Clean up constructor logic and member access for LoopVectorizeHints.

There are public functions that mutate various members as well as
another private member already, so make all the members private to
avoid the discontinuity and add accessors for the values. Should
be no functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207868 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -888,39 +888,32 @@ class LoopVectorizationCostModel {
 
 /// Utility class for getting and setting loop vectorizer hints in the form
 /// of loop metadata.
-struct LoopVectorizeHints {
-  /// Vectorization width.
-  unsigned Width;
-  /// Vectorization unroll factor.
-  unsigned Unroll;
-  /// Vectorization forced
+class LoopVectorizeHints {
+public:
   enum ForceKind {
     FK_Undefined = -1, ///< Not selected.
     FK_Disabled = 0,   ///< Forcing disabled.
     FK_Enabled = 1,    ///< Forcing enabled.
-  } Force;
+  };
 
   LoopVectorizeHints(const Loop *L, bool DisableUnrolling)
-  : Width(VectorizationFactor)
-  , Unroll(DisableUnrolling ? 1 : VectorizationUnroll)
-  , Force(FK_Undefined)
-  , LoopID(L->getLoopID()) {
+      : Width(VectorizationFactor),
+        Unroll(DisableUnrolling),
+        Force(FK_Undefined),
+        LoopID(L->getLoopID()) {
     getHints(L);
-    // The command line options override any loop metadata except for when
-    // width == 1 which is used to indicate the loop is already vectorized.
-    if (VectorizationFactor.getNumOccurrences() > 0 && Width != 1)
-      Width = VectorizationFactor;
+    // force-vector-unroll overrides DisableUnrolling.
     if (VectorizationUnroll.getNumOccurrences() > 0)
       Unroll = VectorizationUnroll;
 
-    DEBUG(if (DisableUnrolling && Unroll == 1)
-            dbgs() << "LV: Unrolling disabled by the pass manager\n");
+    DEBUG(if (DisableUnrolling && Unroll == 1) dbgs()
+          << "LV: Unrolling disabled by the pass manager\n");
   }
 
   /// Return the loop vectorizer metadata prefix.
   static StringRef Prefix() { return "llvm.vectorizer."; }
 
-  MDNode *createHint(LLVMContext &Context, StringRef Name, unsigned V) {
+  MDNode *createHint(LLVMContext &Context, StringRef Name, unsigned V) const {
     SmallVector<Value*, 2> Vals;
     Vals.push_back(MDString::get(Context, Name));
     Vals.push_back(ConstantInt::get(Type::getInt32Ty(Context), V));
@@ -954,9 +947,12 @@ struct LoopVectorizeHints {
     LoopID = NewLoopID;
   }
 
-private:
-  MDNode *LoopID;
+  unsigned getWidth() const { return Width; }
+  unsigned getUnroll() const { return Unroll; }
+  enum ForceKind getForce() const { return Force; }
+  MDNode *getLoopID() const { return LoopID; }
 
+private:
   /// Find hints specified in the loop metadata.
   void getHints(const Loop *L) {
     if (!LoopID)
@@ -1024,6 +1020,15 @@ struct LoopVectorizeHints {
       DEBUG(dbgs() << "LV: ignoring unknown hint " << Hint << '\n');
     }
   }
+
+  /// Vectorization width.
+  unsigned Width;
+  /// Vectorization unroll factor.
+  unsigned Unroll;
+  /// Vectorization forced
+  enum ForceKind Force;
+
+  MDNode *LoopID;
 };
 
 static void addInnerLoop(Loop &L, SmallVectorImpl<Loop *> &V) {
@@ -1114,24 +1119,24 @@ struct LoopVectorize : public FunctionPass {
 
