//===-- 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/TargetLibraryInfo.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/IR/IntrinsicsPowerPC.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/KnownBits.h" #include "llvm/Transforms/InstCombine/InstCombiner.h" #include "llvm/Transforms/Utils/Local.h" using namespace llvm; #define DEBUG_TYPE "ppctti" static cl::opt 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 static cl::opt CacheLineSize("ppc-loop-prefetch-cache-line", cl::Hidden, cl::init(64), cl::desc("The loop prefetch cache line size")); static cl::opt EnablePPCColdCC("ppc-enable-coldcc", cl::Hidden, cl::init(false), cl::desc("Enable using coldcc calling conv for cold " "internal functions")); static cl::opt LsrNoInsnsCost("ppc-lsr-no-insns-cost", cl::Hidden, cl::init(false), cl::desc("Do not add instruction count to lsr cost model")); // The latency of mtctr is only justified if there are more than 4 // comparisons that will be removed as a result. static cl::opt 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; } Optional PPCTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const { Intrinsic::ID IID = II.getIntrinsicID(); switch (IID) { default: break; case Intrinsic::ppc_altivec_lvx: case Intrinsic::ppc_altivec_lvxl: // Turn PPC lvx -> load if the pointer is known aligned. if (getOrEnforceKnownAlignment( II.getArgOperand(0), Align(16), IC.getDataLayout(), &II, &IC.getAssumptionCache(), &IC.getDominatorTree()) >= 16) { Value *Ptr = IC.Builder.CreateBitCast( II.getArgOperand(0), PointerType::getUnqual(II.getType())); return new LoadInst(II.getType(), Ptr, "", false, Align(16)); } break; case Intrinsic::ppc_vsx_lxvw4x: case Intrinsic::ppc_vsx_lxvd2x: { // Turn PPC VSX loads into normal loads. Value *Ptr = IC.Builder.CreateBitCast(II.getArgOperand(0), PointerType::getUnqual(II.getType())); return new LoadInst(II.getType(), Ptr, Twine(""), false, Align(1)); } case Intrinsic::ppc_altivec_stvx: case Intrinsic::ppc_altivec_stvxl: // Turn stvx -> store if the pointer is known aligned. if (getOrEnforceKnownAlignment( II.getArgOperand(1), Align(16), IC.getDataLayout(), &II, &IC.getAssumptionCache(), &IC.getDominatorTree()) >= 16) { Type *OpPtrTy = PointerType::getUnqual(II.getArgOperand(0)->getType()); Value *Ptr = IC.Builder.CreateBitCast(II.getArgOperand(1), OpPtrTy); return new StoreInst(II.getArgOperand(0), Ptr, false, Align(16)); } break; case Intrinsic::ppc_vsx_stxvw4x: case Intrinsic::ppc_vsx_stxvd2x: { // Turn PPC VSX stores into normal stores. Type *OpPtrTy = PointerType::getUnqual(II.getArgOperand(0)->getType()); Value *Ptr = IC.Builder.CreateBitCast(II.getArgOperand(1), OpPtrTy); return new StoreInst(II.getArgOperand(0), Ptr, false, Align(1)); } case Intrinsic::ppc_altivec_vperm: // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant. // Note that ppc_altivec_vperm has a big-endian bias, so when creating // a vectorshuffle for little endian, we must undo the transformation // performed on vec_perm in altivec.h. That is, we must complement // the permutation mask with respect to 31 and reverse the order of // V1 and V2. if (Constant *Mask = dyn_cast(II.getArgOperand(2))) { assert(cast(Mask->getType())->getNumElements() == 16 && "Bad type for intrinsic!"); // Check that all of the elements are integer constants or undefs. bool AllEltsOk = true; for (unsigned i = 0; i != 16; ++i) { Constant *Elt = Mask->getAggregateElement(i); if (!Elt || !