| //===-- PPCTargetTransformInfo.cpp - PPC specific TTI ---------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "PPCTargetTransformInfo.h" |
| #include "llvm/Analysis/CodeMetrics.h" |
| #include "llvm/Analysis/TargetTransformInfo.h" |
| #include "llvm/CodeGen/BasicTTIImpl.h" |
| #include "llvm/CodeGen/CostTable.h" |
| #include "llvm/CodeGen/TargetLowering.h" |
| #include "llvm/CodeGen/TargetSchedule.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Debug.h" |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "ppctti" |
| |
| static cl::opt<bool> DisablePPCConstHoist("disable-ppc-constant-hoisting", |
| cl::desc("disable constant hoisting on PPC"), cl::init(false), cl::Hidden); |
| |
| // This is currently only used for the data prefetch pass which is only enabled |
| // for BG/Q by default. |
| static cl::opt<unsigned> |
| CacheLineSize("ppc-loop-prefetch-cache-line", cl::Hidden, cl::init(64), |
| cl::desc("The loop prefetch cache line size")); |
| |
| static cl::opt<bool> |
| EnablePPCColdCC("ppc-enable-coldcc", cl::Hidden, cl::init(false), |
| cl::desc("Enable using coldcc calling conv for cold " |
| "internal functions")); |
| |
| // The latency of mtctr is only justified if there are more than 4 |
| // comparisons that will be removed as a result. |
| static cl::opt<unsigned> |
| SmallCTRLoopThreshold("min-ctr-loop-threshold", cl::init(4), cl::Hidden, |
| cl::desc("Loops with a constant trip count smaller than " |
| "this value will not use the count register.")); |
| |
| //===----------------------------------------------------------------------===// |
| // |
| // PPC cost model. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| TargetTransformInfo::PopcntSupportKind |
| PPCTTIImpl::getPopcntSupport(unsigned TyWidth) { |
| assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2"); |
| if (ST->hasPOPCNTD() != PPCSubtarget::POPCNTD_Unavailable && TyWidth <= 64) |
| return ST->hasPOPCNTD() == PPCSubtarget::POPCNTD_Slow ? |
| TTI::PSK_SlowHardware : TTI::PSK_FastHardware; |
| return TTI::PSK_Software; |
| } |
| |
| int PPCTTIImpl::getIntImmCost(const APInt &Imm, Type *Ty) { |
| if (DisablePPCConstHoist) |
| return BaseT::getIntImmCost(Imm, Ty); |
| |
| assert(Ty->isIntegerTy()); |
| |
| unsigned BitSize = Ty->getPrimitiveSizeInBits(); |
| if (BitSize == 0) |
| return ~0U; |
| |
| if (Imm == 0) |
| return TTI::TCC_Free; |
| |
| if (Imm.getBitWidth() <= 64) { |
| if (isInt<16>(Imm.getSExtValue())) |
| return TTI::TCC_Basic; |
| |
| if (isInt<32>(Imm.getSExtValue())) { |
| // A constant that can be materialized using lis. |
| if ((Imm.getZExtValue() & 0xFFFF) == 0) |
| return TTI::TCC_Basic; |
| |
| return 2 * TTI::TCC_Basic; |
| } |
| } |
| |
| return 4 * TTI::TCC_Basic; |
| } |
| |
| int PPCTTIImpl::getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm, |
| Type *Ty) { |
| if (DisablePPCConstHoist) |
| return BaseT::getIntImmCost(IID, Idx, Imm, Ty); |
| |
| assert(Ty->isIntegerTy()); |
| |
| unsigned BitSize = Ty->getPrimitiveSizeInBits(); |
| if (BitSize == 0) |
| return ~0U; |
| |
| switch (IID) { |
| default: |
| return TTI::TCC_Free; |
| case Intrinsic::sadd_with_overflow: |
| case Intrinsic::uadd_with_overflow: |
| case Intrinsic::ssub_with_overflow: |
| case Intrinsic::usub_with_overflow: |
| if ((Idx == 1) && Imm.getBitWidth() <= 64 && isInt<16>(Imm.getSExtValue())) |
| return TTI::TCC_Free; |
| break; |
| case Intrinsic::experimental_stackmap: |
| if ((Idx < 2) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue()))) |
| return TTI::TCC_Free; |
| break; |
| case Intrinsic::experimental_patchpoint_void: |
| case Intrinsic::experimental_patchpoint_i64: |
| if ((Idx < 4) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue()))) |
| return TTI::TCC_Free; |
| break; |
| } |
| return PPCTTIImpl::getIntImmCost(Imm, Ty); |
| } |
| |
| int PPCTTIImpl::getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm, |
| Type *Ty) { |
