diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -673,6 +673,16 @@
                            addSanitizerCoveragePass);
   }
 
+  // Move this here, so DFSan runs before ASan.
+  // Also change conditional, so DFSan's instrumentation pass runs when ASan
+  // is enabled.
+  if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addDataFlowSanitizerPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addDataFlowSanitizerPass);
+  }
+
   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
                            addAddressSanitizerPasses);
@@ -722,13 +732,6 @@
                            addThreadSanitizerPass);
   }
 
-  if (LangOpts.Sanitize.has(SanitizerKind::DataFlow)) {
-    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
-                           addDataFlowSanitizerPass);
-    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
-                           addDataFlowSanitizerPass);
-  }
-
   // Set up the per-function pass manager.
   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
   if (CodeGenOpts.VerifyModule)
diff --git a/compiler-rt/lib/asan/asan_globals.cpp b/compiler-rt/lib/asan/asan_globals.cpp
--- a/compiler-rt/lib/asan/asan_globals.cpp
+++ b/compiler-rt/lib/asan/asan_globals.cpp
@@ -26,6 +26,28 @@
 #include "sanitizer_common/sanitizer_stackdepot.h"
 #include "sanitizer_common/sanitizer_symbolizer.h"
 
+typedef __sanitizer::u16 dfsan_label;
+
+SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_retval_tls;
+SANITIZER_INTERFACE_ATTRIBUTE THREADLOCAL dfsan_label __dfsan_arg_tls[64];
+
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE dfsan_label
+__dfsan_union(dfsan_label l1, dfsan_label l2) {
+  //  if (flags().fast16labels)
+  return l1 | l2;
+}
+
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE dfsan_label
+__dfsan_union_load(const dfsan_label *ls, uptr n) {
+  dfsan_label label = ls[0];
+  for (uptr i = 1; i != n; ++i) {
+    dfsan_label next_label = ls[i];
+    if (label != next_label)
+      label = __dfsan_union(label, next_label);
+  }
+  return label;
+}
+
 namespace __asan {
 
 typedef __asan_global Global;
diff --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -1058,6 +1058,12 @@
                                 getArgTLSPtr(), 0, Idx);
 }
 
+static void SetNoSanitizeMetadata(Instruction *I) {
+  I->setMetadata(
+      I->getParent()->getParent()->getParent()->getMDKindID("nosanitize"),
+      MDNode::get(I->getContext(), None));
+}
+
 Value *DFSanFunction::getShadow(Value *V) {
   if (!isa<Argument>(V) && !isa<Instruction>(V))
     return DFS.ZeroShadow;
@@ -1073,8 +1079,10 @@
             DFS.ArgTLS ? &*F->getEntryBlock().begin()
                        : cast<Instruction>(ArgTLSPtr)->getNextNode();
         IRBuilder<> IRB(ArgTLSPos);
-        Shadow =
+        LoadInst *LI =
             IRB.CreateLoad(DFS.ShadowTy, getArgTLS(A->getArgNo(), ArgTLSPos));
+        SetNoSanitizeMetadata(LI);
+        Shadow = LI;
         break;
       }
       case DataFlowSanitizer::IA_Args: {
@@ -1105,9 +1113,11 @@
   assert(Addr != RetvalTLS && "Reinstrumenting?");
   IRBuilder<> IRB(Pos);
   Value *ShadowPtrMaskValue;
-  if (DFSanRuntimeShadowMask)
-    ShadowPtrMaskValue = IRB.CreateLoad(IntptrTy, ExternalShadowMask);
-  else
+  if (DFSanRuntimeShadowMask) {
+    LoadInst *LI = IRB.CreateLoad(IntptrTy, ExternalShadowMask);
+    SetNoSanitizeMetadata(LI);
+    ShadowPtrMaskValue = LI;
+  } else
     ShadowPtrMaskValue = ShadowPtrMask;
   return IRB.CreateIntToPtr(
       IRB.CreateMul(
@@ -1225,7 +1235,9 @@
     const auto i = AllocaShadowMap.find(AI);
     if (i != AllocaShadowMap.end()) {
       IRBuilder<> IRB(Pos);
-      return IRB.CreateLoad(DFS.ShadowTy, i->second);
+      LoadInst *LI = IRB.CreateLoad(DFS.ShadowTy, i->second);
+      SetNoSanitizeMetadata(LI);
+      return LI;
     }
   }
 
