jdk.graal.compiler.nodes.calc.FloatingIntegerDivRemNode Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of compiler Show documentation
Show all versions of compiler Show documentation
The GraalVM compiler and the Graal-truffle optimizer.
/*
* Copyright (c) 2021, 2022, 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 jdk.graal.compiler.nodes.calc;
import static jdk.graal.compiler.nodeinfo.NodeCycles.CYCLES_32;
import static jdk.graal.compiler.nodeinfo.NodeSize.SIZE_1;
import jdk.graal.compiler.core.common.type.ArithmeticOpTable.BinaryOp;
import jdk.graal.compiler.core.common.type.IntegerStamp;
import jdk.graal.compiler.debug.GraalError;
import jdk.graal.compiler.graph.IterableNodeType;
import jdk.graal.compiler.graph.NodeClass;
import jdk.graal.compiler.nodeinfo.InputType;
import jdk.graal.compiler.nodeinfo.NodeInfo;
import jdk.graal.compiler.nodes.AbstractBeginNode;
import jdk.graal.compiler.nodes.FixedGuardNode;
import jdk.graal.compiler.nodes.GraphState;
import jdk.graal.compiler.nodes.GuardNode;
import jdk.graal.compiler.nodes.IfNode;
import jdk.graal.compiler.nodes.NodeView;
import jdk.graal.compiler.nodes.ValueNode;
import jdk.graal.compiler.nodes.extended.GuardedNode;
import jdk.graal.compiler.nodes.extended.GuardingNode;
import jdk.graal.compiler.nodes.extended.MultiGuardNode;
import jdk.graal.compiler.nodes.spi.Lowerable;
import jdk.graal.compiler.nodes.spi.LoweringProvider;
/**
* {@link FloatingNode} version of {@link IntegerDivRemNode} if it is known that this node cannot
* trap nor overflow (if these concepts exist with respect to the target architecture's division
* operation). We distinguish between two reasons to trap: a division by zero or an overflow of
* MIN_VALUE/-1. The division by 0 is typically checked with a zeroGuard. The knowledge about the
* dividend containing MIN_VALUE is either guaranteed by its stamp or externally injected by a
* guard.
*/
@NodeInfo(cycles = CYCLES_32, size = SIZE_1)
public abstract class FloatingIntegerDivRemNode extends BinaryArithmeticNode implements IterableNodeType, GuardedNode, Lowerable {
@SuppressWarnings("rawtypes") public static final NodeClass TYPE = NodeClass.create(FloatingIntegerDivRemNode.class);
@OptionalInput(InputType.Guard) protected GuardingNode floatingGuard;
/**
* Construct a new FloatingIntegerDivRemNode.
*
* @param c the concrete subclass for this node
* @param op the division operation of this node
* @param x the dividend
* @param y the divisor
* @param floatingGuard the guard (potentially a {@link MultiGuardNode}) that represents all
* necessary pre-conditions to allow a floating of the previously fixed
* {@link IntegerDivRemNode}
*/
protected FloatingIntegerDivRemNode(NodeClass> c, BinaryOp op, ValueNode x, ValueNode y, GuardingNode floatingGuard) {
super(c, op, x, y);
this.floatingGuard = floatingGuard;
}
protected FloatingIntegerDivRemNode(NodeClass> c, BinaryOp op, ValueNode x, ValueNode y, GuardingNode floatingGuard,
boolean divisionOverflowIsJVMSCompliant) {
super(c, op, x, y);
this.floatingGuard = floatingGuard;
this.divisionOverflowIsJVMSCompliant = divisionOverflowIsJVMSCompliant;
}
/**
* See {@link LoweringProvider#divisionOverflowIsJVMSCompliant()}.
*/
private boolean divisionOverflowIsJVMSCompliant;
@Override
public GuardingNode getGuard() {
return floatingGuard;
}
public void setDivisionOverflowIsJVMSCompliant() {
this.divisionOverflowIsJVMSCompliant = true;
}
public boolean divisionOverflowIsJVMSCompliant() {
return divisionOverflowIsJVMSCompliant;
}
@Override
public void setGuard(GuardingNode guard) {
updateUsagesInterface(this.floatingGuard, guard);
this.floatingGuard = guard;
}
/**
* Determine if the division operation can potentially be a division by zero, i.e., the divisor
* stamp can contain the value {@code 0}.
*/
protected boolean canDivideByZero() {
IntegerStamp yStamp = (IntegerStamp) y.stamp(NodeView.DEFAULT);
return yStamp.contains(0);
}
private boolean overflowVisibleSideEffect() {
return !SignedDivNode.divisionIsJVMSCompliant(x, y, divisionOverflowIsJVMSCompliant);
}
@Override
public boolean verifyNode() {
/*
* Special case unconditionally deopting rem operations: Other optimziations can lead to
* graphs where the rem operation will unconditionally deopt.
*/
boolean guardWillAlwaysDeopt = false;
if (getGuard() != null) {
GuardingNode guard = getGuard();
if (guard instanceof GuardNode && ((GuardNode) guard).willDeoptUnconditionally()) {
guardWillAlwaysDeopt = true;
} else if (guard instanceof FixedGuardNode && ((FixedGuardNode) guard).willDeoptUnconditionally()) {
guardWillAlwaysDeopt = true;
} else if (guard instanceof AbstractBeginNode) {
AbstractBeginNode abn = (AbstractBeginNode) guard;
if (abn.predecessor() instanceof IfNode) {
IfNode ifGuard = (IfNode) abn.predecessor();
if (ifGuard.successorWillBeEliminated(abn)) {
guardWillAlwaysDeopt = true;
}
}
}
// else unknown, we cannot prove this guard is unconditionally true or false
}
boolean cannotDeopt = (!canDivideByZero() && !overflowVisibleSideEffect());
boolean isAfterStage = graph().isAfterStage(GraphState.StageFlag.FIXED_READS);
GraalError.guarantee(guardWillAlwaysDeopt || cannotDeopt || isAfterStage, "Floating irem must never create an exception or trap");
return super.verifyNode();
}
}