Allow VortexM4 on the direct_SME fast path only for clang-based compilers

Author: martin-frbg

interface/gemm.c

@@ -555,7 +555,11 @@ void CNAME(enum CBLAS_ORDER order, enum CBLAS_TRANSPOSE TransA, enum CBLAS_TRANS
 #endif
 #if defined(ARCH_ARM64) && (defined(USE_SGEMM_KERNEL_DIRECT)||defined(DYNAMIC_ARCH))
 #if defined(DYNAMIC_ARCH)
-if (strcmp(gotoblas_corename(), "armv9sme") == 0 || strcmp(gotoblas_corename(), "vortexm4") == 0)
+if (strcmp(gotoblas_corename(), "armv9sme") == 0
+#if defined(__clang__)
+ || strcmp(gotoblas_corename(), "vortexm4") == 0
+#endif
+)
 // if (support_sme1())
 #endif
   if (order == CblasRowMajor && m==lda && n ==ldb && k==ldc && beta == 0 && alpha == 1.0 && TransA == CblasNoTrans && TransB == CblasNoTrans&& SGEMM_DIRECT_PERFORMANT(m,n,k)) {