// reducer-demo.c
#include <stdint.h>
#include <stdio.h>

typedef struct {
    uint32_t seed;
    uint32_t tweak;
    const char *name;
} Job;

static uint32_t table[8] = {
    0x243f6a88u, 0x85a308d3u, 0x13198a2eu, 0x03707344u,
    0xa4093822u, 0x299f31d0u, 0x082efa98u, 0xec4e6c89u
};

static uint32_t noise(uint32_t x)
{
    x ^= x >> 7;
    x *= 0x9e3779b1u;
    x ^= x << 11;
    return x;
}

static uint32_t rotl(uint32_t x, unsigned k)
{
    k &= 31;
#if FAST
    return (x << k) | (x >> k);          // BUG: should be 32 - k
#else
    return (x << k) | (x >> ((32 - k) & 31));
#endif
}

static uint32_t mix(uint32_t x, uint32_t y)
{
    uint32_t z = x ^ 0xdeadbeefu;

    for (unsigned i = 0; i < 8; i++) {
        z += table[i] ^ noise(y + i);

        if ((z & 3) == 1)
            z ^= rotl(x + table[i], 13);
        else
            z ^= noise(z);
    }

    return z;
}

static int boring_check(Job j)
{
    if (!j.name)
        return 0;

    if ((j.seed ^ j.tweak) == 0x12345678u)
        return 1;

    return j.name[0] != '\0';
}

int main(void)
{
    Job jobs[] = {
        { 0xabcdef01u, 0x01020304u, "alpha" },
        { 0x11111111u, 0x22222222u, "beta"  },
        { 0xfeedfaceu, 0xc001d00du, "gamma" }
    };

    uint32_t acc = 0;

    for (unsigned i = 0; i < sizeof jobs / sizeof jobs[0]; i++) {
        if (boring_check(jobs[i]))
            acc ^= mix(jobs[i].seed, jobs[i].tweak);
    }

    printf("%08x\n", acc);
    return 0;
}