/*!
 * swap-bits.c
 * Interchange bits of a byte in the following pattern:
 * bit7 <-> bit0
 * bit6 <-> bit1
 * bit5 <-> bit2
 * bit4 <-> bit3
 *
 * Vijay Zanvar Feb 03, 2006
 */
#include 
#include 

#define mask(byte, pos) ((byte) & ~(1<<(pos)))
#define get_bit(byte, pos) ((byte) & (1<<(pos)))
#define program_bit(byte, pos, low_high)    \
        byte = mask(byte, pos);             \
        if (low_high)                       \
            byte  = byte | (1<
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