RE: [PATCH v3 3/6] x86/gsseg: make asm_load_gs_index() take an u16

Li, Xin3
2022-10-15T00:15:41Z

> >
> > From: "H. Peter Anvin (Intel)" <hpa@zytor.com>
> >
> > Let gcc know that only the low 16 bits of load_gs_index() argument
> > actually matter. It might allow it to create slightly better code.
> > However, do not propagate this into the prototypes of functions that
> > end up being paravirtualized, to avoid unnecessary changes.
>
> Using u16 will almost always make the code worse.
> At some point the value has to be masked and/or extended to ensure an out of
> range value doesn't appear in a register.

Any potential issue with this patch set?

>
> David
>
> -
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