Clean up float16 a.k.a. Eigen::half support in Eigen. Move the definition of half to Core/arch/Default and move arch-specific packet ops to their respective sub-directories.

13 files changed, 1805 insertions, 1812 deletions

diff --git a/Eigen/Core b/Eigen/Core
index af741a241..e6e31caee 100644
--- a/Eigen/Core
+++ b/Eigen/Core
@@ -160,6 +160,9 @@ using std::ptrdiff_t;
 #include "src/Core/GenericPacketMath.h"
 #include "src/Core/MathFunctionsImpl.h"
 #include "src/Core/arch/Default/ConjHelper.h"
+// Generic half float support
+#include "src/Core/arch/Default/Half.h"
+#include "src/Core/arch/Default/TypeCasting.h"
 
 #if defined EIGEN_VECTORIZE_AVX512
   #include "src/Core/arch/SSE/PacketMath.h"
@@ -207,14 +210,10 @@ using std::ptrdiff_t;
   #include "src/Core/arch/MSA/Complex.h"
 #endif
 
-// Half float support
-#include "src/Core/arch/GPU/Half.h"
-#include "src/Core/arch/GPU/PacketMathHalf.h"
-#include "src/Core/arch/GPU/TypeCasting.h"
-
 #if defined EIGEN_VECTORIZE_GPU
   #include "src/Core/arch/GPU/PacketMath.h"
   #include "src/Core/arch/GPU/MathFunctions.h"
+  #include "src/Core/arch/GPU/TypeCasting.h"
 #endif
 
 #if defined(EIGEN_USE_SYCL)
diff --git a/Eigen/src/Core/arch/AVX/PacketMath.h b/Eigen/src/Core/arch/AVX/PacketMath.h
index 5233195f3..020f6c276 100644
--- a/Eigen/src/Core/arch/AVX/PacketMath.h
+++ b/Eigen/src/Core/arch/AVX/PacketMath.h
@@ -31,10 +31,14 @@ namespace internal {
 typedef __m256  Packet8f;
 typedef __m256i Packet8i;
 typedef __m256d Packet4d;
+typedef struct {
+  __m128i x;
+} Packet8h;
 
 template<> struct is_arithmetic<__m256>  { enum { value = true }; };
 template<> struct is_arithmetic<__m256i> { enum { value = true }; };
 template<> struct is_arithmetic<__m256d> { enum { value = true }; };
+template<> struct is_arithmetic<Packet8h> { enum { value = true }; };
 
 #define _EIGEN_DECLARE_CONST_Packet8f(NAME,X) \
   const Packet8f p8f_##NAME = pset1<Packet8f>(X)
@@ -97,6 +101,35 @@ template<> struct packet_traits<double> : default_packet_traits
     HasCeil = 1
   };
 };
+
+template <>
+struct packet_traits<Eigen::half> : default_packet_traits {
+  typedef Packet8h type;
+  // There is no half-size packet for Packet8h.
+  typedef Packet8h half;
+  enum {
+    Vectorizable = 1,
+    AlignedOnScalar = 1,
+    size = 8,
+    HasHalfPacket = 0,
+    HasAdd    = 1,
+    HasSub    = 1,
+    HasMul    = 1,
+    HasDiv    = 1,
+    HasNegate = 1,
+    HasAbs    = 0,
+    HasAbs2   = 0,
+    HasMin    = 0,
+    HasMax    = 0,
+    HasConj   = 0,
+    HasSetLinear = 0,
+    HasSqrt = 0,
+    HasRsqrt = 0,
+    HasExp = 0,
+    HasLog = 0,
+    HasBlend = 0
+  };
+};
 #endif
 
 template<> struct scalar_div_cost<float,true> { enum { value = 14 }; };
@@ -847,6 +880,335 @@ template<> EIGEN_STRONG_INLINE Packet4d pinsertlast(const Packet4d& a, double b)
   return _mm256_blend_pd(a,pset1<Packet4d>(b),(1<<3));
 }
 
+
+// Packet math for Eigen::half
+template<> struct unpacket_traits<Packet8h> { typedef Eigen::half type; enum {size=8, alignment=Aligned16, vectorizable=true, masked_load_available=false, masked_store_available=false}; typedef Packet8h half; };
+
+template<> EIGEN_STRONG_INLINE Packet8h pset1<Packet8h>(const Eigen::half& from) {
+  Packet8h result;
+  result.x = _mm_set1_epi16(from.x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Eigen::half pfirst<Packet8h>(const Packet8h& from) {
+  return half_impl::raw_uint16_to_half(static_cast<unsigned short>(_mm_extract_epi16(from.x, 0)));
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pload<Packet8h>(const Eigen::half* from) {
+  Packet8h result;
+  result.x = _mm_load_si128(reinterpret_cast<const __m128i*>(from));
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h ploadu<Packet8h>(const Eigen::half* from) {
+  Packet8h result;
+  result.x = _mm_loadu_si128(reinterpret_cast<const __m128i*>(from));
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE void pstore<Eigen::half>(Eigen::half* to, const Packet8h& from) {
+  _mm_store_si128(reinterpret_cast<__m128i*>(to), from.x);
+}
+
+template<> EIGEN_STRONG_INLINE void pstoreu<Eigen::half>(Eigen::half* to, const Packet8h& from) {
+  _mm_storeu_si128(reinterpret_cast<__m128i*>(to), from.x);
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h
+ploaddup<Packet8h>(const Eigen::half*  from) {
+  Packet8h result;
+  unsigned short a = from[0].x;
+  unsigned short b = from[1].x;
+  unsigned short c = from[2].x;
+  unsigned short d = from[3].x;
+  result.x = _mm_set_epi16(d, d, c, c, b, b, a, a);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h
+ploadquad<Packet8h>(const Eigen::half* from) {
+  Packet8h result;
+  unsigned short a = from[0].x;
+  unsigned short b = from[1].x;
+  result.x = _mm_set_epi16(b, b, b, b, a, a, a, a);
+  return result;
+}
+
+EIGEN_STRONG_INLINE Packet8f half2float(const Packet8h& a) {
+#ifdef EIGEN_HAS_FP16_C
+  return _mm256_cvtph_ps(a.x);
+#else
+  EIGEN_ALIGN32 Eigen::half aux[8];
+  pstore(aux, a);
+  float f0(aux[0]);
+  float f1(aux[1]);
+  float f2(aux[2]);
+  float f3(aux[3]);
+  float f4(aux[4]);
+  float f5(aux[5]);
+  float f6(aux[6]);
+  float f7(aux[7]);
+
+  return _mm256_set_ps(f7, f6, f5, f4, f3, f2, f1, f0);
+#endif
+}
+
+EIGEN_STRONG_INLINE Packet8h float2half(const Packet8f& a) {
+#ifdef EIGEN_HAS_FP16_C
+  Packet8h result;
+  result.x = _mm256_cvtps_ph(a, _MM_FROUND_TO_NEAREST_INT|_MM_FROUND_NO_EXC);
+  return result;
+#else
+  EIGEN_ALIGN32 float aux[8];
+  pstore(aux, a);
+  Eigen::half h0(aux[0]);
+  Eigen::half h1(aux[1]);
+  Eigen::half h2(aux[2]);
+  Eigen::half h3(aux[3]);
+  Eigen::half h4(aux[4]);
+  Eigen::half h5(aux[5]);
+  Eigen::half h6(aux[6]);
+  Eigen::half h7(aux[7]);
+
+  Packet8h result;
+  result.x = _mm_set_epi16(h7.x, h6.x, h5.x, h4.x, h3.x, h2.x, h1.x, h0.x);
+  return result;
+#endif
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h ptrue(const Packet8h& a) {
+  Packet8h r; r.x = _mm_cmpeq_epi32(a.x, a.x); return r;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h por(const Packet8h& a,const Packet8h& b) {
+  // in some cases Packet4i is a wrapper around __m128i, so we either need to
+  // cast to Packet4i to directly call the intrinsics as below:
+  Packet8h r; r.x = _mm_or_si128(a.x,b.x); return r;
+}
+template<> EIGEN_STRONG_INLINE Packet8h pxor(const Packet8h& a,const Packet8h& b) {
+  Packet8h r; r.x = _mm_xor_si128(a.x,b.x); return r;
+}
+template<> EIGEN_STRONG_INLINE Packet8h pand(const Packet8h& a,const Packet8h& b) {
+  Packet8h r; r.x = _mm_and_si128(a.x,b.x); return r;
+}
+template<> EIGEN_STRONG_INLINE Packet8h pandnot(const Packet8h& a,const Packet8h& b) {
+  Packet8h r; r.x = _mm_andnot_si128(b.x,a.x); return r;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pselect(const Packet8h& mask, const Packet8h& a, const Packet8h& b) {
+  Packet8h r; r.x = _mm_blendv_epi8(b.x, a.x, mask.x); return r;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pcmp_eq(const Packet8h& a,const Packet8h& b) {
+  Packet8f af = half2float(a);
+  Packet8f bf = half2float(b);
+  Packet8f rf = pcmp_eq(af, bf);
+  // Pack the 32-bit flags into 16-bits flags.
+  Packet8h result; result.x = _mm_packs_epi32(_mm256_extractf128_si256(_mm256_castps_si256(rf), 0),
+                                              _mm256_extractf128_si256(_mm256_castps_si256(rf), 1));
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pconj(const Packet8h& a) { return a; }
+
+template<> EIGEN_STRONG_INLINE Packet8h pnegate(const Packet8h& a) {
+  Packet8h sign_mask; sign_mask.x = _mm_set1_epi16(static_cast<unsigned short>(0x8000));
+  Packet8h result; result.x = _mm_xor_si128(a.x, sign_mask.x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h padd<Packet8h>(const Packet8h& a, const Packet8h& b) {
+  Packet8f af = half2float(a);
+  Packet8f bf = half2float(b);
+  Packet8f rf = padd(af, bf);
+  return float2half(rf);
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h psub<Packet8h>(const Packet8h& a, const Packet8h& b) {
+  Packet8f af = half2float(a);
+  Packet8f bf = half2float(b);
+  Packet8f rf = psub(af, bf);
+  return float2half(rf);
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pmul<Packet8h>(const Packet8h& a, const Packet8h& b) {
+  Packet8f af = half2float(a);
+  Packet8f bf = half2float(b);
+  Packet8f rf = pmul(af, bf);
+  return float2half(rf);
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pdiv<Packet8h>(const Packet8h& a, const Packet8h& b) {
+  Packet8f af = half2float(a);
+  Packet8f bf = half2float(b);
+  Packet8f rf = pdiv(af, bf);
+  return float2half(rf);
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pgather<Eigen::half, Packet8h>(const Eigen::half* from, Index stride)
+{
+  Packet8h result;
+  result.x = _mm_set_epi16(from[7*stride].x, from[6*stride].x, from[5*stride].x, from[4*stride].x, from[3*stride].x, from[2*stride].x, from[1*stride].x, from[0*stride].x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE void pscatter<Eigen::half, Packet8h>(Eigen::half* to, const Packet8h& from, Index stride)
+{
+  EIGEN_ALIGN32 Eigen::half aux[8];
+  pstore(aux, from);
+  to[stride*0].x = aux[0].x;
+  to[stride*1].x = aux[1].x;
+  to[stride*2].x = aux[2].x;
+  to[stride*3].x = aux[3].x;
+  to[stride*4].x = aux[4].x;
+  to[stride*5].x = aux[5].x;
+  to[stride*6].x = aux[6].x;
+  to[stride*7].x = aux[7].x;
+}
+
+template<> EIGEN_STRONG_INLINE Eigen::half predux<Packet8h>(const Packet8h& a) {
+  Packet8f af = half2float(a);
+  float reduced = predux<Packet8f>(af);
+  return Eigen::half(reduced);
+}
+
+template<> EIGEN_STRONG_INLINE Eigen::half predux_max<Packet8h>(const Packet8h& a) {
+  Packet8f af = half2float(a);
+  float reduced = predux_max<Packet8f>(af);
+  return Eigen::half(reduced);
+}
+
+template<> EIGEN_STRONG_INLINE Eigen::half predux_min<Packet8h>(const Packet8h& a) {
+  Packet8f af = half2float(a);
+  float reduced = predux_min<Packet8f>(af);
+  return Eigen::half(reduced);
+}
+
+template<> EIGEN_STRONG_INLINE Eigen::half predux_mul<Packet8h>(const Packet8h& a) {
+  Packet8f af = half2float(a);
+  float reduced = predux_mul<Packet8f>(af);
+  return Eigen::half(reduced);
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h preduxp<Packet8h>(const Packet8h* p) {
+  Packet8f pf[8];
+  pf[0] = half2float(p[0]);
+  pf[1] = half2float(p[1]);
+  pf[2] = half2float(p[2]);
+  pf[3] = half2float(p[3]);
+  pf[4] = half2float(p[4]);
+  pf[5] = half2float(p[5]);
+  pf[6] = half2float(p[6]);
+  pf[7] = half2float(p[7]);
+  Packet8f reduced = preduxp<Packet8f>(pf);
+  return float2half(reduced);
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h preverse(const Packet8h& a)
+{
+  __m128i m = _mm_setr_epi8(14,15,12,13,10,11,8,9,6,7,4,5,2,3,0,1);
+  Packet8h res;
+  res.x = _mm_shuffle_epi8(a.x,m);
+  return res;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pinsertfirst(const Packet8h& a, Eigen::half b)
+{
+  Packet8h res;
+  res.x = _mm_insert_epi16(a.x,int(b.x),0);
+  return res;
+}
+
+template<> EIGEN_STRONG_INLINE Packet8h pinsertlast(const Packet8h& a, Eigen::half b)
+{
+  Packet8h res;
+  res.x = _mm_insert_epi16(a.x,int(b.x),7);
+  return res;
+}
+
+template<int Offset>
+struct palign_impl<Offset,Packet8h>
+{
+  static EIGEN_STRONG_INLINE void run(Packet8h& first, const Packet8h& second)
+  {
+    if (Offset!=0)
+      first.x = _mm_alignr_epi8(second.x,first.x, Offset*2);
+  }
+};
+
+EIGEN_STRONG_INLINE void
+ptranspose(PacketBlock<Packet8h,8>& kernel) {
+  __m128i a = kernel.packet[0].x;
+  __m128i b = kernel.packet[1].x;
+  __m128i c = kernel.packet[2].x;
+  __m128i d = kernel.packet[3].x;
+  __m128i e = kernel.packet[4].x;
+  __m128i f = kernel.packet[5].x;
+  __m128i g = kernel.packet[6].x;
+  __m128i h = kernel.packet[7].x;
+
+  __m128i a03b03 = _mm_unpacklo_epi16(a, b);
+  __m128i c03d03 = _mm_unpacklo_epi16(c, d);
+  __m128i e03f03 = _mm_unpacklo_epi16(e, f);
+  __m128i g03h03 = _mm_unpacklo_epi16(g, h);
+  __m128i a47b47 = _mm_unpackhi_epi16(a, b);
+  __m128i c47d47 = _mm_unpackhi_epi16(c, d);
+  __m128i e47f47 = _mm_unpackhi_epi16(e, f);
+  __m128i g47h47 = _mm_unpackhi_epi16(g, h);
+
+  __m128i a01b01c01d01 = _mm_unpacklo_epi32(a03b03, c03d03);
+  __m128i a23b23c23d23 = _mm_unpackhi_epi32(a03b03, c03d03);
+  __m128i e01f01g01h01 = _mm_unpacklo_epi32(e03f03, g03h03);
+  __m128i e23f23g23h23 = _mm_unpackhi_epi32(e03f03, g03h03);
+  __m128i a45b45c45d45 = _mm_unpacklo_epi32(a47b47, c47d47);
+  __m128i a67b67c67d67 = _mm_unpackhi_epi32(a47b47, c47d47);
+  __m128i e45f45g45h45 = _mm_unpacklo_epi32(e47f47, g47h47);
+  __m128i e67f67g67h67 = _mm_unpackhi_epi32(e47f47, g47h47);
+
+  __m128i a0b0c0d0e0f0g0h0 = _mm_unpacklo_epi64(a01b01c01d01, e01f01g01h01);
+  __m128i a1b1c1d1e1f1g1h1 = _mm_unpackhi_epi64(a01b01c01d01, e01f01g01h01);
+  __m128i a2b2c2d2e2f2g2h2 = _mm_unpacklo_epi64(a23b23c23d23, e23f23g23h23);
+  __m128i a3b3c3d3e3f3g3h3 = _mm_unpackhi_epi64(a23b23c23d23, e23f23g23h23);
+  __m128i a4b4c4d4e4f4g4h4 = _mm_unpacklo_epi64(a45b45c45d45, e45f45g45h45);
+  __m128i a5b5c5d5e5f5g5h5 = _mm_unpackhi_epi64(a45b45c45d45, e45f45g45h45);
+  __m128i a6b6c6d6e6f6g6h6 = _mm_unpacklo_epi64(a67b67c67d67, e67f67g67h67);
+  __m128i a7b7c7d7e7f7g7h7 = _mm_unpackhi_epi64(a67b67c67d67, e67f67g67h67);
+
+  kernel.packet[0].x = a0b0c0d0e0f0g0h0;
+  kernel.packet[1].x = a1b1c1d1e1f1g1h1;
+  kernel.packet[2].x = a2b2c2d2e2f2g2h2;
+  kernel.packet[3].x = a3b3c3d3e3f3g3h3;
+  kernel.packet[4].x = a4b4c4d4e4f4g4h4;
+  kernel.packet[5].x = a5b5c5d5e5f5g5h5;
+  kernel.packet[6].x = a6b6c6d6e6f6g6h6;
+  kernel.packet[7].x = a7b7c7d7e7f7g7h7;
+}
+
+EIGEN_STRONG_INLINE void
+ptranspose(PacketBlock<Packet8h,4>& kernel) {
+  EIGEN_ALIGN32 Eigen::half in[4][8];
+  pstore<Eigen::half>(in[0], kernel.packet[0]);
+  pstore<Eigen::half>(in[1], kernel.packet[1]);
+  pstore<Eigen::half>(in[2], kernel.packet[2]);
+  pstore<Eigen::half>(in[3], kernel.packet[3]);
+
+  EIGEN_ALIGN32 Eigen::half out[4][8];
+
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 4; ++j) {
+      out[i][j] = in[j][2*i];
+    }
+    for (int j = 0; j < 4; ++j) {
+      out[i][j+4] = in[j][2*i+1];
+    }
+  }
+
+  kernel.packet[0] = pload<Packet8h>(out[0]);
+  kernel.packet[1] = pload<Packet8h>(out[1]);
+  kernel.packet[2] = pload<Packet8h>(out[2]);
+  kernel.packet[3] = pload<Packet8h>(out[3]);
+}
+
 } // end namespace internal
 
