#include "VirtRegMap.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/Value.h"
+#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
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"),
cl::desc("Tweak heuristics for joining phys reg with vr"),
cl::init(false), cl::Hidden);
-static RegisterPass<SimpleRegisterCoalescing>
+static RegisterPass<SimpleRegisterCoalescing>
X("simple-register-coalescing", "Simple Register Coalescing");
// Declare that we implement the RegisterCoalescer interface
void SimpleRegisterCoalescing::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesCFG();
+ AU.addRequired<AliasAnalysis>();
AU.addRequired<LiveIntervals>();
AU.addPreserved<LiveIntervals>();
+ AU.addPreserved<SlotIndexes>();
AU.addRequired<MachineLoopInfo>();
AU.addPreserved<MachineLoopInfo>();
AU.addPreservedID(MachineDominatorsID);
bool SimpleRegisterCoalescing::AdjustCopiesBackFrom(LiveInterval &IntA,
LiveInterval &IntB,
MachineInstr *CopyMI) {
- unsigned CopyIdx = li_->getDefIndex(li_->getInstructionIndex(CopyMI));
+ SlotIndex CopyIdx = li_->getInstructionIndex(CopyMI).getDefIndex();
// BValNo is a value number in B that is defined by a copy from A. 'B3' in
// the example above.
LiveInterval::iterator BLR = IntB.FindLiveRangeContaining(CopyIdx);
assert(BLR != IntB.end() && "Live range not found!");
VNInfo *BValNo = BLR->valno;
-
+
// Get the location that B is defined at. Two options: either this value has
- // an unknown definition point or it is defined at CopyIdx. If unknown, we
+ // an unknown definition point or it is defined at CopyIdx. If unknown, we
// can't process it.
if (!BValNo->getCopy()) return false;
assert(BValNo->def == CopyIdx && "Copy doesn't define the value?");
-
+
// AValNo is the value number in A that defines the copy, A3 in the example.
- unsigned CopyUseIdx = li_->getUseIndex(CopyIdx);
+ SlotIndex CopyUseIdx = CopyIdx.getUseIndex();
LiveInterval::iterator ALR = IntA.FindLiveRangeContaining(CopyUseIdx);
assert(ALR != IntA.end() && "Live range not found!");
VNInfo *AValNo = ALR->valno;
// See PR3149:
// 172 %ECX<def> = MOV32rr %reg1039<kill>
// 180 INLINEASM <es:subl $5,$1
- // sbbl $3,$0>, 10, %EAX<def>, 14, %ECX<earlyclobber,def>, 9, %EAX<kill>,
+ // sbbl $3,$0>, 10, %EAX<def>, 14, %ECX<earlyclobber,def>, 9,
+ // %EAX<kill>,
// 36, <fi#0>, 1, %reg0, 0, 9, %ECX<kill>, 36, <fi#1>, 1, %reg0, 0
// 188 %EAX<def> = MOV32rr %EAX<kill>
// 196 %ECX<def> = MOV32rr %ECX<kill>
// The coalescer has no idea there was a def in the middle of [174,230].
if (AValNo->hasRedefByEC())
return false;
-
- // If AValNo is defined as a copy from IntB, we can potentially process this.
+
+ // If AValNo is defined as a copy from IntB, we can potentially process this.
// Get the instruction that defines this value number.
unsigned SrcReg = li_->getVNInfoSourceReg(AValNo);
if (!SrcReg) return false; // Not defined by a copy.
-
+
// If the value number is not defined by a copy instruction, ignore it.
// If the source register comes from an interval other than IntB, we can't
// handle this.
if (SrcReg != IntB.reg) return false;
-
+
// Get the LiveRange in IntB that this value number starts with.
- LiveInterval::iterator ValLR = IntB.FindLiveRangeContaining(AValNo->def-1);
+ LiveInterval::iterator ValLR =
+ IntB.FindLiveRangeContaining(AValNo->def.getPrevSlot());
assert(ValLR != IntB.end() && "Live range not found!");
-
+
// Make sure that the end of the live range is inside the same block as
// CopyMI.
- MachineInstr *ValLREndInst = li_->getInstructionFromIndex(ValLR->end-1);
- if (!ValLREndInst ||
+ MachineInstr *ValLREndInst =
+ li_->getInstructionFromIndex(ValLR->end.getPrevSlot());
+ if (!ValLREndInst ||
ValLREndInst->getParent() != CopyMI->getParent()) return false;
// Okay, we now know that ValLR ends in the same block that the CopyMI
return false;
}
}
-
+
DEBUG({
errs() << "\nExtending: ";
IntB.print(errs(), tri_);
});
-
- unsigned FillerStart = ValLR->end, FillerEnd = BLR->start;
+
+ SlotIndex FillerStart = ValLR->end, FillerEnd = BLR->start;
// We are about to delete CopyMI, so need to remove it as the 'instruction
// that defines this value #'. Update the the valnum with the new defining
// instruction #.
BValNo->def = FillerStart;
BValNo->setCopy(0);
-
+
// Okay, we can merge them. We need to insert a new liverange:
// [ValLR.end, BLR.begin) of either value number, then we merge the
// two value numbers.
IntB.addRange(LiveRange(FillerStart, FillerEnd, BValNo));
// If the IntB live range is assigned to a physical register, and if that
- // physreg has sub-registers, update their live intervals as well.
+ // physreg has sub-registers, update their live intervals as well.
if (TargetRegisterInfo::isPhysicalRegister(IntB.reg)) {
for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR) {
LiveInterval &SRLI = li_->getInterval(*SR);
int UIdx = ValLREndInst->findRegisterUseOperandIdx(IntB.reg, true);
if (UIdx != -1) {
ValLREndInst->getOperand(UIdx).setIsKill(false);
- IntB.removeKill(ValLR->valno, FillerStart);
+ ValLR->valno->removeKill(FillerStart);
}
// If the copy instruction was killing the destination register before the
return false;
}
-/// RemoveCopyByCommutingDef - We found a non-trivially-coalescable copy with IntA
-/// being the source and IntB being the dest, thus this defines a value number
-/// in IntB. If the source value number (in IntA) is defined by a commutable
-/// instruction and its other operand is coalesced to the copy dest register,
-/// see if we can transform the copy into a noop by commuting the definition. For
-/// example,
+static void
+TransferImplicitOps(MachineInstr *MI, MachineInstr *NewMI) {
+ for (unsigned i = MI->getDesc().getNumOperands(), e = MI->getNumOperands();
+ i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isImplicit())
+ NewMI->addOperand(MO);
+ }
+}
+
+/// RemoveCopyByCommutingDef - We found a non-trivially-coalescable copy with
+/// IntA being the source and IntB being the dest, thus this defines a value
+/// number in IntB. If the source value number (in IntA) is defined by a
+/// commutable instruction and its other operand is coalesced to the copy dest
+/// register, see if we can transform the copy into a noop by commuting the
+/// definition. For example,
///
/// A3 = op A2 B0<kill>
/// ...
bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA,
LiveInterval &IntB,
MachineInstr *CopyMI) {
- unsigned CopyIdx = li_->getDefIndex(li_->getInstructionIndex(CopyMI));
+ SlotIndex CopyIdx =
+ li_->getInstructionIndex(CopyMI).getDefIndex();
// FIXME: For now, only eliminate the copy by commuting its def when the
// source register is a virtual register. We want to guard against cases
LiveInterval::iterator BLR = IntB.FindLiveRangeContaining(CopyIdx);
assert(BLR != IntB.end() && "Live range not found!");
VNInfo *BValNo = BLR->valno;
-
+
// Get the location that B is defined at. Two options: either this value has
- // an unknown definition point or it is defined at CopyIdx. If unknown, we
+ // an unknown definition point or it is defined at CopyIdx. If unknown, we
// can't process it.
if (!BValNo->getCopy()) return false;
assert(BValNo->def == CopyIdx && "Copy doesn't define the value?");
-
+
// AValNo is the value number in A that defines the copy, A3 in the example.