| if (DisablePPCConstHoist) |
| return BaseT::getIntImmCost(Opcode, Idx, Imm, Ty); |
| |
| assert(Ty->isIntegerTy()); |
| |
| unsigned BitSize = Ty->getPrimitiveSizeInBits(); |
| if (BitSize == 0) |
| return ~0U; |
| |
| unsigned ImmIdx = ~0U; |
| bool ShiftedFree = false, RunFree = false, UnsignedFree = false, |
| ZeroFree = false; |
| switch (Opcode) { |
| default: |
| return TTI::TCC_Free; |
| case Instruction::GetElementPtr: |
| // Always hoist the base address of a GetElementPtr. This prevents the |
| // creation of new constants for every base constant that gets constant |
| // folded with the offset. |
| if (Idx == 0) |
| return 2 * TTI::TCC_Basic; |
| return TTI::TCC_Free; |
| case Instruction::And: |
| RunFree = true; // (for the rotate-and-mask instructions) |
| LLVM_FALLTHROUGH; |
| case Instruction::Add: |
| case Instruction::Or: |
| case Instruction::Xor: |
| ShiftedFree = true; |
| LLVM_FALLTHROUGH; |
| case Instruction::Sub: |
| case Instruction::Mul: |
| case Instruction::Shl: |
| case Instruction::LShr: |
| case Instruction::AShr: |
| ImmIdx = 1; |
| break; |
| case Instruction::ICmp: |
| UnsignedFree = true; |
| ImmIdx = 1; |
| // Zero comparisons can use record-form instructions. |
| LLVM_FALLTHROUGH; |
| case Instruction::Select: |
| ZeroFree = true; |
| break; |
| case Instruction::PHI: |
| case Instruction::Call: |
| case Instruction::Ret: |
| case Instruction::Load: |
| case Instruction::Store: |
| break; |
| } |
| |
| if (ZeroFree && Imm == 0) |
| return TTI::TCC_Free; |
| |
| if (Idx == ImmIdx && Imm.getBitWidth() <= 64) { |
| if (isInt<16>(Imm.getSExtValue())) |
| return TTI::TCC_Free; |
| |
| if (RunFree) { |
| if (Imm.getBitWidth() <= 32 && |
| (isShiftedMask_32(Imm.getZExtValue()) || |
| isShiftedMask_32(~Imm.getZExtValue()))) |
| return TTI::TCC_Free; |
| |
| if (ST->isPPC64() && |
| (isShiftedMask_64(Imm.getZExtValue()) || |
| isShiftedMask_64(~Imm.getZExtValue()))) |
| return TTI::TCC_Free; |
| } |
| |
| if (UnsignedFree && isUInt<16>(Imm.getZExtValue())) |
| return TTI::TCC_Free; |
| |
| if (ShiftedFree && (Imm.getZExtValue() & 0xFFFF) == 0) |
| return TTI::TCC_Free; |
| } |
| |
| return PPCTTIImpl::getIntImmCost(Imm, Ty); |
| } |
| |
| unsigned PPCTTIImpl::getUserCost(const User *U, |
| ArrayRef<const Value *> Operands) { |
| if (U->getType()->isVectorTy()) { |
| // Instructions that need to be split should cost more. |
| std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, U->getType()); |
| return LT.first * BaseT::getUserCost(U, Operands); |
| } |
| |
| return BaseT::getUserCost(U, Operands); |
| } |
| |
| bool PPCTTIImpl::mightUseCTR(BasicBlock *BB, |
| TargetLibraryInfo *LibInfo) { |
| const PPCTargetMachine &TM = ST->getTargetMachine(); |
| |
| // Loop through the inline asm constraints and look for something that |
| // clobbers ctr. |
| auto asmClobbersCTR = [](InlineAsm *IA) { |
| InlineAsm::ConstraintInfoVector CIV = IA->ParseConstraints(); |
| for (unsigned i = 0, ie = CIV.size(); i < ie; ++i) { |
| InlineAsm::ConstraintInfo &C = CIV[i]; |
| if (C.Type != InlineAsm::isInput) |
| for (unsigned j = 0, je = C.Codes.size(); j < je; ++j) |
| if (StringRef(C.Codes[j]).equals_lower("{ctr}")) |
| return true; |
| } |
| return false; |
| }; |
| |
| // Determining the address of a TLS variable results in a function call in |
| // certain TLS models. |
| std::function<bool(const Value*)> memAddrUsesCTR = |
| [&memAddrUsesCTR, &TM](const Value *MemAddr) -> bool { |
| const auto *GV = dyn_cast<GlobalValue>(MemAddr); |
| if (!GV) { |
| // Recurse to check for constants that refer to TLS global variables. |
| if (const auto *CV = dyn_cast<Constant>(MemAddr)) |
| for (const auto &CO : CV->operands()) |
| if (memAddrUsesCTR(CO)) |
| return true; |
| |
| return false; |
| } |
| |
| if (!GV->isThreadLocal()) |
| return false; |
| TLSModel::Model Model = TM.getTLSModel(GV); |
| return Model == TLSModel::GeneralDynamic || |
