Index: cfe/trunk/lib/CodeGen/CGStmt.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGStmt.cpp
+++ cfe/trunk/lib/CodeGen/CGStmt.cpp
@@ -2194,7 +2194,7 @@
                    llvm::IntegerType::get(getLLVMContext(), (unsigned)TmpSize));
         Tmp = Builder.CreateTrunc(Tmp, TruncTy);
       } else if (TruncTy->isIntegerTy()) {
-        Tmp = Builder.CreateTrunc(Tmp, TruncTy);
+        Tmp = Builder.CreateZExtOrTrunc(Tmp, TruncTy);
       } else if (TruncTy->isVectorTy()) {
         Tmp = Builder.CreateBitCast(Tmp, TruncTy);
       }
Index: cfe/trunk/test/CodeGen/pr34021.c
===================================================================
--- cfe/trunk/test/CodeGen/pr34021.c
+++ cfe/trunk/test/CodeGen/pr34021.c
@@ -0,0 +1,24 @@
+// RUN: %clang_cc1 -fms-extensions %s -triple=i686-unknown-unknown -emit-llvm -o - | FileCheck %s --check-prefix=X86
+// RUN: %clang_cc1 -fms-extensions %s -triple=x86_64-unknown-unknown -emit-llvm -o - | FileCheck %s --check-prefix=X64
+
+typedef int v4si __attribute__ ((vector_size (16)));
+v4si rep() {
+// X86-LABEL: define <4 x i32> @rep
+// X86:      %retval = alloca <4 x i32>, align 16
+// X86-NEXT: %res = alloca <4 x i32>, align 16
+// X86-NEXT: %0 = bitcast <4 x i32>* %retval to i128*
+// X86-NEXT: %1 = call i64 asm sideeffect inteldialect "", "=A,~{dirflag},~{fpsr},~{flags}"()
+// X86-NEXT: %2 = zext i64 %1 to i128
+// X86-NEXT: store i128 %2, i128* %0, align 16
+// X86-NEXT: %3 = load <4 x i32>, <4 x i32>* %res, align 16
+// X86-NEXT: ret <4 x i32> %3
+//
+// X64-LABEL: define <4 x i32> @rep
+// X64:      %res = alloca <4 x i32>, align 16
+// X64-NEXT: call void asm sideeffect inteldialect "", "~{dirflag},~{fpsr},~{flags}"()
+// X64-NEXT: %0 = load <4 x i32>, <4 x i32>* %res, align 16
+// X64-NEXT: ret <4 x i32> %0
+  v4si res;
+  __asm {}
+  return res;
+}