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-rw-r--r--include/llvm/CodeGen/LiveInterval.h35
-rw-r--r--include/llvm/CodeGen/LiveIntervalAnalysis.h6
-rw-r--r--lib/CodeGen/LiveInterval.cpp21
-rw-r--r--lib/CodeGen/LiveIntervalAnalysis.cpp64
-rw-r--r--lib/CodeGen/SimpleRegisterCoalescing.cpp526
-rw-r--r--lib/CodeGen/SimpleRegisterCoalescing.h77
6 files changed, 327 insertions, 402 deletions
diff --git a/include/llvm/CodeGen/LiveInterval.h b/include/llvm/CodeGen/LiveInterval.h
index e7ebb5157d..532d814935 100644
--- a/include/llvm/CodeGen/LiveInterval.h
+++ b/include/llvm/CodeGen/LiveInterval.h
@@ -37,19 +37,18 @@ namespace llvm {
/// merge point), it contains ~0u,x. If the value number is not in use, it
/// contains ~1u,x to indicate that the value # is not used.
/// def - Instruction # of the definition.
- /// reg - Source reg iff val# is defined by a copy; zero otherwise.
+ /// copy - Copy iff val# is defined by a copy; zero otherwise.
/// hasPHIKill - One or more of the kills are PHI nodes.
- /// kills - Instruction # of the kills. If a kill is an odd #, it means
- /// the kill is a phi join point.
+ /// kills - Instruction # of the kills.
struct VNInfo {
unsigned id;
unsigned def;
- unsigned reg;
+ MachineInstr *copy;
bool hasPHIKill;
SmallVector<unsigned, 4> kills;
- VNInfo() : id(~1U), def(~1U), reg(0), hasPHIKill(false) {}
- VNInfo(unsigned i, unsigned d, unsigned r)
- : id(i), def(d), reg(r), hasPHIKill(false) {}
+ VNInfo() : id(~1U), def(~1U), copy(0), hasPHIKill(false) {}
+ VNInfo(unsigned i, unsigned d, MachineInstr *c)
+ : id(i), def(d), copy(c), hasPHIKill(false) {}
};
/// LiveRange structure - This represents a simple register range in the
@@ -159,14 +158,14 @@ namespace llvm {
/// another.
void copyValNumInfo(VNInfo *DstValNo, const VNInfo *SrcValNo) {
DstValNo->def = SrcValNo->def;
- DstValNo->reg = SrcValNo->reg;
+ DstValNo->copy = SrcValNo->copy;
DstValNo->hasPHIKill = SrcValNo->hasPHIKill;
DstValNo->kills = SrcValNo->kills;
}
/// getNextValue - Create a new value number and return it. MIIdx specifies
/// the instruction that defines the value number.
- VNInfo *getNextValue(unsigned MIIdx, unsigned SrcReg,
+ VNInfo *getNextValue(unsigned MIIdx, MachineInstr *CopyMI,
BumpPtrAllocator &VNInfoAllocator) {
#ifdef __GNUC__
unsigned Alignment = __alignof__(VNInfo);
@@ -176,7 +175,7 @@ namespace llvm {
#endif
VNInfo *VNI= static_cast<VNInfo*>(VNInfoAllocator.Allocate(sizeof(VNInfo),
Alignment));
- new (VNI) VNInfo(valnos.size(), MIIdx, SrcReg);
+ new (VNI) VNInfo(valnos.size(), MIIdx, CopyMI);
valnos.push_back(VNI);
return VNI;
}
@@ -199,7 +198,7 @@ namespace llvm {
void addKills(VNInfo *VNI, const SmallVector<unsigned, 4> &kills) {
for (unsigned i = 0, e = kills.size(); i != e; ++i) {
unsigned KillIdx = kills[i];
- if (!liveAt(KillIdx)) {
+ if (!liveBeforeAndAt(KillIdx)) {
SmallVector<unsigned, 4>::iterator
I = std::lower_bound(VNI->kills.begin(), VNI->kills.end(), KillIdx);
VNI->kills.insert(I, KillIdx);
@@ -230,6 +229,15 @@ namespace llvm {
E = std::upper_bound(kills.begin(), kills.end(), End);
kills.erase(I, E);
}
+
+ /// isKill - Return true if the specified index is a kill of the
+ /// specified val#.
+ bool isKill(const VNInfo *VNI, unsigned KillIdx) const {
+ const SmallVector<unsigned, 4> &kills = VNI->kills;
+ SmallVector<unsigned, 4>::const_iterator
+ I = std::lower_bound(kills.begin(), kills.end(), KillIdx);
+ return I != kills.end() && *I == KillIdx;
+ }
/// MergeValueNumberInto - This method is called when two value nubmers
/// are found to be equivalent. This eliminates V1, replacing all
@@ -284,6 +292,11 @@ namespace llvm {
bool liveAt(unsigned index) const;
+ // liveBeforeAndAt - Check if the interval is live at the index and the
+ // index just before it. If index is liveAt, check if it starts a new live
+ // range.If it does, then check if the previous live range ends at index-1.
