1 /*
   2  * Copyright 1997-2008 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 // Portions of code courtesy of Clifford Click
  26 
  27 #include "incls/_precompiled.incl"
  28 #include "incls/_addnode.cpp.incl"
  29 
  30 #define MAXFLOAT        ((float)3.40282346638528860e+38)
  31 
  32 // Classic Add functionality.  This covers all the usual 'add' behaviors for
  33 // an algebraic ring.  Add-integer, add-float, add-double, and binary-or are
  34 // all inherited from this class.  The various identity values are supplied
  35 // by virtual functions.
  36 
  37 
  38 //=============================================================================
  39 //------------------------------hash-------------------------------------------
  40 // Hash function over AddNodes.  Needs to be commutative; i.e., I swap
  41 // (commute) inputs to AddNodes willy-nilly so the hash function must return
  42 // the same value in the presence of edge swapping.
  43 uint AddNode::hash() const {
  44   return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
  45 }
  46 
  47 //------------------------------Identity---------------------------------------
  48 // If either input is a constant 0, return the other input.
  49 Node *AddNode::Identity( PhaseTransform *phase ) {
  50   const Type *zero = add_id();  // The additive identity
  51   if( phase->type( in(1) )->higher_equal( zero ) ) return in(2);
  52   if( phase->type( in(2) )->higher_equal( zero ) ) return in(1);
  53   return this;
  54 }
  55 
  56 //------------------------------commute----------------------------------------
  57 // Commute operands to move loads and constants to the right.
  58 static bool commute( Node *add, int con_left, int con_right ) {
  59   Node *in1 = add->in(1);
  60   Node *in2 = add->in(2);
  61 
  62   // Convert "1+x" into "x+1".
  63   // Right is a constant; leave it
  64   if( con_right ) return false;
  65   // Left is a constant; move it right.
  66   if( con_left ) {
  67     add->swap_edges(1, 2);
  68     return true;
  69   }
  70 
  71   // Convert "Load+x" into "x+Load".
  72   // Now check for loads
  73   if (in2->is_Load()) {
  74     if (!in1->is_Load()) {
  75       // already x+Load to return
  76       return false;
  77     }
  78     // both are loads, so fall through to sort inputs by idx
  79   } else if( in1->is_Load() ) {
  80     // Left is a Load and Right is not; move it right.
  81     add->swap_edges(1, 2);
  82     return true;
  83   }
  84 
  85   PhiNode *phi;
  86   // Check for tight loop increments: Loop-phi of Add of loop-phi
  87   if( in1->is_Phi() && (phi = in1->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add)
  88     return false;
  89   if( in2->is_Phi() && (phi = in2->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add){
  90     add->swap_edges(1, 2);
  91     return true;
  92   }
  93 
  94   // Otherwise, sort inputs (commutativity) to help value numbering.
  95   if( in1->_idx > in2->_idx ) {
  96     add->swap_edges(1, 2);
  97     return true;
  98   }
  99   return false;
 100 }
 101 
 102 //------------------------------Idealize---------------------------------------
 103 // If we get here, we assume we are associative!
 104 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 105   const Type *t1 = phase->type( in(1) );
 106   const Type *t2 = phase->type( in(2) );
 107   int con_left  = t1->singleton();
 108   int con_right = t2->singleton();
 109 
 110   // Check for commutative operation desired
 111   if( commute(this,con_left,con_right) ) return this;
 112 
 113   AddNode *progress = NULL;             // Progress flag
 114 
 115   // Convert "(x+1)+2" into "x+(1+2)".  If the right input is a
 116   // constant, and the left input is an add of a constant, flatten the
 117   // expression tree.
 118   Node *add1 = in(1);
 119   Node *add2 = in(2);
 120   int add1_op = add1->Opcode();
 121   int this_op = Opcode();
 122   if( con_right && t2 != Type::TOP && // Right input is a constant?
 123       add1_op == this_op ) { // Left input is an Add?
 124 
 125     // Type of left _in right input
 126     const Type *t12 = phase->type( add1->in(2) );
 127     if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
 128       // Check for rare case of closed data cycle which can happen inside
 129       // unreachable loops. In these cases the computation is undefined.
