1 //===- ARMTargetTransformInfo.cpp - ARM specific TTI ----------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "ARMTargetTransformInfo.h" 10 #include "ARMSubtarget.h" 11 #include "MCTargetDesc/ARMAddressingModes.h" 12 #include "llvm/ADT/APInt.h" 13 #include "llvm/ADT/SmallVector.h" 14 #include "llvm/Analysis/LoopInfo.h" 15 #include "llvm/CodeGen/CostTable.h" 16 #include "llvm/CodeGen/ISDOpcodes.h" 17 #include "llvm/CodeGen/ValueTypes.h" 18 #include "llvm/CodeGenTypes/MachineValueType.h" 19 #include "llvm/IR/BasicBlock.h" 20 #include "llvm/IR/DataLayout.h" 21 #include "llvm/IR/DerivedTypes.h" 22 #include "llvm/IR/Instruction.h" 23 #include "llvm/IR/Instructions.h" 24 #include "llvm/IR/IntrinsicInst.h" 25 #include "llvm/IR/Intrinsics.h" 26 #include "llvm/IR/IntrinsicsARM.h" 27 #include "llvm/IR/PatternMatch.h" 28 #include "llvm/IR/Type.h" 29 #include "llvm/Support/Casting.h" 30 #include "llvm/Support/KnownBits.h" 31 #include "llvm/Target/TargetMachine.h" 32 #include "llvm/TargetParser/SubtargetFeature.h" 33 #include "llvm/Transforms/InstCombine/InstCombiner.h" 34 #include "llvm/Transforms/Utils/Local.h" 35 #include "llvm/Transforms/Utils/LoopUtils.h" 36 #include "llvm/Transforms/Vectorize/LoopVectorizationLegality.h" 37 #include <algorithm> 38 #include <cassert> 39 #include <cstdint> 40 #include <optional> 41 #include <utility> 42 43 using namespace llvm; 44 45 #define DEBUG_TYPE "armtti" 46 47 static cl::opt<bool> EnableMaskedLoadStores( 48 "enable-arm-maskedldst", cl::Hidden, cl::init(true), 49 cl::desc("Enable the generation of masked loads and stores")); 50 51 static cl::opt<bool> DisableLowOverheadLoops( 52 "disable-arm-loloops", cl::Hidden, cl::init(false), 53 cl::desc("Disable the generation of low-overhead loops")); 54 55 static cl::opt<bool> 56 AllowWLSLoops("allow-arm-wlsloops", cl::Hidden, cl::init(true), 57 cl::desc("Enable the generation of WLS loops")); 58 59 static cl::opt<bool> UseWidenGlobalArrays( 60 "widen-global-strings", cl::Hidden, cl::init(true), 61 cl::desc("Enable the widening of global strings to alignment boundaries")); 62 63 extern cl::opt<TailPredication::Mode> EnableTailPredication; 64 65 extern cl::opt<bool> EnableMaskedGatherScatters; 66 67 extern cl::opt<unsigned> MVEMaxSupportedInterleaveFactor; 68 69 /// Convert a vector load intrinsic into a simple llvm load instruction. 70 /// This is beneficial when the underlying object being addressed comes 71 /// from a constant, since we get constant-folding for free. 72 static Value *simplifyNeonVld1(const IntrinsicInst &II, unsigned MemAlign, 73 InstCombiner::BuilderTy &Builder) { 74 auto *IntrAlign = dyn_cast<ConstantInt>(II.getArgOperand(1)); 75 76 if (!IntrAlign) 77 return nullptr; 78 79 unsigned Alignment = IntrAlign->getLimitedValue() < MemAlign 80 ? MemAlign 81 : IntrAlign->getLimitedValue(); 82 83 if (!isPowerOf2_32(Alignment)) 84 return nullptr; 85 86 auto *BCastInst = Builder.CreateBitCast(II.getArgOperand(0), 87 PointerType::get(II.getType(), 0)); 88 return Builder.CreateAlignedLoad(II.getType(), BCastInst, Align(Alignment)); 89 } 90 91 bool ARMTTIImpl::areInlineCompatible(const Function *Caller, 92 const Function *Callee) const { 93 const TargetMachine &TM = getTLI()->getTargetMachine(); 94 const FeatureBitset &CallerBits = 95 TM.getSubtargetImpl(*Caller)->getFeatureBits(); 96 const FeatureBitset &CalleeBits = 97 TM.getSubtargetImpl(*Callee)->getFeatureBits(); 98 99 // To inline a callee, all features not in the allowed list must match exactly. 100 bool MatchExact = (CallerBits & ~InlineFeaturesAllowed) == 101 (CalleeBits & ~InlineFeaturesAllowed); 102 // For features in the allowed list, the callee's features must be a subset of 103 // the callers'. 104 bool MatchSubset = ((CallerBits & CalleeBits) & InlineFeaturesAllowed) == 105 (CalleeBits & InlineFeaturesAllowed); 106 return MatchExact && MatchSubset; 107 } 108 109 TTI::AddressingModeKind 110 ARMTTIImpl::getPreferredAddressingMode(const Loop *L, 111 ScalarEvolution *SE) const { 112 if (ST->hasMVEIntegerOps()) 113 return TTI::AMK_PostIndexed; 114 115 if (L->getHeader()->getParent()->hasOptSize()) 116 return TTI::AMK_None; 117 118 if (ST->isMClass() && ST->isThumb2() && 119 L->getNumBlocks() == 1) 120 return TTI::AMK_PreIndexed; 121 122 return TTI::AMK_None; 123 } 124 125 std::optional<Instruction *> 126 ARMTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const { 127 using namespace PatternMatch; 128 Intrinsic::ID IID = II.getIntrinsicID(); 129 switch (IID) { 130 default: 131 break; 132 case Intrinsic::arm_neon_vld1: { 133 Align MemAlign = 134 getKnownAlignment(II.getArgOperand(0), IC.getDataLayout(), &II, 135 &IC.getAssumptionCache(), &IC.getDominatorTree()); 136 if (Value *V = simplifyNeonVld1(II, MemAlign.value(), IC.Builder)) { 137 return IC.replaceInstUsesWith(II, V); 138 } 139 break; 140 } 141 142 case Intrinsic::arm_neon_vld2: 143 case Intrinsic::arm_neon_vld3: 144 case Intrinsic::arm_neon_vld4: 145 case Intrinsic::arm_neon_vld2lane: 146 case Intrinsic::arm_neon_vld3lane: 147 case Intrinsic::arm_neon_vld4lane: 148 case Intrinsic::arm_neon_vst1: 149 case Intrinsic::arm_neon_vst2: 150 case Intrinsic::arm_neon_vst3: 151 case Intrinsic::arm_neon_vst4: 152 case Intrinsic::arm_neon_vst2lane: 153 case Intrinsic::arm_neon_vst3lane: 154 case Intrinsic::arm_neon_vst4lane: { 155 Align MemAlign = 156 getKnownAlignment(II.getArgOperand(0), IC.getDataLayout(), &II, 157 &IC.getAssumptionCache(), &IC.getDominatorTree()); 158 unsigned AlignArg = II.arg_size() - 1; 159 Value *AlignArgOp = II.getArgOperand(AlignArg); 160 MaybeAlign Align = cast<ConstantInt>(AlignArgOp)->getMaybeAlignValue(); 161 if (Align && *Align < MemAlign) { 162 return IC.replaceOperand( 163 II, AlignArg, 164 ConstantInt::get(Type::getInt32Ty(II.getContext()), MemAlign.value(), 165 false)); 166 } 167 break; 168 } 169 170 case Intrinsic::arm_neon_vld1x2: 171 case Intrinsic::arm_neon_vld1x3: 172 case Intrinsic::arm_neon_vld1x4: 173 case Intrinsic::arm_neon_vst1x2: 174 case Intrinsic::arm_neon_vst1x3: 175 case Intrinsic::arm_neon_vst1x4: { 176 Align NewAlign = 177 getKnownAlignment(II.getArgOperand(0), IC.getDataLayout(), &II, 178 &IC.getAssumptionCache(), &IC.getDominatorTree()); 179 Align OldAlign = II.getParamAlign(0).valueOrOne(); 180 if (NewAlign > OldAlign) 181 II.addParamAttr(0, 182 Attribute::getWithAlignment(II.getContext(), NewAlign)); 183 break; 184 } 185 186 case Intrinsic::arm_mve_pred_i2v: { 187 Value *Arg = II.getArgOperand(0); 188 Value *ArgArg; 189 if (match(Arg, PatternMatch::m_Intrinsic<Intrinsic::arm_mve_pred_v2i>( 190 PatternMatch::m_Value(ArgArg))) && 191 II.getType() == ArgArg->getType()) { 192 return IC.replaceInstUsesWith(II, ArgArg); 193 } 194 Constant *XorMask; 195 if (match(Arg, m_Xor(PatternMatch::m_Intrinsic<Intrinsic::arm_mve_pred_v2i>( 196 PatternMatch::m_Value(ArgArg)), 197 PatternMatch::m_Constant(XorMask))) && 198 II.getType() == ArgArg->getType()) { 199 if (auto *CI = dyn_cast<ConstantInt>(XorMask)) { 200 if (CI->getValue().trunc(16).isAllOnes()) { 201 auto TrueVector = IC.Builder.CreateVectorSplat( 202 cast<FixedVectorType>(II.getType())->getNumElements(), 203 IC.Builder.getTrue()); 204 return BinaryOperator::Create(Instruction::Xor, ArgArg, TrueVector); 205 } 206 } 207 } 208 KnownBits ScalarKnown(32); 209 if (IC.SimplifyDemandedBits(&II, 0, APInt::getLowBitsSet(32, 16), 210 ScalarKnown)) { 211 return &II; 212 } 213 break; 214 } 215 case Intrinsic::arm_mve_pred_v2i: { 216 Value *Arg = II.getArgOperand(0); 217 Value *ArgArg; 218 if (match(Arg, PatternMatch::m_Intrinsic<Intrinsic::arm_mve_pred_i2v>( 219 PatternMatch::m_Value(ArgArg)))) { 220 return IC.replaceInstUsesWith(II, ArgArg); 221 } 222 223 if (II.getMetadata(LLVMContext::MD_range)) 224 break; 225 226 ConstantRange Range(APInt(32, 0), APInt(32, 0x10000)); 227 228 if (auto CurrentRange = II.getRange()) { 229 Range = Range.intersectWith(*CurrentRange); 230 if (Range == CurrentRange) 231 break; 232 } 233 234 II.addRangeRetAttr(Range); 235 II.addRetAttr(Attribute::NoUndef); 236 return &II; 237 } 238 case Intrinsic::arm_mve_vadc: 239 case Intrinsic::arm_mve_vadc_predicated: { 240 unsigned CarryOp = 241 (II.getIntrinsicID() == Intrinsic::arm_mve_vadc_predicated) ? 3 : 2; 242 assert(II.getArgOperand(CarryOp)->getType()->getScalarSizeInBits() == 32 && 243 "Bad type for intrinsic!"); 244 245 KnownBits CarryKnown(32); 246 if (IC.SimplifyDemandedBits(&II, CarryOp, APInt::getOneBitSet(32, 29), 247 CarryKnown)) { 248 return &II; 249 } 250 break; 251 } 252 case Intrinsic::arm_mve_vmldava: { 253 Instruction *I = cast<Instruction>(&II); 254 if (I->hasOneUse()) { 255 auto *User = cast<Instruction>(*I->user_begin()); 256 Value *OpZ; 257 if (match(User, m_c_Add(m_Specific(I), m_Value(OpZ))) && 258 match(I->getOperand(3), m_Zero())) { 259 Value *OpX = I->getOperand(4); 260 Value *OpY = I->getOperand(5); 261 Type *OpTy = OpX->getType(); 262 263 IC.Builder.SetInsertPoint(User); 264 Value *V = 265 IC.Builder.CreateIntrinsic(Intrinsic::arm_mve_vmldava, {OpTy}, 266 {I->getOperand(0), I->getOperand(1), 267 I->getOperand(2), OpZ, OpX, OpY}); 268 269 IC.replaceInstUsesWith(*User, V); 270 return IC.eraseInstFromFunction(*User); 271 } 272 } 273 return std::nullopt; 274 } 275 } 276 return std::nullopt; 277 } 278 279 std::optional<Value *> ARMTTIImpl::simplifyDemandedVectorEltsIntrinsic( 280 InstCombiner &IC, IntrinsicInst &II, APInt OrigDemandedElts, 281 APInt &UndefElts, APInt &UndefElts2, APInt &UndefElts3, 282 std::function<void(Instruction *, unsigned, APInt, APInt &)> 283 SimplifyAndSetOp) const { 284 285 // Compute the demanded bits for a narrowing MVE intrinsic. The TopOpc is the 286 // opcode specifying a Top/Bottom instruction, which can change between 287 // instructions. 288 auto SimplifyNarrowInstrTopBottom =[&](unsigned TopOpc) { 289 unsigned NumElts = cast<FixedVectorType>(II.getType())->getNumElements(); 290 unsigned IsTop = cast<ConstantInt>(II.getOperand(TopOpc))->getZExtValue(); 291 292 // The only odd/even lanes of operand 0 will only be demanded depending 293 // on whether this is a top/bottom instruction. 294 APInt DemandedElts = 295 APInt::getSplat(NumElts, IsTop ? APInt::getLowBitsSet(2, 1) 296 : APInt::getHighBitsSet(2, 1)); 297 SimplifyAndSetOp(&II, 0, OrigDemandedElts & DemandedElts, UndefElts); 298 // The other lanes will be defined from the inserted elements. 299 UndefElts &= APInt::getSplat(NumElts, IsTop ? APInt::getLowBitsSet(2, 1) 300 : APInt::getHighBitsSet(2, 1)); 301 return std::nullopt; 302 }; 303 304 switch (II.getIntrinsicID()) { 305 default: 306 break; 307 case Intrinsic::arm_mve_vcvt_narrow: 308 SimplifyNarrowInstrTopBottom(2); 309 break; 310 case Intrinsic::arm_mve_vqmovn: 311 SimplifyNarrowInstrTopBottom(4); 312 break; 313 case Intrinsic::arm_mve_vshrn: 314 SimplifyNarrowInstrTopBottom(7); 315 break; 316 } 317 318 return std::nullopt; 319 } 320 321 InstructionCost ARMTTIImpl::getIntImmCost(const APInt &Imm, Type *Ty, 322 TTI::TargetCostKind CostKind) { 323 assert(Ty->isIntegerTy()); 324 325 unsigned Bits = Ty->getPrimitiveSizeInBits(); 326 if (Bits == 0 || Imm.getActiveBits() >= 64) 327 return 4; 328 329 int64_t SImmVal = Imm.getSExtValue(); 330 uint64_t ZImmVal = Imm.getZExtValue(); 331 if (!ST->isThumb()) { 332 if ((SImmVal >= 0 && SImmVal < 65536) || 333 (ARM_AM::getSOImmVal(ZImmVal) != -1) || 334 (ARM_AM::getSOImmVal(~ZImmVal) != -1)) 335 return 1; 336 return ST->hasV6T2Ops() ? 2 : 3; 337 } 338 if (ST->isThumb2()) { 339 if ((SImmVal >= 0 && SImmVal < 65536) || 340 (ARM_AM::getT2SOImmVal(ZImmVal) != -1) || 341 (ARM_AM::getT2SOImmVal(~ZImmVal) != -1)) 342 return 1; 343 return ST->hasV6T2Ops() ? 2 : 3; 344 } 345 // Thumb1, any i8 imm cost 1. 346 if (Bits == 8 || (SImmVal >= 0 && SImmVal < 256)) 347 return 1; 348 if ((~SImmVal < 256) || ARM_AM::isThumbImmShiftedVal(ZImmVal)) 349 return 2; 350 // Load from constantpool. 351 return 3; 352 } 353 354 // Constants smaller than 256 fit in the immediate field of 355 // Thumb1 instructions so we return a zero cost and 1 otherwise. 356 InstructionCost ARMTTIImpl::getIntImmCodeSizeCost(unsigned Opcode, unsigned Idx, 357 const APInt &Imm, Type *Ty) { 358 if (Imm.isNonNegative() && Imm.getLimitedValue() < 256) 359 return 0; 360 361 return 1; 362 } 363 364 // Checks whether Inst is part of a min(max()) or max(min()) pattern 365 // that will match to an SSAT instruction. Returns the instruction being 366 // saturated, or null if no saturation pattern was found. 367 static Value *isSSATMinMaxPattern(Instruction *Inst, const APInt &Imm) { 368 Value *LHS, *RHS; 369 ConstantInt *C; 370 SelectPatternFlavor InstSPF = matchSelectPattern(Inst, LHS, RHS).Flavor; 371 372 if (InstSPF == SPF_SMAX && 373 PatternMatch::match(RHS, PatternMatch::m_ConstantInt(C)) && 374 C->getValue() == Imm && Imm.isNegative() && Imm.isNegatedPowerOf2()) { 375 376 auto isSSatMin = [&](Value *MinInst) { 377 if (isa<SelectInst>(MinInst)) { 378 Value *MinLHS, *MinRHS; 379 ConstantInt *MinC; 380 SelectPatternFlavor MinSPF = 381 matchSelectPattern(MinInst, MinLHS, MinRHS).Flavor; 382 if (MinSPF == SPF_SMIN && 383 PatternMatch::match(MinRHS, PatternMatch::m_ConstantInt(MinC)) && 384 MinC->getValue() == ((-Imm) - 1)) 385 return true; 386 } 387 return false; 388 }; 389 390 if (isSSatMin(Inst->getOperand(1))) 391 return cast<Instruction>(Inst->getOperand(1))->getOperand(1); 392 if (Inst->hasNUses(2) && 393 (isSSatMin(*Inst->user_begin()) || isSSatMin(*(++Inst->user_begin())))) 394 return Inst->getOperand(1); 395 } 396 return nullptr; 397 } 398 399 // Look for a FP Saturation pattern, where the instruction can be simplified to 400 // a fptosi.sat. max(min(fptosi)). The constant in this case is always free. 401 static bool isFPSatMinMaxPattern(Instruction *Inst, const APInt &Imm) { 402 if (Imm.getBitWidth() != 64 || 403 Imm != APInt::getHighBitsSet(64, 33)) // -2147483648 404 return false; 405 Value *FP = isSSATMinMaxPattern(Inst, Imm); 406 if (!FP && isa<ICmpInst>(Inst) && Inst->hasOneUse()) 407 FP = isSSATMinMaxPattern(cast<Instruction>(*Inst->user_begin()), Imm); 408 if (!FP) 409 return false; 410 return isa<FPToSIInst>(FP); 411 } 412 413 InstructionCost ARMTTIImpl::getIntImmCostInst(unsigned Opcode, unsigned Idx, 414 const APInt &Imm, Type *Ty, 415 TTI::TargetCostKind CostKind, 416 Instruction *Inst) { 417 // Division by a constant can be turned into multiplication, but only if we 418 // know it's constant. So it's not so much that the immediate is cheap (it's 419 // not), but that the alternative is worse. 