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/cfgnode.hpp"
  29 #include "opto/connode.hpp"
  30 #include "opto/machnode.hpp"
  31 #include "opto/mulnode.hpp"
  32 #include "opto/phaseX.hpp"
  33 #include "opto/subnode.hpp"
  34 #if INCLUDE_ALL_GCS
  35 #include "gc_implementation/shenandoah/shenandoahSupport.hpp"
  36 #endif
  37 
  38 // Portions of code courtesy of Clifford Click
  39 
  40 // Classic Add functionality.  This covers all the usual 'add' behaviors for
  41 // an algebraic ring.  Add-integer, add-float, add-double, and binary-or are
  42 // all inherited from this class.  The various identity values are supplied
  43 // by virtual functions.
  44 
  45 
  46 //=============================================================================
  47 //------------------------------hash-------------------------------------------
  48 // Hash function over AddNodes.  Needs to be commutative; i.e., I swap
  49 // (commute) inputs to AddNodes willy-nilly so the hash function must return
  50 // the same value in the presence of edge swapping.
  51 uint AddNode::hash() const {
  52   return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
  53 }
  54 
  55 //------------------------------Identity---------------------------------------
  56 // If either input is a constant 0, return the other input.
  57 Node *AddNode::Identity( PhaseTransform *phase ) {
  58   const Type *zero = add_id();  // The additive identity
  59   if( phase->type( in(1) )->higher_equal( zero ) ) return in(2);
  60   if( phase->type( in(2) )->higher_equal( zero ) ) return in(1);
  61   return this;
  62 }
  63 
  64 //------------------------------commute----------------------------------------
  65 // Commute operands to move loads and constants to the right.
  66 static bool commute( Node *add, int con_left, int con_right ) {
  67   Node *in1 = add->in(1);
  68   Node *in2 = add->in(2);
  69 
  70   // Convert "1+x" into "x+1".
  71   // Right is a constant; leave it
  72   if( con_right ) return false;
  73   // Left is a constant; move it right.
  74   if( con_left ) {
  75     add->swap_edges(1, 2);
  76     return true;
  77   }
  78 
  79   // Convert "Load+x" into "x+Load".
  80   // Now check for loads
  81   if (in2->is_Load()) {
  82     if (!in1->is_Load()) {
  83       // already x+Load to return
  84       return false;
  85     }
  86     // both are loads, so fall through to sort inputs by idx
  87   } else if( in1->is_Load() ) {
  88     // Left is a Load and Right is not; move it right.
  89     add->swap_edges(1, 2);
  90     return true;
  91   }
  92 
  93   PhiNode *phi;
  94   // Check for tight loop increments: Loop-phi of Add of loop-phi
  95   if( in1->is_Phi() && (phi = in1->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add)
  96     return false;
  97   if( in2->is_Phi() && (phi = in2->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add){
  98     add->swap_edges(1, 2);
  99     return true;
 100   }
 101 
 102   // Otherwise, sort inputs (commutativity) to help value numbering.
 103   if( in1->_idx > in2->_idx ) {
 104     add->swap_edges(1, 2);
 105     return true;
 106   }
 107   return false;
 108 }
 109 
 110 //------------------------------Idealize---------------------------------------
 111 // If we get here, we assume we are associative!
 112 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 113   const Type *t1 = phase->type( in(1) );
 114   const Type *t2 = phase->type( in(2) );
 115   int con_left  = t1->singleton();
 116   int con_right = t2->singleton();
 117 
 118   // Check for commutative operation desired
 119   if( commute(this,con_left,con_right) ) return this;
 120 
 121   AddNode *progress = NULL;             // Progress flag
 122 
 123   // Convert "(x+1)+2" into "x+(1+2)".  If the right input is a
 124   // constant, and the left input is an add of a constant, flatten the
 125   // expression tree.
 126   Node *add1 = in(1);
 127   Node *add2 = in(2);
 128   int add1_op = add1->Opcode();
 129   int this_op = Opcode();
 130   if( con_right && t2 != Type::TOP && // Right input is a constant?
 131       add1_op == this_op ) { // Left input is an Add?
 132 
 133     // Type of left _in right input
 134     const Type *t12 = phase->type( add1->in(2) );
 135     if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
 136       // Check for rare case of closed data cycle which can happen inside
 137       // unreachable loops. In these cases the computation is undefined.
