why no vsyscall support on x86 or i386 ?

Hi,

Why there is no vsyscall support on i386? I see it only on x86_64. In x86_64 it supports gettimeofday, etc.
In i386, it only uses to support the sysenter optimization. Why there is no support for gettimeofday in i386 as a vsyscall?

-Fredrick