Bitcode: Don't optimize constants when preserving use-list order
[oota-llvm.git] / lib / Bitcode / Writer / ValueEnumerator.cpp
index 15f8034..1430fad 100644 (file)
@@ -18,6 +18,7 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Module.h"
+#include "llvm/IR/UseListOrder.h"
 #include "llvm/IR/ValueSymbolTable.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
@@ -179,6 +180,11 @@ void ValueEnumerator::print(raw_ostream &OS, const ValueMapType &Map,
 void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
   if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
 
+  if (shouldPreserveBitcodeUseListOrder())
+    // Optimizing constants makes the use-list order difficult to predict.
+    // Disable it for now when trying to preserve the order.
+    return;
+
   std::stable_sort(Values.begin() + CstStart, Values.begin() + CstEnd,
                    [this](const std::pair<const Value *, unsigned> &LHS,
                           const std::pair<const Value *, unsigned> &RHS) {