cl::desc("Coalesce copies (default=true)"),
cl::init(true));
-static cl::opt<bool>
-NewHeuristic("new-coalescer-heuristic",
- cl::desc("Use new coalescer heuristic"),
- cl::init(false), cl::Hidden);
-
static cl::opt<bool>
DisableCrossClassJoin("disable-cross-class-join",
cl::desc("Avoid coalescing cross register class copies"),
return true;
}
-/// isBackEdgeCopy - Returns true if CopyMI is a back edge copy.
-///
-bool SimpleRegisterCoalescing::isBackEdgeCopy(MachineInstr *CopyMI,
- unsigned DstReg) const {
- MachineBasicBlock *MBB = CopyMI->getParent();
- const MachineLoop *L = loopInfo->getLoopFor(MBB);
- if (!L)
- return false;
- if (MBB != L->getLoopLatch())
- return false;
-
- LiveInterval &LI = li_->getInterval(DstReg);
- MachineInstrIndex DefIdx = li_->getInstructionIndex(CopyMI);
- LiveInterval::const_iterator DstLR =
- LI.FindLiveRangeContaining(li_->getDefIndex(DefIdx));
- if (DstLR == LI.end())
- return false;
- if (DstLR->valno->kills.size() == 1 && DstLR->valno->kills[0].isPHIIndex())
- return true;
- return false;
-}
-
/// UpdateRegDefsUses - Replace all defs and uses of SrcReg to DstReg and
/// update the subregister number if it is not zero. If DstReg is a
/// physical register and the existing subregister number of the def / use
unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
- if (TheCopy.isBackEdge)
- Threshold *= 2; // Favors back edge copies.
-
unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
float Ratio = 1.0 / Threshold;
if (Length > Threshold &&
if (NewRC)
mri_->setRegClass(DstReg, NewRC);
- if (NewHeuristic) {
- // Add all copies that define val# in the source interval into the queue.
- for (LiveInterval::const_vni_iterator i = ResSrcInt->vni_begin(),
- e = ResSrcInt->vni_end(); i != e; ++i) {
- const VNInfo *vni = *i;
- // FIXME: Do isPHIDef and isDefAccurate both need to be tested?
- if (vni->def == MachineInstrIndex() || vni->isUnused() || vni->isPHIDef() ||
- !vni->isDefAccurate())
- continue;
- MachineInstr *CopyMI = li_->getInstructionFromIndex(vni->def);
- unsigned NewSrcReg, NewDstReg, NewSrcSubIdx, NewDstSubIdx;
- if (CopyMI &&
- JoinedCopies.count(CopyMI) == 0 &&
- tii_->isMoveInstr(*CopyMI, NewSrcReg, NewDstReg,
- NewSrcSubIdx, NewDstSubIdx)) {
- unsigned LoopDepth = loopInfo->getLoopDepth(CopyMBB);
- JoinQueue->push(CopyRec(CopyMI, LoopDepth,
- isBackEdgeCopy(CopyMI, DstReg)));
- }
- }
- }
-
// Remember to delete the copy instruction.
JoinedCopies.insert(CopyMI);
};
}
-/// getRepIntervalSize - Returns the size of the interval that represents the
-/// specified register.
-template<class SF>
-unsigned JoinPriorityQueue<SF>::getRepIntervalSize(unsigned Reg) {
- return Rc->getRepIntervalSize(Reg);
-}
-
-/// CopyRecSort::operator - Join priority queue sorting function.
-///
-bool CopyRecSort::operator()(CopyRec left, CopyRec right) const {
- // Inner loops first.
- if (left.LoopDepth > right.LoopDepth)
- return false;
- else if (left.LoopDepth == right.LoopDepth)
- if (left.isBackEdge && !right.isBackEdge)
- return false;
- return true;
-}
-
void SimpleRegisterCoalescing::CopyCoalesceInMBB(MachineBasicBlock *MBB,
std::vector<CopyRec> &TryAgain) {
DEBUG(errs() << ((Value*)MBB->getBasicBlock())->getName() << ":\n");
std::vector<CopyRec> VirtCopies;
std::vector<CopyRec> PhysCopies;
std::vector<CopyRec> ImpDefCopies;
- unsigned LoopDepth = loopInfo->getLoopDepth(MBB);
for (MachineBasicBlock::iterator MII = MBB->begin(), E = MBB->end();
MII != E;) {
MachineInstr *Inst = MII++;
bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(SrcReg);
bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
- if (NewHeuristic) {
- JoinQueue->push(CopyRec(Inst, LoopDepth, isBackEdgeCopy(Inst, DstReg)));
- } else {
- if (li_->hasInterval(SrcReg) && li_->getInterval(SrcReg).empty())
- ImpDefCopies.push_back(CopyRec(Inst, 0, false));
- else if (SrcIsPhys || DstIsPhys)
- PhysCopies.push_back(CopyRec(Inst, 0, false));
- else
- VirtCopies.push_back(CopyRec(Inst, 0, false));
- }
+ if (li_->hasInterval(SrcReg) && li_->getInterval(SrcReg).empty())
+ ImpDefCopies.push_back(CopyRec(Inst, 0));
+ else if (SrcIsPhys || DstIsPhys)
+ PhysCopies.push_back(CopyRec(Inst, 0));
+ else
+ VirtCopies.push_back(CopyRec(Inst, 0));
}
- if (NewHeuristic)
- return;
-
// Try coalescing implicit copies first, followed by copies to / from
// physical registers, then finally copies from virtual registers to
// virtual registers.
void SimpleRegisterCoalescing::joinIntervals() {
DEBUG(errs() << "********** JOINING INTERVALS ***********\n");
- if (NewHeuristic)
- JoinQueue = new JoinPriorityQueue<CopyRecSort>(this);
-
std::vector<CopyRec> TryAgainList;
if (loopInfo->empty()) {
// If there are no loops in the function, join intervals in function order.
