1 //===-- AArch64TargetTransformInfo.cpp - AArch64 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 "AArch64TargetTransformInfo.h"
10 #include "AArch64ExpandImm.h"
11 #include "AArch64PerfectShuffle.h"
12 #include "MCTargetDesc/AArch64AddressingModes.h"
13 #include "llvm/Analysis/IVDescriptors.h"
14 #include "llvm/Analysis/LoopInfo.h"
15 #include "llvm/Analysis/TargetTransformInfo.h"
16 #include "llvm/CodeGen/BasicTTIImpl.h"
17 #include "llvm/CodeGen/CostTable.h"
18 #include "llvm/CodeGen/TargetLowering.h"
19 #include "llvm/IR/IntrinsicInst.h"
20 #include "llvm/IR/Intrinsics.h"
21 #include "llvm/IR/IntrinsicsAArch64.h"
22 #include "llvm/IR/PatternMatch.h"
23 #include "llvm/Support/Debug.h"
24 #include "llvm/Transforms/InstCombine/InstCombiner.h"
25 #include "llvm/Transforms/Vectorize/LoopVectorizationLegality.h"
26 #include <algorithm>
27 using namespace llvm;
28 using namespace llvm::PatternMatch;
29 
30 #define DEBUG_TYPE "aarch64tti"
31 
32 static cl::opt<bool> EnableFalkorHWPFUnrollFix("enable-falkor-hwpf-unroll-fix",
33                                                cl::init(true), cl::Hidden);
34 
35 static cl::opt<unsigned> SVEGatherOverhead("sve-gather-overhead", cl::init(10),
36                                            cl::Hidden);
37 
38 static cl::opt<unsigned> SVEScatterOverhead("sve-scatter-overhead",
39                                             cl::init(10), cl::Hidden);
40 
41 class TailFoldingKind {
42 private:
43   uint8_t Bits = 0; // Currently defaults to disabled.
44 
45 public:
46   enum TailFoldingOpts {
47     TFDisabled = 0x0,
48     TFReductions = 0x01,
49     TFRecurrences = 0x02,
50     TFSimple = 0x80,
51     TFAll = TFReductions | TFRecurrences | TFSimple
52   };
53 
54   void operator=(const std::string &Val) {
55     if (Val.empty())
56       return;
57     SmallVector<StringRef, 6> TailFoldTypes;
58     StringRef(Val).split(TailFoldTypes, '+', -1, false);
59     for (auto TailFoldType : TailFoldTypes) {
60       if (TailFoldType == "disabled")
61         Bits = 0;
62       else if (TailFoldType == "all")
63         Bits = TFAll;
64       else if (TailFoldType == "default")
65         Bits = 0; // Currently defaults to never tail-folding.
66       else if (TailFoldType == "simple")
67         add(TFSimple);
68       else if (TailFoldType == "reductions")
69         add(TFReductions);
70       else if (TailFoldType == "recurrences")
71         add(TFRecurrences);
72       else if (TailFoldType == "noreductions")
73         remove(TFReductions);
74       else if (TailFoldType == "norecurrences")
75         remove(TFRecurrences);
76       else {
77         errs()
78             << "invalid argument " << TailFoldType.str()
79             << " to -sve-tail-folding=; each element must be one of: disabled, "
80                "all, default, simple, reductions, noreductions, recurrences, "
81                "norecurrences\n";
82       }
83     }
84   }
85 
86   operator uint8_t() const { return Bits; }
87 
88   void add(uint8_t Flag) { Bits |= Flag; }
89   void remove(uint8_t Flag) { Bits &= ~Flag; }
90 };
91 
92 TailFoldingKind TailFoldingKindLoc;
93 
94 cl::opt<TailFoldingKind, true, cl::parser<std::string>> SVETailFolding(
95     "sve-tail-folding",
96     cl::desc(
97         "Control the use of vectorisation using tail-folding for SVE:"
98         "\ndisabled    No loop types will vectorize using tail-folding"
99         "\ndefault     Uses the default tail-folding settings for the target "
100         "CPU"
101         "\nall         All legal loop types will vectorize using tail-folding"
102         "\nsimple      Use tail-folding for simple loops (not reductions or "
103         "recurrences)"
104         "\nreductions  Use tail-folding for loops containing reductions"
105         "\nrecurrences Use tail-folding for loops containing first order "
106         "recurrences"),
107     cl::location(TailFoldingKindLoc));
108 
109 bool AArch64TTIImpl::areInlineCompatible(const Function *Caller,
110                                          const Function *Callee) const {
111   const TargetMachine &TM = getTLI()->getTargetMachine();
112 
113   const FeatureBitset &CallerBits =
114       TM.getSubtargetImpl(*Caller)->getFeatureBits();
115   const FeatureBitset &CalleeBits =
116       TM.getSubtargetImpl(*Callee)->getFeatureBits();
117 
118   // Inline a callee if its target-features are a subset of the callers
119   // target-features.
120   return (CallerBits & CalleeBits) == CalleeBits;
121 }
122 
123 bool AArch64TTIImpl::shouldMaximizeVectorBandwidth(
124     TargetTransformInfo::RegisterKind K) const {
125   assert(K != TargetTransformInfo::RGK_Scalar);
126   return K == TargetTransformInfo::RGK_FixedWidthVector;
127 }
128 
129 /// Calculate the cost of materializing a 64-bit value. This helper
130 /// method might only calculate a fraction of a larger immediate. Therefore it
131 /// is valid to return a cost of ZERO.
132 InstructionCost AArch64TTIImpl::getIntImmCost(int64_t Val) {
133   // Check if the immediate can be encoded within an instruction.
134   if (Val == 0 || AArch64_AM::isLogicalImmediate(Val, 64))
135     return 0;
136 
137   if (Val < 0)
138     Val = ~Val;
139 
140   // Calculate how many moves we will need to materialize this constant.
141   SmallVector<AArch64_IMM::ImmInsnModel, 4> Insn;
142   AArch64_IMM::expandMOVImm(Val, 64, Insn);
143   return Insn.size();
144 }
145 
146 /// Calculate the cost of materializing the given constant.
147 InstructionCost AArch64TTIImpl::getIntImmCost(const APInt &Imm, Type *Ty,
148                                               TTI::TargetCostKind CostKind) {
149   assert(Ty->isIntegerTy());
150 
151   unsigned BitSize = Ty->getPrimitiveSizeInBits();
152   if (BitSize == 0)
153     return ~0U;
154 
155   // Sign-extend all constants to a multiple of 64-bit.
156   APInt ImmVal = Imm;
157   if (BitSize & 0x3f)
158     ImmVal = Imm.sext((BitSize + 63) & ~0x3fU);
159 
160   // Split the constant into 64-bit chunks and calculate the cost for each
161   // chunk.
162   InstructionCost Cost = 0;
163   for (unsigned ShiftVal = 0; ShiftVal < BitSize; ShiftVal += 64) {
164     APInt Tmp = ImmVal.ashr(ShiftVal).sextOrTrunc(64);
165     int64_t Val = Tmp.getSExtValue();
166     Cost += getIntImmCost(Val);
167   }
168   // We need at least one instruction to materialze the constant.
169   return std::max<InstructionCost>(1, Cost);
170 }
171 
172 InstructionCost AArch64TTIImpl::getIntImmCostInst(unsigned Opcode, unsigned Idx,
173                                                   const APInt &Imm, Type *Ty,
174                                                   TTI::TargetCostKind CostKind,
175                                                   Instruction *Inst) {
176   assert(Ty->isIntegerTy());
177 
178   unsigned BitSize = Ty->getPrimitiveSizeInBits();
179   // There is no cost model for constants with a bit size of 0. Return TCC_Free
180   // here, so that constant hoisting will ignore this constant.
181   if (BitSize == 0)
182     return TTI::TCC_Free;
183 
184   unsigned ImmIdx = ~0U;
185   switch (Opcode) {
186   default:
187     return TTI::TCC_Free;
188   case Instruction::GetElementPtr:
189     // Always hoist the base address of a GetElementPtr.
190     if (Idx == 0)
191       return 2 * TTI::TCC_Basic;
192     return TTI::TCC_Free;
193   case Instruction::Store:
194     ImmIdx = 0;
195     break;
196   case Instruction::Add:
197   case Instruction::Sub:
198   case Instruction::Mul:
199   case Instruction::UDiv:
200   case Instruction::SDiv:
201   case Instruction::URem:
202   case Instruction::SRem:
203   case Instruction::And:
204   case Instruction::Or:
205   case Instruction::Xor:
206   case Instruction::ICmp:
207     ImmIdx = 1;
208     break;
209   // Always return TCC_Free for the shift value of a shift instruction.
210   case Instruction::Shl:
211   case Instruction::LShr:
212   case Instruction::AShr:
213     if (Idx == 1)
214       return TTI::TCC_Free;
215     break;
216   case Instruction::Trunc:
217   case Instruction::ZExt:
218   case Instruction::SExt:
219   case Instruction::IntToPtr:
220   case Instruction::PtrToInt:
221   case Instruction::BitCast:
222   case Instruction::PHI:
223   case Instruction::Call:
224   case Instruction::Select:
225   case Instruction::Ret:
226   case Instruction::Load:
227     break;
228   }
229 
230   if (Idx == ImmIdx) {
231     int NumConstants = (BitSize + 63) / 64;
232     InstructionCost Cost = AArch64TTIImpl::getIntImmCost(Imm, Ty, CostKind);
233     return (Cost <= NumConstants * TTI::TCC_Basic)
234                ? static_cast<int>(TTI::TCC_Free)
235                : Cost;
236   }
237   return AArch64TTIImpl::getIntImmCost(Imm, Ty, CostKind);
238 }
239 
240 InstructionCost
241 AArch64TTIImpl::getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx,
242                                     const APInt &Imm, Type *Ty,
243                                     TTI::TargetCostKind CostKind) {
244   assert(Ty->isIntegerTy());
245 
246   unsigned BitSize = Ty->getPrimitiveSizeInBits();
247   // There is no cost model for constants with a bit size of 0. Return TCC_Free
248   // here, so that constant hoisting will ignore this constant.
249   if (BitSize == 0)
250     return TTI::TCC_Free;
251 
252   // Most (all?) AArch64 intrinsics do not support folding immediates into the
253   // selected instruction, so we compute the materialization cost for the
254   // immediate directly.
255   if (IID >= Intrinsic::aarch64_addg && IID <= Intrinsic::aarch64_udiv)
256     return AArch64TTIImpl::getIntImmCost(Imm, Ty, CostKind);
257 
258   switch (IID) {
259   default:
260     return TTI::TCC_Free;
261   case Intrinsic::sadd_with_overflow:
262   case Intrinsic::uadd_with_overflow:
263   case Intrinsic::ssub_with_overflow:
264   case Intrinsic::usub_with_overflow:
265   case Intrinsic::smul_with_overflow:
266   case Intrinsic::umul_with_overflow:
267     if (Idx == 1) {
268       int NumConstants = (BitSize + 63) / 64;
269       InstructionCost Cost = AArch64TTIImpl::getIntImmCost(Imm, Ty, CostKind);
270       return (Cost <= NumConstants * TTI::TCC_Basic)
271                  ? static_cast<int>(TTI::TCC_Free)
272                  : Cost;
273     }
274     break;
275   case Intrinsic::experimental_stackmap:
276     if ((Idx < 2) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue())))
277       return TTI::TCC_Free;
278     break;
279   case Intrinsic::experimental_patchpoint_void:
280   case Intrinsic::experimental_patchpoint_i64:
281     if ((Idx < 4) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue())))
282       return TTI::TCC_Free;
283     break;
284   case Intrinsic::experimental_gc_statepoint:
285     if ((Idx < 5) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue())))
286       return TTI::TCC_Free;
287     break;
288   }
289   return AArch64TTIImpl::getIntImmCost(Imm, Ty, CostKind);
290 }
291 
292 TargetTransformInfo::PopcntSupportKind
293 AArch64TTIImpl::getPopcntSupport(unsigned TyWidth) {
294   assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2");
295   if (TyWidth == 32 || TyWidth == 64)
296     return TTI::PSK_FastHardware;
297   // TODO: AArch64TargetLowering::LowerCTPOP() supports 128bit popcount.
