Sycl gemv beta (#2276)

* BLAS - GEMV: zero out Y when beta == 0 in SYCL TPL code path

* BLAS - GEMV: reverting wrong change from previous PR, my bad.

* Applying clang-format

Author: lucbv

blas/src/KokkosBlas2_gemv.hpp

@@ -165,9 +165,8 @@ void gemv(const ExecutionSpace& space, const char trans[],
   // oneMKL supports both row-major and column-major of A
   // but only supports oneapi::mkl::transpose::nontrans op
   useFallback =
-      useFallback || ((tolower(*trans) == 't' || tolower(*trans) == 'c') &&
-                      std::is_same_v<typename AViewType::memory_space,
-                                     Kokkos::Experimental::SYCLDeviceUSMSpace>);
+      useFallback || !std::is_same_v<typename AViewType::memory_space,
+                                     Kokkos::Experimental::SYCLDeviceUSMSpace>;
 #endif
 #endif
 

blas/tpls/KokkosBlas2_gemv_tpl_spec_decl.hpp

@@ -824,6 +824,10 @@ struct kokkos_to_std_type_map<T, true> {
                      const AViewType& A, const XViewType& X,                   \
                      typename YViewType::const_value_type& beta,               \
                      const YViewType& Y) {                                     \
+      if (beta == Kokkos::ArithTraits<SCALAR>::zero()) {                       \
+        Kokkos::deep_copy(Y, Kokkos::ArithTraits<SCALAR>::zero());             \
+      }                                                                        \
+                                                                               \
       bool row_major       = std::is_same<Kokkos::LayoutRight, LAYOUT>::value; \
       const std::int64_t M = A.extent(0);                                      \
       const std::int64_t N = A.extent(1);                                      \