| 1 | ; $Id: bs3-wc16-I4D.asm 58809 2015-11-21 19:28:49Z vboxsync $
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| 2 | ;; @file
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| 3 | ; BS3Kit - 16-bit Watcom C/C++, 32-bit signed integer division.
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| 4 | ;
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| 5 |
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| 6 | ;
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| 7 | ; Copyright (C) 2007-2015 Oracle Corporation
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| 8 | ;
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| 9 | ; This file is part of VirtualBox Open Source Edition (OSE), as
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| 10 | ; available from http://www.virtualbox.org. This file is free software;
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| 11 | ; you can redistribute it and/or modify it under the terms of the GNU
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| 12 | ; General Public License (GPL) as published by the Free Software
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| 13 | ; Foundation, in version 2 as it comes in the "COPYING" file of the
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| 14 | ; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
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| 15 | ; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
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| 16 | ;
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| 17 | ; The contents of this file may alternatively be used under the terms
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| 18 | ; of the Common Development and Distribution License Version 1.0
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| 19 | ; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
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| 20 | ; VirtualBox OSE distribution, in which case the provisions of the
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| 21 | ; CDDL are applicable instead of those of the GPL.
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| 22 | ;
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| 23 | ; You may elect to license modified versions of this file under the
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| 24 | ; terms and conditions of either the GPL or the CDDL or both.
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| 25 | ;
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| 26 |
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| 27 | %include "bs3kit-template-header.mac"
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| 28 |
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| 29 |
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| 30 | ;;
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| 31 | ; 32-bit signed integer division.
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| 32 | ;
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| 33 | ; @returns DX:AX quotient, CX:BX remainder.
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| 34 | ; @param DX:AX Dividend.
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| 35 | ; @param CX:BX Divisor
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| 36 | ;
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| 37 | ; @uses Nothing.
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| 38 | ;
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| 39 | global $_?I4D
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| 40 | $_?I4D:
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| 41 | ;; @todo no idea if we're getting the negative division stuff right here according to what watcom expectes...
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| 42 | extern TODO_NEGATIVE_SIGNED_DIVISION
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| 43 | ; Move dividend into EDX:EAX
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| 44 | shl eax, 10h
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| 45 | mov ax, dx
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| 46 | sar dx, 0fh
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| 47 | movsx edx, dx
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| 48 |
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| 49 | ; Move divisor into ebx.
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| 50 | shl ebx, 10h
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| 51 | mov bx, cx
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| 52 |
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| 53 | ; Do it!
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| 54 | idiv ebx
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| 55 |
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| 56 | ; Reminder in to CX:BX
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| 57 | mov bx, dx
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| 58 | shr edx, 10h
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| 59 | mov cx, dx
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| 60 |
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| 61 | ; Quotient into DX:AX
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| 62 | mov edx, eax
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| 63 | shr edx, 10h
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| 64 |
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| 65 | ret
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| 66 |
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