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Replace a big gob of old coalescer logic with the new CoalescerPair class.

Browse Source 
CoalescerPair can determine if a copy can be coalesced, and which register gets
merged away. The old logic in SimpleRegisterCoalescing had evolved into
something a bit too convoluted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106701 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2010-06-24 00:12:39 +00:00
parent 774cca70b1
commit e9c59711d3
7 changed files with 229 additions and 555 deletions
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7
include/llvm/CodeGen/LiveIntervalAnalysis.h
View File

@ -133,10 +133,9 @@ namespace llvm {
bool conflictsWithPhysReg(const LiveInterval &li, VirtRegMap &vrm,
unsigned reg);
/// conflictsWithSubPhysRegRef - Similar to conflictsWithPhysRegRef except
/// it checks for sub-register reference and it can check use as well.
bool conflictsWithSubPhysRegRef(LiveInterval &li, unsigned Reg,
bool CheckUse,
/// conflictsWithAliasRef - Similar to conflictsWithPhysRegRef except
/// it checks for alias uses and defs.
bool conflictsWithAliasRef(LiveInterval &li, unsigned Reg,
SmallPtrSet<MachineInstr*,32> &JoinedCopies);
// Interval creation

16
include/llvm/CodeGen/RegisterCoalescer.h
View File

@ -165,9 +165,15 @@ namespace llvm {
/// virtual register.
unsigned subIdx_;
/// origDstReg_ - dstReg_ without subreg adjustments.
unsigned origDstReg_;
/// partial_ - True when the original copy was a partial subregister copy.
bool partial_;
/// crossClass_ - True when both regs are virtual, and newRC is constrained.
bool crossClass_;
/// flipped_ - True when DstReg and SrcReg are reversed from the oriignal copy
/// instruction.
bool flipped_;
@ -186,7 +192,8 @@ namespace llvm {
public:
CoalescerPair(const TargetInstrInfo &tii, const TargetRegisterInfo &tri)
: tii_(tii), tri_(tri), dstReg_(0), srcReg_(0), subIdx_(0),
partial_(false), flipped_(false), newRC_(0) {}
origDstReg_(0), partial_(false), crossClass_(false), flipped_(false),
newRC_(0) {}
/// setRegisters - set registers to match the copy instruction MI. Return
/// false if MI is not a coalescable copy instruction.
@ -207,6 +214,9 @@ namespace llvm {
/// full register, but was a subreg operation.
bool isPartial() const { return partial_; }
/// isCrossClass - Return true if DstReg is virtual and NewRC is a smaller register class than DstReg's.
bool isCrossClass() const { return crossClass_; }
/// isFlipped - Return true when getSrcReg is the register being defined by
/// the original copy instruction.
bool isFlipped() const { return flipped_; }
@ -222,6 +232,10 @@ namespace llvm {
/// coalesced into, or 0.
unsigned getSubIdx() const { return subIdx_; }
/// getOrigDstReg - Return DstReg as it appeared in the original copy
/// instruction before any subreg adjustments.
unsigned getOrigDstReg() const { return isPhys() ? origDstReg_ : dstReg_; }
/// getNewRC - Return the register class of the coalesced register.
const TargetRegisterClass *getNewRC() const { return newRC_; }
};

13
lib/CodeGen/LiveIntervalAnalysis.cpp
View File

@ -218,10 +218,7 @@ bool LiveIntervals::conflictsWithPhysReg(const LiveInterval &li,
return false;
}
/// conflictsWithSubPhysRegRef - Similar to conflictsWithPhysRegRef except
/// it checks for sub-register reference and it can check use as well.
bool LiveIntervals::conflictsWithSubPhysRegRef(LiveInterval &li,
unsigned Reg, bool CheckUse,
bool LiveIntervals::conflictsWithAliasRef(LiveInterval &li, unsigned Reg,
SmallPtrSet<MachineInstr*,32> &JoinedCopies) {
for (LiveInterval::Ranges::const_iterator
I = li.ranges.begin(), E = li.ranges.end(); I != E; ++I) {
@ -239,12 +236,11 @@ bool LiveIntervals::conflictsWithSubPhysRegRef(LiveInterval &li,
MachineOperand& MO = MI->getOperand(i);
if (!MO.isReg())
continue;
if (MO.isUse() && !CheckUse)
continue;
unsigned PhysReg = MO.getReg();
if (PhysReg == 0 || TargetRegisterInfo::isVirtualRegister(PhysReg))
if (PhysReg == 0 || PhysReg == Reg ||
TargetRegisterInfo::isVirtualRegister(PhysReg))
continue;
if (tri_->isSubRegister(Reg, PhysReg))
if (tri_->regsOverlap(Reg, PhysReg))
return true;
}
}
@ -1284,6 +1280,7 @@ bool LiveIntervals::anyKillInMBBAfterIdx(const LiveInterval &li,
continue;
SlotIndex KillIdx = VNI->kills[j];
assert(getInstructionFromIndex(KillIdx) && "Dangling kill");
if (KillIdx > Idx && KillIdx <= End)
return true;
}

20
lib/CodeGen/RegisterCoalescer.cpp
View File

@ -63,7 +63,7 @@ bool CoalescerPair::isMoveInstr(const MachineInstr *MI,
bool CoalescerPair::setRegisters(const MachineInstr *MI) {
srcReg_ = dstReg_ = subIdx_ = 0;
newRC_ = 0;
flipped_ = false;
flipped_ = crossClass_ = false;
unsigned Src, Dst, SrcSub, DstSub;
if (!isMoveInstr(MI, Src, Dst, SrcSub, DstSub))
@ -78,6 +78,7 @@ bool CoalescerPair::setRegisters(const MachineInstr *MI) {
std::swap(SrcSub, DstSub);
flipped_ = true;
}
origDstReg_ = Dst;
const MachineRegisterInfo &MRI = MI->getParent()->getParent()->getRegInfo();
@ -100,11 +101,19 @@ bool CoalescerPair::setRegisters(const MachineInstr *MI) {
} else {
// Both registers are virtual.