298   return TTI::PSK_Software;
299 }
300 
301 InstructionCost
302 AArch64TTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
303                                       TTI::TargetCostKind CostKind) {
304   auto *RetTy = ICA.getReturnType();
305   switch (ICA.getID()) {
306   case Intrinsic::umin:
307   case Intrinsic::umax:
308   case Intrinsic::smin:
309   case Intrinsic::smax: {
310     static const auto ValidMinMaxTys = {MVT::v8i8,  MVT::v16i8, MVT::v4i16,
311                                         MVT::v8i16, MVT::v2i32, MVT::v4i32};
312     auto LT = TLI->getTypeLegalizationCost(DL, RetTy);
313     // v2i64 types get converted to cmp+bif hence the cost of 2
314     if (LT.second == MVT::v2i64)
315       return LT.first * 2;
316     if (any_of(ValidMinMaxTys, [&LT](MVT M) { return M == LT.second; }))
317       return LT.first;
318     break;
319   }
320   case Intrinsic::sadd_sat:
321   case Intrinsic::ssub_sat:
322   case Intrinsic::uadd_sat:
323   case Intrinsic::usub_sat: {
324     static const auto ValidSatTys = {MVT::v8i8,  MVT::v16i8, MVT::v4i16,
325                                      MVT::v8i16, MVT::v2i32, MVT::v4i32,
326                                      MVT::v2i64};
327     auto LT = TLI->getTypeLegalizationCost(DL, RetTy);
328     // This is a base cost of 1 for the vadd, plus 3 extract shifts if we
329     // need to extend the type, as it uses shr(qadd(shl, shl)).
330     unsigned Instrs =
331         LT.second.getScalarSizeInBits() == RetTy->getScalarSizeInBits() ? 1 : 4;
332     if (any_of(ValidSatTys, [&LT](MVT M) { return M == LT.second; }))
333       return LT.first * Instrs;
334     break;
335   }
336   case Intrinsic::abs: {
337     static const auto ValidAbsTys = {MVT::v8i8,  MVT::v16i8, MVT::v4i16,
338                                      MVT::v8i16, MVT::v2i32, MVT::v4i32,
339                                      MVT::v2i64};
340     auto LT = TLI->getTypeLegalizationCost(DL, RetTy);
341     if (any_of(ValidAbsTys, [&LT](MVT M) { return M == LT.second; }))
342       return LT.first;
343     break;
344   }
345   case Intrinsic::experimental_stepvector: {
346     InstructionCost Cost = 1; // Cost of the `index' instruction
347     auto LT = TLI->getTypeLegalizationCost(DL, RetTy);
348     // Legalisation of illegal vectors involves an `index' instruction plus
349     // (LT.first - 1) vector adds.
350     if (LT.first > 1) {
351       Type *LegalVTy = EVT(LT.second).getTypeForEVT(RetTy->getContext());
352       InstructionCost AddCost =
353           getArithmeticInstrCost(Instruction::Add, LegalVTy, CostKind);
354       Cost += AddCost * (LT.first - 1);
355     }
356     return Cost;
357   }
358   case Intrinsic::bitreverse: {
359     static const CostTblEntry BitreverseTbl[] = {
360         {Intrinsic::bitreverse, MVT::i32, 1},
361         {Intrinsic::bitreverse, MVT::i64, 1},
362         {Intrinsic::bitreverse, MVT::v8i8, 1},
363         {Intrinsic::bitreverse, MVT::v16i8, 1},
364         {Intrinsic::bitreverse, MVT::v4i16, 2},
365         {Intrinsic::bitreverse, MVT::v8i16, 2},
366         {Intrinsic::bitreverse, MVT::v2i32, 2},
367         {Intrinsic::bitreverse, MVT::v4i32, 2},
368         {Intrinsic::bitreverse, MVT::v1i64, 2},
369         {Intrinsic::bitreverse, MVT::v2i64, 2},
370     };
371     const auto LegalisationCost = TLI->getTypeLegalizationCost(DL, RetTy);
372     const auto *Entry =
373         CostTableLookup(BitreverseTbl, ICA.getID(), LegalisationCost.second);
374     if (Entry) {
375       // Cost Model is using the legal type(i32) that i8 and i16 will be
376       // converted to +1 so that we match the actual lowering cost
377       if (TLI->getValueType(DL, RetTy, true) == MVT::i8 ||
378           TLI->getValueType(DL, RetTy, true) == MVT::i16)
379         return LegalisationCost.first * Entry->Cost + 1;
380 
381       return LegalisationCost.first * Entry->Cost;
382     }
383     break;
384   }
385   case Intrinsic::ctpop: {
386     static const CostTblEntry CtpopCostTbl[] = {
387         {ISD::CTPOP, MVT::v2i64, 4},
388         {ISD::CTPOP, MVT::v4i32, 3},
389         {ISD::CTPOP, MVT::v8i16, 2},
390         {ISD::CTPOP, MVT::v16i8, 1},
391         {ISD::CTPOP, MVT::i64,   4},
392         {ISD::CTPOP, MVT::v2i32, 3},
393         {ISD::CTPOP, MVT::v4i16, 2},
394         {ISD::CTPOP, MVT::v8i8,  1},
395         {ISD::CTPOP, MVT::i32,   5},
396     };
397     auto LT = TLI->getTypeLegalizationCost(DL, RetTy);
398     MVT MTy = LT.second;
399     if (const auto *Entry = CostTableLookup(CtpopCostTbl, ISD::CTPOP, MTy)) {
400       // Extra cost of +1 when illegal vector types are legalized by promoting
401       // the integer type.
402       int ExtraCost = MTy.isVector() && MTy.getScalarSizeInBits() !=
403                                             RetTy->getScalarSizeInBits()
404                           ? 1
405                           : 0;
406       return LT.first * Entry->Cost + ExtraCost;
407     }
408     break;
409   }
410   case Intrinsic::sadd_with_overflow:
411   case Intrinsic::uadd_with_overflow:
412   case Intrinsic::ssub_with_overflow:
413   case Intrinsic::usub_with_overflow:
414   case Intrinsic::smul_with_overflow:
415   case Intrinsic::umul_with_overflow: {
416     static const CostTblEntry WithOverflowCostTbl[] = {
417         {Intrinsic::sadd_with_overflow, MVT::i8, 3},
418         {Intrinsic::uadd_with_overflow, MVT::i8, 3},
419         {Intrinsic::sadd_with_overflow, MVT::i16, 3},
420         {Intrinsic::uadd_with_overflow, MVT::i16, 3},
421         {Intrinsic::sadd_with_overflow, MVT::i32, 1},
422         {Intrinsic::uadd_with_overflow, MVT::i32, 1},
423         {Intrinsic::sadd_with_overflow, MVT::i64, 1},
424         {Intrinsic::uadd_with_overflow, MVT::i64, 1},
425         {Intrinsic::ssub_with_overflow, MVT::i8, 3},
426         {Intrinsic::usub_with_overflow, MVT::i8, 3},
427         {Intrinsic::ssub_with_overflow, MVT::i16, 3},
428         {Intrinsic::usub_with_overflow, MVT::i16, 3},
429         {Intrinsic::ssub_with_overflow, MVT::i32, 1},
430         {Intrinsic::usub_with_overflow, MVT::i32, 1},
431         {Intrinsic::ssub_with_overflow, MVT::i64, 1},
432         {Intrinsic::usub_with_overflow, MVT::i64, 1},
433         {Intrinsic::smul_with_overflow, MVT::i8, 5},
434         {Intrinsic::umul_with_overflow, MVT::i8, 4},
435         {Intrinsic::smul_with_overflow, MVT::i16, 5},
436         {Intrinsic::umul_with_overflow, MVT::i16, 4},
437         {Intrinsic::smul_with_overflow, MVT::i32, 2}, // eg umull;tst
438         {Intrinsic::umul_with_overflow, MVT::i32, 2}, // eg umull;cmp sxtw
439         {Intrinsic::smul_with_overflow, MVT::i64, 3}, // eg mul;smulh;cmp
440         {Intrinsic::umul_with_overflow, MVT::i64, 3}, // eg mul;umulh;cmp asr
441     };
442     EVT MTy = TLI->getValueType(DL, RetTy->getContainedType(0), true);
443     if (MTy.isSimple())
444       if (const auto *Entry = CostTableLookup(WithOverflowCostTbl, ICA.getID(),
445                                               MTy.getSimpleVT()))
446         return Entry->Cost;
447     break;
448   }
449   case Intrinsic::fptosi_sat:
450   case Intrinsic::fptoui_sat: {
451     if (ICA.getArgTypes().empty())
452       break;
453     bool IsSigned = ICA.getID() == Intrinsic::fptosi_sat;
454     auto LT = TLI->getTypeLegalizationCost(DL, ICA.getArgTypes()[0]);
455     EVT MTy = TLI->getValueType(DL, RetTy);
456     // Check for the legal types, which are where the size of the input and the
457     // output are the same, or we are using cvt f64->i32 or f32->i64.
458     if ((LT.second == MVT::f32 || LT.second == MVT::f64 ||
459          LT.second == MVT::v2f32 || LT.second == MVT::v4f32 ||
460          LT.second == MVT::v2f64) &&
461         (LT.second.getScalarSizeInBits() == MTy.getScalarSizeInBits() ||
462          (LT.second == MVT::f64 && MTy == MVT::i32) ||
463          (LT.second == MVT::f32 && MTy == MVT::i64)))
464       return LT.first;
465     // Similarly for fp16 sizes
466     if (ST->hasFullFP16() &&
467         ((LT.second == MVT::f16 && MTy == MVT::i32) ||
468          ((LT.second == MVT::v4f16 || LT.second == MVT::v8f16) &&
469           (LT.second.getScalarSizeInBits() == MTy.getScalarSizeInBits()))))
470       return LT.first;
471 
472     // Otherwise we use a legal convert followed by a min+max
473     if ((LT.second.getScalarType() == MVT::f32 ||
474          LT.second.getScalarType() == MVT::f64 ||
475          (ST->hasFullFP16() && LT.second.getScalarType() == MVT::f16)) &&
476         LT.second.getScalarSizeInBits() >= MTy.getScalarSizeInBits()) {
477       Type *LegalTy =
478           Type::getIntNTy(RetTy->getContext(), LT.second.getScalarSizeInBits());
479       if (LT.second.isVector())
480         LegalTy = VectorType::get(LegalTy, LT.second.getVectorElementCount());
481       InstructionCost Cost = 1;
482       IntrinsicCostAttributes Attrs1(IsSigned ? Intrinsic::smin : Intrinsic::umin,
483                                     LegalTy, {LegalTy, LegalTy});
484       Cost += getIntrinsicInstrCost(Attrs1, CostKind);
485       IntrinsicCostAttributes Attrs2(IsSigned ? Intrinsic::smax : Intrinsic::umax,
486                                     LegalTy, {LegalTy, LegalTy});
487       Cost += getIntrinsicInstrCost(Attrs2, CostKind);
488       return LT.first * Cost;
489     }
490     break;
491   }
492   default:
493     break;
494   }
495   return BaseT::getIntrinsicInstrCost(ICA, CostKind);
496 }
497 
498 /// The function will remove redundant reinterprets casting in the presence
499 /// of the control flow
500 static Optional<Instruction *> processPhiNode(InstCombiner &IC,
501                                               IntrinsicInst &II) {
502   SmallVector<Instruction *, 32> Worklist;
503   auto RequiredType = II.getType();
504 
505   auto *PN = dyn_cast<PHINode>(II.getArgOperand(0));
506   assert(PN && "Expected Phi Node!");
507 
508   // Don't create a new Phi unless we can remove the old one.
