src/share/vm/opto/subnode.cpp

Fri, 16 May 2014 12:05:14 -0700

author
kvn
date
Fri, 16 May 2014 12:05:14 -0700
changeset 6679
968a17f18337
parent 6375
085b304a1cc5
child 6681
1555c0843770
permissions
-rw-r--r--

8042786: Proper fix for 8032566
Summary: Check for overflow cases in range checks and collapse it if we can.
Reviewed-by: jrose, iveresov

     1 /*
     2  * Copyright (c) 1997, 2013, 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  */
    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"
    40 // Portions of code courtesy of Clifford Click
    42 // Optimization - Graph Style
    44 #include "math.h"
    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");
    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   }
    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);
    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   }
    78   return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
    79 }
    81 //------------------------------Value------------------------------------------
    82 // A subtract node differences it's two inputs.
    83 const Type* SubNode::Value_common(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;
    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();
    96   // Either input is BOTTOM ==> the result is the local BOTTOM
    97   if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
    98     return bottom_type();
   100   return NULL;
   101 }
   103 const Type* SubNode::Value(PhaseTransform *phase) const {
   104   const Type* t = Value_common(phase);
   105   if (t != NULL) {
   106     return t;
   107   }
   108   const Type* t1 = phase->type(in(1));
   109   const Type* t2 = phase->type(in(2));
   110   return sub(t1,t2);            // Local flavor of type subtraction
   112 }
   114 //=============================================================================
   116 //------------------------------Helper function--------------------------------
   117 static bool ok_to_convert(Node* inc, Node* iv) {
   118     // Do not collapse (x+c0)-y if "+" is a loop increment, because the
   119     // "-" is loop invariant and collapsing extends the live-range of "x"
   120     // to overlap with the "+", forcing another register to be used in
   121     // the loop.
   122     // This test will be clearer with '&&' (apply DeMorgan's rule)
   123     // but I like the early cutouts that happen here.
   124     const PhiNode *phi;
   125     if( ( !inc->in(1)->is_Phi() ||
   126           !(phi=inc->in(1)->as_Phi()) ||
   127           phi->is_copy() ||
   128           !phi->region()->is_CountedLoop() ||
   129           inc != phi->region()->as_CountedLoop()->incr() )
   130        &&
   131         // Do not collapse (x+c0)-iv if "iv" is a loop induction variable,
   132         // because "x" maybe invariant.
   133         ( !iv->is_loop_iv() )
   134       ) {
   135       return true;
   136     } else {
   137       return false;
   138     }
   139 }
   140 //------------------------------Ideal------------------------------------------
   141 Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
   142   Node *in1 = in(1);
   143   Node *in2 = in(2);
   144   uint op1 = in1->Opcode();
   145   uint op2 = in2->Opcode();
   147 #ifdef ASSERT
   148   // Check for dead loop
   149   if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
   150       ( op1 == Op_AddI || op1 == Op_SubI ) &&
   151       ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
   152         phase->eqv( in1->in(1), in1  ) || phase->eqv( in1->in(2), in1 ) ) )
   153     assert(false, "dead loop in SubINode::Ideal");
   154 #endif
   156   const Type *t2 = phase->type( in2 );
   157   if( t2 == Type::TOP ) return NULL;
   158   // Convert "x-c0" into "x+ -c0".
   159   if( t2->base() == Type::Int ){        // Might be bottom or top...
   160     const TypeInt *i = t2->is_int();
   161     if( i->is_con() )
   162       return new (phase->C) AddINode(in1, phase->intcon(-i->get_con()));
   163   }
   165   // Convert "(x+c0) - y" into (x-y) + c0"
   166   // Do not collapse (x+c0)-y if "+" is a loop increment or
   167   // if "y" is a loop induction variable.
   168   if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
   169     const Type *tadd = phase->type( in1->in(2) );
   170     if( tadd->singleton() && tadd != Type::TOP ) {
   171       Node *sub2 = phase->transform( new (phase->C) SubINode( in1->in(1), in2 ));
   172       return new (phase->C) AddINode( sub2, in1->in(2) );
   173     }
   174   }
   177   // Convert "x - (y+c0)" into "(x-y) - c0"
   178   // Need the same check as in above optimization but reversed.
   179   if (op2 == Op_AddI && ok_to_convert(in2, in1)) {
   180     Node* in21 = in2->in(1);
   181     Node* in22 = in2->in(2);
   182     const TypeInt* tcon = phase->type(in22)->isa_int();
   183     if (tcon != NULL && tcon->is_con()) {
   184       Node* sub2 = phase->transform( new (phase->C) SubINode(in1, in21) );
   185       Node* neg_c0 = phase->intcon(- tcon->get_con());
   186       return new (phase->C) AddINode(sub2, neg_c0);
   187     }
   188   }
   190   const Type *t1 = phase->type( in1 );
   191   if( t1 == Type::TOP ) return NULL;
   193 #ifdef ASSERT
   194   // Check for dead loop
   195   if( ( op2 == Op_AddI || op2 == Op_SubI ) &&
   196       ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
   197         phase->eqv( in2->in(1), in2  ) || phase->eqv( in2->in(2), in2  ) ) )
   198     assert(false, "dead loop in SubINode::Ideal");
   199 #endif
   201   // Convert "x - (x+y)" into "-y"
   202   if( op2 == Op_AddI &&
   203       phase->eqv( in1, in2->in(1) ) )
   204     return new (phase->C) SubINode( phase->intcon(0),in2->in(2));
   205   // Convert "(x-y) - x" into "-y"
   206   if( op1 == Op_SubI &&
   207       phase->eqv( in1->in(1), in2 ) )
   208     return new (phase->C) SubINode( phase->intcon(0),in1->in(2));
   209   // Convert "x - (y+x)" into "-y"
   210   if( op2 == Op_AddI &&
   211       phase->eqv( in1, in2->in(2) ) )
   212     return new (phase->C) SubINode( phase->intcon(0),in2->in(1));
   214   // Convert "0 - (x-y)" into "y-x"
   215   if( t1 == TypeInt::ZERO && op2 == Op_SubI )
   216     return new (phase->C) SubINode( in2->in(2), in2->in(1) );
   218   // Convert "0 - (x+con)" into "-con-x"
   219   jint con;
   220   if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
   221       (con = in2->in(2)->find_int_con(0)) != 0 )
   222     return new (phase->C) SubINode( phase->intcon(-con), in2->in(1) );
   224   // Convert "(X+A) - (X+B)" into "A - B"
   225   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
   226     return new (phase->C) SubINode( in1->in(2), in2->in(2) );
   228   // Convert "(A+X) - (B+X)" into "A - B"
   229   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
   230     return new (phase->C) SubINode( in1->in(1), in2->in(1) );
   232   // Convert "(A+X) - (X+B)" into "A - B"
   233   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(1) )
   234     return new (phase->C) SubINode( in1->in(1), in2->in(2) );
   236   // Convert "(X+A) - (B+X)" into "A - B"
   237   if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(2) )
   238     return new (phase->C) SubINode( in1->in(2), in2->in(1) );
   240   // Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
   241   // nicer to optimize than subtract.
   242   if( op2 == Op_SubI && in2->outcnt() == 1) {
   243     Node *add1 = phase->transform( new (phase->C) AddINode( in1, in2->in(2) ) );
   244     return new (phase->C) SubINode( add1, in2->in(1) );
   245   }
   247   return NULL;
   248 }
   250 //------------------------------sub--------------------------------------------
   251 // A subtract node differences it's two inputs.
