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
  11
  12 /**
  13   Multiplies a 64-bit unsigned integer by a 64-bit unsigned integer
  14   and generates a 64-bit unsigned result.
  15
  16   This function multiplies the 64-bit unsigned value Multiplicand by the 64-bit
  17   unsigned value Multiplier and generates a 64-bit unsigned result. This 64-
  18   bit unsigned result is returned.
  19
  20   @param  Multiplicand  A 64-bit unsigned value.
  21   @param  Multiplier    A 64-bit unsigned value.
  22
  23   @return Multiplicand * Multiplier
  24
  25 **/
  26 UINT64
  27 EFIAPI
  28 InternalMathMultU64x64 (
  29   IN      UINT64                    Multiplicand,
  30   IN      UINT64                    Multiplier
  31   )
  32 {
  33   _asm {
  34     mov     ebx, dword ptr [Multiplicand + 0]
  35     mov     edx, dword ptr [Multiplier + 0]
  36     mov     ecx, ebx
  37     mov     eax, edx
  38     imul    ebx, dword ptr [Multiplier + 4]
  39     imul    edx, dword ptr [Multiplicand + 4]
  40     add     ebx, edx
  41     mul     ecx
  42     add     edx, ebx
  43   }
  44 }
  45