| Model == TLSModel::LocalDynamic; |
| }; |
| |
| auto isLargeIntegerTy = [](bool Is32Bit, Type *Ty) { |
| if (IntegerType *ITy = dyn_cast<IntegerType>(Ty)) |
| return ITy->getBitWidth() > (Is32Bit ? 32U : 64U); |
| |
| return false; |
| }; |
| |
| for (BasicBlock::iterator J = BB->begin(), JE = BB->end(); |
| J != JE; ++J) { |
| if (CallInst *CI = dyn_cast<CallInst>(J)) { |
| // Inline ASM is okay, unless it clobbers the ctr register. |
| if (InlineAsm *IA = dyn_cast<InlineAsm>(CI->getCalledValue())) { |
| if (asmClobbersCTR(IA)) |
| return true; |
| continue; |
| } |
| |
| if (Function *F = CI->getCalledFunction()) { |
| // Most intrinsics don't become function calls, but some might. |
| // sin, cos, exp and log are always calls. |
| unsigned Opcode = 0; |
| if (F->getIntrinsicID() != Intrinsic::not_intrinsic) { |
| switch (F->getIntrinsicID()) { |
| default: continue; |
| // If we have a call to ppc_is_decremented_ctr_nonzero, or ppc_mtctr |
| // we're definitely using CTR. |
| case Intrinsic::set_loop_iterations: |
| case Intrinsic::loop_decrement: |
| return true; |
| |
| // VisualStudio defines setjmp as _setjmp |
| #if defined(_MSC_VER) && defined(setjmp) && \ |
| !defined(setjmp_undefined_for_msvc) |
| # pragma push_macro("setjmp") |
| # undef setjmp |
| # define setjmp_undefined_for_msvc |
| #endif |
| |
| case Intrinsic::setjmp: |
| |
| #if defined(_MSC_VER) && defined(setjmp_undefined_for_msvc) |
| // let's return it to _setjmp state |
| # pragma pop_macro("setjmp") |
| # undef setjmp_undefined_for_msvc |
| #endif |
| |
| case Intrinsic::longjmp: |
| |
| // Exclude eh_sjlj_setjmp; we don't need to exclude eh_sjlj_longjmp |
| // because, although it does clobber the counter register, the |
| // control can't then return to inside the loop unless there is also |
| // an eh_sjlj_setjmp. |
| case Intrinsic::eh_sjlj_setjmp: |
| |
| case Intrinsic::memcpy: |
| case Intrinsic::memmove: |
| case Intrinsic::memset: |
| case Intrinsic::powi: |
| case Intrinsic::log: |
| case Intrinsic::log2: |
| case Intrinsic::log10: |
| case Intrinsic::exp: |
| case Intrinsic::exp2: |
| case Intrinsic::pow: |
| case Intrinsic::sin: |
| case Intrinsic::cos: |
| return true; |
| case Intrinsic::copysign: |
| if (CI->getArgOperand(0)->getType()->getScalarType()-> |
| isPPC_FP128Ty()) |
| return true; |
| else |
| continue; // ISD::FCOPYSIGN is never a library call. |
| case Intrinsic::sqrt: Opcode = ISD::FSQRT; break; |
| case Intrinsic::floor: Opcode = ISD::FFLOOR; break; |
| case Intrinsic::ceil: Opcode = ISD::FCEIL; break; |
| case Intrinsic::trunc: Opcode = ISD::FTRUNC; break; |
| case Intrinsic::rint: Opcode = ISD::FRINT; break; |
| case Intrinsic::lrint: Opcode = ISD::LRINT; break; |
| case Intrinsic::llrint: Opcode = ISD::LLRINT; break; |
| case Intrinsic::nearbyint: Opcode = ISD::FNEARBYINT; break; |
| case Intrinsic::round: Opcode = ISD::FROUND; break; |
| case Intrinsic::lround: Opcode = ISD::LROUND; break; |
| case Intrinsic::llround: Opcode = ISD::LLROUND; break; |
| case Intrinsic::minnum: Opcode = ISD::FMINNUM; break; |
| case Intrinsic::maxnum: Opcode = ISD::FMAXNUM; break; |
| case Intrinsic::umul_with_overflow: Opcode = ISD::UMULO; break; |
| case Intrinsic::smul_with_overflow: Opcode = ISD::SMULO; break; |
| } |
| } |
| |
| // PowerPC does not use [US]DIVREM or other library calls for |
| // operations on regular types which are not otherwise library calls |
| // (i.e. soft float or atomics). If adapting for targets that do, |
| // additional care is required here. |
| |
| LibFunc Func; |
| if (!F->hasLocalLinkage() && F->hasName() && LibInfo && |
| LibInfo->getLibFunc(F->getName(), Func) && |
| LibInfo->hasOptimizedCodeGen(Func)) { |
| // Non-read-only functions are never treated as intrinsics. |
| if (!CI->onlyReadsMemory()) |
| return true; |
| |
| // Conversion happens only for FP calls. |
| if (!CI->getArgOperand(0)->getType()->isFloatingPointTy()) |
