mirror of
https://github.com/acidanthera/audk.git
synced 2025-10-31 11:13:53 +01:00
97f98500c1
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10987 6f19259b-4bc3-4df7-8a09-765794883524
58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
/** @file
|
|
64-bit Math Worker Function.
|
|
The 32-bit versions of C compiler generate calls to library routines
|
|
to handle 64-bit math. These functions use non-standard calling conventions.
|
|
|
|
Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
|
|
This program and the accompanying materials
|
|
are licensed and made available under the terms and conditions of the BSD License
|
|
which accompanies this distribution. The full text of the license may be found at
|
|
http://opensource.org/licenses/bsd-license.php
|
|
|
|
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
|
|
|
|
**/
|
|
|
|
|
|
/*
|
|
* Shifts a 64-bit unsigned value right by a certain number of bits.
|
|
*/
|
|
__declspec(naked) void __cdecl _aullshr (void)
|
|
{
|
|
_asm {
|
|
;
|
|
; Checking: Only handle 64bit shifting or more
|
|
;
|
|
cmp cl, 64
|
|
jae _Exit
|
|
|
|
;
|
|
; Handle shifting between 0 and 31 bits
|
|
;
|
|
cmp cl, 32
|
|
jae More32
|
|
shrd eax, edx, cl
|
|
shr edx, cl
|
|
ret
|
|
|
|
;
|
|
; Handle shifting of 32-63 bits
|
|
;
|
|
More32:
|
|
mov eax, edx
|
|
xor edx, edx
|
|
and cl, 31
|
|
shr eax, cl
|
|
ret
|
|
|
|
;
|
|
; Invalid number (less then 32bits), return 0
|
|
;
|
|
_Exit:
|
|
xor eax, eax
|
|
xor edx, edx
|
|
ret
|
|
}
|
|
}
|