6 files changed, 144 insertions, 207 deletions

diff --git a/include/llvm/Analysis/ScalarEvolutionExpander.h b/include/llvm/Analysis/ScalarEvolutionExpander.h
index 01df503a5e..796b1685a7 100644
--- a/include/llvm/Analysis/ScalarEvolutionExpander.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpander.h
@@ -167,10 +167,6 @@ namespace llvm {
 
     Value *visitUMaxExpr(const SCEVUMaxExpr *S);
 
-    Value *visitFieldOffsetExpr(const SCEVFieldOffsetExpr *S);
-
-    Value *visitAllocSizeExpr(const SCEVAllocSizeExpr *S);
-
     Value *visitUnknown(const SCEVUnknown *S) {
       return S->getValue();
     }
diff --git a/include/llvm/Analysis/ScalarEvolutionExpressions.h b/include/llvm/Analysis/ScalarEvolutionExpressions.h
index 64b8b0bf78..5b93458f11 100644
--- a/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -27,7 +27,7 @@ namespace llvm {
     // folders simpler.
     scConstant, scTruncate, scZeroExtend, scSignExtend, scAddExpr, scMulExpr,
     scUDivExpr, scAddRecExpr, scUMaxExpr, scSMaxExpr,
-    scFieldOffset, scAllocSize, scUnknown, scCouldNotCompute
+    scUnknown, scCouldNotCompute
   };
 
   //===--------------------------------------------------------------------===//
@@ -512,95 +512,6 @@ namespace llvm {
   };
 
   //===--------------------------------------------------------------------===//
-  /// SCEVTargetDataConstant - This node is the base class for representing
-  /// target-dependent values in a target-independent way.
-  ///
-  class SCEVTargetDataConstant : public SCEV {
-  protected:
-    const Type *Ty;
-    SCEVTargetDataConstant(const FoldingSetNodeID &ID, enum SCEVTypes T,
-                           const Type *ty) :
-      SCEV(ID, T), Ty(ty) {}
-
-  public:
-    virtual bool isLoopInvariant(const Loop *) const { return true; }
-    virtual bool hasComputableLoopEvolution(const Loop *) const {
-      return false; // not computable
-    }
-
-    virtual bool hasOperand(const SCEV *) const {
-      return false;
-    }
-
-    bool dominates(BasicBlock *, DominatorTree *) const {
-      return true;
-    }
-
-    bool properlyDominates(BasicBlock *, DominatorTree *) const {
-      return true;
-    }
-
-    virtual const Type *getType() const { return Ty; }
-
-    /// Methods for support type inquiry through isa, cast, and dyn_cast:
-    static inline bool classof(const SCEVTargetDataConstant *S) { return true; }
-    static inline bool classof(const SCEV *S) {
-      return S->getSCEVType() == scFieldOffset ||
-             S->getSCEVType() == scAllocSize;
-    }
-  };
-
-  //===--------------------------------------------------------------------===//
-  /// SCEVFieldOffsetExpr - This node represents an offsetof expression.
-  ///
-  class SCEVFieldOffsetExpr : public SCEVTargetDataConstant {
-    friend class ScalarEvolution;
-
-    const StructType *STy;
-    unsigned FieldNo;
-    SCEVFieldOffsetExpr(const FoldingSetNodeID &ID, const Type *ty,
-                        const StructType *sty, unsigned fieldno) :
-      SCEVTargetDataConstant(ID, scFieldOffset, ty),
-      STy(sty), FieldNo(fieldno) {}
-
-  public:
-    const StructType *getStructType() const { return STy; }
-    unsigned getFieldNo() const { return FieldNo; }
-
-    virtual void print(raw_ostream &OS) const;
-
-    /// Methods for support type inquiry through isa, cast, and dyn_cast:
-    static inline bool classof(const SCEVFieldOffsetExpr *S) { return true; }
-    static inline bool classof(const SCEV *S) {
-      return S->getSCEVType() == scFieldOffset;
-    }
-  };
-
-  //===--------------------------------------------------------------------===//
-  /// SCEVAllocSize - This node represents a sizeof expression.
-  ///
-  class SCEVAllocSizeExpr : public SCEVTargetDataConstant {
-    friend class ScalarEvolution;
-
-    const Type *AllocTy;
-    SCEVAllocSizeExpr(const FoldingSetNodeID &ID,
-                      const Type *ty, const Type *allocty) :
-      SCEVTargetDataConstant(ID, scAllocSize, ty),
-      AllocTy(allocty) {}
-
-  public:
-    const Type *getAllocType() const { return AllocTy; }
-
-    virtual void print(raw_ostream &OS) const;
-
-    /// Methods for support type inquiry through isa, cast, and dyn_cast:
-    static inline bool classof(const SCEVAllocSizeExpr *S) { return true; }
-    static inline bool classof(const SCEV *S) {
-      return S->getSCEVType() == scAllocSize;
-    }
-  };
-
-  //===--------------------------------------------------------------------===//
   /// SCEVUnknown - This means that we are dealing with an entirely unknown SCEV
   /// value, and only represent it as its LLVM Value.  This is the "bottom"
   /// value for the analysis.
@@ -615,6 +526,16 @@ namespace llvm {
   public:
     Value *getValue() const { return V; }
 