- LiveInterval::iterator ALR = IntA.FindLiveRangeContaining(CopyIdx-1);
+ LiveInterval::iterator ALR =
+ IntA.FindLiveRangeContaining(CopyIdx.getUseIndex()); //
+
assert(ALR != IntA.end() && "Live range not found!");
VNInfo *AValNo = ALR->valno;
// If other defs can reach uses of this def, then it's not safe to perform
for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(IntA.reg),
UE = mri_->use_end(); UI != UE; ++UI) {
MachineInstr *UseMI = &*UI;
- unsigned UseIdx = li_->getInstructionIndex(UseMI);
+ SlotIndex UseIdx = li_->getInstructionIndex(UseMI);
LiveInterval::iterator ULR = IntA.FindLiveRangeContaining(UseIdx);
if (ULR == IntA.end())
continue;
bool BHasPHIKill = BValNo->hasPHIKill();
SmallVector<VNInfo*, 4> BDeadValNos;
VNInfo::KillSet BKills;
- std::map<unsigned, unsigned> BExtend;
+ std::map<SlotIndex, SlotIndex> BExtend;
// If ALR and BLR overlaps and end of BLR extends beyond end of ALR, e.g.
// A = or A, B
++UI;
if (JoinedCopies.count(UseMI))
continue;
- unsigned UseIdx = li_->getInstructionIndex(UseMI);
+ SlotIndex UseIdx = li_->getInstructionIndex(UseMI).getUseIndex();
LiveInterval::iterator ULR = IntA.FindLiveRangeContaining(UseIdx);
if (ULR == IntA.end() || ULR->valno != AValNo)
continue;
if (Extended)
UseMO.setIsKill(false);
else
- BKills.push_back(VNInfo::KillInfo(false, li_->getUseIndex(UseIdx)+1));
+ BKills.push_back(UseIdx.getDefIndex());
}
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (!tii_->isMoveInstr(*UseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx))
// This copy will become a noop. If it's defining a new val#,
// remove that val# as well. However this live range is being
// extended to the end of the existing live range defined by the copy.
- unsigned DefIdx = li_->getDefIndex(UseIdx);
+ SlotIndex DefIdx = UseIdx.getDefIndex();
const LiveRange *DLR = IntB.getLiveRangeContaining(DefIdx);
BHasPHIKill |= DLR->valno->hasPHIKill();
assert(DLR->valno->def == DefIdx);
ValNo->def = AValNo->def;
ValNo->setCopy(0);
for (unsigned j = 0, ee = ValNo->kills.size(); j != ee; ++j) {
- unsigned Kill = ValNo->kills[j].killIdx;
- if (Kill != BLR->end)
- BKills.push_back(VNInfo::KillInfo(ValNo->kills[j].isPHIKill, Kill));
+ if (ValNo->kills[j] != BLR->end)
+ BKills.push_back(ValNo->kills[j]);
}
ValNo->kills.clear();
for (LiveInterval::iterator AI = IntA.begin(), AE = IntA.end();
AI != AE; ++AI) {
if (AI->valno != AValNo) continue;
- unsigned End = AI->end;
- std::map<unsigned, unsigned>::iterator EI = BExtend.find(End);
+ SlotIndex End = AI->end;
+ std::map<SlotIndex, SlotIndex>::iterator
+ EI = BExtend.find(End);
if (EI != BExtend.end())
End = EI->second;
IntB.addRange(LiveRange(AI->start, End, ValNo));
// If the IntB live range is assigned to a physical register, and if that
- // physreg has sub-registers, update their live intervals as well.
+ // physreg has sub-registers, update their live intervals as well.
if (BHasSubRegs) {
for (const unsigned *SR = tri_->getSubRegisters(IntB.reg); *SR; ++SR) {
LiveInterval &SRLI = li_->getInterval(*SR);
- SRLI.MergeInClobberRange(AI->start, End, li_->getVNInfoAllocator());
+ SRLI.MergeInClobberRange(*li_, AI->start, End,
+ li_->getVNInfoAllocator());
}
}
}
/// removeRange - Wrapper for LiveInterval::removeRange. This removes a range
/// from a physical register live interval as well as from the live intervals
/// of its sub-registers.
-static void removeRange(LiveInterval &li, unsigned Start, unsigned End,
+static void removeRange(LiveInterval &li,
+ SlotIndex Start, SlotIndex End,
LiveIntervals *li_, const TargetRegisterInfo *tri_) {
li.removeRange(Start, End, true);
if (TargetRegisterInfo::isPhysicalRegister(li.reg)) {
if (!li_->hasInterval(*SR))
continue;
LiveInterval &sli = li_->getInterval(*SR);
- unsigned RemoveEnd = Start;
+ SlotIndex RemoveStart = Start;
+ SlotIndex RemoveEnd = Start;
+
while (RemoveEnd != End) {
- LiveInterval::iterator LR = sli.FindLiveRangeContaining(Start);
+ LiveInterval::iterator LR = sli.FindLiveRangeContaining(RemoveStart);
if (LR == sli.end())
break;
RemoveEnd = (LR->end < End) ? LR->end : End;
- sli.removeRange(Start, RemoveEnd, true);
- Start = RemoveEnd;
+ sli.removeRange(RemoveStart, RemoveEnd, true);
+ RemoveStart = RemoveEnd;
}
}
}
/// as the copy instruction, trim the live interval to the last use and return
/// true.
bool
-SimpleRegisterCoalescing::TrimLiveIntervalToLastUse(unsigned CopyIdx,
+SimpleRegisterCoalescing::TrimLiveIntervalToLastUse(SlotIndex CopyIdx,
MachineBasicBlock *CopyMBB,
LiveInterval &li,
const LiveRange *LR) {
- unsigned MBBStart = li_->getMBBStartIdx(CopyMBB);
- unsigned LastUseIdx;
- MachineOperand *LastUse = lastRegisterUse(LR->start, CopyIdx-1, li.reg,
- LastUseIdx);
+ SlotIndex MBBStart = li_->getMBBStartIdx(CopyMBB);
+ SlotIndex LastUseIdx;
+ MachineOperand *LastUse =
+ lastRegisterUse(LR->start, CopyIdx.getPrevSlot(), li.reg, LastUseIdx);
if (LastUse) {
MachineInstr *LastUseMI = LastUse->getParent();
if (!isSameOrFallThroughBB(LastUseMI->getParent(), CopyMBB, tii_)) {
// There are uses before the copy, just shorten the live range to the end
// of last use.
