[llvm-commits] [llvm] r106769 - in /llvm/trunk: include/llvm/CodeGen/LiveIntervalAnalysis.h lib/CodeGen/LiveIntervalAnalysis.cpp lib/CodeGen/SimpleRegisterCoalescing.cpp lib/CodeGen/SimpleRegisterCoalescing.h test/CodeGen/ARM/vget_lane.ll
Jakob Stoklund Olesen
stoklund at 2pi.dk
Thu Jun 24 11:15:02 PDT 2010
Author: stoklund
Date: Thu Jun 24 13:15:01 2010
New Revision: 106769
URL: http://llvm.org/viewvc/llvm-project?rev=106769&view=rev
Log:
Replace a big gob of old coalescer logic with the new CoalescerPair class.
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.
This second attempt fixes some crashes that only occurred Linux.
Modified:
llvm/trunk/include/llvm/CodeGen/LiveIntervalAnalysis.h
llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
llvm/trunk/test/CodeGen/ARM/vget_lane.ll
Modified: llvm/trunk/include/llvm/CodeGen/LiveIntervalAnalysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/LiveIntervalAnalysis.h?rev=106769&r1=106768&r2=106769&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/LiveIntervalAnalysis.h (original)
+++ llvm/trunk/include/llvm/CodeGen/LiveIntervalAnalysis.h Thu Jun 24 13:15:01 2010
@@ -133,10 +133,9 @@
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
Modified: llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp?rev=106769&r1=106768&r2=106769&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp Thu Jun 24 13:15:01 2010
@@ -218,10 +218,7 @@
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 @@
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;
}
}
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp?rev=106769&r1=106768&r2=106769&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp Thu Jun 24 13:15:01 2010
@@ -663,6 +663,7 @@
ValNo->isUnused() || ValNo->hasPHIKill())
return false;
MachineInstr *DefMI = li_->getInstructionFromIndex(ValNo->def);
+ assert(DefMI && "Defining instruction disappeared");
const TargetInstrDesc &TID = DefMI->getDesc();
if (!TID.isAsCheapAsAMove())
return false;
@@ -701,26 +702,13 @@
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.
- if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
- for (const unsigned* SR = tri_->getSubRegisters(DstReg); *SR; ++SR) {
- if (!li_->hasInterval(*SR))
- continue;
- const LiveRange *DLR =
- li_->getInterval(*SR).getLiveRangeContaining(DefIdx);
- if (DLR && DLR->valno->getCopy() == CopyMI)
- DLR->valno->setCopy(0);
- }
- }
+ RemoveCopyFlag(DstReg, CopyMI);
// If copy kills the source register, find the last use and propagate
// kill.
bool checkForDeadDef = false;
MachineBasicBlock *MBB = CopyMI->getParent();
- if (SrcLR->valno->isKill(DefIdx))
+ if (SrcLR->valno->isKill(CopyIdx.getDefIndex()))
if (!TrimLiveIntervalToLastUse(CopyIdx, MBB, SrcInt, SrcLR)) {
checkForDeadDef = true;
}
@@ -747,24 +735,8 @@
MachineOperand &MO = CopyMI->getOperand(i);
if (MO.isReg() && MO.isImplicit())
NewMI->addOperand(MO);
- if (MO.isDef() && li_->hasInterval(MO.getReg())) {
- unsigned Reg = MO.getReg();
- const LiveRange *DLR =
- li_->getInterval(Reg).getLiveRangeContaining(DefIdx);
- if (DLR && DLR->valno->getCopy() == CopyMI)
- DLR->valno->setCopy(0);
- // Handle subregs as well
- if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
- for (const unsigned* SR = tri_->getSubRegisters(Reg); *SR; ++SR) {
- if (!li_->hasInterval(*SR))
- continue;
- const LiveRange *DLR =
- li_->getInterval(*SR).getLiveRangeContaining(DefIdx);
