Mercurial > hg > graal-jvmci-8
view jvmci/jdk.vm.ci.meta/src/jdk/vm/ci/meta/LIRKind.java @ 23341:67c84a8b19cc
fixed javadoc and implementation of MemoryAccessProvider methods to only throw IllegalArgumentException (JDK-8152024)
author | Doug Simon <doug.simon@oracle.com> |
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date | Wed, 30 Mar 2016 16:06:48 +0200 |
parents | 4b58c92e939b |
children |
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/* * Copyright (c) 2014, 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 jdk.vm.ci.meta; import java.util.ArrayList; /** * Represents the type of values in the LIR. It is composed of a {@link PlatformKind} that gives the * low level representation of the value, and a {@link #referenceMask} that describes the location * of object references in the value, and optionally a {@link #derivedReferenceBase}. * * <h2>Constructing {@link LIRKind} instances</h2> * * During LIR generation, every new {@link Value} should get a {@link LIRKind} of the correct * {@link PlatformKind} that also contains the correct reference information. {@linkplain LIRKind * LIRKinds} should be created as follows: * * <p> * If the result value is created from one or more input values, the {@link LIRKind} should be * created with {@link LIRKind#combine}(inputs). If the result has a different {@link PlatformKind} * than the inputs, {@link LIRKind#combine}(inputs).{@link #changeType}(resultKind) should be used. * <p> * If the result is an exact copy of one of the inputs, {@link Value#getLIRKind()} can be used. Note * that this is only correct for move-like operations, like conditional move or compare-and-swap. * For convert operations, {@link LIRKind#combine} should be used. * <p> * If it is known that the result will be a reference (e.g. pointer arithmetic where the end result * is a valid oop), {@link LIRKind#reference} should be used. * <p> * If it is known that the result will neither be a reference nor be derived from a reference, * {@link LIRKind#value} can be used. If the operation producing this value has inputs, this is very * likely wrong, and {@link LIRKind#combine} should be used instead. * <p> * If it is known that the result is derived from a reference in a way that the garbage collector * can not track, {@link LIRKind#unknownReference} can be used. In most cases, * {@link LIRKind#combine} should be used instead, since it is able to detect this automatically. */ public final class LIRKind { private enum IllegalKind implements PlatformKind { ILLEGAL; private final EnumKey<IllegalKind> key = new EnumKey<>(this); public Key getKey() { return key; } public int getSizeInBytes() { return 0; } public int getVectorLength() { return 0; } public char getTypeChar() { return '-'; } } /** * The non-type. This uses {@link #unknownReference}, so it can never be part of an oop map. */ public static final LIRKind Illegal = unknownReference(IllegalKind.ILLEGAL); private final PlatformKind platformKind; private final int referenceMask; private AllocatableValue derivedReferenceBase; private static final int UNKNOWN_REFERENCE = -1; private LIRKind(PlatformKind platformKind, int referenceMask, AllocatableValue derivedReferenceBase) { this.platformKind = platformKind; this.referenceMask = referenceMask; this.derivedReferenceBase = derivedReferenceBase; assert derivedReferenceBase == null || !derivedReferenceBase.getLIRKind().isDerivedReference() : "derived reference can't have another derived reference as base"; } /** * Create a {@link LIRKind} of type {@code platformKind} that contains a primitive value. Should * be only used when it's guaranteed that the value is not even indirectly derived from a * reference. Otherwise, {@link #combine(Value...)} should be used instead. */ public static LIRKind value(PlatformKind platformKind) { return new LIRKind(platformKind, 0, null); } /** * Create a {@link LIRKind} of type {@code platformKind} that contains a single tracked oop * reference. */ public static LIRKind reference(PlatformKind platformKind) { return derivedReference(platformKind, null); } /** * Create a {@link LIRKind} of type {@code platformKind} that contains a derived reference. */ public static LIRKind derivedReference(PlatformKind platformKind, AllocatableValue base) { int length = platformKind.getVectorLength(); assert 0 < length && length < 32 : "vector of " + length + " references not supported"; return new LIRKind(platformKind, (1 << length) - 1, base); } /** * Create a {@link LIRKind} of type {@code platformKind} that contains a value