1 /*
   2  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "memory/allocation.inline.hpp"
  28 #include "opto/addnode.hpp"
  29 #include "opto/callnode.hpp"
  30 #include "opto/cfgnode.hpp"
  31 #include "opto/connode.hpp"
  32 #include "opto/loopnode.hpp"
  33 #include "opto/matcher.hpp"
  34 #include "opto/mulnode.hpp"
  35 #include "opto/opcodes.hpp"
  36 #include "opto/phaseX.hpp"
  37 #include "opto/subnode.hpp"
  38 #include "runtime/sharedRuntime.hpp"
  39 
  40 // Portions of code courtesy of Clifford Click
  41 
  42 // Optimization - Graph Style
  43 
  44 #include "math.h"
  45 
  46 //=============================================================================
  47 //------------------------------Identity---------------------------------------
  48 // If right input is a constant 0, return the left input.
  49 Node *SubNode::Identity( PhaseTransform *phase ) {
  50   assert(in(1) != this, "Must already have called Value");
  51   assert(in(2) != this, "Must already have called Value");
  52 
  53   // Remove double negation
  54   const Type *zero = add_id();
  55   if( phase->type( in(1) )->higher_equal( zero ) &&
  56       in(2)->Opcode() == Opcode() &&
  57       phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
  58     return in(2)->in(2);
  59   }
  60 
  61   // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
  62   if( in(1)->Opcode() == Op_AddI ) {
  63     if( phase->eqv(in(1)->in(2),in(2)) )
  64       return in(1)->in(1);
  65     if (phase->eqv(in(1)->in(1),in(2)))
  66       return in(1)->in(2);
  67 
  68     // Also catch: "(X + Opaque2(Y)) - Y".  In this case, 'Y' is a loop-varying
  69     // trip counter and X is likely to be loop-invariant (that's how O2 Nodes
  70     // are originally used, although the optimizer sometimes jiggers things).
  71     // This folding through an O2 removes a loop-exit use of a loop-varying
  72     // value and generally lowers register pressure in and around the loop.
  73     if( in(1)->in(2)->Opcode() == Op_Opaque2 &&
  74         phase->eqv(in(1)->in(2)->in(1),in(2)) )
  75       return in(1)->in(1);
  76   }
  77 
  78   return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
  79 }
  80 
  81 //------------------------------Value------------------------------------------
  82 // A subtract node differences it's two inputs.
  83 const Type *SubNode::Value( PhaseTransform *phase ) const {
  84   const Node* in1 = in(1);
  85   const Node* in2 = in(2);
  86   // Either input is TOP ==> the result is TOP
  87   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
  88   if( t1 == Type::TOP ) return Type::TOP;
  89   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
  90   if( t2 == Type::TOP ) return Type::TOP;
  91 
  92   // Not correct for SubFnode and AddFNode (must check for infinity)
  93   // Equal?  Subtract is zero
  94   if (in1->eqv_uncast(in2))  return add_id();
  95 
  96   // Either input is BOTTOM ==> the result is the local BOTTOM
  97   if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
  98     return bottom_type();
  99 
 100   return sub(t1,t2);            // Local flavor of type subtraction
 101 
 102 }
 103 
 104 //=============================================================================
 105 
 106 //------------------------------Helper function--------------------------------
 107 static bool ok_to_convert(Node* inc, Node* iv) {
 108     // Do not collapse (x+c0)-y if "+" is a loop increment, because the
 109     // "-" is loop invariant and collapsing extends the live-range of "x"
 110     // to overlap with the "+", forcing another register to be used in
 111     // the loop.
 112     // This test will be clearer with '&&' (apply DeMorgan's rule)
 113     // but I like the early cutouts that happen here.
 114     const PhiNode *phi;
 115     if( ( !inc->in(1)->is_Phi() ||
 116           !(phi=inc->in(1)->as_Phi()) ||
 117           phi->is_copy() ||
 118           !phi->region()->is_CountedLoop() ||
 119           inc != phi->region()->as_CountedLoop()->incr() )
 120        &&
 121         // Do not collapse (x+c0)-iv if "iv" is a loop induction variable,
 122         // because "x" maybe invariant.
 123         ( !iv->is_loop_iv() )
 124       ) {
 125       return true;
 126     } else {
 127       return false;
 128     }
 129 }
 130 //------------------------------Ideal------------------------------------------
 131 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
 132   Node *in1 = in(1);
 133   Node *in2 = in(2);
 134   uint op1 = in1->Opcode();
 135   uint op2 = in2->Opcode();
 136 
 137 #ifdef ASSERT
 138   // Check for dead loop
 139   if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
 140       ( op1 == Op_AddI || op1 == Op_SubI ) &&
 141       ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
 142         phase->eqv( in1->in(1), in1  ) || phase->eqv( in1->in(2), in1 ) ) )
 143     assert(false, "dead loop in SubINode::Ideal");
 144 #endif
 145 
 146   const Type *t2 = phase->type( in2 );
 147   if( t2 == Type::TOP ) return NULL;
 148   // Convert "x-c0" into "x+ -c0".
 149   if( t2->base() == Type::Int ){        // Might be bottom or top...
 150     const TypeInt *i = t2->is_int();
 151     if( i->is_con() )
 152       return new (phase->C, 3) AddINode(in1, phase->intcon(-i->get_con()));
 153   }
 154 
 155   // Convert "(x+c0) - y" into (x-y) + c0"
 156   // Do not collapse (x+c0)-y if "+" is a loop increment or
 157   // if "y" is a loop induction variable.
 158   if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
 159     const Type *tadd = phase->type( in1->in(2) );
 160     if( tadd->singleton() && tadd != Type::TOP ) {
 161       Node *sub2 = phase->transform( new (phase->C, 3) SubINode( in1->in(1), in2 ));
 162       return new (phase->C, 3) AddINode( sub2, in1->in(2) );
 163     }
 164   }
 165 
 166 
 167   // Convert "x - (y+c0)" into "(x-y) - c0"
 168   // Need the same check as in above optimization but reversed.
