### view src/share/vm/opto/subnode.cpp @ 212:99bf1609e2a5

6697236: missing Identity for "(X+Y) - X" into Y Reviewed-by: kvn
author never Thu, 12 Jun 2008 09:47:55 -0700 ba764ed4b6f2 1e026f8da827
line wrap: on
line source
```/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/

// Portions of code courtesy of Clifford Click

// Optimization - Graph Style

#include "incls/_precompiled.incl"
#include "incls/_subnode.cpp.incl"
#include "math.h"

//=============================================================================
//------------------------------Identity---------------------------------------
// If right input is a constant 0, return the left input.
Node *SubNode::Identity( PhaseTransform *phase ) {
assert(in(1) != this, "Must already have called Value");
assert(in(2) != this, "Must already have called Value");

// Remove double negation
if( phase->type( in(1) )->higher_equal( zero ) &&
in(2)->Opcode() == Opcode() &&
phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
return in(2)->in(2);
}

// Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
if( in(1)->Opcode() == Op_AddI ) {
if( phase->eqv(in(1)->in(2),in(2)) )
return in(1)->in(1);
if (phase->eqv(in(1)->in(1),in(2)))
return in(1)->in(2);

// Also catch: "(X + Opaque2(Y)) - Y".  In this case, 'Y' is a loop-varying
// trip counter and X is likely to be loop-invariant (that's how O2 Nodes
// are originally used, although the optimizer sometimes jiggers things).
// This folding through an O2 removes a loop-exit use of a loop-varying
// value and generally lowers register pressure in and around the loop.
if( in(1)->in(2)->Opcode() == Op_Opaque2 &&
phase->eqv(in(1)->in(2)->in(1),in(2)) )
return in(1)->in(1);
}

return ( phase->type( in(2) )->higher_equal( zero ) ) ? in(1) : this;
}

//------------------------------Value------------------------------------------
// A subtract node differences it's two inputs.
const Type *SubNode::Value( PhaseTransform *phase ) const {
const Node* in1 = in(1);
const Node* in2 = in(2);
// Either input is TOP ==> the result is TOP
const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
if( t1 == Type::TOP ) return Type::TOP;
const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
if( t2 == Type::TOP ) return Type::TOP;

// Not correct for SubFnode and AddFNode (must check for infinity)
// Equal?  Subtract is zero

// Either input is BOTTOM ==> the result is the local BOTTOM
if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
return bottom_type();

return sub(t1,t2);            // Local flavor of type subtraction

}

//=============================================================================

//------------------------------Helper function--------------------------------
static bool ok_to_convert(Node* inc, Node* iv) {
// Do not collapse (x+c0)-y if "+" is a loop increment, because the
// "-" is loop invariant and collapsing extends the live-range of "x"
// to overlap with the "+", forcing another register to be used in
// the loop.
// This test will be clearer with '&&' (apply DeMorgan's rule)
// but I like the early cutouts that happen here.
const PhiNode *phi;
if( ( !inc->in(1)->is_Phi() ||
!(phi=inc->in(1)->as_Phi()) ||
phi->is_copy() ||
!phi->region()->is_CountedLoop() ||
inc != phi->region()->as_CountedLoop()->incr() )
&&
// Do not collapse (x+c0)-iv if "iv" is a loop induction variable,
// because "x" maybe invariant.
( !iv->is_loop_iv() )
) {
return true;
} else {
return false;
}
}
//------------------------------Ideal------------------------------------------
Node *SubINode::Ideal(PhaseGVN *phase, bool can_reshape){
Node *in1 = in(1);
Node *in2 = in(2);
uint op1 = in1->Opcode();
uint op2 = in2->Opcode();

#ifdef ASSERT
if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
( op1 == Op_AddI || op1 == Op_SubI ) &&
( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
phase->eqv( in1->in(1), in1  ) || phase->eqv( in1->in(2), in1 ) ) )
#endif

const Type *t2 = phase->type( in2 );
if( t2 == Type::TOP ) return NULL;
// Convert "x-c0" into "x+ -c0".
if( t2->base() == Type::Int ){        // Might be bottom or top...
const TypeInt *i = t2->is_int();
if( i->is_con() )
return new (phase->C, 3) AddINode(in1, phase->intcon(-i->get_con()));
}

// Convert "(x+c0) - y" into (x-y) + c0"
// Do not collapse (x+c0)-y if "+" is a loop increment or
// if "y" is a loop induction variable.
if( op1 == Op_AddI && ok_to_convert(in1, in2) ) {
const Type *tadd = phase->type( in1->in(2) );
Node *sub2 = phase->transform( new (phase->C, 3) SubINode( in1->in(1), in2 ));
return new (phase->C, 3) AddINode( sub2, in1->in(2) );
}
}

// Convert "x - (y+c0)" into "(x-y) - c0"
// Need the same check as in above optimization but reversed.
if (op2 == Op_AddI && ok_to_convert(in2, in1)) {
Node* in21 = in2->in(1);
Node* in22 = in2->in(2);
const TypeInt* tcon = phase->type(in22)->isa_int();
if (tcon != NULL && tcon->is_con()) {
Node* sub2 = phase->transform( new (phase->C, 3) SubINode(in1, in21) );
Node* neg_c0 = phase->intcon(- tcon->get_con());
return new (phase->C, 3) AddINode(sub2, neg_c0);
}
}

const Type *t1 = phase->type( in1 );
if( t1 == Type::TOP ) return NULL;

#ifdef ASSERT
if( ( op2 == Op_AddI || op2 == Op_SubI ) &&
( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
phase->eqv( in2->in(1), in2  ) || phase->eqv( in2->in(2), in2  ) ) )
#endif

// Convert "x - (x+y)" into "-y"
phase->eqv( in1, in2->in(1) ) )
return new (phase->C, 3) SubINode( phase->intcon(0),in2->in(2));
// Convert "(x-y) - x" into "-y"
if( op1 == Op_SubI &&
phase->eqv( in1->in(1), in2 ) )
return new (phase->C, 3) SubINode( phase->intcon(0),in1->in(2));
// Convert "x - (y+x)" into "-y"
phase->eqv( in1, in2->in(2) ) )
return new (phase->C, 3) SubINode( phase->intcon(0),in2->in(1));

// Convert "0 - (x-y)" into "y-x"
if( t1 == TypeInt::ZERO && op2 == Op_SubI )
return new (phase->C, 3) SubINode( in2->in(2), in2->in(1) );

// Convert "0 - (x+con)" into "-con-x"
jint con;
if( t1 == TypeInt::ZERO && op2 == Op_AddI &&
(con = in2->in(2)->find_int_con(0)) != 0 )
return new (phase->C, 3) SubINode( phase->intcon(-con), in2->in(1) );

// Convert "(X+A) - (X+B)" into "A - B"
if( op1 == Op_AddI && op2 == Op_AddI && in1->in(1) == in2->in(1) )
return new (phase->C, 3) SubINode( in1->in(2), in2->in(2) );

// Convert "(A+X) - (B+X)" into "A - B"
if( op1 == Op_AddI && op2 == Op_AddI && in1->in(2) == in2->in(2) )
return new (phase->C, 3) SubINode( in1->in(1), in2->in(1) );

// Convert "A-(B-C)" into (A+C)-B", since add is commutative and generally
// nicer to optimize than subtract.
