diff --git a/Eigen/src/Core/GenericPacketMath.h b/Eigen/src/Core/GenericPacketMath.h
index 30878eda6..7979c3aff 100644
--- a/Eigen/src/Core/GenericPacketMath.h
+++ b/Eigen/src/Core/GenericPacketMath.h
@@ -324,13 +324,13 @@ preduxp(const Packet* vecs) { return vecs[0]; }
 template<typename Packet> EIGEN_DEVICE_FUNC inline typename unpacket_traits<Packet>::type predux(const Packet& a)
 { return a; }
 
-/** \internal \returns the sum of the elements of \a a by block of 4 elements.
+/** \internal \returns the sum of the elements of upper and lower half of \a a if \a a is larger than 4.
   * For a packet {a0, a1, a2, a3, a4, a5, a6, a7}, it returns a half packet {a0+a4, a1+a5, a2+a6, a3+a7}
   * For packet-size smaller or equal to 4, this boils down to a noop.
   */
 template<typename Packet> EIGEN_DEVICE_FUNC inline
 typename conditional<(unpacket_traits<Packet>::size%8)==0,typename unpacket_traits<Packet>::half,Packet>::type
-predux_downto4(const Packet& a)
+predux_half_dowto4(const Packet& a)
 { return a; }
 
 /** \internal \returns the product of the elements of \a a*/
diff --git a/Eigen/src/Core/arch/AVX/PacketMath.h b/Eigen/src/Core/arch/AVX/PacketMath.h
index 636230944..af31023f0 100644
--- a/Eigen/src/Core/arch/AVX/PacketMath.h
+++ b/Eigen/src/Core/arch/AVX/PacketMath.h
@@ -412,7 +412,7 @@ template<> EIGEN_STRONG_INLINE double predux<Packet4d>(const Packet4d& a)
   return predux(Packet2d(_mm_add_pd(_mm256_castpd256_pd128(a),_mm256_extractf128_pd(a,1))));
 }
 
-template<> EIGEN_STRONG_INLINE Packet4f predux_downto4<Packet8f>(const Packet8f& a)
+template<> EIGEN_STRONG_INLINE Packet4f predux_half_dowto4<Packet8f>(const Packet8f& a)
 {
   return _mm_add_ps(_mm256_castps256_ps128(a),_mm256_extractf128_ps(a,1));
 }
diff --git a/Eigen/src/Core/arch/AVX512/PacketMath.h b/Eigen/src/Core/arch/AVX512/PacketMath.h
index abece01bc..eb5de43d4 100644
--- a/Eigen/src/Core/arch/AVX512/PacketMath.h
+++ b/Eigen/src/Core/arch/AVX512/PacketMath.h
@@ -888,7 +888,7 @@ EIGEN_STRONG_INLINE double predux<Packet8d>(const Packet8d& a) {
 }
 
 template <>
-EIGEN_STRONG_INLINE Packet8f predux_downto4<Packet16f>(const Packet16f& a) {
+EIGEN_STRONG_INLINE Packet8f predux_half_dowto4<Packet16f>(const Packet16f& a) {
 #ifdef EIGEN_VECTORIZE_AVX512DQ
   __m256 lane0 = _mm512_extractf32x8_ps(a, 0);
   __m256 lane1 = _mm512_extractf32x8_ps(a, 1);
@@ -904,7 +904,7 @@ EIGEN_STRONG_INLINE Packet8f predux_downto4<Packet16f>(const Packet16f& a) {
 #endif
 }
 template <>
-EIGEN_STRONG_INLINE Packet4d predux_downto4<Packet8d>(const Packet8d& a) {
+EIGEN_STRONG_INLINE Packet4d predux_half_dowto4<Packet8d>(const Packet8d& a) {
   __m256d lane0 = _mm512_extractf64x4_pd(a, 0);
   __m256d lane1 = _mm512_extractf64x4_pd(a, 1);
   __m256d res = _mm256_add_pd(lane0, lane1);
diff --git a/Eigen/src/Core/products/GeneralBlockPanelKernel.h b/Eigen/src/Core/products/GeneralBlockPanelKernel.h
index 9072d0ff3..dd4f366ee 100644
--- a/Eigen/src/Core/products/GeneralBlockPanelKernel.h
+++ b/Eigen/src/Core/products/GeneralBlockPanelKernel.h
@@ -580,7 +580,7 @@ DoublePacket<Packet> padd(const DoublePacket<Packet> &a, const DoublePacket<Pack
 }
 
 template<typename Packet>
-const DoublePacket<Packet>& predux_downto4(const DoublePacket<Packet> &a)
+const DoublePacket<Packet>& predux_half_dowto4(const DoublePacket<Packet> &a)
 {
   return a;
 }
@@ -1596,13 +1596,13 @@ void gebp_kernel<LhsScalar,RhsScalar,Index,DataMapper,mr,nr,ConjugateLhs,Conjuga
                 SRhsPacketHalf b0;
                 straits.loadLhsUnaligned(blB, a0);
                 straits.loadRhs(blA, b0);
-                SAccPacketHalf c0 = predux_downto4(C0);
+                SAccPacketHalf c0 = predux_half_dowto4(C0);
                 straits.madd(a0,b0,c0,b0);
                 straits.acc(c0, alphav, R);
               }
               else
               {
-                straits.acc(predux_downto4(C0), alphav, R);
+                straits.acc(predux_half_dowto4(C0), alphav, R);
               }
               res.scatterPacket(i, j2, R);
             }
diff --git a/test/packetmath.cpp b/test/packetmath.cpp
index 31a524af3..53838920e 100644
--- a/test/packetmath.cpp
+++ b/test/packetmath.cpp
@@ -253,8 +253,8 @@ template<typename Scalar> void packetmath()
       ref[i] = 0;
     for (int i=0; i<PacketSize; ++i)
       ref[i%HalfPacketSize] += data1[i];
-    internal::pstore(data2, internal::predux_downto4(internal::pload<Packet>(data1)));
-    VERIFY(areApprox(ref, data2, HalfPacketSize) && "internal::predux_downto4");
+    internal::pstore(data2, internal::predux_half_dowto4(internal::pload<Packet>(data1)));
+    VERIFY(areApprox(ref, data2, HalfPacketSize) && "internal::predux_half_dowto4");
   }
 
   ref[0] = 1;