// Identical sub to sub.
if (SrcSub == DstSub)
// Both registers have subreg indices.
if (SrcSub && DstSub) {
// For now we only handle the case of identical indices in commensurate
// registers: Dreg:ssub_1 + Dreg:ssub_1 -> Dreg
// FIXME: Handle Qreg:ssub_3 + Dreg:ssub_1 as QReg:dsub_1 + Dreg.
if (SrcSub != DstSub)
return false;
const TargetRegisterClass *SrcRC = MRI.getRegClass(Src);
const TargetRegisterClass *DstRC = MRI.getRegClass(Dst);
if (!getCommonSubClass(DstRC, SrcRC))
return false;
SrcSub = DstSub = 0;
else if (SrcSub && DstSub)
return false; // FIXME: Qreg:ssub_3 + Dreg:ssub_1 => QReg:dsub_1 + Dreg.
}
// There can be no SrcSub.
if (SrcSub) {
@ -124,6 +133,7 @@ bool CoalescerPair::setRegisters(const MachineInstr *MI) {
newRC_ = getCommonSubClass(DstRC, SrcRC);
if (!newRC_)
return false;
crossClass_ = newRC_ != DstRC || newRC_ != SrcRC;
}
// Check our invariants
assert(TargetRegisterInfo::isVirtualRegister(Src) && "Src must be virtual");

706
lib/CodeGen/SimpleRegisterCoalescing.cpp
View File

@ -783,14 +783,11 @@ bool SimpleRegisterCoalescing::ReMaterializeTrivialDef(LiveInterval &SrcInt,
/// being updated is not zero, make sure to set it to the correct physical
/// subregister.
void
SimpleRegisterCoalescing::UpdateRegDefsUses(unsigned SrcReg, unsigned DstReg,
unsigned SubIdx) {
bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
if (DstIsPhys && SubIdx) {
// Figure out the real physical register we are updating with.
DstReg = tri_->getSubReg(DstReg, SubIdx);
SubIdx = 0;
}
SimpleRegisterCoalescing::UpdateRegDefsUses(const CoalescerPair &CP) {
bool DstIsPhys = CP.isPhys();
unsigned SrcReg = CP.getSrcReg();
unsigned DstReg = CP.getDstReg();
unsigned SubIdx = CP.getSubIdx();
// Collect all the instructions using SrcReg.
SmallPtrSet<MachineInstr*, 32> Instrs;
@ -1014,25 +1011,6 @@ SimpleRegisterCoalescing::ShortenDeadCopySrcLiveRange(LiveInterval &li,
return removeIntervalIfEmpty(li, li_, tri_);
}
/// CanCoalesceWithImpDef - Returns true if the specified copy instruction
/// from an implicit def to another register can be coalesced away.
bool SimpleRegisterCoalescing::CanCoalesceWithImpDef(MachineInstr *CopyMI,
LiveInterval &li,
LiveInterval &ImpLi) const{
if (!CopyMI->killsRegister(ImpLi.reg))
return false;
// Make sure this is the only use.
for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(ImpLi.reg),
UE = mri_->use_end(); UI != UE;) {
MachineInstr *UseMI = &*UI;
++UI;
if (CopyMI == UseMI || JoinedCopies.count(UseMI))
continue;
return false;
}
return true;
}
/// isWinToJoinCrossClass - Return true if it's profitable to coalesce
/// two virtual registers from different register classes.
@ -1219,17 +1197,6 @@ SimpleRegisterCoalescing::CanJoinInsertSubRegToPhysReg(unsigned DstReg,
return true;
}
/// getRegAllocPreference - Return register allocation preference register.
///
static unsigned getRegAllocPreference(unsigned Reg, MachineFunction &MF,
MachineRegisterInfo *MRI,
const TargetRegisterInfo *TRI) {
if (TargetRegisterInfo::isPhysicalRegister(Reg))
return 0;
std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(Reg);
return TRI->ResolveRegAllocHint(Hint.first, Hint.second, MF);
}
/// JoinCopy - Attempt to join intervals corresponding to SrcReg/DstReg,
/// which are the src/dst of the copy instruction CopyMI. This returns true
/// if the copy was successfully coalesced away. If it is not currently
@ -1244,393 +1211,131 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
DEBUG(dbgs() << li_->getInstructionIndex(CopyMI) << '\t' << *CopyMI);
unsigned SrcReg, DstReg, SrcSubIdx = 0, DstSubIdx = 0;
bool isExtSubReg = CopyMI->isExtractSubreg();
bool isInsSubReg = CopyMI->isInsertSubreg();
bool isSubRegToReg = CopyMI->isSubregToReg();
unsigned SubIdx = 0;
if (isExtSubReg) {
DstReg = CopyMI->getOperand(0).getReg();
DstSubIdx = CopyMI->getOperand(0).getSubReg();
SrcReg = CopyMI->getOperand(1).getReg();
SrcSubIdx = CopyMI->getOperand(2).getImm();
} else if (isInsSubReg || isSubRegToReg) {
DstReg = CopyMI->getOperand(0).getReg();
DstSubIdx = CopyMI->getOperand(3).getImm();
SrcReg = CopyMI->getOperand(2).getReg();
SrcSubIdx = CopyMI->getOperand(2).getSubReg();
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(dbgs() << "\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)) {
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!");
}
// If they are already joined we continue.
if (SrcReg == DstReg) {
DEBUG(dbgs() << "\tCopy already coalesced.\n");
return false; // Not coalescable.
}
CoalescerPair CP(*tii_, *tri_);
if (!CP.setRegisters(CopyMI)) {
DEBUG(dbgs() << "\tNot coalescable.\n");
return false;
}
bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(SrcReg);
bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
// If they are both physical registers, we cannot join them.
if (SrcIsPhys && DstIsPhys) {
DEBUG(dbgs() << "\tCan not coalesce physregs.\n");
// If they are already joined we continue.
if (CP.getSrcReg() == CP.getDstReg()) {
DEBUG(dbgs() << "\tCopy already coalesced.\n");
return false; // Not coalescable.
