org.graalvm.compiler.nodes.calc.IntegerBelowNode Maven / Gradle / Ivy
/*
* Copyright (c) 2011, 2021, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* 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.nodes.calc;
import org.graalvm.compiler.core.common.NumUtil;
import org.graalvm.compiler.core.common.calc.CanonicalCondition;
import org.graalvm.compiler.core.common.type.IntegerStamp;
import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.core.common.type.StampFactory;
import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.LogicConstantNode;
import org.graalvm.compiler.nodes.LogicNegationNode;
import org.graalvm.compiler.nodes.LogicNode;
import org.graalvm.compiler.nodes.NodeView;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.spi.CanonicalizerTool;
import org.graalvm.compiler.options.OptionValues;
import jdk.vm.ci.code.CodeUtil;
import jdk.vm.ci.meta.Constant;
import jdk.vm.ci.meta.ConstantReflectionProvider;
import jdk.vm.ci.meta.MetaAccessProvider;
import jdk.vm.ci.meta.PrimitiveConstant;
import jdk.vm.ci.meta.TriState;
@NodeInfo(shortName = "|<|")
public final class IntegerBelowNode extends IntegerLowerThanNode {
public static final NodeClass TYPE = NodeClass.create(IntegerBelowNode.class);
private static final BelowOp OP = new BelowOp();
public IntegerBelowNode(ValueNode x, ValueNode y) {
super(TYPE, x, y, OP);
Stamp xStamp = x.stamp(NodeView.DEFAULT);
Stamp yStamp = y.stamp(NodeView.DEFAULT);
assert xStamp.isIntegerStamp() : "expected integer x value: " + x;
assert yStamp.isIntegerStamp() : "expected integer y value: " + y;
assert xStamp.isCompatible(yStamp) : "expected compatible stamps: " + xStamp + " / " + yStamp;
}
public static LogicNode create(ValueNode x, ValueNode y, NodeView view) {
return OP.create(x, y, view);
}
public static LogicNode create(ConstantReflectionProvider constantReflection, MetaAccessProvider metaAccess, OptionValues options, Integer smallestCompareWidth, ValueNode x, ValueNode y,
NodeView view) {
LogicNode value = OP.canonical(constantReflection, metaAccess, options, smallestCompareWidth, OP.getCondition(), false, x, y, view);
if (value != null) {
return value;
}
return create(x, y, view);
}
@Override
public Node canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
NodeView view = NodeView.from(tool);
ValueNode value = OP.canonical(tool.getConstantReflection(), tool.getMetaAccess(), tool.getOptions(), tool.smallestCompareWidth(), OP.getCondition(), false, forX, forY, view);
if (value != null) {
return value;
}
return this;
}
public static class BelowOp extends LowerOp {
@Override
protected CompareNode duplicateModified(ValueNode newX, ValueNode newY, boolean unorderedIsTrue, NodeView view) {
assert newX.stamp(NodeView.DEFAULT) instanceof IntegerStamp && newY.stamp(NodeView.DEFAULT) instanceof IntegerStamp;
return new IntegerBelowNode(newX, newY);
}
@Override
protected LogicNode optimizeNormalizeCompare(ConstantReflectionProvider constantReflection, MetaAccessProvider metaAccess, OptionValues options, Integer smallestCompareWidth,
Constant constant, AbstractNormalizeCompareNode normalizeNode, boolean mirrored, NodeView view) {
PrimitiveConstant primitive = (PrimitiveConstant) constant;
long c = primitive.asLong();
/*
* Optimize comparisons like:
*
* @formatter:off
* (a NC b) |<| c (not mirrored)
* c |<| (a NC b) (mirrored)
* @formatter:on
*
* (a NC b) is always (-1, 0, 1) corresponding to a (<, ==, >) b according to some signed or unsigned ordering.
