X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;ds=sidebyside;f=lib%2FTarget%2FARM%2FARMConstantIslandPass.cpp;h=29405eb65d52757aaa14541ef4adac4d2637e6f3;hb=8bca5de6a99a9c9ad682d844a34afeffb438ae41;hp=4891609b336f93fa80c682b57f41b59d5380b99c;hpb=b300455b5817f099d64aad8f9356e0e23fa9a87e;p=oota-llvm.git diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp index 4891609b336..29405eb65d5 100644 --- a/lib/Target/ARM/ARMConstantIslandPass.cpp +++ b/lib/Target/ARM/ARMConstantIslandPass.cpp @@ -13,7 +13,6 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "arm-cp-islands" #include "ARM.h" #include "ARMMachineFunctionInfo.h" #include "MCTargetDesc/ARMAddressingModes.h" @@ -36,6 +35,8 @@ #include using namespace llvm; +#define DEBUG_TYPE "arm-cp-islands" + STATISTIC(NumCPEs, "Number of constpool entries"); STATISTIC(NumSplit, "Number of uncond branches inserted"); STATISTIC(NumCBrFixed, "Number of cond branches fixed"); @@ -128,7 +129,7 @@ namespace { // If the block size isn't a multiple of the known bits, assume the // worst case padding. if (Size & ((1u << Bits) - 1)) - Bits = CountTrailingZeros_32(Size); + Bits = countTrailingZeros(Size); return Bits; } @@ -266,14 +267,15 @@ namespace { static char ID; ARMConstantIslands() : MachineFunctionPass(ID) {} - virtual bool runOnMachineFunction(MachineFunction &MF); + bool runOnMachineFunction(MachineFunction &MF) override; - virtual const char *getPassName() const { + const char *getPassName() const override { return "ARM constant island placement and branch shortening pass"; } private: void doInitialPlacement(std::vector &CPEMIs); + bool BBHasFallthrough(MachineBasicBlock *MBB); CPEntry *findConstPoolEntry(unsigned CPI, const MachineInstr *CPEMI); unsigned getCPELogAlign(const MachineInstr *CPEMI); void scanFunctionJumpTables(); @@ -381,7 +383,9 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) { << MCP->getConstants().size() << " CP entries, aligned to " << MCP->getConstantPoolAlignment() << " bytes *****\n"); - TII = (const ARMBaseInstrInfo*)MF->getTarget().getInstrInfo(); + TII = (const ARMBaseInstrInfo *)MF->getTarget() + .getSubtargetImpl() + ->getInstrInfo(); AFI = MF->getInfo(); STI = &MF->getTarget().getSubtarget(); @@ -528,7 +532,7 @@ ARMConstantIslands::doInitialPlacement(std::vector &CPEMIs) { // identity mapping of CPI's to CPE's. const std::vector &CPs = MCP->getConstants(); - const DataLayout &TD = *MF->getTarget().getDataLayout(); + const DataLayout &TD = *MF->getSubtarget().getDataLayout(); for (unsigned i = 0, e = CPs.size(); i != e; ++i) { unsigned Size = TD.getTypeAllocSize(CPs[i].getType()); assert(Size >= 4 && "Too small constant pool entry"); @@ -553,9 +557,7 @@ ARMConstantIslands::doInitialPlacement(std::vector &CPEMIs) { InsPoint[a] = CPEMI; // Add a new CPEntry, but no corresponding CPUser yet. - std::vector CPEs; - CPEs.push_back(CPEntry(CPEMI, i)); - CPEntries.push_back(CPEs); + CPEntries.emplace_back(1, CPEntry(CPEMI, i)); ++NumCPEs; DEBUG(dbgs() << "Moved CPI#" << i << " to end of function, size = " << Size << ", align = " << Align <<'\n'); @@ -565,20 +567,23 @@ ARMConstantIslands::doInitialPlacement(std::vector &CPEMIs) { /// BBHasFallthrough - Return true if the specified basic block can fallthrough /// into the block immediately after it. -static bool BBHasFallthrough(MachineBasicBlock *MBB) { +bool ARMConstantIslands::BBHasFallthrough(MachineBasicBlock *MBB) { // Get the next machine basic block in the function. MachineFunction::iterator MBBI = MBB; // Can't fall off end of function. - if (llvm::next(MBBI) == MBB->getParent()->end()) + if (std::next(MBBI) == MBB->getParent()->end()) return false; - MachineBasicBlock *NextBB = llvm::next(MBBI); - for (MachineBasicBlock::succ_iterator I = MBB->succ_begin(), - E = MBB->succ_end(); I != E; ++I) - if (*I == NextBB) - return true; + MachineBasicBlock *NextBB = std::next(MBBI); + if (std::find(MBB->succ_begin(), MBB->succ_end(), NextBB) == MBB->succ_end()) + return false; - return false; + // Try to analyze the end of the block. A potential fallthrough may already + // have an unconditional branch for whatever reason. + MachineBasicBlock *TBB, *FBB; + SmallVector