   252 const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
   253   const TypeInt *r0 = t1->is_int(); // Handy access
   254   const TypeInt *r1 = t2->is_int();
   255   int32 lo = r0->_lo - r1->_hi;
   256   int32 hi = r0->_hi - r1->_lo;
   258   // We next check for 32-bit overflow.
   259   // If that happens, we just assume all integers are possible.
   260   if( (((r0->_lo ^ r1->_hi) >= 0) ||    // lo ends have same signs OR
   261        ((r0->_lo ^      lo) >= 0)) &&   // lo results have same signs AND
   262       (((r0->_hi ^ r1->_lo) >= 0) ||    // hi ends have same signs OR
   263        ((r0->_hi ^      hi) >= 0)) )    // hi results have same signs
   264     return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
   265   else                          // Overflow; assume all integers
   266     return TypeInt::INT;
   267 }
   269 //=============================================================================
   270 //------------------------------Ideal------------------------------------------
   271 Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   272   Node *in1 = in(1);
   273   Node *in2 = in(2);
   274   uint op1 = in1->Opcode();
   275   uint op2 = in2->Opcode();
   277 #ifdef ASSERT
   278   // Check for dead loop
   279   if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
   280       ( op1 == Op_AddL || op1 == Op_SubL ) &&
   281       ( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
   282         phase->eqv( in1->in(1), in1  ) || phase->eqv( in1->in(2), in1  ) ) )
   283     assert(false, "dead loop in SubLNode::Ideal");
   284 #endif
   286   if( phase->type( in2 ) == Type::TOP ) return NULL;
   287   const TypeLong *i = phase->type( in2 )->isa_long();
   288   // Convert "x-c0" into "x+ -c0".
   289   if( i &&                      // Might be bottom or top...
   290       i->is_con() )
   291     return new (phase->C) AddLNode(in1, phase->longcon(-i->get_con()));
   293   // Convert "(x+c0) - y" into (x-y) + c0"
   294   // Do not collapse (x+c0)-y if "+" is a loop increment or
   295   // if "y" is a loop induction variable.
   296   if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
   297     Node *in11 = in1->in(1);
   298     const Type *tadd = phase->type( in1->in(2) );
   299     if( tadd->singleton() && tadd != Type::TOP ) {
   300       Node *sub2 = phase->transform( new (phase->C) SubLNode( in11, in2 ));
   301       return new (phase->C) AddLNode( sub2, in1->in(2) );
   302     }
   303   }
   305   // Convert "x - (y+c0)" into "(x-y) - c0"
   306   // Need the same check as in above optimization but reversed.
   307   if (op2 == Op_AddL && ok_to_convert(in2, in1)) {
   308     Node* in21 = in2->in(1);
   309     Node* in22 = in2->in(2);
   310     const TypeLong* tcon = phase->type(in22)->isa_long();
   311     if (tcon != NULL && tcon->is_con()) {
   312       Node* sub2 = phase->transform( new (phase->C) SubLNode(in1, in21) );
   313       Node* neg_c0 = phase->longcon(- tcon->get_con());
   314       return new (phase->C) AddLNode(sub2, neg_c0);
   315     }
   316   }
   318   const Type *t1 = phase->type( in1 );
   319   if( t1 == Type::TOP ) return NULL;
   321 #ifdef ASSERT
   322   // Check for dead loop
   323   if( ( op2 == Op_AddL || op2 == Op_SubL ) &&
   324       ( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
   325         phase->eqv( in2->in(1), in2  ) || phase->eqv( in2->in(2), in2  ) ) )
   326     assert(false, "dead loop in SubLNode::Ideal");
   327 #endif
   329   // Convert "x - (x+y)" into "-y"
   330   if( op2 == Op_AddL &&
   331       phase->eqv( in1, in2->in(1) ) )
   332     return new (phase->C) SubLNode( phase->makecon(TypeLong::ZERO), in2->in(2));
   333   // Convert "x - (y+x)" into "-y"
   334   if( op2 == Op_AddL &&
   335       phase->eqv( in1, in2->in(2) ) )
   336     return new (phase->C) SubLNode( phase->makecon(TypeLong::ZERO),in2->in(1));
   338   // Convert "0 - (x-y)" into "y-x"
   339   if( phase->type( in1 ) == TypeLong::ZERO && op2 == Op_SubL )
   340     return new (phase->C) SubLNode( in2->in(2), in2->in(1) );
   342   // Convert "(X+A) - (X+B)" into "A - B"
   343   if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
   344     return new (phase->C) SubLNode( in1->in(2), in2->in(2) );
   346   // Convert "(A+X) - (B+X)" into "A - B"
   347   if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
   348     return new (phase->C) SubLNode( in1->in(1), in2->in(1) );
   350   // Convert "A-(B-C)" into (A+C)-B"
   351   if( op2 == Op_SubL && in2->outcnt() == 1) {
   352     Node *add1 = phase->transform( new (phase->C) AddLNode( in1, in2->in(2) ) );
   353     return new (phase->C) SubLNode( add1, in2->in(1) );
   354   }
   356   return NULL;
   357 }
   359 //------------------------------sub--------------------------------------------
   360 // A subtract node differences it's two inputs.
   361 const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
   362   const TypeLong *r0 = t1->is_long(); // Handy access
   363   const TypeLong *r1 = t2->is_long();
   364   jlong lo = r0->_lo - r1->_hi;
   365   jlong hi = r0->_hi - r1->_lo;
   367   // We next check for 32-bit overflow.
   368   // If that happens, we just assume all integers are possible.
   369   if( (((r0->_lo ^ r1->_hi) >= 0) ||    // lo ends have same signs OR
   370        ((r0->_lo ^      lo) >= 0)) &&   // lo results have same signs AND
   371       (((r0->_hi ^ r1->_lo) >= 0) ||    // hi ends have same signs OR
   372        ((r0->_hi ^      hi) >= 0)) )    // hi results have same signs
   373     return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
   374   else                          // Overflow; assume all integers
   375     return TypeLong::LONG;
   376 }
   378 //=============================================================================
   379 //------------------------------Value------------------------------------------
   380 // A subtract node differences its two inputs.
   381 const Type *SubFPNode::Value( PhaseTransform *phase ) const {
   382   const Node* in1 = in(1);
   383   const Node* in2 = in(2);
   384   // Either input is TOP ==> the result is TOP
   385   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
   386   if( t1 == Type::TOP ) return Type::TOP;
   387   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
   388   if( t2 == Type::TOP ) return Type::TOP;
   390   // if both operands are infinity of same sign, the result is NaN; do
   391   // not replace with zero
   392   if( (t1->is_finite() && t2->is_finite()) ) {
   393     if( phase->eqv(in1, in2) ) return add_id();
   394   }
   396   // Either input is BOTTOM ==> the result is the local BOTTOM
   397   const Type *bot = bottom_type();
   398   if( (t1 == bot) || (t2 == bot) ||
   399       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   400     return bot;
   402   return sub(t1,t2);            // Local flavor of type subtraction
   403 }
   406 //=============================================================================
   407 //------------------------------Ideal------------------------------------------
   408 Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   409   const Type *t2 = phase->type( in(2) );
   410   // Convert "x-c0" into "x+ -c0".
   411   if( t2->base() == Type::FloatCon ) {  // Might be bottom or top...
