TableGen/SearchableTables: Cast enums to unsigned in generated code

Summary:
This should fix signedness warnings when compiling with MSVC.

Change-Id: I4664cce0ba91e9b42d21a86fd4a7e82f2320c451

Reviewers: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D51097

llvm-svn: 340518

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/utils/TableGen/SearchableTableEmitter.cpp b/llvm/utils/TableGen/SearchableTableEmitter.cpp
index 664de2217e9..61c918bd014 100644
--- a/llvm/utils/TableGen/SearchableTableEmitter.cpp
+++ b/llvm/utils/TableGen/SearchableTableEmitter.cpp
@@ -430,6 +430,15 @@ void SearchableTableEmitter::emitLookupFunction(const GenericTable &Table,
          << ").compare(RHS." << Field.Name << ");\n";
       OS << "      if (Cmp" << Field.Name << " < 0) return true;\n";
       OS << "      if (Cmp" << Field.Name << " > 0) return false;\n";
+    } else if (Field.Enum) {
+      // Explicitly cast to unsigned, because the signedness of enums is
+      // compiler-dependent.
+      OS << "      if ((unsigned)LHS." << Field.Name << " < (unsigned)RHS."
+         << Field.Name << ")\n";
+      OS << "        return true;\n";
+      OS << "      if ((unsigned)LHS." << Field.Name << " > (unsigned)RHS."
+         << Field.Name << ")\n";
+      OS << "        return false;\n";
     } else {
       OS << "      if (LHS." << Field.Name << " < RHS." << Field.Name << ")\n";
       OS << "        return true;\n";