 138 #ifdef ASSERT
 139       Node *add11    = add1->in(1);
 140       int   add11_op = add11->Opcode();
 141       if( (add1 == add1->in(1))
 142          || (add11_op == this_op && add11->in(1) == add1) ) {
 143         assert(false, "dead loop in AddNode::Ideal");
 144       }
 145 #endif
 146       // The Add of the flattened expression
 147       Node *x1 = add1->in(1);
 148       Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 ));
 149       PhaseIterGVN *igvn = phase->is_IterGVN();
 150       if( igvn ) {
 151         set_req_X(2,x2,igvn);
 152         set_req_X(1,x1,igvn);
 153       } else {
 154         set_req(2,x2);
 155         set_req(1,x1);
 156       }
 157       progress = this;            // Made progress
 158       add1 = in(1);
 159       add1_op = add1->Opcode();
 160     }
 161   }
 162 
 163   // Convert "(x+1)+y" into "(x+y)+1".  Push constants down the expression tree.
 164   if( add1_op == this_op && !con_right ) {
 165     Node *a12 = add1->in(2);
 166     const Type *t12 = phase->type( a12 );
 167     if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) &&
 168        !(add1->in(1)->is_Phi() && add1->in(1)->as_Phi()->is_tripcount()) ) {
 169       assert(add1->in(1) != this, "dead loop in AddNode::Ideal");
 170       add2 = add1->clone();
 171       add2->set_req(2, in(2));
 172       add2 = phase->transform(add2);
 173       set_req(1, add2);
 174       set_req(2, a12);
 175       progress = this;
 176       add2 = a12;
 177     }
 178   }
 179 
 180   // Convert "x+(y+1)" into "(x+y)+1".  Push constants down the expression tree.
 181   int add2_op = add2->Opcode();
 182   if( add2_op == this_op && !con_left ) {
 183     Node *a22 = add2->in(2);
 184     const Type *t22 = phase->type( a22 );
 185     if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) &&
 186        !(add2->in(1)->is_Phi() && add2->in(1)->as_Phi()->is_tripcount()) ) {
 187       assert(add2->in(1) != this, "dead loop in AddNode::Ideal");
 188       Node *addx = add2->clone();
 189       addx->set_req(1, in(1));
 190       addx->set_req(2, add2->in(1));
 191       addx = phase->transform(addx);
 192       set_req(1, addx);
 193       set_req(2, a22);
 194       progress = this;
 195       PhaseIterGVN *igvn = phase->is_IterGVN();
 196       if (add2->outcnt() == 0 && igvn) {
 197         // add disconnected.
 198         igvn->_worklist.push(add2);
 199       }
 200     }
 201   }
 202 
 203   return progress;
 204 }
 205 
 206 //------------------------------Value-----------------------------------------
 207 // An add node sums it's two _in.  If one input is an RSD, we must mixin
 208 // the other input's symbols.
 209 const Type *AddNode::Value( PhaseTransform *phase ) const {
 210   // Either input is TOP ==> the result is TOP
 211   const Type *t1 = phase->type( in(1) );
 212   const Type *t2 = phase->type( in(2) );
 213   if( t1 == Type::TOP ) return Type::TOP;
 214   if( t2 == Type::TOP ) return Type::TOP;
 215 
 216   // Either input is BOTTOM ==> the result is the local BOTTOM
 217   const Type *bot = bottom_type();
 218   if( (t1 == bot) || (t2 == bot) ||
 219       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
 220     return bot;
 221 
 222   // Check for an addition involving the additive identity
 223   const Type *tadd = add_of_identity( t1, t2 );
 224   if( tadd ) return tadd;
 225 
 226   return add_ring(t1,t2);               // Local flavor of type addition
 227 }
 228 
 229 //------------------------------add_identity-----------------------------------
 230 // Check for addition of the identity
 231 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
 232   const Type *zero = add_id();  // The additive identity
 233   if( t1->higher_equal( zero ) ) return t2;
 234   if( t2->higher_equal( zero ) ) return t1;
 235 
 236   return NULL;
 237 }
 238 
 239 
 240 //=============================================================================
 241 //------------------------------Idealize---------------------------------------
 242 Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) {
 243   Node* in1 = in(1);
 244   Node* in2 = in(2);
 245   int op1 = in1->Opcode();
 246   int op2 = in2->Opcode();
 247   // Fold (con1-x)+con2 into (con1+con2)-x
 248   if ( op1 == Op_AddI && op2 == Op_SubI ) {
 249     // Swap edges to try optimizations below
 250     in1 = in2;
 251     in2 = in(1);
