diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index b0ea2fa..e8c05d3 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -406,7 +406,7 @@
     return RValue::get(Builder.CreateCall(F));
   }
   case Builtin::BI__builtin_unreachable: {
-    if (CatchUndefined)
+    if (getLangOpts().SanitizeUnreachable)
       EmitCheck(Builder.getFalse(), "builtin_unreachable",
                 EmitCheckSourceLocation(E->getExprLoc()),
                 llvm::ArrayRef<llvm::Value *>());
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 6255585..d1a2889 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -389,7 +389,7 @@
                                                    ReferenceTemporaryDtor,
                                                    ObjCARCReferenceLifetimeType,
                                                    InitializedDecl);
-  if (CatchUndefined && !E->getType()->isFunctionType()) {
+  if (SanitizePerformTypeCheck && !E->getType()->isFunctionType()) {
     // C++11 [dcl.ref]p5 (as amended by core issue 453):
     //   If a glvalue to which a reference is directly bound designates neither
     //   an existing object or function of an appropriate type nor a region of
@@ -476,7 +476,7 @@
 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
                                     llvm::Value *Address,
                                     QualType Ty, CharUnits Alignment) {
-  if (!CatchUndefined)
+  if (!SanitizePerformTypeCheck)
     return;
 
   // Don't check pointers outside the default address space. The null check
@@ -487,19 +487,17 @@
 
   llvm::Value *Cond = 0;
 
-  // The glvalue must not be an empty glvalue.
-  Cond = Builder.CreateICmpNE(
-    Address, llvm::Constant::getNullValue(Address->getType()));
+  if (getLangOpts().SanitizeNull) {
+    // The glvalue must not be an empty glvalue.
+    Cond = Builder.CreateICmpNE(
+        Address, llvm::Constant::getNullValue(Address->getType()));
+  }
 
-  uint64_t AlignVal = Alignment.getQuantity();
-
-  if (!Ty->isIncompleteType()) {
+  if (getLangOpts().SanitizeObjectSize && !Ty->isIncompleteType()) {
     uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
-    if (!AlignVal)
-      AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
 
     // The glvalue must refer to a large enough storage region.
-    // FIXME: If -faddress-sanitizer is enabled, insert dynamic instrumentation
+    // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
     //        to check this.
     llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, IntPtrTy);
     llvm::Value *Min = Builder.getFalse();
@@ -510,13 +508,22 @@
     Cond = Cond ? Builder.CreateAnd(Cond, LargeEnough) : LargeEnough;
   }
 
-  if (AlignVal) {
+  uint64_t AlignVal = 0;
+
+  if (getLangOpts().SanitizeAlignment) {
+    AlignVal = Alignment.getQuantity();
+    if (!Ty->isIncompleteType() && !AlignVal)
+      AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
+
     // The glvalue must be suitably aligned.
-    llvm::Value *Align =
-        Builder.CreateAnd(Builder.CreatePtrToInt(Address, IntPtrTy),
-                          llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
-    Cond = Builder.CreateAnd(Cond,
-        Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0)));
+    if (AlignVal) {
+      llvm::Value *Align =
+          Builder.CreateAnd(Builder.CreatePtrToInt(Address, IntPtrTy),
+                            llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
+      llvm::Value *Aligned =
+        Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
+      Cond = Cond ? Builder.CreateAnd(Cond, Aligned) : Aligned;
+    }
   }
 
   if (Cond) {
@@ -529,14 +536,11 @@
     EmitCheck(Cond, "type_mismatch", StaticData, Address);
   }
 
