1 /*

     2  * Copyright (c) 2002, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 package sun.jvm.hotspot.asm.sparc;

    26 

    27 import sun.jvm.hotspot.asm.*;

    28 

    29 abstract class V9RegisterBranchDecoder extends V9BranchDecoder {

    30     static int getDisp16(int instruction) {

    31         int offset = (DISP_16_LO_MASK & instruction)  |

    32            ((DISP_16_HI_MASK & instruction) >>> (DISP_16_HI_START_BIT - DISP_16_LO_NUMBITS));

    33 

    34         // sign extend and word align

    35         offset = extractSignedIntFromNBits(offset, 16);

    36         offset <<= 2;

    37 

    38         return offset;

    39     }

    40 

    41     String getConditionName(int conditionCode, boolean isAnnuled) {

    42         return null;

    43     }

    44 

    45     abstract String getRegisterConditionName(int rcond);

    46 

    47     public Instruction decode(int instruction, SPARCInstructionFactory factory) {

    48         SPARCV9InstructionFactory v9factory = (SPARCV9InstructionFactory) factory;

    49         int rcond = (BRANCH_RCOND_MASK & instruction) >>> BRANCH_RCOND_START_BIT;

    50         if (rcond == BRANCH_RCOND_RESERVED1 || rcond == BRANCH_RCOND_RESERVED2)

    51             return factory.newIllegalInstruction(instruction);

    52 

    53         SPARCRegister rs1 = SPARCRegisters.getRegister(getSourceRegister1(instruction));

    54         boolean predictTaken = getPredictTaken(instruction);

    55         boolean annuled = getAnnuledBit(instruction);

    56         PCRelativeAddress addr = new PCRelativeAddress(getDisp16(instruction));

    57         String name = getRegisterConditionName(rcond);

    58         return v9factory.newV9RegisterBranchInstruction(name, addr, annuled, rcond, rs1, predictTaken);

    59     }

    60 }