[PATCH] D22141: [BFI] Add option to lazily calculate BFI

[Duncan P. N. Exon Smith via llvm-commits]

David's suggested direction SGTM.

> On 2016-Jul-08, at 12:32, David Li <davidxl at google.com> wrote:
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> davidxl added a comment.
> 
> There are already too many classes related to BFI, so I am not a fan of introducing another LazyBFI.
> 
> I suggest just making BFI lazy itself (when getBlockFreq() is first called ...). In fact  I think the laziness handling should be in BlocFrequencyInfoImpl class. By so doing, MBFI can get the laziness automatically as well.
> 
> 
> http://reviews.llvm.org/D22141
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>