duke@435: /*
duke@435:  * Copyright 1997-2005 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: #include "incls/_precompiled.incl"
duke@435: #include "incls/_rootnode.cpp.incl"
duke@435: 
duke@435: //------------------------------Ideal------------------------------------------
duke@435: // Remove dead inputs
duke@435: Node *RootNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@435:   for( uint i = 1; i < req(); i++ ) { // For all inputs
duke@435:     // Check for and remove dead inputs
duke@435:     if( phase->type(in(i)) == Type::TOP ) {
duke@435:       del_req(i--);             // Delete TOP inputs
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // I used to do tail-splitting in the Ideal graph here, but it does not
duke@435:   // work.  The tail-splitting forces values live into the Return to be
duke@435:   // ready at a point which dominates the split returns.  This forces Stores
duke@435:   // to be hoisted high.  The "proper" fix would be to split Stores down
duke@435:   // each path, but this makes the split unprofitable.  If we want to do this
duke@435:   // optimization, it needs to be done after allocation so we can count all
duke@435:   // the instructions needing to be cloned in the cost metric.
duke@435: 
duke@435:   // There used to be a spoof here for caffeine marks which completely
duke@435:   // eliminated very simple self-recursion recursions, but it's not worth it.
duke@435:   // Deep inlining of self-calls gets nearly all of the same benefits.
duke@435:   // If we want to get the rest of the win later, we should pattern match
duke@435:   // simple recursive call trees to closed-form solutions.
duke@435: 
duke@435:   return NULL;                  // No further opportunities exposed
duke@435: }
duke@435: 
duke@435: //=============================================================================
duke@435: HaltNode::HaltNode( Node *ctrl, Node *frameptr ) : Node(TypeFunc::Parms) {
duke@435:   Node* top = Compile::current()->top();
duke@435:   init_req(TypeFunc::Control,  ctrl        );
duke@435:   init_req(TypeFunc::I_O,      top);
duke@435:   init_req(TypeFunc::Memory,   top);
duke@435:   init_req(TypeFunc::FramePtr, frameptr    );
duke@435:   init_req(TypeFunc::ReturnAdr,top);
duke@435: }
duke@435: 
duke@435: const Type *HaltNode::bottom_type() const { return Type::BOTTOM; }
duke@435: 
duke@435: //------------------------------Ideal------------------------------------------
duke@435: Node *HaltNode::Ideal(PhaseGVN *phase, bool can_reshape) {
duke@435:   return remove_dead_region(phase, can_reshape) ? this : NULL;
duke@435: }
duke@435: 
duke@435: //------------------------------Value------------------------------------------
duke@435: const Type *HaltNode::Value( PhaseTransform *phase ) const {
duke@435:   return ( phase->type(in(TypeFunc::Control)) == Type::TOP)
duke@435:     ? Type::TOP
duke@435:     : Type::BOTTOM;
duke@435: }
duke@435: 
duke@435: const RegMask &HaltNode::out_RegMask() const {
duke@435:   return RegMask::Empty;
duke@435: }