420 // FIXME: this is probably unneeded with GlobalISel. 421 if ((Opcode == Instruction::SDiv || Opcode == Instruction::UDiv || 422 Opcode == Instruction::SRem || Opcode == Instruction::URem) && 423 Idx == 1) 424 return 0; 425 426 // Leave any gep offsets for the CodeGenPrepare, which will do a better job at 427 // splitting any large offsets. 428 if (Opcode == Instruction::GetElementPtr && Idx != 0) 429 return 0; 430 431 if (Opcode == Instruction::And) { 432 // UXTB/UXTH 433 if (Imm == 255 || Imm == 65535) 434 return 0; 435 // Conversion to BIC is free, and means we can use ~Imm instead. 436 return std::min(getIntImmCost(Imm, Ty, CostKind), 437 getIntImmCost(~Imm, Ty, CostKind)); 438 } 439 440 if (Opcode == Instruction::Add) 441 // Conversion to SUB is free, and means we can use -Imm instead. 442 return std::min(getIntImmCost(Imm, Ty, CostKind), 443 getIntImmCost(-Imm, Ty, CostKind)); 444 445 if (Opcode == Instruction::ICmp && Imm.isNegative() && 446 Ty->getIntegerBitWidth() == 32) { 447 int64_t NegImm = -Imm.getSExtValue(); 448 if (ST->isThumb2() && NegImm < 1<<12) 449 // icmp X, #-C -> cmn X, #C 450 return 0; 451 if (ST->isThumb() && NegImm < 1<<8) 452 // icmp X, #-C -> adds X, #C 453 return 0; 454 } 455 456 // xor a, -1 can always be folded to MVN 457 if (Opcode == Instruction::Xor && Imm.isAllOnes()) 458 return 0; 459 460 // Ensures negative constant of min(max()) or max(min()) patterns that 461 // match to SSAT instructions don't get hoisted 462 if (Inst && ((ST->hasV6Ops() && !ST->isThumb()) || ST->isThumb2()) && 463 Ty->getIntegerBitWidth() <= 32) { 464 if (isSSATMinMaxPattern(Inst, Imm) || 465 (isa<ICmpInst>(Inst) && Inst->hasOneUse() && 466 isSSATMinMaxPattern(cast<Instruction>(*Inst->user_begin()), Imm))) 467 return 0; 468 } 469 470 if (Inst && ST->hasVFP2Base() && isFPSatMinMaxPattern(Inst, Imm)) 471 return 0; 472 473 // We can convert <= -1 to < 0, which is generally quite cheap. 474 if (Inst && Opcode == Instruction::ICmp && Idx == 1 && Imm.isAllOnes()) { 475 ICmpInst::Predicate Pred = cast<ICmpInst>(Inst)->getPredicate(); 476 if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLE) 477 return std::min(getIntImmCost(Imm, Ty, CostKind), 478 getIntImmCost(Imm + 1, Ty, CostKind)); 479 } 480 481 return getIntImmCost(Imm, Ty, CostKind); 482 } 483 484 InstructionCost ARMTTIImpl::getCFInstrCost(unsigned Opcode, 485 TTI::TargetCostKind CostKind, 486 const Instruction *I) { 487 if (CostKind == TTI::TCK_RecipThroughput && 488 (ST->hasNEON() || ST->hasMVEIntegerOps())) { 489 // FIXME: The vectorizer is highly sensistive to the cost of these 490 // instructions, which suggests that it may be using the costs incorrectly. 491 // But, for now, just make them free to avoid performance regressions for 492 // vector targets. 493 return 0; 494 } 495 return BaseT::getCFInstrCost(Opcode, CostKind, I); 496 } 497 498 InstructionCost ARMTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst, 499 Type *Src, 500 TTI::CastContextHint CCH, 501 TTI::TargetCostKind CostKind, 502 const Instruction *I) { 503 int ISD = TLI->InstructionOpcodeToISD(Opcode); 504 assert(ISD && "Invalid opcode"); 505 506 // TODO: Allow non-throughput costs that aren't binary. 507 auto AdjustCost = [&CostKind](InstructionCost Cost) -> InstructionCost { 508 if (CostKind != TTI::TCK_RecipThroughput) 509 return Cost == 0 ? 0 : 1; 510 return Cost; 511 }; 512 auto IsLegalFPType = [this](EVT VT) { 513 EVT EltVT = VT.getScalarType(); 514 return (EltVT == MVT::f32 && ST->hasVFP2Base()) || 515 (EltVT == MVT::f64 && ST->hasFP64()) || 516 (EltVT == MVT::f16 && ST->hasFullFP16()); 517 }; 518 519 EVT SrcTy = TLI->getValueType(DL, Src); 520 EVT DstTy = TLI->getValueType(DL, Dst); 521 522 if (!SrcTy.isSimple() || !DstTy.isSimple()) 523 return AdjustCost( 524 BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I)); 525 526 // Extending masked load/Truncating masked stores is expensive because we 527 // currently don't split them. This means that we'll likely end up 528 // loading/storing each element individually (hence the high cost). 529 if ((ST->hasMVEIntegerOps() && 530 (Opcode == Instruction::Trunc || Opcode == Instruction::ZExt || 531 Opcode == Instruction::SExt)) || 532 (ST->hasMVEFloatOps() && 533 (Opcode == Instruction::FPExt || Opcode == Instruction::FPTrunc) && 534 IsLegalFPType(SrcTy) && IsLegalFPType(DstTy))) 535 if (CCH == TTI::CastContextHint::Masked && DstTy.getSizeInBits() > 128) 536 return 2 * DstTy.getVectorNumElements() * 537 ST->getMVEVectorCostFactor(CostKind); 538 539 // The extend of other kinds of load is free 540 if (CCH == TTI::CastContextHint::Normal || 541 CCH == TTI::CastContextHint::Masked) { 542 static const TypeConversionCostTblEntry LoadConversionTbl[] = { 543 {ISD::SIGN_EXTEND, MVT::i32, MVT::i16, 0}, 544 {ISD::ZERO_EXTEND, MVT::i32, MVT::i16, 0}, 545 {ISD::SIGN_EXTEND, MVT::i32, MVT::i8, 0}, 546 {ISD::ZERO_EXTEND, MVT::i32, MVT::i8, 0}, 547 {ISD::SIGN_EXTEND, MVT::i16, MVT::i8, 0}, 548 {ISD::ZERO_EXTEND, MVT::i16, MVT::i8, 0}, 549 {ISD::SIGN_EXTEND, MVT::i64, MVT::i32, 1}, 550 {ISD::ZERO_EXTEND, MVT::i64, MVT::i32, 1}, 551 {ISD::SIGN_EXTEND, MVT::i64, MVT::i16, 1}, 552 {ISD::ZERO_EXTEND, MVT::i64, MVT::i16, 1}, 553 {ISD::SIGN_EXTEND, MVT::i64, MVT::i8, 1}, 554 {ISD::ZERO_EXTEND, MVT::i64, MVT::i8, 1}, 555 }; 556 if (const auto *Entry = ConvertCostTableLookup( 557 LoadConversionTbl, ISD, DstTy.getSimpleVT(), SrcTy.getSimpleVT())) 558 return AdjustCost(Entry->Cost); 559 560 static const TypeConversionCostTblEntry MVELoadConversionTbl[] = { 561 {ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i16, 0}, 562 {ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i16, 0}, 563 {ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i8, 0}, 564 {ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i8, 0}, 565 {ISD::SIGN_EXTEND, MVT::v8i16, MVT::v8i8, 0}, 566 {ISD::ZERO_EXTEND, MVT::v8i16, MVT::v8i8, 0}, 567 // The following extend from a legal type to an illegal type, so need to 568 // split the load. This introduced an extra load operation, but the 569 // extend is still "free". 570 {ISD::SIGN_EXTEND, MVT::v8i32, MVT::v8i16, 1}, 571 {ISD::ZERO_EXTEND, MVT::v8i32, MVT::v8i16, 1}, 572 {ISD::SIGN_EXTEND, MVT::v16i32, MVT::v16i8, 3}, 573 {ISD::ZERO_EXTEND, MVT::v16i32, MVT::v16i8, 3}, 574 {ISD::SIGN_EXTEND, MVT::v16i16, MVT::v16i8, 1}, 575 {ISD::ZERO_EXTEND, MVT::v16i16, MVT::v16i8, 1}, 576 }; 577 if (SrcTy.isVector() && ST->hasMVEIntegerOps()) { 578 if (const auto *Entry = 579 ConvertCostTableLookup(MVELoadConversionTbl, ISD, 580 DstTy.getSimpleVT(), SrcTy.getSimpleVT())) 581 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 582 } 583 584 static const TypeConversionCostTblEntry MVEFLoadConversionTbl[] = { 585 // FPExtends are similar but also require the VCVT instructions. 586 {ISD::FP_EXTEND, MVT::v4f32, MVT::v4f16, 1}, 587 {ISD::FP_EXTEND, MVT::v8f32, MVT::v8f16, 3}, 588 }; 589 if (SrcTy.isVector() && ST->hasMVEFloatOps()) { 590 if (const auto *Entry = 591 ConvertCostTableLookup(MVEFLoadConversionTbl, ISD, 592 DstTy.getSimpleVT(), SrcTy.getSimpleVT())) 593 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 594 } 595 596 // The truncate of a store is free. This is the mirror of extends above. 597 static const TypeConversionCostTblEntry MVEStoreConversionTbl[] = { 598 {ISD::TRUNCATE, MVT::v4i32, MVT::v4i16, 0}, 599 {ISD::TRUNCATE, MVT::v4i32, MVT::v4i8, 0}, 600 {ISD::TRUNCATE, MVT::v8i16, MVT::v8i8, 0}, 601 {ISD::TRUNCATE, MVT::v8i32, MVT::v8i16, 1}, 602 {ISD::TRUNCATE, MVT::v8i32, MVT::v8i8, 1}, 603 {ISD::TRUNCATE, MVT::v16i32, MVT::v16i8, 3}, 604 {ISD::TRUNCATE, MVT::v16i16, MVT::v16i8, 1}, 605 }; 606 if (SrcTy.isVector() && ST->hasMVEIntegerOps()) { 607 if (const auto *Entry = 608 ConvertCostTableLookup(MVEStoreConversionTbl, ISD, 609 SrcTy.getSimpleVT(), DstTy.getSimpleVT())) 610 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 611 } 612 613 static const TypeConversionCostTblEntry MVEFStoreConversionTbl[] = { 614 {ISD::FP_ROUND, MVT::v4f32, MVT::v4f16, 1}, 615 {ISD::FP_ROUND, MVT::v8f32, MVT::v8f16, 3}, 616 }; 617 if (SrcTy.isVector() && ST->hasMVEFloatOps()) { 618 if (const auto *Entry = 619 ConvertCostTableLookup(MVEFStoreConversionTbl, ISD, 620 SrcTy.getSimpleVT(), DstTy.getSimpleVT())) 621 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 622 } 623 } 624 625 // NEON vector operations that can extend their inputs. 626 if ((ISD == ISD::SIGN_EXTEND || ISD == ISD::ZERO_EXTEND) && 627 I && I->hasOneUse() && ST->hasNEON() && SrcTy.isVector()) { 628 static const TypeConversionCostTblEntry NEONDoubleWidthTbl[] = { 629 // vaddl 630 { ISD::ADD, MVT::v4i32, MVT::v4i16, 0 }, 631 { ISD::ADD, MVT::v8i16, MVT::v8i8, 0 }, 632 // vsubl 633 { ISD::SUB, MVT::v4i32, MVT::v4i16, 0 }, 634 { ISD::SUB, MVT::v8i16, MVT::v8i8, 0 }, 635 // vmull 636 { ISD::MUL, MVT::v4i32, MVT::v4i16, 0 }, 637 { ISD::MUL, MVT::v8i16, MVT::v8i8, 0 }, 638 // vshll 639 { ISD::SHL, MVT::v4i32, MVT::v4i16, 0 }, 640 { ISD::SHL, MVT::v8i16, MVT::v8i8, 0 }, 641 }; 642 643 auto *User = cast<Instruction>(*I->user_begin()); 644 int UserISD = TLI->InstructionOpcodeToISD(User->getOpcode()); 645 if (auto *Entry = ConvertCostTableLookup(NEONDoubleWidthTbl, UserISD, 646 DstTy.getSimpleVT(), 647 SrcTy.getSimpleVT())) { 648 return AdjustCost(Entry->Cost); 649 } 650 } 651 652 // Single to/from double precision conversions. 653 if (Src->isVectorTy() && ST->hasNEON() && 654 ((ISD == ISD::FP_ROUND && SrcTy.getScalarType() == MVT::f64 && 655 DstTy.getScalarType() == MVT::f32) || 656 (ISD == ISD::FP_EXTEND && SrcTy.getScalarType() == MVT::f32 && 657 DstTy.getScalarType() == MVT::f64))) { 658 static const CostTblEntry NEONFltDblTbl[] = { 659 // Vector fptrunc/fpext conversions. 660 {ISD::FP_ROUND, MVT::v2f64, 2}, 661 {ISD::FP_EXTEND, MVT::v2f32, 2}, 662 {ISD::FP_EXTEND, MVT::v4f32, 4}}; 663 664 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Src); 665 if (const auto *Entry = CostTableLookup(NEONFltDblTbl, ISD, LT.second)) 666 return AdjustCost(LT.first * Entry->Cost); 667 } 668 669 // Some arithmetic, load and store operations have specific instructions 670 // to cast up/down their types automatically at no extra cost. 671 // TODO: Get these tables to know at least what the related operations are. 672 static const TypeConversionCostTblEntry NEONVectorConversionTbl[] = { 673 { ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i16, 1 }, 674 { ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i16, 1 }, 675 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i32, 1 }, 676 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i32, 1 }, 677 { ISD::TRUNCATE, MVT::v4i32, MVT::v4i64, 0 }, 678 { ISD::TRUNCATE, MVT::v4i16, MVT::v4i32, 1 }, 679 680 // The number of vmovl instructions for the extension. 681 { ISD::SIGN_EXTEND, MVT::v8i16, MVT::v8i8, 1 }, 682 { ISD::ZERO_EXTEND, MVT::v8i16, MVT::v8i8, 1 }, 683 { ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i8, 2 }, 684 { ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i8, 2 }, 685 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i8, 3 }, 686 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i8, 3 }, 687 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i16, 2 }, 688 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i16, 2 }, 689 { ISD::SIGN_EXTEND, MVT::v4i64, MVT::v4i16, 3 }, 690 { ISD::ZERO_EXTEND, MVT::v4i64, MVT::v4i16, 3 }, 691 { ISD::SIGN_EXTEND, MVT::v8i32, MVT::v8i8, 3 }, 692 { ISD::ZERO_EXTEND, MVT::v8i32, MVT::v8i8, 3 }, 693 { ISD::SIGN_EXTEND, MVT::v8i64, MVT::v8i8, 7 }, 694 { ISD::ZERO_EXTEND, MVT::v8i64, MVT::v8i8, 7 }, 695 { ISD::SIGN_EXTEND, MVT::v8i64, MVT::v8i16, 6 }, 696 { ISD::ZERO_EXTEND, MVT::v8i64, MVT::v8i16, 6 }, 697 { ISD::SIGN_EXTEND, MVT::v16i32, MVT::v16i8, 6 }, 698 { ISD::ZERO_EXTEND, MVT::v16i32, MVT::v16i8, 6 }, 699 700 // Operations that we legalize using splitting. 701 { ISD::TRUNCATE, MVT::v16i8, MVT::v16i32, 6 }, 702 { ISD::TRUNCATE, MVT::v8i8, MVT::v8i32, 3 }, 703 704 // Vector float <-> i32 conversions. 705 { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 }, 706 { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 }, 707 708 { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i8, 3 }, 709 { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i8, 3 }, 710 { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i16, 2 }, 711 { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i16, 2 }, 712 { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i32, 1 }, 713 { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i32, 1 }, 714 { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i1, 3 }, 715 { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i1, 3 }, 716 { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i8, 3 }, 717 { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i8, 3 }, 718 { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 }, 719 { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 }, 720 { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i16, 4 }, 721 { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i16, 4 }, 722 { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i32, 2 }, 723 { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i32, 2 }, 724 { ISD::SINT_TO_FP, MVT::v16f32, MVT::v16i16, 8 }, 725 { ISD::UINT_TO_FP, MVT::v16f32, MVT::v16i16, 8 }, 726 { ISD::SINT_TO_FP, MVT::v16f32, MVT::v16i32, 4 }, 727 { ISD::UINT_TO_FP, MVT::v16f32, MVT::v16i32, 4 }, 728 729 { ISD::FP_TO_SINT, MVT::v4i32, MVT::v4f32, 1 }, 730 { ISD::FP_TO_UINT, MVT::v4i32, MVT::v4f32, 1 }, 731 { ISD::FP_TO_SINT, MVT::v4i8, MVT::v4f32, 3 }, 732 { ISD::FP_TO_UINT, MVT::v4i8, MVT::v4f32, 3 }, 733 { ISD::FP_TO_SINT, MVT::v4i16, MVT::v4f32, 2 }, 734 { ISD::FP_TO_UINT, MVT::v4i16, MVT::v4f32, 2 }, 735 736 // Vector double <-> i32 conversions. 