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) + static_cast<uint>(Opcode());
  51 }
  52 
  53 //------------------------------Identity---------------------------------------
  54 // If either input is a constant 0, return the other input.
  55 Node* AddNode::Identity(PhaseGVN* 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, bool con_left, bool 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   bool con_left  = t1->singleton();
 114   bool 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   Opcodes add1_op = add1->Opcode();
 127   Opcodes 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       Opcodes  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   Opcodes 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(PhaseGVN* 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   Opcodes op1 = in1->Opcode();
 244   Opcodes op2 = in2->Opcode();
 245   // Fold (con1-x)+con2 into (con1+con2)-x
 246   if ( op1 == Opcodes::Op_AddI && op2 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::Op_URShiftI && op2 == Opcodes::Op_ConI &&
 310       in1->in(2)->Opcode() == Opcodes::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(PhaseGVN* phase) {
 330   if( in(1)->Opcode() == Opcodes::Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) {
 331     return in(1)->in(1);
 332   }
 333   else if( in(2)->Opcode() == Opcodes::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 = java_add(r0->_lo, r1->_lo);
 348   int hi = java_add(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   Opcodes op1 = in1->Opcode();
 375   Opcodes op2 = in2->Opcode();
 376   // Fold (con1-x)+con2 into (con1+con2)-x
 377   if ( op1 == Opcodes::Op_AddL && op2 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::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 == Opcodes::Op_AddL &&
 433       in2->in(1) == in1 &&
 434       op1 != Opcodes::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(PhaseGVN* phase) {
 447   if( in(1)->Opcode() == Opcodes::Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) {
 448     return in(1)->in(1);
 449   }
 450   else if( in(2)->Opcode() == Opcodes::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 = java_add(r0->_lo, r1->_lo);
 465   jlong hi = java_add(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(PhaseGVN* 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() == Opcodes::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() != Opcodes::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(PhaseGVN* 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(PhaseGVN* 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(PhaseGVN* 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() == Opcodes::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() == Opcodes::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() == Opcodes::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() != Opcodes::Op_MinI ) {
 889     swap_edges(1, 2);
 890     return this;
 891   }
 892 
 893 
 894   if( r->Opcode() == Opcodes::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() == Opcodes::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 }
--- EOF ---