Convert StringMap to using StringRef for its APIs.
[oota-llvm.git] / lib / Analysis / BasicAliasAnalysis.cpp
index fe71f04098b13061a0b04c4dcf2a99bc3fd7f9dd..49d771a42d70836920ca1909a66b18215bdc1f40 100644 (file)
 #include "llvm/GlobalVariable.h"
 #include "llvm/Instructions.h"
 #include "llvm/IntrinsicInst.h"
+#include "llvm/LLVMContext.h"
+#include "llvm/Operator.h"
 #include "llvm/Pass.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/GetElementPtrTypeIterator.h"
-#include "llvm/Support/ManagedStatic.h"
 #include <algorithm>
 using namespace llvm;
 
@@ -36,12 +38,8 @@ using namespace llvm;
 // Useful predicates
 //===----------------------------------------------------------------------===//
 
-static const User *isGEP(const Value *V) {
-  if (isa<GetElementPtrInst>(V) ||
-      (isa<ConstantExpr>(V) &&
-       cast<ConstantExpr>(V)->getOpcode() == Instruction::GetElementPtr))
-    return cast<User>(V);
-  return 0;
+static const GEPOperator *isGEP(const Value *V) {
+  return dyn_cast<GEPOperator>(V);
 }
 
 static const Value *GetGEPOperands(const Value *V, 
@@ -123,7 +121,7 @@ static bool isObjectSmallerThan(const Value *V, unsigned Size,
   }
   
   if (AccessTy->isSized())
-    return TD.getTypePaddedSize(AccessTy) < Size;
+    return TD.getTypeAllocSize(AccessTy) < Size;
   return false;
 }
 
@@ -157,7 +155,7 @@ namespace {
 
     virtual void getArgumentAccesses(Function *F, CallSite CS,
                                      std::vector<PointerAccessInfo> &Info) {
-      assert(0 && "This method may not be called on this function!");
+      llvm_unreachable("This method may not be called on this function!");
     }
 
     virtual void getMustAliases(Value *P, std::vector<Value*> &RetVals) { }
@@ -311,6 +309,8 @@ BasicAliasAnalysis::getModRefInfo(CallSite CS1, CallSite CS2) {
 AliasAnalysis::AliasResult
 BasicAliasAnalysis::alias(const Value *V1, unsigned V1Size,
                           const Value *V2, unsigned V2Size) {
+  LLVMContext &Context = V1->getType()->getContext();
+
   // Strip off any constant expression casts if they exist
   if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(V1))
     if (CE->isCast() && isa<PointerType>(CE->getOperand(0)->getType()))
@@ -395,13 +395,13 @@ BasicAliasAnalysis::alias(const Value *V1, unsigned V1Size,
     // the base pointers.
     while (isGEP(GEP1->getOperand(0)) &&
            GEP1->getOperand(1) ==
-           Constant::getNullValue(GEP1->getOperand(1)->getType()))
+           Context.getNullValue(GEP1->getOperand(1)->getType()))
       GEP1 = cast<User>(GEP1->getOperand(0));
     const Value *BasePtr1 = GEP1->getOperand(0);
 
     while (isGEP(GEP2->getOperand(0)) &&
            GEP2->getOperand(1) ==
-           Constant::getNullValue(GEP2->getOperand(1)->getType()))
+           Context.getNullValue(GEP2->getOperand(1)->getType()))
       GEP2 = cast<User>(GEP2->getOperand(0));
     const Value *BasePtr2 = GEP2->getOperand(0);
 
@@ -481,7 +481,7 @@ BasicAliasAnalysis::alias(const Value *V1, unsigned V1Size,
             for (unsigned i = 0; i != GEPOperands.size(); ++i)
               if (!isa<ConstantInt>(GEPOperands[i]))
                 GEPOperands[i] =
-                  Constant::getNullValue(GEPOperands[i]->getType());
+                  Context.getNullValue(GEPOperands[i]->getType());
             int64_t Offset =
               getTargetData().getIndexedOffset(BasePtr->getType(),
                                                &GEPOperands[0],
@@ -499,16 +499,16 @@ BasicAliasAnalysis::alias(const Value *V1, unsigned V1Size,
 