 252     op1 = op2;
 253     op2 = in2->Opcode();
 254   }
 255   if( op1 == Op_SubI ) {
 256     const Type *t_sub1 = phase->type( in1->in(1) );
 257     const Type *t_2    = phase->type( in2        );
 258     if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
 259       return new (phase->C) SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ),
 260                               in1->in(2) );
 261     // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
 262     if( op2 == Op_SubI ) {
 263       // Check for dead cycle: d = (a-b)+(c-d)
 264       assert( in1->in(2) != this && in2->in(2) != this,
 265               "dead loop in AddINode::Ideal" );
 266       Node *sub  = new (phase->C) SubINode(NULL, NULL);
 267       sub->init_req(1, phase->transform(new (phase->C) AddINode(in1->in(1), in2->in(1) ) ));
 268       sub->init_req(2, phase->transform(new (phase->C) AddINode(in1->in(2), in2->in(2) ) ));
 269       return sub;
 270     }
 271     // Convert "(a-b)+(b+c)" into "(a+c)"
 272     if( op2 == Op_AddI && in1->in(2) == in2->in(1) ) {
 273       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
 274       return new (phase->C) AddINode(in1->in(1), in2->in(2));
 275     }
 276     // Convert "(a-b)+(c+b)" into "(a+c)"
 277     if( op2 == Op_AddI && in1->in(2) == in2->in(2) ) {
 278       assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
 279       return new (phase->C) AddINode(in1->in(1), in2->in(1));
 280     }
 281     // Convert "(a-b)+(b-c)" into "(a-c)"
 282     if( op2 == Op_SubI && in1->in(2) == in2->in(1) ) {
 283       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
 284       return new (phase->C) SubINode(in1->in(1), in2->in(2));
 285     }
 286     // Convert "(a-b)+(c-a)" into "(c-b)"
 287     if( op2 == Op_SubI && in1->in(1) == in2->in(2) ) {
 288       assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
 289       return new (phase->C) SubINode(in2->in(1), in1->in(2));
 290     }
 291   }
 292 
 293   // Convert "x+(0-y)" into "(x-y)"
 294   if( op2 == Op_SubI && phase->type(in2->in(1)) == TypeInt::ZERO )
 295     return new (phase->C) SubINode(in1, in2->in(2) );
 296 
 297   // Convert "(0-y)+x" into "(x-y)"
 298   if( op1 == Op_SubI && phase->type(in1->in(1)) == TypeInt::ZERO )
 299     return new (phase->C) SubINode( in2, in1->in(2) );
 300 
 301   // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
 302   // Helps with array allocation math constant folding
 303   // See 4790063:
 304   // Unrestricted transformation is unsafe for some runtime values of 'x'
 305   // ( x ==  0, z == 1, y == -1 ) fails
 306   // ( x == -5, z == 1, y ==  1 ) fails
 307   // Transform works for small z and small negative y when the addition
 308   // (x + (y << z)) does not cross zero.
 309   // Implement support for negative y and (x >= -(y << z))
 310   // Have not observed cases where type information exists to support
 311   // positive y and (x <= -(y << z))
 312   if( op1 == Op_URShiftI && op2 == Op_ConI &&
 313       in1->in(2)->Opcode() == Op_ConI ) {
 314     jint z = phase->type( in1->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
 315     jint y = phase->type( in2 )->is_int()->get_con();
 316 
 317     if( z < 5 && -5 < y && y < 0 ) {
 318       const Type *t_in11 = phase->type(in1->in(1));
 319       if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) {
 320         Node *a = phase->transform( new (phase->C) AddINode( in1->in(1), phase->intcon(y<<z) ) );
 321         return new (phase->C) URShiftINode( a, in1->in(2) );
 322       }
 323     }
 324   }
 325 
 326   return AddNode::Ideal(phase, can_reshape);
 327 }
 328 
 329 
 330 //------------------------------Identity---------------------------------------
 331 // Fold (x-y)+y  OR  y+(x-y)  into  x
 332 Node *AddINode::Identity( PhaseTransform *phase ) {
 333   if( in(1)->Opcode() == Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) {
 334     return in(1)->in(1);
 335   }
 336   else if( in(2)->Opcode() == Op_SubI && phase->eqv(in(2)->in(2),in(1)) ) {
 337     return in(2)->in(1);
 338   }
 339   return AddNode::Identity(phase);
 340 }
 341 
 342 
 343 //------------------------------add_ring---------------------------------------
 344 // Supplied function returns the sum of the inputs.  Guaranteed never
 345 // to be passed a TOP or BOTTOM type, these are filtered out by
 346 // pre-check.