LastUse->setIsKill();
- removeRange(li, li_->getDefIndex(LastUseIdx), LR->end, li_, tri_);
- li.addKill(LR->valno, LastUseIdx+1, false);
+ removeRange(li, LastUseIdx.getDefIndex(), LR->end, li_, tri_);
+ LR->valno->addKill(LastUseIdx.getDefIndex());
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (tii_->isMoveInstr(*LastUseMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
DstReg == li.reg) {
// Is it livein?
if (LR->start <= MBBStart && LR->end > MBBStart) {
- if (LR->start == 0) {
+ if (LR->start == li_->getZeroIndex()) {
assert(TargetRegisterInfo::isPhysicalRegister(li.reg));
// Live-in to the function but dead. Remove it from entry live-in set.
mf_->begin()->removeLiveIn(li.reg);
unsigned DstReg,
unsigned DstSubIdx,
MachineInstr *CopyMI) {
- unsigned CopyIdx = li_->getUseIndex(li_->getInstructionIndex(CopyMI));
+ SlotIndex CopyIdx = li_->getInstructionIndex(CopyMI).getUseIndex();
LiveInterval::iterator SrcLR = SrcInt.FindLiveRangeContaining(CopyIdx);
assert(SrcLR != SrcInt.end() && "Live range not found!");
VNInfo *ValNo = SrcLR->valno;
const TargetInstrDesc &TID = DefMI->getDesc();
if (!TID.isAsCheapAsAMove())
return false;
- if (!DefMI->getDesc().isRematerializable() ||
- !tii_->isTriviallyReMaterializable(DefMI))
+ if (!tii_->isTriviallyReMaterializable(DefMI, AA))
return false;
bool SawStore = false;
- if (!DefMI->isSafeToMove(tii_, SawStore))
+ if (!DefMI->isSafeToMove(tii_, SawStore, AA))
return false;
if (TID.getNumDefs() != 1)
return false;
return false;
}
- unsigned DefIdx = li_->getDefIndex(CopyIdx);
+ // If destination register has a sub-register index on it, make sure it mtches
+ // the instruction register class.
+ if (DstSubIdx) {
+ const TargetInstrDesc &TID = DefMI->getDesc();
+ if (TID.getNumDefs() != 1)
+ return false;
+ const TargetRegisterClass *DstRC = mri_->getRegClass(DstReg);
+ const TargetRegisterClass *DstSubRC =
+ DstRC->getSubRegisterRegClass(DstSubIdx);
+ const TargetRegisterClass *DefRC = TID.OpInfo[0].getRegClass(tri_);
+ if (DefRC == DstRC)
+ DstSubIdx = 0;
+ else if (DefRC != DstSubRC)
+ return false;
+ }
+
+ SlotIndex DefIdx = CopyIdx.getDefIndex();
const LiveRange *DLR= li_->getInterval(DstReg).getLiveRangeContaining(DefIdx);
DLR->valno->setCopy(0);
// Don't forget to update sub-register intervals.
checkForDeadDef = true;
}
- MachineBasicBlock::iterator MII = next(MachineBasicBlock::iterator(CopyMI));
- tii_->reMaterialize(*MBB, MII, DstReg, DstSubIdx, DefMI);
+ MachineBasicBlock::iterator MII =
+ llvm::next(MachineBasicBlock::iterator(CopyMI));
+ tii_->reMaterialize(*MBB, MII, DstReg, DstSubIdx, DefMI, tri_);
MachineInstr *NewMI = prior(MII);
if (checkForDeadDef) {
// should mark it dead:
if (DefMI->getParent() == MBB) {
DefMI->addRegisterDead(SrcInt.reg, tri_);
- SrcLR->end = SrcLR->start + 1;
+ SrcLR->end = SrcLR->start.getNextSlot();
}
}
}
}
+ TransferImplicitOps(CopyMI, NewMI);
li_->ReplaceMachineInstrInMaps(CopyMI, NewMI);
CopyMI->eraseFromParent();
ReMatCopies.insert(CopyMI);
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);
- unsigned 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].isPHIKill)
- 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
(TargetRegisterInfo::isVirtualRegister(CopyDstReg) ||
allocatableRegs_[CopyDstReg])) {
LiveInterval &LI = li_->getInterval(CopyDstReg);
- unsigned DefIdx = li_->getDefIndex(li_->getInstructionIndex(UseMI));
+ SlotIndex DefIdx =
+ li_->getInstructionIndex(UseMI).getDefIndex();
if (const LiveRange *DLR = LI.getLiveRangeContaining(DefIdx)) {
if (DLR->valno->def == DefIdx)
DLR->valno->setCopy(UseMI);
if (!UseMO.isKill())
continue;
MachineInstr *UseMI = UseMO.getParent();
- unsigned UseIdx = li_->getUseIndex(li_->getInstructionIndex(UseMI));
+ SlotIndex UseIdx =
+ li_->getInstructionIndex(UseMI).getUseIndex();
const LiveRange *LR = LI.getLiveRangeContaining(UseIdx);
- if (!LR || !LI.isKill(LR->valno, UseIdx+1)) {
- if (LR->valno->def != UseIdx+1) {
- // Interesting problem. After coalescing reg1027's def and kill are both
- // at the same point: %reg1027,0.000000e+00 = [56,814:0) 0@70-(814)
- //
- // bb5:
- // 60 %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
- // 68 %reg1027<def> = t2LDRi12 %reg1027<kill>, 8, 14, %reg0
- // 76 t2CMPzri %reg1038<kill,undef>, 0, 14, %reg0, %CPSR<imp-def>
- // 84 %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
- // 96 t2Bcc mbb<bb5,0x2030910>, 1, %CPSR<kill>
- //
- // Do not remove the kill marker on t2LDRi12.
- UseMO.setIsKill(false);
- }
+ if (!LR ||
+ (!LR->valno->isKill(UseIdx.getDefIndex()) &&
+ LR->valno->def != UseIdx.getDefIndex())) {
+ // Interesting problem. After coalescing reg1027's def and kill are both
+ // at the same point: %reg1027,0.000000e+00 = [56,814:0) 0@70-(814)
+ //
+ // bb5:
+ // 60 %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
+ // 68 %reg1027<def> = t2LDRi12 %reg1027<kill>, 8, 14, %reg0
+ // 76 t2CMPzri %reg1038<kill,undef>, 0, 14, %reg0, %CPSR<imp-def>
+ // 84 %reg1027<def> = t2MOVr %reg1027, 14, %reg0, %reg0
+ // 96 t2Bcc mbb<bb5,0x2030910>, 1, %CPSR<kill>
+ //
+ // Do not remove the kill marker on t2LDRi12.
