[PATCH] D19554: Add optimization bisect opt-in calls for PowerPC passes

Hal Finkel via llvm-commits llvm-commits at lists.llvm.org
Tue Apr 26 15:15:51 PDT 2016


hfinkel added a comment.

In http://reviews.llvm.org/D19554#412891, @andrew.w.kaylor wrote:

> In http://reviews.llvm.org/D19554#412767, @hfinkel wrote:
>
> > PPCVSXFMAMutate is an optimization, and should be included in the skippable passes.
>
>
> It looks to me as if PPCVSXFMAMutate is always added (in PPCPassConfig::addPreRegAlloc), even at -O0.  I'm trying to keep the "optnone" function handling and the bisection consistent with -O0.  There's a lit test that verifies that nothing is skipped because of the "optnone" function attribute that is otherwise run at -O0.  I plan to add a similar check for the opt bisect soon.
>
> It makes sense that PPCVSXFMAMutate would be skippable, but I'd prefer not to add it to the bisection unless it is also being omitted at -O0.


Okay; in that case, please change that as well. It can be skipped at -O0 too.

> 

> 

> In http://reviews.llvm.org/D19554#412767, @hfinkel wrote:

> 

> > PPCCTRLoopsVerify is verifying work that PPCCTRLoops performed, and can only be skipped whenever PPCCTRLoops is skipped.

> 

> 

> If I add the skip check to PPCCTRLoopsVerify, it will always be skipped if PPCCTRLoops is skipped (because it runs afterward), but it's possible that PPCCTRLoops could be run and PPCCTRLoopsVerify.  That should be OK, though right?  So should I add the skip check to the verify pass?


No, don't skip it.


Repository:
  rL LLVM

http://reviews.llvm.org/D19554





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