[llvm-commits] [llvm] r133766 - in /llvm/trunk: include/llvm/Analysis/BranchProbabilityInfo.h include/llvm/InitializePasses.h include/llvm/Support/BranchProbability.h lib/Analysis/Analysis.cpp lib/Analysis/BranchProbabilityInfo.cpp lib/Analysis/CMakeLists.txt

[Jakob Stoklund Olesen]

On Jun 23, 2011, at 2:45 PM, Jakub Staszak wrote:

> +  // Get sum of the edge weights going to the BB block.
> +  uint32_t getBackSumForBlock(BasicBlock *BB) const;

This function doesn't make sense. The weights in different predecessors are unrelated, adding them doesn't give you a useful result.

> +  // Return a probability of getting to the DST block through SRC->DST edge.
> +  // Returned value is a fraction between 0 (0% probability) and
> +  // 1 (100% probability), however the value is never equal to 0, and can be 1
> +  // only iff DST block has only one predecesor.
> +  BranchProbability getBackEdgeProbability(BasicBlock *Src,
> +                                           BasicBlock *Dst) const;

Which means that this function is returning nonsense.

/jakob