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comparison src/share/vm/opto/subnode.cpp @ 235:9c2ecc2ffb12 jdk7-b31

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Merge
author trims
date Fri, 11 Jul 2008 01:14:44 -0700
parents d1605aabd0a1 1e026f8da827
children c3e045194476
comparison
equal deleted inserted replaced
197:de141433919f 235:9c2ecc2ffb12
43 in(2)->Opcode() == Opcode() && 43 in(2)->Opcode() == Opcode() &&
44 phase->type( in(2)->in(1) )->higher_equal( zero ) ) { 44 phase->type( in(2)->in(1) )->higher_equal( zero ) ) {
45 return in(2)->in(2); 45 return in(2)->in(2);
46 } 46 }
47 47
48 // Convert "(X+Y) - Y" into X 48 // Convert "(X+Y) - Y" into X and "(X+Y) - X" into Y
49 if( in(1)->Opcode() == Op_AddI ) { 49 if( in(1)->Opcode() == Op_AddI ) {
50 if( phase->eqv(in(1)->in(2),in(2)) ) 50 if( phase->eqv(in(1)->in(2),in(2)) )
51 return in(1)->in(1); 51 return in(1)->in(1);
52 if (phase->eqv(in(1)->in(1),in(2)))
53 return in(1)->in(2);
54
52 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying 55 // Also catch: "(X + Opaque2(Y)) - Y". In this case, 'Y' is a loop-varying
53 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes 56 // trip counter and X is likely to be loop-invariant (that's how O2 Nodes
54 // are originally used, although the optimizer sometimes jiggers things). 57 // are originally used, although the optimizer sometimes jiggers things).
55 // This folding through an O2 removes a loop-exit use of a loop-varying 58 // This folding through an O2 removes a loop-exit use of a loop-varying
56 // value and generally lowers register pressure in and around the loop. 59 // value and generally lowers register pressure in and around the loop.
738 //============================================================================= 741 //=============================================================================
739 //------------------------------sub-------------------------------------------- 742 //------------------------------sub--------------------------------------------
740 // Simplify an CmpN (compare 2 pointers) node, based on local information. 743 // Simplify an CmpN (compare 2 pointers) node, based on local information.
741 // If both inputs are constants, compare them. 744 // If both inputs are constants, compare them.
742 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const { 745 const Type *CmpNNode::sub( const Type *t1, const Type *t2 ) const {
743 const TypePtr *r0 = t1->is_narrowoop()->make_oopptr(); // Handy access 746 const TypePtr *r0 = t1->make_ptr(); // Handy access
744 const TypePtr *r1 = t2->is_narrowoop()->make_oopptr(); 747 const TypePtr *r1 = t2->make_ptr();
745 748
746 // Undefined inputs makes for an undefined result 749 // Undefined inputs makes for an undefined result
747 if( TypePtr::above_centerline(r0->_ptr) || 750 if( TypePtr::above_centerline(r0->_ptr) ||
748 TypePtr::above_centerline(r1->_ptr) ) 751 TypePtr::above_centerline(r1->_ptr) )
749 return Type::TOP; 752 return Type::TOP;