+  // If possible, check that the vptr indicates that there is a subobject of
+  // type Ty at offset zero within this object.
   CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
-  if (TCK != TCK_ConstructorCall &&
+  if (getLangOpts().SanitizeVptr && TCK != TCK_ConstructorCall &&
       RD && RD->hasDefinition() && RD->isDynamicClass()) {
-    // Check that the vptr indicates that there is a subobject of type Ty at
-    // offset zero within this object.
-    // FIXME: Produce a diagnostic if the user tries to combine this check with
-    //        -fno-rtti.
-
     // Compute a hash of the mangled name of the type.
     //
     // FIXME: This is not guaranteed to be deterministic! Move to a
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index b6ce22b..c21cbf6 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -406,14 +406,14 @@
       case LangOptions::SOB_Defined:
         return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
       case LangOptions::SOB_Undefined:
-        if (!CGF.CatchUndefined)
+        if (!CGF.getLangOpts().SanitizeSignedIntegerOverflow)
           return Builder.CreateNSWMul(Ops.LHS, Ops.RHS, "mul");
         // Fall through.
       case LangOptions::SOB_Trapping:
         return EmitOverflowCheckedBinOp(Ops);
       }
     }
-    
+
     if (Ops.LHS->getType()->isFPOrFPVectorTy())
       return Builder.CreateFMul(Ops.LHS, Ops.RHS, "mul");
     return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul");
@@ -731,7 +731,7 @@
 
   // An overflowing conversion has undefined behavior if either the source type
   // or the destination type is a floating-point type.
-  if (CGF.CatchUndefined &&
+  if (CGF.getLangOpts().SanitizeFloatCastOverflow &&
       (OrigSrcType->isFloatingType() || DstType->isFloatingType()))
     EmitFloatConversionCheck(OrigSrc, OrigSrcType, Src, SrcType, DstType, DstTy);
 
@@ -1417,7 +1417,7 @@
   case LangOptions::SOB_Defined:
     return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec");
   case LangOptions::SOB_Undefined:
-    if (!CGF.CatchUndefined)
+    if (!CGF.getLangOpts().SanitizeSignedIntegerOverflow)
       return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec");
     // Fall through.
   case LangOptions::SOB_Trapping:
@@ -1942,7 +1942,7 @@
 }
 
 Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) {
-  if (CGF.CatchUndefined) {
+  if (CGF.getLangOpts().SanitizeDivideByZero) {
     llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
 
     if (Ops.Ty->isIntegerType())
@@ -1970,7 +1970,7 @@
 
 Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) {
   // Rem in C can't be a floating point type: C99 6.5.5p2.
-  if (CGF.CatchUndefined) {
+  if (CGF.getLangOpts().SanitizeDivideByZero) {
     llvm::Value *Zero = llvm::Constant::getNullValue(ConvertType(Ops.Ty));
 
     if (Ops.Ty->isIntegerType()) 
@@ -2021,9 +2021,9 @@
   const std::string *handlerName =
     &CGF.getLangOpts().OverflowHandler;
   if (handlerName->empty()) {
-    // If -fcatch-undefined-behavior is enabled, emit a call to its
+    // If the signed-integer-overflow sanitizer is enabled, emit a call to its
     // runtime. Otherwise, this is a -ftrapv check, so just emit a trap.
-    if (CGF.CatchUndefined)
+    if (CGF.getLangOpts().SanitizeSignedIntegerOverflow)
       EmitBinOpCheck(Builder.CreateNot(overflow), Ops);
     else
       CGF.EmitTrapvCheck(Builder.CreateNot(overflow));
@@ -2241,7 +2241,7 @@
     case LangOptions::SOB_Defined:
       return Builder.CreateAdd(op.LHS, op.RHS, "add");
     case LangOptions::SOB_Undefined:
-      if (!CGF.CatchUndefined)
+      if (!CGF.getLangOpts().SanitizeSignedIntegerOverflow)
         return Builder.CreateNSWAdd(op.LHS, op.RHS, "add");
       // Fall through.
     case LangOptions::SOB_Trapping:
@@ -2268,7 +2268,7 @@
       case LangOptions::SOB_Defined:
         return Builder.CreateSub(op.LHS, op.RHS, "sub");
       case LangOptions::SOB_Undefined:
-        if (!CGF.CatchUndefined)
+        if (!CGF.getLangOpts().SanitizeSignedIntegerOverflow)
           return Builder.CreateNSWSub(op.LHS, op.RHS, "sub");
         // Fall through.
       case LangOptions::SOB_Trapping:
@@ -2351,7 +2351,8 @@
   if (Ops.LHS->getType() != RHS->getType())
     RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
 
