diff options
Diffstat (limited to 'lib/CodeGen/StackSlotColoring.cpp')
-rw-r--r-- | lib/CodeGen/StackSlotColoring.cpp | 75 |
1 files changed, 43 insertions, 32 deletions
diff --git a/lib/CodeGen/StackSlotColoring.cpp b/lib/CodeGen/StackSlotColoring.cpp index 582464478cfc..fad0808c8931 100644 --- a/lib/CodeGen/StackSlotColoring.cpp +++ b/lib/CodeGen/StackSlotColoring.cpp @@ -18,6 +18,7 @@ #include "llvm/CodeGen/LiveStackAnalysis.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineLoopInfo.h" +#include "llvm/CodeGen/MachineMemOperand.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/PseudoSourceValue.h" #include "llvm/Support/CommandLine.h" @@ -97,6 +98,7 @@ namespace { MachineFunctionPass(&ID), ColorWithRegs(RegColor), NextColor(-1) {} virtual void getAnalysisUsage(AnalysisUsage &AU) const { + AU.setPreservesCFG(); AU.addRequired<LiveStacks>(); AU.addRequired<VirtRegMap>(); AU.addPreserved<VirtRegMap>(); @@ -197,7 +199,7 @@ void StackSlotColoring::InitializeSlots() { Assignments.resize(LastFI); // Gather all spill slots into a list. - DOUT << "Spill slot intervals:\n"; + DEBUG(errs() << "Spill slot intervals:\n"); for (LiveStacks::iterator i = LS->begin(), e = LS->end(); i != e; ++i) { LiveInterval &li = i->second; DEBUG(li.dump()); @@ -209,7 +211,7 @@ void StackSlotColoring::InitializeSlots() { OrigSizes[FI] = MFI->getObjectSize(FI); AllColors.set(FI); } - DOUT << '\n'; + DEBUG(errs() << '\n'); // Sort them by weight. std::stable_sort(SSIntervals.begin(), SSIntervals.end(), IntervalSorter()); @@ -241,7 +243,7 @@ StackSlotColoring::ColorSlotsWithFreeRegs(SmallVector<int, 16> &SlotMapping, return false; bool Changed = false; - DOUT << "Assigning unused registers to spill slots:\n"; + DEBUG(errs() << "Assigning unused registers to spill slots:\n"); for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) { LiveInterval *li = SSIntervals[i]; int SS = li->getStackSlotIndex(); @@ -271,7 +273,8 @@ StackSlotColoring::ColorSlotsWithFreeRegs(SmallVector<int, 16> &SlotMapping, AllColored = false; continue; } else { - DOUT << "Assigning fi#" << RSS << " to " << TRI->getName(Reg) << '\n'; + DEBUG(errs() << "Assigning fi#" << RSS << " to " + << TRI->getName(Reg) << '\n'); ColoredRegs.push_back(Reg); SlotMapping[RSS] = Reg; SlotIsReg.set(RSS); @@ -298,7 +301,7 @@ StackSlotColoring::ColorSlotsWithFreeRegs(SmallVector<int, 16> &SlotMapping, ++NumEliminated; } } - DOUT << '\n'; + DEBUG(errs() << '\n'); return Changed; } @@ -333,7 +336,7 @@ int StackSlotColoring::ColorSlot(LiveInterval *li) { // Record the assignment. Assignments[Color].push_back(li); int FI = li->getStackSlotIndex(); - DOUT << "Assigning fi#" << FI << " to fi#" << Color << "\n"; + DEBUG(errs() << "Assigning fi#" << FI << " to fi#" << Color << "\n"); // Change size and alignment of the allocated slot. If there are multiple // objects sharing the same slot, then make sure the size and alignment @@ -357,7 +360,7 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) { BitVector SlotIsReg(NumObjs); BitVector UsedColors(NumObjs); - DOUT << "Color spill slot intervals:\n"; + DEBUG(errs() << "Color spill slot intervals:\n"); bool Changed = false; for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) { LiveInterval *li = SSIntervals[i]; @@ -371,7 +374,7 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) { Changed |= (SS != NewSS); } - DOUT << "\nSpill slots after coloring:\n"; + DEBUG(errs() << "\nSpill slots after coloring:\n"); for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) { LiveInterval *li = SSIntervals[i]; int SS = li->getStackSlotIndex(); @@ -383,7 +386,7 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) { #ifndef NDEBUG for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) DEBUG(SSIntervals[i]->dump()); - DOUT << '\n'; + DEBUG(errs() << '\n'); #endif // Can we "color" a stack slot with a unused register? @@ -415,7 +418,7 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) { // Delete unused stack slots. while (NextColor != -1) { - DOUT << "Removing unused stack object fi#" << NextColor << "\n"; + DEBUG(errs() << "Removing unused stack object fi#" << NextColor << "\n"); MFI->RemoveStackObject(NextColor); NextColor = AllColors.find_next(NextColor); } @@ -449,6 +452,7 @@ bool StackSlotColoring::AllMemRefsCanBeUnfolded(int