diff --git a/Eigen/src/Core/arch/AltiVec/MatrixProduct.h b/Eigen/src/Core/arch/AltiVec/MatrixProduct.h
index 1c8551c04..2919dda8b 100644
--- a/Eigen/src/Core/arch/AltiVec/MatrixProduct.h
+++ b/Eigen/src/Core/arch/AltiVec/MatrixProduct.h
@@ -193,7 +193,7 @@ EIGEN_STRONG_INLINE void symm_pack_complex_lhs_helper(std::complex<Scalar>* bloc
   const_blas_data_mapper<std::complex<Scalar>, Index, StorageOrder> lhs(_lhs, lhsStride);
   const Index vectorSize = quad_traits<Scalar>::vectorsize;
   const Index vectorDelta = vectorSize * depth;
-  Scalar* blockAf = (Scalar *)(blockA);
+  Scalar* blockAf = reinterpret_cast<Scalar *>(blockA);
 
   Index rir = 0, rii, j = 0;
   for(; j + vectorSize <= rows; j+=vectorSize)
@@ -1269,8 +1269,8 @@ const static Packet4i mask43 = { -1, -1, -1,  0 };
 
 const static Packet2l mask21 = { -1, 0 };
 
-template<typename Packet>
-EIGEN_ALWAYS_INLINE Packet bmask(const int remaining_rows)
+template<typename Packet, typename Index>
+EIGEN_ALWAYS_INLINE Packet bmask(const Index remaining_rows)
 {
   if (remaining_rows == 0) {
     return pset1<Packet>(float(0.0));  // Not used
@@ -1284,7 +1284,7 @@ EIGEN_ALWAYS_INLINE Packet bmask(const int remaining_rows)
 }
 
 template<>
-EIGEN_ALWAYS_INLINE Packet2d bmask<Packet2d>(const int remaining_rows)
+EIGEN_ALWAYS_INLINE Packet2d bmask<Packet2d,Index>(const Index remaining_rows)
 {
   if (remaining_rows == 0) {
     return pset1<Packet2d>(double(0.0));  // Not used
@@ -1748,7 +1748,7 @@ EIGEN_STRONG_INLINE void gemm(const DataMapper& res, const Scalar* blockA, const
       if( strideB == -1 ) strideB = depth;
 
       const Packet pAlpha = pset1<Packet>(alpha);
-      const Packet pMask  = bmask<Packet>((const int)(remaining_rows));
+      const Packet pMask  = bmask<Packet>(remaining_rows);
 
       Index col = 0;
       for(; col + accRows <= cols; col += accRows)
@@ -2208,7 +2208,7 @@ EIGEN_STRONG_INLINE void gemm_complex(const DataMapper& res, const LhsScalar* bl
 
       const Packet pAlphaReal = pset1<Packet>(alpha.real());
       const Packet pAlphaImag = pset1<Packet>(alpha.imag());
-      const Packet pMask = bmask<Packet>((const int)(remaining_rows));
+      const Packet pMask = bmask<Packet>(remaining_rows);
 
       const Scalar* blockA = (Scalar *) blockAc;
       const Scalar* blockB = (Scalar *) blockBc;
diff --git a/Eigen/src/Core/arch/AltiVec/MatrixProductCommon.h b/Eigen/src/Core/arch/AltiVec/MatrixProductCommon.h
index 768d9c7c4..d92b67815 100644
--- a/Eigen/src/Core/arch/AltiVec/MatrixProductCommon.h
+++ b/Eigen/src/Core/arch/AltiVec/MatrixProductCommon.h
@@ -44,8 +44,8 @@ EIGEN_STRONG_INLINE void gemm_extra_cols(
   const Packet& pAlpha,
   const Packet& pMask);
 
-template<typename Packet>
-EIGEN_ALWAYS_INLINE Packet bmask(const int remaining_rows);
+template<typename Packet, typename Index>
+EIGEN_ALWAYS_INLINE Packet bmask(const Index remaining_rows);
 
 template<typename Scalar, typename Packet, typename Packetc, typename DataMapper, typename Index, const Index accRows, const Index accCols, bool ConjugateLhs, bool ConjugateRhs, bool LhsIsReal, bool RhsIsReal>
 EIGEN_ALWAYS_INLINE void gemm_complex_extra_row(
@@ -87,7 +87,7 @@ template<typename Scalar, typename Packet>
 EIGEN_ALWAYS_INLINE Packet ploadLhs(const Scalar* lhs);
 
