Slightly improve generated code in a degenerate case.
Should remove a warning from MSVC.
llvm-svn: 71603
diff --git a/llvm/utils/TableGen/DAGISelEmitter.cpp b/llvm/utils/TableGen/DAGISelEmitter.cpp
index 39791e2..0e2e615 100644
--- a/llvm/utils/TableGen/DAGISelEmitter.cpp
+++ b/llvm/utils/TableGen/DAGISelEmitter.cpp
@@ -2025,6 +2025,14 @@
OpcodeVTMap.find(OpName);
std::vector<std::string> &OpVTs = OpVTI->second;
OS << " case " << OpName << ": {\n";
+ // If we have only one variant and it's the default, elide the
+ // switch. Marginally faster, and makes MSVC happier.
+ if (OpVTs.size()==1 && OpVTs[0].empty()) {
+ OS << " return Select_" << getLegalCName(OpName) << "(N);\n";
+ OS << " break;\n";
+ OS << " }\n";
+ continue;
+ }
// Keep track of whether we see a pattern that has an iPtr result.
bool HasPtrPattern = false;
bool HasDefaultPattern = false;