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|
; $Id: __I4D.asm $
;; @file
; Compiler support routines.
;
;
; Copyright (C) 2012-2023 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>.
;
; SPDX-License-Identifier: GPL-3.0-only
;
;*******************************************************************************
;* Exported Symbols *
;*******************************************************************************
public __I4D
if VBOX_BIOS_CPU lt 80386
extrn NeedToImplementOn8086__I4D:near
endif
; MASM (ML.EXE) is used for PXE and no longer understands the .8086 directive.
; WASM is used for the BIOS and understands it just fine.
ifdef __WASM__
.8086
endif
_TEXT segment public 'CODE' use16
assume cs:_TEXT
;;
; 32-bit signed division.
;
; @param dx:ax Dividend.
; @param cx:bx Divisor.
; @returns dx:ax Quotient.
; cx:bx Remainder.
;
__I4D:
pushf
if VBOX_BIOS_CPU ge 80386
.386
push eax
push edx
push ecx
rol eax, 16
mov ax, dx
ror eax, 16
xor edx, edx
shr ecx, 16
mov cx, bx
idiv ecx ; eax:edx / ecx -> eax=quotient, edx=remainder.
mov bx, dx
pop ecx
shr edx, 16
mov cx, dx
pop edx
ror eax, 16
mov dx, ax
add sp, 2
pop ax
rol eax, 16
ifdef __WASM__
.8086
endif
else
call NeedToImplementOn8086__I4D
endif
popf
ret
_TEXT ends
end
|