 169   if (op2 == Op_AddI && ok_to_convert(in2, in1)) {
 170     Node* in21 = in2->in(1);
 171     Node* in22 = in2->in(2);
 172     const TypeInt* tcon = phase->type(in22)->isa_int();
 173     if (tcon != NULL && tcon->is_con()) {
 174       Node* sub2 = phase->transform( new (phase->C, 3) SubINode(in1, in21) );
 175       Node* neg_c0 = phase->intcon(- tcon->get_con());
 176       return new (phase->C, 3) AddINode(sub2, neg_c0);
 177     }
 178   }
 179 
 180   const Type *t1 = phase->type( in1 );
 181   if( t1 == Type::TOP ) return NULL;
 182 
 183 #ifdef ASSERT
 184   // Check for dead loop
 185   if( ( op2 == Op_AddI || op2 == Op_SubI ) &&
 186       ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
 187         phase->eqv( in2->in(1), in2  ) || phase->eqv( in2->in(2), in2  ) ) )
 188     assert(false, "dead loop in SubINode::Ideal");
 189 #endif
 190 
 191   // Convert "x - (x+y)" into "-y"
 192   if( op2 == Op_AddI &&
 193       phase->eqv( in1, in2->in(1) ) )
 194     return new (phase->C, 3) SubINode( phase->intcon(0),in2->in(2));
 195   // Convert "(x-y) - x" into "-y"
 196   if( op1 == Op_SubI &&
 197       phase->eqv( in1->in(1), in2 ) )
 198     return new (phase->C, 3) SubINode( phase->intcon(0),in1->in(2));
 199   // Convert "x - (y+x)" into "-y"
 200   if( op2 == Op_AddI &&
 201       phase->eqv( in1, in2->in(2) ) )
 202     return new (phase->C, 3) SubINode( phase->intcon(0),in2->in(1));
 203 
 204   // Convert "0 - (x-y)" into "y-x"
 205   if( t1 == TypeInt::ZERO && op2 == Op_SubI )
 206     return new (phase->C, 3) SubINode( in2->in(2), in2->in(1) );
 207 
 208   // Convert "0 - (x+con)" into "-con-x"
 209   jint con;
 210   if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
 211       (con = in2->in(2)->find_int_con(0)) != 0 )
 212     return new (phase->C, 3) SubINode( phase->intcon(-con), in2->in(1) );
 213 
 214   // Convert "(X+A) - (X+B)" into "A - B"
 215   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
 216     return new (phase->C, 3) SubINode( in1->in(2), in2->in(2) );
 217 
 218   // Convert "(A+X) - (B+X)" into "A - B"
 219   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
 220     return new (phase->C, 3) SubINode( in1->in(1), in2->in(1) );
 221 
 222   // Convert "(A+X) - (X+B)" into "A - B"
 223   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
 224     return new (phase->C, 3) SubINode( in1->in(1), in2->in(2) );
 225 
 226   // Convert "(X+A) - (B+X)" into "A - B"
 227   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
 228     return new (phase->C, 3) SubINode( in1->in(2), in2->in(1) );
 229 
 230   // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
 231   // nicer to optimize than subtract.
 232   if( op2 == Op_SubI && in2->outcnt() == 1) {
 233     Node *add1 = phase->transform( new (phase->C, 3) AddINode( in1, in2->in(2) ) );
 234     return new (phase->C, 3) SubINode( add1, in2->in(1) );
 235   }
 236 
 237   return NULL;
 238 }
 239 
 240 //------------------------------sub--------------------------------------------
 241 // A subtract node differences it's two inputs.
 242 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
 243   const TypeInt *r0 = t1->is_int(); // Handy access
 244   const TypeInt *r1 = t2->is_int();
 245   int32 lo = r0->_lo - r1->_hi;
 246   int32 hi = r0->_hi - r1->_lo;
 247 
 248   // We next check for 32-bit overflow.
 249   // If that happens, we just assume all integers are possible.
 250   if( (((r0->_lo ^ r1->_hi) >= 0) ||    // lo ends have same signs OR
 251        ((r0->_lo ^      lo) >= 0)) &&   // lo results have same signs AND
 252       (((r0->_hi ^ r1->_lo) >= 0) ||    // hi ends have same signs OR
 253        ((r0->_hi ^      hi) >= 0)) )    // hi results have same signs
 254     return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
 255   else                          // Overflow; assume all integers
 256     return TypeInt::INT;
 257 }
 258 
 259 //=============================================================================
 260 //------------------------------Ideal------------------------------------------
 261 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 262   Node *in1 = in(1);
 263   Node *in2 = in(2);
 264   uint op1 = in1->Opcode();
 265   uint op2 = in2->Opcode();
 266 
 267 #ifdef ASSERT
 268   // Check for dead loop
 269   if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
 270       ( op1 == Op_AddL || op1 == Op_SubL ) &&
 271       ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
 272         phase->eqv( in1->in(1), in1  ) || phase->eqv( in1->in(2), in1  ) ) )
 273     assert(false, "dead loop in SubLNode::Ideal");
 274 #endif
 275 
 276   if( phase->type( in2 ) == Type::TOP ) return NULL;
 277   const TypeLong *i = phase->type( in2 )->isa_long();
 278   // Convert "x-c0" into "x+ -c0".
 279   if( i &&                      // Might be bottom or top...
 280       i->is_con() )
 281     return new (phase->C, 3) AddLNode(in1, phase->longcon(-i->get_con()));
 282 
 283   // Convert "(x+c0) - y" into (x-y) + c0"
 284   // Do not collapse (x+c0)-y if "+" is a loop increment or
 285   // if "y" is a loop induction variable.
 286   if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
 287     Node *in11 = in1->in(1);
 288     const Type *tadd = phase->type( in1->in(2) );
 289     if( tadd->singleton() && tadd != Type::TOP ) {
 290       Node *sub2 = phase->transform( new (phase->C, 3) SubLNode( in11, in2 ));
 291       return new (phase->C, 3) AddLNode( sub2, in1->in(2) );
 292     }
 293   }
 294 
 295   // Convert "x - (y+c0)" into "(x-y) - c0"
 296   // Need the same check as in above optimization but reversed.
 297   if (op2 == Op_AddL && ok_to_convert(in2, in1)) {
 298     Node* in21 = in2->in(1);
 299     Node* in22 = in2->in(2);
 300     const TypeLong* tcon = phase->type(in22)->isa_long();
 301     if (tcon != NULL && tcon->is_con()) {
 302       Node* sub2 = phase->transform( new (phase->C, 3) SubLNode(in1, in21) );
 303       Node* neg_c0 = phase->longcon(- tcon->get_con());
 304       return new (phase->C, 3) AddLNode(sub2, neg_c0);
 305     }
 306   }
 307 
 308   const Type *t1 = phase->type( in1 );
 309   if( t1 == Type::TOP ) return NULL;
 310 
 311 #ifdef ASSERT
 312   // Check for dead loop
 313   if( ( op2 == Op_AddL || op2 == Op_SubL ) &&
 314       ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
 315         phase->eqv( in2->in(1), in2  ) || phase->eqv( in2->in(2), in2  ) ) )
 316     assert(false, "dead loop in SubLNode::Ideal");
 317 #endif
 318 
 319   // Convert "x - (x+y)" into "-y"
 320   if( op2 == Op_AddL &&
 321       phase->eqv( in1, in2->in(1) ) )
 322     return new (phase->C, 3) SubLNode( phase->makecon(TypeLong::ZERO), in2->in(2));
 323   // Convert "x - (y+x)" into "-y"
 324   if( op2 == Op_AddL &&
 325       phase->eqv( in1, in2->in(2) ) )
 326     return new (phase->C, 3) SubLNode( phase->makecon(TypeLong::ZERO),in2->in(1));
 327 
 328   // Convert "0 - (x-y)" into "y-x"
 329   if( phase->type( in1 ) == TypeLong::ZERO && op2 == Op_SubL )
 330     return new (phase->C, 3) SubLNode( in2->in(2), in2->in(1) );
 331 
 332   // Convert "(X+A) - (X+B)" into "A - B"
 333   if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
 334     return new (phase->C, 3) SubLNode( in1->in(2), in2->in(2) );
 335 
 336   // Convert "(A+X) - (B+X)" into "A - B"
 337   if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
 338     return new (phase->C, 3) SubLNode( in1->in(1), in2->in(1) );
 339 
 340   // Convert "A-(B-C)" into (A+C)-B"
 341   if( op2 == Op_SubL && in2->outcnt() == 1) {
 342     Node *add1 = phase->transform( new (phase->C, 3) AddLNode( in1, in2->in(2) ) );
 343     return new (phase->C, 3) SubLNode( add1, in2->in(1) );
 344   }
 345 
 346   return NULL;
 347 }
 348 
 349 //------------------------------sub--------------------------------------------
 350 // A subtract node differences it's two inputs.
