static inline void
u64to8_le(uint8_t *p, uint64_t v)
{
U32TO8_LE(p, v.lo);
U32TO8_LE(p + 4, v.hi);
}
int halfsiphash(const uint8_t *in, const size_t inlen, const uint8_t *k,
uint8_t *out, const size_t outlen) {
assert((outlen == 4) || (outlen == 8));
uint32_t v0 = 0;
uint32_t v1 = 0;
uint32_t v2 = 0x6c796765;
uint32_t v3 = 0x74656462;
uint32_t k0 = U8TO32_LE(k);
uint32_t k1 = U8TO32_LE(k + 4);
uint32_t m;
int i;
const uint8_t *end = in + inlen - (inlen % sizeof(uint32_t));
const int left = inlen & 3;
uint32_t b = ((uint32_t)inlen) << 24;
v3 ^= k1;
v2 ^= k0;
v1 ^= k1;
v0 ^= k0;
if (outlen == 8)
v1 ^= 0xee;
for (; in != end; in += 4) {
m = U8TO32_LE(in);
v3 ^= m;
TRACE;
for (i = 0; i < cROUNDS; ++i)
SIPROUND;
v0 ^= m;
}
switch (left) {
case 3:
b |= ((uint32_t)in[2]) << 16;
case 2:
b |= ((uint32_t)in[1]) << 8;
case 1:
b |= ((uint32_t)in[0]);
break;
case 0:
break;
}
v3 ^= b;
TRACE;
for (i = 0; i < cROUNDS; ++i)
SIPROUND;
v0 ^= b;
if (outlen == 8)
v2 ^= 0xee;
else
v2 ^= 0xff;
TRACE;
for (i = 0; i < dROUNDS; ++i)
SIPROUND;
b = v1 ^ v3;
U32TO8_LE(out, b);
if (outlen == 4)
return 0;
v1 ^= 0xdd;
TRACE;
for (i = 0; i < dROUNDS; ++i)
SIPROUND;
b = v1 ^ v3;
U32TO8_LE(out + 4, b);
return 0;
}
