*** old/src/share/vm/opto/addnode.cpp	Wed Oct  1 10:07:14 2008
--- new/src/share/vm/opto/addnode.cpp	Wed Oct  1 10:07:14 2008

*** 154,164 ****
--- 154,165 ----
  
    // Convert "(x+1)+y" into "(x+y)+1".  Push constants down the expression tree.
    if( add1_op == this_op && !con_right ) {
      Node *a12 = add1->in(2);
      const Type *t12 = phase->type( a12 );
!     if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) ) {
!     if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) &&
+        !(add1->in(1)->is_Phi() && add1->in(1)->as_Phi()->is_tripcount()) ) {
        assert(add1->in(1) != this, "dead loop in AddNode::Ideal");
        add2 = add1->clone();
        add2->set_req(2, in(2));
        add2 = phase->transform(add2);
        set_req(1, add2);

*** 171,181 ****
--- 172,183 ----
    // Convert "x+(y+1)" into "(x+y)+1".  Push constants down the expression tree.
    int add2_op = add2->Opcode();
    if( add2_op == this_op && !con_left ) {
      Node *a22 = add2->in(2);
      const Type *t22 = phase->type( a22 );
!     if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) ) {
!     if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) &&
+        !(add2->in(1)->is_Phi() && add2->in(1)->as_Phi()->is_tripcount()) ) {
        assert(add2->in(1) != this, "dead loop in AddNode::Ideal");
        Node *addx = add2->clone();
        addx->set_req(1, in(1));
        addx->set_req(2, add2->in(1));
        addx = phase->transform(addx);

*** 223,260 ****
--- 225,291 ----
  
  
  //=============================================================================
  //------------------------------Idealize---------------------------------------
  Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) {
!   int op1 = in(1)->Opcode();
!   int op2 = in(2)->Opcode();
!   Node* in1 = in(1);
!   Node* in2 = in(2);
+   int op1 = in1->Opcode();
+   int op2 = in2->Opcode();
    // Fold (con1-x)+con2 into (con1+con2)-x
+   if ( op1 == Op_AddI && op2 == Op_SubI ) {
+     // Swap edges to try optimizations below
+     in1 = in2;
+     in2 = in(1);
+     op1 = op2;
+     op2 = in2->Opcode();
+   }
    if( op1 == Op_SubI ) {
!     const Type *t_sub1 = phase->type( in(1)->in(1) );
!     const Type *t_2    = phase->type( in(2)        );
!     const Type *t_2    = phase->type( in2        );
      if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
        return new (phase->C, 3) SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ),
!                               in(1)->in(2) );
      // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
      if( op2 == Op_SubI ) {
        // Check for dead cycle: d = (a-b)+(c-d)
!       assert( in(1)->in(2) != this && in(2)->in(2) != this,
!       assert( in1->in(2) != this && in2->in(2) != this,
                "dead loop in AddINode::Ideal" );
        Node *sub  = new (phase->C, 3) SubINode(NULL, NULL);
!       sub->init_req(1, phase->transform(new (phase->C, 3) AddINode(in(1)->in(1), in(2)->in(1) ) ));
!       sub->init_req(2, phase->transform(new (phase->C, 3) AddINode(in(1)->in(2), in(2)->in(2) ) ));
!       sub->init_req(1, phase->transform(new (phase->C, 3) AddINode(in1->in(1), in2->in(1) ) ));
!       sub->init_req(2, phase->transform(new (phase->C, 3) AddINode(in1->in(2), in2->in(2) ) ));
        return sub;
      }
+     // Convert "(a-b)+(b+c)" into "(a+c)"
+     if( op2 == Op_AddI && in1->in(2) == in2->in(1) ) {
+       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
+       return new (phase->C, 3) AddINode(in1->in(1), in2->in(2));
      }
+     // Convert "(a-b)+(c+b)" into "(a+c)"
+     if( op2 == Op_AddI && in1->in(2) == in2->in(2) ) {
+       assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
+       return new (phase->C, 3) AddINode(in1->in(1), in2->in(1));
+     }
+     // Convert "(a-b)+(b-c)" into "(a-c)"
+     if( op2 == Op_SubI && in1->in(2) == in2->in(1) ) {
+       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
+       return new (phase->C, 3) SubINode(in1->in(1), in2->in(2));
+     }
+     // Convert "(a-b)+(c-a)" into "(c-b)"
+     if( op2 == Op_SubI && in1->in(1) == in2->in(2) ) {
+       assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
+       return new (phase->C, 3) SubINode(in2->in(1), in1->in(2));
+     }
+   }
  
    // Convert "x+(0-y)" into "(x-y)"
!   if( op2 == Op_SubI && phase->type(in(2)->in(1)) == TypeInt::ZERO )
!     return new (phase->C, 3) SubINode(in(1), in(2)->in(2) );
!     return new (phase->C, 3) SubINode(in1, in2->in(2) );
  
    // Convert "(0-y)+x" into "(x-y)"
!   if( op1 == Op_SubI && phase->type(in(1)->in(1)) == TypeInt::ZERO )
!     return new (phase->C, 3) SubINode( in(2), in(1)->in(2) );
!     return new (phase->C, 3) SubINode( in2, in1->in(2) );
  
    // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
    // Helps with array allocation math constant folding
    // See 4790063:
    // Unrestricted transformation is unsafe for some runtime values of 'x'