 351 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
 352   const TypeLong *r0 = t1->is_long(); // Handy access
 353   const TypeLong *r1 = t2->is_long();
 354   jlong lo = r0->_lo - r1->_hi;
 355   jlong hi = r0->_hi - r1->_lo;
 356 
 357   // We next check for 32-bit overflow.
 358   // If that happens, we just assume all integers are possible.
 359   if( (((r0->_lo ^ r1->_hi) >= 0) ||    // lo ends have same signs OR
 360        ((r0->_lo ^      lo) >= 0)) &&   // lo results have same signs AND
 361       (((r0->_hi ^ r1->_lo) >= 0) ||    // hi ends have same signs OR
 362        ((r0->_hi ^      hi) >= 0)) )    // hi results have same signs
 363     return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
 364   else                          // Overflow; assume all integers
 365     return TypeLong::LONG;
 366 }
 367 
 368 //=============================================================================
 369 //------------------------------Value------------------------------------------
 370 // A subtract node differences its two inputs.
 371 const Type *SubFPNode::Value( PhaseTransform *phase ) const {
 372   const Node* in1 = in(1);
 373   const Node* in2 = in(2);
 374   // Either input is TOP ==> the result is TOP
 375   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
 376   if( t1 == Type::TOP ) return Type::TOP;
 377   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
 378   if( t2 == Type::TOP ) return Type::TOP;
 379 
 380   // if both operands are infinity of same sign, the result is NaN; do
 381   // not replace with zero
 382   if( (t1->is_finite() && t2->is_finite()) ) {
 383     if( phase->eqv(in1, in2) ) return add_id();
 384   }
 385 
 386   // Either input is BOTTOM ==> the result is the local BOTTOM
 387   const Type *bot = bottom_type();
 388   if( (t1 == bot) || (t2 == bot) ||
 389       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
 390     return bot;
 391 
 392   return sub(t1,t2);            // Local flavor of type subtraction
 393 }
 394 
 395 
 396 //=============================================================================
 397 //------------------------------Ideal------------------------------------------
 398 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 399   const Type *t2 = phase->type( in(2) );
 400   // Convert "x-c0" into "x+ -c0".
 401   if( t2->base() == Type::FloatCon ) {  // Might be bottom or top...
 402     // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
 403   }
 404 
 405   // Not associative because of boundary conditions (infinity)
 406   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
 407     // Convert "x - (x+y)" into "-y"
 408     if( in(2)->is_Add() &&
 409         phase->eqv(in(1),in(2)->in(1) ) )
 410       return new (phase->C, 3) SubFNode( phase->makecon(TypeF::ZERO),in(2)->in(2));
 411   }
 412 
 413   // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
 414   // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
 415   //if( phase->type(in(1)) == TypeF::ZERO )
 416   //return new (phase->C, 2) NegFNode(in(2));
 417 
 418   return NULL;
 419 }
 420 
 421 //------------------------------sub--------------------------------------------
 422 // A subtract node differences its two inputs.
 423 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
 424   // no folding if one of operands is infinity or NaN, do not do constant folding
 425   if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
 426     return TypeF::make( t1->getf() - t2->getf() );
 427   }
 428   else if( g_isnan(t1->getf()) ) {
 429     return t1;
 430   }
 431   else if( g_isnan(t2->getf()) ) {
 432     return t2;
 433   }
 434   else {
 435     return Type::FLOAT;
 436   }
 437 }
 438 
 439 //=============================================================================
 440 //------------------------------Ideal------------------------------------------
 441 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
 442   const Type *t2 = phase->type( in(2) );
 443   // Convert "x-c0" into "x+ -c0".
 444   if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
 445     // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
 446   }
 447 
 448   // Not associative because of boundary conditions (infinity)
 449   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
 450     // Convert "x - (x+y)" into "-y"
 451     if( in(2)->is_Add() &&
 452         phase->eqv(in(1),in(2)->in(1) ) )
 453       return new (phase->C, 3) SubDNode( phase->makecon(TypeD::ZERO),in(2)->in(2));
 454   }
 455 
 456   // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
 457   // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
 458   //if( phase->type(in(1)) == TypeD::ZERO )
 459   //return new (phase->C, 2) NegDNode(in(2));
 460 
 461   return NULL;
 462 }
 463 
 464 //------------------------------sub--------------------------------------------
 465 // A subtract node differences its two inputs.
 466 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
 467   // no folding if one of operands is infinity or NaN, do not do constant folding
 468   if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
 469     return TypeD::make( t1->getd() - t2->getd() );
 470   }
 471   else if( g_isnan(t1->getd()) ) {
 472     return t1;
 473   }
 474   else if( g_isnan(t2->getd()) ) {
 475     return t2;
 476   }
 477   else {
 478     return Type::DOUBLE;
 479   }
 480 }
 481 
 482 //=============================================================================
 483 //------------------------------Idealize---------------------------------------
 484 // Unlike SubNodes, compare must still flatten return value to the
 485 // range -1, 0, 1.
 486 // And optimizations like those for (X + Y) - X fail if overflow happens.
 487 Node *CmpNode::Identity( PhaseTransform *phase ) {
 488   return this;
 489 }
 490 
 491 //=============================================================================
 492 //------------------------------cmp--------------------------------------------
 493 // Simplify a CmpI (compare 2 integers) node, based on local information.
 494 // If both inputs are constants, compare them.
 495 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
 496   const TypeInt *r0 = t1->is_int(); // Handy access
 497   const TypeInt *r1 = t2->is_int();
 498 
 499   if( r0->_hi < r1->_lo )       // Range is always low?
 500     return TypeInt::CC_LT;
 501   else if( r0->_lo > r1->_hi )  // Range is always high?
 502     return TypeInt::CC_GT;
 503 
 504   else if( r0->is_con() && r1->is_con() ) { // comparing constants?
 505     assert(r0->get_con() == r1->get_con(), "must be equal");
 506     return TypeInt::CC_EQ;      // Equal results.
 507   } else if( r0->_hi == r1->_lo ) // Range is never high?
 508     return TypeInt::CC_LE;
 509   else if( r0->_lo == r1->_hi ) // Range is never low?
 510     return TypeInt::CC_GE;
 511   return TypeInt::CC;           // else use worst case results
 512 }
 513 
 514 // Simplify a CmpU (compare 2 integers) node, based on local information.