 } // end namespace Eigen
diff --git a/Eigen/src/Core/arch/AVX/TypeCasting.h b/Eigen/src/Core/arch/AVX/TypeCasting.h
index 7d2e1e67f..910fc06ca 100644
--- a/Eigen/src/Core/arch/AVX/TypeCasting.h
+++ b/Eigen/src/Core/arch/AVX/TypeCasting.h
@@ -52,6 +52,33 @@ template<> EIGEN_STRONG_INLINE Packet8f preinterpret<Packet8f,Packet8i>(const Pa
   return _mm256_castsi256_ps(a);
 }
 
+
+template <>
+struct type_casting_traits<Eigen::half, float> {
+  enum {
+    VectorizedCast = 1,
+    SrcCoeffRatio = 1,
+    TgtCoeffRatio = 1
+  };
+};
+
+template<> EIGEN_STRONG_INLINE Packet8f pcast<Packet8h, Packet8f>(const Packet8h& a) {
+  return half2float(a);
+}
+
+template <>
+struct type_casting_traits<float, Eigen::half> {
+  enum {
+    VectorizedCast = 1,
+    SrcCoeffRatio = 1,
+    TgtCoeffRatio = 1
+  };
+};
+
+template<> EIGEN_STRONG_INLINE Packet8h pcast<Packet8f, Packet8h>(const Packet8f& a) {
+  return float2half(a);
+}
+
 } // end namespace internal
 
 } // end namespace Eigen
diff --git a/Eigen/src/Core/arch/AVX512/PacketMath.h b/Eigen/src/Core/arch/AVX512/PacketMath.h
index 0a81fe02d..e37855693 100644
--- a/Eigen/src/Core/arch/AVX512/PacketMath.h
+++ b/Eigen/src/Core/arch/AVX512/PacketMath.h
@@ -44,6 +44,41 @@ template <>
 struct is_arithmetic<__m512d> {
   enum { value = true };
 };
+typedef struct {
+  __m256i x;
+} Packet16h;
+
+
+template<> struct is_arithmetic<Packet16h> { enum { value = true }; };
+
+template <>
+struct packet_traits<half> : default_packet_traits {
+  typedef Packet16h type;
+  // There is no half-size packet for Packet16h.
+  typedef Packet16h half;
+  enum {
+    Vectorizable = 1,
+    AlignedOnScalar = 1,
+    size = 16,
+    HasHalfPacket = 0,
+    HasAdd    = 1,
+    HasSub    = 1,
+    HasMul    = 1,
+    HasDiv    = 1,
+    HasNegate = 1,
+    HasAbs    = 0,
+    HasAbs2   = 0,
+    HasMin    = 0,
+    HasMax    = 0,
+    HasConj   = 0,
+    HasSetLinear = 0,
+    HasSqrt = 0,
+    HasRsqrt = 0,
+    HasExp = 0,
+    HasLog = 0,
+    HasBlend = 0
+  };
+};
 
 template<> struct packet_traits<float>  : default_packet_traits
 {
@@ -60,8 +95,8 @@ template<> struct packet_traits<float>  : default_packet_traits
 #if EIGEN_GNUC_AT_LEAST(5, 3) || (!EIGEN_COMP_GNUC_STRICT)
 #ifdef EIGEN_VECTORIZE_AVX512DQ
     HasLog = 1,
-    HasLog1p = 1,
-    HasExpm1 = 1,
+    HasLog1p  = 1,
+    HasExpm1  = 1,
 #endif
     HasExp = 1,
     HasSqrt = EIGEN_FAST_MATH,
@@ -120,6 +155,13 @@ struct unpacket_traits<Packet16i> {
   enum { size = 16, alignment=Aligned64, vectorizable=false, masked_load_available=false, masked_store_available=false };
 };
 
+template<>
+struct unpacket_traits<Packet16h> {
+  typedef Eigen::half type;
+  typedef Packet16h half;
+  enum {size=16, alignment=Aligned32, vectorizable=true, masked_load_available=false, masked_store_available=false};
+};
+
 template <>
 EIGEN_STRONG_INLINE Packet16f pset1<Packet16f>(const float& from) {
   return _mm512_set1_ps(from);
@@ -1397,6 +1439,467 @@ template<> EIGEN_STRONG_INLINE Packet16f preinterpret<Packet16f,Packet16i>(const
   return _mm512_castsi512_ps(a);
 }
 
+
+// Packet math for Eigen::half
+template<> EIGEN_STRONG_INLINE Packet16h pset1<Packet16h>(const Eigen::half& from) {
+  Packet16h result;
+  result.x = _mm256_set1_epi16(from.x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Eigen::half pfirst<Packet16h>(const Packet16h& from) {
+  return half_impl::raw_uint16_to_half(static_cast<unsigned short>(_mm256_extract_epi16(from.x, 0)));
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pload<Packet16h>(const Eigen::half* from) {
+  Packet16h result;
+  result.x = _mm256_load_si256(reinterpret_cast<const __m256i*>(from));
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h ploadu<Packet16h>(const Eigen::half* from) {
+  Packet16h result;
+  result.x = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(from));
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE void pstore<half>(Eigen::half* to, const Packet16h& from) {
+  // (void*) -> workaround clang warning:
+  // cast from 'Eigen::half *' to '__m256i *' increases required alignment from 2 to 32
+  _mm256_store_si256((__m256i*)(void*)to, from.x);
+}
+
+template<> EIGEN_STRONG_INLINE void pstoreu<half>(Eigen::half* to, const Packet16h& from) {
+  // (void*) -> workaround clang warning:
+  // cast from 'Eigen::half *' to '__m256i *' increases required alignment from 2 to 32
+  _mm256_storeu_si256((__m256i*)(void*)to, from.x);
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h
+ploaddup<Packet16h>(const Eigen::half*  from) {
+  Packet16h result;
+  unsigned short a = from[0].x;
+  unsigned short b = from[1].x;
+  unsigned short c = from[2].x;
+  unsigned short d = from[3].x;
+  unsigned short e = from[4].x;
+  unsigned short f = from[5].x;
+  unsigned short g = from[6].x;
+  unsigned short h = from[7].x;
+  result.x = _mm256_set_epi16(h, h, g, g, f, f, e, e, d, d, c, c, b, b, a, a);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h
+ploadquad(const Eigen::half* from) {
+  Packet16h result;
+  unsigned short a = from[0].x;
+  unsigned short b = from[1].x;
+  unsigned short c = from[2].x;
+  unsigned short d = from[3].x;
+  result.x = _mm256_set_epi16(d, d, d, d, c, c, c, c, b, b, b, b, a, a, a, a);
+  return result;
+}
+
+EIGEN_STRONG_INLINE Packet16f half2float(const Packet16h& a) {
+#ifdef EIGEN_HAS_FP16_C
+  return _mm512_cvtph_ps(a.x);
+#else
+  EIGEN_ALIGN64 half aux[16];
+  pstore(aux, a);
+  float f0(aux[0]);
+  float f1(aux[1]);
+  float f2(aux[2]);
+  float f3(aux[3]);
+  float f4(aux[4]);
+  float f5(aux[5]);
+  float f6(aux[6]);
+  float f7(aux[7]);
+  float f8(aux[8]);
+  float f9(aux[9]);
+  float fa(aux[10]);
+  float fb(aux[11]);
+  float fc(aux[12]);
+  float fd(aux[13]);
+  float fe(aux[14]);
+  float ff(aux[15]);
+
+  return _mm512_set_ps(
+      ff, fe, fd, fc, fb, fa, f9, f8, f7, f6, f5, f4, f3, f2, f1, f0);
+#endif
+}
+
+EIGEN_STRONG_INLINE Packet16h float2half(const Packet16f& a) {
+#ifdef EIGEN_HAS_FP16_C
+  Packet16h result;
+  result.x = _mm512_cvtps_ph(a, _MM_FROUND_TO_NEAREST_INT|_MM_FROUND_NO_EXC);
+  return result;
+#else
+  EIGEN_ALIGN64 float aux[16];
+  pstore(aux, a);
+  half h0(aux[0]);
+  half h1(aux[1]);
+  half h2(aux[2]);
+  half h3(aux[3]);
+  half h4(aux[4]);
+  half h5(aux[5]);
+  half h6(aux[6]);
+  half h7(aux[7]);
+  half h8(aux[8]);
+  half h9(aux[9]);
+  half ha(aux[10]);
+  half hb(aux[11]);
+  half hc(aux[12]);
+  half hd(aux[13]);
+  half he(aux[14]);
+  half hf(aux[15]);
+
+  Packet16h result;
+  result.x = _mm256_set_epi16(
+      hf.x, he.x, hd.x, hc.x, hb.x, ha.x, h9.x, h8.x,
+      h7.x, h6.x, h5.x, h4.x, h3.x, h2.x, h1.x, h0.x);
+  return result;
+#endif
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pnot(const Packet16h& a) {
+  Packet16h r; r.x = _mm256_xor_si256(a.x, pcmp_eq(a.x, a.x)); return r;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h ptrue(const Packet16h& a) {
+  Packet16h r; r.x = Packet8i(ptrue(a.x)); return r;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h por(const Packet16h& a,const Packet16h& b) {
+  // in some cases Packet8i is a wrapper around __m256i, so we need to
+  // cast to Packet8i to call the correct overload.
+  Packet16h r; r.x = por(Packet8i(a.x),Packet8i(b.x)); return r;
+}
+template<> EIGEN_STRONG_INLINE Packet16h pxor(const Packet16h& a,const Packet16h& b) {
+  Packet16h r; r.x = pxor(Packet8i(a.x),Packet8i(b.x)); return r;
+}
+template<> EIGEN_STRONG_INLINE Packet16h pand(const Packet16h& a,const Packet16h& b) {
+  Packet16h r; r.x = pand(Packet8i(a.x),Packet8i(b.x)); return r;
+}
+template<> EIGEN_STRONG_INLINE Packet16h pandnot(const Packet16h& a,const Packet16h& b) {
+  Packet16h r; r.x = pandnot(Packet8i(a.x),Packet8i(b.x)); return r;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pselect(const Packet16h& mask, const Packet16h& a, const Packet16h& b) {
+  Packet16h r; r.x = _mm256_blendv_epi8(b.x, a.x, mask.x); return r;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pcmp_eq(const Packet16h& a,const Packet16h& b) {
+  Packet16f af = half2float(a);
+  Packet16f bf = half2float(b);
+  Packet16f rf = pcmp_eq(af, bf);
+  // Pack the 32-bit flags into 16-bits flags.
+  __m256i lo = _mm256_castps_si256(extract256<0>(rf));
+  __m256i hi = _mm256_castps_si256(extract256<1>(rf));
+  __m128i result_lo = _mm_packs_epi32(_mm256_extractf128_si256(lo, 0),
+                                      _mm256_extractf128_si256(lo, 1));
+  __m128i result_hi = _mm_packs_epi32(_mm256_extractf128_si256(hi, 0),
+                                      _mm256_extractf128_si256(hi, 1));
+  Packet16h result; result.x = _mm256_insertf128_si256(_mm256_castsi128_si256(result_lo), result_hi, 1);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pnegate(const Packet16h& a) {
+  Packet16h sign_mask; sign_mask.x = _mm256_set1_epi16(static_cast<unsigned short>(0x8000));
+  Packet16h result; result.x = _mm256_xor_si256(a.x, sign_mask.x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h padd<Packet16h>(const Packet16h& a, const Packet16h& b) {
+  Packet16f af = half2float(a);
+  Packet16f bf = half2float(b);
+  Packet16f rf = padd(af, bf);
+  return float2half(rf);
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h psub<Packet16h>(const Packet16h& a, const Packet16h& b) {
+  Packet16f af = half2float(a);
+  Packet16f bf = half2float(b);
+  Packet16f rf = psub(af, bf);
+  return float2half(rf);
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pmul<Packet16h>(const Packet16h& a, const Packet16h& b) {
+  Packet16f af = half2float(a);
+  Packet16f bf = half2float(b);
+  Packet16f rf = pmul(af, bf);
+  return float2half(rf);
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pdiv<Packet16h>(const Packet16h& a, const Packet16h& b) {
+  Packet16f af = half2float(a);
+  Packet16f bf = half2float(b);
+  Packet16f rf = pdiv(af, bf);
+  return float2half(rf);
+}
+
+template<> EIGEN_STRONG_INLINE half predux<Packet16h>(const Packet16h& from) {
+  Packet16f from_float = half2float(from);
+  return half(predux(from_float));
+}
+
+template<> EIGEN_STRONG_INLINE half predux_mul<Packet16h>(const Packet16h& from) {
+  Packet16f from_float = half2float(from);
+  return half(predux_mul(from_float));
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h preduxp<Packet16h>(const Packet16h* p) {
+  Packet16f pf[16];
+  pf[0] = half2float(p[0]);
+  pf[1] = half2float(p[1]);
+  pf[2] = half2float(p[2]);
+  pf[3] = half2float(p[3]);
+  pf[4] = half2float(p[4]);
+  pf[5] = half2float(p[5]);
+  pf[6] = half2float(p[6]);
+  pf[7] = half2float(p[7]);
+  pf[8] = half2float(p[8]);
+  pf[9] = half2float(p[9]);
+  pf[10] = half2float(p[10]);
+  pf[11] = half2float(p[11]);
+  pf[12] = half2float(p[12]);
+  pf[13] = half2float(p[13]);
+  pf[14] = half2float(p[14]);
+  pf[15] = half2float(p[15]);
+  Packet16f reduced = preduxp<Packet16f>(pf);
+  return float2half(reduced);
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h preverse(const Packet16h& a)
+{
+  __m128i m = _mm_setr_epi8(14,15,12,13,10,11,8,9,6,7,4,5,2,3,0,1);
+  Packet16h res;
+  res.x = _mm256_insertf128_si256(
+                    _mm256_castsi128_si256(_mm_shuffle_epi8(_mm256_extractf128_si256(a.x,1),m)),
+                                           _mm_shuffle_epi8(_mm256_extractf128_si256(a.x,0),m), 1);
+  return res;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pinsertfirst(const Packet16h& a, Eigen::half b)
+{
+  Packet16h res;
+  res.x = _mm256_insert_epi16(a.x,b.x,0);
+  return res;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pinsertlast(const Packet16h& a, Eigen::half b)
+{
+  Packet16h res;
+  res.x = _mm256_insert_epi16(a.x,b.x,15);
+  return res;
+}
+
+template<> EIGEN_STRONG_INLINE Packet16h pgather<Eigen::half, Packet16h>(const Eigen::half* from, Index stride)
+{
+  Packet16h result;
+  result.x = _mm256_set_epi16(
+      from[15*stride].x, from[14*stride].x, from[13*stride].x, from[12*stride].x,
+      from[11*stride].x, from[10*stride].x, from[9*stride].x, from[8*stride].x,
+      from[7*stride].x, from[6*stride].x, from[5*stride].x, from[4*stride].x,
+      from[3*stride].x, from[2*stride].x, from[1*stride].x, from[0*stride].x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE void pscatter<half, Packet16h>(half* to, const Packet16h& from, Index stride)
+{
+  EIGEN_ALIGN64 half aux[16];
+  pstore(aux, from);
+  to[stride*0].x = aux[0].x;
+  to[stride*1].x = aux[1].x;
+  to[stride*2].x = aux[2].x;
+  to[stride*3].x = aux[3].x;
+  to[stride*4].x = aux[4].x;
+  to[stride*5].x = aux[5].x;
+  to[stride*6].x = aux[6].x;
+  to[stride*7].x = aux[7].x;
+  to[stride*8].x = aux[8].x;
+  to[stride*9].x = aux[9].x;
+  to[stride*10].x = aux[10].x;
+  to[stride*11].x = aux[11].x;
+  to[stride*12].x = aux[12].x;
+  to[stride*13].x = aux[13].x;
+  to[stride*14].x = aux[14].x;
+  to[stride*15].x = aux[15].x;
+}
+
+EIGEN_STRONG_INLINE void
+ptranspose(PacketBlock<Packet16h,16>& kernel) {
+  __m256i a = kernel.packet[0].x;
+  __m256i b = kernel.packet[1].x;
+  __m256i c = kernel.packet[2].x;
+  __m256i d = kernel.packet[3].x;
+  __m256i e = kernel.packet[4].x;
+  __m256i f = kernel.packet[5].x;
+  __m256i g = kernel.packet[6].x;
+  __m256i h = kernel.packet[7].x;
+  __m256i i = kernel.packet[8].x;
+  __m256i j = kernel.packet[9].x;
+  __m256i k = kernel.packet[10].x;
+  __m256i l = kernel.packet[11].x;
+  __m256i m = kernel.packet[12].x;
+  __m256i n = kernel.packet[13].x;
+  __m256i o = kernel.packet[14].x;
+  __m256i p = kernel.packet[15].x;
+
+  __m256i ab_07 = _mm256_unpacklo_epi16(a, b);
+  __m256i cd_07 = _mm256_unpacklo_epi16(c, d);
+  __m256i ef_07 = _mm256_unpacklo_epi16(e, f);
+  __m256i gh_07 = _mm256_unpacklo_epi16(g, h);
+  __m256i ij_07 = _mm256_unpacklo_epi16(i, j);
+  __m256i kl_07 = _mm256_unpacklo_epi16(k, l);
+  __m256i mn_07 = _mm256_unpacklo_epi16(m, n);
+  __m256i op_07 = _mm256_unpacklo_epi16(o, p);
+
+  __m256i ab_8f = _mm256_unpackhi_epi16(a, b);
+  __m256i cd_8f = _mm256_unpackhi_epi16(c, d);
+  __m256i ef_8f = _mm256_unpackhi_epi16(e, f);
+  __m256i gh_8f = _mm256_unpackhi_epi16(g, h);
+  __m256i ij_8f = _mm256_unpackhi_epi16(i, j);
+  __m256i kl_8f = _mm256_unpackhi_epi16(k, l);
+  __m256i mn_8f = _mm256_unpackhi_epi16(m, n);
+  __m256i op_8f = _mm256_unpackhi_epi16(o, p);
+
+  __m256i abcd_03 = _mm256_unpacklo_epi32(ab_07, cd_07);
+  __m256i abcd_47 = _mm256_unpackhi_epi32(ab_07, cd_07);
+  __m256i efgh_03 = _mm256_unpacklo_epi32(ef_07, gh_07);
+  __m256i efgh_47 = _mm256_unpackhi_epi32(ef_07, gh_07);
+  __m256i ijkl_03 = _mm256_unpacklo_epi32(ij_07, kl_07);
+  __m256i ijkl_47 = _mm256_unpackhi_epi32(ij_07, kl_07);
+  __m256i mnop_03 = _mm256_unpacklo_epi32(mn_07, op_07);
+  __m256i mnop_47 = _mm256_unpackhi_epi32(mn_07, op_07);
+
+  __m256i abcd_8b = _mm256_unpacklo_epi32(ab_8f, cd_8f);
+  __m256i abcd_cf = _mm256_unpackhi_epi32(ab_8f, cd_8f);
+  __m256i efgh_8b = _mm256_unpacklo_epi32(ef_8f, gh_8f);
+  __m256i efgh_cf = _mm256_unpackhi_epi32(ef_8f, gh_8f);
+  __m256i ijkl_8b = _mm256_unpacklo_epi32(ij_8f, kl_8f);
+  __m256i ijkl_cf = _mm256_unpackhi_epi32(ij_8f, kl_8f);
+  __m256i mnop_8b = _mm256_unpacklo_epi32(mn_8f, op_8f);
+  __m256i mnop_cf = _mm256_unpackhi_epi32(mn_8f, op_8f);
+
+  __m256i abcdefgh_01 = _mm256_unpacklo_epi64(abcd_03, efgh_03);
+  __m256i abcdefgh_23 = _mm256_unpackhi_epi64(abcd_03, efgh_03);
+  __m256i ijklmnop_01 = _mm256_unpacklo_epi64(ijkl_03, mnop_03);
+  __m256i ijklmnop_23 = _mm256_unpackhi_epi64(ijkl_03, mnop_03);
+  __m256i abcdefgh_45 = _mm256_unpacklo_epi64(abcd_47, efgh_47);
+  __m256i abcdefgh_67 = _mm256_unpackhi_epi64(abcd_47, efgh_47);
+  __m256i ijklmnop_45 = _mm256_unpacklo_epi64(ijkl_47, mnop_47);
+  __m256i ijklmnop_67 = _mm256_unpackhi_epi64(ijkl_47, mnop_47);
+  __m256i abcdefgh_89 = _mm256_unpacklo_epi64(abcd_8b, efgh_8b);
+  __m256i abcdefgh_ab = _mm256_unpackhi_epi64(abcd_8b, efgh_8b);
+  __m256i ijklmnop_89 = _mm256_unpacklo_epi64(ijkl_8b, mnop_8b);
+  __m256i ijklmnop_ab = _mm256_unpackhi_epi64(ijkl_8b, mnop_8b);
+  __m256i abcdefgh_cd = _mm256_unpacklo_epi64(abcd_cf, efgh_cf);
+  __m256i abcdefgh_ef = _mm256_unpackhi_epi64(abcd_cf, efgh_cf);
+  __m256i ijklmnop_cd = _mm256_unpacklo_epi64(ijkl_cf, mnop_cf);
+  __m256i ijklmnop_ef = _mm256_unpackhi_epi64(ijkl_cf, mnop_cf);
+
+  // NOTE: no unpacklo/hi instr in this case, so using permute instr.
+  __m256i a_p_0 = _mm256_permute2x128_si256(abcdefgh_01, ijklmnop_01, 0x20);
+  __m256i a_p_1 = _mm256_permute2x128_si256(abcdefgh_23, ijklmnop_23, 0x20);
+  __m256i a_p_2 = _mm256_permute2x128_si256(abcdefgh_45, ijklmnop_45, 0x20);
+  __m256i a_p_3 = _mm256_permute2x128_si256(abcdefgh_67, ijklmnop_67, 0x20);
+  __m256i a_p_4 = _mm256_permute2x128_si256(abcdefgh_89, ijklmnop_89, 0x20);
+  __m256i a_p_5 = _mm256_permute2x128_si256(abcdefgh_ab, ijklmnop_ab, 0x20);
+  __m256i a_p_6 = _mm256_permute2x128_si256(abcdefgh_cd, ijklmnop_cd, 0x20);
+  __m256i a_p_7 = _mm256_permute2x128_si256(abcdefgh_ef, ijklmnop_ef, 0x20);
+  __m256i a_p_8 = _mm256_permute2x128_si256(abcdefgh_01, ijklmnop_01, 0x31);
+  __m256i a_p_9 = _mm256_permute2x128_si256(abcdefgh_23, ijklmnop_23, 0x31);
+  __m256i a_p_a = _mm256_permute2x128_si256(abcdefgh_45, ijklmnop_45, 0x31);
+  __m256i a_p_b = _mm256_permute2x128_si256(abcdefgh_67, ijklmnop_67, 0x31);
+  __m256i a_p_c = _mm256_permute2x128_si256(abcdefgh_89, ijklmnop_89, 0x31);
+  __m256i a_p_d = _mm256_permute2x128_si256(abcdefgh_ab, ijklmnop_ab, 0x31);
+  __m256i a_p_e = _mm256_permute2x128_si256(abcdefgh_cd, ijklmnop_cd, 0x31);
+  __m256i a_p_f = _mm256_permute2x128_si256(abcdefgh_ef, ijklmnop_ef, 0x31);
+
+  kernel.packet[0].x = a_p_0;
+  kernel.packet[1].x = a_p_1;
+  kernel.packet[2].x = a_p_2;
+  kernel.packet[3].x = a_p_3;
+  kernel.packet[4].x = a_p_4;
+  kernel.packet[5].x = a_p_5;
+  kernel.packet[6].x = a_p_6;
+  kernel.packet[7].x = a_p_7;
+  kernel.packet[8].x = a_p_8;
+  kernel.packet[9].x = a_p_9;
+  kernel.packet[10].x = a_p_a;
+  kernel.packet[11].x = a_p_b;
+  kernel.packet[12].x = a_p_c;
+  kernel.packet[13].x = a_p_d;
+  kernel.packet[14].x = a_p_e;
+  kernel.packet[15].x = a_p_f;
+}
+
+EIGEN_STRONG_INLINE void
+ptranspose(PacketBlock<Packet16h,8>& kernel) {
+  EIGEN_ALIGN64 half in[8][16];
+  pstore<half>(in[0], kernel.packet[0]);
+  pstore<half>(in[1], kernel.packet[1]);
+  pstore<half>(in[2], kernel.packet[2]);
+  pstore<half>(in[3], kernel.packet[3]);
+  pstore<half>(in[4], kernel.packet[4]);
+  pstore<half>(in[5], kernel.packet[5]);
+  pstore<half>(in[6], kernel.packet[6]);
+  pstore<half>(in[7], kernel.packet[7]);
+
+  EIGEN_ALIGN64 half out[8][16];
+
+  for (int i = 0; i < 8; ++i) {
+    for (int j = 0; j < 8; ++j) {
+      out[i][j] = in[j][2*i];
+    }
+    for (int j = 0; j < 8; ++j) {
+      out[i][j+8] = in[j][2*i+1];
+    }
+  }
+
+  kernel.packet[0] = pload<Packet16h>(out[0]);
+  kernel.packet[1] = pload<Packet16h>(out[1]);
+  kernel.packet[2] = pload<Packet16h>(out[2]);
+  kernel.packet[3] = pload<Packet16h>(out[3]);
+  kernel.packet[4] = pload<Packet16h>(out[4]);
+  kernel.packet[5] = pload<Packet16h>(out[5]);
+  kernel.packet[6] = pload<Packet16h>(out[6]);
+  kernel.packet[7] = pload<Packet16h>(out[7]);
+}
+
+EIGEN_STRONG_INLINE void
+ptranspose(PacketBlock<Packet16h,4>& kernel) {
+  EIGEN_ALIGN64 half in[4][16];
+  pstore<half>(in[0], kernel.packet[0]);
+  pstore<half>(in[1], kernel.packet[1]);
+  pstore<half>(in[2], kernel.packet[2]);
+  pstore<half>(in[3], kernel.packet[3]);
+
+  EIGEN_ALIGN64 half out[4][16];
+
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 4; ++j) {
+      out[i][j] = in[j][4*i];
+    }
+    for (int j = 0; j < 4; ++j) {
+      out[i][j+4] = in[j][4*i+1];
+    }
+    for (int j = 0; j < 4; ++j) {
+      out[i][j+8] = in[j][4*i+2];
+    }
+    for (int j = 0; j < 4; ++j) {
+      out[i][j+12] = in[j][4*i+3];
+    }
+  }
+
+  kernel.packet[0] = pload<Packet16h>(out[0]);
+  kernel.packet[1] = pload<Packet16h>(out[1]);
+  kernel.packet[2] = pload<Packet16h>(out[2]);
+  kernel.packet[3] = pload<Packet16h>(out[3]);
+}
+
+
 } // end namespace internal
 