509   if (!PN->hasOneUse())
510     return None;
511 
512   for (Value *IncValPhi : PN->incoming_values()) {
513     auto *Reinterpret = dyn_cast<IntrinsicInst>(IncValPhi);
514     if (!Reinterpret ||
515         Reinterpret->getIntrinsicID() !=
516             Intrinsic::aarch64_sve_convert_to_svbool ||
517         RequiredType != Reinterpret->getArgOperand(0)->getType())
518       return None;
519   }
520 
521   // Create the new Phi
522   LLVMContext &Ctx = PN->getContext();
523   IRBuilder<> Builder(Ctx);
524   Builder.SetInsertPoint(PN);
525   PHINode *NPN = Builder.CreatePHI(RequiredType, PN->getNumIncomingValues());
526   Worklist.push_back(PN);
527 
528   for (unsigned I = 0; I < PN->getNumIncomingValues(); I++) {
529     auto *Reinterpret = cast<Instruction>(PN->getIncomingValue(I));
530     NPN->addIncoming(Reinterpret->getOperand(0), PN->getIncomingBlock(I));
531     Worklist.push_back(Reinterpret);
532   }
533 
534   // Cleanup Phi Node and reinterprets
535   return IC.replaceInstUsesWith(II, NPN);
536 }
537 
538 // (from_svbool (binop (to_svbool pred) (svbool_t _) (svbool_t _))))
539 // => (binop (pred) (from_svbool _) (from_svbool _))
540 //
541 // The above transformation eliminates a `to_svbool` in the predicate
542 // operand of bitwise operation `binop` by narrowing the vector width of
543 // the operation. For example, it would convert a `<vscale x 16 x i1>
544 // and` into a `<vscale x 4 x i1> and`. This is profitable because
545 // to_svbool must zero the new lanes during widening, whereas
546 // from_svbool is free.
547 static Optional<Instruction *> tryCombineFromSVBoolBinOp(InstCombiner &IC,
548                                                          IntrinsicInst &II) {
549   auto BinOp = dyn_cast<IntrinsicInst>(II.getOperand(0));
550   if (!BinOp)
551     return None;
552 
553   auto IntrinsicID = BinOp->getIntrinsicID();
554   switch (IntrinsicID) {
555   case Intrinsic::aarch64_sve_and_z:
556   case Intrinsic::aarch64_sve_bic_z:
557   case Intrinsic::aarch64_sve_eor_z:
558   case Intrinsic::aarch64_sve_nand_z:
559   case Intrinsic::aarch64_sve_nor_z:
560   case Intrinsic::aarch64_sve_orn_z:
561   case Intrinsic::aarch64_sve_orr_z:
562     break;
563   default:
564     return None;
565   }
566 
567   auto BinOpPred = BinOp->getOperand(0);
568   auto BinOpOp1 = BinOp->getOperand(1);
569   auto BinOpOp2 = BinOp->getOperand(2);
570 
571   auto PredIntr = dyn_cast<IntrinsicInst>(BinOpPred);
572   if (!PredIntr ||
573       PredIntr->getIntrinsicID() != Intrinsic::aarch64_sve_convert_to_svbool)
574     return None;
575 
576   auto PredOp = PredIntr->getOperand(0);
577   auto PredOpTy = cast<VectorType>(PredOp->getType());
578   if (PredOpTy != II.getType())
579     return None;
580 
581   IRBuilder<> Builder(II.getContext());
582   Builder.SetInsertPoint(&II);
583 
584   SmallVector<Value *> NarrowedBinOpArgs = {PredOp};
585   auto NarrowBinOpOp1 = Builder.CreateIntrinsic(
586       Intrinsic::aarch64_sve_convert_from_svbool, {PredOpTy}, {BinOpOp1});
587   NarrowedBinOpArgs.push_back(NarrowBinOpOp1);
588   if (BinOpOp1 == BinOpOp2)
589     NarrowedBinOpArgs.push_back(NarrowBinOpOp1);
590   else
591     NarrowedBinOpArgs.push_back(Builder.CreateIntrinsic(
592         Intrinsic::aarch64_sve_convert_from_svbool, {PredOpTy}, {BinOpOp2}));
593 
594   auto NarrowedBinOp =
595       Builder.CreateIntrinsic(IntrinsicID, {PredOpTy}, NarrowedBinOpArgs);
596   return IC.replaceInstUsesWith(II, NarrowedBinOp);
597 }
598 
599 static Optional<Instruction *> instCombineConvertFromSVBool(InstCombiner &IC,
600                                                             IntrinsicInst &II) {
601   // If the reinterpret instruction operand is a PHI Node
602   if (isa<PHINode>(II.getArgOperand(0)))
603     return processPhiNode(IC, II);
604 
605   if (auto BinOpCombine = tryCombineFromSVBoolBinOp(IC, II))
606     return BinOpCombine;
607 
608   SmallVector<Instruction *, 32> CandidatesForRemoval;
609   Value *Cursor = II.getOperand(0), *EarliestReplacement = nullptr;
610 
611   const auto *IVTy = cast<VectorType>(II.getType());
612 
613   // Walk the chain of conversions.
614   while (Cursor) {
615     // If the type of the cursor has fewer lanes than the final result, zeroing
616     // must take place, which breaks the equivalence chain.
617     const auto *CursorVTy = cast<VectorType>(Cursor->getType());
618     if (CursorVTy->getElementCount().getKnownMinValue() <
619         IVTy->getElementCount().getKnownMinValue())
620       break;
621 
622     // If the cursor has the same type as I, it is a viable replacement.
623     if (Cursor->getType() == IVTy)
624       EarliestReplacement = Cursor;
625 
626     auto *IntrinsicCursor = dyn_cast<IntrinsicInst>(Cursor);
627 
628     // If this is not an SVE conversion intrinsic, this is the end of the chain.
629     if (!IntrinsicCursor || !(IntrinsicCursor->getIntrinsicID() ==
630                                   Intrinsic::aarch64_sve_convert_to_svbool ||
631                               IntrinsicCursor->getIntrinsicID() ==
632                                   Intrinsic::aarch64_sve_convert_from_svbool))
633       break;
634 
635     CandidatesForRemoval.insert(CandidatesForRemoval.begin(), IntrinsicCursor);
636     Cursor = IntrinsicCursor->getOperand(0);
637   }
638 
639   // If no viable replacement in the conversion chain was found, there is
640   // nothing to do.
641   if (!EarliestReplacement)
642     return None;
643 
644   return IC.replaceInstUsesWith(II, EarliestReplacement);
645 }
646 
647 static Optional<Instruction *> instCombineSVESel(InstCombiner &IC,
648                                                  IntrinsicInst &II) {
649   IRBuilder<> Builder(&II);
650   auto Select = Builder.CreateSelect(II.getOperand(0), II.getOperand(1),
651                                      II.getOperand(2));
652   return IC.replaceInstUsesWith(II, Select);
653 }
654 
655 static Optional<Instruction *> instCombineSVEDup(InstCombiner &IC,
656                                                  IntrinsicInst &II) {
657   IntrinsicInst *Pg = dyn_cast<IntrinsicInst>(II.getArgOperand(1));
658   if (!Pg)
659     return None;
660 
661   if (Pg->getIntrinsicID() != Intrinsic::aarch64_sve_ptrue)
662     return None;
663 
664   const auto PTruePattern =
665       cast<ConstantInt>(Pg->getOperand(0))->getZExtValue();
666   if (PTruePattern != AArch64SVEPredPattern::vl1)
667     return None;
668 
669   // The intrinsic is inserting into lane zero so use an insert instead.
670   auto *IdxTy = Type::getInt64Ty(II.getContext());
671   auto *Insert = InsertElementInst::Create(
672       II.getArgOperand(0), II.getArgOperand(2), ConstantInt::get(IdxTy, 0));
673   Insert->insertBefore(&II);
674   Insert->takeName(&II);
675 
676   return IC.replaceInstUsesWith(II, Insert);
677 }
678 
679 static Optional<Instruction *> instCombineSVEDupX(InstCombiner &IC,
680                                                   IntrinsicInst &II) {
681   // Replace DupX with a regular IR splat.
682   IRBuilder<> Builder(II.getContext());
683   Builder.SetInsertPoint(&II);
684   auto *RetTy = cast<ScalableVectorType>(II.getType());
685   Value *Splat =
686       Builder.CreateVectorSplat(RetTy->getElementCount(), II.getArgOperand(0));
687   Splat->takeName(&II);
688   return IC.replaceInstUsesWith(II, Splat);
689 }
690 
691 static Optional<Instruction *> instCombineSVECmpNE(InstCombiner &IC,
692                                                    IntrinsicInst &II) {
693   LLVMContext &Ctx = II.getContext();
694   IRBuilder<> Builder(Ctx);
695   Builder.SetInsertPoint(&II);
696 
697   // Check that the predicate is all active
698   auto *Pg = dyn_cast<IntrinsicInst>(II.getArgOperand(0));
699   if (!Pg || Pg->getIntrinsicID() != Intrinsic::aarch64_sve_ptrue)
700     return None;
701 
702   const auto PTruePattern =
703       cast<ConstantInt>(Pg->getOperand(0))->getZExtValue();
704   if (PTruePattern != AArch64SVEPredPattern::all)
705     return None;
706 
707   // Check that we have a compare of zero..