if( op2 == Op_SubI && in2->outcnt() == 1) {
Node *add1 = phase->transform( new (phase->C, 3) AddINode( in1, in2->in(2) ) );
return new (phase->C, 3) SubINode( add1, in2->in(1) );
}

return NULL;
}

//------------------------------sub--------------------------------------------
// A subtract node differences it's two inputs.
const Type *SubINode::sub( const Type *t1, const Type *t2 ) const {
const TypeInt *r0 = t1->is_int(); // Handy access
const TypeInt *r1 = t2->is_int();
int32 lo = r0->_lo - r1->_hi;
int32 hi = r0->_hi - r1->_lo;

// We next check for 32-bit overflow.
// If that happens, we just assume all integers are possible.
if( (((r0->_lo ^ r1->_hi) >= 0) ||    // lo ends have same signs OR
((r0->_lo ^      lo) >= 0)) &&   // lo results have same signs AND
(((r0->_hi ^ r1->_lo) >= 0) ||    // hi ends have same signs OR
((r0->_hi ^      hi) >= 0)) )    // hi results have same signs
return TypeInt::make(lo,hi,MAX2(r0->_widen,r1->_widen));
else                          // Overflow; assume all integers
return TypeInt::INT;
}

//=============================================================================
//------------------------------Ideal------------------------------------------
Node *SubLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
Node *in1 = in(1);
Node *in2 = in(2);
uint op1 = in1->Opcode();
uint op2 = in2->Opcode();

#ifdef ASSERT
if( phase->eqv( in1, this ) || phase->eqv( in2, this ) ||
( op1 == Op_AddL || op1 == Op_SubL ) &&
( phase->eqv( in1->in(1), this ) || phase->eqv( in1->in(2), this ) ||
phase->eqv( in1->in(1), in1  ) || phase->eqv( in1->in(2), in1  ) ) )
#endif

if( phase->type( in2 ) == Type::TOP ) return NULL;
const TypeLong *i = phase->type( in2 )->isa_long();
// Convert "x-c0" into "x+ -c0".
if( i &&                      // Might be bottom or top...
i->is_con() )
return new (phase->C, 3) AddLNode(in1, phase->longcon(-i->get_con()));

// Convert "(x+c0) - y" into (x-y) + c0"
// Do not collapse (x+c0)-y if "+" is a loop increment or
// if "y" is a loop induction variable.
if( op1 == Op_AddL && ok_to_convert(in1, in2) ) {
Node *in11 = in1->in(1);
const Type *tadd = phase->type( in1->in(2) );
Node *sub2 = phase->transform( new (phase->C, 3) SubLNode( in11, in2 ));
return new (phase->C, 3) AddLNode( sub2, in1->in(2) );
}
}

// Convert "x - (y+c0)" into "(x-y) - c0"
// Need the same check as in above optimization but reversed.
if (op2 == Op_AddL && ok_to_convert(in2, in1)) {
Node* in21 = in2->in(1);
Node* in22 = in2->in(2);
const TypeLong* tcon = phase->type(in22)->isa_long();
if (tcon != NULL && tcon->is_con()) {
Node* sub2 = phase->transform( new (phase->C, 3) SubLNode(in1, in21) );
Node* neg_c0 = phase->longcon(- tcon->get_con());
return new (phase->C, 3) AddLNode(sub2, neg_c0);
}
}

const Type *t1 = phase->type( in1 );
if( t1 == Type::TOP ) return NULL;

#ifdef ASSERT
if( ( op2 == Op_AddL || op2 == Op_SubL ) &&
( phase->eqv( in2->in(1), this ) || phase->eqv( in2->in(2), this ) ||
phase->eqv( in2->in(1), in2  ) || phase->eqv( in2->in(2), in2  ) ) )
#endif

// Convert "x - (x+y)" into "-y"
phase->eqv( in1, in2->in(1) ) )
return new (phase->C, 3) SubLNode( phase->makecon(TypeLong::ZERO), in2->in(2));
// Convert "x - (y+x)" into "-y"
phase->eqv( in1, in2->in(2) ) )
return new (phase->C, 3) SubLNode( phase->makecon(TypeLong::ZERO),in2->in(1));

// Convert "0 - (x-y)" into "y-x"
if( phase->type( in1 ) == TypeLong::ZERO && op2 == Op_SubL )
return new (phase->C, 3) SubLNode( in2->in(2), in2->in(1) );

// Convert "(X+A) - (X+B)" into "A - B"
if( op1 == Op_AddL && op2 == Op_AddL && in1->in(1) == in2->in(1) )
return new (phase->C, 3) SubLNode( in1->in(2), in2->in(2) );

// Convert "(A+X) - (B+X)" into "A - B"
if( op1 == Op_AddL && op2 == Op_AddL && in1->in(2) == in2->in(2) )
return new (phase->C, 3) SubLNode( in1->in(1), in2->in(1) );

// Convert "A-(B-C)" into (A+C)-B"
if( op2 == Op_SubL && in2->outcnt() == 1) {
Node *add1 = phase->transform( new (phase->C, 3) AddLNode( in1, in2->in(2) ) );
return new (phase->C, 3) SubLNode( add1, in2->in(1) );
}

return NULL;
}

//------------------------------sub--------------------------------------------
// A subtract node differences it's two inputs.
const Type *SubLNode::sub( const Type *t1, const Type *t2 ) const {
const TypeLong *r0 = t1->is_long(); // Handy access
const TypeLong *r1 = t2->is_long();
jlong lo = r0->_lo - r1->_hi;
jlong hi = r0->_hi - r1->_lo;

// We next check for 32-bit overflow.
