diff options
| author |  Rasmus Munk Larsen <rmlarsen@google.com> | 2020-10-15 18:39:58 -0700 |
|---|---|---|
| committer | Rasmus Munk Larsen <rmlarsen@google.com> | 2020-10-15 18:39:58 -0700 |
| commit | 21edea5eddb282f12d38938d657973b1f8720779 (patch) | |
| tree | 09e67527da22b58a455f392772d40cb4cff918d7 /Eigen/src/Core/arch/AVX | |
| parent | 011e0db31d1bed8b7f73662be6d57d9f30fa457a (diff) | |
Fix the specialization of pfrexp for AVX to be faster when AVX2/AVX512DQ is not available, and avoid undefined behavior in C++. Also mask off the sign bit when extracting the exponent.
Diffstat (limited to 'Eigen/src/Core/arch/AVX')
| -rw-r--r-- | Eigen/src/Core/arch/AVX/PacketMath.h | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/Eigen/src/Core/arch/AVX/PacketMath.h b/Eigen/src/Core/arch/AVX/PacketMath.h index 5dbb84616..ae4c4aaaa 100644 --- a/Eigen/src/Core/arch/AVX/PacketMath.h +++ b/Eigen/src/Core/arch/AVX/PacketMath.h @@ -691,26 +691,27 @@ template<> EIGEN_STRONG_INLINE Packet8f pfrexp<Packet8f>(const Packet8f& a, Pack template<> EIGEN_STRONG_INLINE Packet4d pfrexp<Packet4d>(const Packet4d& a, Packet4d& exponent) { const Packet4d cst_1022d = pset1<Packet4d>(1022.0); const Packet4d cst_half = pset1<Packet4d>(0.5); - const Packet4d cst_inv_mant_mask = pset1frombits<Packet4d>(static_cast<uint64_t>(~0x7ff0000000000000ull)); - __m256i a_expo = _mm256_castpd_si256(a); + const Packet4d cst_exp_mask = pset1frombits<Packet4d>(static_cast<uint64_t>(0x7ff0000000000000ull)); + __m256i a_expo = _mm256_castpd_si256(pand(a, cst_exp_mask)); #ifdef EIGEN_VECTORIZE_AVX2 a_expo = _mm256_srli_epi64(a_expo, 52); -#else - __m128i lo = _mm_srli_epi64(_mm256_extractf128_si256(a_expo, 0), 52); - __m128i hi = _mm_srli_epi64(_mm256_extractf128_si256(a_expo, 1), 52); - a_expo = _mm256_insertf128_si256(_mm256_castsi128_si256(lo), (hi), 1); #endif -#ifdef EIGEN_VECTORIZE_AVX512DQ - // AVX512DQ finally provides an instruction for this +#if defined(EIGEN_VECTORIZE_AVX2) && defined(EIGEN_VECTORIZE_AVX512DQ) exponent = _mm256_cvtepi64_pd(a_expo); -#else - exponent = _mm256_set_pd(static_cast<double>(_mm256_extract_epi64(a_expo, 3)), - static_cast<double>(_mm256_extract_epi64(a_expo, 2)), - static_cast<double>(_mm256_extract_epi64(a_expo, 1)), - static_cast<double>(_mm256_extract_epi64(a_expo, 0))); -#endif +#else + __m128i lo = _mm256_extractf128_si256(a_expo, 0); + __m128i hi = _mm256_extractf128_si256(a_expo, 1); +#ifndef EIGEN_VECTORIZE_AVX2 + lo = _mm_srli_epi64(lo, 52); + hi = _mm_srli_epi64(hi, 52); +#endif + Packet2d exponent_lo = _mm_cvtepi32_pd(vec4i_swizzle1(lo, 0, 2, 1, 3)); + Packet2d exponent_hi = _mm_cvtepi32_pd(vec4i_swizzle1(hi, 0, 2, 1, 3)); + exponent = _mm256_set_m128d(exponent_hi, exponent_lo); +#endif // EIGEN_VECTORIZE_AVX512DQ exponent = psub(exponent, cst_1022d); - return por(pand(a, cst_inv_mant_mask), cst_half); + const Packet4d cst_mant_mask = pset1frombits<Packet4d>(static_cast<uint64_t>(~0x7ff0000000000000ull)); + return por(pand(a, cst_mant_mask), cst_half); } template<> EIGEN_STRONG_INLINE Packet8f pldexp<Packet8f>(const Packet8f& a, const Packet8f& exponent) { |