Mercurial > hg > truffle
view graal/com.oracle.max.asmdis/src/com/sun/max/asm/InstructionWithOffset.java @ 4269:ffd5ce8fc736
Moved IDE project configuration into mx.py.
Added capability for generating NetBeans project configurations.
author | Doug Simon <doug.simon@oracle.com> |
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date | Wed, 11 Jan 2012 15:14:45 +0100 |
parents | e233f5660da4 |
children |
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/* * Copyright (c) 2007, 2011, 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 com.sun.max.asm; import com.sun.max.lang.*; /** * An instruction that addresses some data as an offset from itself. */ public abstract class InstructionWithOffset extends InstructionWithLabel { /** * The mask of all the valid offset sizes supported by the union of all instructions that can address some data via an offset. */ public static final int ALL_VALID_OFFSET_SIZES_MASK = WordWidth.BITS_8.numberOfBytes | WordWidth.BITS_16.numberOfBytes | WordWidth.BITS_32.numberOfBytes | WordWidth.BITS_64.numberOfBytes; private final int validOffsetSizesMask; private int offsetSize; /** * Creates an object representing an instruction that addresses some data as an offset from itself. * * @param startPosition the current position in the instruction stream of the instruction's first byte * @param endPosition the current position in the instruction stream one byte past the instruction's last byte * @param label a label representing the position referred to by this instruction * @param validOffsetSizesMask a mask of the offset sizes supported by a concrete instruction. This value must not * be 0 and its set of non-zero bits must be a subset of the non-zero bits of * {@link #ALL_VALID_OFFSET_SIZES_MASK}. The one-bit integer values (i.e. the powers of two) * corresponding with each set bit in the mask are the offset sizes for which there is an available * concrete instruction. The concrete instruction emitted once the label has been bound is the one with * smallest offset size that can represent the distance between the label's position and this * instruction. */ protected InstructionWithOffset(Assembler assembler, int startPosition, int endPosition, Label label, int validOffsetSizesMask) { super(assembler, startPosition, endPosition, label); this.validOffsetSizesMask = validOffsetSizesMask; assert validOffsetSizesMask != 0; assert (validOffsetSizesMask & ~ALL_VALID_OFFSET_SIZES_MASK) == 0; if (Ints.isPowerOfTwoOrZero(validOffsetSizesMask)) { assembler.addFixedSizeAssembledObject(this); this.offsetSize = validOffsetSizesMask; } else { assembler.addSpanDependentInstruction(this); this.offsetSize = Integer.lowestOneBit(validOffsetSizesMask); } } protected InstructionWithOffset(Assembler assembler, int startPosition, int endPosition, Label label) { super(assembler, startPosition, endPosition, label); this.validOffsetSizesMask = 0; assembler.addFixedSizeAssembledObject(this); } void setSize(int nBytes) { variableSize = nBytes; } protected final int labelSize() { return offsetSize; } /** * Updates the size of this instruction's label based on the value bound to the label. * * @return true if the size of this instruction's label was changed */ boolean updateLabelSize() throws AssemblyException { if (validOffsetSizesMask == 0) { return false; } int newOffsetSize = WordWidth.signedEffective(offset()).numberOfBytes; if (newOffsetSize > this.offsetSize) { final int maxLabelSize = Integer.highestOneBit(validOffsetSizesMask); if (newOffsetSize > maxLabelSize) { throw new AssemblyException("instruction cannot accomodate number of bits required for offset"); } while ((newOffsetSize & validOffsetSizesMask) == 0) { newOffsetSize = newOffsetSize << 1; } this.offsetSize = newOffsetSize; return true; } return false; } private int offset() throws AssemblyException { return assembler().offsetInstructionRelative(label(), this); } protected byte offsetAsByte() throws AssemblyException { if (assembler().selectingLabelInstructions()) { return (byte) 0; } final int result = offset(); if (Ints.numberOfEffectiveSignedBits(result) > 8) { throw new AssemblyException("label out of 8-bit range"); } return (byte) result; } protected short offsetAsShort() throws AssemblyException { if (assembler().selectingLabelInstructions()) { return (short) 0; } final int result = offset(); if (Ints.numberOfEffectiveSignedBits(result) > 16) { throw new AssemblyException("label out of 16-bit range"); } return (short) result; } protected int offsetAsInt() throws AssemblyException { if (assembler().selectingLabelInstructions()) { return 0; } return offset(); } }