737 { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 }, 738 { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 }, 739 740 { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i8, 4 }, 741 { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i8, 4 }, 742 { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i16, 3 }, 743 { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i16, 3 }, 744 { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 }, 745 { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 }, 746 747 { ISD::FP_TO_SINT, MVT::v2i32, MVT::v2f64, 2 }, 748 { ISD::FP_TO_UINT, MVT::v2i32, MVT::v2f64, 2 }, 749 { ISD::FP_TO_SINT, MVT::v8i16, MVT::v8f32, 4 }, 750 { ISD::FP_TO_UINT, MVT::v8i16, MVT::v8f32, 4 }, 751 { ISD::FP_TO_SINT, MVT::v16i16, MVT::v16f32, 8 }, 752 { ISD::FP_TO_UINT, MVT::v16i16, MVT::v16f32, 8 } 753 }; 754 755 if (SrcTy.isVector() && ST->hasNEON()) { 756 if (const auto *Entry = ConvertCostTableLookup(NEONVectorConversionTbl, ISD, 757 DstTy.getSimpleVT(), 758 SrcTy.getSimpleVT())) 759 return AdjustCost(Entry->Cost); 760 } 761 762 // Scalar float to integer conversions. 763 static const TypeConversionCostTblEntry NEONFloatConversionTbl[] = { 764 { ISD::FP_TO_SINT, MVT::i1, MVT::f32, 2 }, 765 { ISD::FP_TO_UINT, MVT::i1, MVT::f32, 2 }, 766 { ISD::FP_TO_SINT, MVT::i1, MVT::f64, 2 }, 767 { ISD::FP_TO_UINT, MVT::i1, MVT::f64, 2 }, 768 { ISD::FP_TO_SINT, MVT::i8, MVT::f32, 2 }, 769 { ISD::FP_TO_UINT, MVT::i8, MVT::f32, 2 }, 770 { ISD::FP_TO_SINT, MVT::i8, MVT::f64, 2 }, 771 { ISD::FP_TO_UINT, MVT::i8, MVT::f64, 2 }, 772 { ISD::FP_TO_SINT, MVT::i16, MVT::f32, 2 }, 773 { ISD::FP_TO_UINT, MVT::i16, MVT::f32, 2 }, 774 { ISD::FP_TO_SINT, MVT::i16, MVT::f64, 2 }, 775 { ISD::FP_TO_UINT, MVT::i16, MVT::f64, 2 }, 776 { ISD::FP_TO_SINT, MVT::i32, MVT::f32, 2 }, 777 { ISD::FP_TO_UINT, MVT::i32, MVT::f32, 2 }, 778 { ISD::FP_TO_SINT, MVT::i32, MVT::f64, 2 }, 779 { ISD::FP_TO_UINT, MVT::i32, MVT::f64, 2 }, 780 { ISD::FP_TO_SINT, MVT::i64, MVT::f32, 10 }, 781 { ISD::FP_TO_UINT, MVT::i64, MVT::f32, 10 }, 782 { ISD::FP_TO_SINT, MVT::i64, MVT::f64, 10 }, 783 { ISD::FP_TO_UINT, MVT::i64, MVT::f64, 10 } 784 }; 785 if (SrcTy.isFloatingPoint() && ST->hasNEON()) { 786 if (const auto *Entry = ConvertCostTableLookup(NEONFloatConversionTbl, ISD, 787 DstTy.getSimpleVT(), 788 SrcTy.getSimpleVT())) 789 return AdjustCost(Entry->Cost); 790 } 791 792 // Scalar integer to float conversions. 793 static const TypeConversionCostTblEntry NEONIntegerConversionTbl[] = { 794 { ISD::SINT_TO_FP, MVT::f32, MVT::i1, 2 }, 795 { ISD::UINT_TO_FP, MVT::f32, MVT::i1, 2 }, 796 { ISD::SINT_TO_FP, MVT::f64, MVT::i1, 2 }, 797 { ISD::UINT_TO_FP, MVT::f64, MVT::i1, 2 }, 798 { ISD::SINT_TO_FP, MVT::f32, MVT::i8, 2 }, 799 { ISD::UINT_TO_FP, MVT::f32, MVT::i8, 2 }, 800 { ISD::SINT_TO_FP, MVT::f64, MVT::i8, 2 }, 801 { ISD::UINT_TO_FP, MVT::f64, MVT::i8, 2 }, 802 { ISD::SINT_TO_FP, MVT::f32, MVT::i16, 2 }, 803 { ISD::UINT_TO_FP, MVT::f32, MVT::i16, 2 }, 804 { ISD::SINT_TO_FP, MVT::f64, MVT::i16, 2 }, 805 { ISD::UINT_TO_FP, MVT::f64, MVT::i16, 2 }, 806 { ISD::SINT_TO_FP, MVT::f32, MVT::i32, 2 }, 807 { ISD::UINT_TO_FP, MVT::f32, MVT::i32, 2 }, 808 { ISD::SINT_TO_FP, MVT::f64, MVT::i32, 2 }, 809 { ISD::UINT_TO_FP, MVT::f64, MVT::i32, 2 }, 810 { ISD::SINT_TO_FP, MVT::f32, MVT::i64, 10 }, 811 { ISD::UINT_TO_FP, MVT::f32, MVT::i64, 10 }, 812 { ISD::SINT_TO_FP, MVT::f64, MVT::i64, 10 }, 813 { ISD::UINT_TO_FP, MVT::f64, MVT::i64, 10 } 814 }; 815 816 if (SrcTy.isInteger() && ST->hasNEON()) { 817 if (const auto *Entry = ConvertCostTableLookup(NEONIntegerConversionTbl, 818 ISD, DstTy.getSimpleVT(), 819 SrcTy.getSimpleVT())) 820 return AdjustCost(Entry->Cost); 821 } 822 823 // MVE extend costs, taken from codegen tests. i8->i16 or i16->i32 is one 824 // instruction, i8->i32 is two. i64 zexts are an VAND with a constant, sext 825 // are linearised so take more. 826 static const TypeConversionCostTblEntry MVEVectorConversionTbl[] = { 827 { ISD::SIGN_EXTEND, MVT::v8i16, MVT::v8i8, 1 }, 828 { ISD::ZERO_EXTEND, MVT::v8i16, MVT::v8i8, 1 }, 829 { ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i8, 2 }, 830 { ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i8, 2 }, 831 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i8, 10 }, 832 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i8, 2 }, 833 { ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i16, 1 }, 834 { ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i16, 1 }, 835 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i16, 10 }, 836 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i16, 2 }, 837 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i32, 8 }, 838 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i32, 2 }, 839 }; 840 841 if (SrcTy.isVector() && ST->hasMVEIntegerOps()) { 842 if (const auto *Entry = ConvertCostTableLookup(MVEVectorConversionTbl, 843 ISD, DstTy.getSimpleVT(), 844 SrcTy.getSimpleVT())) 845 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 846 } 847 848 if (ISD == ISD::FP_ROUND || ISD == ISD::FP_EXTEND) { 849 // As general rule, fp converts that were not matched above are scalarized 850 // and cost 1 vcvt for each lane, so long as the instruction is available. 851 // If not it will become a series of function calls. 852 const InstructionCost CallCost = 853 getCallInstrCost(nullptr, Dst, {Src}, CostKind); 854 int Lanes = 1; 855 if (SrcTy.isFixedLengthVector()) 856 Lanes = SrcTy.getVectorNumElements(); 857 858 if (IsLegalFPType(SrcTy) && IsLegalFPType(DstTy)) 859 return Lanes; 860 else 861 return Lanes * CallCost; 862 } 863 864 if (ISD == ISD::TRUNCATE && ST->hasMVEIntegerOps() && 865 SrcTy.isFixedLengthVector()) { 866 // Treat a truncate with larger than legal source (128bits for MVE) as 867 // expensive, 2 instructions per lane. 868 if ((SrcTy.getScalarType() == MVT::i8 || 869 SrcTy.getScalarType() == MVT::i16 || 870 SrcTy.getScalarType() == MVT::i32) && 871 SrcTy.getSizeInBits() > 128 && 872 SrcTy.getSizeInBits() > DstTy.getSizeInBits()) 873 return SrcTy.getVectorNumElements() * 2; 874 } 875 876 // Scalar integer conversion costs. 877 static const TypeConversionCostTblEntry ARMIntegerConversionTbl[] = { 878 // i16 -> i64 requires two dependent operations. 879 { ISD::SIGN_EXTEND, MVT::i64, MVT::i16, 2 }, 880 881 // Truncates on i64 are assumed to be free. 882 { ISD::TRUNCATE, MVT::i32, MVT::i64, 0 }, 883 { ISD::TRUNCATE, MVT::i16, MVT::i64, 0 }, 884 { ISD::TRUNCATE, MVT::i8, MVT::i64, 0 }, 885 { ISD::TRUNCATE, MVT::i1, MVT::i64, 0 } 886 }; 887 888 if (SrcTy.isInteger()) { 889 if (const auto *Entry = ConvertCostTableLookup(ARMIntegerConversionTbl, ISD, 890 DstTy.getSimpleVT(), 891 SrcTy.getSimpleVT())) 892 return AdjustCost(Entry->Cost); 893 } 894 895 int BaseCost = ST->hasMVEIntegerOps() && Src->isVectorTy() 896 ? ST->getMVEVectorCostFactor(CostKind) 897 : 1; 898 return AdjustCost( 899 BaseCost * BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I)); 900 } 901 902 InstructionCost ARMTTIImpl::getVectorInstrCost(unsigned Opcode, Type *ValTy, 903 TTI::TargetCostKind CostKind, 904 unsigned Index, Value *Op0, 905 Value *Op1) { 906 // Penalize inserting into an D-subregister. We end up with a three times 907 // lower estimated throughput on swift. 908 if (ST->hasSlowLoadDSubregister() && Opcode == Instruction::InsertElement && 909 ValTy->isVectorTy() && ValTy->getScalarSizeInBits() <= 32) 910 return 3; 911 912 if (ST->hasNEON() && (Opcode == Instruction::InsertElement || 913 Opcode == Instruction::ExtractElement)) { 914 // Cross-class copies are expensive on many microarchitectures, 915 // so assume they are expensive by default. 916 if (cast<VectorType>(ValTy)->getElementType()->isIntegerTy()) 917 return 3; 918 919 // Even if it's not a cross class copy, this likely leads to mixing 920 // of NEON and VFP code and should be therefore penalized. 921 if (ValTy->isVectorTy() && 922 ValTy->getScalarSizeInBits() <= 32) 923 return std::max<InstructionCost>( 924 BaseT::getVectorInstrCost(Opcode, ValTy, CostKind, Index, Op0, Op1), 925 2U); 926 } 927 928 if (ST->hasMVEIntegerOps() && (Opcode == Instruction::InsertElement || 929 Opcode == Instruction::ExtractElement)) { 930 // Integer cross-lane moves are more expensive than float, which can 931 // sometimes just be vmovs. Integer involve being passes to GPR registers, 932 // causing more of a delay. 933 std::pair<InstructionCost, MVT> LT = 934 getTypeLegalizationCost(ValTy->getScalarType()); 935 return LT.first * (ValTy->getScalarType()->isIntegerTy() ? 4 : 1); 936 } 937 938 return BaseT::getVectorInstrCost(Opcode, ValTy, CostKind, Index, Op0, Op1); 939 } 940 941 InstructionCost ARMTTIImpl::getCmpSelInstrCost( 942 unsigned Opcode, Type *ValTy, Type *CondTy, CmpInst::Predicate VecPred, 943 TTI::TargetCostKind CostKind, TTI::OperandValueInfo Op1Info, 944 TTI::OperandValueInfo Op2Info, const Instruction *I) { 945 int ISD = TLI->InstructionOpcodeToISD(Opcode); 946 947 // Thumb scalar code size cost for select. 948 if (CostKind == TTI::TCK_CodeSize && ISD == ISD::SELECT && 949 ST->isThumb() && !ValTy->isVectorTy()) { 950 // Assume expensive structs. 951 if (TLI->getValueType(DL, ValTy, true) == MVT::Other) 952 return TTI::TCC_Expensive; 953 954 // Select costs can vary because they: 955 // - may require one or more conditional mov (including an IT), 956 // - can't operate directly on immediates, 957 // - require live flags, which we can't copy around easily. 958 InstructionCost Cost = getTypeLegalizationCost(ValTy).first; 959 960 // Possible IT instruction for Thumb2, or more for Thumb1. 961 ++Cost; 962 963 // i1 values may need rematerialising by using mov immediates and/or 964 // flag setting instructions. 965 if (ValTy->isIntegerTy(1)) 966 ++Cost; 967 968 return Cost; 969 } 970 971 // If this is a vector min/max/abs, use the cost of that intrinsic directly 972 // instead. Hopefully when min/max intrinsics are more prevalent this code 973 // will not be needed. 974 const Instruction *Sel = I; 975 if ((Opcode == Instruction::ICmp || Opcode == Instruction::FCmp) && Sel && 976 Sel->hasOneUse()) 977 Sel = cast<Instruction>(Sel->user_back()); 978 if (Sel && ValTy->isVectorTy() && 979 (ValTy->isIntOrIntVectorTy() || ValTy->isFPOrFPVectorTy())) { 980 const Value *LHS, *RHS; 981 SelectPatternFlavor SPF = matchSelectPattern(Sel, LHS, RHS).Flavor; 982 unsigned IID = 0; 983 switch (SPF) { 984 case SPF_ABS: 985 IID = Intrinsic::abs; 986 break; 987 case SPF_SMIN: 988 IID = Intrinsic::smin; 989 break; 990 case SPF_SMAX: 991 IID = Intrinsic::smax; 992 break; 993 case SPF_UMIN: 994 IID = Intrinsic::umin; 995 break; 996 case SPF_UMAX: 997 IID = Intrinsic::umax; 998 break; 999 case SPF_FMINNUM: 1000 IID = Intrinsic::minnum; 1001 break; 1002 case SPF_FMAXNUM: 1003 IID = Intrinsic::maxnum; 1004 break; 1005 default: 1006 break; 1007 } 1008 if (IID) { 1009 // The ICmp is free, the select gets the cost of the min/max/etc 1010 if (Sel != I) 1011 return 0; 1012 IntrinsicCostAttributes CostAttrs(IID, ValTy, {ValTy, ValTy}); 1013 return getIntrinsicInstrCost(CostAttrs, CostKind); 1014 } 1015 } 1016 1017 // On NEON a vector select gets lowered to vbsl. 1018 if (ST->hasNEON() && ValTy->isVectorTy() && ISD == ISD::SELECT && CondTy) { 1019 // Lowering of some vector selects is currently far from perfect. 1020 static const TypeConversionCostTblEntry NEONVectorSelectTbl[] = { 1021 { ISD::SELECT, MVT::v4i1, MVT::v4i64, 4*4 + 1*2 + 1 }, 1022 { ISD::SELECT, MVT::v8i1, MVT::v8i64, 50 }, 1023 { ISD::SELECT, MVT::v16i1, MVT::v16i64, 100 } 1024 }; 1025 1026 EVT SelCondTy = TLI->getValueType(DL, CondTy); 1027 EVT SelValTy = TLI->getValueType(DL, ValTy); 1028 if (SelCondTy.isSimple() && SelValTy.isSimple()) { 1029 if (const auto *Entry = ConvertCostTableLookup(NEONVectorSelectTbl, ISD, 1030 SelCondTy.getSimpleVT(), 1031 SelValTy.getSimpleVT())) 1032 return Entry->Cost; 1033 } 1034 1035 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1036 return LT.first; 1037 } 1038 1039 if (ST->hasMVEIntegerOps() && ValTy->isVectorTy() && 1040 (Opcode == Instruction::ICmp || Opcode == Instruction::FCmp) && 1041 cast<FixedVectorType>(ValTy)->getNumElements() > 1) { 1042 FixedVectorType *VecValTy = cast<FixedVectorType>(ValTy); 1043 FixedVectorType *VecCondTy = dyn_cast_or_null<FixedVectorType>(CondTy); 1044 if (!VecCondTy) 1045 VecCondTy = cast<FixedVectorType>(CmpInst::makeCmpResultType(VecValTy)); 1046 1047 // If we don't have mve.fp any fp operations will need to be scalarized. 1048 if (Opcode == Instruction::FCmp && !ST->hasMVEFloatOps()) { 1049 // One scalaization insert, one scalarization extract and the cost of the 1050 // fcmps. 1051 return BaseT::getScalarizationOverhead(VecValTy, /*Insert*/ false, 1052 /*Extract*/ true, CostKind) + 1053 BaseT::getScalarizationOverhead(VecCondTy, /*Insert*/ true, 1054 /*Extract*/ false, CostKind) + 1055 VecValTy->getNumElements() * 1056 getCmpSelInstrCost(Opcode, ValTy->getScalarType(), 1057 VecCondTy->getScalarType(), VecPred, 1058 CostKind, Op1Info, Op2Info, I); 1059 } 1060 1061 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1062 int BaseCost = ST->getMVEVectorCostFactor(CostKind); 1063 // There are two types - the input that specifies the type of the compare 1064 // and the output vXi1 type. Because we don't know how the output will be 1065 // split, we may need an expensive shuffle to get two in sync. This has the 1066 // effect of making larger than legal compares (v8i32 for example) 1067 // expensive. 