@@ -1366,7 +1378,8 @@
     const auto i = AllocaShadowMap.find(AI);
     if (i != AllocaShadowMap.end()) {
       IRBuilder<> IRB(Pos);
-      IRB.CreateStore(Shadow, i->second);
+      StoreInst *SI = IRB.CreateStore(Shadow, i->second);
+      SetNoSanitizeMetadata(SI);
       return;
     }
   }
@@ -1559,7 +1572,8 @@
     case DataFlowSanitizer::IA_TLS: {
       Value *S = DFSF.getShadow(RI.getReturnValue());
       IRBuilder<> IRB(&RI);
-      IRB.CreateStore(S, DFSF.getRetvalTLS());
+      StoreInst *SI = IRB.CreateStore(S, DFSF.getRetvalTLS());
+      SetNoSanitizeMetadata(SI);
       break;
     }
     case DataFlowSanitizer::IA_Args: {
@@ -1666,7 +1680,8 @@
 
           for (unsigned n = 0; i != CB.arg_end(); ++i, ++n) {
             auto LabelVAPtr = IRB.CreateStructGEP(LabelVATy, LabelVAAlloca, n);
-            IRB.CreateStore(DFSF.getShadow(*i), LabelVAPtr);
+            StoreInst *SI = IRB.CreateStore(DFSF.getShadow(*i), LabelVAPtr);
+            SetNoSanitizeMetadata(SI);
           }
 
           Args.push_back(IRB.CreateStructGEP(LabelVATy, LabelVAAlloca, 0));
@@ -1702,6 +1717,7 @@
         if (!FT->getReturnType()->isVoidTy()) {
           LoadInst *LabelLoad =
               IRB.CreateLoad(DFSF.DFS.ShadowTy, DFSF.LabelReturnAlloca);
+          SetNoSanitizeMetadata(LabelLoad);
           DFSF.setShadow(CustomCI, LabelLoad);
         }
 
@@ -1716,8 +1732,9 @@
   FunctionType *FT = CB.getFunctionType();
   if (DFSF.DFS.getInstrumentedABI() == DataFlowSanitizer::IA_TLS) {
     for (unsigned i = 0, n = FT->getNumParams(); i != n; ++i) {
-      IRB.CreateStore(DFSF.getShadow(CB.getArgOperand(i)),
-                      DFSF.getArgTLS(i, &CB));
+      StoreInst *SI = IRB.CreateStore(DFSF.getShadow(CB.getArgOperand(i)),
+                                      DFSF.getArgTLS(i, &CB));
+      SetNoSanitizeMetadata(SI);
     }
   }
 
@@ -1739,6 +1756,7 @@
     if (DFSF.DFS.getInstrumentedABI() == DataFlowSanitizer::IA_TLS) {
       IRBuilder<> NextIRB(Next);
       LoadInst *LI = NextIRB.CreateLoad(DFSF.DFS.ShadowTy, DFSF.getRetvalTLS());
+      SetNoSanitizeMetadata(LI);
       DFSF.SkipInsts.insert(LI);
       DFSF.setShadow(&CB, LI);
       DFSF.NonZeroChecks.push_back(LI);
@@ -1769,9 +1787,10 @@
                        "", &DFSF.F->getEntryBlock().front());
       Args.push_back(IRB.CreateConstGEP2_32(VarArgArrayTy, VarArgShadow, 0, 0));
       for (unsigned n = 0; i != E; ++i, ++n) {
-        IRB.CreateStore(
+        StoreInst *SI = IRB.CreateStore(
             DFSF.getShadow(*i),
             IRB.CreateConstGEP2_32(VarArgArrayTy, VarArgShadow, 0, n));
+        SetNoSanitizeMetadata(SI);
         Args.push_back(*i);
       }
     }
diff --git a/load.c b/load.c
new file mode 100644
--- /dev/null
+++ b/load.c
@@ -0,0 +1,6 @@
+int load(int *p) { return *p; }
+
+int main() {
+  int i = 10;
+  load(&i);
+}