| /* |
| * 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<IntegerMulExactNode> 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); |
| } |
| } |
