/*
* 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.gen.cisc.x86;
/**
*/
public final class X86Field {
public final int shift;
public final int mask;
private X86Field(int shift, int width) {
this.shift = shift;
this.mask = ~(0xffffffff << width);
}
public int shift() {
return shift;
}
public int extract(byte b) {
final int ub = b & 0xff;
return (ub >> shift) & mask;
}
public int inPlace(byte value) {
return value << shift;
}
public static final X86Field RM = new X86Field(0, 3);
public static final X86Field REG = new X86Field(3, 3);
public static final X86Field MOD = new X86Field(6, 2);
public static final X86Field BASE = new X86Field(0, 3);
public static final X86Field INDEX = new X86Field(3, 3);
public static final X86Field SCALE = new X86Field(6, 2);
public static final int REX_B_BIT_INDEX = 0;
public static final int REX_X_BIT_INDEX = 1;
public static final int REX_R_BIT_INDEX = 2;
public static final int REX_W_BIT_INDEX = 3;
public static int extractRexValue(int rexBitIndex, byte rexByte) {
final int urexByte = rexByte & 0xff;
return ((urexByte >> rexBitIndex) & 1) << 3;
}
public static int inRexPlace(int rexBitIndex, byte rexValue) {
final int urexValue = rexValue & 0xff;
return ((urexValue >> 3) & 1) << rexBitIndex;
}
}