Syncboot/efi/lib/arm/math.c
Curle 4300dc655c Add EFI documentation, libraries and includes.
The lib/inc folders are from the GNU-EFI project.
The documentation is from the uefi.org site.

Yes, I know there are duplicate includes. I have a plan for them.
2019-07-17 15:11:52 +01:00

68 lines
1.7 KiB
C

/*
* Copright (C) 2014 Linaro Ltd.
* Author: Ard Biesheuvel <ard.biesheuvel@linaro.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice and this list of conditions, without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License as published by the Free Software Foundation;
* either version 2 of the License, or (at your option) any later version.
*/
#include "lib.h"
UINT64
LShiftU64 (
IN UINT64 Operand,
IN UINTN Count
)
// Left shift 64bit by 32bit and get a 64bit result
{
return Operand << Count;
}
UINT64
RShiftU64 (
IN UINT64 Operand,
IN UINTN Count
)
// Right shift 64bit by 32bit and get a 64bit result
{
return Operand >> Count;
}
UINT64
MultU64x32 (
IN UINT64 Multiplicand,
IN UINTN Multiplier
)
// Multiply 64bit by 32bit and get a 64bit result
{
return Multiplicand * Multiplier;
}
UINT64
DivU64x32 (
IN UINT64 Dividend,
IN UINTN Divisor,
OUT UINTN *Remainder OPTIONAL
)
{
/*
* GCC turns a division into a multiplication and shift with precalculated
* constants if the divisor is constant and the dividend fits into a 32 bit
* variable. Otherwise, it will turn this into calls into the 32-bit div
* library functions.
*/
if (Remainder)
*Remainder = Dividend % Divisor;
return Dividend / Divisor;
}