diff options
Diffstat (limited to 'src/VBox/ValidationKit/bootsectors/bs3kit/bs3-wc16-I4D.asm')
| -rw-r--r-- | src/VBox/ValidationKit/bootsectors/bs3kit/bs3-wc16-I4D.asm | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-wc16-I4D.asm b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-wc16-I4D.asm new file mode 100644 index 00000000..2fd75d90 --- /dev/null +++ b/src/VBox/ValidationKit/bootsectors/bs3kit/bs3-wc16-I4D.asm @@ -0,0 +1,80 @@ +; $Id: bs3-wc16-I4D.asm $ +;; @file +; BS3Kit - 16-bit Watcom C/C++, 32-bit signed integer division. +; + +; +; Copyright (C) 2007-2023 Oracle and/or its affiliates. +; +; This file is part of VirtualBox base platform packages, as +; available from https://www.virtualbox.org. +; +; This program is free software; you can redistribute it and/or +; modify it under the terms of the GNU General Public License +; as published by the Free Software Foundation, in version 3 of the +; License. +; +; This program is distributed in the hope that it will be useful, but +; WITHOUT ANY WARRANTY; without even the implied warranty of +; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +; General Public License for more details. +; +; You should have received a copy of the GNU General Public License +; along with this program; if not, see <https://www.gnu.org/licenses>. +; +; The contents of this file may alternatively be used under the terms +; of the Common Development and Distribution License Version 1.0 +; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included +; in the VirtualBox distribution, in which case the provisions of the +; CDDL are applicable instead of those of the GPL. +; +; You may elect to license modified versions of this file under the +; terms and conditions of either the GPL or the CDDL or both. +; +; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 +; + +%include "bs3kit-template-header.mac" + + +;; +; 32-bit signed integer division. +; +; @returns DX:AX quotient, CX:BX remainder. +; @param DX:AX Dividend. +; @param CX:BX Divisor +; +; @uses Nothing. +; +global $_?I4D +$_?I4D: +;; @todo no idea if we're getting the negative division stuff right here according to what watcom expectes... +extern TODO_NEGATIVE_SIGNED_DIVISION + ; Move dividend into EDX:EAX + shl eax, 10h + mov ax, dx + sar dx, 0fh + movsx edx, dx + + ; Move divisor into ebx. + shl ebx, 10h + mov bx, cx + + ; Do it! + idiv ebx + + ; Reminder in to CX:BX + mov bx, dx + shr edx, 10h + mov cx, dx + + ; Quotient into DX:AX + mov edx, eax + shr edx, 10h + +%ifdef ASM_MODEL_FAR_CODE + retf +%else + ret +%endif + |