From 59398aa2bb2f11ac988712b46b063aba9866e820 Mon Sep 17 00:00:00 2001 From: Gael Guennebaud Date: Tue, 3 Apr 2018 23:16:43 +0200 Subject: [PATCH] comment unreachable code (grafted from 112c8993049ea0c4ef8e3e4f257880626f8b39e1 ) --- Eigen/src/Core/arch/AVX/PacketMath.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/Eigen/src/Core/arch/AVX/PacketMath.h b/Eigen/src/Core/arch/AVX/PacketMath.h index 195d40fb4..c747341f7 100644 --- a/Eigen/src/Core/arch/AVX/PacketMath.h +++ b/Eigen/src/Core/arch/AVX/PacketMath.h @@ -333,9 +333,12 @@ 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