   412     // return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
   413   }
   415   // Not associative because of boundary conditions (infinity)
   416   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
   417     // Convert "x - (x+y)" into "-y"
   418     if( in(2)->is_Add() &&
   419         phase->eqv(in(1),in(2)->in(1) ) )
   420       return new (phase->C) SubFNode( phase->makecon(TypeF::ZERO),in(2)->in(2));
   421   }
   423   // Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
   424   // 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
   425   //if( phase->type(in(1)) == TypeF::ZERO )
   426   //return new (phase->C, 2) NegFNode(in(2));
   428   return NULL;
   429 }
   431 //------------------------------sub--------------------------------------------
   432 // A subtract node differences its two inputs.
   433 const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
   434   // no folding if one of operands is infinity or NaN, do not do constant folding
   435   if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
   436     return TypeF::make( t1->getf() - t2->getf() );
   437   }
   438   else if( g_isnan(t1->getf()) ) {
   439     return t1;
   440   }
   441   else if( g_isnan(t2->getf()) ) {
   442     return t2;
   443   }
   444   else {
   445     return Type::FLOAT;
   446   }
   447 }
   449 //=============================================================================
   450 //------------------------------Ideal------------------------------------------
   451 Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
   452   const Type *t2 = phase->type( in(2) );
   453   // Convert "x-c0" into "x+ -c0".
   454   if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
   455     // return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
   456   }
   458   // Not associative because of boundary conditions (infinity)
   459   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
   460     // Convert "x - (x+y)" into "-y"
   461     if( in(2)->is_Add() &&
   462         phase->eqv(in(1),in(2)->in(1) ) )
   463       return new (phase->C) SubDNode( phase->makecon(TypeD::ZERO),in(2)->in(2));
   464   }
   466   // Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
   467   // 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
   468   //if( phase->type(in(1)) == TypeD::ZERO )
   469   //return new (phase->C, 2) NegDNode(in(2));
   471   return NULL;
   472 }
   474 //------------------------------sub--------------------------------------------
   475 // A subtract node differences its two inputs.
   476 const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
   477   // no folding if one of operands is infinity or NaN, do not do constant folding
   478   if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
   479     return TypeD::make( t1->getd() - t2->getd() );
   480   }
   481   else if( g_isnan(t1->getd()) ) {
   482     return t1;
   483   }
   484   else if( g_isnan(t2->getd()) ) {
   485     return t2;
   486   }
   487   else {
   488     return Type::DOUBLE;
   489   }
   490 }
   492 //=============================================================================
   493 //------------------------------Idealize---------------------------------------
   494 // Unlike SubNodes, compare must still flatten return value to the
   495 // range -1, 0, 1.
   496 // And optimizations like those for (X + Y) - X fail if overflow happens.
   497 Node *CmpNode::Identity( PhaseTransform *phase ) {
   498   return this;
   499 }
   501 //=============================================================================
   502 //------------------------------cmp--------------------------------------------
   503 // Simplify a CmpI (compare 2 integers) node, based on local information.
   504 // If both inputs are constants, compare them.
   505 const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
   506   const TypeInt *r0 = t1->is_int(); // Handy access
   507   const TypeInt *r1 = t2->is_int();
   509   if( r0->_hi < r1->_lo )       // Range is always low?
   510     return TypeInt::CC_LT;
   511   else if( r0->_lo > r1->_hi )  // Range is always high?
   512     return TypeInt::CC_GT;
   514   else if( r0->is_con() && r1->is_con() ) { // comparing constants?
   515     assert(r0->get_con() == r1->get_con(), "must be equal");
   516     return TypeInt::CC_EQ;      // Equal results.
   517   } else if( r0->_hi == r1->_lo ) // Range is never high?
   518     return TypeInt::CC_LE;
   519   else if( r0->_lo == r1->_hi ) // Range is never low?
   520     return TypeInt::CC_GE;
   521   return TypeInt::CC;           // else use worst case results
   522 }
   524 // Simplify a CmpU (compare 2 integers) node, based on local information.
   525 // If both inputs are constants, compare them.
   526 const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
   527   assert(!t1->isa_ptr(), "obsolete usage of CmpU");
   529   // comparing two unsigned ints
   530   const TypeInt *r0 = t1->is_int();   // Handy access
   531   const TypeInt *r1 = t2->is_int();
   533   // Current installed version
   534   // Compare ranges for non-overlap
   535   juint lo0 = r0->_lo;
   536   juint hi0 = r0->_hi;
   537   juint lo1 = r1->_lo;
   538   juint hi1 = r1->_hi;
   540   // If either one has both negative and positive values,
   541   // it therefore contains both 0 and -1, and since [0..-1] is the
   542   // full unsigned range, the type must act as an unsigned bottom.
   543   bool bot0 = ((jint)(lo0 ^ hi0) < 0);
   544   bool bot1 = ((jint)(lo1 ^ hi1) < 0);
   546   if (bot0 || bot1) {
   547     // All unsigned values are LE -1 and GE 0.
   548     if (lo0 == 0 && hi0 == 0) {
   549       return TypeInt::CC_LE;            //   0 <= bot
   550     } else if (lo1 == 0 && hi1 == 0) {
   551       return TypeInt::CC_GE;            // bot >= 0
   552     }
   553   } else {
   554     // We can use ranges of the form [lo..hi] if signs are the same.
   555     assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
   556     // results are reversed, '-' > '+' for unsigned compare
   557     if (hi0 < lo1) {
   558       return TypeInt::CC_LT;            // smaller
   559     } else if (lo0 > hi1) {
   560       return TypeInt::CC_GT;            // greater
   561     } else if (hi0 == lo1 && lo0 == hi1) {
   562       return TypeInt::CC_EQ;            // Equal results
   563     } else if (lo0 >= hi1) {
   564       return TypeInt::CC_GE;
   565     } else if (hi0 <= lo1) {
   566       // Check for special case in Hashtable::get.  (See below.)
   567       if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
   568         return TypeInt::CC_LT;
   569       return TypeInt::CC_LE;
   570     }
   571   }
   572   // Check for special case in Hashtable::get - the hash index is
   573   // mod'ed to the table size so the following range check is useless.
   574   // Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
   575   // to be positive.
   576   // (This is a gross hack, since the sub method never
   577   // looks at the structure of the node in any other case.)
   578   if ((jint)lo0 >= 0 && (jint)lo1 >= 0 && is_index_range_check())
   579     return TypeInt::CC_LT;
   580   return TypeInt::CC;                   // else use worst case results
   581 }
   583 const Type* CmpUNode::Value(PhaseTransform *phase) const {
   584   const Type* t = SubNode::Value_common(phase);
   585   if (t != NULL) {
   586     return t;
   587   }
   588   const Node* in1 = in(1);
   589   const Node* in2 = in(2);
   590   const Type* t1 = phase->type(in1);
   591   const Type* t2 = phase->type(in2);
   592   assert(t1->isa_int(), "CmpU has only Int type inputs");
   593   if (t2 == TypeInt::INT) { // Compare to bottom?
   594     return bottom_type();
   595   }
   596   uint in1_op = in1->Opcode();
   597   if (in1_op == Op_AddI || in1_op == Op_SubI) {
   598     // The problem rise when result of AddI(SubI) may overflow
   599     // signed integer value. Let say the input type is
   600     // [256, maxint] then +128 will create 2 ranges due to
   601     // overflow: [minint, minint+127] and [384, maxint].
   602     // But C2 type system keep only 1 type range and as result
   603     // it use general [minint, maxint] for this case which we
   604     // can't optimize.
   605     //
   606     // Make 2 separate type ranges based on types of AddI(SubI) inputs
   607     // and compare results of their compare. If results are the same
   608     // CmpU node can be optimized.
