Re: [PATCH 2/2] arm: lib: xor-neon: disable clang vectorization

[Adrian Ratiu]

On Sat, 07 Nov 2020, Russell King - ARM Linux admin 
<linux@xxxxxxxxxxxxxxx> wrote:
> On Fri, Nov 06, 2020 at 07:14:36AM +0200, Adrian Ratiu wrote: 
> > diff --git a/arch/arm/lib/xor-neon.c b/arch/arm/lib/xor-neon.c 
> > index e1e76186ec23..84c91c48dfa2 100644 --- 
> > a/arch/arm/lib/xor-neon.c +++ b/arch/arm/lib/xor-neon.c @@ 
> > -18,6 +18,10 @@ MODULE_LICENSE("GPL"); 
> >   * Pull in the reference implementations while instructing GCC 
> >   (through * -ftree-vectorize) to attempt to exploit implicit 
> >   parallelism and emit * NEON instructions. 
> > + 
>
> Please tidy this up before submission; we normally continue the 
> "*" for blank lines in comment blocks. Thanks. 

Indeed, thank you. I will fix it if I don't replace this patch 
entirely with something similar to what Nick suggested.

Perhaps adding a checkpatch test for this is a good idea?

Adrian

> > + * On Clang the loop vectorizer is enabled by default, but due to a bug
> > + * (https://bugs.llvm.org/show_bug.cgi?id=40976) vectorization is broke
> > + * so xor-neon is disabled in favor of the default reg implementations.
> >   */
> >  #ifdef CONFIG_CC_IS_GCC
> >  #pragma GCC optimize "tree-vectorize"
> > --
> > 2.29.0
>
> --
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