 } // end namespace Eigen
diff --git a/Eigen/src/Core/arch/AVX512/TypeCasting.h b/Eigen/src/Core/arch/AVX512/TypeCasting.h
new file mode 100644
index 000000000..777a26ae4
--- /dev/null
+++ b/Eigen/src/Core/arch/AVX512/TypeCasting.h
@@ -0,0 +1,25 @@
+template <>
+struct type_casting_traits<half, float> {
+  enum {
+    VectorizedCast = 1,
+    SrcCoeffRatio = 1,
+    TgtCoeffRatio = 1
+  };
+};
+
+template<> EIGEN_STRONG_INLINE Packet16f pcast<Packet16h, Packet16f>(const Packet16h& a) {
+  return half2float(a);
+}
+
+template <>
+struct type_casting_traits<float, half> {
+  enum {
+    VectorizedCast = 1,
+    SrcCoeffRatio = 1,
+    TgtCoeffRatio = 1
+  };
+};
+
+template<> EIGEN_STRONG_INLINE Packet16h pcast<Packet16f, Packet16h>(const Packet16f& a) {
+  return float2half(a);
+}
diff --git a/Eigen/src/Core/arch/GPU/Half.h b/Eigen/src/Core/arch/Default/Half.h
index 655dc20d5..56782b340 100644
--- a/Eigen/src/Core/arch/GPU/Half.h
+++ b/Eigen/src/Core/arch/Default/Half.h
@@ -33,8 +33,8 @@
 // to disk and the likes), but fast on GPUs.
 
 
-#ifndef EIGEN_HALF_GPU_H
-#define EIGEN_HALF_GPU_H
+#ifndef EIGEN_HALF_H
+#define EIGEN_HALF_H
 
 #if __cplusplus > 199711L
 #define EIGEN_EXPLICIT_CAST(tgt_type) explicit operator tgt_type()
@@ -76,7 +76,6 @@ EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC float half_to_float(__half_raw h);
 
 struct half_base : public __half_raw {
   EIGEN_DEVICE_FUNC half_base() {}
-  EIGEN_DEVICE_FUNC half_base(const half_base& h) : __half_raw(h) {}
   EIGEN_DEVICE_FUNC half_base(const __half_raw& h) : __half_raw(h) {}
 
 #if defined(EIGEN_HAS_GPU_FP16)
@@ -114,8 +113,7 @@ struct half : public half_impl::half_base {
   EIGEN_DEVICE_FUNC half() {}
 
   EIGEN_DEVICE_FUNC half(const __half_raw& h) : half_impl::half_base(h) {}
-  EIGEN_DEVICE_FUNC half(const half& h) : half_impl::half_base(h) {}
-  
+
 #if defined(EIGEN_HAS_GPU_FP16)
  #if defined(EIGEN_HAS_HIP_FP16)
   EIGEN_DEVICE_FUNC half(const __half& h) : half_impl::half_base(h) {}
@@ -125,7 +123,7 @@ struct half : public half_impl::half_base {
   #endif
  #endif
 #endif
-  
+
 
   explicit EIGEN_DEVICE_FUNC half(bool b)
       : half_impl::half_base(half_impl::raw_uint16_to_half(b ? 0x3c00 : 0)) {}
@@ -175,12 +173,6 @@ struct half : public half_impl::half_base {
   EIGEN_DEVICE_FUNC EIGEN_EXPLICIT_CAST(double) const {
     return static_cast<double>(half_impl::half_to_float(*this));
   }
-
-  EIGEN_DEVICE_FUNC half& operator=(const half& other) {
-    x = other.x;
-    return *this;
-  }
-
 };
 
 } // end namespace Eigen
@@ -761,4 +753,4 @@ bool (isfinite)(const Eigen::half& h) {
 }  // namespace numext
 #endif
 
-#endif // EIGEN_HALF_GPU_H
+#endif // EIGEN_HALF_H
diff --git a/Eigen/src/Core/arch/Default/TypeCasting.h b/Eigen/src/Core/arch/Default/TypeCasting.h
new file mode 100644
index 000000000..b6df98468
--- /dev/null
+++ b/Eigen/src/Core/arch/Default/TypeCasting.h
@@ -0,0 +1,77 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2016 Benoit Steiner <benoit.steiner.goog@gmail.com>
+// Copyright (C) 2019 Rasmus Munk Larsen <rmlarsen@google.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef EIGEN_GENERIC_TYPE_CASTING_H
+#define EIGEN_GENERIC_TYPE_CASTING_H
+
+namespace Eigen {
+
+namespace internal {
+
+template<>
+struct scalar_cast_op<float, Eigen::half> {
+  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
+  typedef Eigen::half result_type;
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half operator() (const float& a) const {
+    #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
+      (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIP_DEVICE_COMPILE))
+      return __float2half(a);
+    #else
+      return Eigen::half(a);
+    #endif
+  }
+};
+
+template<>
+struct functor_traits<scalar_cast_op<float, Eigen::half> >
+{ enum { Cost = NumTraits<float>::AddCost, PacketAccess = false }; };
+
+
+template<>
+struct scalar_cast_op<int, Eigen::half> {
+  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
+  typedef Eigen::half result_type;
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half operator() (const int& a) const {
+    #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
+      (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIP_DEVICE_COMPILE))
+      return __float2half(static_cast<float>(a));
+    #else
+      return Eigen::half(static_cast<float>(a));
+    #endif
+  }
+};
+
+template<>
+struct functor_traits<scalar_cast_op<int, Eigen::half> >
+{ enum { Cost = NumTraits<float>::AddCost, PacketAccess = false }; };
+
+
+template<>
+struct scalar_cast_op<Eigen::half, float> {
+  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
+  typedef float result_type;
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE float operator() (const Eigen::half& a) const {
+    #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
+      (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIP_DEVICE_COMPILE))
+      return __half2float(a);
+    #else
+      return static_cast<float>(a);
+    #endif
+  }
+};
+
+template<>
+struct functor_traits<scalar_cast_op<Eigen::half, float> >
+{ enum { Cost = NumTraits<float>::AddCost, PacketAccess = false }; };
+
+}
+}
+
+#endif  // EIGEN_GENERIC_TYPE_CASTING_H
diff --git a/Eigen/src/Core/arch/GPU/PacketMath.h b/Eigen/src/Core/arch/GPU/PacketMath.h
index 5084fc786..d1df26e57 100644
--- a/Eigen/src/Core/arch/GPU/PacketMath.h
+++ b/Eigen/src/Core/arch/GPU/PacketMath.h
@@ -458,6 +458,546 @@ ptranspose(PacketBlock<double2,2>& kernel) {
 
