From e89652ccad7b2685387a8327961a46f8bac0978b Mon Sep 17 00:00:00 2001
From: Torok Edwin <edwintorok@gmail.com>
Date: Wed, 4 Aug 2010 11:42:45 +0000
Subject: [PATCH] Add a missing function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110195 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Analysis/PointerTracking.h |  1 +
 lib/Analysis/PointerTracking.cpp        | 49 +++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/include/llvm/Analysis/PointerTracking.h b/include/llvm/Analysis/PointerTracking.h
index 6c4f838430b..6b49e18c1b6 100644
--- a/include/llvm/Analysis/PointerTracking.h
+++ b/include/llvm/Analysis/PointerTracking.h
@@ -98,6 +98,7 @@ namespace llvm {
     virtual bool runOnFunction(Function &F);
     virtual void getAnalysisUsage(AnalysisUsage &AU) const;
     void print(raw_ostream &OS, const Module* = 0) const;
+    Value *computeAllocationCountValue(Value *P, const Type *&Ty) const;
   private:
     Function *FF;
     TargetData *TD;
diff --git a/lib/Analysis/PointerTracking.cpp b/lib/Analysis/PointerTracking.cpp
index 142066e42ba..03d3059fdbb 100644
--- a/lib/Analysis/PointerTracking.cpp
+++ b/lib/Analysis/PointerTracking.cpp
@@ -144,6 +144,55 @@ const SCEV *PointerTracking::computeAllocationCount(Value *P,
   return SE->getCouldNotCompute();
 }
 
+Value *PointerTracking::computeAllocationCountValue(Value *P, const Type *&Ty) const 
+{
+  Value *V = P->stripPointerCasts();
+  if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
+    Ty = AI->getAllocatedType();
+    // arraySize elements of type Ty.
+    return AI->getArraySize();
+  }
+
+  if (CallInst *CI = extractMallocCall(V)) {
+    Ty = getMallocAllocatedType(CI);
+    if (!Ty)
+      return 0;
+    Value *arraySize = getMallocArraySize(CI, TD);
+    if (!arraySize) {
+      Ty = Type::getInt8Ty(P->getContext());
+      return CI->getArgOperand(0);
+    }
+    // arraySize elements of type Ty.
+    return arraySize;
+  }
+
+  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
+    if (GV->hasDefinitiveInitializer()) {
+      Constant *C = GV->getInitializer();
+      if (const ArrayType *ATy = dyn_cast<ArrayType>(C->getType())) {
+        Ty = ATy->getElementType();
+        return ConstantInt::get(Type::getInt32Ty(P->getContext()),
+                               ATy->getNumElements());
+      }
+    }
+    Ty = cast<PointerType>(GV->getType())->getElementType();
+    return ConstantInt::get(Type::getInt32Ty(P->getContext()), 1);
+    //TODO: implement more tracking for globals
+  }
+
+  if (CallInst *CI = dyn_cast<CallInst>(V)) {
+    CallSite CS(CI);
+    Function *F = dyn_cast<Function>(CS.getCalledValue()->stripPointerCasts());
+    if (F == reallocFunc) {
+      Ty = Type::getInt8Ty(P->getContext());
+      // realloc allocates arg1 bytes.
+      return CS.getArgument(1);
+    }
+  }
+
+  return 0;
+}
+
 // Calculates the number of elements of type Ty allocated for P.
 const SCEV *PointerTracking::computeAllocationCountForType(Value *P,
                                                            const Type *Ty)
-- 
2.34.1