   609     const Node* in11 = in1->in(1);
   610     const Node* in12 = in1->in(2);
   611     const Type* t11 = (in11 == in1) ? Type::TOP : phase->type(in11);
   612     const Type* t12 = (in12 == in1) ? Type::TOP : phase->type(in12);
   613     // Skip cases when input types are top or bottom.
   614     if ((t11 != Type::TOP) && (t11 != TypeInt::INT) &&
   615         (t12 != Type::TOP) && (t12 != TypeInt::INT)) {
   616       const TypeInt *r0 = t11->is_int();
   617       const TypeInt *r1 = t12->is_int();
   618       jlong lo_r0 = r0->_lo;
   619       jlong hi_r0 = r0->_hi;
   620       jlong lo_r1 = r1->_lo;
   621       jlong hi_r1 = r1->_hi;
   622       if (in1_op == Op_SubI) {
   623         jlong tmp = hi_r1;
   624         hi_r1 = -lo_r1;
   625         lo_r1 = -tmp;
   626         // Note, for substructing [minint,x] type range
   627         // long arithmetic provides correct overflow answer.
   628         // The confusion come from the fact that in 32-bit
   629         // -minint == minint but in 64-bit -minint == maxint+1.
   630       }
   631       jlong lo_long = lo_r0 + lo_r1;
   632       jlong hi_long = hi_r0 + hi_r1;
   633       int lo_tr1 = min_jint;
   634       int hi_tr1 = (int)hi_long;
   635       int lo_tr2 = (int)lo_long;
   636       int hi_tr2 = max_jint;
   637       bool underflow = lo_long != (jlong)lo_tr2;
   638       bool overflow  = hi_long != (jlong)hi_tr1;
   639       // Use sub(t1, t2) when there is no overflow (one type range)
   640       // or when both overflow and underflow (too complex).
   641       if ((underflow != overflow) && (hi_tr1 < lo_tr2)) {
   642         // Overflow only on one boundary, compare 2 separate type ranges.
   643         int w = MAX2(r0->_widen, r1->_widen); // _widen does not matter here
   644         const TypeInt* tr1 = TypeInt::make(lo_tr1, hi_tr1, w);
   645         const TypeInt* tr2 = TypeInt::make(lo_tr2, hi_tr2, w);
   646         const Type* cmp1 = sub(tr1, t2);
   647         const Type* cmp2 = sub(tr2, t2);
   648         if (cmp1 == cmp2) {
   649           return cmp1; // Hit!
   650         }
   651       }
   652     }
   653   }
   655   return sub(t1, t2);            // Local flavor of type subtraction
   656 }
   658 bool CmpUNode::is_index_range_check() const {
   659   // Check for the "(X ModI Y) CmpU Y" shape
   660   return (in(1)->Opcode() == Op_ModI &&
   661           in(1)->in(2)->eqv_uncast(in(2)));
   662 }
   664 //------------------------------Idealize---------------------------------------
   665 Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
   666   if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
   667     switch (in(1)->Opcode()) {
   668     case Op_CmpL3:              // Collapse a CmpL3/CmpI into a CmpL
   669       return new (phase->C) CmpLNode(in(1)->in(1),in(1)->in(2));
   670     case Op_CmpF3:              // Collapse a CmpF3/CmpI into a CmpF
   671       return new (phase->C) CmpFNode(in(1)->in(1),in(1)->in(2));
   672     case Op_CmpD3:              // Collapse a CmpD3/CmpI into a CmpD
   673       return new (phase->C) CmpDNode(in(1)->in(1),in(1)->in(2));
   674     //case Op_SubI:
   675       // If (x - y) cannot overflow, then ((x - y) <?> 0)
   676       // can be turned into (x <?> y).
   677       // This is handled (with more general cases) by Ideal_sub_algebra.
   678     }
   679   }
   680   return NULL;                  // No change
   681 }
   684 //=============================================================================
   685 // Simplify a CmpL (compare 2 longs ) node, based on local information.
   686 // If both inputs are constants, compare them.
   687 const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
   688   const TypeLong *r0 = t1->is_long(); // Handy access
   689   const TypeLong *r1 = t2->is_long();
   691   if( r0->_hi < r1->_lo )       // Range is always low?
   692     return TypeInt::CC_LT;
   693   else if( r0->_lo > r1->_hi )  // Range is always high?
   694     return TypeInt::CC_GT;
   696   else if( r0->is_con() && r1->is_con() ) { // comparing constants?
   697     assert(r0->get_con() == r1->get_con(), "must be equal");
   698     return TypeInt::CC_EQ;      // Equal results.
   699   } else if( r0->_hi == r1->_lo ) // Range is never high?
   700     return TypeInt::CC_LE;
   701   else if( r0->_lo == r1->_hi ) // Range is never low?
   702     return TypeInt::CC_GE;
   703   return TypeInt::CC;           // else use worst case results
   704 }
   706 //=============================================================================
   707 //------------------------------sub--------------------------------------------
   708 // Simplify an CmpP (compare 2 pointers) node, based on local information.
   709 // If both inputs are constants, compare them.
   710 const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
   711   const TypePtr *r0 = t1->is_ptr(); // Handy access
   712   const TypePtr *r1 = t2->is_ptr();
   714   // Undefined inputs makes for an undefined result
   715   if( TypePtr::above_centerline(r0->_ptr) ||
   716       TypePtr::above_centerline(r1->_ptr) )
   717     return Type::TOP;
   719   if (r0 == r1 && r0->singleton()) {
   720     // Equal pointer constants (klasses, nulls, etc.)
   721     return TypeInt::CC_EQ;
   722   }
   724   // See if it is 2 unrelated classes.
   725   const TypeOopPtr* p0 = r0->isa_oopptr();
   726   const TypeOopPtr* p1 = r1->isa_oopptr();
   727   if (p0 && p1) {
   728     Node* in1 = in(1)->uncast();
   729     Node* in2 = in(2)->uncast();
   730     AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
   731     AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
   732     if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
   733       return TypeInt::CC_GT;  // different pointers
   734     }
   735     ciKlass* klass0 = p0->klass();
   736     bool    xklass0 = p0->klass_is_exact();
   737     ciKlass* klass1 = p1->klass();
   738     bool    xklass1 = p1->klass_is_exact();
   739     int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
   740     if (klass0 && klass1 &&
   741         kps != 1 &&             // both or neither are klass pointers
   742         klass0->is_loaded() && !klass0->is_interface() && // do not trust interfaces
   743         klass1->is_loaded() && !klass1->is_interface() &&
   744         (!klass0->is_obj_array_klass() ||
   745          !klass0->as_obj_array_klass()->base_element_klass()->is_interface()) &&
   746         (!klass1->is_obj_array_klass() ||
   747          !klass1->as_obj_array_klass()->base_element_klass()->is_interface())) {
   748       bool unrelated_classes = false;
   749       // See if neither subclasses the other, or if the class on top
   750       // is precise.  In either of these cases, the compare is known
   751       // to fail if at least one of the pointers is provably not null.
   752       if (klass0->equals(klass1)) {  // if types are unequal but klasses are equal
   753         // Do nothing; we know nothing for imprecise types
   754       } else if (klass0->is_subtype_of(klass1)) {
   755         // If klass1's type is PRECISE, then classes are unrelated.
   756         unrelated_classes = xklass1;
   757       } else if (klass1->is_subtype_of(klass0)) {
   758         // If klass0's type is PRECISE, then classes are unrelated.