1068 if (LT.second.isVector() && LT.second.getVectorNumElements() > 2) { 1069 if (LT.first > 1) 1070 return LT.first * BaseCost + 1071 BaseT::getScalarizationOverhead(VecCondTy, /*Insert*/ true, 1072 /*Extract*/ false, CostKind); 1073 return BaseCost; 1074 } 1075 } 1076 1077 // Default to cheap (throughput/size of 1 instruction) but adjust throughput 1078 // for "multiple beats" potentially needed by MVE instructions. 1079 int BaseCost = 1; 1080 if (ST->hasMVEIntegerOps() && ValTy->isVectorTy()) 1081 BaseCost = ST->getMVEVectorCostFactor(CostKind); 1082 1083 return BaseCost * BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, 1084 CostKind, Op1Info, Op2Info, I); 1085 } 1086 1087 InstructionCost ARMTTIImpl::getAddressComputationCost(Type *Ty, 1088 ScalarEvolution *SE, 1089 const SCEV *Ptr) { 1090 // Address computations in vectorized code with non-consecutive addresses will 1091 // likely result in more instructions compared to scalar code where the 1092 // computation can more often be merged into the index mode. The resulting 1093 // extra micro-ops can significantly decrease throughput. 1094 unsigned NumVectorInstToHideOverhead = 10; 1095 int MaxMergeDistance = 64; 1096 1097 if (ST->hasNEON()) { 1098 if (Ty->isVectorTy() && SE && 1099 !BaseT::isConstantStridedAccessLessThan(SE, Ptr, MaxMergeDistance + 1)) 1100 return NumVectorInstToHideOverhead; 1101 1102 // In many cases the address computation is not merged into the instruction 1103 // addressing mode. 1104 return 1; 1105 } 1106 return BaseT::getAddressComputationCost(Ty, SE, Ptr); 1107 } 1108 1109 bool ARMTTIImpl::isProfitableLSRChainElement(Instruction *I) { 1110 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) { 1111 // If a VCTP is part of a chain, it's already profitable and shouldn't be 1112 // optimized, else LSR may block tail-predication. 1113 switch (II->getIntrinsicID()) { 1114 case Intrinsic::arm_mve_vctp8: 1115 case Intrinsic::arm_mve_vctp16: 1116 case Intrinsic::arm_mve_vctp32: 1117 case Intrinsic::arm_mve_vctp64: 1118 return true; 1119 default: 1120 break; 1121 } 1122 } 1123 return false; 1124 } 1125 1126 bool ARMTTIImpl::isLegalMaskedLoad(Type *DataTy, Align Alignment) { 1127 if (!EnableMaskedLoadStores || !ST->hasMVEIntegerOps()) 1128 return false; 1129 1130 if (auto *VecTy = dyn_cast<FixedVectorType>(DataTy)) { 1131 // Don't support v2i1 yet. 1132 if (VecTy->getNumElements() == 2) 1133 return false; 1134 1135 // We don't support extending fp types. 1136 unsigned VecWidth = DataTy->getPrimitiveSizeInBits(); 1137 if (VecWidth != 128 && VecTy->getElementType()->isFloatingPointTy()) 1138 return false; 1139 } 1140 1141 unsigned EltWidth = DataTy->getScalarSizeInBits(); 1142 return (EltWidth == 32 && Alignment >= 4) || 1143 (EltWidth == 16 && Alignment >= 2) || (EltWidth == 8); 1144 } 1145 1146 bool ARMTTIImpl::isLegalMaskedGather(Type *Ty, Align Alignment) { 1147 if (!EnableMaskedGatherScatters || !ST->hasMVEIntegerOps()) 1148 return false; 1149 1150 unsigned EltWidth = Ty->getScalarSizeInBits(); 1151 return ((EltWidth == 32 && Alignment >= 4) || 1152 (EltWidth == 16 && Alignment >= 2) || EltWidth == 8); 1153 } 1154 1155 /// Given a memcpy/memset/memmove instruction, return the number of memory 1156 /// operations performed, via querying findOptimalMemOpLowering. Returns -1 if a 1157 /// call is used. 1158 int ARMTTIImpl::getNumMemOps(const IntrinsicInst *I) const { 1159 MemOp MOp; 1160 unsigned DstAddrSpace = ~0u; 1161 unsigned SrcAddrSpace = ~0u; 1162 const Function *F = I->getParent()->getParent(); 1163 1164 if (const auto *MC = dyn_cast<MemTransferInst>(I)) { 1165 ConstantInt *C = dyn_cast<ConstantInt>(MC->getLength()); 1166 // If 'size' is not a constant, a library call will be generated. 1167 if (!C) 1168 return -1; 1169 1170 const unsigned Size = C->getValue().getZExtValue(); 1171 const Align DstAlign = *MC->getDestAlign(); 1172 const Align SrcAlign = *MC->getSourceAlign(); 1173 1174 MOp = MemOp::Copy(Size, /*DstAlignCanChange*/ false, DstAlign, SrcAlign, 1175 /*IsVolatile*/ false); 1176 DstAddrSpace = MC->getDestAddressSpace(); 1177 SrcAddrSpace = MC->getSourceAddressSpace(); 1178 } 1179 else if (const auto *MS = dyn_cast<MemSetInst>(I)) { 1180 ConstantInt *C = dyn_cast<ConstantInt>(MS->getLength()); 1181 // If 'size' is not a constant, a library call will be generated. 1182 if (!C) 1183 return -1; 1184 1185 const unsigned Size = C->getValue().getZExtValue(); 1186 const Align DstAlign = *MS->getDestAlign(); 1187 1188 MOp = MemOp::Set(Size, /*DstAlignCanChange*/ false, DstAlign, 1189 /*IsZeroMemset*/ false, /*IsVolatile*/ false); 1190 DstAddrSpace = MS->getDestAddressSpace(); 1191 } 1192 else 1193 llvm_unreachable("Expected a memcpy/move or memset!"); 1194 1195 unsigned Limit, Factor = 2; 1196 switch(I->getIntrinsicID()) { 1197 case Intrinsic::memcpy: 1198 Limit = TLI->getMaxStoresPerMemcpy(F->hasMinSize()); 1199 break; 1200 case Intrinsic::memmove: 1201 Limit = TLI->getMaxStoresPerMemmove(F->hasMinSize()); 1202 break; 1203 case Intrinsic::memset: 1204 Limit = TLI->getMaxStoresPerMemset(F->hasMinSize()); 1205 Factor = 1; 1206 break; 1207 default: 1208 llvm_unreachable("Expected a memcpy/move or memset!"); 1209 } 1210 1211 // MemOps will be poplulated with a list of data types that needs to be 1212 // loaded and stored. That's why we multiply the number of elements by 2 to 1213 // get the cost for this memcpy. 1214 std::vector<EVT> MemOps; 1215 if (getTLI()->findOptimalMemOpLowering( 1216 MemOps, Limit, MOp, DstAddrSpace, 1217 SrcAddrSpace, F->getAttributes())) 1218 return MemOps.size() * Factor; 1219 1220 // If we can't find an optimal memop lowering, return the default cost 1221 return -1; 1222 } 1223 1224 InstructionCost ARMTTIImpl::getMemcpyCost(const Instruction *I) { 1225 int NumOps = getNumMemOps(cast<IntrinsicInst>(I)); 1226 1227 // To model the cost of a library call, we assume 1 for the call, and 1228 // 3 for the argument setup. 1229 if (NumOps == -1) 1230 return 4; 1231 return NumOps; 1232 } 1233 1234 InstructionCost ARMTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, 1235 VectorType *Tp, ArrayRef<int> Mask, 1236 TTI::TargetCostKind CostKind, 1237 int Index, VectorType *SubTp, 1238 ArrayRef<const Value *> Args, 1239 const Instruction *CxtI) { 1240 Kind = improveShuffleKindFromMask(Kind, Mask, Tp, Index, SubTp); 1241 // Treat extractsubvector as single op permutation. 1242 bool IsExtractSubvector = Kind == TTI::SK_ExtractSubvector; 1243 if (IsExtractSubvector) 1244 Kind = TTI::SK_PermuteSingleSrc; 1245 if (ST->hasNEON()) { 1246 if (Kind == TTI::SK_Broadcast) { 1247 static const CostTblEntry NEONDupTbl[] = { 1248 // VDUP handles these cases. 1249 {ISD::VECTOR_SHUFFLE, MVT::v2i32, 1}, 1250 {ISD::VECTOR_SHUFFLE, MVT::v2f32, 1}, 1251 {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1}, 1252 {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1}, 1253 {ISD::VECTOR_SHUFFLE, MVT::v4i16, 1}, 1254 {ISD::VECTOR_SHUFFLE, MVT::v8i8, 1}, 1255 1256 {ISD::VECTOR_SHUFFLE, MVT::v4i32, 1}, 1257 {ISD::VECTOR_SHUFFLE, MVT::v4f32, 1}, 1258 {ISD::VECTOR_SHUFFLE, MVT::v8i16, 1}, 1259 {ISD::VECTOR_SHUFFLE, MVT::v16i8, 1}}; 1260 1261 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1262 if (const auto *Entry = 1263 CostTableLookup(NEONDupTbl, ISD::VECTOR_SHUFFLE, LT.second)) 1264 return LT.first * Entry->Cost; 1265 } 1266 if (Kind == TTI::SK_Reverse) { 1267 static const CostTblEntry NEONShuffleTbl[] = { 1268 // Reverse shuffle cost one instruction if we are shuffling within a 1269 // double word (vrev) or two if we shuffle a quad word (vrev, vext). 1270 {ISD::VECTOR_SHUFFLE, MVT::v2i32, 1}, 1271 {ISD::VECTOR_SHUFFLE, MVT::v2f32, 1}, 1272 {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1}, 1273 {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1}, 1274 {ISD::VECTOR_SHUFFLE, MVT::v4i16, 1}, 1275 {ISD::VECTOR_SHUFFLE, MVT::v8i8, 1}, 1276 1277 {ISD::VECTOR_SHUFFLE, MVT::v4i32, 2}, 1278 {ISD::VECTOR_SHUFFLE, MVT::v4f32, 2}, 1279 {ISD::VECTOR_SHUFFLE, MVT::v8i16, 2}, 1280 {ISD::VECTOR_SHUFFLE, MVT::v16i8, 2}}; 1281 1282 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1283 if (const auto *Entry = 1284 CostTableLookup(NEONShuffleTbl, ISD::VECTOR_SHUFFLE, LT.second)) 1285 return LT.first * Entry->Cost; 1286 } 1287 if (Kind == TTI::SK_Select) { 1288 static const CostTblEntry NEONSelShuffleTbl[] = { 1289 // Select shuffle cost table for ARM. Cost is the number of 1290 // instructions 1291 // required to create the shuffled vector. 1292 1293 {ISD::VECTOR_SHUFFLE, MVT::v2f32, 1}, 1294 {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1}, 1295 {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1}, 1296 {ISD::VECTOR_SHUFFLE, MVT::v2i32, 1}, 1297 1298 {ISD::VECTOR_SHUFFLE, MVT::v4i32, 2}, 1299 {ISD::VECTOR_SHUFFLE, MVT::v4f32, 2}, 1300 {ISD::VECTOR_SHUFFLE, MVT::v4i16, 2}, 1301 1302 {ISD::VECTOR_SHUFFLE, MVT::v8i16, 16}, 1303 1304 {ISD::VECTOR_SHUFFLE, MVT::v16i8, 32}}; 1305 1306 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1307 if (const auto *Entry = CostTableLookup(NEONSelShuffleTbl, 1308 ISD::VECTOR_SHUFFLE, LT.second)) 1309 return LT.first * Entry->Cost; 1310 } 1311 } 1312 if (ST->hasMVEIntegerOps()) { 1313 if (Kind == TTI::SK_Broadcast) { 1314 static const CostTblEntry MVEDupTbl[] = { 1315 // VDUP handles these cases. 1316 {ISD::VECTOR_SHUFFLE, MVT::v4i32, 1}, 1317 {ISD::VECTOR_SHUFFLE, MVT::v8i16, 1}, 1318 {ISD::VECTOR_SHUFFLE, MVT::v16i8, 1}, 1319 {ISD::VECTOR_SHUFFLE, MVT::v4f32, 1}, 1320 {ISD::VECTOR_SHUFFLE, MVT::v8f16, 1}}; 1321 1322 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1323 if (const auto *Entry = CostTableLookup(MVEDupTbl, ISD::VECTOR_SHUFFLE, 1324 LT.second)) 1325 return LT.first * Entry->Cost * 1326 ST->getMVEVectorCostFactor(TTI::TCK_RecipThroughput); 1327 } 1328 1329 if (!Mask.empty()) { 1330 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1331 if (LT.second.isVector() && 1332 Mask.size() <= LT.second.getVectorNumElements() && 1333 (isVREVMask(Mask, LT.second, 16) || isVREVMask(Mask, LT.second, 32) || 1334 isVREVMask(Mask, LT.second, 64))) 1335 return ST->getMVEVectorCostFactor(TTI::TCK_RecipThroughput) * LT.first; 1336 } 1337 } 1338 1339 // Restore optimal kind. 1340 if (IsExtractSubvector) 1341 Kind = TTI::SK_ExtractSubvector; 1342 int BaseCost = ST->hasMVEIntegerOps() && Tp->isVectorTy() 1343 ? ST->getMVEVectorCostFactor(TTI::TCK_RecipThroughput) 1344 : 1; 1345 return BaseCost * 1346 BaseT::getShuffleCost(Kind, Tp, Mask, CostKind, Index, SubTp); 1347 } 1348 1349 InstructionCost ARMTTIImpl::getArithmeticInstrCost( 1350 unsigned Opcode, Type *Ty, TTI::TargetCostKind CostKind, 1351 TTI::OperandValueInfo Op1Info, TTI::OperandValueInfo Op2Info, 1352 ArrayRef<const Value *> Args, 1353 const Instruction *CxtI) { 1354 int ISDOpcode = TLI->InstructionOpcodeToISD(Opcode); 1355 if (ST->isThumb() && CostKind == TTI::TCK_CodeSize && Ty->isIntegerTy(1)) { 1356 // Make operations on i1 relatively expensive as this often involves 1357 // combining predicates. AND and XOR should be easier to handle with IT 1358 // blocks. 1359 switch (ISDOpcode) { 1360 default: 1361 break; 1362 case ISD::AND: 1363 case ISD::XOR: 1364 return 2; 1365 case ISD::OR: 1366 return 3; 1367 } 1368 } 1369 1370 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Ty); 1371 1372 if (ST->hasNEON()) { 1373 const unsigned FunctionCallDivCost = 20; 1374 const unsigned ReciprocalDivCost = 10; 1375 static const CostTblEntry CostTbl[] = { 1376 // Division. 1377 // These costs are somewhat random. Choose a cost of 20 to indicate that 1378 // vectorizing devision (added function call) is going to be very expensive. 1379 // Double registers types. 1380 { ISD::SDIV, MVT::v1i64, 1 * FunctionCallDivCost}, 1381 { ISD::UDIV, MVT::v1i64, 1 * FunctionCallDivCost}, 1382 { ISD::SREM, MVT::v1i64, 1 * FunctionCallDivCost}, 1383 { ISD::UREM, MVT::v1i64, 1 * FunctionCallDivCost}, 1384 { ISD::SDIV, MVT::v2i32, 2 * FunctionCallDivCost}, 1385 { ISD::UDIV, MVT::v2i32, 2 * FunctionCallDivCost}, 1386 { ISD::SREM, MVT::v2i32, 2 * FunctionCallDivCost}, 1387 { ISD::UREM, MVT::v2i32, 2 * FunctionCallDivCost}, 1388 { ISD::SDIV, MVT::v4i16, ReciprocalDivCost}, 1389 { ISD::UDIV, MVT::v4i16, ReciprocalDivCost}, 1390 { ISD::SREM, MVT::v4i16, 4 * FunctionCallDivCost}, 1391 { ISD::UREM, MVT::v4i16, 4 * FunctionCallDivCost}, 1392 { ISD::SDIV, MVT::v8i8, ReciprocalDivCost}, 1393 { ISD::UDIV, MVT::v8i8, ReciprocalDivCost}, 1394 { ISD::SREM, MVT::v8i8, 8 * FunctionCallDivCost}, 1395 { ISD::UREM, MVT::v8i8, 8 * FunctionCallDivCost}, 1396 // Quad register types. 1397 { ISD::SDIV, MVT::v2i64, 2 * FunctionCallDivCost}, 1398 { ISD::UDIV, MVT::v2i64, 2 * FunctionCallDivCost}, 1399 { ISD::SREM, MVT::v2i64, 2 * FunctionCallDivCost}, 1400 { ISD::UREM, MVT::v2i64, 2 * FunctionCallDivCost}, 1401 { ISD::SDIV, MVT::v4i32, 4 * FunctionCallDivCost}, 1402 { ISD::UDIV, MVT::v4i32, 4 * FunctionCallDivCost}, 1403 { ISD::SREM, MVT::v4i32, 4 * FunctionCallDivCost}, 1404 { ISD::UREM, MVT::v4i32, 4 * FunctionCallDivCost}, 1405 { ISD::SDIV, MVT::v8i16, 8 * FunctionCallDivCost}, 1406 { ISD::UDIV, MVT::v8i16, 8 * FunctionCallDivCost}, 1407 { ISD::SREM, MVT::v8i16, 8 * FunctionCallDivCost}, 1408 { ISD::UREM, MVT::v8i16, 8 * FunctionCallDivCost}, 1409 { ISD::SDIV, MVT::v16i8, 16 * FunctionCallDivCost}, 1410 { ISD::UDIV, MVT::v16i8, 16 * FunctionCallDivCost}, 1411 { ISD::SREM, MVT::v16i8, 16 * FunctionCallDivCost}, 1412 { ISD::UREM, MVT::v16i8, 16 * FunctionCallDivCost}, 1413 // Multiplication. 