Add "const" in GetUnderlyingObjects. NFC

Summary:
Both the input Value pointer and the returned Value
pointers in GetUnderlyingObjects are now declared as
const.

It turned out that all current (in-tree) uses of
GetUnderlyingObjects were trivial to update, being
satisfied with have those Value pointers declared
as const. Actually, in the past several of the users
had to use const_cast, just because of ValueTracking
not providing a version of GetUnderlyingObjects with
"const" Value pointers. With this patch we get rid
of those const casts.

Reviewers: hfinkel, materi, jkorous

Reviewed By: jkorous

Subscribers: dexonsmith, jkorous, jholewinski, sdardis, eraman, hiraditya, jrtc27, atanasyan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61038

llvm-svn: 359072

4 files changed, 19 insertions, 18 deletions

diff --git a/llvm/lib/Analysis/GlobalsModRef.cpp b/llvm/lib/Analysis/GlobalsModRef.cpp
index 2c967c87458..0d6c0ffb18a 100644
--- a/llvm/lib/Analysis/GlobalsModRef.cpp
+++ b/llvm/lib/Analysis/GlobalsModRef.cpp
@@ -896,13 +896,13 @@ ModRefInfo GlobalsAAResult::getModRefInfoForArgument(const CallBase *Call,
   // Iterate through all the arguments to the called function. If any argument
   // is based on GV, return the conservative result.
   for (auto &A : Call->args()) {
-    SmallVector<Value*, 4> Objects;
+    SmallVector<const Value*, 4> Objects;
     GetUnderlyingObjects(A, Objects, DL);
 
     // All objects must be identified.
     if (!all_of(Objects, isIdentifiedObject) &&
         // Try ::alias to see if all objects are known not to alias GV.
-        !all_of(Objects, [&](Value *V) {
+        !all_of(Objects, [&](const Value *V) {
           return this->alias(MemoryLocation(V), MemoryLocation(GV), AAQI) ==
                  NoAlias;
         }))
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index f41256b8bb2..87e0df29bbd 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -2281,12 +2281,12 @@ computePointerICmp(const DataLayout &DL, const TargetLibraryInfo *TLI,
     // come from a pointer that cannot overlap with dynamically-allocated
     // memory within the lifetime of the current function (allocas, byval
     // arguments, globals), then determine the comparison result here.
-    SmallVector<Value *, 8> LHSUObjs, RHSUObjs;
+    SmallVector<const Value *, 8> LHSUObjs, RHSUObjs;
     GetUnderlyingObjects(LHS, LHSUObjs, DL);
     GetUnderlyingObjects(RHS, RHSUObjs, DL);
 
     // Is the set of underlying objects all noalias calls?
-    auto IsNAC = [](ArrayRef<Value *> Objects) {
+    auto IsNAC = [](ArrayRef<const Value *> Objects) {
       return all_of(Objects, isNoAliasCall);
     };
 
@@ -2296,8 +2296,8 @@ computePointerICmp(const DataLayout &DL, const TargetLibraryInfo *TLI,
     // live with the compared-to allocation). For globals, we exclude symbols
     // that might be resolve lazily to symbols in another dynamically-loaded
     // library (and, thus, could be malloc'ed by the implementation).
-    auto IsAllocDisjoint = [](ArrayRef<Value *> Objects) {
-      return all_of(Objects, [](Value *V) {
+    auto IsAllocDisjoint = [](ArrayRef<const Value *> Objects) {
+      return all_of(Objects, [](const Value *V) {
         if (const AllocaInst *AI = dyn_cast<AllocaInst>(V))
           return AI->getParent() && AI->getFunction() && AI->isStaticAlloca();
         if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index 6ec138c42a4..d6fbf6f2827 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -842,7 +842,7 @@ void AccessAnalysis::processMemAccesses() {
     bool SetHasWrite = false;
 
     // Map of pointers to last access encountered.
-    typedef DenseMap<Value*, MemAccessInfo> UnderlyingObjToAccessMap;
+    typedef DenseMap<const Value*, MemAccessInfo> UnderlyingObjToAccessMap;
     UnderlyingObjToAccessMap ObjToLastAccess;
 
     // Set of access to check after all writes have been processed.
@@ -903,13 +903,13 @@ void AccessAnalysis::processMemAccesses() {
 
           // Create sets of pointers connected by a shared alias set and
           // underlying object.
-          typedef SmallVector<Value *, 16> ValueVector;
+          typedef SmallVector<const Value *, 16> ValueVector;
           ValueVector TempObjects;
 
           GetUnderlyingObjects(Ptr, TempObjects, DL, LI);
           LLVM_DEBUG(dbgs()
                      << "Underlying objects for pointer " << *Ptr << "\n");
-          for (Value *UnderlyingObj : TempObjects) {
+          for (const Value *UnderlyingObj : TempObjects) {
             // nullptr never alias, don't join sets for pointer that have "null"
             // in their UnderlyingObjects list.
             if (isa<ConstantPointerNull>(UnderlyingObj) &&
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 3b08a2dc7a1..7c16b21c928 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -3771,26 +3771,27 @@ Value *llvm::GetUnderlyingObject(Value *V, const DataLayout &DL,
   return V;
 }
 
-void llvm::GetUnderlyingObjects(Value *V, SmallVectorImpl<Value *> &Objects,
+void llvm::GetUnderlyingObjects(const Value *V,
+                                SmallVectorImpl<const Value *> &Objects,
                                 const DataLayout &DL, LoopInfo *LI,
                                 unsigned MaxLookup) {
-  SmallPtrSet<Value *, 4> Visited;
-  SmallVector<Value *, 4> Worklist;
+  SmallPtrSet<const Value *, 4> Visited;
+  SmallVector<const Value *, 4> Worklist;
   Worklist.push_back(V);
   do {
-    Value *P = Worklist.pop_back_val();
+    const Value *P = Worklist.pop_back_val();
     P = GetUnderlyingObject(P, DL, MaxLookup);
 
     if (!Visited.insert(P).second)
       continue;
 
-    if (SelectInst *SI = dyn_cast<SelectInst>(P)) {
+    if (auto *SI = dyn_cast<SelectInst>(P)) {
       Worklist.push_back(SI->getTrueValue());
       Worklist.push_back(SI->getFalseValue());
       continue;
     }
 
-    if (PHINode *PN = dyn_cast<PHINode>(P)) {
+    if (auto *PN = dyn_cast<PHINode>(P)) {
       // If this PHI changes the underlying object in every iteration of the
       // loop, don't look through it.  Consider:
       //   int **A;
@@ -3851,10 +3852,10 @@ bool llvm::getUnderlyingObjectsForCodeGen(const Value *V,
   do {
     V = Working.pop_back_val();
 
-    SmallVector<Value *, 4> Objs;
-    GetUnderlyingObjects(const_cast<Value *>(V), Objs, DL);
+    SmallVector<const Value *, 4> Objs;
+    GetUnderlyingObjects(V, Objs, DL);
 
-    for (Value *V : Objs) {
+    for (const Value *V : Objs) {
       if (!Visited.insert(V).second)
         continue;
       if (Operator::getOpcode(V) == Instruction::IntToPtr) {