 #endif
 
+// Packet math for Eigen::half
+// Most of the following operations require arch >= 3.0
+#if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDACC) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
+  (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIPCC) && defined(EIGEN_HIP_DEVICE_COMPILE)) || \
+  (defined(EIGEN_HAS_CUDA_FP16) && defined(__clang__) && defined(__CUDA__))
+
+template<> struct is_arithmetic<half2> { enum { value = true }; };
+
+template<> struct packet_traits<Eigen::half> : default_packet_traits
+{
+  typedef half2 type;
+  typedef half2 half;
+  enum {
+    Vectorizable = 1,
+    AlignedOnScalar = 1,
+    size=2,
+    HasHalfPacket = 0,
+    HasAdd    = 1,
+    HasSub    = 1,
+    HasMul    = 1,
+    HasDiv    = 1,
+    HasSqrt   = 1,
+    HasRsqrt  = 1,
+    HasExp    = 1,
+    HasExpm1  = 1,
+    HasLog    = 1,
+    HasLog1p  = 1
+  };
+};
+
+template<> struct unpacket_traits<half2> { typedef Eigen::half type; enum {size=2, alignment=Aligned16, vectorizable=true, masked_load_available=false, masked_store_available=false}; typedef half2 half; };
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pset1<half2>(const Eigen::half& from) {
+#if !defined(EIGEN_CUDA_ARCH) && !defined(EIGEN_HIP_DEVICE_COMPILE)
+  half2 r;
+  r.x = from;
+  r.y = from;
+  return r;
+#else
+  return __half2half2(from);
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pload<half2>(const Eigen::half* from) {
+  return *reinterpret_cast<const half2*>(from);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 ploadu<half2>(const Eigen::half* from) {
+  return __halves2half2(from[0], from[1]);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 ploaddup<half2>(const Eigen::half*  from) {
+  return __halves2half2(from[0], from[0]);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void pstore<Eigen::half>(Eigen::half* to, const half2& from) {
+  *reinterpret_cast<half2*>(to) = from;
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void pstoreu<Eigen::half>(Eigen::half* to, const half2& from) {
+#if !defined(EIGEN_CUDA_ARCH) && !defined(EIGEN_HIP_DEVICE_COMPILE)
+  to[0] = from.x;
+  to[1] = from.y;
+#else
+  to[0] = __low2half(from);
+  to[1] = __high2half(from);
+#endif
+}
+
+template<>
+ EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE half2 ploadt_ro<half2, Aligned>(const Eigen::half* from) {
+
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __ldg((const half2*)from);
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 350
+   return __ldg((const half2*)from);
+#else
+  return __halves2half2(*(from+0), *(from+1));
+#endif
+
+#endif
+}
+
+template<>
+EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE half2 ploadt_ro<half2, Unaligned>(const Eigen::half* from) {
+
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __halves2half2(__ldg(from+0), __ldg(from+1));
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 350
+   return __halves2half2(__ldg(from+0), __ldg(from+1));
+#else
+  return __halves2half2(*(from+0), *(from+1));
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pgather<Eigen::half, half2>(const Eigen::half* from, Index stride) {
+  return __halves2half2(from[0*stride], from[1*stride]);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void pscatter<Eigen::half, half2>(Eigen::half* to, const half2& from, Index stride) {
+  to[stride*0] = __low2half(from);
+  to[stride*1] = __high2half(from);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half pfirst<half2>(const half2& a) {
+  return __low2half(a);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pabs<half2>(const half2& a) {
+  half a1 = __low2half(a);
+  half a2 = __high2half(a);
+  half result1 = half_impl::raw_uint16_to_half(a1.x & 0x7FFF);
+  half result2 = half_impl::raw_uint16_to_half(a2.x & 0x7FFF);
+  return __halves2half2(result1, result2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 ptrue<half2>(const half2& a) {
+  half true_half = half_impl::raw_uint16_to_half(0xffffu);
+  return pset1<half2>(true_half);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pzero<half2>(const half2& a) {
+  half false_half = half_impl::raw_uint16_to_half(0x0000u);
+  return pset1<half2>(false_half);
+}
+
+EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void
+ptranspose(PacketBlock<half2,2>& kernel) {
+  __half a1 = __low2half(kernel.packet[0]);
+  __half a2 = __high2half(kernel.packet[0]);
+  __half b1 = __low2half(kernel.packet[1]);
+  __half b2 = __high2half(kernel.packet[1]);
+  kernel.packet[0] = __halves2half2(a1, b1);
+  kernel.packet[1] = __halves2half2(a2, b2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 plset<half2>(const Eigen::half& a) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __halves2half2(a, __hadd(a, __float2half(1.0f)));
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  return __halves2half2(a, __hadd(a, __float2half(1.0f)));
+#else
+  float f = __half2float(a) + 1.0f;
+  return __halves2half2(a, __float2half(f));
+#endif
+
+#endif
+}
+
+template <>
+EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pselect<half2>(const half2& mask,
+                                                           const half2& a,
+                                                           const half2& b) {
+  half mask_low = __low2half(mask);
+  half mask_high = __high2half(mask);
+  half result_low = mask_low == half(0) ? __low2half(b) : __low2half(a);
+  half result_high = mask_high == half(0) ? __high2half(b) : __high2half(a);
+  return __halves2half2(result_low, result_high);
+}
+
+template <>
+EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pcmp_eq<half2>(const half2& a,
+                                                           const half2& b) {
+  half true_half = half_impl::raw_uint16_to_half(0xffffu);
+  half false_half = half_impl::raw_uint16_to_half(0x0000u);
+  half a1 = __low2half(a);
+  half a2 = __high2half(a);
+  half b1 = __low2half(b);
+  half b2 = __high2half(b);
+  half eq1 = __half2float(a1) == __half2float(b1) ? true_half : false_half;
+  half eq2 = __half2float(a2) == __half2float(b2) ? true_half : false_half;
+  return __halves2half2(eq1, eq2);
+}
+
+template <>
+EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pand<half2>(const half2& a,
+                                                        const half2& b) {
+  half a1 = __low2half(a);
+  half a2 = __high2half(a);
+  half b1 = __low2half(b);
+  half b2 = __high2half(b);
+  half result1 = half_impl::raw_uint16_to_half(a1.x & b1.x);
+  half result2 = half_impl::raw_uint16_to_half(a2.x & b2.x);
+  return __halves2half2(result1, result2);
+}
+
+template <>
+EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 por<half2>(const half2& a,
+                                                       const half2& b) {
+  half a1 = __low2half(a);
+  half a2 = __high2half(a);
+  half b1 = __low2half(b);
+  half b2 = __high2half(b);
+  half result1 = half_impl::raw_uint16_to_half(a1.x | b1.x);
+  half result2 = half_impl::raw_uint16_to_half(a2.x | b2.x);
+  return __halves2half2(result1, result2);
+}
+
+template <>
+EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pxor<half2>(const half2& a,
+                                                        const half2& b) {
+  half a1 = __low2half(a);
+  half a2 = __high2half(a);
+  half b1 = __low2half(b);
+  half b2 = __high2half(b);
+  half result1 = half_impl::raw_uint16_to_half(a1.x ^ b1.x);
+  half result2 = half_impl::raw_uint16_to_half(a2.x ^ b2.x);
+  return __halves2half2(result1, result2);
+}
+
+template <>
+EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pandnot<half2>(const half2& a,
+                                                           const half2& b) {
+  half a1 = __low2half(a);
+  half a2 = __high2half(a);
+  half b1 = __low2half(b);
+  half b2 = __high2half(b);
+  half result1 = half_impl::raw_uint16_to_half(a1.x & ~b1.x);
+  half result2 = half_impl::raw_uint16_to_half(a2.x & ~b2.x);
+  return __halves2half2(result1, result2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 padd<half2>(const half2& a, const half2& b) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __hadd2(a, b);
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  return __hadd2(a, b);
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float b1 = __low2float(b);
+  float b2 = __high2float(b);
+  float r1 = a1 + b1;
+  float r2 = a2 + b2;
+  return __floats2half2_rn(r1, r2);
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 psub<half2>(const half2& a, const half2& b) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __hsub2(a, b);
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  return __hsub2(a, b);
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float b1 = __low2float(b);
+  float b2 = __high2float(b);
+  float r1 = a1 - b1;
+  float r2 = a2 - b2;
+  return __floats2half2_rn(r1, r2);
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pnegate(const half2& a) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __hneg2(a);
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  return __hneg2(a);
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  return __floats2half2_rn(-a1, -a2);
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pconj(const half2& a) { return a; }
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pmul<half2>(const half2& a, const half2& b) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __hmul2(a, b);
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  return __hmul2(a, b);
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float b1 = __low2float(b);
+  float b2 = __high2float(b);
+  float r1 = a1 * b1;
+  float r2 = a2 * b2;
+  return __floats2half2_rn(r1, r2);
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pmadd<half2>(const half2& a, const half2& b, const half2& c) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+   return __hfma2(a, b, c);
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+   return __hfma2(a, b, c);
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float b1 = __low2float(b);
+  float b2 = __high2float(b);
+  float c1 = __low2float(c);
+  float c2 = __high2float(c);
+  float r1 = a1 * b1 + c1;
+  float r2 = a2 * b2 + c2;
+  return __floats2half2_rn(r1, r2);
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pdiv<half2>(const half2& a, const half2& b) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __h2div(a, b);
+
+#else // EIGEN_CUDA_ARCH
+
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float b1 = __low2float(b);
+  float b2 = __high2float(b);
+  float r1 = a1 / b1;
+  float r2 = a2 / b2;
+  return __floats2half2_rn(r1, r2);
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pmin<half2>(const half2& a, const half2& b) {
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float b1 = __low2float(b);
+  float b2 = __high2float(b);
+  __half r1 = a1 < b1 ? __low2half(a) : __low2half(b);
+  __half r2 = a2 < b2 ? __high2half(a) : __high2half(b);
+  return __halves2half2(r1, r2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pmax<half2>(const half2& a, const half2& b) {
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float b1 = __low2float(b);
+  float b2 = __high2float(b);
+  __half r1 = a1 > b1 ? __low2half(a) : __low2half(b);
+  __half r2 = a2 > b2 ? __high2half(a) : __high2half(b);
+  return __halves2half2(r1, r2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half predux<half2>(const half2& a) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __hadd(__low2half(a), __high2half(a));
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  return __hadd(__low2half(a), __high2half(a));
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  return Eigen::half(__float2half(a1 + a2));
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half predux_max<half2>(const half2& a) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  __half first = __low2half(a);
+  __half second = __high2half(a);
+  return __hgt(first, second) ? first : second;
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  __half first = __low2half(a);
+  __half second = __high2half(a);
+  return __hgt(first, second) ? first : second;
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  return a1 > a2 ? __low2half(a) : __high2half(a);
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half predux_min<half2>(const half2& a) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  __half first = __low2half(a);
+  __half second = __high2half(a);
+  return __hlt(first, second) ? first : second;
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  __half first = __low2half(a);
+  __half second = __high2half(a);
+  return __hlt(first, second) ? first : second;
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  return a1 < a2 ? __low2half(a) : __high2half(a);
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half predux_mul<half2>(const half2& a) {
+#if defined(EIGEN_HIP_DEVICE_COMPILE)
+
+  return __hmul(__low2half(a), __high2half(a));
+
+#else  // EIGEN_CUDA_ARCH
+
+#if EIGEN_CUDA_ARCH >= 530
+  return __hmul(__low2half(a), __high2half(a));
+#else
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  return Eigen::half(__float2half(a1 * a2));
+#endif
+
+#endif
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 plog1p<half2>(const half2& a) {
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float r1 = log1pf(a1);
+  float r2 = log1pf(a2);
+  return __floats2half2_rn(r1, r2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pexpm1<half2>(const half2& a) {
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float r1 = expm1f(a1);
+  float r2 = expm1f(a2);
+  return __floats2half2_rn(r1, r2);
+}
+
+#if (EIGEN_CUDA_SDK_VER >= 80000 && defined EIGEN_CUDA_ARCH && EIGEN_CUDA_ARCH >= 530) || \
+  defined(EIGEN_HIP_DEVICE_COMPILE)
+
+template<>  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
+half2 plog<half2>(const half2& a) {
+  return h2log(a);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
+half2 pexp<half2>(const half2& a) {
+  return h2exp(a);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
+half2 psqrt<half2>(const half2& a) {
+  return h2sqrt(a);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
+half2 prsqrt<half2>(const half2& a) {
+  return h2rsqrt(a);
+}
+
+#else
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 plog<half2>(const half2& a) {
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float r1 = logf(a1);
+  float r2 = logf(a2);
+  return __floats2half2_rn(r1, r2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pexp<half2>(const half2& a) {
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float r1 = expf(a1);
+  float r2 = expf(a2);
+  return __floats2half2_rn(r1, r2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 psqrt<half2>(const half2& a) {
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float r1 = sqrtf(a1);
+  float r2 = sqrtf(a2);
+  return __floats2half2_rn(r1, r2);
+}
+
+template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 prsqrt<half2>(const half2& a) {
+  float a1 = __low2float(a);
+  float a2 = __high2float(a);
+  float r1 = rsqrtf(a1);
+  float r2 = rsqrtf(a2);
+  return __floats2half2_rn(r1, r2);
+}
+#endif
+
+#endif
+
 } // end namespace internal
 
