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/*++
Copyright (c) 2004, 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:
Math.c
Abstract:
Math worker functions.
--*/
#include "Tiano.h"
UINT64
LShiftU64 (
IN UINT64 Operand,
IN UINTN Count
)
/*++
Routine Description:
This routine allows a 64 bit value to be left shifted by 32 bits and
returns the shifted value.
Count is valid up 63. (Only Bits 0-5 is valid for Count)
Arguments:
Operand - Value to be shifted
Count - Number of times to shift left.
Returns:
Value shifted left identified by the Count.
--*/
{
return Operand << Count;
}
UINT64
MultU64x32 (
IN UINT64 Multiplicand,
IN UINTN Multiplier
)
/*++
Routine Description:
This routine allows a 64 bit value to be multiplied with a 32 bit
value returns 64bit result.
No checking if the result is greater than 64bits
Arguments:
Multiplicand - multiplicand
Multiplier - multiplier
Returns:
Multiplicand * Multiplier
--*/
{
return Multiplicand * Multiplier;
}
UINT64
RShiftU64 (
IN UINT64 Operand,
IN UINTN Count
)
/*++
Routine Description:
This routine allows a 64 bit value to be right shifted by 32 bits and returns the
shifted value.
Count is valid up 63. (Only Bits 0-5 is valid for Count)
Arguments:
Operand - Value to be shifted
Count - Number of times to shift right.
Returns:
Value shifted right identified by the Count.
--*/
{
return Operand >> Count;
}
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
--*/
{
if (Remainder != NULL) {
*Remainder = Dividend % Divisor;
}
return Dividend / Divisor;
}
UINT8
Log2 (
IN UINT64 Operand
)
/*++
Routine Description:
This function computes rounded down log2 of the Operand. This is an equivalent
of the position of the highest bit set in the Operand treated as a mask.
E.g., Log2 (0x0001) == 0, Log2 (0x0002) == 1, Log2 (0x0003) == 1, Log2 (0x0005) == 2
Log2 (0x4000) == 14, Log2 (0x8000) == 15, Log2 (0xC000) == 15, Log2 (0xFFFF) == 15, etc.
Arguments:
Operand - value of which the Log2 is to be computed.
Returns:
Rounded down log2 of the Operand or 0xFF if zero passed in.
--*/
{
UINT8 Bitpos;
Bitpos = 0;
if (Operand == 0) {
return (0xff);
}
while (Operand != 0) {
Operand >>= 1;
Bitpos++;
}
return (Bitpos - 1);
}
UINT64
GetPowerOfTwo (
IN UINT64 Operand
)
/*++
Routine Description:
Calculates the largest integer that is both
a power of two and less than Input
Arguments:
Operand - value to calculate power of two
Returns:
the largest integer that is both a power of
two and less than Input
--*/
{
UINT8 Bitpos;
Bitpos = 0;
if (Operand == 0) {
return 0;
}
while (Operand != 0) {
Operand >>= 1;
Bitpos++;
}
Operand = 1;
Bitpos--;
while (Bitpos != 0) {
Operand <<= 1;
Bitpos--;
}
return Operand;
}
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