(isa(Elt) || isa(Elt))) { AllEltsOk = false; break; } } if (AllEltsOk) { // Cast the input vectors to byte vectors. Value *Op0 = IC.Builder.CreateBitCast(II.getArgOperand(0), Mask->getType()); Value *Op1 = IC.Builder.CreateBitCast(II.getArgOperand(1), Mask->getType()); Value *Result = UndefValue::get(Op0->getType()); // Only extract each element once. Value *ExtractedElts[32]; memset(ExtractedElts, 0, sizeof(ExtractedElts)); for (unsigned i = 0; i != 16; ++i) { if (isa(Mask->getAggregateElement(i))) continue; unsigned Idx = cast(Mask->getAggregateElement(i))->getZExtValue(); Idx &= 31; // Match the hardware behavior. if (DL.isLittleEndian()) Idx = 31 - Idx; if (!ExtractedElts[Idx]) { Value *Op0ToUse = (DL.isLittleEndian()) ? Op1 : Op0; Value *Op1ToUse = (DL.isLittleEndian()) ? Op0 : Op1; ExtractedElts[Idx] = IC.Builder.CreateExtractElement( Idx < 16 ? Op0ToUse : Op1ToUse, IC.Builder.getInt32(Idx & 15)); } // Insert this value into the result vector. Result = IC.Builder.CreateInsertElement(Result, ExtractedElts[Idx], IC.Builder.getInt32(i)); } return CastInst::Create(Instruction::BitCast, Result, II.getType()); } } break; } return None; } int PPCTTIImpl::getIntImmCost(const APInt &Imm, Type *Ty, TTI::TargetCostKind CostKind) { if (DisablePPCConstHoist) return BaseT::getIntImmCost(Imm, Ty, CostKind); 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::getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx, const APInt &Imm, Type *Ty, TTI::TargetCostKind CostKind) { if (DisablePPCConstHoist) return BaseT::getIntImmCostIntrin(IID, Idx, Imm, Ty, CostKind); 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, CostKind); } int PPCTTIImpl::getIntImmCostInst(unsigned Opcode, unsigned Idx, const APInt &Imm, Type *Ty, TTI::TargetCostKind CostKind, Instruction *Inst) { if (DisablePPCConstHoist) return BaseT::getIntImmCostInst(Opcode, Idx, Imm, Ty, CostKind, Inst); 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, CostKind); } unsigned PPCTTIImpl::getUserCost(const User *U, ArrayRef Operands, TTI::TargetCostKind CostKind) { // We already implement getCastInstrCost and getMemoryOpCost where we perform // the vector adjustment there. if (isa(U) || isa(U) || isa(U)) return BaseT::getUserCost(U, Operands, CostKind); if (U->getType()->isVectorTy()) { // Instructions that need to be split should cost more. std::pair LT = TLI->getTypeLegalizationCost(DL, U->getType()); return LT.first * BaseT::getUserCost(U, Operands, CostKind); } return BaseT::getUserCost(U, Operands, CostKind); } // Determining the address of a TLS variable results in a function call in // certain TLS models. static bool memAddrUsesCTR(const Value *MemAddr, const PPCTargetMachine &TM, SmallPtrSetImpl &Visited) { // No need to traverse again if we already checked this operand. if (!Visited.insert(MemAddr).second) return false; const auto *GV = dyn_cast(MemAddr); if (!GV) { // Recurse to check for constants that refer to TLS global variables. if (const auto *CV = dyn_cast(MemAddr)) for (const auto &CO : CV->operands()) if (memAddrUsesCTR(CO, TM, Visited)) return true; return false; } if (!GV->isThreadLocal()) return false; TLSModel::Model Model = TM.getTLSModel(GV); return Model == TLSModel::GeneralDynamic || Model == TLSModel::LocalDynamic; } bool PPCTTIImpl::mightUseCTR(BasicBlock *BB, TargetLibraryInfo *LibInfo, SmallPtrSetImpl &Visited) { 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; }; auto isLargeIntegerTy = [](bool Is32Bit, Type *Ty) { if (IntegerType *ITy = dyn_cast(Ty)) return ITy->getBitWidth() > (Is32Bit ? 