MdePkg/Library/BaseLib/Ia32/DivU64x32Remainder.c

   1 /** @file
   2   Set error flag for all division functions
   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
  17
  18 /**
  19   Divides a 64-bit unsigned integer by a 32-bit unsigned integer and
  20   generates a 64-bit unsigned result and an optional 32-bit unsigned remainder.
  21
  22   This function divides the 64-bit unsigned value Dividend by the 32-bit
  23   unsigned value Divisor and generates a 64-bit unsigned quotient. If Remainder
  24   is not NULL, then the 32-bit unsigned remainder is returned in Remainder.
  25   This function returns the 64-bit unsigned quotient.
  26
  27   @param  Dividend  A 64-bit unsigned value.
  28   @param  Divisor   A 32-bit unsigned value.
  29   @param  Remainder A pointer to a 32-bit unsigned value. This parameter is
  30                     optional and may be NULL.
  31
  32   @return Dividend / Divisor
  33
  34 **/
  35 UINT64
  36 EFIAPI
  37 InternalMathDivRemU64x32 (
  38   IN      UINT64                    Dividend,
  39   IN      UINT32                    Divisor,
  40   OUT     UINT32                    *Remainder
  41   )
  42 {
  43   _asm {
  44     mov     ecx, Divisor
  45     mov     eax, dword ptr [Dividend + 4]
  46     xor     edx, edx
  47     div     ecx
  48     push    eax
  49     mov     eax, dword ptr [Dividend + 0]
  50     div     ecx
  51     mov     ecx, Remainder
  52     jecxz   RemainderNull                      // abandon remainder if Remainder == NULL
  53     mov     [ecx], edx
  54 RemainderNull:
  55     pop     edx
  56   }
  57 }
  58