#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
#define DEBUG_TYPE "tailduplication"
typedef std::vector<std::pair<MachineBasicBlock*,unsigned> > AvailableValsTy;
namespace {
- /// TailDuplicatePass - Perform tail duplication.
+ /// Perform tail duplication.
class TailDuplicatePass : public MachineFunctionPass {
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
std::unique_ptr<RegScavenger> RS;
bool PreRegAlloc;
- // SSAUpdateVRs - A list of virtual registers for which to update SSA form.
+ // A list of virtual registers for which to update SSA form.
SmallVector<unsigned, 16> SSAUpdateVRs;
- // SSAUpdateVals - For each virtual register in SSAUpdateVals keep a list of
- // source virtual registers.
+ // For each virtual register in SSAUpdateVals keep a list of source virtual
+ // registers.
DenseMap<unsigned, AvailableValsTy> SSAUpdateVals;
public:
if (skipOptnoneFunction(*MF.getFunction()))
return false;
- TII = MF.getTarget().getInstrInfo();
- TRI = MF.getTarget().getRegisterInfo();
+ TII = MF.getSubtarget().getInstrInfo();
+ TRI = MF.getSubtarget().getRegisterInfo();
MRI = &MF.getRegInfo();
MMI = getAnalysisIfAvailable<MachineModuleInfo>();
MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
}
}
-/// TailDuplicateAndUpdate - Tail duplicate the block and cleanup.
+/// Tail duplicate the block and cleanup.
bool
TailDuplicatePass::TailDuplicateAndUpdate(MachineBasicBlock *MBB,
bool IsSimple,
return true;
}
-/// TailDuplicateBlocks - Look for small blocks that are unconditionally
-/// branched to and do not fall through. Tail-duplicate their instructions
-/// into their predecessors to eliminate (dynamic) branches.
+/// Look for small blocks that are unconditionally branched to and do not fall
+/// through. Tail-duplicate their instructions into their predecessors to
+/// eliminate (dynamic) branches.
bool TailDuplicatePass::TailDuplicateBlocks(MachineFunction &MF) {
bool MadeChange = false;
}
}
-/// AddSSAUpdateEntry - Add a definition and source virtual registers pair for
-/// SSA update.
+/// Add a definition and source virtual registers pair for SSA update.
void TailDuplicatePass::AddSSAUpdateEntry(unsigned OrigReg, unsigned NewReg,
MachineBasicBlock *BB) {
DenseMap<unsigned, AvailableValsTy>::iterator LI= SSAUpdateVals.find(OrigReg);
}
}
-/// ProcessPHI - Process PHI node in TailBB by turning it into a copy in PredBB.
-/// Remember the source register that's contributed by PredBB and update SSA
-/// update map.
+/// Process PHI node in TailBB by turning it into a copy in PredBB. Remember the
+/// source register that's contributed by PredBB and update SSA update map.
void TailDuplicatePass::ProcessPHI(
MachineInstr *MI, MachineBasicBlock *TailBB, MachineBasicBlock *PredBB,
DenseMap<unsigned, unsigned> &LocalVRMap,
MI->eraseFromParent();
}
-/// DuplicateInstruction - Duplicate a TailBB instruction to PredBB and update
+/// Duplicate a TailBB instruction to PredBB and update
/// the source operands due to earlier PHI translation.
void TailDuplicatePass::DuplicateInstruction(MachineInstr *MI,
MachineBasicBlock *TailBB,
DenseMap<unsigned, unsigned>::iterator VI = LocalVRMap.find(Reg);
if (VI != LocalVRMap.end()) {
MO.setReg(VI->second);
+ // Clear any kill flags from this operand. The new register could have
+ // uses after this one, so kills are not valid here.
+ MO.setIsKill(false);
MRI->constrainRegClass(VI->second, MRI->getRegClass(Reg));
}
}
PredBB->insert(PredBB->instr_end(), NewMI);
}
-/// UpdateSuccessorsPHIs - After FromBB is tail duplicated into its predecessor
-/// blocks, the successors have gained new predecessors. Update the PHI
-/// instructions in them accordingly.
+/// After FromBB is tail duplicated into its predecessor blocks, the successors
+/// have gained new predecessors. Update the PHI instructions in them
+/// accordingly.
void
TailDuplicatePass::UpdateSuccessorsPHIs(MachineBasicBlock *FromBB, bool isDead,
SmallVectorImpl<MachineBasicBlock *> &TDBBs,
}
}
-/// shouldTailDuplicate - Determine if it is profitable to duplicate this block.
