diff --git a/llvm/include/llvm/Transforms/IPO/Attributor.h b/llvm/include/llvm/Transforms/IPO/Attributor.h
--- a/llvm/include/llvm/Transforms/IPO/Attributor.h
+++ b/llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -172,7 +172,8 @@
                                      const Optional<Value *> &B, Type *Ty);
 
 /// Return the initial value of \p Obj with type \p Ty if that is a constant.
-Constant *getInitialValueForObj(Value &Obj, Type &Ty);
+Constant *getInitialValueForObj(Value &Obj, Type &Ty,
+                                const TargetLibraryInfo *TLI);
 
 /// Collect all potential underlying objects of \p Ptr at position \p CtxI in
 /// \p Objects. Assumed information is used and dependences onto \p QueryingAA
diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -22,6 +22,7 @@
 #include "llvm/ADT/TinyPtrVector.h"
 #include "llvm/Analysis/InlineCost.h"
 #include "llvm/Analysis/LazyValueInfo.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/Analysis/MemorySSAUpdater.h"
 #include "llvm/Analysis/MustExecute.h"
 #include "llvm/Analysis/ValueTracking.h"
@@ -202,9 +203,17 @@
   return NoRecurseAA.isAssumedNoRecurse();
 }
 
-Constant *AA::getInitialValueForObj(Value &Obj, Type &Ty) {
+Constant *AA::getInitialValueForObj(Value &Obj, Type &Ty,
+                                    const TargetLibraryInfo *TLI) {
   if (isa<AllocaInst>(Obj))
     return UndefValue::get(&Ty);
+  if (isNoAliasFn(&Obj, TLI)) {
+    if (isMallocLikeFn(&Obj, TLI) || isAlignedAllocLikeFn(&Obj, TLI))
+      return UndefValue::get(&Ty);
+    if (isCallocLikeFn(&Obj, TLI))
+      return Constant::getNullValue(&Ty);
+    return nullptr;
+  }
   auto *GV = dyn_cast<GlobalVariable>(&Obj);
   if (!GV || !GV->hasLocalLinkage())
     return nullptr;
@@ -300,6 +309,8 @@
   SmallVector<const AAPointerInfo *> PIs;
   SmallVector<Value *> NewCopies;
 
+  const auto *TLI =
+      A.getInfoCache().getTargetLibraryInfoForFunction(*SI.getFunction());
   for (Value *Obj : Objects) {
     LLVM_DEBUG(dbgs() << "Visit underlying object " << *Obj << "\n");
     if (isa<UndefValue>(Obj))
@@ -316,7 +327,8 @@
           dbgs() << "Underlying object is a valid nullptr, giving up.\n";);
       return false;
     }
-    if (!isa<AllocaInst>(Obj) && !isa<GlobalVariable>(Obj)) {
+    if (!isa<AllocaInst>(Obj) && !isa<GlobalVariable>(Obj) &&
+        !isNoAliasFn(Obj, TLI)) {
       LLVM_DEBUG(dbgs() << "Underlying object is not supported yet: " << *Obj
                         << "\n";);
       return false;
diff --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -1175,6 +1175,10 @@
       return true;
     };
 
+    const auto *TLI = getAnchorScope()
+                          ? A.getInfoCache().getTargetLibraryInfoForFunction(
+                                *getAnchorScope())
+                          : nullptr;
     auto UsePred = [&](const Use &U, bool &Follow) -> bool {
       Value *CurPtr = U.get();
       User *Usr = U.getUser();
@@ -1285,6 +1289,8 @@
       if (auto *CB = dyn_cast<CallBase>(Usr)) {
         if (CB->isLifetimeStartOrEnd())
           return true;
+        if (TLI && isFreeCall(CB, TLI))
+          return true;
         if (CB->isArgOperand(&U)) {
           unsigned ArgNo = CB->getArgOperandNo(&U);
           const auto &CSArgPI = A.getAAFor<AAPointerInfo>(
@@ -5245,6 +5251,8 @@
     if (!AA::getAssumedUnderlyingObjects(A, Ptr, Objects, AA, &L))
       return false;
 