| return true; |
| |
| switch (Func) { |
| default: return true; |
| case LibFunc_copysign: |
| case LibFunc_copysignf: |
| continue; // ISD::FCOPYSIGN is never a library call. |
| case LibFunc_copysignl: |
| return true; |
| case LibFunc_fabs: |
| case LibFunc_fabsf: |
| case LibFunc_fabsl: |
| continue; // ISD::FABS is never a library call. |
| case LibFunc_sqrt: |
| case LibFunc_sqrtf: |
| case LibFunc_sqrtl: |
| Opcode = ISD::FSQRT; break; |
| case LibFunc_floor: |
| case LibFunc_floorf: |
| case LibFunc_floorl: |
| Opcode = ISD::FFLOOR; break; |
| case LibFunc_nearbyint: |
| case LibFunc_nearbyintf: |
| case LibFunc_nearbyintl: |
| Opcode = ISD::FNEARBYINT; break; |
| case LibFunc_ceil: |
| case LibFunc_ceilf: |
| case LibFunc_ceill: |
| Opcode = ISD::FCEIL; break; |
| case LibFunc_rint: |
| case LibFunc_rintf: |
| case LibFunc_rintl: |
| Opcode = ISD::FRINT; break; |
| case LibFunc_round: |
| case LibFunc_roundf: |
| case LibFunc_roundl: |
| Opcode = ISD::FROUND; break; |
| case LibFunc_trunc: |
| case LibFunc_truncf: |
| case LibFunc_truncl: |
| Opcode = ISD::FTRUNC; break; |
| case LibFunc_fmin: |
| case LibFunc_fminf: |
| case LibFunc_fminl: |
| Opcode = ISD::FMINNUM; break; |
| case LibFunc_fmax: |
| case LibFunc_fmaxf: |
| case LibFunc_fmaxl: |
| Opcode = ISD::FMAXNUM; break; |
| } |
| } |
| |
| if (Opcode) { |
| EVT EVTy = |
| TLI->getValueType(DL, CI->getArgOperand(0)->getType(), true); |
| |
| if (EVTy == MVT::Other) |
| return true; |
| |
| if (TLI->isOperationLegalOrCustom(Opcode, EVTy)) |
| continue; |
| else if (EVTy.isVector() && |
| TLI->isOperationLegalOrCustom(Opcode, EVTy.getScalarType())) |
| continue; |
| |
| return true; |
| } |
| } |
| |
| return true; |
| } else if (isa<BinaryOperator>(J) && |
| J->getType()->getScalarType()->isPPC_FP128Ty()) { |
| // Most operations on ppc_f128 values become calls. |
| return true; |
| } else if (isa<UIToFPInst>(J) || isa<SIToFPInst>(J) || |
| isa<FPToUIInst>(J) || isa<FPToSIInst>(J)) { |
| CastInst *CI = cast<CastInst>(J); |
| if (CI->getSrcTy()->getScalarType()->isPPC_FP128Ty() || |
| CI->getDestTy()->getScalarType()->isPPC_FP128Ty() || |
| isLargeIntegerTy(!TM.isPPC64(), CI->getSrcTy()->getScalarType()) || |
| isLargeIntegerTy(!TM.isPPC64(), CI->getDestTy()->getScalarType())) |
| return true; |
| } else if (isLargeIntegerTy(!TM.isPPC64(), |
| J->getType()->getScalarType()) && |
| (J->getOpcode() == Instruction::UDiv || |
| J->getOpcode() == Instruction::SDiv || |
| J->getOpcode() == Instruction::URem || |
| J->getOpcode() == Instruction::SRem)) { |
| return true; |
| } else if (!TM.isPPC64() && |
| isLargeIntegerTy(false, J->getType()->getScalarType()) && |
| (J->getOpcode() == Instruction::Shl || |
| J->getOpcode() == Instruction::AShr || |
| J->getOpcode() == Instruction::LShr)) { |
| // Only on PPC32, for 128-bit integers (specifically not 64-bit |
| // integers), these might be runtime calls. |
| return true; |
| } else if (isa<IndirectBrInst>(J) || isa<InvokeInst>(J)) { |
| // On PowerPC, indirect jumps use the counter register. |
| return true; |
| } else if (SwitchInst *SI = dyn_cast<SwitchInst>(J)) { |
| if (SI->getNumCases() + 1 >= (unsigned)TLI->getMinimumJumpTableEntries()) |
| return true; |
| } |
| |
| // FREM is always a call. |
| if (J->getOpcode() == Instruction::FRem) |
| return true; |
| |
| if (ST->useSoftFloat()) { |
| switch(J->getOpcode()) { |
| case Instruction::FAdd: |
| case Instruction::FSub: |
| case Instruction::FMul: |
| case Instruction::FDiv: |
| case Instruction::FPTrunc: |
| case Instruction::FPExt: |
| case Instruction::FPToUI: |
| case Instruction::FPToSI: |
| case Instruction::UIToFP: |
| case Instruction::SIToFP: |
| case Instruction::FCmp: |
| return true; |
| } |
| } |
| |
| for (Value *Operand : J->operands()) |
| if (memAddrUsesCTR(Operand)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool PPCTTIImpl::isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE, |
