dismips.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 677 行 · 第 1/2 页

/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
*    NON-INFRINGEMENT. Please see the License for the specific language
*    governing rights and limitations under the License.
*
*  ========================================================================
*
* Description:  Instruction decoding for MIPS R4000 architecture.
*
****************************************************************************/


#include <string.h>
#include <ctype.h>
#include "distypes.h"
#include "dis.h"

extern long SEX( unsigned long v, unsigned bit );

extern const dis_range          MIPSRangeTable[];
extern const int                MIPSRangeTablePos[];
extern const unsigned char      MIPSMaxInsName;

typedef union {
    unsigned_32     full;
#ifdef __BIG_ENDIAN__
    struct {
        unsigned_32 op          : 6;
        unsigned_32 rs          : 5;
        unsigned_32 rt          : 5;
        unsigned_32 immediate   : 16;
    }           itype;
    struct {
        unsigned_32 op          : 6;
        unsigned_32 target      : 26;
    }           jtype;
    struct {
        unsigned_32 op          : 6;
        unsigned_32 rs          : 5;
        unsigned_32 rt          : 5;
        unsigned_32 rd          : 5;
        unsigned_32 sa          : 5;
        unsigned_32 funct       : 6;
    }           rtype;
    struct {
        unsigned_32 op          : 6;
        unsigned_32 fmt         : 5;
        unsigned_32 ft          : 5;
        unsigned_32 fs          : 5;
        unsigned_32 fd          : 5;
        unsigned_32 funct       : 6;
    }           frtype;
    struct {
        unsigned_32 op          : 6;
        unsigned_32 code        : 20;
        unsigned_32 funct       : 6;
    }           break_t;
    struct {
        unsigned_32 op          : 6;
        unsigned_32 rs          : 5;
        unsigned_32 rt          : 5;
        unsigned_32 code        : 10;
        unsigned_32 op2         : 6;
    }           trap_t;
#else
    struct {
        unsigned_32 immediate   : 16;
        unsigned_32 rt          : 5;
        unsigned_32 rs          : 5;
        unsigned_32 op          : 6;
    }           itype;
    struct {
        unsigned_32 target      : 26;
        unsigned_32 op          : 6;
    }           jtype;
    struct {
        unsigned_32 funct       : 6;
        unsigned_32 sa          : 5;
        unsigned_32 rd          : 5;
        unsigned_32 rt          : 5;
        unsigned_32 rs          : 5;
        unsigned_32 op          : 6;
    }           rtype;
    struct {
        unsigned_32 funct       : 6;
        unsigned_32 fd          : 5;
        unsigned_32 fs          : 5;
        unsigned_32 ft          : 5;
        unsigned_32 fmt         : 5;
        unsigned_32 op          : 6;
    }           frtype;
    struct {
        unsigned_32 funct       : 6;
        unsigned_32 code        : 20;
        unsigned_32 op          : 6;
    }           break_t;
    struct {
        unsigned_32 op2         : 6;
        unsigned_32 code        : 10;
        unsigned_32 rt          : 5;
        unsigned_32 rs          : 5;
        unsigned_32 op          : 6;
    }           trap_t;
#endif
} mips_ins;


static dis_format_flags MIPSFloatFmt( unsigned_32 fmt )
{
    dis_format_flags    flags;

    switch( fmt ) {
    case 16:
        flags = DIF_MIPS_FF_S;
        break;
    case 17:
        flags = DIF_MIPS_FF_D;
        break;
    case 20:
        flags = DIF_MIPS_FF_W;
        break;
    case 21:
        flags = DIF_MIPS_FF_L;
        break;
    case 22:
        flags = DIF_MIPS_FF_PS;
        break;
    default:
        flags = 0;
    }
    return( flags );
}

dis_handler_return MIPSNull( dis_handle *h, void *d, dis_dec_ins *ins )
{
    ins->num_ops = 0;
    return( DHR_DONE );
}

dis_handler_return MIPSJType( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_ABSOLUTE;
    ins->op[0].value = code.jtype.target << 2;
    ins->num_ops = 1;
    if( code.jtype.op & 1 )
        ins->flags |= DIF_MIPS_LINK;
    return( DHR_DONE );
}