 515 // If both inputs are constants, compare them.
 516 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
 517   assert(!t1->isa_ptr(), "obsolete usage of CmpU");
 518 
 519   // comparing two unsigned ints
 520   const TypeInt *r0 = t1->is_int();   // Handy access
 521   const TypeInt *r1 = t2->is_int();
 522 
 523   // Current installed version
 524   // Compare ranges for non-overlap
 525   juint lo0 = r0->_lo;
 526   juint hi0 = r0->_hi;
 527   juint lo1 = r1->_lo;
 528   juint hi1 = r1->_hi;
 529 
 530   // If either one has both negative and positive values,
 531   // it therefore contains both 0 and -1, and since [0..-1] is the
 532   // full unsigned range, the type must act as an unsigned bottom.
 533   bool bot0 = ((jint)(lo0 ^ hi0) < 0);
 534   bool bot1 = ((jint)(lo1 ^ hi1) < 0);
 535 
 536   if (bot0 || bot1) {
 537     // All unsigned values are LE -1 and GE 0.
 538     if (lo0 == 0 && hi0 == 0) {
 539       return TypeInt::CC_LE;            //   0 <= bot
 540     } else if (lo1 == 0 && hi1 == 0) {
 541       return TypeInt::CC_GE;            // bot >= 0
 542     }
 543   } else {
 544     // We can use ranges of the form [lo..hi] if signs are the same.
 545     assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
 546     // results are reversed, '-' > '+' for unsigned compare
 547     if (hi0 < lo1) {
 548       return TypeInt::CC_LT;            // smaller
 549     } else if (lo0 > hi1) {
 550       return TypeInt::CC_GT;            // greater
 551     } else if (hi0 == lo1 && lo0 == hi1) {
 552       return TypeInt::CC_EQ;            // Equal results
 553     } else if (lo0 >= hi1) {
 554       return TypeInt::CC_GE;
 555     } else if (hi0 <= lo1) {
 556       // Check for special case in Hashtable::get.  (See below.)
 557       if ((jint)lo0 >= 0 && (jint)lo1 >= 0 &&
 558           in(1)->Opcode() == Op_ModI &&
 559           in(1)->in(2) == in(2) )
 560         return TypeInt::CC_LT;
 561       return TypeInt::CC_LE;
 562     }
 563   }
 564   // Check for special case in Hashtable::get - the hash index is
 565   // mod'ed to the table size so the following range check is useless.
 566   // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
 567   // to be positive.
 568   // (This is a gross hack, since the sub method never
 569   // looks at the structure of the node in any other case.)
 570   if ((jint)lo0 >= 0 && (jint)lo1 >= 0 &&
 571       in(1)->Opcode() == Op_ModI &&
 572       in(1)->in(2)->uncast() == in(2)->uncast())
 573     return TypeInt::CC_LT;
 574   return TypeInt::CC;                   // else use worst case results
 575 }
 576 
 577 //------------------------------Idealize---------------------------------------
 578 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
 579   if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
 580     switch (in(1)->Opcode()) {
 581     case Op_CmpL3:              // Collapse a CmpL3/CmpI into a CmpL
 582       return new (phase->C, 3) CmpLNode(in(1)->in(1),in(1)->in(2));
 583     case Op_CmpF3:              // Collapse a CmpF3/CmpI into a CmpF
 584       return new (phase->C, 3) CmpFNode(in(1)->in(1),in(1)->in(2));
 585     case Op_CmpD3:              // Collapse a CmpD3/CmpI into a CmpD
 586       return new (phase->C, 3) CmpDNode(in(1)->in(1),in(1)->in(2));
 587     //case Op_SubI:
 588       // If (x - y) cannot overflow, then ((x - y) <?> 0)
 589       // can be turned into (x <?> y).
 590       // This is handled (with more general cases) by Ideal_sub_algebra.
 591     }
 592   }
 593   return NULL;                  // No change
 594 }
 595 
 596 
 597 //=============================================================================
 598 // Simplify a CmpL (compare 2 longs ) node, based on local information.
 599 // If both inputs are constants, compare them.
 600 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
 601   const TypeLong *r0 = t1->is_long(); // Handy access
 602   const TypeLong *r1 = t2->is_long();
 603 
 604   if( r0->_hi < r1->_lo )       // Range is always low?
 605     return TypeInt::CC_LT;
 606   else if( r0->_lo > r1->_hi )  // Range is always high?
 607     return TypeInt::CC_GT;
 608 
 609   else if( r0->is_con() && r1->is_con() ) { // comparing constants?
 610     assert(r0->get_con() == r1->get_con(), "must be equal");
 611     return TypeInt::CC_EQ;      // Equal results.
 612   } else if( r0->_hi == r1->_lo ) // Range is never high?
 613     return TypeInt::CC_LE;
 614   else if( r0->_lo == r1->_hi ) // Range is never low?
 615     return TypeInt::CC_GE;
 616   return TypeInt::CC;           // else use worst case results
 617 }
 618 
 619 //=============================================================================
 620 //------------------------------sub--------------------------------------------
 621 // Simplify an CmpP (compare 2 pointers) node, based on local information.
 622 // If both inputs are constants, compare them.
 623 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
 624   const TypePtr *r0 = t1->is_ptr(); // Handy access
 625   const TypePtr *r1 = t2->is_ptr();
 626 
 627   // Undefined inputs makes for an undefined result
 628   if( TypePtr::above_centerline(r0->_ptr) ||
 629       TypePtr::above_centerline(r1->_ptr) )
 630     return Type::TOP;
 631 
 632   if (r0 == r1 && r0->singleton()) {
 633     // Equal pointer constants (klasses, nulls, etc.)
 634     return TypeInt::CC_EQ;
 635   }
 636 
 637   // See if it is 2 unrelated classes.
 638   const TypeOopPtr* p0 = r0->isa_oopptr();
 639   const TypeOopPtr* p1 = r1->isa_oopptr();
 640   if (p0 && p1) {
 641     Node* in1 = in(1)->uncast();
 642     Node* in2 = in(2)->uncast();
 643     AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
 644     AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
 645     if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
 646       return TypeInt::CC_GT;  // different pointers
 647     }
 648     ciKlass* klass0 = p0->klass();
 649     bool    xklass0 = p0->klass_is_exact();
 650     ciKlass* klass1 = p1->klass();
 651     bool    xklass1 = p1->klass_is_exact();
 652     int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
 653     if (klass0 && klass1 &&
 654         kps != 1 &&             // both or neither are klass pointers
 655         klass0->is_loaded() && !klass0->is_interface() && // do not trust interfaces
 656         klass1->is_loaded() && !klass1->is_interface() &&
 657         (!klass0->is_obj_array_klass() ||
 658          !klass0->as_obj_array_klass()->base_element_klass()->is_interface()) &&
 659         (!klass1->is_obj_array_klass() ||
 660          !klass1->as_obj_array_klass()->base_element_klass()->is_interface())) {
 661       bool unrelated_classes = false;
 662       // See if neither subclasses the other, or if the class on top
 663       // is precise.  In either of these cases, the compare is known
 664       // to fail if at least one of the pointers is provably not null.