}
// We only join virtual registers with allocatable physical registers.
if (SrcIsPhys && !allocatableRegs_[SrcReg]) {
DEBUG(dbgs() << "\tSrc reg is unallocatable physreg.\n");
return false; // Not coalescable.
}
if (DstIsPhys && !allocatableRegs_[DstReg]) {
DEBUG(dbgs() << "\tDst reg is unallocatable physreg.\n");
return false; // Not coalescable.
}
DEBUG(dbgs() << "\tConsidering merging %reg" << CP.getSrcReg());
// We cannot handle dual subreg indices and mismatched classes at the same
// time.
if (SrcSubIdx && DstSubIdx && differingRegisterClasses(SrcReg, DstReg)) {
DEBUG(dbgs() << "\tCannot handle subreg indices and mismatched classes.\n");
return false;
}
// Check that a physical source register is compatible with dst regclass
if (SrcIsPhys) {
unsigned SrcSubReg = SrcSubIdx ?
tri_->getSubReg(SrcReg, SrcSubIdx) : SrcReg;
const TargetRegisterClass *DstRC = mri_->getRegClass(DstReg);
const TargetRegisterClass *DstSubRC = DstRC;
if (DstSubIdx)
DstSubRC = DstRC->getSubRegisterRegClass(DstSubIdx);
assert(DstSubRC && "Illegal subregister index");
if (!DstSubRC->contains(SrcSubReg)) {
DEBUG(dbgs() << "\tIncompatible destination regclass: "
<< "none of the super-registers of "
<< tri_->getName(SrcSubReg) << " are in "
<< DstSubRC->getName() << ".\n");
return false; // Not coalescable.
// Enforce policies.
if (CP.isPhys()) {
DEBUG(dbgs() <<" with physreg %" << tri_->getName(CP.getDstReg()) << "\n");
// Only coalesce to allocatable physreg.
if (!allocatableRegs_[CP.getDstReg()]) {
DEBUG(dbgs() << "\tRegister is an unallocatable physreg.\n");
return false; // Not coalescable.
}
}
// Check that a physical dst register is compatible with source regclass
if (DstIsPhys) {
unsigned DstSubReg = DstSubIdx ?
tri_->getSubReg(DstReg, DstSubIdx) : DstReg;
const TargetRegisterClass *SrcRC = mri_->getRegClass(SrcReg);
const TargetRegisterClass *SrcSubRC = SrcRC;
if (SrcSubIdx)
SrcSubRC = SrcRC->getSubRegisterRegClass(SrcSubIdx);
assert(SrcSubRC && "Illegal subregister index");
if (!SrcSubRC->contains(DstSubReg)) {
DEBUG(dbgs() << "\tIncompatible source regclass: "
<< "none of the super-registers of "
<< tri_->getName(DstSubReg) << " are in "
<< SrcSubRC->getName() << ".\n");
(void)DstSubReg;
return false; // Not coalescable.
}
}
// Should be non-null only when coalescing to a sub-register class.
bool CrossRC = false;
const TargetRegisterClass *SrcRC= SrcIsPhys ? 0 : mri_->getRegClass(SrcReg);
const TargetRegisterClass *DstRC= DstIsPhys ? 0 : mri_->getRegClass(DstReg);
const TargetRegisterClass *NewRC = NULL;
unsigned RealDstReg = 0;
unsigned RealSrcReg = 0;
if (isExtSubReg || isInsSubReg || isSubRegToReg) {
SubIdx = CopyMI->getOperand(isExtSubReg ? 2 : 3).getImm();
if (SrcIsPhys && isExtSubReg) {
// r1024 = EXTRACT_SUBREG EAX, 0 then r1024 is really going to be
// coalesced with AX.
unsigned DstSubIdx = CopyMI->getOperand(0).getSubReg();
if (DstSubIdx) {
// r1024<2> = EXTRACT_SUBREG EAX, 2. Then r1024 has already been
// coalesced to a larger register so the subreg indices cancel out.
if (DstSubIdx != SubIdx) {
DEBUG(dbgs() << "\t Sub-register indices mismatch.\n");
return false; // Not coalescable.
}
} else
SrcReg = tri_->getSubReg(SrcReg, SubIdx);
SubIdx = 0;
} else if (DstIsPhys && (isInsSubReg || isSubRegToReg)) {
// EAX = INSERT_SUBREG EAX, r1024, 0
unsigned SrcSubIdx = CopyMI->getOperand(2).getSubReg();
if (SrcSubIdx) {
// EAX = INSERT_SUBREG EAX, r1024<2>, 2 Then r1024 has already been
// coalesced to a larger register so the subreg indices cancel out.
if (SrcSubIdx != SubIdx) {
DEBUG(dbgs() << "\t Sub-register indices mismatch.\n");
return false; // Not coalescable.
}
} else
DstReg = tri_->getSubReg(DstReg, SubIdx);
SubIdx = 0;
} else if ((DstIsPhys && isExtSubReg) ||
(SrcIsPhys && (isInsSubReg || isSubRegToReg))) {
if (!isSubRegToReg && CopyMI->getOperand(1).getSubReg()) {
DEBUG(dbgs() << "\tSrc of extract_subreg already coalesced with reg"
<< " of a super-class.\n");
return false; // Not coalescable.
}
// FIXME: The following checks are somewhat conservative. Perhaps a better
// way to implement this is to treat this as coalescing a vr with the
// super physical register.
if (isExtSubReg) {
if (!CanJoinExtractSubRegToPhysReg(DstReg, SrcReg, SubIdx, RealDstReg))
return false; // Not coalescable
} else {
if (!CanJoinInsertSubRegToPhysReg(DstReg, SrcReg, SubIdx, RealSrcReg))
return false; // Not coalescable
}
SubIdx = 0;
} else {
unsigned OldSubIdx = isExtSubReg ? CopyMI->getOperand(0).getSubReg()
: CopyMI->getOperand(2).getSubReg();
if (OldSubIdx) {
if (OldSubIdx == SubIdx && !differingRegisterClasses(SrcReg, DstReg))
// r1024<2> = EXTRACT_SUBREG r1025, 2. Then r1024 has already been
// coalesced to a larger register so the subreg indices cancel out.