 130 #ifdef ASSERT
 131       Node *add11    = add1->in(1);
 132       int   add11_op = add11->Opcode();
 133       if( (add1 == add1->in(1))
 134          || (add11_op == this_op && add11->in(1) == add1) ) {
 135         assert(false, "dead loop in AddNode::Ideal");
 136       }
 137 #endif
 138       // The Add of the flattened expression
 139       Node *x1 = add1->in(1);
 140       Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 ));
 141       PhaseIterGVN *igvn = phase->is_IterGVN();
 142       if( igvn ) {
 143         set_req_X(2,x2,igvn);
 144         set_req_X(1,x1,igvn);
 145       } else {
 146         set_req(2,x2);
 147         set_req(1,x1);
 148       }
 149       progress = this;            // Made progress
 150       add1 = in(1);
 151       add1_op = add1->Opcode();
 152     }
 153   }
 154 
 155   // Convert "(x+1)+y" into "(x+y)+1".  Push constants down the expression tree.
 156   if( add1_op == this_op && !con_right ) {
 157     Node *a12 = add1->in(2);
 158     const Type *t12 = phase->type( a12 );
 159     if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) ) {
 160       if (add1->in(1) == this)
 161         return phase->C->top(); // Dead loop
 162       add2 = add1->clone();
 163       add2->set_req(2, in(2));
 164       add2 = phase->transform(add2);
 165       set_req(1, add2);
 166       set_req(2, a12);
 167       progress = this;
 168       add2 = a12;
 169     }
 170   }
 171 
 172   // Convert "x+(y+1)" into "(x+y)+1".  Push constants down the expression tree.
 173   int add2_op = add2->Opcode();
 174   if( add2_op == this_op && !con_left ) {
 175     Node *a22 = add2->in(2);
 176     const Type *t22 = phase->type( a22 );
 177     if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) ) {
 178       if (add2->in(1) == this)
 179         return phase->C->top(); // Dead loop
 180       Node *addx = add2->clone();
 181       addx->set_req(1, in(1));
 182       addx->set_req(2, add2->in(1));
 183       addx = phase->transform(addx);
 184       set_req(1, addx);
 185       set_req(2, a22);
 186       progress = this;
 187     }
 188   }
 189 
 190   return progress;
 191 }
 192 
 193 //------------------------------Value-----------------------------------------
 194 // An add node sums it's two _in.  If one input is an RSD, we must mixin
 195 // the other input's symbols.
 196 const Type *AddNode::Value( PhaseTransform *phase ) const {
 197   // Either input is TOP ==> the result is TOP
 198   const Type *t1 = phase->type( in(1) );
 199   const Type *t2 = phase->type( in(2) );
 200   if( t1 == Type::TOP ) return Type::TOP;
 201   if( t2 == Type::TOP ) return Type::TOP;
 202 
 203   // Either input is BOTTOM ==> the result is the local BOTTOM
 204   const Type *bot = bottom_type();
 205   if( (t1 == bot) || (t2 == bot) ||
 206       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
 207     return bot;
 208 
 209   // Check for an addition involving the additive identity
 210   const Type *tadd = add_of_identity( t1, t2 );
 211   if( tadd ) return tadd;
 212 
 213   return add_ring(t1,t2);               // Local flavor of type addition
 214 }
 215 
 216 //------------------------------add_identity-----------------------------------
 217 // Check for addition of the identity
 218 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
 219   const Type *zero = add_id();  // The additive identity
 220   if( t1->higher_equal( zero ) ) return t2;
 221   if( t2->higher_equal( zero ) ) return t1;
 222 
 223   return NULL;
 224 }
 225 
 226 
 227 //=============================================================================
 228 //------------------------------Idealize---------------------------------------
 229 Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) {
 230   int op1 = in(1)->Opcode();
 231   int op2 = in(2)->Opcode();
 232   // Fold (con1-x)+con2 into (con1+con2)-x
 233   if( op1 == Op_SubI ) {
 234     const Type *t_sub1 = phase->type( in(1)->in(1) );
 235     const Type *t_2    = phase->type( in(2)        );
 236     if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
 237       return new (phase->C, 3) SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ),
 238                               in(1)->in(2) );
 239     // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
 240     if( op2 == Op_SubI ) {
 241       // Check for dead cycle: d = (a-b)+(c-d)
 242       assert( in(1)->in(2) != this && in(2)->in(2) != this,
 243               "dead loop in AddINode::Ideal" );
 244       Node *sub  = new (phase->C, 3) SubINode(NULL, NULL);
 245       sub->init_req(1, phase->transform(new (phase->C, 3) AddINode(in(1)->in(1), in(2)->in(1) ) ));
 246       sub->init_req(2, phase->transform(new (phase->C, 3) AddINode(in(1)->in(2), in(2)->in(2) ) ));
 247       return sub;
 248     }
 249   }
 250 
 251   // Convert "x+(0-y)" into "(x-y)"
 252   if( op2 == Op_SubI && phase->type(in(2)->in(1)) == TypeInt::ZERO )
 253     return new (phase->C, 3) SubINode(in(1), in(2)->in(2) );
 254 
 255   // Convert "(0-y)+x" into "(x-y)"
 256   if( op1 == Op_SubI && phase->type(in(1)->in(1)) == TypeInt::ZERO )
 257     return new (phase->C, 3) SubINode( in(2), in(1)->in(2) );
 258 
 259   // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
 260   // Helps with array allocation math constant folding
 261   // See 4790063:
 262   // Unrestricted transformation is unsafe for some runtime values of 'x'
 263   // ( x ==  0, z == 1, y == -1 ) fails
 264   // ( x == -5, z == 1, y ==  1 ) fails
 265   // Transform works for small z and small negative y when the addition
 266   // (x + (y << z)) does not cross zero.