32U : 64U); return false; }; auto supportedHalfPrecisionOp = [](Instruction *Inst) { switch (Inst->getOpcode()) { default: return false; case Instruction::FPTrunc: case Instruction::FPExt: case Instruction::Load: case Instruction::Store: case Instruction::FPToUI: case Instruction::UIToFP: case Instruction::FPToSI: case Instruction::SIToFP: return true; } }; for (BasicBlock::iterator J = BB->begin(), JE = BB->end(); J != JE; ++J) { // There are no direct operations on half precision so assume that // anything with that type requires a call except for a few select // operations with Power9. if (Instruction *CurrInst = dyn_cast(J)) { for (const auto &Op : CurrInst->operands()) { if (Op->getType()->getScalarType()->isHalfTy() || CurrInst->getType()->getScalarType()->isHalfTy()) return !(ST->isISA3_0() && supportedHalfPrecisionOp(CurrInst)); } } if (CallInst *CI = dyn_cast(J)) { // Inline ASM is okay, unless it clobbers the ctr register. if (InlineAsm *IA = dyn_cast(CI->getCalledOperand())) { 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 loop_decrement or set_loop_iterations, // we're definitely using CTR. case Intrinsic::set_loop_iterations: case Intrinsic::loop_decrement: return true; // Binary operations on 128-bit value will use CTR. case Intrinsic::experimental_constrained_fadd: case Intrinsic::experimental_constrained_fsub: case Intrinsic::experimental_constrained_fmul: case Intrinsic::experimental_constrained_fdiv: case Intrinsic::experimental_constrained_frem: if (F->getType()->getScalarType()->isFP128Ty() || F->getType()->getScalarType()->isPPC_FP128Ty()) return true; break; case Intrinsic::experimental_constrained_fptosi: case Intrinsic::experimental_constrained_fptoui: case Intrinsic::experimental_constrained_sitofp: case Intrinsic::experimental_constrained_uitofp: { Type *SrcType = CI->getArgOperand(0)->getType()->getScalarType(); Type *DstType = CI->getType()->getScalarType(); if (SrcType->isPPC_FP128Ty() || DstType->isPPC_FP128Ty() || isLargeIntegerTy(!TM.isPPC64(), SrcType) || isLargeIntegerTy(!TM.isPPC64(), DstType)) return true; break; } // 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: case Intrinsic::experimental_constrained_powi: case Intrinsic::experimental_constrained_log: case Intrinsic::experimental_constrained_log2: case Intrinsic::experimental_constrained_log10: case Intrinsic::experimental_constrained_exp: case Intrinsic::experimental_constrained_exp2: case Intrinsic::experimental_constrained_pow: case Intrinsic::experimental_constrained_sin: case Intrinsic::experimental_constrained_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::fma: Opcode = ISD::FMA; break; 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::experimental_constrained_fcmp: Opcode = ISD::STRICT_FSETCC; break; case Intrinsic::experimental_constrained_fcmps: Opcode = ISD::STRICT_FSETCCS; break; case Intrinsic::experimental_constrained_fma: Opcode = ISD::STRICT_FMA; break; case Intrinsic::experimental_constrained_sqrt: Opcode = ISD::STRICT_FSQRT; break; case Intrinsic::experimental_constrained_floor: Opcode = ISD::STRICT_FFLOOR; break; case Intrinsic::experimental_constrained_ceil: Opcode = ISD::STRICT_FCEIL; break; case Intrinsic::experimental_constrained_trunc: Opcode = ISD::STRICT_FTRUNC; break; case Intrinsic::experimental_constrained_rint: Opcode = ISD::STRICT_FRINT; break; case Intrinsic::experimental_constrained_lrint: Opcode = ISD::STRICT_LRINT; break; case Intrinsic::experimental_constrained_llrint: Opcode = ISD::STRICT_LLRINT; break; case Intrinsic::experimental_constrained_nearbyint: Opcode = ISD::STRICT_FNEARBYINT; break; case Intrinsic::experimental_constrained_round: Opcode = ISD::STRICT_FROUND; break; case Intrinsic::experimental_constrained_lround: Opcode = ISD::STRICT_LROUND; break; case Intrinsic::experimental_constrained_llround: Opcode = ISD::STRICT_LLROUND; break; case Intrinsic::experimental_constrained_minnum: Opcode = ISD::STRICT_FMINNUM; break; case Intrinsic::experimental_constrained_maxnum: Opcode = ISD::STRICT_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(J) && (J->getType()->getScalarType()->isFP128Ty() || J->getType()->getScalarType()->isPPC_FP128Ty())) { // Most operations on f128 or ppc_f128 values become calls. return true; } else if (isa(J) || isa(J) || isa(J) || isa(J)) { CastInst *CI = cast(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(J) || isa(J)) { // On PowerPC, indirect jumps use the counter register. return true; } else if (SwitchInst *SI = dyn_cast(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, TM, Visited)) 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 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. SmallPtrSet Visited; for (Loop::block_iterator I = L->block_begin(), IE = L->block_end(); I != IE; ++I) if (mightUseCTR(*I, LibInfo, Visited)) return false; SmallVector 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(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; } } // If an exit block has a PHI that accesses a TLS variable as one of the // incoming values from the loop, we cannot produce a CTR loop because the // address for that value will be computed in the loop. SmallVector ExitBlocks; L->getExitBlocks(ExitBlocks); for (auto &BB : ExitBlocks) { for (auto &PHI : BB->phis()) { for (int Idx = 0, EndIdx = PHI.getNumIncomingValues(); Idx < EndIdx; Idx++) { const BasicBlock *IncomingBB = PHI.getIncomingBlock(Idx); const Value *IncomingValue = PHI.getIncomingValue(Idx); if (L->contains(IncomingBB) && memAddrUsesCTR(IncomingValue, TM, Visited)) 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->getCPUDirective() == 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); } void PPCTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE, TTI::PeelingPreferences &PP) { BaseT::getPeelingPreferences(L, SE, PP); } // 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. if (ST->getCPUDirective() == 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(unsigned ClassID) const { assert(ClassID == GPRRC || ClassID == FPRRC || ClassID == VRRC || ClassID == VSXRC); if (ST->hasVSX()) { assert(ClassID == GPRRC || ClassID == VSXRC || ClassID == VRRC); return ClassID == VSXRC ? 64 : 32; } assert(ClassID == GPRRC || ClassID == FPRRC || ClassID == VRRC); return 32; } unsigned PPCTTIImpl::getRegisterClassForType(bool Vector, Type *Ty) const { if (Vector) return ST->hasVSX() ? VSXRC : VRRC; else if (Ty && (Ty->getScalarType()->isFloatTy() || Ty->getScalarType()->isDoubleTy())) return ST->hasVSX() ? VSXRC : FPRRC; else if (Ty && (Ty->getScalarType()->isFP128Ty() || Ty->getScalarType()->isPPC_FP128Ty())) return VRRC; else if (Ty && Ty->getScalarType()->isHalfTy()) return VSXRC; else return GPRRC; } const char* PPCTTIImpl::getRegisterClassName(unsigned ClassID) const { switch (ClassID) { default: llvm_unreachable("unknown register class"); return "PPC::unknown register class"; case GPRRC: return "PPC::GPRRC"; case FPRRC: return "PPC::FPRRC"; case VRRC: return "PPC::VRRC"; case VSXRC: return "PPC::VSXRC"; } } unsigned PPCTTIImpl::getRegisterBitWidth(bool Vector) const { if (Vector) { if (ST->hasAltivec()) return 128; return 0; } if (ST->isPPC64()) return 64; return 32; } unsigned PPCTTIImpl::getCacheLineSize() const { // Check first if the user specified a custom line size. if (CacheLineSize.getNumOccurrences() > 0) return CacheLineSize; // Starting with P7 we have a cache line size of 128. unsigned Directive = ST->getCPUDirective(); // Assume that Future CPU has the same cache line size as the others. if (Directive == PPC::DIR_PWR7 || Directive == PPC::DIR_PWR8 || Directive == PPC::DIR_PWR9 || Directive == PPC::DIR_PWR10 || Directive == PPC::DIR_PWR_FUTURE) return 