+ UseMO.setIsKill(false);
}
}
}
/// Return true if live interval is removed.
bool SimpleRegisterCoalescing::ShortenDeadCopyLiveRange(LiveInterval &li,
MachineInstr *CopyMI) {
- unsigned CopyIdx = li_->getInstructionIndex(CopyMI);
+ SlotIndex CopyIdx = li_->getInstructionIndex(CopyMI);
LiveInterval::iterator MLR =
- li.FindLiveRangeContaining(li_->getDefIndex(CopyIdx));
+ li.FindLiveRangeContaining(CopyIdx.getDefIndex());
if (MLR == li.end())
return false; // Already removed by ShortenDeadCopySrcLiveRange.
- unsigned RemoveStart = MLR->start;
- unsigned RemoveEnd = MLR->end;
- unsigned DefIdx = li_->getDefIndex(CopyIdx);
+ SlotIndex RemoveStart = MLR->start;
+ SlotIndex RemoveEnd = MLR->end;
+ SlotIndex DefIdx = CopyIdx.getDefIndex();
// Remove the liverange that's defined by this.
- if (RemoveStart == DefIdx && RemoveEnd == DefIdx+1) {
+ if (RemoveStart == DefIdx && RemoveEnd == DefIdx.getStoreIndex()) {
removeRange(li, RemoveStart, RemoveEnd, li_, tri_);
return removeIntervalIfEmpty(li, li_, tri_);
}
/// the val# it defines. If the live interval becomes empty, remove it as well.
bool SimpleRegisterCoalescing::RemoveDeadDef(LiveInterval &li,
MachineInstr *DefMI) {
- unsigned DefIdx = li_->getDefIndex(li_->getInstructionIndex(DefMI));
+ SlotIndex DefIdx = li_->getInstructionIndex(DefMI).getDefIndex();
LiveInterval::iterator MLR = li.FindLiveRangeContaining(DefIdx);
if (DefIdx != MLR->valno->def)
return false;
/// PropagateDeadness - Propagate the dead marker to the instruction which
/// defines the val#.
static void PropagateDeadness(LiveInterval &li, MachineInstr *CopyMI,
- unsigned &LRStart, LiveIntervals *li_,
+ SlotIndex &LRStart, LiveIntervals *li_,
const TargetRegisterInfo* tri_) {
MachineInstr *DefMI =
- li_->getInstructionFromIndex(li_->getDefIndex(LRStart));
+ li_->getInstructionFromIndex(LRStart.getDefIndex());
if (DefMI && DefMI != CopyMI) {
int DeadIdx = DefMI->findRegisterDefOperandIdx(li.reg, false);
if (DeadIdx != -1)
DefMI->getOperand(DeadIdx).setIsDead();
else
DefMI->addOperand(MachineOperand::CreateReg(li.reg,
- true, true, false, true));
- ++LRStart;
+ /*def*/true, /*implicit*/true, /*kill*/false, /*dead*/true));
+ LRStart = LRStart.getNextSlot();
}
}
bool
SimpleRegisterCoalescing::ShortenDeadCopySrcLiveRange(LiveInterval &li,
MachineInstr *CopyMI) {
- unsigned CopyIdx = li_->getInstructionIndex(CopyMI);
- if (CopyIdx == 0) {
+ SlotIndex CopyIdx = li_->getInstructionIndex(CopyMI);
+ if (CopyIdx == SlotIndex()) {
// FIXME: special case: function live in. It can be a general case if the
// first instruction index starts at > 0 value.
assert(TargetRegisterInfo::isPhysicalRegister(li.reg));
return removeIntervalIfEmpty(li, li_, tri_);
}
- LiveInterval::iterator LR = li.FindLiveRangeContaining(CopyIdx-1);
+ LiveInterval::iterator LR =
+ li.FindLiveRangeContaining(CopyIdx.getPrevIndex().getStoreIndex());
if (LR == li.end())
// Livein but defined by a phi.
return false;
- unsigned RemoveStart = LR->start;
- unsigned RemoveEnd = li_->getDefIndex(CopyIdx)+1;
+ SlotIndex RemoveStart = LR->start;
+ SlotIndex RemoveEnd = CopyIdx.getStoreIndex();
if (LR->end > RemoveEnd)
// More uses past this copy? Nothing to do.
return false;
// If the live range starts in another mbb and the copy mbb is not a fall
// through mbb, then we can only cut the range from the beginning of the
// copy mbb.
- RemoveStart = li_->getMBBStartIdx(CopyMBB) + 1;
+ RemoveStart = li_->getMBBStartIdx(CopyMBB).getNextIndex().getBaseIndex();
if (LR->valno->def == RemoveStart) {
// If the def MI defines the val# and this copy is the only kill of the
PropagateDeadness(li, CopyMI, RemoveStart, li_, tri_);
++numDeadValNo;
- if (li.isKill(LR->valno, RemoveEnd))
- li.removeKill(LR->valno, RemoveEnd);
+ if (LR->valno->isKill(RemoveEnd))
+ LR->valno->removeKill(RemoveEnd);
}
removeRange(li, RemoveStart, RemoveEnd, li_, tri_);
// If the virtual register live interval extends into a loop, turn down
// aggressiveness.
- unsigned CopyIdx = li_->getDefIndex(li_->getInstructionIndex(CopyMI));
+ SlotIndex CopyIdx =
+ li_->getInstructionIndex(CopyMI).getDefIndex();
const MachineLoop *L = loopInfo->getLoopFor(CopyMBB);
if (!L) {
// Let's see if the virtual register live interval extends into the loop.
LiveInterval::iterator DLR = DstInt.FindLiveRangeContaining(CopyIdx);
assert(DLR != DstInt.end() && "Live range not found!");
- DLR = DstInt.FindLiveRangeContaining(DLR->end+1);
+ DLR = DstInt.FindLiveRangeContaining(DLR->end.getNextSlot());
if (DLR != DstInt.end()) {
CopyMBB = li_->getMBBFromIndex(DLR->start);
L = loopInfo->getLoopFor(CopyMBB);
if (!L || Length <= Threshold)
return true;
- unsigned UseIdx = li_->getUseIndex(CopyIdx);
+ SlotIndex UseIdx = CopyIdx.getUseIndex();
LiveInterval::iterator SLR = SrcInt.FindLiveRangeContaining(UseIdx);
MachineBasicBlock *SMBB = li_->getMBBFromIndex(SLR->start);
if (loopInfo->getLoopFor(SMBB) != L) {
if (SuccMBB == CopyMBB)
continue;
if (DstInt.overlaps(li_->getMBBStartIdx(SuccMBB),
- li_->getMBBEndIdx(SuccMBB)+1))
+ li_->getMBBEndIdx(SuccMBB).getNextIndex().getBaseIndex()))
return false;
}
}
// If the virtual register live interval is defined or cross a loop, turn
// down aggressiveness.