// Also check if the other larger register is of the same register
// class as the would be resulting register.
SubIdx = 0;
else {
DEBUG(dbgs() << "\t Sub-register indices mismatch.\n");
return false; // Not coalescable.
}
}
if (SubIdx) {
if (!DstIsPhys && !SrcIsPhys) {
if (isInsSubReg || isSubRegToReg) {
NewRC = tri_->getMatchingSuperRegClass(DstRC, SrcRC, SubIdx);
} else // extract_subreg {
NewRC = tri_->getMatchingSuperRegClass(SrcRC, DstRC, SubIdx);
}
if (!NewRC) {
DEBUG(dbgs() << "\t Conflicting sub-register indices.\n");
return false; // Not coalescable
}
if (!isWinToJoinCrossClass(SrcReg, DstReg, SrcRC, DstRC, NewRC)) {
DEBUG(dbgs() << "\tAvoid coalescing to constrained register class: "
<< SrcRC->getName() << "/"
<< DstRC->getName() << " -> "
<< NewRC->getName() << ".\n");
Again = true; // May be possible to coalesce later.
return false;
}
}
}
} else if (differingRegisterClasses(SrcReg, DstReg)) {
if (DisableCrossClassJoin)
return false;
CrossRC = true;
// FIXME: What if the result of a EXTRACT_SUBREG is then coalesced
// with another? If it's the resulting destination register, then
// the subidx must be propagated to uses (but only those defined
// by the EXTRACT_SUBREG). If it's being coalesced into another
// register, it should be safe because register is assumed to have
// the register class of the super-register.
// Process moves where one of the registers have a sub-register index.
MachineOperand *DstMO = CopyMI->findRegisterDefOperand(DstReg);
MachineOperand *SrcMO = CopyMI->findRegisterUseOperand(SrcReg);
SubIdx = DstMO->getSubReg();
if (SubIdx) {
if (SrcMO->getSubReg())
// FIXME: can we handle this?
return false;
// This is not an insert_subreg but it looks like one.
// e.g. %reg1024:4 = MOV32rr %EAX
isInsSubReg = true;
if (SrcIsPhys) {
if (!CanJoinInsertSubRegToPhysReg(DstReg, SrcReg, SubIdx, RealSrcReg))
return false; // Not coalescable
SubIdx = 0;
}
} else {
SubIdx = SrcMO->getSubReg();
if (SubIdx) {
// This is not a extract_subreg but it looks like one.
// e.g. %cl = MOV16rr %reg1024:1
isExtSubReg = true;
if (DstIsPhys) {
if (!CanJoinExtractSubRegToPhysReg(DstReg, SrcReg, SubIdx,RealDstReg))
return false; // Not coalescable
SubIdx = 0;
}
}
}
// Now determine the register class of the joined register.
if (!SrcIsPhys && !DstIsPhys) {
if (isExtSubReg) {
NewRC =
SubIdx ? tri_->getMatchingSuperRegClass(SrcRC, DstRC, SubIdx) : SrcRC;
} else if (isInsSubReg) {
NewRC =
SubIdx ? tri_->getMatchingSuperRegClass(DstRC, SrcRC, SubIdx) : DstRC;
} else {
NewRC = getCommonSubClass(SrcRC, DstRC);
}
if (!NewRC) {
DEBUG(dbgs() << "\tDisjoint regclasses: "
<< SrcRC->getName() << ", "
<< DstRC->getName() << ".\n");
return false; // Not coalescable.
}
// If we are joining two virtual registers and the resulting register
// class is more restrictive (fewer register, smaller size). Check if it's
// worth doing the merge.
if (!isWinToJoinCrossClass(SrcReg, DstReg, SrcRC, DstRC, NewRC)) {
DEBUG(dbgs() << "\tAvoid coalescing to constrained register class: "
<< SrcRC->getName() << "/"
<< DstRC->getName() << " -> "
<< NewRC->getName() << ".\n");
// Allow the coalescer to try again in case either side gets coalesced to
// a physical register that's compatible with the other side. e.g.
// r1024 = MOV32to32_ r1025
// But later r1024 is assigned EAX then r1025 may be coalesced with EAX.
Again = true; // May be possible to coalesce later.
return false;
}
}
}
// Will it create illegal extract_subreg / insert_subreg?
if (SrcIsPhys && HasIncompatibleSubRegDefUse(CopyMI, DstReg, SrcReg))
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 &&
"Register mapping is horribly broken!");
DEBUG({
dbgs() << "\t\tInspecting ";
if (SrcRC) dbgs() << SrcRC->getName() << ": ";
SrcInt.print(dbgs(), tri_);
dbgs() << "\n\t\t and ";
if (DstRC) dbgs() << DstRC->getName() << ": ";
DstInt.print(dbgs(), tri_);
dbgs() << "\n";
} else {
DEBUG({
dbgs() << " with reg%" << CP.getDstReg();
if (CP.getSubIdx())
dbgs() << ":" << tri_->getSubRegIndexName(CP.getSubIdx());
dbgs() << " to " << CP.getNewRC()->getName() << "\n";
});
// Save a copy of the virtual register live interval. We'll manually
// merge this into the "real" physical register live interval this is
// coalesced with.
OwningPtr<LiveInterval> SavedLI;
if (RealDstReg)
SavedLI.reset(li_->dupInterval(&SrcInt));
else if (RealSrcReg)
SavedLI.reset(li_->dupInterval(&DstInt));
if (!isExtSubReg && !isInsSubReg && !isSubRegToReg) {
// Check if it is necessary to propagate "isDead" property.
