mirror of https://github.com/acidanthera/audk.git
76 lines
2.4 KiB
C
76 lines
2.4 KiB
C
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/*++
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Copyright (c) 2006, Intel Corporation
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All rights reserved. This program and the accompanying materials
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are licensed and made available under the terms and conditions of the BSD License
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which accompanies this distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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Module Name:
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DivU64x32.c
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Abstract:
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64-bit division function for IA-32
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--*/
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#include "Tiano.h"
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UINT64
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DivU64x32 (
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IN UINT64 Dividend,
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IN UINTN Divisor,
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OUT UINTN *Remainder OPTIONAL
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)
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/*++
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Routine Description:
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This routine allows a 64 bit value to be divided with a 32 bit value returns
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64bit result and the Remainder.
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Arguments:
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Dividend - dividend
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Divisor - divisor
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Remainder - buffer for remainder
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Returns:
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Dividend / Divisor
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Remainder = Dividend mod Divisor
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N.B. only works for 31bit divisors!!
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--*/
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{
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__asm {
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xor edx, edx ; Clear EDX
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mov eax, dword ptr Dividend[4] ; Put high 32 bits of 64-bit dividend in EAX
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mov ecx, Divisor ; Put 32 bits divisor in ECX
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div ecx ; Dividend Divisor Quoitent...Remainder
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; 0:EAX / ECX = EAX EDX
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push eax ; Push quoitent in stack
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mov eax, dword ptr Dividend[0] ; Put low 32 bits of 64-bit dividend in EAX
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div ecx ; Leave the REMAINDER in EDX as High 32-bit of new dividend
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; Dividend Divisor Quoitent...Remainder
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; EDX:EAX / ECX = EAX EDX
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mov ecx, Remainder ; Put &REMAINDER to ecx
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jecxz Label1 ; If ecx == 0, no remainder exist, return with quoitent in EDX directly
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mov dword ptr [ecx], edx ; Put EDX through REMAINDER pointer in ECX
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Label1:
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pop edx ; Pop High 32-bit QUOITENT to EDX
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}
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}
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