--- /dev/null 2016-05-31 09:42:47.975716356 -0700 +++ new/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.replacements/src/org/graalvm/compiler/replacements/nodes/arithmetic/IntegerMulExactNode.java 2016-12-09 00:57:13.531775517 -0800 @@ -0,0 +1,166 @@ +/* + * Copyright (c) 2013, 2015, 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 org.graalvm.compiler.replacements.nodes.arithmetic; + +import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_4; +import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_2; + +import org.graalvm.compiler.core.common.type.IntegerStamp; +import org.graalvm.compiler.graph.NodeClass; +import org.graalvm.compiler.graph.spi.CanonicalizerTool; +import org.graalvm.compiler.nodeinfo.NodeInfo; +import org.graalvm.compiler.nodes.AbstractBeginNode; +import org.graalvm.compiler.nodes.ConstantNode; +import org.graalvm.compiler.nodes.ValueNode; +import org.graalvm.compiler.nodes.calc.MulNode; +import org.graalvm.compiler.nodes.spi.LoweringTool; + +import jdk.vm.ci.meta.JavaConstant; +import jdk.vm.ci.meta.JavaKind; + +/** + * Node representing an exact integer multiplication that will throw an {@link ArithmeticException} + * in case the addition would overflow the 32 bit range. + */ +@NodeInfo(cycles = CYCLES_4, cyclesRationale = "mul+cmp", size = SIZE_2) +public final class IntegerMulExactNode extends MulNode implements IntegerExactArithmeticNode { + public static final NodeClass TYPE = NodeClass.create(IntegerMulExactNode.class); + + public IntegerMulExactNode(ValueNode x, ValueNode y) { + super(TYPE, x, y); + setStamp(x.stamp().unrestricted()); + assert x.stamp().isCompatible(y.stamp()) && x.stamp() instanceof IntegerStamp; + } + + @Override + public boolean inferStamp() { + /* + * Note: it is not allowed to use the foldStamp method of the regular mul node as we do not + * know the result stamp of this node if we do not know whether we may deopt. If we know we + * can never overflow we will replace this node with its non overflow checking counterpart + * anyway. + */ + return false; + } + + @Override + public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) { + if (forX.isConstant() && !forY.isConstant()) { + return new IntegerMulExactNode(forY, forX); + } + if (forX.isConstant()) { + return canonicalXconstant(forX, forY); + } else if (forY.isConstant()) { + long c = forY.asJavaConstant().asLong(); + if (c == 1) { + return forX; + } + if (c == 0) { + return ConstantNode.forIntegerStamp(stamp(), 0); + } + } + if (!mayOverFlow((IntegerStamp) x.stamp(), (IntegerStamp) y.stamp())) { + return new MulNode(x, y).canonical(tool); + } + return this; + } + + private static boolean mayOverFlow(IntegerStamp a, IntegerStamp b) { + // see IntegerStamp#foldStamp for details + assert a.getBits() == b.getBits(); + if (a.upMask() == 0) { + return false; + } else if (b.upMask() == 0) { + return false; + } + if (a.isUnrestricted()) { + return true; + } + if (b.isUnrestricted()) { + return true; + } + int bits = a.getBits(); + // Checkstyle: stop + long minN_a = a.lowerBound(); + long maxN_a = Math.min(0, a.upperBound()); + long minP_a = Math.max(0, a.lowerBound()); + long maxP_a = a.upperBound(); + + long minN_b = b.lowerBound(); + long maxN_b = Math.min(0, b.upperBound()); + long minP_b = Math.max(0, b.lowerBound()); + long maxP_b = b.upperBound(); + // Checkstyle: resume + + boolean mayOverflow = false; + if (a.canBePositive()) { + if (b.canBePositive()) { + mayOverflow |= IntegerStamp.multiplicationOverflows(maxP_a, maxP_b, bits); + mayOverflow |= IntegerStamp.multiplicationOverflows(minP_a, minP_b, bits); + } + if (b.canBeNegative()) { + mayOverflow |= IntegerStamp.multiplicationOverflows(minP_a, maxN_b, bits); + mayOverflow |= IntegerStamp.multiplicationOverflows(maxP_a, minN_b, bits); + + } + } + if (a.canBeNegative()) { + if (b.canBePositive()) { + mayOverflow |= IntegerStamp.multiplicationOverflows(maxN_a, minP_b, bits); + mayOverflow |= IntegerStamp.multiplicationOverflows(minN_a, maxP_b, bits); + } + if (b.canBeNegative()) { + mayOverflow |= IntegerStamp.multiplicationOverflows(minN_a, minN_b, bits); + mayOverflow |= IntegerStamp.multiplicationOverflows(maxN_a, maxN_b, bits); + } + } + return mayOverflow; + } + + private ValueNode canonicalXconstant(ValueNode forX, ValueNode forY) { + JavaConstant xConst = forX.asJavaConstant(); + JavaConstant yConst = forY.asJavaConstant(); + assert xConst.getJavaKind() == yConst.getJavaKind(); + try { + if (xConst.getJavaKind() == JavaKind.Int) { + return ConstantNode.forInt(Math.multiplyExact(xConst.asInt(), yConst.asInt())); + } else { + assert xConst.getJavaKind() == JavaKind.Long; + return ConstantNode.forLong(Math.multiplyExact(xConst.asLong(), yConst.asLong())); + } + } catch (ArithmeticException ex) { + // The operation will result in an overflow exception, so do not canonicalize. + } + return this; + } + + @Override + public IntegerExactArithmeticSplitNode createSplit(AbstractBeginNode next, AbstractBeginNode deopt) { + return graph().add(new IntegerMulExactSplitNode(stamp(), getX(), getY(), next, deopt)); + } + + @Override + public void lower(LoweringTool tool) { + IntegerExactArithmeticSplitNode.lower(tool, this); + } +}