dis_handler_return MIPSCode( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_IMMED;
    ins->op[0].value = code.break_t.code;
    if( code.break_t.code )     // hide zero "opcode"
        ins->num_ops = 1;
    else
        ins->num_ops = 0;
    return( DHR_DONE );
}

dis_handler_return MIPSImmed1( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.itype.rt + DR_MIPS_r0;
    ins->op[1].type = DO_IMMED;
    ins->op[1].value = code.itype.immediate;
    ins->num_ops = 2;
    return( DHR_DONE );
}

dis_handler_return MIPSImmed2( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.itype.rt + DR_MIPS_r0;
    ins->op[1].type = DO_REG;
    ins->op[1].base = code.itype.rs + DR_MIPS_r0;
    ins->op[2].type = DO_IMMED;
    ins->op[2].value = SEX( code.itype.immediate, 15 );
    ins->num_ops = 3;
    return( DHR_DONE );
}

dis_handler_return MIPSImmed2U( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.itype.rt + DR_MIPS_r0;
    ins->op[1].type = DO_REG;
    ins->op[1].base = code.itype.rs + DR_MIPS_r0;
    ins->op[2].type = DO_IMMED;
    ins->op[2].value = code.itype.immediate;
    ins->num_ops = 3;
    return( DHR_DONE );
}

dis_handler_return MIPSShift( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.rtype.rd + DR_MIPS_r0;
    ins->op[1].type = DO_REG;
    ins->op[1].base = code.rtype.rt + DR_MIPS_r0;
    ins->op[2].type = DO_IMMED;
    ins->op[2].value = code.rtype.sa;
    ins->num_ops = 3;
    return( DHR_DONE );
}

dis_handler_return MIPSTrap1( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.itype.rs + DR_MIPS_r0;
    ins->op[1].type = DO_IMMED;
    ins->op[1].value = SEX( code.itype.immediate, 15 );
    ins->num_ops = 2;
    return( DHR_DONE );
}

dis_handler_return MIPSTrap2( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.trap_t.rs + DR_MIPS_r0;
    ins->op[1].type = DO_REG;
    ins->op[1].base = code.trap_t.rt + DR_MIPS_r0;
// What do we do with 'code'?
//    ins->op[2].type = DO_IMMED;
//    ins->op[2].value = code.trap_t.code;
//    ins->num_ops = 3;
    ins->num_ops = 2;
    return( DHR_DONE );
}

dis_handler_return MIPSRegD( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.rtype.rd + DR_MIPS_r0;
    ins->num_ops = 1;
    return( DHR_DONE );
}

dis_handler_return MIPSRegS( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.rtype.rs + DR_MIPS_r0;
    ins->num_ops = 1;
    return( DHR_DONE );
}

dis_handler_return MIPSReg2( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.rtype.rt + DR_MIPS_r0;
    ins->op[1].type = DO_REG;
    ins->op[1].base = code.rtype.rd + DR_MIPS_r0;
    ins->num_ops = 2;
    return( DHR_DONE );
}

dis_handler_return MIPSReg3( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.rtype.rd + DR_MIPS_r0;
    ins->op[1].type = DO_REG;
    ins->op[1].base = code.rtype.rs + DR_MIPS_r0;
    ins->op[2].type = DO_REG;
    ins->op[2].base = code.rtype.rt + DR_MIPS_r0;
    ins->num_ops = 3;
    return( DHR_DONE );
}

dis_handler_return MIPSMulDiv( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;

    code.full = ins->opcode;
    ins->op[0].type = DO_REG;
    ins->op[0].base = code.rtype.rs + DR_MIPS_r0;
    ins->op[1].type = DO_REG;
    ins->op[1].base = code.rtype.rt + DR_MIPS_r0;
    ins->num_ops = 2;
    return( DHR_DONE );
}

dis_handler_return MIPSCache( dis_handle *h, void *d, dis_dec_ins *ins )
{
    mips_ins    code;