 } // end namespace Eigen
diff --git a/Eigen/src/Core/arch/GPU/PacketMathHalf.h b/Eigen/src/Core/arch/GPU/PacketMathHalf.h
deleted file mode 100644
index 5e143e65a..000000000
--- a/Eigen/src/Core/arch/GPU/PacketMathHalf.h
+++ /dev/null
@@ -1,1630 +0,0 @@
-// This file is part of Eigen, a lightweight C++ template library
-// for linear algebra.
-//
-// Copyright (C) 2016 Benoit Steiner <benoit.steiner.goog@gmail.com>
-//
-// This Source Code Form is subject to the terms of the Mozilla
-// Public License v. 2.0. If a copy of the MPL was not distributed
-// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-#ifndef EIGEN_PACKET_MATH_HALF_GPU_H
-#define EIGEN_PACKET_MATH_HALF_GPU_H
-
-
-namespace Eigen {
-namespace internal {
-
-// Most of the following operations require arch >= 3.0
-#if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDACC) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
-  (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIPCC) && defined(EIGEN_HIP_DEVICE_COMPILE)) || \
-  (defined(EIGEN_HAS_CUDA_FP16) && defined(__clang__) && defined(__CUDA__))
-
-template<> struct is_arithmetic<half2> { enum { value = true }; };
-
-template<> struct packet_traits<Eigen::half> : default_packet_traits
-{
-  typedef half2 type;
-  typedef half2 half;
-  enum {
-    Vectorizable = 1,
-    AlignedOnScalar = 1,
-    size=2,
-    HasHalfPacket = 0,
-    HasAdd    = 1,
-    HasSub    = 1,
-    HasMul    = 1,
-    HasDiv    = 1,
-    HasSqrt   = 1,
-    HasRsqrt  = 1,
-    HasExp    = 1,
-    HasExpm1  = 1,
-    HasLog    = 1,
-    HasLog1p  = 1
-  };
-};
-
-template<> struct unpacket_traits<half2> { typedef Eigen::half type; enum {size=2, alignment=Aligned16, vectorizable=true, masked_load_available=false, masked_store_available=false}; typedef half2 half; };
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pset1<half2>(const Eigen::half& from) {
-#if !defined(EIGEN_CUDA_ARCH) && !defined(EIGEN_HIP_DEVICE_COMPILE)
-  half2 r;
-  r.x = from;
-  r.y = from;
-  return r;
-#else
-  return __half2half2(from);
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pload<half2>(const Eigen::half* from) {
-  return *reinterpret_cast<const half2*>(from);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 ploadu<half2>(const Eigen::half* from) {
-  return __halves2half2(from[0], from[1]);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 ploaddup<half2>(const Eigen::half*  from) {
-  return __halves2half2(from[0], from[0]);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void pstore<Eigen::half>(Eigen::half* to, const half2& from) {
-  *reinterpret_cast<half2*>(to) = from;
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void pstoreu<Eigen::half>(Eigen::half* to, const half2& from) {
-#if !defined(EIGEN_CUDA_ARCH) && !defined(EIGEN_HIP_DEVICE_COMPILE)
-  to[0] = from.x;
-  to[1] = from.y;
-#else
-  to[0] = __low2half(from);
-  to[1] = __high2half(from);
-#endif
-}
-
-template<>
- EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE half2 ploadt_ro<half2, Aligned>(const Eigen::half* from) {
-
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  return __ldg((const half2*)from);
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 350
-   return __ldg((const half2*)from);
-#else
-  return __halves2half2(*(from+0), *(from+1));
-#endif
-
-#endif
-}
-
-template<>
-EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE half2 ploadt_ro<half2, Unaligned>(const Eigen::half* from) {
-
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  return __halves2half2(__ldg(from+0), __ldg(from+1));
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 350
-   return __halves2half2(__ldg(from+0), __ldg(from+1));
-#else
-  return __halves2half2(*(from+0), *(from+1));
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pgather<Eigen::half, half2>(const Eigen::half* from, Index stride) {
-  return __halves2half2(from[0*stride], from[1*stride]);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void pscatter<Eigen::half, half2>(Eigen::half* to, const half2& from, Index stride) {
-  to[stride*0] = __low2half(from);
-  to[stride*1] = __high2half(from);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half pfirst<half2>(const half2& a) {
-  return __low2half(a);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pabs<half2>(const half2& a) {
-  half a1 = __low2half(a);
-  half a2 = __high2half(a);
-  half result1 = half_impl::raw_uint16_to_half(a1.x & 0x7FFF);
-  half result2 = half_impl::raw_uint16_to_half(a2.x & 0x7FFF);
-  return __halves2half2(result1, result2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 ptrue<half2>(const half2& a) {
-  half true_half = half_impl::raw_uint16_to_half(0xffffu);
-  return pset1<half2>(true_half);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pzero<half2>(const half2& a) {
-  half false_half = half_impl::raw_uint16_to_half(0x0000u);
-  return pset1<half2>(false_half);
-}
-
-EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void
-ptranspose(PacketBlock<half2,2>& kernel) {
-  __half a1 = __low2half(kernel.packet[0]);
-  __half a2 = __high2half(kernel.packet[0]);
-  __half b1 = __low2half(kernel.packet[1]);
-  __half b2 = __high2half(kernel.packet[1]);
-  kernel.packet[0] = __halves2half2(a1, b1);
-  kernel.packet[1] = __halves2half2(a2, b2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 plset<half2>(const Eigen::half& a) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-  
-  return __halves2half2(a, __hadd(a, __float2half(1.0f)));
-  
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  return __halves2half2(a, __hadd(a, __float2half(1.0f)));
-#else
-  float f = __half2float(a) + 1.0f;
-  return __halves2half2(a, __float2half(f));
-#endif
-
-#endif
-}
-
-template <>
-EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pselect<half2>(const half2& mask,
-                                                           const half2& a,
-                                                           const half2& b) {
-  half mask_low = __low2half(mask);
-  half mask_high = __high2half(mask);
-  half result_low = mask_low == half(0) ? __low2half(b) : __low2half(a);
-  half result_high = mask_high == half(0) ? __high2half(b) : __high2half(a);
-  return __halves2half2(result_low, result_high);
-}
-
-template <>
-EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pcmp_eq<half2>(const half2& a,
-                                                           const half2& b) {
-  half true_half = half_impl::raw_uint16_to_half(0xffffu);
-  half false_half = half_impl::raw_uint16_to_half(0x0000u);
-  half a1 = __low2half(a);
-  half a2 = __high2half(a);
-  half b1 = __low2half(b);
-  half b2 = __high2half(b);
-  half eq1 = __half2float(a1) == __half2float(b1) ? true_half : false_half;
-  half eq2 = __half2float(a2) == __half2float(b2) ? true_half : false_half;
-  return __halves2half2(eq1, eq2);
-}
-
-template <>
-EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pand<half2>(const half2& a,
-                                                        const half2& b) {
-  half a1 = __low2half(a);
-  half a2 = __high2half(a);
-  half b1 = __low2half(b);
-  half b2 = __high2half(b);
-  half result1 = half_impl::raw_uint16_to_half(a1.x & b1.x);
-  half result2 = half_impl::raw_uint16_to_half(a2.x & b2.x);
-  return __halves2half2(result1, result2);
-}
-
-template <>
-EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 por<half2>(const half2& a,
-                                                       const half2& b) {
-  half a1 = __low2half(a);
-  half a2 = __high2half(a);
-  half b1 = __low2half(b);
-  half b2 = __high2half(b);
-  half result1 = half_impl::raw_uint16_to_half(a1.x | b1.x);
-  half result2 = half_impl::raw_uint16_to_half(a2.x | b2.x);
-  return __halves2half2(result1, result2);
-}
-
-template <>
-EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pxor<half2>(const half2& a,
-                                                        const half2& b) {
-  half a1 = __low2half(a);
-  half a2 = __high2half(a);
-  half b1 = __low2half(b);
-  half b2 = __high2half(b);
-  half result1 = half_impl::raw_uint16_to_half(a1.x ^ b1.x);
-  half result2 = half_impl::raw_uint16_to_half(a2.x ^ b2.x);
-  return __halves2half2(result1, result2);
-}
-
-template <>
-EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pandnot<half2>(const half2& a,
-                                                           const half2& b) {
-  half a1 = __low2half(a);
-  half a2 = __high2half(a);
-  half b1 = __low2half(b);
-  half b2 = __high2half(b);
-  half result1 = half_impl::raw_uint16_to_half(a1.x & ~b1.x);
-  half result2 = half_impl::raw_uint16_to_half(a2.x & ~b2.x);
-  return __halves2half2(result1, result2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 padd<half2>(const half2& a, const half2& b) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  return __hadd2(a, b);
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  return __hadd2(a, b);
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float b1 = __low2float(b);
-  float b2 = __high2float(b);
-  float r1 = a1 + b1;
-  float r2 = a2 + b2;
-  return __floats2half2_rn(r1, r2);
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 psub<half2>(const half2& a, const half2& b) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  return __hsub2(a, b);
-  
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  return __hsub2(a, b);
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float b1 = __low2float(b);
-  float b2 = __high2float(b);
-  float r1 = a1 - b1;
-  float r2 = a2 - b2;
-  return __floats2half2_rn(r1, r2);
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pnegate(const half2& a) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  return __hneg2(a);
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  return __hneg2(a);
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  return __floats2half2_rn(-a1, -a2);
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pconj(const half2& a) { return a; }
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pmul<half2>(const half2& a, const half2& b) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  return __hmul2(a, b);
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  return __hmul2(a, b);
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float b1 = __low2float(b);
-  float b2 = __high2float(b);
-  float r1 = a1 * b1;
-  float r2 = a2 * b2;
-  return __floats2half2_rn(r1, r2);
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pmadd<half2>(const half2& a, const half2& b, const half2& c) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-   return __hfma2(a, b, c);
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-   return __hfma2(a, b, c);
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float b1 = __low2float(b);
-  float b2 = __high2float(b);
-  float c1 = __low2float(c);
-  float c2 = __high2float(c);
-  float r1 = a1 * b1 + c1;
-  float r2 = a2 * b2 + c2;
-  return __floats2half2_rn(r1, r2);
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pdiv<half2>(const half2& a, const half2& b) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-  
-  return __h2div(a, b);
-  
-#else // EIGEN_CUDA_ARCH
-  
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float b1 = __low2float(b);
-  float b2 = __high2float(b);
-  float r1 = a1 / b1;
-  float r2 = a2 / b2;
-  return __floats2half2_rn(r1, r2);
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pmin<half2>(const half2& a, const half2& b) {
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float b1 = __low2float(b);
-  float b2 = __high2float(b);
-  __half r1 = a1 < b1 ? __low2half(a) : __low2half(b);
-  __half r2 = a2 < b2 ? __high2half(a) : __high2half(b);
-  return __halves2half2(r1, r2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pmax<half2>(const half2& a, const half2& b) {
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float b1 = __low2float(b);
-  float b2 = __high2float(b);
-  __half r1 = a1 > b1 ? __low2half(a) : __low2half(b);
-  __half r2 = a2 > b2 ? __high2half(a) : __high2half(b);
-  return __halves2half2(r1, r2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half predux<half2>(const half2& a) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  return __hadd(__low2half(a), __high2half(a));
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  return __hadd(__low2half(a), __high2half(a));
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  return Eigen::half(__float2half(a1 + a2));
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half predux_max<half2>(const half2& a) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  __half first = __low2half(a);
-  __half second = __high2half(a);
-  return __hgt(first, second) ? first : second;
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  __half first = __low2half(a);
-  __half second = __high2half(a);
-  return __hgt(first, second) ? first : second;
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  return a1 > a2 ? __low2half(a) : __high2half(a);
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half predux_min<half2>(const half2& a) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  __half first = __low2half(a);
-  __half second = __high2half(a);
-  return __hlt(first, second) ? first : second;
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  __half first = __low2half(a);
-  __half second = __high2half(a);
-  return __hlt(first, second) ? first : second;
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  return a1 < a2 ? __low2half(a) : __high2half(a);
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half predux_mul<half2>(const half2& a) {
-#if defined(EIGEN_HIP_DEVICE_COMPILE)
-
-  return __hmul(__low2half(a), __high2half(a));
-
-#else  // EIGEN_CUDA_ARCH
-
-#if EIGEN_CUDA_ARCH >= 530
-  return __hmul(__low2half(a), __high2half(a));
-#else
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  return Eigen::half(__float2half(a1 * a2));
-#endif
-
-#endif
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 plog1p<half2>(const half2& a) {
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float r1 = log1pf(a1);
-  float r2 = log1pf(a2);
-  return __floats2half2_rn(r1, r2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pexpm1<half2>(const half2& a) {
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float r1 = expm1f(a1);
-  float r2 = expm1f(a2);
-  return __floats2half2_rn(r1, r2);
-}
-
-#if (EIGEN_CUDA_SDK_VER >= 80000 && defined EIGEN_CUDA_ARCH && EIGEN_CUDA_ARCH >= 530) || \
-  defined(EIGEN_HIP_DEVICE_COMPILE)
-
-template<>  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
-half2 plog<half2>(const half2& a) {
-  return h2log(a);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
-half2 pexp<half2>(const half2& a) {
-  return h2exp(a);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
-half2 psqrt<half2>(const half2& a) {
-  return h2sqrt(a);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
-half2 prsqrt<half2>(const half2& a) {
-  return h2rsqrt(a);
-}
-
-#else
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 plog<half2>(const half2& a) {
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float r1 = logf(a1);
-  float r2 = logf(a2);
-  return __floats2half2_rn(r1, r2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pexp<half2>(const half2& a) {
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float r1 = expf(a1);
-  float r2 = expf(a2);
-  return __floats2half2_rn(r1, r2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 psqrt<half2>(const half2& a) {
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float r1 = sqrtf(a1);
-  float r2 = sqrtf(a2);
-  return __floats2half2_rn(r1, r2);
-}
-
-template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 prsqrt<half2>(const half2& a) {
-  float a1 = __low2float(a);
-  float a2 = __high2float(a);
-  float r1 = rsqrtf(a1);
-  float r2 = rsqrtf(a2);
-  return __floats2half2_rn(r1, r2);
-}
-
-#endif
-
-#elif defined EIGEN_VECTORIZE_AVX512
-
-typedef struct {
-  __m256i x;
-} Packet16h;
-
-
-template<> struct is_arithmetic<Packet16h> { enum { value = true }; };
-
-template <>
-struct packet_traits<half> : default_packet_traits {
-  typedef Packet16h type;
-  // There is no half-size packet for Packet16h.
-  typedef Packet16h half;
-  enum {
-    Vectorizable = 1,
-    AlignedOnScalar = 1,
-    size = 16,
-    HasHalfPacket = 0,
-    HasAdd    = 1,
-    HasSub    = 1,
-    HasMul    = 1,
-    HasDiv    = 1,
-    HasNegate = 1,
-    HasAbs    = 0,
-    HasAbs2   = 0,
-    HasMin    = 0,
-    HasMax    = 0,
-    HasConj   = 0,
-    HasSetLinear = 0,
-    HasSqrt = 0,
-    HasRsqrt = 0,
-    HasExp = 0,
-    HasLog = 0,
-    HasBlend = 0
-  };
-};
-
-
-template<> struct unpacket_traits<Packet16h> { typedef Eigen::half type; enum {size=16, alignment=Aligned32, vectorizable=true, masked_load_available=false, masked_store_available=false}; typedef Packet16h half; };
-
-template<> EIGEN_STRONG_INLINE Packet16h pset1<Packet16h>(const Eigen::half& from) {
-  Packet16h result;
-  result.x = _mm256_set1_epi16(from.x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Eigen::half pfirst<Packet16h>(const Packet16h& from) {
-  return half_impl::raw_uint16_to_half(static_cast<unsigned short>(_mm256_extract_epi16(from.x, 0)));
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pload<Packet16h>(const Eigen::half* from) {
-  Packet16h result;
-  result.x = _mm256_load_si256(reinterpret_cast<const __m256i*>(from));
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h ploadu<Packet16h>(const Eigen::half* from) {