// Joining intervals can allow other intervals to be joined. Iteratively join
// until we make no progress.
- if (NewHeuristic) {
- SmallVector<CopyRec, 16> TryAgain;
- bool ProgressMade = true;
- while (ProgressMade) {
- ProgressMade = false;
- while (!JoinQueue->empty()) {
- CopyRec R = JoinQueue->pop();
- bool Again = false;
- bool Success = JoinCopy(R, Again);
- if (Success)
- ProgressMade = true;
- else if (Again)
- TryAgain.push_back(R);
- }
+ bool ProgressMade = true;
+ while (ProgressMade) {
+ ProgressMade = false;
- if (ProgressMade) {
- while (!TryAgain.empty()) {
- JoinQueue->push(TryAgain.back());
- TryAgain.pop_back();
- }
- }
- }
- } else {
- bool ProgressMade = true;
- while (ProgressMade) {
- ProgressMade = false;
-
- for (unsigned i = 0, e = TryAgainList.size(); i != e; ++i) {
- CopyRec &TheCopy = TryAgainList[i];
- if (TheCopy.MI) {
- bool Again = false;
- bool Success = JoinCopy(TheCopy, Again);
- if (Success || !Again) {
- TheCopy.MI = 0; // Mark this one as done.
- ProgressMade = true;
- }
- }
+ for (unsigned i = 0, e = TryAgainList.size(); i != e; ++i) {
+ CopyRec &TheCopy = TryAgainList[i];
+ if (!TheCopy.MI)
+ continue;
+
+ bool Again = false;
+ bool Success = JoinCopy(TheCopy, Again);
+ if (Success || !Again) {
+ TheCopy.MI = 0; // Mark this one as done.
+ ProgressMade = true;
}
}
}
-
- if (NewHeuristic)
- delete JoinQueue;
}
/// Return true if the two specified registers belong to different register
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/RegisterCoalescer.h"
#include "llvm/ADT/BitVector.h"
-#include <queue>
namespace llvm {
class SimpleRegisterCoalescing;
struct CopyRec {
MachineInstr *MI;
unsigned LoopDepth;
- bool isBackEdge;
- CopyRec(MachineInstr *mi, unsigned depth, bool be)
- : MI(mi), LoopDepth(depth), isBackEdge(be) {};
- };
-
- template<class SF> class JoinPriorityQueue;
-
- /// CopyRecSort - Sorting function for coalescer queue.
- ///
- struct CopyRecSort : public std::binary_function<CopyRec,CopyRec,bool> {
- JoinPriorityQueue<CopyRecSort> *JPQ;
- explicit CopyRecSort(JoinPriorityQueue<CopyRecSort> *jpq) : JPQ(jpq) {}
- CopyRecSort(const CopyRecSort &RHS) : JPQ(RHS.JPQ) {}
- bool operator()(CopyRec left, CopyRec right) const;
- };
-
- /// JoinQueue - A priority queue of copy instructions the coalescer is
- /// going to process.
- template<class SF>
- class JoinPriorityQueue {
- SimpleRegisterCoalescing *Rc;
- std::priority_queue<CopyRec, std::vector<CopyRec>, SF> Queue;
-
- public:
- explicit JoinPriorityQueue(SimpleRegisterCoalescing *rc)
- : Rc(rc), Queue(SF(this)) {}
-
- bool empty() const { return Queue.empty(); }
- void push(CopyRec R) { Queue.push(R); }
- CopyRec pop() {
- if (empty()) return CopyRec(0, 0, false);
- CopyRec R = Queue.top();
- Queue.pop();
- return R;
- }
-
- // Callbacks to SimpleRegisterCoalescing.
- unsigned getRepIntervalSize(unsigned Reg);
+ CopyRec(MachineInstr *mi, unsigned depth)
+ : MI(mi), LoopDepth(depth) {};
};
class SimpleRegisterCoalescing : public MachineFunctionPass,
BitVector allocatableRegs_;
DenseMap<const TargetRegisterClass*, BitVector> allocatableRCRegs_;
- /// JoinQueue - A priority queue of copy instructions the coalescer is
- /// going to process.
- JoinPriorityQueue<CopyRecSort> *JoinQueue;
-
/// JoinedCopies - Keep track of copies eliminated due to coalescing.
///
SmallPtrSet<MachineInstr*, 32> JoinedCopies;
return false;
};
- /// getRepIntervalSize - Called from join priority queue sorting function.
- /// It returns the size of the interval that represent the given register.
- unsigned getRepIntervalSize(unsigned Reg) {
- if (!li_->hasInterval(Reg))
- return 0;
- return li_->getApproximateInstructionCount(li_->getInterval(Reg)) *
- LiveInterval::InstrSlots::NUM;
- }
-
/// print - Implement the dump method.
virtual void print(raw_ostream &O, const Module* = 0) const;
bool RangeIsDefinedByCopyFromReg(LiveInterval &li, LiveRange *LR,
unsigned Reg);
- /// isBackEdgeCopy - Return true if CopyMI is a back edge copy.
- ///
- bool isBackEdgeCopy(MachineInstr *CopyMI, unsigned DstReg) const;
-
/// UpdateRegDefsUses - Replace all defs and uses of SrcReg to DstReg and
/// update the subregister number if it is not zero. If DstReg is a
/// physical register and the existing subregister number of the def / use
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