that is derived * from a reference in a non-linear way. Values of this {@link LIRKind} can not be live at * safepoints. In most cases, this should not be called directly. {@link #combine} should be * used instead to automatically propagate this information. */ public static LIRKind unknownReference(PlatformKind platformKind) { return new LIRKind(platformKind, UNKNOWN_REFERENCE, null); } /** * Create a derived reference. * * @param base An {@link AllocatableValue} containing the base pointer of the derived reference. */ public LIRKind makeDerivedReference(AllocatableValue base) { assert !isUnknownReference() && derivedReferenceBase == null; if (Value.ILLEGAL.equals(base)) { return makeUnknownReference(); } else { if (isValue()) { return derivedReference(platformKind, base); } else { return new LIRKind(platformKind, referenceMask, base); } } } /** * Derive a new type from inputs. The result will have the {@link PlatformKind} of one of the * inputs. If all inputs are values, the result is a value. Otherwise, the result is an unknown * reference. * * This method should be used to construct the result {@link LIRKind} of any operation that * modifies values (e.g. arithmetics). */ public static LIRKind combine(Value... inputs) { assert inputs.length > 0; for (Value input : inputs) { LIRKind kind = input.getLIRKind(); if (kind.isUnknownReference()) { return kind; } else if (!kind.isValue()) { return kind.makeUnknownReference(); } } // all inputs are values, just return one of them return inputs[0].getLIRKind(); } /** * Merge the types of the inputs. The result will have the {@link PlatformKind} of one of the * inputs. If all inputs are values (references), the result is a value (reference). Otherwise, * the result is an unknown reference. * * This method should be used to construct the result {@link LIRKind} of merge operation that * does not modify values (e.g. phis). */ public static LIRKind merge(Value... inputs) { assert inputs.length > 0; ArrayList<LIRKind> kinds = new ArrayList<>(inputs.length); for (int i = 0; i < inputs.length; i++) { kinds.add(inputs[i].getLIRKind()); } return merge(kinds); } /** * Helper method to construct derived reference kinds. Returns the base value of a reference or * derived reference. For values it returns {@code null}, and for unknown references it returns * {@link Value#ILLEGAL}. */ public static AllocatableValue derivedBaseFromValue(AllocatableValue value) { LIRKind kind = value.getLIRKind(); if (kind.isValue()) { return null; } else if (kind.isDerivedReference()) { return kind.getDerivedReferenceBase(); } else if (kind.isUnknownReference()) { return Value.ILLEGAL; } else { // kind is a reference return value; } } /** * Helper method to construct derived reference kinds. If one of {@code base1} or {@code base2} * are set, it creates a derived reference using it as the base. If both are set, the result is * an unknown reference. */ public static LIRKind combineDerived(LIRKind kind, AllocatableValue base1, AllocatableValue base2) { if (base1 == null && base2 == null) { return kind; } else if (base1 == null) { return kind.makeDerivedReference(base2); } else if (base2 == null) { return kind.makeDerivedReference(base1); } else { return kind.makeUnknownReference(); } } /** * @see #merge(Value...) */ public static LIRKind merge(Iterable<LIRKind> kinds) { LIRKind mergeKind = null; for (LIRKind kind : kinds) { if (kind.isUnknownReference()) { /** * Kind is an unknown reference, therefore the result can only be also an unknown * reference. */ mergeKind = kind; break; } if (mergeKind == null) { mergeKind = kind; continue; } if (kind.isValue()) { /* Kind is a value. */ if (mergeKind.referenceMask != 0) { /* * Inputs consists of values and references. Make the result an unknown * reference. */ mergeKind = mergeKind.makeUnknownReference(); break; } /* Check that other inputs are also values. */ } else { /* Kind is a reference. */ if (mergeKind.referenceMask != kind.referenceMask) { /* * Reference maps do not match so the result can only be an unknown reference. */ mergeKind = mergeKind.makeUnknownReference(); break; } } } assert mergeKind != null && verifyMerge(mergeKind, kinds); // all inputs are values or references, just return one of them return mergeKind; } private static boolean verifyMerge(LIRKind mergeKind, Iterable<LIRKind> kinds) { for (LIRKind kind : kinds) { assert mergeKind == null || verifyMoveKinds(mergeKind, kind) : String.format("Input kinds do not match %s vs. %s", mergeKind, kind); } return true; } /** * Create a new {@link