+    const auto *TLI =
+        A.getInfoCache().getTargetLibraryInfoForFunction(*L.getFunction());
     for (Value *Obj : Objects) {
       LLVM_DEBUG(dbgs() << "Visit underlying object " << *Obj << "\n");
       if (isa<UndefValue>(Obj))
@@ -5259,9 +5267,10 @@
           continue;
         return false;
       }
-      if (!isa<AllocaInst>(Obj) && !isa<GlobalVariable>(Obj))
+      if (!isa<AllocaInst>(Obj) && !isa<GlobalVariable>(Obj) &&
+          !isNoAliasFn(Obj, TLI))
         return false;
-      Constant *InitialVal = AA::getInitialValueForObj(*Obj, *L.getType());
+      Constant *InitialVal = AA::getInitialValueForObj(*Obj, *L.getType(), TLI);
       if (!InitialVal || !Union(*InitialVal))
         return false;
 
diff --git a/llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll b/llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll
--- a/llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll
+++ b/llvm/test/Transforms/Attributor/heap_to_stack_gpu.ll
@@ -494,7 +494,6 @@
 ; CHECK:       8:
 ; CHECK-NEXT:    [[TMP9:%.*]] = call noalias i8* @malloc(i64 noundef 4)
 ; CHECK-NEXT:    [[TMP10:%.*]] = bitcast i8* [[TMP9]] to i32*
-; CHECK-NEXT:    store i32 1, i32* [[TMP10]], align 8
 ; CHECK-NEXT:    br label [[TMP4]]
 ; CHECK:       11:
 ; CHECK-NEXT:    ret i32 5
diff --git a/llvm/test/Transforms/Attributor/memory_locations.ll b/llvm/test/Transforms/Attributor/memory_locations.ll
--- a/llvm/test/Transforms/Attributor/memory_locations.ll
+++ b/llvm/test/Transforms/Attributor/memory_locations.ll
@@ -122,11 +122,18 @@
 
 define dso_local i8* @internal_only_rec_static_helper_malloc_noescape(i32 %arg) {
 ; FIXME: This is actually inaccessiblememonly because the malloced memory does not escape
-; CHECK-LABEL: define {{[^@]+}}@internal_only_rec_static_helper_malloc_noescape
-; CHECK-SAME: (i32 [[ARG:%.*]]) {
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[CALL:%.*]] = call noalias i8* @internal_only_rec_static_malloc_noescape(i32 [[ARG]])
-; CHECK-NEXT:    ret i8* [[CALL]]
+; IS__TUNIT____-LABEL: define {{[^@]+}}@internal_only_rec_static_helper_malloc_noescape
+; IS__TUNIT____-SAME: (i32 [[ARG:%.*]]) {
+; IS__TUNIT____-NEXT:  entry:
+; IS__TUNIT____-NEXT:    [[CALL:%.*]] = call noalias i8* @internal_only_rec_static_malloc_noescape(i32 [[ARG]])
+; IS__TUNIT____-NEXT:    ret i8* [[CALL]]
+;
+; IS__CGSCC____: Function Attrs: inaccessiblememonly
+; IS__CGSCC____-LABEL: define {{[^@]+}}@internal_only_rec_static_helper_malloc_noescape
+; IS__CGSCC____-SAME: (i32 [[ARG:%.*]]) #[[ATTR0]] {
+; IS__CGSCC____-NEXT:  entry:
+; IS__CGSCC____-NEXT:    [[CALL:%.*]] = call noalias i8* @internal_only_rec_static_malloc_noescape(i32 [[ARG]])
+; IS__CGSCC____-NEXT:    ret i8* [[CALL]]
 ;
 entry:
   %call = call i8* @internal_only_rec_static_malloc_noescape(i32 %arg)
@@ -135,24 +142,42 @@
 
