On Sun, 2002-08-04 at 21:43, Luca Barbieri wrote:
> > When we use MMX/SSE we need the view to be consistent anyway so the
> > various copying routines already handle this internally.
> That's why sfence is not used unless CONFIG_X86_OOSTORE (and
> CONFIG_X86_MMXEXT) is defined.
> mfence and lfence instead replace the "lock; addl $0,0(%%esp)". Is this
> wrong?
I'm trying to understand why you think they are needed at all. Except
for code that specifically does non-temporal we don't need fences on an
X86, and the code that uses non temporal stores has its own fences built
in.
So as far as I can see the only cases we ever have to care about are
PPro - processor bug
IDT Winchip - because we run it in oostore module not strict x86 mode
I don't see why you are generating extra fence instructions for other
cases
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This archive was generated by hypermail 2b29 : Wed Aug 07 2002 - 22:00:25 EST