diff --git a/Eigen/src/Core/arch/AltiVec/MatrixProductMMA.h b/Eigen/src/Core/arch/AltiVec/MatrixProductMMA.h
index 37db1a6f1..64f11727f 100644
--- a/Eigen/src/Core/arch/AltiVec/MatrixProductMMA.h
+++ b/Eigen/src/Core/arch/AltiVec/MatrixProductMMA.h
@@ -212,12 +212,18 @@ template<>
 EIGEN_STRONG_INLINE void pgerMMA<Packet4f, __vector_pair, false>(__vector_quad *acc, const __vector_pair& a, const Packet4f& b)
 {
   // Just for compilation
+  EIGEN_UNUSED_VARIABLE(acc)
+  EIGEN_UNUSED_VARIABLE(a)
+  EIGEN_UNUSED_VARIABLE(b)
 }
 
 template<>
 EIGEN_STRONG_INLINE void pgerMMA<Packet4f, __vector_pair, true>(__vector_quad *acc, const __vector_pair& a, const Packet4f& b)
 {
   // Just for compilation
+  EIGEN_UNUSED_VARIABLE(acc)
+  EIGEN_UNUSED_VARIABLE(a)
+  EIGEN_UNUSED_VARIABLE(b)
 }
 
 // This is necessary because ploadRhs for double returns a pair of vectors when MMA is enabled.
diff --git a/Eigen/src/Core/arch/Default/BFloat16.h b/Eigen/src/Core/arch/Default/BFloat16.h
index 81af56a3f..3c0cd39df 100644
--- a/Eigen/src/Core/arch/Default/BFloat16.h
+++ b/Eigen/src/Core/arch/Default/BFloat16.h
@@ -67,7 +67,7 @@ struct bfloat16 : public bfloat16_impl::bfloat16_base {
       : bfloat16_impl::bfloat16_base(bfloat16_impl::raw_uint16_to_bfloat16(b ? 0x3f80 : 0)) {}
 
   template<class T>
-  explicit EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR bfloat16(const T& val)
+  explicit EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR bfloat16(T val)
       : bfloat16_impl::bfloat16_base(bfloat16_impl::float_to_bfloat16_rtne<internal::is_integral<T>::value>(static_cast<float>(val))) {}
 
   explicit EIGEN_DEVICE_FUNC bfloat16(float f)
diff --git a/Eigen/src/Core/arch/Default/Half.h b/Eigen/src/Core/arch/Default/Half.h
index c91b0ce2f..3779ebc98 100644
--- a/Eigen/src/Core/arch/Default/Half.h
+++ b/Eigen/src/Core/arch/Default/Half.h
@@ -147,7 +147,7 @@ struct half : public half_impl::half_base {
   explicit EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR half(bool b)
       : half_impl::half_base(half_impl::raw_uint16_to_half(b ? 0x3c00 : 0)) {}
   template<class T>
-  explicit EIGEN_DEVICE_FUNC half(const T& val)
+  explicit EIGEN_DEVICE_FUNC half(T val)
       : half_impl::half_base(half_impl::float_to_half_rtne(static_cast<float>(val))) {}
   explicit EIGEN_DEVICE_FUNC half(float f)
       : half_impl::half_base(half_impl::float_to_half_rtne(f)) {}
diff --git a/test/array_cwise.cpp b/test/array_cwise.cpp
index 92abf6968..6a88e0e27 100644
--- a/test/array_cwise.cpp
+++ b/test/array_cwise.cpp
@@ -25,7 +25,7 @@ void pow_test() {
   const Scalar denorm_min = std::numeric_limits<Scalar>::denorm_min();
   const Scalar min = (std::numeric_limits<Scalar>::min)();
   const Scalar max = (std::numeric_limits<Scalar>::max)();
-  const Scalar max_exp = (static_cast<Scalar>(std::numeric_limits<Scalar>::max_exponent) * Scalar(EIGEN_LN2)) / eps;
+  const Scalar max_exp = (static_cast<Scalar>(int(std::numeric_limits<Scalar>::max_exponent)) * Scalar(EIGEN_LN2)) / eps;
 
   const static Scalar abs_vals[] = {zero,
                                     denorm_min,