*/
if (mirrored) {
/* @formatter:off
* c |<| (a NC b) (mirrored)
* cases for c:
* UMAX (=-1) -> false
* 0 -> a != b
* [1, UMAX-1] -> a < b
* @formatter:on
*/
if (c == -1) {
return LogicConstantNode.contradiction();
} else if (c == 0) {
LogicNode equal = normalizeNode.createEqualComparison(constantReflection, metaAccess, options, smallestCompareWidth, view);
return LogicNegationNode.create(equal);
} else {
return normalizeNode.createLowerComparison(constantReflection, metaAccess, options, smallestCompareWidth, view);
}
} else {
/* @formatter:off
* (a NC b) |<| c (not mirrored)
* cases for c:
* 0 -> false
* 1 -> a == b
* [2, UMAX] -> a >= b
* @formatter:on
*/
if (c == 0) {
return LogicConstantNode.contradiction();
} else if (c == 1) {
return normalizeNode.createEqualComparison(constantReflection, metaAccess, options, smallestCompareWidth, view);
} else {
// a >= b -> !(a < b)
LogicNode compare = normalizeNode.createLowerComparison(constantReflection, metaAccess, options, smallestCompareWidth, view);
return LogicNegationNode.create(compare);
}
}
}
@Override
protected LogicNode findSynonym(ValueNode forX, ValueNode forY, NodeView view) {
LogicNode result = super.findSynonym(forX, forY, view);
if (result != null) {
return result;
}
if (forX.stamp(view) instanceof IntegerStamp) {
assert forY.stamp(view) instanceof IntegerStamp;
IntegerStamp xStamp = (IntegerStamp) forX.stamp(view);
IntegerStamp yStamp = (IntegerStamp) forY.stamp(view);
int bits = xStamp.getBits();
assert yStamp.getBits() == bits;
LogicNode logic = canonicalizeRangeFlip(forX, forY, bits, false, view);
if (logic != null) {
return logic;
}
if (xStamp.isPositive() && forY instanceof ConditionalNode && ((ConditionalNode) forY).condition() instanceof IntegerBelowNode) {
logic = canonicalizeBelowCanonicalOfBelow(forX, (ConditionalNode) forY, view);
if (logic != null) {
return logic;
}
}
}
return null;
}
private static LogicNode canonicalizeBelowCanonicalOfBelow(ValueNode forX, ConditionalNode forY, NodeView view) {
IntegerBelowNode below = (IntegerBelowNode) forY.condition();
ValueNode n = below.getX();
if (((IntegerStamp) n.stamp(view)).isPositive() && forY.trueValue().isDefaultConstant() && below.getY().isJavaConstant() && forY.falseValue() instanceof AddNode) {
AddNode add = (AddNode) forY.falseValue();
if (add.getX() == below.getX() && add.getY().isJavaConstant() && add.getY().asJavaConstant().asLong() < 0 &&
add.getY().asJavaConstant().asLong() == -below.getY().asJavaConstant().asLong()) {
ValueNode c = below.getY();
/*
* We have:
*
* x |<| (n |<| C ? 0 : n - C)
*
* where we know that both x (checked by the caller) and n are non-negative.
* This is the same as:
*
* x < n - C
*/
return IntegerLessThanNode.create(forX, SubNode.create(n, c, view), view);
}
}
return null;
}
@Override
protected boolean isMatchingBitExtendNode(ValueNode node) {
return node instanceof ZeroExtendNode;
}
@Override
protected boolean addCanOverflow(IntegerStamp a, IntegerStamp b) {
assert a.getBits() == b.getBits();
// a + b |<| a
if (a.getBits() == Long.SIZE) {
return Long.compareUnsigned(upperBound(a) + upperBound(b), upperBound(a)) < 0;
}
if (a.getBits() == Integer.SIZE) {
return Integer.compareUnsigned((int) upperBound(a) + (int) upperBound(b), (int) upperBound(a)) < 0;
}
return true;
}
@Override
protected boolean leftShiftCanOverflow(IntegerStamp a, long shift) {
// leading zeros, adjusted to stamp bits
int leadingZeroForBits = Long.numberOfLeadingZeros(a.mayBeSet()) - (Long.SIZE - a.getBits());
return leadingZeroForBits < shift;
}
@Override
protected long upperBound(IntegerStamp stamp) {
return stamp.unsignedUpperBound();
}
@Override
protected long lowerBound(IntegerStamp stamp) {
return stamp.unsignedLowerBound();
}
@Override
protected int compare(long a, long b) {
return Long.compareUnsigned(a, b);
}
@Override
protected long min(long a, long b) {
return NumUtil.minUnsigned(a, b);
}
@Override
protected long max(long a, long b) {
return NumUtil.maxUnsigned(a, b);
}
@Override
protected long cast(long a, int bits) {
return CodeUtil.zeroExtend(a, bits);
}
@Override
protected long minValue(int bits) {
return 0;
}
@Override
protected long maxValue(int bits) {
return NumUtil.maxValueUnsigned(bits);
}
@Override
protected IntegerStamp forInteger(int bits, long min, long max) {
return StampFactory.forUnsignedInteger(bits, min, max);
}
@Override
protected CanonicalCondition getCondition() {
return CanonicalCondition.BT;
}
@Override
protected IntegerLowerThanNode createNode(ValueNode x, ValueNode y) {
return new IntegerBelowNode(x, y);
}
}
@Override
public TriState implies(boolean thisNegated, LogicNode other) {
if (other instanceof LogicNegationNode) {
// Unwrap negations.
TriState result = implies(thisNegated, ((LogicNegationNode) other).getValue());
if (result.isKnown()) {
return TriState.get(!result.toBoolean());
}
}
if (!thisNegated) {
if (other instanceof IntegerLessThanNode) {
IntegerLessThanNode integerLessThanNode = (IntegerLessThanNode) other;
IntegerStamp stampL = (IntegerStamp) this.getY().stamp(NodeView.DEFAULT);
// if L >= 0:
if (stampL.isPositive()) { // L >= 0
if (this.getX() == integerLessThanNode.getX()) {
// x |<| L implies x < L
if (this.getY() == integerLessThanNode.getY()) {
return TriState.TRUE;
}
// x |<| L implies !(x < 0)
if (integerLessThanNode.getY().isConstant() &&
IntegerStamp.OPS.getAdd().isNeutral(integerLessThanNode.getY().asConstant())) {
return TriState.FALSE;
}
}
}
}
}
return super.implies(thisNegated, other);
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy