Clang compiler (x86): 80 bit long double

I'm trying to use native 80 bit long double on x86 Windows platform. The GCC option -mlong-double-80 doesn't seem to work with clang. I tried

clang -target i386-windows -mlong-double-80 -c -O3 "test.c"

But the compiler shows me the error:

clang: error: unknown argument: '-mlong-double-80'