[llvm-dev] (RFC) Adjusting default loop fully unroll threshold

Dehao Chen via llvm-dev llvm-dev at lists.llvm.org
Wed Feb 15 10:17:58 PST 2017


Thanks all for the comments.

On Tue, Feb 14, 2017 at 12:53 PM, Gerolf Hoflehner via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
>
> If there is clear insight where the gains are coming from O2 is fine. IMHO if we just have the “better” numbers we should go for a higher opt level since not everyone will benefit. Some users will only pay higher compile-times.

As from my previous reply, for the google applications that we see
gains from the threshold increase, the benefits are simply coming from
reduced instructions from unrolled loops.

Looks like that we all agree that the threshold increase is OK at O2.
If there is no objection by the end of day today, I will submit the
patch.

Thanks,
Dehao


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