Add a pinsertlast function replacing the last entry of a packet by a scalar.

(useful to vectorize LinSpaced)
This commit is contained in:
Gael Guennebaud 2016-10-25 16:48:49 +02:00
parent 2634f9386c
commit 13fc18d3a2
4 changed files with 53 additions and 0 deletions

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@ -558,6 +558,19 @@ pblend(const Selector<unpacket_traits<Packet>::size>& ifPacket, const Packet& th
return ifPacket.select[0] ? thenPacket : elsePacket;
}
/** \internal \returns \a a with last coefficients replaced by the scalar b */
template<typename Packet> EIGEN_DEVICE_FUNC Packet pinsertlast(const Packet& a, typename unpacket_traits<Packet>::type b)
{
// Default implementation based on pblend.
// It must be specialized for higher performance.
Selector<unpacket_traits<Packet>::size> mask;
// This for loop should be optimized away by the compiler.
for(Index i=0; i<unpacket_traits<Packet>::size-1; ++i)
mask.select[i] = false;
mask.select[unpacket_traits<Packet>::size-1] = true;
return pblend(mask, pset1<Packet>(b), a);
}
} // end namespace internal
} // end namespace Eigen

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@ -604,6 +604,16 @@ template<> EIGEN_STRONG_INLINE Packet4d pblend(const Selector<4>& ifPacket, cons
return _mm256_blendv_pd(thenPacket, elsePacket, false_mask);
}
template<> EIGEN_DEVICE_FUNC Packet8f pinsertlast(const Packet8f& a, float b)
{
return _mm256_blend_ps(a,pset1<Packet8f>(b),(1<<7));
}
template<> EIGEN_DEVICE_FUNC Packet4d pinsertlast(const Packet4d& a, double b)
{
return _mm256_blend_pd(a,pset1<Packet4d>(b),(1<<3));
}
} // end namespace internal
} // end namespace Eigen

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@ -818,6 +818,26 @@ template<> EIGEN_STRONG_INLINE Packet2d pblend(const Selector<2>& ifPacket, cons
#endif
}
template<> EIGEN_DEVICE_FUNC Packet4f pinsertlast(const Packet4f& a, float b)
{
#ifdef EIGEN_VECTORIZE_SSE4_1
return _mm_blend_ps(a,pset1<Packet4f>(b),(1<<3));
#else
const Packet4f mask = _mm_castsi128_ps(_mm_setr_epi32(0x0,0x0,0x0,0xFFFFFFFF));
return _mm_or_ps(_mm_andnot_pd(mask, a), _mm_and_pd(mask, pset1<Packet4f>(b)));
#endif
}
template<> EIGEN_DEVICE_FUNC Packet2d pinsertlast(const Packet2d& a, double b)
{
#ifdef EIGEN_VECTORIZE_SSE4_1
return _mm_blend_pd(a,pset1<Packet2d>(b),(1<<1));
#else
const Packet2d mask = _mm_castsi128_pd(_mm_setr_epi32(0x0,0x0,0xFFFFFFFF,0xFFFFFFFF));
return _mm_or_pd(_mm_andnot_pd(mask, a), _mm_and_pd(mask, pset1<Packet2d>(b)));
#endif
}
// Scalar path for pmadd with FMA to ensure consistency with vectorized path.
#ifdef __FMA__
template<> EIGEN_STRONG_INLINE float pmadd(const float& a, const float& b, const float& c) {

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@ -289,6 +289,16 @@ template<typename Scalar> void packetmath()
VERIFY(isApproxAbs(result[i], (selector.select[i] ? data1[i] : data2[i]), refvalue));
}
}
if (PacketTraits::HasBlend) {
// pinsertlast
for (int i=0; i<PacketSize; ++i)
ref[i] = data1[i];
Scalar s = internal::random<Scalar>();
ref[PacketSize-1] = s;
internal::pstore(data2, internal::pinsertlast(internal::pload<Packet>(data1),s));
VERIFY(areApprox(ref, data2, PacketSize) && "internal::pinsertlast");
}
}
template<typename Scalar> void packetmath_real()