1414 }; 1415 1416 if (const auto *Entry = CostTableLookup(CostTbl, ISDOpcode, LT.second)) 1417 return LT.first * Entry->Cost; 1418 1419 InstructionCost Cost = BaseT::getArithmeticInstrCost( 1420 Opcode, Ty, CostKind, Op1Info, Op2Info); 1421 1422 // This is somewhat of a hack. The problem that we are facing is that SROA 1423 // creates a sequence of shift, and, or instructions to construct values. 1424 // These sequences are recognized by the ISel and have zero-cost. Not so for 1425 // the vectorized code. Because we have support for v2i64 but not i64 those 1426 // sequences look particularly beneficial to vectorize. 1427 // To work around this we increase the cost of v2i64 operations to make them 1428 // seem less beneficial. 1429 if (LT.second == MVT::v2i64 && Op2Info.isUniform() && Op2Info.isConstant()) 1430 Cost += 4; 1431 1432 return Cost; 1433 } 1434 1435 // If this operation is a shift on arm/thumb2, it might well be folded into 1436 // the following instruction, hence having a cost of 0. 1437 auto LooksLikeAFreeShift = [&]() { 1438 if (ST->isThumb1Only() || Ty->isVectorTy()) 1439 return false; 1440 1441 if (!CxtI || !CxtI->hasOneUse() || !CxtI->isShift()) 1442 return false; 1443 if (!Op2Info.isUniform() || !Op2Info.isConstant()) 1444 return false; 1445 1446 // Folded into a ADC/ADD/AND/BIC/CMP/EOR/MVN/ORR/ORN/RSB/SBC/SUB 1447 switch (cast<Instruction>(CxtI->user_back())->getOpcode()) { 1448 case Instruction::Add: 1449 case Instruction::Sub: 1450 case Instruction::And: 1451 case Instruction::Xor: 1452 case Instruction::Or: 1453 case Instruction::ICmp: 1454 return true; 1455 default: 1456 return false; 1457 } 1458 }; 1459 if (LooksLikeAFreeShift()) 1460 return 0; 1461 1462 // Default to cheap (throughput/size of 1 instruction) but adjust throughput 1463 // for "multiple beats" potentially needed by MVE instructions. 1464 int BaseCost = 1; 1465 if (ST->hasMVEIntegerOps() && Ty->isVectorTy()) 1466 BaseCost = ST->getMVEVectorCostFactor(CostKind); 1467 1468 // The rest of this mostly follows what is done in BaseT::getArithmeticInstrCost, 1469 // without treating floats as more expensive that scalars or increasing the 1470 // costs for custom operations. The results is also multiplied by the 1471 // MVEVectorCostFactor where appropriate. 1472 if (TLI->isOperationLegalOrCustomOrPromote(ISDOpcode, LT.second)) 1473 return LT.first * BaseCost; 1474 1475 // Else this is expand, assume that we need to scalarize this op. 1476 if (auto *VTy = dyn_cast<FixedVectorType>(Ty)) { 1477 unsigned Num = VTy->getNumElements(); 1478 InstructionCost Cost = 1479 getArithmeticInstrCost(Opcode, Ty->getScalarType(), CostKind); 1480 // Return the cost of multiple scalar invocation plus the cost of 1481 // inserting and extracting the values. 1482 SmallVector<Type *> Tys(Args.size(), Ty); 1483 return BaseT::getScalarizationOverhead(VTy, Args, Tys, CostKind) + 1484 Num * Cost; 1485 } 1486 1487 return BaseCost; 1488 } 1489 1490 InstructionCost ARMTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src, 1491 MaybeAlign Alignment, 1492 unsigned AddressSpace, 1493 TTI::TargetCostKind CostKind, 1494 TTI::OperandValueInfo OpInfo, 1495 const Instruction *I) { 1496 // TODO: Handle other cost kinds. 1497 if (CostKind != TTI::TCK_RecipThroughput) 1498 return 1; 1499 1500 // Type legalization can't handle structs 1501 if (TLI->getValueType(DL, Src, true) == MVT::Other) 1502 return BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, 1503 CostKind); 1504 1505 if (ST->hasNEON() && Src->isVectorTy() && 1506 (Alignment && *Alignment != Align(16)) && 1507 cast<VectorType>(Src)->getElementType()->isDoubleTy()) { 1508 // Unaligned loads/stores are extremely inefficient. 1509 // We need 4 uops for vst.1/vld.1 vs 1uop for vldr/vstr. 1510 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Src); 1511 return LT.first * 4; 1512 } 1513 1514 // MVE can optimize a fpext(load(4xhalf)) using an extending integer load. 1515 // Same for stores. 1516 if (ST->hasMVEFloatOps() && isa<FixedVectorType>(Src) && I && 1517 ((Opcode == Instruction::Load && I->hasOneUse() && 1518 isa<FPExtInst>(*I->user_begin())) || 1519 (Opcode == Instruction::Store && isa<FPTruncInst>(I->getOperand(0))))) { 1520 FixedVectorType *SrcVTy = cast<FixedVectorType>(Src); 1521 Type *DstTy = 1522 Opcode == Instruction::Load 1523 ? (*I->user_begin())->getType() 1524 : cast<Instruction>(I->getOperand(0))->getOperand(0)->getType(); 1525 if (SrcVTy->getNumElements() == 4 && SrcVTy->getScalarType()->isHalfTy() && 1526 DstTy->getScalarType()->isFloatTy()) 1527 return ST->getMVEVectorCostFactor(CostKind); 1528 } 1529 1530 int BaseCost = ST->hasMVEIntegerOps() && Src->isVectorTy() 1531 ? ST->getMVEVectorCostFactor(CostKind) 1532 : 1; 1533 return BaseCost * BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, 1534 CostKind, OpInfo, I); 1535 } 1536 1537 InstructionCost 1538 ARMTTIImpl::getMaskedMemoryOpCost(unsigned Opcode, Type *Src, Align Alignment, 1539 unsigned AddressSpace, 1540 TTI::TargetCostKind CostKind) { 1541 if (ST->hasMVEIntegerOps()) { 1542 if (Opcode == Instruction::Load && isLegalMaskedLoad(Src, Alignment)) 1543 return ST->getMVEVectorCostFactor(CostKind); 1544 if (Opcode == Instruction::Store && isLegalMaskedStore(Src, Alignment)) 1545 return ST->getMVEVectorCostFactor(CostKind); 1546 } 1547 if (!isa<FixedVectorType>(Src)) 1548 return BaseT::getMaskedMemoryOpCost(Opcode, Src, Alignment, AddressSpace, 1549 CostKind); 1550 // Scalar cost, which is currently very high due to the efficiency of the 1551 // generated code. 1552 return cast<FixedVectorType>(Src)->getNumElements() * 8; 1553 } 1554 1555 InstructionCost ARMTTIImpl::getInterleavedMemoryOpCost( 1556 unsigned Opcode, Type *VecTy, unsigned Factor, ArrayRef<unsigned> Indices, 1557 Align Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind, 1558 bool UseMaskForCond, bool UseMaskForGaps) { 1559 assert(Factor >= 2 && "Invalid interleave factor"); 1560 assert(isa<VectorType>(VecTy) && "Expect a vector type"); 1561 1562 // vldN/vstN doesn't support vector types of i64/f64 element. 1563 bool EltIs64Bits = DL.getTypeSizeInBits(VecTy->getScalarType()) == 64; 1564 1565 if (Factor <= TLI->getMaxSupportedInterleaveFactor() && !EltIs64Bits && 1566 !UseMaskForCond && !UseMaskForGaps) { 1567 unsigned NumElts = cast<FixedVectorType>(VecTy)->getNumElements(); 1568 auto *SubVecTy = 1569 FixedVectorType::get(VecTy->getScalarType(), NumElts / Factor); 1570 1571 // vldN/vstN only support legal vector types of size 64 or 128 in bits. 1572 // Accesses having vector types that are a multiple of 128 bits can be 1573 // matched to more than one vldN/vstN instruction. 1574 int BaseCost = 1575 ST->hasMVEIntegerOps() ? ST->getMVEVectorCostFactor(CostKind) : 1; 1576 if (NumElts % Factor == 0 && 1577 TLI->isLegalInterleavedAccessType(Factor, SubVecTy, Alignment, DL)) 1578 return Factor * BaseCost * TLI->getNumInterleavedAccesses(SubVecTy, DL); 1579 1580 // Some smaller than legal interleaved patterns are cheap as we can make 1581 // use of the vmovn or vrev patterns to interleave a standard load. This is 1582 // true for v4i8, v8i8 and v4i16 at least (but not for v4f16 as it is 1583 // promoted differently). The cost of 2 here is then a load and vrev or 1584 // vmovn. 1585 if (ST->hasMVEIntegerOps() && Factor == 2 && NumElts / Factor > 2 && 1586 VecTy->isIntOrIntVectorTy() && 1587 DL.getTypeSizeInBits(SubVecTy).getFixedValue() <= 64) 1588 return 2 * BaseCost; 1589 } 1590 1591 return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices, 1592 Alignment, AddressSpace, CostKind, 1593 UseMaskForCond, UseMaskForGaps); 1594 } 1595 1596 InstructionCost ARMTTIImpl::getGatherScatterOpCost( 1597 unsigned Opcode, Type *DataTy, const Value *Ptr, bool VariableMask, 1598 Align Alignment, TTI::TargetCostKind CostKind, const Instruction *I) { 1599 using namespace PatternMatch; 1600 if (!ST->hasMVEIntegerOps() || !EnableMaskedGatherScatters) 1601 return BaseT::getGatherScatterOpCost(Opcode, DataTy, Ptr, VariableMask, 1602 Alignment, CostKind, I); 1603 1604 assert(DataTy->isVectorTy() && "Can't do gather/scatters on scalar!"); 1605 auto *VTy = cast<FixedVectorType>(DataTy); 1606 1607 // TODO: Splitting, once we do that. 1608 1609 unsigned NumElems = VTy->getNumElements(); 1610 unsigned EltSize = VTy->getScalarSizeInBits(); 1611 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(DataTy); 1612 1613 // For now, it is assumed that for the MVE gather instructions the loads are 1614 // all effectively serialised. This means the cost is the scalar cost 1615 // multiplied by the number of elements being loaded. This is possibly very 1616 // conservative, but even so we still end up vectorising loops because the 1617 // cost per iteration for many loops is lower than for scalar loops. 1618 InstructionCost VectorCost = 1619 NumElems * LT.first * ST->getMVEVectorCostFactor(CostKind); 1620 // The scalarization cost should be a lot higher. We use the number of vector 1621 // elements plus the scalarization overhead. If masking is required then a lot 1622 // of little blocks will be needed and potentially a scalarized p0 mask, 1623 // greatly increasing the cost. 1624 InstructionCost ScalarCost = 1625 NumElems * LT.first + (VariableMask ? NumElems * 5 : 0) + 1626 BaseT::getScalarizationOverhead(VTy, /*Insert*/ true, /*Extract*/ false, 1627 CostKind) + 1628 BaseT::getScalarizationOverhead(VTy, /*Insert*/ false, /*Extract*/ true, 1629 CostKind); 1630 1631 if (EltSize < 8 || Alignment < EltSize / 8) 1632 return ScalarCost; 1633 1634 unsigned ExtSize = EltSize; 1635 // Check whether there's a single user that asks for an extended type 1636 if (I != nullptr) { 1637 // Dependent of the caller of this function, a gather instruction will 1638 // either have opcode Instruction::Load or be a call to the masked_gather 1639 // intrinsic 1640 if ((I->getOpcode() == Instruction::Load || 1641 match(I, m_Intrinsic<Intrinsic::masked_gather>())) && 1642 I->hasOneUse()) { 1643 const User *Us = *I->users().begin(); 1644 if (isa<ZExtInst>(Us) || isa<SExtInst>(Us)) { 1645 // only allow valid type combinations 1646 unsigned TypeSize = 1647 cast<Instruction>(Us)->getType()->getScalarSizeInBits(); 1648 if (((TypeSize == 32 && (EltSize == 8 || EltSize == 16)) || 1649 (TypeSize == 16 && EltSize == 8)) && 1650 TypeSize * NumElems == 128) { 1651 ExtSize = TypeSize; 1652 } 1653 } 1654 } 1655 // Check whether the input data needs to be truncated 1656 TruncInst *T; 1657 if ((I->getOpcode() == Instruction::Store || 1658 match(I, m_Intrinsic<Intrinsic::masked_scatter>())) && 1659 (T = dyn_cast<TruncInst>(I->getOperand(0)))) { 1660 // Only allow valid type combinations 1661 unsigned TypeSize = T->getOperand(0)->getType()->getScalarSizeInBits(); 1662 if (((EltSize == 16 && TypeSize == 32) || 1663 (EltSize == 8 && (TypeSize == 32 || TypeSize == 16))) && 1664 TypeSize * NumElems == 128) 1665 ExtSize = TypeSize; 1666 } 1667 } 1668 1669 if (ExtSize * NumElems != 128 || NumElems < 4) 1670 return ScalarCost; 1671 1672 // Any (aligned) i32 gather will not need to be scalarised. 1673 if (ExtSize == 32) 1674 return VectorCost; 1675 // For smaller types, we need to ensure that the gep's inputs are correctly 1676 // extended from a small enough value. Other sizes (including i64) are 1677 // scalarized for now. 1678 if (ExtSize != 8 && ExtSize != 16) 1679 return ScalarCost; 1680 1681 if (const auto *BC = dyn_cast<BitCastInst>(Ptr)) 1682 Ptr = BC->getOperand(0); 1683 if (const auto *GEP = dyn_cast<GetElementPtrInst>(Ptr)) { 1684 if (GEP->getNumOperands() != 2) 1685 return ScalarCost; 1686 unsigned Scale = DL.getTypeAllocSize(GEP->getResultElementType()); 1687 // Scale needs to be correct (which is only relevant for i16s). 1688 if (Scale != 1 && Scale * 8 != ExtSize) 1689 return ScalarCost; 1690 // And we need to zext (not sext) the indexes from a small enough type. 1691 if (const auto *ZExt = dyn_cast<ZExtInst>(GEP->getOperand(1))) { 1692 if (ZExt->getOperand(0)->getType()->getScalarSizeInBits() <= ExtSize) 1693 return VectorCost; 1694 } 1695 return ScalarCost; 1696 } 1697 return ScalarCost; 1698 } 1699 1700 InstructionCost 1701 ARMTTIImpl::getArithmeticReductionCost(unsigned Opcode, VectorType *ValTy, 1702 std::optional<FastMathFlags> FMF, 1703 TTI::TargetCostKind CostKind) { 1704 1705 EVT ValVT = TLI->getValueType(DL, ValTy); 1706 int ISD = TLI->InstructionOpcodeToISD(Opcode); 1707 unsigned EltSize = ValVT.getScalarSizeInBits(); 1708 1709 // In general floating point reductions are a series of elementwise 1710 // operations, with free extracts on each step. These are either in-order or 1711 // treewise depending on whether that is allowed by the fast math flags. 1712 if ((ISD == ISD::FADD || ISD == ISD::FMUL) && 1713 ((EltSize == 32 && ST->hasVFP2Base()) || 1714 (EltSize == 64 && ST->hasFP64()) || 1715 (EltSize == 16 && ST->hasFullFP16()))) { 1716 unsigned NumElts = cast<FixedVectorType>(ValTy)->getNumElements(); 1717 unsigned VecLimit = ST->hasMVEFloatOps() ? 128 : (ST->hasNEON() ? 64 : -1); 1718 InstructionCost VecCost = 0; 1719 while (!TTI::requiresOrderedReduction(FMF) && isPowerOf2_32(NumElts) && 1720 NumElts * EltSize > VecLimit) { 1721 Type *VecTy = FixedVectorType::get(ValTy->getElementType(), NumElts / 2); 1722 VecCost += getArithmeticInstrCost(Opcode, VecTy, CostKind); 1723 NumElts /= 2; 1724 } 1725 1726 // For fp16 we need to extract the upper lane elements. MVE can add a 1727 // VREV+FMIN/MAX to perform another vector step instead. 