   759         unrelated_classes = xklass0;
   760       } else {                  // Neither subtypes the other
   761         unrelated_classes = true;
   762       }
   763       if (unrelated_classes) {
   764         // The oops classes are known to be unrelated. If the joined PTRs of
   765         // two oops is not Null and not Bottom, then we are sure that one
   766         // of the two oops is non-null, and the comparison will always fail.
   767         TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
   768         if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
   769           return TypeInt::CC_GT;
   770         }
   771       }
   772     }
   773   }
   775   // Known constants can be compared exactly
   776   // Null can be distinguished from any NotNull pointers
   777   // Unknown inputs makes an unknown result
   778   if( r0->singleton() ) {
   779     intptr_t bits0 = r0->get_con();
   780     if( r1->singleton() )
   781       return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
   782     return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
   783   } else if( r1->singleton() ) {
   784     intptr_t bits1 = r1->get_con();
   785     return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
   786   } else
   787     return TypeInt::CC;
   788 }
   790 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
   791   // Return the klass node for
   792   //   LoadP(AddP(foo:Klass, #java_mirror))
   793   //   or NULL if not matching.
   794   if (n->Opcode() != Op_LoadP) return NULL;
   796   const TypeInstPtr* tp = phase->type(n)->isa_instptr();
   797   if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
   799   Node* adr = n->in(MemNode::Address);
   800   intptr_t off = 0;
   801   Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
   802   if (k == NULL)  return NULL;
   803   const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
   804   if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return NULL;
   806   // We've found the klass node of a Java mirror load.
   807   return k;
   808 }
   810 static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
   811   // for ConP(Foo.class) return ConP(Foo.klass)
   812   // otherwise return NULL
   813   if (!n->is_Con()) return NULL;
   815   const TypeInstPtr* tp = phase->type(n)->isa_instptr();
   816   if (!tp) return NULL;
   818   ciType* mirror_type = tp->java_mirror_type();
   819   // TypeInstPtr::java_mirror_type() returns non-NULL for compile-
   820   // time Class constants only.
   821   if (!mirror_type) return NULL;
   823   // x.getClass() == int.class can never be true (for all primitive types)
   824   // Return a ConP(NULL) node for this case.
   825   if (mirror_type->is_classless()) {
   826     return phase->makecon(TypePtr::NULL_PTR);
   827   }
   829   // return the ConP(Foo.klass)
   830   assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
   831   return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass()));
   832 }
   834 //------------------------------Ideal------------------------------------------
   835 // Normalize comparisons between Java mirror loads to compare the klass instead.
   836 //
   837 // Also check for the case of comparing an unknown klass loaded from the primary
   838 // super-type array vs a known klass with no subtypes.  This amounts to
   839 // checking to see an unknown klass subtypes a known klass with no subtypes;
   840 // this only happens on an exact match.  We can shorten this test by 1 load.
   841 Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
   842   // Normalize comparisons between Java mirrors into comparisons of the low-
   843   // level klass, where a dependent load could be shortened.
   844   //
   845   // The new pattern has a nice effect of matching the same pattern used in the
   846   // fast path of instanceof/checkcast/Class.isInstance(), which allows
   847   // redundant exact type check be optimized away by GVN.
   848   // For example, in
   849   //   if (x.getClass() == Foo.class) {
   850   //     Foo foo = (Foo) x;
   851   //     // ... use a ...
   852   //   }
   853   // a CmpPNode could be shared between if_acmpne and checkcast
   854   {
   855     Node* k1 = isa_java_mirror_load(phase, in(1));
   856     Node* k2 = isa_java_mirror_load(phase, in(2));
   857     Node* conk2 = isa_const_java_mirror(phase, in(2));
   859     if (k1 && (k2 || conk2)) {
   860       Node* lhs = k1;
   861       Node* rhs = (k2 != NULL) ? k2 : conk2;
   862       this->set_req(1, lhs);
   863       this->set_req(2, rhs);
   864       return this;
   865     }
   866   }
   868   // Constant pointer on right?
   869   const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
   870   if (t2 == NULL || !t2->klass_is_exact())
   871     return NULL;
   872   // Get the constant klass we are comparing to.
   873   ciKlass* superklass = t2->klass();
   875   // Now check for LoadKlass on left.
   876   Node* ldk1 = in(1);
   877   if (ldk1->is_DecodeNKlass()) {
   878     ldk1 = ldk1->in(1);
   879     if (ldk1->Opcode() != Op_LoadNKlass )
   880       return NULL;
   881   } else if (ldk1->Opcode() != Op_LoadKlass )
   882     return NULL;
   883   // Take apart the address of the LoadKlass:
   884   Node* adr1 = ldk1->in(MemNode::Address);
   885   intptr_t con2 = 0;
   886   Node* ldk2 = AddPNode::Ideal_base_and_offset(adr1, phase, con2);
   887   if (ldk2 == NULL)
   888     return NULL;
   889   if (con2 == oopDesc::klass_offset_in_bytes()) {
   890     // We are inspecting an object's concrete class.
   891     // Short-circuit the check if the query is abstract.
   892     if (superklass->is_interface() ||
   893         superklass->is_abstract()) {
   894       // Make it come out always false:
   895       this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
   896       return this;
   897     }
   898   }
   900   // Check for a LoadKlass from primary supertype array.
   901   // Any nested loadklass from loadklass+con must be from the p.s. array.
   902   if (ldk2->is_DecodeNKlass()) {
   903     // Keep ldk2 as DecodeN since it could be used in CmpP below.
   904     if (ldk2->in(1)->Opcode() != Op_LoadNKlass )
   905       return NULL;
   906   } else if (ldk2->Opcode() != Op_LoadKlass)
   907     return NULL;
   909   // Verify that we understand the situation
   910   if (con2 != (intptr_t) superklass->super_check_offset())
   911     return NULL;                // Might be element-klass loading from array klass
   913   // If 'superklass' has no subklasses and is not an interface, then we are
   914   // assured that the only input which will pass the type check is
   915   // 'superklass' itself.
   916   //
   917   // We could be more liberal here, and allow the optimization on interfaces
   918   // which have a single implementor.  This would require us to increase the
   919   // expressiveness of the add_dependency() mechanism.
   920   // %%% Do this after we fix TypeOopPtr:  Deps are expressive enough now.
   922   // Object arrays must have their base element have no subtypes
   923   while (superklass->is_obj_array_klass()) {
   924     ciType* elem = superklass->as_obj_array_klass()->element_type();
   925     superklass = elem->as_klass();
   926   }
   927   if (superklass->is_instance_klass()) {
   928     ciInstanceKlass* ik = superklass->as_instance_klass();
   929     if (ik->has_subklass() || ik->is_interface())  return NULL;
   930     // Add a dependency if there is a chance that a subclass will be added later.
   931     if (!ik->is_final()) {
   932       phase->C->dependencies()->assert_leaf_type(ik);
   933     }
   934   }
   936   // Bypass the dependent load, and compare directly
   937   this->set_req(1,ldk2);
   939   return this;
   940 }
   942 //=============================================================================
   943 //------------------------------sub--------------------------------------------
   944 // Simplify an CmpN (compare 2 pointers) node, based on local information.
   945 // If both inputs are constants, compare them.
