[llvm-dev] LLVM LNT floating point performance tests on X86 - using the llvm-test-suite benchmarks

[Blower, Melanie I via llvm-dev]

Hello.
I have a patch to commit to community https://reviews.llvm.org/D74436?id=282577 that changes command line settings for floating point.  When I committed it previously, it was ultimately rolled back due to bot failures with LNT. 

Looking for suggestions on how to use the llvm-test-suite benchmarks to analyze this issue so I can commit this change.

We think the key difference in the tests that regressed when I tried to commit the change was caused by differences in unrolling decisions when the fmuladd intrinsic was present.

As far as I can tell, the LNT bots aren't currently running on any x86 systems, so I have no idea what settings the bots used when they were running. I'm really not sure how to proceed.

It seems to me that FMA should give better performance on systems that support it on any non-trivial benchmark.

Thanks!