// If that happens, we just assume all integers are possible.
if( (((r0->_lo ^ r1->_hi) >= 0) ||    // lo ends have same signs OR
((r0->_lo ^      lo) >= 0)) &&   // lo results have same signs AND
(((r0->_hi ^ r1->_lo) >= 0) ||    // hi ends have same signs OR
((r0->_hi ^      hi) >= 0)) )    // hi results have same signs
return TypeLong::make(lo,hi,MAX2(r0->_widen,r1->_widen));
else                          // Overflow; assume all integers
return TypeLong::LONG;
}

//=============================================================================
//------------------------------Value------------------------------------------
// A subtract node differences its two inputs.
const Type *SubFPNode::Value( PhaseTransform *phase ) const {
const Node* in1 = in(1);
const Node* in2 = in(2);
// Either input is TOP ==> the result is TOP
const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
if( t1 == Type::TOP ) return Type::TOP;
const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
if( t2 == Type::TOP ) return Type::TOP;

// if both operands are infinity of same sign, the result is NaN; do
// not replace with zero
if( (t1->is_finite() && t2->is_finite()) ) {
if( phase->eqv(in1, in2) ) return add_id();
}

// Either input is BOTTOM ==> the result is the local BOTTOM
const Type *bot = bottom_type();
if( (t1 == bot) || (t2 == bot) ||
(t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
return bot;

return sub(t1,t2);            // Local flavor of type subtraction
}

//=============================================================================
//------------------------------Ideal------------------------------------------
Node *SubFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
const Type *t2 = phase->type( in(2) );
// Convert "x-c0" into "x+ -c0".
if( t2->base() == Type::FloatCon ) {  // Might be bottom or top...
// return new (phase->C, 3) AddFNode(in(1), phase->makecon( TypeF::make(-t2->getf()) ) );
}

// Not associative because of boundary conditions (infinity)
if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
// Convert "x - (x+y)" into "-y"
phase->eqv(in(1),in(2)->in(1) ) )
return new (phase->C, 3) SubFNode( phase->makecon(TypeF::ZERO),in(2)->in(2));
}

// Cannot replace 0.0-X with -X because a 'fsub' bytecode computes
// 0.0-0.0 as +0.0, while a 'fneg' bytecode computes -0.0.
//if( phase->type(in(1)) == TypeF::ZERO )
//return new (phase->C, 2) NegFNode(in(2));

return NULL;
}

//------------------------------sub--------------------------------------------
// A subtract node differences its two inputs.
const Type *SubFNode::sub( const Type *t1, const Type *t2 ) const {
// no folding if one of operands is infinity or NaN, do not do constant folding
if( g_isfinite(t1->getf()) && g_isfinite(t2->getf()) ) {
return TypeF::make( t1->getf() - t2->getf() );
}
else if( g_isnan(t1->getf()) ) {
return t1;
}
else if( g_isnan(t2->getf()) ) {
return t2;
}
else {
return Type::FLOAT;
}
}

//=============================================================================
//------------------------------Ideal------------------------------------------
Node *SubDNode::Ideal(PhaseGVN *phase, bool can_reshape){
const Type *t2 = phase->type( in(2) );
// Convert "x-c0" into "x+ -c0".
if( t2->base() == Type::DoubleCon ) { // Might be bottom or top...
// return new (phase->C, 3) AddDNode(in(1), phase->makecon( TypeD::make(-t2->getd()) ) );
}

// Not associative because of boundary conditions (infinity)
if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
// Convert "x - (x+y)" into "-y"
phase->eqv(in(1),in(2)->in(1) ) )
return new (phase->C, 3) SubDNode( phase->makecon(TypeD::ZERO),in(2)->in(2));
}

// Cannot replace 0.0-X with -X because a 'dsub' bytecode computes
// 0.0-0.0 as +0.0, while a 'dneg' bytecode computes -0.0.
//if( phase->type(in(1)) == TypeD::ZERO )
//return new (phase->C, 2) NegDNode(in(2));

return NULL;
}

//------------------------------sub--------------------------------------------
// A subtract node differences its two inputs.
const Type *SubDNode::sub( const Type *t1, const Type *t2 ) const {
// no folding if one of operands is infinity or NaN, do not do constant folding
if( g_isfinite(t1->getd()) && g_isfinite(t2->getd()) ) {
return TypeD::make( t1->getd() - t2->getd() );
}
else if( g_isnan(t1->getd()) ) {
return t1;
}
else if( g_isnan(t2->getd()) ) {
return t2;
}
else {
return Type::DOUBLE;
}
}

//=============================================================================
//------------------------------Idealize---------------------------------------
// Unlike SubNodes, compare must still flatten return value to the
// range -1, 0, 1.
// And optimizations like those for (X + Y) - X fail if overflow happens.
Node *CmpNode::Identity( PhaseTransform *phase ) {
return this;
}

//=============================================================================
//------------------------------cmp--------------------------------------------
// Simplify a CmpI (compare 2 integers) node, based on local information.
// If both inputs are constants, compare them.
const Type *CmpINode::sub( const Type *t1, const Type *t2 ) const {
const TypeInt *r0 = t1->is_int(); // Handy access
const TypeInt *r1 = t2->is_int();

if( r0->_hi < r1->_lo )       // Range is always low?
return TypeInt::CC_LT;
else if( r0->_lo > r1->_hi )  // Range is always high?
return TypeInt::CC_GT;

else if( r0->is_con() && r1->is_con() ) { // comparing constants?
assert(r0->get_con() == r1->get_con(), "must be equal");
return TypeInt::CC_EQ;      // Equal results.
} else if( r0->_hi == r1->_lo ) // Range is never high?
return TypeInt::CC_LE;
else if( r0->_lo == r1->_hi ) // Range is never low?
return TypeInt::CC_GE;
return TypeInt::CC;           // else use worst case results
}

// Simplify a CmpU (compare 2 integers) node, based on local information.