 267   // Implement support for negative y and (x >= -(y << z))
 268   // Have not observed cases where type information exists to support
 269   // positive y and (x <= -(y << z))
 270   if( op1 == Op_URShiftI && op2 == Op_ConI &&
 271       in(1)->in(2)->Opcode() == Op_ConI ) {
 272     jint z = phase->type( in(1)->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
 273     jint y = phase->type( in(2) )->is_int()->get_con();
 274 
 275     if( z < 5 && -5 < y && y < 0 ) {
 276       const Type *t_in11 = phase->type(in(1)->in(1));
 277       if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) {
 278         Node *a = phase->transform( new (phase->C, 3) AddINode( in(1)->in(1), phase->intcon(y<<z) ) );
 279         return new (phase->C, 3) URShiftINode( a, in(1)->in(2) );
 280       }
 281     }
 282   }
 283 
 284   return AddNode::Ideal(phase, can_reshape);
 285 }
 286 
 287 
 288 //------------------------------Identity---------------------------------------
 289 // Fold (x-y)+y  OR  y+(x-y)  into  x
 290 Node *AddINode::Identity( PhaseTransform *phase ) {
 291   if( in(1)->Opcode() == Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) {
 292     return in(1)->in(1);
 293   }
 294   else if( in(2)->Opcode() == Op_SubI && phase->eqv(in(2)->in(2),in(1)) ) {
 295     return in(2)->in(1);
 296   }
 297   return AddNode::Identity(phase);
 298 }
 299 
 300 
 301 //------------------------------add_ring---------------------------------------
 302 // Supplied function returns the sum of the inputs.  Guaranteed never
 303 // to be passed a TOP or BOTTOM type, these are filtered out by
 304 // pre-check.
 305 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
 306   const TypeInt *r0 = t0->is_int(); // Handy access
 307   const TypeInt *r1 = t1->is_int();
 308   int lo = r0->_lo + r1->_lo;
 309   int hi = r0->_hi + r1->_hi;
 310   if( !(r0->is_con() && r1->is_con()) ) {
 311     // Not both constants, compute approximate result
 312     if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
 313       lo = min_jint; hi = max_jint; // Underflow on the low side
 314     }
 315     if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
 316       lo = min_jint; hi = max_jint; // Overflow on the high side
 317     }
 318     if( lo > hi ) {               // Handle overflow
 319       lo = min_jint; hi = max_jint;
 320     }
 321   } else {
 322     // both constants, compute precise result using 'lo' and 'hi'
 323     // Semantics define overflow and underflow for integer addition
 324     // as expected.  In particular: 0x80000000 + 0x80000000 --> 0x0
 325   }
 326   return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
 327 }
 328 
 329 
 330 //=============================================================================
 331 //------------------------------Idealize---------------------------------------
 332 Node *AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 333   int op1 = in(1)->Opcode();
 334   int op2 = in(2)->Opcode();
 335   // Fold (con1-x)+con2 into (con1+con2)-x
 336   if( op1 == Op_SubL ) {
 337     const Type *t_sub1 = phase->type( in(1)->in(1) );
 338     const Type *t_2    = phase->type( in(2)        );
 339     if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
 340       return new (phase->C, 3) SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ),
 341                               in(1)->in(2) );
 342     // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
 343     if( op2 == Op_SubL ) {
 344       // Check for dead cycle: d = (a-b)+(c-d)
 345       assert( in(1)->in(2) != this && in(2)->in(2) != this,
 346               "dead loop in AddLNode::Ideal" );
 347       Node *sub  = new (phase->C, 3) SubLNode(NULL, NULL);
 348       sub->init_req(1, phase->transform(new (phase->C, 3) AddLNode(in(1)->in(1), in(2)->in(1) ) ));
 349       sub->init_req(2, phase->transform(new (phase->C, 3) AddLNode(in(1)->in(2), in(2)->in(2) ) ));
 350       return sub;
 351     }
 352   }
 353 
 354   // Convert "x+(0-y)" into "(x-y)"
 355   if( op2 == Op_SubL && phase->type(in(2)->in(1)) == TypeLong::ZERO )
 356     return new (phase->C, 3) SubLNode(in(1), in(2)->in(2) );
 357 
 358   // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)"
 359   // into "(X<<1)+Y" and let shift-folding happen.
