diff --git a/clang/lib/CIR/CodeGen/CIRGenDecl.cpp b/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
index 3d15a70d1d6ac..d7cbb4f64b2ea 100644
--- a/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenDecl.cpp
@@ -276,6 +276,14 @@ void CIRGenFunction::emitDecl(const Decl &d) {
   case Decl::OpenACCRoutine:
     emitOpenACCRoutine(cast<OpenACCRoutineDecl>(d));
     return;
+  case Decl::Typedef:     // typedef int X;
+  case Decl::TypeAlias: { // using X = int; [C++0x]
+    QualType ty = cast<TypedefNameDecl>(d).getUnderlyingType();
+    assert(!cir::MissingFeatures::generateDebugInfo());
+    if (ty->isVariablyModifiedType())
+      cgm.errorNYI(d.getSourceRange(), "emitDecl: variably modified type");
+    return;
+  }
   default:
     cgm.errorNYI(d.getSourceRange(),
                  std::string("emitDecl: unhandled decl type: ") +
diff --git a/clang/lib/CIR/CodeGen/CIRGenModule.cpp b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
index 1b504546162c1..3b13d495be5e3 100644
--- a/clang/lib/CIR/CodeGen/CIRGenModule.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenModule.cpp
@@ -618,6 +618,8 @@ void CIRGenModule::emitTopLevelDecl(Decl *decl) {
     emitGlobalOpenACCDecl(cast<OpenACCDeclareDecl>(decl));
     break;
 
+  case Decl::Typedef:
+  case Decl::TypeAlias: // using foo = bar; [C++11]
   case Decl::Record:
   case Decl::CXXRecord:
     assert(!cir::MissingFeatures::generateDebugInfo());
diff --git a/clang/test/CIR/CodeGen/basic.c b/clang/test/CIR/CodeGen/basic.c
index 8ce8106b0c6cc..1845d3b64bf68 100644
--- a/clang/test/CIR/CodeGen/basic.c
+++ b/clang/test/CIR/CodeGen/basic.c
@@ -232,3 +232,24 @@ int f8(int *p) {
 // OGCG:   store i32 2, ptr %[[P]], align 4
 // OGCG:   %[[P2:.*]] = load ptr, ptr %[[P_PTR]], align 8
 // OGCG:   %[[STAR_P:.*]] = load i32, ptr %[[P2]], align 4
+
+typedef unsigned long size_type;
+typedef unsigned long _Tp;
+
+size_type max_size(void) {
+  return (size_type)~0 / sizeof(_Tp);
+}
+
+// CIR: cir.func @max_size()
+// CIR:   %0 = cir.alloca !u64i, !cir.ptr<!u64i>, ["__retval"] {alignment = 8 : i64}
+// CIR:   %1 = cir.const #cir.int<0> : !s32i
+// CIR:   %2 = cir.unary(not, %1) : !s32i, !s32i
+// CIR:   %3 = cir.cast(integral, %2 : !s32i), !u64i
+// CIR:   %4 = cir.const #cir.int<8> : !u64i
+// CIR:   %5 = cir.binop(div, %3, %4) : !u64i
+
+// LLVM: define i64 @max_size()
+// LLVM:   store i64 2305843009213693951, ptr
+
+// OGCG: define{{.*}} i64 @max_size()
+// OGCG:   ret i64 2305843009213693951
diff --git a/clang/test/CIR/CodeGen/basic.cpp b/clang/test/CIR/CodeGen/basic.cpp
index 9665b29719004..0f8431325a86f 100644
--- a/clang/test/CIR/CodeGen/basic.cpp
+++ b/clang/test/CIR/CodeGen/basic.cpp
@@ -87,3 +87,18 @@ int *f5() {
 // CHECK-NEXT:   cir.store %[[P]], %[[RET_ADDR]] : !cir.ptr<!s32i>, !cir.ptr<!cir.ptr<!s32i>>
 // CHECK-NEXT:   %[[RET_VAL:.*]] = cir.load %[[RET_ADDR]] : !cir.ptr<!cir.ptr<!s32i>>, !cir.ptr<!s32i>
 // CHECK-NEXT:   cir.return %[[RET_VAL]] : !cir.ptr<!s32i>
+
+using size_type = unsigned long;
+using _Tp = unsigned long;
+
+size_type max_size() {
+  return size_type(~0) / sizeof(_Tp);
+}
+
+// CHECK: cir.func @max_size()
+// CHECK:   %0 = cir.alloca !u64i, !cir.ptr<!u64i>, ["__retval"] {alignment = 8 : i64}
+// CHECK:   %1 = cir.const #cir.int<0> : !s32i
+// CHECK:   %2 = cir.unary(not, %1) : !s32i, !s32i
+// CHECK:   %3 = cir.cast(integral, %2 : !s32i), !u64i
+// CHECK:   %4 = cir.const #cir.int<8> : !u64i
+// CHECK:   %5 = cir.binop(div, %3, %4) : !u64i
diff --git a/clang/test/CIR/CodeGen/typedef.c b/clang/test/CIR/CodeGen/typedef.c
new file mode 100644
index 0000000000000..17fce13abf38a
--- /dev/null
+++ b/clang/test/CIR/CodeGen/typedef.c
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-llvm %s -o %t-cir.ll
+// RUN: FileCheck --input-file=%t-cir.ll %s -check-prefix=LLVM
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG
+
+void local_typedef(void) {
+  typedef struct {int a;} Struct;
+  Struct s;
+}
+
+// CIR:      cir.func @local_typedef()
+// CIR:        cir.alloca !cir.record<struct "Struct" {!s32i}>,
+// CIR-SAME:       !cir.ptr<!cir.record<struct "Struct" {!s32i}>>, ["s"]
+// CIR-SAME:       {alignment = 4 : i64}
+// CIR:        cir.return
+
+// LLVM: %struct.Struct = type { i32 }
+// LLVM: define void @local_typedef()
+// LLVM:   alloca %struct.Struct, i64 1, align 4
+// LLVM:   ret void
+
+// OGCG: %struct.Struct = type { i32 }
+// OGCG: define{{.*}} void @local_typedef()
+// OGCG:   alloca %struct.Struct, align 4
+// OGCG:   ret void