*** 264,282 ****
--- 295,313 ----
    // (x + (y << z)) does not cross zero.
    // Implement support for negative y and (x >= -(y << z))
    // Have not observed cases where type information exists to support
    // positive y and (x <= -(y << z))
    if( op1 == Op_URShiftI && op2 == Op_ConI &&
!       in(1)->in(2)->Opcode() == Op_ConI ) {
!     jint z = phase->type( in(1)->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
!     jint y = phase->type( in(2) )->is_int()->get_con();
!     jint z = phase->type( in1->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
!     jint y = phase->type( in2 )->is_int()->get_con();
  
      if( z < 5 && -5 < y && y < 0 ) {
!       const Type *t_in11 = phase->type(in(1)->in(1));
        if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) {
!         Node *a = phase->transform( new (phase->C, 3) AddINode( in(1)->in(1), phase->intcon(y<
!         return new (phase->C, 3) URShiftINode( a, in(1)->in(2) );
!         return new (phase->C, 3) URShiftINode( a, in1->in(2) );
        }
      }
    }
  
    return AddNode::Ideal(phase, can_reshape);

*** 326,368 ****
--- 357,433 ----
  
  
  //=============================================================================
  //------------------------------Idealize---------------------------------------
  Node *AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
!   int op1 = in(1)->Opcode();
!   int op2 = in(2)->Opcode();
!   Node* in1 = in(1);
!   Node* in2 = in(2);
+   int op1 = in1->Opcode();
+   int op2 = in2->Opcode();
    // Fold (con1-x)+con2 into (con1+con2)-x
+   if ( op1 == Op_AddL && op2 == Op_SubL ) {
+     // Swap edges to try optimizations below
+     in1 = in2;
+     in2 = in(1);
+     op1 = op2;
+     op2 = in2->Opcode();
+   }
+   // Fold (con1-x)+con2 into (con1+con2)-x
    if( op1 == Op_SubL ) {
!     const Type *t_sub1 = phase->type( in(1)->in(1) );
!     const Type *t_2    = phase->type( in(2)        );
!     const Type *t_2    = phase->type( in2        );
      if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
        return new (phase->C, 3) SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ),
!                               in(1)->in(2) );
      // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
      if( op2 == Op_SubL ) {
        // Check for dead cycle: d = (a-b)+(c-d)
!       assert( in(1)->in(2) != this && in(2)->in(2) != this,
!       assert( in1->in(2) != this && in2->in(2) != this,
                "dead loop in AddLNode::Ideal" );
        Node *sub  = new (phase->C, 3) SubLNode(NULL, NULL);
!       sub->init_req(1, phase->transform(new (phase->C, 3) AddLNode(in(1)->in(1), in(2)->in(1) ) ));
!       sub->init_req(2, phase->transform(new (phase->C, 3) AddLNode(in(1)->in(2), in(2)->in(2) ) ));
!       sub->init_req(1, phase->transform(new (phase->C, 3) AddLNode(in1->in(1), in2->in(1) ) ));
!       sub->init_req(2, phase->transform(new (phase->C, 3) AddLNode(in1->in(2), in2->in(2) ) ));
        return sub;
      }
+     // Convert "(a-b)+(b+c)" into "(a+c)"
+     if( op2 == Op_AddL && in1->in(2) == in2->in(1) ) {
+       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
+       return new (phase->C, 3) AddLNode(in1->in(1), in2->in(2));
      }
+     // Convert "(a-b)+(c+b)" into "(a+c)"
+     if( op2 == Op_AddL && in1->in(2) == in2->in(2) ) {
+       assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
+       return new (phase->C, 3) AddLNode(in1->in(1), in2->in(1));
+     }
+     // Convert "(a-b)+(b-c)" into "(a-c)"
+     if( op2 == Op_SubL && in1->in(2) == in2->in(1) ) {
+       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
+       return new (phase->C, 3) SubLNode(in1->in(1), in2->in(2));
+     }
+     // Convert "(a-b)+(c-a)" into "(c-b)"
+     if( op2 == Op_SubL && in1->in(1) == in1->in(2) ) {
+       assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
+       return new (phase->C, 3) SubLNode(in2->in(1), in1->in(2));
+     }
+   }
  
    // Convert "x+(0-y)" into "(x-y)"
!   if( op2 == Op_SubL && phase->type(in(2)->in(1)) == TypeLong::ZERO )
!     return new (phase->C, 3) SubLNode(in(1), in(2)->in(2) );
!     return new (phase->C, 3) SubLNode( in1, in2->in(2) );
  
+   // Convert "(0-y)+x" into "(x-y)"
+   if( op1 == Op_SubL && phase->type(in1->in(1)) == TypeInt::ZERO )
+     return new (phase->C, 3) SubLNode( in2, in1->in(2) );
+ 
    // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)"
    // into "(X<<1)+Y" and let shift-folding happen.
    if( op2 == Op_AddL &&
!       in(2)->in(1) == in(1) &&
!       in2->in(1) == in1 &&
        op1 != Op_ConL &&
        0 ) {
!     Node *shift = phase->transform(new (phase->C, 3) LShiftLNode(in(1),phase->intcon(1)));
!     return new (phase->C, 3) AddLNode(shift,in(2)->in(2));
!     return new (phase->C, 3) AddLNode(shift,in2->in(2));
    }
  
    return AddNode::Ideal(phase, can_reshape);
  }