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 return Builder.CreateAlignedLoad(II.getType(), II.getArgOperand(0), 87 Align(Alignment)); 88 } 89 90 bool ARMTTIImpl::areInlineCompatible(const Function *Caller, 91 const Function *Callee) const { 92 const TargetMachine &TM = getTLI()->getTargetMachine(); 93 const FeatureBitset &CallerBits = 94 TM.getSubtargetImpl(*Caller)->getFeatureBits(); 95 const FeatureBitset &CalleeBits = 96 TM.getSubtargetImpl(*Callee)->getFeatureBits(); 97 98 // To inline a callee, all features not in the allowed list must match exactly. 99 bool MatchExact = (CallerBits & ~InlineFeaturesAllowed) == 100 (CalleeBits & ~InlineFeaturesAllowed); 101 // For features in the allowed list, the callee's features must be a subset of 102 // the callers'. 103 bool MatchSubset = ((CallerBits & CalleeBits) & InlineFeaturesAllowed) == 104 (CalleeBits & InlineFeaturesAllowed); 105 return MatchExact && MatchSubset; 106 } 107 108 TTI::AddressingModeKind 109 ARMTTIImpl::getPreferredAddressingMode(const Loop *L, 110 ScalarEvolution *SE) const { 111 if (ST->hasMVEIntegerOps()) 112 return TTI::AMK_PostIndexed; 113 114 if (L->getHeader()->getParent()->hasOptSize()) 115 return TTI::AMK_None; 116 117 if (ST->isMClass() && ST->isThumb2() && 118 L->getNumBlocks() == 1) 119 return TTI::AMK_PreIndexed; 120 121 return TTI::AMK_None; 122 } 123 124 std::optional<Instruction *> 125 ARMTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const { 126 using namespace PatternMatch; 127 Intrinsic::ID IID = II.getIntrinsicID(); 128 switch (IID) { 129 default: 130 break; 131 case Intrinsic::arm_neon_vld1: { 132 Align MemAlign = 133 getKnownAlignment(II.getArgOperand(0), IC.getDataLayout(), &II, 134 &IC.getAssumptionCache(), &IC.getDominatorTree()); 135 if (Value *V = simplifyNeonVld1(II, MemAlign.value(), IC.Builder)) { 136 return IC.replaceInstUsesWith(II, V); 137 } 138 break; 139 } 140 141 case Intrinsic::arm_neon_vld2: 142 case Intrinsic::arm_neon_vld3: 143 case Intrinsic::arm_neon_vld4: 144 case Intrinsic::arm_neon_vld2lane: 145 case Intrinsic::arm_neon_vld3lane: 146 case Intrinsic::arm_neon_vld4lane: 147 case Intrinsic::arm_neon_vst1: 148 case Intrinsic::arm_neon_vst2: 149 case Intrinsic::arm_neon_vst3: 150 case Intrinsic::arm_neon_vst4: 151 case Intrinsic::arm_neon_vst2lane: 152 case Intrinsic::arm_neon_vst3lane: 153 case Intrinsic::arm_neon_vst4lane: { 154 Align MemAlign = 155 getKnownAlignment(II.getArgOperand(0), IC.getDataLayout(), &II, 156 &IC.getAssumptionCache(), &IC.getDominatorTree()); 157 unsigned AlignArg = II.arg_size() - 1; 158 Value *AlignArgOp = II.getArgOperand(AlignArg); 159 MaybeAlign Align = cast<ConstantInt>(AlignArgOp)->getMaybeAlignValue(); 160 if (Align && *Align < MemAlign) { 161 return IC.replaceOperand( 162 II, AlignArg, 163 ConstantInt::get(Type::getInt32Ty(II.getContext()), MemAlign.value(), 164 false)); 165 } 166 break; 167 } 168 169 case Intrinsic::arm_neon_vld1x2: 170 case Intrinsic::arm_neon_vld1x3: 171 case Intrinsic::arm_neon_vld1x4: 172 case Intrinsic::arm_neon_vst1x2: 173 case Intrinsic::arm_neon_vst1x3: 174 case Intrinsic::arm_neon_vst1x4: { 175 Align NewAlign = 176 getKnownAlignment(II.getArgOperand(0), IC.getDataLayout(), &II, 177 &IC.getAssumptionCache(), &IC.getDominatorTree()); 178 Align OldAlign = II.getParamAlign(0).valueOrOne(); 179 if (NewAlign > OldAlign) 180 II.addParamAttr(0, 181 Attribute::getWithAlignment(II.getContext(), NewAlign)); 182 break; 183 } 184 185 case Intrinsic::arm_mve_pred_i2v: { 186 Value *Arg = II.getArgOperand(0); 187 Value *ArgArg; 188 if (match(Arg, PatternMatch::m_Intrinsic<Intrinsic::arm_mve_pred_v2i>( 189 PatternMatch::m_Value(ArgArg))) && 190 II.getType() == ArgArg->getType()) { 191 return IC.replaceInstUsesWith(II, ArgArg); 192 } 193 Constant *XorMask; 194 if (match(Arg, m_Xor(PatternMatch::m_Intrinsic<Intrinsic::arm_mve_pred_v2i>( 195 PatternMatch::m_Value(ArgArg)), 196 PatternMatch::m_Constant(XorMask))) && 197 II.getType() == ArgArg->getType()) { 198 if (auto *CI = dyn_cast<ConstantInt>(XorMask)) { 199 if (CI->getValue().trunc(16).isAllOnes()) { 200 auto TrueVector = IC.Builder.CreateVectorSplat( 201 cast<FixedVectorType>(II.getType())->getNumElements(), 202 IC.Builder.getTrue()); 203 return BinaryOperator::Create(Instruction::Xor, ArgArg, TrueVector); 204 } 205 } 206 } 207 KnownBits ScalarKnown(32); 208 if (IC.SimplifyDemandedBits(&II, 0, APInt::getLowBitsSet(32, 16), 209 ScalarKnown)) { 210 return &II; 211 } 212 break; 213 } 214 case Intrinsic::arm_mve_pred_v2i: { 215 Value *Arg = II.getArgOperand(0); 216 Value *ArgArg; 217 if (match(Arg, PatternMatch::m_Intrinsic<Intrinsic::arm_mve_pred_i2v>( 218 PatternMatch::m_Value(ArgArg)))) { 219 return IC.replaceInstUsesWith(II, ArgArg); 220 } 221 222 if (II.getMetadata(LLVMContext::MD_range)) 223 break; 224 225 ConstantRange Range(APInt(32, 0), APInt(32, 0x10000)); 226 227 if (auto CurrentRange = II.getRange()) { 228 Range = Range.intersectWith(*CurrentRange); 229 if (Range == CurrentRange) 230 break; 231 } 232 233 II.addRangeRetAttr(Range); 234 II.addRetAttr(Attribute::NoUndef); 235 return &II; 236 } 237 case Intrinsic::arm_mve_vadc: 238 case Intrinsic::arm_mve_vadc_predicated: { 239 unsigned CarryOp = 240 (II.getIntrinsicID() == Intrinsic::arm_mve_vadc_predicated) ? 3 : 2; 241 assert(II.getArgOperand(CarryOp)->getType()->getScalarSizeInBits() == 32 && 242 "Bad type for intrinsic!"); 243 244 KnownBits CarryKnown(32); 245 if (IC.SimplifyDemandedBits(&II, CarryOp, APInt::getOneBitSet(32, 29), 246 CarryKnown)) { 247 return &II; 248 } 249 break; 250 } 251 case Intrinsic::arm_mve_vmldava: { 252 Instruction *I = cast<Instruction>(&II); 253 if (I->hasOneUse()) { 254 auto *User = cast<Instruction>(*I->user_begin()); 255 Value *OpZ; 256 if (match(User, m_c_Add(m_Specific(I), m_Value(OpZ))) && 257 match(I->getOperand(3), m_Zero())) { 258 Value *OpX = I->getOperand(4); 259 Value *OpY = I->getOperand(5); 260 Type *OpTy = OpX->getType(); 261 262 IC.Builder.SetInsertPoint(User); 263 Value *V = 264 IC.Builder.CreateIntrinsic(Intrinsic::arm_mve_vmldava, {OpTy}, 265 {I->getOperand(0), I->getOperand(1), 266 I->getOperand(2), OpZ, OpX, OpY}); 267 268 IC.replaceInstUsesWith(*User, V); 269 return IC.eraseInstFromFunction(*User); 270 } 271 } 272 return std::nullopt; 273 } 274 } 275 return std::nullopt; 276 } 277 278 std::optional<Value *> ARMTTIImpl::simplifyDemandedVectorEltsIntrinsic( 279 InstCombiner &IC, IntrinsicInst &II, APInt OrigDemandedElts, 280 APInt &UndefElts, APInt &UndefElts2, APInt &UndefElts3, 281 std::function<void(Instruction *, unsigned, APInt, APInt &)> 282 SimplifyAndSetOp) const { 283 284 // Compute the demanded bits for a narrowing MVE intrinsic. The TopOpc is the 285 // opcode specifying a Top/Bottom instruction, which can change between 286 // instructions. 287 auto SimplifyNarrowInstrTopBottom =[&](unsigned TopOpc) { 288 unsigned NumElts = cast<FixedVectorType>(II.getType())->getNumElements(); 289 unsigned IsTop = cast<ConstantInt>(II.getOperand(TopOpc))->getZExtValue(); 290 291 // The only odd/even lanes of operand 0 will only be demanded depending 292 // on whether this is a top/bottom instruction. 293 APInt DemandedElts = 294 APInt::getSplat(NumElts, IsTop ? APInt::getLowBitsSet(2, 1) 295 : APInt::getHighBitsSet(2, 1)); 296 SimplifyAndSetOp(&II, 0, OrigDemandedElts & DemandedElts, UndefElts); 297 // The other lanes will be defined from the inserted elements. 298 UndefElts &= APInt::getSplat(NumElts, IsTop ? APInt::getLowBitsSet(2, 1) 299 : APInt::getHighBitsSet(2, 1)); 300 return std::nullopt; 301 }; 302 303 switch (II.getIntrinsicID()) { 304 default: 305 break; 306 case Intrinsic::arm_mve_vcvt_narrow: 307 SimplifyNarrowInstrTopBottom(2); 308 break; 309 case Intrinsic::arm_mve_vqmovn: 310 SimplifyNarrowInstrTopBottom(4); 311 break; 312 case Intrinsic::arm_mve_vshrn: 313 SimplifyNarrowInstrTopBottom(7); 314 break; 315 } 316 317 return std::nullopt; 318 } 319 320 InstructionCost ARMTTIImpl::getIntImmCost(const APInt &Imm, Type *Ty, 321 TTI::TargetCostKind CostKind) { 322 assert(Ty->isIntegerTy()); 323 324 unsigned Bits = Ty->getPrimitiveSizeInBits(); 325 if (Bits == 0 || Imm.getActiveBits() >= 64) 326 return 4; 327 328 int64_t SImmVal = Imm.getSExtValue(); 329 uint64_t ZImmVal = Imm.getZExtValue(); 330 if (!ST->isThumb()) { 331 if ((SImmVal >= 0 && SImmVal < 65536) || 332 (ARM_AM::getSOImmVal(ZImmVal) != -1) || 333 (ARM_AM::getSOImmVal(~ZImmVal) != -1)) 334 return 1; 335 return ST->hasV6T2Ops() ? 2 : 3; 336 } 337 if (ST->isThumb2()) { 338 if ((SImmVal >= 0 && SImmVal < 65536) || 339 (ARM_AM::getT2SOImmVal(ZImmVal) != -1) || 340 (ARM_AM::getT2SOImmVal(~ZImmVal) != -1)) 341 return 1; 342 return ST->hasV6T2Ops() ? 2 : 3; 343 } 344 // Thumb1, any i8 imm cost 1. 345 if (Bits == 8 || (SImmVal >= 0 && SImmVal < 256)) 346 return 1; 347 if ((~SImmVal < 256) || ARM_AM::isThumbImmShiftedVal(ZImmVal)) 348 return 2; 349 // Load from constantpool. 350 return 3; 351 } 352 353 // Constants smaller than 256 fit in the immediate field of 354 // Thumb1 instructions so we return a zero cost and 1 otherwise. 355 InstructionCost ARMTTIImpl::getIntImmCodeSizeCost(unsigned Opcode, unsigned Idx, 356 const APInt &Imm, Type *Ty) { 357 if (Imm.isNonNegative() && Imm.getLimitedValue() < 256) 358 return 0; 359 360 return 1; 361 } 362 363 // Checks whether Inst is part of a min(max()) or max(min()) pattern 364 // that will match to an SSAT instruction. Returns the instruction being 365 // saturated, or null if no saturation pattern was found. 366 static Value *isSSATMinMaxPattern(Instruction *Inst, const APInt &Imm) { 367 Value *LHS, *RHS; 368 ConstantInt *C; 369 SelectPatternFlavor InstSPF = matchSelectPattern(Inst, LHS, RHS).Flavor; 370 371 if (InstSPF == SPF_SMAX && 372 PatternMatch::match(RHS, PatternMatch::m_ConstantInt(C)) && 373 C->getValue() == Imm && Imm.isNegative() && Imm.isNegatedPowerOf2()) { 374 375 auto isSSatMin = [&](Value *MinInst) { 376 if (isa<SelectInst>(MinInst)) { 377 Value *MinLHS, *MinRHS; 378 ConstantInt *MinC; 379 SelectPatternFlavor MinSPF = 380 matchSelectPattern(MinInst, MinLHS, MinRHS).Flavor; 381 if (MinSPF == SPF_SMIN && 382 PatternMatch::match(MinRHS, PatternMatch::m_ConstantInt(MinC)) && 383 MinC->getValue() == ((-Imm) - 1)) 384 return true; 385 } 386 return false; 387 }; 388 389 if (isSSatMin(Inst->getOperand(1))) 390 return cast<Instruction>(Inst->getOperand(1))->getOperand(1); 391 if (Inst->hasNUses(2) && 392 (isSSatMin(*Inst->user_begin()) || isSSatMin(*(++Inst->user_begin())))) 393 return Inst->getOperand(1); 394 } 395 return nullptr; 396 } 397 398 // Look for a FP Saturation pattern, where the instruction can be simplified to 399 // a fptosi.sat. max(min(fptosi)). The constant in this case is always free. 400 static bool isFPSatMinMaxPattern(Instruction *Inst, const APInt &Imm) { 401 if (Imm.getBitWidth() != 64 || 402 Imm != APInt::getHighBitsSet(64, 33)) // -2147483648 403 return false; 404 Value *FP = isSSATMinMaxPattern(Inst, Imm); 405 if (!FP && isa<ICmpInst>(Inst) && Inst->hasOneUse()) 406 FP = isSSATMinMaxPattern(cast<Instruction>(*Inst->user_begin()), Imm); 407 if (!FP) 408 return false; 409 return isa<FPToSIInst>(FP); 410 } 411 412 InstructionCost ARMTTIImpl::getIntImmCostInst(unsigned Opcode, unsigned Idx, 413 const APInt &Imm, Type *Ty, 414 TTI::TargetCostKind CostKind, 415 Instruction *Inst) { 416 // Division by a constant can be turned into multiplication, but only if we 417 // know it's constant. So it's not so much that the immediate is cheap (it's 418 // not), but that the alternative is worse. 