Auto-upgrade free instructions to calls to the builtin free function.

Update all analysis passes and transforms to treat free calls just like FreeInst.
Remove RaiseAllocations and all its tests since FreeInst no longer needs to be raised.

llvm-svn: 84987

1 files changed, 45 insertions, 0 deletions

diff --git a/llvm/lib/VMCore/Instructions.cpp b/llvm/lib/VMCore/Instructions.cpp
index 99a28594e6c..60e203a7e0b 100644
--- a/llvm/lib/VMCore/Instructions.cpp
+++ b/llvm/lib/VMCore/Instructions.cpp
@@ -559,6 +559,51 @@ Instruction *CallInst::CreateMalloc(BasicBlock *InsertAtEnd,
                       ArraySize, MallocF, Name);
 }
 
+static Instruction* createFree(Value* Source, Instruction *InsertBefore,
+                               BasicBlock *InsertAtEnd) {
+  assert(((!InsertBefore && InsertAtEnd) || (InsertBefore && !InsertAtEnd)) &&
+         "createFree needs either InsertBefore or InsertAtEnd");
+  assert(isa<PointerType>(Source->getType()) &&
+         "Can not free something of nonpointer type!");
+
+  BasicBlock* BB = InsertBefore ? InsertBefore->getParent() : InsertAtEnd;
+  Module* M = BB->getParent()->getParent();
+
+  const Type *VoidTy = Type::getVoidTy(M->getContext());
+  const Type *IntPtrTy = Type::getInt8PtrTy(M->getContext());
+  // prototype free as "void free(void*)"
+  Constant *FreeFunc = M->getOrInsertFunction("free", VoidTy, IntPtrTy, NULL);
+
+  CallInst* Result = NULL;
+  Value *PtrCast = Source;
+  if (InsertBefore) {
+    if (Source->getType() != IntPtrTy)
+      PtrCast = new BitCastInst(Source, IntPtrTy, "", InsertBefore);
+    Result = CallInst::Create(FreeFunc, PtrCast, "", InsertBefore);
+  } else {
+    if (Source->getType() != IntPtrTy)
+      PtrCast = new BitCastInst(Source, IntPtrTy, "", InsertAtEnd);
+    Result = CallInst::Create(FreeFunc, PtrCast, "");
+  }
+  Result->setTailCall();
+
+  return Result;
+}
+
+/// CreateFree - Generate the IR for a call to the builtin free function.
+void CallInst::CreateFree(Value* Source, Instruction *InsertBefore) {
+  createFree(Source, InsertBefore, NULL);
+}
+
+/// CreateFree - Generate the IR for a call to the builtin free function.
+/// Note: This function does not add the call to the basic block, that is the
+/// responsibility of the caller.
+Instruction* CallInst::CreateFree(Value* Source, BasicBlock *InsertAtEnd) {
+  Instruction* FreeCall = createFree(Source, NULL, InsertAtEnd);
+  assert(FreeCall && "CreateFree did not create a CallInst");
+  return FreeCall;
+}
+
 //===----------------------------------------------------------------------===//
 //                        InvokeInst Implementation
 //===----------------------------------------------------------------------===//