Take another .7 seconds off of linear scan time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17936 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 3 deletions

diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index 3c7e8dd763..4a1720f701 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -68,14 +68,16 @@ bool LiveInterval::overlapsFrom(const LiveInterval& other,
   const_iterator je = other.end();
 
   assert((StartPos->start <= i->start || StartPos == other.begin()) &&
-         "Bogus start position hint!");
+         StartPos != other.end() && "Bogus start position hint!");
 
   if (i->start < j->start) {
     i = std::upper_bound(i, ie, j->start);
     if (i != ranges.begin()) --i;
   } else if (j->start < i->start) {
-    j = std::upper_bound(j, je, i->start);
-    if (j != other.ranges.begin()) --j;
+    if ((++StartPos)->start <= i->start) {
+      j = std::upper_bound(j, je, i->start);
+      if (j != other.ranges.begin()) --j;
+    }
   } else {
     return true;
   }