+ bool liveBeforeAndAt(unsigned index) const;
+
/// getLiveRangeContaining - Return the live range that contains the
/// specified index, or null if there is none.
const LiveRange *getLiveRangeContaining(unsigned Idx) const {
diff --git a/include/llvm/CodeGen/LiveIntervalAnalysis.h b/include/llvm/CodeGen/LiveIntervalAnalysis.h
index 1667ee3a75..440ae6ec5b 100644
--- a/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -229,6 +229,10 @@ namespace llvm {
BumpPtrAllocator& getVNInfoAllocator() { return VNInfoAllocator; }
+ /// getVNInfoSourceReg - Helper function that parses the specified VNInfo
+ /// copy field and returns the source register that defines it.
+ unsigned getVNInfoSourceReg(const VNInfo *VNI) const;
+
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
virtual void releaseMemory();
@@ -276,7 +280,7 @@ namespace llvm {
MachineBasicBlock::iterator mi,
unsigned MIIdx,
LiveInterval &interval,
- unsigned SrcReg);
+ MachineInstr *CopyMI);
/// handleLiveInRegister - Create interval for a livein register.
void handleLiveInRegister(MachineBasicBlock* mbb,
diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index b09ffd48e6..741c35c43a 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -44,6 +44,27 @@ bool LiveInterval::liveAt(unsigned I) const {
return r->contains(I);
}
+// liveBeforeAndAt - Check if the interval is live at the index and the index
+// just before it. If index is liveAt, check if it starts a new live range.
+// If it does, then check if the previous live range ends at index-1.
+bool LiveInterval::liveBeforeAndAt(unsigned I) const {
+ Ranges::const_iterator r = std::upper_bound(ranges.begin(), ranges.end(), I);
+
+ if (r == ranges.begin())
+ return false;
+
+ --r;
+ if (!r->contains(I))
+ return false;
+ if (I != r->start)
+ return true;
+ // I is the start of a live range. Check if the previous live range ends
+ // at I-1.
+ if (r == ranges.begin())
+ return false;
+ return r->end == I;
+}
+
// overlaps - Return true if the intersection of the two live intervals is
// not empty.
//
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index d32fc62379..a64bf60f3b 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -224,14 +224,12 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
// Get the Idx of the defining instructions.
unsigned defIndex = getDefIndex(MIIdx);
VNInfo *ValNo;
+ MachineInstr *CopyMI = NULL;
unsigned SrcReg, DstReg;
- if (tii_->isMoveInstr(*mi, SrcReg, DstReg))
- ValNo = interval.getNextValue(defIndex, SrcReg, VNInfoAllocator);
- else if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG)
- ValNo = interval.getNextValue(defIndex, mi->getOperand(1).getReg(),
- VNInfoAllocator);
- else
- ValNo = interval.getNextValue(defIndex, 0, VNInfoAllocator);
+ if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
+ tii_->isMoveInstr(*mi, SrcReg, DstReg))
+ CopyMI = mi;
+ ValNo = interval.getNextValue(defIndex, CopyMI, VNInfoAllocator);
assert(ValNo->id == 0 && "First value in interval is not 0?");
@@ -326,13 +324,12 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
// The new value number (#1) is defined by the instruction we claimed
// defined value #0.
- VNInfo *ValNo = interval.getNextValue(0, 0, VNInfoAllocator);
- ValNo->def = OldValNo->def;
- ValNo->reg = OldValNo->reg;
+ VNInfo *ValNo = interval.getNextValue(OldValNo->def, OldValNo->copy,
+ VNInfoAllocator);
// Value#0 is now defined by the 2-addr instruction.
- OldValNo->def = RedefIndex;
- OldValNo->reg = 0;
+ OldValNo->def = RedefIndex;
+ OldValNo->copy = 0;
// Add the new live interval which replaces the range for the input copy.
