MdePkg/Library/BaseLib/Ia32/DivU64x32Remainder.c

   1 /** @file
   2   Set error flag for all division functions
   3
   4   Copyright (c) 2006 - 2008, 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   Divides a 64-bit unsigned integer by a 32-bit unsigned integer and
  17   generates a 64-bit unsigned result and an optional 32-bit unsigned remainder.
  18
  19   This function divides the 64-bit unsigned value Dividend by the 32-bit
  20   unsigned value Divisor and generates a 64-bit unsigned quotient. If Remainder
  21   is not NULL, then the 32-bit unsigned remainder is returned in Remainder.
  22   This function returns the 64-bit unsigned quotient.
  23
  24   @param  Dividend  A 64-bit unsigned value.
  25   @param  Divisor   A 32-bit unsigned value.
  26   @param  Remainder A pointer to a 32-bit unsigned value. This parameter is
  27                     optional and may be NULL.
  28
  29   @return Dividend / Divisor
  30
  31 **/
  32 UINT64
  33 EFIAPI
  34 InternalMathDivRemU64x32 (
  35   IN      UINT64                    Dividend,
  36   IN      UINT32                    Divisor,
  37   OUT     UINT32                    *Remainder
  38   )
  39 {
  40   _asm {
  41     mov     ecx, Divisor
  42     mov     eax, dword ptr [Dividend + 4]
  43     xor     edx, edx
  44     div     ecx
  45     push    eax
  46     mov     eax, dword ptr [Dividend + 0]
  47     div     ecx
  48     mov     ecx, Remainder
  49     jecxz   RemainderNull                      // abandon remainder if Remainder == NULL
  50     mov     [ecx], edx
  51 RemainderNull:
  52     pop     edx
  53   }
  54 }
  55