708   auto *SplatValue =
709       dyn_cast_or_null<ConstantInt>(getSplatValue(II.getArgOperand(2)));
710   if (!SplatValue || !SplatValue->isZero())
711     return None;
712 
713   // ..against a dupq
714   auto *DupQLane = dyn_cast<IntrinsicInst>(II.getArgOperand(1));
715   if (!DupQLane ||
716       DupQLane->getIntrinsicID() != Intrinsic::aarch64_sve_dupq_lane)
717     return None;
718 
719   // Where the dupq is a lane 0 replicate of a vector insert
720   if (!cast<ConstantInt>(DupQLane->getArgOperand(1))->isZero())
721     return None;
722 
723   auto *VecIns = dyn_cast<IntrinsicInst>(DupQLane->getArgOperand(0));
724   if (!VecIns || VecIns->getIntrinsicID() != Intrinsic::vector_insert)
725     return None;
726 
727   // Where the vector insert is a fixed constant vector insert into undef at
728   // index zero
729   if (!isa<UndefValue>(VecIns->getArgOperand(0)))
730     return None;
731 
732   if (!cast<ConstantInt>(VecIns->getArgOperand(2))->isZero())
733     return None;
734 
735   auto *ConstVec = dyn_cast<Constant>(VecIns->getArgOperand(1));
736   if (!ConstVec)
737     return None;
738 
739   auto *VecTy = dyn_cast<FixedVectorType>(ConstVec->getType());
740   auto *OutTy = dyn_cast<ScalableVectorType>(II.getType());
741   if (!VecTy || !OutTy || VecTy->getNumElements() != OutTy->getMinNumElements())
742     return None;
743 
744   unsigned NumElts = VecTy->getNumElements();
745   unsigned PredicateBits = 0;
746 
747   // Expand intrinsic operands to a 16-bit byte level predicate
748   for (unsigned I = 0; I < NumElts; ++I) {
749     auto *Arg = dyn_cast<ConstantInt>(ConstVec->getAggregateElement(I));
750     if (!Arg)
751       return None;
752     if (!Arg->isZero())
753       PredicateBits |= 1 << (I * (16 / NumElts));
754   }
755 
756   // If all bits are zero bail early with an empty predicate
757   if (PredicateBits == 0) {
758     auto *PFalse = Constant::getNullValue(II.getType());
759     PFalse->takeName(&II);
760     return IC.replaceInstUsesWith(II, PFalse);
761   }
762 
763   // Calculate largest predicate type used (where byte predicate is largest)
764   unsigned Mask = 8;
765   for (unsigned I = 0; I < 16; ++I)
766     if ((PredicateBits & (1 << I)) != 0)
767       Mask |= (I % 8);
768 
769   unsigned PredSize = Mask & -Mask;
770   auto *PredType = ScalableVectorType::get(
771       Type::getInt1Ty(Ctx), AArch64::SVEBitsPerBlock / (PredSize * 8));
772 
773   // Ensure all relevant bits are set
774   for (unsigned I = 0; I < 16; I += PredSize)
775     if ((PredicateBits & (1 << I)) == 0)
776       return None;
777 
778   auto *PTruePat =
779       ConstantInt::get(Type::getInt32Ty(Ctx), AArch64SVEPredPattern::all);
780   auto *PTrue = Builder.CreateIntrinsic(Intrinsic::aarch64_sve_ptrue,
781                                         {PredType}, {PTruePat});
782   auto *ConvertToSVBool = Builder.CreateIntrinsic(
783       Intrinsic::aarch64_sve_convert_to_svbool, {PredType}, {PTrue});
784   auto *ConvertFromSVBool =
785       Builder.CreateIntrinsic(Intrinsic::aarch64_sve_convert_from_svbool,
786                               {II.getType()}, {ConvertToSVBool});
787 
788   ConvertFromSVBool->takeName(&II);
789   return IC.replaceInstUsesWith(II, ConvertFromSVBool);
790 }
791 
792 static Optional<Instruction *> instCombineSVELast(InstCombiner &IC,
793                                                   IntrinsicInst &II) {
794   IRBuilder<> Builder(II.getContext());
795   Builder.SetInsertPoint(&II);
796   Value *Pg = II.getArgOperand(0);
797   Value *Vec = II.getArgOperand(1);
798   auto IntrinsicID = II.getIntrinsicID();
799   bool IsAfter = IntrinsicID == Intrinsic::aarch64_sve_lasta;
800 
801   // lastX(splat(X)) --> X
802   if (auto *SplatVal = getSplatValue(Vec))
803     return IC.replaceInstUsesWith(II, SplatVal);
804 
805   // If x and/or y is a splat value then:
806   // lastX (binop (x, y)) --> binop(lastX(x), lastX(y))
807   Value *LHS, *RHS;
808   if (match(Vec, m_OneUse(m_BinOp(m_Value(LHS), m_Value(RHS))))) {
809     if (isSplatValue(LHS) || isSplatValue(RHS)) {
810       auto *OldBinOp = cast<BinaryOperator>(Vec);
811       auto OpC = OldBinOp->getOpcode();
812       auto *NewLHS =
813           Builder.CreateIntrinsic(IntrinsicID, {Vec->getType()}, {Pg, LHS});
814       auto *NewRHS =
815           Builder.CreateIntrinsic(IntrinsicID, {Vec->getType()}, {Pg, RHS});
816       auto *NewBinOp = BinaryOperator::CreateWithCopiedFlags(
817           OpC, NewLHS, NewRHS, OldBinOp, OldBinOp->getName(), &II);
818       return IC.replaceInstUsesWith(II, NewBinOp);
819     }
820   }
821 
822   auto *C = dyn_cast<Constant>(Pg);
823   if (IsAfter && C && C->isNullValue()) {
824     // The intrinsic is extracting lane 0 so use an extract instead.
825     auto *IdxTy = Type::getInt64Ty(II.getContext());
826     auto *Extract = ExtractElementInst::Create(Vec, ConstantInt::get(IdxTy, 0));
827     Extract->insertBefore(&II);
828     Extract->takeName(&II);
829     return IC.replaceInstUsesWith(II, Extract);
830   }
831 
832   auto *IntrPG = dyn_cast<IntrinsicInst>(Pg);
833   if (!IntrPG)
834     return None;
835 
836   if (IntrPG->getIntrinsicID() != Intrinsic::aarch64_sve_ptrue)
837     return None;
838 
839   const auto PTruePattern =
840       cast<ConstantInt>(IntrPG->getOperand(0))->getZExtValue();
841 
842   // Can the intrinsic's predicate be converted to a known constant index?
843   unsigned MinNumElts = getNumElementsFromSVEPredPattern(PTruePattern);
844   if (!MinNumElts)
845     return None;
846 
847   unsigned Idx = MinNumElts - 1;
848   // Increment the index if extracting the element after the last active
849   // predicate element.
850   if (IsAfter)
851     ++Idx;
852 
853   // Ignore extracts whose index is larger than the known minimum vector
854   // length. NOTE: This is an artificial constraint where we prefer to
855   // maintain what the user asked for until an alternative is proven faster.
856   auto *PgVTy = cast<ScalableVectorType>(Pg->getType());
857   if (Idx >= PgVTy->getMinNumElements())
858     return None;
859 
860   // The intrinsic is extracting a fixed lane so use an extract instead.
861   auto *IdxTy = Type::getInt64Ty(II.getContext());
862   auto *Extract = ExtractElementInst::Create(Vec, ConstantInt::get(IdxTy, Idx));
863   Extract->insertBefore(&II);
864   Extract->takeName(&II);
865   return IC.replaceInstUsesWith(II, Extract);
866 }
867 
868 static Optional<Instruction *> instCombineSVECondLast(InstCombiner &IC,
869                                                       IntrinsicInst &II) {
870   // The SIMD&FP variant of CLAST[AB] is significantly faster than the scalar
871   // integer variant across a variety of micro-architectures. Replace scalar
872   // integer CLAST[AB] intrinsic with optimal SIMD&FP variant. A simple
873   // bitcast-to-fp + clast[ab] + bitcast-to-int will cost a cycle or two more
874   // depending on the micro-architecture, but has been observed as generally
875   // being faster, particularly when the CLAST[AB] op is a loop-carried
876   // dependency.
877   IRBuilder<> Builder(II.getContext());
878   Builder.SetInsertPoint(&II);
879   Value *Pg = II.getArgOperand(0);
880   Value *Fallback = II.getArgOperand(1);
881   Value *Vec = II.getArgOperand(2);
882   Type *Ty = II.getType();
883 
884   if (!Ty->isIntegerTy())
885     return None;
886 
887   Type *FPTy;
888   switch (cast<IntegerType>(Ty)->getBitWidth()) {
889   default:
890     return None;
891   case 16:
892     FPTy = Builder.getHalfTy();
893     break;
894   case 32:
895     FPTy = Builder.getFloatTy();
896     break;
897   case 64:
898     FPTy = Builder.getDoubleTy();
899     break;
900   }
901 
902   Value *FPFallBack = Builder.CreateBitCast(Fallback, FPTy);
903   auto *FPVTy = VectorType::get(
904       FPTy, cast<VectorType>(Vec->getType())->getElementCount());
905   Value *FPVec = Builder.CreateBitCast(Vec, FPVTy);
906   auto *FPII = Builder.CreateIntrinsic(II.getIntrinsicID(), {FPVec->getType()},
907                                        {Pg, FPFallBack, FPVec});
908   Value *FPIItoInt = Builder.CreateBitCast(FPII, II.getType());
909   return IC.replaceInstUsesWith(II, FPIItoInt);
910 }
911 
912 static Optional<Instruction *> instCombineRDFFR(InstCombiner &IC,
913                                                 IntrinsicInst &II) {
914   LLVMContext &Ctx = II.getContext();
915   IRBuilder<> Builder(Ctx);
916   Builder.SetInsertPoint(&II);
917   // Replace rdffr with predicated rdffr.z intrinsic, so that optimizePTestInstr
918   // can work with RDFFR_PP for ptest elimination.
919   auto *AllPat =
920       ConstantInt::get(Type::getInt32Ty(Ctx), AArch64SVEPredPattern::all);
921   auto *PTrue = Builder.CreateIntrinsic(Intrinsic::aarch64_sve_ptrue,
922                                         {II.getType()}, {AllPat});
923   auto *RDFFR =
924       Builder.CreateIntrinsic(Intrinsic::aarch64_sve_rdffr_z, {}, {PTrue});
925   RDFFR->takeName(&II);
926   return IC.replaceInstUsesWith(II, RDFFR);
927 }
928 
929 static Optional<Instruction *>
930 instCombineSVECntElts(InstCombiner &IC, IntrinsicInst &II, unsigned NumElts) {
931   const auto Pattern = cast<ConstantInt>(II.getArgOperand(0))->getZExtValue();
932 
933   if (Pattern == AArch64SVEPredPattern::all) {
934     LLVMContext &Ctx = II.getContext();
935     IRBuilder<> Builder(Ctx);
936     Builder.SetInsertPoint(&II);
937 
938     Constant *StepVal = ConstantInt::get(II.getType(), NumElts);
939     auto *VScale = Builder.CreateVScale(StepVal);
940     VScale->takeName(&II);
941     return IC.replaceInstUsesWith(II, VScale);
942   }
943 
944   unsigned MinNumElts = getNumElementsFromSVEPredPattern(Pattern);
945 
946   return MinNumElts && NumElts >= MinNumElts
947              ? Optional<Instruction *>(IC.replaceInstUsesWith(
948                    II, ConstantInt::get(II.getType(), MinNumElts)))
949              : None;
950 }
951 
952 static Optional<Instruction *> instCombineSVEPTest(InstCombiner &IC,
953                                                    IntrinsicInst &II) {
954   IntrinsicInst *Op1 = dyn_cast<IntrinsicInst>(II.getArgOperand(0));
955   IntrinsicInst *Op2 = dyn_cast<IntrinsicInst>(II.getArgOperand(1));
956 
957   if (Op1 && Op2 &&
958       Op1->getIntrinsicID() == Intrinsic::aarch64_sve_convert_to_svbool &&
959       Op2->getIntrinsicID() == Intrinsic::aarch64_sve_convert_to_svbool &&
960       Op1->getArgOperand(0)->getType() == Op2->getArgOperand(0)->getType()) {
961 
962     IRBuilder<> Builder(II.getContext());
963     Builder.SetInsertPoint(&II);
964 
965     Value *Ops[] = {Op1->getArgOperand(0), Op2->getArgOperand(0)};
966     Type *Tys[] = {Op1->getArgOperand(0)->getType()};
967 
968     auto *PTest = Builder.CreateIntrinsic(II.getIntrinsicID(), Tys, Ops);
969 
970     PTest->takeName(&II);
971     return IC.replaceInstUsesWith(II, PTest);
972   }
973 
974   return None;
975 }
976 
977 static Optional<Instruction *> instCombineSVEVectorFMLA(InstCombiner &IC,
978                                                         IntrinsicInst &II) {
979   // fold (fadd p a (fmul p b c)) -> (fma p a b c)
980   Value *P = II.getOperand(0);
981   Value *A = II.getOperand(1);
982   auto FMul = II.getOperand(2);
983   Value *B, *C;
984   if (!match(FMul, m_Intrinsic<Intrinsic::aarch64_sve_fmul>(
985                        m_Specific(P), m_Value(B), m_Value(C))))
986     return None;
987 
988   if (!FMul->hasOneUse())
989     return None;
990 
991   llvm::FastMathFlags FAddFlags = II.getFastMathFlags();
992   // Stop the combine when the flags on the inputs differ in case dropping flags
993   // would lead to us missing out on more beneficial optimizations.