// If both inputs are constants, compare them.
const Type *CmpUNode::sub( const Type *t1, const Type *t2 ) const {
assert(!t1->isa_ptr(), "obsolete usage of CmpU");

// comparing two unsigned ints
const TypeInt *r0 = t1->is_int();   // Handy access
const TypeInt *r1 = t2->is_int();

// Current installed version
// Compare ranges for non-overlap
juint lo0 = r0->_lo;
juint hi0 = r0->_hi;
juint lo1 = r1->_lo;
juint hi1 = r1->_hi;

// If either one has both negative and positive values,
// it therefore contains both 0 and -1, and since [0..-1] is the
// full unsigned range, the type must act as an unsigned bottom.
bool bot0 = ((jint)(lo0 ^ hi0) < 0);
bool bot1 = ((jint)(lo1 ^ hi1) < 0);

if (bot0 || bot1) {
// All unsigned values are LE -1 and GE 0.
if (lo0 == 0 && hi0 == 0) {
return TypeInt::CC_LE;            //   0 <= bot
} else if (lo1 == 0 && hi1 == 0) {
return TypeInt::CC_GE;            // bot >= 0
}
} else {
// We can use ranges of the form [lo..hi] if signs are the same.
assert(lo0 <= hi0 && lo1 <= hi1, "unsigned ranges are valid");
// results are reversed, '-' > '+' for unsigned compare
if (hi0 < lo1) {
return TypeInt::CC_LT;            // smaller
} else if (lo0 > hi1) {
return TypeInt::CC_GT;            // greater
} else if (hi0 == lo1 && lo0 == hi1) {
return TypeInt::CC_EQ;            // Equal results
} else if (lo0 >= hi1) {
return TypeInt::CC_GE;
} else if (hi0 <= lo1) {
// Check for special case in Hashtable::get.  (See below.)
if ((jint)lo0 >= 0 && (jint)lo1 >= 0 &&
in(1)->Opcode() == Op_ModI &&
in(1)->in(2) == in(2) )
return TypeInt::CC_LT;
return TypeInt::CC_LE;
}
}
// Check for special case in Hashtable::get - the hash index is
// mod'ed to the table size so the following range check is useless.
// Check for: (X Mod Y) CmpU Y, where the mod result and Y both have
// to be positive.
// (This is a gross hack, since the sub method never
// looks at the structure of the node in any other case.)
if ((jint)lo0 >= 0 && (jint)lo1 >= 0 &&
in(1)->Opcode() == Op_ModI &&
in(1)->in(2)->uncast() == in(2)->uncast())
return TypeInt::CC_LT;
return TypeInt::CC;                   // else use worst case results
}

//------------------------------Idealize---------------------------------------
Node *CmpINode::Ideal( PhaseGVN *phase, bool can_reshape ) {
if (phase->type(in(2))->higher_equal(TypeInt::ZERO)) {
switch (in(1)->Opcode()) {
case Op_CmpL3:              // Collapse a CmpL3/CmpI into a CmpL
return new (phase->C, 3) CmpLNode(in(1)->in(1),in(1)->in(2));
case Op_CmpF3:              // Collapse a CmpF3/CmpI into a CmpF
return new (phase->C, 3) CmpFNode(in(1)->in(1),in(1)->in(2));
case Op_CmpD3:              // Collapse a CmpD3/CmpI into a CmpD
return new (phase->C, 3) CmpDNode(in(1)->in(1),in(1)->in(2));
//case Op_SubI:
// If (x - y) cannot overflow, then ((x - y) <?> 0)
// can be turned into (x <?> y).
// This is handled (with more general cases) by Ideal_sub_algebra.
}
}
return NULL;                  // No change
}

//=============================================================================
// Simplify a CmpL (compare 2 longs ) node, based on local information.
// If both inputs are constants, compare them.
const Type *CmpLNode::sub( const Type *t1, const Type *t2 ) const {
const TypeLong *r0 = t1->is_long(); // Handy access
const TypeLong *r1 = t2->is_long();

if( r0->_hi < r1->_lo )       // Range is always low?
return TypeInt::CC_LT;
else if( r0->_lo > r1->_hi )  // Range is always high?
return TypeInt::CC_GT;

else if( r0->is_con() && r1->is_con() ) { // comparing constants?
assert(r0->get_con() == r1->get_con(), "must be equal");
return TypeInt::CC_EQ;      // Equal results.
} else if( r0->_hi == r1->_lo ) // Range is never high?
return TypeInt::CC_LE;
else if( r0->_lo == r1->_hi ) // Range is never low?
return TypeInt::CC_GE;
return TypeInt::CC;           // else use worst case results
}

//=============================================================================
//------------------------------sub--------------------------------------------
// Simplify an CmpP (compare 2 pointers) node, based on local information.
// If both inputs are constants, compare them.
const Type *CmpPNode::sub( const Type *t1, const Type *t2 ) const {
const TypePtr *r0 = t1->is_ptr(); // Handy access
const TypePtr *r1 = t2->is_ptr();

// Undefined inputs makes for an undefined result
if( TypePtr::above_centerline(r0->_ptr) ||
TypePtr::above_centerline(r1->_ptr) )
return Type::TOP;

if (r0 == r1 && r0->singleton()) {
// Equal pointer constants (klasses, nulls, etc.)
return TypeInt::CC_EQ;
}

// See if it is 2 unrelated classes.
const TypeOopPtr* p0 = r0->isa_oopptr();
const TypeOopPtr* p1 = r1->isa_oopptr();
if (p0 && p1) {
Node* in1 = in(1)->uncast();
Node* in2 = in(2)->uncast();
AllocateNode* alloc1 = AllocateNode::Ideal_allocation(in1, NULL);
AllocateNode* alloc2 = AllocateNode::Ideal_allocation(in2, NULL);
if (MemNode::detect_ptr_independence(in1, alloc1, in2, alloc2, NULL)) {
return TypeInt::CC_GT;  // different pointers
}
ciKlass* klass0 = p0->klass();
bool    xklass0 = p0->klass_is_exact();
ciKlass* klass1 = p1->klass();
bool    xklass1 = p1->klass_is_exact();
int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
if (klass0 && klass1 &&
kps != 1 &&             // both or neither are klass pointers
!klass0->is_interface() && // do not trust interfaces
!klass1->is_interface()) {
// See if neither subclasses the other, or if the class on top
// is precise.  In either of these cases, the compare must fail.
if (klass0->equals(klass1)   ||   // if types are unequal but klasses are
!klass0->is_java_klass() ||   // types not part of Java language?
!klass1->is_java_klass()) {   // types not part of Java language?