 665       if (klass0->equals(klass1)   ||   // if types are unequal but klasses are
 666           !klass0->is_java_klass() ||   // types not part of Java language?
 667           !klass1->is_java_klass()) {   // types not part of Java language?
 668         // Do nothing; we know nothing for imprecise types
 669       } else if (klass0->is_subtype_of(klass1)) {
 670         // If klass1's type is PRECISE, then classes are unrelated.
 671         unrelated_classes = xklass1;
 672       } else if (klass1->is_subtype_of(klass0)) {
 673         // If klass0's type is PRECISE, then classes are unrelated.
 674         unrelated_classes = xklass0;
 675       } else {                  // Neither subtypes the other
 676         unrelated_classes = true;
 677       }
 678       if (unrelated_classes) {
 679         // The oops classes are known to be unrelated. If the joined PTRs of
 680         // two oops is not Null and not Bottom, then we are sure that one
 681         // of the two oops is non-null, and the comparison will always fail.
 682         TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
 683         if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
 684           return TypeInt::CC_GT;
 685         }
 686       }
 687     }
 688   }
 689 
 690   // Known constants can be compared exactly
 691   // Null can be distinguished from any NotNull pointers
 692   // Unknown inputs makes an unknown result
 693   if( r0->singleton() ) {
 694     intptr_t bits0 = r0->get_con();
 695     if( r1->singleton() )
 696       return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
 697     return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
 698   } else if( r1->singleton() ) {
 699     intptr_t bits1 = r1->get_con();
 700     return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
 701   } else
 702     return TypeInt::CC;
 703 }
 704 
 705 //------------------------------Ideal------------------------------------------
 706 // Check for the case of comparing an unknown klass loaded from the primary
 707 // super-type array vs a known klass with no subtypes.  This amounts to
 708 // checking to see an unknown klass subtypes a known klass with no subtypes;
 709 // this only happens on an exact match.  We can shorten this test by 1 load.
 710 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
 711   // Constant pointer on right?
 712   const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
 713   if (t2 == NULL || !t2->klass_is_exact())
 714     return NULL;
 715   // Get the constant klass we are comparing to.
 716   ciKlass* superklass = t2->klass();
 717 
 718   // Now check for LoadKlass on left.
 719   Node* ldk1 = in(1);
 720   if (ldk1->is_DecodeN()) {
 721     ldk1 = ldk1->in(1);
 722     if (ldk1->Opcode() != Op_LoadNKlass )
 723       return NULL;
 724   } else if (ldk1->Opcode() != Op_LoadKlass )
 725     return NULL;
 726   // Take apart the address of the LoadKlass:
 727   Node* adr1 = ldk1->in(MemNode::Address);
 728   intptr_t con2 = 0;
 729   Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
 730   if (ldk2 == NULL)
 731     return NULL;
 732   if (con2 == oopDesc::klass_offset_in_bytes()) {
 733     // We are inspecting an object's concrete class.
 734     // Short-circuit the check if the query is abstract.
 735     if (superklass->is_interface() ||
 736         superklass->is_abstract()) {
 737       // Make it come out always false:
 738       this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
 739       return this;
 740     }
 741   }
 742 
 743   // Check for a LoadKlass from primary supertype array.
 744   // Any nested loadklass from loadklass+con must be from the p.s. array.
 745   if (ldk2->is_DecodeN()) {
 746     // Keep ldk2 as DecodeN since it could be used in CmpP below.
 747     if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
 748       return NULL;
 749   } else if (ldk2->Opcode() != Op_LoadKlass)
 750     return NULL;
 751 
 752   // Verify that we understand the situation
 753   if (con2 != (intptr_t) superklass->super_check_offset())
 754     return NULL;                // Might be element-klass loading from array klass
 755 
 756   // If 'superklass' has no subklasses and is not an interface, then we are
 757   // assured that the only input which will pass the type check is
 758   // 'superklass' itself.
 759   //
 760   // We could be more liberal here, and allow the optimization on interfaces
 761   // which have a single implementor.  This would require us to increase the
 762   // expressiveness of the add_dependency() mechanism.
 763   // %%% Do this after we fix TypeOopPtr:  Deps are expressive enough now.
 764 
 765   // Object arrays must have their base element have no subtypes
 766   while (superklass->is_obj_array_klass()) {
 767     ciType* elem = superklass->as_obj_array_klass()->element_type();
 768     superklass = elem->as_klass();
 769   }
 770   if (superklass->is_instance_klass()) {
 771     ciInstanceKlass* ik = superklass->as_instance_klass();
 772     if (ik->has_subklass() || ik->is_interface())  return NULL;
 773     // Add a dependency if there is a chance that a subclass will be added later.
 774     if (!ik->is_final()) {
 775       phase->C->dependencies()->assert_leaf_type(ik);
 776     }
 777   }
 778 
 779   // Bypass the dependent load, and compare directly
 780   this->set_req(1,ldk2);
 781 
 782   return this;
 783 }
 784 
 785 //=============================================================================
 786 //------------------------------sub--------------------------------------------
 787 // Simplify an CmpN (compare 2 pointers) node, based on local information.
 788 // If both inputs are constants, compare them.
 789 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
 790   const TypePtr *r0 = t1->make_ptr(); // Handy access
 791   const TypePtr *r1 = t2->make_ptr();
 792 
 793   // Undefined inputs makes for an undefined result
 794   if( TypePtr::above_centerline(r0->_ptr) ||
 795       TypePtr::above_centerline(r1->_ptr) )
 796     return Type::TOP;
 797 
 798   if (r0 == r1 && r0->singleton()) {
 799     // Equal pointer constants (klasses, nulls, etc.)
 800     return TypeInt::CC_EQ;
 801   }
 802 
 803   // See if it is 2 unrelated classes.
 804   const TypeOopPtr* p0 = r0->isa_oopptr();
 805   const TypeOopPtr* p1 = r1->isa_oopptr();
 806   if (p0 && p1) {
 807     ciKlass* klass0 = p0->klass();
 808     bool    xklass0 = p0->klass_is_exact();
 809     ciKlass* klass1 = p1->klass();
 810     bool    xklass1 = p1->klass_is_exact();
 811     int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
 812     if (klass0 && klass1 &&
 813         kps != 1 &&             // both or neither are klass pointers
 814         !klass0->is_interface() && // do not trust interfaces
 815         !klass1->is_interface()) {
 816       bool unrelated_classes = false;
 817       // See if neither subclasses the other, or if the class on top
 818       // is precise.  In either of these cases, the compare is known
 819       // to fail if at least one of the pointers is provably not null.
 820       if (klass0->equals(klass1)   ||   // if types are unequal but klasses are
 821           !klass0->is_java_klass() ||   // types not part of Java language?
 822           !klass1->is_java_klass()) {   // types not part of Java language?
 823         // Do nothing; we know nothing for imprecise types
 824       } else if (klass0->is_subtype_of(klass1)) {
 825         // If klass1's type is PRECISE, then classes are unrelated.