419 // FIXME: this is probably unneeded with GlobalISel. 420 if ((Opcode == Instruction::SDiv || Opcode == Instruction::UDiv || 421 Opcode == Instruction::SRem || Opcode == Instruction::URem) && 422 Idx == 1) 423 return 0; 424 425 // Leave any gep offsets for the CodeGenPrepare, which will do a better job at 426 // splitting any large offsets. 427 if (Opcode == Instruction::GetElementPtr && Idx != 0) 428 return 0; 429 430 if (Opcode == Instruction::And) { 431 // UXTB/UXTH 432 if (Imm == 255 || Imm == 65535) 433 return 0; 434 // Conversion to BIC is free, and means we can use ~Imm instead. 435 return std::min(getIntImmCost(Imm, Ty, CostKind), 436 getIntImmCost(~Imm, Ty, CostKind)); 437 } 438 439 if (Opcode == Instruction::Add) 440 // Conversion to SUB is free, and means we can use -Imm instead. 441 return std::min(getIntImmCost(Imm, Ty, CostKind), 442 getIntImmCost(-Imm, Ty, CostKind)); 443 444 if (Opcode == Instruction::ICmp && Imm.isNegative() && 445 Ty->getIntegerBitWidth() == 32) { 446 int64_t NegImm = -Imm.getSExtValue(); 447 if (ST->isThumb2() && NegImm < 1<<12) 448 // icmp X, #-C -> cmn X, #C 449 return 0; 450 if (ST->isThumb() && NegImm < 1<<8) 451 // icmp X, #-C -> adds X, #C 452 return 0; 453 } 454 455 // xor a, -1 can always be folded to MVN 456 if (Opcode == Instruction::Xor && Imm.isAllOnes()) 457 return 0; 458 459 // Ensures negative constant of min(max()) or max(min()) patterns that 460 // match to SSAT instructions don't get hoisted 461 if (Inst && ((ST->hasV6Ops() && !ST->isThumb()) || ST->isThumb2()) && 462 Ty->getIntegerBitWidth() <= 32) { 463 if (isSSATMinMaxPattern(Inst, Imm) || 464 (isa<ICmpInst>(Inst) && Inst->hasOneUse() && 465 isSSATMinMaxPattern(cast<Instruction>(*Inst->user_begin()), Imm))) 466 return 0; 467 } 468 469 if (Inst && ST->hasVFP2Base() && isFPSatMinMaxPattern(Inst, Imm)) 470 return 0; 471 472 // We can convert <= -1 to < 0, which is generally quite cheap. 473 if (Inst && Opcode == Instruction::ICmp && Idx == 1 && Imm.isAllOnes()) { 474 ICmpInst::Predicate Pred = cast<ICmpInst>(Inst)->getPredicate(); 475 if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLE) 476 return std::min(getIntImmCost(Imm, Ty, CostKind), 477 getIntImmCost(Imm + 1, Ty, CostKind)); 478 } 479 480 return getIntImmCost(Imm, Ty, CostKind); 481 } 482 483 InstructionCost ARMTTIImpl::getCFInstrCost(unsigned Opcode, 484 TTI::TargetCostKind CostKind, 485 const Instruction *I) { 486 if (CostKind == TTI::TCK_RecipThroughput && 487 (ST->hasNEON() || ST->hasMVEIntegerOps())) { 488 // FIXME: The vectorizer is highly sensistive to the cost of these 489 // instructions, which suggests that it may be using the costs incorrectly. 490 // But, for now, just make them free to avoid performance regressions for 491 // vector targets. 492 return 0; 493 } 494 return BaseT::getCFInstrCost(Opcode, CostKind, I); 495 } 496 497 InstructionCost ARMTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst, 498 Type *Src, 499 TTI::CastContextHint CCH, 500 TTI::TargetCostKind CostKind, 501 const Instruction *I) { 502 int ISD = TLI->InstructionOpcodeToISD(Opcode); 503 assert(ISD && "Invalid opcode"); 504 505 // TODO: Allow non-throughput costs that aren't binary. 506 auto AdjustCost = [&CostKind](InstructionCost Cost) -> InstructionCost { 507 if (CostKind != TTI::TCK_RecipThroughput) 508 return Cost == 0 ? 0 : 1; 509 return Cost; 510 }; 511 auto IsLegalFPType = [this](EVT VT) { 512 EVT EltVT = VT.getScalarType(); 513 return (EltVT == MVT::f32 && ST->hasVFP2Base()) || 514 (EltVT == MVT::f64 && ST->hasFP64()) || 515 (EltVT == MVT::f16 && ST->hasFullFP16()); 516 }; 517 518 EVT SrcTy = TLI->getValueType(DL, Src); 519 EVT DstTy = TLI->getValueType(DL, Dst); 520 521 if (!SrcTy.isSimple() || !DstTy.isSimple()) 522 return AdjustCost( 523 BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I)); 524 525 // Extending masked load/Truncating masked stores is expensive because we 526 // currently don't split them. This means that we'll likely end up 527 // loading/storing each element individually (hence the high cost). 528 if ((ST->hasMVEIntegerOps() && 529 (Opcode == Instruction::Trunc || Opcode == Instruction::ZExt || 530 Opcode == Instruction::SExt)) || 531 (ST->hasMVEFloatOps() && 532 (Opcode == Instruction::FPExt || Opcode == Instruction::FPTrunc) && 533 IsLegalFPType(SrcTy) && IsLegalFPType(DstTy))) 534 if (CCH == TTI::CastContextHint::Masked && DstTy.getSizeInBits() > 128) 535 return 2 * DstTy.getVectorNumElements() * 536 ST->getMVEVectorCostFactor(CostKind); 537 538 // The extend of other kinds of load is free 539 if (CCH == TTI::CastContextHint::Normal || 540 CCH == TTI::CastContextHint::Masked) { 541 static const TypeConversionCostTblEntry LoadConversionTbl[] = { 542 {ISD::SIGN_EXTEND, MVT::i32, MVT::i16, 0}, 543 {ISD::ZERO_EXTEND, MVT::i32, MVT::i16, 0}, 544 {ISD::SIGN_EXTEND, MVT::i32, MVT::i8, 0}, 545 {ISD::ZERO_EXTEND, MVT::i32, MVT::i8, 0}, 546 {ISD::SIGN_EXTEND, MVT::i16, MVT::i8, 0}, 547 {ISD::ZERO_EXTEND, MVT::i16, MVT::i8, 0}, 548 {ISD::SIGN_EXTEND, MVT::i64, MVT::i32, 1}, 549 {ISD::ZERO_EXTEND, MVT::i64, MVT::i32, 1}, 550 {ISD::SIGN_EXTEND, MVT::i64, MVT::i16, 1}, 551 {ISD::ZERO_EXTEND, MVT::i64, MVT::i16, 1}, 552 {ISD::SIGN_EXTEND, MVT::i64, MVT::i8, 1}, 553 {ISD::ZERO_EXTEND, MVT::i64, MVT::i8, 1}, 554 }; 555 if (const auto *Entry = ConvertCostTableLookup( 556 LoadConversionTbl, ISD, DstTy.getSimpleVT(), SrcTy.getSimpleVT())) 557 return AdjustCost(Entry->Cost); 558 559 static const TypeConversionCostTblEntry MVELoadConversionTbl[] = { 560 {ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i16, 0}, 561 {ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i16, 0}, 562 {ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i8, 0}, 563 {ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i8, 0}, 564 {ISD::SIGN_EXTEND, MVT::v8i16, MVT::v8i8, 0}, 565 {ISD::ZERO_EXTEND, MVT::v8i16, MVT::v8i8, 0}, 566 // The following extend from a legal type to an illegal type, so need to 567 // split the load. This introduced an extra load operation, but the 568 // extend is still "free". 569 {ISD::SIGN_EXTEND, MVT::v8i32, MVT::v8i16, 1}, 570 {ISD::ZERO_EXTEND, MVT::v8i32, MVT::v8i16, 1}, 571 {ISD::SIGN_EXTEND, MVT::v16i32, MVT::v16i8, 3}, 572 {ISD::ZERO_EXTEND, MVT::v16i32, MVT::v16i8, 3}, 573 {ISD::SIGN_EXTEND, MVT::v16i16, MVT::v16i8, 1}, 574 {ISD::ZERO_EXTEND, MVT::v16i16, MVT::v16i8, 1}, 575 }; 576 if (SrcTy.isVector() && ST->hasMVEIntegerOps()) { 577 if (const auto *Entry = 578 ConvertCostTableLookup(MVELoadConversionTbl, ISD, 579 DstTy.getSimpleVT(), SrcTy.getSimpleVT())) 580 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 581 } 582 583 static const TypeConversionCostTblEntry MVEFLoadConversionTbl[] = { 584 // FPExtends are similar but also require the VCVT instructions. 585 {ISD::FP_EXTEND, MVT::v4f32, MVT::v4f16, 1}, 586 {ISD::FP_EXTEND, MVT::v8f32, MVT::v8f16, 3}, 587 }; 588 if (SrcTy.isVector() && ST->hasMVEFloatOps()) { 589 if (const auto *Entry = 590 ConvertCostTableLookup(MVEFLoadConversionTbl, ISD, 591 DstTy.getSimpleVT(), SrcTy.getSimpleVT())) 592 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 593 } 594 595 // The truncate of a store is free. This is the mirror of extends above. 596 static const TypeConversionCostTblEntry MVEStoreConversionTbl[] = { 597 {ISD::TRUNCATE, MVT::v4i32, MVT::v4i16, 0}, 598 {ISD::TRUNCATE, MVT::v4i32, MVT::v4i8, 0}, 599 {ISD::TRUNCATE, MVT::v8i16, MVT::v8i8, 0}, 600 {ISD::TRUNCATE, MVT::v8i32, MVT::v8i16, 1}, 601 {ISD::TRUNCATE, MVT::v8i32, MVT::v8i8, 1}, 602 {ISD::TRUNCATE, MVT::v16i32, MVT::v16i8, 3}, 603 {ISD::TRUNCATE, MVT::v16i16, MVT::v16i8, 1}, 604 }; 605 if (SrcTy.isVector() && ST->hasMVEIntegerOps()) { 606 if (const auto *Entry = 607 ConvertCostTableLookup(MVEStoreConversionTbl, ISD, 608 SrcTy.getSimpleVT(), DstTy.getSimpleVT())) 609 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 610 } 611 612 static const TypeConversionCostTblEntry MVEFStoreConversionTbl[] = { 613 {ISD::FP_ROUND, MVT::v4f32, MVT::v4f16, 1}, 614 {ISD::FP_ROUND, MVT::v8f32, MVT::v8f16, 3}, 615 }; 616 if (SrcTy.isVector() && ST->hasMVEFloatOps()) { 617 if (const auto *Entry = 618 ConvertCostTableLookup(MVEFStoreConversionTbl, ISD, 619 SrcTy.getSimpleVT(), DstTy.getSimpleVT())) 620 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 621 } 622 } 623 624 // NEON vector operations that can extend their inputs. 625 if ((ISD == ISD::SIGN_EXTEND || ISD == ISD::ZERO_EXTEND) && 626 I && I->hasOneUse() && ST->hasNEON() && SrcTy.isVector()) { 627 static const TypeConversionCostTblEntry NEONDoubleWidthTbl[] = { 628 // vaddl 629 { ISD::ADD, MVT::v4i32, MVT::v4i16, 0 }, 630 { ISD::ADD, MVT::v8i16, MVT::v8i8, 0 }, 631 // vsubl 632 { ISD::SUB, MVT::v4i32, MVT::v4i16, 0 }, 633 { ISD::SUB, MVT::v8i16, MVT::v8i8, 0 }, 634 // vmull 635 { ISD::MUL, MVT::v4i32, MVT::v4i16, 0 }, 636 { ISD::MUL, MVT::v8i16, MVT::v8i8, 0 }, 637 // vshll 638 { ISD::SHL, MVT::v4i32, MVT::v4i16, 0 }, 639 { ISD::SHL, MVT::v8i16, MVT::v8i8, 0 }, 640 }; 641 642 auto *User = cast<Instruction>(*I->user_begin()); 643 int UserISD = TLI->InstructionOpcodeToISD(User->getOpcode()); 644 if (auto *Entry = ConvertCostTableLookup(NEONDoubleWidthTbl, UserISD, 645 DstTy.getSimpleVT(), 646 SrcTy.getSimpleVT())) { 647 return AdjustCost(Entry->Cost); 648 } 649 } 650 651 // Single to/from double precision conversions. 652 if (Src->isVectorTy() && ST->hasNEON() && 653 ((ISD == ISD::FP_ROUND && SrcTy.getScalarType() == MVT::f64 && 654 DstTy.getScalarType() == MVT::f32) || 655 (ISD == ISD::FP_EXTEND && SrcTy.getScalarType() == MVT::f32 && 656 DstTy.getScalarType() == MVT::f64))) { 657 static const CostTblEntry NEONFltDblTbl[] = { 658 // Vector fptrunc/fpext conversions. 659 {ISD::FP_ROUND, MVT::v2f64, 2}, 660 {ISD::FP_EXTEND, MVT::v2f32, 2}, 661 {ISD::FP_EXTEND, MVT::v4f32, 4}}; 662 663 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Src); 664 if (const auto *Entry = CostTableLookup(NEONFltDblTbl, ISD, LT.second)) 665 return AdjustCost(LT.first * Entry->Cost); 666 } 667 668 // Some arithmetic, load and store operations have specific instructions 669 // to cast up/down their types automatically at no extra cost. 670 // TODO: Get these tables to know at least what the related operations are. 671 static const TypeConversionCostTblEntry NEONVectorConversionTbl[] = { 672 { ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i16, 1 }, 673 { ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i16, 1 }, 674 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i32, 1 }, 675 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i32, 1 }, 676 { ISD::TRUNCATE, MVT::v4i32, MVT::v4i64, 0 }, 677 { ISD::TRUNCATE, MVT::v4i16, MVT::v4i32, 1 }, 678 679 // The number of vmovl instructions for the extension. 