| AssumptionCache &AC, |
| TargetLibraryInfo *LibInfo, |
| HardwareLoopInfo &HWLoopInfo) { |
| const PPCTargetMachine &TM = ST->getTargetMachine(); |
| TargetSchedModel SchedModel; |
| SchedModel.init(ST); |
| |
| // Do not convert small short loops to CTR loop. |
| unsigned ConstTripCount = SE.getSmallConstantTripCount(L); |
| if (ConstTripCount && ConstTripCount < SmallCTRLoopThreshold) { |
| SmallPtrSet<const Value *, 32> EphValues; |
| CodeMetrics::collectEphemeralValues(L, &AC, EphValues); |
| CodeMetrics Metrics; |
| for (BasicBlock *BB : L->blocks()) |
| Metrics.analyzeBasicBlock(BB, *this, EphValues); |
| // 6 is an approximate latency for the mtctr instruction. |
| if (Metrics.NumInsts <= (6 * SchedModel.getIssueWidth())) |
| return false; |
| } |
| |
| // We don't want to spill/restore the counter register, and so we don't |
| // want to use the counter register if the loop contains calls. |
| for (Loop::block_iterator I = L->block_begin(), IE = L->block_end(); |
| I != IE; ++I) |
| if (mightUseCTR(*I, LibInfo)) |
| return false; |
| |
| SmallVector<BasicBlock*, 4> ExitingBlocks; |
| L->getExitingBlocks(ExitingBlocks); |
| |
| // If there is an exit edge known to be frequently taken, |
| // we should not transform this loop. |
| for (auto &BB : ExitingBlocks) { |
| Instruction *TI = BB->getTerminator(); |
| if (!TI) continue; |
| |
| if (BranchInst *BI = dyn_cast<BranchInst>(TI)) { |
| uint64_t TrueWeight = 0, FalseWeight = 0; |
| if (!BI->isConditional() || |
| !BI->extractProfMetadata(TrueWeight, FalseWeight)) |
| continue; |
| |
| // If the exit path is more frequent than the loop path, |
| // we return here without further analysis for this loop. |
| bool TrueIsExit = !L->contains(BI->getSuccessor(0)); |
| if (( TrueIsExit && FalseWeight < TrueWeight) || |
| (!TrueIsExit && FalseWeight > TrueWeight)) |
| return false; |
| } |
| } |
| |
| LLVMContext &C = L->getHeader()->getContext(); |
| HWLoopInfo.CountType = TM.isPPC64() ? |
| Type::getInt64Ty(C) : Type::getInt32Ty(C); |
| HWLoopInfo.LoopDecrement = ConstantInt::get(HWLoopInfo.CountType, 1); |
| return true; |
| } |
| |
| void PPCTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE, |
| TTI::UnrollingPreferences &UP) { |
| if (ST->getDarwinDirective() == PPC::DIR_A2) { |
| // The A2 is in-order with a deep pipeline, and concatenation unrolling |
| // helps expose latency-hiding opportunities to the instruction scheduler. |
| UP.Partial = UP.Runtime = true; |
| |
| // We unroll a lot on the A2 (hundreds of instructions), and the benefits |
| // often outweigh the cost of a division to compute the trip count. |
| UP.AllowExpensiveTripCount = true; |
| } |
| |
| BaseT::getUnrollingPreferences(L, SE, UP); |
| } |
| |
| // This function returns true to allow using coldcc calling convention. |
| // Returning true results in coldcc being used for functions which are cold at |
| // all call sites when the callers of the functions are not calling any other |
| // non coldcc functions. |
| bool PPCTTIImpl::useColdCCForColdCall(Function &F) { |
| return EnablePPCColdCC; |
| } |
| |
| bool PPCTTIImpl::enableAggressiveInterleaving(bool LoopHasReductions) { |
| // On the A2, always unroll aggressively. For QPX unaligned loads, we depend |
| // on combining the loads generated for consecutive accesses, and failure to |
| // do so is particularly expensive. This makes it much more likely (compared |
| // to only using concatenation unrolling). |
| if (ST->getDarwinDirective() == PPC::DIR_A2) |
| return true; |
| |
| return LoopHasReductions; |
| } |
| |
| PPCTTIImpl::TTI::MemCmpExpansionOptions |
| PPCTTIImpl::enableMemCmpExpansion(bool OptSize, bool IsZeroCmp) const { |
| TTI::MemCmpExpansionOptions Options; |
| Options.LoadSizes = {8, 4, 2, 1}; |
| Options.MaxNumLoads = TLI->getMaxExpandSizeMemcmp(OptSize); |
| return Options; |
| } |
| |
