Index: lib/Analysis/ValueTracking.cpp
===================================================================
--- lib/Analysis/ValueTracking.cpp
+++ lib/Analysis/ValueTracking.cpp
@@ -2016,6 +2016,18 @@
     if (isKnownNonNullFromDominatingCondition(V, Q.CxtI, Q.DT))
       return true;
 
+    {
+      // Look through operations that do not alter the value.
+      if (const BitCastOperator *BCO = dyn_cast<BitCastOperator>(V))
+        return isKnownNonZero(BCO->getOperand(0), Depth, Q);
+
+      if (const AddrSpaceCastInst *ASC = dyn_cast<AddrSpaceCastInst>(V))
+        return isKnownNonZero(ASC->getPointerOperand(), Depth, Q);
+
+      if (const PtrToIntOperator *P2I = dyn_cast<PtrToIntOperator>(V))
+        return isKnownNonZero(P2I->getPointerOperand(), Depth, Q);
+    }
+
     if (const GEPOperator *GEP = dyn_cast<GEPOperator>(V))
       if (isGEPKnownNonNull(GEP, Depth, Q))
         return true;
Index: test/Transforms/InstCombine/alloca-cast-debuginfo.ll
===================================================================
--- test/Transforms/InstCombine/alloca-cast-debuginfo.ll
+++ test/Transforms/InstCombine/alloca-cast-debuginfo.ll
@@ -45,7 +45,7 @@
 ; Another dbg.value for "local" would be redundant here.
 ; CHECK-NOT: call void @llvm.dbg.value(metadata i8* [[simplified]], metadata !22, metadata !DIExpression())
 ;
-; CHECK: call void @escape(i8* [[simplified]])
+; CHECK: call void @escape(i8* nonnull [[simplified]])
 ; CHECK: ret void
 
 declare void @llvm.dbg.declare(metadata, metadata, metadata)
Index: test/Transforms/InstCombine/memcpy-from-global.ll
===================================================================
--- test/Transforms/InstCombine/memcpy-from-global.ll
+++ test/Transforms/InstCombine/memcpy-from-global.ll
@@ -103,7 +103,7 @@
 ; CHECK-NEXT: addrspacecast
 