// Do nothing; we know nothing for imprecise types
} else if (klass0->is_subtype_of(klass1)) {
// If klass1's type is PRECISE, then we can fail.
if (xklass1)  return TypeInt::CC_GT;
} else if (klass1->is_subtype_of(klass0)) {
// If klass0's type is PRECISE, then we can fail.
if (xklass0)  return TypeInt::CC_GT;
} else {                  // Neither subtypes the other
return TypeInt::CC_GT;  // ...so always fail
}
}
}

// Known constants can be compared exactly
// Null can be distinguished from any NotNull pointers
// Unknown inputs makes an unknown result
if( r0->singleton() ) {
intptr_t bits0 = r0->get_con();
if( r1->singleton() )
return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
} else if( r1->singleton() ) {
intptr_t bits1 = r1->get_con();
return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
} else
return TypeInt::CC;
}

//------------------------------Ideal------------------------------------------
// Check for the case of comparing an unknown klass loaded from the primary
// super-type array vs a known klass with no subtypes.  This amounts to
// checking to see an unknown klass subtypes a known klass with no subtypes;
// this only happens on an exact match.  We can shorten this test by 1 load.
Node *CmpPNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
// Constant pointer on right?
const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
if (t2 == NULL || !t2->klass_is_exact())
return NULL;
// Get the constant klass we are comparing to.
ciKlass* superklass = t2->klass();

// Now check for LoadKlass on left.
Node* ldk1 = in(1);
return NULL;
intptr_t con2 = 0;
if (ldk2 == NULL)
return NULL;
if (con2 == oopDesc::klass_offset_in_bytes()) {
// We are inspecting an object's concrete class.
// Short-circuit the check if the query is abstract.
if (superklass->is_interface() ||
superklass->is_abstract()) {
// Make it come out always false:
this->set_req(2, phase->makecon(TypePtr::NULL_PTR));
return this;
}
}

// Check for a LoadKlass from primary supertype array.
// Any nested loadklass from loadklass+con must be from the p.s. array.
return NULL;

// Verify that we understand the situation
if (con2 != (intptr_t) superklass->super_check_offset())

// If 'superklass' has no subklasses and is not an interface, then we are
// assured that the only input which will pass the type check is
// 'superklass' itself.
//
// We could be more liberal here, and allow the optimization on interfaces
// which have a single implementor.  This would require us to increase the
// expressiveness of the add_dependency() mechanism.
// %%% Do this after we fix TypeOopPtr:  Deps are expressive enough now.

// Object arrays must have their base element have no subtypes
while (superklass->is_obj_array_klass()) {
ciType* elem = superklass->as_obj_array_klass()->element_type();
superklass = elem->as_klass();
}
if (superklass->is_instance_klass()) {
ciInstanceKlass* ik = superklass->as_instance_klass();
if (ik->has_subklass() || ik->is_interface())  return NULL;
// Add a dependency if there is a chance that a subclass will be added later.
if (!ik->is_final()) {
phase->C->dependencies()->assert_leaf_type(ik);
}
}

// Bypass the dependent load, and compare directly
this->set_req(1,ldk2);

return this;
}

//=============================================================================
//------------------------------sub--------------------------------------------
// Simplify an CmpN (compare 2 pointers) node, based on local information.
// If both inputs are constants, compare them.
const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
const TypePtr *r0 = t1->is_narrowoop()->make_oopptr(); // Handy access
const TypePtr *r1 = t2->is_narrowoop()->make_oopptr();

// Undefined inputs makes for an undefined result
if( TypePtr::above_centerline(r0->_ptr) ||
TypePtr::above_centerline(r1->_ptr) )
return Type::TOP;

if (r0 == r1 && r0->singleton()) {
// Equal pointer constants (klasses, nulls, etc.)
return TypeInt::CC_EQ;
}

// See if it is 2 unrelated classes.
const TypeOopPtr* p0 = r0->isa_oopptr();
const TypeOopPtr* p1 = r1->isa_oopptr();
if (p0 && p1) {
ciKlass* klass0 = p0->klass();
bool    xklass0 = p0->klass_is_exact();
ciKlass* klass1 = p1->klass();
bool    xklass1 = p1->klass_is_exact();
int kps = (p0->isa_klassptr()?1:0) + (p1->isa_klassptr()?1:0);
if (klass0 && klass1 &&
kps != 1 &&             // both or neither are klass pointers
!klass0->is_interface() && // do not trust interfaces
!klass1->is_interface()) {
// See if neither subclasses the other, or if the class on top
// is precise.  In either of these cases, the compare must fail.
if (klass0->equals(klass1)   ||   // if types are unequal but klasses are
!klass0->is_java_klass() ||   // types not part of Java language?
!klass1->is_java_klass()) {   // types not part of Java language?
// Do nothing; we know nothing for imprecise types
} else if (klass0->is_subtype_of(klass1)) {
// If klass1's type is PRECISE, then we can fail.
if (xklass1)  return TypeInt::CC_GT;
} else if (klass1->is_subtype_of(klass0)) {
// If klass0's type is PRECISE, then we can fail.
if (xklass0)  return TypeInt::CC_GT;
} else {                  // Neither subtypes the other
return TypeInt::CC_GT;  // ...so always fail
}
}
}

// Known constants can be compared exactly
// Null can be distinguished from any NotNull pointers
// Unknown inputs makes an unknown result
if( r0->singleton() ) {
intptr_t bits0 = r0->get_con();
if( r1->singleton() )
return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
} else if( r1->singleton() ) {
intptr_t bits1 = r1->get_con();
return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
} else
return TypeInt::CC;
}

//------------------------------Ideal------------------------------------------
Node *CmpNNode::Ideal( PhaseGVN *phase, bool can_reshape ) {
return NULL;
}

//=============================================================================
//------------------------------Value------------------------------------------
// Simplify an CmpF (compare 2 floats ) node, based on local information.
// If both inputs are constants, compare them.
const Type *CmpFNode::Value( PhaseTransform *phase ) const {
const Node* in1 = in(1);
const Node* in2 = in(2);
// Either input is TOP ==> the result is TOP
const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
if( t1 == Type::TOP ) return Type::TOP;
const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
if( t2 == Type::TOP ) return Type::TOP;

// Not constants?  Don't know squat - even if they are the same
// value!  If they are NaN's they compare to LT instead of EQ.
const TypeF *tf1 = t1->isa_float_constant();
const TypeF *tf2 = t2->isa_float_constant();
if( !tf1 || !tf2 ) return TypeInt::CC;

// This implements the Java bytecode fcmpl, so unordered returns -1.
if( tf1->is_nan() || tf2->is_nan() )
return TypeInt::CC_LT;

if( tf1->_f < tf2->_f ) return TypeInt::CC_LT;
if( tf1->_f > tf2->_f ) return TypeInt::CC_GT;
assert( tf1->_f == tf2->_f, "do not understand FP behavior" );
return TypeInt::CC_EQ;
}

//=============================================================================
//------------------------------Value------------------------------------------
// Simplify an CmpD (compare 2 doubles ) node, based on local information.