+/// Determine if it is profitable to duplicate this block.
bool
TailDuplicatePass::shouldTailDuplicate(const MachineFunction &MF,
bool IsSimple,
// compensate for the duplication.
unsigned MaxDuplicateCount;
if (TailDuplicateSize.getNumOccurrences() == 0 &&
- MF.getFunction()->getAttributes().
- hasAttribute(AttributeSet::FunctionIndex, Attribute::OptimizeForSize))
+ // FIXME: Use Function::optForSize().
+ MF.getFunction()->hasFnAttribute(Attribute::OptimizeForSize))
MaxDuplicateCount = 1;
else
MaxDuplicateCount = TailDuplicateSize;
// Check the instructions in the block to determine whether tail-duplication
// is invalid or unlikely to be profitable.
unsigned InstrCount = 0;
- for (MachineBasicBlock::iterator I = TailBB.begin(); I != TailBB.end(); ++I) {
+ for (MachineInstr &MI : TailBB) {
// Non-duplicable things shouldn't be tail-duplicated.
- if (I->isNotDuplicable())
+ if (MI.isNotDuplicable())
return false;
// Do not duplicate 'return' instructions if this is a pre-regalloc run.
// A return may expand into a lot more instructions (e.g. reload of callee
// saved registers) after PEI.
- if (PreRegAlloc && I->isReturn())
+ if (PreRegAlloc && MI.isReturn())
return false;
// Avoid duplicating calls before register allocation. Calls presents a
// barrier to register allocation so duplicating them may end up increasing
// spills.
- if (PreRegAlloc && I->isCall())
+ if (PreRegAlloc && MI.isCall())
return false;
- if (!I->isPHI() && !I->isDebugValue())
+ if (!MI.isPHI() && !MI.isDebugValue())
InstrCount += 1;
if (InstrCount > MaxDuplicateCount)
return canCompletelyDuplicateBB(TailBB);
}
-/// isSimpleBB - True if this BB has only one unconditional jump.
+/// True if this BB has only one unconditional jump.
bool
TailDuplicatePass::isSimpleBB(MachineBasicBlock *TailBB) {
if (TailBB->succ_size() != 1)
return false;
if (TailBB->pred_empty())
return false;
- MachineBasicBlock::iterator I = TailBB->begin();
- MachineBasicBlock::iterator E = TailBB->end();
- while (I != E && I->isDebugValue())
- ++I;
- if (I == E)
+ MachineBasicBlock::iterator I = TailBB->getFirstNonDebugInstr();
+ if (I == TailBB->end())
return true;
return I->isUnconditionalBranch();
}
static bool
bothUsedInPHI(const MachineBasicBlock &A,
SmallPtrSet<MachineBasicBlock*, 8> SuccsB) {
- for (MachineBasicBlock::const_succ_iterator SI = A.succ_begin(),
- SE = A.succ_end(); SI != SE; ++SI) {
- MachineBasicBlock *BB = *SI;
+ for (MachineBasicBlock *BB : A.successors())
if (SuccsB.count(BB) && !BB->empty() && BB->begin()->isPHI())
return true;
- }
return false;
}
bool
TailDuplicatePass::canCompletelyDuplicateBB(MachineBasicBlock &BB) {
- for (MachineBasicBlock::pred_iterator PI = BB.pred_begin(),
- PE = BB.pred_end(); PI != PE; ++PI) {
- MachineBasicBlock *PredBB = *PI;
-
+ for (MachineBasicBlock *PredBB : BB.predecessors()) {
if (PredBB->succ_size() > 1)
return false;
return Changed;
}
-/// TailDuplicate - If it is profitable, duplicate TailBB's contents in each
+/// If it is profitable, duplicate TailBB's contents in each
/// of its predecessors.
bool
TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB,
RS->enterBasicBlock(PredBB);
if (!PredBB->empty())
RS->forward(std::prev(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])
+ for (unsigned LI : TailBB->liveins()) {
+ if (!RS->isRegUsed(LI, false))
// 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);
+ PredBB->addLiveIn(LI);
}
}
return Changed;
}
-/// RemoveDeadBlock - Remove the specified dead machine basic block from the
-/// function, updating the CFG.
+/// Remove the specified dead machine basic block from the function, updating
+/// the CFG.
void TailDuplicatePass::RemoveDeadBlock(MachineBasicBlock *MBB) {
assert(MBB->pred_empty() && "MBB must be dead!");
DEBUG(dbgs() << "\nRemoving MBB: " << *MBB);
projects / oota-llvm.git / blobdiff