 ; use @G instead of %A
-; CHECK-NEXT: call void @llvm.memcpy.p1i8.p1i8.i64(i8 addrspace(1)* align 4 %{{.*}},
+; CHECK-NEXT: call void @llvm.memcpy.p1i8.p1i8.i64(i8 addrspace(1)* nonnull align 4 %{{.*}},
   call void @llvm.memcpy.p1i8.p0i8.i64(i8 addrspace(1)* align 4 %a, i8* align 4 bitcast (%T* @G to i8*), i64 124, i1 false)
   call void @llvm.memcpy.p1i8.p1i8.i64(i8 addrspace(1)* align 4 %b, i8 addrspace(1)* align 4 %a, i64 124, i1 false)
   call void @bar_as1(i8 addrspace(1)* %b)
Index: test/Transforms/InstCombine/objsize.ll
===================================================================
--- test/Transforms/InstCombine/objsize.ll
+++ test/Transforms/InstCombine/objsize.ll
@@ -114,7 +114,7 @@
   %1 = bitcast %struct.data* %0 to i8*
   %2 = call i32 @llvm.objectsize.i32.p0i8(i8* %1, i1 false, i1 false) nounwind
 ; CHECK-NOT: @llvm.objectsize
-; CHECK: @llvm.memset.p0i8.i32(i8* align 8 %1, i8 0, i32 1824, i1 false)
+; CHECK: @llvm.memset.p0i8.i32(i8* nonnull align 8 %1, i8 0, i32 1824, i1 false)
   %3 = call i8* @__memset_chk(i8* %1, i32 0, i32 1824, i32 %2) nounwind
   store i8* %1, i8** %esc
   ret i32 0
Index: test/Transforms/InstCombine/select.ll
===================================================================
--- test/Transforms/InstCombine/select.ll
+++ test/Transforms/InstCombine/select.ll
@@ -1141,7 +1141,7 @@
 ; CHECK-NEXT:    [[Y:%.*]] = alloca i32, align 4
 ; CHECK-NEXT:    [[X1:%.*]] = bitcast float* [[X]] to i32*
 ; CHECK-NEXT:    [[Y1:%.*]] = bitcast i32* [[Y]] to float*
-; CHECK-NEXT:    call void @scribble_on_i32(i32* [[X1]])
+; CHECK-NEXT:    call void @scribble_on_i32(i32* nonnull [[X1]])
 ; CHECK-NEXT:    call void @scribble_on_i32(i32* nonnull [[Y]])
 ; CHECK-NEXT:    [[TMP:%.*]] = load float, float* [[X]], align 4
 ; CHECK-NEXT:    store float [[TMP]], float* [[Y1]], align 4
@@ -1172,8 +1172,8 @@
 ; CHECK-NEXT:    [[Y:%.*]] = alloca i8*, align 8
 ; CHECK-NEXT:    [[TMPCAST:%.*]] = bitcast i8** [[Y]] to i64*
 ; CHECK-NEXT:    [[X1:%.*]] = bitcast i8** [[X]] to i64*
-; CHECK-NEXT:    call void @scribble_on_i64(i64* [[X1]])
-; CHECK-NEXT:    call void @scribble_on_i64(i64* [[TMPCAST]])
+; CHECK-NEXT:    call void @scribble_on_i64(i64* nonnull [[X1]])
+; CHECK-NEXT:    call void @scribble_on_i64(i64* nonnull [[TMPCAST]])
 ; CHECK-NEXT:    [[TMP:%.*]] = load i64, i64* [[X1]], align 8
 ; CHECK-NEXT:    store i64 [[TMP]], i64* [[TMPCAST]], align 8
 ; CHECK-NEXT:    [[V:%.*]] = inttoptr i64 [[TMP]] to i8*
@@ -1200,8 +1200,8 @@
 ; CHECK-NEXT:    [[Y:%.*]] = alloca i8*, align 8
 ; CHECK-NEXT:    [[TMPCAST:%.*]] = bitcast i8** [[Y]] to i64*
 ; CHECK-NEXT:    [[X1:%.*]] = bitcast i8** [[X]] to i64*
-; CHECK-NEXT:    call void @scribble_on_i64(i64* [[X1]])
-; CHECK-NEXT:    call void @scribble_on_i64(i64* [[TMPCAST]])
+; CHECK-NEXT:    call void @scribble_on_i64(i64* nonnull [[X1]])
+; CHECK-NEXT:    call void @scribble_on_i64(i64* nonnull [[TMPCAST]])
 ; CHECK-NEXT:    [[TMP:%.*]] = load i8*, i8** [[X]], align 8
 ; CHECK-NEXT:    store i8* [[TMP]], i8** [[Y]], align 8
 ; CHECK-NEXT:    [[V:%.*]] = ptrtoint i8* [[TMP]] to i64
@@ -1230,7 +1230,7 @@
 ; CHECK-NEXT:    [[X1_SUB:%.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[X1]], i64 0, i64 0
 ; CHECK-NEXT:    [[X2:%.*]] = bitcast [2 x i8*]* [[X1]] to i128*
 ; CHECK-NEXT:    [[Y1:%.*]] = bitcast i128* [[Y]] to i8**
-; CHECK-NEXT:    call void @scribble_on_i128(i128* [[X2]])
+; CHECK-NEXT:    call void @scribble_on_i128(i128* nonnull [[X2]])
 ; CHECK-NEXT:    call void @scribble_on_i128(i128* nonnull [[Y]])
 ; CHECK-NEXT:    [[TMP:%.*]] = load i128, i128* [[X2]], align 8
 ; CHECK-NEXT:    store i128 [[TMP]], i128* [[Y]], align 8
@@ -1263,7 +1263,7 @@
 ; CHECK-NEXT:    [[X1_SUB:%.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* [[X1]], i64 0, i64 0
 ; CHECK-NEXT:    [[X2:%.*]] = bitcast [2 x i8*]* [[X1]] to i128*
 ; CHECK-NEXT:    [[Y1:%.*]] = bitcast i128* [[Y]] to i8**
-; CHECK-NEXT:    call void @scribble_on_i128(i128* [[X2]])
+; CHECK-NEXT:    call void @scribble_on_i128(i128* nonnull [[X2]])
 ; CHECK-NEXT:    call void @scribble_on_i128(i128* nonnull [[Y]])
 ; CHECK-NEXT:    [[TMP:%.*]] = load i8*, i8** [[X1_SUB]], align 8
 ; CHECK-NEXT:    store i8* [[TMP]], i8** [[Y1]], align 8