 template<typename DataMapper, typename Packet, typename Index, const Index accCols, int StorageOrder, bool Complex, int N>
-EIGEN_ALWAYS_INLINE void bload(PacketBlock<Packet,N>& acc, const DataMapper& res, Index row, Index col);
+EIGEN_ALWAYS_INLINE void bload(PacketBlock<Packet,N*(Complex?2:1)>& acc, const DataMapper& res, Index row, Index col);
 
 template<typename Packet, int N>
 EIGEN_ALWAYS_INLINE void bscale(PacketBlock<Packet,N>& acc, PacketBlock<Packet,N>& accZ, const Packet& pAlpha);
diff --git a/Eigen/src/Core/arch/AltiVec/MatrixProductMMA.h b/Eigen/src/Core/arch/AltiVec/MatrixProductMMA.h
index 9a3132276..8104697a1 100644
--- a/Eigen/src/Core/arch/AltiVec/MatrixProductMMA.h
+++ b/Eigen/src/Core/arch/AltiVec/MatrixProductMMA.h
@@ -11,7 +11,9 @@
 #ifndef EIGEN_MATRIX_PRODUCT_MMA_ALTIVEC_H
 #define EIGEN_MATRIX_PRODUCT_MMA_ALTIVEC_H
 
+#if !EIGEN_COMP_LLVM
 #pragma GCC target("cpu=power10,htm")
+#endif
 
 #ifdef __has_builtin
 #if !__has_builtin(__builtin_vsx_assemble_pair)
@@ -80,7 +82,7 @@ EIGEN_ALWAYS_INLINE void pgerMMA(__vector_quad* acc, const RhsPacket& a, const L
 template<typename LhsPacket, typename RhsPacket, bool NegativeAccumulate>
 EIGEN_ALWAYS_INLINE void pgerMMA(__vector_quad* acc, const PacketBlock<Packet2d,2>& a, const Packet2d& b)
 {
-  __vector_pair* a0 = (__vector_pair *)(&a.packet[0]);
+  __vector_pair* a0 = reinterpret_cast<__vector_pair *>(const_cast<Packet2d *>(&a.packet[0]));
   if(NegativeAccumulate)
   {
     __builtin_mma_xvf64gernp(acc, *a0, (__vector unsigned char)b);
@@ -133,8 +135,8 @@ EIGEN_ALWAYS_INLINE void ploadRhsMMA(const Scalar* rhs, Packet& rhsV)
 template<>
 EIGEN_ALWAYS_INLINE void ploadRhsMMA<double, PacketBlock<Packet2d, 2> >(const double* rhs, PacketBlock<Packet2d, 2>& rhsV)
 {
-  rhsV.packet[0] = ploadRhs<double, Packet2d>((const double *)((Packet2d *)rhs      ));
-  rhsV.packet[1] = ploadRhs<double, Packet2d>((const double *)(((Packet2d *)rhs) + 1));
+  rhsV.packet[0] = ploadRhs<double, Packet2d>(rhs);
+  rhsV.packet[1] = ploadRhs<double, Packet2d>(rhs + (sizeof(Packet2d) / sizeof(double)));
 }
 
 template<>
@@ -142,8 +144,8 @@ EIGEN_ALWAYS_INLINE void ploadRhsMMA<double, __vector_pair>(const double* rhs, _
 {
 #if EIGEN_COMP_LLVM
   __builtin_vsx_assemble_pair(&rhsV,
-    (__vector unsigned char)(ploadRhs<double, Packet2d>((const double *)(((Packet2d *)rhs) + 1))),
-    (__vector unsigned char)(ploadRhs<double, Packet2d>((const double *)((Packet2d *)rhs      ))));
+    reinterpret_cast<__vector unsigned char>(ploadRhs<double, Packet2d>(rhs + (sizeof(Packet2d) / sizeof(double)))),
+    reinterpret_cast<__vector unsigned char>(ploadRhs<double, Packet2d>(rhs)));
 #else
   __asm__ ("lxvp %x0,%1" : "=wa" (rhsV) : "Y" (*rhs));
 #endif
@@ -360,7 +362,7 @@ void gemmMMA(const DataMapper& res, const Scalar* blockA, const Scalar* blockB,
       if( strideB == -1 ) strideB = depth;
 
       const Packet pAlpha = pset1<Packet>(alpha);
-      const Packet pMask  = bmask<Packet>((const int)(remaining_rows));
+      const Packet pMask  = bmask<Packet>(remaining_rows);
 
