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 - 2008, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9
  10
  11
  12 /**
  13   Multiples a 64-bit unsigned integer by a 32-bit unsigned integer
  14   and generates a 64-bit unsigned result.
  15
  16   This function multiples the 64-bit unsigned value Multiplicand by the 32-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 32-bit unsigned value.
  22
  23   @return Multiplicand * Multiplier
  24
  25 **/
  26 UINT64
  27 EFIAPI
  28 InternalMathMultU64x32 (
  29   IN      UINT64                    Multiplicand,
  30   IN      UINT32                    Multiplier
  31   )
  32 {
  33   _asm {
  34     mov     ecx, Multiplier
  35     mov     eax, ecx
  36     imul    ecx, dword ptr [Multiplicand + 4]  // overflow not detectable
  37     mul     dword ptr [Multiplicand + 0]
  38     add     edx, ecx
  39   }
  40 }
  41