 826         unrelated_classes = xklass1;
 827       } else if (klass1->is_subtype_of(klass0)) {
 828         // If klass0's type is PRECISE, then classes are unrelated.
 829         unrelated_classes = xklass0;
 830       } else {                  // Neither subtypes the other
 831         unrelated_classes = true;
 832       }
 833       if (unrelated_classes) {
 834         // The oops classes are known to be unrelated. If the joined PTRs of
 835         // two oops is not Null and not Bottom, then we are sure that one
 836         // of the two oops is non-null, and the comparison will always fail.
 837         TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
 838         if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
 839           return TypeInt::CC_GT;
 840         }
 841       }
 842     }
 843   }
 844 
 845   // Known constants can be compared exactly
 846   // Null can be distinguished from any NotNull pointers
 847   // Unknown inputs makes an unknown result
 848   if( r0->singleton() ) {
 849     intptr_t bits0 = r0->get_con();
 850     if( r1->singleton() )
 851       return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
 852     return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
 853   } else if( r1->singleton() ) {
 854     intptr_t bits1 = r1->get_con();
 855     return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
 856   } else
 857     return TypeInt::CC;
 858 }
 859 
 860 //------------------------------Ideal------------------------------------------
 861 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
 862   return NULL;
 863 }
 864 
 865 //=============================================================================
 866 //------------------------------Value------------------------------------------
 867 // Simplify an CmpF (compare 2 floats ) node, based on local information.
 868 // If both inputs are constants, compare them.
 869 const Type *CmpFNode::Value( PhaseTransform *phase ) const {
 870   const Node* in1 = in(1);
 871   const Node* in2 = in(2);
 872   // Either input is TOP ==> the result is TOP
 873   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
 874   if( t1 == Type::TOP ) return Type::TOP;
 875   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
 876   if( t2 == Type::TOP ) return Type::TOP;
 877 
 878   // Not constants?  Don't know squat - even if they are the same
 879   // value!  If they are NaN's they compare to LT instead of EQ.
 880   const TypeF *tf1 = t1->isa_float_constant();
 881   const TypeF *tf2 = t2->isa_float_constant();
 882   if( !tf1 || !tf2 ) return TypeInt::CC;
 883 
 884   // This implements the Java bytecode fcmpl, so unordered returns -1.
 885   if( tf1->is_nan() || tf2->is_nan() )
 886     return TypeInt::CC_LT;
 887 
 888   if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
 889   if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
 890   assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
 891   return TypeInt::CC_EQ;
 892 }
 893 
 894 
 895 //=============================================================================
 896 //------------------------------Value------------------------------------------
 897 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
 898 // If both inputs are constants, compare them.
 899 const Type *CmpDNode::Value( PhaseTransform *phase ) const {
 900   const Node* in1 = in(1);
 901   const Node* in2 = in(2);
 902   // Either input is TOP ==> the result is TOP
 903   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
 904   if( t1 == Type::TOP ) return Type::TOP;
 905   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
 906   if( t2 == Type::TOP ) return Type::TOP;
 907 
 908   // Not constants?  Don't know squat - even if they are the same
 909   // value!  If they are NaN's they compare to LT instead of EQ.
 910   const TypeD *td1 = t1->isa_double_constant();
 911   const TypeD *td2 = t2->isa_double_constant();
 912   if( !td1 || !td2 ) return TypeInt::CC;
 913 
 914   // This implements the Java bytecode dcmpl, so unordered returns -1.
 915   if( td1->is_nan() || td2->is_nan() )
 916     return TypeInt::CC_LT;
 917 
 918   if( td1->_d < td2->_d ) return TypeInt::CC_LT;
 919   if( td1->_d > td2->_d ) return TypeInt::CC_GT;
 920   assert( td1->_d == td2->_d, "do not understand FP behavior" );
 921   return TypeInt::CC_EQ;
 922 }
 923 
 924 //------------------------------Ideal------------------------------------------
 925 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
 926   // Check if we can change this to a CmpF and remove a ConvD2F operation.
 927   // Change  (CMPD (F2D (float)) (ConD value))
 928   // To      (CMPF      (float)  (ConF value))
 929   // Valid when 'value' does not lose precision as a float.
 930   // Benefits: eliminates conversion, does not require 24-bit mode
 931 
 932   // NaNs prevent commuting operands.  This transform works regardless of the
 933   // order of ConD and ConvF2D inputs by preserving the original order.
 934   int idx_f2d = 1;              // ConvF2D on left side?
 935   if( in(idx_f2d)->Opcode() != Op_ConvF2D )
 936     idx_f2d = 2;                // No, swap to check for reversed args
 937   int idx_con = 3-idx_f2d;      // Check for the constant on other input
 938 
 939   if( ConvertCmpD2CmpF &&
 940       in(idx_f2d)->Opcode() == Op_ConvF2D &&
 941       in(idx_con)->Opcode() == Op_ConD ) {
 942     const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
 943     double t2_value_as_double = t2->_d;
 944     float  t2_value_as_float  = (float)t2_value_as_double;
 945     if( t2_value_as_double == (double)t2_value_as_float ) {
 946       // Test value can be represented as a float
 947       // Eliminate the conversion to double and create new comparison
 948       Node *new_in1 = in(idx_f2d)->in(1);
 949       Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
 950       if( idx_f2d != 1 ) {      // Must flip args to match original order
 951         Node *tmp = new_in1;
 952         new_in1 = new_in2;
 953         new_in2 = tmp;
 954       }
 955       CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
 956         ? new (phase->C, 3) CmpF3Node( new_in1, new_in2 )
 957         : new (phase->C, 3) CmpFNode ( new_in1, new_in2 ) ;
 958       return new_cmp;           // Changed to CmpFNode
 959     }
 960     // Testing value required the precision of a double
 961   }
 962   return NULL;                  // No change
 963 }
 964 
 965 
 966 //=============================================================================
 967 //------------------------------cc2logical-------------------------------------
 968 // Convert a condition code type to a logical type
 969 const Type *BoolTest::cc2logical( const Type *CC ) const {
 970   if( CC == Type::TOP ) return Type::TOP;
 971   if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
 972   const TypeInt *ti = CC->is_int();
 973   if( ti->is_con() ) {          // Only 1 kind of condition codes set?