       Index col = 0;
       for(; col + accRows <= cols; col += accRows)
@@ -595,7 +597,7 @@ void gemm_complexMMA(const DataMapper& res, const LhsScalar* blockAc, const RhsS
 
       const Packet pAlphaReal = pset1<Packet>(alpha.real());
       const Packet pAlphaImag = pset1<Packet>(alpha.imag());
-      const Packet pMask = bmask<Packet>((const int)(remaining_rows));
+      const Packet pMask = bmask<Packet>(remaining_rows);
 
       const Scalar* blockA = (Scalar *) blockAc;
       const Scalar* blockB = (Scalar *) blockBc;
@@ -613,7 +615,9 @@ void gemm_complexMMA(const DataMapper& res, const LhsScalar* blockAc, const RhsS
 #undef advanceRows
 #undef advanceCols
 
+#if !EIGEN_COMP_LLVM
 #pragma GCC reset_options
+#endif
 } // end namespace internal
 
 } // end namespace Eigen
diff --git a/Eigen/src/Core/arch/AltiVec/MatrixVectorProduct.h b/Eigen/src/Core/arch/AltiVec/MatrixVectorProduct.h
index 86ce4631d..d40ae534f 100644
--- a/Eigen/src/Core/arch/AltiVec/MatrixVectorProduct.h
+++ b/Eigen/src/Core/arch/AltiVec/MatrixVectorProduct.h
@@ -167,7 +167,7 @@ EIGEN_ALWAYS_INLINE void storeMaddData(ResScalar* res, ResScalar& alpha, ResScal
   if (GEMV_GETN(N) > iter1) { \
     if (GEMV_IS_FLOAT) { \
       LhsPacket h[2]; \
-      __builtin_vsx_disassemble_pair((void*)(h), &b##iter2); \
+      __builtin_vsx_disassemble_pair(reinterpret_cast<void*>(h), &b##iter2); \
       pger_vecMMA_acc<LhsPacket, RhsPacket, true>(&e##iter2, a0, h[0]); \
       pger_vecMMA_acc<LhsPacket, RhsPacket, true>(&e##iter3, a0, h[1]); \
     } else { \
@@ -302,6 +302,8 @@ EIGEN_ALWAYS_INLINE void storeMaddData(ResScalar* res, ResScalar& alpha, ResScal
 #define GEMV_INIT(iter, N) \
   if (N > iter) { \
     c##iter = pset1<ResPacket>(ResScalar(0)); \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(c##iter); \
   }
 
 #ifdef EIGEN_POWER_USE_GEMV_PREFETCH
@@ -407,9 +409,11 @@ EIGEN_STRONG_INLINE void gemv_col(
         RhsPacketSize = Traits::RhsPacketSize,
     };
 
+#ifndef GCC_ONE_VECTORPAIR_BUG
     const Index n8 = rows - 8 * ResPacketSize + 1;
     const Index n4 = rows - 4 * ResPacketSize + 1;
     const Index n2 = rows - 2 * ResPacketSize + 1;
+#endif
     const Index n1 = rows - 1 * ResPacketSize + 1;
 #ifdef EIGEN_POWER_USE_GEMV_PREFETCH
     const Index prefetch_dist = 64 * LhsPacketSize;
@@ -1289,10 +1293,10 @@ EIGEN_ALWAYS_INLINE void gemv_mult_complex_MMA(LhsType& a0, RhsType* b, __vector
     gemv_mult_complex_real_MMA<ScalarPacket, LhsPacket, SLhsPacket, RhsScalar, ResPacket, ConjugateLhs, ConjugateRhs, StorageOrder>(a0, b, c0); \
 }
 
-GEMV_MULT_COMPLEX_REAL_MMA(Packet2cf,     float);
-GEMV_MULT_COMPLEX_REAL_MMA(Packet1cd,     double);
-GEMV_MULT_COMPLEX_REAL_MMA(__vector_pair, float);
-GEMV_MULT_COMPLEX_REAL_MMA(__vector_pair, double);
+GEMV_MULT_COMPLEX_REAL_MMA(Packet2cf,     float)
+GEMV_MULT_COMPLEX_REAL_MMA(Packet1cd,     double)
+GEMV_MULT_COMPLEX_REAL_MMA(__vector_pair, float)
+GEMV_MULT_COMPLEX_REAL_MMA(__vector_pair, double)
 