// If both inputs are constants, compare them.
const Type *CmpDNode::Value( PhaseTransform *phase ) const {
const Node* in1 = in(1);
const Node* in2 = in(2);
// Either input is TOP ==> the result is TOP
const Type* t1 = (in1 == this) ? Type::TOP : phase->type(in1);
if( t1 == Type::TOP ) return Type::TOP;
const Type* t2 = (in2 == this) ? Type::TOP : phase->type(in2);
if( t2 == Type::TOP ) return Type::TOP;

// Not constants?  Don't know squat - even if they are the same
// value!  If they are NaN's they compare to LT instead of EQ.
const TypeD *td1 = t1->isa_double_constant();
const TypeD *td2 = t2->isa_double_constant();
if( !td1 || !td2 ) return TypeInt::CC;

// This implements the Java bytecode dcmpl, so unordered returns -1.
if( td1->is_nan() || td2->is_nan() )
return TypeInt::CC_LT;

if( td1->_d < td2->_d ) return TypeInt::CC_LT;
if( td1->_d > td2->_d ) return TypeInt::CC_GT;
assert( td1->_d == td2->_d, "do not understand FP behavior" );
return TypeInt::CC_EQ;
}

//------------------------------Ideal------------------------------------------
Node *CmpDNode::Ideal(PhaseGVN *phase, bool can_reshape){
// Check if we can change this to a CmpF and remove a ConvD2F operation.
// Change  (CMPD (F2D (float)) (ConD value))
// To      (CMPF      (float)  (ConF value))
// Valid when 'value' does not lose precision as a float.
// Benefits: eliminates conversion, does not require 24-bit mode

// NaNs prevent commuting operands.  This transform works regardless of the
// order of ConD and ConvF2D inputs by preserving the original order.
int idx_f2d = 1;              // ConvF2D on left side?
if( in(idx_f2d)->Opcode() != Op_ConvF2D )
idx_f2d = 2;                // No, swap to check for reversed args
int idx_con = 3-idx_f2d;      // Check for the constant on other input

if( ConvertCmpD2CmpF &&
in(idx_f2d)->Opcode() == Op_ConvF2D &&
in(idx_con)->Opcode() == Op_ConD ) {
const TypeD *t2 = in(idx_con)->bottom_type()->is_double_constant();
double t2_value_as_double = t2->_d;
float  t2_value_as_float  = (float)t2_value_as_double;
if( t2_value_as_double == (double)t2_value_as_float ) {
// Test value can be represented as a float
// Eliminate the conversion to double and create new comparison
Node *new_in1 = in(idx_f2d)->in(1);
Node *new_in2 = phase->makecon( TypeF::make(t2_value_as_float) );
if( idx_f2d != 1 ) {      // Must flip args to match original order
Node *tmp = new_in1;
new_in1 = new_in2;
new_in2 = tmp;
}
CmpFNode *new_cmp = (Opcode() == Op_CmpD3)
? new (phase->C, 3) CmpF3Node( new_in1, new_in2 )
: new (phase->C, 3) CmpFNode ( new_in1, new_in2 ) ;
return new_cmp;           // Changed to CmpFNode
}
// Testing value required the precision of a double
}
return NULL;                  // No change
}

//=============================================================================
//------------------------------cc2logical-------------------------------------
// Convert a condition code type to a logical type
const Type *BoolTest::cc2logical( const Type *CC ) const {
if( CC == Type::TOP ) return Type::TOP;
if( CC->base() != Type::Int ) return TypeInt::BOOL; // Bottom or worse
const TypeInt *ti = CC->is_int();
if( ti->is_con() ) {          // Only 1 kind of condition codes set?
// Match low order 2 bits
int tmp = ((ti->get_con()&3) == (_test&3)) ? 1 : 0;
if( _test & 4 ) tmp = 1-tmp;     // Optionally complement result
return TypeInt::make(tmp);       // Boolean result
}

if( CC == TypeInt::CC_GE ) {
if( _test == ge ) return TypeInt::ONE;
if( _test == lt ) return TypeInt::ZERO;
}
if( CC == TypeInt::CC_LE ) {
if( _test == le ) return TypeInt::ONE;
if( _test == gt ) return TypeInt::ZERO;
}

return TypeInt::BOOL;
}

//------------------------------dump_spec-------------------------------------
// Print special per-node info
#ifndef PRODUCT
void BoolTest::dump_on(outputStream *st) const {
const char *msg[] = {"eq","gt","??","lt","ne","le","??","ge"};
st->print(msg[_test]);
}
#endif

//=============================================================================
uint BoolNode::hash() const { return (Node::hash() << 3)|(_test._test+1); }
uint BoolNode::size_of() const { return sizeof(BoolNode); }

//------------------------------operator==-------------------------------------
uint BoolNode::cmp( const Node &n ) const {
const BoolNode *b = (const BoolNode *)&n; // Cast up
return (_test._test == b->_test._test);
}

//------------------------------clone_cmp--------------------------------------
// Clone a compare/bool tree
static Node *clone_cmp( Node *cmp, Node *cmp1, Node *cmp2, PhaseGVN *gvn, BoolTest::mask test ) {
Node *ncmp = cmp->clone();
ncmp->set_req(1,cmp1);
ncmp->set_req(2,cmp2);
ncmp = gvn->transform( ncmp );
return new (gvn->C, 2) BoolNode( ncmp, test );
}

//-------------------------------make_predicate--------------------------------
Node* BoolNode::make_predicate(Node* test_value, PhaseGVN* phase) {
if (test_value->is_Con())   return test_value;
if (test_value->is_Bool())  return test_value;
Compile* C = phase->C;
if (test_value->is_CMove() &&
test_value->in(CMoveNode::Condition)->is_Bool()) {
BoolNode*   bol   = test_value->in(CMoveNode::Condition)->as_Bool();
const Type* ftype = phase->type(test_value->in(CMoveNode::IfFalse));
const Type* ttype = phase->type(test_value->in(CMoveNode::IfTrue));
if (ftype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ttype)) {
return bol;
} else if (ttype == TypeInt::ZERO && !TypeInt::ZERO->higher_equal(ftype)) {
return phase->transform( bol->negate(phase) );
}
// Else fall through.  The CMove gets in the way of the test.