| bool PPCTTIImpl::enableInterleavedAccessVectorization() { |
| return true; |
| } |
| |
| unsigned PPCTTIImpl::getNumberOfRegisters(bool Vector) { |
| if (Vector && !ST->hasAltivec() && !ST->hasQPX()) |
| return 0; |
| return ST->hasVSX() ? 64 : 32; |
| } |
| |
| unsigned PPCTTIImpl::getRegisterBitWidth(bool Vector) const { |
| if (Vector) { |
| if (ST->hasQPX()) return 256; |
| if (ST->hasAltivec()) return 128; |
| return 0; |
| } |
| |
| if (ST->isPPC64()) |
| return 64; |
| return 32; |
| |
| } |
| |
| unsigned PPCTTIImpl::getCacheLineSize() { |
| // Check first if the user specified a custom line size. |
| if (CacheLineSize.getNumOccurrences() > 0) |
| return CacheLineSize; |
| |
| // On P7, P8 or P9 we have a cache line size of 128. |
| unsigned Directive = ST->getDarwinDirective(); |
| if (Directive == PPC::DIR_PWR7 || Directive == PPC::DIR_PWR8 || |
| Directive == PPC::DIR_PWR9) |
| return 128; |
| |
| // On other processors return a default of 64 bytes. |
| return 64; |
| } |
| |
| unsigned PPCTTIImpl::getPrefetchDistance() { |
| // This seems like a reasonable default for the BG/Q (this pass is enabled, by |
| // default, only on the BG/Q). |
| return 300; |
| } |
| |
| unsigned PPCTTIImpl::getMaxInterleaveFactor(unsigned VF) { |
| unsigned Directive = ST->getDarwinDirective(); |
| // The 440 has no SIMD support, but floating-point instructions |
| // have a 5-cycle latency, so unroll by 5x for latency hiding. |
| if (Directive == PPC::DIR_440) |
| return 5; |
| |
| // The A2 has no SIMD support, but floating-point instructions |
| // have a 6-cycle latency, so unroll by 6x for latency hiding. |
| if (Directive == PPC::DIR_A2) |
| return 6; |
| |
| // FIXME: For lack of any better information, do no harm... |
| if (Directive == PPC::DIR_E500mc || Directive == PPC::DIR_E5500) |
| return 1; |
| |
| // For P7 and P8, floating-point instructions have a 6-cycle latency and |
| // there are two execution units, so unroll by 12x for latency hiding. |
| // FIXME: the same for P9 as previous gen until POWER9 scheduling is ready |
| if (Directive == PPC::DIR_PWR7 || Directive == PPC::DIR_PWR8 || |
| Directive == PPC::DIR_PWR9) |
| return 12; |
| |
| // For most things, modern systems have two execution units (and |
| // out-of-order execution). |
| return 2; |
| } |
| |
| // Adjust the cost of vector instructions on targets which there is overlap |
| // between the vector and scalar units, thereby reducing the overall throughput |
| // of vector code wrt. scalar code. |
| int PPCTTIImpl::vectorCostAdjustment(int Cost, unsigned Opcode, Type *Ty1, |
| Type *Ty2) { |
| if (!ST->vectorsUseTwoUnits() || !Ty1->isVectorTy()) |
| return Cost; |
| |
| std::pair<int, MVT> LT1 = TLI->getTypeLegalizationCost(DL, Ty1); |
| // If type legalization involves splitting the vector, we don't want to |
| // double the cost at every step - only the last step. |
| if (LT1.first != 1 || !LT1.second.isVector()) |
| return Cost; |
| |
| int ISD = TLI->InstructionOpcodeToISD(Opcode); |
| if (TLI->isOperationExpand(ISD, LT1.second)) |
| return Cost; |
| |
| if (Ty2) { |
| std::pair<int, MVT> LT2 = TLI->getTypeLegalizationCost(DL, Ty2); |
| if (LT2.first != 1 || !LT2.second.isVector()) |
| return Cost; |
| } |
| |
| return Cost * 2; |
| } |
| |
| int PPCTTIImpl::getArithmeticInstrCost( |
| unsigned Opcode, Type *Ty, TTI::OperandValueKind Op1Info, |
| TTI::OperandValueKind Op2Info, TTI::OperandValueProperties Opd1PropInfo, |
| TTI::OperandValueProperties Opd2PropInfo, ArrayRef<const Value *> Args) { |
| assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode"); |
| |
| // Fallback to the default implementation. |
| int Cost = BaseT::getArithmeticInstrCost(Opcode, Ty, Op1Info, Op2Info, |
| Opd1PropInfo, Opd2PropInfo); |
| return vectorCostAdjustment(Cost, Opcode, Ty, nullptr); |
| } |
| |
| int PPCTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, int Index, |
| Type *SubTp) { |
