[FIX] [MSVC] Enabling SIMD functionality for VS2019

Author: mandrono

src/common/dnnl_thread.hpp

@@ -184,8 +184,11 @@ inline int dnnl_get_current_num_threads() {
 #define OMP_GET_NUM_THREADS() 1
 #endif
 
-// MSVC still supports omp 2.0 only
-#if defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+/* MSVC still supports omp 2.0 only,
+   however VS2019 also now offers SIMD functionality
+   with the -openmp:experimental compilation switch that enables additional OpenMP features
+   not available when using the -openmp switch */
+#if defined(_MSC_VER) && (_MSC_VER < 1900) && !defined(__clang__) && !defined(__INTEL_COMPILER)
 #define collapse(x)
 #define PRAGMA_OMP_SIMD(...)
 #else

src/cpu/gemm/f32/ref_gemm_f32.cpp

@@ -38,7 +38,10 @@ template <typename data_t>
 void copy_A(
         bool isTransA, dim_t K, const data_t *A, const dim_t lda, data_t *ws) {
     for (dim_t k = 0; k < K; k++) {
+#if !defined(_MSC_VER)
+        // Compilation with '#pragma omp simd' in this place on VS2019 to lead to fatal error C1001
         PRAGMA_OMP_SIMD()
+#endif
         for (dim_t i = 0; i < unroll_factor<data_t>::m; i++) {
             ws[i] = isTransA ? A[i * lda + k] : A[i + k * lda];
         }