 347 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
 348   const TypeInt *r0 = t0->is_int(); // Handy access
 349   const TypeInt *r1 = t1->is_int();
 350   int lo = java_add(r0->_lo, r1->_lo);
 351   int hi = java_add(r0->_hi, r1->_hi);
 352   if( !(r0->is_con() && r1->is_con()) ) {
 353     // Not both constants, compute approximate result
 354     if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
 355       lo = min_jint; hi = max_jint; // Underflow on the low side
 356     }
 357     if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
 358       lo = min_jint; hi = max_jint; // Overflow on the high side
 359     }
 360     if( lo > hi ) {               // Handle overflow
 361       lo = min_jint; hi = max_jint;
 362     }
 363   } else {
 364     // both constants, compute precise result using 'lo' and 'hi'
 365     // Semantics define overflow and underflow for integer addition
 366     // as expected.  In particular: 0x80000000 + 0x80000000 --> 0x0
 367   }
 368   return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
 369 }
 370 
 371 
 372 //=============================================================================
 373 //------------------------------Idealize---------------------------------------
 374 Node *AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 375   Node* in1 = in(1);
 376   Node* in2 = in(2);
 377   int op1 = in1->Opcode();
 378   int op2 = in2->Opcode();
 379   // Fold (con1-x)+con2 into (con1+con2)-x
 380   if ( op1 == Op_AddL && op2 == Op_SubL ) {
 381     // Swap edges to try optimizations below
 382     in1 = in2;
 383     in2 = in(1);
 384     op1 = op2;
 385     op2 = in2->Opcode();
 386   }
 387   // Fold (con1-x)+con2 into (con1+con2)-x
 388   if( op1 == Op_SubL ) {
 389     const Type *t_sub1 = phase->type( in1->in(1) );
 390     const Type *t_2    = phase->type( in2        );
 391     if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
 392       return new (phase->C) SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ),
 393                               in1->in(2) );
 394     // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
 395     if( op2 == Op_SubL ) {
 396       // Check for dead cycle: d = (a-b)+(c-d)
 397       assert( in1->in(2) != this && in2->in(2) != this,
 398               "dead loop in AddLNode::Ideal" );
 399       Node *sub  = new (phase->C) SubLNode(NULL, NULL);
 400       sub->init_req(1, phase->transform(new (phase->C) AddLNode(in1->in(1), in2->in(1) ) ));
 401       sub->init_req(2, phase->transform(new (phase->C) AddLNode(in1->in(2), in2->in(2) ) ));
 402       return sub;
 403     }
 404     // Convert "(a-b)+(b+c)" into "(a+c)"
 405     if( op2 == Op_AddL && in1->in(2) == in2->in(1) ) {
 406       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
 407       return new (phase->C) AddLNode(in1->in(1), in2->in(2));
 408     }
 409     // Convert "(a-b)+(c+b)" into "(a+c)"
 410     if( op2 == Op_AddL && in1->in(2) == in2->in(2) ) {
 411       assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
 412       return new (phase->C) AddLNode(in1->in(1), in2->in(1));
 413     }
 414     // Convert "(a-b)+(b-c)" into "(a-c)"
 415     if( op2 == Op_SubL && in1->in(2) == in2->in(1) ) {
 416       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
 417       return new (phase->C) SubLNode(in1->in(1), in2->in(2));
 418     }
 419     // Convert "(a-b)+(c-a)" into "(c-b)"
 420     if( op2 == Op_SubL && in1->in(1) == in1->in(2) ) {
 421       assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
 422       return new (phase->C) SubLNode(in2->in(1), in1->in(2));
 423     }
 424   }
 425 
 426   // Convert "x+(0-y)" into "(x-y)"
 427   if( op2 == Op_SubL && phase->type(in2->in(1)) == TypeLong::ZERO )
 428     return new (phase->C) SubLNode( in1, in2->in(2) );
 429 
 430   // Convert "(0-y)+x" into "(x-y)"
 431   if( op1 == Op_SubL && phase->type(in1->in(1)) == TypeInt::ZERO )
 432     return new (phase->C) SubLNode( in2, in1->in(2) );
 433 
 434   // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)"
 435   // into "(X<<1)+Y" and let shift-folding happen.
 436   if( op2 == Op_AddL &&
 437       in2->in(1) == in1 &&
 438       op1 != Op_ConL &&
 439       0 ) {
 440     Node *shift = phase->transform(new (phase->C) LShiftLNode(in1,phase->intcon(1)));
 441     return new (phase->C) AddLNode(shift,in2->in(2));
 442   }
 443 
 444   return AddNode::Ideal(phase, can_reshape);
 445 }
 446 
 447 
 448 //------------------------------Identity---------------------------------------
 449 // Fold (x-y)+y  OR  y+(x-y)  into  x
 450 Node *AddLNode::Identity( PhaseTransform *phase ) {
 451   if( in(1)->Opcode() == Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) {
 452     return in(1)->in(1);
 453   }
 454   else if( in(2)->Opcode() == Op_SubL && phase->eqv(in(2)->in(2),in(1)) ) {
 455     return in(2)->in(1);
 456   }
 457   return AddNode::Identity(phase);
 458 }
 459 
 460 
 461 //------------------------------add_ring---------------------------------------
 462 // Supplied function returns the sum of the inputs.  Guaranteed never
 463 // to be passed a TOP or BOTTOM type, these are filtered out by
 464 // pre-check.