994   if (FAddFlags != cast<CallInst>(FMul)->getFastMathFlags())
995     return None;
996   if (!FAddFlags.allowContract())
997     return None;
998 
999   IRBuilder<> Builder(II.getContext());
1000   Builder.SetInsertPoint(&II);
1001   auto FMLA = Builder.CreateIntrinsic(Intrinsic::aarch64_sve_fmla,
1002                                       {II.getType()}, {P, A, B, C}, &II);
1003   FMLA->setFastMathFlags(FAddFlags);
1004   return IC.replaceInstUsesWith(II, FMLA);
1005 }
1006 
1007 static bool isAllActivePredicate(Value *Pred) {
1008   // Look through convert.from.svbool(convert.to.svbool(...) chain.
1009   Value *UncastedPred;
1010   if (match(Pred, m_Intrinsic<Intrinsic::aarch64_sve_convert_from_svbool>(
1011                       m_Intrinsic<Intrinsic::aarch64_sve_convert_to_svbool>(
1012                           m_Value(UncastedPred)))))
1013     // If the predicate has the same or less lanes than the uncasted
1014     // predicate then we know the casting has no effect.
1015     if (cast<ScalableVectorType>(Pred->getType())->getMinNumElements() <=
1016         cast<ScalableVectorType>(UncastedPred->getType())->getMinNumElements())
1017       Pred = UncastedPred;
1018 
1019   return match(Pred, m_Intrinsic<Intrinsic::aarch64_sve_ptrue>(
1020                          m_ConstantInt<AArch64SVEPredPattern::all>()));
1021 }
1022 
1023 static Optional<Instruction *>
1024 instCombineSVELD1(InstCombiner &IC, IntrinsicInst &II, const DataLayout &DL) {
1025   IRBuilder<> Builder(II.getContext());
1026   Builder.SetInsertPoint(&II);
1027 
1028   Value *Pred = II.getOperand(0);
1029   Value *PtrOp = II.getOperand(1);
1030   Type *VecTy = II.getType();
1031   Value *VecPtr = Builder.CreateBitCast(PtrOp, VecTy->getPointerTo());
1032 
1033   if (isAllActivePredicate(Pred)) {
1034     LoadInst *Load = Builder.CreateLoad(VecTy, VecPtr);
1035     Load->copyMetadata(II);
1036     return IC.replaceInstUsesWith(II, Load);
1037   }
1038 
1039   CallInst *MaskedLoad =
1040       Builder.CreateMaskedLoad(VecTy, VecPtr, PtrOp->getPointerAlignment(DL),
1041                                Pred, ConstantAggregateZero::get(VecTy));
1042   MaskedLoad->copyMetadata(II);
1043   return IC.replaceInstUsesWith(II, MaskedLoad);
1044 }
1045 
1046 static Optional<Instruction *>
1047 instCombineSVEST1(InstCombiner &IC, IntrinsicInst &II, const DataLayout &DL) {
1048   IRBuilder<> Builder(II.getContext());
1049   Builder.SetInsertPoint(&II);
1050 
1051   Value *VecOp = II.getOperand(0);
1052   Value *Pred = II.getOperand(1);
1053   Value *PtrOp = II.getOperand(2);
1054   Value *VecPtr =
1055       Builder.CreateBitCast(PtrOp, VecOp->getType()->getPointerTo());
1056 
1057   if (isAllActivePredicate(Pred)) {
1058     StoreInst *Store = Builder.CreateStore(VecOp, VecPtr);
1059     Store->copyMetadata(II);
1060     return IC.eraseInstFromFunction(II);
1061   }
1062 
1063   CallInst *MaskedStore = Builder.CreateMaskedStore(
1064       VecOp, VecPtr, PtrOp->getPointerAlignment(DL), Pred);
1065   MaskedStore->copyMetadata(II);
1066   return IC.eraseInstFromFunction(II);
1067 }
1068 
1069 static Instruction::BinaryOps intrinsicIDToBinOpCode(unsigned Intrinsic) {
1070   switch (Intrinsic) {
1071   case Intrinsic::aarch64_sve_fmul:
1072     return Instruction::BinaryOps::FMul;
1073   case Intrinsic::aarch64_sve_fadd:
1074     return Instruction::BinaryOps::FAdd;
1075   case Intrinsic::aarch64_sve_fsub:
1076     return Instruction::BinaryOps::FSub;
1077   default:
1078     return Instruction::BinaryOpsEnd;
1079   }
1080 }
1081 
1082 static Optional<Instruction *> instCombineSVEVectorBinOp(InstCombiner &IC,
1083                                                          IntrinsicInst &II) {
1084   auto *OpPredicate = II.getOperand(0);
1085   auto BinOpCode = intrinsicIDToBinOpCode(II.getIntrinsicID());
1086   if (BinOpCode == Instruction::BinaryOpsEnd ||
1087       !match(OpPredicate, m_Intrinsic<Intrinsic::aarch64_sve_ptrue>(
1088                               m_ConstantInt<AArch64SVEPredPattern::all>())))
1089     return None;
1090   IRBuilder<> Builder(II.getContext());
1091   Builder.SetInsertPoint(&II);
1092   Builder.setFastMathFlags(II.getFastMathFlags());
1093   auto BinOp =
1094       Builder.CreateBinOp(BinOpCode, II.getOperand(1), II.getOperand(2));
1095   return IC.replaceInstUsesWith(II, BinOp);
1096 }
1097 
1098 static Optional<Instruction *> instCombineSVEVectorFAdd(InstCombiner &IC,
1099                                                         IntrinsicInst &II) {
1100   if (auto FMLA = instCombineSVEVectorFMLA(IC, II))
1101     return FMLA;
1102   return instCombineSVEVectorBinOp(IC, II);
1103 }
1104 
1105 static Optional<Instruction *> instCombineSVEVectorMul(InstCombiner &IC,
1106                                                        IntrinsicInst &II) {
1107   auto *OpPredicate = II.getOperand(0);
1108   auto *OpMultiplicand = II.getOperand(1);
1109   auto *OpMultiplier = II.getOperand(2);
1110 
1111   IRBuilder<> Builder(II.getContext());
1112   Builder.SetInsertPoint(&II);
1113 
1114   // Return true if a given instruction is a unit splat value, false otherwise.
1115   auto IsUnitSplat = [](auto *I) {
1116     auto *SplatValue = getSplatValue(I);
1117     if (!SplatValue)
1118       return false;
1119     return match(SplatValue, m_FPOne()) || match(SplatValue, m_One());
1120   };
1121 
1122   // Return true if a given instruction is an aarch64_sve_dup intrinsic call
1123   // with a unit splat value, false otherwise.
1124   auto IsUnitDup = [](auto *I) {
1125     auto *IntrI = dyn_cast<IntrinsicInst>(I);
1126     if (!IntrI || IntrI->getIntrinsicID() != Intrinsic::aarch64_sve_dup)
1127       return false;
1128 
1129     auto *SplatValue = IntrI->getOperand(2);
1130     return match(SplatValue, m_FPOne()) || match(SplatValue, m_One());
1131   };
1132 
1133   if (IsUnitSplat(OpMultiplier)) {
1134     // [f]mul pg %n, (dupx 1) => %n
1135     OpMultiplicand->takeName(&II);
1136     return IC.replaceInstUsesWith(II, OpMultiplicand);
1137   } else if (IsUnitDup(OpMultiplier)) {
1138     // [f]mul pg %n, (dup pg 1) => %n
1139     auto *DupInst = cast<IntrinsicInst>(OpMultiplier);
1140     auto *DupPg = DupInst->getOperand(1);
1141     // TODO: this is naive. The optimization is still valid if DupPg
1142     // 'encompasses' OpPredicate, not only if they're the same predicate.
1143     if (OpPredicate == DupPg) {
1144       OpMultiplicand->takeName(&II);
1145       return IC.replaceInstUsesWith(II, OpMultiplicand);
1146     }
1147   }
1148 
1149   return instCombineSVEVectorBinOp(IC, II);
1150 }
1151 
1152 static Optional<Instruction *> instCombineSVEUnpack(InstCombiner &IC,
1153                                                     IntrinsicInst &II) {
1154   IRBuilder<> Builder(II.getContext());
1155   Builder.SetInsertPoint(&II);
1156   Value *UnpackArg = II.getArgOperand(0);
1157   auto *RetTy = cast<ScalableVectorType>(II.getType());
1158   bool IsSigned = II.getIntrinsicID() == Intrinsic::aarch64_sve_sunpkhi ||
1159                   II.getIntrinsicID() == Intrinsic::aarch64_sve_sunpklo;
1160 
1161   // Hi = uunpkhi(splat(X)) --> Hi = splat(extend(X))
1162   // Lo = uunpklo(splat(X)) --> Lo = splat(extend(X))
1163   if (auto *ScalarArg = getSplatValue(UnpackArg)) {
1164     ScalarArg =
1165         Builder.CreateIntCast(ScalarArg, RetTy->getScalarType(), IsSigned);
1166     Value *NewVal =
1167         Builder.CreateVectorSplat(RetTy->getElementCount(), ScalarArg);
1168     NewVal->takeName(&II);
1169     return IC.replaceInstUsesWith(II, NewVal);
1170   }
1171 
1172   return None;
1173 }
1174 static Optional<Instruction *> instCombineSVETBL(InstCombiner &IC,
1175                                                  IntrinsicInst &II) {
1176   auto *OpVal = II.getOperand(0);
1177   auto *OpIndices = II.getOperand(1);
1178   VectorType *VTy = cast<VectorType>(II.getType());
1179 
1180   // Check whether OpIndices is a constant splat value < minimal element count
1181   // of result.
1182   auto *SplatValue = dyn_cast_or_null<ConstantInt>(getSplatValue(OpIndices));
1183   if (!SplatValue ||
1184       SplatValue->getValue().uge(VTy->getElementCount().getKnownMinValue()))
1185     return None;
1186 
1187   // Convert sve_tbl(OpVal sve_dup_x(SplatValue)) to
1188   // splat_vector(extractelement(OpVal, SplatValue)) for further optimization.
1189   IRBuilder<> Builder(II.getContext());
1190   Builder.SetInsertPoint(&II);
1191   auto *Extract = Builder.CreateExtractElement(OpVal, SplatValue);
1192   auto *VectorSplat =
1193       Builder.CreateVectorSplat(VTy->getElementCount(), Extract);
1194 
1195   VectorSplat->takeName(&II);
1196   return IC.replaceInstUsesWith(II, VectorSplat);
1197 }
1198 
1199 static Optional<Instruction *> instCombineSVETupleGet(InstCombiner &IC,
1200                                                       IntrinsicInst &II) {
1201   // Try to remove sequences of tuple get/set.
