preset optimization level for apple clang
-//#if defined(__apple_build_version__) && __clang_major__ == 11 && __clang_minor__ == 0 && __clang_patchlevel__ == 3
-//#pragma clang optimize off
-//#endif
+#if defined(__apple_build_version__) && __clang_major__ == 11 && __clang_minor__ == 0 && __clang_patchlevel__ == 3
+#pragma clang optimize "O2"
+#endif
/* %0 = "+r"(a_pointer), %1 = "+r"(b_pointer), %2 = "+r"(c_pointer), %3 = "+r"(ldc_in_bytes), %4 for k_count, %5 for c_store */
