1 /*
   2  * Copyright 2002 Sun Microsystems, Inc.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 package sun.jvm.hotspot.asm.sparc;
  26 
  27 import sun.jvm.hotspot.asm.*;
  28 
  29 class ShiftDecoder extends InstructionDecoder {
  30     final int op3;
  31     final String name;
  32     final int rtlOperation;
  33 
  34     ShiftDecoder(int op3, String name, int rtlOperation) {
  35         this.op3 = op3;
  36         this.name = name;
  37         this.rtlOperation = rtlOperation;
  38     }
  39 
  40     private ImmediateOrRegister getShiftLength(int instruction) {
  41         boolean iBit = isIBitSet(instruction);
  42         ImmediateOrRegister operand2 = null;
  43         if (iBit) {
  44             int value = instruction & SHIFT_COUNT_5_MASK;
  45             operand2 = new Immediate(new Short((short)value));
  46         } else {
  47             operand2 = SPARCRegisters.getRegister(getSourceRegister2(instruction));
  48         }
  49         return operand2;
  50     }
  51 
  52     Instruction decode(int instruction,
  53                        SPARCInstructionFactory factory) {
  54         SPARCRegister rs1 = SPARCRegisters.getRegister(getSourceRegister1(instruction));
  55         SPARCRegister rd = SPARCRegisters.getRegister(getDestinationRegister(instruction));
  56         ImmediateOrRegister operand2 = getShiftLength(instruction);
  57         return factory.newShiftInstruction(name, op3, rtlOperation, rs1, operand2, rd);
  58     }
  59 }