1 files changed, 108 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/IPO/RaiseAllocations.cpp b/llvm/lib/Transforms/IPO/RaiseAllocations.cpp
new file mode 100644
index 00000000000..a0719e12bf9
--- /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;
+}