680 { ISD::SIGN_EXTEND, MVT::v8i16, MVT::v8i8, 1 }, 681 { ISD::ZERO_EXTEND, MVT::v8i16, MVT::v8i8, 1 }, 682 { ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i8, 2 }, 683 { ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i8, 2 }, 684 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i8, 3 }, 685 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i8, 3 }, 686 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i16, 2 }, 687 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i16, 2 }, 688 { ISD::SIGN_EXTEND, MVT::v4i64, MVT::v4i16, 3 }, 689 { ISD::ZERO_EXTEND, MVT::v4i64, MVT::v4i16, 3 }, 690 { ISD::SIGN_EXTEND, MVT::v8i32, MVT::v8i8, 3 }, 691 { ISD::ZERO_EXTEND, MVT::v8i32, MVT::v8i8, 3 }, 692 { ISD::SIGN_EXTEND, MVT::v8i64, MVT::v8i8, 7 }, 693 { ISD::ZERO_EXTEND, MVT::v8i64, MVT::v8i8, 7 }, 694 { ISD::SIGN_EXTEND, MVT::v8i64, MVT::v8i16, 6 }, 695 { ISD::ZERO_EXTEND, MVT::v8i64, MVT::v8i16, 6 }, 696 { ISD::SIGN_EXTEND, MVT::v16i32, MVT::v16i8, 6 }, 697 { ISD::ZERO_EXTEND, MVT::v16i32, MVT::v16i8, 6 }, 698 699 // Operations that we legalize using splitting. 700 { ISD::TRUNCATE, MVT::v16i8, MVT::v16i32, 6 }, 701 { ISD::TRUNCATE, MVT::v8i8, MVT::v8i32, 3 }, 702 703 // Vector float <-> i32 conversions. 704 { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 }, 705 { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 }, 706 707 { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i8, 3 }, 708 { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i8, 3 }, 709 { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i16, 2 }, 710 { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i16, 2 }, 711 { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i32, 1 }, 712 { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i32, 1 }, 713 { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i1, 3 }, 714 { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i1, 3 }, 715 { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i8, 3 }, 716 { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i8, 3 }, 717 { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 }, 718 { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 }, 719 { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i16, 4 }, 720 { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i16, 4 }, 721 { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i32, 2 }, 722 { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i32, 2 }, 723 { ISD::SINT_TO_FP, MVT::v16f32, MVT::v16i16, 8 }, 724 { ISD::UINT_TO_FP, MVT::v16f32, MVT::v16i16, 8 }, 725 { ISD::SINT_TO_FP, MVT::v16f32, MVT::v16i32, 4 }, 726 { ISD::UINT_TO_FP, MVT::v16f32, MVT::v16i32, 4 }, 727 728 { ISD::FP_TO_SINT, MVT::v4i32, MVT::v4f32, 1 }, 729 { ISD::FP_TO_UINT, MVT::v4i32, MVT::v4f32, 1 }, 730 { ISD::FP_TO_SINT, MVT::v4i8, MVT::v4f32, 3 }, 731 { ISD::FP_TO_UINT, MVT::v4i8, MVT::v4f32, 3 }, 732 { ISD::FP_TO_SINT, MVT::v4i16, MVT::v4f32, 2 }, 733 { ISD::FP_TO_UINT, MVT::v4i16, MVT::v4f32, 2 }, 734 735 // Vector double <-> i32 conversions. 736 { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 }, 737 { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 }, 738 739 { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i8, 4 }, 740 { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i8, 4 }, 741 { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i16, 3 }, 742 { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i16, 3 }, 743 { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 }, 744 { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 }, 745 746 { ISD::FP_TO_SINT, MVT::v2i32, MVT::v2f64, 2 }, 747 { ISD::FP_TO_UINT, MVT::v2i32, MVT::v2f64, 2 }, 748 { ISD::FP_TO_SINT, MVT::v8i16, MVT::v8f32, 4 }, 749 { ISD::FP_TO_UINT, MVT::v8i16, MVT::v8f32, 4 }, 750 { ISD::FP_TO_SINT, MVT::v16i16, MVT::v16f32, 8 }, 751 { ISD::FP_TO_UINT, MVT::v16i16, MVT::v16f32, 8 } 752 }; 753 754 if (SrcTy.isVector() && ST->hasNEON()) { 755 if (const auto *Entry = ConvertCostTableLookup(NEONVectorConversionTbl, ISD, 756 DstTy.getSimpleVT(), 757 SrcTy.getSimpleVT())) 758 return AdjustCost(Entry->Cost); 759 } 760 761 // Scalar float to integer conversions. 762 static const TypeConversionCostTblEntry NEONFloatConversionTbl[] = { 763 { ISD::FP_TO_SINT, MVT::i1, MVT::f32, 2 }, 764 { ISD::FP_TO_UINT, MVT::i1, MVT::f32, 2 }, 765 { ISD::FP_TO_SINT, MVT::i1, MVT::f64, 2 }, 766 { ISD::FP_TO_UINT, MVT::i1, MVT::f64, 2 }, 767 { ISD::FP_TO_SINT, MVT::i8, MVT::f32, 2 }, 768 { ISD::FP_TO_UINT, MVT::i8, MVT::f32, 2 }, 769 { ISD::FP_TO_SINT, MVT::i8, MVT::f64, 2 }, 770 { ISD::FP_TO_UINT, MVT::i8, MVT::f64, 2 }, 771 { ISD::FP_TO_SINT, MVT::i16, MVT::f32, 2 }, 772 { ISD::FP_TO_UINT, MVT::i16, MVT::f32, 2 }, 773 { ISD::FP_TO_SINT, MVT::i16, MVT::f64, 2 }, 774 { ISD::FP_TO_UINT, MVT::i16, MVT::f64, 2 }, 775 { ISD::FP_TO_SINT, MVT::i32, MVT::f32, 2 }, 776 { ISD::FP_TO_UINT, MVT::i32, MVT::f32, 2 }, 777 { ISD::FP_TO_SINT, MVT::i32, MVT::f64, 2 }, 778 { ISD::FP_TO_UINT, MVT::i32, MVT::f64, 2 }, 779 { ISD::FP_TO_SINT, MVT::i64, MVT::f32, 10 }, 780 { ISD::FP_TO_UINT, MVT::i64, MVT::f32, 10 }, 781 { ISD::FP_TO_SINT, MVT::i64, MVT::f64, 10 }, 782 { ISD::FP_TO_UINT, MVT::i64, MVT::f64, 10 } 783 }; 784 if (SrcTy.isFloatingPoint() && ST->hasNEON()) { 785 if (const auto *Entry = ConvertCostTableLookup(NEONFloatConversionTbl, ISD, 786 DstTy.getSimpleVT(), 787 SrcTy.getSimpleVT())) 788 return AdjustCost(Entry->Cost); 789 } 790 791 // Scalar integer to float conversions. 792 static const TypeConversionCostTblEntry NEONIntegerConversionTbl[] = { 793 { ISD::SINT_TO_FP, MVT::f32, MVT::i1, 2 }, 794 { ISD::UINT_TO_FP, MVT::f32, MVT::i1, 2 }, 795 { ISD::SINT_TO_FP, MVT::f64, MVT::i1, 2 }, 796 { ISD::UINT_TO_FP, MVT::f64, MVT::i1, 2 }, 797 { ISD::SINT_TO_FP, MVT::f32, MVT::i8, 2 }, 798 { ISD::UINT_TO_FP, MVT::f32, MVT::i8, 2 }, 799 { ISD::SINT_TO_FP, MVT::f64, MVT::i8, 2 }, 800 { ISD::UINT_TO_FP, MVT::f64, MVT::i8, 2 }, 801 { ISD::SINT_TO_FP, MVT::f32, MVT::i16, 2 }, 802 { ISD::UINT_TO_FP, MVT::f32, MVT::i16, 2 }, 803 { ISD::SINT_TO_FP, MVT::f64, MVT::i16, 2 }, 804 { ISD::UINT_TO_FP, MVT::f64, MVT::i16, 2 }, 805 { ISD::SINT_TO_FP, MVT::f32, MVT::i32, 2 }, 806 { ISD::UINT_TO_FP, MVT::f32, MVT::i32, 2 }, 807 { ISD::SINT_TO_FP, MVT::f64, MVT::i32, 2 }, 808 { ISD::UINT_TO_FP, MVT::f64, MVT::i32, 2 }, 809 { ISD::SINT_TO_FP, MVT::f32, MVT::i64, 10 }, 810 { ISD::UINT_TO_FP, MVT::f32, MVT::i64, 10 }, 811 { ISD::SINT_TO_FP, MVT::f64, MVT::i64, 10 }, 812 { ISD::UINT_TO_FP, MVT::f64, MVT::i64, 10 } 813 }; 814 815 if (SrcTy.isInteger() && ST->hasNEON()) { 816 if (const auto *Entry = ConvertCostTableLookup(NEONIntegerConversionTbl, 817 ISD, DstTy.getSimpleVT(), 818 SrcTy.getSimpleVT())) 819 return AdjustCost(Entry->Cost); 820 } 821 822 // MVE extend costs, taken from codegen tests. i8->i16 or i16->i32 is one 823 // instruction, i8->i32 is two. i64 zexts are an VAND with a constant, sext 824 // are linearised so take more. 825 static const TypeConversionCostTblEntry MVEVectorConversionTbl[] = { 826 { ISD::SIGN_EXTEND, MVT::v8i16, MVT::v8i8, 1 }, 827 { ISD::ZERO_EXTEND, MVT::v8i16, MVT::v8i8, 1 }, 828 { ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i8, 2 }, 829 { ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i8, 2 }, 830 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i8, 10 }, 831 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i8, 2 }, 832 { ISD::SIGN_EXTEND, MVT::v4i32, MVT::v4i16, 1 }, 833 { ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i16, 1 }, 834 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i16, 10 }, 835 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i16, 2 }, 836 { ISD::SIGN_EXTEND, MVT::v2i64, MVT::v2i32, 8 }, 837 { ISD::ZERO_EXTEND, MVT::v2i64, MVT::v2i32, 2 }, 838 }; 839 840 if (SrcTy.isVector() && ST->hasMVEIntegerOps()) { 841 if (const auto *Entry = ConvertCostTableLookup(MVEVectorConversionTbl, 842 ISD, DstTy.getSimpleVT(), 843 SrcTy.getSimpleVT())) 844 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind); 845 } 846 847 if (ISD == ISD::FP_ROUND || ISD == ISD::FP_EXTEND) { 848 // As general rule, fp converts that were not matched above are scalarized 849 // and cost 1 vcvt for each lane, so long as the instruction is available. 850 // If not it will become a series of function calls. 851 const InstructionCost CallCost = 852 getCallInstrCost(nullptr, Dst, {Src}, CostKind); 853 int Lanes = 1; 854 if (SrcTy.isFixedLengthVector()) 855 Lanes = SrcTy.getVectorNumElements(); 856 857 if (IsLegalFPType(SrcTy) && IsLegalFPType(DstTy)) 858 return Lanes; 859 else 860 return Lanes * CallCost; 861 } 862 863 if (ISD == ISD::TRUNCATE && ST->hasMVEIntegerOps() && 864 SrcTy.isFixedLengthVector()) { 865 // Treat a truncate with larger than legal source (128bits for MVE) as 866 // expensive, 2 instructions per lane. 867 if ((SrcTy.getScalarType() == MVT::i8 || 868 SrcTy.getScalarType() == MVT::i16 || 869 SrcTy.getScalarType() == MVT::i32) && 870 SrcTy.getSizeInBits() > 128 && 871 SrcTy.getSizeInBits() > DstTy.getSizeInBits()) 872 return SrcTy.getVectorNumElements() * 2; 873 } 874 875 // Scalar integer conversion costs. 876 static const TypeConversionCostTblEntry ARMIntegerConversionTbl[] = { 877 // i16 -> i64 requires two dependent operations. 878 { ISD::SIGN_EXTEND, MVT::i64, MVT::i16, 2 }, 879 880 // Truncates on i64 are assumed to be free. 881 { ISD::TRUNCATE, MVT::i32, MVT::i64, 0 }, 882 { ISD::TRUNCATE, MVT::i16, MVT::i64, 0 }, 883 { ISD::TRUNCATE, MVT::i8, MVT::i64, 0 }, 884 { ISD::TRUNCATE, MVT::i1, MVT::i64, 0 } 885 }; 886 887 if (SrcTy.isInteger()) { 888 if (const auto *Entry = ConvertCostTableLookup(ARMIntegerConversionTbl, ISD, 889 DstTy.getSimpleVT(), 890 SrcTy.getSimpleVT())) 891 return AdjustCost(Entry->Cost); 892 } 893 894 int BaseCost = ST->hasMVEIntegerOps() && Src->isVectorTy() 895 ? ST->getMVEVectorCostFactor(CostKind) 896 : 1; 897 return AdjustCost( 898 BaseCost * BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I)); 899 } 900 901 InstructionCost ARMTTIImpl::getVectorInstrCost(unsigned Opcode, Type *ValTy, 902 TTI::TargetCostKind CostKind, 903 unsigned Index, Value *Op0, 904 Value *Op1) { 905 // Penalize inserting into an D-subregister. We end up with a three times 906 // lower estimated throughput on swift. 907 if (ST->hasSlowLoadDSubregister() && Opcode == Instruction::InsertElement && 908 ValTy->isVectorTy() && ValTy->getScalarSizeInBits() <= 32) 909 return 3; 910 911 if (ST->hasNEON() && (Opcode == Instruction::InsertElement || 912 Opcode == Instruction::ExtractElement)) { 913 // Cross-class copies are expensive on many microarchitectures, 914 // so assume they are expensive by default. 915 if (cast<VectorType>(ValTy)->getElementType()->isIntegerTy()) 916 return 3; 917 918 // Even if it's not a cross class copy, this likely leads to mixing 919 // of NEON and VFP code and should be therefore penalized. 