- netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";;
- *) gl_cv_func_frexp_works="guessing yes";;
+ netbsd* | irix*) gl_cv_func_frexp_works="guessing no" ;;
+ mingw*) # Guess yes with MSVC, no with mingw.
+ AC_EGREP_CPP([Good], [
+#ifdef _MSC_VER
+ Good
+#endif
+ ],
+ [gl_cv_func_frexp_works="guessing yes"],
+ [gl_cv_func_frexp_works="guessing no"])
+ ;;
+ *) gl_cv_func_frexp_works="guessing yes" ;;