MachineOperand *mopd = CopyMI->findRegisterDefOperand(DstReg, false);
bool isDead = mopd->isDead();
// We need to be careful about coalescing a source physical register with a
// virtual register. Once the coalescing is done, it cannot be broken and
// these are not spillable! If the destination interval uses are far away,
// think twice about coalescing them!
if (!isDead && (SrcIsPhys || DstIsPhys)) {
// 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;
LiveInterval &JoinPInt = SrcIsPhys ? SrcInt : DstInt;
unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
// Don't join with physregs that have a ridiculous number of live
// ranges. The data structure performance is really bad when that
// happens.
if (JoinPInt.ranges.size() > 1000) {
mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
++numAborts;
DEBUG(dbgs()
<< "\tPhysical register live interval too complicated, abort!\n");
// Avoid constraining virtual register regclass too much.
if (CP.isCrossClass()) {
if (DisableCrossClassJoin) {
DEBUG(dbgs() << "\tCross-class joins disabled.\n");
return false;
}
const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
if (Length > Threshold &&
std::distance(mri_->use_nodbg_begin(JoinVReg),
mri_->use_nodbg_end()) * Threshold < Length) {
// Before giving up coalescing, if definition of source is defined by
// trivial computation, try rematerializing it.
if (ReMaterializeTrivialDef(SrcInt, DstReg, DstSubIdx, CopyMI))
return true;
mri_->setRegAllocationHint(JoinVInt.reg, 0, JoinPReg);
++numAborts;
DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
if (!isWinToJoinCrossClass(CP.getSrcReg(), CP.getDstReg(),
mri_->getRegClass(CP.getSrcReg()),
mri_->getRegClass(CP.getDstReg()),
CP.getNewRC())) {
DEBUG(dbgs() << "\tAvoid coalescing to constrained register class: "
<< CP.getNewRC()->getName() << ".\n");
Again = true; // May be possible to coalesce later.
return false;
}
}
// When possible, let DstReg be the larger interval.
if (!CP.getSubIdx() && li_->getInterval(CP.getSrcReg()).ranges.size() >
li_->getInterval(CP.getDstReg()).ranges.size())
CP.flip();
}
// We need to be careful about coalescing a source physical register with a
// virtual register. Once the coalescing is done, it cannot be broken and
// these are not spillable! If the destination interval uses are far away,
// think twice about coalescing them!
// FIXME: Why are we skipping this test for partial copies?
// CodeGen/X86/phys_subreg_coalesce-3.ll needs it.
if (!CP.isPartial() && CP.isPhys()) {
LiveInterval &JoinVInt = li_->getInterval(CP.getSrcReg());
// Don't join with physregs that have a ridiculous number of live
// ranges. The data structure performance is really bad when that
// happens.
if (li_->hasInterval(CP.getDstReg()) &&
li_->getInterval(CP.getDstReg()).ranges.size() > 1000) {
mri_->setRegAllocationHint(CP.getSrcReg(), 0, CP.getDstReg());
++numAborts;
DEBUG(dbgs()
<< "\tPhysical register live interval too complicated, abort!\n");
return false;
}
const TargetRegisterClass *RC = mri_->getRegClass(CP.getSrcReg());
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
if (Length > Threshold &&
std::distance(mri_->use_nodbg_begin(CP.getSrcReg()),
mri_->use_nodbg_end()) * Threshold < Length) {
// Before giving up coalescing, if definition of source is defined by
// trivial computation, try rematerializing it.
if (!CP.isFlipped() &&
ReMaterializeTrivialDef(JoinVInt, CP.getDstReg(), 0, CopyMI))
return true;
mri_->setRegAllocationHint(CP.getSrcReg(), 0, CP.getDstReg());
++numAborts;
DEBUG(dbgs() << "\tMay tie down a physical register, abort!\n");
Again = true; // May be possible to coalesce later.
return false;
}
}
// We may need the source interval after JoinIntervals has destroyed it.
OwningPtr<LiveInterval> SavedLI;
if (CP.getOrigDstReg() != CP.getDstReg())
SavedLI.reset(li_->dupInterval(&li_->getInterval(CP.getSrcReg())));
// Okay, attempt to join these two intervals. On failure, this returns false.
// Otherwise, if one of the intervals being joined is a physreg, this method
// always canonicalizes DstInt to be it. The output "SrcInt" will not have
// been modified, so we can use this information below to update aliases.
bool Swapped = false;
// If SrcInt is implicitly defined, it's safe to coalesce.
if (SrcInt.empty()) {
if (!CanCoalesceWithImpDef(CopyMI, DstInt, SrcInt)) {
// Only coalesce an empty interval (defined by implicit_def) with
// another interval which has a valno defined by the CopyMI and the CopyMI
// is a kill of the implicit def.
DEBUG(dbgs() << "\tNot profitable!\n");
return false;
}
} else if (!JoinIntervals(DstInt, SrcInt, Swapped, CP)) {
if (!JoinIntervals(CP)) {
// Coalescing failed.
// If definition of source is defined by trivial computation, try
// rematerializing it.
if (!isExtSubReg && !isInsSubReg && !isSubRegToReg &&
ReMaterializeTrivialDef(SrcInt, DstReg, DstSubIdx, CopyMI))
if (!CP.isFlipped() &&
ReMaterializeTrivialDef(li_->getInterval(CP.getSrcReg()),
CP.getDstReg(), 0, 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) ||
RemoveCopyByCommutingDef(SrcInt, DstInt, CopyMI))) {
JoinedCopies.insert(CopyMI);
DEBUG(dbgs() << "\tTrivial!\n");
return true;
if (!CP.isPartial()) {
LiveInterval *UseInt = &li_->getInterval(CP.getSrcReg());
LiveInterval *DefInt = &li_->getInterval(CP.getDstReg());
if (CP.isFlipped())
std::swap(UseInt, DefInt);
if (AdjustCopiesBackFrom(*UseInt, *DefInt, CopyMI) ||
RemoveCopyByCommutingDef(*UseInt, *DefInt, CopyMI)) {
JoinedCopies.insert(CopyMI);
DEBUG(dbgs() << "\tTrivial!\n");
return true;
}
}
// Otherwise, we are unable to join the intervals.