920 if (ValTy->isVectorTy() && 921 ValTy->getScalarSizeInBits() <= 32) 922 return std::max<InstructionCost>( 923 BaseT::getVectorInstrCost(Opcode, ValTy, CostKind, Index, Op0, Op1), 924 2U); 925 } 926 927 if (ST->hasMVEIntegerOps() && (Opcode == Instruction::InsertElement || 928 Opcode == Instruction::ExtractElement)) { 929 // Integer cross-lane moves are more expensive than float, which can 930 // sometimes just be vmovs. Integer involve being passes to GPR registers, 931 // causing more of a delay. 932 std::pair<InstructionCost, MVT> LT = 933 getTypeLegalizationCost(ValTy->getScalarType()); 934 return LT.first * (ValTy->getScalarType()->isIntegerTy() ? 4 : 1); 935 } 936 937 return BaseT::getVectorInstrCost(Opcode, ValTy, CostKind, Index, Op0, Op1); 938 } 939 940 InstructionCost ARMTTIImpl::getCmpSelInstrCost( 941 unsigned Opcode, Type *ValTy, Type *CondTy, CmpInst::Predicate VecPred, 942 TTI::TargetCostKind CostKind, TTI::OperandValueInfo Op1Info, 943 TTI::OperandValueInfo Op2Info, const Instruction *I) { 944 int ISD = TLI->InstructionOpcodeToISD(Opcode); 945 946 // Thumb scalar code size cost for select. 947 if (CostKind == TTI::TCK_CodeSize && ISD == ISD::SELECT && 948 ST->isThumb() && !ValTy->isVectorTy()) { 949 // Assume expensive structs. 950 if (TLI->getValueType(DL, ValTy, true) == MVT::Other) 951 return TTI::TCC_Expensive; 952 953 // Select costs can vary because they: 954 // - may require one or more conditional mov (including an IT), 955 // - can't operate directly on immediates, 956 // - require live flags, which we can't copy around easily. 957 InstructionCost Cost = getTypeLegalizationCost(ValTy).first; 958 959 // Possible IT instruction for Thumb2, or more for Thumb1. 960 ++Cost; 961 962 // i1 values may need rematerialising by using mov immediates and/or 963 // flag setting instructions. 964 if (ValTy->isIntegerTy(1)) 965 ++Cost; 966 967 return Cost; 968 } 969 970 // If this is a vector min/max/abs, use the cost of that intrinsic directly 971 // instead. Hopefully when min/max intrinsics are more prevalent this code 972 // will not be needed. 973 const Instruction *Sel = I; 974 if ((Opcode == Instruction::ICmp || Opcode == Instruction::FCmp) && Sel && 975 Sel->hasOneUse()) 976 Sel = cast<Instruction>(Sel->user_back()); 977 if (Sel && ValTy->isVectorTy() && 978 (ValTy->isIntOrIntVectorTy() || ValTy->isFPOrFPVectorTy())) { 979 const Value *LHS, *RHS; 980 SelectPatternFlavor SPF = matchSelectPattern(Sel, LHS, RHS).Flavor; 981 unsigned IID = 0; 982 switch (SPF) { 983 case SPF_ABS: 984 IID = Intrinsic::abs; 985 break; 986 case SPF_SMIN: 987 IID = Intrinsic::smin; 988 break; 989 case SPF_SMAX: 990 IID = Intrinsic::smax; 991 break; 992 case SPF_UMIN: 993 IID = Intrinsic::umin; 994 break; 995 case SPF_UMAX: 996 IID = Intrinsic::umax; 997 break; 998 case SPF_FMINNUM: 999 IID = Intrinsic::minnum; 1000 break; 1001 case SPF_FMAXNUM: 1002 IID = Intrinsic::maxnum; 1003 break; 1004 default: 1005 break; 1006 } 1007 if (IID) { 1008 // The ICmp is free, the select gets the cost of the min/max/etc 1009 if (Sel != I) 1010 return 0; 1011 IntrinsicCostAttributes CostAttrs(IID, ValTy, {ValTy, ValTy}); 1012 return getIntrinsicInstrCost(CostAttrs, CostKind); 1013 } 1014 } 1015 1016 // On NEON a vector select gets lowered to vbsl. 1017 if (ST->hasNEON() && ValTy->isVectorTy() && ISD == ISD::SELECT && CondTy) { 1018 // Lowering of some vector selects is currently far from perfect. 1019 static const TypeConversionCostTblEntry NEONVectorSelectTbl[] = { 1020 { ISD::SELECT, MVT::v4i1, MVT::v4i64, 4*4 + 1*2 + 1 }, 1021 { ISD::SELECT, MVT::v8i1, MVT::v8i64, 50 }, 1022 { ISD::SELECT, MVT::v16i1, MVT::v16i64, 100 } 1023 }; 1024 1025 EVT SelCondTy = TLI->getValueType(DL, CondTy); 1026 EVT SelValTy = TLI->getValueType(DL, ValTy); 1027 if (SelCondTy.isSimple() && SelValTy.isSimple()) { 1028 if (const auto *Entry = ConvertCostTableLookup(NEONVectorSelectTbl, ISD, 1029 SelCondTy.getSimpleVT(), 1030 SelValTy.getSimpleVT())) 1031 return Entry->Cost; 1032 } 1033 1034 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1035 return LT.first; 1036 } 1037 1038 if (ST->hasMVEIntegerOps() && ValTy->isVectorTy() && 1039 (Opcode == Instruction::ICmp || Opcode == Instruction::FCmp) && 1040 cast<FixedVectorType>(ValTy)->getNumElements() > 1) { 1041 FixedVectorType *VecValTy = cast<FixedVectorType>(ValTy); 1042 FixedVectorType *VecCondTy = dyn_cast_or_null<FixedVectorType>(CondTy); 1043 if (!VecCondTy) 1044 VecCondTy = cast<FixedVectorType>(CmpInst::makeCmpResultType(VecValTy)); 1045 1046 // If we don't have mve.fp any fp operations will need to be scalarized. 1047 if (Opcode == Instruction::FCmp && !ST->hasMVEFloatOps()) { 1048 // One scalaization insert, one scalarization extract and the cost of the 1049 // fcmps. 1050 return BaseT::getScalarizationOverhead(VecValTy, /*Insert*/ false, 1051 /*Extract*/ true, CostKind) + 1052 BaseT::getScalarizationOverhead(VecCondTy, /*Insert*/ true, 1053 /*Extract*/ false, CostKind) + 1054 VecValTy->getNumElements() * 1055 getCmpSelInstrCost(Opcode, ValTy->getScalarType(), 1056 VecCondTy->getScalarType(), VecPred, 1057 CostKind, Op1Info, Op2Info, I); 1058 } 1059 1060 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1061 int BaseCost = ST->getMVEVectorCostFactor(CostKind); 1062 // There are two types - the input that specifies the type of the compare 1063 // and the output vXi1 type. Because we don't know how the output will be 1064 // split, we may need an expensive shuffle to get two in sync. This has the 1065 // effect of making larger than legal compares (v8i32 for example) 1066 // expensive. 1067 if (LT.second.isVector() && LT.second.getVectorNumElements() > 2) { 1068 if (LT.first > 1) 1069 return LT.first * BaseCost + 1070 BaseT::getScalarizationOverhead(VecCondTy, /*Insert*/ true, 1071 /*Extract*/ false, CostKind); 1072 return BaseCost; 1073 } 1074 } 1075 1076 // Default to cheap (throughput/size of 1 instruction) but adjust throughput 1077 // for "multiple beats" potentially needed by MVE instructions. 1078 int BaseCost = 1; 1079 if (ST->hasMVEIntegerOps() && ValTy->isVectorTy()) 1080 BaseCost = ST->getMVEVectorCostFactor(CostKind); 1081 1082 return BaseCost * BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, 1083 CostKind, Op1Info, Op2Info, I); 1084 } 1085 1086 InstructionCost ARMTTIImpl::getAddressComputationCost(Type *Ty, 1087 ScalarEvolution *SE, 1088 const SCEV *Ptr) { 1089 // Address computations in vectorized code with non-consecutive addresses will 1090 // likely result in more instructions compared to scalar code where the 1091 // computation can more often be merged into the index mode. The resulting 1092 // extra micro-ops can significantly decrease throughput. 1093 unsigned NumVectorInstToHideOverhead = 10; 1094 int MaxMergeDistance = 64; 1095 1096 if (ST->hasNEON()) { 1097 if (Ty->isVectorTy() && SE && 1098 !BaseT::isConstantStridedAccessLessThan(SE, Ptr, MaxMergeDistance + 1)) 1099 return NumVectorInstToHideOverhead; 1100 1101 // In many cases the address computation is not merged into the instruction 1102 // addressing mode. 1103 return 1; 1104 } 1105 return BaseT::getAddressComputationCost(Ty, SE, Ptr); 1106 } 1107 1108 bool ARMTTIImpl::isProfitableLSRChainElement(Instruction *I) { 1109 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) { 1110 // If a VCTP is part of a chain, it's already profitable and shouldn't be 1111 // optimized, else LSR may block tail-predication. 1112 switch (II->getIntrinsicID()) { 1113 case Intrinsic::arm_mve_vctp8: 1114 case Intrinsic::arm_mve_vctp16: 1115 case Intrinsic::arm_mve_vctp32: 1116 case Intrinsic::arm_mve_vctp64: 1117 return true; 1118 default: 1119 break; 1120 } 1121 } 1122 return false; 1123 } 1124 1125 bool ARMTTIImpl::isLegalMaskedLoad(Type *DataTy, Align Alignment) { 1126 if (!EnableMaskedLoadStores || !ST->hasMVEIntegerOps()) 1127 return false; 1128 1129 if (auto *VecTy = dyn_cast<FixedVectorType>(DataTy)) { 1130 // Don't support v2i1 yet. 1131 if (VecTy->getNumElements() == 2) 1132 return false; 1133 1134 // We don't support extending fp types. 1135 unsigned VecWidth = DataTy->getPrimitiveSizeInBits(); 1136 if (VecWidth != 128 && VecTy->getElementType()->isFloatingPointTy()) 1137 return false; 1138 } 1139 1140 unsigned EltWidth = DataTy->getScalarSizeInBits(); 1141 return (EltWidth == 32 && Alignment >= 4) || 1142 (EltWidth == 16 && Alignment >= 2) || (EltWidth == 8); 1143 } 1144 1145 bool ARMTTIImpl::isLegalMaskedGather(Type *Ty, Align Alignment) { 1146 if (!EnableMaskedGatherScatters || !ST->hasMVEIntegerOps()) 1147 return false; 1148 1149 unsigned EltWidth = Ty->getScalarSizeInBits(); 1150 return ((EltWidth == 32 && Alignment >= 4) || 1151 (EltWidth == 16 && Alignment >= 2) || EltWidth == 8); 1152 } 1153 1154 /// Given a memcpy/memset/memmove instruction, return the number of memory 1155 /// operations performed, via querying findOptimalMemOpLowering. Returns -1 if a 1156 /// call is used. 1157 int ARMTTIImpl::getNumMemOps(const IntrinsicInst *I) const { 1158 MemOp MOp; 1159 unsigned DstAddrSpace = ~0u; 1160 unsigned SrcAddrSpace = ~0u; 1161 const Function *F = I->getParent()->getParent(); 1162 1163 if (const auto *MC = dyn_cast<MemTransferInst>(I)) { 1164 ConstantInt *C = dyn_cast<ConstantInt>(MC->getLength()); 1165 // If 'size' is not a constant, a library call will be generated. 1166 if (!C) 1167 return -1; 1168 1169 const unsigned Size = C->getValue().getZExtValue(); 1170 const Align DstAlign = *MC->getDestAlign(); 1171 const Align SrcAlign = *MC->getSourceAlign(); 1172 1173 MOp = MemOp::Copy(Size, /*DstAlignCanChange*/ false, DstAlign, SrcAlign, 1174 /*IsVolatile*/ false); 1175 DstAddrSpace = MC->getDestAddressSpace(); 1176 SrcAddrSpace = MC->getSourceAddressSpace(); 1177 } 1178 else if (const auto *MS = dyn_cast<MemSetInst>(I)) { 1179 ConstantInt *C = dyn_cast<ConstantInt>(MS->getLength()); 1180 // If 'size' is not a constant, a library call will be generated. 1181 if (!C) 1182 return -1; 1183 1184 const unsigned Size = C->getValue().getZExtValue(); 1185 const Align DstAlign = *MS->getDestAlign(); 1186 1187 MOp = MemOp::Set(Size, /*DstAlignCanChange*/ false, DstAlign, 1188 /*IsZeroMemset*/ false, /*IsVolatile*/ false); 1189 DstAddrSpace = MS->getDestAddressSpace(); 1190 } 1191 else 1192 llvm_unreachable("Expected a memcpy/move or memset!"); 1193 1194 unsigned Limit, Factor = 2; 1195 switch(I->getIntrinsicID()) { 1196 case Intrinsic::memcpy: 1197 Limit = TLI->getMaxStoresPerMemcpy(F->hasMinSize()); 1198 break; 1199 case Intrinsic::memmove: 1200 Limit = TLI->getMaxStoresPerMemmove(F->hasMinSize()); 1201 break; 1202 case Intrinsic::memset: 1203 Limit = TLI->getMaxStoresPerMemset(F->hasMinSize()); 1204 Factor = 1; 1205 break; 1206 default: 1207 llvm_unreachable("Expected a memcpy/move or memset!"); 1208 } 1209 1210 // MemOps will be poplulated with a list of data types that needs to be 1211 // loaded and stored. That's why we multiply the number of elements by 2 to 1212 // get the cost for this memcpy. 