Split ChangeAllocations.cpp into Raise & LowerAllocations.cpp
llvm-svn: 2529
diff --git a/llvm/lib/Transforms/IPO/RaiseAllocations.cpp b/llvm/lib/Transforms/IPO/RaiseAllocations.cpp
new file mode 100644
index 0000000..a0719e1
--- /dev/null
+++ b/llvm/lib/Transforms/IPO/RaiseAllocations.cpp
@@ -0,0 +1,108 @@
+//===- ChangeAllocations.cpp - Modify %malloc & %free calls -----------------=//
+//
+// This file defines two passes that convert malloc and free instructions to
+// calls to and from %malloc & %free function calls. The LowerAllocations
+// transformation is a target dependant tranformation because it depends on the
+// size of data types and alignment constraints.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/ChangeAllocations.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Module.h"
+#include "llvm/Function.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/iMemory.h"
+#include "llvm/iOther.h"
+#include "llvm/Pass.h"
+
+namespace {
+
+// RaiseAllocations - Turn %malloc and %free calls into the appropriate
+// instruction.
+//
+class RaiseAllocations : public BasicBlockPass {
+ Function *MallocFunc; // Functions in the module we are processing
+ Function *FreeFunc; // Initialized by doPassInitializationVirt
+public:
+ inline RaiseAllocations() : MallocFunc(0), FreeFunc(0) {}
+
+ const char *getPassName() const { return "Raise Allocations"; }
+
+ // doPassInitialization - For the raise allocations pass, this finds a
+ // declaration for malloc and free if they exist.
+ //
+ bool doInitialization(Module *M);
+
+ // runOnBasicBlock - This method does the actual work of converting
+ // instructions over, assuming that the pass has already been initialized.
+ //
+ bool runOnBasicBlock(BasicBlock *BB);
+};
+
+} // end anonymous namespace
+
+
+// createRaiseAllocationsPass - The interface to this file...
+Pass *createRaiseAllocationsPass() {
+ return new RaiseAllocations();
+}
+
+
+bool RaiseAllocations::doInitialization(Module *M) {
+ // If the module has a symbol table, they might be referring to the malloc
+ // and free functions. If this is the case, grab the method pointers that
+ // the module is using.
+ //
+ // Lookup %malloc and %free in the symbol table, for later use. If they
+ // don't exist, or are not external, we do not worry about converting calls
+ // to that function into the appropriate instruction.
+ //
+ const FunctionType *MallocType = // Get the type for malloc
+ FunctionType::get(PointerType::get(Type::SByteTy),
+ std::vector<const Type*>(1, Type::UIntTy), false);
+
+ const FunctionType *FreeType = // Get the type for free
+ FunctionType::get(Type::VoidTy,
+ std::vector<const Type*>(1, PointerType::get(Type::SByteTy)),
+ false);
+
+ MallocFunc = M->getFunction("malloc", MallocType);
+ FreeFunc = M->getFunction("free" , FreeType);
+
+ // Don't mess with locally defined versions of these functions...
+ if (MallocFunc && !MallocFunc->isExternal()) MallocFunc = 0;
+ if (FreeFunc && !FreeFunc->isExternal()) FreeFunc = 0;
+ return false;
+}
+
+// doOneCleanupPass - Do one pass over the input method, fixing stuff up.
+//
+bool RaiseAllocations::runOnBasicBlock(BasicBlock *BB) {
+ bool Changed = false;
+ BasicBlock::InstListType &BIL = BB->getInstList();
+
+ for (BasicBlock::iterator BI = BB->begin(); BI != BB->end();) {
+ Instruction *I = *BI;
+
+ if (CallInst *CI = dyn_cast<CallInst>(I)) {
+ if (CI->getCalledValue() == MallocFunc) { // Replace call to malloc?
+ const Type *PtrSByte = PointerType::get(Type::SByteTy);
+ MallocInst *MallocI = new MallocInst(PtrSByte, CI->getOperand(1),
+ CI->getName());
+ CI->setName("");
+ ReplaceInstWithInst(BIL, BI, MallocI);
+ Changed = true;
+ continue; // Skip the ++BI
+ } else if (CI->getCalledValue() == FreeFunc) { // Replace call to free?
+ ReplaceInstWithInst(BIL, BI, new FreeInst(CI->getOperand(1)));
+ Changed = true;
+ continue; // Skip the ++BI
+ }
+ }
+
+ ++BI;
+ }
+
+ return Changed;
+}