- unsigned CopyIdx = li_->getDefIndex(li_->getInstructionIndex(CopyMI));
- unsigned UseIdx = li_->getUseIndex(CopyIdx);
+ SlotIndex CopyIdx =
+ li_->getInstructionIndex(CopyMI).getDefIndex();
+ SlotIndex UseIdx = CopyIdx.getUseIndex();
LiveInterval::iterator SLR = SrcInt.FindLiveRangeContaining(UseIdx);
assert(SLR != SrcInt.end() && "Live range not found!");
- SLR = SrcInt.FindLiveRangeContaining(SLR->start-1);
+ SLR = SrcInt.FindLiveRangeContaining(SLR->start.getPrevSlot());
if (SLR == SrcInt.end())
return true;
MachineBasicBlock *SMBB = li_->getMBBFromIndex(SLR->start);
if (PredMBB == SMBB)
continue;
if (SrcInt.overlaps(li_->getMBBStartIdx(PredMBB),
- li_->getMBBEndIdx(PredMBB)+1))
+ li_->getMBBEndIdx(PredMBB).getNextIndex().getBaseIndex()))
return false;
}
}
if (SrcSubIdx && SrcSubIdx != DstSubIdx) {
// r1025 = INSERT_SUBREG r1025, r1024<2>, 2 Then r1024 has already been
// coalesced to a larger register so the subreg indices cancel out.
- DEBUG(errs() << "\tSource of insert_subreg is already coalesced "
- << "to another register.\n");
+ DEBUG(errs() << "\tSource of insert_subreg or subreg_to_reg is already "
+ "coalesced to another register.\n");
return false; // Not coalescable.
}
- } else if (!tii_->isMoveInstr(*CopyMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)){
+ } else if (tii_->isMoveInstr(*CopyMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)) {
+ if (SrcSubIdx && DstSubIdx && SrcSubIdx != DstSubIdx) {
+ // e.g. %reg16404:1<def> = MOV8rr %reg16412:2<kill>
+ Again = true;
+ return false; // Not coalescable.
+ }
+ } else {
llvm_unreachable("Unrecognized copy instruction!");
}
DEBUG(errs() << "\tCopy already coalesced.\n");
return false; // Not coalescable.
}
-
+
bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(SrcReg);
bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
DEBUG(errs() << "\tCan not coalesce physregs.\n");
return false; // Not coalescable.
}
-
+
// We only join virtual registers with allocatable physical registers.
if (SrcIsPhys && !allocatableRegs_[SrcReg]) {
DEBUG(errs() << "\tSrc reg is unallocatable physreg.\n");
if (SrcSubIdx)
SrcSubRC = SrcRC->getSubRegisterRegClass(SrcSubIdx);
assert(SrcSubRC && "Illegal subregister index");
- if (!SrcSubRC->contains(DstReg)) {
+ if (!SrcSubRC->contains(DstSubReg)) {
DEBUG(errs() << "\tIncompatible source regclass: "
<< tri_->getName(DstSubReg) << " not in "
<< SrcSubRC->getName() << ".\n");
return false;
if (DstIsPhys && HasIncompatibleSubRegDefUse(CopyMI, SrcReg, DstReg))
return false;
-
+
LiveInterval &SrcInt = li_->getInterval(SrcReg);
LiveInterval &DstInt = li_->getInterval(DstReg);
assert(SrcInt.reg == SrcReg && DstInt.reg == DstReg &&
}
}
} else {
- // If the virtual register live interval is long but it has low use desity,
- // do not join them, instead mark the physical register as its allocation
- // preference.
+ // If the virtual register live interval is long but it has low use
+ // density, do not join them, instead mark the physical register as its
+ // allocation preference.
LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
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 (!isExtSubReg && !isInsSubReg && !isSubRegToReg &&
ReMaterializeTrivialDef(SrcInt, DstReg, DstSubIdx, CopyMI))
return true;
-
+
// If we can eliminate the copy without merging the live ranges, do so now.
if (!isExtSubReg && !isInsSubReg && !isSubRegToReg &&
(AdjustCopiesBackFrom(SrcInt, DstInt, CopyMI) ||
JoinedCopies.insert(CopyMI);
return true;
}
-
+
// Otherwise, we are unable to join the intervals.
DEBUG(errs() << "Interference!\n");
Again = true; // May be possible to coalesce later.
}
assert(TargetRegisterInfo::isVirtualRegister(SrcReg) &&
"LiveInterval::join didn't work right!");
-
+
// If we're about to merge live ranges into a physical register live interval,
// we have to update any aliased register's live ranges to indicate that they
// have clobbered values for this range.
RealInt.addKills(NewValNo, ValNo->kills);
RealInt.MergeValueInAsValue(*SavedLI, ValNo, NewValNo);
}
- RealInt.weight += SavedLI->weight;
+ RealInt.weight += SavedLI->weight;
DstReg = RealDstReg ? RealDstReg : RealSrcReg;
}
// Update the liveintervals of sub-registers.
for (const unsigned *AS = tri_->getSubRegisters(DstReg); *AS; ++AS)
- li_->getOrCreateInterval(*AS).MergeInClobberRanges(*ResSrcInt,
+ li_->getOrCreateInterval(*AS).MergeInClobberRanges(*li_, *ResSrcInt,
li_->getVNInfoAllocator());
}
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 || 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);
// been computed, return it.
if (OtherValNoAssignments[OtherValNo->id] >= 0)
return ThisValNoAssignments[VN] = OtherValNoAssignments[OtherValNo->id];
-
+
// Mark this value number as currently being computed, then ask what the
// ultimate value # of the other value is.
ThisValNoAssignments[VN] = -2;
return std::find(V.begin(), V.end(), Val) != V.end();
}
+static bool isValNoDefMove(const MachineInstr *MI, unsigned DR, unsigned SR,
+ const TargetInstrInfo *TII,
+ const TargetRegisterInfo *TRI) {
+ unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
+ if (TII->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx))
+ ;
+ else if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
+ DstReg = MI->getOperand(0).getReg();
+ SrcReg = MI->getOperand(1).getReg();
+ } else if (MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG ||
+ MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG) {
+ DstReg = MI->getOperand(0).getReg();
+ SrcReg = MI->getOperand(2).getReg();
+ } else
+ return false;
+ return (SrcReg == SR || TRI->isSuperRegister(SR, SrcReg)) &&
+ (DstReg == DR || TRI->isSuperRegister(DR, DstReg));
+}
+
/// RangeIsDefinedByCopyFromReg - Return true if the specified live range of
/// the specified live interval is defined by a copy from the specified
/// register.
// It's a sub-register live interval, we may not have precise information.
// Re-compute it.
MachineInstr *DefMI = li_->getInstructionFromIndex(LR->start);
- unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
- if (DefMI &&
- tii_->isMoveInstr(*DefMI, SrcReg, DstReg, SrcSubIdx, DstSubIdx) &&
- DstReg == li.reg && SrcReg == Reg) {
+ if (DefMI && isValNoDefMove(DefMI, li.reg, Reg, tii_, tri_)) {
// Cache computed info.
- LR->valno->def = LR->start;
+ LR->valno->def = LR->start;
LR->valno->setCopy(DefMI);
return true;
}
return false;
}
+
+/// ValueLiveAt - Return true if the LiveRange pointed to by the given
+/// iterator, or any subsequent range with the same value number,
+/// is live at the given point.