1213 std::vector<EVT> MemOps; 1214 if (getTLI()->findOptimalMemOpLowering( 1215 MemOps, Limit, MOp, DstAddrSpace, 1216 SrcAddrSpace, F->getAttributes())) 1217 return MemOps.size() * Factor; 1218 1219 // If we can't find an optimal memop lowering, return the default cost 1220 return -1; 1221 } 1222 1223 InstructionCost ARMTTIImpl::getMemcpyCost(const Instruction *I) { 1224 int NumOps = getNumMemOps(cast<IntrinsicInst>(I)); 1225 1226 // To model the cost of a library call, we assume 1 for the call, and 1227 // 3 for the argument setup. 1228 if (NumOps == -1) 1229 return 4; 1230 return NumOps; 1231 } 1232 1233 InstructionCost ARMTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, 1234 VectorType *Tp, ArrayRef<int> Mask, 1235 TTI::TargetCostKind CostKind, 1236 int Index, VectorType *SubTp, 1237 ArrayRef<const Value *> Args, 1238 const Instruction *CxtI) { 1239 Kind = improveShuffleKindFromMask(Kind, Mask, Tp, Index, SubTp); 1240 // Treat extractsubvector as single op permutation. 1241 bool IsExtractSubvector = Kind == TTI::SK_ExtractSubvector; 1242 if (IsExtractSubvector) 1243 Kind = TTI::SK_PermuteSingleSrc; 1244 if (ST->hasNEON()) { 1245 if (Kind == TTI::SK_Broadcast) { 1246 static const CostTblEntry NEONDupTbl[] = { 1247 // VDUP handles these cases. 1248 {ISD::VECTOR_SHUFFLE, MVT::v2i32, 1}, 1249 {ISD::VECTOR_SHUFFLE, MVT::v2f32, 1}, 1250 {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1}, 1251 {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1}, 1252 {ISD::VECTOR_SHUFFLE, MVT::v4i16, 1}, 1253 {ISD::VECTOR_SHUFFLE, MVT::v8i8, 1}, 1254 1255 {ISD::VECTOR_SHUFFLE, MVT::v4i32, 1}, 1256 {ISD::VECTOR_SHUFFLE, MVT::v4f32, 1}, 1257 {ISD::VECTOR_SHUFFLE, MVT::v8i16, 1}, 1258 {ISD::VECTOR_SHUFFLE, MVT::v16i8, 1}}; 1259 1260 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1261 if (const auto *Entry = 1262 CostTableLookup(NEONDupTbl, ISD::VECTOR_SHUFFLE, LT.second)) 1263 return LT.first * Entry->Cost; 1264 } 1265 if (Kind == TTI::SK_Reverse) { 1266 static const CostTblEntry NEONShuffleTbl[] = { 1267 // Reverse shuffle cost one instruction if we are shuffling within a 1268 // double word (vrev) or two if we shuffle a quad word (vrev, vext). 1269 {ISD::VECTOR_SHUFFLE, MVT::v2i32, 1}, 1270 {ISD::VECTOR_SHUFFLE, MVT::v2f32, 1}, 1271 {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1}, 1272 {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1}, 1273 {ISD::VECTOR_SHUFFLE, MVT::v4i16, 1}, 1274 {ISD::VECTOR_SHUFFLE, MVT::v8i8, 1}, 1275 1276 {ISD::VECTOR_SHUFFLE, MVT::v4i32, 2}, 1277 {ISD::VECTOR_SHUFFLE, MVT::v4f32, 2}, 1278 {ISD::VECTOR_SHUFFLE, MVT::v8i16, 2}, 1279 {ISD::VECTOR_SHUFFLE, MVT::v16i8, 2}}; 1280 1281 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1282 if (const auto *Entry = 1283 CostTableLookup(NEONShuffleTbl, ISD::VECTOR_SHUFFLE, LT.second)) 1284 return LT.first * Entry->Cost; 1285 } 1286 if (Kind == TTI::SK_Select) { 1287 static const CostTblEntry NEONSelShuffleTbl[] = { 1288 // Select shuffle cost table for ARM. Cost is the number of 1289 // instructions 1290 // required to create the shuffled vector. 1291 1292 {ISD::VECTOR_SHUFFLE, MVT::v2f32, 1}, 1293 {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1}, 1294 {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1}, 1295 {ISD::VECTOR_SHUFFLE, MVT::v2i32, 1}, 1296 1297 {ISD::VECTOR_SHUFFLE, MVT::v4i32, 2}, 1298 {ISD::VECTOR_SHUFFLE, MVT::v4f32, 2}, 1299 {ISD::VECTOR_SHUFFLE, MVT::v4i16, 2}, 1300 1301 {ISD::VECTOR_SHUFFLE, MVT::v8i16, 16}, 1302 1303 {ISD::VECTOR_SHUFFLE, MVT::v16i8, 32}}; 1304 1305 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1306 if (const auto *Entry = CostTableLookup(NEONSelShuffleTbl, 1307 ISD::VECTOR_SHUFFLE, LT.second)) 1308 return LT.first * Entry->Cost; 1309 } 1310 } 1311 if (ST->hasMVEIntegerOps()) { 1312 if (Kind == TTI::SK_Broadcast) { 1313 static const CostTblEntry MVEDupTbl[] = { 1314 // VDUP handles these cases. 1315 {ISD::VECTOR_SHUFFLE, MVT::v4i32, 1}, 1316 {ISD::VECTOR_SHUFFLE, MVT::v8i16, 1}, 1317 {ISD::VECTOR_SHUFFLE, MVT::v16i8, 1}, 1318 {ISD::VECTOR_SHUFFLE, MVT::v4f32, 1}, 1319 {ISD::VECTOR_SHUFFLE, MVT::v8f16, 1}}; 1320 1321 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1322 if (const auto *Entry = CostTableLookup(MVEDupTbl, ISD::VECTOR_SHUFFLE, 1323 LT.second)) 1324 return LT.first * Entry->Cost * 1325 ST->getMVEVectorCostFactor(TTI::TCK_RecipThroughput); 1326 } 1327 1328 if (!Mask.empty()) { 1329 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp); 1330 if (LT.second.isVector() && 1331 Mask.size() <= LT.second.getVectorNumElements() && 1332 (isVREVMask(Mask, LT.second, 16) || isVREVMask(Mask, LT.second, 32) || 1333 isVREVMask(Mask, LT.second, 64))) 1334 return ST->getMVEVectorCostFactor(TTI::TCK_RecipThroughput) * LT.first; 1335 } 1336 } 1337 1338 // Restore optimal kind. 1339 if (IsExtractSubvector) 1340 Kind = TTI::SK_ExtractSubvector; 1341 int BaseCost = ST->hasMVEIntegerOps() && Tp->isVectorTy() 1342 ? ST->getMVEVectorCostFactor(TTI::TCK_RecipThroughput) 1343 : 1; 1344 return BaseCost * 1345 BaseT::getShuffleCost(Kind, Tp, Mask, CostKind, Index, SubTp); 1346 } 1347 1348 InstructionCost ARMTTIImpl::getArithmeticInstrCost( 1349 unsigned Opcode, Type *Ty, TTI::TargetCostKind CostKind, 1350 TTI::OperandValueInfo Op1Info, TTI::OperandValueInfo Op2Info, 1351 ArrayRef<const Value *> Args, 1352 const Instruction *CxtI) { 1353 int ISDOpcode = TLI->InstructionOpcodeToISD(Opcode); 1354 if (ST->isThumb() && CostKind == TTI::TCK_CodeSize && Ty->isIntegerTy(1)) { 1355 // Make operations on i1 relatively expensive as this often involves 1356 // combining predicates. AND and XOR should be easier to handle with IT 1357 // blocks. 1358 switch (ISDOpcode) { 1359 default: 1360 break; 1361 case ISD::AND: 1362 case ISD::XOR: 1363 return 2; 1364 case ISD::OR: 1365 return 3; 1366 } 1367 } 1368 1369 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Ty); 1370 1371 if (ST->hasNEON()) { 1372 const unsigned FunctionCallDivCost = 20; 1373 const unsigned ReciprocalDivCost = 10; 1374 static const CostTblEntry CostTbl[] = { 1375 // Division. 1376 // These costs are somewhat random. Choose a cost of 20 to indicate that 1377 // vectorizing devision (added function call) is going to be very expensive. 1378 // Double registers types. 1379 { ISD::SDIV, MVT::v1i64, 1 * FunctionCallDivCost}, 1380 { ISD::UDIV, MVT::v1i64, 1 * FunctionCallDivCost}, 1381 { ISD::SREM, MVT::v1i64, 1 * FunctionCallDivCost}, 1382 { ISD::UREM, MVT::v1i64, 1 * FunctionCallDivCost}, 1383 { ISD::SDIV, MVT::v2i32, 2 * FunctionCallDivCost}, 1384 { ISD::UDIV, MVT::v2i32, 2 * FunctionCallDivCost}, 1385 { ISD::SREM, MVT::v2i32, 2 * FunctionCallDivCost}, 1386 { ISD::UREM, MVT::v2i32, 2 * FunctionCallDivCost}, 1387 { ISD::SDIV, MVT::v4i16, ReciprocalDivCost}, 1388 { ISD::UDIV, MVT::v4i16, ReciprocalDivCost}, 1389 { ISD::SREM, MVT::v4i16, 4 * FunctionCallDivCost}, 1390 { ISD::UREM, MVT::v4i16, 4 * FunctionCallDivCost}, 1391 { ISD::SDIV, MVT::v8i8, ReciprocalDivCost}, 1392 { ISD::UDIV, MVT::v8i8, ReciprocalDivCost}, 1393 { ISD::SREM, MVT::v8i8, 8 * FunctionCallDivCost}, 1394 { ISD::UREM, MVT::v8i8, 8 * FunctionCallDivCost}, 1395 // Quad register types. 1396 { ISD::SDIV, MVT::v2i64, 2 * FunctionCallDivCost}, 1397 { ISD::UDIV, MVT::v2i64, 2 * FunctionCallDivCost}, 1398 { ISD::SREM, MVT::v2i64, 2 * FunctionCallDivCost}, 1399 { ISD::UREM, MVT::v2i64, 2 * FunctionCallDivCost}, 1400 { ISD::SDIV, MVT::v4i32, 4 * FunctionCallDivCost}, 1401 { ISD::UDIV, MVT::v4i32, 4 * FunctionCallDivCost}, 1402 { ISD::SREM, MVT::v4i32, 4 * FunctionCallDivCost}, 1403 { ISD::UREM, MVT::v4i32, 4 * FunctionCallDivCost}, 1404 { ISD::SDIV, MVT::v8i16, 8 * FunctionCallDivCost}, 1405 { ISD::UDIV, MVT::v8i16, 8 * FunctionCallDivCost}, 1406 { ISD::SREM, MVT::v8i16, 8 * FunctionCallDivCost}, 1407 { ISD::UREM, MVT::v8i16, 8 * FunctionCallDivCost}, 1408 { ISD::SDIV, MVT::v16i8, 16 * FunctionCallDivCost}, 1409 { ISD::UDIV, MVT::v16i8, 16 * FunctionCallDivCost}, 1410 { ISD::SREM, MVT::v16i8, 16 * FunctionCallDivCost}, 1411 { ISD::UREM, MVT::v16i8, 16 * FunctionCallDivCost}, 1412 // Multiplication. 1413 }; 1414 1415 if (const auto *Entry = CostTableLookup(CostTbl, ISDOpcode, LT.second)) 1416 return LT.first * Entry->Cost; 1417 1418 InstructionCost Cost = BaseT::getArithmeticInstrCost( 1419 Opcode, Ty, CostKind, Op1Info, Op2Info); 1420 1421 // This is somewhat of a hack. The problem that we are facing is that SROA 1422 // creates a sequence of shift, and, or instructions to construct values. 1423 // These sequences are recognized by the ISel and have zero-cost. Not so for 1424 // the vectorized code. Because we have support for v2i64 but not i64 those 1425 // sequences look particularly beneficial to vectorize. 1426 // To work around this we increase the cost of v2i64 operations to make them 1427 // seem less beneficial. 1428 if (LT.second == MVT::v2i64 && Op2Info.isUniform() && Op2Info.isConstant()) 1429 Cost += 4; 1430 1431 return Cost; 1432 } 1433 1434 // If this operation is a shift on arm/thumb2, it might well be folded into 1435 // the following instruction, hence having a cost of 0. 1436 auto LooksLikeAFreeShift = [&]() { 1437 if (ST->isThumb1Only() || Ty->isVectorTy()) 1438 return false; 1439 1440 if (!CxtI || !CxtI->hasOneUse() || !CxtI->isShift()) 1441 return false; 1442 if (!Op2Info.isUniform() || !Op2Info.isConstant()) 1443 return false; 1444 1445 // Folded into a ADC/ADD/AND/BIC/CMP/EOR/MVN/ORR/ORN/RSB/SBC/SUB 1446 switch (cast<Instruction>(CxtI->user_back())->getOpcode()) { 1447 case Instruction::Add: 1448 case Instruction::Sub: 1449 case Instruction::And: 1450 case Instruction::Xor: 1451 case Instruction::Or: 1452 case Instruction::ICmp: 1453 return true; 1454 default: 1455 return false; 1456 } 1457 }; 1458 if (LooksLikeAFreeShift()) 1459 return 0; 1460 1461 // Default to cheap (throughput/size of 1 instruction) but adjust throughput 1462 // for "multiple beats" potentially needed by MVE instructions. 1463 int BaseCost = 1; 1464 if (ST->hasMVEIntegerOps() && Ty->isVectorTy()) 1465 BaseCost = ST->getMVEVectorCostFactor(CostKind); 1466 1467 // The rest of this mostly follows what is done in BaseT::getArithmeticInstrCost, 1468 // without treating floats as more expensive that scalars or increasing the 1469 // costs for custom operations. The results is also multiplied by the 1470 // MVEVectorCostFactor where appropriate. 1471 if (TLI->isOperationLegalOrCustomOrPromote(ISDOpcode, LT.second)) 1472 return LT.first * BaseCost; 1473 1474 // Else this is expand, assume that we need to scalarize this op. 1475 if (auto *VTy = dyn_cast<FixedVectorType>(Ty)) { 1476 unsigned Num = VTy->getNumElements(); 1477 InstructionCost Cost = 1478 getArithmeticInstrCost(Opcode, Ty->getScalarType(), CostKind); 1479 // Return the cost of multiple scalar invocation plus the cost of 1480 // inserting and extracting the values. 1481 SmallVector<Type *> Tys(Args.size(), Ty); 1482 return BaseT::getScalarizationOverhead(VTy, Args, Tys, CostKind) + 1483 Num * Cost; 1484 } 1485 1486 return BaseCost; 1487 } 1488 1489 InstructionCost ARMTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src, 1490 MaybeAlign Alignment, 1491 unsigned AddressSpace, 1492 TTI::TargetCostKind CostKind, 1493 TTI::OperandValueInfo OpInfo, 1494 const Instruction *I) { 1495 // TODO: Handle other cost kinds. 