1728 InstructionCost ExtractCost = 0; 1729 if (!TTI::requiresOrderedReduction(FMF) && ST->hasMVEFloatOps() && 1730 ValVT.getVectorElementType() == MVT::f16 && NumElts == 8) { 1731 VecCost += ST->getMVEVectorCostFactor(CostKind) * 2; 1732 NumElts /= 2; 1733 } else if (ValVT.getVectorElementType() == MVT::f16) 1734 ExtractCost = NumElts / 2; 1735 1736 return VecCost + ExtractCost + 1737 NumElts * 1738 getArithmeticInstrCost(Opcode, ValTy->getElementType(), CostKind); 1739 } 1740 1741 if ((ISD == ISD::AND || ISD == ISD::OR || ISD == ISD::XOR) && 1742 (EltSize == 64 || EltSize == 32 || EltSize == 16 || EltSize == 8)) { 1743 unsigned NumElts = cast<FixedVectorType>(ValTy)->getNumElements(); 1744 unsigned VecLimit = 1745 ST->hasMVEIntegerOps() ? 128 : (ST->hasNEON() ? 64 : -1); 1746 InstructionCost VecCost = 0; 1747 while (isPowerOf2_32(NumElts) && NumElts * EltSize > VecLimit) { 1748 Type *VecTy = FixedVectorType::get(ValTy->getElementType(), NumElts / 2); 1749 VecCost += getArithmeticInstrCost(Opcode, VecTy, CostKind); 1750 NumElts /= 2; 1751 } 1752 // For i16/i8, MVE will perform a VREV + VORR/VAND/VEOR for the 64bit vector 1753 // step. 1754 if (ST->hasMVEIntegerOps() && ValVT.getScalarSizeInBits() <= 16 && 1755 NumElts * EltSize == 64) { 1756 Type *VecTy = FixedVectorType::get(ValTy->getElementType(), NumElts); 1757 VecCost += ST->getMVEVectorCostFactor(CostKind) + 1758 getArithmeticInstrCost(Opcode, VecTy, CostKind); 1759 NumElts /= 2; 1760 } 1761 1762 // From here we extract the elements and perform the and/or/xor. 1763 InstructionCost ExtractCost = NumElts; 1764 return VecCost + ExtractCost + 1765 (NumElts - 1) * getArithmeticInstrCost( 1766 Opcode, ValTy->getElementType(), CostKind); 1767 } 1768 1769 if (!ST->hasMVEIntegerOps() || !ValVT.isSimple() || ISD != ISD::ADD || 1770 TTI::requiresOrderedReduction(FMF)) 1771 return BaseT::getArithmeticReductionCost(Opcode, ValTy, FMF, CostKind); 1772 1773 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1774 1775 static const CostTblEntry CostTblAdd[]{ 1776 {ISD::ADD, MVT::v16i8, 1}, 1777 {ISD::ADD, MVT::v8i16, 1}, 1778 {ISD::ADD, MVT::v4i32, 1}, 1779 }; 1780 if (const auto *Entry = CostTableLookup(CostTblAdd, ISD, LT.second)) 1781 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind) * LT.first; 1782 1783 return BaseT::getArithmeticReductionCost(Opcode, ValTy, FMF, CostKind); 1784 } 1785 1786 InstructionCost ARMTTIImpl::getExtendedReductionCost( 1787 unsigned Opcode, bool IsUnsigned, Type *ResTy, VectorType *ValTy, 1788 FastMathFlags FMF, TTI::TargetCostKind CostKind) { 1789 EVT ValVT = TLI->getValueType(DL, ValTy); 1790 EVT ResVT = TLI->getValueType(DL, ResTy); 1791 1792 int ISD = TLI->InstructionOpcodeToISD(Opcode); 1793 1794 switch (ISD) { 1795 case ISD::ADD: 1796 if (ST->hasMVEIntegerOps() && ValVT.isSimple() && ResVT.isSimple()) { 1797 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1798 1799 // The legal cases are: 1800 // VADDV u/s 8/16/32 1801 // VADDLV u/s 32 1802 // Codegen currently cannot always handle larger than legal vectors very 1803 // well, especially for predicated reductions where the mask needs to be 1804 // split, so restrict to 128bit or smaller input types. 1805 unsigned RevVTSize = ResVT.getSizeInBits(); 1806 if (ValVT.getSizeInBits() <= 128 && 1807 ((LT.second == MVT::v16i8 && RevVTSize <= 32) || 1808 (LT.second == MVT::v8i16 && RevVTSize <= 32) || 1809 (LT.second == MVT::v4i32 && RevVTSize <= 64))) 1810 return ST->getMVEVectorCostFactor(CostKind) * LT.first; 1811 } 1812 break; 1813 default: 1814 break; 1815 } 1816 return BaseT::getExtendedReductionCost(Opcode, IsUnsigned, ResTy, ValTy, FMF, 1817 CostKind); 1818 } 1819 1820 InstructionCost 1821 ARMTTIImpl::getMulAccReductionCost(bool IsUnsigned, Type *ResTy, 1822 VectorType *ValTy, 1823 TTI::TargetCostKind CostKind) { 1824 EVT ValVT = TLI->getValueType(DL, ValTy); 1825 EVT ResVT = TLI->getValueType(DL, ResTy); 1826 1827 if (ST->hasMVEIntegerOps() && ValVT.isSimple() && ResVT.isSimple()) { 1828 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1829 1830 // The legal cases are: 1831 // VMLAV u/s 8/16/32 1832 // VMLALV u/s 16/32 1833 // Codegen currently cannot always handle larger than legal vectors very 1834 // well, especially for predicated reductions where the mask needs to be 1835 // split, so restrict to 128bit or smaller input types. 1836 unsigned RevVTSize = ResVT.getSizeInBits(); 1837 if (ValVT.getSizeInBits() <= 128 && 1838 ((LT.second == MVT::v16i8 && RevVTSize <= 32) || 1839 (LT.second == MVT::v8i16 && RevVTSize <= 64) || 1840 (LT.second == MVT::v4i32 && RevVTSize <= 64))) 1841 return ST->getMVEVectorCostFactor(CostKind) * LT.first; 1842 } 1843 1844 return BaseT::getMulAccReductionCost(IsUnsigned, ResTy, ValTy, CostKind); 1845 } 1846 1847 InstructionCost 1848 ARMTTIImpl::getMinMaxReductionCost(Intrinsic::ID IID, VectorType *Ty, 1849 FastMathFlags FMF, 1850 TTI::TargetCostKind CostKind) { 1851 EVT ValVT = TLI->getValueType(DL, Ty); 1852 1853 // In general floating point reductions are a series of elementwise 1854 // operations, with free extracts on each step. These are either in-order or 1855 // treewise depending on whether that is allowed by the fast math flags. 1856 if ((IID == Intrinsic::minnum || IID == Intrinsic::maxnum) && 1857 ((ValVT.getVectorElementType() == MVT::f32 && ST->hasVFP2Base()) || 1858 (ValVT.getVectorElementType() == MVT::f64 && ST->hasFP64()) || 1859 (ValVT.getVectorElementType() == MVT::f16 && ST->hasFullFP16()))) { 1860 unsigned NumElts = cast<FixedVectorType>(Ty)->getNumElements(); 1861 unsigned EltSize = ValVT.getScalarSizeInBits(); 1862 unsigned VecLimit = ST->hasMVEFloatOps() ? 128 : (ST->hasNEON() ? 64 : -1); 1863 InstructionCost VecCost; 1864 while (isPowerOf2_32(NumElts) && NumElts * EltSize > VecLimit) { 1865 Type *VecTy = FixedVectorType::get(Ty->getElementType(), NumElts/2); 1866 IntrinsicCostAttributes ICA(IID, VecTy, {VecTy, VecTy}, FMF); 1867 VecCost += getIntrinsicInstrCost(ICA, CostKind); 1868 NumElts /= 2; 1869 } 1870 1871 // For fp16 we need to extract the upper lane elements. MVE can add a 1872 // VREV+FMIN/MAX to perform another vector step instead. 1873 InstructionCost ExtractCost = 0; 1874 if (ST->hasMVEFloatOps() && ValVT.getVectorElementType() == MVT::f16 && 1875 NumElts == 8) { 1876 VecCost += ST->getMVEVectorCostFactor(CostKind) * 2; 1877 NumElts /= 2; 1878 } else if (ValVT.getVectorElementType() == MVT::f16) 1879 ExtractCost = cast<FixedVectorType>(Ty)->getNumElements() / 2; 1880 1881 IntrinsicCostAttributes ICA(IID, Ty->getElementType(), 1882 {Ty->getElementType(), Ty->getElementType()}, 1883 FMF); 1884 return VecCost + ExtractCost + 1885 (NumElts - 1) * getIntrinsicInstrCost(ICA, CostKind); 1886 } 1887 1888 if (IID == Intrinsic::smin || IID == Intrinsic::smax || 1889 IID == Intrinsic::umin || IID == Intrinsic::umax) { 1890 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Ty); 1891 1892 // All costs are the same for u/s min/max. These lower to vminv, which are 1893 // given a slightly higher cost as they tend to take multiple cycles for 1894 // smaller type sizes. 1895 static const CostTblEntry CostTblAdd[]{ 1896 {ISD::SMIN, MVT::v16i8, 4}, 1897 {ISD::SMIN, MVT::v8i16, 3}, 1898 {ISD::SMIN, MVT::v4i32, 2}, 1899 }; 1900 if (const auto *Entry = CostTableLookup(CostTblAdd, ISD::SMIN, LT.second)) 1901 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind) * LT.first; 1902 } 1903 1904 return BaseT::getMinMaxReductionCost(IID, Ty, FMF, CostKind); 1905 } 1906 1907 InstructionCost 1908 ARMTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA, 1909 TTI::TargetCostKind CostKind) { 1910 unsigned Opc = ICA.getID(); 1911 switch (Opc) { 1912 case Intrinsic::get_active_lane_mask: 1913 // Currently we make a somewhat optimistic assumption that 1914 // active_lane_mask's are always free. In reality it may be freely folded 1915 // into a tail predicated loop, expanded into a VCPT or expanded into a lot 1916 // of add/icmp code. We may need to improve this in the future, but being 1917 // able to detect if it is free or not involves looking at a lot of other 1918 // code. We currently assume that the vectorizer inserted these, and knew 1919 // what it was doing in adding one. 1920 if (ST->hasMVEIntegerOps()) 1921 return 0; 1922 break; 1923 case Intrinsic::sadd_sat: 1924 case Intrinsic::ssub_sat: 1925 case Intrinsic::uadd_sat: 1926 case Intrinsic::usub_sat: { 1927 bool IsAdd = (Opc == Intrinsic::sadd_sat || Opc == Intrinsic::ssub_sat); 1928 bool IsSigned = (Opc == Intrinsic::sadd_sat || Opc == Intrinsic::ssub_sat); 1929 Type *RetTy = ICA.getReturnType(); 1930 1931 if (auto *ITy = dyn_cast<IntegerType>(RetTy)) { 1932 if (IsSigned && ST->hasDSP() && ITy->getBitWidth() == 32) 1933 return 1; // qadd / qsub 1934 if (ST->hasDSP() && (ITy->getBitWidth() == 8 || ITy->getBitWidth() == 16)) 1935 return 2; // uqadd16 / qadd16 / uqsub16 / qsub16 + possible extend. 1936 // Otherwise return the cost of expanding the node. Generally an add + 1937 // icmp + sel. 1938 CmpInst::Predicate Pred = CmpInst::ICMP_SGT; 1939 Type *CondTy = RetTy->getWithNewBitWidth(1); 1940 return getArithmeticInstrCost(IsAdd ? Instruction::Add : Instruction::Sub, 1941 RetTy, CostKind) + 1942 2 * getCmpSelInstrCost(BinaryOperator::ICmp, RetTy, CondTy, Pred, 1943 CostKind) + 1944 2 * getCmpSelInstrCost(BinaryOperator::Select, RetTy, CondTy, Pred, 1945 CostKind); 1946 } 1947 1948 if (!ST->hasMVEIntegerOps()) 1949 break; 1950 1951 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(RetTy); 1952 if (LT.second == MVT::v4i32 || LT.second == MVT::v8i16 || 1953 LT.second == MVT::v16i8) { 1954 // This is a base cost of 1 for the vqadd, plus 3 extract shifts if we 1955 // need to extend the type, as it uses shr(qadd(shl, shl)). 1956 unsigned Instrs = 1957 LT.second.getScalarSizeInBits() == RetTy->getScalarSizeInBits() ? 1 1958 : 4; 1959 return LT.first * ST->getMVEVectorCostFactor(CostKind) * Instrs; 1960 } 1961 break; 1962 } 1963 case Intrinsic::abs: 1964 case Intrinsic::smin: 1965 case Intrinsic::smax: 1966 case Intrinsic::umin: 1967 case Intrinsic::umax: { 1968 if (!ST->hasMVEIntegerOps()) 1969 break; 1970 Type *VT = ICA.getReturnType(); 1971 1972 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(VT); 1973 if (LT.second == MVT::v4i32 || LT.second == MVT::v8i16 || 1974 LT.second == MVT::v16i8) 1975 return LT.first * ST->getMVEVectorCostFactor(CostKind); 1976 break; 1977 } 1978 case Intrinsic::minnum: 1979 case Intrinsic::maxnum: { 1980 if (!ST->hasMVEFloatOps()) 1981 break; 1982 Type *VT = ICA.getReturnType(); 1983 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(VT); 1984 if (LT.second == MVT::v4f32 || LT.second == MVT::v8f16) 1985 return LT.first * ST->getMVEVectorCostFactor(CostKind); 1986 break; 1987 } 1988 case Intrinsic::fptosi_sat: 1989 case Intrinsic::fptoui_sat: { 1990 if (ICA.getArgTypes().empty()) 1991 break; 1992 bool IsSigned = Opc == Intrinsic::fptosi_sat; 1993 auto LT = getTypeLegalizationCost(ICA.getArgTypes()[0]); 1994 EVT MTy = TLI->getValueType(DL, ICA.getReturnType()); 1995 // Check for the legal types, with the corect subtarget features. 1996 if ((ST->hasVFP2Base() && LT.second == MVT::f32 && MTy == MVT::i32) || 1997 (ST->hasFP64() && LT.second == MVT::f64 && MTy == MVT::i32) || 1998 (ST->hasFullFP16() && LT.second == MVT::f16 && MTy == MVT::i32)) 1999 return LT.first; 2000 2001 // Equally for MVE vector types 2002 if (ST->hasMVEFloatOps() && 2003 (LT.second == MVT::v4f32 || LT.second == MVT::v8f16) && 2004 LT.second.getScalarSizeInBits() == MTy.getScalarSizeInBits()) 2005 return LT.first * ST->getMVEVectorCostFactor(CostKind); 2006 2007 // If we can we use a legal convert followed by a min+max 2008 if (((ST->hasVFP2Base() && LT.second == MVT::f32) || 2009 (ST->hasFP64() && LT.second == MVT::f64) || 2010 (ST->hasFullFP16() && LT.second == MVT::f16) || 2011 (ST->hasMVEFloatOps() && 2012 (LT.second == MVT::v4f32 || LT.second == MVT::v8f16))) && 2013 LT.second.getScalarSizeInBits() >= MTy.getScalarSizeInBits()) { 2014 Type *LegalTy = Type::getIntNTy(ICA.getReturnType()->getContext(), 2015 LT.second.getScalarSizeInBits()); 2016 InstructionCost Cost = 2017 LT.second.isVector() ? ST->getMVEVectorCostFactor(CostKind) : 1; 2018 IntrinsicCostAttributes Attrs1(IsSigned ? Intrinsic::smin 2019 : Intrinsic::umin, 2020 LegalTy, {LegalTy, LegalTy}); 2021 Cost += getIntrinsicInstrCost(Attrs1, CostKind); 2022 IntrinsicCostAttributes Attrs2(IsSigned ? Intrinsic::smax 2023 : Intrinsic::umax, 2024 LegalTy, {LegalTy, LegalTy}); 2025 Cost += getIntrinsicInstrCost(Attrs2, CostKind); 2026 return LT.first * Cost; 2027 } 2028 // Otherwise we need to follow the default expansion that clamps the value 2029 // using a float min/max with a fcmp+sel for nan handling when signed. 2030 Type *FPTy = ICA.getArgTypes()[0]; 2031 Type *RetTy = ICA.getReturnType(); 2032 IntrinsicCostAttributes Attrs1(Intrinsic::minnum, FPTy, {FPTy, FPTy}); 2033 InstructionCost Cost = getIntrinsicInstrCost(Attrs1, CostKind); 2034 IntrinsicCostAttributes Attrs2(Intrinsic::maxnum, FPTy, {FPTy, FPTy}); 2035 Cost += getIntrinsicInstrCost(Attrs2, CostKind); 2036 Cost += 2037 getCastInstrCost(IsSigned ? Instruction::FPToSI : Instruction::FPToUI, 2038 RetTy, FPTy, TTI::CastContextHint::None, CostKind); 2039 if (IsSigned) { 2040 Type *CondTy = RetTy->getWithNewBitWidth(1); 2041 Cost += getCmpSelInstrCost(BinaryOperator::FCmp, FPTy, CondTy, 2042 CmpInst::FCMP_UNO, CostKind); 2043 Cost += getCmpSelInstrCost(BinaryOperator::Select, RetTy, CondTy, 2044 CmpInst::FCMP_UNO, CostKind); 2045 } 2046 return Cost; 2047 } 2048 } 2049 2050 return BaseT::getIntrinsicInstrCost(ICA, CostKind); 2051 } 2052 2053 bool ARMTTIImpl::isLoweredToCall(const Function *F) { 2054 if (!F->isIntrinsic()) 2055 return BaseT::isLoweredToCall(F); 2056 2057 // Assume all Arm-specific intrinsics map to an instruction. 