2 files changed, 10 insertions, 2 deletions
diff --git a/lib/Transforms/IPO/DeadArgumentElimination.cpp b/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 47df235424..e8b168e457 100644
--- a/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -791,7 +791,8 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
       } else if (New->getType()->isVoidTy()) {
         // Our return value has uses, but they will get removed later on.
         // Replace by null for now.
-        Call->replaceAllUsesWith(Constant::getNullValue(Call->getType()));
+        if (!Call->getType()->isX86_MMXTy())
+          Call->replaceAllUsesWith(Constant::getNullValue(Call->getType()));
       } else {
         assert(RetTy->isStructTy() &&
                "Return type changed, but not into a void. The old return type"
@@ -854,7 +855,8 @@ bool DAE::RemoveDeadStuffFromFunction(Function *F) {
     } else {
       // If this argument is dead, replace any uses of it with null constants
       // (these are guaranteed to become unused later on).
-      I->replaceAllUsesWith(Constant::getNullValue(I->getType()));
+      if (!I->getType()->isX86_MMXTy())
+        I->replaceAllUsesWith(Constant::getNullValue(I->getType()));
     }
 
   // If we change the return value of the function we must rewrite any return
diff --git a/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index fee317dbd9..33ecb5bf9b 100644
--- a/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -321,6 +321,9 @@ bool ConvertToScalarInfo::CanConvertToScalar(Value *V, uint64_t Offset) {
       // Don't break volatile loads.
       if (LI->isVolatile())
         return false;
+      // Don't touch MMX operations.
+      if (LI->getType()->isX86_MMXTy())
+        return false;
       MergeInType(LI->getType(), Offset);
       continue;
     }
@@ -328,6 +331,9 @@ bool ConvertToScalarInfo::CanConvertToScalar(Value *V, uint64_t Offset) {
     if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
       // Storing the pointer, not into the value?
       if (SI->getOperand(0) == V || SI->isVolatile()) return false;
+      // Don't touch MMX operations.
+      if (SI->getOperand(0)->getType()->isX86_MMXTy())
+        return false;
       MergeInType(SI->getOperand(0)->getType(), Offset);
       continue;
     }