path: root/lib/Transforms/InstCombine/InstCombineCalls.cpp

//===- InstCombineCalls.cpp -----------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the visitCall and visitInvoke functions.
//
//===----------------------------------------------------------------------===//

#include "InstCombine.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Transforms/Utils/BuildLibCalls.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;

/// getPromotedType - Return the specified type promoted as it would be to pass
/// though a va_arg area.
static Type *getPromotedType(Type *Ty) {
  if (IntegerType* ITy = dyn_cast<IntegerType>(Ty)) {
    if (ITy->getBitWidth() < 32)
      return Type::getInt32Ty(Ty->getContext());
  }
  return Ty;
}


Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
  unsigned DstAlign = getKnownAlignment(MI->getArgOperand(0), TD);
  unsigned SrcAlign = getKnownAlignment(MI->getArgOperand(1), TD);
  unsigned MinAlign = std::min(DstAlign, SrcAlign);
  unsigned CopyAlign = MI->getAlignment();

  if (CopyAlign < MinAlign) {
    MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
                                             MinAlign, false));
    return MI;
  }

  // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with
  // load/store.
  ConstantInt *MemOpLength = dyn_cast<ConstantInt>