 360   if( op2 == Op_AddL &&
 361       in(2)->in(1) == in(1) &&
 362       op1 != Op_ConL &&
 363       0 ) {
 364     Node *shift = phase->transform(new (phase->C, 3) LShiftLNode(in(1),phase->intcon(1)));
 365     return new (phase->C, 3) AddLNode(shift,in(2)->in(2));
 366   }
 367 
 368   return AddNode::Ideal(phase, can_reshape);
 369 }
 370 
 371 
 372 //------------------------------Identity---------------------------------------
 373 // Fold (x-y)+y  OR  y+(x-y)  into  x
 374 Node *AddLNode::Identity( PhaseTransform *phase ) {
 375   if( in(1)->Opcode() == Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) {
 376     return in(1)->in(1);
 377   }
 378   else if( in(2)->Opcode() == Op_SubL && phase->eqv(in(2)->in(2),in(1)) ) {
 379     return in(2)->in(1);
 380   }
 381   return AddNode::Identity(phase);
 382 }
 383 
 384 
 385 //------------------------------add_ring---------------------------------------
 386 // Supplied function returns the sum of the inputs.  Guaranteed never
 387 // to be passed a TOP or BOTTOM type, these are filtered out by
 388 // pre-check.
 389 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
 390   const TypeLong *r0 = t0->is_long(); // Handy access
 391   const TypeLong *r1 = t1->is_long();
 392   jlong lo = r0->_lo + r1->_lo;
 393   jlong hi = r0->_hi + r1->_hi;
 394   if( !(r0->is_con() && r1->is_con()) ) {
 395     // Not both constants, compute approximate result
 396     if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
 397       lo =min_jlong; hi = max_jlong; // Underflow on the low side
 398     }
 399     if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
 400       lo = min_jlong; hi = max_jlong; // Overflow on the high side
 401     }
 402     if( lo > hi ) {               // Handle overflow
 403       lo = min_jlong; hi = max_jlong;
 404     }
 405   } else {
 406     // both constants, compute precise result using 'lo' and 'hi'
 407     // Semantics define overflow and underflow for integer addition
 408     // as expected.  In particular: 0x80000000 + 0x80000000 --> 0x0
 409   }
 410   return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
 411 }
 412 
 413 
 414 //=============================================================================
 415 //------------------------------add_of_identity--------------------------------
 416 // Check for addition of the identity
 417 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
 418   // x ADD 0  should return x unless 'x' is a -zero
 419   //
 420   // const Type *zero = add_id();     // The additive identity
 421   // jfloat f1 = t1->getf();
 422   // jfloat f2 = t2->getf();
 423   //
 424   // if( t1->higher_equal( zero ) ) return t2;
 425   // if( t2->higher_equal( zero ) ) return t1;
 426 
 427   return NULL;
 428 }
 429 
 430 //------------------------------add_ring---------------------------------------
 431 // Supplied function returns the sum of the inputs.
 432 // This also type-checks the inputs for sanity.  Guaranteed never to
 433 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 434 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
 435   // We must be adding 2 float constants.
 436   return TypeF::make( t0->getf() + t1->getf() );
 437 }
 438 
 439 //------------------------------Ideal------------------------------------------
 440 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 441   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
 442     return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
 443   }
 444 
 445   // Floating point additions are not associative because of boundary conditions (infinity)
 446   return commute(this,
 447                  phase->type( in(1) )->singleton(),
 448                  phase->type( in(2) )->singleton() ) ? this : NULL;
 449 }
 450 
 451 
 452 //=============================================================================
 453 //------------------------------add_of_identity--------------------------------
 454 // Check for addition of the identity
 455 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
 456   // x ADD 0  should return x unless 'x' is a -zero
 457   //
 458   // const Type *zero = add_id();     // The additive identity
 459   // jfloat f1 = t1->getf();
 460   // jfloat f2 = t2->getf();
 461   //
 462   // if( t1->higher_equal( zero ) ) return t2;
 463   // if( t2->higher_equal( zero ) ) return t1;
 464 
 465   return NULL;
 466 }
 467 //------------------------------add_ring---------------------------------------
 468 // Supplied function returns the sum of the inputs.
 469 // This also type-checks the inputs for sanity.  Guaranteed never to
 470 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 471 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
 472   // We must be adding 2 double constants.
