diff options
Diffstat (limited to 'EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/DivU64x32.c')
-rw-r--r-- | EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/DivU64x32.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/DivU64x32.c b/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/DivU64x32.c new file mode 100644 index 0000000000..51aedf7c2e --- /dev/null +++ b/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/DivU64x32.c @@ -0,0 +1,75 @@ +/*++
+
+Copyright (c) 2006, Intel Corporation
+All rights reserved. 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.
+
+Module Name:
+
+ DivU64x32.c
+
+Abstract:
+
+ 64-bit division function for IA-32
+
+--*/
+
+#include "Tiano.h"
+
+UINT64
+DivU64x32 (
+ IN UINT64 Dividend,
+ IN UINTN Divisor,
+ OUT UINTN *Remainder OPTIONAL
+ )
+/*++
+
+Routine Description:
+
+ This routine allows a 64 bit value to be divided with a 32 bit value returns
+ 64bit result and the Remainder.
+
+Arguments:
+
+ Dividend - dividend
+ Divisor - divisor
+ Remainder - buffer for remainder
+
+Returns:
+
+ Dividend / Divisor
+ Remainder = Dividend mod Divisor
+
+N.B. only works for 31bit divisors!!
+
+--*/
+{
+ __asm {
+ xor edx, edx ; Clear EDX
+
+ mov eax, dword ptr Dividend[4] ; Put high 32 bits of 64-bit dividend in EAX
+ mov ecx, Divisor ; Put 32 bits divisor in ECX
+ div ecx ; Dividend Divisor Quoitent...Remainder
+ ; 0:EAX / ECX = EAX EDX
+
+ push eax ; Push quoitent in stack
+
+ mov eax, dword ptr Dividend[0] ; Put low 32 bits of 64-bit dividend in EAX
+ div ecx ; Leave the REMAINDER in EDX as High 32-bit of new dividend
+ ; Dividend Divisor Quoitent...Remainder
+ ; EDX:EAX / ECX = EAX EDX
+
+ mov ecx, Remainder ; Put &REMAINDER to ecx
+
+ jecxz Label1 ; If ecx == 0, no remainder exist, return with quoitent in EDX directly
+ mov dword ptr [ecx], edx ; Put EDX through REMAINDER pointer in ECX
+
+Label1:
+ pop edx ; Pop High 32-bit QUOITENT to EDX
+ }
+}
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