comment unreachable code

This commit is contained in:
Gael Guennebaud 2018-04-03 23:16:43 +02:00
parent a1292395d6
commit 112c899304

View File

@ -343,9 +343,12 @@ template<> EIGEN_STRONG_INLINE Packet4d preverse(const Packet4d& a)
{
__m256d tmp = _mm256_shuffle_pd(a,a,5);
return _mm256_permute2f128_pd(tmp, tmp, 1);
#if 0
// This version is unlikely to be faster as _mm256_shuffle_ps and _mm256_permute_pd
// exhibit the same latency/throughput, but it is here for future reference/benchmarking...
__m256d swap_halves = _mm256_permute2f128_pd(a,a,1);
return _mm256_permute_pd(swap_halves,5);
#endif
}
// pabs should be ok