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 //
  16 // Include common header file for this module.
  17 //
  18
  19
  20 /**
  21   Multiples a 64-bit unsigned integer by a 32-bit unsigned integer
  22   and generates a 64-bit unsigned result.
  23
  24   This function multiples the 64-bit unsigned value Multiplicand by the 32-bit
  25   unsigned value Multiplier and generates a 64-bit unsigned result. This 64-
  26   bit unsigned result is returned.
  27
  28   @param  Multiplicand  A 64-bit unsigned value.
  29   @param  Multiplier    A 32-bit unsigned value.
  30
  31   @return Multiplicand * Multiplier
  32
  33 **/
  34 UINT64
  35 EFIAPI
  36 InternalMathMultU64x32 (
  37   IN      UINT64                    Multiplicand,
  38   IN      UINT32                    Multiplier
  39   )
  40 {
  41   _asm {
  42     mov     ecx, Multiplier
  43     mov     eax, ecx
  44     imul    ecx, dword ptr [Multiplicand + 4]  // overflow not detectable
  45     mul     dword ptr [Multiplicand + 0]
  46     add     edx, ecx
  47   }
  48 }
  49