add_u64_u32
#define add_u64_u32 add_u64_u32
#ifndef add_u64_u32
#define mul_add(a, b, c) add_u64_u32(mul_u32_u32(a, b), c)
y = add_u64_u32(y, x >> 32);
return add_u64_u32(z, y >> 32);
n_med = add_u64_u32(n_med, n_lo >> 32);
#define add_u64_long(a, b) add_u64_u32(a, b)
n_hi = add_u64_u32(n_hi << 16, n_lo >> 48);
n_hi = add_u64_u32(n_hi << BITS_PER_ITER, n_lo >> (64 - BITS_PER_ITER));