-  if (CGF.CatchUndefined && isa<llvm::IntegerType>(Ops.LHS->getType())) {
+  if (CGF.getLangOpts().SanitizeShift &&
+      isa<llvm::IntegerType>(Ops.LHS->getType())) {
     unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
     llvm::Value *WidthMinusOne =
       llvm::ConstantInt::get(RHS->getType(), Width - 1);
@@ -2390,7 +2391,8 @@
   if (Ops.LHS->getType() != RHS->getType())
     RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom");
 
-  if (CGF.CatchUndefined && isa<llvm::IntegerType>(Ops.LHS->getType())) {
+  if (CGF.getLangOpts().SanitizeShift &&
+      isa<llvm::IntegerType>(Ops.LHS->getType())) {
     unsigned Width = cast<llvm::IntegerType>(Ops.LHS->getType())->getBitWidth();
     llvm::Value *WidthVal = llvm::ConstantInt::get(RHS->getType(), Width);
     EmitBinOpCheck(Builder.CreateICmpULT(RHS, WidthVal), Ops);
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 140f1cb..18f1623 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -32,6 +32,10 @@
   : CodeGenTypeCache(cgm), CGM(cgm),
     Target(CGM.getContext().getTargetInfo()),
     Builder(cgm.getModule().getContext()),
+    SanitizePerformTypeCheck(CGM.getLangOpts().SanitizeNull |
+                             CGM.getLangOpts().SanitizeAlignment |
+                             CGM.getLangOpts().SanitizeObjectSize |
+                             CGM.getLangOpts().SanitizeVptr),
     AutoreleaseResult(false), BlockInfo(0), BlockPointer(0),
     LambdaThisCaptureField(0), NormalCleanupDest(0), NextCleanupDestIndex(1),
     FirstBlockInfo(0), EHResumeBlock(0), ExceptionSlot(0), EHSelectorSlot(0),
@@ -40,8 +44,6 @@
     CXXABIThisDecl(0), CXXABIThisValue(0), CXXThisValue(0), CXXVTTDecl(0),
     CXXVTTValue(0), OutermostConditional(0), TerminateLandingPad(0),
     TerminateHandler(0), TrapBB(0) {
-
-  CatchUndefined = getLangOpts().CatchUndefined;
   if (!suppressNewContext)
     CGM.getCXXABI().getMangleContext().startNewFunction();
 }
@@ -543,7 +545,7 @@
   //   function call is used by the caller, the behavior is undefined.
   if (getLangOpts().CPlusPlus && !FD->hasImplicitReturnZero() &&
       !FD->getResultType()->isVoidType() && Builder.GetInsertBlock()) {
-    if (CatchUndefined)
+    if (getLangOpts().SanitizeReturn)
       EmitCheck(Builder.getFalse(), "missing_return",
                 EmitCheckSourceLocation(FD->getLocation()),
                 llvm::ArrayRef<llvm::Value*>());
@@ -1128,7 +1130,8 @@
           //   If the size is an expression that is not an integer constant
           //   expression [...] each time it is evaluated it shall have a value
           //   greater than zero.
-          if (CatchUndefined && size->getType()->isSignedIntegerType()) {
+          if (getLangOpts().SanitizeVLABound &&
+              size->getType()->isSignedIntegerType()) {
             llvm::Value *Zero = llvm::Constant::getNullValue(Size->getType());
             llvm::Constant *StaticArgs[] = {
               EmitCheckSourceLocation(size->getLocStart()),
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 1e9fd00..fadc391 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -594,8 +594,9 @@
   /// potentially higher performance penalties.
   unsigned char BoundsChecking;
 
-  /// CatchUndefined - Emit run-time checks to catch undefined behaviors.
-  bool CatchUndefined;
+  /// \brief Whether any type-checking sanitizers are enabled. If \c false,
+  /// calls to EmitTypeCheck can be skipped.
+  bool SanitizePerformTypeCheck;
 
   /// In ARC, whether we should autorelease the return value.
   bool AutoreleaseResult;