expensive the most useful interface to this analysis is.
Fun story -- it's also not correct. That's getting fixed in another
patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144523
91177308-0d34-0410-b5e6-
96231b3b80d8
// Return a probability as a fraction between 0 (0% probability) and
// 1 (100% probability), however the value is never equal to 0, and can be 1
// only iff SRC block has only one successor.
+ // NB: This routine's complexity is linear on the number of successors of
+ // Src. Querying sequentially for each successor's probability is a quadratic
+ // query pattern.
BranchProbability getEdgeProbability(MachineBasicBlock *Src,
MachineBasicBlock *Dst) const;