| // Legalize the type. |
| std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, Tp); |
| |
| // PPC, for both Altivec/VSX and QPX, support cheap arbitrary permutations |
| // (at least in the sense that there need only be one non-loop-invariant |
| // instruction). We need one such shuffle instruction for each actual |
| // register (this is not true for arbitrary shuffles, but is true for the |
| // structured types of shuffles covered by TTI::ShuffleKind). |
| return vectorCostAdjustment(LT.first, Instruction::ShuffleVector, Tp, |
| nullptr); |
| } |
| |
| int PPCTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src, |
| const Instruction *I) { |
| assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode"); |
| |
| int Cost = BaseT::getCastInstrCost(Opcode, Dst, Src); |
| return vectorCostAdjustment(Cost, Opcode, Dst, Src); |
| } |
| |
| int PPCTTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy, |
| const Instruction *I) { |
| int Cost = BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, I); |
| return vectorCostAdjustment(Cost, Opcode, ValTy, nullptr); |
| } |
| |
| int PPCTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) { |
| assert(Val->isVectorTy() && "This must be a vector type"); |
| |
| int ISD = TLI->InstructionOpcodeToISD(Opcode); |
| assert(ISD && "Invalid opcode"); |
| |
| int Cost = BaseT::getVectorInstrCost(Opcode, Val, Index); |
| Cost = vectorCostAdjustment(Cost, Opcode, Val, nullptr); |
| |
| if (ST->hasVSX() && Val->getScalarType()->isDoubleTy()) { |
| // Double-precision scalars are already located in index #0 (or #1 if LE). |
| if (ISD == ISD::EXTRACT_VECTOR_ELT && |
| Index == (ST->isLittleEndian() ? 1 : 0)) |
| return 0; |
| |
| return Cost; |
| |
| } else if (ST->hasQPX() && Val->getScalarType()->isFloatingPointTy()) { |
| // Floating point scalars are already located in index #0. |
| if (Index == 0) |
| return 0; |
| |
| return Cost; |
| } |
| |
| // Estimated cost of a load-hit-store delay. This was obtained |
| // experimentally as a minimum needed to prevent unprofitable |
| // vectorization for the paq8p benchmark. It may need to be |
| // raised further if other unprofitable cases remain. |
| unsigned LHSPenalty = 2; |
| if (ISD == ISD::INSERT_VECTOR_ELT) |
| LHSPenalty += 7; |
| |
| // Vector element insert/extract with Altivec is very expensive, |
| // because they require store and reload with the attendant |
| // processor stall for load-hit-store. Until VSX is available, |
| // these need to be estimated as very costly. |
| if (ISD == ISD::EXTRACT_VECTOR_ELT || |
| ISD == ISD::INSERT_VECTOR_ELT) |
| return LHSPenalty + Cost; |
| |
| return Cost; |
| } |
| |
| int PPCTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment, |
| unsigned AddressSpace, const Instruction *I) { |
| // Legalize the type. |
| std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, Src); |
| assert((Opcode == Instruction::Load || Opcode == Instruction::Store) && |
| "Invalid Opcode"); |
| |
| int Cost = BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace); |
| Cost = vectorCostAdjustment(Cost, Opcode, Src, nullptr); |
| |
| bool IsAltivecType = ST->hasAltivec() && |
| (LT.second == MVT::v16i8 || LT.second == MVT::v8i16 || |
| LT.second == MVT::v4i32 || LT.second == MVT::v4f32); |
| bool IsVSXType = ST->hasVSX() && |
| (LT.second == MVT::v2f64 || LT.second == MVT::v2i64); |
| bool IsQPXType = ST->hasQPX() && |
| (LT.second == MVT::v4f64 || LT.second == MVT::v4f32); |
| |
| // VSX has 32b/64b load instructions. Legalization can handle loading of |
| // 32b/64b to VSR correctly and cheaply. But BaseT::getMemoryOpCost and |
| // PPCTargetLowering can't compute the cost appropriately. So here we |
| // explicitly check this case. |
| unsigned MemBytes = Src->getPrimitiveSizeInBits(); |
| if (Opcode == Instruction::Load && ST->hasVSX() && IsAltivecType && |
| (MemBytes == 64 || (ST->hasP8Vector() && MemBytes == 32))) |
