diff options
Diffstat (limited to 'lib/CodeGen/SimpleRegisterCoalescing.cpp')
| -rw-r--r-- | lib/CodeGen/SimpleRegisterCoalescing.cpp | 266 |
1 files changed, 0 insertions, 266 deletions
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp index 7aa39c5160..06ed66fee7 100644 --- a/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -47,7 +47,6 @@ STATISTIC(numExtends , "Number of copies extended"); STATISTIC(NumReMats , "Number of instructions re-materialized"); STATISTIC(numPeep , "Number of identity moves eliminated after coalescing"); STATISTIC(numAborts , "Number of times interval joining aborted"); -STATISTIC(numDeadValNo, "Number of valno def marked dead"); char SimpleRegisterCoalescing::ID = 0; static cl::opt<bool> @@ -503,98 +502,6 @@ bool SimpleRegisterCoalescing::RemoveCopyByCommutingDef(const CoalescerPair &CP, return true; } -/// isSameOrFallThroughBB - Return true if MBB == SuccMBB or MBB simply -/// fallthoughs to SuccMBB. -static bool isSameOrFallThroughBB(MachineBasicBlock *MBB, - MachineBasicBlock *SuccMBB, - const TargetInstrInfo *tii_) { - if (MBB == SuccMBB) - return true; - MachineBasicBlock *TBB = 0, *FBB = 0; - SmallVector<MachineOperand, 4> Cond; - return !tii_->AnalyzeBranch(*MBB, TBB, FBB, Cond) && !TBB && !FBB && - MBB->isSuccessor(SuccMBB); -} - -/// removeRange - Wrapper for LiveInterval::removeRange. This removes a range -/// from a physical register live interval as well as from the live intervals -/// of its sub-registers. -static void removeRange(LiveInterval &li, - SlotIndex Start, SlotIndex End, - LiveIntervals *li_, const TargetRegisterInfo *tri_) { - li.removeRange(Start, End, true); - if (TargetRegisterInfo::isPhysicalRegister(li.reg)) { - for (const unsigned* SR = tri_->getSubRegisters(li.reg); *SR; ++SR) { - if (!li_->hasInterval(*SR)) - continue; - LiveInterval &sli = li_->getInterval(*SR); - SlotIndex RemoveStart = Start; - SlotIndex RemoveEnd = Start; - - while (RemoveEnd != End) { - LiveInterval::iterator LR = sli.FindLiveRangeContaining(RemoveStart); - if (LR == sli.end()) - break; - RemoveEnd = (LR->end < End) ? LR->end : End; - sli.removeRange(RemoveStart, RemoveEnd, true); - RemoveStart = RemoveEnd; - } - } - } -} - -/// TrimLiveIntervalToLastUse - If there is a last use in the same basic block -/// as the copy instruction, trim the live interval to the last use and return -/// true. -bool -SimpleRegisterCoalescing::TrimLiveIntervalToLastUse(SlotIndex CopyIdx, - MachineBasicBlock *CopyMBB, - LiveInterval &li, - const LiveRange *LR) { - SlotIndex MBBStart = li_->getMBBStartIdx(CopyMBB); - SlotIndex LastUseIdx; - MachineOperand *LastUse = - lastRegisterUse(LR->start, CopyIdx.getPrevSlot(), li.reg, LastUseIdx); - if (LastUse) { - MachineInstr *LastUseMI = LastUse->getParent(); - if (!isSameOrFallThroughBB(LastUseMI->getParent(), CopyMBB, tii_)) { - // r1024 = op - // ... - // BB1: - // = r1024 - // - // BB2: - // r1025<dead> = r1024<kill> - if (MBBStart < LR->end) - removeRange(li, MBBStart, LR->end, li_, tri_); - return true; - } - - // There are uses before the copy, just shorten the live range to the end - // of last use. - LastUse->setIsKill(); - removeRange(li, LastUseIdx.getDefIndex(), LR->end, li_, tri_); - if (LastUseMI->isCopy()) { - MachineOperand &DefMO = LastUseMI->getOperand(0); - if (DefMO.getReg() == li.reg && !DefMO.getSubReg()) - DefMO.setIsDead(); - } - return true; - } - - // Is it livein? - if (LR->start <= MBBStart && LR->end > MBBStart) { - if (LR->start == li_->getZeroIndex()) { - assert(TargetRegisterInfo::isPhysicalRegister(li.reg)); - // Live-in to the function but dead. Remove it from entry live-in