diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 5ed285d..631aa1f 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -985,6 +985,9 @@
   }
   virtual bool validateAsmConstraint(const char *&Name,
                                      TargetInfo::ConstraintInfo &info) const;
+  virtual const llvm::Type* adjustInlineAsmType(std::string& Constraint,
+                                     const llvm::Type* Ty,
+                                     llvm::LLVMContext& Context) const;
   virtual std::string convertConstraint(const char Constraint) const;
   virtual const char *getClobbers() const {
     return "~{dirflag},~{fpsr},~{flags}";
@@ -1306,6 +1309,16 @@
   return false;
 }
 
+const llvm::Type*
+X86TargetInfo::adjustInlineAsmType(std::string& Constraint,
+                                   const llvm::Type* Ty,
+                                   llvm::LLVMContext &Context) const {
+  if (Constraint=="y" && Ty->isVectorTy())
+    return llvm::Type::getX86_MMXTy(Context);
+  return Ty;
+}
+
+
 std::string
 X86TargetInfo::convertConstraint(const char Constraint) const {
   switch (Constraint) {
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 4de505a..282541b 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -1046,6 +1046,10 @@
           ResultRegTypes.back() = ConvertType(InputTy);
         }
       }
+      if (const llvm::Type* AdjTy = 
+            Target.adjustInlineAsmType(OutputConstraint, ResultRegTypes.back(),
+                                       VMContext))
+        ResultRegTypes.back() = AdjTy;
     } else {
       ArgTypes.push_back(Dest.getAddress()->getType());
       Args.push_back(Dest.getAddress());
@@ -1109,7 +1113,10 @@
           Arg = Builder.CreateFPExt(Arg, OutputTy);
       }
     }
-
+    if (const llvm::Type* AdjTy = 
+              Target.adjustInlineAsmType(InputConstraint, Arg->getType(),
+                                         VMContext))
+      Arg = Builder.CreateBitCast(Arg, AdjTy);
 
     ArgTypes.push_back(Arg->getType());
     Args.push_back(Arg);
@@ -1204,6 +1211,8 @@
         Tmp = Builder.CreateTrunc(Tmp, TruncTy);
       } else if (TruncTy->isIntegerTy()) {
         Tmp = Builder.CreateTrunc(Tmp, TruncTy);
+      } else if (TruncTy->isVectorTy()) {
+        Tmp = Builder.CreateBitCast(Tmp, TruncTy);
       }
     }