[PATCH] D35411: [SimplifyCFG] Defer folding unconditional branches to LateSimplifyCFG if it can destroy canonical loop structure.

[Balaram Makam via Phabricator via llvm-commits]

bmakam added a comment.

In https://reviews.llvm.org/D35411#811150, @ashutosh.nema wrote:

> Thanks Balaram for posting this patch, in general idea looks good to preserve the canonical form of the loops.
>
> Any idea why these benchmark regressed:
>
> spec2006/bzip2:ref       -2.18
>  spec2017/omnetpp:ref     -1.2
>  spec2006/perlbench:ref   -1.07


Thanks Ashutosh,

I rerun these 3 benchmarks and compared with the tip of trunk today and the regression in spec2006/bzip2 and spec2006/perlbench were found to be dubious. spec2017/omnetpp is still regressed by same ~1%. I looked at all the perf counters and nothing was obvious. Perhaps an alignment issue?


https://reviews.llvm.org/D35411