   946 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
   947   const TypePtr *r0 = t1->make_ptr(); // Handy access
   948   const TypePtr *r1 = t2->make_ptr();
   950   // Undefined inputs makes for an undefined result
   951   if ((r0 == NULL) || (r1 == NULL) ||
   952       TypePtr::above_centerline(r0->_ptr) ||
   953       TypePtr::above_centerline(r1->_ptr)) {
   954     return Type::TOP;
   955   }
   956   if (r0 == r1 && r0->singleton()) {
   957     // Equal pointer constants (klasses, nulls, etc.)
   958     return TypeInt::CC_EQ;
   959   }
   961   // See if it is 2 unrelated classes.
   962   const TypeOopPtr* p0 = r0->isa_oopptr();
   963   const TypeOopPtr* p1 = r1->isa_oopptr();
   964   if (p0 && p1) {
   965     ciKlass* klass0 = p0->klass();
   966     bool    xklass0 = p0->klass_is_exact();
   967     ciKlass* klass1 = p1->klass();
   968     bool    xklass1 = p1->klass_is_exact();
   969     int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
   970     if (klass0 && klass1 &&
   971         kps != 1 &&             // both or neither are klass pointers
   972         !klass0->is_interface() && // do not trust interfaces
   973         !klass1->is_interface()) {
   974       bool unrelated_classes = false;
   975       // See if neither subclasses the other, or if the class on top
   976       // is precise.  In either of these cases, the compare is known
   977       // to fail if at least one of the pointers is provably not null.
   978       if (klass0->equals(klass1)) { // if types are unequal but klasses are equal
   979         // Do nothing; we know nothing for imprecise types
   980       } else if (klass0->is_subtype_of(klass1)) {
   981         // If klass1's type is PRECISE, then classes are unrelated.
   982         unrelated_classes = xklass1;
   983       } else if (klass1->is_subtype_of(klass0)) {
   984         // If klass0's type is PRECISE, then classes are unrelated.
   985         unrelated_classes = xklass0;
   986       } else {                  // Neither subtypes the other
   987         unrelated_classes = true;
   988       }
   989       if (unrelated_classes) {
   990         // The oops classes are known to be unrelated. If the joined PTRs of
   991         // two oops is not Null and not Bottom, then we are sure that one
   992         // of the two oops is non-null, and the comparison will always fail.
   993         TypePtr::PTR jp = r0->join_ptr(r1->_ptr);
   994         if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
   995           return TypeInt::CC_GT;
   996         }
   997       }
   998     }
   999   }
  1001   // Known constants can be compared exactly
  1002   // Null can be distinguished from any NotNull pointers
  1003   // Unknown inputs makes an unknown result
  1004   if( r0->singleton() ) {
  1005     intptr_t bits0 = r0->get_con();
  1006     if( r1->singleton() )
  1007       return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
  1008     return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
  1009   } else if( r1->singleton() ) {
  1010     intptr_t bits1 = r1->get_con();
  1011     return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
  1012   } else
  1013     return TypeInt::CC;
  1016 //------------------------------Ideal------------------------------------------
  1017 Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
  1018   return NULL;
  1021 //=============================================================================
  1022 //------------------------------Value------------------------------------------
  1023 // Simplify an CmpF (compare 2 floats ) node, based on local information.
  1024 // If both inputs are constants, compare them.
  1025 const Type *CmpFNode::Value( PhaseTransform *phase ) const {
  1026   const Node* in1 = in(1);
  1027   const Node* in2 = in(2);
  1028   // Either input is TOP ==> the result is TOP
  1029   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
  1030   if( t1 == Type::TOP ) return Type::TOP;
  1031   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
  1032   if( t2 == Type::TOP ) return Type::TOP;
  1034   // Not constants?  Don't know squat - even if they are the same
  1035   // value!  If they are NaN's they compare to LT instead of EQ.
  1036   const TypeF *tf1 = t1->isa_float_constant();
  1037   const TypeF *tf2 = t2->isa_float_constant();
  1038   if( !tf1 || !tf2 ) return TypeInt::CC;
  1040   // This implements the Java bytecode fcmpl, so unordered returns -1.
  1041   if( tf1->is_nan() || tf2->is_nan() )
  1042     return TypeInt::CC_LT;
  1044   if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
  1045   if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
  1046   assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
  1047   return TypeInt::CC_EQ;
  1051 //=============================================================================
  1052 //------------------------------Value------------------------------------------
  1053 // Simplify an CmpD (compare 2 doubles ) node, based on local information.
  1054 // If both inputs are constants, compare them.
  1055 const Type *CmpDNode::Value( PhaseTransform *phase ) const {
  1056   const Node* in1 = in(1);
  1057   const Node* in2 = in(2);
  1058   // Either input is TOP ==> the result is TOP
  1059   const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
  1060   if( t1 == Type::TOP ) return Type::TOP;
  1061   const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
  1062   if( t2 == Type::TOP ) return Type::TOP;
  1064   // Not constants?  Don't know squat - even if they are the same
  1065   // value!  If they are NaN's they compare to LT instead of EQ.
  1066   const TypeD *td1 = t1->isa_double_constant();
  1067   const TypeD *td2 = t2->isa_double_constant();
  1068   if( !td1 || !td2 ) return TypeInt::CC;
  1070   // This implements the Java bytecode dcmpl, so unordered returns -1.
  1071   if( td1->is_nan() || td2->is_nan() )
  1072     return TypeInt::CC_LT;
  1074   if( td1->_d < td2->_d ) return TypeInt::CC_LT;
  1075   if( td1->_d > td2->_d ) return TypeInt::CC_GT;
  1076   assert( td1->_d == td2->_d, "do not understand FP behavior" );
  1077   return TypeInt::CC_EQ;
  1080 //------------------------------Ideal------------------------------------------
  1081 Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
  1082   // Check if we can change this to a CmpF and remove a ConvD2F operation.
  1083   // Change  (CMPD (F2D (float)) (ConD value))
  1084   // To      (CMPF      (float)  (ConF value))
  1085   // Valid when 'value' does not lose precision as a float.
  1086   // Benefits: eliminates conversion, does not require 24-bit mode
  1088   // NaNs prevent commuting operands.  This transform works regardless of the
  1089   // order of ConD and ConvF2D inputs by preserving the original order.
  1090   int idx_f2d = 1;              // ConvF2D on left side?
  1091   if( in(idx_f2d)->Opcode() != Op_ConvF2D )
  1092     idx_f2d = 2;                // No, swap to check for reversed args
  1093   int idx_con = 3-idx_f2d;      // Check for the constant on other input
  1095   if( ConvertCmpD2CmpF &&
  1096       in(idx_f2d)->Opcode() == Op_ConvF2D &&
  1097       in(idx_con)->Opcode() == Op_ConD ) {
  1098     const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
  1099     double t2_value_as_double = t2->_d;
  1100     float  t2_value_as_float  = (float)t2_value_as_double;
  1101     if( t2_value_as_double == (double)t2_value_as_float ) {
  1102       // Test value can be represented as a float
  1103       // Eliminate the conversion to double and create new comparison
  1104       Node *new_in1 = in(idx_f2d)->in(1);
  1105       Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
  1106       if( idx_f2d != 1 ) {      // Must flip args to match original order
  1107         Node *tmp = new_in1;
  1108         new_in1 = new_in2;
  1109         new_in2 = tmp;
  1111       CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
  1112         ? new (phase->C) CmpF3Node( new_in1, new_in2 )
  1113         : new (phase->C) CmpFNode ( new_in1, new_in2 ) ;
  1114       return new_cmp;           // Changed to CmpFNode
  1116     // Testing value required the precision of a double
  1118   return NULL;                  // No change
  1122 //=============================================================================
  1123 //------------------------------cc2logical-------------------------------------
  1124 // Convert a condition code type to a logical type
  1125 const Type *BoolTest::cc2logical( const Type *CC ) const {
  1126   if( CC == Type::TOP ) return Type::TOP;
  1127   if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
  1128   const TypeInt *ti = CC->is_int();
  1129   if( ti->is_con() ) {          // Only 1 kind of condition codes set?