128; // On other processors return a default of 64 bytes. return 64; } unsigned PPCTTIImpl::getPrefetchDistance() const { return 300; } unsigned PPCTTIImpl::getMaxInterleaveFactor(unsigned VF) { unsigned Directive = ST->getCPUDirective(); // 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 // FIXME: the same for P10 as previous gen until POWER10 scheduling is ready // Assume that future is the same as the others. if (Directive == PPC::DIR_PWR7 || Directive == PPC::DIR_PWR8 || Directive == PPC::DIR_PWR9 || Directive == PPC::DIR_PWR10 || Directive == PPC::DIR_PWR_FUTURE) 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 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 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::TargetCostKind CostKind, TTI::OperandValueKind Op1Info, TTI::OperandValueKind Op2Info, TTI::OperandValueProperties Opd1PropInfo, TTI::OperandValueProperties Opd2PropInfo, ArrayRef Args, const Instruction *CxtI) { assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode"); // TODO: Handle more cost kinds. if (CostKind != TTI::TCK_RecipThroughput) return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Op1Info, Op2Info, Opd1PropInfo, Opd2PropInfo, Args, CxtI); // Fallback to the default implementation. int Cost = BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, 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 LT = TLI->getTypeLegalizationCost(DL, Tp); // PPC, for both Altivec/VSX, 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::getCFInstrCost(unsigned Opcode, TTI::TargetCostKind CostKind) { if (CostKind != TTI::TCK_RecipThroughput) return Opcode == Instruction::PHI ? 0 : 1; // Branches are assumed to be predicted. return CostKind == TTI::TCK_RecipThroughput ? 0 : 1; } int PPCTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src, TTI::CastContextHint CCH, TTI::TargetCostKind CostKind, const Instruction *I) { assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode"); int Cost = BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I); Cost = vectorCostAdjustment(Cost, Opcode, Dst, Src); // TODO: Allow non-throughput costs that aren't binary. if (CostKind != TTI::TCK_RecipThroughput) return Cost == 0 ? 0 : 1; return Cost; } int PPCTTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy, CmpInst::Predicate VecPred, TTI::TargetCostKind CostKind, const Instruction *I) { int Cost = BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, CostKind, I); // TODO: Handle other cost kinds. if (CostKind != TTI::TCK_RecipThroughput) return Cost; 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 (Val->getScalarType()->isIntegerTy() && Index != -1U) { if (ST->hasP9Altivec()) { if (ISD == ISD::INSERT_VECTOR_ELT) // A move-to VSR and a permute/insert. Assume vector operation cost // for both (cost will be 2x on P9). return vectorCostAdjustment(2, Opcode, Val, nullptr); // It's an extract. Maybe we can do a cheap move-from VSR. unsigned EltSize = Val->getScalarSizeInBits(); if (EltSize == 64) { unsigned MfvsrdIndex = ST->isLittleEndian() ? 1 : 0; if (Index == MfvsrdIndex) return 1; } else if (EltSize == 32) { unsigned MfvsrwzIndex = ST->isLittleEndian() ? 