MdePkg/Library/BaseLib/Ia32/DivU64x32Remainder.c

/** @file
  Set error flag for all division functions

  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

/**
  Divides a 64-bit unsigned integer by a 32-bit unsigned integer and
  generates a 64-bit unsigned result and an optional 32-bit unsigned remainder.

  This function divides the 64-bit unsigned value Dividend by the 32-bit
  unsigned value Divisor and generates a 64-bit unsigned quotient. If Remainder
  is not NULL, then the 32-bit unsigned remainder is returned in Remainder.
  This function returns the 64-bit unsigned quotient.

  @param  Dividend  A 64-bit unsigned value.
  @param  Divisor   A 32-bit unsigned value.
  @param  Remainder A pointer to a 32-bit unsigned value. This parameter is
                    optional and may be NULL.

  @return Dividend / Divisor

**/
UINT64
EFIAPI
InternalMathDivRemU64x32 (
  IN      UINT64  Dividend,
  IN      UINT32  Divisor,
  OUT     UINT32  *Remainder
  )
{
  _asm {
    mov     ecx, Divisor
    mov     eax, dword ptr [Dividend + 4]
    xor     edx, edx
    div     ecx
    push    eax
    mov     eax, dword ptr [Dividend + 0]
    div     ecx
    mov     ecx, Remainder
    jecxz   RemainderNull                      // abandon remainder if Remainder == NULL
    mov     [ecx], edx
RemainderNull:
    pop     edx
  }
}