Re: [PATCH v2] compiler: prevent dead store elimination

From: Andi Kleen
Date: Tue Mar 02 2010 - 07:24:31 EST


>
> >> +#define ARRAY_PREVENT_DSE(p, n)
> >
> > Who says the Intel compiler doesn't need this?
>
> There was a comment in include/linux/compiler-intel.h that it's not supported.

That's true for the ia64 version, but not for the x86 version which supports
gcc compatible inline assembler. So on x86 you can use it. On Itanium
it probably would need some other compiler built in.

Also in any case some form of memory clobber is needed because it'll surely
do dead-store-optimization.

-Andi

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