MdePkg/Library/BaseLib/Ia32/MultU64x32.c

   1 /** @file
   2   Calculate the product of a 64-bit integer and a 32-bit integer
   3
   4   Copyright (c) 2006 - 2007, Intel Corporation<BR>
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 UINT64
  16 EFIAPI
  17 InternalMathMultU64x32 (
  18   IN      UINT64                    Multiplicand,
  19   IN      UINT32                    Multiplier
  20   )
  21 {
  22   _asm {
  23     mov     ecx, Multiplier
  24     mov     eax, ecx
  25     imul    ecx, dword ptr [Multiplicand + 4]  // overflow not detectable
  26     mul     dword ptr [Multiplicand + 0]
  27     add     edx, ecx
  28   }
  29 }
  30