 473   return TypeD::make( t0->getd() + t1->getd() );
 474 }
 475 
 476 //------------------------------Ideal------------------------------------------
 477 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 478   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
 479     return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
 480   }
 481 
 482   // Floating point additions are not associative because of boundary conditions (infinity)
 483   return commute(this,
 484                  phase->type( in(1) )->singleton(),
 485                  phase->type( in(2) )->singleton() ) ? this : NULL;
 486 }
 487 
 488 
 489 //=============================================================================
 490 //------------------------------Identity---------------------------------------
 491 // If one input is a constant 0, return the other input.
 492 Node *AddPNode::Identity( PhaseTransform *phase ) {
 493   return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
 494 }
 495 
 496 //------------------------------Idealize---------------------------------------
 497 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 498   // Bail out if dead inputs
 499   if( phase->type( in(Address) ) == Type::TOP ) return NULL;
 500 
 501   // If the left input is an add of a constant, flatten the expression tree.
 502   const Node *n = in(Address);
 503   if (n->is_AddP() && n->in(Base) == in(Base)) {
 504     const AddPNode *addp = n->as_AddP(); // Left input is an AddP
 505     assert( !addp->in(Address)->is_AddP() ||
 506              addp->in(Address)->as_AddP() != addp,
 507             "dead loop in AddPNode::Ideal" );
 508     // Type of left input's right input
 509     const Type *t = phase->type( addp->in(Offset) );
 510     if( t == Type::TOP ) return NULL;
 511     const TypeX *t12 = t->is_intptr_t();
 512     if( t12->is_con() ) {       // Left input is an add of a constant?
 513       // If the right input is a constant, combine constants
 514       const Type *temp_t2 = phase->type( in(Offset) );
 515       if( temp_t2 == Type::TOP ) return NULL;
 516       const TypeX *t2 = temp_t2->is_intptr_t();
 517       Node* address;
 518       Node* offset;
 519       if( t2->is_con() ) {
 520         // The Add of the flattened expression
 521         address = addp->in(Address);
 522         offset  = phase->MakeConX(t2->get_con() + t12->get_con());
 523       } else {
 524         // Else move the constant to the right.  ((A+con)+B) into ((A+B)+con)
 525         address = phase->transform(new (phase->C, 4) AddPNode(in(Base),addp->in(Address),in(Offset)));
 526         offset  = addp->in(Offset);
 527       }
 528       PhaseIterGVN *igvn = phase->is_IterGVN();
 529       if( igvn ) {
 530         set_req_X(Address,address,igvn);
 531         set_req_X(Offset,offset,igvn);
 532       } else {
 533         set_req(Address,address);
 534         set_req(Offset,offset);
 535       }
 536       return this;
 537     }
 538   }
 539 
 540   // Raw pointers?
 541   if( in(Base)->bottom_type() == Type::TOP ) {
 542     // If this is a NULL+long form (from unsafe accesses), switch to a rawptr.
 543     if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
 544       Node* offset = in(Offset);
 545       return new (phase->C, 2) CastX2PNode(offset);
 546     }
 547   }
 548 
 549   // If the right is an add of a constant, push the offset down.
 550   // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
 551   // The idea is to merge array_base+scaled_index groups together,
 552   // and only have different constant offsets from the same base.
 553   const Node *add = in(Offset);
 554   if( add->Opcode() == Op_AddX && add->in(1) != add ) {
 555     const Type *t22 = phase->type( add->in(2) );
 556     if( t22->singleton() && (t22 != Type::TOP) ) {  // Right input is an add of a constant?
 557       set_req(Address, phase->transform(new (phase->C, 4) AddPNode(in(Base),in(Address),add->in(1))));
 558       set_req(Offset, add->in(2));
 559       return this;              // Made progress
 560     }
 561   }
 562 
 563   return NULL;                  // No progress
 564 }
 565 
 566 //------------------------------bottom_type------------------------------------
 567 // Bottom-type is the pointer-type with unknown offset.
 568 const Type *AddPNode::bottom_type() const {
 569   if (in(Address) == NULL)  return TypePtr::BOTTOM;
 570   const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
 571   if( !tp ) return Type::TOP;   // TOP input means TOP output
 572   assert( in(Offset)->Opcode() != Op_ConP, "" );
 573   const Type *t = in(Offset)->bottom_type();
 574   if( t == Type::TOP )
 575     return tp->add_offset(Type::OffsetTop);
 576   const TypeX *tx = t->is_intptr_t();
 577   intptr_t txoffset = Type::OffsetBot;
 578   if (tx->is_con()) {   // Left input is an add of a constant?
