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      1 /** @file
      2   64-bit Math Worker Function.
      3   The 32-bit versions of C compiler generate calls to library routines
      4   to handle 64-bit math. These functions use non-standard calling conventions.
      5 
      6   Copyright (c) 2009 - 2011, Intel Corporation. All rights reserved.<BR>
      7   This program and the accompanying materials are licensed and made available
      8   under the terms and conditions of the BSD License which accompanies this
      9   distribution.  The full text of the license may be found at
     10   http://opensource.org/licenses/bsd-license.php.
     11 
     12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
     13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
     14 
     15 **/
     16 
     17 #include <Library/BaseLib.h>
     18 
     19 
     20 /*
     21  * Divides a 64-bit signed value with a 64-bit signed value and returns
     22  * a 64-bit signed result.
     23  */
     24 __declspec(naked) void __cdecl _alldiv (void)
     25 {
     26   //
     27   // Wrapper Implementation over EDKII DivS64x64Remainder() routine
     28   //    INT64
     29   //    EFIAPI
     30   //    DivS64x64Remainder (
     31   //      IN      UINT64     Dividend,
     32   //      IN      UINT64     Divisor,
     33   //      OUT     UINT64     *Remainder  OPTIONAL
     34   //      )
     35   //
     36   _asm {
     37 
     38     ;Entry:
     39     ;       Arguments are passed on the stack:
     40     ;               1st pushed: divisor (QWORD)
     41     ;               2nd pushed: dividend (QWORD)
     42     ;
     43     ;Exit:
     44     ;       EDX:EAX contains the quotient (dividend/divisor)
     45     ;       NOTE: this routine removes the parameters from the stack.
     46     ;
     47     ; Original local stack when calling _alldiv
     48     ;               -----------------
     49     ;               |               |
     50     ;               |---------------|
     51     ;               |               |
     52     ;               |--  Divisor  --|
     53     ;               |               |
     54     ;               |---------------|
     55     ;               |               |
     56     ;               |--  Dividend --|
     57     ;               |               |
     58     ;               |---------------|
     59     ;               |  ReturnAddr** |
     60     ;       ESP---->|---------------|
     61     ;
     62 
     63     ;
     64     ; Set up the local stack for NULL Reminder pointer
     65     ;
     66     xor  eax, eax
     67     push eax
     68 
     69     ;
     70     ; Set up the local stack for Divisor parameter
     71     ;
     72     mov  eax, [esp + 20]
     73     push eax
     74     mov  eax, [esp + 20]
     75     push eax
     76 
     77     ;
     78     ; Set up the local stack for Dividend parameter
     79     ;
     80     mov  eax, [esp + 20]
     81     push eax
     82     mov  eax, [esp + 20]
     83     push eax
     84 
     85     ;
     86     ; Call native DivS64x64Remainder of BaseLib
     87     ;
     88     call DivS64x64Remainder
     89 
     90     ;
     91     ; Adjust stack
     92     ;
     93     add  esp, 20
     94 
     95     ret  16
     96   }
     97 }
     98