avr-libc  2.1.0
Standard C library for AVR-GCC

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Macros
<util/parity.h>: Parity bit generation

Macros

#define parity_even_bit(val)
 

Detailed Description

#include <util/parity.h>

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

Macro Definition Documentation

◆ parity_even_bit

#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.