1496 if (CostKind != TTI::TCK_RecipThroughput) 1497 return 1; 1498 1499 // Type legalization can't handle structs 1500 if (TLI->getValueType(DL, Src, true) == MVT::Other) 1501 return BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, 1502 CostKind); 1503 1504 if (ST->hasNEON() && Src->isVectorTy() && 1505 (Alignment && *Alignment != Align(16)) && 1506 cast<VectorType>(Src)->getElementType()->isDoubleTy()) { 1507 // Unaligned loads/stores are extremely inefficient. 1508 // We need 4 uops for vst.1/vld.1 vs 1uop for vldr/vstr. 1509 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Src); 1510 return LT.first * 4; 1511 } 1512 1513 // MVE can optimize a fpext(load(4xhalf)) using an extending integer load. 1514 // Same for stores. 1515 if (ST->hasMVEFloatOps() && isa<FixedVectorType>(Src) && I && 1516 ((Opcode == Instruction::Load && I->hasOneUse() && 1517 isa<FPExtInst>(*I->user_begin())) || 1518 (Opcode == Instruction::Store && isa<FPTruncInst>(I->getOperand(0))))) { 1519 FixedVectorType *SrcVTy = cast<FixedVectorType>(Src); 1520 Type *DstTy = 1521 Opcode == Instruction::Load 1522 ? (*I->user_begin())->getType() 1523 : cast<Instruction>(I->getOperand(0))->getOperand(0)->getType(); 1524 if (SrcVTy->getNumElements() == 4 && SrcVTy->getScalarType()->isHalfTy() && 1525 DstTy->getScalarType()->isFloatTy()) 1526 return ST->getMVEVectorCostFactor(CostKind); 1527 } 1528 1529 int BaseCost = ST->hasMVEIntegerOps() && Src->isVectorTy() 1530 ? ST->getMVEVectorCostFactor(CostKind) 1531 : 1; 1532 return BaseCost * BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, 1533 CostKind, OpInfo, I); 1534 } 1535 1536 InstructionCost 1537 ARMTTIImpl::getMaskedMemoryOpCost(unsigned Opcode, Type *Src, Align Alignment, 1538 unsigned AddressSpace, 1539 TTI::TargetCostKind CostKind) { 1540 if (ST->hasMVEIntegerOps()) { 1541 if (Opcode == Instruction::Load && isLegalMaskedLoad(Src, Alignment)) 1542 return ST->getMVEVectorCostFactor(CostKind); 1543 if (Opcode == Instruction::Store && isLegalMaskedStore(Src, Alignment)) 1544 return ST->getMVEVectorCostFactor(CostKind); 1545 } 1546 if (!isa<FixedVectorType>(Src)) 1547 return BaseT::getMaskedMemoryOpCost(Opcode, Src, Alignment, AddressSpace, 1548 CostKind); 1549 // Scalar cost, which is currently very high due to the efficiency of the 1550 // generated code. 1551 return cast<FixedVectorType>(Src)->getNumElements() * 8; 1552 } 1553 1554 InstructionCost ARMTTIImpl::getInterleavedMemoryOpCost( 1555 unsigned Opcode, Type *VecTy, unsigned Factor, ArrayRef<unsigned> Indices, 1556 Align Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind, 1557 bool UseMaskForCond, bool UseMaskForGaps) { 1558 assert(Factor >= 2 && "Invalid interleave factor"); 1559 assert(isa<VectorType>(VecTy) && "Expect a vector type"); 1560 1561 // vldN/vstN doesn't support vector types of i64/f64 element. 1562 bool EltIs64Bits = DL.getTypeSizeInBits(VecTy->getScalarType()) == 64; 1563 1564 if (Factor <= TLI->getMaxSupportedInterleaveFactor() && !EltIs64Bits && 1565 !UseMaskForCond && !UseMaskForGaps) { 1566 unsigned NumElts = cast<FixedVectorType>(VecTy)->getNumElements(); 1567 auto *SubVecTy = 1568 FixedVectorType::get(VecTy->getScalarType(), NumElts / Factor); 1569 1570 // vldN/vstN only support legal vector types of size 64 or 128 in bits. 1571 // Accesses having vector types that are a multiple of 128 bits can be 1572 // matched to more than one vldN/vstN instruction. 1573 int BaseCost = 1574 ST->hasMVEIntegerOps() ? ST->getMVEVectorCostFactor(CostKind) : 1; 1575 if (NumElts % Factor == 0 && 1576 TLI->isLegalInterleavedAccessType(Factor, SubVecTy, Alignment, DL)) 1577 return Factor * BaseCost * TLI->getNumInterleavedAccesses(SubVecTy, DL); 1578 1579 // Some smaller than legal interleaved patterns are cheap as we can make 1580 // use of the vmovn or vrev patterns to interleave a standard load. This is 1581 // true for v4i8, v8i8 and v4i16 at least (but not for v4f16 as it is 1582 // promoted differently). The cost of 2 here is then a load and vrev or 1583 // vmovn. 1584 if (ST->hasMVEIntegerOps() && Factor == 2 && NumElts / Factor > 2 && 1585 VecTy->isIntOrIntVectorTy() && 1586 DL.getTypeSizeInBits(SubVecTy).getFixedValue() <= 64) 1587 return 2 * BaseCost; 1588 } 1589 1590 return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices, 1591 Alignment, AddressSpace, CostKind, 1592 UseMaskForCond, UseMaskForGaps); 1593 } 1594 1595 InstructionCost ARMTTIImpl::getGatherScatterOpCost( 1596 unsigned Opcode, Type *DataTy, const Value *Ptr, bool VariableMask, 1597 Align Alignment, TTI::TargetCostKind CostKind, const Instruction *I) { 1598 using namespace PatternMatch; 1599 if (!ST->hasMVEIntegerOps() || !EnableMaskedGatherScatters) 1600 return BaseT::getGatherScatterOpCost(Opcode, DataTy, Ptr, VariableMask, 1601 Alignment, CostKind, I); 1602 1603 assert(DataTy->isVectorTy() && "Can't do gather/scatters on scalar!"); 1604 auto *VTy = cast<FixedVectorType>(DataTy); 1605 1606 // TODO: Splitting, once we do that. 1607 1608 unsigned NumElems = VTy->getNumElements(); 1609 unsigned EltSize = VTy->getScalarSizeInBits(); 1610 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(DataTy); 1611 1612 // For now, it is assumed that for the MVE gather instructions the loads are 1613 // all effectively serialised. This means the cost is the scalar cost 1614 // multiplied by the number of elements being loaded. This is possibly very 1615 // conservative, but even so we still end up vectorising loops because the 1616 // cost per iteration for many loops is lower than for scalar loops. 1617 InstructionCost VectorCost = 1618 NumElems * LT.first * ST->getMVEVectorCostFactor(CostKind); 1619 // The scalarization cost should be a lot higher. We use the number of vector 1620 // elements plus the scalarization overhead. If masking is required then a lot 1621 // of little blocks will be needed and potentially a scalarized p0 mask, 1622 // greatly increasing the cost. 1623 InstructionCost ScalarCost = 1624 NumElems * LT.first + (VariableMask ? NumElems * 5 : 0) + 1625 BaseT::getScalarizationOverhead(VTy, /*Insert*/ true, /*Extract*/ false, 1626 CostKind) + 1627 BaseT::getScalarizationOverhead(VTy, /*Insert*/ false, /*Extract*/ true, 1628 CostKind); 1629 1630 if (EltSize < 8 || Alignment < EltSize / 8) 1631 return ScalarCost; 1632 1633 unsigned ExtSize = EltSize; 1634 // Check whether there's a single user that asks for an extended type 1635 if (I != nullptr) { 1636 // Dependent of the caller of this function, a gather instruction will 1637 // either have opcode Instruction::Load or be a call to the masked_gather 1638 // intrinsic 1639 if ((I->getOpcode() == Instruction::Load || 1640 match(I, m_Intrinsic<Intrinsic::masked_gather>())) && 1641 I->hasOneUse()) { 1642 const User *Us = *I->users().begin(); 1643 if (isa<ZExtInst>(Us) || isa<SExtInst>(Us)) { 1644 // only allow valid type combinations 1645 unsigned TypeSize = 1646 cast<Instruction>(Us)->getType()->getScalarSizeInBits(); 1647 if (((TypeSize == 32 && (EltSize == 8 || EltSize == 16)) || 1648 (TypeSize == 16 && EltSize == 8)) && 1649 TypeSize * NumElems == 128) { 1650 ExtSize = TypeSize; 1651 } 1652 } 1653 } 1654 // Check whether the input data needs to be truncated 1655 TruncInst *T; 1656 if ((I->getOpcode() == Instruction::Store || 1657 match(I, m_Intrinsic<Intrinsic::masked_scatter>())) && 1658 (T = dyn_cast<TruncInst>(I->getOperand(0)))) { 1659 // Only allow valid type combinations 1660 unsigned TypeSize = T->getOperand(0)->getType()->getScalarSizeInBits(); 1661 if (((EltSize == 16 && TypeSize == 32) || 1662 (EltSize == 8 && (TypeSize == 32 || TypeSize == 16))) && 1663 TypeSize * NumElems == 128) 1664 ExtSize = TypeSize; 1665 } 1666 } 1667 1668 if (ExtSize * NumElems != 128 || NumElems < 4) 1669 return ScalarCost; 1670 1671 // Any (aligned) i32 gather will not need to be scalarised. 1672 if (ExtSize == 32) 1673 return VectorCost; 1674 // For smaller types, we need to ensure that the gep's inputs are correctly 1675 // extended from a small enough value. Other sizes (including i64) are 1676 // scalarized for now. 1677 if (ExtSize != 8 && ExtSize != 16) 1678 return ScalarCost; 1679 1680 if (const auto *BC = dyn_cast<BitCastInst>(Ptr)) 1681 Ptr = BC->getOperand(0); 1682 if (const auto *GEP = dyn_cast<GetElementPtrInst>(Ptr)) { 1683 if (GEP->getNumOperands() != 2) 1684 return ScalarCost; 1685 unsigned Scale = DL.getTypeAllocSize(GEP->getResultElementType()); 1686 // Scale needs to be correct (which is only relevant for i16s). 1687 if (Scale != 1 && Scale * 8 != ExtSize) 1688 return ScalarCost; 1689 // And we need to zext (not sext) the indexes from a small enough type. 1690 if (const auto *ZExt = dyn_cast<ZExtInst>(GEP->getOperand(1))) { 1691 if (ZExt->getOperand(0)->getType()->getScalarSizeInBits() <= ExtSize) 1692 return VectorCost; 1693 } 1694 return ScalarCost; 1695 } 1696 return ScalarCost; 1697 } 1698 1699 InstructionCost 1700 ARMTTIImpl::getArithmeticReductionCost(unsigned Opcode, VectorType *ValTy, 1701 std::optional<FastMathFlags> FMF, 1702 TTI::TargetCostKind CostKind) { 1703 1704 EVT ValVT = TLI->getValueType(DL, ValTy); 1705 int ISD = TLI->InstructionOpcodeToISD(Opcode); 1706 unsigned EltSize = ValVT.getScalarSizeInBits(); 1707 1708 // In general floating point reductions are a series of elementwise 1709 // operations, with free extracts on each step. These are either in-order or 1710 // treewise depending on whether that is allowed by the fast math flags. 1711 if ((ISD == ISD::FADD || ISD == ISD::FMUL) && 1712 ((EltSize == 32 && ST->hasVFP2Base()) || 1713 (EltSize == 64 && ST->hasFP64()) || 1714 (EltSize == 16 && ST->hasFullFP16()))) { 1715 unsigned NumElts = cast<FixedVectorType>(ValTy)->getNumElements(); 1716 unsigned VecLimit = ST->hasMVEFloatOps() ? 128 : (ST->hasNEON() ? 64 : -1); 1717 InstructionCost VecCost = 0; 1718 while (!TTI::requiresOrderedReduction(FMF) && isPowerOf2_32(NumElts) && 1719 NumElts * EltSize > VecLimit) { 1720 Type *VecTy = FixedVectorType::get(ValTy->getElementType(), NumElts / 2); 1721 VecCost += getArithmeticInstrCost(Opcode, VecTy, CostKind); 1722 NumElts /= 2; 1723 } 1724 1725 // For fp16 we need to extract the upper lane elements. MVE can add a 1726 // VREV+FMIN/MAX to perform another vector step instead. 1727 InstructionCost ExtractCost = 0; 1728 if (!TTI::requiresOrderedReduction(FMF) && ST->hasMVEFloatOps() && 1729 ValVT.getVectorElementType() == MVT::f16 && NumElts == 8) { 1730 VecCost += ST->getMVEVectorCostFactor(CostKind) * 2; 1731 NumElts /= 2; 1732 } else if (ValVT.getVectorElementType() == MVT::f16) 1733 ExtractCost = NumElts / 2; 1734 1735 return VecCost + ExtractCost + 1736 NumElts * 1737 getArithmeticInstrCost(Opcode, ValTy->getElementType(), CostKind); 1738 } 1739 1740 if ((ISD == ISD::AND || ISD == ISD::OR || ISD == ISD::XOR) && 1741 (EltSize == 64 || EltSize == 32 || EltSize == 16 || EltSize == 8)) { 1742 unsigned NumElts = cast<FixedVectorType>(ValTy)->getNumElements(); 1743 unsigned VecLimit = 1744 ST->hasMVEIntegerOps() ? 128 : (ST->hasNEON() ? 