LiveRange LR(DefIndex, RedefIndex, ValNo);
@@ -364,7 +361,6 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
DOUT << " Removing [" << Start << "," << End << "] from: ";
interval.print(DOUT, tri_); DOUT << "\n";
interval.removeRange(Start, End);
- interval.addKill(VNI, Start);
VNI->hasPHIKill = true;
DOUT << " RESULT: "; interval.print(DOUT, tri_);
@@ -383,14 +379,12 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
unsigned defIndex = getDefIndex(MIIdx);
VNInfo *ValNo;
+ MachineInstr *CopyMI = NULL;
unsigned SrcReg, DstReg;
- if (tii_->isMoveInstr(*mi, SrcReg, DstReg))
- ValNo = interval.getNextValue(defIndex, SrcReg, VNInfoAllocator);
- else if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG)
- ValNo = interval.getNextValue(defIndex, mi->getOperand(1).getReg(),
- VNInfoAllocator);
- else
- ValNo = interval.getNextValue(defIndex, 0, VNInfoAllocator);
+ if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
+ tii_->isMoveInstr(*mi, SrcReg, DstReg))
+ CopyMI = mi;
+ ValNo = interval.getNextValue(defIndex, CopyMI, VNInfoAllocator);
unsigned killIndex = getInstructionIndex(&mbb->back()) + InstrSlots::NUM;
LiveRange LR(defIndex, killIndex, ValNo);
@@ -408,7 +402,7 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB,
MachineBasicBlock::iterator mi,
unsigned MIIdx,
LiveInterval &interval,
- unsigned SrcReg) {
+ MachineInstr *CopyMI) {
// A physical register cannot be live across basic block, so its
// lifetime must end somewhere in its defining basic block.
DOUT << "\t\tregister: "; DEBUG(printRegName(interval.reg));
@@ -449,7 +443,7 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB,
// The only case we should have a dead physreg here without a killing or
// instruction where we know it's dead is if it is live-in to the function
// and never used.
- assert(!SrcReg && "physreg was not killed in defining block!");
+ assert(!CopyMI && "physreg was not killed in defining block!");
end = getDefIndex(start) + 1; // It's dead.
exit:
@@ -458,7 +452,7 @@ exit:
// Already exists? Extend old live interval.
LiveInterval::iterator OldLR = interval.FindLiveRangeContaining(start);
VNInfo *ValNo = (OldLR != interval.end())
- ? OldLR->valno : interval.getNextValue(start, SrcReg, VNInfoAllocator);
+ ? OldLR->valno : interval.getNextValue(start, CopyMI, VNInfoAllocator);
LiveRange LR(start, end, ValNo);
interval.addRange(LR);
interval.addKill(LR.valno, end);
@@ -472,12 +466,12 @@ void LiveIntervals::handleRegisterDef(MachineBasicBlock *MBB,
if (TargetRegisterInfo::isVirtualRegister(reg))
handleVirtualRegisterDef(MBB, MI, MIIdx, getOrCreateInterval(reg));
else if (allocatableRegs_[reg]) {
+ MachineInstr *CopyMI = NULL;
unsigned SrcReg, DstReg;
- if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG)
- SrcReg = MI->getOperand(1).getReg();
- else if (!tii_->isMoveInstr(*MI, SrcReg, DstReg))
- SrcReg = 0;
- handlePhysicalRegisterDef(MBB, MI, MIIdx, getOrCreateInterval(reg), SrcReg);
+ if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
+ tii_->isMoveInstr(*MI, SrcReg, DstReg))
+ CopyMI = MI;
+ handlePhysicalRegisterDef(MBB, MI, MIIdx, getOrCreateInterval(reg), CopyMI);
// Def of a register also defines its sub-registers.
for (const unsigned* AS = tri_->getSubRegisters(reg); *AS; ++AS)
// Avoid processing some defs more than once.
@@ -601,6 +595,20 @@ LiveInterval LiveIntervals::createInterval(unsigned reg) {
return LiveInterval(reg, Weight);
}
+/// getVNInfoSourceReg - Helper function that parses the specified VNInfo
+/// copy field and returns the source register that defines it.
+unsigned LiveIntervals::getVNInfoSourceReg(const VNInfo *VNI) const {
+ if (!VNI->copy)
+ return 0;
+
+ if (VNI->copy->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG)
+ return VNI->copy->getOperand(1).getReg();
+ unsigned SrcReg, DstReg;
+ if (tii_->isMoveInstr(*VNI->copy, SrcReg, DstReg))
+ return SrcReg;
+ assert(0 && "Unrecognized copy instruction!");
+ return 0;
+}
//===----------------------------------------------------------------------===//
// Register allocator hooks.
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 4734d22571..0c83933726 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -106,9 +106,8 @@ bool SimpleRegisterCoalescing::AdjustCopiesBackFrom(LiveInterval &IntA,
// Get the location that B is defined at. Two options: either this value has
// an unknown definition point or it is defined at CopyIdx. If unknown, we
// can't process it.
- if (!BValNo->reg) return false;
- assert(BValNo->def == CopyIdx &&
- "Copy doesn't define the value?");
+ if (!BValNo->copy) return false;
+ assert(BValNo->def == CopyIdx && "Copy doesn't define the value?");
// AValNo is the value number in A that defines the copy, A3 in the example.