 // This function is used to determine if the indices of two GEP instructions are
 // equal. V1 and V2 are the indices.
-static bool IndexOperandsEqual(Value *V1, Value *V2) {
+static bool IndexOperandsEqual(Value *V1, Value *V2, LLVMContext &Context) {
   if (V1->getType() == V2->getType())
     return V1 == V2;
   if (Constant *C1 = dyn_cast<Constant>(V1))
     if (Constant *C2 = dyn_cast<Constant>(V2)) {
       // Sign extend the constants to long types, if necessary
       if (C1->getType() != Type::Int64Ty)
-        C1 = ConstantExpr::getSExt(C1, Type::Int64Ty);
+        C1 = Context.getConstantExprSExt(C1, Type::Int64Ty);
       if (C2->getType() != Type::Int64Ty) 
-        C2 = ConstantExpr::getSExt(C2, Type::Int64Ty);
+        C2 = Context.getConstantExprSExt(C2, Type::Int64Ty);
       return C1 == C2;
     }
   return false;
@@ -529,6 +529,8 @@ BasicAliasAnalysis::CheckGEPInstructions(
 
   const PointerType *GEPPointerTy = cast<PointerType>(BasePtr1Ty);
 
+  LLVMContext &Context = GEPPointerTy->getContext();
+
   // Find the (possibly empty) initial sequence of equal values... which are not
   // necessarily constants.
   unsigned NumGEP1Operands = NumGEP1Ops, NumGEP2Operands = NumGEP2Ops;
@@ -536,7 +538,8 @@ BasicAliasAnalysis::CheckGEPInstructions(
   unsigned MaxOperands = std::max(NumGEP1Operands, NumGEP2Operands);
   unsigned UnequalOper = 0;
   while (UnequalOper != MinOperands &&
-         IndexOperandsEqual(GEP1Ops[UnequalOper], GEP2Ops[UnequalOper])) {
+         IndexOperandsEqual(GEP1Ops[UnequalOper], GEP2Ops[UnequalOper],
+         Context)) {
     // Advance through the type as we go...
     ++UnequalOper;
     if (const CompositeType *CT = dyn_cast<CompositeType>(BasePtr1Ty))
@@ -601,9 +604,9 @@ BasicAliasAnalysis::CheckGEPInstructions(
           if (G1OC->getType() != G2OC->getType()) {
             // Sign extend both operands to long.
             if (G1OC->getType() != Type::Int64Ty)
-              G1OC = ConstantExpr::getSExt(G1OC, Type::Int64Ty);
+              G1OC = Context.getConstantExprSExt(G1OC, Type::Int64Ty);
             if (G2OC->getType() != Type::Int64Ty) 
-              G2OC = ConstantExpr::getSExt(G2OC, Type::Int64Ty);
+              G2OC = Context.getConstantExprSExt(G2OC, Type::Int64Ty);
             GEP1Ops[FirstConstantOper] = G1OC;
             GEP2Ops[FirstConstantOper] = G2OC;
           }
@@ -611,18 +614,39 @@ BasicAliasAnalysis::CheckGEPInstructions(
           if (G1OC != G2OC) {
             // Handle the "be careful" case above: if this is an array/vector
             // subscript, scan for a subsequent variable array index.
-            if (isa<SequentialType>(BasePtr1Ty))  {
-              const Type *NextTy =
-                cast<SequentialType>(BasePtr1Ty)->getElementType();
+            if (const SequentialType *STy =
+                  dyn_cast<SequentialType>(BasePtr1Ty)) {
+              const Type *NextTy = STy;
               bool isBadCase = false;
               