// It should be the case that make_predicate(bol->as_int_value()) == bol.
}
Node* cmp = new (C, 3) CmpINode(test_value, phase->intcon(0));
cmp = phase->transform(cmp);
Node* bol = new (C, 2) BoolNode(cmp, BoolTest::ne);
return phase->transform(bol);
}

//--------------------------------as_int_value---------------------------------
Node* BoolNode::as_int_value(PhaseGVN* phase) {
// Inverse to make_predicate.  The CMove probably boils down to a Conv2B.
Node* cmov = CMoveNode::make(phase->C, NULL, this,
phase->intcon(0), phase->intcon(1),
TypeInt::BOOL);
return phase->transform(cmov);
}

//----------------------------------negate-------------------------------------
BoolNode* BoolNode::negate(PhaseGVN* phase) {
Compile* C = phase->C;
return new (C, 2) BoolNode(in(1), _test.negate());
}

//------------------------------Ideal------------------------------------------
Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
// Change "bool tst (cmp con x)" into "bool ~tst (cmp x con)".
// This moves the constant to the right.  Helps value-numbering.
Node *cmp = in(1);
if( !cmp->is_Sub() ) return NULL;
int cop = cmp->Opcode();
if( cop == Op_FastLock || cop == Op_FastUnlock ) return NULL;
Node *cmp1 = cmp->in(1);
Node *cmp2 = cmp->in(2);
if( !cmp1 ) return NULL;

// Constant on left?
Node *con = cmp1;
uint op2 = cmp2->Opcode();
// Move constants to the right of compare's to canonicalize.
// Do not muck with Opaque1 nodes, as this indicates a loop
// guard that cannot change shape.
if( con->is_Con() && !cmp2->is_Con() && op2 != Op_Opaque1 &&
// Because of NaN's, CmpD and CmpF are not commutative
cop != Op_CmpD && cop != Op_CmpF &&
// Protect against swapping inputs to a compare when it is used by a
// counted loop exit, which requires maintaining the loop-limit as in(2)
!is_counted_loop_exit_test() ) {
// Ok, commute the constant to the right of the cmp node.
// Clone the Node, getting a new Node of the same class
cmp = cmp->clone();
// Swap inputs to the clone
cmp->swap_edges(1, 2);
cmp = phase->transform( cmp );
return new (phase->C, 2) BoolNode( cmp, _test.commute() );
}

// Change "bool eq/ne (cmp (xor X 1) 0)" into "bool ne/eq (cmp X 0)".
// The XOR-1 is an idiom used to flip the sense of a bool.  We flip the
int cmp1_op = cmp1->Opcode();
const TypeInt* cmp2_type = phase->type(cmp2)->isa_int();
if (cmp2_type == NULL)  return NULL;
Node* j_xor = cmp1;
if( cmp2_type == TypeInt::ZERO &&
cmp1_op == Op_XorI &&
j_xor->in(1) != j_xor &&          // An xor of itself is dead
phase->type( j_xor->in(2) ) == TypeInt::ONE &&
(_test._test == BoolTest::eq ||
_test._test == BoolTest::ne) ) {
Node *ncmp = phase->transform(new (phase->C, 3) CmpINode(j_xor->in(1),cmp2));
return new (phase->C, 2) BoolNode( ncmp, _test.negate() );
}

// Change "bool eq/ne (cmp (Conv2B X) 0)" into "bool eq/ne (cmp X 0)".
// This is a standard idiom for branching on a boolean value.
Node *c2b = cmp1;
if( cmp2_type == TypeInt::ZERO &&
cmp1_op == Op_Conv2B &&
(_test._test == BoolTest::eq ||
_test._test == BoolTest::ne) ) {
Node *ncmp = phase->transform(phase->type(c2b->in(1))->isa_int()
? (Node*)new (phase->C, 3) CmpINode(c2b->in(1),cmp2)
: (Node*)new (phase->C, 3) CmpPNode(c2b->in(1),phase->makecon(TypePtr::NULL_PTR))
);
return new (phase->C, 2) BoolNode( ncmp, _test._test );
}

// Comparing a SubI against a zero is equal to comparing the SubI
// arguments directly.  This only works for eq and ne comparisons
// due to possible integer overflow.
if ((_test._test == BoolTest::eq || _test._test == BoolTest::ne) &&
(cop == Op_CmpI) &&
(cmp1->Opcode() == Op_SubI) &&
( cmp2_type == TypeInt::ZERO ) ) {
Node *ncmp = phase->transform( new (phase->C, 3) CmpINode(cmp1->in(1),cmp1->in(2)));
return new (phase->C, 2) BoolNode( ncmp, _test._test );
}

// Change (-A vs 0) into (A vs 0) by commuting the test.  Disallow in the
// most general case because negating 0x80000000 does nothing.  Needed for
// the CmpF3/SubI/CmpI idiom.
if( cop == Op_CmpI &&
cmp1->Opcode() == Op_SubI &&
cmp2_type == TypeInt::ZERO &&
phase->type( cmp1->in(1) ) == TypeInt::ZERO &&
phase->type( cmp1->in(2) )->higher_equal(TypeInt::SYMINT) ) {
Node *ncmp = phase->transform( new (phase->C, 3) CmpINode(cmp1->in(2),cmp2));
return new (phase->C, 2) BoolNode( ncmp, _test.commute() );
}

//  The transformation below is not valid for either signed or unsigned
//  comparisons due to wraparound concerns at MAX_VALUE and MIN_VALUE.
//  This transformation can be resurrected when we are able to
//  make inferences about the range of values being subtracted from
//  (or added to) relative to the wraparound point.
//
//    // Remove +/-1's if possible.
//    // "X <= Y-1" becomes "X <  Y"
//    // "X+1 <= Y" becomes "X <  Y"
//    // "X <  Y+1" becomes "X <= Y"
//    // "X-1 <  Y" becomes "X <= Y"
//    // Do not this to compares off of the counted-loop-end.  These guys are
//    // checking the trip counter and they want to use the post-incremented
//    // counter.  If they use the PRE-incremented counter, then the counter has
//    // to be incremented in a private block on a loop backedge.
//    if( du && du->cnt(this) && du->out(this)[0]->Opcode() == Op_CountedLoopEnd )
//      return NULL;
//  #ifndef PRODUCT
//    // Do not do this in a wash GVN pass during verification.
