audk/OldMdePkg/Library/BaseLib/Ia32/MultU64x64.asm

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;------------------------------------------------------------------------------
;
; Copyright (c) 2006, Intel Corporation
; All rights reserved. This program and the accompanying materials
; are licensed and made available under the terms and conditions of the BSD License
; which accompanies this distribution. The full text of the license may be found at
; http://opensource.org/licenses/bsd-license.php
;
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
;
; Module Name:
;
; MultU64x64.asm
;
; Abstract:
;
; Calculate the product of a 64-bit integer and another 64-bit integer
;
;------------------------------------------------------------------------------
.386
.model flat,C
.code
;------------------------------------------------------------------------------
; UINT64
; EFIAPI
; InternalMathMultU64x64 (
; IN UINT64 Multiplicand,
; IN UINT64 Multiplier
; );
;------------------------------------------------------------------------------
InternalMathMultU64x64 PROC USES ebx
mov ebx, [esp + 8] ; ebx <- M1[0..31]
mov edx, [esp + 16] ; edx <- M2[0..31]
mov ecx, ebx
mov eax, edx
imul ebx, [esp + 20] ; ebx <- M1[0..31] * M2[32..63]
imul edx, [esp + 12] ; edx <- M1[32..63] * M2[0..31]
add ebx, edx ; carries are abandoned
mul ecx ; edx:eax <- M1[0..31] * M2[0..31]
add edx, ebx ; carries are abandoned
ret
InternalMathMultU64x64 ENDP
END