//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "tailduplication"
-#include "llvm/Function.h"
#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineSSAUpdater.h"
-#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/IR/Function.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/SmallSet.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/Statistic.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
STATISTIC(NumTails , "Number of tails duplicated");
namespace {
/// TailDuplicatePass - Perform tail duplication.
class TailDuplicatePass : public MachineFunctionPass {
- bool PreRegAlloc;
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.
SmallVector<unsigned, 16> SSAUpdateVRs;
public:
static char ID;
- explicit TailDuplicatePass(bool PreRA) :
- MachineFunctionPass(ID), PreRegAlloc(PreRA) {}
+ explicit TailDuplicatePass() :
+ MachineFunctionPass(ID), PreRegAlloc(false) {}
virtual bool runOnMachineFunction(MachineFunction &MF);
- virtual const char *getPassName() const { return "Tail Duplication"; }
private:
void AddSSAUpdateEntry(unsigned OrigReg, unsigned NewReg,
char TailDuplicatePass::ID = 0;
}
-FunctionPass *llvm::createTailDuplicatePass(bool PreRegAlloc) {
- return new TailDuplicatePass(PreRegAlloc);
-}
+char &llvm::TailDuplicateID = TailDuplicatePass::ID;
+
+INITIALIZE_PASS(TailDuplicatePass, "tailduplication", "Tail Duplication",
+ false, false)
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))
continue;
unsigned Dst = Copy->getOperand(0).getReg();
unsigned Src = Copy->getOperand(1).getReg();
- MachineRegisterInfo::use_iterator UI = MRI->use_begin(Src);
- if (++UI == MRI->use_end()) {
+ if (MRI->hasOneNonDBGUse(Src) &&
+ MRI->constrainRegClass(Src, MRI->getRegClass(Dst))) {
// Copy is the only use. Do trivial copy propagation here.
MRI->replaceRegWith(Dst, Src);
Copy->eraseFromParent();
AddSSAUpdateEntry(Reg, NewReg, PredBB);
} else {
DenseMap<unsigned, unsigned>::iterator VI = LocalVRMap.find(Reg);
- if (VI != LocalVRMap.end())
+ if (VI != LocalVRMap.end()) {
MO.setReg(VI->second);
+ MRI->constrainRegClass(VI->second, MRI->getRegClass(Reg));
+ }
}
}
- PredBB->insert(PredBB->end(), NewMI);
+ PredBB->insert(PredBB->instr_end(), NewMI);
}
/// UpdateSuccessorsPHIs - After FromBB is tail duplicated into its predecessor
II != EE; ++II) {
if (!II->isPHI())
break;
+ MachineInstrBuilder MIB(*FromBB->getParent(), II);
unsigned Idx = 0;
for (unsigned i = 1, e = II->getNumOperands(); i != e; i += 2) {
MachineOperand &MO = II->getOperand(i+1);
II->getOperand(Idx+1).setMBB(SrcBB);
Idx = 0;
} else {
- II->addOperand(MachineOperand::CreateReg(SrcReg, false));
- II->addOperand(MachineOperand::CreateMBB(SrcBB));
+ MIB.addReg(SrcReg).addMBB(SrcBB);
}
}
} else {
II->getOperand(Idx+1).setMBB(SrcBB);
Idx = 0;
} else {
- II->addOperand(MachineOperand::CreateReg(Reg, false));
- II->addOperand(MachineOperand::CreateMBB(SrcBB));
+ MIB.addReg(Reg).addMBB(SrcBB);
}
}
}
// compensate for the duplication.
unsigned MaxDuplicateCount;
if (TailDuplicateSize.getNumOccurrences() == 0 &&
- MF.getFunction()->hasFnAttr(Attribute::OptimizeForSize))
+ MF.getFunction()->getAttributes().
+ hasAttribute(AttributeSet::FunctionIndex, Attribute::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;
- MachineBasicBlock::iterator I = TailBB->begin();
- while (I != TailBB->end()) {
+ // Use instr_iterator here to properly handle bundles, e.g.
+ // ARM Thumb2 IT block.
+ MachineBasicBlock::instr_iterator I = TailBB->instr_begin();
+ while (I != TailBB->instr_end()) {
MachineInstr *MI = &*I;
++I;
if (MI->isPHI()) {
SmallVector<MachineOperand, 4> PriorCond;
// This has to check PrevBB->succ_size() because EH edges are ignored by
// AnalyzeBranch.
- if (PrevBB->succ_size() == 1 &&
+ if (PrevBB->succ_size() == 1 &&
!TII->AnalyzeBranch(*PrevBB, PriorTBB, PriorFBB, PriorCond, true) &&
PriorCond.empty() && !PriorTBB && TailBB->pred_size() == 1 &&
!TailBB->hasAddressTaken()) {
// Replace def of virtual registers with new registers, and update
// uses with PHI source register or the new registers.
MachineInstr *MI = &*I++;
+ assert(!MI->isBundle() && "Not expecting bundles before regalloc!");
DuplicateInstruction(MI, TailBB, PrevBB, MF, LocalVRMap, UsedByPhi);
MI->eraseFromParent();
}
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