//    // Gets triggered by too many simple optimizations to be bothered with
//    // re-trying it again and again.
//    if( !phase->allow_progress() ) return NULL;
//  #endif
//    // Not valid for unsigned compare because of corner cases in involving zero.
//    // For example, replacing "X-1 <u Y" with "X <=u Y" fails to throw an
//    // exception in case X is 0 (because 0-1 turns into 4billion unsigned but
//    // "0 <=u Y" is always true).
//    if( cmp->Opcode() == Op_CmpU ) return NULL;
//    int cmp2_op = cmp2->Opcode();
//    if( _test._test == BoolTest::le ) {
//      if( cmp1_op == Op_AddI &&
//          phase->type( cmp1->in(2) ) == TypeInt::ONE )
//        return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::lt );
//      else if( cmp2_op == Op_AddI &&
//         phase->type( cmp2->in(2) ) == TypeInt::MINUS_1 )
//        return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::lt );
//    } else if( _test._test == BoolTest::lt ) {
//      if( cmp1_op == Op_AddI &&
//          phase->type( cmp1->in(2) ) == TypeInt::MINUS_1 )
//        return clone_cmp( cmp, cmp1->in(1), cmp2, phase, BoolTest::le );
//      else if( cmp2_op == Op_AddI &&
//         phase->type( cmp2->in(2) ) == TypeInt::ONE )
//        return clone_cmp( cmp, cmp1, cmp2->in(1), phase, BoolTest::le );
//    }

return NULL;
}

//------------------------------Value------------------------------------------
// Simplify a Bool (convert condition codes to boolean (1 or 0)) node,
// based on local information.   If the input is constant, do it.
const Type *BoolNode::Value( PhaseTransform *phase ) const {
return _test.cc2logical( phase->type( in(1) ) );
}

//------------------------------dump_spec--------------------------------------
// Dump special per-node info
#ifndef PRODUCT
void BoolNode::dump_spec(outputStream *st) const {
st->print("[");
_test.dump_on(st);
st->print("]");
}
#endif

//------------------------------is_counted_loop_exit_test--------------------------------------
// Returns true if node is used by a counted loop node.
bool BoolNode::is_counted_loop_exit_test() {
for( DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++ ) {
Node* use = fast_out(i);
if (use->is_CountedLoopEnd()) {
return true;
}
}
return false;
}

//=============================================================================
//------------------------------NegNode----------------------------------------
Node *NegFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
if( in(1)->Opcode() == Op_SubF )
return new (phase->C, 3) SubFNode( in(1)->in(2), in(1)->in(1) );
return NULL;
}

Node *NegDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
if( in(1)->Opcode() == Op_SubD )
return new (phase->C, 3) SubDNode( in(1)->in(2), in(1)->in(1) );
return NULL;
}

//=============================================================================
//------------------------------Value------------------------------------------
// Compute sqrt
const Type *SqrtDNode::Value( PhaseTransform *phase ) const {
const Type *t1 = phase->type( in(1) );
if( t1 == Type::TOP ) return Type::TOP;
if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
double d = t1->getd();
if( d < 0.0 ) return Type::DOUBLE;
return TypeD::make( sqrt( d ) );
}

//=============================================================================
//------------------------------Value------------------------------------------
// Compute cos
const Type *CosDNode::Value( PhaseTransform *phase ) const {
const Type *t1 = phase->type( in(1) );
if( t1 == Type::TOP ) return Type::TOP;
if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
double d = t1->getd();
if( d < 0.0 ) return Type::DOUBLE;
return TypeD::make( SharedRuntime::dcos( d ) );
}

//=============================================================================
//------------------------------Value------------------------------------------
// Compute sin
const Type *SinDNode::Value( PhaseTransform *phase ) const {
const Type *t1 = phase->type( in(1) );
if( t1 == Type::TOP ) return Type::TOP;
if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
double d = t1->getd();
if( d < 0.0 ) return Type::DOUBLE;
return TypeD::make( SharedRuntime::dsin( d ) );
}

//=============================================================================
//------------------------------Value------------------------------------------
// Compute tan
const Type *TanDNode::Value( PhaseTransform *phase ) const {
const Type *t1 = phase->type( in(1) );
if( t1 == Type::TOP ) return Type::TOP;
if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
double d = t1->getd();
if( d < 0.0 ) return Type::DOUBLE;
return TypeD::make( SharedRuntime::dtan( d ) );
}

//=============================================================================
//------------------------------Value------------------------------------------
// Compute log
const Type *LogDNode::Value( PhaseTransform *phase ) const {
const Type *t1 = phase->type( in(1) );
if( t1 == Type::TOP ) return Type::TOP;
if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
double d = t1->getd();
if( d < 0.0 ) return Type::DOUBLE;
return TypeD::make( SharedRuntime::dlog( d ) );
}

//=============================================================================
//------------------------------Value------------------------------------------
// Compute log10
const Type *Log10DNode::Value( PhaseTransform *phase ) const {
const Type *t1 = phase->type( in(1) );
if( t1 == Type::TOP ) return Type::TOP;
if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
double d = t1->getd();
if( d < 0.0 ) return Type::DOUBLE;
return TypeD::make( SharedRuntime::dlog10( d ) );
}

//=============================================================================
//------------------------------Value------------------------------------------
// Compute exp
const Type *ExpDNode::Value( PhaseTransform *phase ) const {
const Type *t1 = phase->type( in(1) );
if( t1 == Type::TOP ) return Type::TOP;
if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
double d = t1->getd();
if( d < 0.0 ) return Type::DOUBLE;
return TypeD::make( SharedRuntime::dexp( d ) );
}

//=============================================================================
//------------------------------Value------------------------------------------
// Compute pow
const Type *PowDNode::Value( PhaseTransform *phase ) const {
const Type *t1 = phase->type( in(1) );
if( t1 == Type::TOP ) return Type::TOP;
if( t1->base() != Type::DoubleCon ) return Type::DOUBLE;
const Type *t2 = phase->type( in(2) );
if( t2 == Type::TOP ) return Type::TOP;
if( t2->base() != Type::DoubleCon ) return Type::DOUBLE;
double d1 = t1->getd();
double d2 = t2->getd();
if( d1 < 0.0 ) return Type::DOUBLE;
if( d2 < 0.0 ) return Type::DOUBLE;
return TypeD::make( SharedRuntime::dpow( d1, d2 ) );
}```