X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTarget%2FARM%2FARMConstantIslandPass.cpp;h=3c2540856478b62591643f7215c42f3262332fb8;hb=7721e7f279c4c01b29583011eaff48250ec6cdd9;hp=9742d2d7911d69e5d83e83ba75226db8ae59eb1e;hpb=dec6de92d1425c88f319179fb4a0b0a23f781df9;p=oota-llvm.git diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp index 9742d2d7911..3c254085647 100644 --- a/lib/Target/ARM/ARMConstantIslandPass.cpp +++ b/lib/Target/ARM/ARMConstantIslandPass.cpp @@ -18,9 +18,9 @@ #include "ARMAddressingModes.h" #include "ARMMachineFunctionInfo.h" #include "ARMInstrInfo.h" +#include "Thumb2InstrInfo.h" #include "llvm/CodeGen/MachineConstantPool.h" #include "llvm/CodeGen/MachineFunctionPass.h" -#include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineJumpTableInfo.h" #include "llvm/Target/TargetData.h" #include "llvm/Target/TargetMachine.h" @@ -162,7 +162,10 @@ namespace { /// the branch fix up pass. bool HasFarJump; - const TargetInstrInfo *TII; + /// HasInlineAsm - True if the function contains inline assembly. + bool HasInlineAsm; + + const ARMInstrInfo *TII; const ARMSubtarget *STI; ARMFunctionInfo *AFI; bool isThumb; @@ -170,7 +173,7 @@ namespace { bool isThumb2; public: static char ID; - ARMConstantIslands() : MachineFunctionPass(&ID) {} + ARMConstantIslands() : MachineFunctionPass(ID) {} virtual bool runOnMachineFunction(MachineFunction &MF); @@ -236,10 +239,19 @@ void ARMConstantIslands::verify(MachineFunction &MF) { if (!MBB->empty() && MBB->begin()->getOpcode() == ARM::CONSTPOOL_ENTRY) { unsigned MBBId = MBB->getNumber(); - assert((BBOffsets[MBBId]%4 == 0 && BBSizes[MBBId]%4 == 0) || + assert(HasInlineAsm || + (BBOffsets[MBBId]%4 == 0 && BBSizes[MBBId]%4 == 0) || (BBOffsets[MBBId]%4 != 0 && BBSizes[MBBId]%4 != 0)); } } + for (unsigned i = 0, e = CPUsers.size(); i != e; ++i) { + CPUser &U = CPUsers[i]; + unsigned UserOffset = GetOffsetOf(U.MI) + (isThumb ? 4 : 8); + unsigned CPEOffset = GetOffsetOf(U.CPEMI); + unsigned Disp = UserOffset < CPEOffset ? CPEOffset - UserOffset : + UserOffset - CPEOffset; + assert(Disp <= U.MaxDisp || "Constant pool entry out of range!"); + } #endif } @@ -260,7 +272,7 @@ FunctionPass *llvm::createARMConstantIslandPass() { bool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { MachineConstantPool &MCP = *MF.getConstantPool(); - TII = MF.getTarget().getInstrInfo(); + TII = (const ARMInstrInfo*)MF.getTarget().getInstrInfo(); AFI = MF.getInfo(); STI = &MF.getTarget().getSubtarget(); @@ -269,6 +281,7 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { isThumb2 = AFI->isThumb2Function(); HasFarJump = false; + HasInlineAsm = false; // Renumber all of the machine basic blocks in the function, guaranteeing that // the numbers agree with the position of the block in the function. @@ -289,9 +302,9 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { // Thumb1 functions containing constant pools get 4-byte alignment. // This is so we can keep exact track of where the alignment padding goes. - // Set default. Thumb1 function is 2-byte aligned, ARM and Thumb2 are 4-byte - // aligned. - AFI->setAlign(isThumb1 ? 