  1130     // Match low order 2 bits
  1131     int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
  1132     if( _test & 4 ) tmp = 1-tmp;     // Optionally complement result
  1133     return TypeInt::make(tmp);       // Boolean result
  1136   if( CC == TypeInt::CC_GE ) {
  1137     if( _test == ge ) return TypeInt::ONE;
  1138     if( _test == lt ) return TypeInt::ZERO;
  1140   if( CC == TypeInt::CC_LE ) {
  1141     if( _test == le ) return TypeInt::ONE;
  1142     if( _test == gt ) return TypeInt::ZERO;
  1145   return TypeInt::BOOL;
  1148 //------------------------------dump_spec-------------------------------------
  1149 // Print special per-node info
  1150 #ifndef PRODUCT
  1151 void BoolTest::dump_on(outputStream *st) const {
  1152   const char *msg[] = {"eq","gt","of","lt","ne","le","nof","ge"};
  1153   st->print(msg[_test]);
  1155 #endif
  1157 //=============================================================================
  1158 uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
  1159 uint BoolNode::size_of() const { return sizeof(BoolNode); }
  1161 //------------------------------operator==-------------------------------------
  1162 uint BoolNode::cmp( const Node &n ) const {
  1163   const BoolNode *b = (const BoolNode *)&n; // Cast up
  1164   return (_test._test == b->_test._test);
  1167 //-------------------------------make_predicate--------------------------------
  1168 Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
  1169   if (test_value->is_Con())   return test_value;
  1170   if (test_value->is_Bool())  return test_value;
  1171   Compile* C = phase->C;
  1172   if (test_value->is_CMove() &&
  1173       test_value->in(CMoveNode::Condition)->is_Bool()) {
  1174     BoolNode*   bol   = test_value->in(CMoveNode::Condition)->as_Bool();
  1175     const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
  1176     const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
  1177     if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
  1178       return bol;
  1179     } else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
  1180       return phase->transform( bol->negate(phase) );
  1182     // Else fall through.  The CMove gets in the way of the test.
  1183     // It should be the case that make_predicate(bol->as_int_value()) == bol.
  1185   Node* cmp = new (C) CmpINode(test_value, phase->intcon(0));
  1186   cmp = phase->transform(cmp);
  1187   Node* bol = new (C) BoolNode(cmp, BoolTest::ne);
  1188   return phase->transform(bol);
  1191 //--------------------------------as_int_value---------------------------------
  1192 Node* BoolNode::as_int_value(PhaseGVN* phase) {
  1193   // Inverse to make_predicate.  The CMove probably boils down to a Conv2B.
  1194   Node* cmov = CMoveNode::make(phase->C, NULL, this,
  1195                                phase->intcon(0), phase->intcon(1),
  1196                                TypeInt::BOOL);
  1197   return phase->transform(cmov);
  1200 //----------------------------------negate-------------------------------------
  1201 BoolNode* BoolNode::negate(PhaseGVN* phase) {
  1202   Compile* C = phase->C;
  1203   return new (C) BoolNode(in(1), _test.negate());
  1207 //------------------------------Ideal------------------------------------------
  1208 Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
  1209   // Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
  1210   // This moves the constant to the right.  Helps value-numbering.
  1211   Node *cmp = in(1);
  1212   if( !cmp->is_Sub() ) return NULL;
  1213   int cop = cmp->Opcode();
  1214   if( cop == Op_FastLock || cop == Op_FastUnlock) return NULL;
  1215   Node *cmp1 = cmp->in(1);
  1216   Node *cmp2 = cmp->in(2);
  1217   if( !cmp1 ) return NULL;
  1219   if (_test._test == BoolTest::overflow || _test._test == BoolTest::no_overflow) {
  1220     return NULL;
  1223   // Constant on left?
  1224   Node *con = cmp1;
  1225   uint op2 = cmp2->Opcode();
  1226   // Move constants to the right of compare's to canonicalize.
  1227   // Do not muck with Opaque1 nodes, as this indicates a loop
  1228   // guard that cannot change shape.
  1229   if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 &&
  1230       // Because of NaN's, CmpD and CmpF are not commutative
  1231       cop != Op_CmpD && cop != Op_CmpF &&
  1232       // Protect against swapping inputs to a compare when it is used by a
  1233       // counted loop exit, which requires maintaining the loop-limit as in(2)
  1234       !is_counted_loop_exit_test() ) {
  1235     // Ok, commute the constant to the right of the cmp node.
  1236     // Clone the Node, getting a new Node of the same class
  1237     cmp = cmp->clone();
  1238     // Swap inputs to the clone
  1239     cmp->swap_edges(1, 2);
  1240     cmp = phase->transform( cmp );
  1241     return new (phase->C) BoolNode( cmp, _test.commute() );
  1244   // Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
  1245   // The XOR-1 is an idiom used to flip the sense of a bool.  We flip the
  1246   // test instead.
  1247   int cmp1_op = cmp1->Opcode();
  1248   const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
  1249   if (cmp2_type == NULL)  return NULL;
  1250   Node* j_xor = cmp1;
  1251   if( cmp2_type == TypeInt::ZERO &&
  1252       cmp1_op == Op_XorI &&
  1253       j_xor->in(1) != j_xor &&          // An xor of itself is dead
  1254       phase->type( j_xor->in(1) ) == TypeInt::BOOL &&
  1255       phase->type( j_xor->in(2) ) == TypeInt::ONE &&
  1256       (_test._test == BoolTest::eq ||
  1257        _test._test == BoolTest::ne) ) {
  1258     Node *ncmp = phase->transform(new (phase->C) CmpINode(j_xor->in(1),cmp2));
  1259     return new (phase->C) BoolNode( ncmp, _test.negate() );
  1262   // Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
  1263   // This is a standard idiom for branching on a boolean value.
  1264   Node *c2b = cmp1;
  1265   if( cmp2_type == TypeInt::ZERO &&
  1266       cmp1_op == Op_Conv2B &&
  1267       (_test._test == BoolTest::eq ||
  1268        _test._test == BoolTest::ne) ) {
  1269     Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
  1270        ? (Node*)new (phase->C) CmpINode(c2b->in(1),cmp2)
  1271        : (Node*)new (phase->C) CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
  1272     );
  1273     return new (phase->C) BoolNode( ncmp, _test._test );
  1276   // Comparing a SubI against a zero is equal to comparing the SubI
  1277   // arguments directly.  This only works for eq and ne comparisons
  1278   // due to possible integer overflow.
  1279   if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
  1280         (cop == Op_CmpI) &&
  1281         (cmp1->Opcode() == Op_SubI) &&
  1282         ( cmp2_type == TypeInt::ZERO ) ) {
  1283     Node *ncmp = phase->transform( new (phase->C) CmpINode(cmp1->in(1),cmp1->in(2)));
  1284     return new (phase->C) BoolNode( ncmp, _test._test );
  1287   // Change (-A vs 0) into (A vs 0) by commuting the test.  Disallow in the
  1288   // most general case because negating 0x80000000 does nothing.  Needed for
  1289   // the CmpF3/SubI/CmpI idiom.