+    /// isSizeOf, isAlignOf, isOffsetOf - Test whether this is a special
+    /// constant representing a type size, alignment, or field offset in
+    /// a target-independent manner, and hasn't happened to have been
+    /// folded with other operations into something unrecognizable. This
+    /// is mainly only useful for pretty-printing and other situations
+    /// where it isn't absolutely required for these to succeed.
+    bool isSizeOf(const Type *&AllocTy) const;
+    bool isAlignOf(const Type *&AllocTy) const;
+    bool isOffsetOf(const StructType *&STy, Constant *&FieldNo) const;
+
     virtual bool isLoopInvariant(const Loop *L) const;
     virtual bool hasComputableLoopEvolution(const Loop *QL) const {
       return false; // not computable
@@ -665,10 +586,6 @@ namespace llvm {
         return ((SC*)this)->visitSMaxExpr((const SCEVSMaxExpr*)S);
       case scUMaxExpr:
         return ((SC*)this)->visitUMaxExpr((const SCEVUMaxExpr*)S);
-      case scFieldOffset:
-        return ((SC*)this)->visitFieldOffsetExpr((const SCEVFieldOffsetExpr*)S);
-      case scAllocSize:
-        return ((SC*)this)->visitAllocSizeExpr((const SCEVAllocSizeExpr*)S);
       case scUnknown:
         return ((SC*)this)->visitUnknown((const SCEVUnknown*)S);
       case scCouldNotCompute:
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index b2395af924..f19e153e0d 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -321,15 +321,6 @@ void SCEVAddRecExpr::print(raw_ostream &OS) const {
   OS << ">";
 }
 
-void SCEVFieldOffsetExpr::print(raw_ostream &OS) const {
-  // LLVM struct fields don't have names, so just print the field number.
-  OS << "offsetof(" << *STy << ", " << FieldNo << ")";
-}
-
-void SCEVAllocSizeExpr::print(raw_ostream &OS) const {
-  OS << "sizeof(" << *AllocTy << ")";
-}
-
 bool SCEVUnknown::isLoopInvariant(const Loop *L) const {
   // All non-instruction values are loop invariant.  All instructions are loop
   // invariant if they are not contained in the specified loop.
@@ -356,7 +347,90 @@ const Type *SCEVUnknown::getType() const {
   return V->getType();
 }
 