LiveInterval::iterator ALR = IntA.FindLiveRangeContaining(CopyIdx-1);
@@ -116,14 +115,14 @@ bool SimpleRegisterCoalescing::AdjustCopiesBackFrom(LiveInterval &IntA,
// If AValNo is defined as a copy from IntB, we can potentially process this.
// Get the instruction that defines this value number.
- unsigned SrcReg = AValNo->reg;
+ unsigned SrcReg = li_->getVNInfoSourceReg(AValNo);
if (!SrcReg) return false; // Not defined by a copy.
// If the value number is not defined by a copy instruction, ignore it.
-
+
// If the source register comes from an interval other than IntB, we can't
// handle this.
- if (rep(SrcReg) != IntB.reg) return false;
+ if (SrcReg != IntB.reg) return false;
// Get the LiveRange in IntB that this value number starts with.
LiveInterval::iterator ValLR = IntB.FindLiveRangeContaining(AValNo->def-1);
@@ -158,8 +157,8 @@ bool SimpleRegisterCoalescing::AdjustCopiesBackFrom(LiveInterval &IntA,
// We are about to delete CopyMI, so need to remove it as the 'instruction
// that defines this value #'. Update the the valnum with the new defining
// instruction #.
- BValNo->def = FillerStart;
- BValNo->reg = 0;
+ BValNo->def = FillerStart;
+ BValNo->copy = NULL;
// Okay, we can merge them. We need to insert a new liverange:
// [ValLR.end, BLR.begin) of either value number, then we merge the
@@ -223,7 +222,7 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA,
unsigned CopyIdx = li_->getDefIndex(li_->getInstructionIndex(CopyMI));
- // BValNo is a value number in B that is defined by a copy from A. 'B3' in
+ // BValNo is a value number in B that is defined by a copy from A. 'B3' in
// the example above.
LiveInterval::iterator BLR = IntB.FindLiveRangeContaining(CopyIdx);
VNInfo *BValNo = BLR->valno;
@@ -231,7 +230,7 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA,
// Get the location that B is defined at. Two options: either this value has
// an unknown definition point or it is defined at CopyIdx. If unknown, we
// can't process it.
- if (!BValNo->reg) return false;
+ if (!BValNo->copy) return false;
assert(BValNo->def == CopyIdx && "Copy doesn't define the value?");
// AValNo is the value number in A that defines the copy, A3 in the example.
@@ -243,35 +242,14 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA,
return false;
MachineInstr *DefMI = li_->getInstructionFromIndex(AValNo->def);
const TargetInstrDesc &TID = DefMI->getDesc();
- if (!TID.isCommutable())
- return false;
- int Idx = -1;
- for (unsigned i = 0, e = DefMI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = DefMI->getOperand(i);
- if (!MO.isRegister()) continue;
- unsigned Reg = MO.getReg();
- if (Reg && TargetRegisterInfo::isVirtualRegister(Reg)) {
- if (rep(Reg) == IntA.reg) {
- // If the dest register comes from an interval other than IntA, we
- // can't handle this.
- if (Reg != IntA.reg)
- return false;
- continue;
- }
- if (Idx != -1)
- // FIXME: Being overly careful here. We just need to figure out the
- // which register operand will become the new def.
- return false;
- Idx = i;
- }
- }
- if (Idx == -1)
- // Something like %reg1024 = add %reg1024, %reg1024
+ unsigned NewDstIdx;
+ if (!TID.isCommutable() ||
+ !tii_->CommuteChangesDestination(DefMI, NewDstIdx))
return false;
- MachineOperand &MO = DefMI->getOperand(Idx);
- unsigned NewReg = MO.getReg();
- if (rep(NewReg) != IntB.reg || !MO.isKill())
+ MachineOperand &NewDstMO = DefMI->getOperand(NewDstIdx);
+ unsigned NewReg = NewDstMO.getReg();
+ if (NewReg != IntB.reg || !NewDstMO.isKill())
return false;
// Make sure there are no other definitions of IntB that would reach the
@@ -329,16 +307,7 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA,
unsigned SrcReg, DstReg;
if (!tii_->isMoveInstr(*UseMI, SrcReg, DstReg))
continue;
- unsigned repDstReg = rep(DstReg);
- if (repDstReg != IntB.reg) {
- // Update dst register interval val# since its source register has
- // changed.
- LiveInterval &DLI = li_->getInterval(repDstReg);
- LiveInterval::iterator DLR =
- DLI.FindLiveRangeContaining(li_->getDefIndex(UseIdx));
- DLR->valno->reg = NewReg;
- ChangedCopies.insert(UseMI);
- } else {
+ if (DstReg == IntB.reg) {
// This copy will become a noop. If it's defining a new val#,
// remove that val# as well. However this live range is being
// extended to the end of the existing live range defined by the copy.