| return 1; |
| |
| // Aligned loads and stores are easy. |
| unsigned SrcBytes = LT.second.getStoreSize(); |
| if (!SrcBytes || !Alignment || Alignment >= SrcBytes) |
| return Cost; |
| |
| // If we can use the permutation-based load sequence, then this is also |
| // relatively cheap (not counting loop-invariant instructions): one load plus |
| // one permute (the last load in a series has extra cost, but we're |
| // neglecting that here). Note that on the P7, we could do unaligned loads |
| // for Altivec types using the VSX instructions, but that's more expensive |
| // than using the permutation-based load sequence. On the P8, that's no |
| // longer true. |
| if (Opcode == Instruction::Load && |
| ((!ST->hasP8Vector() && IsAltivecType) || IsQPXType) && |
| Alignment >= LT.second.getScalarType().getStoreSize()) |
| return Cost + LT.first; // Add the cost of the permutations. |
| |
| // For VSX, we can do unaligned loads and stores on Altivec/VSX types. On the |
| // P7, unaligned vector loads are more expensive than the permutation-based |
| // load sequence, so that might be used instead, but regardless, the net cost |
| // is about the same (not counting loop-invariant instructions). |
| if (IsVSXType || (ST->hasVSX() && IsAltivecType)) |
| return Cost; |
| |
| // Newer PPC supports unaligned memory access. |
| if (TLI->allowsMisalignedMemoryAccesses(LT.second, 0)) |
| return Cost; |
| |
| // PPC in general does not support unaligned loads and stores. They'll need |
| // to be decomposed based on the alignment factor. |
| |
| // Add the cost of each scalar load or store. |
| Cost += LT.first*(SrcBytes/Alignment-1); |
| |
| // For a vector type, there is also scalarization overhead (only for |
| // stores, loads are expanded using the vector-load + permutation sequence, |
| // which is much less expensive). |
| if (Src->isVectorTy() && Opcode == Instruction::Store) |
| for (int i = 0, e = Src->getVectorNumElements(); i < e; ++i) |
| Cost += getVectorInstrCost(Instruction::ExtractElement, Src, i); |
| |
| return Cost; |
| } |
| |
| int PPCTTIImpl::getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy, |
| unsigned Factor, |
| ArrayRef<unsigned> Indices, |
| unsigned Alignment, |
| unsigned AddressSpace, |
| bool UseMaskForCond, |
| bool UseMaskForGaps) { |
| if (UseMaskForCond || UseMaskForGaps) |
| return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices, |
| Alignment, AddressSpace, |
| UseMaskForCond, UseMaskForGaps); |
| |
| assert(isa<VectorType>(VecTy) && |
| "Expect a vector type for interleaved memory op"); |
| |
| // Legalize the type. |
| std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, VecTy); |
| |
| // Firstly, the cost of load/store operation. |
| int Cost = getMemoryOpCost(Opcode, VecTy, Alignment, AddressSpace); |
| |
| // PPC, for both Altivec/VSX and QPX, support cheap arbitrary permutations |
| // (at least in the sense that there need only be one non-loop-invariant |
| // instruction). For each result vector, we need one shuffle per incoming |
| // vector (except that the first shuffle can take two incoming vectors |
| // because it does not need to take itself). |
| Cost += Factor*(LT.first-1); |
| |
| return Cost; |
| } |
| |
| bool PPCTTIImpl::canSaveCmp(Loop *L, BranchInst **BI, ScalarEvolution *SE, |
| LoopInfo *LI, DominatorTree *DT, |
| AssumptionCache *AC, TargetLibraryInfo *LibInfo) { |
| // Process nested loops first. |
| for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I) |
| if (canSaveCmp(*I, BI, SE, LI, DT, AC, LibInfo)) |
| return false; // Stop search. |
| |
| HardwareLoopInfo HWLoopInfo(L); |
| |
| if (!HWLoopInfo.canAnalyze(*LI)) |
| return false; |
| |
| if (!isHardwareLoopProfitable(L, *SE, *AC, LibInfo, HWLoopInfo)) |
| return false; |
| |
| if (!HWLoopInfo.isHardwareLoopCandidate(*SE, *LI, *DT)) |
| return false; |
| |
| *BI = HWLoopInfo.ExitBranch; |
| return true; |
| } |
