byteswap.c File Reference

This file contains various implementations of fast byteswapping routines. More...

#include <byteswap.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include "clib.h"
#include "fast-byteswap.h"

Go to the source code of this file.

Functions
void	byteswap_ (char *data, int *nbyte, int *nnum)
	Byteswap. More...
int	fast_byteswap (void *data, int bytes, size_t count)
	Fast byteswap. More...
void	fast_byteswap_errors (int flag)
	Set a flag to turn warnings off for non-aligned pointers. More...
static int	macro_swap_64 (void *data, size_t len)
	Use the GNU macros, which are specialized byteswap ASM instructions. More...
static int	simple_swap_16 (void *data, size_t len)
	Simple single-value loops. More...
static int	simple_swap_32 (void *data, size_t len)
	Simple single-value loops. More...

Variables
static int	send_errors = 1
	If non-zero, warn about non-aligned pointers. More...

Detailed Description

This file contains various implementations of fast byteswapping routines.

The main entry point, fast_byteswap(), is the only one you should need, and it should be modified to use whatever method is fastest on your architecture.

In all cases, the routines return 1 on success and 0 on failure. They only fail if your data is non-aligned. All routines require that arrays of N-bit data be N-bit aligned. If they are not, an error will be sent to stderr and the routine will return non-zero. To silence the error message, call fast_byteswap_errors(0).

Author

Dexin Zhang, Jun Wang, Ed Hartnett

Definition in file byteswap.c.

Function Documentation

byteswap_()

void byteswap_	(	char *	data,
		int *	nbyte,
		int *	nnum
	)

Byteswap.

Parameters

data	Data
nbyte	Number of bytes.
nnum	NNUM

Definition at line 161 of file byteswap.c.

References fast_byteswap().

fast_byteswap()

int fast_byteswap	(	void *	data,
		int	bytes,
		size_t	count
	)

Fast byteswap.

Parameters

data	data
bytes	Number of bytes
count	Count.

Returns

0 for error, 1 otherwise.

Definition at line 136 of file byteswap.c.

References macro_swap_64(), simple_swap_16(), and simple_swap_32().

Referenced by byteswap_().

fast_byteswap_errors()

void fast_byteswap_errors

(

int

flag

)

Set a flag to turn warnings off for non-aligned pointers.

Parameters

flag	Set to 0 to turn off warnings, non-zero to turn them on (the default).

Definition at line 39 of file byteswap.c.

References send_errors.

macro_swap_64()

static int macro_swap_64 ( void *  data, size_t  len  )

static

Use the GNU macros, which are specialized byteswap ASM instructions.

Parameters

data	data
len	Length

Returns

0 for error, 1 otherwise.

Definition at line 110 of file byteswap.c.

References send_errors.

Referenced by fast_byteswap().

simple_swap_16()

static int simple_swap_16 ( void *  data, size_t  len  )

static

Simple single-value loops.

Parameters

data	data
len	Length

Returns

0 for error, 1 otherwise.

Definition at line 82 of file byteswap.c.

References send_errors.

Referenced by fast_byteswap().

simple_swap_32()

static int simple_swap_32 ( void *  data, size_t  len  )

static

Simple single-value loops.

Parameters

data	data
len	Length

Returns

0 for error, 1 otherwise.

Definition at line 53 of file byteswap.c.

References send_errors.

Referenced by fast_byteswap().

Variable Documentation

send_errors

int send_errors = 1

static

If non-zero, warn about non-aligned pointers.

Definition at line 30 of file byteswap.c.

Referenced by fast_byteswap_errors(), macro_swap_64(), simple_swap_16(), and simple_swap_32().