[cfe-dev] clang auto-vectorization feedback is confusing

[Sean McBride via cfe-dev]

On Fri, 8 Jul 2016 16:03:22 -0700, Adam Nemet said:

>> Another question if I may: sometimes clang will output something
>pretty clear like:
>> 
>> "remark: loop not vectorized: loop control flow is not understood by
>vectorizer [-Rpass-analysis=loop-vectorize]"
>> 
>> Other times I'll see:
>> 
>> "remark: the cost-model indicates that interleaving is not beneficial
>[-Rpass-analysis=loop-vectorize]"
>> 
>> From the sounds of it, that's telling me that the loop was *not*
>vectorized, right?  If so, I find it odd that the "loop not vectorized:"
>prefix is not present.
>
>Yes and yes.  Can you please file a bug report on this too?

Thanks for confirming.  Here's the ticket:
<https://llvm.org/bugs/show_bug.cgi?id=28477>

Cheers,

Sean