/* * Copyright (c) 2015, 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.lir.ssa; import java.util.ArrayList; import java.util.Arrays; import org.graalvm.compiler.core.common.LIRKind; import org.graalvm.compiler.core.common.cfg.AbstractBlockBase; import org.graalvm.compiler.lir.LIR; import org.graalvm.compiler.lir.LIRInstruction; import org.graalvm.compiler.lir.LIRInstruction.OperandMode; import org.graalvm.compiler.lir.StandardOp.BlockEndOp; import org.graalvm.compiler.lir.StandardOp.JumpOp; import org.graalvm.compiler.lir.StandardOp.LabelOp; import org.graalvm.compiler.lir.ValueConsumer; import jdk.vm.ci.meta.Value; /** * Utilities for working with Static-Single-Assignment LIR form. * *
PHI
sPHI
{@linkplain LIRInstruction}. Instead, they are implemented
* as parallel copy that span across a control-flow edge.
*
* The variables introduced by PHI
s of a specific {@linkplain AbstractBlockBase merge
* block} are {@linkplain LabelOp#setIncomingValues attached} to the {@linkplain LabelOp} of the
* block. The outgoing values from the predecessor are {@link JumpOp#getOutgoingValue input} to the
* {@linkplain BlockEndOp} of the predecessor. Because there are no critical edges we know that the
* {@link BlockEndOp} of the predecessor has to be a {@link JumpOp}.
*
* * B0 -> B1 * ... * v0|i = ... * JUMP ~[v0|i, int[0|0x0]] destination: B0 -> B1 * ________________________________________________ * * B2 -> B1 * ... * v1|i = ... * v2|i = ... * JUMP ~[v1|i, v2|i] destination: B2 -> B1 * ________________________________________________ * * B1 <- B0,B2 * [v3|i, v4|i] = LABEL * ... **/ public final class SSAUtil { public interface PhiValueVisitor { /** * @param phiIn the incoming value at the merge block * @param phiOut the outgoing value from the predecessor block */ void visit(Value phiIn, Value phiOut); } /** * Visits each phi value pair of an edge, i.e. the outgoing value from the predecessor and the * incoming value to the merge block. */ public static void forEachPhiValuePair(LIR lir, AbstractBlockBase> merge, AbstractBlockBase> pred, PhiValueVisitor visitor) { if (merge.getPredecessorCount() < 2) { return; } assert Arrays.asList(merge.getPredecessors()).contains(pred) : String.format("%s not in predecessor list: %s", pred, Arrays.toString(merge.getPredecessors())); assert pred.getSuccessorCount() == 1 : String.format("Merge predecessor block %s has more than one successor? %s", pred, Arrays.toString(pred.getSuccessors())); assert pred.getSuccessors()[0] == merge : String.format("Predecessor block %s has wrong successor: %s, should be: %s", pred, pred.getSuccessors()[0], merge); JumpOp jump = phiOut(lir, pred); LabelOp label = phiIn(lir, merge); assert label.getPhiSize() == jump.getPhiSize() : String.format("Phi In/Out size mismatch: in=%d vs. out=%d", label.getPhiSize(), jump.getPhiSize()); for (int i = 0; i < label.getPhiSize(); i++) { visitor.visit(label.getIncomingValue(i), jump.getOutgoingValue(i)); } } public static JumpOp phiOut(LIR lir, AbstractBlockBase> block) { assert block.getSuccessorCount() == 1; ArrayList