- if (DLR && DLR->valno->getCopy() == CopyMI)
- DLR->valno->setCopy(0);
- }
- }
- }
+ if (MO.isDef())
+ RemoveCopyFlag(MO.getReg(), CopyMI);
}
TransferImplicitOps(CopyMI, NewMI);
@@ -783,14 +755,11 @@
/// 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;
@@ -933,6 +902,27 @@
return removeIntervalIfEmpty(li, li_, tri_);
}
+void SimpleRegisterCoalescing::RemoveCopyFlag(unsigned DstReg,
+ const MachineInstr *CopyMI) {
+ SlotIndex DefIdx = li_->getInstructionIndex(CopyMI).getDefIndex();
+ if (li_->hasInterval(DstReg)) {
+ LiveInterval &LI = li_->getInterval(DstReg);
+ if (const LiveRange *LR = LI.getLiveRangeContaining(DefIdx))
+ if (LR->valno->getCopy() == CopyMI)
+ LR->valno->setCopy(0);
+ }
+ if (!TargetRegisterInfo::isPhysicalRegister(DstReg))
+ return;
+ for (const unsigned* AS = tri_->getAliasSet(DstReg); *AS; ++AS) {
+ if (!li_->hasInterval(*AS))
+ continue;
+ LiveInterval &LI = li_->getInterval(*AS);
+ if (const LiveRange *LR = LI.getLiveRangeContaining(DefIdx))
+ if (LR->valno->getCopy() == CopyMI)
+ LR->valno->setCopy(0);
+ }
+}
+
/// PropagateDeadness - Propagate the dead marker to the instruction which
/// defines the val#.
static void PropagateDeadness(LiveInterval &li, MachineInstr *CopyMI,
@@ -1014,25 +1004,6 @@
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.
@@ -1078,157 +1049,6 @@
return true;
}
-/// HasIncompatibleSubRegDefUse - If we are trying to coalesce a virtual
-/// register with a physical register, check if any of the virtual register
-/// operand is a sub-register use or def. If so, make sure it won't result
-/// in an illegal extract_subreg or insert_subreg instruction. e.g.
-/// vr1024 = extract_subreg vr1025, 1
-/// ...
-/// vr1024 = mov8rr AH
-/// If vr1024 is coalesced with AH, the extract_subreg is now illegal since
-/// AH does not have a super-reg whose sub-register 1 is AH.
-bool
-SimpleRegisterCoalescing::HasIncompatibleSubRegDefUse(MachineInstr *CopyMI,
- unsigned VirtReg,
- unsigned PhysReg) {
- for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(VirtReg),
- E = mri_->reg_end(); I != E; ++I) {
- MachineOperand &O = I.getOperand();
- if (O.isDebug())
- continue;
- MachineInstr *MI = &*I;
- if (MI == CopyMI || JoinedCopies.count(MI))
- continue;
- unsigned SubIdx = O.getSubReg();
- if (SubIdx && !tri_->getSubReg(PhysReg, SubIdx))
- return true;
- if (MI->isExtractSubreg()) {
- SubIdx = MI->getOperand(2).getImm();
- if (O.isUse() && !tri_->getSubReg(PhysReg, SubIdx))
- return true;
- if (O.isDef()) {
- unsigned SrcReg = MI->getOperand(1).getReg();
- const TargetRegisterClass *RC =
- TargetRegisterInfo::isPhysicalRegister(SrcReg)
- ? tri_->getPhysicalRegisterRegClass(SrcReg)
- : mri_->getRegClass(SrcReg);
- if (!tri_->getMatchingSuperReg(PhysReg, SubIdx, RC))
- return true;
- }
- }
- if (MI->isInsertSubreg() || MI->isSubregToReg()) {
- SubIdx = MI->getOperand(3).getImm();
- if (VirtReg == MI->getOperand(0).getReg()) {
- if (!tri_->getSubReg(PhysReg, SubIdx))
- return true;
- } else {
- unsigned DstReg = MI->getOperand(0).getReg();
- const TargetRegisterClass *RC =
- TargetRegisterInfo::isPhysicalRegister(DstReg)
- ? tri_->getPhysicalRegisterRegClass(DstReg)
- : mri_->getRegClass(DstReg);
- if (!tri_->getMatchingSuperReg(PhysReg, SubIdx, RC))
- return true;
- }
- }
- }
- return false;
-}
-
-
-/// CanJoinExtractSubRegToPhysReg - Return true if it's possible to coalesce
-/// an extract_subreg where dst is a physical register, e.g.