  1290   if( cop == Op_CmpI &&
  1291       cmp1->Opcode() == Op_SubI &&
  1292       cmp2_type == TypeInt::ZERO &&
  1293       phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
  1294       phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
  1295     Node *ncmp = phase->transform( new (phase->C) CmpINode(cmp1->in(2),cmp2));
  1296     return new (phase->C) BoolNode( ncmp, _test.commute() );
  1299   //  The transformation below is not valid for either signed or unsigned
  1300   //  comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
  1301   //  This transformation can be resurrected when we are able to
  1302   //  make inferences about the range of values being subtracted from
  1303   //  (or added to) relative to the wraparound point.
  1304   //
  1305   //    // Remove +/-1's if possible.
  1306   //    // "X <= Y-1" becomes "X <  Y"
  1307   //    // "X+1 <= Y" becomes "X <  Y"
  1308   //    // "X <  Y+1" becomes "X <= Y"
  1309   //    // "X-1 <  Y" becomes "X <= Y"
  1310   //    // Do not this to compares off of the counted-loop-end.  These guys are
  1311   //    // checking the trip counter and they want to use the post-incremented
  1312   //    // counter.  If they use the PRE-incremented counter, then the counter has
  1313   //    // to be incremented in a private block on a loop backedge.
  1314   //    if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
  1315   //      return NULL;
  1316   //  #ifndef PRODUCT
  1317   //    // Do not do this in a wash GVN pass during verification.
  1318   //    // Gets triggered by too many simple optimizations to be bothered with
  1319   //    // re-trying it again and again.
  1320   //    if( !phase->allow_progress() ) return NULL;
  1321   //  #endif
  1322   //    // Not valid for unsigned compare because of corner cases in involving zero.
  1323   //    // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
  1324   //    // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
  1325   //    // "0 <=u Y" is always true).
  1326   //    if( cmp->Opcode() == Op_CmpU ) return NULL;
  1327   //    int cmp2_op = cmp2->Opcode();
  1328   //    if( _test._test == BoolTest::le ) {
  1329   //      if( cmp1_op == Op_AddI &&
  1330   //          phase->type( cmp1->in(2) ) == TypeInt::ONE )
  1331   //        return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
  1332   //      else if( cmp2_op == Op_AddI &&
  1333   //         phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
  1334   //        return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
  1335   //    } else if( _test._test == BoolTest::lt ) {
  1336   //      if( cmp1_op == Op_AddI &&
  1337   //          phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
  1338   //        return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
  1339   //      else if( cmp2_op == Op_AddI &&
  1340   //         phase->type( cmp2->in(2) ) == TypeInt::ONE )
  1341   //        return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
  1342   //    }
  1344   return NULL;
  1347 //------------------------------Value------------------------------------------
  1348 // Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
  1349 // based on local information.   If the input is constant, do it.
  1350 const Type *BoolNode::Value( PhaseTransform *phase ) const {
  1351   return _test.cc2logical( phase->type( in(1) ) );
  1354 //------------------------------dump_spec--------------------------------------
  1355 // Dump special per-node info
  1356 #ifndef PRODUCT
  1357 void BoolNode::dump_spec(outputStream *st) const {
  1358   st->print("[");
  1359   _test.dump_on(st);
  1360   st->print("]");
  1362 #endif
  1364 //------------------------------is_counted_loop_exit_test--------------------------------------
  1365 // Returns true if node is used by a counted loop node.
  1366 bool BoolNode::is_counted_loop_exit_test() {
  1367   for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
  1368     Node* use = fast_out(i);
  1369     if (use->is_CountedLoopEnd()) {
  1370       return true;
  1373   return false;
  1376 //=============================================================================
  1377 //------------------------------Value------------------------------------------
  1378 // Compute sqrt
  1379 const Type *SqrtDNode::Value( PhaseTransform *phase ) const {
  1380   const Type *t1 = phase->type( in(1) );
  1381   if( t1 == Type::TOP ) return Type::TOP;
  1382   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
  1383   double d = t1->getd();
  1384   if( d < 0.0 ) return Type::DOUBLE;
  1385   return TypeD::make( sqrt( d ) );
  1388 //=============================================================================
  1389 //------------------------------Value------------------------------------------
  1390 // Compute cos
  1391 const Type *CosDNode::Value( PhaseTransform *phase ) const {
  1392   const Type *t1 = phase->type( in(1) );
  1393   if( t1 == Type::TOP ) return Type::TOP;
  1394   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
  1395   double d = t1->getd();
  1396   return TypeD::make( StubRoutines::intrinsic_cos( d ) );
  1399 //=============================================================================
  1400 //------------------------------Value------------------------------------------
  1401 // Compute sin
  1402 const Type *SinDNode::Value( PhaseTransform *phase ) const {
  1403   const Type *t1 = phase->type( in(1) );
  1404   if( t1 == Type::TOP ) return Type::TOP;
  1405   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
  1406   double d = t1->getd();
  1407   return TypeD::make( StubRoutines::intrinsic_sin( d ) );
  1410 //=============================================================================
  1411 //------------------------------Value------------------------------------------
  1412 // Compute tan
  1413 const Type *TanDNode::Value( PhaseTransform *phase ) const {
  1414   const Type *t1 = phase->type( in(1) );
  1415   if( t1 == Type::TOP ) return Type::TOP;
  1416   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
  1417   double d = t1->getd();
  1418   return TypeD::make( StubRoutines::intrinsic_tan( d ) );
  1421 //=============================================================================
  1422 //------------------------------Value------------------------------------------
  1423 // Compute log
  1424 const Type *LogDNode::Value( PhaseTransform *phase ) const {
  1425   const Type *t1 = phase->type( in(1) );
  1426   if( t1 == Type::TOP ) return Type::TOP;
  1427   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
  1428   double d = t1->getd();
  1429   return TypeD::make( StubRoutines::intrinsic_log( d ) );
  1432 //=============================================================================
  1433 //------------------------------Value------------------------------------------
  1434 // Compute log10
  1435 const Type *Log10DNode::Value( PhaseTransform *phase ) const {
  1436   const Type *t1 = phase->type( in(1) );
  1437   if( t1 == Type::TOP ) return Type::TOP;
  1438   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
  1439   double d = t1->getd();
  1440   return TypeD::make( StubRoutines::intrinsic_log10( d ) );
  1443 //=============================================================================
  1444 //------------------------------Value------------------------------------------
  1445 // Compute exp
  1446 const Type *ExpDNode::Value( PhaseTransform *phase ) const {
  1447   const Type *t1 = phase->type( in(1) );
  1448   if( t1 == Type::TOP ) return Type::TOP;
  1449   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
  1450   double d = t1->getd();
  1451   return TypeD::make( StubRoutines::intrinsic_exp( d ) );
  1455 //=============================================================================
  1456 //------------------------------Value------------------------------------------
  1457 // Compute pow
  1458 const Type *PowDNode::Value( PhaseTransform *phase ) const {
  1459   const Type *t1 = phase->type( in(1) );
  1460   if( t1 == Type::TOP ) return Type::TOP;
  1461   if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
  1462   const Type *t2 = phase->type( in(2) );
  1463   if( t2 == Type::TOP ) return Type::TOP;
  1464   if( t2->base() != Type::DoubleCon ) return Type::DOUBLE;
  1465   double d1 = t1->getd();
  1466   double d2 = t2->getd();
  1467   return TypeD::make( StubRoutines::intrinsic_pow( d1, d2 ) );

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