2 files changed, 26 insertions, 1 deletions
diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index 882ab106a37..7d02a3956ff 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -13,6 +13,7 @@
 
 #include "llvm/IR/Module.h"
 #include "SymbolTableListTraitsImpl.h"
+#include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
@@ -507,6 +508,24 @@ void Module::setPIELevel(PIELevel::Level PL) {
   addModuleFlag(ModFlagBehavior::Max, "PIE Level", PL);
 }
 
+Optional<CodeModel::Model> Module::getCodeModel() const {
+  auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("Code Model"));
+
+  if (!Val)
+    return None;
+
+  return static_cast<CodeModel::Model>(
+      cast<ConstantInt>(Val->getValue())->getZExtValue());
+}
+
+void Module::setCodeModel(CodeModel::Model CL) {
+  // Linking object files with different code models is undefined behavior
+  // because the compiler would have to generate additional code (to span
+  // longer jumps) if a larger code model is used with a smaller one.
+  // Therefore we will treat attempts to mix code models as an error.
+  addModuleFlag(ModFlagBehavior::Error, "Code Model", CL);
+}
+
 void Module::setProfileSummary(Metadata *M) {
   addModuleFlag(ModFlagBehavior::Error, "ProfileSummary", M);
 }
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index eadbb410bd5..be33ab84933 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -138,9 +138,15 @@ createTargetMachine(Config &Conf, const Target *TheTarget, Module &M) {
     RelocModel =
         M.getPICLevel() == PICLevel::NotPIC ? Reloc::Static : Reloc::PIC_;
 
+  Optional<CodeModel::Model> CodeModel;
+  if (Conf.CodeModel)
+    CodeModel = *Conf.CodeModel;
+  else
+    CodeModel = M.getCodeModel();
+
   return std::unique_ptr<TargetMachine>(TheTarget->createTargetMachine(
       TheTriple, Conf.CPU, Features.getString(), Conf.Options, RelocModel,
-      Conf.CodeModel, Conf.CGOptLevel));
+      CodeModel, Conf.CGOptLevel));
 }
 
 static void runNewPMPasses(Config &Conf, Module &Mod, TargetMachine *TM,