 465 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
 466   const TypeLong *r0 = t0->is_long(); // Handy access
 467   const TypeLong *r1 = t1->is_long();
 468   jlong lo = java_add(r0->_lo, r1->_lo);
 469   jlong hi = java_add(r0->_hi, r1->_hi);
 470   if( !(r0->is_con() && r1->is_con()) ) {
 471     // Not both constants, compute approximate result
 472     if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
 473       lo =min_jlong; hi = max_jlong; // Underflow on the low side
 474     }
 475     if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
 476       lo = min_jlong; hi = max_jlong; // Overflow on the high side
 477     }
 478     if( lo > hi ) {               // Handle overflow
 479       lo = min_jlong; hi = max_jlong;
 480     }
 481   } else {
 482     // both constants, compute precise result using 'lo' and 'hi'
 483     // Semantics define overflow and underflow for integer addition
 484     // as expected.  In particular: 0x80000000 + 0x80000000 --> 0x0
 485   }
 486   return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
 487 }
 488 
 489 
 490 //=============================================================================
 491 //------------------------------add_of_identity--------------------------------
 492 // Check for addition of the identity
 493 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
 494   // x ADD 0  should return x unless 'x' is a -zero
 495   //
 496   // const Type *zero = add_id();     // The additive identity
 497   // jfloat f1 = t1->getf();
 498   // jfloat f2 = t2->getf();
 499   //
 500   // if( t1->higher_equal( zero ) ) return t2;
 501   // if( t2->higher_equal( zero ) ) return t1;
 502 
 503   return NULL;
 504 }
 505 
 506 //------------------------------add_ring---------------------------------------
 507 // Supplied function returns the sum of the inputs.
 508 // This also type-checks the inputs for sanity.  Guaranteed never to
 509 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 510 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
 511   // We must be adding 2 float constants.
 512   return TypeF::make( t0->getf() + t1->getf() );
 513 }
 514 
 515 //------------------------------Ideal------------------------------------------
 516 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 517   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
 518     return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
 519   }
 520 
 521   // Floating point additions are not associative because of boundary conditions (infinity)
 522   return commute(this,
 523                  phase->type( in(1) )->singleton(),
 524                  phase->type( in(2) )->singleton() ) ? this : NULL;
 525 }
 526 
 527 
 528 //=============================================================================
 529 //------------------------------add_of_identity--------------------------------
 530 // Check for addition of the identity
 531 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
 532   // x ADD 0  should return x unless 'x' is a -zero
 533   //
 534   // const Type *zero = add_id();     // The additive identity
 535   // jfloat f1 = t1->getf();
 536   // jfloat f2 = t2->getf();
 537   //
 538   // if( t1->higher_equal( zero ) ) return t2;
 539   // if( t2->higher_equal( zero ) ) return t1;
 540 
 541   return NULL;
 542 }
 543 //------------------------------add_ring---------------------------------------
 544 // Supplied function returns the sum of the inputs.
 545 // This also type-checks the inputs for sanity.  Guaranteed never to
 546 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 547 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
 548   // We must be adding 2 double constants.
 549   return TypeD::make( t0->getd() + t1->getd() );
 550 }
 551 
 552 //------------------------------Ideal------------------------------------------
 553 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 554   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
 555     return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
 556   }
 557 
 558   // Floating point additions are not associative because of boundary conditions (infinity)
 559   return commute(this,
 560                  phase->type( in(1) )->singleton(),
 561                  phase->type( in(2) )->singleton() ) ? this : NULL;
 562 }
 563 
 564 
 565 //=============================================================================
 566 //------------------------------Identity---------------------------------------
 567 // If one input is a constant 0, return the other input.
 568 Node *AddPNode::Identity( PhaseTransform *phase ) {
 569   return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
 570 }
 571 
 572 //------------------------------Idealize---------------------------------------
 573 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 574   // Bail out if dead inputs
 575   if( phase->type( in(Address) ) == Type::TOP ) return NULL;
 576 
 577   // If the left input is an add of a constant, flatten the expression tree.
 578   const Node *n = in(Address);
 579   if (n->is_AddP() && n->in(Base) == in(Base)) {
 580     const AddPNode *addp = n->as_AddP(); // Left input is an AddP
 581     assert( !addp->in(Address)->is_AddP() ||
 582              addp->in(Address)->as_AddP() != addp,
 583             "dead loop in AddPNode::Ideal" );
 584     // Type of left input's right input
 585     const Type *t = phase->type( addp->in(Offset) );
 586     if( t == Type::TOP ) return NULL;
 587     const TypeX *t12 = t->is_intptr_t();
 588     if( t12->is_con() ) {       // Left input is an add of a constant?