64 : -1); 1745 InstructionCost VecCost = 0; 1746 while (isPowerOf2_32(NumElts) && NumElts * EltSize > VecLimit) { 1747 Type *VecTy = FixedVectorType::get(ValTy->getElementType(), NumElts / 2); 1748 VecCost += getArithmeticInstrCost(Opcode, VecTy, CostKind); 1749 NumElts /= 2; 1750 } 1751 // For i16/i8, MVE will perform a VREV + VORR/VAND/VEOR for the 64bit vector 1752 // step. 1753 if (ST->hasMVEIntegerOps() && ValVT.getScalarSizeInBits() <= 16 && 1754 NumElts * EltSize == 64) { 1755 Type *VecTy = FixedVectorType::get(ValTy->getElementType(), NumElts); 1756 VecCost += ST->getMVEVectorCostFactor(CostKind) + 1757 getArithmeticInstrCost(Opcode, VecTy, CostKind); 1758 NumElts /= 2; 1759 } 1760 1761 // From here we extract the elements and perform the and/or/xor. 1762 InstructionCost ExtractCost = NumElts; 1763 return VecCost + ExtractCost + 1764 (NumElts - 1) * getArithmeticInstrCost( 1765 Opcode, ValTy->getElementType(), CostKind); 1766 } 1767 1768 if (!ST->hasMVEIntegerOps() || !ValVT.isSimple() || ISD != ISD::ADD || 1769 TTI::requiresOrderedReduction(FMF)) 1770 return BaseT::getArithmeticReductionCost(Opcode, ValTy, FMF, CostKind); 1771 1772 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1773 1774 static const CostTblEntry CostTblAdd[]{ 1775 {ISD::ADD, MVT::v16i8, 1}, 1776 {ISD::ADD, MVT::v8i16, 1}, 1777 {ISD::ADD, MVT::v4i32, 1}, 1778 }; 1779 if (const auto *Entry = CostTableLookup(CostTblAdd, ISD, LT.second)) 1780 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind) * LT.first; 1781 1782 return BaseT::getArithmeticReductionCost(Opcode, ValTy, FMF, CostKind); 1783 } 1784 1785 InstructionCost ARMTTIImpl::getExtendedReductionCost( 1786 unsigned Opcode, bool IsUnsigned, Type *ResTy, VectorType *ValTy, 1787 FastMathFlags FMF, TTI::TargetCostKind CostKind) { 1788 EVT ValVT = TLI->getValueType(DL, ValTy); 1789 EVT ResVT = TLI->getValueType(DL, ResTy); 1790 1791 int ISD = TLI->InstructionOpcodeToISD(Opcode); 1792 1793 switch (ISD) { 1794 case ISD::ADD: 1795 if (ST->hasMVEIntegerOps() && ValVT.isSimple() && ResVT.isSimple()) { 1796 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1797 1798 // The legal cases are: 1799 // VADDV u/s 8/16/32 1800 // VADDLV u/s 32 1801 // Codegen currently cannot always handle larger than legal vectors very 1802 // well, especially for predicated reductions where the mask needs to be 1803 // split, so restrict to 128bit or smaller input types. 1804 unsigned RevVTSize = ResVT.getSizeInBits(); 1805 if (ValVT.getSizeInBits() <= 128 && 1806 ((LT.second == MVT::v16i8 && RevVTSize <= 32) || 1807 (LT.second == MVT::v8i16 && RevVTSize <= 32) || 1808 (LT.second == MVT::v4i32 && RevVTSize <= 64))) 1809 return ST->getMVEVectorCostFactor(CostKind) * LT.first; 1810 } 1811 break; 1812 default: 1813 break; 1814 } 1815 return BaseT::getExtendedReductionCost(Opcode, IsUnsigned, ResTy, ValTy, FMF, 1816 CostKind); 1817 } 1818 1819 InstructionCost 1820 ARMTTIImpl::getMulAccReductionCost(bool IsUnsigned, Type *ResTy, 1821 VectorType *ValTy, 1822 TTI::TargetCostKind CostKind) { 1823 EVT ValVT = TLI->getValueType(DL, ValTy); 1824 EVT ResVT = TLI->getValueType(DL, ResTy); 1825 1826 if (ST->hasMVEIntegerOps() && ValVT.isSimple() && ResVT.isSimple()) { 1827 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(ValTy); 1828 1829 // The legal cases are: 1830 // VMLAV u/s 8/16/32 1831 // VMLALV u/s 16/32 1832 // Codegen currently cannot always handle larger than legal vectors very 1833 // well, especially for predicated reductions where the mask needs to be 1834 // split, so restrict to 128bit or smaller input types. 1835 unsigned RevVTSize = ResVT.getSizeInBits(); 1836 if (ValVT.getSizeInBits() <= 128 && 1837 ((LT.second == MVT::v16i8 && RevVTSize <= 32) || 1838 (LT.second == MVT::v8i16 && RevVTSize <= 64) || 1839 (LT.second == MVT::v4i32 && RevVTSize <= 64))) 1840 return ST->getMVEVectorCostFactor(CostKind) * LT.first; 1841 } 1842 1843 return BaseT::getMulAccReductionCost(IsUnsigned, ResTy, ValTy, CostKind); 1844 } 1845 1846 InstructionCost 1847 ARMTTIImpl::getMinMaxReductionCost(Intrinsic::ID IID, VectorType *Ty, 1848 FastMathFlags FMF, 1849 TTI::TargetCostKind CostKind) { 1850 EVT ValVT = TLI->getValueType(DL, Ty); 1851 1852 // In general floating point reductions are a series of elementwise 1853 // operations, with free extracts on each step. These are either in-order or 1854 // treewise depending on whether that is allowed by the fast math flags. 1855 if ((IID == Intrinsic::minnum || IID == Intrinsic::maxnum) && 1856 ((ValVT.getVectorElementType() == MVT::f32 && ST->hasVFP2Base()) || 1857 (ValVT.getVectorElementType() == MVT::f64 && ST->hasFP64()) || 1858 (ValVT.getVectorElementType() == MVT::f16 && ST->hasFullFP16()))) { 1859 unsigned NumElts = cast<FixedVectorType>(Ty)->getNumElements(); 1860 unsigned EltSize = ValVT.getScalarSizeInBits(); 1861 unsigned VecLimit = ST->hasMVEFloatOps() ? 128 : (ST->hasNEON() ? 64 : -1); 1862 InstructionCost VecCost; 1863 while (isPowerOf2_32(NumElts) && NumElts * EltSize > VecLimit) { 1864 Type *VecTy = FixedVectorType::get(Ty->getElementType(), NumElts/2); 1865 IntrinsicCostAttributes ICA(IID, VecTy, {VecTy, VecTy}, FMF); 1866 VecCost += getIntrinsicInstrCost(ICA, CostKind); 1867 NumElts /= 2; 1868 } 1869 1870 // For fp16 we need to extract the upper lane elements. MVE can add a 1871 // VREV+FMIN/MAX to perform another vector step instead. 1872 InstructionCost ExtractCost = 0; 1873 if (ST->hasMVEFloatOps() && ValVT.getVectorElementType() == MVT::f16 && 1874 NumElts == 8) { 1875 VecCost += ST->getMVEVectorCostFactor(CostKind) * 2; 1876 NumElts /= 2; 1877 } else if (ValVT.getVectorElementType() == MVT::f16) 1878 ExtractCost = cast<FixedVectorType>(Ty)->getNumElements() / 2; 1879 1880 IntrinsicCostAttributes ICA(IID, Ty->getElementType(), 1881 {Ty->getElementType(), Ty->getElementType()}, 1882 FMF); 1883 return VecCost + ExtractCost + 1884 (NumElts - 1) * getIntrinsicInstrCost(ICA, CostKind); 1885 } 1886 1887 if (IID == Intrinsic::smin || IID == Intrinsic::smax || 1888 IID == Intrinsic::umin || IID == Intrinsic::umax) { 1889 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Ty); 1890 1891 // All costs are the same for u/s min/max. These lower to vminv, which are 1892 // given a slightly higher cost as they tend to take multiple cycles for 1893 // smaller type sizes. 1894 static const CostTblEntry CostTblAdd[]{ 1895 {ISD::SMIN, MVT::v16i8, 4}, 1896 {ISD::SMIN, MVT::v8i16, 3}, 1897 {ISD::SMIN, MVT::v4i32, 2}, 1898 }; 1899 if (const auto *Entry = CostTableLookup(CostTblAdd, ISD::SMIN, LT.second)) 1900 return Entry->Cost * ST->getMVEVectorCostFactor(CostKind) * LT.first; 1901 } 1902 1903 return BaseT::getMinMaxReductionCost(IID, Ty, FMF, CostKind); 1904 } 1905 1906 InstructionCost 1907 ARMTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA, 1908 TTI::TargetCostKind CostKind) { 1909 unsigned Opc = ICA.getID(); 1910 switch (Opc) { 1911 case Intrinsic::get_active_lane_mask: 1912 // Currently we make a somewhat optimistic assumption that 1913 // active_lane_mask's are always free. In reality it may be freely folded 1914 // into a tail predicated loop, expanded into a VCPT or expanded into a lot 1915 // of add/icmp code. We may need to improve this in the future, but being 1916 // able to detect if it is free or not involves looking at a lot of other 1917 // code. We currently assume that the vectorizer inserted these, and knew 1918 // what it was doing in adding one. 1919 if (ST->hasMVEIntegerOps()) 1920 return 0; 1921 break; 1922 case Intrinsic::sadd_sat: 1923 case Intrinsic::ssub_sat: 1924 case Intrinsic::uadd_sat: 1925 case Intrinsic::usub_sat: { 1926 bool IsAdd = (Opc == Intrinsic::sadd_sat || Opc == Intrinsic::ssub_sat); 1927 bool IsSigned = (Opc == Intrinsic::sadd_sat || Opc == Intrinsic::ssub_sat); 1928 Type *RetTy = ICA.getReturnType(); 1929 1930 if (auto *ITy = dyn_cast<IntegerType>(RetTy)) { 1931 if (IsSigned && ST->hasDSP() && ITy->getBitWidth() == 32) 1932 return 1; // qadd / qsub 1933 if (ST->hasDSP() && (ITy->getBitWidth() == 8 || ITy->getBitWidth() == 16)) 1934 return 2; // uqadd16 / qadd16 / uqsub16 / qsub16 + possible extend. 1935 // Otherwise return the cost of expanding the node. Generally an add + 1936 // icmp + sel. 1937 CmpInst::Predicate Pred = CmpInst::ICMP_SGT; 1938 Type *CondTy = RetTy->getWithNewBitWidth(1); 1939 return getArithmeticInstrCost(IsAdd ? Instruction::Add : Instruction::Sub, 1940 RetTy, CostKind) + 1941 2 * getCmpSelInstrCost(BinaryOperator::ICmp, RetTy, CondTy, Pred, 1942 CostKind) + 1943 2 * getCmpSelInstrCost(BinaryOperator::Select, RetTy, CondTy, Pred, 1944 CostKind); 1945 } 1946 1947 if (!ST->hasMVEIntegerOps()) 1948 break; 1949 1950 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(RetTy); 1951 if (LT.second == MVT::v4i32 || LT.second == MVT::v8i16 || 1952 LT.second == MVT::v16i8) { 1953 // This is a base cost of 1 for the vqadd, plus 3 extract shifts if we 1954 // need to extend the type, as it uses shr(qadd(shl, shl)). 1955 unsigned Instrs = 1956 LT.second.getScalarSizeInBits() == RetTy->getScalarSizeInBits() ? 1 1957 : 4; 1958 return LT.first * ST->getMVEVectorCostFactor(CostKind) * Instrs; 1959 } 1960 break; 1961 } 1962 case Intrinsic::abs: 1963 case Intrinsic::smin: 1964 case Intrinsic::smax: 1965 case Intrinsic::umin: 1966 case Intrinsic::umax: { 1967 if (!ST->hasMVEIntegerOps()) 1968 break; 1969 Type *VT = ICA.getReturnType(); 1970 1971 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(VT); 1972 if (LT.second == MVT::v4i32 || LT.second == MVT::v8i16 || 1973 LT.second == MVT::v16i8) 1974 return LT.first * ST->getMVEVectorCostFactor(CostKind); 1975 break; 1976 } 1977 case Intrinsic::minnum: 1978 case Intrinsic::maxnum: { 1979 if (!ST->hasMVEFloatOps()) 1980 break; 1981 Type *VT = ICA.getReturnType(); 1982 std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(VT); 1983 if (LT.second == MVT::v4f32 || LT.second == MVT::v8f16) 1984 return LT.first * ST->getMVEVectorCostFactor(CostKind); 1985 break; 1986 } 1987 case Intrinsic::fptosi_sat: 1988 case Intrinsic::fptoui_sat: { 1989 if (ICA.getArgTypes().empty()) 1990 break; 1991 bool IsSigned = Opc == Intrinsic::fptosi_sat; 1992 auto LT = getTypeLegalizationCost(ICA.getArgTypes()[0]); 1993 EVT MTy = TLI->getValueType(DL, ICA.getReturnType()); 1994 // Check for the legal types, with the corect subtarget features. 1995 if ((ST->hasVFP2Base() && LT.second == MVT::f32 && MTy == MVT::i32) || 1996 (ST->hasFP64() && LT.second == MVT::f64 && MTy == MVT::i32) || 1997 (ST->hasFullFP16() && LT.second == MVT::f16 && MTy == MVT::i32)) 1998 return LT.first; 1999 2000 // Equally for MVE vector types 2001 if (ST->hasMVEFloatOps() && 2002 (LT.second == MVT::v4f32 || LT.second == MVT::v8f16) && 2003 LT.second.getScalarSizeInBits() == MTy.getScalarSizeInBits()) 2004 return LT.first * ST->getMVEVectorCostFactor(CostKind); 2005 2006 // If we can we use a legal convert followed by a min+max 2007 if (((ST->hasVFP2Base() && LT.second == MVT::f32) || 2008 (ST->hasFP64() && LT.second == MVT::f64) || 2009 (ST->hasFullFP16() && LT.second == MVT::f16) || 2010 (ST->hasMVEFloatOps() && 2011 (LT.second == MVT::v4f32 || LT.second == MVT::v8f16))) && 2012 LT.second.getScalarSizeInBits() >= MTy.getScalarSizeInBits()) { 2013 Type *LegalTy = Type::getIntNTy(ICA.getReturnType()->getContext(), 2014 LT.second.getScalarSizeInBits()); 2015 InstructionCost Cost = 2016 LT.second.isVector() ? ST->getMVEVectorCostFactor(CostKind) : 1; 2017 IntrinsicCostAttributes Attrs1(IsSigned ? Intrinsic::smin 2018 : Intrinsic::umin, 2019 LegalTy, {LegalTy, LegalTy}); 2020 Cost += getIntrinsicInstrCost(Attrs1, CostKind); 2021 IntrinsicCostAttributes Attrs2(IsSigned ? Intrinsic::smax 2022 : Intrinsic::umax, 2023 LegalTy, {LegalTy, LegalTy}); 2024 Cost += getIntrinsicInstrCost(Attrs2, CostKind); 2025 return LT.first * Cost; 2026 } 2027 // Otherwise we need to follow the default expansion that clamps the value 2028 // using a float min/max with a fcmp+sel for nan handling when signed. 