[IfConversion] Only renormalize probabilities if branches are analyzable
If a block has non-analyzable branches, the listed successors don't need
to add up to one. For example, if a block has a conditional tail call,
that tail call will not have a corresponding successor in the successor
list, but will still be a possible branch.
Differential Revision: https://reviews.llvm.org/D30556
llvm-svn: 297054
diff --git a/llvm/lib/CodeGen/IfConversion.cpp b/llvm/lib/CodeGen/IfConversion.cpp
index 8b87aa1..37fe415 100644
--- a/llvm/lib/CodeGen/IfConversion.cpp
+++ b/llvm/lib/CodeGen/IfConversion.cpp
@@ -2148,7 +2148,8 @@
// unknown probabilities into known ones.
// FIXME: This usage is too tricky and in the future we would like to
// eliminate all unknown probabilities in MBB.
- ToBBI.BB->normalizeSuccProbs();
+ if (ToBBI.IsBrAnalyzable)
+ ToBBI.BB->normalizeSuccProbs();
SmallVector<MachineBasicBlock *, 4> FromSuccs(FromMBB.succ_begin(),
FromMBB.succ_end());
@@ -2228,7 +2229,8 @@
// Normalize the probabilities of ToBBI.BB's successors with all adjustment
// we've done above.
- ToBBI.BB->normalizeSuccProbs();
+ if (ToBBI.IsBrAnalyzable && FromBBI.IsBrAnalyzable)
+ ToBBI.BB->normalizeSuccProbs();
ToBBI.Predicate.append(FromBBI.Predicate.begin(), FromBBI.Predicate.end());
FromBBI.Predicate.clear();