set. - mf_->begin()->removeLiveIn(li.reg); - } - // FIXME: Shorten intervals in BBs that reaches this BB. - } - - return false; -} - /// ReMaterializeTrivialDef - If the source of a copy is defined by a trivial /// computation, replace the copy by rematerialize the definition. bool SimpleRegisterCoalescing::ReMaterializeTrivialDef(LiveInterval &SrcInt, @@ -781,26 +688,6 @@ static bool removeIntervalIfEmpty(LiveInterval &li, LiveIntervals *li_, return false; } -/// ShortenDeadCopyLiveRange - Shorten a live range defined by a dead copy. -/// Return true if live interval is removed. -bool SimpleRegisterCoalescing::ShortenDeadCopyLiveRange(LiveInterval &li, - MachineInstr *CopyMI) { - SlotIndex CopyIdx = li_->getInstructionIndex(CopyMI); - LiveInterval::iterator MLR = - li.FindLiveRangeContaining(CopyIdx.getDefIndex()); - if (MLR == li.end()) - return false; // Already removed by ShortenDeadCopySrcLiveRange. - SlotIndex RemoveStart = MLR->start; - SlotIndex RemoveEnd = MLR->end; - SlotIndex DefIdx = CopyIdx.getDefIndex(); - // Remove the liverange that's defined by this. - if (RemoveStart == DefIdx && RemoveEnd == DefIdx.getStoreIndex()) { - removeRange(li, RemoveStart, RemoveEnd, li_, tri_); - return removeIntervalIfEmpty(li, li_, tri_); - } - return false; -} - /// RemoveDeadDef - If a def of a live interval is now determined dead, remove /// the val# it defines. If the live interval becomes empty, remove it as well. bool SimpleRegisterCoalescing::RemoveDeadDef(LiveInterval &li, @@ -834,84 +721,6 @@ void SimpleRegisterCoalescing::RemoveCopyFlag(unsigned DstReg, } } -/// PropagateDeadness - Propagate the dead marker to the instruction which -/// defines the val#. -static void PropagateDeadness(LiveInterval &li, MachineInstr *CopyMI, - SlotIndex &LRStart, LiveIntervals *li_, - const TargetRegisterInfo* tri_) { - MachineInstr *DefMI = - li_->getInstructionFromIndex(LRStart.getDefIndex()); - if (DefMI && DefMI != CopyMI) { - int DeadIdx = DefMI->findRegisterDefOperandIdx(li.reg); - if (DeadIdx != -1) - DefMI->getOperand(DeadIdx).setIsDead(); - else - DefMI->addOperand(MachineOperand::CreateReg(li.reg, - /*def*/true, /*implicit*/true, /*kill*/false, /*dead*/true)); - LRStart = LRStart.getNextSlot(); - } -} - -/// ShortenDeadCopySrcLiveRange - Shorten a live range as it's artificially -/// extended by a dead copy. Mark the last use (if any) of the val# as kill as -/// ends the live range there. If there isn't another use, then this live range -/// is dead. Return true if live interval is removed. -bool -SimpleRegisterCoalescing::ShortenDeadCopySrcLiveRange(LiveInterval &li, - MachineInstr *CopyMI) { - SlotIndex CopyIdx = li_->getInstructionIndex(CopyMI); - if (CopyIdx == SlotIndex()) { - // FIXME: special case: function live in. It can be a general case if the - // first instruction index starts at > 0 value. - assert(TargetRegisterInfo::isPhysicalRegister(li.reg)); - // Live-in to the function but dead. Remove it from entry live-in set. - if (mf_->begin()->isLiveIn(li.reg)) - mf_->begin()->removeLiveIn(li.reg); - if (const LiveRange *LR = li.getLiveRangeContaining(CopyIdx)) - removeRange(li, LR->start, LR->end, li_, tri_); - return removeIntervalIfEmpty(li, li_, tri_); - } - - LiveInterval::iterator LR = - li.FindLiveRangeContaining(CopyIdx.getPrevIndex().getStoreIndex()); - if (LR == li.end()) - // Livein but defined by a phi. - return false; - - SlotIndex RemoveStart = LR->start; - SlotIndex RemoveEnd = CopyIdx.getStoreIndex(); - if (LR->end > RemoveEnd) - // More uses past this copy? Nothing to do. - return false; - - // If there is a last use in the same bb, we can't remove the live range. - // Shorten the