-  Packet16h result;
-  result.x = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(from));
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE void pstore<half>(Eigen::half* to, const Packet16h& from) {
-  // (void*) -> workaround clang warning:
-  // cast from 'Eigen::half *' to '__m256i *' increases required alignment from 2 to 32
-  _mm256_store_si256((__m256i*)(void*)to, from.x);
-}
-
-template<> EIGEN_STRONG_INLINE void pstoreu<half>(Eigen::half* to, const Packet16h& from) {
-  // (void*) -> workaround clang warning:
-  // cast from 'Eigen::half *' to '__m256i *' increases required alignment from 2 to 32
-  _mm256_storeu_si256((__m256i*)(void*)to, from.x);
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h
-ploaddup<Packet16h>(const Eigen::half*  from) {
-  Packet16h result;
-  unsigned short a = from[0].x;
-  unsigned short b = from[1].x;
-  unsigned short c = from[2].x;
-  unsigned short d = from[3].x;
-  unsigned short e = from[4].x;
-  unsigned short f = from[5].x;
-  unsigned short g = from[6].x;
-  unsigned short h = from[7].x;
-  result.x = _mm256_set_epi16(h, h, g, g, f, f, e, e, d, d, c, c, b, b, a, a);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h
-ploadquad(const Eigen::half* from) {
-  Packet16h result;
-  unsigned short a = from[0].x;
-  unsigned short b = from[1].x;
-  unsigned short c = from[2].x;
-  unsigned short d = from[3].x;
-  result.x = _mm256_set_epi16(d, d, d, d, c, c, c, c, b, b, b, b, a, a, a, a);
-  return result;
-}
-
-EIGEN_STRONG_INLINE Packet16f half2float(const Packet16h& a) {
-#ifdef EIGEN_HAS_FP16_C
-  return _mm512_cvtph_ps(a.x);
-#else
-  EIGEN_ALIGN64 half aux[16];
-  pstore(aux, a);
-  float f0(aux[0]);
-  float f1(aux[1]);
-  float f2(aux[2]);
-  float f3(aux[3]);
-  float f4(aux[4]);
-  float f5(aux[5]);
-  float f6(aux[6]);
-  float f7(aux[7]);
-  float f8(aux[8]);
-  float f9(aux[9]);
-  float fa(aux[10]);
-  float fb(aux[11]);
-  float fc(aux[12]);
-  float fd(aux[13]);
-  float fe(aux[14]);
-  float ff(aux[15]);
-
-  return _mm512_set_ps(
-      ff, fe, fd, fc, fb, fa, f9, f8, f7, f6, f5, f4, f3, f2, f1, f0);
-#endif
-}
-
-EIGEN_STRONG_INLINE Packet16h float2half(const Packet16f& a) {
-#ifdef EIGEN_HAS_FP16_C
-  Packet16h result;
-  result.x = _mm512_cvtps_ph(a, _MM_FROUND_TO_NEAREST_INT|_MM_FROUND_NO_EXC);
-  return result;
-#else
-  EIGEN_ALIGN64 float aux[16];
-  pstore(aux, a);
-  half h0(aux[0]);
-  half h1(aux[1]);
-  half h2(aux[2]);
-  half h3(aux[3]);
-  half h4(aux[4]);
-  half h5(aux[5]);
-  half h6(aux[6]);
-  half h7(aux[7]);
-  half h8(aux[8]);
-  half h9(aux[9]);
-  half ha(aux[10]);
-  half hb(aux[11]);
-  half hc(aux[12]);
-  half hd(aux[13]);
-  half he(aux[14]);
-  half hf(aux[15]);
-
-  Packet16h result;
-  result.x = _mm256_set_epi16(
-      hf.x, he.x, hd.x, hc.x, hb.x, ha.x, h9.x, h8.x,
-      h7.x, h6.x, h5.x, h4.x, h3.x, h2.x, h1.x, h0.x);
-  return result;
-#endif
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pnot(const Packet16h& a) {
-  Packet16h r; r.x = _mm256_xor_si256(a.x, pcmp_eq(a.x, a.x)); return r;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h ptrue(const Packet16h& a) {
-  Packet16h r; r.x = Packet8i(ptrue(a.x)); return r;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h por(const Packet16h& a,const Packet16h& b) {
-  // in some cases Packet8i is a wrapper around __m256i, so we need to 
-  // cast to Packet8i to call the correct overload.
-  Packet16h r; r.x = por(Packet8i(a.x),Packet8i(b.x)); return r;
-}
-template<> EIGEN_STRONG_INLINE Packet16h pxor(const Packet16h& a,const Packet16h& b) {
-  Packet16h r; r.x = pxor(Packet8i(a.x),Packet8i(b.x)); return r;
-}
-template<> EIGEN_STRONG_INLINE Packet16h pand(const Packet16h& a,const Packet16h& b) {
-  Packet16h r; r.x = pand(Packet8i(a.x),Packet8i(b.x)); return r;
-}
-template<> EIGEN_STRONG_INLINE Packet16h pandnot(const Packet16h& a,const Packet16h& b) {
-  Packet16h r; r.x = pandnot(Packet8i(a.x),Packet8i(b.x)); return r;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pselect(const Packet16h& mask, const Packet16h& a, const Packet16h& b) {
-  Packet16h r; r.x = _mm256_blendv_epi8(b.x, a.x, mask.x); return r;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pcmp_eq(const Packet16h& a,const Packet16h& b) {
-  Packet16f af = half2float(a);
-  Packet16f bf = half2float(b);
-  Packet16f rf = pcmp_eq(af, bf);
-  // Pack the 32-bit flags into 16-bits flags.
-  __m256i lo = _mm256_castps_si256(extract256<0>(rf));
-  __m256i hi = _mm256_castps_si256(extract256<1>(rf));
-  __m128i result_lo = _mm_packs_epi32(_mm256_extractf128_si256(lo, 0),
-                                      _mm256_extractf128_si256(lo, 1));
-  __m128i result_hi = _mm_packs_epi32(_mm256_extractf128_si256(hi, 0),
-                                      _mm256_extractf128_si256(hi, 1));
-  Packet16h result; result.x = _mm256_insertf128_si256(_mm256_castsi128_si256(result_lo), result_hi, 1);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pnegate(const Packet16h& a) {
-  Packet16h sign_mask; sign_mask.x = _mm256_set1_epi16(static_cast<unsigned short>(0x8000));
-  Packet16h result; result.x = _mm256_xor_si256(a.x, sign_mask.x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h padd<Packet16h>(const Packet16h& a, const Packet16h& b) {
-  Packet16f af = half2float(a);
-  Packet16f bf = half2float(b);
-  Packet16f rf = padd(af, bf);
-  return float2half(rf);
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h psub<Packet16h>(const Packet16h& a, const Packet16h& b) {
-  Packet16f af = half2float(a);
-  Packet16f bf = half2float(b);
-  Packet16f rf = psub(af, bf);
-  return float2half(rf);
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pmul<Packet16h>(const Packet16h& a, const Packet16h& b) {
-  Packet16f af = half2float(a);
-  Packet16f bf = half2float(b);
-  Packet16f rf = pmul(af, bf);
-  return float2half(rf);
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pdiv<Packet16h>(const Packet16h& a, const Packet16h& b) {
-  Packet16f af = half2float(a);
-  Packet16f bf = half2float(b);
-  Packet16f rf = pdiv(af, bf);
-  return float2half(rf);
-}
-
-template<> EIGEN_STRONG_INLINE half predux<Packet16h>(const Packet16h& from) {
-  Packet16f from_float = half2float(from);
-  return half(predux(from_float));
-}
-
-template<> EIGEN_STRONG_INLINE half predux_mul<Packet16h>(const Packet16h& from) {
-  Packet16f from_float = half2float(from);
-  return half(predux_mul(from_float));
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h preduxp<Packet16h>(const Packet16h* p) {
-  Packet16f pf[16];
-  pf[0] = half2float(p[0]);
-  pf[1] = half2float(p[1]);
-  pf[2] = half2float(p[2]);
-  pf[3] = half2float(p[3]);
-  pf[4] = half2float(p[4]);
-  pf[5] = half2float(p[5]);
-  pf[6] = half2float(p[6]);
-  pf[7] = half2float(p[7]);
-  pf[8] = half2float(p[8]);
-  pf[9] = half2float(p[9]);
-  pf[10] = half2float(p[10]);
-  pf[11] = half2float(p[11]);
-  pf[12] = half2float(p[12]);
-  pf[13] = half2float(p[13]);
-  pf[14] = half2float(p[14]);
-  pf[15] = half2float(p[15]);
-  Packet16f reduced = preduxp<Packet16f>(pf);
-  return float2half(reduced);
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h preverse(const Packet16h& a)
-{
-  __m128i m = _mm_setr_epi8(14,15,12,13,10,11,8,9,6,7,4,5,2,3,0,1);
-  Packet16h res;
-  res.x = _mm256_insertf128_si256(
-                    _mm256_castsi128_si256(_mm_shuffle_epi8(_mm256_extractf128_si256(a.x,1),m)),
-                                           _mm_shuffle_epi8(_mm256_extractf128_si256(a.x,0),m), 1);
-  return res;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pinsertfirst(const Packet16h& a, Eigen::half b)
-{
-  Packet16h res;
-  res.x = _mm256_insert_epi16(a.x,b.x,0);
-  return res;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pinsertlast(const Packet16h& a, Eigen::half b)
-{
-  Packet16h res;
-  res.x = _mm256_insert_epi16(a.x,b.x,15);
-  return res;
-}
-
-template<> EIGEN_STRONG_INLINE Packet16h pgather<Eigen::half, Packet16h>(const Eigen::half* from, Index stride)
-{
-  Packet16h result;
-  result.x = _mm256_set_epi16(
-      from[15*stride].x, from[14*stride].x, from[13*stride].x, from[12*stride].x,
-      from[11*stride].x, from[10*stride].x, from[9*stride].x, from[8*stride].x,
-      from[7*stride].x, from[6*stride].x, from[5*stride].x, from[4*stride].x,
-      from[3*stride].x, from[2*stride].x, from[1*stride].x, from[0*stride].x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE void pscatter<half, Packet16h>(half* to, const Packet16h& from, Index stride)
-{
-  EIGEN_ALIGN64 half aux[16];
-  pstore(aux, from);
-  to[stride*0].x = aux[0].x;
-  to[stride*1].x = aux[1].x;
-  to[stride*2].x = aux[2].x;
-  to[stride*3].x = aux[3].x;
-  to[stride*4].x = aux[4].x;
-  to[stride*5].x = aux[5].x;
-  to[stride*6].x = aux[6].x;
-  to[stride*7].x = aux[7].x;
-  to[stride*8].x = aux[8].x;
-  to[stride*9].x = aux[9].x;
-  to[stride*10].x = aux[10].x;
-  to[stride*11].x = aux[11].x;
-  to[stride*12].x = aux[12].x;
-  to[stride*13].x = aux[13].x;
-  to[stride*14].x = aux[14].x;
-  to[stride*15].x = aux[15].x;
-}
-
-EIGEN_STRONG_INLINE void
-ptranspose(PacketBlock<Packet16h,16>& kernel) {
-  __m256i a = kernel.packet[0].x;
-  __m256i b = kernel.packet[1].x;
-  __m256i c = kernel.packet[2].x;
-  __m256i d = kernel.packet[3].x;
-  __m256i e = kernel.packet[4].x;
-  __m256i f = kernel.packet[5].x;
-  __m256i g = kernel.packet[6].x;
-  __m256i h = kernel.packet[7].x;
-  __m256i i = kernel.packet[8].x;
-  __m256i j = kernel.packet[9].x;
-  __m256i k = kernel.packet[10].x;
-  __m256i l = kernel.packet[11].x;
-  __m256i m = kernel.packet[12].x;
-  __m256i n = kernel.packet[13].x;
-  __m256i o = kernel.packet[14].x;
-  __m256i p = kernel.packet[15].x;
-
-  __m256i ab_07 = _mm256_unpacklo_epi16(a, b);
-  __m256i cd_07 = _mm256_unpacklo_epi16(c, d);
-  __m256i ef_07 = _mm256_unpacklo_epi16(e, f);
-  __m256i gh_07 = _mm256_unpacklo_epi16(g, h);
-  __m256i ij_07 = _mm256_unpacklo_epi16(i, j);
-  __m256i kl_07 = _mm256_unpacklo_epi16(k, l);
-  __m256i mn_07 = _mm256_unpacklo_epi16(m, n);
-  __m256i op_07 = _mm256_unpacklo_epi16(o, p);
-
-  __m256i ab_8f = _mm256_unpackhi_epi16(a, b);
-  __m256i cd_8f = _mm256_unpackhi_epi16(c, d);
-  __m256i ef_8f = _mm256_unpackhi_epi16(e, f);
-  __m256i gh_8f = _mm256_unpackhi_epi16(g, h);
-  __m256i ij_8f = _mm256_unpackhi_epi16(i, j);
-  __m256i kl_8f = _mm256_unpackhi_epi16(k, l);
-  __m256i mn_8f = _mm256_unpackhi_epi16(m, n);
-  __m256i op_8f = _mm256_unpackhi_epi16(o, p);
-
-  __m256i abcd_03 = _mm256_unpacklo_epi32(ab_07, cd_07);
-  __m256i abcd_47 = _mm256_unpackhi_epi32(ab_07, cd_07);
-  __m256i efgh_03 = _mm256_unpacklo_epi32(ef_07, gh_07);
-  __m256i efgh_47 = _mm256_unpackhi_epi32(ef_07, gh_07);
-  __m256i ijkl_03 = _mm256_unpacklo_epi32(ij_07, kl_07);
-  __m256i ijkl_47 = _mm256_unpackhi_epi32(ij_07, kl_07);
-  __m256i mnop_03 = _mm256_unpacklo_epi32(mn_07, op_07);
-  __m256i mnop_47 = _mm256_unpackhi_epi32(mn_07, op_07);
-
-  __m256i abcd_8b = _mm256_unpacklo_epi32(ab_8f, cd_8f);
-  __m256i abcd_cf = _mm256_unpackhi_epi32(ab_8f, cd_8f);
-  __m256i efgh_8b = _mm256_unpacklo_epi32(ef_8f, gh_8f);
-  __m256i efgh_cf = _mm256_unpackhi_epi32(ef_8f, gh_8f);
-  __m256i ijkl_8b = _mm256_unpacklo_epi32(ij_8f, kl_8f);
-  __m256i ijkl_cf = _mm256_unpackhi_epi32(ij_8f, kl_8f);
-  __m256i mnop_8b = _mm256_unpacklo_epi32(mn_8f, op_8f);
-  __m256i mnop_cf = _mm256_unpackhi_epi32(mn_8f, op_8f);
-
-  __m256i abcdefgh_01 = _mm256_unpacklo_epi64(abcd_03, efgh_03);
-  __m256i abcdefgh_23 = _mm256_unpackhi_epi64(abcd_03, efgh_03);
-  __m256i ijklmnop_01 = _mm256_unpacklo_epi64(ijkl_03, mnop_03);
-  __m256i ijklmnop_23 = _mm256_unpackhi_epi64(ijkl_03, mnop_03);
-  __m256i abcdefgh_45 = _mm256_unpacklo_epi64(abcd_47, efgh_47);
-  __m256i abcdefgh_67 = _mm256_unpackhi_epi64(abcd_47, efgh_47);
-  __m256i ijklmnop_45 = _mm256_unpacklo_epi64(ijkl_47, mnop_47);
-  __m256i ijklmnop_67 = _mm256_unpackhi_epi64(ijkl_47, mnop_47);
-  __m256i abcdefgh_89 = _mm256_unpacklo_epi64(abcd_8b, efgh_8b);
-  __m256i abcdefgh_ab = _mm256_unpackhi_epi64(abcd_8b, efgh_8b);
-  __m256i ijklmnop_89 = _mm256_unpacklo_epi64(ijkl_8b, mnop_8b);
-  __m256i ijklmnop_ab = _mm256_unpackhi_epi64(ijkl_8b, mnop_8b);
-  __m256i abcdefgh_cd = _mm256_unpacklo_epi64(abcd_cf, efgh_cf);
-  __m256i abcdefgh_ef = _mm256_unpackhi_epi64(abcd_cf, efgh_cf);
-  __m256i ijklmnop_cd = _mm256_unpacklo_epi64(ijkl_cf, mnop_cf);
-  __m256i ijklmnop_ef = _mm256_unpackhi_epi64(ijkl_cf, mnop_cf);
-
-  // NOTE: no unpacklo/hi instr in this case, so using permute instr.
-  __m256i a_p_0 = _mm256_permute2x128_si256(abcdefgh_01, ijklmnop_01, 0x20);
-  __m256i a_p_1 = _mm256_permute2x128_si256(abcdefgh_23, ijklmnop_23, 0x20);
-  __m256i a_p_2 = _mm256_permute2x128_si256(abcdefgh_45, ijklmnop_45, 0x20);
-  __m256i a_p_3 = _mm256_permute2x128_si256(abcdefgh_67, ijklmnop_67, 0x20);
-  __m256i a_p_4 = _mm256_permute2x128_si256(abcdefgh_89, ijklmnop_89, 0x20);
-  __m256i a_p_5 = _mm256_permute2x128_si256(abcdefgh_ab, ijklmnop_ab, 0x20);
-  __m256i a_p_6 = _mm256_permute2x128_si256(abcdefgh_cd, ijklmnop_cd, 0x20);
-  __m256i a_p_7 = _mm256_permute2x128_si256(abcdefgh_ef, ijklmnop_ef, 0x20);
-  __m256i a_p_8 = _mm256_permute2x128_si256(abcdefgh_01, ijklmnop_01, 0x31);
-  __m256i a_p_9 = _mm256_permute2x128_si256(abcdefgh_23, ijklmnop_23, 0x31);
-  __m256i a_p_a = _mm256_permute2x128_si256(abcdefgh_45, ijklmnop_45, 0x31);
-  __m256i a_p_b = _mm256_permute2x128_si256(abcdefgh_67, ijklmnop_67, 0x31);
-  __m256i a_p_c = _mm256_permute2x128_si256(abcdefgh_89, ijklmnop_89, 0x31);
-  __m256i a_p_d = _mm256_permute2x128_si256(abcdefgh_ab, ijklmnop_ab, 0x31);
-  __m256i a_p_e = _mm256_permute2x128_si256(abcdefgh_cd, ijklmnop_cd, 0x31);
-  __m256i a_p_f = _mm256_permute2x128_si256(abcdefgh_ef, ijklmnop_ef, 0x31);
-
-  kernel.packet[0].x = a_p_0;
-  kernel.packet[1].x = a_p_1;
-  kernel.packet[2].x = a_p_2;
-  kernel.packet[3].x = a_p_3;
-  kernel.packet[4].x = a_p_4;
-  kernel.packet[5].x = a_p_5;
-  kernel.packet[6].x = a_p_6;
-  kernel.packet[7].x = a_p_7;
-  kernel.packet[8].x = a_p_8;
-  kernel.packet[9].x = a_p_9;
-  kernel.packet[10].x = a_p_a;
-  kernel.packet[11].x = a_p_b;
-  kernel.packet[12].x = a_p_c;
-  kernel.packet[13].x = a_p_d;
-  kernel.packet[14].x = a_p_e;
-  kernel.packet[15].x = a_p_f;
-}
-
-EIGEN_STRONG_INLINE void
-ptranspose(PacketBlock<Packet16h,8>& kernel) {
-  EIGEN_ALIGN64 half in[8][16];
-  pstore<half>(in[0], kernel.packet[0]);
-  pstore<half>(in[1], kernel.packet[1]);
-  pstore<half>(in[2], kernel.packet[2]);
-  pstore<half>(in[3], kernel.packet[3]);
-  pstore<half>(in[4], kernel.packet[4]);
-  pstore<half>(in[5], kernel.packet[5]);
-  pstore<half>(in[6], kernel.packet[6]);
-  pstore<half>(in[7], kernel.packet[7]);
-
-  EIGEN_ALIGN64 half out[8][16];
-
-  for (int i = 0; i < 8; ++i) {
-    for (int j = 0; j < 8; ++j) {
-      out[i][j] = in[j][2*i];
-    }
-    for (int j = 0; j < 8; ++j) {
-      out[i][j+8] = in[j][2*i+1];
-    }
-  }
-
-  kernel.packet[0] = pload<Packet16h>(out[0]);
-  kernel.packet[1] = pload<Packet16h>(out[1]);
-  kernel.packet[2] = pload<Packet16h>(out[2]);
-  kernel.packet[3] = pload<Packet16h>(out[3]);
-  kernel.packet[4] = pload<Packet16h>(out[4]);
-  kernel.packet[5] = pload<Packet16h>(out[5]);
-  kernel.packet[6] = pload<Packet16h>(out[6]);
-  kernel.packet[7] = pload<Packet16h>(out[7]);
-}
-
-EIGEN_STRONG_INLINE void
-ptranspose(PacketBlock<Packet16h,4>& kernel) {
-  EIGEN_ALIGN64 half in[4][16];
-  pstore<half>(in[0], kernel.packet[0]);
-  pstore<half>(in[1], kernel.packet[1]);
-  pstore<half>(in[2], kernel.packet[2]);
-  pstore<half>(in[3], kernel.packet[3]);
-
-  EIGEN_ALIGN64 half out[4][16];
-
-  for (int i = 0; i < 4; ++i) {
-    for (int j = 0; j < 4; ++j) {
-      out[i][j] = in[j][4*i];
-    }
-    for (int j = 0; j < 4; ++j) {
-      out[i][j+4] = in[j][4*i+1];
-    }
-    for (int j = 0; j < 4; ++j) {
-      out[i][j+8] = in[j][4*i+2];
-    }
-    for (int j = 0; j < 4; ++j) {
-      out[i][j+12] = in[j][4*i+3];
-    }
-  }
-
-  kernel.packet[0] = pload<Packet16h>(out[0]);
-  kernel.packet[1] = pload<Packet16h>(out[1]);
-  kernel.packet[2] = pload<Packet16h>(out[2]);
-  kernel.packet[3] = pload<Packet16h>(out[3]);
-}
-
-
-#elif defined EIGEN_VECTORIZE_AVX
-
-typedef struct {
-  __m128i x;
-} Packet8h;
-
-
-template<> struct is_arithmetic<Packet8h> { enum { value = true }; };
-
-template <>
-struct packet_traits<Eigen::half> : default_packet_traits {
-  typedef Packet8h type;
-  // There is no half-size packet for Packet8h.
-  typedef Packet8h half;
-  enum {
-    Vectorizable = 1,
-    AlignedOnScalar = 1,
-    size = 8,
-    HasHalfPacket = 0,
-    HasAdd    = 1,
-    HasSub    = 1,
-    HasMul    = 1,
-    HasDiv    = 1,
-    HasNegate = 1,
-    HasAbs    = 0,
-    HasAbs2   = 0,
-    HasMin    = 0,
-    HasMax    = 0,
-    HasConj   = 0,
-    HasSetLinear = 0,
-    HasSqrt = 0,
-    HasRsqrt = 0,
-    HasExp = 0,
-    HasLog = 0,
-    HasBlend = 0
-  };
-};
-
-
-template<> struct unpacket_traits<Packet8h> { typedef Eigen::half type; enum {size=8, alignment=Aligned16, vectorizable=true, masked_load_available=false, masked_store_available=false}; typedef Packet8h half; };
-
-template<> EIGEN_STRONG_INLINE Packet8h pset1<Packet8h>(const Eigen::half& from) {
-  Packet8h result;
-  result.x = _mm_set1_epi16(from.x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Eigen::half pfirst<Packet8h>(const Packet8h& from) {
-  return half_impl::raw_uint16_to_half(static_cast<unsigned short>(_mm_extract_epi16(from.x, 0)));
