MdePkg/Library/BaseLib/Ia32/DivU64x32Remainder.c

   1 /** @file
   2   Set error flag for all division functions
   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   Divides a 64-bit unsigned integer by a 32-bit unsigned integer and
  11   generates a 64-bit unsigned result and an optional 32-bit unsigned remainder.
  12
  13   This function divides the 64-bit unsigned value Dividend by the 32-bit
  14   unsigned value Divisor and generates a 64-bit unsigned quotient. If Remainder
  15   is not NULL, then the 32-bit unsigned remainder is returned in Remainder.
  16   This function returns the 64-bit unsigned quotient.
  17
  18   @param  Dividend  A 64-bit unsigned value.
  19   @param  Divisor   A 32-bit unsigned value.
  20   @param  Remainder A pointer to a 32-bit unsigned value. This parameter is
  21                     optional and may be NULL.
  22
  23   @return Dividend / Divisor
  24
  25 **/
  26 UINT64
  27 EFIAPI
  28 InternalMathDivRemU64x32 (
  29   IN      UINT64                    Dividend,
  30   IN      UINT32                    Divisor,
  31   OUT     UINT32                    *Remainder
  32   )
  33 {
  34   _asm {
  35     mov     ecx, Divisor
  36     mov     eax, dword ptr [Dividend + 4]
  37     xor     edx, edx
  38     div     ecx
  39     push    eax
  40     mov     eax, dword ptr [Dividend + 0]
  41     div     ecx
  42     mov     ecx, Remainder
  43     jecxz   RemainderNull                      // abandon remainder if Remainder == NULL
  44     mov     [ecx], edx
  45 RemainderNull:
  46     pop     edx
  47   }
  48 }
  49