utils.h File Reference

Utility functions for SpiNNaker. More...

#include <stdint.h>

Go to the source code of this file.

Functions
static uint32_t	__hi (uint64_t x)
	This function returns the most significant 32-bit word of a 64-bit unsigned integer.
static uint32_t	__lo (uint64_t x)
	This function returns the least significant 32-bit word of a 64-bit unsigned integer.
static uint64_t	round64 (uint64_t x)
	The function treats the 64-bit number as if it were a 32-bit integer and a 32-bit fraction, rounding the fractional part.
static uint64_t	scale64 (uint64_t x, uint32_t y)
	The function scales the 64-bit number x, treating y as if it were an unsigned long fract, rounding the fractional part.
static uint32_t	scale32 (uint32_t x, uint32_t y)
	The function scales the 32-bit number x, treating y as if it were an unsigned long fract, rounding the fractional part.
static uint32_t	log_next_power_of_2 (uint32_t v)
	Returns the log of the next highest power of 2 of a value.
static uint32_t	ilog_2 (uint32_t v)
	Returns the integer part of the log to base 2 of a number.
static uint32_t	next_power_of_2 (uint32_t v)
	Returns the next highest power of 2 of a value.
static bool	is_power_of_2 (uint32_t v)
	Returns True if the value is a power of 2.

Detailed Description

Utility functions for SpiNNaker.

Author

Dave Lester (david.nosp@m..r.l.nosp@m.ester.nosp@m.@man.nosp@m.chest.nosp@m.er.a.nosp@m.c.uk)

Copyright

© Dave Lester and The University of Manchester, 2013. All rights reserved. SpiNNaker Project Advanced Processor Technologies Group School of Computer Science The University of Manchester Manchester M13 9PL, UK

Date

12 December, 2013

Function Documentation

__hi()

static uint32_t __hi ( uint64_t  x )

inlinestatic

This function returns the most significant 32-bit word of a 64-bit unsigned integer.

Parameters

[in]

x

The 64-bit number

Returns

The most significant 32-bits of x.

__lo()

static uint32_t __lo ( uint64_t  x )

inlinestatic

This function returns the least significant 32-bit word of a 64-bit unsigned integer.

Parameters

[in]

x

The 64-bit number

Returns

The least significant 32-bits of x.

round64()

static uint64_t round64 ( uint64_t  x )

inlinestatic

The function treats the 64-bit number as if it were a 32-bit integer and a 32-bit fraction, rounding the fractional part.

Parameters

[in]

x

The 64-bit number

Returns

The rounded result.

scale64()

static uint64_t scale64 ( uint64_t  x, uint32_t  y  )

inlinestatic

The function scales the 64-bit number x, treating y as if it were an unsigned long fract, rounding the fractional part.

Parameters

[in]	x	A 64-bit unsigned integer.
[in]	y	A 32-bit unsigned integer treated as if it is an unsigned long fract.

Returns

The rounded result.

scale32()

static uint32_t scale32 ( uint32_t  x, uint32_t  y  )

inlinestatic

The function scales the 32-bit number x, treating y as if it were an unsigned long fract, rounding the fractional part.

Parameters

[in]	x	A 32-bit unsigned integer.
[in]	y	A 32-bit unsigned integer treated as if it is an unsigned long fract.

Returns

The rounded result.

log_next_power_of_2()

static uint32_t log_next_power_of_2 ( uint32_t  v )

inlinestatic

Returns the log of the next highest power of 2 of a value.

Parameters

[in]

v

A 32-bit unsigned integer

Returns

The log of the next highest power of 2

ilog_2()

static uint32_t ilog_2 ( uint32_t  v )

inlinestatic

Returns the integer part of the log to base 2 of a number.

Parameters

[in]

v

A 32-bit unsigned integer

Returns

The log to the base 2

next_power_of_2()

static uint32_t next_power_of_2 ( uint32_t  v )

inlinestatic

Returns the next highest power of 2 of a value.

Parameters

[in]

v

A 32-bit unsigned integer

Returns

The next highest power of 2

is_power_of_2()

static bool is_power_of_2 ( uint32_t  v )

inlinestatic

Returns True if the value is a power of 2.

Parameters

[in]

v

A 32-bit unsigned integer

Returns

True if the value is a power of 2, False if not