Have SRoA explicitly track the kind of scalar it is promoting. This is pretty

spartan right now, but I plan to encode more information in this enum to improve
the correctness and reliability of SRoA. At least this first pass makes it
possible to make VectorTy an actual VectorType.

llvm-svn: 132937

1 files changed, 21 insertions, 10 deletions

diff --git a/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index b50e32846b4..5644b0e9096 100644
--- a/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/llvm/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -228,10 +228,18 @@ class ConvertToScalarInfo {
   /// which means that mem2reg can't promote it.
   bool IsNotTrivial;
 
+  /// ScalarKind - Tracks the kind of alloca being considered for promotion,
+  /// computed based on the uses of the alloca rather than the LLVM type system.
+  enum {
+    Unknown,
+    Vector,
+    Integer
+  } ScalarKind;
+
   /// VectorTy - This tracks the type that we should promote the vector to if
   /// it is possible to turn it into a vector.  This starts out null, and if it
   /// isn't possible to turn into a vector type, it gets set to VoidTy.
-  const Type *VectorTy;
+  const VectorType *VectorTy;
 
   /// HadAVector - True if there is at least one vector access to the alloca.
   /// We don't want to turn random arrays into vectors and use vector element
@@ -246,8 +254,8 @@ class ConvertToScalarInfo {
 
 public:
   explicit ConvertToScalarInfo(unsigned Size, const TargetData &td)
-    : AllocaSize(Size), TD(td), IsNotTrivial(false), VectorTy(0),
-      HadAVector(false), HadNonMemTransferAccess(false) { }
+    : AllocaSize(Size), TD(td), IsNotTrivial(false), ScalarKind(Unknown),
+      VectorTy(0), HadAVector(false), HadNonMemTransferAccess(false) { }
 
   AllocaInst *TryConvert(AllocaInst *AI);
 
@@ -281,7 +289,7 @@ AllocaInst *ConvertToScalarInfo::TryConvert(AllocaInst *AI) {
   // we just get a lot of insert/extracts.  If at least one vector is
   // involved, then we probably really do have a union of vector/array.
   const Type *NewTy;
-  if (VectorTy && VectorTy->isVectorTy() && HadAVector) {
+  if (ScalarKind != Integer && VectorTy && HadAVector) {
     DEBUG(dbgs() << "CONVERT TO VECTOR: " << *AI << "\n  TYPE = "
           << *VectorTy << '\n');
     NewTy = VectorTy;  // Use the vector type.
@@ -319,7 +327,7 @@ AllocaInst *ConvertToScalarInfo::TryConvert(AllocaInst *AI) {
 void ConvertToScalarInfo::MergeInType(const Type *In, uint64_t Offset) {
   // If we already decided to turn this into a blob of integer memory, there is
   // nothing to be done.
-  if (VectorTy && VectorTy->isVoidTy())
+  if (ScalarKind == Integer)
     return;
 
   // If this could be contributing to a vector, analyze it.
@@ -344,11 +352,12 @@ void ConvertToScalarInfo::MergeInType(const Type *In, uint64_t Offset) {
     if (Offset % EltSize == 0 && AllocaSize % EltSize == 0 &&
         (!VectorTy || Offset * 8 < VectorTy->getPrimitiveSizeInBits())) {
       if (!VectorTy) {
+        ScalarKind = Vector;
         VectorTy = VectorType::get(In, AllocaSize/EltSize);
         return;
       }
 
-      unsigned CurrentEltSize = cast<VectorType>(VectorTy)->getElementType()
+      unsigned CurrentEltSize = VectorTy->getElementType()
                                 ->getPrimitiveSizeInBits()/8;
       if (EltSize == CurrentEltSize)
         return;
@@ -360,7 +369,8 @@ void ConvertToScalarInfo::MergeInType(const Type *In, uint64_t Offset) {
 
   // Otherwise, we have a case that we can't handle with an optimized vector
   // form.  We can still turn this into a large integer.
-  VectorTy = Type::getVoidTy(In->getContext());
+  ScalarKind = Integer;
+  VectorTy = 0;
 }
 
 /// MergeInVectorType - Handles the vector case of MergeInType, returning true
@@ -381,19 +391,20 @@ bool ConvertToScalarInfo::MergeInVectorType(const VectorType *VInTy,
   // If this the first vector we see, remember the type so that we know the
   // element size.
   if (!VectorTy) {
+    ScalarKind = Vector;
     VectorTy = VInTy;
     return true;
   }
 
-  unsigned BitWidth = cast<VectorType>(VectorTy)->getBitWidth();
+  unsigned BitWidth = VectorTy->getBitWidth();
   unsigned InBitWidth = VInTy->getBitWidth();
 
   // Vectors of the same size can be converted using a simple bitcast.
   if (InBitWidth == BitWidth && AllocaSize == (InBitWidth / 8))
     return true;
 
-  const Type *ElementTy = cast<VectorType>(VectorTy)->getElementType();
-  const Type *InElementTy = cast<VectorType>(VInTy)->getElementType();
+  const Type *ElementTy = VectorTy->getElementType();
+  const Type *InElementTy = VInTy->getElementType();
 
   // Do not allow mixed integer and floating-point accesses from vectors of
   // different sizes.