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 BranchDecoder extends InstructionDecoder {

    30 

    31     // format 2 - condition code names.

    32     // Appendix F - Opcodes and Condition Codes - Page 231 - Table F-7.

    33     static final String integerConditionNames[] = {

    34         "bn", "be", "ble", "bl", "bleu", "bcs", "bneg", "bvs",

    35         "ba", "bne", "bg", "bge", "bgu", "bcc", "bpos", "bvc"

    36     };

    37 

    38     static final String integerAnnuledConditionNames[] = {

    39         "bn,a", "be,a", "ble,a", "bl,a", "bleu,a", "bcs,a", "bneg,a", "bvs,a",

    40         "ba,a", "bne,a", "bg,a", "bge,a", "bgu,a", "bcc,a", "bpos,a", "bvc,a"

    41     };

    42 

    43     // format 2 - condition code names.

    44     // Appendix F - Opcodes and Condition Codes - Page 231 - Table F-7.

    45     static final String floatConditionNames[] = {

    46         "fbn", "fbne", "fblg", "fbul", "fbl", "fbug", "fbg", "fbu",

    47         "fba", "fbe",  "fbue", "fbge", "fbuge", "fble", "fbule", "fbo"

    48     };

    49 

    50     static final String floatAnnuledConditionNames[] = {

    51         "fbn,a", "fbne,a", "fblg,a", "fbul,a", "fbl,a", "fbug,a", "fbg,a", "fbu,a",

    52         "fba,a", "fbe,a",  "fbue,a", "fbge,a", "fbuge,a", "fble,a", "fbule,a", "fbo,a"

    53     };

    54 

    55     static boolean getAnnuledBit(int instruction) {

    56         return (instruction & ANNUL_MASK) != 0;

    57     }

    58 

    59     Instruction decode(int instruction, SPARCInstructionFactory factory) {

    60         boolean isAnnuled = getAnnuledBit(instruction);

    61         int conditionCode = getConditionCode(instruction);

    62         String conditionName = getConditionName(conditionCode, isAnnuled);

    63         int offset = extractSignedIntFromNBits(instruction, 22);

    64         // word align the offset by right shifting 2 bits

    65         offset <<= 2;

    66         PCRelativeAddress addr = new PCRelativeAddress(offset);

    67         return factory.newBranchInstruction(conditionName, addr, isAnnuled, conditionCode);

    68     }

    69 

    70     abstract String getConditionName(int conditionCode, boolean isAnnuled);

    71 }