[PATCH] D107357: [getUnderlyingObject] support ptr_provenance

[Jeroen Dobbelaere via Phabricator via llvm-commits]

jeroen.dobbelaere updated this revision to Diff 378681.
jeroen.dobbelaere added a reviewer: asbirlea.
jeroen.dobbelaere added a comment.

Refer to UnknownProvenance instead of ConstantPointerNull in comment of getUnderlyingObject.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107357/new/

https://reviews.llvm.org/D107357

Files:
  llvm/include/llvm/Analysis/ValueTracking.h
  llvm/lib/Analysis/ValueTracking.cpp


Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -4374,7 +4374,8 @@
   return true;
 }
 
-const Value *llvm::getUnderlyingObject(const Value *V, unsigned MaxLookup) {
+const Value *llvm::getUnderlyingObject(const Value *V, unsigned MaxLookup,
+                                       bool FollowProvenance) {
   if (!V->getType()->isPointerTy())
     return V;
   for (unsigned Count = 0; MaxLookup == 0 || Count < MaxLookup; ++Count) {
@@ -4397,6 +4398,11 @@
           continue;
         }
       } else if (auto *Call = dyn_cast<CallBase>(V)) {
+        if (Call->getIntrinsicID() == Intrinsic::experimental_ptr_provenance) {
+          V = Call->getArgOperand(FollowProvenance ? 1 : 0);
+          continue;
+        }
+
         // CaptureTracking can know about special capturing properties of some
         // intrinsics like launder.invariant.group, that can't be expressed with
         // the attributes, but have properties like returning aliasing pointer.
@@ -4421,13 +4427,14 @@
 
 void llvm::getUnderlyingObjects(const Value *V,
                                 SmallVectorImpl<const Value *> &Objects,
-                                LoopInfo *LI, unsigned MaxLookup) {
+                                LoopInfo *LI, unsigned MaxLookup,
+                                bool FollowProvenance) {
   SmallPtrSet<const Value *, 4> Visited;
   SmallVector<const Value *, 4> Worklist;
   Worklist.push_back(V);
   do {
     const Value *P = Worklist.pop_back_val();
-    P = getUnderlyingObject(P, MaxLookup);
+    P = getUnderlyingObject(P, MaxLookup, FollowProvenance);
 
     if (!Visited.insert(P).second)
       continue;
Index: llvm/include/llvm/Analysis/ValueTracking.h
===================================================================
--- llvm/include/llvm/Analysis/ValueTracking.h
+++ llvm/include/llvm/Analysis/ValueTracking.h
@@ -369,9 +369,14 @@
   /// the specified value, returning the original object being addressed. Note
   /// that the returned value has pointer type if the specified value does. If
   /// the MaxLookup value is non-zero, it limits the number of instructions to
-  /// be stripped off.
-  const Value *getUnderlyingObject(const Value *V, unsigned MaxLookup = 6);
-  inline Value *getUnderlyingObject(Value *V, unsigned MaxLookup = 6) {
+  /// be stripped off. When FollowProvenance is set, the provenance side of
+  /// llvm.experimental.ptr.provenance is taken. For provenance,
+  /// `UnknownProvenance` indicates that any valid object can be the underlying
+  /// object.
+  const Value *getUnderlyingObject(const Value *V, unsigned MaxLookup = 6,
+                                   bool FollowProvenance = false);
+  inline Value *getUnderlyingObject(Value *V, unsigned MaxLookup = 6,
+                                    bool FollowProvenance = false) {
     // Force const to avoid infinite recursion.
     const Value *VConst = V;
     return const_cast<Value *>(getUnderlyingObject(VConst, MaxLookup));
@@ -405,9 +410,12 @@
   /// Since A[i] and A[i-1] are independent pointers, getUnderlyingObjects
   /// should not assume that Curr and Prev share the same underlying object thus
   /// it shouldn't look through the phi above.
+  /// When FollowProvenance is set, the provenance side of
+  /// llvm.experimental.ptr.provenance is taken.
   void getUnderlyingObjects(const Value *V,
                             SmallVectorImpl<const Value *> &Objects,
-                            LoopInfo *LI = nullptr, unsigned MaxLookup = 6);
+                            LoopInfo *LI = nullptr, unsigned MaxLookup = 6,
+                            bool FollowProvenance = false);
 
   /// This is a wrapper around getUnderlyingObjects and adds support for basic
   /// ptrtoint+arithmetic+inttoptr sequences.


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