TargetLowering: Don't index into empty string.

(This is triggered by current lit tests)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192549 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Will Dietz 2013-10-13 03:08:49 +00:00
parent 6dd7893e8c
commit 833a29c296

View File

@ -2012,7 +2012,7 @@ void TargetLowering::LowerAsmOperandForConstraint(SDValue Op,
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?");