+bool SCEVUnknown::isOffsetOf(const StructType *&STy, Constant *&FieldNo) const {
+  if (ConstantExpr *VCE = dyn_cast<ConstantExpr>(V))
+    if (VCE->getOpcode() == Instruction::PtrToInt)
+      if (ConstantExpr *CE = dyn_cast<ConstantExpr>(VCE->getOperand(0)))
+        if (CE->getOpcode() == Instruction::GetElementPtr)
+          if (CE->getOperand(0)->isNullValue()) {
+            const Type *Ty =
+              cast<PointerType>(CE->getOperand(0)->getType())->getElementType();
+            if (const StructType *StructTy = dyn_cast<StructType>(Ty))
+              if (CE->getNumOperands() == 3 &&
+                  CE->getOperand(1)->isNullValue()) {
+                STy = StructTy;
+                FieldNo = CE->getOperand(2);
+                return true;
+              }
+          }
+
+  return false;
+}
+
+bool SCEVUnknown::isSizeOf(const Type *&AllocTy) const {
+  if (ConstantExpr *VCE = dyn_cast<ConstantExpr>(V))
+    if (VCE->getOpcode() == Instruction::PtrToInt)
+      if (ConstantExpr *CE = dyn_cast<ConstantExpr>(VCE->getOperand(0)))
+        if (CE->getOpcode() == Instruction::GetElementPtr)
+          if (CE->getOperand(0)->isNullValue()) {
+            const Type *Ty =
+              cast<PointerType>(CE->getOperand(0)->getType())->getElementType();
+            if (CE->getNumOperands() == 2)
+              if (ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(1)))
+                if (CI->isOne()) {
+                  AllocTy = Ty;
+                  return true;
+                }
+          }
+
+  return false;
+}
+
+bool SCEVUnknown::isAlignOf(const Type *&AllocTy) const {
+  if (ConstantExpr *VCE = dyn_cast<ConstantExpr>(V))
+    if (VCE->getOpcode() == Instruction::PtrToInt)
+      if (ConstantExpr *CE = dyn_cast<ConstantExpr>(VCE->getOperand(0)))
+        if (CE->getOpcode() == Instruction::GetElementPtr)
+          if (CE->getOperand(0)->isNullValue()) {
+            const Type *Ty =
+              cast<PointerType>(CE->getOperand(0)->getType())->getElementType();
+            if (const StructType *STy = dyn_cast<StructType>(Ty))
+              if (CE->getNumOperands() == 3 &&
+                  CE->getOperand(1)->isNullValue()) {
+                if (ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(2)))
+                  if (CI->isOne() &&
+                      STy->getNumElements() == 2 &&
+                      STy->getElementType(0)->isInteger(1)) {
+                    AllocTy = STy->getElementType(1);
+                    return true;
+                  }
+              }
+          }
+
+  return false;
+}
+
 void SCEVUnknown::print(raw_ostream &OS) const {
+  const Type *AllocTy;
+  if (isSizeOf(AllocTy)) {
+    OS << "sizeof(" << *AllocTy << ")";
+    return;
+  }
+  if (isAlignOf(AllocTy)) {
+    OS << "alignof(" << *AllocTy << ")";
+    return;
+  }
+
+  const StructType *STy;
+  Constant *FieldNo;
+  if (isOffsetOf(STy, FieldNo)) {
+    OS << "offsetof(" << *STy << ", ";
+    WriteAsOperand(OS, FieldNo, false);
+    OS << ")";
+    return;
+  }
+
+  // Otherwise just print it normally.
   WriteAsOperand(OS, V, false);
 }
 
@@ -515,21 +589,6 @@ namespace {
         return operator()(LC->getOperand(), RC->getOperand());
       }
 
-      // Compare offsetof expressions.
-      if (const SCEVFieldOffsetExpr *LA = dyn_cast<SCEVFieldOffsetExpr>(LHS)) {
-        const SCEVFieldOffsetExpr *RA = cast<SCEVFieldOffsetExpr>(RHS);
-        if (CompareTypes(LA->getStructType(), RA->getStructType()) ||
-            CompareTypes(RA->getStructType(), LA->getStructType()))
-          return CompareTypes(LA->getStructType(), RA->getStructType());
-        return LA->getFieldNo() < RA->getFieldNo();
-      }
-
-      // Compare sizeof expressions by the allocation type.
-      if (const SCEVAllocSizeExpr *LA = dyn_cast<SCEVAllocSizeExpr>(LHS)) {
-        const SCEVAllocSizeExpr *RA = cast<SCEVAllocSizeExpr>(RHS);
-        return CompareTypes(LA->getAllocType(), RA->getAllocType());
-      }
-
       llvm_unreachable("Unknown SCEV kind!");
       return false;
     }
@@ -2174,72 +2233,19 @@ const SCEV *ScalarEvolution::getUMinExpr(const SCEV *LHS,
 