-/// cl = EXTRACT_SUBREG reg1024, 1
-bool
-SimpleRegisterCoalescing::CanJoinExtractSubRegToPhysReg(unsigned DstReg,
- unsigned SrcReg, unsigned SubIdx,
- unsigned &RealDstReg) {
- const TargetRegisterClass *RC = mri_->getRegClass(SrcReg);
- RealDstReg = tri_->getMatchingSuperReg(DstReg, SubIdx, RC);
- if (!RealDstReg) {
- DEBUG(dbgs() << "\tIncompatible source regclass: "
- << "none of the super-registers of " << tri_->getName(DstReg)
- << " are in " << RC->getName() << ".\n");
- return false;
- }
-
- LiveInterval &RHS = li_->getInterval(SrcReg);
- // For this type of EXTRACT_SUBREG, conservatively
- // check if the live interval of the source register interfere with the
- // actual super physical register we are trying to coalesce with.
- if (li_->hasInterval(RealDstReg) &&
- RHS.overlaps(li_->getInterval(RealDstReg))) {
- DEBUG({
- dbgs() << "\t\tInterfere with register ";
- li_->getInterval(RealDstReg).print(dbgs(), tri_);
- });
- return false; // Not coalescable
- }
- for (const unsigned* SR = tri_->getSubRegisters(RealDstReg); *SR; ++SR)
- // Do not check DstReg or its sub-register. JoinIntervals() will take care
- // of that.
- if (*SR != DstReg &&
- !tri_->isSubRegister(DstReg, *SR) &&
- li_->hasInterval(*SR) && RHS.overlaps(li_->getInterval(*SR))) {
- DEBUG({
- dbgs() << "\t\tInterfere with sub-register ";
- li_->getInterval(*SR).print(dbgs(), tri_);
- });
- return false; // Not coalescable
- }
- return true;
-}
-
-/// CanJoinInsertSubRegToPhysReg - Return true if it's possible to coalesce
-/// an insert_subreg where src is a physical register, e.g.
-/// reg1024 = INSERT_SUBREG reg1024, c1, 0
-bool
-SimpleRegisterCoalescing::CanJoinInsertSubRegToPhysReg(unsigned DstReg,
- unsigned SrcReg, unsigned SubIdx,
- unsigned &RealSrcReg) {
- const TargetRegisterClass *RC = mri_->getRegClass(DstReg);
- RealSrcReg = tri_->getMatchingSuperReg(SrcReg, SubIdx, RC);
- if (!RealSrcReg) {
- DEBUG(dbgs() << "\tIncompatible destination regclass: "
- << "none of the super-registers of " << tri_->getName(SrcReg)
- << " are in " << RC->getName() << ".\n");
- return false;
- }
-
- LiveInterval &LHS = li_->getInterval(DstReg);
- if (li_->hasInterval(RealSrcReg) &&
- LHS.overlaps(li_->getInterval(RealSrcReg))) {
- DEBUG({
- dbgs() << "\t\tInterfere with register ";
- li_->getInterval(RealSrcReg).print(dbgs(), tri_);
- });
- return false; // Not coalescable
- }
- for (const unsigned* SR = tri_->getSubRegisters(RealSrcReg); *SR; ++SR)
- // Do not check SrcReg or its sub-register. JoinIntervals() will take care
- // of that.
- if (*SR != SrcReg &&
- !tri_->isSubRegister(SrcReg, *SR) &&
- li_->hasInterval(*SR) && LHS.overlaps(li_->getInterval(*SR))) {
- DEBUG({
- dbgs() << "\t\tInterfere with sub-register ";
- li_->getInterval(*SR).print(dbgs(), tri_);
- });
- return false; // Not coalescable
- }
- 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
@@ -1244,393 +1064,131 @@
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");
- 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");
+ // If they are already joined we continue.
+ if (CP.getSrcReg() == CP.getDstReg()) {
+ DEBUG(dbgs() << "\tCopy already coalesced.\n");
return false; // Not coalescable.