 579     txoffset = tx->get_con();
 580   }
 581   return tp->add_offset(txoffset);
 582 }
 583 
 584 //------------------------------Value------------------------------------------
 585 const Type *AddPNode::Value( PhaseTransform *phase ) const {
 586   // Either input is TOP ==> the result is TOP
 587   const Type *t1 = phase->type( in(Address) );
 588   const Type *t2 = phase->type( in(Offset) );
 589   if( t1 == Type::TOP ) return Type::TOP;
 590   if( t2 == Type::TOP ) return Type::TOP;
 591 
 592   // Left input is a pointer
 593   const TypePtr *p1 = t1->isa_ptr();
 594   // Right input is an int
 595   const TypeX *p2 = t2->is_intptr_t();
 596   // Add 'em
 597   intptr_t p2offset = Type::OffsetBot;
 598   if (p2->is_con()) {   // Left input is an add of a constant?
 599     p2offset = p2->get_con();
 600   }
 601   return p1->add_offset(p2offset);
 602 }
 603 
 604 //------------------------Ideal_base_and_offset--------------------------------
 605 // Split an oop pointer into a base and offset.
 606 // (The offset might be Type::OffsetBot in the case of an array.)
 607 // Return the base, or NULL if failure.
 608 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseTransform* phase,
 609                                       // second return value:
 610                                       intptr_t& offset) {
 611   if (ptr->is_AddP()) {
 612     Node* base = ptr->in(AddPNode::Base);
 613     Node* addr = ptr->in(AddPNode::Address);
 614     Node* offs = ptr->in(AddPNode::Offset);
 615     if (base == addr || base->is_top()) {
 616       offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
 617       if (offset != Type::OffsetBot) {
 618         return addr;
 619       }
 620     }
 621   }
 622   offset = Type::OffsetBot;
 623   return NULL;
 624 }
 625 
 626 //------------------------------unpack_offsets----------------------------------
 627 // Collect the AddP offset values into the elements array, giving up
 628 // if there are more than length.
 629 int AddPNode::unpack_offsets(Node* elements[], int length) {
 630   int count = 0;
 631   Node* addr = this;
 632   Node* base = addr->in(AddPNode::Base);
 633   while (addr->is_AddP()) {
 634     if (addr->in(AddPNode::Base) != base) {
 635       // give up
 636       return -1;
 637     }
 638     elements[count++] = addr->in(AddPNode::Offset);
 639     if (count == length) {
 640       // give up
 641       return -1;
 642     }
 643     addr = addr->in(AddPNode::Address);
 644   }
 645   return count;
 646 }
 647 
 648 //------------------------------match_edge-------------------------------------
 649 // Do we Match on this edge index or not?  Do not match base pointer edge
 650 uint AddPNode::match_edge(uint idx) const {
 651   return idx > Base;
 652 }
 653 
 654 //---------------------------mach_bottom_type----------------------------------
 655 // Utility function for use by ADLC.  Implements bottom_type for matched AddP.
 656 const Type *AddPNode::mach_bottom_type( const MachNode* n) {
 657   Node* base = n->in(Base);
 658   const Type *t = base->bottom_type();
 659   if ( t == Type::TOP ) {
 660     // an untyped pointer
 661     return TypeRawPtr::BOTTOM;
 662   }
 663   const TypePtr* tp = t->isa_oopptr();
 664   if ( tp == NULL )  return t;
 665   if ( tp->_offset == TypePtr::OffsetBot )  return tp;
 666 
 667   // We must carefully add up the various offsets...
 668   intptr_t offset = 0;
 669   const TypePtr* tptr = NULL;
 670 
 671   uint numopnds = n->num_opnds();
 672   uint index = n->oper_input_base();
 673   for ( uint i = 1; i < numopnds; i++ ) {
 674     MachOper *opnd = n->_opnds[i];
 675     // Check for any interesting operand info.
 676     // In particular, check for both memory and non-memory operands.
 677     // %%%%% Clean this up: use xadd_offset
 678     intptr_t con = opnd->constant();
 679     if ( con == TypePtr::OffsetBot )  goto bottom_out;
 680     offset += con;
 681     con = opnd->constant_disp();
 682     if ( con == TypePtr::OffsetBot )  goto bottom_out;
 683     offset += con;
 684     if( opnd->scale() != 0 ) goto bottom_out;
 685 
 686     // Check each operand input edge.  Find the 1 allowed pointer
 687     // edge.  Other edges must be index edges; track exact constant
 688     // inputs and otherwise assume the worst.
