eliminate the Constant::getVectorElements method. There are better (and

more robust) ways to do what it was doing now.  Also, add static methods
for decoding a ShuffleVector mask.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149028 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 32 insertions, 69 deletions

diff --git a/include/llvm/Constant.h b/include/llvm/Constant.h
index f7d4dd2d32..11a02e080f 100644
--- a/include/llvm/Constant.h
+++ b/include/llvm/Constant.h
@@ -91,12 +91,6 @@ public:
   /// FIXME: This really should not be in VMCore.
   PossibleRelocationsTy getRelocationInfo() const;
   
-  /// getVectorElements - This method, which is only valid on constant of vector
-  /// type, returns the elements of the vector in the specified smallvector.
-  /// This handles breaking down a vector undef into undef elements, etc.  For
-  /// constant exprs and other cases we can't handle, we return an empty vector.
-  void getVectorElements(SmallVectorImpl<Constant*> &Elts) const;
-
   /// getAggregateElement - For aggregates (struct/array/vector) return the
   /// constant that corresponds to the specified element if possible, or null if
   /// not.  This can return null if the element index is a ConstantExpr, or if
diff --git a/include/llvm/Instructions.h b/include/llvm/Instructions.h
index 35cb025e94..c27c6fa097 100644
--- a/include/llvm/Instructions.h
+++ b/include/llvm/Instructions.h
@@ -1677,11 +1677,19 @@ public:
   /// getMaskValue - Return the index from the shuffle mask for the specified
   /// output result.  This is either -1 if the element is undef or a number less
   /// than 2*numelements.
-  int getMaskValue(unsigned i) const;
+  static int getMaskValue(Constant *Mask, unsigned i);
+
+  int getMaskValue(unsigned i) const {
+    return getMaskValue(getMask(), i);
+  }
   
   /// getShuffleMask - Return the full mask for this instruction, where each
   /// element is the element number and undef's are returned as -1.
-  void getShuffleMask(SmallVectorImpl<int> &Mask) const;
+  static void getShuffleMask(Constant *Mask, SmallVectorImpl<int> &Result);
+
+  void getShuffleMask(SmallVectorImpl<int> &Result) const {
+    return getShuffleMask(getMask(), Result);
+  }
 
   SmallVector<int, 16> getShuffleMask() const {
     SmallVector<int, 16> Mask;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 7731f7c6b2..bc807dedc6 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2806,22 +2806,13 @@ static bool isSequentialInRange(const SmallVectorImpl<int> &Mask,
 }
 
 void SelectionDAGBuilder::visitShuffleVector(const User &I) {
-  SmallVector<int, 8> Mask;
   SDValue Src1 = getValue(I.getOperand(0));
   SDValue Src2 = getValue(I.getOperand(1));
 
-  // Convert the ConstantVector mask operand into an array of ints, with -1
-  // representing undef values.
-  SmallVector<Constant*, 8> MaskElts;
-  cast<Constant>(I.getOperand(2))->getVectorElements(MaskElts);
-  unsigned MaskNumElts = MaskElts.size();
-  for (unsigned i = 0; i != MaskNumElts; ++i) {
-    if (isa<UndefValue>(MaskElts[i]))
-      Mask.push_back(-1);
-    else
-      Mask.push_back(cast<ConstantInt>(MaskElts[i])->getSExtValue());
-  }
-
+  SmallVector<int, 8> Mask;
+  ShuffleVectorInst::getShuffleMask(cast<Constant>(I.getOperand(2)), Mask);
+  unsigned MaskNumElts = Mask.size();
+  
   EVT VT = TLI.getValueType(I.getType());
   EVT SrcVT = Src1.getValueType();
   unsigned SrcNumElts = SrcVT.getVectorNumElements();
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp
index 9a3a99164e..abc019ff4e 100644
--- a/lib/VMCore/ConstantFold.cpp
+++ b/lib/VMCore/ConstantFold.cpp
@@ -1697,20 +1697,20 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred,
                                         R==APFloat::cmpEqual);
     }
   } else if (C1->getType()->isVectorTy()) {
-    SmallVector<Constant*, 16> C1Elts, C2Elts;
-    C1->getVectorElements(C1Elts);
-    C2->getVectorElements(C2Elts);
-    if (C1Elts.empty() || C2Elts.empty())
-      return 0;
-
     // If we can constant fold the comparison of each element, constant fold
     // the whole vector comparison.
     SmallVector<Constant*, 4> ResElts;
     // Compare the elements, producing an i1 result or constant expr.
-    for (unsigned i = 0, e = C1Elts.size(); i != e; ++i)
-      ResElts.push_back(ConstantExpr::getCompare(pred, C1Elts[i], C2Elts[i]));
-
-    return ConstantVector::get(ResElts);
+    for (unsigned i = 0, e = C1->getType()->getVectorNumElements(); i != e;++i){
+      Constant *C1E = C1->getAggregateElement(i);
+      Constant *C2E = C2->getAggregateElement(i);
+      if (C1E == 0 || C2E == 0) break;
+      
+      ResElts.push_back(ConstantExpr::getCompare(pred, C1E, C2E));
+    }
+    
+    if (ResElts.size() == C1->getType()->getVectorNumElements())
+      return ConstantVector::get(ResElts);
   }
 