+bool SimpleRegisterCoalescing::ValueLiveAt(LiveInterval::iterator LRItr,
+ LiveInterval::iterator LREnd,
+ SlotIndex defPoint) const {
+ for (const VNInfo *valno = LRItr->valno;
+ (LRItr != LREnd) && (LRItr->valno == valno); ++LRItr) {
+ if (LRItr->contains(defPoint))
+ return true;
+ }
+
+ return false;
+}
+
+
/// SimpleJoin - Attempt to joint the specified interval into this one. The
/// caller of this method must guarantee that the RHS only contains a single
/// value number and that the RHS is not defined by a copy from this
/// joins them and returns true.
bool SimpleRegisterCoalescing::SimpleJoin(LiveInterval &LHS, LiveInterval &RHS){
assert(RHS.containsOneValue());
-
+
// Some number (potentially more than one) value numbers in the current
// interval may be defined as copies from the RHS. Scan the overlapping
// portions of the LHS and RHS, keeping track of this and looking for
// overlapping live ranges that are NOT defined as copies. If these exist, we
// cannot coalesce.
-
+
LiveInterval::iterator LHSIt = LHS.begin(), LHSEnd = LHS.end();
LiveInterval::iterator RHSIt = RHS.begin(), RHSEnd = RHS.end();
-
+
if (LHSIt->start < RHSIt->start) {
LHSIt = std::upper_bound(LHSIt, LHSEnd, RHSIt->start);
if (LHSIt != LHS.begin()) --LHSIt;
RHSIt = std::upper_bound(RHSIt, RHSEnd, LHSIt->start);
if (RHSIt != RHS.begin()) --RHSIt;
}
-
+
SmallVector<VNInfo*, 8> EliminatedLHSVals;
-
+
while (1) {
// Determine if these live intervals overlap.
bool Overlaps = false;
Overlaps = LHSIt->end > RHSIt->start;
else
Overlaps = RHSIt->end > LHSIt->start;
-
+
// If the live intervals overlap, there are two interesting cases: if the
// LHS interval is defined by a copy from the RHS, it's ok and we record
// that the LHS value # is the same as the RHS. If it's not, then we cannot
if (Overlaps) {
// If we haven't already recorded that this value # is safe, check it.
if (!InVector(LHSIt->valno, EliminatedLHSVals)) {
+ // If it's re-defined by an early clobber somewhere in the live range,
+ // then conservatively abort coalescing.
+ if (LHSIt->valno->hasRedefByEC())
+ return false;
// Copy from the RHS?
if (!RangeIsDefinedByCopyFromReg(LHS, LHSIt, RHS.reg))
return false; // Nope, bail out.
- if (LHSIt->contains(RHSIt->valno->def))
+ if (ValueLiveAt(LHSIt, LHS.end(), RHSIt->valno->def))
// Here is an interesting situation:
// BB1:
// vr1025 = copy vr1024
// ..
// BB2:
- // vr1024 = op
+ // vr1024 = op
// = vr1025
// Even though vr1025 is copied from vr1024, it's not safe to
// coalesce them since the live range of vr1025 intersects the
return false;
EliminatedLHSVals.push_back(LHSIt->valno);
}
-
+
// We know this entire LHS live range is okay, so skip it now.
if (++LHSIt == LHSEnd) break;
continue;
}
-
+
if (LHSIt->end < RHSIt->end) {
if (++LHSIt == LHSEnd) break;
} else {
// if coalescing succeeds. Just skip the liverange.
if (++LHSIt == LHSEnd) break;
} else {
+ // If it's re-defined by an early clobber somewhere in the live range,
+ // then conservatively abort coalescing.
+ if (LHSIt->valno->hasRedefByEC())
+ return false;
// Otherwise, if this is a copy from the RHS, mark it as being merged
// in.
if (RangeIsDefinedByCopyFromReg(LHS, LHSIt, RHS.reg)) {
- if (LHSIt->contains(RHSIt->valno->def))
+ if (ValueLiveAt(LHSIt, LHS.end(), RHSIt->valno->def))
// Here is an interesting situation:
// BB1:
// vr1025 = copy vr1024
// ..
// BB2:
- // vr1024 = op
+ // vr1024 = op
// = vr1025
// Even though vr1025 is copied from vr1024, it's not safe to
// coalesced them since live range of vr1025 intersects the
}
}
}
-
+
if (++RHSIt == RHSEnd) break;
}
}
-
+
// If we got here, we know that the coalescing will be successful and that
// the value numbers in EliminatedLHSVals will all be merged together. Since
// the most common case is that EliminatedLHSVals has a single number, we
} else {
LHSValNo = EliminatedLHSVals[0];
}
-
+
// Okay, now that there is a single LHS value number that we're merging the
// RHS into, update the value number info for the LHS to indicate that the
// value number is defined where the RHS value number was.
const VNInfo *VNI = RHS.getValNumInfo(0);
LHSValNo->def = VNI->def;
LHSValNo->setCopy(VNI->getCopy());
-
+
// Okay, the final step is to loop over the RHS live intervals, adding them to
// the LHS.
if (VNI->hasPHIKill())
LHS.ComputeJoinedWeight(RHS);
// Update regalloc hint if both are virtual registers.
- if (TargetRegisterInfo::isVirtualRegister(LHS.reg) &&
+ if (TargetRegisterInfo::isVirtualRegister(LHS.reg) &&
TargetRegisterInfo::isVirtualRegister(RHS.reg)) {
std::pair<unsigned, unsigned> RHSPref = mri_->getRegAllocationHint(RHS.reg);
std::pair<unsigned, unsigned> LHSPref = mri_->getRegAllocationHint(LHS.reg);
// Update the liveintervals of sub-registers.
if (TargetRegisterInfo::isPhysicalRegister(LHS.reg))
for (const unsigned *AS = tri_->getSubRegisters(LHS.reg); *AS; ++AS)
- li_->getOrCreateInterval(*AS).MergeInClobberRanges(LHS,
+ li_->getOrCreateInterval(*AS).MergeInClobberRanges(*li_, LHS,
li_->getVNInfoAllocator());
return true;
}
}
}
-
+
// Compute ultimate value numbers for the LHS and RHS values.
if (RHS.containsOneValue()) {
// Copies from a liveinterval with a single value are simple to handle and
// very common, handle the special case here. This is important, because
// often RHS is small and LHS is large (e.g. a physreg).
-
+
// Find out if the RHS is defined as a copy from some value in the LHS.
int RHSVal0DefinedFromLHS = -1;
int RHSValID = -1;
}
} else {
// It was defined as a copy from the LHS, find out what value # it is.
- RHSValNoInfo = LHS.getLiveRangeContaining(RHSValNoInfo0->def-1)->valno;
+ RHSValNoInfo =
+ LHS.getLiveRangeContaining(RHSValNoInfo0->def.getPrevSlot())->valno;
RHSValID = RHSValNoInfo->id;
RHSVal0DefinedFromLHS = RHSValID;
}
-
+
LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
RHSValNoAssignments.resize(RHS.getNumValNums(), -1);
NewVNInfo.resize(LHS.getNumValNums(), NULL);
-
+
// Okay, *all* of the values in LHS that are defined as a copy from RHS
// should now get updated.
for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
LHSValNoAssignments[VN] = VN;
}
}
-
+
assert(RHSValID != -1 && "Didn't find value #?");
RHSValNoAssignments[0] = RHSValID;
if (RHSVal0DefinedFromLHS != -1) {
VNInfo *VNI = *i;
if (VNI->isUnused() || VNI->getCopy() == 0) // Src not defined by a copy?
continue;
-
+
// DstReg is known to be a register in the LHS interval. If the src is
// from the RHS interval, we can use its value #.
if (li_->getVNInfoSourceReg(VNI) != RHS.reg)
continue;
-
+
// Figure out the value # from the RHS.