 589       // If the right input is a constant, combine constants
 590       const Type *temp_t2 = phase->type( in(Offset) );
 591       if( temp_t2 == Type::TOP ) return NULL;
 592       const TypeX *t2 = temp_t2->is_intptr_t();
 593       Node* address;
 594       Node* offset;
 595       if( t2->is_con() ) {
 596         // The Add of the flattened expression
 597         address = addp->in(Address);
 598         offset  = phase->MakeConX(t2->get_con() + t12->get_con());
 599       } else {
 600         // Else move the constant to the right.  ((A+con)+B) into ((A+B)+con)
 601         address = phase->transform(new (phase->C) AddPNode(in(Base),addp->in(Address),in(Offset)));
 602         offset  = addp->in(Offset);
 603       }
 604       PhaseIterGVN *igvn = phase->is_IterGVN();
 605       if( igvn ) {
 606         set_req_X(Address,address,igvn);
 607         set_req_X(Offset,offset,igvn);
 608       } else {
 609         set_req(Address,address);
 610         set_req(Offset,offset);
 611       }
 612       return this;
 613     }
 614   }
 615 
 616   // Raw pointers?
 617   if( in(Base)->bottom_type() == Type::TOP ) {
 618     // If this is a NULL+long form (from unsafe accesses), switch to a rawptr.
 619     if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
 620       Node* offset = in(Offset);
 621       return new (phase->C) CastX2PNode(offset);
 622     }
 623   }
 624 
 625   // If the right is an add of a constant, push the offset down.
 626   // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
 627   // The idea is to merge array_base+scaled_index groups together,
 628   // and only have different constant offsets from the same base.
 629   const Node *add = in(Offset);
 630   if( add->Opcode() == Op_AddX && add->in(1) != add ) {
 631     const Type *t22 = phase->type( add->in(2) );
 632     if( t22->singleton() && (t22 != Type::TOP) ) {  // Right input is an add of a constant?
 633       set_req(Address, phase->transform(new (phase->C) AddPNode(in(Base),in(Address),add->in(1))));
 634       set_req(Offset, add->in(2));
 635       PhaseIterGVN *igvn = phase->is_IterGVN();
 636       if (add->outcnt() == 0 && igvn) {
 637         // add disconnected.
 638         igvn->_worklist.push((Node*)add);
 639       }
 640       return this;              // Made progress
 641     }
 642   }
 643 
 644   return NULL;                  // No progress
 645 }
 646 
 647 //------------------------------bottom_type------------------------------------
 648 // Bottom-type is the pointer-type with unknown offset.
 649 const Type *AddPNode::bottom_type() const {
 650   if (in(Address) == NULL)  return TypePtr::BOTTOM;
 651   const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
 652   if( !tp ) return Type::TOP;   // TOP input means TOP output
 653   assert( in(Offset)->Opcode() != Op_ConP, "" );
 654   const Type *t = in(Offset)->bottom_type();
 655   if( t == Type::TOP )
 656     return tp->add_offset(Type::OffsetTop);
 657   const TypeX *tx = t->is_intptr_t();
 658   intptr_t txoffset = Type::OffsetBot;
 659   if (tx->is_con()) {   // Left input is an add of a constant?
 660     txoffset = tx->get_con();
 661   }
 662   return tp->add_offset(txoffset);
 663 }
 664 
 665 //------------------------------Value------------------------------------------
 666 const Type *AddPNode::Value( PhaseTransform *phase ) const {
 667   // Either input is TOP ==> the result is TOP
 668   const Type *t1 = phase->type( in(Address) );
 669   const Type *t2 = phase->type( in(Offset) );
 670   if( t1 == Type::TOP ) return Type::TOP;
 671   if( t2 == Type::TOP ) return Type::TOP;
 672 
 673   // Left input is a pointer
 674   const TypePtr *p1 = t1->isa_ptr();
 675   // Right input is an int
 676   const TypeX *p2 = t2->is_intptr_t();
 677   // Add 'em
 678   intptr_t p2offset = Type::OffsetBot;
 679   if (p2->is_con()) {   // Left input is an add of a constant?
 680     p2offset = p2->get_con();
 681   }
 682   return p1->add_offset(p2offset);
 683 }
 684 
 685 //------------------------Ideal_base_and_offset--------------------------------
 686 // Split an oop pointer into a base and offset.
 687 // (The offset might be Type::OffsetBot in the case of an array.)
 688 // Return the base, or NULL if failure.
 689 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseTransform* phase,
 690                                       // second return value:
 691                                       intptr_t& offset) {
 692   if (ptr->is_AddP()) {
 693     Node* base = ptr->in(AddPNode::Base);
 694     Node* addr = ptr->in(AddPNode::Address);
 695     Node* offs = ptr->in(AddPNode::Offset);
 696     if (base == addr || base->is_top()) {
 697       offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
 698       if (offset != Type::OffsetBot) {
 699         return addr;
 700       }
 701     }
 702   }
 703   offset = Type::OffsetBot;
 704   return NULL;
 705 }
 706 
 707 //------------------------------unpack_offsets----------------------------------
 708 // Collect the AddP offset values into the elements array, giving up
 709 // if there are more than length.
