[PATCH] D56772: [MIR] Add simple PRE pass to MachineCSE

Fri Jul 19 00:42:19 PDT 2019

anton-afanasyev marked 3 inline comments as done.
anton-afanasyev added a comment.

In D56772#1592951 <https://reviews.llvm.org/D56772#1592951>, @LuoYuanke wrote:

> @anton-afanasyev
>  Hi, 
>  Did you look into the SPEC cpu2017/500.perlbench_r issue? There is some significant performance drop on X86 with the patch. I ask you to revert the patch first, and when the SPEC2017 regression is fixed, we can submit the patch again. How do you think?

Hi @LuoYuanke, I'm sorry, it looks like my previous answer to you remained unsubmitted.
Here it is:

> Hi @LuoYuanke , I have only access to SPEC cpu2006, I see 400.perlbench there. Could it be the case you know regressed sample from cpu2006?
>  Also, I have prepared new patch for review: https://reviews.llvm.org/D63934 -- I believe it can potentially decrease reg pressure.

At the moment, I believe that another patch (from Kai Luo) https://reviews.llvm.org/D64394 fixes this regression.

Repository:
  rL LLVM

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https://reviews.llvm.org/D56772