 689     for ( uint j = opnd->num_edges(); j > 0; j-- ) {
 690       Node* edge = n->in(index++);
 691       const Type*    et  = edge->bottom_type();
 692       const TypeX*   eti = et->isa_intptr_t();
 693       if ( eti == NULL ) {
 694         // there must be one pointer among the operands
 695         guarantee(tptr == NULL, "must be only one pointer operand");
 696         tptr = et->isa_oopptr();
 697         guarantee(tptr != NULL, "non-int operand must be pointer");
 698         if (tptr->higher_equal(tp->add_offset(tptr->offset())))
 699           tp = tptr; // Set more precise type for bailout
 700         continue;
 701       }
 702       if ( eti->_hi != eti->_lo )  goto bottom_out;
 703       offset += eti->_lo;
 704     }
 705   }
 706   guarantee(tptr != NULL, "must be exactly one pointer operand");
 707   return tptr->add_offset(offset);
 708 
 709  bottom_out:
 710   return tp->add_offset(TypePtr::OffsetBot);
 711 }
 712 
 713 //=============================================================================
 714 //------------------------------Identity---------------------------------------
 715 Node *OrINode::Identity( PhaseTransform *phase ) {
 716   // x | x => x
 717   if (phase->eqv(in(1), in(2))) {
 718     return in(1);
 719   }
 720 
 721   return AddNode::Identity(phase);
 722 }
 723 
 724 //------------------------------add_ring---------------------------------------
 725 // Supplied function returns the sum of the inputs IN THE CURRENT RING.  For
 726 // the logical operations the ring's ADD is really a logical OR function.
 727 // This also type-checks the inputs for sanity.  Guaranteed never to
 728 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 729 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
 730   const TypeInt *r0 = t0->is_int(); // Handy access
 731   const TypeInt *r1 = t1->is_int();
 732 
 733   // If both args are bool, can figure out better types
 734   if ( r0 == TypeInt::BOOL ) {
 735     if ( r1 == TypeInt::ONE) {
 736       return TypeInt::ONE;
 737     } else if ( r1 == TypeInt::BOOL ) {
 738       return TypeInt::BOOL;
 739     }
 740   } else if ( r0 == TypeInt::ONE ) {
 741     if ( r1 == TypeInt::BOOL ) {
 742       return TypeInt::ONE;
 743     }
 744   }
 745 
 746   // If either input is not a constant, just return all integers.
 747   if( !r0->is_con() || !r1->is_con() )
 748     return TypeInt::INT;        // Any integer, but still no symbols.
 749 
 750   // Otherwise just OR them bits.
 751   return TypeInt::make( r0->get_con() | r1->get_con() );
 752 }
 753 
 754 //=============================================================================
 755 //------------------------------Identity---------------------------------------
 756 Node *OrLNode::Identity( PhaseTransform *phase ) {
 757   // x | x => x
 758   if (phase->eqv(in(1), in(2))) {
 759     return in(1);
 760   }
 761 
 762   return AddNode::Identity(phase);
 763 }
 764 
 765 //------------------------------add_ring---------------------------------------
 766 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
 767   const TypeLong *r0 = t0->is_long(); // Handy access
 768   const TypeLong *r1 = t1->is_long();
 769 
 770   // If either input is not a constant, just return all integers.
 771   if( !r0->is_con() || !r1->is_con() )
 772     return TypeLong::LONG;      // Any integer, but still no symbols.
 773 
 774   // Otherwise just OR them bits.
 775   return TypeLong::make( r0->get_con() | r1->get_con() );
 776 }
 777 
 778 //=============================================================================
 779 //------------------------------add_ring---------------------------------------
 780 // Supplied function returns the sum of the inputs IN THE CURRENT RING.  For
 781 // the logical operations the ring's ADD is really a logical OR function.
 782 // This also type-checks the inputs for sanity.  Guaranteed never to
 783 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
 784 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
 785   const TypeInt *r0 = t0->is_int(); // Handy access
 786   const TypeInt *r1 = t1->is_int();
 787 
 788   // Complementing a boolean?
 789   if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
 790                                || r1 == TypeInt::BOOL))
 791     return TypeInt::BOOL;
 792 
 793   if( !r0->is_con() || !r1->is_con() ) // Not constants
 794     return TypeInt::INT;        // Any integer, but still no symbols.
 795 
 796   // Otherwise just XOR them bits.
 797   return TypeInt::make( r0->get_con() ^ r1->get_con() );
 798 }
 799 
 800 //=============================================================================
 801 //------------------------------add_ring---------------------------------------
 802 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
 803   const TypeLong *r0 = t0->is_long(); // Handy access
 804   const TypeLong *r1 = t1->is_long();
 805 
 806   // If either input is not a constant, just return all integers.
 807   if( !r0->is_con() || !r1->is_con() )
 808     return TypeLong::LONG;      // Any integer, but still no symbols.
