--- /dev/null 2015-10-08 07:24:51.000000000 -1000 +++ new/src/jdk.vm.ci/share/classes/jdk.vm.ci.code/src/jdk/vm/ci/code/DataSection.java 2015-10-08 07:24:51.000000000 -1000 @@ -0,0 +1,288 @@ +/* + * Copyright (c) 2014, 2014, 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.code; + +import static jdk.vm.ci.meta.MetaUtil.*; + +import java.nio.*; +import java.util.*; +import java.util.function.*; + +import jdk.vm.ci.code.CompilationResult.*; +import jdk.vm.ci.code.DataSection.*; +import jdk.vm.ci.meta.*; + +public final class DataSection implements Iterable { + + @FunctionalInterface + public interface DataBuilder { + + void emit(ByteBuffer buffer, Consumer patch); + + static DataBuilder raw(byte[] data) { + return (buffer, patch) -> buffer.put(data); + } + + static DataBuilder serializable(SerializableConstant c) { + return (buffer, patch) -> c.serialize(buffer); + } + + static DataBuilder zero(int size) { + switch (size) { + case 1: + return (buffer, patch) -> buffer.put((byte) 0); + case 2: + return (buffer, patch) -> buffer.putShort((short) 0); + case 4: + return (buffer, patch) -> buffer.putInt(0); + case 8: + return (buffer, patch) -> buffer.putLong(0L); + default: + return (buffer, patch) -> { + int rest = size; + while (rest > 8) { + buffer.putLong(0L); + rest -= 8; + } + while (rest > 0) { + buffer.put((byte) 0); + rest--; + } + }; + } + } + } + + public static final class Data { + + private int alignment; + private final int size; + private final DataBuilder builder; + + private DataSectionReference ref; + + public Data(int alignment, int size, DataBuilder builder) { + this.alignment = alignment; + this.size = size; + this.builder = builder; + + // initialized in DataSection.insertData(Data) + ref = null; + } + + public void updateAlignment(int newAlignment) { + if (newAlignment == alignment) { + return; + } + alignment = lcm(alignment, newAlignment); + } + + public int getAlignment() { + return alignment; + } + + public int getSize() { + return size; + } + + public DataBuilder getBuilder() { + return builder; + } + + @Override + public int hashCode() { + // Data instances should not be used as hash map keys + throw new UnsupportedOperationException("hashCode"); + } + + @Override + public String toString() { + return identityHashCodeString(this); + } + + @Override + public boolean equals(Object obj) { + assert ref != null; + if (obj == this) { + return true; + } + if (obj instanceof Data) { + Data that = (Data) obj; + if (this.alignment == that.alignment && this.size == that.size && this.ref.equals(that.ref)) { + return true; + } + } + return false; + } + } + + private final ArrayList dataItems = new ArrayList<>(); + + private boolean finalLayout; + private int sectionAlignment; + private int sectionSize; + + @Override + public int hashCode() { + // DataSection instances should not be used as hash map keys + throw new UnsupportedOperationException("hashCode"); + } + + @Override + public String toString() { + return identityHashCodeString(this); + } + + @Override + public boolean equals(Object obj) { + if (this == obj) { + return true; + } + if (obj instanceof DataSection) { + DataSection that = (DataSection) obj; + if (this.finalLayout == that.finalLayout && this.sectionAlignment == that.sectionAlignment && this.sectionSize == that.sectionSize && Objects.equals(this.dataItems, that.dataItems)) { + return true; + } + } + return false; + } + + /** + * Insert a {@link Data} item into the data section. If the item is already in the data section, + * the same {@link DataSectionReference} is returned. + * + * @param data the {@link Data} item to be inserted + * @return a unique {@link DataSectionReference} identifying the {@link Data} item + */ + public DataSectionReference insertData(Data data) { + assert !finalLayout; + if (data.ref == null) { + data.ref = new DataSectionReference(); + dataItems.add(data); + } + return data.ref; + } + + /** + * Compute the layout of the data section. This can be called only once, and after it has been + * called, the data section can no longer be modified. + */ + public void finalizeLayout() { + assert !finalLayout; + finalLayout = true; + + // simple heuristic: put items with larger alignment requirement first + dataItems.sort((a, b) -> a.alignment - b.alignment); + + int position = 0; + for (Data d : dataItems) { + sectionAlignment = lcm(sectionAlignment, d.alignment); + position = align(position, d.alignment); + + d.ref.setOffset(position); + position += d.size; + } + + sectionSize = position; + } + + public boolean isFinalized() { + return finalLayout; + } + + /** + * Get the size of the data section. Can only be called after {@link #finalizeLayout}. + */ + public int getSectionSize() { + assert finalLayout; + return sectionSize; + } + + /** + * Get the minimum alignment requirement of the data section. Can only be called after + * {@link #finalizeLayout}. + */ + public int getSectionAlignment() { + assert finalLayout; + return sectionAlignment; + } + + /** + * Build the data section. Can only be called after {@link #finalizeLayout}. + * + * @param buffer The {@link ByteBuffer} where the data section should be built. The buffer must + * hold at least {@link #getSectionSize()} bytes. + * @param patch A {@link Consumer} to receive {@link DataPatch data patches} for relocations in + * the data section. + */ + public void buildDataSection(ByteBuffer buffer, Consumer patch) { + assert finalLayout; + for (Data d : dataItems) { + buffer.position(d.ref.getOffset()); + d.builder.emit(buffer, patch); + } + } + + public Data findData(DataSectionReference ref) { + for (Data d : dataItems) { + if (d.ref == ref) { + return d; + } + } + return null; + } + + public Iterator iterator() { + return dataItems.iterator(); + } + + public static int lcm(int x, int y) { + if (x == 0) { + return y; + } else if (y == 0) { + return x; + } + + int a = Math.max(x, y); + int b = Math.min(x, y); + while (b > 0) { + int tmp = a % b; + a = b; + b = tmp; + } + + int gcd = a; + return x * y / gcd; + } + + private static int align(int position, int alignment) { + return ((position + alignment - 1) / alignment) * alignment; + } + + public void clear() { + assert !finalLayout; + this.dataItems.clear(); + this.sectionAlignment = 0; + this.sectionSize = 0; + } +}