1202   Value *SetTuple, *SetIndex, *SetValue;
1203   auto *GetTuple = II.getArgOperand(0);
1204   auto *GetIndex = II.getArgOperand(1);
1205   // Check that we have tuple_get(GetTuple, GetIndex) where GetTuple is a
1206   // call to tuple_set i.e. tuple_set(SetTuple, SetIndex, SetValue).
1207   // Make sure that the types of the current intrinsic and SetValue match
1208   // in order to safely remove the sequence.
1209   if (!match(GetTuple,
1210              m_Intrinsic<Intrinsic::aarch64_sve_tuple_set>(
1211                  m_Value(SetTuple), m_Value(SetIndex), m_Value(SetValue))) ||
1212       SetValue->getType() != II.getType())
1213     return None;
1214   // Case where we get the same index right after setting it.
1215   // tuple_get(tuple_set(SetTuple, SetIndex, SetValue), GetIndex) --> SetValue
1216   if (GetIndex == SetIndex)
1217     return IC.replaceInstUsesWith(II, SetValue);
1218   // If we are getting a different index than what was set in the tuple_set
1219   // intrinsic. We can just set the input tuple to the one up in the chain.
1220   // tuple_get(tuple_set(SetTuple, SetIndex, SetValue), GetIndex)
1221   // --> tuple_get(SetTuple, GetIndex)
1222   return IC.replaceOperand(II, 0, SetTuple);
1223 }
1224 
1225 static Optional<Instruction *> instCombineSVEZip(InstCombiner &IC,
1226                                                  IntrinsicInst &II) {
1227   // zip1(uzp1(A, B), uzp2(A, B)) --> A
1228   // zip2(uzp1(A, B), uzp2(A, B)) --> B
1229   Value *A, *B;
1230   if (match(II.getArgOperand(0),
1231             m_Intrinsic<Intrinsic::aarch64_sve_uzp1>(m_Value(A), m_Value(B))) &&
1232       match(II.getArgOperand(1), m_Intrinsic<Intrinsic::aarch64_sve_uzp2>(
1233                                      m_Specific(A), m_Specific(B))))
1234     return IC.replaceInstUsesWith(
1235         II, (II.getIntrinsicID() == Intrinsic::aarch64_sve_zip1 ? A : B));
1236 
1237   return None;
1238 }
1239 
1240 static Optional<Instruction *> instCombineLD1GatherIndex(InstCombiner &IC,
1241                                                          IntrinsicInst &II) {
1242   Value *Mask = II.getOperand(0);
1243   Value *BasePtr = II.getOperand(1);
1244   Value *Index = II.getOperand(2);
1245   Type *Ty = II.getType();
1246   Value *PassThru = ConstantAggregateZero::get(Ty);
1247 
1248   // Contiguous gather => masked load.
1249   // (sve.ld1.gather.index Mask BasePtr (sve.index IndexBase 1))
1250   // => (masked.load (gep BasePtr IndexBase) Align Mask zeroinitializer)
1251   Value *IndexBase;
1252   if (match(Index, m_Intrinsic<Intrinsic::aarch64_sve_index>(
1253                        m_Value(IndexBase), m_SpecificInt(1)))) {
1254     IRBuilder<> Builder(II.getContext());
1255     Builder.SetInsertPoint(&II);
1256 
1257     Align Alignment =
1258         BasePtr->getPointerAlignment(II.getModule()->getDataLayout());
1259 
1260     Type *VecPtrTy = PointerType::getUnqual(Ty);
1261     Value *Ptr = Builder.CreateGEP(
1262         cast<VectorType>(Ty)->getElementType(), BasePtr, IndexBase);
1263     Ptr = Builder.CreateBitCast(Ptr, VecPtrTy);
1264     CallInst *MaskedLoad =
1265         Builder.CreateMaskedLoad(Ty, Ptr, Alignment, Mask, PassThru);
1266     MaskedLoad->takeName(&II);
1267     return IC.replaceInstUsesWith(II, MaskedLoad);
1268   }
1269 
1270   return None;
1271 }
1272 
1273 static Optional<Instruction *> instCombineST1ScatterIndex(InstCombiner &IC,
1274                                                           IntrinsicInst &II) {
1275   Value *Val = II.getOperand(0);
1276   Value *Mask = II.getOperand(1);
1277   Value *BasePtr = II.getOperand(2);
1278   Value *Index = II.getOperand(3);
1279   Type *Ty = Val->getType();
1280 
1281   // Contiguous scatter => masked store.
1282   // (sve.st1.scatter.index Value Mask BasePtr (sve.index IndexBase 1))
1283   // => (masked.store Value (gep BasePtr IndexBase) Align Mask)
1284   Value *IndexBase;
1285   if (match(Index, m_Intrinsic<Intrinsic::aarch64_sve_index>(
1286                        m_Value(IndexBase), m_SpecificInt(1)))) {
1287     IRBuilder<> Builder(II.getContext());
1288     Builder.SetInsertPoint(&II);
1289 
1290     Align Alignment =
1291         BasePtr->getPointerAlignment(II.getModule()->getDataLayout());
1292 
1293     Value *Ptr = Builder.CreateGEP(
1294         cast<VectorType>(Ty)->getElementType(), BasePtr, IndexBase);
1295     Type *VecPtrTy = PointerType::getUnqual(Ty);
1296     Ptr = Builder.CreateBitCast(Ptr, VecPtrTy);
1297 
1298     (void)Builder.CreateMaskedStore(Val, Ptr, Alignment, Mask);
1299 
1300     return IC.eraseInstFromFunction(II);
1301   }
1302 
1303   return None;
1304 }
1305 
1306 static Optional<Instruction *> instCombineSVESDIV(InstCombiner &IC,
1307                                                   IntrinsicInst &II) {
1308   IRBuilder<> Builder(II.getContext());
1309   Builder.SetInsertPoint(&II);
1310   Type *Int32Ty = Builder.getInt32Ty();
1311   Value *Pred = II.getOperand(0);
1312   Value *Vec = II.getOperand(1);
1313   Value *DivVec = II.getOperand(2);
1314 
1315   Value *SplatValue = getSplatValue(DivVec);
1316   ConstantInt *SplatConstantInt = dyn_cast_or_null<ConstantInt>(SplatValue);
1317   if (!SplatConstantInt)
1318     return None;
1319   APInt Divisor = SplatConstantInt->getValue();
1320 
1321   if (Divisor.isPowerOf2()) {
1322     Constant *DivisorLog2 = ConstantInt::get(Int32Ty, Divisor.logBase2());
1323     auto ASRD = Builder.CreateIntrinsic(
1324         Intrinsic::aarch64_sve_asrd, {II.getType()}, {Pred, Vec, DivisorLog2});
1325     return IC.replaceInstUsesWith(II, ASRD);
1326   }
1327   if (Divisor.isNegatedPowerOf2()) {
1328     Divisor.negate();
1329     Constant *DivisorLog2 = ConstantInt::get(Int32Ty, Divisor.logBase2());
1330     auto ASRD = Builder.CreateIntrinsic(
1331         Intrinsic::aarch64_sve_asrd, {II.getType()}, {Pred, Vec, DivisorLog2});
1332     auto NEG = Builder.CreateIntrinsic(Intrinsic::aarch64_sve_neg,
1333                                        {ASRD->getType()}, {ASRD, Pred, ASRD});
1334     return IC.replaceInstUsesWith(II, NEG);
1335   }
1336 
1337   return None;
1338 }
1339 
1340 static Optional<Instruction *> instCombineMaxMinNM(InstCombiner &IC,
1341                                                    IntrinsicInst &II) {
1342   Value *A = II.getArgOperand(0);
1343   Value *B = II.getArgOperand(1);
1344   if (A == B)
1345     return IC.replaceInstUsesWith(II, A);
1346 
1347   return None;
1348 }
1349 
1350 static Optional<Instruction *> instCombineSVESrshl(InstCombiner &IC,
1351                                                    IntrinsicInst &II) {
1352   IRBuilder<> Builder(&II);
1353   Value *Pred = II.getOperand(0);
1354   Value *Vec = II.getOperand(1);
1355   Value *Shift = II.getOperand(2);
1356 
1357   // Convert SRSHL into the simpler LSL intrinsic when fed by an ABS intrinsic.
1358   Value *AbsPred, *MergedValue;
1359   if (!match(Vec, m_Intrinsic<Intrinsic::aarch64_sve_sqabs>(
1360                       m_Value(MergedValue), m_Value(AbsPred), m_Value())) &&
1361       !match(Vec, m_Intrinsic<Intrinsic::aarch64_sve_abs>(
1362                       m_Value(MergedValue), m_Value(AbsPred), m_Value())))
1363 
1364     return None;
1365 
1366   // Transform is valid if any of the following are true:
1367   // * The ABS merge value is an undef or non-negative
1368   // * The ABS predicate is all active
1369   // * The ABS predicate and the SRSHL predicates are the same
1370   if (!isa<UndefValue>(MergedValue) &&
1371       !match(MergedValue, m_NonNegative()) &&
1372       AbsPred != Pred && !isAllActivePredicate(AbsPred))
1373     return None;
1374 
1375   // Only valid when the shift amount is non-negative, otherwise the rounding
1376   // behaviour of SRSHL cannot be ignored.
