diff --git a/clang/test/CodeGenCXX/new-overflow.cpp b/clang/test/CodeGenCXX/new-overflow.cpp
new file mode 100644
index 000000000000..e16b30e54095
--- /dev/null
+++ b/clang/test/CodeGenCXX/new-overflow.cpp
@@ -0,0 +1,211 @@
+// RUN: %clang_cc1 -triple i386-unknown-unknown %s -emit-llvm -o - | FileCheck %s
+
+// rdar://problem/9246208
+
+// CHECK: [[OVR_T:%.*]] = type { i32, i1 }
+
+// Basic test.
+namespace test0 {
+  struct A {
+    A();
+    int x;
+  };
+
+  typedef A elt;
+
+  // CHECK:    define [[A:%.*]]* @_ZN5test04testEs(i16 signext
+  // CHECK:      [[N:%.*]] = sext i16 {{%.*}} to i32
+  // CHECK-NEXT: [[T0:%.*]] = call [[OVR_T]] @llvm.umul.with.overflow.i32(i32 [[N]], i32 4)
+  // CHECK-NEXT: [[T1:%.*]] = extractvalue [[OVR_T]] [[T0]], 1
+  // CHECK-NEXT: [[T2:%.*]] = extractvalue [[OVR_T]] [[T0]], 0
+  // CHECK-NEXT: [[T3:%.*]] = select i1 [[T1]], i32 -1, i32 [[T2]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T3]])
+  // CHECK:      icmp ult i32 {{.*}}, [[N]]
+  elt *test(short s) {
+    return new elt[s];
+  }
+}
+
+// test0 with a nested array.
+namespace test1 {
+  struct A {
+    A();
+    int x;
+  };
+
+  typedef A elt[100];
+
+  // CHECK:    define [100 x [[A:%.*]]]* @_ZN5test14testEs(i16 signext
+  // CHECK:      [[N:%.*]] = sext i16 {{%.*}} to i32
+  // CHECK-NEXT: [[T0:%.*]] = call [[OVR_T]] @llvm.umul.with.overflow.i32(i32 [[N]], i32 400)
+  // CHECK-NEXT: [[T1:%.*]] = extractvalue [[OVR_T]] [[T0]], 1
+  // CHECK-NEXT: [[T2:%.*]] = extractvalue [[OVR_T]] [[T0]], 0
+  // CHECK-NEXT: [[T3:%.*]] = mul i32 [[N]], 100
+  // CHECK-NEXT: [[T4:%.*]] = select i1 [[T1]], i32 -1, i32 [[T2]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T4]])
+  // CHECK:      icmp ult i32 {{.*}}, [[T3]]
+  elt *test(short s) {
+    return new elt[s];
+  }
+}
+
+// test1 with an array cookie.
+namespace test2 {
+  struct A {
+    A();
+    ~A();
+    int x;
+  };
+
+  typedef A elt[100];
+
+  // CHECK:    define [100 x [[A:%.*]]]* @_ZN5test24testEs(i16 signext
+  // CHECK:      [[N:%.*]] = sext i16 {{%.*}} to i32
+  // CHECK-NEXT: [[T0:%.*]] = call [[OVR_T]] @llvm.umul.with.overflow.i32(i32 [[N]], i32 400)
+  // CHECK-NEXT: [[T1:%.*]] = extractvalue [[OVR_T]] [[T0]], 1
+  // CHECK-NEXT: [[T2:%.*]] = extractvalue [[OVR_T]] [[T0]], 0
+  // CHECK-NEXT: [[T3:%.*]] = mul i32 [[N]], 100
+  // CHECK-NEXT: [[T4:%.*]] = call [[OVR_T]] @llvm.uadd.with.overflow.i32(i32 [[T2]], i32 4)
+  // CHECK-NEXT: [[T5:%.*]] = extractvalue [[OVR_T]] [[T4]], 1
+  // CHECK-NEXT: [[T6:%.*]] = or i1 [[T1]], [[T5]]
+  // CHECK-NEXT: [[T7:%.*]] = extractvalue [[OVR_T]] [[T4]], 0
+  // CHECK-NEXT: [[T8:%.*]] = select i1 [[T6]], i32 -1, i32 [[T7]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T8]])
+  // CHECK:      icmp ult i32 {{.*}}, [[T3]]
+  elt *test(short s) {
+    return new elt[s];
+  }
+}
+
+// test0 with a 1-byte element.
+namespace test4 {
+  struct A {
+    A();
+  };
+
+  typedef A elt;
+
+  // CHECK:    define [[A:%.*]]* @_ZN5test44testEs(i16 signext
+  // CHECK:      [[N:%.*]] = sext i16 {{%.*}} to i32
+  // CHECK-NEXT: [[T0:%.*]] = icmp slt i32 [[N]], 0
+  // CHECK-NEXT: [[T1:%.*]] = select i1 [[T0]], i32 -1, i32 [[N]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T1]])
+  // CHECK:      icmp ult i32 {{.*}}, [[N]]
+  elt *test(short s) {
+    return new elt[s];
+  }
+}
+
+// test4 with no sext required.
+namespace test5 {
+  struct A {
+    A();
+  };
+
+  typedef A elt;
+
+  // CHECK:    define [[A:%.*]]* @_ZN5test54testEi(i32
+  // CHECK:      [[N:%.*]] = load i32*
+  // CHECK-NEXT: [[T0:%.*]] = icmp slt i32 [[N]], 0
+  // CHECK-NEXT: [[T1:%.*]] = select i1 [[T0]], i32 -1, i32 [[N]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T1]])
+  // CHECK:      icmp ult i32 {{.*}}, [[N]]
+  elt *test(int s) {
+    return new elt[s];
+  }
+}
+
+// test0 with an unsigned size.
