template <typename T, T m, int k>
constexpr T swapbits(T p) {
 T q = ((p>>k)^p)&m;
 return p^q^(q<<k);
}

constexpr uint64_t bitreverse(uint64_t n)
{
 constexpr uint64_t m1 = ((uint64_t(1)<<63)-1)/(1+(1<<1)+(1<<2));
 constexpr uint64_t m2 = ((uint64_t(1)<<63)-1)/(1+(1<<3)+(1<<6));
 constexpr uint64_t m3 = ((uint64_t(1)<<9)-1)+(((uint64_t(1)<<9)-1)<<36);
 constexpr uint64_t m4 = (uint64_t(1)<<27)-1;
 n = swapbits<uint64_t, m1, 2>(n);
 n = swapbits<uint64_t, m2, 6>(n);
 n = swapbits<uint64_t, m3, 18>(n);
 n = swapbits<uint64_t, m4, 36>(n);
 n = (n >> 63) | (n << 1);
 return n;
}

static_assert(bitreverse(1ULL) == 0x8000000000000000ULL, "!");


uint64_t bitreverse2(uint64_t n)
{
   _storebe_i64(&n, __bswap_64(n));
   return n;
}

The Intel Intrinsics Guide is an interactive reference tool for Intel intrinsic instructions, which are C style functions that provide access to many Intel instructions - including Intel® SSE, AVX, AVX-512, and more - without the need to write assembly code.