<util/parity.h>: Parity bit generation

Defines

Detailed Description

 #include <util/parity.h>

This header file contains optimized assembler code to calculate the parity bit for a byte.

Define Documentation

#define parity_even_bit ( val )

Value:

(__extension__({ \
 unsigned char __t; \
 __asm__ ( \
 "mov __tmp_reg__,%0" "\n\t" \
 "swap %0" "\n\t" \
 "eor %0,__tmp_reg__" "\n\t" \
 "mov __tmp_reg__,%0" "\n\t" \
 "lsr %0" "\n\t" \
 "lsr %0" "\n\t" \
 "eor %0,__tmp_reg__" \
 : "=r" (__t) \
 : "0" ((unsigned char)(val)) \
 : "r0" \
 ); \
 (((__t + 1) >> 1) & 1); \
 }))

Returns:: 1 if val has an odd number of bits set.

Automatically generated by Doxygen 1.5.7 on 6 Nov 2008.