 /** \internal disassemble MMA accumulator results into packets */
 template <typename Scalar, typename ScalarPacket, typename LhsPacket, typename RhsPacket, bool ConjugateLhs, bool ConjugateRhs>
@@ -1439,7 +1443,7 @@ EIGEN_ALWAYS_INLINE void disassembleResults(__vector_quad* c0, PacketBlock<Scala
   if (GEMV_GETN_COMPLEX(N) > iter1) { \
     if (GEMV_IS_COMPLEX_FLOAT) { \
       PLhsPacket g[2]; \
-      __builtin_vsx_disassemble_pair((void*)(g), &a##iter2); \
+      __builtin_vsx_disassemble_pair(reinterpret_cast<void*>(g), &a##iter2); \
       gemv_mult_complex_MMA<ScalarPacket, LhsScalar, PLhsPacket, PLhsPacket, RhsScalar, RhsPacket, ResPacket, ConjugateLhs, ConjugateRhs, ColMajor>(g[0], b, &e0##iter2); \
       gemv_mult_complex_MMA<ScalarPacket, LhsScalar, PLhsPacket, PLhsPacket, RhsScalar, RhsPacket, ResPacket, ConjugateLhs, ConjugateRhs, ColMajor>(g[1], b, &e0##iter3); \
     } else { \
@@ -1525,12 +1529,17 @@ EIGEN_ALWAYS_INLINE void disassembleResults(__vector_quad* c0, PacketBlock<Scala
   if (N > iter) { \
     c0##iter = pset_zero<PResPacket>(); \
     c1##iter = pset_init<ResPacket, LhsPacket, RhsPacket>(c1##iter); \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(c0##iter); \
+    EIGEN_UNUSED_VARIABLE(c1##iter); \
   }
 
 #define GEMV_WORK_COL_COMPLEX(iter, N) \
   if (N > iter) { \
     f##iter = GEMV_LOADPACKET_COL_COMPLEX(iter); \
     gemv_mult_complex<ScalarPacket, PLhsPacket, RhsScalar, RhsPacket, PResPacket, ResPacket, ConjugateLhs, ConjugateRhs, ColMajor>(f##iter, b, c0##iter, c1##iter); \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(f##iter); \
   }
 
 #define GEMV_STORE_COL_COMPLEX(iter, N) \
@@ -1616,9 +1625,11 @@ EIGEN_STRONG_INLINE void gemv_complex_col(
     const Index prefetch_dist = 64 * LhsPacketSize;
 #endif
 
+#ifndef GCC_ONE_VECTORPAIR_BUG
     const Index n8 = rows - 8 * ResPacketSize + 1;
     const Index n4 = rows - 4 * ResPacketSize + 1;
     const Index n2 = rows - 2 * ResPacketSize + 1;
+#endif
     const Index n1 = rows - 1 * ResPacketSize + 1;
 
     // TODO: improve the following heuristic:
@@ -1661,10 +1672,10 @@ EIGEN_STRONG_INLINE void gemv_complex_col(
         {
             GEMV_PROCESS_COL_COMPLEX(2)
         }
+        if (i < n1)
 #else
         while (i < n1)
 #endif
-        if (i < n1)
         {
             GEMV_PROCESS_COL_COMPLEX_ONE(1)
         }
@@ -1861,11 +1872,15 @@ EIGEN_ALWAYS_INLINE ScalarBlock<ResScalar, 2> predux_complex(ResPacket& a, ResPa
     } else { \
       cc##iter1 = predux_real<ResScalar, ResPacket>(&c##iter1); \
     } \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(cc##iter1); \
   }
 #else
 #define GEMV_INIT_ROW(iter, N) \
   if (N > iter) { \
     c##iter = pset1<ResPacket>(ResScalar(0)); \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(c##iter); \
   }
 
 #define GEMV_WORK_ROW(iter, N) \
@@ -1876,6 +1891,8 @@ EIGEN_ALWAYS_INLINE ScalarBlock<ResScalar, 2> predux_complex(ResPacket& a, ResPa
 #define GEMV_PREDUX2(iter1, iter2, iter3, N) \
   if (N > iter1) { \
     cc##iter1 = predux_real<ResScalar, ResPacket>(c##iter2, c##iter3); \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(cc##iter1); \
   }
 #endif
 
@@ -1933,9 +1950,11 @@ EIGEN_STRONG_INLINE void gemv_row(
 
     // TODO: fine tune the following heuristic. The rationale is that if the matrix is very large,
     //       processing 8 rows at once might be counter productive wrt cache.
+#ifndef GCC_ONE_VECTORPAIR_BUG
     const Index n8 = lhs.stride() * sizeof(LhsScalar) > 32000 ? (rows - 7) : (rows - 7);
     const Index n4 = rows - 3;
     const Index n2 = rows - 1;
+#endif
 
