| /* |
| * 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.Arrays; |
| import java.util.List; |
| |
| 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. |
| * |
| * <h2>Representation of <code>PHI</code>s</h2> |
| * |
| * There is no explicit <code>PHI</code> {@linkplain LIRInstruction}. Instead, they are implemented |
| * as parallel copy that span across a control-flow edge. |
| * |
| * The variables introduced by <code>PHI</code>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#setOutgoingValues 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}. |
| * |
| * <h3>Example:</h3> |
| * |
| * <pre> |
| * 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 |
| * ... |
| * </pre> |
| */ |
| 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.getIncomingSize() == jump.getOutgoingSize() : String.format("Phi In/Out size mismatch: in=%d vs. out=%d", label.getIncomingSize(), jump.getOutgoingSize()); |
| 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)); |
| } |
| } |
| |
| private static JumpOp phiOut(LIR lir, AbstractBlockBase<?> block) { |
| assert block.getSuccessorCount() == 1; |
| List<LIRInstruction> instructions = lir.getLIRforBlock(block); |
| int index = instructions.size() - 1; |
| LIRInstruction op = instructions.get(index); |
| return (JumpOp) op; |
| } |
| |
| public static int phiOutIndex(LIR lir, AbstractBlockBase<?> block) { |
| assert block.getSuccessorCount() == 1; |
| List<LIRInstruction> instructions = lir.getLIRforBlock(block); |
| int index = instructions.size() - 1; |
| assert instructions.get(index) instanceof JumpOp; |
| return index; |
| } |
| |
| private static LabelOp phiIn(LIR lir, AbstractBlockBase<?> block) { |
| assert block.getPredecessorCount() > 1; |
| LabelOp label = (LabelOp) lir.getLIRforBlock(block).get(0); |
| return label; |
| } |
| |
| public static void removePhiOut(LIR lir, AbstractBlockBase<?> block) { |
| JumpOp jump = phiOut(lir, block); |
| jump.clearOutgoingValues(); |
| } |
| |
| public static void removePhiIn(LIR lir, AbstractBlockBase<?> block) { |
| LabelOp label = phiIn(lir, block); |
| label.clearIncomingValues(); |
| } |
| |
| public static boolean verifySSAForm(LIR lir) { |
| return new SSAVerifier(lir).verify(); |
| } |
| |
| public static void verifyPhi(LIR lir, AbstractBlockBase<?> merge) { |
| assert merge.getPredecessorCount() > 1; |
| for (AbstractBlockBase<?> pred : merge.getPredecessors()) { |
| forEachPhiValuePair(lir, merge, pred, (phiIn, phiOut) -> { |
| assert phiIn.getValueKind().equals(phiOut.getValueKind()) || |
| (phiIn.getPlatformKind().equals(phiOut.getPlatformKind()) && LIRKind.isUnknownReference(phiIn) && LIRKind.isValue(phiOut)); |
| }); |
| } |
| } |
| |
| public static void forEachPhiRegisterHint(LIR lir, AbstractBlockBase<?> block, LabelOp label, Value targetValue, OperandMode mode, ValueConsumer valueConsumer) { |
| assert mode == OperandMode.DEF : "Wrong operand mode: " + mode; |
| assert lir.getLIRforBlock(block).get(0).equals(label) : String.format("Block %s and Label %s do not match!", block, label); |
| |
| if (!label.isPhiIn()) { |
| return; |
| } |
| int idx = indexOfValue(label, targetValue); |
| assert idx >= 0 : String.format("Value %s not in label %s", targetValue, label); |
| |
| for (AbstractBlockBase<?> pred : block.getPredecessors()) { |
| JumpOp jump = phiOut(lir, pred); |
| Value sourceValue = jump.getOutgoingValue(idx); |
| valueConsumer.visitValue(jump, sourceValue, null, null); |
| } |
| |
| } |
| |
| private static int indexOfValue(LabelOp label, Value value) { |
| for (int i = 0; i < label.getIncomingSize(); i++) { |
| if (label.getIncomingValue(i).equals(value)) { |
| return i; |
| } |
| } |
| return -1; |
| } |
| |
| } |