Cond; + bool TooDifficult = TII->AnalyzeBranch(*MBB, TBB, FBB, Cond); + return TooDifficult || FBB == nullptr; } /// findConstPoolEntry - Given the constpool index and CONSTPOOL_ENTRY MI, @@ -593,7 +598,7 @@ ARMConstantIslands::CPEntry if (CPEs[i].CPEMI == CPEMI) return &CPEs[i]; } - return NULL; + return nullptr; } /// getCPELogAlign - Returns the required alignment of the constant pool entry @@ -753,6 +758,7 @@ initializeFunctionInfo(const std::vector &CPEMIs) { Scale = 4; break; + case ARM::LDRBi12: case ARM::LDRi12: case ARM::LDRcp: case ARM::t2LDRpci: @@ -916,7 +922,7 @@ MachineBasicBlock *ARMConstantIslands::splitBlockBeforeInstr(MachineInstr *MI) { CompareMBBNumbers); MachineBasicBlock* WaterBB = *IP; if (WaterBB == OrigBB) - WaterList.insert(llvm::next(IP), NewBB); + WaterList.insert(std::next(IP), NewBB); else WaterList.insert(IP, OrigBB); NewWaterList.insert(OrigBB); @@ -1101,7 +1107,7 @@ bool ARMConstantIslands::decrementCPEReferenceCount(unsigned CPI, assert(CPE && "Unexpected!"); if (--CPE->RefCount == 0) { removeDeadCPEMI(CPEMI); - CPE->CPEMI = NULL; + CPE->CPEMI = nullptr; --NumCPEs; return true; } @@ -1134,7 +1140,7 @@ int ARMConstantIslands::findInRangeCPEntry(CPUser& U, unsigned UserOffset) if (CPEs[i].CPEMI == CPEMI) continue; // Removing CPEs can leave empty entries, skip - if (CPEs[i].CPEMI == NULL) + if (CPEs[i].CPEMI == nullptr) continue; if (isCPEntryInRange(UserMI, UserOffset, CPEs[i].CPEMI, U.getMaxDisp(), U.NegOk)) { @@ -1187,7 +1193,7 @@ bool ARMConstantIslands::findAvailableWater(CPUser &U, unsigned UserOffset, return false; unsigned BestGrowth = ~0u; - for (water_iterator IP = prior(WaterList.end()), B = WaterList.begin();; + for (water_iterator IP = std::prev(WaterList.end()), B = WaterList.begin();; --IP) { MachineBasicBlock* WaterBB = *IP; // Check if water is in range and is either at a lower address than the @@ -1201,7 +1207,8 @@ bool ARMConstantIslands::findAvailableWater(CPUser &U, unsigned UserOffset, unsigned Growth; if (isWaterInRange(UserOffset, WaterBB, U, Growth) && (WaterBB->getNumber() < U.HighWaterMark->getNumber() || - NewWaterList.count(WaterBB)) && Growth < BestGrowth) { + NewWaterList.count(WaterBB) || WaterBB == U.MI->getParent()) && + Growth < BestGrowth) { // This is the least amount of required padding seen so far. BestGrowth = Growth; WaterIter = IP; @@ -1248,7 +1255,7 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex, if (isOffsetInRange(UserOffset, CPEOffset, U)) { DEBUG(dbgs() << "Split at end of BB#" << UserMBB->getNumber() << format(", expected CPE offset %#x\n", CPEOffset)); - NewMBB = llvm::next(MachineFunction::iterator(UserMBB)); + NewMBB = std::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 @@ -1307,7 +1314,12 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex, // Back past any possible branches (allow for a conditional and a maximally // long unconditional). if (BaseInsertOffset + 8 >= UserBBI.postOffset()) { - BaseInsertOffset = UserBBI.postOffset() - UPad - 8; + // Ensure BaseInsertOffset is larger than the offset of the instruction + // following UserMI so that the loop which searches for the split point + // iterates at least once. + BaseInsertOffset = + std::max(UserBBI.postOffset() - UPad - 8, + UserOffset + TII->GetInstSizeInBytes(UserMI) + 1); DEBUG(dbgs() << format("Move inside block: %#x\n", BaseInsertOffset)); } unsigned EndInsertOffset = BaseInsertOffset + 4 + UPad + @@ -1316,11 +1328,10 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex, ++MI; unsigned CPUIndex = CPUserIndex+1; unsigned NumCPUsers = CPUsers.size(); - MachineInstr *LastIT = 0; + MachineInstr *LastIT = nullptr; for (unsigned Offset = UserOffset+TII->GetInstSizeInBytes(UserMI); Offset < BaseInsertOffset; - Offset += TII->GetInstSizeInBytes(MI), - MI = llvm::next(MI)) { + Offset += TII->GetInstSizeInBytes(MI), MI = std::next(MI)) { assert(MI != UserMBB->end() && "Fell off end of block"); if (CPUIndex < NumCPUsers && CPUsers[CPUIndex].MI == MI) { CPUser &U = CPUsers[CPUIndex]; @@ -1351,6 +1362,11 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex, if (CC != ARMCC::AL) MI = LastIT; } + + // We really must