#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineSSAUpdater.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
/// TailDuplicatePass - Perform tail duplication.
class TailDuplicatePass : public MachineFunctionPass {
const TargetInstrInfo *TII;
+ const TargetRegisterInfo *TRI;
MachineModuleInfo *MMI;
MachineRegisterInfo *MRI;
+ OwningPtr<RegScavenger> RS;
bool PreRegAlloc;
// SSAUpdateVRs - A list of virtual registers for which to update SSA form.
bool TailDuplicatePass::runOnMachineFunction(MachineFunction &MF) {
TII = MF.getTarget().getInstrInfo();
+ TRI = MF.getTarget().getRegisterInfo();
MRI = &MF.getRegInfo();
MMI = getAnalysisIfAvailable<MachineModuleInfo>();
PreRegAlloc = MRI->isSSA();
+ RS.reset();
+ if (MRI->tracksLiveness() && TRI->trackLivenessAfterRegAlloc(MF))
+ RS.reset(new RegScavenger());
bool MadeChange = false;
while (TailDuplicateBlocks(MF))
// compensate for the duplication.
unsigned MaxDuplicateCount;
if (TailDuplicateSize.getNumOccurrences() == 0 &&
- MF.getFunction()->hasFnAttr(Attribute::OptimizeForSize))
+ MF.getFunction()->getFnAttributes().
+ hasAttribute(Attributes::OptimizeForSize))
MaxDuplicateCount = 1;
else
MaxDuplicateCount = TailDuplicateSize;
// Remove PredBB's unconditional branch.
TII->RemoveBranch(*PredBB);
+ if (RS && !TailBB->livein_empty()) {
+ // Update PredBB livein.
+ RS->enterBasicBlock(PredBB);
+ if (!PredBB->empty())
+ RS->forward(prior(PredBB->end()));
+ BitVector RegsLiveAtExit(TRI->getNumRegs());
+ RS->getRegsUsed(RegsLiveAtExit, false);
+ for (MachineBasicBlock::livein_iterator I = TailBB->livein_begin(),
+ E = TailBB->livein_end(); I != E; ++I) {
+ if (!RegsLiveAtExit[*I])
+ // If a register is previously livein to the tail but it's not live
+ // at the end of predecessor BB, then it should be added to its
+ // livein list.
+ PredBB->addLiveIn(*I);
+ }
+ }
+
// Clone the contents of TailBB into PredBB.
DenseMap<unsigned, unsigned> LocalVRMap;
SmallVector<std::pair<unsigned,unsigned>, 4> CopyInfos;