2058 if (F->getName().starts_with("llvm.arm")) 2059 return false; 2060 2061 switch (F->getIntrinsicID()) { 2062 default: break; 2063 case Intrinsic::powi: 2064 case Intrinsic::sin: 2065 case Intrinsic::cos: 2066 case Intrinsic::pow: 2067 case Intrinsic::log: 2068 case Intrinsic::log10: 2069 case Intrinsic::log2: 2070 case Intrinsic::exp: 2071 case Intrinsic::exp2: 2072 return true; 2073 case Intrinsic::sqrt: 2074 case Intrinsic::fabs: 2075 case Intrinsic::copysign: 2076 case Intrinsic::floor: 2077 case Intrinsic::ceil: 2078 case Intrinsic::trunc: 2079 case Intrinsic::rint: 2080 case Intrinsic::nearbyint: 2081 case Intrinsic::round: 2082 case Intrinsic::canonicalize: 2083 case Intrinsic::lround: 2084 case Intrinsic::llround: 2085 case Intrinsic::lrint: 2086 case Intrinsic::llrint: 2087 if (F->getReturnType()->isDoubleTy() && !ST->hasFP64()) 2088 return true; 2089 if (F->getReturnType()->isHalfTy() && !ST->hasFullFP16()) 2090 return true; 2091 // Some operations can be handled by vector instructions and assume 2092 // unsupported vectors will be expanded into supported scalar ones. 2093 // TODO Handle scalar operations properly. 2094 return !ST->hasFPARMv8Base() && !ST->hasVFP2Base(); 2095 case Intrinsic::masked_store: 2096 case Intrinsic::masked_load: 2097 case Intrinsic::masked_gather: 2098 case Intrinsic::masked_scatter: 2099 return !ST->hasMVEIntegerOps(); 2100 case Intrinsic::sadd_with_overflow: 2101 case Intrinsic::uadd_with_overflow: 2102 case Intrinsic::ssub_with_overflow: 2103 case Intrinsic::usub_with_overflow: 2104 case Intrinsic::sadd_sat: 2105 case Intrinsic::uadd_sat: 2106 case Intrinsic::ssub_sat: 2107 case Intrinsic::usub_sat: 2108 return false; 2109 } 2110 2111 return BaseT::isLoweredToCall(F); 2112 } 2113 2114 bool ARMTTIImpl::maybeLoweredToCall(Instruction &I) { 2115 unsigned ISD = TLI->InstructionOpcodeToISD(I.getOpcode()); 2116 EVT VT = TLI->getValueType(DL, I.getType(), true); 2117 if (TLI->getOperationAction(ISD, VT) == TargetLowering::LibCall) 2118 return true; 2119 2120 // Check if an intrinsic will be lowered to a call and assume that any 2121 // other CallInst will generate a bl. 2122 if (auto *Call = dyn_cast<CallInst>(&I)) { 2123 if (auto *II = dyn_cast<IntrinsicInst>(Call)) { 2124 switch(II->getIntrinsicID()) { 2125 case Intrinsic::memcpy: 2126 case Intrinsic::memset: 2127 case Intrinsic::memmove: 2128 return getNumMemOps(II) == -1; 2129 default: 2130 if (const Function *F = Call->getCalledFunction()) 2131 return isLoweredToCall(F); 2132 } 2133 } 2134 return true; 2135 } 2136 2137 // FPv5 provides conversions between integer, double-precision, 2138 // single-precision, and half-precision formats. 2139 switch (I.getOpcode()) { 2140 default: 2141 break; 2142 case Instruction::FPToSI: 2143 case Instruction::FPToUI: 2144 case Instruction::SIToFP: 2145 case Instruction::UIToFP: 2146 case Instruction::FPTrunc: 2147 case Instruction::FPExt: 2148 return !ST->hasFPARMv8Base(); 2149 } 2150 2151 // FIXME: Unfortunately the approach of checking the Operation Action does 2152 // not catch all cases of Legalization that use library calls. Our 2153 // Legalization step categorizes some transformations into library calls as 2154 // Custom, Expand or even Legal when doing type legalization. So for now 2155 // we have to special case for instance the SDIV of 64bit integers and the 2156 // use of floating point emulation. 2157 if (VT.isInteger() && VT.getSizeInBits() >= 64) { 2158 switch (ISD) { 2159 default: 2160 break; 2161 case ISD::SDIV: 2162 case ISD::UDIV: 2163 case ISD::SREM: 2164 case ISD::UREM: 2165 case ISD::SDIVREM: 2166 case ISD::UDIVREM: 2167 return true; 2168 } 2169 } 2170 2171 // Assume all other non-float operations are supported. 2172 if (!VT.isFloatingPoint()) 2173 return false; 2174 2175 // We'll need a library call to handle most floats when using soft. 2176 if (TLI->useSoftFloat()) { 2177 switch (I.getOpcode()) { 2178 default: 2179 return true; 2180 case Instruction::Alloca: 2181 case Instruction::Load: 2182 case Instruction::Store: 2183 case Instruction::Select: 2184 case Instruction::PHI: 2185 return false; 2186 } 2187 } 2188 2189 // We'll need a libcall to perform double precision operations on a single 2190 // precision only FPU. 2191 if (I.getType()->isDoubleTy() && !ST->hasFP64()) 2192 return true; 2193 2194 // Likewise for half precision arithmetic. 2195 if (I.getType()->isHalfTy() && !ST->hasFullFP16()) 2196 return true; 2197 2198 return false; 2199 } 2200 2201 bool ARMTTIImpl::isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE, 2202 AssumptionCache &AC, 2203 TargetLibraryInfo *LibInfo, 2204 HardwareLoopInfo &HWLoopInfo) { 2205 // Low-overhead branches are only supported in the 'low-overhead branch' 2206 // extension of v8.1-m. 2207 if (!ST->hasLOB() || DisableLowOverheadLoops) { 2208 LLVM_DEBUG(dbgs() << "ARMHWLoops: Disabled\n"); 2209 return false; 2210 } 2211 2212 if (!SE.hasLoopInvariantBackedgeTakenCount(L)) { 2213 LLVM_DEBUG(dbgs() << "ARMHWLoops: No BETC\n"); 2214 return false; 2215 } 2216 2217 const SCEV *BackedgeTakenCount = SE.getBackedgeTakenCount(L); 2218 if (isa<SCEVCouldNotCompute>(BackedgeTakenCount)) { 2219 LLVM_DEBUG(dbgs() << "ARMHWLoops: Uncomputable BETC\n"); 2220 return false; 2221 } 2222 2223 const SCEV *TripCountSCEV = 2224 SE.getAddExpr(BackedgeTakenCount, 2225 SE.getOne(BackedgeTakenCount->getType())); 2226 2227 // We need to store the trip count in LR, a 32-bit register. 2228 if (SE.getUnsignedRangeMax(TripCountSCEV).getBitWidth() > 32) { 2229 LLVM_DEBUG(dbgs() << "ARMHWLoops: Trip count does not fit into 32bits\n"); 2230 return false; 2231 } 2232 2233 // Making a call will trash LR and clear LO_BRANCH_INFO, so there's little 2234 // point in generating a hardware loop if that's going to happen. 2235 2236 auto IsHardwareLoopIntrinsic = [](Instruction &I) { 2237 if (auto *Call = dyn_cast<IntrinsicInst>(&I)) { 2238 switch (Call->getIntrinsicID()) { 2239 default: 2240 break; 2241 case Intrinsic::start_loop_iterations: 2242 case Intrinsic::test_start_loop_iterations: 2243 case Intrinsic::loop_decrement: 2244 case Intrinsic::loop_decrement_reg: 2245 return true; 2246 } 2247 } 2248 return false; 2249 }; 2250 2251 // Scan the instructions to see if there's any that we know will turn into a 2252 // call or if this loop is already a low-overhead loop or will become a tail 2253 // predicated loop. 2254 bool IsTailPredLoop = false; 2255 auto ScanLoop = [&](Loop *L) { 2256 for (auto *BB : L->getBlocks()) { 2257 for (auto &I : *BB) { 2258 if (maybeLoweredToCall(I) || IsHardwareLoopIntrinsic(I) || 2259 isa<InlineAsm>(I)) { 2260 LLVM_DEBUG(dbgs() << "ARMHWLoops: Bad instruction: " << I << "\n"); 2261 return false; 2262 } 2263 if (auto *II = dyn_cast<IntrinsicInst>(&I)) 2264 IsTailPredLoop |= 2265 II->getIntrinsicID() == Intrinsic::get_active_lane_mask || 2266 II->getIntrinsicID() == Intrinsic::arm_mve_vctp8 || 2267 II->getIntrinsicID() == Intrinsic::arm_mve_vctp16 || 2268 II->getIntrinsicID() == Intrinsic::arm_mve_vctp32 || 2269 II->getIntrinsicID() == Intrinsic::arm_mve_vctp64; 2270 } 2271 } 2272 return true; 2273 }; 2274 2275 // Visit inner loops. 2276 for (auto *Inner : *L) 2277 if (!ScanLoop(Inner)) 2278 return false; 2279 2280 if (!ScanLoop(L)) 2281 return false; 2282 2283 // TODO: Check whether the trip count calculation is expensive. If L is the 2284 // inner loop but we know it has a low trip count, calculating that trip 2285 // count (in the parent loop) may be detrimental. 2286 2287 LLVMContext &C = L->getHeader()->getContext(); 2288 HWLoopInfo.CounterInReg = true; 2289 HWLoopInfo.IsNestingLegal = false; 2290 HWLoopInfo.PerformEntryTest = AllowWLSLoops && !IsTailPredLoop; 2291 HWLoopInfo.CountType = Type::getInt32Ty(C); 2292 HWLoopInfo.LoopDecrement = ConstantInt::get(HWLoopInfo.CountType, 1); 2293 return true; 2294 } 2295 2296 static bool canTailPredicateInstruction(Instruction &I, int &ICmpCount) { 2297 // We don't allow icmp's, and because we only look at single block loops, 2298 // we simply count the icmps, i.e. there should only be 1 for the backedge. 2299 if (isa<ICmpInst>(&I) && ++ICmpCount > 1) 2300 return false; 2301 // FIXME: This is a workaround for poor cost modelling. Min/Max intrinsics are 2302 // not currently canonical, but soon will be. Code without them uses icmp, and 2303 // so is not tail predicated as per the condition above. In order to get the 2304 // same performance we treat min and max the same as an icmp for tailpred 2305 // purposes for the moment (we often rely on non-tailpred and higher VF's to 2306 // pick more optimial instructions like VQDMULH. They need to be recognized 2307 // directly by the vectorizer). 2308 if (auto *II = dyn_cast<IntrinsicInst>(&I)) 2309 if ((II->getIntrinsicID() == Intrinsic::smin || 2310 II->getIntrinsicID() == Intrinsic::smax || 2311 II->getIntrinsicID() == Intrinsic::umin || 2312 II->getIntrinsicID() == Intrinsic::umax) && 2313 ++ICmpCount > 1) 2314 return false; 2315 2316 if (isa<FCmpInst>(&I)) 2317 return false; 2318 2319 // We could allow extending/narrowing FP loads/stores, but codegen is 2320 // too inefficient so reject this for now. 2321 if (isa<FPExtInst>(&I) || isa<FPTruncInst>(&I)) 2322 return false; 2323 2324 // Extends have to be extending-loads 2325 if (isa<SExtInst>(&I) || isa<ZExtInst>(&I) ) 2326 if (!I.getOperand(0)->hasOneUse() || !isa<LoadInst>(I.getOperand(0))) 2327 return false; 2328 2329 // Truncs have to be narrowing-stores 2330 if (isa<TruncInst>(&I) ) 2331 if (!I.hasOneUse() || !isa<StoreInst>(*I.user_begin())) 2332 return false; 2333 2334 return true; 2335 } 2336 2337 // To set up a tail-predicated loop, we need to know the total number of 2338 // elements processed by that loop. Thus, we need to determine the element 2339 // size and: 2340 // 1) it should be uniform for all operations in the vector loop, so we 2341 // e.g. don't want any widening/narrowing operations. 2342 // 2) it should be smaller than i64s because we don't have vector operations 2343 // that work on i64s. 2344 // 3) we don't want elements to be reversed or shuffled, to make sure the 2345 // tail-predication masks/predicates the right lanes. 2346 // 2347 static bool canTailPredicateLoop(Loop *L, LoopInfo *LI, ScalarEvolution &SE, 2348 const DataLayout &DL, 2349 const LoopAccessInfo *LAI) { 2350 LLVM_DEBUG(dbgs() << "Tail-predication: checking allowed instructions\n"); 2351 2352 // If there are live-out values, it is probably a reduction. We can predicate 2353 // most reduction operations freely under MVE using a combination of 2354 // prefer-predicated-reduction-select and inloop reductions. We limit this to 2355 // floating point and integer reductions, but don't check for operators 2356 // specifically here. If the value ends up not being a reduction (and so the 2357 // vectorizer cannot tailfold the loop), we should fall back to standard 2358 // vectorization automatically. 2359 SmallVector< Instruction *, 8 > LiveOuts; 2360 LiveOuts = llvm::findDefsUsedOutsideOfLoop(L); 2361 bool ReductionsDisabled = 2362 EnableTailPredication == TailPredication::EnabledNoReductions || 2363 EnableTailPredication == TailPredication::ForceEnabledNoReductions; 2364 2365 for (auto *I : LiveOuts) { 2366 if (!I->getType()->isIntegerTy() && !I->getType()->isFloatTy() && 2367 !I->getType()->isHalfTy()) { 2368 LLVM_DEBUG(dbgs() << "Don't tail-predicate loop with non-integer/float " 2369 "live-out value\n"); 2370 return false; 2371 } 2372 if (ReductionsDisabled) { 2373 LLVM_DEBUG(dbgs() << "Reductions not enabled\n"); 2374 return false; 2375 } 2376 } 2377 2378 // Next, check that all instructions can be tail-predicated. 2379 PredicatedScalarEvolution PSE = LAI->getPSE(); 2380 SmallVector<Instruction *, 16> LoadStores; 2381 int ICmpCount = 0; 2382 2383 for (BasicBlock *BB : L->blocks()) { 2384 for (Instruction &I : BB->instructionsWithoutDebug()) { 2385 if (isa<PHINode>(&I)) 2386 continue; 2387 if (!canTailPredicateInstruction(I, ICmpCount)) { 2388 LLVM_DEBUG(dbgs() << "Instruction not allowed: "; I.dump()); 2389 return false; 2390 } 2391 2392 Type *T = I.getType(); 2393 if (T->getScalarSizeInBits() > 32) { 2394 LLVM_DEBUG(dbgs() << "Unsupported Type: "; T->dump()); 2395 return false; 2396 } 2397 if (isa<StoreInst>(I) || isa<LoadInst>(I)) { 2398 Value *Ptr = getLoadStorePointerOperand(&I); 2399 Type *AccessTy = getLoadStoreType(&I); 2400 int64_t NextStride = getPtrStride(PSE, AccessTy, Ptr, L).value_or(0); 2401 if (NextStride == 1) { 2402 // TODO: for now only allow consecutive strides of 1. We could support 2403 // other strides as long as it is uniform, but let's keep it simple 2404 // for now. 2405 continue; 2406 } else if (NextStride == -1 || 2407 (NextStride == 2 && MVEMaxSupportedInterleaveFactor >= 2) || 2408 (NextStride == 4 && MVEMaxSupportedInterleaveFactor >= 4)) { 2409 LLVM_DEBUG(dbgs() 2410 << "Consecutive strides of 2 found, vld2/vstr2 can't " 2411 "be tail-predicated\n."); 2412 return false; 2413 // TODO: don't tail predicate if there is a reversed load? 2414 } else if (EnableMaskedGatherScatters) { 2415 // Gather/scatters do allow loading from arbitrary strides, at 2416 // least if they are loop invariant. 2417 // TODO: Loop variant strides should in theory work, too, but 2418 // this requires further testing. 2419 const SCEV *PtrScev = PSE.getSE()->getSCEV(Ptr); 2420 if (auto AR = dyn_cast<SCEVAddRecExpr>(PtrScev)) { 2421 const SCEV *Step = AR->getStepRecurrence(*PSE.getSE()); 2422 if (PSE.getSE()->isLoopInvariant(Step, L)) 2423 continue; 2424 } 2425 } 2426 LLVM_DEBUG(dbgs() << "Bad stride found, can't " 2427 "tail-predicate\n."); 2428 return false; 2429 } 2430 } 2431 } 2432 2433 LLVM_DEBUG(dbgs() << "tail-predication: all instructions allowed!\n"); 2434 return true; 2435 } 2436 2437 bool ARMTTIImpl::preferPredicateOverEpilogue(TailFoldingInfo *TFI) { 2438 if (!EnableTailPredication) { 2439 LLVM_DEBUG(dbgs() << "Tail-predication not enabled.