 809 
 810   // Otherwise just OR them bits.
 811   return TypeLong::make( r0->get_con() ^ r1->get_con() );
 812 }
 813 
 814 //=============================================================================
 815 //------------------------------add_ring---------------------------------------
 816 // Supplied function returns the sum of the inputs.
 817 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
 818   const TypeInt *r0 = t0->is_int(); // Handy access
 819   const TypeInt *r1 = t1->is_int();
 820 
 821   // Otherwise just MAX them bits.
 822   return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
 823 }
 824 
 825 //=============================================================================
 826 //------------------------------Idealize---------------------------------------
 827 // MINs show up in range-check loop limit calculations.  Look for
 828 // "MIN2(x+c0,MIN2(y,x+c1))".  Pick the smaller constant: "MIN2(x+c0,y)"
 829 Node *MinINode::Ideal(PhaseGVN *phase, bool can_reshape) {
 830   Node *progress = NULL;
 831   // Force a right-spline graph
 832   Node *l = in(1);
 833   Node *r = in(2);
 834   // Transform  MinI1( MinI2(a,b), c)  into  MinI1( a, MinI2(b,c) )
 835   // to force a right-spline graph for the rest of MinINode::Ideal().
 836   if( l->Opcode() == Op_MinI ) {
 837     assert( l != l->in(1), "dead loop in MinINode::Ideal" );
 838     r = phase->transform(new (phase->C, 3) MinINode(l->in(2),r));
 839     l = l->in(1);
 840     set_req(1, l);
 841     set_req(2, r);
 842     return this;
 843   }
 844 
 845   // Get left input & constant
 846   Node *x = l;
 847   int x_off = 0;
 848   if( x->Opcode() == Op_AddI && // Check for "x+c0" and collect constant
 849       x->in(2)->is_Con() ) {
 850     const Type *t = x->in(2)->bottom_type();
 851     if( t == Type::TOP ) return NULL;  // No progress
 852     x_off = t->is_int()->get_con();
 853     x = x->in(1);
 854   }
 855 
 856   // Scan a right-spline-tree for MINs
 857   Node *y = r;
 858   int y_off = 0;
 859   // Check final part of MIN tree
 860   if( y->Opcode() == Op_AddI && // Check for "y+c1" and collect constant
 861       y->in(2)->is_Con() ) {
 862     const Type *t = y->in(2)->bottom_type();
 863     if( t == Type::TOP ) return NULL;  // No progress
 864     y_off = t->is_int()->get_con();
 865     y = y->in(1);
 866   }
 867   if( x->_idx > y->_idx && r->Opcode() != Op_MinI ) {
 868     swap_edges(1, 2);
 869     return this;
 870   }
 871 
 872 
 873   if( r->Opcode() == Op_MinI ) {
 874     assert( r != r->in(2), "dead loop in MinINode::Ideal" );
 875     y = r->in(1);
 876     // Check final part of MIN tree
 877     if( y->Opcode() == Op_AddI &&// Check for "y+c1" and collect constant
 878         y->in(2)->is_Con() ) {
 879       const Type *t = y->in(2)->bottom_type();
 880       if( t == Type::TOP ) return NULL;  // No progress
 881       y_off = t->is_int()->get_con();
 882       y = y->in(1);
 883     }
 884 
 885     if( x->_idx > y->_idx )
 886       return new (phase->C, 3) MinINode(r->in(1),phase->transform(new (phase->C, 3) MinINode(l,r->in(2))));
 887 
 888     // See if covers: MIN2(x+c0,MIN2(y+c1,z))
 889     if( !phase->eqv(x,y) ) return NULL;
 890     // If (y == x) transform MIN2(x+c0, MIN2(x+c1,z)) into
 891     // MIN2(x+c0 or x+c1 which less, z).
 892     return new (phase->C, 3) MinINode(phase->transform(new (phase->C, 3) AddINode(x,phase->intcon(MIN2(x_off,y_off)))),r->in(2));
 893   } else {
 894     // See if covers: MIN2(x+c0,y+c1)
 895     if( !phase->eqv(x,y) ) return NULL;
 896     // If (y == x) transform MIN2(x+c0,x+c1) into x+c0 or x+c1 which less.
 897     return new (phase->C, 3) AddINode(x,phase->intcon(MIN2(x_off,y_off)));
 898   }
 899 
 900 }
 901 
 902 //------------------------------add_ring---------------------------------------
 903 // Supplied function returns the sum of the inputs.
 904 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
 905   const TypeInt *r0 = t0->is_int(); // Handy access
 906   const TypeInt *r1 = t1->is_int();
 907 
 908   // Otherwise just MIN them bits.
 909   return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
 910 }