Mercurial > hg > graal-compiler
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/calc/UnsignedRightShiftNode.java @ 11851:04b039d82e86
Simplify constant folding.
author | Roland Schatz <roland.schatz@oracle.com> |
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date | Wed, 02 Oct 2013 12:09:51 +0200 |
parents | 2ad1435489d1 |
children | 673f93db4adc |
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/* * Copyright (c) 2011, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.oracle.graal.nodes.calc; import com.oracle.graal.api.meta.*; import com.oracle.graal.graph.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.spi.*; import com.oracle.graal.nodes.type.*; @NodeInfo(shortName = ">>>") public final class UnsignedRightShiftNode extends ShiftNode implements Canonicalizable { public UnsignedRightShiftNode(Kind kind, ValueNode x, ValueNode y) { super(kind, x, y); } @Override public boolean inferStamp() { return updateStamp(StampTool.unsignedRightShift(x().stamp(), y().stamp())); } @Override public Constant evalConst(Constant... inputs) { assert inputs.length == 2; if (kind() == Kind.Int) { return Constant.forInt(inputs[0].asInt() >>> inputs[1].asInt()); } else { assert kind() == Kind.Long; return Constant.forLong(inputs[0].asLong() >>> inputs[1].asLong()); } } @Override public ValueNode canonical(CanonicalizerTool tool) { if (x().isConstant() && y().isConstant()) { return ConstantNode.forPrimitive(evalConst(x().asConstant(), y().asConstant()), graph()); } else if (y().isConstant()) { int amount = y().asConstant().asInt(); int originalAmout = amount; int mask; if (kind() == Kind.Int) { mask = 0x1f; } else { assert kind() == Kind.Long; mask = 0x3f; } amount &= mask; if (amount == 0) { return x(); } if (x() instanceof ShiftNode) { ShiftNode other = (ShiftNode) x(); if (other.y().isConstant()) { int otherAmount = other.y().asConstant().asInt() & mask; if (other instanceof UnsignedRightShiftNode) { int total = amount + otherAmount; if (total != (total & mask)) { return ConstantNode.forIntegerKind(kind(), 0, graph()); } return graph().unique(new UnsignedRightShiftNode(kind(), other.x(), ConstantNode.forInt(total, graph()))); } else if (other instanceof LeftShiftNode && otherAmount == amount) { if (kind() == Kind.Long) { return graph().unique(new AndNode(kind(), other.x(), ConstantNode.forLong(-1L >>> amount, graph()))); } else { assert kind() == Kind.Int; return graph().unique(new AndNode(kind(), other.x(), ConstantNode.forInt(-1 >>> amount, graph()))); } } } } if (originalAmout != amount) { return graph().unique(new UnsignedRightShiftNode(kind(), x(), ConstantNode.forInt(amount, graph()))); } } return this; } @Override public void generate(ArithmeticLIRGenerator gen) { gen.setResult(this, gen.emitUShr(gen.operand(x()), gen.operand(y()))); } }