1 files changed, 11 insertions, 0 deletions
diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
index c9751c093d6..f4d501aceba 100644
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -45,6 +45,17 @@ using namespace cl;
 
 #define DEBUG_TYPE "commandline"
 
+#if LLVM_ENABLE_ABI_BREAKING_CHECKS
+namespace llvm {
+// If LLVM_ENABLE_ABI_BREAKING_CHECKS is set the flag -mllvm -reverse-iterate
+// can be used to toggle forward/reverse iteration of unordered containers.
+// This will help uncover differences in codegen caused due to undefined
+// iteration order.
+static cl::opt<bool, true> ReverseIteration("reverse-iterate",
+  cl::location(ReverseIterate<bool>::value), cl::init(true));
+}
+#endif
+
 //===----------------------------------------------------------------------===//
 // Template instantiations and anchors.
 //