}
- // 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;
- }
+ DEBUG(dbgs() << "\tConsidering merging %reg" << CP.getSrcReg());
- // 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.
- }
- }
-
- // 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;
- }
- }
+ // 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.
}
- } else if (differingRegisterClasses(SrcReg, DstReg)) {
- if (DisableCrossClassJoin)
- return false;
- CrossRC = true;
+ } else {
+ DEBUG({
+ dbgs() << " with reg%" << CP.getDstReg();
+ if (CP.getSubIdx())
+ dbgs() << ":" << tri_->getSubRegIndexName(CP.getSubIdx());
+ dbgs() << " to " << CP.getNewRC()->getName() << "\n";
+ });
- // 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?
+ // Avoid constraining virtual register regclass too much.
+ if (CP.isCrossClass()) {
+ if (DisableCrossClassJoin) {
+ DEBUG(dbgs() << "\tCross-class joins disabled.\n");
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)) {
+ if (!isWinToJoinCrossClass(CP.getSrcReg(), CP.getDstReg(),
+ mri_->getRegClass(CP.getSrcReg()),
+ mri_->getRegClass(CP.getDstReg()),
+ CP.getNewRC())) {
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.
+ << CP.getNewRC()->getName() << ".\n");
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";
- });
+ // 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;
+ }
- // 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");
- 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;
- 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");
- Again = true; // May be possible to coalesce later.
- return false;
- }
+ 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 +1197,15 @@
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 +1217,45 @@
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 +1263,17 @@
// 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 +1331,24 @@
}
/// 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 +1368,11 @@
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 +1381,19 @@
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 +1482,17 @@
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 +1514,10 @@
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 +1542,15 @@
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 +1830,8 @@
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 +1840,7 @@
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 +1898,11 @@
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);
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h?rev=106769&r1=106768&r2=106769&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h Thu Jun 24 13:15:01 2010
@@ -105,14 +105,11 @@
/// 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 @@
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,
@@ -162,31 +154,12 @@
const TargetRegisterClass *DstRC,
const TargetRegisterClass *NewRC);
- /// HasIncompatibleSubRegDefUse - If we are trying to coalesce a virtual
- /// register with a physical register, check if any of the virtual register
- /// operand is a sub-register use or def. If so, make sure it won't result
- /// in an illegal extract_subreg or insert_subreg instruction.
- bool HasIncompatibleSubRegDefUse(MachineInstr *CopyMI,
- unsigned VirtReg, unsigned PhysReg);
-
- /// CanJoinExtractSubRegToPhysReg - Return true if it's possible to coalesce
- /// an extract_subreg where dst is a physical register, e.g.
- /// cl = EXTRACT_SUBREG reg1024, 1
- bool CanJoinExtractSubRegToPhysReg(unsigned DstReg, unsigned SrcReg,
- unsigned SubIdx, unsigned &RealDstReg);
-
- /// CanJoinInsertSubRegToPhysReg - Return true if it's possible to coalesce
- /// an insert_subreg where src is a physical register, e.g.
- /// reg1024 = INSERT_SUBREG reg1024, c1, 0
- bool CanJoinInsertSubRegToPhysReg(unsigned DstReg, unsigned SrcReg,
- unsigned SubIdx, unsigned &RealDstReg);
-
/// 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
/// 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.
@@ -203,6 +176,10 @@
/// it as well.
bool RemoveDeadDef(LiveInterval &li, MachineInstr *DefMI);
+ /// RemoveCopyFlag - If DstReg is no longer defined by CopyMI, clear the
+ /// VNInfo copy flag for DstReg and all aliases.
+ void RemoveCopyFlag(unsigned DstReg, const MachineInstr *CopyMI);
+
/// lastRegisterUse - Returns the last use of the specific register between
/// cycles Start and End or NULL if there are no uses.
MachineOperand *lastRegisterUse(SlotIndex Start, SlotIndex End,
Modified: llvm/trunk/test/CodeGen/ARM/vget_lane.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/vget_lane.ll?rev=106769&r1=106768&r2=106769&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/vget_lane.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/vget_lane.ll Thu Jun 24 13:15:01 2010
@@ -204,8 +204,8 @@
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
More information about the llvm-commits
mailing list