   if (C1->getType()->isFloatingPointTy()) {
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index f5239e1569..2530b63d8a 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -312,36 +312,6 @@ Constant::PossibleRelocationsTy Constant::getRelocationInfo() const {
   return Result;
 }
 
-
-/// getVectorElements - This method, which is only valid on constant of vector
-/// type, returns the elements of the vector in the specified smallvector.
-/// This handles breaking down a vector undef into undef elements, etc.  For
-/// constant exprs and other cases we can't handle, we return an empty vector.
-void Constant::getVectorElements(SmallVectorImpl<Constant*> &Elts) const {
-  assert(getType()->isVectorTy() && "Not a vector constant!");
-  
-  if (const ConstantVector *CV = dyn_cast<ConstantVector>(this)) {
-    for (unsigned i = 0, e = CV->getNumOperands(); i != e; ++i)
-      Elts.push_back(CV->getOperand(i));
-    return;
-  }
-  
-  VectorType *VT = cast<VectorType>(getType());
-  if (isa<ConstantAggregateZero>(this)) {
-    Elts.assign(VT->getNumElements(), 
-                Constant::getNullValue(VT->getElementType()));
-    return;
-  }
-  
-  if (isa<UndefValue>(this)) {
-    Elts.assign(VT->getNumElements(), UndefValue::get(VT->getElementType()));
-    return;
-  }
-  
-  // Unknown type, must be constant expr etc.
-}
-
-
 /// removeDeadUsersOfConstant - If the specified constantexpr is dead, remove
 /// it.  This involves recursively eliminating any dead users of the
 /// constantexpr.
diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index 1de7c01c0d..a0fb91aada 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -1625,11 +1625,11 @@ bool ShuffleVectorInst::isValidOperands(const Value *V1, const Value *V2,
 /// getMaskValue - Return the index from the shuffle mask for the specified
 /// output result.  This is either -1 if the element is undef or a number less
 /// than 2*numelements.
-int ShuffleVectorInst::getMaskValue(unsigned i) const {
-  assert(i < getType()->getNumElements() && "Index out of range");
-  if (ConstantDataSequential *CDS =dyn_cast<ConstantDataSequential>(getMask()))
+int ShuffleVectorInst::getMaskValue(Constant *Mask, unsigned i) {
+  assert(i < Mask->getType()->getVectorNumElements() && "Index out of range");
+  if (ConstantDataSequential *CDS =dyn_cast<ConstantDataSequential>(Mask))
     return CDS->getElementAsInteger(i);
-  Constant *C = getMask()->getAggregateElement(i);
+  Constant *C = Mask->getAggregateElement(i);
   if (isa<UndefValue>(C))
     return -1;
   return cast<ConstantInt>(C)->getZExtValue();
@@ -1637,15 +1637,15 @@ int ShuffleVectorInst::getMaskValue(unsigned i) const {
 
 /// getShuffleMask - Return the full mask for this instruction, where each
 /// element is the element number and undef's are returned as -1.
-void ShuffleVectorInst::getShuffleMask(SmallVectorImpl<int> &Result) const {
-  unsigned NumElts = getType()->getNumElements();
+void ShuffleVectorInst::getShuffleMask(Constant *Mask,
+                                       SmallVectorImpl<int> &Result) {
+  unsigned NumElts = Mask->getType()->getVectorNumElements();
   
-  if (ConstantDataSequential *CDS=dyn_cast<ConstantDataSequential>(getMask())) {
+  if (ConstantDataSequential *CDS=dyn_cast<ConstantDataSequential>(Mask)) {
     for (unsigned i = 0; i != NumElts; ++i)
       Result.push_back(CDS->getElementAsInteger(i));
     return;
   }    
-  Constant *Mask = getMask();
   for (unsigned i = 0; i != NumElts; ++i) {
     Constant *C = Mask->getAggregateElement(i);
     Result.push_back(isa<UndefValue>(C) ? -1 :