     DEBUG(dbgs() << "LV: Loop hints:"
                  << " force="
-                 << (Hints.Force == LoopVectorizeHints::FK_Disabled
+                 << (Hints.getForce() == LoopVectorizeHints::FK_Disabled
                          ? "disabled"
-                         : (Hints.Force == LoopVectorizeHints::FK_Enabled
+                         : (Hints.getForce() == LoopVectorizeHints::FK_Enabled
                                 ? "enabled"
-                                : "?")) << " width=" << Hints.Width
-                 << " unroll=" << Hints.Unroll << "\n");
+                                : "?")) << " width=" << Hints.getWidth()
+                 << " unroll=" << Hints.getUnroll() << "\n");
 
-    if (Hints.Force == LoopVectorizeHints::FK_Disabled) {
+    if (Hints.getForce() == LoopVectorizeHints::FK_Disabled) {
       DEBUG(dbgs() << "LV: Not vectorizing: #pragma vectorize disable.\n");
       return false;
     }
 
-    if (!AlwaysVectorize && Hints.Force != LoopVectorizeHints::FK_Enabled) {
+    if (!AlwaysVectorize && Hints.getForce() != LoopVectorizeHints::FK_Enabled) {
       DEBUG(dbgs() << "LV: Not vectorizing: No #pragma vectorize enable.\n");
       return false;
     }
 
-    if (Hints.Width == 1 && Hints.Unroll == 1) {
+    if (Hints.getWidth() == 1 && Hints.getUnroll() == 1) {
       DEBUG(dbgs() << "LV: Not vectorizing: Disabled/already vectorized.\n");
       return false;
     }
@@ -1143,7 +1148,7 @@ struct LoopVectorize : public FunctionPass {
     if (TC > 0u && TC < TinyTripCountVectorThreshold) {
       DEBUG(dbgs() << "LV: Found a loop with a very small trip count. "
                    << "This loop is not worth vectorizing.");
-      if (Hints.Force == LoopVectorizeHints::FK_Enabled)
+      if (Hints.getForce() == LoopVectorizeHints::FK_Enabled)
         DEBUG(dbgs() << " But vectorizing was explicitly forced.\n");
       else {
         DEBUG(dbgs() << "\n");
@@ -1164,7 +1169,7 @@ struct LoopVectorize : public FunctionPass {
     // Check the function attributes to find out if this function should be
     // optimized for size.
     Function *F = L->getHeader()->getParent();
-    bool OptForSize = Hints.Force != LoopVectorizeHints::FK_Enabled &&
+    bool OptForSize = Hints.getForce() != LoopVectorizeHints::FK_Enabled &&
                       F->hasFnAttribute(Attribute::OptimizeForSize);
 
     // Compute the weighted frequency of this loop being executed and see if it
@@ -1174,7 +1179,7 @@ struct LoopVectorize : public FunctionPass {
     // exactly what block frequency models.
     if (LoopVectorizeWithBlockFrequency) {
       BlockFrequency LoopEntryFreq = BFI->getBlockFreq(L->getLoopPreheader());
-      if (Hints.Force != LoopVectorizeHints::FK_Enabled &&
+      if (Hints.getForce() != LoopVectorizeHints::FK_Enabled &&
           LoopEntryFreq < ColdEntryFreq)
         OptForSize = true;
     }
@@ -1191,13 +1196,13 @@ struct LoopVectorize : public FunctionPass {
 
     // Select the optimal vectorization factor.
     const LoopVectorizationCostModel::VectorizationFactor VF =
-        CM.selectVectorizationFactor(OptForSize, Hints.Width,
-                                     Hints.Force ==
+        CM.selectVectorizationFactor(OptForSize, Hints.getWidth(),
+                                     Hints.getForce() ==
                                          LoopVectorizeHints::FK_Enabled);
 
     // Select the unroll factor.
-    const unsigned UF = CM.selectUnrollFactor(OptForSize, Hints.Unroll, VF.Width,
-                                        VF.Cost);
+    const unsigned UF =
+        CM.selectUnrollFactor(OptForSize, Hints.getUnroll(), VF.Width, VF.Cost);
 
     DEBUG(dbgs() << "LV: Found a vectorizable loop ("
                  << VF.Width << ") in "