asm/x86/FloatGRPDecoder.java

/*
 * Copyright (c) 2002, 2003, 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 sun.jvm.hotspot.asm.x86;

import sun.jvm.hotspot.asm.*;

public class FloatGRPDecoder extends FPInstructionDecoder {

   final private int number;

   //Please refer to IA-32 Intel Architecture Software Developer's Manual Volume 2
   //APPENDIX A - Escape opcodes

   private static final FPInstructionDecoder floatGRPMap[][] = {
      /* d9_2 */
      {
      new FPInstructionDecoder("fnop"),
      null,
      null,
      null,
      null,
      null,
      null,
      null
      },
      /*  d9_4 */
      {
      new FPInstructionDecoder("fchs"),
      new FPInstructionDecoder("fabs"),
      null,
      null,
      new FPInstructionDecoder("ftst"),
      new FPInstructionDecoder("fxam"),
      null,
      null
      },
      /* d9_5 */
      {
      new FPInstructionDecoder("fld1"),
      new FPInstructionDecoder("fldl2t"),
      new FPInstructionDecoder("fldl2e"),
      new FPInstructionDecoder("fldpi"),
      new FPInstructionDecoder("fldlg2"),
      new FPInstructionDecoder("fldln2"),
      new FPInstructionDecoder("fldz"),
      null
      },
      /* d9_6 */
      {
      new FPInstructionDecoder("f2xm1"),
      new FPInstructionDecoder("fyl2x"),
      new FPInstructionDecoder("fptan"),
      new FPInstructionDecoder("fpatan"),
      new FPInstructionDecoder("fxtract"),
      new FPInstructionDecoder("fprem1"),
      new FPInstructionDecoder("fdecstp"),
      new FPInstructionDecoder("fincstp")
      },
      /* d9_7 */
      {
      new FPInstructionDecoder("fprem"),
      new FPInstructionDecoder("fyl2xp1"),
      new FPInstructionDecoder("fsqrt"),
      new FPInstructionDecoder("fsincos"),
      new FPInstructionDecoder("frndint"),
      new FPInstructionDecoder("fscale"),
      new FPInstructionDecoder("fsin"),
      new FPInstructionDecoder("fcos")
      },
      /* da_5 */
      {
      null,
      new FPInstructionDecoder("fucompp"),
      null,
      null,
      null,
      null,
      null,
      null
      },
      /* db_4 */
      {
      new FPInstructionDecoder("feni(287 only)"),
      new FPInstructionDecoder("fdisi(287 only)"),
      new FPInstructionDecoder("fNclex"),
      new FPInstructionDecoder("fNinit"),
      new FPInstructionDecoder("fNsetpm(287 only)"),
      null,
      null,
      null
      },
      /* de_3 */
      {
      null,
      new FPInstructionDecoder("fcompp"),
      null,
      null,
      null,
      null,
      null,
      null
      },
      /* df_4 */
      {
      new FPInstructionDecoder("fNstsw"),
      null,
      null,
      null,
      null,
      null,
      null,
      null
      }
   };

   public FloatGRPDecoder(String name, int number) {
      super(name);
      this.number = number;
   }

   public Instruction decode(byte[] bytesArray, int index, int instrStartIndex, int segmentOverride, int prefixes, X86InstructionFactory factory) {
      this.byteIndex = index;
      this.instrStartIndex = instrStartIndex;
      this.prefixes = prefixes;

      int ModRM = readByte(bytesArray, byteIndex);
      int rm = ModRM & 7;

      FPInstructionDecoder instrDecoder = null;
      instrDecoder = floatGRPMap[number][rm];

      Instruction instr = null;
      if(instrDecoder != null) {
         instr = instrDecoder.decode(bytesArray, byteIndex, instrStartIndex, segmentOverride, prefixes, factory);
         byteIndex = instrDecoder.getCurrentIndex();
      } else {
         instr = factory.newIllegalInstruction();
      }
      return instr;
   }
}