 const SCEV *ScalarEvolution::getFieldOffsetExpr(const StructType *STy,
                                                 unsigned FieldNo) {
-  // If we have TargetData we can determine the constant offset.
-  if (TD) {
-    const Type *IntPtrTy = TD->getIntPtrType(getContext());
-    const StructLayout &SL = *TD->getStructLayout(STy);
-    uint64_t Offset = SL.getElementOffset(FieldNo);
-    return getIntegerSCEV(Offset, IntPtrTy);
-  }
-
-  // Field 0 is always at offset 0.
-  if (FieldNo == 0) {
-    const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(STy));
-    return getIntegerSCEV(0, Ty);
-  }
-
-  // Okay, it looks like we really DO need an offsetof expr.  Check to see if we
-  // already have one, otherwise create a new one.
-  FoldingSetNodeID ID;
-  ID.AddInteger(scFieldOffset);
-  ID.AddPointer(STy);
-  ID.AddInteger(FieldNo);
-  void *IP = 0;
-  if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
-  SCEV *S = SCEVAllocator.Allocate<SCEVFieldOffsetExpr>();
+  Constant *C = ConstantExpr::getOffsetOf(STy, FieldNo);
+  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
+    C = ConstantFoldConstantExpression(CE, TD);
   const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(STy));
-  new (S) SCEVFieldOffsetExpr(ID, Ty, STy, FieldNo);
-  UniqueSCEVs.InsertNode(S, IP);
-  return S;
+  return getTruncateOrZeroExtend(getSCEV(C), Ty);
 }
 
 const SCEV *ScalarEvolution::getAllocSizeExpr(const Type *AllocTy) {
-  // If we have TargetData we can determine the constant size.
-  if (TD && AllocTy->isSized()) {
-    const Type *IntPtrTy = TD->getIntPtrType(getContext());
-    return getIntegerSCEV(TD->getTypeAllocSize(AllocTy), IntPtrTy);
-  }
-
-  // Expand an array size into the element size times the number
-  // of elements.
-  if (const ArrayType *ATy = dyn_cast<ArrayType>(AllocTy)) {
-    const SCEV *E = getAllocSizeExpr(ATy->getElementType());
-    return getMulExpr(
-      E, getConstant(ConstantInt::get(cast<IntegerType>(E->getType()),
-                                      ATy->getNumElements())));
-  }
-
-  // Expand a vector size into the element size times the number
-  // of elements.
-  if (const VectorType *VTy = dyn_cast<VectorType>(AllocTy)) {
-    const SCEV *E = getAllocSizeExpr(VTy->getElementType());
-    return getMulExpr(
-      E, getConstant(ConstantInt::get(cast<IntegerType>(E->getType()),
-                                      VTy->getNumElements())));
-  }
-
-  // Okay, it looks like we really DO need a sizeof expr.  Check to see if we
-  // already have one, otherwise create a new one.
-  FoldingSetNodeID ID;
-  ID.AddInteger(scAllocSize);
-  ID.AddPointer(AllocTy);
-  void *IP = 0;
-  if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
-  SCEV *S = SCEVAllocator.Allocate<SCEVAllocSizeExpr>();
+  Constant *C = ConstantExpr::getSizeOf(AllocTy);
+  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
+    C = ConstantFoldConstantExpression(CE, TD);
   const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(AllocTy));
-  new (S) SCEVAllocSizeExpr(ID, Ty, AllocTy);
-  UniqueSCEVs.InsertNode(S, IP);
-  return S;
+  return getTruncateOrZeroExtend(getSCEV(C), Ty);
 }
 
 const SCEV *ScalarEvolution::getUnknown(Value *V) {
@@ -4242,9 +4248,6 @@ const SCEV *ScalarEvolution::computeSCEVAtScope(const SCEV *V, const Loop *L) {
     return getTruncateExpr(Op, Cast->getType());
   }
 
-  if (isa<SCEVTargetDataConstant>(V))
-    return V;
-
   llvm_unreachable("Unknown SCEV type!");
   return 0;
 }
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index a72f58f64f..9e2e712cdd 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -427,22 +427,22 @@ Value *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin,
             }
           }
       } else {
-        // Without TargetData, just check for a SCEVFieldOffsetExpr of the
+        // Without TargetData, just check for an offsetof expression of the
         // appropriate struct type.
         for (unsigned i = 0, e = Ops.size(); i != e; ++i)
-          if (const SCEVFieldOffsetExpr *FO =
-                dyn_cast<SCEVFieldOffsetExpr>(Ops[i]))
-            if (FO->getStructType() == STy) {
-              unsigned FieldNo = FO->getFieldNo();
-              GepIndices.push_back(
-                  ConstantInt::get(Type::getInt32Ty(Ty->getContext()),
-                                   FieldNo));
-              ElTy = STy->getTypeAtIndex(FieldNo);
+          if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Ops[i])) {
+            const StructType *StructTy;
+            Constant *FieldNo;
+            if (U->isOffsetOf(StructTy, FieldNo) && StructTy == STy) {
+              GepIndices.push_back(FieldNo);
+              ElTy =
+                STy->getTypeAtIndex(cast<ConstantInt>(FieldNo)->getZExtValue());
               Ops[i] = SE.getConstant(Ty, 0);
               AnyNonZeroIndices = true;
               FoundFieldNo = true;
               break;
             }
+          }
       }
       // If no struct field offsets were found, tentatively assume that
       // field zero was selected (since the zero offset would obviously
@@ -1001,14 +1001,6 @@ Value *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) {
   return LHS;
 }
 
