypeInt *r0 = t0->is_int(); // Handy access 807 const TypeInt *r1 = t1->is_int(); 808 809 // Complementing a boolean? 810 if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE 811 || r1 == TypeInt::BOOL)) 812 return TypeInt::BOOL; 813 814 if( !r0->is_con() || !r1->is_con() ) // Not constants 815 return TypeInt::INT; // Any integer, but still no symbols. 816 817 // Otherwise just XOR them bits. 818 return TypeInt::make( r0->get_con() ^ r1->get_con() ); 819 } 820 821 //============================================================================= 822 //------------------------------add_ring--------------------------------------- 823 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const { 824 const TypeLong *r0 = t0->is_long(); // Handy access 825 const TypeLong *r1 = t1->is_long(); 826 827 // If either input is not a constant, just return all integers. 828 if( !r0->is_con() || !r1->is_con() ) 829 return TypeLong::LONG; // Any integer, but still no symbols. 830 831 // Otherwise just OR them bits. 832 return TypeLong::make( r0->get_con() ^ r1->get_con() ); 833 } 834 835 //============================================================================= 836 //------------------------------add_ring--------------------------------------- 837 // Supplied function returns the sum of the inputs. 838 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const { 839 const TypeInt *r0 = t0->is_int(); // Handy access 840 const TypeInt *r1 = t1->is_int(); 841 842 // Otherwise just MAX them bits. 843 return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) ); 844 } 845 846 //============================================================================= 847 //------------------------------Idealize--------------------------------------- 848 // MINs show up in range-check loop limit calculations. Look for 849 // "MIN2(x+c0,MIN2(y,x+c1))". Pick the smaller constant: "MIN2(x+c0,y)" 850 Node *MinINode::Ideal(PhaseGVN *phase, bool can_reshape) { 851 Node *progress = NULL; 852 // Force a right-spline graph 853 Node *l = in(1); 854 Node *r = in(2); 855 // Transform MinI1( MinI2(a,b), c) into MinI1( a, MinI2(b,c) ) 856 // to force a right-spline graph for the rest of MinINode::Ideal(). 857 if( l->Opcode() == Op_MinI ) { 858 assert( l != l->in(1), "dead loop in MinINode::Ideal" ); 859 r = phase->transform(new MinINode(l->in(2),r)); 860 l = l->in(1); 861 set_req(1, l); 862 set_req(2, r); 863 return this; 864 } 865 866 // Get left input & constant 867 Node *x = l; 868 int x_off = 0; 869 if( x->Opcode() == Op_AddI && // Check for "x+c0" and collect constant 870 x->in(2)->is_Con() ) { 871 const Type *t = x->in(2)->bottom_type(); 872 if( t == Type::TOP ) return NULL; // No progress 873 x_off = t->is_int()->get_con(); 874 x = x->in(1); 875 } 876 877 // Scan a right-spline-tree for MINs 878 Node *y = r; 879 int y_off = 0; 880 // Check final part of MIN tree 881 if( y->Opcode() == Op_AddI && // Check for "y+c1" and collect constant 882 y->in(2)->is_Con() ) { 883 const Type *t = y->in(2)->bottom_type(); 884 if( t == Type::TOP ) return NULL; // No progress 885 y_off = t->is_int()->get_con(); 886 y = y->in(1); 887 } 888 if( x->_idx > y->_idx && r->Opcode() != Op_MinI ) { 889 swap_edges(1, 2); 890 return this; 891 } 892 893 894 if( r->Opcode() == Op_MinI ) { 895 assert( r != r->in(2), "dead loop in MinINode::Ideal" ); 896 y = r->in(1); 897 // Check final part of MIN tree 898 if( y->Opcode() == Op_AddI &&// Check for "y+c1" and collect constant 899 y->in(2)->is_Con() ) { 900 const Type *t = y->in(2)->bottom_type(); 901 if( t == Type::TOP ) return NULL; // No progress 902 y_off = t->is_int()->get_con(); 903 y = y->in(1); 904 } 905 906 if( x->_idx > y->_idx ) 907 return new MinINode(r->in(1),phase->transform(new MinINode(l,r->in(2)))); 908 909 // See if covers: MIN2(x+c0,MIN2(y+c1,z)) 910 if( !phase->eqv(x,y) ) return NULL; 911 // If (y == x) transform MIN2(x+c0, MIN2(x+c1,z)) into 912 // MIN2(x+c0 or x+c1 which less, z). 913 return new MinINode(phase->transform(new AddINode(x,phase->intcon(MIN2(x_off,y_off)))),r->in(2)); 914 } else { 915 // See if covers: MIN2(x+c0,y+c1) 916 if( !phase->eqv(x,y) ) return NULL; 917 // If (y == x) transform MIN2(x+c0,x+c1) into x+c0 or x+c1 which less. 918 return new AddINode(x,phase->intcon(MIN2(x_off,y_off))); 919 } 920 921 } 922 923 //------------------------------add_ring--------------------------------------- 924 // Supplied function returns the sum of the inputs. 925 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const { 926 const TypeInt *r0 = t0->is_int(); // Handy access 927 const TypeInt *r1 = t1->is_int(); 928 929 // Otherwise just MIN them bits. 930 return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) ); 931 }