 974     // Match low order 2 bits
 975     int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
 976     if( _test & 4 ) tmp = 1-tmp;     // Optionally complement result
 977     return TypeInt::make(tmp);       // Boolean result
 978   }
 979 
 980   if( CC == TypeInt::CC_GE ) {
 981     if( _test == ge ) return TypeInt::ONE;
 982     if( _test == lt ) return TypeInt::ZERO;
 983   }
 984   if( CC == TypeInt::CC_LE ) {
 985     if( _test == le ) return TypeInt::ONE;
 986     if( _test == gt ) return TypeInt::ZERO;
 987   }
 988 
 989   return TypeInt::BOOL;
 990 }
 991 
 992 //------------------------------dump_spec-------------------------------------
 993 // Print special per-node info
 994 #ifndef PRODUCT
 995 void BoolTest::dump_on(outputStream *st) const {
 996   const char *msg[] = {"eq","gt","??","lt","ne","le","??","ge"};
 997   st->print(msg[_test]);
 998 }
 999 #endif
1000 
1001 //=============================================================================
1002 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
1003 uint BoolNode::size_of() const { return sizeof(BoolNode); }
1004 
1005 //------------------------------operator==-------------------------------------
1006 uint BoolNode::cmp( const Node &n ) const {
1007   const BoolNode *b = (const BoolNode *)&n; // Cast up
1008   return (_test._test == b->_test._test);
1009 }
1010 
1011 //------------------------------clone_cmp--------------------------------------
1012 // Clone a compare/bool tree
1013 static Node *clone_cmp( Node *cmp, Node *cmp1, Node *cmp2, PhaseGVN *gvn, BoolTest::mask test ) {
1014   Node *ncmp = cmp->clone();
1015   ncmp->set_req(1,cmp1);
1016   ncmp->set_req(2,cmp2);
1017   ncmp = gvn->transform( ncmp );
1018   return new (gvn->C, 2) BoolNode( ncmp, test );
1019 }
1020 
1021 //-------------------------------make_predicate--------------------------------
1022 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
1023   if (test_value->is_Con())   return test_value;
1024   if (test_value->is_Bool())  return test_value;
1025   Compile* C = phase->C;
1026   if (test_value->is_CMove() &&
1027       test_value->in(CMoveNode::Condition)->is_Bool()) {
1028     BoolNode*   bol   = test_value->in(CMoveNode::Condition)->as_Bool();
1029     const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
1030     const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
1031     if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
1032       return bol;
1033     } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
1034       return phase->transform( bol->negate(phase) );
1035     }
1036     // Else fall through.  The CMove gets in the way of the test.
1037     // It should be the case that make_predicate(bol->as_int_value()) == bol.
1038   }
1039   Node* cmp = new (C, 3) CmpINode(test_value, phase->intcon(0));
1040   cmp = phase->transform(cmp);
1041   Node* bol = new (C, 2) BoolNode(cmp, BoolTest::ne);
1042   return phase->transform(bol);
1043 }
1044 
1045 //--------------------------------as_int_value---------------------------------
1046 Node* BoolNode::as_int_value(PhaseGVN* phase) {
1047   // Inverse to make_predicate.  The CMove probably boils down to a Conv2B.
1048   Node* cmov = CMoveNode::make(phase->C, NULL, this,
1049                                phase->intcon(0), phase->intcon(1),
1050                                TypeInt::BOOL);
1051   return phase->transform(cmov);
1052 }
1053 
1054 //----------------------------------negate-------------------------------------
1055 BoolNode* BoolNode::negate(PhaseGVN* phase) {
1056   Compile* C = phase->C;
1057   return new (C, 2) BoolNode(in(1), _test.negate());
1058 }
1059 
1060 
1061 //------------------------------Ideal------------------------------------------
1062 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1063   // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
1064   // This moves the constant to the right.  Helps value-numbering.
1065   Node *cmp = in(1);
1066   if( !cmp->is_Sub() ) return NULL;
1067   int cop = cmp->Opcode();
1068   if( cop == Op_FastLock || cop == Op_FastUnlock ) return NULL;
1069   Node *cmp1 = cmp->in(1);
1070   Node *cmp2 = cmp->in(2);
1071   if( !cmp1 ) return NULL;
1072 
1073   // Constant on left?
1074   Node *con = cmp1;
1075   uint op2 = cmp2->Opcode();
1076   // Move constants to the right of compare's to canonicalize.
1077   // Do not muck with Opaque1 nodes, as this indicates a loop
1078   // guard that cannot change shape.
1079   if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 &&
1080       // Because of NaN's, CmpD and CmpF are not commutative
1081       cop != Op_CmpD && cop != Op_CmpF &&
1082       // Protect against swapping inputs to a compare when it is used by a
1083       // counted loop exit, which requires maintaining the loop-limit as in(2)
1084       !is_counted_loop_exit_test() ) {
1085     // Ok, commute the constant to the right of the cmp node.
1086     // Clone the Node, getting a new Node of the same class
1087     cmp = cmp->clone();
1088     // Swap inputs to the clone
1089     cmp->swap_edges(1, 2);
1090     cmp = phase->transform( cmp );
1091     return new (phase->C, 2) BoolNode( cmp, _test.commute() );
1092   }
1093 
1094   // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
1095   // The XOR-1 is an idiom used to flip the sense of a bool.  We flip the
1096   // test instead.
1097   int cmp1_op = cmp1->Opcode();
1098   const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
1099   if (cmp2_type == NULL)  return NULL;
1100   Node* j_xor = cmp1;
1101   if( cmp2_type == TypeInt::ZERO &&
1102       cmp1_op == Op_XorI &&
1103       j_xor->in(1) != j_xor &&          // An xor of itself is dead
1104       phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
1105       phase->type( j_xor->in(2) ) == TypeInt::ONE &&
1106       (_test._test == BoolTest::eq ||
1107        _test._test == BoolTest::ne) ) {
1108     Node *ncmp = phase->transform(new (phase->C, 3) CmpINode(j_xor->in(1),cmp2));
1109     return new (phase->C, 2) BoolNode( ncmp, _test.negate() );
1110   }
1111 
1112   // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
1113   // This is a standard idiom for branching on a boolean value.
1114   Node *c2b = cmp1;
1115   if( cmp2_type == TypeInt::ZERO &&
1116       cmp1_op == Op_Conv2B &&
1117       (_test._test == BoolTest::eq ||
1118        _test._test == BoolTest::ne) ) {
1119     Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
1120        ? (Node*)new (phase->C, 3) CmpINode(c2b->in(1),cmp2)
1121        : (Node*)new (phase->C, 3) CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
1122     );
1123     return new (phase->C, 2) BoolNode( ncmp, _test._test );
1124   }
1125 
1126   // Comparing a SubI against a zero is equal to comparing the SubI
1127   // arguments directly.  This only works for eq and ne comparisons
1128   // due to possible integer overflow.
1129   if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
1130         (cop == Op_CmpI) &&
1131         (cmp1->Opcode() == Op_SubI) &&
1132         ( cmp2_type == TypeInt::ZERO ) ) {
1133     Node *ncmp = phase->transform( new (phase->C, 3) CmpINode(cmp1->in(1),cmp1->in(2)));
1134     return new (phase->C, 2) BoolNode( ncmp, _test._test );
1135   }
1136 
1137   // Change (-A vs 0) into (A vs 0) by commuting the test.  Disallow in the
1138   // most general case because negating 0x80000000 does nothing.  Needed for
1139   // the CmpF3/SubI/CmpI idiom.
1140   if( cop == Op_CmpI &&
1141       cmp1->Opcode() == Op_SubI &&
1142       cmp2_type == TypeInt::ZERO &&
1143       phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
1144       phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
1145     Node *ncmp = phase->transform( new (phase->C, 3) CmpINode(cmp1->in(2),cmp2));
1146     return new (phase->C, 2) BoolNode( ncmp, _test.commute() );
1147   }
1148 
1149   //  The transformation below is not valid for either signed or unsigned
1150   //  comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
1151   //  This transformation can be resurrected when we are able to
1152   //  make inferences about the range of values being subtracted from
1153   //  (or added to) relative to the wraparound point.