1U : 2U); + // ARM and Thumb2 functions need to be 4-byte aligned. + if (!isThumb1) + MF.EnsureAlignment(2); // 2 = log2(4) // Perform the initial placement of the constant pool entries. To start with, // we put them all at the end of the function. @@ -299,7 +312,7 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { if (!MCP.isEmpty()) { DoInitialPlacement(MF, CPEMIs); if (isThumb1) - AFI->setAlign(2U); + MF.EnsureAlignment(2); // 2 = log2(4) } /// The next UID to take is the first unused one. @@ -310,6 +323,8 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { // constant pool users. InitialFunctionScan(MF, CPEMIs); CPEMIs.clear(); + DEBUG(dumpBBs()); + /// Remove dead constant pool entries. RemoveUnusedCPEntries(); @@ -324,7 +339,7 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { if (CPChange && ++NoCPIters > 30) llvm_unreachable("Constant Island pass failed to converge!"); DEBUG(dumpBBs()); - + // Clear NewWaterList now. If we split a block for branches, it should // appear as "new water" for the next iteration of constant pool placement. NewWaterList.clear(); @@ -342,17 +357,19 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &MF) { } // Shrink 32-bit Thumb2 branch, load, and store instructions. - if (isThumb2) + if (isThumb2 && !STI->prefers32BitThumb()) MadeChange |= OptimizeThumb2Instructions(MF); // After a while, this might be made debug-only, but it is not expensive. verify(MF); - // If LR has been forced spilled and no far jumps (i.e. BL) has been issued. - // Undo the spill / restore of LR if possible. + // If LR has been forced spilled and no far jump (i.e. BL) has been issued, + // undo the spill / restore of LR if possible. if (isThumb && !HasFarJump && AFI->isLRSpilledForFarJump()) MadeChange |= UndoLRSpillRestore(); + DEBUG(errs() << '\n'; dumpBBs()); + BBSizes.clear(); BBOffsets.clear(); WaterList.clear(); @@ -386,15 +403,15 @@ void ARMConstantIslands::DoInitialPlacement(MachineFunction &MF, // aligned. assert((Size & 3) == 0 && "CP Entry not multiple of 4 bytes!"); MachineInstr *CPEMI = - BuildMI(BB, DebugLoc::getUnknownLoc(), TII->get(ARM::CONSTPOOL_ENTRY)) - .addImm(i).addConstantPoolIndex(i).addImm(Size); + BuildMI(BB, DebugLoc(), TII->get(ARM::CONSTPOOL_ENTRY)) + .addImm(i).addConstantPoolIndex(i).addImm(Size); CPEMIs.push_back(CPEMI); // Add a new CPEntry, but no corresponding CPUser yet. std::vector CPEs; CPEs.push_back(CPEntry(CPEMI, i)); CPEntries.push_back(CPEs); - NumCPEs++; + ++NumCPEs; DEBUG(errs() << "Moved CPI#" << i << " to end of function as #" << i << "\n"); } @@ -405,10 +422,11 @@ void ARMConstantIslands::DoInitialPlacement(MachineFunction &MF, static bool BBHasFallthrough(MachineBasicBlock *MBB) { // Get the next machine basic block in the function. MachineFunction::iterator MBBI = MBB; - if (next(MBBI) == MBB->getParent()->end()) // Can't fall off end of function. + // Can't fall off end of function. + if (llvm::next(MBBI) == MBB->getParent()->end()) return false; - MachineBasicBlock *NextBB = next(MBBI); + MachineBasicBlock *NextBB = llvm::next(MBBI); for (MachineBasicBlock::succ_iterator I = MBB->succ_begin(), E = MBB->succ_end(); I != E; ++I) if (*I == NextBB) @@ -452,6 +470,19 @@ void