--- /dev/null 2017-01-22 10:16:57.869617664 -0800 +++ new/src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotMemoryAccessProviderImpl.java 2017-02-15 16:55:49.792336054 -0800 @@ -0,0 +1,238 @@ +/* + * Copyright (c) 2011, 2016, 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.hotspot; + +import static jdk.vm.ci.hotspot.UnsafeAccess.UNSAFE; + +import jdk.vm.ci.meta.Constant; +import jdk.vm.ci.meta.JavaConstant; +import jdk.vm.ci.meta.JavaKind; +import jdk.vm.ci.meta.MemoryAccessProvider; +import jdk.vm.ci.meta.PrimitiveConstant; + +/** + * HotSpot implementation of {@link MemoryAccessProvider}. + */ +class HotSpotMemoryAccessProviderImpl implements HotSpotMemoryAccessProvider { + + protected final HotSpotJVMCIRuntimeProvider runtime; + + HotSpotMemoryAccessProviderImpl(HotSpotJVMCIRuntimeProvider runtime) { + this.runtime = runtime; + } + + private static Object asObject(Constant base) { + if (base instanceof HotSpotObjectConstantImpl) { + return ((HotSpotObjectConstantImpl) base).object(); + } else { + return null; + } + } + + private boolean isValidObjectFieldDisplacement(Constant base, long displacement) { + if (base instanceof HotSpotMetaspaceConstant) { + MetaspaceWrapperObject metaspaceObject = HotSpotMetaspaceConstantImpl.getMetaspaceObject(base); + if (metaspaceObject instanceof HotSpotResolvedObjectTypeImpl) { + if (displacement == runtime.getConfig().classMirrorOffset) { + // Klass::_java_mirror is valid for all Klass* values + return true; + } + } else { + throw new IllegalArgumentException(String.valueOf(metaspaceObject)); + } + } + return false; + } + + private static long asRawPointer(Constant base) { + if (base instanceof HotSpotMetaspaceConstantImpl) { + MetaspaceWrapperObject meta = HotSpotMetaspaceConstantImpl.getMetaspaceObject(base); + return meta.getMetaspacePointer(); + } else if (base instanceof PrimitiveConstant) { + PrimitiveConstant prim = (PrimitiveConstant) base; + if (prim.getJavaKind().isNumericInteger()) { + return prim.asLong(); + } + } + throw new IllegalArgumentException(String.valueOf(base)); + } + + private static long readRawValue(Constant baseConstant, long displacement, int bits) { + Object base = asObject(baseConstant); + if (base != null) { + switch (bits) { + case Byte.SIZE: + return UNSAFE.getByte(base, displacement); + case Short.SIZE: + return UNSAFE.getShort(base, displacement); + case Integer.SIZE: + return UNSAFE.getInt(base, displacement); + case Long.SIZE: + return UNSAFE.getLong(base, displacement); + default: + throw new IllegalArgumentException(String.valueOf(bits)); + } + } else { + long pointer = asRawPointer(baseConstant); + switch (bits) { + case Byte.SIZE: + return UNSAFE.getByte(pointer + displacement); + case Short.SIZE: + return UNSAFE.getShort(pointer + displacement); + case Integer.SIZE: + return UNSAFE.getInt(pointer + displacement); + case Long.SIZE: + return UNSAFE.getLong(pointer + displacement); + default: + throw new IllegalArgumentException(String.valueOf(bits)); + } + } + } + + private boolean verifyReadRawObject(Object expected, Constant base, long displacement) { + if (base instanceof HotSpotMetaspaceConstant) { + MetaspaceWrapperObject metaspaceObject = HotSpotMetaspaceConstantImpl.getMetaspaceObject(base); + if (metaspaceObject instanceof HotSpotResolvedObjectTypeImpl) { + if (displacement == runtime.getConfig().classMirrorOffset) { + assert expected == ((HotSpotResolvedObjectTypeImpl) metaspaceObject).mirror(); + } + } + } + return true; + } + + private Object readRawObject(Constant baseConstant, long initialDisplacement, boolean compressed) { + long displacement = initialDisplacement; + + Object ret; + Object base = asObject(baseConstant); + if (base == null) { + assert !compressed; + displacement += asRawPointer(baseConstant); + ret = UNSAFE.getUncompressedObject(displacement); + assert verifyReadRawObject(ret, baseConstant, initialDisplacement); + } else { + assert runtime.getConfig().useCompressedOops == compressed; + ret = UNSAFE.getObject(base, displacement); + } + return ret; + } + + /** + * Reads