@ -1639,25 +1344,15 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
return false;
}
LiveInterval *ResSrcInt = &SrcInt;
LiveInterval *ResDstInt = &DstInt;
if (Swapped) {
std::swap(SrcReg, DstReg);
std::swap(ResSrcInt, ResDstInt);
}
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.
if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
if (CP.isPhys()) {
// If this is a extract_subreg where dst is a physical register, e.g.
// cl = EXTRACT_SUBREG reg1024, 1
// then create and update the actual physical register allocated to RHS.
if (RealDstReg || RealSrcReg) {
LiveInterval &RealInt =
li_->getOrCreateInterval(RealDstReg ? RealDstReg : RealSrcReg);
unsigned LargerDstReg = CP.getDstReg();
if (CP.getOrigDstReg() != CP.getDstReg()) {
if (tri_->isSubRegister(CP.getOrigDstReg(), LargerDstReg))
LargerDstReg = CP.getOrigDstReg();
LiveInterval &RealInt = li_->getOrCreateInterval(CP.getDstReg());
for (LiveInterval::const_vni_iterator I = SavedLI->vni_begin(),
E = SavedLI->vni_end(); I != E; ++I) {
const VNInfo *ValNo = *I;
@ -1669,56 +1364,45 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
RealInt.MergeValueInAsValue(*SavedLI, ValNo, NewValNo);
}
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(*li_, *ResSrcInt,
li_->getVNInfoAllocator());
}
// If this is a EXTRACT_SUBREG, make sure the result of coalescing is the
// larger super-register.
if ((isExtSubReg || isInsSubReg || isSubRegToReg) &&
!SrcIsPhys && !DstIsPhys) {
if ((isExtSubReg && !Swapped) ||
((isInsSubReg || isSubRegToReg) && Swapped)) {
ResSrcInt->Copy(*ResDstInt, mri_, li_->getVNInfoAllocator());
std::swap(SrcReg, DstReg);
std::swap(ResSrcInt, ResDstInt);
LiveInterval &LargerInt = li_->getInterval(LargerDstReg);
for (const unsigned *AS = tri_->getSubRegisters(LargerDstReg); *AS; ++AS) {
LiveInterval &SRI = li_->getOrCreateInterval(*AS);
SRI.MergeInClobberRanges(*li_, LargerInt, li_->getVNInfoAllocator());
DEBUG({
dbgs() << "\t\tsubreg: "; SRI.print(dbgs(), tri_); dbgs() << "\n";
});
}
}
// Coalescing to a virtual register that is of a sub-register class of the
// other. Make sure the resulting register is set to the right register class.
if (CrossRC)
if (CP.isCrossClass()) {
++numCrossRCs;
// This may happen even if it's cross-rc coalescing. e.g.
// %reg1026<def> = SUBREG_TO_REG 0, %reg1037<kill>, 4
// reg1026 -> GR64, reg1037 -> GR32_ABCD. The resulting register will have to
// be allocate a register from GR64_ABCD.
if (NewRC)
mri_->setRegClass(DstReg, NewRC);
mri_->setRegClass(CP.getDstReg(), CP.getNewRC());
}
// Remember to delete the copy instruction.
JoinedCopies.insert(CopyMI);
UpdateRegDefsUses(SrcReg, DstReg, SubIdx);
UpdateRegDefsUses(CP);
// If we have extended the live range of a physical register, make sure we
// update live-in lists as well.
if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
const LiveInterval &VRegInterval = li_->getInterval(SrcReg);
if (CP.isPhys()) {
SmallVector<MachineBasicBlock*, 16> BlockSeq;
for (LiveInterval::const_iterator I = VRegInterval.begin(),
E = VRegInterval.end(); I != E; ++I ) {
// JoinIntervals invalidates the VNInfos in SrcInt, but we only need the
// ranges for this, and they are preserved.
LiveInterval &SrcInt = li_->getInterval(CP.getSrcReg());
for (LiveInterval::const_iterator I = SrcInt.begin(), E = SrcInt.end();
I != E; ++I ) {
li_->findLiveInMBBs(I->start, I->end, BlockSeq);
for (unsigned idx = 0, size = BlockSeq.size(); idx != size; ++idx) {
MachineBasicBlock &block = *BlockSeq[idx];
if (!block.isLiveIn(DstReg))
block.addLiveIn(DstReg);
if (!block.isLiveIn(CP.getDstReg()))
block.addLiveIn(CP.getDstReg());
}
BlockSeq.clear();
}
@ -1726,32 +1410,17 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
// SrcReg is guarateed to be the register whose live interval that is
// being merged.
li_->removeInterval(SrcReg);
li_->removeInterval(CP.getSrcReg());
// Update regalloc hint.
tri_->UpdateRegAllocHint(SrcReg, DstReg, *mf_);
// Manually deleted the live interval copy.
if (SavedLI) {
SavedLI->clear();
SavedLI.reset();
}
// If resulting interval has a preference that no longer fits because of subreg
// coalescing, just clear the preference.
unsigned Preference = getRegAllocPreference(ResDstInt->reg, *mf_, mri_, tri_);
if (Preference && (isExtSubReg || isInsSubReg || isSubRegToReg) &&
TargetRegisterInfo::isVirtualRegister(ResDstInt->reg)) {
const TargetRegisterClass *RC = mri_->getRegClass(ResDstInt->reg);
if (!RC->contains(Preference))
mri_->setRegAllocationHint(ResDstInt->reg, 0, 0);
}
tri_->UpdateRegAllocHint(CP.getSrcReg(), CP.getDstReg(), *mf_);
DEBUG({
dbgs() << "\t\tJoined. Result = ";
ResDstInt->print(dbgs(), tri_);
dbgs() << "\n";
});
LiveInterval &DstInt = li_->getInterval(CP.getDstReg());
dbgs() << "\tJoined. Result = ";
DstInt.print(dbgs(), tri_);
dbgs() << "\n";
});
++numJoins;
return true;
@ -1809,26 +1478,24 @@ static unsigned ComputeUltimateVN(VNInfo *VNI,
}
/// JoinIntervals - Attempt to join these two intervals. On failure, this
/// returns false. Otherwise, if one of the intervals being joined is a
/// physreg, this method always canonicalizes LHS to be it. The output
/// "RHS" will not have been modified, so we can use this information
/// below to update aliases.
bool
SimpleRegisterCoalescing::JoinIntervals(LiveInterval &LHS, LiveInterval &RHS,
bool &Swapped, CoalescerPair &CP) {
// Compute the final value assignment, assuming that the live ranges can be
// coalesced.
