src/share/vm/opto/ifnode.cpp

*** 1623,1632 ****
--- 1623,1643 ----
    }
    // no progress
    return this;
  }
  
+ Node* IfProjNode::Ideal(PhaseGVN* phase, bool can_reshape) {
+   const Type* t = phase->type(in(0));
+   if (in(0)->outcnt() == 2 && t != Type::TOP && always_taken(t->is_tuple())) {
+     // cut off dead branch if this branch is always taken
+     Node* other = in(0)->as_If()->proj_out(!is_IfTrue());
+     other->set_req(0, phase->C->top());
+     return this;
+   }
+   return NULL;
+ }
+ 
  #ifndef PRODUCT
  //-------------------------------related---------------------------------------
  // An IfProjNode's related node set consists of its input (an IfNode) including
  // the IfNode's condition, plus all of its outputs at level 1. In compact mode,
  // the restrictions for IfNode apply (see IfNode::rel).