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 unsigned value by another 64-bit unsigned value and returns
22 * the 64-bit unsigned remainder.
23 */
_aullrem(void)24 __declspec(naked) void __cdecl _aullrem(void)
25 {
26 //
27 // Wrapper Implementation over EDKII DivU64x64Remainder() routine
28 // UINT64
29 // EFIAPI
30 // DivU64x64Remainder (
31 // IN UINT64 Dividend,
32 // IN UINT64 Divisor,
33 // OUT UINT64 *Remainder OPTIONAL
34 // )
35 //
36 _asm {
37 ; Original local stack when calling _aullrem
38 ; -----------------
39 ; | |
40 ; |---------------|
41 ; | |
42 ; |-- Divisor --|
43 ; | |
44 ; |---------------|
45 ; | |
46 ; |-- Dividend --|
47 ; | |
48 ; |---------------|
49 ; | ReturnAddr** |
50 ; ESP---->|---------------|
51 ;
52
53 ;
54 ; Set up the local stack for Reminder pointer
55 ;
56 sub esp, 8
57 push esp
58
59 ;
60 ; Set up the local stack for Divisor parameter
61 ;
62 mov eax, [esp + 28]
63 push eax
64 mov eax, [esp + 28]
65 push eax
66
67 ;
68 ; Set up the local stack for Dividend parameter
69 ;
70 mov eax, [esp + 28]
71 push eax
72 mov eax, [esp + 28]
73 push eax
74
75 ;
76 ; Call native DivU64x64Remainder of BaseLib
77 ;
78 call DivU64x64Remainder
79
80 ;
81 ; Put the Reminder in EDX:EAX as return value
82 ;
83 mov eax, [esp + 20]
84 mov edx, [esp + 24]
85
86 ;
87 ; Adjust stack
88 ;
89 add esp, 28
90
91 ret 16
92 }
93 }
94