@@ -389,14 +358,23 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(LiveInterval &IntA,
return true;
}
-/// AddSubRegIdxPairs - Recursively mark all the registers represented by the
-/// specified register as sub-registers. The recursion level is expected to be
-/// shallow.
-void SimpleRegisterCoalescing::AddSubRegIdxPairs(unsigned Reg, unsigned SubIdx) {
- std::vector<unsigned> &JoinedRegs = r2rRevMap_[Reg];
- for (unsigned i = 0, e = JoinedRegs.size(); i != e; ++i) {
- SubRegIdxes.push_back(std::make_pair(JoinedRegs[i], SubIdx));
- AddSubRegIdxPairs(JoinedRegs[i], SubIdx);
+/// RemoveUnnecessaryKills - Remove kill markers that are no longer accurate
+/// due to live range lengthening as the result of coalescing.
+void SimpleRegisterCoalescing::RemoveUnnecessaryKills(unsigned Reg,
+ LiveInterval &LI) {
+ for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(Reg),
+ UE = mri_->use_end(); UI != UE; ++UI) {
+ MachineOperand &UseMO = UI.getOperand();
+ if (UseMO.isKill()) {
+ MachineInstr *UseMI = UseMO.getParent();
+ unsigned UseIdx = li_->getUseIndex(li_->getInstructionIndex(UseMI));
+ if (JoinedCopies.count(UseMI))
+ continue;
+ LiveInterval::const_iterator UI = LI.FindLiveRangeContaining(UseIdx);
+ assert(UI != LI.end());
+ if (!LI.isKill(UI->valno, UseIdx+1))
+ UseMO.setIsKill(false);
+ }
}
}
@@ -411,7 +389,6 @@ bool SimpleRegisterCoalescing::isBackEdgeCopy(MachineInstr *CopyMI,
if (MBB != L->getLoopLatch())
return false;
- DstReg = rep(DstReg);
LiveInterval &LI = li_->getInterval(DstReg);
unsigned DefIdx = li_->getInstructionIndex(CopyMI);
LiveInterval::const_iterator DstLR =
@@ -425,6 +402,42 @@ bool SimpleRegisterCoalescing::isBackEdgeCopy(MachineInstr *CopyMI,
return false;
}
+/// UpdateRegDefsUses - Replace all defs and uses of SrcReg to DstReg and
+/// update the subregister number if it is not zero. If DstReg is a
+/// physical register and the existing subregister number of the def / use
+/// 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;
+ }
+
+ for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(SrcReg),
+ E = mri_->reg_end(); I != E; ) {
+ MachineOperand &O = I.getOperand();
+ ++I;
+ if (DstIsPhys) {
+ unsigned UseSubIdx = O.getSubReg();
+ unsigned UseDstReg = DstReg;
+ if (UseSubIdx)
+ UseDstReg = tri_->getSubReg(DstReg, UseSubIdx);
+ O.setReg(UseDstReg);
+ O.setSubReg(0);
+ } else {
+ unsigned OldSubIdx = O.getSubReg();
+ assert((!SubIdx || !OldSubIdx) && "Conflicting sub-register index!");
+ if (SubIdx)
+ O.setSubReg(SubIdx);
+ O.setReg(DstReg);
+ }
+ }
+}
+
/// 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
@@ -439,35 +452,26 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
DOUT << li_->getInstructionIndex(CopyMI) << '\t' << *CopyMI;
- // Get representative registers.
- unsigned SrcReg = TheCopy.SrcReg;
- unsigned DstReg = TheCopy.DstReg;
-
- // CopyMI has been modified due to commuting.
- if (ChangedCopies.count(CopyMI)) {
- if (tii_->isMoveInstr(*CopyMI, SrcReg, DstReg))
- ;
- else if (CopyMI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
- DstReg = CopyMI->getOperand(0).getReg();
- SrcReg = CopyMI->getOperand(1).getReg();
- } else
- assert(0 && "Unrecognized move instruction!");
- TheCopy.SrcReg = SrcReg;
- TheCopy.DstReg = DstReg;
- ChangedCopies.erase(CopyMI);
+ unsigned SrcReg;
+ unsigned DstReg;
+ bool isExtSubReg = CopyMI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG;
+ unsigned SubIdx = 0;
+ if (isExtSubReg) {
+ DstReg = CopyMI->getOperand(0).getReg();
+ SrcReg = CopyMI->getOperand(1).getReg();
+ } else if (!tii_->isMoveInstr(*CopyMI, SrcReg, DstReg)) {
+ assert(0 && "Unrecognized copy instruction!");
+ return false;
}
- unsigned repSrcReg = rep(SrcReg);
- unsigned repDstReg = rep(DstReg);
-
// If they are already joined we continue.
- if (repSrcReg == repDstReg) {
+ if (SrcReg == DstReg) {
DOUT << "\tCopy already coalesced.\n";
return false; // Not coalescable.