- LHSValsDefinedFromRHS[VNI]=RHS.getLiveRangeContaining(VNI->def-1)->valno;
+ LHSValsDefinedFromRHS[VNI]=
+ RHS.getLiveRangeContaining(VNI->def.getPrevSlot())->valno;
}
-
+
// Loop over the value numbers of the RHS, seeing if any are defined from
// the LHS.
for (LiveInterval::vni_iterator i = RHS.vni_begin(), e = RHS.vni_end();
VNInfo *VNI = *i;
if (VNI->isUnused() || VNI->getCopy() == 0) // Src not defined by a copy?
continue;
-
+
// DstReg is known to be a register in the RHS interval. If the src is
// from the LHS interval, we can use its value #.
if (li_->getVNInfoSourceReg(VNI) != LHS.reg)
continue;
-
+
// Figure out the value # from the LHS.
- RHSValsDefinedFromLHS[VNI]=LHS.getLiveRangeContaining(VNI->def-1)->valno;
+ RHSValsDefinedFromLHS[VNI]=
+ LHS.getLiveRangeContaining(VNI->def.getPrevSlot())->valno;
}
-
+
LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
RHSValNoAssignments.resize(RHS.getNumValNums(), -1);
NewVNInfo.reserve(LHS.getNumValNums() + RHS.getNumValNums());
-
+
for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
i != e; ++i) {
VNInfo *VNI = *i;
unsigned VN = VNI->id;
- if (LHSValNoAssignments[VN] >= 0 || VNI->isUnused())
+ if (LHSValNoAssignments[VN] >= 0 || VNI->isUnused())
continue;
ComputeUltimateVN(VNI, NewVNInfo,
LHSValsDefinedFromRHS, RHSValsDefinedFromLHS,
RHSValNoAssignments[VN] = NewVNInfo.size()-1;
continue;
}
-
+
ComputeUltimateVN(VNI, NewVNInfo,
RHSValsDefinedFromLHS, LHSValsDefinedFromRHS,
RHSValNoAssignments, LHSValNoAssignments);
}
}
-
+
// Armed with the mappings of LHS/RHS values to ultimate values, walk the
// interval lists to see if these intervals are coalescable.
LiveInterval::const_iterator I = LHS.begin();
LiveInterval::const_iterator IE = LHS.end();
LiveInterval::const_iterator J = RHS.begin();
LiveInterval::const_iterator JE = RHS.end();
-
+
// Skip ahead until the first place of potential sharing.
if (I->start < J->start) {
I = std::upper_bound(I, IE, J->start);
J = std::upper_bound(J, JE, I->start);
if (J != RHS.begin()) --J;
}
-
+
while (1) {
// Determine if these two live ranges overlap.
bool Overlaps;
if (LHSValNoAssignments[I->valno->id] !=
RHSValNoAssignments[J->valno->id])
return false;
+ // If it's re-defined by an early clobber somewhere in the live range,
+ // then conservatively abort coalescing.
+ if (NewVNInfo[LHSValNoAssignments[I->valno->id]]->hasRedefByEC())
+ return false;
}
-
+
if (I->end < J->end) {
++I;
if (I == IE) break;
E = LHSValsDefinedFromRHS.end(); I != E; ++I) {
VNInfo *VNI = I->first;
unsigned LHSValID = LHSValNoAssignments[VNI->id];
- LiveInterval::removeKill(NewVNInfo[LHSValID], VNI->def);
+ NewVNInfo[LHSValID]->removeKill(VNI->def);
if (VNI->hasPHIKill())
NewVNInfo[LHSValID]->setHasPHIKill(true);
RHS.addKills(NewVNInfo[LHSValID], VNI->kills);
E = RHSValsDefinedFromLHS.end(); I != E; ++I) {
VNInfo *VNI = I->first;
unsigned RHSValID = RHSValNoAssignments[VNI->id];
- LiveInterval::removeKill(NewVNInfo[RHSValID], VNI->def);
+ NewVNInfo[RHSValID]->removeKill(VNI->def);
if (VNI->hasPHIKill())
NewVNInfo[RHSValID]->setHasPHIKill(true);
LHS.addKills(NewVNInfo[RHSValID], VNI->kills);
struct DepthMBBCompare {
typedef std::pair<unsigned, MachineBasicBlock*> DepthMBBPair;
bool operator()(const DepthMBBPair &LHS, const DepthMBBPair &RHS) const {
- if (LHS.first > RHS.first) return true; // Deeper loops first
- return LHS.first == RHS.first &&
- LHS.second->getNumber() < RHS.second->getNumber();
+ // Deeper loops first
+ if (LHS.first != RHS.first)
+ return LHS.first > RHS.first;
+
+ // Prefer blocks that are more connected in the CFG. This takes care of
+ // the most difficult copies first while intervals are short.
+ unsigned cl = LHS.second->pred_size() + LHS.second->succ_size();
+ unsigned cr = RHS.second->pred_size() + RHS.second->succ_size();
+ if (cl != cr)
+ return cl > cr;
+
+ // As a last resort, sort by block number.
+ return LHS.second->getNumber() < RHS.second->getNumber();
}
};
}
-/// 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");
+ DEBUG(errs() << MBB->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++;
-
+
// If this isn't a copy nor a extract_subreg, we can't join intervals.
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
+ bool isInsUndef = false;
if (Inst->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
DstReg = Inst->getOperand(0).getReg();
SrcReg = Inst->getOperand(1).getReg();
+ } else if (Inst->getOpcode() == TargetInstrInfo::INSERT_SUBREG) {
+ DstReg = Inst->getOperand(0).getReg();
+ SrcReg = Inst->getOperand(2).getReg();
+ if (Inst->getOperand(1).isUndef())
+ isInsUndef = true;
} else if (Inst->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
Inst->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) {
DstReg = Inst->getOperand(0).getReg();
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 (isInsUndef ||
+ (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.
+ // Try coalescing implicit copies and insert_subreg <undef> first,
+ // followed by copies to / from physical registers, then finally copies
+ // from virtual registers to virtual registers.
for (unsigned i = 0, e = ImpDefCopies.size(); i != e; ++i) {
CopyRec &TheCopy = ImpDefCopies[i];
bool Again = false;
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.
for (unsigned i = 0, e = MBBs.size(); i != e; ++i)
CopyCoalesceInMBB(MBBs[i].second, TryAgainList);
}
-
+
// 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
/// lastRegisterUse - Returns the last use of the specific register between
/// cycles Start and End or NULL if there are no uses.
