Calling movnti without sfence?

[rajagopal, dwarak]

Yes, sfence should be used in the place where you suggested.

- Dwarak

> -----Original Message-----
> From: libc-alpha-owner@sourceware.org [mailto:libc-alpha-
> owner@sourceware.org] On Behalf Of H.J. Lu
> Sent: Wednesday, November 07, 2007 8:46 AM
> To: GNU C Library
> Cc: aj@suse.de
> Subject: Calling movnti without sfence?
> 
> While working on improving x86-64 memset, I noticed that movnti
> is called without sfence:
> 
> 11:
>         movnti  %r8,(%rcx)
>         movnti  %r8,0x8(%rcx)
>         movnti  %r8,0x10(%rcx)
>         movnti  %r8,0x18(%rcx)
>         movnti  %r8,0x20(%rcx)
>         movnti  %r8,0x28(%rcx)
>         movnti  %r8,0x30(%rcx)
>         movnti  %r8,0x38(%rcx)
>         add     $0x40,%rcx
>         dec     %rax
>         jne     11b
>         jmp     4b
> 
> Is that intentional? Shouldn't it be
> 
> 11:
>         movnti  %r8,(%rcx)
>         movnti  %r8,0x8(%rcx)
>         movnti  %r8,0x10(%rcx)
>         movnti  %r8,0x18(%rcx)
>         movnti  %r8,0x20(%rcx)
>         movnti  %r8,0x28(%rcx)
>         movnti  %r8,0x30(%rcx)
>         movnti  %r8,0x38(%rcx)
>         add     $0x40,%rcx
>         dec     %rax
>         jne     11b
> 	sfence
>         jmp     4b
> 
> 
> H.J.
>