[PATCH] D21299: [Codegen Prepare] Swap commutative binops before splitting branch condition.

[Renato Golin via llvm-commits]

rengolin added a comment.

In http://reviews.llvm.org/D21299#459899, @bmakam wrote:

> The main motivation for this patch is to fix the regressions we see in spec2006/mcf when http://reviews.llvm.org/D20030 is enabled. I have so far tested this patch in combination with http://reviews.llvm.org/D20030 on spec2006 on Kryo and overall the results are positive(better) for LTO config:


Right, but this is a change in the generic codegen prepare, not even AArch64 specific. So, testing only on Kryo seems very dangerous.

I encourage you to run the same benchmarks on other architectures (AArch64 A57, ARMv7, x86_64 at least) before concluding that this is an overall winning strategy.

Or, you lower this piece of the code into the AArch64-specific part, and make sure to wrap around a target feature flag if it's only beneficial to Kryo.

cheers,
--renato


http://reviews.llvm.org/D21299