+namespace test6 {
+  struct A {
+    A();
+    int x;
+  };
+
+  typedef A elt;
+
+  // CHECK:    define [[A:%.*]]* @_ZN5test64testEt(i16 zeroext
+  // CHECK:      [[N:%.*]] = zext i16 {{%.*}} to i32
+  // CHECK-NEXT: [[T0:%.*]] = call [[OVR_T]] @llvm.umul.with.overflow.i32(i32 [[N]], i32 4)
+  // CHECK-NEXT: [[T1:%.*]] = extractvalue [[OVR_T]] [[T0]], 1
+  // CHECK-NEXT: [[T2:%.*]] = extractvalue [[OVR_T]] [[T0]], 0
+  // CHECK-NEXT: [[T3:%.*]] = select i1 [[T1]], i32 -1, i32 [[T2]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T3]])
+  // CHECK:      icmp ult i32 {{.*}}, [[N]]
+  elt *test(unsigned short s) {
+    return new elt[s];
+  }
+}
+
+// test1 with an unsigned size.
+namespace test7 {
+  struct A {
+    A();
+    int x;
+  };
+
+  typedef A elt[100];
+
+  // CHECK:    define [100 x [[A:%.*]]]* @_ZN5test74testEt(i16 zeroext
+  // CHECK:      [[N:%.*]] = zext i16 {{%.*}} to i32
+  // CHECK-NEXT: [[T0:%.*]] = call [[OVR_T]] @llvm.umul.with.overflow.i32(i32 [[N]], i32 400)
+  // CHECK-NEXT: [[T1:%.*]] = extractvalue [[OVR_T]] [[T0]], 1
+  // CHECK-NEXT: [[T2:%.*]] = extractvalue [[OVR_T]] [[T0]], 0
+  // CHECK-NEXT: [[T3:%.*]] = mul i32 [[N]], 100
+  // CHECK-NEXT: [[T4:%.*]] = select i1 [[T1]], i32 -1, i32 [[T2]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T4]])
+  // CHECK:      icmp ult i32 {{.*}}, [[T3]]
+  elt *test(unsigned short s) {
+    return new elt[s];
+  }
+}
+
+// test0 with a signed type larger than size_t.
+namespace test8 {
+  struct A {
+    A();
+    int x;
+  };
+
+  typedef A elt;
+
+  // CHECK:    define [[A:%.*]]* @_ZN5test84testEx(i64
+  // CHECK:      [[N:%.*]] = load i64*
+  // CHECK-NEXT: [[T0:%.*]] = icmp uge i64 [[N]], 4294967296
+  // CHECK-NEXT: [[T1:%.*]] = trunc i64 [[N]] to i32
+  // CHECK-NEXT: [[T2:%.*]] = call [[OVR_T]] @llvm.umul.with.overflow.i32(i32 [[T1]], i32 4)
+  // CHECK-NEXT: [[T3:%.*]] = extractvalue [[OVR_T]] [[T2]], 1
+  // CHECK-NEXT: [[T4:%.*]] = or i1 [[T0]], [[T3]]
+  // CHECK-NEXT: [[T5:%.*]] = extractvalue [[OVR_T]] [[T2]], 0
+  // CHECK-NEXT: [[T6:%.*]] = select i1 [[T4]], i32 -1, i32 [[T5]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T6]])
+  // CHECK:      icmp ult i32 {{.*}}, [[T1]]
+  elt *test(long long s) {
+    return new elt[s];
+  }
+}
+
+// test8 with an unsigned type.
+namespace test9 {
+  struct A {
+    A();
+    int x;
+  };
+
+  typedef A elt;
+
+  // CHECK:    define [[A:%.*]]* @_ZN5test94testEy(i64
+  // CHECK:      [[N:%.*]] = load i64*
+  // CHECK-NEXT: [[T0:%.*]] = icmp uge i64 [[N]], 4294967296
+  // CHECK-NEXT: [[T1:%.*]] = trunc i64 [[N]] to i32
+  // CHECK-NEXT: [[T2:%.*]] = call [[OVR_T]] @llvm.umul.with.overflow.i32(i32 [[T1]], i32 4)
+  // CHECK-NEXT: [[T3:%.*]] = extractvalue [[OVR_T]] [[T2]], 1
+  // CHECK-NEXT: [[T4:%.*]] = or i1 [[T0]], [[T3]]
+  // CHECK-NEXT: [[T5:%.*]] = extractvalue [[OVR_T]] [[T2]], 0
+  // CHECK-NEXT: [[T6:%.*]] = select i1 [[T4]], i32 -1, i32 [[T5]]
+  // CHECK-NEXT: call noalias i8* @_Znaj(i32 [[T6]])
+  // CHECK:      icmp ult i32 {{.*}}, [[T1]]
+  elt *test(unsigned long long s) {
+    return new elt[s];
+  }
+}
diff --git a/clang/test/Sema/sign-conversion.c b/clang/test/Sema/sign-conversion.c
new file mode 100644
index 000000000000..4b1ee7542158
--- /dev/null
+++ b/clang/test/Sema/sign-conversion.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wsign-conversion %s
+
+// PR9345: make a subgroup of -Wconversion for signedness changes
+
+void test(int x) {
+  unsigned t0 = x; // expected-warning {{implicit conversion changes signedness}}
+  unsigned t1 = (t0 == 5 ? x : 0); // expected-warning {{operand of ? changes signedness}}
+}