2 : 1; if (Index == MfvsrwzIndex) return 1; } // We need a vector extract (or mfvsrld). Assume vector operation cost. // The cost of the load constant for a vector extract is disregarded // (invariant, easily schedulable). return vectorCostAdjustment(1, Opcode, Val, nullptr); } else if (ST->hasDirectMove()) // Assume permute has standard cost. // Assume move-to/move-from VSR have 2x standard cost. return 3; } // 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, MaybeAlign Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind, const Instruction *I) { if (TLI->getValueType(DL, Src, true) == MVT::Other) return BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, CostKind); // Legalize the type. std::pair LT = TLI->getTypeLegalizationCost(DL, Src); assert((Opcode == Instruction::Load || Opcode == Instruction::Store) && "Invalid Opcode"); int Cost = BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, CostKind); // TODO: Handle other cost kinds. if (CostKind != TTI::TCK_RecipThroughput) return Cost; 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); // 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) && *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. assert(Alignment); Cost += LT.first * ((SrcBytes / Alignment->value()) - 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 = cast(Src)->getNumElements(); i < e; ++i) Cost += getVectorInstrCost(Instruction::ExtractElement, Src, i); return Cost; } int PPCTTIImpl::getInterleavedMemoryOpCost( unsigned Opcode, Type *VecTy, unsigned Factor, ArrayRef Indices, Align Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind, bool UseMaskForCond, bool UseMaskForGaps) { if (UseMaskForCond || UseMaskForGaps) return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices, Alignment, AddressSpace, CostKind, UseMaskForCond, UseMaskForGaps); assert(isa(VecTy) && "Expect a vector type for interleaved memory op"); // Legalize the type. std::pair LT = TLI->getTypeLegalizationCost(DL, VecTy); // Firstly, the cost of load/store operation. int Cost = getMemoryOpCost(Opcode, VecTy, MaybeAlign(Alignment), AddressSpace, CostKind); // PPC, for both Altivec/VSX, 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; } unsigned PPCTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA, TTI::TargetCostKind CostKind) { return BaseT::getIntrinsicInstrCost(ICA, CostKind); } 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; } bool PPCTTIImpl::isLSRCostLess(TargetTransformInfo::LSRCost &C1, TargetTransformInfo::LSRCost &C2) { // PowerPC default behaviour here is "instruction number 1st priority". // If LsrNoInsnsCost is set, call default implementation. if (!LsrNoInsnsCost) return std::tie(C1.Insns, C1.NumRegs, C1.AddRecCost, C1.NumIVMuls, C1.NumBaseAdds, C1.ScaleCost, C1.ImmCost, C1.SetupCost) < std::tie(C2.Insns, C2.NumRegs, C2.AddRecCost, C2.NumIVMuls, C2.NumBaseAdds, C2.ScaleCost, C2.ImmCost, C2.SetupCost); else return TargetTransformInfoImplBase::isLSRCostLess(C1, C2); } bool PPCTTIImpl::isNumRegsMajorCostOfLSR() { return false; } bool PPCTTIImpl::getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info) { switch (Inst->getIntrinsicID()) { case Intrinsic::ppc_altivec_lvx: case Intrinsic::ppc_altivec_lvxl: case Intrinsic::ppc_altivec_lvebx: case Intrinsic::ppc_altivec_lvehx: case Intrinsic::ppc_altivec_lvewx: case Intrinsic::ppc_vsx_lxvd2x: case Intrinsic::ppc_vsx_lxvw4x: case Intrinsic::ppc_vsx_lxvd2x_be: case Intrinsic::ppc_vsx_lxvw4x_be: case Intrinsic::ppc_vsx_lxvl: case Intrinsic::ppc_vsx_lxvll: case Intrinsic::ppc_vsx_lxvp: { Info.PtrVal = Inst->getArgOperand(0); Info.ReadMem = true; Info.WriteMem = false; return true; } case Intrinsic::ppc_altivec_stvx: case Intrinsic::ppc_altivec_stvxl: case Intrinsic::ppc_altivec_stvebx: case Intrinsic::ppc_altivec_stvehx: case Intrinsic::ppc_altivec_stvewx: case Intrinsic::ppc_vsx_stxvd2x: case Intrinsic::ppc_vsx_stxvw4x: case Intrinsic::ppc_vsx_stxvd2x_be: case Intrinsic::ppc_vsx_stxvw4x_be: case Intrinsic::ppc_vsx_stxvl: case Intrinsic::ppc_vsx_stxvll: case Intrinsic::ppc_vsx_stxvp: { Info.PtrVal = Inst->getArgOperand(1); Info.ReadMem = false; Info.WriteMem = true; return true; } default: break; } return false; }