-Value *SCEVExpander::visitFieldOffsetExpr(const SCEVFieldOffsetExpr *S) {
-  return ConstantExpr::getOffsetOf(S->getStructType(), S->getFieldNo());
-}
-
-Value *SCEVExpander::visitAllocSizeExpr(const SCEVAllocSizeExpr *S) {
-  return ConstantExpr::getSizeOf(S->getAllocType());
-}
-
 Value *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty) {
   // Expand the code for this SCEV.
   Value *V = expand(SH);
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp
index ddd55878cb..24b78ae969 100644
--- a/lib/VMCore/ConstantFold.cpp
+++ b/lib/VMCore/ConstantFold.cpp
@@ -415,9 +415,38 @@ Constant *llvm::ConstantFoldCastInstruction(LLVMContext &Context,
       return ConstantPointerNull::get(cast<PointerType>(DestTy));
     return 0;                   // Other pointer types cannot be casted
   case Instruction::PtrToInt:   // always treated as unsigned
-    if (V->isNullValue())       // is it a null pointer value?
+    // Is it a null pointer value?
+    if (V->isNullValue())
       return ConstantInt::get(DestTy, 0);
-    return 0;                   // Other pointer types cannot be casted
+    // If this is a sizeof of an array or vector, pull out a multiplication
+    // by the element size to expose it to subsequent folding.
+    if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
+      if (CE->getOpcode() == Instruction::GetElementPtr &&
+          CE->getNumOperands() == 2 &&
+          CE->getOperand(0)->isNullValue())
+        if (ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(1)))
+          if (CI->isOne()) {
+            const Type *Ty =
+              cast<PointerType>(CE->getOperand(0)->getType())->getElementType();
+            if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+              Constant *N = ConstantInt::get(DestTy, ATy->getNumElements());
+              Constant *E = ConstantExpr::getSizeOf(ATy->getElementType());
+              E = ConstantExpr::getCast(CastInst::getCastOpcode(E, false,
+                                                                DestTy, false),
+                                        E, DestTy);
+              return ConstantExpr::getMul(N, E);
+            }
+            if (const VectorType *VTy = dyn_cast<VectorType>(Ty)) {
+              Constant *N = ConstantInt::get(DestTy, VTy->getNumElements());
+              Constant *E = ConstantExpr::getSizeOf(VTy->getElementType());
+              E = ConstantExpr::getCast(CastInst::getCastOpcode(E, false,
+                                                                DestTy, false),
+                                        E, DestTy);
+              return ConstantExpr::getMul(N, E);
+            }
+          }
+    // Other pointer types cannot be casted
+    return 0;
   case Instruction::UIToFP:
   case Instruction::SIToFP:
     if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 436083f62b..9e1154e95e 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -1479,10 +1479,10 @@ Constant* ConstantExpr::getSizeOf(const Type* Ty) {
 }
 
 Constant* ConstantExpr::getAlignOf(const Type* Ty) {
-  // alignof is implemented as: (i64) gep ({i8,Ty}*)null, 0, 1
+  // alignof is implemented as: (i64) gep ({i1,Ty}*)null, 0, 1
   // Note that a non-inbounds gep is used, as null isn't within any object.
   const Type *AligningTy = StructType::get(Ty->getContext(),
-                                   Type::getInt8Ty(Ty->getContext()), Ty, NULL);
+                                   Type::getInt1Ty(Ty->getContext()), Ty, NULL);
   Constant *NullPtr = Constant::getNullValue(AligningTy->getPointerTo());
   Constant *Zero = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 0);
   Constant *One = ConstantInt::get(Type::getInt32Ty(Ty->getContext()), 1);