change OperandsSignature to use SmallVector<char> instead of std::vector<string>
since the strings are always exactly one character, and there are usually only 2-3 operands.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129678 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenInstruction.h b/utils/TableGen/CodeGenInstruction.h
index 6d2d8fb..5f1e0be 100644
--- a/utils/TableGen/CodeGenInstruction.h
+++ b/utils/TableGen/CodeGenInstruction.h
@@ -137,6 +137,7 @@
     bool isVariadic;
 
     // Provide transparent accessors to the operand list.
+    bool empty() const { return OperandList.empty(); }
     unsigned size() const { return OperandList.size(); }
     const OperandInfo &operator[](unsigned i) const { return OperandList[i]; }
     OperandInfo &operator[](unsigned i) { return OperandList[i]; }