// Public domain / CC0. Use freely for any purpose. RoyR 2026
// bitwise.cm - Bitwise operations
// Demonstrates: bitwise operators, bit manipulation, shifts

void printf(uint8 *fmt);

void print_binary(uint32 n) {
    printf("0b");
    for (int32 i = 31; i >= 0; i = i - 1) {
        printf("%d", (n >> i) & 1);
        if (i % 4 == 0 && i != 0) printf("_");
    }
}

int32 count_set_bits(uint32 n) {
    int32 count = 0;
    while (n) {
        count = count + (n & 1);
        n = n >> 1;
    }
    return count;
}

uint32 reverse_bits(uint32 n) {
    uint32 result = 0;
    for (int32 i = 0; i < 32; i = i + 1) {
        result = result << 1;
        result = result | (n & 1);
        n = n >> 1;
    }
    return result;
}

int32 is_power_of_two(uint32 n) {
    return n && ((n & (n - 1)) == 0);
}

int32 main(void) {
    uint32 a = 0xAB;
    uint32 b = 0x55;
    
    printf("a = %d = ", a); print_binary(a); printf("\n");
    printf("b = %d = ", b); print_binary(b); printf("\n");
    
    printf("\nBitwise AND: %d = ", a & b); print_binary(a & b); printf("\n");
    printf("Bitwise OR:  %d = ", a | b); print_binary(a | b); printf("\n");
    printf("Bitwise XOR: %d = ", a ^ b); print_binary(a ^ b); printf("\n");
    printf("Bitwise NOT: %d = ", ~a); print_binary(~a); printf("\n");
    
    printf("\nLeft shift (a << 2):  %d\n", a << 2);
    printf("Right shift (a >> 2): %d\n", a >> 2);
    
    printf("\nSet bits in a: %d\n", count_set_bits(a));
    printf("Set bits in b: %d\n", count_set_bits(b));
    
    printf("\nIs 64 power of two? %d\n", is_power_of_two(64));
    printf("Is 63 power of two? %d\n", is_power_of_two(63));
    
    return 0;
}