Reuse the logic in getEdgeProbability within getHotSucc in order to
correctly handle blocks whose successor weights sum to more than
UINT32_MAX. This is slightly less efficient, but the entire thing is
already linear on the number of successors. Calling it within any hot
routine is a mistake, and indeed no one is calling it. It also
simplifies the code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144527 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineBranchProbabilityInfo.cpp b/lib/CodeGen/MachineBranchProbabilityInfo.cpp
index 0037d52..e3cfa9e 100644
--- a/lib/CodeGen/MachineBranchProbabilityInfo.cpp
+++ b/lib/CodeGen/MachineBranchProbabilityInfo.cpp
@@ -76,26 +76,18 @@
MachineBasicBlock *
MachineBranchProbabilityInfo::getHotSucc(MachineBasicBlock *MBB) const {
- uint32_t Sum = 0;
uint32_t MaxWeight = 0;
MachineBasicBlock *MaxSucc = 0;
-
for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
E = MBB->succ_end(); I != E; ++I) {
- MachineBasicBlock *Succ = *I;
- uint32_t Weight = getEdgeWeight(MBB, Succ);
- uint32_t PrevSum = Sum;
-
- Sum += Weight;
- assert(Sum > PrevSum); (void) PrevSum;
-
+ uint32_t Weight = getEdgeWeight(MBB, *I);
if (Weight > MaxWeight) {
MaxWeight = Weight;
- MaxSucc = Succ;
+ MaxSucc = *I;
}
}
- if (BranchProbability(MaxWeight, Sum) >= BranchProbability(4, 5))
+ if (getEdgeProbability(MBB, MaxSucc) >= BranchProbability(4, 5))
return MaxSucc;
return 0;