-              for (unsigned Idx = FirstConstantOper+1;
+              for (unsigned Idx = FirstConstantOper;
                    Idx != MinOperands && isa<SequentialType>(NextTy); ++Idx) {
                 const Value *V1 = GEP1Ops[Idx], *V2 = GEP2Ops[Idx];
                 if (!isa<Constant>(V1) || !isa<Constant>(V2)) {
                   isBadCase = true;
                   break;
                 }
+                // If the array is indexed beyond the bounds of the static type
+                // at this level, it will also fall into the "be careful" case.
+                // It would theoretically be possible to analyze these cases,
+                // but for now just be conservatively correct.
+                if (const ArrayType *ATy = dyn_cast<ArrayType>(STy))
+                  if (cast<ConstantInt>(G1OC)->getZExtValue() >=
+                        ATy->getNumElements() ||
+                      cast<ConstantInt>(G2OC)->getZExtValue() >=
+                        ATy->getNumElements()) {
+                    isBadCase = true;
+                    break;
+                  }
+                if (const VectorType *VTy = dyn_cast<VectorType>(STy))
+                  if (cast<ConstantInt>(G1OC)->getZExtValue() >=
+                        VTy->getNumElements() ||
+                      cast<ConstantInt>(G2OC)->getZExtValue() >=
+                        VTy->getNumElements()) {
+                    isBadCase = true;
+                    break;
+                  }
+                STy = cast<SequentialType>(NextTy);
                 NextTy = cast<SequentialType>(NextTy)->getElementType();
               }
               
@@ -669,7 +693,7 @@ BasicAliasAnalysis::CheckGEPInstructions(
           // TargetData::getIndexedOffset.
           for (i = 0; i != MaxOperands; ++i)
             if (!isa<ConstantInt>(GEP1Ops[i]))
-              GEP1Ops[i] = Constant::getNullValue(GEP1Ops[i]->getType());
+              GEP1Ops[i] = Context.getNullValue(GEP1Ops[i]->getType());
           // Okay, now get the offset.  This is the relative offset for the full
           // instruction.
           const TargetData &TD = getTargetData();
@@ -714,7 +738,7 @@ BasicAliasAnalysis::CheckGEPInstructions(
   const Type *ZeroIdxTy = GEPPointerTy;
   for (unsigned i = 0; i != FirstConstantOper; ++i) {
     if (!isa<StructType>(ZeroIdxTy))
-      GEP1Ops[i] = GEP2Ops[i] = Constant::getNullValue(Type::Int32Ty);
+      GEP1Ops[i] = GEP2Ops[i] = Context.getNullValue(Type::Int32Ty);
 
     if (const CompositeType *CT = dyn_cast<CompositeType>(ZeroIdxTy))
       ZeroIdxTy = CT->getTypeAtIndex(GEP1Ops[i]);
@@ -729,7 +753,7 @@ BasicAliasAnalysis::CheckGEPInstructions(
     // If they are equal, use a zero index...
     if (Op1 == Op2 && BasePtr1Ty == BasePtr2Ty) {
       if (!isa<ConstantInt>(Op1))
-        GEP1Ops[i] = GEP2Ops[i] = Constant::getNullValue(Op1->getType());
+        GEP1Ops[i] = GEP2Ops[i] = Context.getNullValue(Op1->getType());
       // Otherwise, just keep the constants we have.
     } else {
       if (Op1) {
@@ -755,9 +779,11 @@ BasicAliasAnalysis::CheckGEPInstructions(
           // value possible.
           //
           if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty))
-            GEP1Ops[i] = ConstantInt::get(Type::Int64Ty,AT->getNumElements()-1);
+            GEP1Ops[i] =
+                  Context.getConstantInt(Type::Int64Ty,AT->getNumElements()-1);
           else if (const VectorType *VT = dyn_cast<VectorType>(BasePtr1Ty))
-            GEP1Ops[i] = ConstantInt::get(Type::Int64Ty,VT->getNumElements()-1);
+            GEP1Ops[i] = 
+                  Context.getConstantInt(Type::Int64Ty,VT->getNumElements()-1);
         }
       }
 
@@ -772,7 +798,7 @@ BasicAliasAnalysis::CheckGEPInstructions(
               return MayAlias;  // Be conservative with out-of-range accesses
           }
         } else {  // Conservatively assume the minimum value for this index
-          GEP2Ops[i] = Constant::getNullValue(Op2->getType());
+          GEP2Ops[i] = Context.getNullValue(Op2->getType());
         }
       }
     }