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, 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 #if _MSC_EXTENSIONS
  16
  17 UINT64
  18 EFIAPI
  19 InternalMathMultU64x32 (
  20   IN      UINT64                    Multiplicand,
  21   IN      UINT32                    Multiplier
  22   )
  23 {
  24   _asm {
  25     mov     ecx, Multiplier
  26     mov     eax, ecx
  27     imul    ecx, dword ptr [Multiplicand + 4]  // overflow not detectable
  28     mul     dword ptr [Multiplicand + 0]
  29     add     edx, ecx
  30   }
  31 }
  32
  33 #endif