1377   if (!match(Shift, m_NonNegative()))
1378     return None;
1379 
1380   auto LSL = Builder.CreateIntrinsic(Intrinsic::aarch64_sve_lsl, {II.getType()},
1381                                      {Pred, Vec, Shift});
1382 
1383   return IC.replaceInstUsesWith(II, LSL);
1384 }
1385 
1386 Optional<Instruction *>
1387 AArch64TTIImpl::instCombineIntrinsic(InstCombiner &IC,
1388                                      IntrinsicInst &II) const {
1389   Intrinsic::ID IID = II.getIntrinsicID();
1390   switch (IID) {
1391   default:
1392     break;
1393   case Intrinsic::aarch64_neon_fmaxnm:
1394   case Intrinsic::aarch64_neon_fminnm:
1395     return instCombineMaxMinNM(IC, II);
1396   case Intrinsic::aarch64_sve_convert_from_svbool:
1397     return instCombineConvertFromSVBool(IC, II);
1398   case Intrinsic::aarch64_sve_dup:
1399     return instCombineSVEDup(IC, II);
1400   case Intrinsic::aarch64_sve_dup_x:
1401     return instCombineSVEDupX(IC, II);
1402   case Intrinsic::aarch64_sve_cmpne:
1403   case Intrinsic::aarch64_sve_cmpne_wide:
1404     return instCombineSVECmpNE(IC, II);
1405   case Intrinsic::aarch64_sve_rdffr:
1406     return instCombineRDFFR(IC, II);
1407   case Intrinsic::aarch64_sve_lasta:
1408   case Intrinsic::aarch64_sve_lastb:
1409     return instCombineSVELast(IC, II);
1410   case Intrinsic::aarch64_sve_clasta_n:
1411   case Intrinsic::aarch64_sve_clastb_n:
1412     return instCombineSVECondLast(IC, II);
1413   case Intrinsic::aarch64_sve_cntd:
1414     return instCombineSVECntElts(IC, II, 2);
1415   case Intrinsic::aarch64_sve_cntw:
1416     return instCombineSVECntElts(IC, II, 4);
1417   case Intrinsic::aarch64_sve_cnth:
1418     return instCombineSVECntElts(IC, II, 8);
1419   case Intrinsic::aarch64_sve_cntb:
1420     return instCombineSVECntElts(IC, II, 16);
1421   case Intrinsic::aarch64_sve_ptest_any:
1422   case Intrinsic::aarch64_sve_ptest_first:
1423   case Intrinsic::aarch64_sve_ptest_last:
1424     return instCombineSVEPTest(IC, II);
1425   case Intrinsic::aarch64_sve_mul:
1426   case Intrinsic::aarch64_sve_fmul:
1427     return instCombineSVEVectorMul(IC, II);
1428   case Intrinsic::aarch64_sve_fadd:
1429     return instCombineSVEVectorFAdd(IC, II);
1430   case Intrinsic::aarch64_sve_fsub:
1431     return instCombineSVEVectorBinOp(IC, II);
1432   case Intrinsic::aarch64_sve_tbl:
1433     return instCombineSVETBL(IC, II);
1434   case Intrinsic::aarch64_sve_uunpkhi:
1435   case Intrinsic::aarch64_sve_uunpklo:
1436   case Intrinsic::aarch64_sve_sunpkhi:
1437   case Intrinsic::aarch64_sve_sunpklo:
1438     return instCombineSVEUnpack(IC, II);
1439   case Intrinsic::aarch64_sve_tuple_get:
1440     return instCombineSVETupleGet(IC, II);
1441   case Intrinsic::aarch64_sve_zip1:
1442   case Intrinsic::aarch64_sve_zip2:
1443     return instCombineSVEZip(IC, II);
1444   case Intrinsic::aarch64_sve_ld1_gather_index:
1445     return instCombineLD1GatherIndex(IC, II);
1446   case Intrinsic::aarch64_sve_st1_scatter_index:
1447     return instCombineST1ScatterIndex(IC, II);
1448   case Intrinsic::aarch64_sve_ld1:
1449     return instCombineSVELD1(IC, II, DL);
1450   case Intrinsic::aarch64_sve_st1:
1451     return instCombineSVEST1(IC, II, DL);
1452   case Intrinsic::aarch64_sve_sdiv:
1453     return instCombineSVESDIV(IC, II);
1454   case Intrinsic::aarch64_sve_sel:
1455     return instCombineSVESel(IC, II);
1456   case Intrinsic::aarch64_sve_srshl:
1457     return instCombineSVESrshl(IC, II);
1458   }
1459 
1460   return None;
1461 }
1462 
1463 Optional<Value *> AArch64TTIImpl::simplifyDemandedVectorEltsIntrinsic(
1464     InstCombiner &IC, IntrinsicInst &II, APInt OrigDemandedElts,
1465     APInt &UndefElts, APInt &UndefElts2, APInt &UndefElts3,
1466     std::function<void(Instruction *, unsigned, APInt, APInt &)>
1467         SimplifyAndSetOp) const {
1468   switch (II.getIntrinsicID()) {
1469   default:
1470     break;
1471   case Intrinsic::aarch64_neon_fcvtxn:
1472   case Intrinsic::aarch64_neon_rshrn:
1473   case Intrinsic::aarch64_neon_sqrshrn:
1474   case Intrinsic::aarch64_neon_sqrshrun:
1475   case Intrinsic::aarch64_neon_sqshrn:
1476   case Intrinsic::aarch64_neon_sqshrun:
1477   case Intrinsic::aarch64_neon_sqxtn:
1478   case Intrinsic::aarch64_neon_sqxtun:
1479   case Intrinsic::aarch64_neon_uqrshrn:
1480   case Intrinsic::aarch64_neon_uqshrn:
1481   case Intrinsic::aarch64_neon_uqxtn:
1482     SimplifyAndSetOp(&II, 0, OrigDemandedElts, UndefElts);
1483     break;
1484   }
1485 
1486   return None;
1487 }
1488 
1489 bool AArch64TTIImpl::isWideningInstruction(Type *DstTy, unsigned Opcode,
1490                                            ArrayRef<const Value *> Args) {
1491 
1492   // A helper that returns a vector type from the given type. The number of
1493   // elements in type Ty determines the vector width.
1494   auto toVectorTy = [&](Type *ArgTy) {
1495     return VectorType::get(ArgTy->getScalarType(),
1496                            cast<VectorType>(DstTy)->getElementCount());
1497   };
1498 
1499   // Exit early if DstTy is not a vector type whose elements are at least
1500   // 16-bits wide.
1501   if (!DstTy->isVectorTy() || DstTy->getScalarSizeInBits() < 16)
1502     return false;
1503 
1504   // Determine if the operation has a widening variant. We consider both the
1505   // "long" (e.g., usubl) and "wide" (e.g., usubw) versions of the
1506   // instructions.
1507   //
1508   // TODO: Add additional widening operations (e.g., shl, etc.) once we
1509   //       verify that their extending operands are eliminated during code
1510   //       generation.
1511   switch (Opcode) {
1512   case Instruction::Add: // UADDL(2), SADDL(2), UADDW(2), SADDW(2).
1513   case Instruction::Sub: // USUBL(2), SSUBL(2), USUBW(2), SSUBW(2).
1514   case Instruction::Mul: // SMULL(2), UMULL(2)
1515     break;
1516   default:
1517     return false;
1518   }
1519 
1520   // To be a widening instruction (either the "wide" or "long" versions), the
1521   // second operand must be a sign- or zero extend.
1522   if (Args.size() != 2 ||
1523       (!isa<SExtInst>(Args[1]) && !isa<ZExtInst>(Args[1])))
1524     return false;
1525   auto *Extend = cast<CastInst>(Args[1]);
1526   auto *Arg0 = dyn_cast<CastInst>(Args[0]);
1527 
1528   // A mul only has a mull version (not like addw). Both operands need to be
1529   // extending and the same type.
1530   if (Opcode == Instruction::Mul &&
1531       (!Arg0 || Arg0->getOpcode() != Extend->getOpcode() ||
1532        Arg0->getOperand(0)->getType() != Extend->getOperand(0)->getType()))
1533     return false;
1534 
1535   // Legalize the destination type and ensure it can be used in a widening
1536   // operation.
1537   auto DstTyL = TLI->getTypeLegalizationCost(DL, DstTy);
1538   unsigned DstElTySize = DstTyL.second.getScalarSizeInBits();
1539   if (!DstTyL.second.isVector() || DstElTySize != DstTy->getScalarSizeInBits())
1540     return false;
1541 
1542   // Legalize the source type and ensure it can be used in a widening
1543   // operation.
1544   auto *SrcTy = toVectorTy(Extend->getSrcTy());
1545   auto SrcTyL = TLI->getTypeLegalizationCost(DL, SrcTy);
1546   unsigned SrcElTySize = SrcTyL.second.getScalarSizeInBits();
1547   if (!SrcTyL.second.isVector() || SrcElTySize != SrcTy->getScalarSizeInBits())
1548     return false;
1549 
1550   // Get the total number of vector elements in the legalized types.
1551   InstructionCost NumDstEls =
1552       DstTyL.first * DstTyL.second.getVectorMinNumElements();
1553   InstructionCost NumSrcEls =
1554       SrcTyL.first * SrcTyL.second.getVectorMinNumElements();
1555 
1556   // Return true if the legalized types have the same number of vector elements
1557   // and the destination element type size is twice that of the source type.
1558   return NumDstEls == NumSrcEls && 2 * SrcElTySize == DstElTySize;
1559 }
1560 
1561 InstructionCost AArch64TTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst,
1562                                                  Type *Src,
1563                                                  TTI::CastContextHint CCH,
1564                                                  TTI::TargetCostKind CostKind,
1565                                                  const Instruction *I) {
1566   int ISD = TLI->InstructionOpcodeToISD(Opcode);
1567   assert(ISD && "Invalid opcode");
1568 
1569   // If the cast is observable, and it is used by a widening instruction (e.g.,
1570   // uaddl, saddw, etc.), it may be free.
1571   if (I && I->hasOneUser()) {
1572     auto *SingleUser = cast<Instruction>(*I->user_begin());
1573     SmallVector<const Value *, 4> Operands(SingleUser->operand_values());
1574     if (isWideningInstruction(Dst, SingleUser->getOpcode(), Operands)) {
1575       // If the cast is the second operand, it is free. We will generate either
1576       // a "wide" or "long" version of the widening instruction.
1577       if (I == SingleUser->getOperand(1))
1578         return 0;
1579       // If the cast is not the second operand, it will be free if it looks the
1580       // same as the second operand. In this case, we will generate a "long"
1581       // version of the widening instruction.
1582       if (auto *Cast = dyn_cast<CastInst>(SingleUser->getOperand(1)))
1583         if (I->getOpcode() == unsigned(Cast->getOpcode()) &&
1584             cast<CastInst>(I)->getSrcTy() == Cast->getSrcTy())
1585           return 0;
1586     }
1587   }
1588 
1589   // TODO: Allow non-throughput costs that aren't binary.
1590   auto AdjustCost = [&CostKind](InstructionCost Cost) -> InstructionCost {
1591     if (CostKind != TTI::TCK_RecipThroughput)
1592       return Cost == 0 ? 0 : 1;
1593     return Cost;
1594   };
1595 
1596   EVT SrcTy = TLI->getValueType(DL, Src);
1597   EVT DstTy = TLI->getValueType(DL, Dst);
1598 
1599   if (!SrcTy.isSimple() || !DstTy.isSimple())
1600     return AdjustCost(
1601         BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I));
1602 
1603   static const TypeConversionCostTblEntry
1604   ConversionTbl[] = {
1605     { ISD::TRUNCATE, MVT::v4i16, MVT::v4i32,  1 },
1606     { ISD::TRUNCATE, MVT::v4i32, MVT::v4i64,  0 },
1607     { ISD::TRUNCATE, MVT::v8i8,  MVT::v8i32,  3 },
1608     { ISD::TRUNCATE, MVT::v16i8, MVT::v16i32, 6 },
1609 
1610     // Truncations on nxvmiN
1611     { ISD::TRUNCATE, MVT::nxv2i1, MVT::nxv2i16, 1 },
1612     { ISD::TRUNCATE, MVT::nxv2i1, MVT::nxv2i32, 1 },
1613     { ISD::TRUNCATE, MVT::nxv2i1, MVT::nxv2i64, 1 },
1614     { ISD::TRUNCATE, MVT::nxv4i1, MVT::nxv4i16, 1 },
1615     { ISD::TRUNCATE, MVT::nxv4i1, MVT::nxv4i32, 1 },
1616     { ISD::TRUNCATE, MVT::nxv4i1, MVT::nxv4i64, 2 },
1617     { ISD::TRUNCATE, MVT::nxv8i1, MVT::nxv8i16, 1 },
1618     { ISD::TRUNCATE, MVT::nxv8i1, MVT::nxv8i32, 3 },
1619     { ISD::TRUNCATE, MVT::nxv8i1, MVT::nxv8i64, 5 },
1620     { ISD::TRUNCATE, MVT::nxv16i1, MVT::nxv16i8, 1 },
1621     { ISD::TRUNCATE, MVT::nxv2i16, MVT::nxv2i32, 1 },
1622     { ISD::TRUNCATE, MVT::nxv2i32, MVT::nxv2i64, 1 },
1623     { ISD::TRUNCATE, MVT::nxv4i16, MVT::nxv4i32, 1 },
1624     { ISD::TRUNCATE, MVT::nxv4i32, MVT::nxv4i64, 2 },
1625     { ISD::TRUNCATE, MVT::nxv8i16, MVT::nxv8i32, 3 },
1626     { ISD::TRUNCATE, MVT::nxv8i32, MVT::nxv8i64, 6 },
1627 
1628     // The number of shll instructions for the extension.