1154   //
1155   //    // Remove +/-1's if possible.
1156   //    // "X <= Y-1" becomes "X <  Y"
1157   //    // "X+1 <= Y" becomes "X <  Y"
1158   //    // "X <  Y+1" becomes "X <= Y"
1159   //    // "X-1 <  Y" becomes "X <= Y"
1160   //    // Do not this to compares off of the counted-loop-end.  These guys are
1161   //    // checking the trip counter and they want to use the post-incremented
1162   //    // counter.  If they use the PRE-incremented counter, then the counter has
1163   //    // to be incremented in a private block on a loop backedge.
1164   //    if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
1165   //      return NULL;
1166   //  #ifndef PRODUCT
1167   //    // Do not do this in a wash GVN pass during verification.
1168   //    // Gets triggered by too many simple optimizations to be bothered with
1169   //    // re-trying it again and again.
1170   //    if( !phase->allow_progress() ) return NULL;
1171   //  #endif
1172   //    // Not valid for unsigned compare because of corner cases in involving zero.
1173   //    // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
1174   //    // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
1175   //    // "0 <=u Y" is always true).
1176   //    if( cmp->Opcode() == Op_CmpU ) return NULL;
1177   //    int cmp2_op = cmp2->Opcode();
1178   //    if( _test._test == BoolTest::le ) {
1179   //      if( cmp1_op == Op_AddI &&
1180   //          phase->type( cmp1->in(2) ) == TypeInt::ONE )
1181   //        return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
1182   //      else if( cmp2_op == Op_AddI &&
1183   //         phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
1184   //        return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
1185   //    } else if( _test._test == BoolTest::lt ) {
1186   //      if( cmp1_op == Op_AddI &&
1187   //          phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
1188   //        return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
1189   //      else if( cmp2_op == Op_AddI &&
1190   //         phase->type( cmp2->in(2) ) == TypeInt::ONE )
1191   //        return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
1192   //    }
1193 
1194   return NULL;
1195 }
1196 
1197 //------------------------------Value------------------------------------------
1198 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
1199 // based on local information.   If the input is constant, do it.
1200 const Type *BoolNode::Value( PhaseTransform *phase ) const {
1201   return _test.cc2logical( phase->type( in(1) ) );
1202 }
1203 
1204 //------------------------------dump_spec--------------------------------------
1205 // Dump special per-node info
1206 #ifndef PRODUCT
1207 void BoolNode::dump_spec(outputStream *st) const {
1208   st->print("[");
1209   _test.dump_on(st);
1210   st->print("]");
1211 }
1212 #endif
1213 
1214 //------------------------------is_counted_loop_exit_test--------------------------------------
1215 // Returns true if node is used by a counted loop node.
1216 bool BoolNode::is_counted_loop_exit_test() {
1217   for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
1218     Node* use = fast_out(i);
1219     if (use->is_CountedLoopEnd()) {
1220       return true;
1221     }
1222   }
1223   return false;
1224 }
1225 
1226 //=============================================================================
1227 //------------------------------Value------------------------------------------
1228 // Compute sqrt
1229 const Type *SqrtDNode::Value( PhaseTransform *phase ) const {
1230   const Type *t1 = phase->type( in(1) );
1231   if( t1 == Type::TOP ) return Type::TOP;
1232   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1233   double d = t1->getd();
1234   if( d < 0.0 ) return Type::DOUBLE;
1235   return TypeD::make( sqrt( d ) );
1236 }
1237 
1238 //=============================================================================
1239 //------------------------------Value------------------------------------------
1240 // Compute cos
1241 const Type *CosDNode::Value( PhaseTransform *phase ) const {
1242   const Type *t1 = phase->type( in(1) );
1243   if( t1 == Type::TOP ) return Type::TOP;
1244   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1245   double d = t1->getd();
1246   return TypeD::make( StubRoutines::intrinsic_cos( d ) );
1247 }
1248 
1249 //=============================================================================
1250 //------------------------------Value------------------------------------------
1251 // Compute sin
1252 const Type *SinDNode::Value( PhaseTransform *phase ) const {
1253   const Type *t1 = phase->type( in(1) );
1254   if( t1 == Type::TOP ) return Type::TOP;
1255   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1256   double d = t1->getd();
1257   return TypeD::make( StubRoutines::intrinsic_sin( d ) );
1258 }
1259 
1260 //=============================================================================
1261 //------------------------------Value------------------------------------------
1262 // Compute tan
1263 const Type *TanDNode::Value( PhaseTransform *phase ) const {
1264   const Type *t1 = phase->type( in(1) );
1265   if( t1 == Type::TOP ) return Type::TOP;
1266   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1267   double d = t1->getd();
1268   return TypeD::make( StubRoutines::intrinsic_tan( d ) );
1269 }
1270 
1271 //=============================================================================
1272 //------------------------------Value------------------------------------------
1273 // Compute log
1274 const Type *LogDNode::Value( PhaseTransform *phase ) const {
1275   const Type *t1 = phase->type( in(1) );
1276   if( t1 == Type::TOP ) return Type::TOP;
1277   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1278   double d = t1->getd();
1279   return TypeD::make( StubRoutines::intrinsic_log( d ) );
1280 }
1281 
1282 //=============================================================================
1283 //------------------------------Value------------------------------------------
1284 // Compute log10
1285 const Type *Log10DNode::Value( PhaseTransform *phase ) const {
1286   const Type *t1 = phase->type( in(1) );
1287   if( t1 == Type::TOP ) return Type::TOP;
1288   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1289   double d = t1->getd();
1290   return TypeD::make( StubRoutines::intrinsic_log10( d ) );
1291 }
1292 
1293 //=============================================================================
1294 //------------------------------Value------------------------------------------
1295 // Compute exp
1296 const Type *ExpDNode::Value( PhaseTransform *phase ) const {
1297   const Type *t1 = phase->type( in(1) );
1298   if( t1 == Type::TOP ) return Type::TOP;
1299   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1300   double d = t1->getd();
1301   return TypeD::make( StubRoutines::intrinsic_exp( d ) );
1302 }
1303 
1304 
1305 //=============================================================================
1306 //------------------------------Value------------------------------------------
1307 // Compute pow
1308 const Type *PowDNode::Value( PhaseTransform *phase ) const {
1309   const Type *t1 = phase->type( in(1) );
1310   if( t1 == Type::TOP ) return Type::TOP;
1311   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
1312   const Type *t2 = phase->type( in(2) );
1313   if( t2 == Type::TOP ) return Type::TOP;
1314   if( t2->base() != Type::DoubleCon ) return Type::DOUBLE;
1315   double d1 = t1->getd();
1316   double d2 = t2->getd();
1317   if( d1 < 0.0 ) return Type::DOUBLE;
1318   if( d2 < 0.0 ) return Type::DOUBLE;
1319   return TypeD::make( StubRoutines::intrinsic_pow( d1, d2 ) );
1320 }