[PATCH] D18763: [ThinLTO] Move summary computation from BitcodeWriter to new pass

[Teresa Johnson via llvm-commits]

tejohnson added inline comments.

================
Comment at: lib/Analysis/ModuleSummaryAnalysis.cpp:144
@@ +143,3 @@
+    else if (F.getEntryCount().hasValue()) {
+      Function &Func = const_cast<Function &>(F);
+      LoopInfo LI{DominatorTree(Func)};
----------------
joker.eph wrote:
> tejohnson wrote:
> > joker.eph wrote:
> > > Why is this `const_cast` needed?
> > Because the BlockFrequencyInfo (or BranchProbabilityInfo, can't remember which one) takes a non-const F. When called through the pass the Module is not const. But when this class is constructed from llvm-as the Module is constant so the Module pointer is constant in the builder. 
> Ok I update BFI upstream, but DomTree seems a lot more involved...
> 
> You should be able to update to:
> 
> ```
>       LoopInfo LI{DominatorTree(const_cast<Function &>(F))};
>       BranchProbabilityInfo BPI{F, LI};
>       BFIPtr = llvm::make_unique<BlockFrequencyInfo>(F, BPI, LI);
> ```
Just saw that, thanks! Will do.


http://reviews.llvm.org/D18763