[PATCH] D69437: [RAGreedy] Enable -consider-local-interval-cost by default

Thu Oct 31 07:22:56 PDT 2019

jsji added a comment.

In D69437#1728128 <https://reviews.llvm.org/D69437#1728128>, @ZhangKang wrote:

> For base test, this patch has not a good performance on PPC.

Thanks @ZhangKang for the testing results.

In D69437#1728336 <https://reviews.llvm.org/D69437#1728336>, @dmgreen wrote:

> I'm guessing the flags you use between base and peak are quite different?

BASE and PEAK options are similar to what used in SPEC publish, yes, they are quite different.

>   How noisy are these results? What kind of a confidence interval do you have?

@ZhangKang , please double confirm the results 
(I believe the result should be quite reliable if you are using our standard perf testing harness, which will run it 3 times on the quiet performance machine)

> It may be simpler to make this AArch64 only instead,

I am not sure other target like RISCV, but if above result on PowerPC is reliable, 
then yes, I would prefer we **don't enable it by default for PowerPC for now**.
We need to look into details of those big degradations first, fix the problems if any, then we can consider enable it by default.

Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D69437