commit ae726a93e31e2c16ce78cba296469d0c288f21d5
author Will Dietz <wdietz2@illinois.edu> Sun Oct 13 03:08:49 2013 +0000
committer Will Dietz <wdietz2@illinois.edu> Sun Oct 13 03:08:49 2013 +0000
tree c0d0de1a7244e842d72ea7b931f55b8bd7d83061
parent 9f21325ac732ab6f0b57dbad7f2099b0679156cf

TargetLowering: Don't index into empty string.

(This is triggered by current lit tests)

llvm-svn: 192549

llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 05b025c..17631c0 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2012,7 +2012,7 @@
 std::pair<unsigned, const TargetRegisterClass*> TargetLowering::
 getRegForInlineAsmConstraint(const std::string &Constraint,
                              MVT VT) const {
-  if (Constraint[0] != '{')
+  if (Constraint.empty() || Constraint[0] != '{')
     return std::make_pair(0u, static_cast<TargetRegisterClass*>(0));
   assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?");