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pload<Packet8h>(const Eigen::half* from) {
-  Packet8h result;
-  result.x = _mm_load_si128(reinterpret_cast<const __m128i*>(from));
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h ploadu<Packet8h>(const Eigen::half* from) {
-  Packet8h result;
-  result.x = _mm_loadu_si128(reinterpret_cast<const __m128i*>(from));
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE void pstore<Eigen::half>(Eigen::half* to, const Packet8h& from) {
-  _mm_store_si128(reinterpret_cast<__m128i*>(to), from.x);
-}
-
-template<> EIGEN_STRONG_INLINE void pstoreu<Eigen::half>(Eigen::half* to, const Packet8h& from) {
-  _mm_storeu_si128(reinterpret_cast<__m128i*>(to), from.x);
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h
-ploaddup<Packet8h>(const Eigen::half*  from) {
-  Packet8h result;
-  unsigned short a = from[0].x;
-  unsigned short b = from[1].x;
-  unsigned short c = from[2].x;
-  unsigned short d = from[3].x;
-  result.x = _mm_set_epi16(d, d, c, c, b, b, a, a);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h
-ploadquad<Packet8h>(const Eigen::half* from) {
-  Packet8h result;
-  unsigned short a = from[0].x;
-  unsigned short b = from[1].x;
-  result.x = _mm_set_epi16(b, b, b, b, a, a, a, a);
-  return result;
-}
-
-EIGEN_STRONG_INLINE Packet8f half2float(const Packet8h& a) {
-#ifdef EIGEN_HAS_FP16_C
-  return _mm256_cvtph_ps(a.x);
-#else
-  EIGEN_ALIGN32 Eigen::half aux[8];
-  pstore(aux, a);
-  float f0(aux[0]);
-  float f1(aux[1]);
-  float f2(aux[2]);
-  float f3(aux[3]);
-  float f4(aux[4]);
-  float f5(aux[5]);
-  float f6(aux[6]);
-  float f7(aux[7]);
-
-  return _mm256_set_ps(f7, f6, f5, f4, f3, f2, f1, f0);
-#endif
-}
-
-EIGEN_STRONG_INLINE Packet8h float2half(const Packet8f& a) {
-#ifdef EIGEN_HAS_FP16_C
-  Packet8h result;
-  result.x = _mm256_cvtps_ph(a, _MM_FROUND_TO_NEAREST_INT|_MM_FROUND_NO_EXC);
-  return result;
-#else
-  EIGEN_ALIGN32 float aux[8];
-  pstore(aux, a);
-  Eigen::half h0(aux[0]);
-  Eigen::half h1(aux[1]);
-  Eigen::half h2(aux[2]);
-  Eigen::half h3(aux[3]);
-  Eigen::half h4(aux[4]);
-  Eigen::half h5(aux[5]);
-  Eigen::half h6(aux[6]);
-  Eigen::half h7(aux[7]);
-
-  Packet8h result;
-  result.x = _mm_set_epi16(h7.x, h6.x, h5.x, h4.x, h3.x, h2.x, h1.x, h0.x);
-  return result;
-#endif
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h ptrue(const Packet8h& a) {
-  Packet8h r; r.x = _mm_cmpeq_epi32(a.x, a.x); return r;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h por(const Packet8h& a,const Packet8h& b) {
-  // in some cases Packet4i is a wrapper around __m128i, so we either need to 
-  // cast to Packet4i to directly call the intrinsics as below:
-  Packet8h r; r.x = _mm_or_si128(a.x,b.x); return r;
-}
-template<> EIGEN_STRONG_INLINE Packet8h pxor(const Packet8h& a,const Packet8h& b) {
-  Packet8h r; r.x = _mm_xor_si128(a.x,b.x); return r;
-}
-template<> EIGEN_STRONG_INLINE Packet8h pand(const Packet8h& a,const Packet8h& b) {
-  Packet8h r; r.x = _mm_and_si128(a.x,b.x); return r;
-}
-template<> EIGEN_STRONG_INLINE Packet8h pandnot(const Packet8h& a,const Packet8h& b) {
-  Packet8h r; r.x = _mm_andnot_si128(b.x,a.x); return r;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pselect(const Packet8h& mask, const Packet8h& a, const Packet8h& b) {
-  Packet8h r; r.x = _mm_blendv_epi8(b.x, a.x, mask.x); return r;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pcmp_eq(const Packet8h& a,const Packet8h& b) {
-  Packet8f af = half2float(a);
-  Packet8f bf = half2float(b);
-  Packet8f rf = pcmp_eq(af, bf);
-  // Pack the 32-bit flags into 16-bits flags.
-  Packet8h result; result.x = _mm_packs_epi32(_mm256_extractf128_si256(_mm256_castps_si256(rf), 0),
-                                              _mm256_extractf128_si256(_mm256_castps_si256(rf), 1));
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pconj(const Packet8h& a) { return a; }
-
-template<> EIGEN_STRONG_INLINE Packet8h pnegate(const Packet8h& a) {
-  Packet8h sign_mask; sign_mask.x = _mm_set1_epi16(static_cast<unsigned short>(0x8000));
-  Packet8h result; result.x = _mm_xor_si128(a.x, sign_mask.x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h padd<Packet8h>(const Packet8h& a, const Packet8h& b) {
-  Packet8f af = half2float(a);
-  Packet8f bf = half2float(b);
-  Packet8f rf = padd(af, bf);
-  return float2half(rf);
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h psub<Packet8h>(const Packet8h& a, const Packet8h& b) {
-  Packet8f af = half2float(a);
-  Packet8f bf = half2float(b);
-  Packet8f rf = psub(af, bf);
-  return float2half(rf);
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pmul<Packet8h>(const Packet8h& a, const Packet8h& b) {
-  Packet8f af = half2float(a);
-  Packet8f bf = half2float(b);
-  Packet8f rf = pmul(af, bf);
-  return float2half(rf);
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pdiv<Packet8h>(const Packet8h& a, const Packet8h& b) {
-  Packet8f af = half2float(a);
-  Packet8f bf = half2float(b);
-  Packet8f rf = pdiv(af, bf);
-  return float2half(rf);
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pgather<Eigen::half, Packet8h>(const Eigen::half* from, Index stride)
-{
-  Packet8h result;
-  result.x = _mm_set_epi16(from[7*stride].x, from[6*stride].x, from[5*stride].x, from[4*stride].x, from[3*stride].x, from[2*stride].x, from[1*stride].x, from[0*stride].x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE void pscatter<Eigen::half, Packet8h>(Eigen::half* to, const Packet8h& from, Index stride)
-{
-  EIGEN_ALIGN32 Eigen::half aux[8];
-  pstore(aux, from);
-  to[stride*0].x = aux[0].x;
-  to[stride*1].x = aux[1].x;
-  to[stride*2].x = aux[2].x;
-  to[stride*3].x = aux[3].x;
-  to[stride*4].x = aux[4].x;
-  to[stride*5].x = aux[5].x;
-  to[stride*6].x = aux[6].x;
-  to[stride*7].x = aux[7].x;
-}
-
-template<> EIGEN_STRONG_INLINE Eigen::half predux<Packet8h>(const Packet8h& a) {
-  Packet8f af = half2float(a);
-  float reduced = predux<Packet8f>(af);
-  return Eigen::half(reduced);
-}
-
-template<> EIGEN_STRONG_INLINE Eigen::half predux_max<Packet8h>(const Packet8h& a) {
-  Packet8f af = half2float(a);
-  float reduced = predux_max<Packet8f>(af);
-  return Eigen::half(reduced);
-}
-
-template<> EIGEN_STRONG_INLINE Eigen::half predux_min<Packet8h>(const Packet8h& a) {
-  Packet8f af = half2float(a);
-  float reduced = predux_min<Packet8f>(af);
-  return Eigen::half(reduced);
-}
-
-template<> EIGEN_STRONG_INLINE Eigen::half predux_mul<Packet8h>(const Packet8h& a) {
-  Packet8f af = half2float(a);
-  float reduced = predux_mul<Packet8f>(af);
-  return Eigen::half(reduced);
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h preduxp<Packet8h>(const Packet8h* p) {
-  Packet8f pf[8];
-  pf[0] = half2float(p[0]);
-  pf[1] = half2float(p[1]);
-  pf[2] = half2float(p[2]);
-  pf[3] = half2float(p[3]);
-  pf[4] = half2float(p[4]);
-  pf[5] = half2float(p[5]);
-  pf[6] = half2float(p[6]);
-  pf[7] = half2float(p[7]);
-  Packet8f reduced = preduxp<Packet8f>(pf);
-  return float2half(reduced);
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h preverse(const Packet8h& a)
-{
-  __m128i m = _mm_setr_epi8(14,15,12,13,10,11,8,9,6,7,4,5,2,3,0,1);
-  Packet8h res;
-  res.x = _mm_shuffle_epi8(a.x,m);
-  return res;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pinsertfirst(const Packet8h& a, Eigen::half b)
-{
-  Packet8h res;
-  res.x = _mm_insert_epi16(a.x,int(b.x),0);
-  return res;
-}
-
-template<> EIGEN_STRONG_INLINE Packet8h pinsertlast(const Packet8h& a, Eigen::half b)
-{
-  Packet8h res;
-  res.x = _mm_insert_epi16(a.x,int(b.x),7);
-  return res;
-}
-
-template<int Offset>
-struct palign_impl<Offset,Packet8h>
-{
-  static EIGEN_STRONG_INLINE void run(Packet8h& first, const Packet8h& second)
-  {
-    if (Offset!=0)
-      first.x = _mm_alignr_epi8(second.x,first.x, Offset*2);
-  }
-};
-
-EIGEN_STRONG_INLINE void
-ptranspose(PacketBlock<Packet8h,8>& kernel) {
-  __m128i a = kernel.packet[0].x;
-  __m128i b = kernel.packet[1].x;
-  __m128i c = kernel.packet[2].x;
-  __m128i d = kernel.packet[3].x;
-  __m128i e = kernel.packet[4].x;
-  __m128i f = kernel.packet[5].x;
-  __m128i g = kernel.packet[6].x;
-  __m128i h = kernel.packet[7].x;
-
-  __m128i a03b03 = _mm_unpacklo_epi16(a, b);
-  __m128i c03d03 = _mm_unpacklo_epi16(c, d);
-  __m128i e03f03 = _mm_unpacklo_epi16(e, f);
-  __m128i g03h03 = _mm_unpacklo_epi16(g, h);
-  __m128i a47b47 = _mm_unpackhi_epi16(a, b);
-  __m128i c47d47 = _mm_unpackhi_epi16(c, d);
-  __m128i e47f47 = _mm_unpackhi_epi16(e, f);
-  __m128i g47h47 = _mm_unpackhi_epi16(g, h);
-
-  __m128i a01b01c01d01 = _mm_unpacklo_epi32(a03b03, c03d03);
-  __m128i a23b23c23d23 = _mm_unpackhi_epi32(a03b03, c03d03);
-  __m128i e01f01g01h01 = _mm_unpacklo_epi32(e03f03, g03h03);
-  __m128i e23f23g23h23 = _mm_unpackhi_epi32(e03f03, g03h03);
-  __m128i a45b45c45d45 = _mm_unpacklo_epi32(a47b47, c47d47);
-  __m128i a67b67c67d67 = _mm_unpackhi_epi32(a47b47, c47d47);
-  __m128i e45f45g45h45 = _mm_unpacklo_epi32(e47f47, g47h47);
-  __m128i e67f67g67h67 = _mm_unpackhi_epi32(e47f47, g47h47);
-
-  __m128i a0b0c0d0e0f0g0h0 = _mm_unpacklo_epi64(a01b01c01d01, e01f01g01h01);
-  __m128i a1b1c1d1e1f1g1h1 = _mm_unpackhi_epi64(a01b01c01d01, e01f01g01h01);
-  __m128i a2b2c2d2e2f2g2h2 = _mm_unpacklo_epi64(a23b23c23d23, e23f23g23h23);
-  __m128i a3b3c3d3e3f3g3h3 = _mm_unpackhi_epi64(a23b23c23d23, e23f23g23h23);
-  __m128i a4b4c4d4e4f4g4h4 = _mm_unpacklo_epi64(a45b45c45d45, e45f45g45h45);
-  __m128i a5b5c5d5e5f5g5h5 = _mm_unpackhi_epi64(a45b45c45d45, e45f45g45h45);
-  __m128i a6b6c6d6e6f6g6h6 = _mm_unpacklo_epi64(a67b67c67d67, e67f67g67h67);
-  __m128i a7b7c7d7e7f7g7h7 = _mm_unpackhi_epi64(a67b67c67d67, e67f67g67h67);
-
-  kernel.packet[0].x = a0b0c0d0e0f0g0h0;
-  kernel.packet[1].x = a1b1c1d1e1f1g1h1;
-  kernel.packet[2].x = a2b2c2d2e2f2g2h2;
-  kernel.packet[3].x = a3b3c3d3e3f3g3h3;
-  kernel.packet[4].x = a4b4c4d4e4f4g4h4;
-  kernel.packet[5].x = a5b5c5d5e5f5g5h5;
-  kernel.packet[6].x = a6b6c6d6e6f6g6h6;
-  kernel.packet[7].x = a7b7c7d7e7f7g7h7;
-}
-
-EIGEN_STRONG_INLINE void
-ptranspose(PacketBlock<Packet8h,4>& kernel) {
-  EIGEN_ALIGN32 Eigen::half in[4][8];
-  pstore<Eigen::half>(in[0], kernel.packet[0]);
-  pstore<Eigen::half>(in[1], kernel.packet[1]);
-  pstore<Eigen::half>(in[2], kernel.packet[2]);
-  pstore<Eigen::half>(in[3], kernel.packet[3]);
-
-  EIGEN_ALIGN32 Eigen::half out[4][8];
-
-  for (int i = 0; i < 4; ++i) {
-    for (int j = 0; j < 4; ++j) {
-      out[i][j] = in[j][2*i];
-    }
-    for (int j = 0; j < 4; ++j) {
-      out[i][j+4] = in[j][2*i+1];
-    }
-  }
-
-  kernel.packet[0] = pload<Packet8h>(out[0]);
-  kernel.packet[1] = pload<Packet8h>(out[1]);
-  kernel.packet[2] = pload<Packet8h>(out[2]);
-  kernel.packet[3] = pload<Packet8h>(out[3]);
-}
-
-
-// Disable the following code since it's broken on too many platforms / compilers.
-//#elif defined(EIGEN_VECTORIZE_SSE) && (!EIGEN_ARCH_x86_64) && (!EIGEN_COMP_MSVC)
-#elif 0
-
-typedef struct {
-  __m64 x;
-} Packet4h;
-
-
-template<> struct is_arithmetic<Packet4h> { enum { value = true }; };
-
-template <>
-struct packet_traits<Eigen::half> : default_packet_traits {
-  typedef Packet4h type;
-  // There is no half-size packet for Packet4h.
-  typedef Packet4h half;
-  enum {
-    Vectorizable = 1,
-    AlignedOnScalar = 1,
-    size = 4,
-    HasHalfPacket = 0,
-    HasAdd    = 1,
-    HasSub    = 1,
-    HasMul    = 1,
-    HasDiv    = 1,
-    HasNegate = 0,
-    HasAbs    = 0,
-    HasAbs2   = 0,
-    HasMin    = 0,
-    HasMax    = 0,
-    HasConj   = 0,
-    HasSetLinear = 0,
-    HasSqrt = 0,
-    HasRsqrt = 0,
-    HasExp = 0,
-    HasLog = 0,
-    HasBlend = 0
-  };
-};
-
-
-template<> struct unpacket_traits<Packet4h> { typedef Eigen::half type; enum {size=4, alignment=Aligned16, vectorizable=true, masked_load_available=false, masked_store_available=false}; typedef Packet4h half; };
-
-template<> EIGEN_STRONG_INLINE Packet4h pset1<Packet4h>(const Eigen::half& from) {
-  Packet4h result;
-  result.x = _mm_set1_pi16(from.x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Eigen::half pfirst<Packet4h>(const Packet4h& from) {
-  return half_impl::raw_uint16_to_half(static_cast<unsigned short>(_mm_cvtsi64_si32(from.x)));
-}
-
-template<> EIGEN_STRONG_INLINE Packet4h pconj(const Packet4h& a) { return a; }
-
-template<> EIGEN_STRONG_INLINE Packet4h padd<Packet4h>(const Packet4h& a, const Packet4h& b) {
-  __int64_t a64 = _mm_cvtm64_si64(a.x);
-  __int64_t b64 = _mm_cvtm64_si64(b.x);
-
-  Eigen::half h[4];
-
-  Eigen::half ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64));
-  Eigen::half hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64));
-  h[0] = ha + hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 16));
-  h[1] = ha + hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 32));
-  h[2] = ha + hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 48));
-  h[3] = ha + hb;
-  Packet4h result;
-  result.x = _mm_set_pi16(h[3].x, h[2].x, h[1].x, h[0].x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet4h psub<Packet4h>(const Packet4h& a, const Packet4h& b) {
-  __int64_t a64 = _mm_cvtm64_si64(a.x);
-  __int64_t b64 = _mm_cvtm64_si64(b.x);
-
-  Eigen::half h[4];
-
-  Eigen::half ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64));
-  Eigen::half hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64));
-  h[0] = ha - hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 16));
-  h[1] = ha - hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 32));
-  h[2] = ha - hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 48));
-  h[3] = ha - hb;
-  Packet4h result;
-  result.x = _mm_set_pi16(h[3].x, h[2].x, h[1].x, h[0].x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet4h pmul<Packet4h>(const Packet4h& a, const Packet4h& b) {
-  __int64_t a64 = _mm_cvtm64_si64(a.x);
-  __int64_t b64 = _mm_cvtm64_si64(b.x);
-
-  Eigen::half h[4];
-
-  Eigen::half ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64));
-  Eigen::half hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64));
-  h[0] = ha * hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 16));
-  h[1] = ha * hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 32));
-  h[2] = ha * hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 48));
-  h[3] = ha * hb;
-  Packet4h result;
-  result.x = _mm_set_pi16(h[3].x, h[2].x, h[1].x, h[0].x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet4h pdiv<Packet4h>(const Packet4h& a, const Packet4h& b) {
-  __int64_t a64 = _mm_cvtm64_si64(a.x);
-  __int64_t b64 = _mm_cvtm64_si64(b.x);
-
-  Eigen::half h[4];
-
-  Eigen::half ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64));
-  Eigen::half hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64));
-  h[0] = ha / hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 16));
-  h[1] = ha / hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 32));
-  h[2] = ha / hb;
-  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
-  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 48));
-  h[3] = ha / hb;
-  Packet4h result;
-  result.x = _mm_set_pi16(h[3].x, h[2].x, h[1].x, h[0].x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet4h pload<Packet4h>(const Eigen::half* from) {
-  Packet4h result;
-  result.x = _mm_cvtsi64_m64(*reinterpret_cast<const __int64_t*>(from));
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE Packet4h ploadu<Packet4h>(const Eigen::half* from) {
-  Packet4h result;
-  result.x = _mm_cvtsi64_m64(*reinterpret_cast<const __int64_t*>(from));
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE void pstore<Eigen::half>(Eigen::half* to, const Packet4h& from) {
-  __int64_t r = _mm_cvtm64_si64(from.x);
-  *(reinterpret_cast<__int64_t*>(to)) = r;
-}
-
-template<> EIGEN_STRONG_INLINE void pstoreu<Eigen::half>(Eigen::half* to, const Packet4h& from) {
-  __int64_t r = _mm_cvtm64_si64(from.x);
-  *(reinterpret_cast<__int64_t*>(to)) = r;
-}
-
-template<> EIGEN_STRONG_INLINE Packet4h
-ploadquad<Packet4h>(const Eigen::half* from) {
-  return pset1<Packet4h>(*from);
-}
-
-template<> EIGEN_STRONG_INLINE Packet4h pgather<Eigen::half, Packet4h>(const Eigen::half* from, Index stride)
-{
-  Packet4h result;
-  result.x = _mm_set_pi16(from[3*stride].x, from[2*stride].x, from[1*stride].x, from[0*stride].x);
-  return result;
-}
-
-template<> EIGEN_STRONG_INLINE void pscatter<Eigen::half, Packet4h>(Eigen::half* to, const Packet4h& from, Index stride)
-{
-  __int64_t a = _mm_cvtm64_si64(from.x);
-  to[stride*0].x = static_cast<unsigned short>(a);
-  to[stride*1].x = static_cast<unsigned short>(a >> 16);
-  to[stride*2].x = static_cast<unsigned short>(a >> 32);
-  to[stride*3].x = static_cast<unsigned short>(a >> 48);
-}
-
-EIGEN_STRONG_INLINE void
-ptranspose(PacketBlock<Packet4h,4>& kernel) {
-  __m64 T0 = _mm_unpacklo_pi16(kernel.packet[0].x, kernel.packet[1].x);
-  __m64 T1 = _mm_unpacklo_pi16(kernel.packet[2].x, kernel.packet[3].x);
-  __m64 T2 = _mm_unpackhi_pi16(kernel.packet[0].x, kernel.packet[1].x);
-  __m64 T3 = _mm_unpackhi_pi16(kernel.packet[2].x, kernel.packet[3].x);
-
-  kernel.packet[0].x = _mm_unpacklo_pi32(T0, T1);
-  kernel.packet[1].x = _mm_unpackhi_pi32(T0, T1);
-  kernel.packet[2].x = _mm_unpacklo_pi32(T2, T3);
-  kernel.packet[3].x = _mm_unpackhi_pi32(T2, T3);
-}
-
-#endif
-
-}
-}
-
-#endif // EIGEN_PACKET_MATH_HALF_GPU_H
diff --git a/Eigen/src/Core/arch/GPU/TypeCasting.h b/Eigen/src/Core/arch/GPU/TypeCasting.h
index 57a55d08b..c278f3fe8 100644
--- a/Eigen/src/Core/arch/GPU/TypeCasting.h
+++ b/Eigen/src/Core/arch/GPU/TypeCasting.h
@@ -14,64 +14,6 @@ namespace Eigen {
 
