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 V9PopcDecoder extends InstructionDecoder
  30               implements V9InstructionDecoder {
  31     Instruction decode(int instruction, SPARCInstructionFactory factory) {
  32         SPARCV9InstructionFactory v9factory = (SPARCV9InstructionFactory) factory;
  33         int rs1Num = getSourceRegister1(instruction);
  34         Instruction instr = null;
  35         // in POPC, rs1 should be zero. see page 205 - A.41 Population Count
  36         if (rs1Num != 0) {
  37             instr = v9factory.newIllegalInstruction(instruction);
  38         } else {
  39             SPARCRegister rd = SPARCRegisters.getRegister(getDestinationRegister(instruction));
  40             instr = v9factory.newV9PopcInstruction(getOperand2(instruction), rd);
  41         }
  42         return instr;
  43     }
  44 }