     // TODO: for padded aligned inputs, we could enable aligned reads
     enum {
@@ -1952,8 +1971,8 @@ EIGEN_STRONG_INLINE void gemv_row(
 #else
     ResPacket c0, c1, c2, c3, c4, c5, c6, c7;
 #endif
-    ScalarBlock<ResScalar, 2> cc0, cc1, cc2, cc3;
 #ifndef GCC_ONE_VECTORPAIR_BUG
+    ScalarBlock<ResScalar, 2> cc0, cc1, cc2, cc3;
     GEMV_PROCESS_ROW(8)
     GEMV_PROCESS_ROW(4)
     GEMV_PROCESS_ROW(2)
@@ -2061,6 +2080,8 @@ EIGEN_ALWAYS_INLINE ScalarBlock<ResScalar, 2> predux_complex(PResPacket& a0, PRe
     } else { \
       cc##iter1 = predux_complex<ResScalar, ScalarPacket, LhsPacket, RhsPacket, ConjugateLhs, ConjugateRhs>(&e0##iter1); \
     } \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(cc##iter1); \
   }
 
 #define GEMV_PROCESS_ROW_COMPLEX_SINGLE_MMA(N) \
@@ -2084,6 +2105,8 @@ EIGEN_ALWAYS_INLINE ScalarBlock<ResScalar, 2> predux_complex(PResPacket& a0, PRe
 #define GEMV_PREDUX4_COMPLEX(iter1, iter2, iter3, N) \
   if (N > iter1) { \
     cc##iter1 = predux_complex<ResScalar, PResPacket, ResPacket, LhsPacket, RhsPacket>(c0##iter2, c0##iter3, c1##iter2, c1##iter3); \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(cc##iter1); \
   }
 
 #define GEMV_MULT_COMPLEX(iter1, iter2, iter3, N) \
@@ -2133,9 +2156,11 @@ EIGEN_ALWAYS_INLINE ScalarBlock<ResScalar, 2> predux_complex(PResPacket& a0, PRe
   lhs.template load<LhsPacket, LhsAlignment>(i + (iter), j)
 
 #define GEMV_INIT_COMPLEX_OLD(iter, N) \
+  EIGEN_UNUSED_VARIABLE(c0##iter); \
   if (N > iter) { \
     c1##iter = pset_zero<ResPacket>(); \
-    EIGEN_UNUSED_VARIABLE(c0##iter); \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(c1##iter); \
   }
 
 #define GEMV_WORK_ROW_COMPLEX_OLD(iter, N) \
@@ -2148,6 +2173,8 @@ EIGEN_ALWAYS_INLINE ScalarBlock<ResScalar, 2> predux_complex(PResPacket& a0, PRe
   if (N > iter1) { \
     cc##iter1.scalar[0] = predux(c1##iter2); \
     cc##iter1.scalar[1] = predux(c1##iter3); \
+  } else { \
+    EIGEN_UNUSED_VARIABLE(cc##iter1); \
   }
 
 #define GEMV_PROCESS_ROW_COMPLEX_SINGLE_OLD(N) \
@@ -2237,9 +2264,11 @@ EIGEN_STRONG_INLINE void gemv_complex_row(
 
     // TODO: fine tune the following heuristic. The rationale is that if the matrix is very large,
     //       processing 8 rows at once might be counter productive wrt cache.
+#ifndef GCC_ONE_VECTORPAIR_BUG
     const Index n8 = lhs.stride() * sizeof(LhsScalar) > 32000 ? (rows - 7) : (rows - 7);
     const Index n4 = rows - 3;
     const Index n2 = rows - 1;
+#endif
 
     // TODO: for padded aligned inputs, we could enable aligned reads
     enum {
@@ -2258,12 +2287,12 @@ EIGEN_STRONG_INLINE void gemv_complex_row(
     GEMV_UNUSED_EXTRA(1, c0)
     GEMV_UNUSED_EXTRA(1, c1)
 #endif
-    ScalarBlock<ResScalar, 2> cc0, cc1, cc2, cc3;
     ResScalar dd0;
-#if !defined(GCC_ONE_VECTORPAIR_BUG) && defined(USE_GEMV_MMA)
+#ifndef GCC_ONE_VECTORPAIR_BUG
+    ScalarBlock<ResScalar, 2> cc0, cc1, cc2, cc3;
+#ifdef USE_GEMV_MMA
     if (!GEMV_IS_COMPLEX_COMPLEX)
 #endif
-#ifndef GCC_ONE_VECTORPAIR_BUG
     {
         GEMV_PROCESS_ROW_COMPLEX(8)
     }