LIRKind} with the same reference information and a new * {@linkplain #getPlatformKind platform kind}. If the new kind is a longer vector than this, * the new elements are marked as untracked values. */ public LIRKind changeType(PlatformKind newPlatformKind) { if (newPlatformKind == platformKind) { return this; } else if (isUnknownReference()) { return unknownReference(newPlatformKind); } else if (referenceMask == 0) { // value type return LIRKind.value(newPlatformKind); } else { // reference type int newLength = Math.min(32, newPlatformKind.getVectorLength()); int newReferenceMask = referenceMask & (0xFFFFFFFF >>> (32 - newLength)); assert newReferenceMask != UNKNOWN_REFERENCE; return new LIRKind(newPlatformKind, newReferenceMask, derivedReferenceBase); } } /** * Create a new {@link LIRKind} with a new {@linkplain #getPlatformKind platform kind}. If the * new kind is longer than this, the reference positions are repeated to fill the vector. */ public LIRKind repeat(PlatformKind newPlatformKind) { if (isUnknownReference()) { return unknownReference(newPlatformKind); } else if (referenceMask == 0) { // value type return LIRKind.value(newPlatformKind); } else { // reference type int oldLength = platformKind.getVectorLength(); int newLength = newPlatformKind.getVectorLength(); assert oldLength <= newLength && newLength < 32 && (newLength % oldLength) == 0; // repeat reference mask to fill new kind int newReferenceMask = 0; for (int i = 0; i < newLength; i += platformKind.getVectorLength()) { newReferenceMask |= referenceMask << i; } assert newReferenceMask != UNKNOWN_REFERENCE; return new LIRKind(newPlatformKind, newReferenceMask, derivedReferenceBase); } } /** * Create a new {@link LIRKind} with the same type, but marked as containing an * {@link LIRKind#unknownReference}. */ public LIRKind makeUnknownReference() { return new LIRKind(platformKind, UNKNOWN_REFERENCE, null); } /** * Get the low level type that is used in code generation. */ public PlatformKind getPlatformKind() { return platformKind; } /** * Check whether this value is a derived reference. */ public boolean isDerivedReference() { return getDerivedReferenceBase() != null; } /** * Get the base value of a derived reference. */ public AllocatableValue getDerivedReferenceBase() { return derivedReferenceBase; } /** * Change the base value of a derived reference. This must be called on derived references only. */ public void setDerivedReferenceBase(AllocatableValue derivedReferenceBase) { assert isDerivedReference(); this.derivedReferenceBase = derivedReferenceBase; } /** * Check whether this value is derived from a reference in a non-linear way. If this returns * {@code true}, this value must not be live at safepoints. */ public boolean isUnknownReference() { return referenceMask == UNKNOWN_REFERENCE; } public int getReferenceCount() { assert !isUnknownReference(); return Integer.bitCount(referenceMask); } /** * Check whether the {@code idx}th part of this value is a reference that must be tracked at * safepoints. * * @param idx The index into the vector if this is a vector kind. Must be 0 if this is a scalar * kind. */ public boolean isReference(int idx) { assert 0 <= idx && idx < platformKind.getVectorLength() : "invalid index " + idx + " in " + this; return !isUnknownReference() && (referenceMask & 1 << idx) != 0; } /** * Check whether this kind is a value type that doesn't need to be tracked at safepoints. */ public boolean isValue() { return referenceMask == 0; } @Override public String toString() { if (isValue()) { return platformKind.name(); } else if (isUnknownReference()) { return platformKind.name() + "[*]"; } else { StringBuilder ret = new StringBuilder(); ret.append(platformKind.name()); ret.append('['); for (int i = 0; i < platformKind.getVectorLength(); i++) { if (isReference(i)) { ret.append('.'); } else { ret.append(' '); } } ret.append(']'); return ret.toString(); } } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((platformKind == null) ? 0 : platformKind.hashCode()); result = prime * result + referenceMask; return result; } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (!(obj instanceof LIRKind)) { return false; } LIRKind other = (LIRKind) obj; return platformKind == other.platformKind && referenceMask == other.referenceMask; } public static boolean verifyMoveKinds(LIRKind dst, LIRKind src) { if (src.equals(dst)) { return true; } if (src.getPlatformKind().equals(dst.getPlatformKind())) { return !src.isUnknownReference() || dst.isUnknownReference(); } return false; } }