ARMConstantIslands::JumpTableFunctionScan(MachineFunction &MF) { /// and finding all of the constant pool users. void ARMConstantIslands::InitialFunctionScan(MachineFunction &MF, const std::vector &CPEMIs) { + // First thing, see if the function has any inline assembly in it. If so, + // we have to be conservative about alignment assumptions, as we don't + // know for sure the size of any instructions in the inline assembly. + for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end(); + MBBI != E; ++MBBI) { + MachineBasicBlock &MBB = *MBBI; + for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); + I != E; ++I) + if (I->getOpcode() == ARM::INLINEASM) + HasInlineAsm = true; + } + + // Now go back through the instructions and build up our data structures unsigned Offset = 0; for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end(); MBBI != E; ++MBBI) { @@ -465,6 +496,8 @@ void ARMConstantIslands::InitialFunctionScan(MachineFunction &MF, unsigned MBBSize = 0; for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I) { + if (I->isDebugValue()) + continue; // Add instruction size to MBBSize. MBBSize += TII->GetInstSizeInBytes(I); @@ -480,8 +513,12 @@ void ARMConstantIslands::InitialFunctionScan(MachineFunction &MF, case ARM::tBR_JTr: // A Thumb1 table jump may involve padding; for the offsets to // be right, functions containing these must be 4-byte aligned. - AFI->setAlign(2U); - if ((Offset+MBBSize)%4 != 0) + // tBR_JTr expands to a mov pc followed by .align 2 and then the jump + // table entries. So this code checks whether offset of tBR_JTr + 2 + // is aligned. That is held in Offset+MBBSize, which already has + // 2 added in for the size of the mov pc instruction. + MF.EnsureAlignment(2U); + if ((Offset+MBBSize)%4 != 0 || HasInlineAsm) // FIXME: Add a pseudo ALIGN instruction instead. MBBSize += 2; // padding continue; // Does not get an entry in ImmBranches @@ -566,7 +603,7 @@ void ARMConstantIslands::InitialFunctionScan(MachineFunction &MF, Scale = 4; break; - case ARM::LDR: + case ARM::LDRi12: case ARM::LDRcp: case ARM::t2LDRpci: Bits = 12; // +-offset_12 @@ -609,7 +646,7 @@ void ARMConstantIslands::InitialFunctionScan(MachineFunction &MF, if (isThumb && !MBB.empty() && MBB.begin()->getOpcode() == ARM::CONSTPOOL_ENTRY && - (Offset%4) != 0) + ((Offset%4) != 0 || HasInlineAsm)) MBBSize += 2; BBSizes.push_back(MBBSize); @@ -633,7 +670,7 @@ unsigned ARMConstantIslands::GetOffsetOf(MachineInstr *MI) const { // alignment padding, and compensate if so. if (isThumb && MI->getOpcode() == ARM::CONSTPOOL_ENTRY && - Offset%4 != 0) + (Offset%4 != 0 || HasInlineAsm)) Offset += 2; // Sum instructions before MI in MBB. @@ -695,8 +732,8 @@ MachineBasicBlock *ARMConstantIslands::SplitBlockBeforeInstr(MachineInstr *MI) { // There doesn't seem to be meaningful DebugInfo available; this doesn't // correspond to anything in the source. unsigned Opc = isThumb ? (isThumb2 ? ARM::t2B : ARM::tB) : ARM::B; - BuildMI(OrigBB, DebugLoc::getUnknownLoc(), TII->get(Opc)).addMBB(NewBB); - NumSplit++; + BuildMI(OrigBB, DebugLoc(), TII->get(Opc)).addMBB(NewBB); + ++NumSplit; // Update the CFG. All succs of OrigBB are now succs of NewBB. while (!OrigBB->succ_empty()) { @@ -706,7 +743,7 @@ MachineBasicBlock *ARMConstantIslands::SplitBlockBeforeInstr(MachineInstr *MI) { // This pass should be run after register allocation, so there should be no // PHI nodes to update. - assert((Succ->empty() || Succ->begin()->getOpcode() != TargetInstrInfo::PHI) + assert((Succ->empty() || !Succ->begin()->isPHI()) && "PHI nodes should be eliminated by now!"); } @@ -734,33 +771,59 @@ MachineBasicBlock *ARMConstantIslands::SplitBlockBeforeInstr(MachineInstr *MI) { CompareMBBNumbers); MachineBasicBlock* WaterBB = *IP; if (WaterBB == OrigBB) - WaterList.insert(next(IP), NewBB); + WaterList.insert(llvm::next(IP), NewBB); else WaterList.insert(IP, OrigBB); NewWaterList.insert(OrigBB); - // Figure out how large the first NewMBB is. (It cannot - // contain a constpool_entry or tablejump.) - unsigned NewBBSize = 0; - for (MachineBasicBlock::iterator I = NewBB->begin(), E = NewBB->end(); - I != E; ++I) - NewBBSize += TII->GetInstSizeInBytes(I); - unsigned OrigBBI = OrigBB->getNumber(); unsigned NewBBI = NewBB->getNumber(); - // Set the size of NewBB in BBSizes. - BBSizes[NewBBI] = NewBBSize; - // We removed instructions from UserMBB, subtract that off from its size. - // Add 2 or 4 to the block to count the unconditional branch we added to it. int delta = isThumb1 ? 2 : 4; - BBSizes[OrigBBI] -= NewBBSize - delta; + + // Figure out how large the OrigBB is. As the first half of the original + // block, it cannot contain a tablejump. The size includes + // the new jump we added. (It should be possible to do this without + // recounting everything, but it's very confusing, and this is rarely + // executed.) + unsigned OrigBBSize = 0; + for (MachineBasicBlock::iterator I = OrigBB->begin(), E = OrigBB->end(); + I != E; ++I) + OrigBBSize += TII->GetInstSizeInBytes(I); + BBSizes[OrigBBI] = OrigBBSize; // ...and adjust BBOffsets for NewBB accordingly. BBOffsets[NewBBI] = BBOffsets[OrigBBI] + BBSizes[OrigBBI]; + // Figure out how large the NewMBB is. As the second half of the original + // block, it may contain a tablejump. + unsigned NewBBSize = 0; + for (MachineBasicBlock::iterator I = NewBB->begin(), E = NewBB->end(); + I != E; ++I) + NewBBSize += TII->GetInstSizeInBytes(I); + // Set the size of NewBB in BBSizes. It does not include any padding now. + BBSizes[NewBBI] = NewBBSize; + + MachineInstr* ThumbJTMI = prior(NewBB->end()); + if (ThumbJTMI->getOpcode() == ARM::tBR_JTr) { + // We've added another 2-byte instruction before this tablejump, which + // means we will always need padding if we didn't before, and vice versa. + + // The original offset of the jump instruction was: + unsigned OrigOffset = BBOffsets[OrigBBI] + BBSizes[OrigBBI] - delta; + if (OrigOffset%4 == 0) { + // We had padding before and now we don't. No net change in code size. + delta = 0; + } else { + // We didn't have padding before and now we do. + BBSizes[NewBBI] += 2; + delta = 4; + } + } + // All BBOffsets following these blocks must be modified. - AdjustBBOffsetsAfter(NewBB, delta); + if (delta) + AdjustBBOffsetsAfter(NewBB, delta); return NewBB; } @@ -829,7 +892,7 @@ bool ARMConstantIslands::CPEIsInRange(MachineInstr *MI, unsigned UserOffset, MachineInstr *CPEMI, unsigned MaxDisp, bool NegOk, bool DoDump) { unsigned CPEOffset = GetOffsetOf(CPEMI); - assert(CPEOffset%4 == 0 && "Misaligned CPE"); + assert((CPEOffset%4 == 0 || HasInlineAsm) && "Misaligned CPE"); if (DoDump) { DEBUG(errs() << "User of CPE#" << CPEMI->getOperand(0).getImm() @@ -861,7 +924,7 @@ static bool BBIsJumpedOver(MachineBasicBlock *MBB) { void ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB, int delta) { - MachineFunction::iterator MBBI = BB; MBBI = next(MBBI); + MachineFunction::iterator MBBI = BB; MBBI = llvm::next(MBBI); for(unsigned i = BB->getNumber()+1, e = BB->getParent()->getNumBlockIDs(); i < e; ++i) { BBOffsets[i] += delta; @@ -870,7 +933,7 @@ void ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB, if (!isThumb) continue; MachineBasicBlock *MBB = MBBI; - if (!MBB->empty()) { + if (!MBB->empty() && !HasInlineAsm) { // Constant pool entries require padding. if (MBB->begin()->getOpcode() == ARM::CONSTPOOL_ENTRY) { unsigned OldOffset = BBOffsets[i] - delta; @@ -886,6 +949,10 @@ void ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB, } // Thumb1 jump tables require padding. They should be at the end; // following unconditional branches are removed by AnalyzeBranch. + // tBR_JTr expands to a mov pc followed by .align 2 and then the jump + // table entries. So this code checks whether offset of tBR_JTr + // is aligned; if it is, the offset of the jump table following the + // instruction will not be aligned, and we need padding. MachineInstr *ThumbJTMI = prior(MBB->end()); if (ThumbJTMI->getOpcode() == ARM::tBR_JTr) { unsigned NewMIOffset = GetOffsetOf(ThumbJTMI); @@ -903,7 +970,7 @@ void ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB, if (delta==0) return; } - MBBI = next(MBBI); + MBBI = llvm::next(MBBI); } } @@ -919,7 +986,7 @@ bool ARMConstantIslands::DecrementOldEntry(unsigned CPI, MachineInstr *CPEMI) { if (--CPE->RefCount == 0) { RemoveDeadCPEMI(CPEMI); CPE->CPEMI = NULL; - NumCPEs--; + --NumCPEs; return true; } return false; @@ -1070,15 +1137,14 @@ void ARMConstantIslands::CreateNewWater(unsigned CPUserIndex, DEBUG(errs() << "Split at end of block\n"); if (&UserMBB->back() == UserMI) assert(BBHasFallthrough(UserMBB) && "Expected a fallthrough BB!"); - NewMBB = next(MachineFunction::iterator(UserMBB)); + NewMBB = llvm::next(MachineFunction::iterator(UserMBB)); // Add an unconditional branch from UserMBB to fallthrough block. // Record it for branch lengthening; this new branch will not get out of // range, but if the preceding conditional branch is out of range, the // targets will be exchanged, and the altered branch may be out of // range, so the machinery has to know about it. int UncondBr = isThumb ? ((isThumb2) ? ARM::t2B : ARM::tB) : ARM::B; - BuildMI(UserMBB, DebugLoc::getUnknownLoc(), - TII->get(UncondBr)).addMBB(NewMBB); + BuildMI(UserMBB, DebugLoc(), TII->get(UncondBr)).addMBB(NewMBB); unsigned MaxDisp = getUnconditionalBrDisp(UncondBr); ImmBranches.push_back(ImmBranch(&UserMBB->back(), MaxDisp, false, UncondBr)); @@ -1115,11 +1181,13 @@ void ARMConstantIslands::CreateNewWater(unsigned CPUserIndex, MachineBasicBlock::iterator