[PATCH] D19950: Use frequency info to guide Loop Invariant Code Motion.

[Dehao Chen via llvm-commits]

danielcdh added inline comments.

================
Comment at: lib/Transforms/Scalar/LICM.cpp:357
@@ -346,3 +356,3 @@
   bool Changed = false;
   if (!inSubLoop(BB, CurLoop, LI))
     for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E;) {
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davidxl wrote:
> Better to do this:
> 
> if (ShouldHoist && !inSubLoop(BB, CurLoop, LI)) 
> 
> 
> Chad's suggestion of doing 
> 
> ShouldHoist = BFI->getBlockFreq(BB) >= .. is also good.
Updated with Chad's suggestion. But I cannot move the ShouldHoist check outside the loop because there is still constant folding opportunities inside the loop.


http://reviews.llvm.org/D19950