}
- bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(repSrcReg);
- bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(repDstReg);
+ bool SrcIsPhys = TargetRegisterInfo::isPhysicalRegister(SrcReg);
+ bool DstIsPhys = TargetRegisterInfo::isPhysicalRegister(DstReg);
// If they are both physical registers, we cannot join them.
if (SrcIsPhys && DstIsPhys) {
@@ -476,31 +480,31 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
}
// We only join virtual registers with allocatable physical registers.
- if (SrcIsPhys && !allocatableRegs_[repSrcReg]) {
+ if (SrcIsPhys && !allocatableRegs_[SrcReg]) {
DOUT << "\tSrc reg is unallocatable physreg.\n";
return false; // Not coalescable.
}
- if (DstIsPhys && !allocatableRegs_[repDstReg]) {
+ if (DstIsPhys && !allocatableRegs_[DstReg]) {
DOUT << "\tDst reg is unallocatable physreg.\n";
return false; // Not coalescable.
}
- bool isExtSubReg = CopyMI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG;
unsigned RealDstReg = 0;
if (isExtSubReg) {
- unsigned SubIdx = CopyMI->getOperand(2).getImm();
- if (SrcIsPhys)
+ SubIdx = CopyMI->getOperand(2).getImm();
+ if (SrcIsPhys) {
// r1024 = EXTRACT_SUBREG EAX, 0 then r1024 is really going to be
// coalesced with AX.
- repSrcReg = tri_->getSubReg(repSrcReg, SubIdx);
- else if (DstIsPhys) {
+ SrcReg = tri_->getSubReg(SrcReg, SubIdx);
+ SubIdx = 0;
+ } else if (DstIsPhys) {
// 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.
- const TargetRegisterClass *RC = mri_->getRegClass(repSrcReg);
- for (const unsigned *SRs = tri_->getSuperRegisters(repDstReg);
+ const TargetRegisterClass *RC = mri_->getRegClass(SrcReg);
+ for (const unsigned *SRs = tri_->getSuperRegisters(DstReg);
unsigned SR = *SRs; ++SRs) {
- if (repDstReg == tri_->getSubReg(SR, SubIdx) &&
+ if (DstReg == tri_->getSubReg(SR, SubIdx) &&
RC->contains(SR)) {
RealDstReg = SR;
break;
@@ -511,7 +515,7 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
// 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.
- LiveInterval &RHS = li_->getInterval(repSrcReg);
+ LiveInterval &RHS = li_->getInterval(SrcReg);
if (li_->hasInterval(RealDstReg) &&
RHS.overlaps(li_->getInterval(RealDstReg))) {
DOUT << "Interfere with register ";
@@ -524,24 +528,32 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
DEBUG(li_->getInterval(*SR).print(DOUT, tri_));
return false; // Not coalescable
}
+ SubIdx = 0;
} else {
- unsigned SrcSize= li_->getInterval(repSrcReg).getSize() / InstrSlots::NUM;
- unsigned DstSize= li_->getInterval(repDstReg).getSize() / InstrSlots::NUM;
- const TargetRegisterClass *RC=mf_->getRegInfo().getRegClass(repDstReg);
+ unsigned SrcSize= li_->getInterval(SrcReg).getSize() / InstrSlots::NUM;
+ unsigned DstSize= li_->getInterval(DstReg).getSize() / InstrSlots::NUM;
+ const TargetRegisterClass *RC = mri_->getRegClass(DstReg);
unsigned Threshold = allocatableRCRegs_[RC].count();
// Be conservative. If both sides are virtual registers, do not coalesce
// if this will cause a high use density interval to target a smaller set
// of registers.
if (DstSize > Threshold || SrcSize > Threshold) {
- LiveVariables::VarInfo &svi = lv_->getVarInfo(repSrcReg);
- LiveVariables::VarInfo &dvi = lv_->getVarInfo(repDstReg);
+ LiveVariables::VarInfo &svi = lv_->getVarInfo(SrcReg);
+ LiveVariables::VarInfo &dvi = lv_->getVarInfo(DstReg);
if ((float)dvi.NumUses / DstSize < (float)svi.NumUses / SrcSize) {
Again = true; // May be possible to coalesce later.
return false;
}
}
}
- } else if (differingRegisterClasses(repSrcReg, repDstReg)) {
+ } else if (differingRegisterClasses(SrcReg, DstReg)) {
+ // FIXME: What if the resul 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.
+
// If they are not of the same register class, we cannot join them.
