Don't crash when the Assignments vector is empty.

Reported by Vincent Lejeune using an out-of-tree target.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166398 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/RegisterCoalescer.cpp b/lib/CodeGen/RegisterCoalescer.cpp
index ba6b4569a8fb0dcfa1cb01673231b51cf727586b..2ca67d63257f96d0ced0e3b1f4c9fe60f2f0b336 100644 (file)
--- a/lib/CodeGen/RegisterCoalescer.cpp
+++ b/lib/CodeGen/RegisterCoalescer.cpp
@@ -1302,7 +1302,7 @@ public:
                    SmallVectorImpl<unsigned> &ShrinkRegs);
 
   /// Get the value assignments suitable for passing to LiveInterval::join.
-  const int *getAssignments() const { return &Assignments[0]; }
+  const int *getAssignments() const { return Assignments.data(); }
 };
 } // end anonymous namespace