-//===--- LiveRangeEdit.cpp - Basic tools for editing a register live range --===//
+//===-- LiveRangeEdit.cpp - Basic tools for editing a register live range -===//
//
// The LLVM Compiler Infrastructure
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "regalloc"
-#include "LiveRangeEdit.h"
#include "VirtRegMap.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/CalcSpillWeights.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/LiveRangeEdit.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Support/Debug.h"
STATISTIC(NumDCEFoldedLoads, "Number of single use loads folded after DCE");
STATISTIC(NumFracRanges, "Number of live ranges fractured by DCE");
-LiveInterval &LiveRangeEdit::createFrom(unsigned OldReg,
- LiveIntervals &LIS,
- VirtRegMap &VRM) {
- MachineRegisterInfo &MRI = VRM.getRegInfo();
+void LiveRangeEdit::Delegate::anchor() { }
+
+LiveInterval &LiveRangeEdit::createFrom(unsigned OldReg) {
unsigned VReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));
- VRM.grow();
- VRM.setIsSplitFromReg(VReg, VRM.getOriginal(OldReg));
+ if (VRM) {
+ VRM->grow();
+ VRM->setIsSplitFromReg(VReg, VRM->getOriginal(OldReg));
+ }
LiveInterval &LI = LIS.getOrCreateInterval(VReg);
newRegs_.push_back(&LI);
return LI;
bool LiveRangeEdit::checkRematerializable(VNInfo *VNI,
const MachineInstr *DefMI,
- const TargetInstrInfo &tii,
AliasAnalysis *aa) {
assert(DefMI && "Missing instruction");
scannedRemattable_ = true;
- if (!tii.isTriviallyReMaterializable(DefMI, aa))
+ if (!TII.isTriviallyReMaterializable(DefMI, aa))
return false;
remattable_.insert(VNI);
return true;
}
-void LiveRangeEdit::scanRemattable(LiveIntervals &lis,
- const TargetInstrInfo &tii,
- AliasAnalysis *aa) {
+void LiveRangeEdit::scanRemattable(AliasAnalysis *aa) {
for (LiveInterval::vni_iterator I = parent_.vni_begin(),
E = parent_.vni_end(); I != E; ++I) {
VNInfo *VNI = *I;
if (VNI->isUnused())
continue;
- MachineInstr *DefMI = lis.getInstructionFromIndex(VNI->def);
+ MachineInstr *DefMI = LIS.getInstructionFromIndex(VNI->def);
if (!DefMI)
continue;
- checkRematerializable(VNI, DefMI, tii, aa);
+ checkRematerializable(VNI, DefMI, aa);
}
scannedRemattable_ = true;
}
-bool LiveRangeEdit::anyRematerializable(LiveIntervals &lis,
- const TargetInstrInfo &tii,
- AliasAnalysis *aa) {
+bool LiveRangeEdit::anyRematerializable(AliasAnalysis *aa) {
if (!scannedRemattable_)
- scanRemattable(lis, tii, aa);
+ scanRemattable(aa);
return !remattable_.empty();
}
/// OrigIdx are also available with the same value at UseIdx.
bool LiveRangeEdit::allUsesAvailableAt(const MachineInstr *OrigMI,
SlotIndex OrigIdx,
- SlotIndex UseIdx,
- LiveIntervals &lis) {
+ SlotIndex UseIdx) {
OrigIdx = OrigIdx.getRegSlot(true);
UseIdx = UseIdx.getRegSlot(true);
for (unsigned i = 0, e = OrigMI->getNumOperands(); i != e; ++i) {
if (!MO.isReg() || !MO.getReg() || MO.isDef())
continue;
// Reserved registers are OK.
- if (MO.isUndef() || !lis.hasInterval(MO.getReg()))
+ if (MO.isUndef() || !LIS.hasInterval(MO.getReg()))
continue;
- // We cannot depend on virtual registers in uselessRegs_.
- if (uselessRegs_)
- for (unsigned ui = 0, ue = uselessRegs_->size(); ui != ue; ++ui)
- if ((*uselessRegs_)[ui]->reg == MO.getReg())
- return false;
- LiveInterval &li = lis.getInterval(MO.getReg());
+ LiveInterval &li = LIS.getInterval(MO.getReg());
const VNInfo *OVNI = li.getVNInfoAt(OrigIdx);
if (!OVNI)
continue;
bool LiveRangeEdit::canRematerializeAt(Remat &RM,
SlotIndex UseIdx,
- bool cheapAsAMove,
- LiveIntervals &lis) {
+ bool cheapAsAMove) {
assert(scannedRemattable_ && "Call anyRematerializable first");
// Use scanRemattable info.
// No defining instruction provided.
SlotIndex DefIdx;
if (RM.OrigMI)
- DefIdx = lis.getInstructionIndex(RM.OrigMI);
+ DefIdx = LIS.getInstructionIndex(RM.OrigMI);
else {
DefIdx = RM.ParentVNI->def;
- RM.OrigMI = lis.getInstructionFromIndex(DefIdx);
+ RM.OrigMI = LIS.getInstructionFromIndex(DefIdx);
assert(RM.OrigMI && "No defining instruction for remattable value");
}
// If only cheap remats were requested, bail out early.
