3 files changed, 4 insertions, 7 deletions
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 5c9744f4e8..57bf2fca4e 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -8543,9 +8543,6 @@ bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
             (LHSValue.Base && isZeroSized(RHSValue)))
           return Error(E);
         // Pointers with different bases cannot represent the same object.
-        // (Note that clang defaults to -fmerge-all-constants, which can
-        // lead to inconsistent results for comparisons involving the address
-        // of a constant; this generally doesn't matter in practice.)
         return Success(E->getOpcode() == BO_NE, E);
       }
 
diff --git a/lib/Driver/ToolChains/Clang.cpp b/lib/Driver/ToolChains/Clang.cpp
index 484df52001..a2821b70d7 100644
--- a/lib/Driver/ToolChains/Clang.cpp
+++ b/lib/Driver/ToolChains/Clang.cpp
@@ -3288,9 +3288,9 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
 
   Args.AddLastArg(CmdArgs, options::OPT_fveclib);
 
-  if (!Args.hasFlag(options::OPT_fmerge_all_constants,
-                    options::OPT_fno_merge_all_constants))
-    CmdArgs.push_back("-fno-merge-all-constants");
+  if (Args.hasFlag(options::OPT_fmerge_all_constants,
+                   options::OPT_fno_merge_all_constants, false))
+    CmdArgs.push_back("-fmerge-all-constants");
 
   // LLVM Code Generator Options.
 
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 6ce719aac6..438a48083e 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -552,7 +552,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
       Args.hasFlag(OPT_ffine_grained_bitfield_accesses,
                    OPT_fno_fine_grained_bitfield_accesses, false);
   Opts.DwarfDebugFlags = Args.getLastArgValue(OPT_dwarf_debug_flags);
-  Opts.MergeAllConstants = !Args.hasArg(OPT_fno_merge_all_constants);
+  Opts.MergeAllConstants = Args.hasArg(OPT_fmerge_all_constants);
   Opts.NoCommon = Args.hasArg(OPT_fno_common);
   Opts.NoImplicitFloat = Args.hasArg(OPT_no_implicit_float);
   Opts.OptimizeSize = getOptimizationLevelSize(Args);