live interval and return. - MachineBasicBlock *CopyMBB = CopyMI->getParent(); - if (TrimLiveIntervalToLastUse(CopyIdx, CopyMBB, li, LR)) - return false; - - // There are other kills of the val#. Nothing to do. - if (!li.isOnlyLROfValNo(LR)) - return false; - - MachineBasicBlock *StartMBB = li_->getMBBFromIndex(RemoveStart); - if (!isSameOrFallThroughBB(StartMBB, CopyMBB, tii_)) - // If the live range starts in another mbb and the copy mbb is not a fall - // through mbb, then we can only cut the range from the beginning of the - // copy mbb. - RemoveStart = li_->getMBBStartIdx(CopyMBB).getNextIndex().getBaseIndex(); - - if (LR->valno->def == RemoveStart) { - // If the def MI defines the val# and this copy is the only kill of the - // val#, then propagate the dead marker. - PropagateDeadness(li, CopyMI, RemoveStart, li_, tri_); - ++numDeadValNo; - } - - removeRange(li, RemoveStart, RemoveEnd, li_, tri_); - return removeIntervalIfEmpty(li, li_, tri_); -} - /// shouldJoinPhys - Return true if a copy involving a physreg should be joined. /// 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 @@ -1558,81 +1367,6 @@ void SimpleRegisterCoalescing::joinIntervals() { } } -/// Return true if the two specified registers belong to different register -/// classes. The registers may be either phys or virt regs. -bool -SimpleRegisterCoalescing::differingRegisterClasses(unsigned RegA, - unsigned RegB) const { - // Get the register classes for the first reg. - if (TargetRegisterInfo::isPhysicalRegister(RegA)) { - assert(TargetRegisterInfo::isVirtualRegister(RegB) && - "Shouldn't consider two physregs!"); - return !mri_->getRegClass(RegB)->contains(RegA); - } - - // Compare against the regclass for the second reg. - const TargetRegisterClass *RegClassA = mri_->getRegClass(RegA); - if (TargetRegisterInfo::isVirtualRegister(RegB)) { - const TargetRegisterClass *RegClassB = mri_->getRegClass(RegB); - return RegClassA != RegClassB; - } - return !RegClassA->contains(RegB); -} - -/// lastRegisterUse - Returns the last (non-debug) use of the specific register -/// between cycles Start and End or NULL if there are no uses. -MachineOperand * -SimpleRegisterCoalescing::lastRegisterUse(SlotIndex Start, - SlotIndex End, - unsigned Reg, - SlotIndex &UseIdx) const{ - UseIdx = SlotIndex(); - if (TargetRegisterInfo::isVirtualRegister(Reg)) { - MachineOperand *LastUse = NULL; - for (MachineRegisterInfo::use_nodbg_iterator I = mri_->use_nodbg_begin(Reg), - E = mri_->use_nodbg_end(); I != E; ++I) { - MachineOperand &Use = I.getOperand(); - MachineInstr *UseMI = Use.getParent(); - if (UseMI->isIdentityCopy()) - continue; - SlotIndex Idx = li_->getInstructionIndex(UseMI); - if (Idx >= Start && Idx < End && (!UseIdx.isValid() || Idx >= UseIdx)) { - LastUse = &Use; - UseIdx = Idx.getUseIndex(); - } - } - return LastUse; - } - - SlotIndex s = Start; - SlotIndex e = End.getPrevSlot().getBaseIndex(); - while (e >= s) { - // Skip deleted instructions - MachineInstr *MI = li_->getInstructionFromIndex(e); - while (e != SlotIndex() && e.getPrevIndex() >= s && !MI) { - e = e.getPrevIndex(); - MI = li_->getInstructionFromIndex(e); - } - if (e < s || MI == NULL) - return NULL; - - // Ignore identity copies. - if (!MI->isIdentityCopy()) - for (unsigned i = 0, NumOps = MI->getNumOperands(); i != NumOps; ++i) { - MachineOperand &Use = MI->getOperand(i); - if (Use.isReg() && Use.isUse() && Use.getReg() && - tri_->regsOverlap(Use.getReg(), Reg)) { - UseIdx = e.getUseIndex(); - return &Use; - } - } - - e = e.getPrevIndex(); - } - - return NULL; -} - void SimpleRegisterCoalescing::releaseMemory() { JoinedCopies.clear(); ReMatCopies.clear(); |