Index: cfe/trunk/lib/CodeGen/CGExprScalar.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGExprScalar.cpp
+++ cfe/trunk/lib/CodeGen/CGExprScalar.cpp
@@ -2751,8 +2751,8 @@
            isa<llvm::IntegerType>(Ops.LHS->getType())) {
     CodeGenFunction::SanitizerScope SanScope(&CGF);
     SmallVector<std::pair<Value *, SanitizerMask>, 2> Checks;
-    llvm::Value *WidthMinusOne = GetWidthMinusOneValue(Ops.LHS, RHS);
-    llvm::Value *ValidExponent = Builder.CreateICmpULE(RHS, WidthMinusOne);
+    llvm::Value *WidthMinusOne = GetWidthMinusOneValue(Ops.LHS, Ops.RHS);
+    llvm::Value *ValidExponent = Builder.CreateICmpULE(Ops.RHS, WidthMinusOne);
 
     if (SanitizeExponent) {
       Checks.push_back(
Index: cfe/trunk/test/CodeGen/ubsan-shift.c
===================================================================
--- cfe/trunk/test/CodeGen/ubsan-shift.c
+++ cfe/trunk/test/CodeGen/ubsan-shift.c
@@ -0,0 +1,29 @@
+// RUN: %clang_cc1 -triple=x86_64-apple-darwin -fsanitize=shift-exponent -emit-llvm %s -o - | FileCheck %s
+
+// CHECK-LABEL: define i32 @f1
+int f1(int c, int shamt) {
+// CHECK: icmp ule i32 %{{.*}}, 31, !nosanitize
+// CHECK: icmp ule i32 %{{.*}}, 31, !nosanitize
+  return 1 << (c << shamt);
+}
+
+// CHECK-LABEL: define i32 @f2
+int f2(long c, int shamt) {
+// CHECK: icmp ule i32 %{{.*}}, 63, !nosanitize
+// CHECK: icmp ule i64 %{{.*}}, 31, !nosanitize
+  return 1 << (c << shamt);
+}
+
+// CHECK-LABEL: define i32 @f3
+unsigned f3(unsigned c, int shamt) {
+// CHECK: icmp ule i32 %{{.*}}, 31, !nosanitize
+// CHECK: icmp ule i32 %{{.*}}, 31, !nosanitize
+  return 1U << (c << shamt);
+}
+
+// CHECK-LABEL: define i32 @f4
+unsigned f4(unsigned long c, int shamt) {
+// CHECK: icmp ule i32 %{{.*}}, 63, !nosanitize
+// CHECK: icmp ule i64 %{{.*}}, 31, !nosanitize
+  return 1U << (c << shamt);
+}