SmallVector<int, 16> LHSValNoAssignments;
SmallVector<int, 16> RHSValNoAssignments;
DenseMap<VNInfo*, VNInfo*> LHSValsDefinedFromRHS;
DenseMap<VNInfo*, VNInfo*> RHSValsDefinedFromLHS;
SmallVector<VNInfo*, 16> NewVNInfo;
/// returns false.
bool SimpleRegisterCoalescing::JoinIntervals(CoalescerPair &CP) {
LiveInterval &RHS = li_->getInterval(CP.getSrcReg());
DEBUG({ dbgs() << "\t\tRHS = "; RHS.print(dbgs(), tri_); dbgs() << "\n"; });
// FIXME: Join into CP.getDstReg instead of CP.getOrigDstReg.
// When looking at
// %reg2000 = EXTRACT_SUBREG %EAX, sub_16bit
// we really want to join %reg2000 with %AX ( = CP.getDstReg). We are actually
// joining into %EAX ( = CP.getOrigDstReg) because it is guaranteed to have an
// existing live interval, and we are better equipped to handle interference.
// JoinCopy cleans up the mess by taking a copy of RHS before calling here,
// and merging that copy into CP.getDstReg after.
// If a live interval is a physical register, conservatively check if any
// of its sub-registers is overlapping the live interval of the virtual
// register. If so, do not coalesce.
if (TargetRegisterInfo::isPhysicalRegister(LHS.reg) &&
*tri_->getSubRegisters(LHS.reg)) {
if (CP.isPhys() && *tri_->getSubRegisters(CP.getOrigDstReg())) {
// If it's coalescing a virtual register to a physical register, estimate
// its live interval length. This is the *cost* of scanning an entire live
// interval. If the cost is low, we'll do an exhaustive check instead.
@ -1848,10 +1515,11 @@ SimpleRegisterCoalescing::JoinIntervals(LiveInterval &LHS, LiveInterval &RHS,
li_->intervalIsInOneMBB(RHS) &&
li_->getApproximateInstructionCount(RHS) <= 10) {
// Perform a more exhaustive check for some common cases.
if (li_->conflictsWithSubPhysRegRef(RHS, LHS.reg, true, JoinedCopies))
if (li_->conflictsWithAliasRef(RHS, CP.getOrigDstReg(), JoinedCopies))
return false;
} else {
for (const unsigned* SR = tri_->getSubRegisters(LHS.reg); *SR; ++SR)
for (const unsigned* SR = tri_->getAliasSet(CP.getOrigDstReg()); *SR;
++SR)
if (li_->hasInterval(*SR) && RHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
dbgs() << "\tInterfere with sub-register ";
@ -1860,25 +1528,19 @@ SimpleRegisterCoalescing::JoinIntervals(LiveInterval &LHS, LiveInterval &RHS,
return false;
}
}
} else if (TargetRegisterInfo::isPhysicalRegister(RHS.reg) &&
*tri_->getSubRegisters(RHS.reg)) {
if (LHS.containsOneValue() &&
li_->getApproximateInstructionCount(LHS) <= 10) {
// Perform a more exhaustive check for some common cases.
if (li_->conflictsWithSubPhysRegRef(LHS, RHS.reg, false, JoinedCopies))
return false;
} else {
for (const unsigned* SR = tri_->getSubRegisters(RHS.reg); *SR; ++SR)
if (li_->hasInterval(*SR) && LHS.overlaps(li_->getInterval(*SR))) {
DEBUG({
dbgs() << "\tInterfere with sub-register ";
li_->getInterval(*SR).print(dbgs(), tri_);
});
return false;
}
}
}
// Compute the final value assignment, assuming that the live ranges can be
// coalesced.
SmallVector<int, 16> LHSValNoAssignments;
SmallVector<int, 16> RHSValNoAssignments;
DenseMap<VNInfo*, VNInfo*> LHSValsDefinedFromRHS;
DenseMap<VNInfo*, VNInfo*> RHSValsDefinedFromLHS;
SmallVector<VNInfo*, 16> NewVNInfo;
LiveInterval &LHS = li_->getInterval(CP.getOrigDstReg());
DEBUG({ dbgs() << "\t\tLHS = "; LHS.print(dbgs(), tri_); dbgs() << "\n"; });
// Loop over the value numbers of the LHS, seeing if any are defined from
// the RHS.
for (LiveInterval::vni_iterator i = LHS.vni_begin(), e = LHS.vni_end();
@ -1967,15 +1629,17 @@ SimpleRegisterCoalescing::JoinIntervals(LiveInterval &LHS, LiveInterval &RHS,
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);
if (I != LHS.begin()) --I;
} else if (J->start < I->start) {
J = std::upper_bound(J, JE, I->start);
if (J != RHS.begin()) --J;
if (I != IE && J != JE) {
if (I->start < J->start) {
I = std::upper_bound(I, IE, J->start);
if (I != LHS.begin()) --I;
} else if (J->start < I->start) {
J = std::upper_bound(J, JE, I->start);
if (J != RHS.begin()) --J;
}
}
while (1) {
while (I != IE && J != JE) {
// Determine if these two live ranges overlap.
bool Overlaps;
if (I->start < J->start) {
@ -1997,13 +1661,10 @@ SimpleRegisterCoalescing::JoinIntervals(LiveInterval &LHS, LiveInterval &RHS,
return false;
}
if (I->end < J->end) {
if (I->end < J->end)
++I;
if (I == IE) break;
} else {
else
++J;
if (J == JE) break;
}
}
// Update kill info. Some live ranges are extended due to copy coalescing.