MachineOperand *
-SimpleRegisterCoalescing::lastRegisterUse(unsigned Start, unsigned End,
- unsigned Reg, unsigned &UseIdx) const{
- UseIdx = 0;
+SimpleRegisterCoalescing::lastRegisterUse(SlotIndex Start,
+ SlotIndex End,
+ unsigned Reg,
+ SlotIndex &UseIdx) const{
+ UseIdx = SlotIndex();
if (TargetRegisterInfo::isVirtualRegister(Reg)) {
MachineOperand *LastUse = NULL;
for (MachineRegisterInfo::use_iterator I = mri_->use_begin(Reg),
SrcReg == DstReg)
// Ignore identity copies.
continue;
- unsigned Idx = li_->getInstructionIndex(UseMI);
+ SlotIndex Idx = li_->getInstructionIndex(UseMI);
+ // FIXME: Should this be Idx != UseIdx? SlotIndex() will return something
+ // that compares higher than any other interval.
if (Idx >= Start && Idx < End && Idx >= UseIdx) {
LastUse = &Use;
- UseIdx = li_->getUseIndex(Idx);
+ UseIdx = Idx.getUseIndex();
}
}
return LastUse;
}
- int e = (End-1) / InstrSlots::NUM * InstrSlots::NUM;
- int s = Start;
+ SlotIndex s = Start;
+ SlotIndex e = End.getPrevSlot().getBaseIndex();
while (e >= s) {
// Skip deleted instructions
MachineInstr *MI = li_->getInstructionFromIndex(e);
- while ((e - InstrSlots::NUM) >= s && !MI) {
- e -= InstrSlots::NUM;
+ while (e != SlotIndex() && e.getPrevIndex() >= s && !MI) {
+ e = e.getPrevIndex();
MI = li_->getInstructionFromIndex(e);
}
if (e < s || MI == NULL)
MachineOperand &Use = MI->getOperand(i);
if (Use.isReg() && Use.isUse() && Use.getReg() &&
tri_->regsOverlap(Use.getReg(), Reg)) {
- UseIdx = li_->getUseIndex(e);
+ UseIdx = e.getUseIndex();
return &Use;
}
}
- e -= InstrSlots::NUM;
+ e = e.getPrevIndex();
}
return NULL;
ReMatDefs.clear();
}
-static bool isZeroLengthInterval(LiveInterval *li) {
- for (LiveInterval::Ranges::const_iterator
- i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i)
- if (i->end - i->start > LiveInterval::InstrSlots::NUM)
- return false;
- return true;
-}
-
-
bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
mf_ = &fn;
mri_ = &fn.getRegInfo();
tri_ = tm_->getRegisterInfo();
tii_ = tm_->getInstrInfo();
li_ = &getAnalysis<LiveIntervals>();
+ AA = &getAnalysis<AliasAnalysis>();
loopInfo = &getAnalysis<MachineLoopInfo>();
DEBUG(errs() << "********** SIMPLE REGISTER COALESCING **********\n"
joinIntervals();
DEBUG({
errs() << "********** INTERVALS POST JOINING **********\n";
- for (LiveIntervals::iterator I = li_->begin(), E = li_->end(); I != E; ++I){
+ for (LiveIntervals::iterator I = li_->begin(), E = li_->end();
+ I != E; ++I){
I->second->print(errs(), tri_);
errs() << "\n";
}
for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
mbbi != mbbe; ++mbbi) {
MachineBasicBlock* mbb = mbbi;
- unsigned loopDepth = loopInfo->getLoopDepth(mbb);
-
for (MachineBasicBlock::iterator mii = mbb->begin(), mie = mbb->end();
mii != mie; ) {
MachineInstr *MI = mii;
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
if (JoinedCopies.count(MI)) {
// Delete all coalesced copies.
+ bool DoDelete = true;
if (!tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)) {
assert((MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) &&
"Unrecognized copy instruction");
DstReg = MI->getOperand(0).getReg();
+ if (TargetRegisterInfo::isPhysicalRegister(DstReg))
+ // Do not delete extract_subreg, insert_subreg of physical
+ // registers unless the definition is dead. e.g.
+ // %DO<def> = INSERT_SUBREG %D0<undef>, %S0<kill>, 1
+ // or else the scavenger may complain. LowerSubregs will
+ // delete them later.
+ DoDelete = false;
}
if (MI->registerDefIsDead(DstReg)) {
LiveInterval &li = li_->getInterval(DstReg);
if (!ShortenDeadCopySrcLiveRange(li, MI))
ShortenDeadCopyLiveRange(li, MI);
+ DoDelete = true;
+ }
+ if (!DoDelete)
+ mii = llvm::next(mii);
+ else {
+ li_->RemoveMachineInstrFromMaps(MI);
+ mii = mbbi->erase(mii);
+ ++numPeep;
}
- li_->RemoveMachineInstrFromMaps(MI);
- mii = mbbi->erase(mii);
- ++numPeep;
continue;
}
mii = mbbi->erase(mii);
++numPeep;
} else {
- SmallSet<unsigned, 4> UniqueUses;
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- const MachineOperand &mop = MI->getOperand(i);
- if (mop.isReg() && mop.getReg() &&
- TargetRegisterInfo::isVirtualRegister(mop.getReg())) {
- unsigned reg = mop.getReg();
- // Multiple uses of reg by the same instruction. It should not
- // contribute to spill weight again.
- if (UniqueUses.count(reg) != 0)
- continue;
- LiveInterval &RegInt = li_->getInterval(reg);
- RegInt.weight +=
- li_->getSpillWeight(mop.isDef(), mop.isUse(), loopDepth);
- UniqueUses.insert(reg);
- }
- }
++mii;
}
}
}
- for (LiveIntervals::iterator I = li_->begin(), E = li_->end(); I != E; ++I) {
- LiveInterval &LI = *I->second;
- if (TargetRegisterInfo::isVirtualRegister(LI.reg)) {
- // If the live interval length is essentially zero, i.e. in every live
- // range the use follows def immediately, it doesn't make sense to spill
- // it and hope it will be easier to allocate for this li.
- if (isZeroLengthInterval(&LI))
- LI.weight = HUGE_VALF;
- else {
- bool isLoad = false;
- SmallVector<LiveInterval*, 4> SpillIs;
- if (li_->isReMaterializable(LI, SpillIs, isLoad)) {
- // If all of the definitions of the interval are re-materializable,
- // it is a preferred candidate for spilling. If non of the defs are
- // loads, then it's potentially very cheap to re-materialize.
- // FIXME: this gets much more complicated once we support non-trivial
- // re-materialization.
- if (isLoad)
- LI.weight *= 0.9F;
- else
- LI.weight *= 0.5F;
- }
- }
-
- // Slightly prefer live interval that has been assigned a preferred reg.
- std::pair<unsigned, unsigned> Hint = mri_->getRegAllocationHint(LI.reg);
- if (Hint.first || Hint.second)
- LI.weight *= 1.01F;
-
- // Divide the weight of the interval by its size. This encourages
- // spilling of intervals that are large and have few uses, and
- // discourages spilling of small intervals with many uses.
- LI.weight /= li_->getApproximateInstructionCount(LI) * InstrSlots::NUM;
- }
- }
-
DEBUG(dump());
return true;
}
projects / oota-llvm.git / blobdiff