DOUT << "\tSrc/Dest are different register classes.\n";
// Allow the coalescer to try again in case either side gets coalesced to
@@ -552,9 +564,9 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
return false;
}
- LiveInterval &SrcInt = li_->getInterval(repSrcReg);
- LiveInterval &DstInt = li_->getInterval(repDstReg);
- assert(SrcInt.reg == repSrcReg && DstInt.reg == repDstReg &&
+ LiveInterval &SrcInt = li_->getInterval(SrcReg);
+ LiveInterval &DstInt = li_->getInterval(DstReg);
+ assert(SrcInt.reg == SrcReg && DstInt.reg == DstReg &&
"Register mapping is horribly broken!");
DOUT << "\t\tInspecting "; SrcInt.print(DOUT, tri_);
@@ -580,19 +592,20 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
if (SrcEnd > li_->getDefIndex(CopyIdx)) {
isDead = false;
} else {
- MachineOperand *MOU;
- MachineInstr *LastUse= lastRegisterUse(SrcStart, CopyIdx, repSrcReg, MOU);
+ unsigned LastUseIdx;
+ MachineOperand *LastUse =
+ lastRegisterUse(SrcStart, CopyIdx, SrcReg, LastUseIdx);
if (LastUse) {
// Shorten the liveinterval to the end of last use.
- MOU->setIsKill();
+ LastUse->setIsKill();
isDead = false;
isShorten = true;
- RemoveStart = li_->getDefIndex(li_->getInstructionIndex(LastUse));
- RemoveEnd = SrcEnd;
+ RemoveStart = li_->getDefIndex(LastUseIdx);
+ RemoveEnd = SrcEnd;
} else {
MachineInstr *SrcMI = li_->getInstructionFromIndex(SrcStart);
if (SrcMI) {
- MachineOperand *mops = findDefOperand(SrcMI, repSrcReg);
+ MachineOperand *mops = findDefOperand(SrcMI, SrcReg);
if (mops)
// A dead def should have a single cycle interval.
++RemoveStart;
@@ -607,9 +620,9 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
// think twice about coalescing them!
if (!mopd->isDead() && (SrcIsPhys || DstIsPhys) && !isExtSubReg) {
LiveInterval &JoinVInt = SrcIsPhys ? DstInt : SrcInt;
- unsigned JoinVReg = SrcIsPhys ? repDstReg : repSrcReg;
- unsigned JoinPReg = SrcIsPhys ? repSrcReg : repDstReg;
- const TargetRegisterClass *RC = mf_->getRegInfo().getRegClass(JoinVReg);
+ unsigned JoinVReg = SrcIsPhys ? DstReg : SrcReg;
+ unsigned JoinPReg = SrcIsPhys ? SrcReg : DstReg;
+ const TargetRegisterClass *RC = mri_->getRegClass(JoinVReg);
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
if (TheCopy.isBackEdge)
Threshold *= 2; // Favors back edge copies.
@@ -638,15 +651,15 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
if (isDead) {
// Result of the copy is dead. Propagate this property.
if (SrcStart == 0) {
- assert(TargetRegisterInfo::isPhysicalRegister(repSrcReg) &&
+ assert(TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
"Live-in must be a physical register!");
// Live-in to the function but dead. Remove it from entry live-in set.
// JoinIntervals may end up swapping the two intervals.
- mf_->begin()->removeLiveIn(repSrcReg);
+ mf_->begin()->removeLiveIn(SrcReg);
} else {
MachineInstr *SrcMI = li_->getInstructionFromIndex(SrcStart);
if (SrcMI) {
- MachineOperand *mops = findDefOperand(SrcMI, repSrcReg);
+ MachineOperand *mops = findDefOperand(SrcMI, SrcReg);
if (mops)
mops->setIsDead();
}
@@ -679,21 +692,21 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
LiveInterval *ResSrcInt = &SrcInt;
LiveInterval *ResDstInt = &DstInt;
if (Swapped) {
- std::swap(repSrcReg, repDstReg);
+ std::swap(SrcReg, DstReg);
std::swap(ResSrcInt, ResDstInt);
}
- assert(TargetRegisterInfo::isVirtualRegister(repSrcReg) &&
+ assert(TargetRegisterInfo::isVirtualRegister(SrcReg) &&
"LiveInterval::join didn't work right!");
// If we're about to merge live ranges into a physical register live range,
// we have to update any aliased register's live ranges to indicate that they
// have clobbered values for this range.
- if (TargetRegisterInfo::isPhysicalRegister(repDstReg)) {
+ if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
// Unset unnecessary kills.
if (!ResDstInt->containsOneValue()) {
for (LiveInterval::Ranges::const_iterator I = ResSrcInt->begin(),
E = ResSrcInt->end(); I != E; ++I)
- unsetRegisterKills(I->start, I->end, repDstReg);
+ unsetRegisterKills(I->start, I->end, DstReg);
}
// If this is a extract_subreg where dst is a physical register, e.g.
