[LoopAccesses] Change LAA:getInfo to return a constant reference

As expected, this required a few more const-correctness fixes.

Based on Hal's feedback on D7684.

llvm-svn: 229634

include/llvm/Analysis/LoopAccessAnalysis.h

@@ -153,9 +153,11 @@ public:
 
   /// Return true we can analyze the memory accesses in the loop and there are
   /// no memory dependence cycles.
-  bool canVectorizeMemory() { return CanVecMem; }
+  bool canVectorizeMemory() const { return CanVecMem; }
 
-  RuntimePointerCheck *getRuntimePointerCheck() { return &PtrRtCheck; }
+  const RuntimePointerCheck *getRuntimePointerCheck() const {
+    return &PtrRtCheck;
+  }
 
   /// Return true if the block BB needs to be predicated in order for the loop
   /// to be vectorized.
@@ -163,7 +165,7 @@ public:
                                     DominatorTree *DT);
 
   /// Returns true if the value V is uniform within the loop.
-  bool isUniform(Value *V);
+  bool isUniform(Value *V) const;
 
   unsigned getMaxSafeDepDistBytes() const { return MaxSafeDepDistBytes; }
   unsigned getNumStores() const { return NumStores; }
@@ -174,11 +176,12 @@ public:
   /// Returns a pair of instructions where the first element is the first
   /// instruction generated in possibly a sequence of instructions and the
   /// second value is the final comparator value or NULL if no check is needed.
-  std::pair<Instruction *, Instruction *> addRuntimeCheck(Instruction *Loc);
+  std::pair<Instruction *, Instruction *>
+    addRuntimeCheck(Instruction *Loc) const;
 
   /// \brief The diagnostics report generated for the analysis.  E.g. why we
   /// couldn't analyze the loop.
-  Optional<LoopAccessReport> &getReport() { return Report; }
+  const Optional<LoopAccessReport> &getReport() const { return Report; }
 
   /// \brief Print the information about the memory accesses in the loop.
   void print(raw_ostream &OS, unsigned Depth = 0) const;
@@ -258,7 +261,7 @@ public:
   /// of symbolic strides, \p Strides provides the mapping (see
   /// replaceSymbolicStrideSCEV).  If there is no cached result available run
   /// the analysis.
-  LoopAccessInfo &getInfo(Loop *L, ValueToValueMap &Strides);
+  const LoopAccessInfo &getInfo(Loop *L, ValueToValueMap &Strides);
 
   void releaseMemory() override {
     // Invalidate the cache when the pass is freed.

lib/Analysis/LoopAccessAnalysis.cpp

@@ -1173,7 +1173,7 @@ void LoopAccessInfo::emitAnalysis(LoopAccessReport &Message) {
   Report = Message;
 }
 
-bool LoopAccessInfo::isUniform(Value *V) {
+bool LoopAccessInfo::isUniform(Value *V) const {
   return (SE->isLoopInvariant(SE->getSCEV(V), TheLoop));
 }
 
@@ -1189,7 +1189,7 @@ static Instruction *getFirstInst(Instruction *FirstInst, Value *V,
 }
 
 std::pair<Instruction *, Instruction *>
-LoopAccessInfo::addRuntimeCheck(Instruction *Loc) {
+LoopAccessInfo::addRuntimeCheck(Instruction *Loc) const {
   Instruction *tnullptr = nullptr;
   if (!PtrRtCheck.Need)
     return std::pair<Instruction *, Instruction *>(tnullptr, tnullptr);
@@ -1301,7 +1301,8 @@ void LoopAccessInfo::print(raw_ostream &OS, unsigned Depth) const {
   OS << "\n";
 }
 
-LoopAccessInfo &LoopAccessAnalysis::getInfo(Loop *L, ValueToValueMap &Strides) {
+const LoopAccessInfo &LoopAccessAnalysis::getInfo(Loop *L,
+                                                  ValueToValueMap &Strides) {
   auto &LAI = LoopAccessInfoMap[L];
 
 #ifndef NDEBUG

lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -756,11 +756,11 @@ public:
   bool isUniformAfterVectorization(Instruction* I) { return Uniforms.count(I); }
 
   /// Returns the information that we collected about runtime memory check.
-  LoopAccessInfo::RuntimePointerCheck *getRuntimePointerCheck() {
+  const LoopAccessInfo::RuntimePointerCheck *getRuntimePointerCheck() const {
     return LAI->getRuntimePointerCheck();
   }
 
-  LoopAccessInfo *getLAI() {
+  const LoopAccessInfo *getLAI() const {
     return LAI;
   }
 
@@ -877,7 +877,7 @@ private:
   LoopAccessAnalysis *LAA;
   // And the loop-accesses info corresponding to this loop.  This pointer is
   // null until canVectorizeMemory sets it up.
-  LoopAccessInfo *LAI;
+  const LoopAccessInfo *LAI;
 
   //  ---  vectorization state --- //