SS) { /// to old frame index with new one. void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI, int NewFI, MachineFunction &MF) { + // Update the operands. for (unsigned i = 0, ee = MI->getNumOperands(); i != ee; ++i) { MachineOperand &MO = MI->getOperand(i); if (!MO.isFI()) @@ -459,22 +463,15 @@ void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI, MO.setIndex(NewFI); } - // Update the MachineMemOperand for the new memory location. - // FIXME: We need a better method of managing these too. - SmallVector<MachineMemOperand, 2> MMOs(MI->memoperands_begin(), - MI->memoperands_end()); - MI->clearMemOperands(MF); + // Update the memory references. This changes the MachineMemOperands + // directly. They may be in use by multiple instructions, however all + // instructions using OldFI are being rewritten to use NewFI. const Value *OldSV = PseudoSourceValue::getFixedStack(OldFI); - for (unsigned i = 0, ee = MMOs.size(); i != ee; ++i) { - if (MMOs[i].getValue() != OldSV) - MI->addMemOperand(MF, MMOs[i]); - else { - MachineMemOperand MMO(PseudoSourceValue::getFixedStack(NewFI), - MMOs[i].getFlags(), MMOs[i].getOffset(), - MMOs[i].getSize(), MMOs[i].getAlignment()); - MI->addMemOperand(MF, MMO); - } - } + const Value *NewSV = PseudoSourceValue::getFixedStack(NewFI); + for (MachineInstr::mmo_iterator I = MI->memoperands_begin(), + E = MI->memoperands_end(); I != E; ++I) + if ((*I)->getValue() == OldSV) + (*I)->setValue(NewSV); } /// PropagateBackward - Traverse backward and look for the definition of @@ -503,7 +500,16 @@ bool StackSlotColoring::PropagateBackward(MachineBasicBlock::iterator MII, if (Reg == OldReg) { if (MO.isImplicit()) return false; - const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, TID, i); + + // Abort the use is actually a sub-register def. We don't have enough + // information to figure out if it is really legal. + if (MO.getSubReg() || + TID.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG || + TID.getOpcode() == TargetInstrInfo::INSERT_SUBREG || + TID.getOpcode() == TargetInstrInfo::SUBREG_TO_REG) + return false; + + const TargetRegisterClass *RC = TID.OpInfo[i].getRegClass(TRI); if (RC && !RC->contains(NewReg)) return false; @@ -547,7 +553,6 @@ bool StackSlotColoring::PropagateForward(MachineBasicBlock::iterator MII, SmallVector<MachineOperand*, 4> Uses; while (++MII != MBB->end()) { - bool FoundUse = false; bool FoundKill = false; const TargetInstrDesc &TID = MII->getDesc(); for (unsigned i = 0, e = MII->getNumOperands(); i != e; ++i) { @@ -561,12 +566,18 @@ bool StackSlotColoring::PropagateForward(MachineBasicBlock::iterator MII, if (MO.isDef() || MO.isImplicit()) return false; - const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, TID, i); + // Abort the use is actually a sub-register use. We don't have enough + // information to figure out if it is really legal. + if (MO.getSubReg() || + TID.getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) + return false; + + const TargetRegisterClass *RC = TID.OpInfo[i].getRegClass(TRI); if (RC && !RC->contains(NewReg)) return false; - FoundUse = true; if (MO.isKill()) FoundKill = true; + Uses.push_back(&MO); } else if (TRI->regsOverlap(Reg, NewReg) || TRI->regsOverlap(Reg, OldReg)) @@ -593,7 +604,7 @@ StackSlotColoring::UnfoldAndRewriteInstruction(MachineInstr *MI, int OldFI, MachineBasicBlock *MBB = MI->getParent(); if (unsigned DstReg = TII->isLoadFromStackSlot(MI, OldFI)) { if (PropagateForward(MI, MBB, DstReg, Reg)) { - DOUT << "Eliminated load: "; + DEBUG(errs() << "Eliminated load: "); DEBUG(MI->dump()); ++NumLoadElim; } else { @@ -609,7 +620,7 @@ StackSlotColoring::UnfoldAndRewriteInstruction(MachineInstr *MI, int OldFI, } } else if (unsigned SrcReg = TII->isStoreToStackSlot(MI, OldFI)) { if (MI->killsRegister(SrcReg) && PropagateBackward(MI, MBB, SrcReg, Reg)) { - DOUT << "Eliminated store: "; + DEBUG(errs() << "Eliminated store: "); DEBUG(MI->dump()); ++NumStoreElim; } else { @@ -687,7 +698,7 @@ bool StackSlotColoring::RemoveDeadStores(MachineBasicBlock* MBB) { bool StackSlotColoring::runOnMachineFunction(MachineFunction &MF) { - DOUT << "********** Stack Slot Coloring **********\n"; + DEBUG(errs() << "********** Stack Slot Coloring **********\n"); MFI = MF.getFrameInfo(); MRI = &MF.getRegInfo(); |