not split an IT block. + DEBUG(unsigned PredReg; + assert(!isThumb || getITInstrPredicate(MI, PredReg) == ARMCC::AL)); + NewMBB = splitBlockBeforeInstr(MI); } @@ -1392,7 +1408,7 @@ bool ARMConstantIslands::handleConstantPoolUser(unsigned CPUserIndex) { NewWaterList.insert(NewIsland); // The new CPE goes before the following block (NewMBB). - NewMBB = llvm::next(MachineFunction::iterator(WaterBB)); + NewMBB = std::next(MachineFunction::iterator(WaterBB)); } else { // No water found. @@ -1404,7 +1420,7 @@ bool ARMConstantIslands::handleConstantPoolUser(unsigned CPUserIndex) { // next iteration for constant pools, but in this context, we don't want // it. Check for this so it will be removed from the WaterList. // Also remove any entry from NewWaterList. - MachineBasicBlock *WaterBB = prior(MachineFunction::iterator(NewMBB)); + MachineBasicBlock *WaterBB = std::prev(MachineFunction::iterator(NewMBB)); IP = std::find(WaterList.begin(), WaterList.end(), WaterBB); if (IP != WaterList.end()) NewWaterList.erase(WaterBB); @@ -1442,7 +1458,7 @@ bool ARMConstantIslands::handleConstantPoolUser(unsigned CPUserIndex) { // Increase the size of the island block to account for the new entry. BBInfo[NewIsland->getNumber()].Size += Size; - adjustBBOffsetsAfter(llvm::prior(MachineFunction::iterator(NewIsland))); + adjustBBOffsetsAfter(std::prev(MachineFunction::iterator(NewIsland))); // Finally, change the CPI in the instruction operand to be ID. for (unsigned i = 0, e = UserMI->getNumOperands(); i != e; ++i) @@ -1491,7 +1507,7 @@ bool ARMConstantIslands::removeUnusedCPEntries() { for (unsigned j = 0, ee = CPEs.size(); j != ee; ++j) { if (CPEs[j].RefCount == 0 && CPEs[j].CPEMI) { removeDeadCPEMI(CPEs[j].CPEMI); - CPEs[j].CPEMI = NULL; + CPEs[j].CPEMI = nullptr; MadeChange = true; } } @@ -1591,7 +1607,7 @@ ARMConstantIslands::fixupConditionalBr(ImmBranch &Br) { ++NumCBrFixed; if (BMI != MI) { - if (llvm::next(MachineBasicBlock::iterator(MI)) == prior(MBB->end()) && + if (std::next(MachineBasicBlock::iterator(MI)) == std::prev(MBB->end()) && BMI->getOpcode() == Br.UncondBr) { // Last MI in the BB is an unconditional branch. Can we simply invert the // condition and swap destinations: @@ -1621,7 +1637,7 @@ ARMConstantIslands::fixupConditionalBr(ImmBranch &Br) { MBB->back().eraseFromParent(); // BBInfo[SplitBB].Offset is wrong temporarily, fixed below } - MachineBasicBlock *NextBB = llvm::next(MachineFunction::iterator(MBB)); + MachineBasicBlock *NextBB = std::next(MachineFunction::iterator(MBB)); DEBUG(dbgs() << " Insert B to BB#" << DestBB->getNumber() << " also invert condition and change dest. to BB#" @@ -1844,7 +1860,7 @@ bool ARMConstantIslands::optimizeThumb2JumpTables() { // FIXME: After the tables are shrunk, can we get rid some of the // constantpool tables? MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); - if (MJTI == 0) return false; + if (!MJTI) return false; const std::vector &JT = MJTI->getJumpTables(); for (unsigned i = 0, e = T2JumpTables.size(); i != e; ++i) { @@ -1970,7 +1986,7 @@ bool ARMConstantIslands::reorderThumb2JumpTables() { bool MadeChange = false; MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); - if (MJTI == 0) return false; + if (!MJTI) return false; const std::vector &JT = MJTI->getJumpTables(); for (unsigned i = 0, e = T2JumpTables.size(); i != e; ++i) { @@ -2012,11 +2028,11 @@ adjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) { // 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. - MachineBasicBlock *TBB = 0, *FBB = 0; + MachineBasicBlock *TBB = nullptr, *FBB = nullptr; SmallVector Cond; SmallVector CondPrior; MachineFunction::iterator BBi = BB; - MachineFunction::iterator OldPrior = prior(BBi); + MachineFunction::iterator OldPrior = std::prev(BBi); // If the block terminator isn't analyzable, don't try to move the block bool B = TII->AnalyzeBranch(*BB, TBB, FBB, Cond); @@ -2032,7 +2048,7 @@ adjustJTTargetBlockForward(MachineBasicBlock *BB, MachineBasicBlock *JTBB) { // Update numbering to account for the block being moved. MF->RenumberBlocks(); ++NumJTMoved; - return NULL; + return nullptr; } // Create a new MBB for the code after the jump BB.