 define internal i8* @internal_only_rec_static_malloc_noescape(i32 %arg) {
 ; FIXME: This is actually inaccessiblememonly because the malloced memory does not escape
-; CHECK-LABEL: define {{[^@]+}}@internal_only_rec_static_malloc_noescape
-; CHECK-SAME: (i32 [[ARG:%.*]]) {
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[REM:%.*]] = srem i32 [[ARG]], 2
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[REM]], 1
-; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
-; CHECK:       if.then:
-; CHECK-NEXT:    [[DIV:%.*]] = sdiv i32 [[ARG]], 2
-; CHECK-NEXT:    [[CALL:%.*]] = call noalias i8* @internal_only_rec(i32 [[DIV]])
-; CHECK-NEXT:    br label [[RETURN:%.*]]
-; CHECK:       if.end:
-; CHECK-NEXT:    [[CONV:%.*]] = sext i32 [[ARG]] to i64
-; CHECK-NEXT:    [[CALL1:%.*]] = call noalias i8* @malloc(i64 [[CONV]])
-; CHECK-NEXT:    store i8 0, i8* [[CALL1]], align 1
-; CHECK-NEXT:    br label [[RETURN]]
-; CHECK:       return:
-; CHECK-NEXT:    [[RETVAL_0:%.*]] = phi i8* [ [[CALL]], [[IF_THEN]] ], [ null, [[IF_END]] ]
-; CHECK-NEXT:    ret i8* [[RETVAL_0]]
+; IS__TUNIT____-LABEL: define {{[^@]+}}@internal_only_rec_static_malloc_noescape
+; IS__TUNIT____-SAME: (i32 [[ARG:%.*]]) {
+; IS__TUNIT____-NEXT:  entry:
+; IS__TUNIT____-NEXT:    [[REM:%.*]] = srem i32 [[ARG]], 2
+; IS__TUNIT____-NEXT:    [[CMP:%.*]] = icmp eq i32 [[REM]], 1
+; IS__TUNIT____-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; IS__TUNIT____:       if.then:
+; IS__TUNIT____-NEXT:    [[DIV:%.*]] = sdiv i32 [[ARG]], 2
+; IS__TUNIT____-NEXT:    [[CALL:%.*]] = call noalias i8* @internal_only_rec(i32 [[DIV]])
+; IS__TUNIT____-NEXT:    br label [[RETURN:%.*]]
+; IS__TUNIT____:       if.end:
+; IS__TUNIT____-NEXT:    [[CONV:%.*]] = sext i32 [[ARG]] to i64
+; IS__TUNIT____-NEXT:    [[CALL1:%.*]] = call noalias i8* @malloc(i64 [[CONV]])
+; IS__TUNIT____-NEXT:    br label [[RETURN]]
+; IS__TUNIT____:       return:
+; IS__TUNIT____-NEXT:    [[RETVAL_0:%.*]] = phi i8* [ [[CALL]], [[IF_THEN]] ], [ null, [[IF_END]] ]
+; IS__TUNIT____-NEXT:    ret i8* [[RETVAL_0]]
+;
+; IS__CGSCC____: Function Attrs: inaccessiblememonly
+; IS__CGSCC____-LABEL: define {{[^@]+}}@internal_only_rec_static_malloc_noescape
+; IS__CGSCC____-SAME: (i32 [[ARG:%.*]]) #[[ATTR0]] {
+; IS__CGSCC____-NEXT:  entry:
+; IS__CGSCC____-NEXT:    [[REM:%.*]] = srem i32 [[ARG]], 2
+; IS__CGSCC____-NEXT:    [[CMP:%.*]] = icmp eq i32 [[REM]], 1
+; IS__CGSCC____-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_END:%.*]]
+; IS__CGSCC____:       if.then:
+; IS__CGSCC____-NEXT:    [[DIV:%.*]] = sdiv i32 [[ARG]], 2
+; IS__CGSCC____-NEXT:    [[CALL:%.*]] = call noalias i8* @internal_only_rec(i32 [[DIV]])
+; IS__CGSCC____-NEXT:    br label [[RETURN:%.*]]
+; IS__CGSCC____:       if.end:
+; IS__CGSCC____-NEXT:    [[CONV:%.*]] = sext i32 [[ARG]] to i64
+; IS__CGSCC____-NEXT:    [[CALL1:%.*]] = call noalias i8* @malloc(i64 [[CONV]])
+; IS__CGSCC____-NEXT:    br label [[RETURN]]
+; IS__CGSCC____:       return:
+; IS__CGSCC____-NEXT:    [[RETVAL_0:%.*]] = phi i8* [ [[CALL]], [[IF_THEN]] ], [ null, [[IF_END]] ]
+; IS__CGSCC____-NEXT:    ret i8* [[RETVAL_0]]
 ;
 entry:
   %rem = srem i32 %arg, 2