a value of this kind using a base address and a displacement. No bounds checking or + * type checking is performed. Returns {@code null} if the value is not available at this point. + * + * @param baseConstant the base address from which the value is read. + * @param displacement the displacement within the object in bytes + * @return the read value encapsulated in a {@link JavaConstant} object, or {@code null} if the + * value cannot be read. + * @throws IllegalArgumentException if {@code kind} is {@code null}, {@link JavaKind#Void}, not + * {@link JavaKind#Object} or not {@linkplain JavaKind#isPrimitive() primitive} kind + */ + JavaConstant readUnsafeConstant(JavaKind kind, JavaConstant baseConstant, long displacement) { + if (kind == null) { + throw new IllegalArgumentException("null JavaKind"); + } + if (kind == JavaKind.Object) { + Object o = readRawObject(baseConstant, displacement, runtime.getConfig().useCompressedOops); + return HotSpotObjectConstantImpl.forObject(o); + } else { + int bits = kind.getByteCount() * Byte.SIZE; + return readPrimitiveConstant(kind, baseConstant, displacement, bits); + } + } + + @Override + public JavaConstant readPrimitiveConstant(JavaKind kind, Constant baseConstant, long initialDisplacement, int bits) { + try { + long rawValue = readRawValue(baseConstant, initialDisplacement, bits); + switch (kind) { + case Boolean: + return JavaConstant.forBoolean(rawValue != 0); + case Byte: + return JavaConstant.forByte((byte) rawValue); + case Char: + return JavaConstant.forChar((char) rawValue); + case Short: + return JavaConstant.forShort((short) rawValue); + case Int: + return JavaConstant.forInt((int) rawValue); + case Long: + return JavaConstant.forLong(rawValue); + case Float: + return JavaConstant.forFloat(Float.intBitsToFloat((int) rawValue)); + case Double: + return JavaConstant.forDouble(Double.longBitsToDouble(rawValue)); + default: + throw new IllegalArgumentException("Unsupported kind: " + kind); + } + } catch (NullPointerException e) { + return null; + } + } + + @Override + public JavaConstant readObjectConstant(Constant base, long displacement) { + if (!isValidObjectFieldDisplacement(base, displacement)) { + return null; + } + return HotSpotObjectConstantImpl.forObject(readRawObject(base, displacement, false)); + } + + @Override + public JavaConstant readNarrowOopConstant(Constant base, long displacement) { + return HotSpotObjectConstantImpl.forObject(readRawObject(base, displacement, true), true); + } + + private HotSpotResolvedObjectTypeImpl readKlass(Constant base, long displacement, boolean compressed) { + assert (base instanceof HotSpotMetaspaceConstantImpl) || (base instanceof HotSpotObjectConstantImpl) : base.getClass(); + Object baseObject = (base instanceof HotSpotMetaspaceConstantImpl) ? ((HotSpotMetaspaceConstantImpl) base).asResolvedJavaType() : ((HotSpotObjectConstantImpl) base).object(); + return runtime.getCompilerToVM().getResolvedJavaType(baseObject, displacement, compressed); + } + + @Override + public Constant readKlassPointerConstant(Constant base, long displacement) { + HotSpotResolvedObjectTypeImpl klass = readKlass(base, displacement, false); + if (klass == null) { + return JavaConstant.NULL_POINTER; + } + return HotSpotMetaspaceConstantImpl.forMetaspaceObject(klass, false); + } + + @Override + public Constant readNarrowKlassPointerConstant(Constant base, long displacement) { + HotSpotResolvedObjectTypeImpl klass = readKlass(base, displacement, true); + if (klass == null) { + return HotSpotCompressedNullConstant.COMPRESSED_NULL; + } + return HotSpotMetaspaceConstantImpl.forMetaspaceObject(klass, true); + } + + @Override + public Constant readMethodPointerConstant(Constant base, long displacement) { + assert (base instanceof HotSpotObjectConstantImpl); + Object baseObject = ((HotSpotObjectConstantImpl) base).object(); + HotSpotResolvedJavaMethodImpl method = runtime.getCompilerToVM().getResolvedJavaMethod(baseObject, displacement); + return HotSpotMetaspaceConstantImpl.forMetaspaceObject(method, false); + } +}