Mercurial > hg > graal-compiler
view src/share/vm/opto/rootnode.cpp @ 1333:3f12a94552cc
Added tag jdk7-b88 for changeset 4b60f23c4223
author | mikejwre |
---|---|
date | Thu, 08 Apr 2010 17:02:41 -0700 |
parents | a61af66fc99e |
children | c18cbe5936b8 |
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/* * Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ #include "incls/_precompiled.incl" #include "incls/_rootnode.cpp.incl" //------------------------------Ideal------------------------------------------ // Remove dead inputs Node *RootNode::Ideal(PhaseGVN *phase, bool can_reshape) { for( uint i = 1; i < req(); i++ ) { // For all inputs // Check for and remove dead inputs if( phase->type(in(i)) == Type::TOP ) { del_req(i--); // Delete TOP inputs } } // I used to do tail-splitting in the Ideal graph here, but it does not // work. The tail-splitting forces values live into the Return to be // ready at a point which dominates the split returns. This forces Stores // to be hoisted high. The "proper" fix would be to split Stores down // each path, but this makes the split unprofitable. If we want to do this // optimization, it needs to be done after allocation so we can count all // the instructions needing to be cloned in the cost metric. // There used to be a spoof here for caffeine marks which completely // eliminated very simple self-recursion recursions, but it's not worth it. // Deep inlining of self-calls gets nearly all of the same benefits. // If we want to get the rest of the win later, we should pattern match // simple recursive call trees to closed-form solutions. return NULL; // No further opportunities exposed } //============================================================================= HaltNode::HaltNode( Node *ctrl, Node *frameptr ) : Node(TypeFunc::Parms) { Node* top = Compile::current()->top(); init_req(TypeFunc::Control, ctrl ); init_req(TypeFunc::I_O, top); init_req(TypeFunc::Memory, top); init_req(TypeFunc::FramePtr, frameptr ); init_req(TypeFunc::ReturnAdr,top); } const Type *HaltNode::bottom_type() const { return Type::BOTTOM; } //------------------------------Ideal------------------------------------------ Node *HaltNode::Ideal(PhaseGVN *phase, bool can_reshape) { return remove_dead_region(phase, can_reshape) ? this : NULL; } //------------------------------Value------------------------------------------ const Type *HaltNode::Value( PhaseTransform *phase ) const { return ( phase->type(in(TypeFunc::Control)) == Type::TOP) ? Type::TOP : Type::BOTTOM; } const RegMask &HaltNode::out_RegMask() const { return RegMask::Empty; }