diff options
author | Ilya Tokar <tokarip@google.com> | 2019-12-12 14:04:56 -0500 |
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committer | Ilya Tokar <tokarip@google.com> | 2019-12-12 17:38:53 -0500 |
commit | 06e99aaf409eff4693c4256e59bb58313052818d (patch) | |
tree | 1d8c03970355f441cd3710ba49c6448db20a0108 | |
parent | 73a8d572f5d2e7020b71026d48bfdf99decf8d5b (diff) |
Bug 1785: fix pround on x86 to use the same rounding mode as std::round.
This also adds pset1frombits helper to Packet[24]d.
Makes round ~45% slower for SSE: 1.65µs ± 1% before vs 2.45µs ± 2% after,
stil an order of magnitude faster than scalar version: 33.8µs ± 2%.
-rw-r--r-- | Eigen/src/Core/arch/AVX/PacketMath.h | 16 | ||||
-rwxr-xr-x | Eigen/src/Core/arch/SSE/PacketMath.h | 16 | ||||
-rw-r--r-- | test/packetmath.cpp | 8 |
3 files changed, 35 insertions, 5 deletions
diff --git a/Eigen/src/Core/arch/AVX/PacketMath.h b/Eigen/src/Core/arch/AVX/PacketMath.h index ed8acfc61..00c3ae5d0 100644 --- a/Eigen/src/Core/arch/AVX/PacketMath.h +++ b/Eigen/src/Core/arch/AVX/PacketMath.h @@ -311,9 +311,6 @@ template<> EIGEN_STRONG_INLINE Packet8i pcmp_eq(const Packet8i& a, const Packet8 #endif } -template<> EIGEN_STRONG_INLINE Packet8f pround<Packet8f>(const Packet8f& a) { return _mm256_round_ps(a, _MM_FROUND_CUR_DIRECTION); } -template<> EIGEN_STRONG_INLINE Packet4d pround<Packet4d>(const Packet4d& a) { return _mm256_round_pd(a, _MM_FROUND_CUR_DIRECTION); } - template<> EIGEN_STRONG_INLINE Packet8f pceil<Packet8f>(const Packet8f& a) { return _mm256_ceil_ps(a); } template<> EIGEN_STRONG_INLINE Packet4d pceil<Packet4d>(const Packet4d& a) { return _mm256_ceil_pd(a); } @@ -391,6 +388,19 @@ template<> EIGEN_STRONG_INLINE Packet8i pandnot<Packet8i>(const Packet8i& a, con #endif } +template<> EIGEN_STRONG_INLINE Packet8f pround<Packet8f>(const Packet8f& a) +{ + const Packet8f mask = pset1frombits<Packet8f>(0x80000000u); + const Packet8f prev0dot5 = pset1frombits<Packet8f>(0x3EFFFFFFu); + return _mm256_round_ps(padd(por(pand(a, mask), prev0dot5), a), _MM_FROUND_TO_ZERO); +} +template<> EIGEN_STRONG_INLINE Packet4d pround<Packet4d>(const Packet4d& a) +{ + const Packet4d mask = _mm256_castsi256_pd(_mm256_set_epi64x(0x8000000000000000ull, 0x8000000000000000ull, 0x8000000000000000ull, 0x8000000000000000ull)); + const Packet4d prev0dot5 = _mm256_castsi256_pd(_mm256_set_epi64x(0x3FDFFFFFFFFFFFFFull, 0x3FDFFFFFFFFFFFFFull, 0x3FDFFFFFFFFFFFFFull, 0x3FDFFFFFFFFFFFFFull)); + return _mm256_round_pd(padd(por(pand(a, mask), prev0dot5), a), _MM_FROUND_TO_ZERO); +} + template<> EIGEN_STRONG_INLINE Packet8f pselect<Packet8f>(const Packet8f& mask, const Packet8f& a, const Packet8f& b) { return _mm256_blendv_ps(b,a,mask); } template<> EIGEN_STRONG_INLINE Packet4d pselect<Packet4d>(const Packet4d& mask, const Packet4d& a, const Packet4d& b) diff --git a/Eigen/src/Core/arch/SSE/PacketMath.h b/Eigen/src/Core/arch/SSE/PacketMath.h index 4a772d078..c9aa391e3 100755 --- a/Eigen/src/Core/arch/SSE/PacketMath.h +++ b/Eigen/src/Core/arch/SSE/PacketMath.h @@ -421,8 +421,20 @@ template<int N> EIGEN_STRONG_INLINE Packet4i pshiftright(Packet4i a) { return _m template<int N> EIGEN_STRONG_INLINE Packet4i pshiftleft(Packet4i a) { return _mm_slli_epi32(a,N); } #ifdef EIGEN_VECTORIZE_SSE4_1 -template<> EIGEN_STRONG_INLINE Packet4f pround<Packet4f>(const Packet4f& a) { return _mm_round_ps(a, 0); } -template<> EIGEN_STRONG_INLINE Packet2d pround<Packet2d>(const Packet2d& a) { return _mm_round_pd(a, 0); } +template<> EIGEN_STRONG_INLINE Packet4f pround<Packet4f>(const Packet4f& a) +{ + // Unfortunatly _mm_round_ps doesn't have a rounding mode to implement numext::round. + const Packet4f mask = pset1frombits<Packet4f>(0x80000000u); + const Packet4f prev0dot5 = pset1frombits<Packet4f>(0x3EFFFFFFu); + return _mm_round_ps(padd(por(pand(a, mask), prev0dot5), a), _MM_FROUND_TO_ZERO); +} + +template<> EIGEN_STRONG_INLINE Packet2d pround<Packet2d>(const Packet2d& a) +{ + const Packet2d mask = _mm_castsi128_pd(_mm_set_epi64x(0x8000000000000000ull, 0x8000000000000000ull)); + const Packet2d prev0dot5 = _mm_castsi128_pd(_mm_set_epi64x(0x3FDFFFFFFFFFFFFFull, 0x3FDFFFFFFFFFFFFFull)); + return _mm_round_pd(padd(por(pand(a, mask), prev0dot5), a), _MM_FROUND_TO_ZERO); +} template<> EIGEN_STRONG_INLINE Packet4f pceil<Packet4f>(const Packet4f& a) { return _mm_ceil_ps(a); } template<> EIGEN_STRONG_INLINE Packet2d pceil<Packet2d>(const Packet2d& a) { return _mm_ceil_pd(a); } diff --git a/test/packetmath.cpp b/test/packetmath.cpp index 00f5f042b..ed0ec7efe 100644 --- a/test/packetmath.cpp +++ b/test/packetmath.cpp @@ -518,6 +518,14 @@ template<typename Scalar,typename Packet> void packetmath_real() CHECK_CWISE1_IF(PacketTraits::HasCeil, numext::ceil, internal::pceil); CHECK_CWISE1_IF(PacketTraits::HasFloor, numext::floor, internal::pfloor); + // See bug 1785. + for (int i=0; i<size; ++i) + { + data1[i] = -1.5 + i; + data2[i] = -1.5 + i; + } + CHECK_CWISE1_IF(PacketTraits::HasRound, numext::round, internal::pround); + for (int i=0; i<size; ++i) { data1[i] = internal::random<Scalar>(-1,1); |