\n"); 2440 return false; 2441 } 2442 2443 // Creating a predicated vector loop is the first step for generating a 2444 // tail-predicated hardware loop, for which we need the MVE masked 2445 // load/stores instructions: 2446 if (!ST->hasMVEIntegerOps()) 2447 return false; 2448 2449 LoopVectorizationLegality *LVL = TFI->LVL; 2450 Loop *L = LVL->getLoop(); 2451 2452 // For now, restrict this to single block loops. 2453 if (L->getNumBlocks() > 1) { 2454 LLVM_DEBUG(dbgs() << "preferPredicateOverEpilogue: not a single block " 2455 "loop.\n"); 2456 return false; 2457 } 2458 2459 assert(L->isInnermost() && "preferPredicateOverEpilogue: inner-loop expected"); 2460 2461 LoopInfo *LI = LVL->getLoopInfo(); 2462 HardwareLoopInfo HWLoopInfo(L); 2463 if (!HWLoopInfo.canAnalyze(*LI)) { 2464 LLVM_DEBUG(dbgs() << "preferPredicateOverEpilogue: hardware-loop is not " 2465 "analyzable.\n"); 2466 return false; 2467 } 2468 2469 AssumptionCache *AC = LVL->getAssumptionCache(); 2470 ScalarEvolution *SE = LVL->getScalarEvolution(); 2471 2472 // This checks if we have the low-overhead branch architecture 2473 // extension, and if we will create a hardware-loop: 2474 if (!isHardwareLoopProfitable(L, *SE, *AC, TFI->TLI, HWLoopInfo)) { 2475 LLVM_DEBUG(dbgs() << "preferPredicateOverEpilogue: hardware-loop is not " 2476 "profitable.\n"); 2477 return false; 2478 } 2479 2480 DominatorTree *DT = LVL->getDominatorTree(); 2481 if (!HWLoopInfo.isHardwareLoopCandidate(*SE, *LI, *DT)) { 2482 LLVM_DEBUG(dbgs() << "preferPredicateOverEpilogue: hardware-loop is not " 2483 "a candidate.\n"); 2484 return false; 2485 } 2486 2487 return canTailPredicateLoop(L, LI, *SE, DL, LVL->getLAI()); 2488 } 2489 2490 TailFoldingStyle 2491 ARMTTIImpl::getPreferredTailFoldingStyle(bool IVUpdateMayOverflow) const { 2492 if (!ST->hasMVEIntegerOps() || !EnableTailPredication) 2493 return TailFoldingStyle::DataWithoutLaneMask; 2494 2495 // Intrinsic @llvm.get.active.lane.mask is supported. 2496 // It is used in the MVETailPredication pass, which requires the number of 2497 // elements processed by this vector loop to setup the tail-predicated 2498 // loop. 2499 return TailFoldingStyle::Data; 2500 } 2501 void ARMTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE, 2502 TTI::UnrollingPreferences &UP, 2503 OptimizationRemarkEmitter *ORE) { 2504 // Enable Upper bound unrolling universally, providing that we do not see an 2505 // active lane mask, which will be better kept as a loop to become tail 2506 // predicated than to be conditionally unrolled. 2507 UP.UpperBound = 2508 !ST->hasMVEIntegerOps() || !any_of(*L->getHeader(), [](Instruction &I) { 2509 return isa<IntrinsicInst>(I) && 2510 cast<IntrinsicInst>(I).getIntrinsicID() == 2511 Intrinsic::get_active_lane_mask; 2512 }); 2513 2514 // Only currently enable these preferences for M-Class cores. 2515 if (!ST->isMClass()) 2516 return BasicTTIImplBase::getUnrollingPreferences(L, SE, UP, ORE); 2517 2518 // Disable loop unrolling for Oz and Os. 2519 UP.OptSizeThreshold = 0; 2520 UP.PartialOptSizeThreshold = 0; 2521 if (L->getHeader()->getParent()->hasOptSize()) 2522 return; 2523 2524 SmallVector<BasicBlock*, 4> ExitingBlocks; 2525 L->getExitingBlocks(ExitingBlocks); 2526 LLVM_DEBUG(dbgs() << "Loop has:\n" 2527 << "Blocks: " << L->getNumBlocks() << "\n" 2528 << "Exit blocks: " << ExitingBlocks.size() << "\n"); 2529 2530 // Only allow another exit other than the latch. This acts as an early exit 2531 // as it mirrors the profitability calculation of the runtime unroller. 2532 if (ExitingBlocks.size() > 2) 2533 return; 2534 2535 // Limit the CFG of the loop body for targets with a branch predictor. 2536 // Allowing 4 blocks permits if-then-else diamonds in the body. 2537 if (ST->hasBranchPredictor() && L->getNumBlocks() > 4) 2538 return; 2539 2540 // Don't unroll vectorized loops, including the remainder loop 2541 if (getBooleanLoopAttribute(L, "llvm.loop.isvectorized")) 2542 return; 2543 2544 // Scan the loop: don't unroll loops with calls as this could prevent 2545 // inlining. 2546 InstructionCost Cost = 0; 2547 for (auto *BB : L->getBlocks()) { 2548 for (auto &I : *BB) { 2549 // Don't unroll vectorised loop. MVE does not benefit from it as much as 2550 // scalar code. 2551 if (I.getType()->isVectorTy()) 2552 return; 2553 2554 if (isa<CallInst>(I) || isa<InvokeInst>(I)) { 2555 if (const Function *F = cast<CallBase>(I).getCalledFunction()) { 2556 if (!isLoweredToCall(F)) 2557 continue; 2558 } 2559 return; 2560 } 2561 2562 SmallVector<const Value*, 4> Operands(I.operand_values()); 2563 Cost += getInstructionCost(&I, Operands, 2564 TargetTransformInfo::TCK_SizeAndLatency); 2565 } 2566 } 2567 2568 // On v6m cores, there are very few registers available. We can easily end up 2569 // spilling and reloading more registers in an unrolled loop. Look at the 2570 // number of LCSSA phis as a rough measure of how many registers will need to 2571 // be live out of the loop, reducing the default unroll count if more than 1 2572 // value is needed. In the long run, all of this should be being learnt by a 2573 // machine. 2574 unsigned UnrollCount = 4; 2575 if (ST->isThumb1Only()) { 2576 unsigned ExitingValues = 0; 2577 SmallVector<BasicBlock *, 4> ExitBlocks; 2578 L->getExitBlocks(ExitBlocks); 2579 for (auto *Exit : ExitBlocks) { 2580 // Count the number of LCSSA phis. Exclude values coming from GEP's as 2581 // only the last is expected to be needed for address operands. 2582 unsigned LiveOuts = count_if(Exit->phis(), [](auto &PH) { 2583 return PH.getNumOperands() != 1 || 2584 !isa<GetElementPtrInst>(PH.getOperand(0)); 2585 }); 2586 ExitingValues = ExitingValues < LiveOuts ? LiveOuts : ExitingValues; 2587 } 2588 if (ExitingValues) 2589 UnrollCount /= ExitingValues; 2590 if (UnrollCount <= 1) 2591 return; 2592 } 2593 2594 LLVM_DEBUG(dbgs() << "Cost of loop: " << Cost << "\n"); 2595 LLVM_DEBUG(dbgs() << "Default Runtime Unroll Count: " << UnrollCount << "\n"); 2596 2597 UP.Partial = true; 2598 UP.Runtime = true; 2599 UP.UnrollRemainder = true; 2600 UP.DefaultUnrollRuntimeCount = UnrollCount; 2601 UP.UnrollAndJam = true; 2602 UP.UnrollAndJamInnerLoopThreshold = 60; 2603 2604 // Force unrolling small loops can be very useful because of the branch 2605 // taken cost of the backedge. 2606 if (Cost < 12) 2607 UP.Force = true; 2608 } 2609 2610 void ARMTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE, 2611 TTI::PeelingPreferences &PP) { 2612 BaseT::getPeelingPreferences(L, SE, PP); 2613 } 2614 2615 bool ARMTTIImpl::preferInLoopReduction(unsigned Opcode, Type *Ty, 2616 TTI::ReductionFlags Flags) const { 2617 if (!ST->hasMVEIntegerOps()) 2618 return false; 2619 2620 unsigned ScalarBits = Ty->getScalarSizeInBits(); 2621 switch (Opcode) { 2622 case Instruction::Add: 2623 return ScalarBits <= 64; 2624 default: 2625 return false; 2626 } 2627 } 2628 2629 bool ARMTTIImpl::preferPredicatedReductionSelect( 2630 unsigned Opcode, Type *Ty, TTI::ReductionFlags Flags) const { 2631 if (!ST->hasMVEIntegerOps()) 2632 return false; 2633 return true; 2634 } 2635 2636 InstructionCost ARMTTIImpl::getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, 2637 StackOffset BaseOffset, 2638 bool HasBaseReg, int64_t Scale, 2639 unsigned AddrSpace) const { 2640 TargetLoweringBase::AddrMode AM; 2641 AM.BaseGV = BaseGV; 2642 AM.BaseOffs = BaseOffset.getFixed(); 2643 AM.HasBaseReg = HasBaseReg; 2644 AM.Scale = Scale; 2645 AM.ScalableOffset = BaseOffset.getScalable(); 2646 if (getTLI()->isLegalAddressingMode(DL, AM, Ty, AddrSpace)) { 2647 if (ST->hasFPAO()) 2648 return AM.Scale < 0 ? 1 : 0; // positive offsets execute faster 2649 return 0; 2650 } 2651 return -1; 2652 } 2653 2654 bool ARMTTIImpl::hasArmWideBranch(bool Thumb) const { 2655 if (Thumb) { 2656 // B.W is available in any Thumb2-supporting target, and also in every 2657 // version of Armv8-M, even Baseline which does not include the rest of 2658 // Thumb2. 2659 return ST->isThumb2() || ST->hasV8MBaselineOps(); 2660 } else { 2661 // B is available in all versions of the Arm ISA, so the only question is 2662 // whether that ISA is available at all. 2663 return ST->hasARMOps(); 2664 } 2665 } 2666 2667 /// Check if Ext1 and Ext2 are extends of the same type, doubling the bitwidth 2668 /// of the vector elements. 2669 static bool areExtractExts(Value *Ext1, Value *Ext2) { 2670 using namespace PatternMatch; 2671 2672 auto areExtDoubled = [](Instruction *Ext) { 2673 return Ext->getType()->getScalarSizeInBits() == 2674 2 * Ext->getOperand(0)->getType()->getScalarSizeInBits(); 2675 }; 2676 2677 if (!match(Ext1, m_ZExtOrSExt(m_Value())) || 2678 !match(Ext2, m_ZExtOrSExt(m_Value())) || 2679 !areExtDoubled(cast<Instruction>(Ext1)) || 2680 !areExtDoubled(cast<Instruction>(Ext2))) 2681 return false; 2682 2683 return true; 2684 } 2685 2686 /// Check if sinking \p I's operands to I's basic block is profitable, because 2687 /// the operands can be folded into a target instruction, e.g. 2688 /// sext/zext can be folded into vsubl. 2689 bool ARMTTIImpl::isProfitableToSinkOperands(Instruction *I, 2690 SmallVectorImpl<Use *> &Ops) const { 2691 using namespace PatternMatch; 2692 2693 if (!I->getType()->isVectorTy()) 2694 return false; 2695 2696 if (ST->hasNEON()) { 2697 switch (I->getOpcode()) { 2698 case Instruction::Sub: 2699 case Instruction::Add: { 2700 if (!areExtractExts(I->getOperand(0), I->getOperand(1))) 2701 return false; 2702 Ops.push_back(&I->getOperandUse(0)); 2703 Ops.push_back(&I->getOperandUse(1)); 2704 return true; 2705 } 2706 default: 2707 return false; 2708 } 2709 } 2710 2711 if (!ST->hasMVEIntegerOps()) 2712 return false; 2713 2714 auto IsFMSMul = [&](Instruction *I) { 2715 if (!I->hasOneUse()) 2716 return false; 2717 auto *Sub = cast<Instruction>(*I->users().begin()); 2718 return Sub->getOpcode() == Instruction::FSub && Sub->getOperand(1) == I; 2719 }; 2720 auto IsFMS = [&](Instruction *I) { 2721 if (match(I->getOperand(0), m_FNeg(m_Value())) || 2722 match(I->getOperand(1), m_FNeg(m_Value()))) 2723 return true; 2724 return false; 2725 }; 2726 2727 auto IsSinker = [&](Instruction *I, int Operand) { 2728 switch (I->getOpcode()) { 2729 case Instruction::Add: 2730 case Instruction::Mul: 2731 case Instruction::FAdd: 2732 case Instruction::ICmp: 2733 case Instruction::FCmp: 2734 return true; 2735 case Instruction::FMul: 2736 return !IsFMSMul(I); 2737 case Instruction::Sub: 2738 case Instruction::FSub: 2739 case Instruction::Shl: 2740 case Instruction::LShr: 2741 case Instruction::AShr: 2742 return Operand == 1; 2743 case Instruction::Call: 2744 if (auto *II = dyn_cast<IntrinsicInst>(I)) { 2745 switch (II->getIntrinsicID()) { 2746 case Intrinsic::fma: 2747 return !IsFMS(I); 2748 case Intrinsic::sadd_sat: 2749 case Intrinsic::uadd_sat: 2750 case Intrinsic::arm_mve_add_predicated: 2751 case Intrinsic::arm_mve_mul_predicated: 2752 case Intrinsic::arm_mve_qadd_predicated: 2753 case Intrinsic::arm_mve_vhadd: 2754 case Intrinsic::arm_mve_hadd_predicated: 2755 case Intrinsic::arm_mve_vqdmull: 2756 case Intrinsic::arm_mve_vqdmull_predicated: 2757 case Intrinsic::arm_mve_vqdmulh: 2758 case Intrinsic::arm_mve_qdmulh_predicated: 2759 case Intrinsic::arm_mve_vqrdmulh: 2760 case Intrinsic::arm_mve_qrdmulh_predicated: 2761 case Intrinsic::arm_mve_fma_predicated: 2762 return true; 2763 case Intrinsic::ssub_sat: 2764 case Intrinsic::usub_sat: 2765 case Intrinsic::arm_mve_sub_predicated: 2766 case Intrinsic::arm_mve_qsub_predicated: 2767 case Intrinsic::arm_mve_hsub_predicated: 2768 case Intrinsic::arm_mve_vhsub: 2769 return Operand == 1; 2770 default: 2771 return false; 2772 } 2773 } 2774 return false; 2775 default: 2776 return false; 2777 } 2778 }; 2779 2780 for (auto OpIdx : enumerate(I->operands())) { 2781 Instruction *Op = dyn_cast<Instruction>(OpIdx.value().get()); 2782 // Make sure we are not already sinking this operand 2783 if (!Op || any_of(Ops, [&](Use *U) { return U->get() == Op; })) 2784 continue; 2785 2786 Instruction *Shuffle = Op; 2787 if (Shuffle->getOpcode() == Instruction::BitCast) 2788 Shuffle = dyn_cast<Instruction>(Shuffle->getOperand(0)); 2789 // We are looking for a splat that can be sunk. 2790 if (!Shuffle || !match(Shuffle, m_Shuffle(m_InsertElt(m_Undef(), m_Value(), 2791 m_ZeroInt()), 2792 m_Undef(), m_ZeroMask()))) 2793 continue; 2794 if (!IsSinker(I, OpIdx.index())) 2795 continue; 2796 2797 // All uses of the shuffle should be sunk to avoid duplicating it across gpr 2798 // and vector registers 2799 for (Use &U : Op->uses()) { 2800 Instruction *Insn = cast<Instruction>(U.getUser()); 2801 if (!IsSinker(Insn, U.getOperandNo())) 2802 return false; 2803 } 2804 2805 Ops.push_back(&Shuffle->getOperandUse(0)); 2806 if (Shuffle != Op) 2807 Ops.push_back(&Op->getOperandUse(0)); 2808 Ops.push_back(&OpIdx.value()); 2809 } 2810 return true; 2811 } 2812 2813 unsigned ARMTTIImpl::getNumBytesToPadGlobalArray(unsigned Size, 2814 Type *ArrayType) const { 2815 if (!UseWidenGlobalArrays) { 2816 LLVM_DEBUG(dbgs() << "Padding global arrays disabled\n"); 2817 return false; 2818 } 2819 2820 // Don't modify none integer array types 2821 if (!ArrayType || !ArrayType->isArrayTy() || 2822 !ArrayType->getArrayElementType()->isIntegerTy()) 2823 return 0; 2824 2825 // We pad to 4 byte boundaries 2826 if (Size % 4 == 0) 2827 return 0; 2828 2829 unsigned NumBytesToPad = 4 - (Size % 4); 2830 unsigned NewSize = Size + NumBytesToPad; 2831 2832 // Max number of bytes that memcpy allows for lowering to load/stores before 2833 // it uses library function (__aeabi_memcpy). 2834 unsigned MaxMemIntrinsicSize = getMaxMemIntrinsicInlineSizeThreshold(); 2835 2836 if (NewSize > MaxMemIntrinsicSize) 2837 return 0; 2838 2839 return NumBytesToPad; 2840 } 2841