//------------------------------Ideal------------------------------------------
Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
}
// Floating point additions are not associative because of boundary conditions (infinity)
return commute(this,
phase->type( in(1) )->singleton(),
phase->type( in(2) )->singleton() ) ? this : NULL;
}
bool
can_pull (patch p1, patch p2) {
return commute (p2, p1);
}
//------------------------------Idealize---------------------------------------
// If we get here, we assume we are associative!
Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
const Type *t1 = phase->type( in(1) );
const Type *t2 = phase->type( in(2) );
int con_left = t1->singleton();
int con_right = t2->singleton();
// Check for commutative operation desired
if( commute(this,con_left,con_right) ) return this;
AddNode *progress = NULL; // Progress flag
// Convert "(x+1)+2" into "x+(1+2)". If the right input is a
// constant, and the left input is an add of a constant, flatten the
// expression tree.
Node *add1 = in(1);
Node *add2 = in(2);
int add1_op = add1->Opcode();
int this_op = Opcode();
if( con_right && t2 != Type::TOP && // Right input is a constant?
add1_op == this_op ) { // Left input is an Add?
// Type of left _in right input
const Type *t12 = phase->type( add1->in(2) );
if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
// Check for rare case of closed data cycle which can happen inside
// unreachable loops. In these cases the computation is undefined.
#ifdef ASSERT
Node *add11 = add1->in(1);
int add11_op = add11->Opcode();
if( (add1 == add1->in(1))
|| (add11_op == this_op && add11->in(1) == add1) ) {
assert(false, "dead loop in AddNode::Ideal");
}
#endif
// The Add of the flattened expression
Node *x1 = add1->in(1);
Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 ));
PhaseIterGVN *igvn = phase->is_IterGVN();
if( igvn ) {
set_req_X(2,x2,igvn);
set_req_X(1,x1,igvn);
} else {
set_req(2,x2);
set_req(1,x1);
}
progress = this; // Made progress
add1 = in(1);
add1_op = add1->Opcode();
}
}
// 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)) &&
!(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);
set_req(2, a12);
progress = this;
add2 = a12;
}
}
// 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)) &&
!(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);
set_req(1, addx);
set_req(2, a22);
progress = this;
PhaseIterGVN *igvn = phase->is_IterGVN();
if (add2->outcnt() == 0 && igvn) {
// add disconnected.
igvn->_worklist.push(add2);
}
}
}
return progress;
}
bool
can_pull (modification m1, modification m2) {
return commute (m2, m1);
}