 namespace internal {
 
-template<>
-struct scalar_cast_op<float, Eigen::half> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
-  typedef Eigen::half result_type;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half operator() (const float& a) const {
-    #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
-      (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIP_DEVICE_COMPILE))
-      return __float2half(a);
-    #else
-      return Eigen::half(a);
-    #endif
-  }
-};
-
-template<>
-struct functor_traits<scalar_cast_op<float, Eigen::half> >
-{ enum { Cost = NumTraits<float>::AddCost, PacketAccess = false }; };
-
-
-template<>
-struct scalar_cast_op<int, Eigen::half> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
-  typedef Eigen::half result_type;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Eigen::half operator() (const int& a) const {
-    #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
-      (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIP_DEVICE_COMPILE))
-      return __float2half(static_cast<float>(a));
-    #else
-      return Eigen::half(static_cast<float>(a));
-    #endif
-  }
-};
-
-template<>
-struct functor_traits<scalar_cast_op<int, Eigen::half> >
-{ enum { Cost = NumTraits<float>::AddCost, PacketAccess = false }; };
-
-
-template<>
-struct scalar_cast_op<Eigen::half, float> {
-  EIGEN_EMPTY_STRUCT_CTOR(scalar_cast_op)
-  typedef float result_type;
-  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE float operator() (const Eigen::half& a) const {
-    #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
-      (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIP_DEVICE_COMPILE))
-      return __half2float(a);
-    #else
-      return static_cast<float>(a);
-    #endif
-  }
-};
-
-template<>
-struct functor_traits<scalar_cast_op<Eigen::half, float> >
-{ enum { Cost = NumTraits<float>::AddCost, PacketAccess = false }; };
-
-
-
 #if (defined(EIGEN_HAS_CUDA_FP16) && defined(EIGEN_CUDA_ARCH) && EIGEN_CUDA_ARCH >= 300) || \
   (defined(EIGEN_HAS_HIP_FP16) && defined(EIGEN_HIP_DEVICE_COMPILE))
 
@@ -104,109 +46,6 @@ template<> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE half2 pcast<float4, half2>(cons
   return __floats2half2_rn(a.x, a.y);
 }
 
-#elif defined EIGEN_VECTORIZE_AVX512
-template <>
-struct type_casting_traits<half, float> {
-  enum {
-    VectorizedCast = 1,
-    SrcCoeffRatio = 1,
-    TgtCoeffRatio = 1
-  };
-};
-
-template<> EIGEN_STRONG_INLINE Packet16f pcast<Packet16h, Packet16f>(const Packet16h& a) {
-  return half2float(a);
-}
-
-template <>
-struct type_casting_traits<float, half> {
-  enum {
-    VectorizedCast = 1,
-    SrcCoeffRatio = 1,
-    TgtCoeffRatio = 1
-  };
-};
-
-template<> EIGEN_STRONG_INLINE Packet16h pcast<Packet16f, Packet16h>(const Packet16f& a) {
-  return float2half(a);
-}
-
-#elif defined EIGEN_VECTORIZE_AVX
-
-template <>
-struct type_casting_traits<Eigen::half, float> {
-  enum {
-    VectorizedCast = 1,
-    SrcCoeffRatio = 1,
-    TgtCoeffRatio = 1
-  };
-};
-
-template<> EIGEN_STRONG_INLINE Packet8f pcast<Packet8h, Packet8f>(const Packet8h& a) {
-  return half2float(a);
-}
-
-template <>
-struct type_casting_traits<float, Eigen::half> {
-  enum {
-    VectorizedCast = 1,
-    SrcCoeffRatio = 1,
-    TgtCoeffRatio = 1
-  };
-};
-
-template<> EIGEN_STRONG_INLINE Packet8h pcast<Packet8f, Packet8h>(const Packet8f& a) {
-  return float2half(a);
-}
-
-// Disable the following code since it's broken on too many platforms / compilers.
-//#elif defined(EIGEN_VECTORIZE_SSE) && (!EIGEN_ARCH_x86_64) && (!EIGEN_COMP_MSVC)
-#elif 0
-
-template <>
-struct type_casting_traits<Eigen::half, float> {
-  enum {
-    VectorizedCast = 1,
-    SrcCoeffRatio = 1,
-    TgtCoeffRatio = 1
-  };
-};
-
-template<> EIGEN_STRONG_INLINE Packet4f pcast<Packet4h, Packet4f>(const Packet4h& a) {
-  __int64_t a64 = _mm_cvtm64_si64(a.x);
-  Eigen::half h = raw_uint16_to_half(static_cast<unsigned short>(a64));
-  float f1 = static_cast<float>(h);
-  h = raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
-  float f2 = static_cast<float>(h);
-  h = raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
-  float f3 = static_cast<float>(h);
-  h = raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
-  float f4 = static_cast<float>(h);
-  return _mm_set_ps(f4, f3, f2, f1);
-}
-
-template <>
-struct type_casting_traits<float, Eigen::half> {
-  enum {
-    VectorizedCast = 1,
-    SrcCoeffRatio = 1,
-    TgtCoeffRatio = 1
-  };
-};
-
-template<> EIGEN_STRONG_INLINE Packet4h pcast<Packet4f, Packet4h>(const Packet4f& a) {
-  EIGEN_ALIGN16 float aux[4];
-  pstore(aux, a);
-  Eigen::half h0(aux[0]);
-  Eigen::half h1(aux[1]);
-  Eigen::half h2(aux[2]);
-  Eigen::half h3(aux[3]);
-
-  Packet4h result;
-  result.x = _mm_set_pi16(h3.x, h2.x, h1.x, h0.x);
-  return result;
-}
-
 #endif
 
 } // end namespace internal
diff --git a/Eigen/src/Core/arch/SSE/PacketMath.h b/Eigen/src/Core/arch/SSE/PacketMath.h
index 94603dd55..b59e2c602 100755
--- a/Eigen/src/Core/arch/SSE/PacketMath.h
+++ b/Eigen/src/Core/arch/SSE/PacketMath.h
@@ -1055,6 +1055,214 @@ template<> EIGEN_STRONG_INLINE double pmadd(const double& a, const double& b, co
 }
 #endif
 
+
+// Packet math for Eigen::half
+// Disable the following code since it's broken on too many platforms / compilers.
+//#elif defined(EIGEN_VECTORIZE_SSE) && (!EIGEN_ARCH_x86_64) && (!EIGEN_COMP_MSVC)
+#if 0
+
+typedef struct {
+  __m64 x;
+} Packet4h;
+
+
+template<> struct is_arithmetic<Packet4h> { enum { value = true }; };
+
+template <>
+struct packet_traits<Eigen::half> : default_packet_traits {
+  typedef Packet4h type;
+  // There is no half-size packet for Packet4h.
+  typedef Packet4h half;
+  enum {
+    Vectorizable = 1,
+    AlignedOnScalar = 1,
+    size = 4,
+    HasHalfPacket = 0,
+    HasAdd    = 1,
+    HasSub    = 1,
+    HasMul    = 1,
+    HasDiv    = 1,
+    HasNegate = 0,
+    HasAbs    = 0,
+    HasAbs2   = 0,
+    HasMin    = 0,
+    HasMax    = 0,
+    HasConj   = 0,
+    HasSetLinear = 0,
+    HasSqrt = 0,
+    HasRsqrt = 0,
+    HasExp = 0,
+    HasLog = 0,
+    HasBlend = 0
+  };
+};
+
+
+template<> struct unpacket_traits<Packet4h> { typedef Eigen::half type; enum {size=4, alignment=Aligned16, vectorizable=true, masked_load_available=false, masked_store_available=false}; typedef Packet4h half; };
+
+template<> EIGEN_STRONG_INLINE Packet4h pset1<Packet4h>(const Eigen::half& from) {
+  Packet4h result;
+  result.x = _mm_set1_pi16(from.x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Eigen::half pfirst<Packet4h>(const Packet4h& from) {
+  return half_impl::raw_uint16_to_half(static_cast<unsigned short>(_mm_cvtsi64_si32(from.x)));
+}
+
+template<> EIGEN_STRONG_INLINE Packet4h pconj(const Packet4h& a) { return a; }
+
+template<> EIGEN_STRONG_INLINE Packet4h padd<Packet4h>(const Packet4h& a, const Packet4h& b) {
+  __int64_t a64 = _mm_cvtm64_si64(a.x);
+  __int64_t b64 = _mm_cvtm64_si64(b.x);
+
+  Eigen::half h[4];
+
+  Eigen::half ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64));
+  Eigen::half hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64));
+  h[0] = ha + hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 16));
+  h[1] = ha + hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 32));
+  h[2] = ha + hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 48));
+  h[3] = ha + hb;
+  Packet4h result;
+  result.x = _mm_set_pi16(h[3].x, h[2].x, h[1].x, h[0].x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet4h psub<Packet4h>(const Packet4h& a, const Packet4h& b) {
+  __int64_t a64 = _mm_cvtm64_si64(a.x);
+  __int64_t b64 = _mm_cvtm64_si64(b.x);
+
+  Eigen::half h[4];
+
+  Eigen::half ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64));
+  Eigen::half hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64));
+  h[0] = ha - hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 16));
+  h[1] = ha - hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 32));
+  h[2] = ha - hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 48));
+  h[3] = ha - hb;
+  Packet4h result;
+  result.x = _mm_set_pi16(h[3].x, h[2].x, h[1].x, h[0].x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet4h pmul<Packet4h>(const Packet4h& a, const Packet4h& b) {
+  __int64_t a64 = _mm_cvtm64_si64(a.x);
+  __int64_t b64 = _mm_cvtm64_si64(b.x);
+
+  Eigen::half h[4];
+
+  Eigen::half ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64));
+  Eigen::half hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64));
+  h[0] = ha * hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 16));
+  h[1] = ha * hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 32));
+  h[2] = ha * hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 48));
+  h[3] = ha * hb;
+  Packet4h result;
+  result.x = _mm_set_pi16(h[3].x, h[2].x, h[1].x, h[0].x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet4h pdiv<Packet4h>(const Packet4h& a, const Packet4h& b) {
+  __int64_t a64 = _mm_cvtm64_si64(a.x);
+  __int64_t b64 = _mm_cvtm64_si64(b.x);
+
+  Eigen::half h[4];
+
+  Eigen::half ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64));
+  Eigen::half hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64));
+  h[0] = ha / hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 16));
+  h[1] = ha / hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 32));
+  h[2] = ha / hb;
+  ha = half_impl::raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
+  hb = half_impl::raw_uint16_to_half(static_cast<unsigned short>(b64 >> 48));
+  h[3] = ha / hb;
+  Packet4h result;
+  result.x = _mm_set_pi16(h[3].x, h[2].x, h[1].x, h[0].x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet4h pload<Packet4h>(const Eigen::half* from) {
+  Packet4h result;
+  result.x = _mm_cvtsi64_m64(*reinterpret_cast<const __int64_t*>(from));
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE Packet4h ploadu<Packet4h>(const Eigen::half* from) {
+  Packet4h result;
+  result.x = _mm_cvtsi64_m64(*reinterpret_cast<const __int64_t*>(from));
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE void pstore<Eigen::half>(Eigen::half* to, const Packet4h& from) {
+  __int64_t r = _mm_cvtm64_si64(from.x);
+  *(reinterpret_cast<__int64_t*>(to)) = r;
+}
+
+template<> EIGEN_STRONG_INLINE void pstoreu<Eigen::half>(Eigen::half* to, const Packet4h& from) {
+  __int64_t r = _mm_cvtm64_si64(from.x);
+  *(reinterpret_cast<__int64_t*>(to)) = r;
+}
+
+template<> EIGEN_STRONG_INLINE Packet4h
+ploadquad<Packet4h>(const Eigen::half* from) {
+  return pset1<Packet4h>(*from);
+}
+
+template<> EIGEN_STRONG_INLINE Packet4h pgather<Eigen::half, Packet4h>(const Eigen::half* from, Index stride)
+{
+  Packet4h result;
+  result.x = _mm_set_pi16(from[3*stride].x, from[2*stride].x, from[1*stride].x, from[0*stride].x);
+  return result;
+}
+
+template<> EIGEN_STRONG_INLINE void pscatter<Eigen::half, Packet4h>(Eigen::half* to, const Packet4h& from, Index stride)
+{
+  __int64_t a = _mm_cvtm64_si64(from.x);
+  to[stride*0].x = static_cast<unsigned short>(a);
+  to[stride*1].x = static_cast<unsigned short>(a >> 16);
+  to[stride*2].x = static_cast<unsigned short>(a >> 32);
+  to[stride*3].x = static_cast<unsigned short>(a >> 48);
+}
+
+EIGEN_STRONG_INLINE void
+ptranspose(PacketBlock<Packet4h,4>& kernel) {
+  __m64 T0 = _mm_unpacklo_pi16(kernel.packet[0].x, kernel.packet[1].x);
+  __m64 T1 = _mm_unpacklo_pi16(kernel.packet[2].x, kernel.packet[3].x);
+  __m64 T2 = _mm_unpackhi_pi16(kernel.packet[0].x, kernel.packet[1].x);
+  __m64 T3 = _mm_unpackhi_pi16(kernel.packet[2].x, kernel.packet[3].x);
+
+  kernel.packet[0].x = _mm_unpacklo_pi32(T0, T1);
+  kernel.packet[1].x = _mm_unpackhi_pi32(T0, T1);
+  kernel.packet[2].x = _mm_unpacklo_pi32(T2, T3);
+  kernel.packet[3].x = _mm_unpackhi_pi32(T2, T3);
+}
+
+#endif
+
+
 } // end namespace internal
 
 } // end namespace Eigen
diff --git a/Eigen/src/Core/arch/SSE/TypeCasting.h b/Eigen/src/Core/arch/SSE/TypeCasting.h
index f607366f0..1b8e9a550 100644
--- a/Eigen/src/Core/arch/SSE/TypeCasting.h
+++ b/Eigen/src/Core/arch/SSE/TypeCasting.h
@@ -77,6 +77,57 @@ template<> EIGEN_STRONG_INLINE Packet4f preinterpret<Packet4f,Packet4i>(const Pa
   return _mm_castsi128_ps(a);
 }
 
+
+// Disable the following code since it's broken on too many platforms / compilers.
+//#elif defined(EIGEN_VECTORIZE_SSE) && (!EIGEN_ARCH_x86_64) && (!EIGEN_COMP_MSVC)
+#if 0
+
+template <>
+struct type_casting_traits<Eigen::half, float> {
+  enum {
+    VectorizedCast = 1,
+    SrcCoeffRatio = 1,
+    TgtCoeffRatio = 1
+  };
+};
+
+template<> EIGEN_STRONG_INLINE Packet4f pcast<Packet4h, Packet4f>(const Packet4h& a) {
+  __int64_t a64 = _mm_cvtm64_si64(a.x);
+  Eigen::half h = raw_uint16_to_half(static_cast<unsigned short>(a64));
+  float f1 = static_cast<float>(h);
+  h = raw_uint16_to_half(static_cast<unsigned short>(a64 >> 16));
+  float f2 = static_cast<float>(h);
+  h = raw_uint16_to_half(static_cast<unsigned short>(a64 >> 32));
+  float f3 = static_cast<float>(h);
+  h = raw_uint16_to_half(static_cast<unsigned short>(a64 >> 48));
+  float f4 = static_cast<float>(h);
+  return _mm_set_ps(f4, f3, f2, f1);
+}
+
+template <>
+struct type_casting_traits<float, Eigen::half> {
+  enum {
+    VectorizedCast = 1,
+    SrcCoeffRatio = 1,
+    TgtCoeffRatio = 1
+  };
+};
+
+template<> EIGEN_STRONG_INLINE Packet4h pcast<Packet4f, Packet4h>(const Packet4f& a) {
+  EIGEN_ALIGN16 float aux[4];
+  pstore(aux, a);
+  Eigen::half h0(aux[0]);
+  Eigen::half h1(aux[1]);
+  Eigen::half h2(aux[2]);
+  Eigen::half h3(aux[3]);
+
+  Packet4h result;
+  result.x = _mm_set_pi16(h3.x, h2.x, h1.x, h0.x);
+  return result;
+}
+
+#endif
+
 } // end namespace internal
 
 } // end namespace Eigen
diff --git a/test/half_float.cpp b/test/half_float.cpp
index 2a7f9b497..48afdb21b 100644
--- a/test/half_float.cpp
+++ b/test/half_float.cpp
@@ -9,7 +9,7 @@
 
 #include "main.h"
 
-#include <Eigen/src/Core/arch/GPU/Half.h>
+#include <Eigen/src/Core/arch/Default/Half.h>
 
 // Make sure it's possible to forward declare Eigen::half
 namespace Eigen {