MI = UserMI; ++MI; unsigned CPUIndex = CPUserIndex+1; + unsigned NumCPUsers = CPUsers.size(); + MachineInstr *LastIT = 0; for (unsigned Offset = UserOffset+TII->GetInstSizeInBytes(UserMI); Offset < BaseInsertOffset; Offset += TII->GetInstSizeInBytes(MI), - MI = next(MI)) { - if (CPUIndex < CPUsers.size() && CPUsers[CPUIndex].MI == MI) { + MI = llvm::next(MI)) { + if (CPUIndex < NumCPUsers && CPUsers[CPUIndex].MI == MI) { CPUser &U = CPUsers[CPUIndex]; if (!OffsetIsInRange(Offset, EndInsertOffset, U.MaxDisp, U.NegOk, U.IsSoImm)) { @@ -1131,9 +1199,23 @@ void ARMConstantIslands::CreateNewWater(unsigned CPUserIndex, EndInsertOffset += CPUsers[CPUIndex].CPEMI->getOperand(2).getImm(); CPUIndex++; } + + // Remember the last IT instruction. + if (MI->getOpcode() == ARM::t2IT) + LastIT = MI; } + DEBUG(errs() << "Split in middle of big block\n"); - NewMBB = SplitBlockBeforeInstr(prior(MI)); + --MI; + + // Avoid splitting an IT block. + if (LastIT) { + unsigned PredReg = 0; + ARMCC::CondCodes CC = llvm::getITInstrPredicate(MI, PredReg); + if (CC != ARMCC::AL) + MI = LastIT; + } + NewMBB = SplitBlockBeforeInstr(MI); } } @@ -1178,7 +1260,7 @@ bool ARMConstantIslands::HandleConstantPoolUser(MachineFunction &MF, NewWaterList.insert(NewIsland); } // The new CPE goes before the following block (NewMBB). - NewMBB = next(MachineFunction::iterator(WaterBB)); + NewMBB = llvm::next(MachineFunction::iterator(WaterBB)); } else { // No water found. @@ -1218,15 +1300,14 @@ bool ARMConstantIslands::HandleConstantPoolUser(MachineFunction &MF, // Now that we have an island to add the CPE to, clone the original CPE and // add it to the island. U.HighWaterMark = NewIsland; - U.CPEMI = BuildMI(NewIsland, DebugLoc::getUnknownLoc(), - TII->get(ARM::CONSTPOOL_ENTRY)) + U.CPEMI = BuildMI(NewIsland, DebugLoc(), TII->get(ARM::CONSTPOOL_ENTRY)) .addImm(ID).addConstantPoolIndex(CPI).addImm(Size); CPEntries[CPI].push_back(CPEntry(U.CPEMI, ID, 1)); - NumCPEs++; + ++NumCPEs; BBOffsets[NewIsland->getNumber()] = BBOffsets[NewMBB->getNumber()]; // Compensate for .align 2 in thumb mode. - if (isThumb && BBOffsets[NewIsland->getNumber()]%4 != 0) + if (isThumb && (BBOffsets[NewIsland->getNumber()]%4 != 0 || HasInlineAsm)) Size += 2; // Increase the size of the island block to account for the new entry. BBSizes[NewIsland->getNumber()] += Size; @@ -1345,7 +1426,7 @@ ARMConstantIslands::FixUpUnconditionalBr(MachineFunction &MF, ImmBranch &Br) { BBSizes[MBB->getNumber()] += 2; AdjustBBOffsetsAfter(MBB, 2); HasFarJump = true; - NumUBrFixed++; + ++NumUBrFixed; DEBUG(errs() << " Changed B to long jump " << *MI); @@ -1378,9 +1459,9 @@ ARMConstantIslands::FixUpConditionalBr(MachineFunction &MF, ImmBranch &Br) { MachineInstr *BMI = &MBB->back(); bool NeedSplit = (BMI != MI) || !BBHasFallthrough(MBB); - NumCBrFixed++; + ++NumCBrFixed; if (BMI != MI) { - if (next(MachineBasicBlock::iterator(MI)) == prior(MBB->end()) && + if (llvm::next(MachineBasicBlock::iterator(MI)) == prior(MBB->end()) && BMI->getOpcode() == Br.UncondBr) { // Last MI in the BB is an unconditional branch. Can we simply invert the // condition and swap destinations: @@ -1407,12 +1488,12 @@ ARMConstantIslands::FixUpConditionalBr(MachineFunction &MF, ImmBranch &Br) { // branch to the destination. int delta = TII->GetInstSizeInBytes(&MBB->back()); BBSizes[MBB->getNumber()] -= delta; - MachineBasicBlock* SplitBB = next(MachineFunction::iterator(MBB)); + MachineBasicBlock* SplitBB = llvm::next(MachineFunction::iterator(MBB)); AdjustBBOffsetsAfter(SplitBB, -delta); MBB->back().eraseFromParent(); // BBOffsets[SplitBB] is wrong temporarily, fixed below } - MachineBasicBlock *NextBB = next(MachineFunction::iterator(MBB)); + MachineBasicBlock *NextBB = llvm::next(MachineFunction::iterator(MBB)); DEBUG(errs() << " Insert B to BB#" << DestBB->getNumber() << " also invert condition and change dest. to BB#" @@ -1420,12 +1501,11 @@ ARMConstantIslands::FixUpConditionalBr(MachineFunction &MF, ImmBranch &Br) { // Insert a new conditional branch and a new unconditional branch. // Also update the ImmBranch as well as adding a new entry for the new branch. - BuildMI(MBB, DebugLoc::getUnknownLoc(), - TII->get(MI->getOpcode())) + BuildMI(MBB, DebugLoc(), TII->get(MI->getOpcode())) .addMBB(NextBB).addImm(CC).addReg(CCReg); Br.MI = &MBB->back(); BBSizes[MBB->getNumber()] += TII->GetInstSizeInBytes(&MBB->back()); - BuildMI(MBB, DebugLoc::getUnknownLoc(), TII->get(Br.UncondBr)).addMBB(DestBB); + BuildMI(MBB, DebugLoc(), TII->get(Br.UncondBr)).addMBB(DestBB); BBSizes[MBB->getNumber()] += TII->GetInstSizeInBytes(&MBB->back()); unsigned MaxDisp = getUnconditionalBrDisp(Br.UncondBr); ImmBranches.push_back(ImmBranch(&MBB->back(), MaxDisp, false, Br.UncondBr)); @@ -1447,11 +1527,10 @@ bool ARMConstantIslands::UndoLRSpillRestore() { bool MadeChange = false; for (unsigned i = 0, e = PushPopMIs.size(); i != e; ++i) { MachineInstr *MI = PushPopMIs[i]; - // First two operands are predicates, the third is a zero since there - // is no writeback. + // First two operands are predicates. if (MI->getOpcode() == ARM::tPOP_RET && - MI->getOperand(3).getReg() == ARM::PC && - MI->getNumExplicitOperands() == 4) { + MI->getOperand(2).getReg() == ARM::PC && + MI->getNumExplicitOperands() == 3) { BuildMI(MI->getParent(), MI->getDebugLoc(), TII->get(ARM::tBX_RET)); MI->eraseFromParent(); MadeChange = true; @@ -1598,6 +1677,8 @@ bool ARMConstantIslands::OptimizeThumb2JumpTables(MachineFunction &MF) { // FIXME: After the tables are shrunk, can we get rid some of the // constantpool tables? MachineJumpTableInfo *MJTI = MF.getJumpTableInfo(); + if (MJTI == 0) return false; + const std::vector &JT = MJTI->getJumpTables(); for (unsigned i = 0, e = T2JumpTables.size(); i != e; ++i) { MachineInstr *MI = T2JumpTables[i]; @@ -1634,15 +1715,25 @@ bool ARMConstantIslands::OptimizeThumb2JumpTables(MachineFunction &MF) { continue; unsigned IdxReg = MI->getOperand(1).getReg(); bool IdxRegKill = MI->getOperand(1).isKill(); + + // Scan backwards to find the instruction that defines the base + // register. Due to post-RA scheduling, we can't count on it + // immediately preceding the branch instruction. MachineBasicBlock::iterator PrevI = MI; - if (PrevI == MBB->begin()) + MachineBasicBlock::iterator B = MBB->begin(); + while (PrevI != B && !PrevI->definesRegister(BaseReg)) + --PrevI; + + // If for some reason we didn't find it, we can't do anything, so + // just skip this one. + if (!PrevI->definesRegister(BaseReg)) continue; - MachineInstr *AddrMI = --PrevI; + MachineInstr *AddrMI = PrevI; bool OptOk = true; - // Examine the instruction that calculate the jumptable entry address. - // If it's not the one just before the t2BR_JT, we won't delete it, then - // it's not worth doing the optimization. + // Examine the instruction that calculates the jumptable entry address. + // Make sure it only defines the base register and kills any uses + // other than the index register. for (unsigned k = 0, eee = AddrMI->getNumOperands(); k != eee; ++k) { const MachineOperand &MO = AddrMI->getOperand(k); if (!MO.isReg() || !MO.getReg()) @@ -1659,9 +1750,14 @@ bool ARMConstantIslands::OptimizeThumb2JumpTables(MachineFunction &MF) { if (!OptOk) continue; - // The previous instruction should be a tLEApcrel or t2LEApcrelJT, we want + // Now scan back again to find the tLEApcrel or t2LEApcrelJT instruction + // that gave us the initial base register definition. + for (--PrevI; PrevI != B && !PrevI->definesRegister(BaseReg); --PrevI) + ; + + // The instruction should be a tLEApcrel or t2LEApcrelJT; we want // to delete it as well. - MachineInstr *LeaMI = --PrevI; + MachineInstr *LeaMI = PrevI; if ((LeaMI->getOpcode() != ARM::tLEApcrelJT && LeaMI->getOpcode() != ARM::t2LEApcrelJT) || LeaMI->getOperand(0).getReg() != BaseReg) @@ -1670,7 +1766,7 @@ bool ARMConstantIslands::OptimizeThumb2JumpTables(MachineFunction &MF) { if (!OptOk) continue; - unsigned Opc = ByteOk ? ARM::t2TBB : ARM::t2TBH; + unsigned Opc = ByteOk ? ARM::t2TBB_JT : ARM::t2TBH_JT; MachineInstr *NewJTMI = BuildMI(MBB, MI->getDebugLoc(), TII->get(Opc)) .addReg(IdxReg, getKillRegState(IdxRegKill)) .addJumpTableIndex(JTI, JTOP.getTargetFlags()) @@ -1704,6 +1800,8 @@ bool ARMConstantIslands::ReorderThumb2JumpTables(MachineFunction &MF) { bool MadeChange = false; MachineJumpTableInfo *MJTI = MF.getJumpTableInfo(); + if (MJTI == 0) return false; + const std::vector &JT = MJTI->getJumpTables(); for (unsigned i = 0, e = T2JumpTables.size(); i != e; ++i) { MachineInstr *MI = T2JumpTables[i]; @@ -1743,7 +1841,7 @@ AdjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) { MachineFunction &MF = *BB->getParent(); - // If it's the destination block is terminated by an unconditional branch, + // If the destination block is terminated by an unconditional branch, // try to move it; otherwise, create a new block following the jump // table that branches back to the actual target. This is a very simple // heuristic. FIXME: We can definitely improve it. @@ -1780,7 +1878,7 @@ AdjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) // There doesn't seem to be meaningful DebugInfo available; this doesn't // correspond directly to anything in the source. assert (isThumb2 && "Adjusting for TB[BH] but not in Thumb2?"); - BuildMI(NewBB, DebugLoc::getUnknownLoc(), TII->get(ARM::t2B)).addMBB(BB); + BuildMI(NewBB, DebugLoc(), TII->get(ARM::t2B)).addMBB(BB); // Update internal data structures to account for the newly inserted MBB. MF.RenumberBlocks(NewBB);