@@ -709,58 +722,52 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
assert(DstLR != ResDstInt->end() && "Invalid joined interval!");
const VNInfo *DstValNo = DstLR->valno;
if (CopiedValNos.insert(DstValNo)) {
- VNInfo *ValNo = RealDstInt.getNextValue(DstValNo->def, DstValNo->reg,
+ VNInfo *ValNo = RealDstInt.getNextValue(DstValNo->def, DstValNo->copy,
li_->getVNInfoAllocator());
ValNo->hasPHIKill = DstValNo->hasPHIKill;
RealDstInt.addKills(ValNo, DstValNo->kills);
RealDstInt.MergeValueInAsValue(*ResDstInt, DstValNo, ValNo);
}
}
- repDstReg = RealDstReg;
+ DstReg = RealDstReg;
}
// Update the liveintervals of sub-registers.
- for (const unsigned *AS = tri_->getSubRegisters(repDstReg); *AS; ++AS)
+ for (const unsigned *AS = tri_->getSubRegisters(DstReg); *AS; ++AS)
li_->getOrCreateInterval(*AS).MergeInClobberRanges(*ResSrcInt,
li_->getVNInfoAllocator());
} else {
// Merge use info if the destination is a virtual register.
- LiveVariables::VarInfo& dVI = lv_->getVarInfo(repDstReg);
- LiveVariables::VarInfo& sVI = lv_->getVarInfo(repSrcReg);
+ LiveVariables::VarInfo& dVI = lv_->getVarInfo(DstReg);
+ LiveVariables::VarInfo& sVI = lv_->getVarInfo(SrcReg);
dVI.NumUses += sVI.NumUses;
}
- // Remember these liveintervals have been joined.
- JoinedLIs.set(repSrcReg - TargetRegisterInfo::FirstVirtualRegister);
- if (TargetRegisterInfo::isVirtualRegister(repDstReg))
- JoinedLIs.set(repDstReg - TargetRegisterInfo::FirstVirtualRegister);
-
+ // If this is a EXTRACT_SUBREG, make sure the result of coalescing is the
+ // larger super-register.
if (isExtSubReg && !SrcIsPhys && !DstIsPhys) {
if (!Swapped) {
- // Make sure we allocate the larger super-register.
ResSrcInt->Copy(*ResDstInt, li_->getVNInfoAllocator());
- std::swap(repSrcReg, repDstReg);
+ std::swap(SrcReg, DstReg);
std::swap(ResSrcInt, ResDstInt);
}
- unsigned SubIdx = CopyMI->getOperand(2).getImm();
- SubRegIdxes.push_back(std::make_pair(repSrcReg, SubIdx));
- AddSubRegIdxPairs(repSrcReg, SubIdx);
}
if (NewHeuristic) {
+ // Add all copies that define val# in the source interval into the queue.
for (LiveInterval::const_vni_iterator i = ResSrcInt->vni_begin(),
e = ResSrcInt->vni_end(); i != e; ++i) {
const VNInfo *vni = *i;
- if (vni->def && vni->def != ~1U && vni->def != ~0U) {
- MachineInstr *CopyMI = li_->getInstructionFromIndex(vni->def);
- unsigned SrcReg, DstReg;
- if (CopyMI &&
- JoinedCopies.count(CopyMI) == 0 &&
- tii_->isMoveInstr(*CopyMI, SrcReg, DstReg)) {
- unsigned LoopDepth = loopInfo->getLoopDepth(CopyMI->getParent());
- JoinQueue->push(CopyRec(CopyMI, SrcReg, DstReg, LoopDepth,
- isBackEdgeCopy(CopyMI, DstReg)));
- }
+ if (!vni->def || vni->def == ~1U || vni->def == ~0U)
+ continue;
+ MachineInstr *CopyMI = li_->getInstructionFromIndex(vni->def);
+ unsigned NewSrcReg, NewDstReg;
+ if (CopyMI &&
+ JoinedCopies.count(CopyMI) == 0 &&
+ tii_->isMoveInstr(*CopyMI, NewSrcReg, NewDstReg)) {
+ unsigned LoopDepth = loopInfo->getLoopDepth(CopyMI->getParent());
+ JoinQueue->push(CopyRec(CopyMI, LoopDepth,
+ isBackEdgeCopy(CopyMI, DstReg)));
}
}
}
@@ -768,14 +775,20 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
DOUT << "\n\t\tJoined. Result = "; ResDstInt->print(DOUT, tri_);
DOUT << "\n";
- // repSrcReg is guarateed to be the register whose live interval that is
+ // Remember to delete the copy instruction.
+ JoinedCopies.insert(CopyMI);
+
+ // Some live range has been lengthened due to colaescing, eliminate the
+ // unnecessary kills.
+ RemoveUnnecessaryKills(SrcReg, *ResDstInt);
+ if (TargetRegisterInfo::isVirtualRegister(DstReg))