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 V9ShiftDecoder extends InstructionDecoder
  30                      implements V9InstructionDecoder {
  31     final int op3;
  32     final String name;
  33     final int rtlOperation;
  34 
  35     V9ShiftDecoder(int op3, String name, int rtlOperation) {
  36         this.op3 = op3;
  37         this.name = name;
  38         this.rtlOperation = rtlOperation;
  39     }
  40 
  41     static boolean isXBitSet(int instruction) {
  42         return (instruction & X_MASK) != 0;
  43     }
  44 
  45     Instruction decode(int instruction,
  46                        SPARCInstructionFactory factory) {
  47         SPARCRegister rs1 = SPARCRegisters.getRegister(getSourceRegister1(instruction));
  48         SPARCRegister rd = SPARCRegisters.getRegister(getDestinationRegister(instruction));
  49         boolean xBit = isXBitSet(instruction);
  50         ImmediateOrRegister operand2 = null;
  51 
  52         if (isIBitSet(instruction)) {
  53             // look for 64 bits shift operations.
  54             int value = instruction & ( xBit ? SHIFT_COUNT_6_MASK : SHIFT_COUNT_5_MASK);
  55             operand2 = new Immediate(new Short((short) value));
  56         } else {
  57             operand2 = SPARCRegisters.getRegister(getSourceRegister2(instruction));
  58         }
  59 
  60         return factory.newShiftInstruction(xBit? name + "x" : name, op3, rtlOperation, rs1, operand2, rd);
  61     }
  62 }