 710 int AddPNode::unpack_offsets(Node* elements[], int length) {
 711   int count = 0;
 712   Node* addr = this;
 713   Node* base = addr->in(AddPNode::Base);
 714   while (addr->is_AddP()) {
 715     if (addr->in(AddPNode::Base) != base) {
 716       // give up
 717       return -1;
 718     }
 719     elements[count++] = addr->in(AddPNode::Offset);
 720     if (count == length) {
 721       // give up
 722       return -1;
 723     }
 724     addr = addr->in(AddPNode::Address);
 725   }
 726   if (addr != base) {
 727     return -1;
 728   }
 729   return count;
 730 }
 731 
 732 //------------------------------match_edge-------------------------------------
 733 // Do we Match on this edge index or not?  Do not match base pointer edge
 734 uint AddPNode::match_edge(uint idx) const {
 735   return idx > Base;
 736 }
 737 
 738 //=============================================================================
 739 //------------------------------Identity---------------------------------------
 740 Node *OrINode::Identity( PhaseTransform *phase ) {
 741   // x | x => x
 742   if (phase->eqv(in(1), in(2))) {
 743     return in(1);
 744   }
 745 
 746   return AddNode::Identity(phase);
 747 }
 748 
 749 //------------------------------add_ring---------------------------------------
 750 // Supplied function returns the sum of the inputs IN THE CURRENT RING.  For
 751 // the logical operations the ring's ADD is really a logical OR function.
 752 // This also type-checks the inputs for sanity.  Guaranteed never to
 753 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 754 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
 755   const TypeInt *r0 = t0->is_int(); // Handy access
 756   const TypeInt *r1 = t1->is_int();
 757 
 758   // If both args are bool, can figure out better types
 759   if ( r0 == TypeInt::BOOL ) {
 760     if ( r1 == TypeInt::ONE) {
 761       return TypeInt::ONE;
 762     } else if ( r1 == TypeInt::BOOL ) {
 763       return TypeInt::BOOL;
 764     }
 765   } else if ( r0 == TypeInt::ONE ) {
 766     if ( r1 == TypeInt::BOOL ) {
 767       return TypeInt::ONE;
 768     }
 769   }
 770 
 771   // If either input is not a constant, just return all integers.
 772   if( !r0->is_con() || !r1->is_con() )
 773     return TypeInt::INT;        // Any integer, but still no symbols.
 774 
 775   // Otherwise just OR them bits.
 776   return TypeInt::make( r0->get_con() | r1->get_con() );
 777 }
 778 
 779 //=============================================================================
 780 //------------------------------Identity---------------------------------------
 781 Node *OrLNode::Identity( PhaseTransform *phase ) {
 782   // x | x => x
 783   if (phase->eqv(in(1), in(2))) {
 784     return in(1);
 785   }
 786 
 787   return AddNode::Identity(phase);
 788 }
 789 
 790 //------------------------------add_ring---------------------------------------
 791 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
 792   const TypeLong *r0 = t0->is_long(); // Handy access
 793   const TypeLong *r1 = t1->is_long();
 794 
 795   // If either input is not a constant, just return all integers.
 796   if( !r0->is_con() || !r1->is_con() )
 797     return TypeLong::LONG;      // Any integer, but still no symbols.
 798 
 799   // Otherwise just OR them bits.
 800   return TypeLong::make( r0->get_con() | r1->get_con() );
 801 }
 802 
 803 //=============================================================================
 804 //------------------------------add_ring---------------------------------------
 805 // Supplied function returns the sum of the inputs IN THE CURRENT RING.  For
 806 // the logical operations the ring's ADD is really a logical OR function.
 807 // This also type-checks the inputs for sanity.  Guaranteed never to
 808 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 809 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
 810   const TypeInt *r0 = t0->is_int(); // Handy access
 811   const TypeInt *r1 = t1->is_int();
 812 
 813   // Complementing a boolean?
 814   if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
 815                                || r1 == TypeInt::BOOL))
 816     return TypeInt::BOOL;
 817 
 818   if( !r0->is_con() || !r1->is_con() ) // Not constants
 819     return TypeInt::INT;        // Any integer, but still no symbols.
 820 
 821   // Otherwise just XOR them bits.
 822   return TypeInt::make( r0->get_con() ^ r1->get_con() );
 823 }
 824 
 825 //=============================================================================
 826 //------------------------------add_ring---------------------------------------
 827 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
 828   const TypeLong *r0 = t0->is_long(); // Handy access
 829   const TypeLong *r1 = t1->is_long();
 830 
 831   // If either input is not a constant, just return all integers.