@ -2028,19 +1689,15 @@ SimpleRegisterCoalescing::JoinIntervals(LiveInterval &LHS, LiveInterval &RHS,
LHS.addKills(NewVNInfo[RHSValID], VNI->kills);
}
if (LHSValNoAssignments.empty())
LHSValNoAssignments.push_back(-1);
if (RHSValNoAssignments.empty())
RHSValNoAssignments.push_back(-1);
// If we get here, we know that we can coalesce the live ranges. Ask the
// intervals to coalesce themselves now.
if ((RHS.ranges.size() > LHS.ranges.size() &&
TargetRegisterInfo::isVirtualRegister(LHS.reg)) ||
TargetRegisterInfo::isPhysicalRegister(RHS.reg)) {
RHS.join(LHS, &RHSValNoAssignments[0], &LHSValNoAssignments[0], NewVNInfo,
mri_);
Swapped = true;
} else {
LHS.join(RHS, &LHSValNoAssignments[0], &RHSValNoAssignments[0], NewVNInfo,
mri_);
Swapped = false;
}
LHS.join(RHS, &LHSValNoAssignments[0], &RHSValNoAssignments[0], NewVNInfo,
mri_);
return true;
}
@ -2320,8 +1977,8 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
if (!tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubIdx, DstSubIdx)) {
assert((MI->isExtractSubreg() || MI->isInsertSubreg() ||
MI->isSubregToReg()) && "Unrecognized copy instruction");
DstReg = MI->getOperand(0).getReg();
if (TargetRegisterInfo::isPhysicalRegister(DstReg))
SrcReg = MI->getOperand(MI->isSubregToReg() ? 2 : 1).getReg();
if (TargetRegisterInfo::isPhysicalRegister(SrcReg))
// 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
@ -2330,7 +1987,7 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
DoDelete = false;
}
if (MI->allDefsAreDead()) {
LiveInterval &li = li_->getInterval(DstReg);
LiveInterval &li = li_->getInterval(SrcReg);
if (!ShortenDeadCopySrcLiveRange(li, MI))
ShortenDeadCopyLiveRange(li, MI);
DoDelete = true;
@ -2388,6 +2045,11 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
if (MI->registerDefIsDead(DstReg)) {
if (!ShortenDeadCopySrcLiveRange(RegInt, MI))
ShortenDeadCopyLiveRange(RegInt, MI);
} else {
// If a value is killed here remove the marker.
SlotIndex UseIdx = li_->getInstructionIndex(MI).getUseIndex();
if (const LiveRange *LR = RegInt.getLiveRangeContaining(UseIdx))
LR->valno->removeKill(UseIdx.getDefIndex());
}
}
li_->RemoveMachineInstrFromMaps(MI);

18
lib/CodeGen/SimpleRegisterCoalescing.h
View File

@ -105,14 +105,11 @@ namespace llvm {
/// possible to coalesce this interval, but it may be possible if other
/// things get coalesced, then it returns true by reference in 'Again'.
bool JoinCopy(CopyRec &TheCopy, bool &Again);
/// JoinIntervals - Attempt to join these two intervals. On failure, this
/// returns false. Otherwise, if one of the intervals being joined is a
/// physreg, this method always canonicalizes DestInt to be it. The output
/// "SrcInt" will not have been modified, so we can use this information
/// below to update aliases.
bool JoinIntervals(LiveInterval &LHS, LiveInterval &RHS, bool &Swapped,
CoalescerPair &CP);
/// returns false. The output "SrcInt" will not have been modified, so we can
/// use this information below to update aliases.
bool JoinIntervals(CoalescerPair &CP);
/// Return true if the two specified registers belong to different register
/// classes. The registers may be either phys or virt regs.
@ -149,11 +146,6 @@ namespace llvm {
bool ReMaterializeTrivialDef(LiveInterval &SrcInt, unsigned DstReg,
unsigned DstSubIdx, MachineInstr *CopyMI);
/// CanCoalesceWithImpDef - Returns true if the specified copy instruction
/// from an implicit def to another register can be coalesced away.
bool CanCoalesceWithImpDef(MachineInstr *CopyMI,
LiveInterval &li, LiveInterval &ImpLi) const;
/// isWinToJoinCrossClass - Return true if it's profitable to coalesce
/// two virtual registers from different register classes.
bool isWinToJoinCrossClass(unsigned SrcReg,
@ -186,7 +178,7 @@ namespace llvm {
/// physical register and the existing subregister number of the def / use
/// being updated is not zero, make sure to set it to the correct physical
/// subregister.
void UpdateRegDefsUses(unsigned SrcReg, unsigned DstReg, unsigned SubIdx);
void UpdateRegDefsUses(const CoalescerPair &CP);
/// ShortenDeadCopyLiveRange - Shorten a live range defined by a dead copy.
/// Return true if live interval is removed.

4
test/CodeGen/ARM/vget_lane.ll
View File

@ -204,8 +204,8 @@ define <4 x i32> @vsetQ_lane32(<4 x i32>* %A, i32 %B) nounwind {
define arm_aapcs_vfpcc <2 x float> @test_vset_lanef32(float %arg0_float32_t, <2 x float> %arg1_float32x2_t) nounwind {
;CHECK: test_vset_lanef32:
;CHECK: vmov.f32
;CHECK: vmov.f32
;CHECK: vmov.f32 s3, s0
;CHECK: vmov.f64 d0, d1
entry:
%0 = insertelement <2 x float> %arg1_float32x2_t, float %arg0_float32_t, i32 1 ; <<2 x float>> [#uses=1]
ret <2 x float> %0