[PATCH] D66576: [Regalloc][WIP] Increase CSR cost in RegAllocGreedy to favour splitting/spill over CSR first use

Fri Oct 11 02:34:35 PDT 2019

ZhangKang added a comment.

In D66576#1705534 <https://reviews.llvm.org/D66576#1705534>, @lebedev.ri wrote:

> In D66576#1660216 <https://reviews.llvm.org/D66576#1660216>, @steven.zhang wrote:
>
> > .AMDGPU also override the getCSRFirstUseCost() but your patch didn't catch that. And would you please post some improve number for powerpc of this patch ?
>
>
> Not done; would be good to have some perf numbers here, for ppc and x86

We have test this patch(`getCSRFirstUseCost ()` return 1) on PowerPC.
For spec base, there are 6 cases has improved more that 1%, the largest improvement case is 3.63%, no case degraded more than 1%. 
For spec peak, there are 5 cases has improved more that 1%, the largest improvement case is 5.9%, only one case degraded more than 1%(1.76%).
Overall, the base & peak reset has been improved after this patch on PPC.

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