MdePkg/Library/BaseLib/Ia32/MultU64x64.c

   1 /** @file
   2   Calculate the product of a 64-bit integer and another 64-bit integer
   3
   4   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 /**
  10   Multiplies a 64-bit unsigned integer by a 64-bit unsigned integer
  11   and generates a 64-bit unsigned result.
  12
  13   This function multiplies the 64-bit unsigned value Multiplicand by the 64-bit
  14   unsigned value Multiplier and generates a 64-bit unsigned result. This 64-
  15   bit unsigned result is returned.
  16
  17   @param  Multiplicand  A 64-bit unsigned value.
  18   @param  Multiplier    A 64-bit unsigned value.
  19
  20   @return Multiplicand * Multiplier
  21
  22 **/
  23 UINT64
  24 EFIAPI
  25 InternalMathMultU64x64 (
  26   IN      UINT64  Multiplicand,
  27   IN      UINT64  Multiplier
  28   )
  29 {
  30   _asm {
  31     mov     ebx, dword ptr [Multiplicand + 0]
  32     mov     edx, dword ptr [Multiplier + 0]
  33     mov     ecx, ebx
  34     mov     eax, edx
  35     imul    ebx, dword ptr [Multiplier + 4]
  36     imul    edx, dword ptr [Multiplicand + 4]
  37     add     ebx, edx
  38     mul     ecx
  39     add     edx, ebx
  40   }
  41 }