- if (cheapAsAMove && !RM.OrigMI->getDesc().isAsCheapAsAMove())
+ if (cheapAsAMove && !RM.OrigMI->isAsCheapAsAMove())
return false;
// Verify that all used registers are available with the same values.
- if (!allUsesAvailableAt(RM.OrigMI, DefIdx, UseIdx, lis))
+ if (!allUsesAvailableAt(RM.OrigMI, DefIdx, UseIdx))
return false;
return true;
MachineBasicBlock::iterator MI,
unsigned DestReg,
const Remat &RM,
- LiveIntervals &lis,
- const TargetInstrInfo &tii,
const TargetRegisterInfo &tri,
bool Late) {
assert(RM.OrigMI && "Invalid remat");
- tii.reMaterialize(MBB, MI, DestReg, 0, RM.OrigMI, tri);
+ TII.reMaterialize(MBB, MI, DestReg, 0, RM.OrigMI, tri);
rematted_.insert(RM.ParentVNI);
- return lis.getSlotIndexes()->insertMachineInstrInMaps(--MI, Late)
+ return LIS.getSlotIndexes()->insertMachineInstrInMaps(--MI, Late)
.getRegSlot();
}
-void LiveRangeEdit::eraseVirtReg(unsigned Reg, LiveIntervals &LIS) {
+void LiveRangeEdit::eraseVirtReg(unsigned Reg) {
if (delegate_ && delegate_->LRE_CanEraseVirtReg(Reg))
LIS.removeInterval(Reg);
}
bool LiveRangeEdit::foldAsLoad(LiveInterval *LI,
- SmallVectorImpl<MachineInstr*> &Dead,
- MachineRegisterInfo &MRI,
- LiveIntervals &LIS,
- const TargetInstrInfo &TII) {
+ SmallVectorImpl<MachineInstr*> &Dead) {
MachineInstr *DefMI = 0, *UseMI = 0;
// Check that there is a single def and a single use.
if (MO.isDef()) {
if (DefMI && DefMI != MI)
return false;
- if (!MI->getDesc().canFoldAsLoad())
+ if (!MI->canFoldAsLoad())
return false;
DefMI = MI;
} else if (!MO.isUndef()) {
}
void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
- LiveIntervals &LIS, VirtRegMap &VRM,
- const TargetInstrInfo &TII) {
+ ArrayRef<unsigned> RegsBeingSpilled) {
SetVector<LiveInterval*,
SmallVector<LiveInterval*, 8>,
SmallPtrSet<LiveInterval*, 8> > ToShrink;
- MachineRegisterInfo &MRI = VRM.getRegInfo();
for (;;) {
// Erase all dead defs.
LI.removeValNo(VNI);
if (LI.empty()) {
ToShrink.remove(&LI);
- eraseVirtReg(Reg, LIS);
+ eraseVirtReg(Reg);
}
}
}
// Shrink just one live interval. Then delete new dead defs.
LiveInterval *LI = ToShrink.back();
ToShrink.pop_back();
- if (foldAsLoad(LI, Dead, MRI, LIS, TII))
+ if (foldAsLoad(LI, Dead))
continue;
if (delegate_)
delegate_->LRE_WillShrinkVirtReg(LI->reg);
if (!LIS.shrinkToUses(LI, &Dead))
continue;
+
+ // Don't create new intervals for a register being spilled.
+ // The new intervals would have to be spilled anyway so its not worth it.
+ // Also they currently aren't spilled so creating them and not spilling
+ // them results in incorrect code.
+ bool BeingSpilled = false;
+ for (unsigned i = 0, e = RegsBeingSpilled.size(); i != e; ++i) {
+ if (LI->reg == RegsBeingSpilled[i]) {
+ BeingSpilled = true;
+ break;
+ }
+ }
+
+ if (BeingSpilled) continue;
// LI may have been separated, create new intervals.
LI->RenumberValues(LIS);
if (NumComp <= 1)
continue;
++NumFracRanges;
- bool IsOriginal = VRM.getOriginal(LI->reg) == LI->reg;
+ bool IsOriginal = VRM && VRM->getOriginal(LI->reg) == LI->reg;
DEBUG(dbgs() << NumComp << " components: " << *LI << '\n');
SmallVector<LiveInterval*, 8> Dups(1, LI);
for (unsigned i = 1; i != NumComp; ++i) {
- Dups.push_back(&createFrom(LI->reg, LIS, VRM));
+ Dups.push_back(&createFrom(LI->reg));
// If LI is an original interval that hasn't been split yet, make the new
// intervals their own originals instead of referring to LI. The original
// interval must contain all the split products, and LI doesn't.
if (IsOriginal)
- VRM.setIsSplitFromReg(Dups.back()->reg, 0);
+ VRM->setIsSplitFromReg(Dups.back()->reg, 0);
if (delegate_)
delegate_->LRE_DidCloneVirtReg(Dups.back()->reg, LI->reg);
}
}
void LiveRangeEdit::calculateRegClassAndHint(MachineFunction &MF,
- LiveIntervals &LIS,
const MachineLoopInfo &Loops) {
VirtRegAuxInfo VRAI(MF, LIS, Loops);
- MachineRegisterInfo &MRI = MF.getRegInfo();
for (iterator I = begin(), E = end(); I != E; ++I) {
LiveInterval &LI = **I;
if (MRI.recomputeRegClass(LI.reg, MF.getTarget()))
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