i86ilen.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 71 行

/****************************************************************************
*
*                            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:  WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
*               DESCRIBE IT HERE!
*
****************************************************************************/


#include "optwif.h"

static byte NopList[] = {
    2,                  /* objlen of first NOP pattern */
    0x89, 0xc0,         /* MOV AX,AX */
    0xfc                /* CLD */
};

byte *NopLists[] = { NopList, NopList };

static  byte    InsSize[ 4 ][ OC_DEST_FAR+1 ] = {
/*      OC_DEST_SHORT   OC_DEST_NEAR    OC_DEST_CHEAP   OC_DEST_FAR */
{       0,              3,              4,              5 },    /* CALL */
{       2,              3,              0,              5 },    /* JMP */
{       2,              5,              0,              0 },    /* JCOND */
{       2,              4,              0,              0 },    /* JCOND,386 */
};

extern  int     OptInsSize( oc_class class, oc_dest_attr attr) {
/**************************************************************/

    int         i = 0;

    if( class == OC_LREF ) return( 2 );
    switch( class ) {
    case OC_CALL:
        i = 0;
        break;
    case OC_JMP:
        i = 1;
        break;
    case OC_JCOND:
        i = _CPULevel( CPU_386 ) ? 3 : 2;
        break;
    }
    return( InsSize[ i ][ attr ] );
}