2029 Type *FPTy = ICA.getArgTypes()[0]; 2030 Type *RetTy = ICA.getReturnType(); 2031 IntrinsicCostAttributes Attrs1(Intrinsic::minnum, FPTy, {FPTy, FPTy}); 2032 InstructionCost Cost = getIntrinsicInstrCost(Attrs1, CostKind); 2033 IntrinsicCostAttributes Attrs2(Intrinsic::maxnum, FPTy, {FPTy, FPTy}); 2034 Cost += getIntrinsicInstrCost(Attrs2, CostKind); 2035 Cost += 2036 getCastInstrCost(IsSigned ? Instruction::FPToSI : Instruction::FPToUI, 2037 RetTy, FPTy, TTI::CastContextHint::None, CostKind); 2038 if (IsSigned) { 2039 Type *CondTy = RetTy->getWithNewBitWidth(1); 2040 Cost += getCmpSelInstrCost(BinaryOperator::FCmp, FPTy, CondTy, 2041 CmpInst::FCMP_UNO, CostKind); 2042 Cost += getCmpSelInstrCost(BinaryOperator::Select, RetTy, CondTy, 2043 CmpInst::FCMP_UNO, CostKind); 2044 } 2045 return Cost; 2046 } 2047 } 2048 2049 return BaseT::getIntrinsicInstrCost(ICA, CostKind); 2050 } 2051 2052 bool ARMTTIImpl::isLoweredToCall(const Function *F) { 2053 if (!F->isIntrinsic()) 2054 return BaseT::isLoweredToCall(F); 2055 2056 // Assume all Arm-specific intrinsics map to an instruction. 2057 if (F->getName().starts_with("llvm.arm")) 2058 return false; 2059 2060 switch (F->getIntrinsicID()) { 2061 default: break; 2062 case Intrinsic::powi: 2063 case Intrinsic::sin: 2064 case Intrinsic::cos: 2065 case Intrinsic::sincos: 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 // For processors with low overhead branching (LOB), runtime unrolling the 2595 // innermost loop is often detrimental to performance. In these cases the loop 2596 // remainder gets unrolled into a series of compare-and-jump blocks, which in 2597 // deeply nested loops get executed multiple times, negating the benefits of 2598 // LOB. This is particularly noticable when the loop trip count of the 2599 // innermost loop varies within the outer loop, such as in the case of 2600 // triangular matrix decompositions. In these cases we will prefer to not 2601 // unroll the innermost loop, with the intention for it to be executed as a 2602 // low overhead loop. 2603 bool Runtime = true; 2604 if (ST->hasLOB()) { 2605 if (SE.hasLoopInvariantBackedgeTakenCount(L)) { 2606 const auto *BETC = SE.getBackedgeTakenCount(L); 2607 auto *Outer = L->getOutermostLoop(); 2608 if ((L != Outer && Outer != L->getParentLoop()) || 2609 (L != Outer && BETC && !SE.isLoopInvariant(BETC, Outer))) { 2610 Runtime = false; 2611 } 2612 } 2613 } 2614 2615 LLVM_DEBUG(dbgs() << "Cost of loop: " << Cost << "\n"); 2616 LLVM_DEBUG(dbgs() << "Default Runtime Unroll Count: " << UnrollCount << "\n"); 2617 2618 UP.Partial = true; 2619 UP.Runtime = Runtime; 2620 UP.UnrollRemainder = true; 2621 UP.DefaultUnrollRuntimeCount = UnrollCount; 2622 UP.UnrollAndJam = true; 2623 UP.UnrollAndJamInnerLoopThreshold = 60; 2624 2625 // Force unrolling small loops can be very useful because of the branch 2626 // taken cost of the backedge. 2627 if (Cost < 12) 2628 UP.Force = true; 2629 } 2630 2631 void ARMTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE, 2632 TTI::PeelingPreferences &PP) { 2633 BaseT::getPeelingPreferences(L, SE, PP); 2634 } 2635 2636 bool ARMTTIImpl::preferInLoopReduction(unsigned Opcode, Type *Ty, 2637 TTI::ReductionFlags Flags) const { 2638 if (!ST->hasMVEIntegerOps()) 2639 return false; 2640 2641 unsigned ScalarBits = Ty->getScalarSizeInBits(); 2642 switch (Opcode) { 2643 case Instruction::Add: 2644 return ScalarBits <= 64; 2645 default: 2646 return false; 2647 } 2648 } 2649 2650 bool ARMTTIImpl::preferPredicatedReductionSelect( 2651 unsigned Opcode, Type *Ty, TTI::ReductionFlags Flags) const { 2652 if (!ST->hasMVEIntegerOps()) 2653 return false; 2654 return true; 2655 } 2656 2657 InstructionCost ARMTTIImpl::getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, 2658 StackOffset BaseOffset, 2659 bool HasBaseReg, int64_t Scale, 2660 unsigned AddrSpace) const { 2661 TargetLoweringBase::AddrMode AM; 2662 AM.BaseGV = BaseGV; 2663 AM.BaseOffs = BaseOffset.getFixed(); 2664 AM.HasBaseReg = HasBaseReg; 2665 AM.Scale = Scale; 2666 AM.ScalableOffset = BaseOffset.getScalable(); 2667 if (getTLI()->isLegalAddressingMode(DL, AM, Ty, AddrSpace)) { 2668 if (ST->hasFPAO()) 2669 return AM.Scale < 0 ? 1 : 0; // positive offsets execute faster 2670 return 0; 2671 } 2672 return -1; 2673 } 2674 2675 bool ARMTTIImpl::hasArmWideBranch(bool Thumb) const { 2676 if (Thumb) { 2677 // B.W is available in any Thumb2-supporting target, and also in every 2678 // version of Armv8-M, even Baseline which does not include the rest of 2679 // Thumb2. 2680 return ST->isThumb2() || ST->hasV8MBaselineOps(); 2681 } else { 2682 // B is available in all versions of the Arm ISA, so the only question is 2683 // whether that ISA is available at all. 2684 return ST->hasARMOps(); 2685 } 2686 } 2687 2688 /// Check if Ext1 and Ext2 are extends of the same type, doubling the bitwidth 2689 /// of the vector elements. 2690 static bool areExtractExts(Value *Ext1, Value *Ext2) { 2691 using namespace PatternMatch; 2692 2693 auto areExtDoubled = [](Instruction *Ext) { 2694 return Ext->getType()->getScalarSizeInBits() == 2695 2 * Ext->getOperand(0)->getType()->getScalarSizeInBits(); 2696 }; 2697 2698 if (!match(Ext1, m_ZExtOrSExt(m_Value())) || 2699 !match(Ext2, m_ZExtOrSExt(m_Value())) || 2700 !areExtDoubled(cast<Instruction>(Ext1)) || 2701 !areExtDoubled(cast<Instruction>(Ext2))) 2702 return false; 2703 2704 return true; 2705 } 2706 2707 /// Check if sinking \p I's operands to I's basic block is profitable, because 2708 /// the operands can be folded into a target instruction, e.g. 2709 /// sext/zext can be folded into vsubl. 2710 bool ARMTTIImpl::isProfitableToSinkOperands(Instruction *I, 2711 SmallVectorImpl<Use *> &Ops) const { 2712 using namespace PatternMatch; 2713 2714 if (!I->getType()->isVectorTy()) 2715 return false; 2716 2717 if (ST->hasNEON()) { 2718 switch (I->getOpcode()) { 2719 case Instruction::Sub: 2720 case Instruction::Add: { 2721 if (!areExtractExts(I->getOperand(0), I->getOperand(1))) 2722 return false; 2723 Ops.push_back(&I->getOperandUse(0)); 2724 Ops.push_back(&I->getOperandUse(1)); 2725 return true; 2726 } 2727 default: 2728 return false; 2729 } 2730 } 2731 2732 if (!ST->hasMVEIntegerOps()) 2733 return false; 2734 2735 auto IsFMSMul = [&](Instruction *I) { 2736 if (!I->hasOneUse()) 2737 return false; 2738 auto *Sub = cast<Instruction>(*I->users().begin()); 2739 return Sub->getOpcode() == Instruction::FSub && Sub->getOperand(1) == I; 2740 }; 2741 auto IsFMS = [&](Instruction *I) { 2742 if (match(I->getOperand(0), m_FNeg(m_Value())) || 2743 match(I->getOperand(1), m_FNeg(m_Value()))) 2744 return true; 2745 return false; 2746 }; 2747 2748 auto IsSinker = [&](Instruction *I, int Operand) { 2749 switch (I->getOpcode()) { 2750 case Instruction::Add: 2751 case Instruction::Mul: 2752 case Instruction::FAdd: 2753 case Instruction::ICmp: 2754 case Instruction::FCmp: 2755 return true; 2756 case Instruction::FMul: 2757 return !IsFMSMul(I); 2758 case Instruction::Sub: 2759 case Instruction::FSub: 2760 case Instruction::Shl: 2761 case Instruction::LShr: 2762 case Instruction::AShr: 2763 return Operand == 1; 2764 case Instruction::Call: 2765 if (auto *II = dyn_cast<IntrinsicInst>(I)) { 2766 switch (II->getIntrinsicID()) { 2767 case Intrinsic::fma: 2768 return !IsFMS(I); 2769 case Intrinsic::sadd_sat: 2770 case Intrinsic::uadd_sat: 2771 case Intrinsic::arm_mve_add_predicated: 2772 case Intrinsic::arm_mve_mul_predicated: 2773 case Intrinsic::arm_mve_qadd_predicated: 2774 case Intrinsic::arm_mve_vhadd: 2775 case Intrinsic::arm_mve_hadd_predicated: 2776 case Intrinsic::arm_mve_vqdmull: 2777 case Intrinsic::arm_mve_vqdmull_predicated: 2778 case Intrinsic::arm_mve_vqdmulh: 2779 case Intrinsic::arm_mve_qdmulh_predicated: 2780 case Intrinsic::arm_mve_vqrdmulh: 2781 case Intrinsic::arm_mve_qrdmulh_predicated: 2782 case Intrinsic::arm_mve_fma_predicated: 2783 return true; 2784 case Intrinsic::ssub_sat: 2785 case Intrinsic::usub_sat: 2786 case Intrinsic::arm_mve_sub_predicated: 2787 case Intrinsic::arm_mve_qsub_predicated: 2788 case Intrinsic::arm_mve_hsub_predicated: 2789 case Intrinsic::arm_mve_vhsub: 2790 return Operand == 1; 2791 default: 2792 return false; 2793 } 2794 } 2795 return false; 2796 default: 2797 return false; 2798 } 2799 }; 2800 2801 for (auto OpIdx : enumerate(I->operands())) { 2802 Instruction *Op = dyn_cast<Instruction>(OpIdx.value().get()); 2803 // Make sure we are not already sinking this operand 2804 if (!Op || any_of(Ops, [&](Use *U) { return U->get() == Op; })) 2805 continue; 2806 2807 Instruction *Shuffle = Op; 2808 if (Shuffle->getOpcode() == Instruction::BitCast) 2809 Shuffle = dyn_cast<Instruction>(Shuffle->getOperand(0)); 2810 // We are looking for a splat that can be sunk. 2811 if (!Shuffle || !match(Shuffle, m_Shuffle(m_InsertElt(m_Undef(), m_Value(), 2812 m_ZeroInt()), 2813 m_Undef(), m_ZeroMask()))) 2814 continue; 2815 if (!IsSinker(I, OpIdx.index())) 2816 continue; 2817 2818 // All uses of the shuffle should be sunk to avoid duplicating it across gpr 2819 // and vector registers 2820 for (Use &U : Op->uses()) { 2821 Instruction *Insn = cast<Instruction>(U.getUser()); 2822 if (!IsSinker(Insn, U.getOperandNo())) 2823 return false; 2824 } 2825 2826 Ops.push_back(&Shuffle->getOperandUse(0)); 2827 if (Shuffle != Op) 2828 Ops.push_back(&Op->getOperandUse(0)); 2829 Ops.push_back(&OpIdx.value()); 2830 } 2831 return true; 2832 } 2833 2834 unsigned ARMTTIImpl::getNumBytesToPadGlobalArray(unsigned Size, 2835 Type *ArrayType) const { 2836 if (!UseWidenGlobalArrays) { 2837 LLVM_DEBUG(dbgs() << "Padding global arrays disabled\n"); 2838 return false; 2839 } 2840 2841 // Don't modify none integer array types 2842 if (!ArrayType || !ArrayType->isArrayTy() || 2843 !ArrayType->getArrayElementType()->isIntegerTy()) 2844 return 0; 2845 2846 // We pad to 4 byte boundaries 2847 if (Size % 4 == 0) 2848 return 0; 2849 2850 unsigned NumBytesToPad = 4 - (Size % 4); 2851 unsigned NewSize = Size + NumBytesToPad; 2852 2853 // Max number of bytes that memcpy allows for lowering to load/stores before 2854 // it uses library function (__aeabi_memcpy). 2855 unsigned MaxMemIntrinsicSize = getMaxMemIntrinsicInlineSizeThreshold(); 2856 2857 if (NewSize > MaxMemIntrinsicSize) 2858 return 0; 2859 2860 return NumBytesToPad; 2861 } 2862