[SYCL Function pointer Issue]: SYCL does not support function pointer inside the kernel, due to the portability issue of a function pointer and memory address space among host and accelerators. To fix the issue, function pointers have been replaced by function objects.

Eigen/src/Core/arch/SYCL/InteropHeaders.h

@@ -59,6 +59,9 @@ struct sycl_packet_traits : default_packet_traits {
     HasIGammac = 0,
     HasBetaInc = 0,
     HasBlend = has_blend,
+    // This flag is used to indicate whether packet comparison is supported.
+    // pcmp_eq, pcmp_lt and pcmp_le should be defined for it to be true.
+    HasCmp = 1,
     HasMax = 1,
     HasMin = 1,
     HasMul = 1,

Eigen/src/Core/arch/SYCL/MathFunctions.h

@@ -20,7 +20,6 @@
 
 #ifndef EIGEN_MATH_FUNCTIONS_SYCL_H
 #define EIGEN_MATH_FUNCTIONS_SYCL_H
-
 namespace Eigen {
 
 namespace internal {
@@ -238,7 +237,7 @@ SYCL_PROUND(cl::sycl::cl_double2)
 #undef SYCL_PROUND
 
 #define SYCL_PRINT(packet_type)                                         \
-  template<>                                                            \
+  template <>                                                           \
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE packet_type print<packet_type>( \
       const packet_type& a) {                                           \
     return cl::sycl::rint(a);                                           \
@@ -295,7 +294,6 @@ SYCL_PLDEXP(cl::sycl::cl_double2)
 #undef SYCL_PLDEXP
 
 #endif
-
 }  // end namespace internal
 
 }  // end namespace Eigen