 832   if( !r0->is_con() || !r1->is_con() )
 833     return TypeLong::LONG;      // Any integer, but still no symbols.
 834 
 835   // Otherwise just OR them bits.
 836   return TypeLong::make( r0->get_con() ^ r1->get_con() );
 837 }
 838 
 839 //=============================================================================
 840 //------------------------------add_ring---------------------------------------
 841 // Supplied function returns the sum of the inputs.
 842 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
 843   const TypeInt *r0 = t0->is_int(); // Handy access
 844   const TypeInt *r1 = t1->is_int();
 845 
 846   // Otherwise just MAX them bits.
 847   return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
 848 }
 849 
 850 //=============================================================================
 851 //------------------------------Idealize---------------------------------------
 852 // MINs show up in range-check loop limit calculations.  Look for
 853 // "MIN2(x+c0,MIN2(y,x+c1))".  Pick the smaller constant: "MIN2(x+c0,y)"
 854 Node *MinINode::Ideal(PhaseGVN *phase, bool can_reshape) {
 855   Node *progress = NULL;
 856   // Force a right-spline graph
 857   Node *l = in(1);
 858   Node *r = in(2);
 859   // Transform  MinI1( MinI2(a,b), c)  into  MinI1( a, MinI2(b,c) )
 860   // to force a right-spline graph for the rest of MinINode::Ideal().
 861   if( l->Opcode() == Op_MinI ) {
 862     assert( l != l->in(1), "dead loop in MinINode::Ideal" );
 863     r = phase->transform(new (phase->C) MinINode(l->in(2),r));
 864     l = l->in(1);
 865     set_req(1, l);
 866     set_req(2, r);
 867     return this;
 868   }
 869 
 870   // Get left input & constant
 871   Node *x = l;
 872   int x_off = 0;
 873   if( x->Opcode() == Op_AddI && // Check for "x+c0" and collect constant
 874       x->in(2)->is_Con() ) {
 875     const Type *t = x->in(2)->bottom_type();
 876     if( t == Type::TOP ) return NULL;  // No progress
 877     x_off = t->is_int()->get_con();
 878     x = x->in(1);
 879   }
 880 
 881   // Scan a right-spline-tree for MINs
 882   Node *y = r;
 883   int y_off = 0;
 884   // Check final part of MIN tree
 885   if( y->Opcode() == Op_AddI && // Check for "y+c1" and collect constant
 886       y->in(2)->is_Con() ) {
 887     const Type *t = y->in(2)->bottom_type();
 888     if( t == Type::TOP ) return NULL;  // No progress
 889     y_off = t->is_int()->get_con();
 890     y = y->in(1);
 891   }
 892   if( x->_idx > y->_idx && r->Opcode() != Op_MinI ) {
 893     swap_edges(1, 2);
 894     return this;
 895   }
 896 
 897 
 898   if( r->Opcode() == Op_MinI ) {
 899     assert( r != r->in(2), "dead loop in MinINode::Ideal" );
 900     y = r->in(1);
 901     // Check final part of MIN tree
 902     if( y->Opcode() == Op_AddI &&// Check for "y+c1" and collect constant
 903         y->in(2)->is_Con() ) {
 904       const Type *t = y->in(2)->bottom_type();
 905       if( t == Type::TOP ) return NULL;  // No progress
 906       y_off = t->is_int()->get_con();
 907       y = y->in(1);
 908     }
 909 
 910     if( x->_idx > y->_idx )
 911       return new (phase->C) MinINode(r->in(1),phase->transform(new (phase->C) MinINode(l,r->in(2))));
 912 
 913     // See if covers: MIN2(x+c0,MIN2(y+c1,z))
 914     if( !phase->eqv(x,y) ) return NULL;
 915     // If (y == x) transform MIN2(x+c0, MIN2(x+c1,z)) into
 916     // MIN2(x+c0 or x+c1 which less, z).
 917     return new (phase->C) MinINode(phase->transform(new (phase->C) AddINode(x,phase->intcon(MIN2(x_off,y_off)))),r->in(2));
 918   } else {
 919     // See if covers: MIN2(x+c0,y+c1)
 920     if( !phase->eqv(x,y) ) return NULL;
 921     // If (y == x) transform MIN2(x+c0,x+c1) into x+c0 or x+c1 which less.
 922     return new (phase->C) AddINode(x,phase->intcon(MIN2(x_off,y_off)));
 923   }
 924 
 925 }
 926 
 927 //------------------------------add_ring---------------------------------------
 928 // Supplied function returns the sum of the inputs.
 929 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
 930   const TypeInt *r0 = t0->is_int(); // Handy access
 931   const TypeInt *r1 = t1->is_int();
 932 
 933   // Otherwise just MIN them bits.
 934   return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
 935 }