Fix LiveInterval::overlaps so it doesn't claim touching intervals overlap.

Also, one binary search is enough.

llvm-svn: 108261

1 files changed, 2 insertions, 10 deletions

diff --git a/llvm/lib/CodeGen/LiveInterval.cpp b/llvm/lib/CodeGen/LiveInterval.cpp
index 21a9b7d4db6..9b057b0fec2 100644
--- a/llvm/lib/CodeGen/LiveInterval.cpp
+++ b/llvm/lib/CodeGen/LiveInterval.cpp
@@ -161,16 +161,8 @@ bool LiveInterval::overlapsFrom(const LiveInterval& other,
 /// by [Start, End).
 bool LiveInterval::overlaps(SlotIndex Start, SlotIndex End) const {
   assert(Start < End && "Invalid range");
-  const_iterator I  = begin();
-  const_iterator E  = end();
-  const_iterator si = std::upper_bound(I, E, Start);
-  const_iterator ei = std::upper_bound(I, E, End);
-  if (si != ei)
-    return true;
-  if (si == I)
-    return false;
-  --si;
-  return si->contains(Start);
+  const_iterator I = std::lower_bound(begin(), end(), End);
+  return I != begin() && (--I)->end > Start;
 }
 
 /// extendIntervalEndTo - This method is used when we want to extend the range