Compress Interleaved Bits Reverse Bit Spreading

Code

#include <stdio.h>
#include <stdint.h>

uint8_t compress_bits(uint16_t val) {
    val &= 0x5555;
    val = (val | (val >> 1)) & 0x3333; // groups of 2 bits
    val= (val | (val >> 2))  & 0x0F0F; // groups of 4 bits
    val = (val | (val >> 4)) & 0x00FF; // groups of 8 bits
    return (uint8_t) val;
}

int main() {
    uint16_t val;
    scanf("%hu", &val);

    uint8_t result = compress_bits(val);
    printf("%u", result);
    return 0;
}

Solving Approach