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 // Include common header file for this module.
  17 //
  18
  19
  20 /**
  21   Divides a 64-bit unsigned integer by a 32-bit unsigned integer and
  22   generates a 64-bit unsigned result and an optional 32-bit unsigned remainder.
  23
  24   This function divides the 64-bit unsigned value Dividend by the 32-bit
  25   unsigned value Divisor and generates a 64-bit unsigned quotient. If Remainder
  26   is not NULL, then the 32-bit unsigned remainder is returned in Remainder.
  27   This function returns the 64-bit unsigned quotient.
  28
  29   @param  Dividend  A 64-bit unsigned value.
  30   @param  Divisor   A 32-bit unsigned value.
  31   @param  Remainder A pointer to a 32-bit unsigned value. This parameter is
  32                     optional and may be NULL.
  33
  34   @return Dividend / Divisor
  35
  36 **/
  37 UINT64
  38 EFIAPI
  39 InternalMathDivRemU64x32 (
  40   IN      UINT64                    Dividend,
  41   IN      UINT32                    Divisor,
  42   OUT     UINT32                    *Remainder
  43   )
  44 {
  45   _asm {
  46     mov     ecx, Divisor
  47     mov     eax, dword ptr [Dividend + 4]
  48     xor     edx, edx
  49     div     ecx
  50     push    eax
  51     mov     eax, dword ptr [Dividend + 0]
  52     div     ecx
  53     mov     ecx, Remainder
  54     jecxz   RemainderNull                      // abandon remainder if Remainder == NULL
  55     mov     [ecx], edx
  56 RemainderNull:
  57     pop     edx
  58   }
  59 }
  60