1629     { ISD::SIGN_EXTEND, MVT::v4i64,  MVT::v4i16, 3 },
1630     { ISD::ZERO_EXTEND, MVT::v4i64,  MVT::v4i16, 3 },
1631     { ISD::SIGN_EXTEND, MVT::v4i64,  MVT::v4i32, 2 },
1632     { ISD::ZERO_EXTEND, MVT::v4i64,  MVT::v4i32, 2 },
1633     { ISD::SIGN_EXTEND, MVT::v8i32,  MVT::v8i8,  3 },
1634     { ISD::ZERO_EXTEND, MVT::v8i32,  MVT::v8i8,  3 },
1635     { ISD::SIGN_EXTEND, MVT::v8i32,  MVT::v8i16, 2 },
1636     { ISD::ZERO_EXTEND, MVT::v8i32,  MVT::v8i16, 2 },
1637     { ISD::SIGN_EXTEND, MVT::v8i64,  MVT::v8i8,  7 },
1638     { ISD::ZERO_EXTEND, MVT::v8i64,  MVT::v8i8,  7 },
1639     { ISD::SIGN_EXTEND, MVT::v8i64,  MVT::v8i16, 6 },
1640     { ISD::ZERO_EXTEND, MVT::v8i64,  MVT::v8i16, 6 },
1641     { ISD::SIGN_EXTEND, MVT::v16i16, MVT::v16i8, 2 },
1642     { ISD::ZERO_EXTEND, MVT::v16i16, MVT::v16i8, 2 },
1643     { ISD::SIGN_EXTEND, MVT::v16i32, MVT::v16i8, 6 },
1644     { ISD::ZERO_EXTEND, MVT::v16i32, MVT::v16i8, 6 },
1645 
1646     // LowerVectorINT_TO_FP:
1647     { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i32, 1 },
1648     { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 },
1649     { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i64, 1 },
1650     { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i32, 1 },
1651     { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i32, 1 },
1652     { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i64, 1 },
1653 
1654     // Complex: to v2f32
1655     { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i8,  3 },
1656     { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i16, 3 },
1657     { ISD::SINT_TO_FP, MVT::v2f32, MVT::v2i64, 2 },
1658     { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i8,  3 },
1659     { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i16, 3 },
1660     { ISD::UINT_TO_FP, MVT::v2f32, MVT::v2i64, 2 },
1661 
1662     // Complex: to v4f32
1663     { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i8,  4 },
1664     { ISD::SINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 },
1665     { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i8,  3 },
1666     { ISD::UINT_TO_FP, MVT::v4f32, MVT::v4i16, 2 },
1667 
1668     // Complex: to v8f32
1669     { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i8,  10 },
1670     { ISD::SINT_TO_FP, MVT::v8f32, MVT::v8i16, 4 },
1671     { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i8,  10 },
1672     { ISD::UINT_TO_FP, MVT::v8f32, MVT::v8i16, 4 },
1673 
1674     // Complex: to v16f32
1675     { ISD::SINT_TO_FP, MVT::v16f32, MVT::v16i8, 21 },
1676     { ISD::UINT_TO_FP, MVT::v16f32, MVT::v16i8, 21 },
1677 
1678     // Complex: to v2f64
1679     { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i8,  4 },
1680     { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i16, 4 },
1681     { ISD::SINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 },
1682     { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i8,  4 },
1683     { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i16, 4 },
1684     { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i32, 2 },
1685 
1686 
1687     // LowerVectorFP_TO_INT
1688     { ISD::FP_TO_SINT, MVT::v2i32, MVT::v2f32, 1 },
1689     { ISD::FP_TO_SINT, MVT::v4i32, MVT::v4f32, 1 },
1690     { ISD::FP_TO_SINT, MVT::v2i64, MVT::v2f64, 1 },
1691     { ISD::FP_TO_UINT, MVT::v2i32, MVT::v2f32, 1 },
1692     { ISD::FP_TO_UINT, MVT::v4i32, MVT::v4f32, 1 },
1693     { ISD::FP_TO_UINT, MVT::v2i64, MVT::v2f64, 1 },
1694 
1695     // Complex, from v2f32: legal type is v2i32 (no cost) or v2i64 (1 ext).
1696     { ISD::FP_TO_SINT, MVT::v2i64, MVT::v2f32, 2 },
1697     { ISD::FP_TO_SINT, MVT::v2i16, MVT::v2f32, 1 },
1698     { ISD::FP_TO_SINT, MVT::v2i8,  MVT::v2f32, 1 },
1699     { ISD::FP_TO_UINT, MVT::v2i64, MVT::v2f32, 2 },
1700     { ISD::FP_TO_UINT, MVT::v2i16, MVT::v2f32, 1 },
1701     { ISD::FP_TO_UINT, MVT::v2i8,  MVT::v2f32, 1 },
1702 
1703     // Complex, from v4f32: legal type is v4i16, 1 narrowing => ~2
1704     { ISD::FP_TO_SINT, MVT::v4i16, MVT::v4f32, 2 },
1705     { ISD::FP_TO_SINT, MVT::v4i8,  MVT::v4f32, 2 },
1706     { ISD::FP_TO_UINT, MVT::v4i16, MVT::v4f32, 2 },
1707     { ISD::FP_TO_UINT, MVT::v4i8,  MVT::v4f32, 2 },
1708 
1709     // Complex, from nxv2f32.
1710     { ISD::FP_TO_SINT, MVT::nxv2i64, MVT::nxv2f32, 1 },
1711     { ISD::FP_TO_SINT, MVT::nxv2i32, MVT::nxv2f32, 1 },
1712     { ISD::FP_TO_SINT, MVT::nxv2i16, MVT::nxv2f32, 1 },
1713     { ISD::FP_TO_SINT, MVT::nxv2i8,  MVT::nxv2f32, 1 },
1714     { ISD::FP_TO_UINT, MVT::nxv2i64, MVT::nxv2f32, 1 },
1715     { ISD::FP_TO_UINT, MVT::nxv2i32, MVT::nxv2f32, 1 },
1716     { ISD::FP_TO_UINT, MVT::nxv2i16, MVT::nxv2f32, 1 },
1717     { ISD::FP_TO_UINT, MVT::nxv2i8,  MVT::nxv2f32, 1 },
1718 
1719     // Complex, from v2f64: legal type is v2i32, 1 narrowing => ~2.
1720     { ISD::FP_TO_SINT, MVT::v2i32, MVT::v2f64, 2 },
1721     { ISD::FP_TO_SINT, MVT::v2i16, MVT::v2f64, 2 },
1722     { ISD::FP_TO_SINT, MVT::v2i8,  MVT::v2f64, 2 },
1723     { ISD::FP_TO_UINT, MVT::v2i32, MVT::v2f64, 2 },
1724     { ISD::FP_TO_UINT, MVT::v2i16, MVT::v2f64, 2 },
1725     { ISD::FP_TO_UINT, MVT::v2i8,  MVT::v2f64, 2 },
1726 
1727     // Complex, from nxv2f64.
1728     { ISD::FP_TO_SINT, MVT::nxv2i64, MVT::nxv2f64, 1 },
1729     { ISD::FP_TO_SINT, MVT::nxv2i32, MVT::nxv2f64, 1 },
1730     { ISD::FP_TO_SINT, MVT::nxv2i16, MVT::nxv2f64, 1 },
1731     { ISD::FP_TO_SINT, MVT::nxv2i8,  MVT::nxv2f64, 1 },
1732     { ISD::FP_TO_UINT, MVT::nxv2i64, MVT::nxv2f64, 1 },
1733     { ISD::FP_TO_UINT, MVT::nxv2i32, MVT::nxv2f64, 1 },
1734     { ISD::FP_TO_UINT, MVT::nxv2i16, MVT::nxv2f64, 1 },
1735     { ISD::FP_TO_UINT, MVT::nxv2i8,  MVT::nxv2f64, 1 },
1736 
1737     // Complex, from nxv4f32.
1738     { ISD::FP_TO_SINT, MVT::nxv4i64, MVT::nxv4f32, 4 },
1739     { ISD::FP_TO_SINT, MVT::nxv4i32, MVT::nxv4f32, 1 },
1740     { ISD::FP_TO_SINT, MVT::nxv4i16, MVT::nxv4f32, 1 },
1741     { ISD::FP_TO_SINT, MVT::nxv4i8,  MVT::nxv4f32, 1 },
1742     { ISD::FP_TO_UINT, MVT::nxv4i64, MVT::nxv4f32, 4 },
1743     { ISD::FP_TO_UINT, MVT::nxv4i32, MVT::nxv4f32, 1 },
1744     { ISD::FP_TO_UINT, MVT::nxv4i16, MVT::nxv4f32, 1 },
1745     { ISD::FP_TO_UINT, MVT::nxv4i8,  MVT::nxv4f32, 1 },
1746 
1747     // Complex, from nxv8f64. Illegal -> illegal conversions not required.
1748     { ISD::FP_TO_SINT, MVT::nxv8i16, MVT::nxv8f64, 7 },
1749     { ISD::FP_TO_SINT, MVT::nxv8i8,  MVT::nxv8f64, 7 },
1750     { ISD::FP_TO_UINT, MVT::nxv8i16, MVT::nxv8f64, 7 },
1751     { ISD::FP_TO_UINT, MVT::nxv8i8,  MVT::nxv8f64, 7 },
1752 
1753     // Complex, from nxv4f64. Illegal -> illegal conversions not required.
1754     { ISD::FP_TO_SINT, MVT::nxv4i32, MVT::nxv4f64, 3 },
1755     { ISD::FP_TO_SINT, MVT::nxv4i16, MVT::nxv4f64, 3 },
1756     { ISD::FP_TO_SINT, MVT::nxv4i8,  MVT::nxv4f64, 3 },
1757     { ISD::FP_TO_UINT, MVT::nxv4i32, MVT::nxv4f64, 3 },
1758     { ISD::FP_TO_UINT, MVT::nxv4i16, MVT::nxv4f64, 3 },
1759     { ISD::FP_TO_UINT, MVT::nxv4i8,  MVT::nxv4f64, 3 },
1760 
1761     // Complex, from nxv8f32. Illegal -> illegal conversions not required.
1762     { ISD::FP_TO_SINT, MVT::nxv8i16, MVT::nxv8f32, 3 },
1763     { ISD::FP_TO_SINT, MVT::nxv8i8,  MVT::nxv8f32, 3 },
1764     { ISD::FP_TO_UINT, MVT::nxv8i16, MVT::nxv8f32, 3 },
1765     { ISD::FP_TO_UINT, MVT::nxv8i8,  MVT::nxv8f32, 3 },
1766 
1767     // Complex, from nxv8f16.
1768     { ISD::FP_TO_SINT, MVT::nxv8i64, MVT::nxv8f16, 10 },
1769     { ISD::FP_TO_SINT, MVT::nxv8i32, MVT::nxv8f16, 4 },
1770     { ISD::FP_TO_SINT, MVT::nxv8i16, MVT::nxv8f16, 1 },
1771     { ISD::FP_TO_SINT, MVT::nxv8i8,  MVT::nxv8f16, 1 },
1772     { ISD::FP_TO_UINT, MVT::nxv8i64, MVT::nxv8f16, 10 },
1773     { ISD::FP_TO_UINT, MVT::nxv8i32, MVT::nxv8f16, 4 },
1774     { ISD::FP_TO_UINT, MVT::nxv8i16, MVT::nxv8f16, 1 },
1775     { ISD::FP_TO_UINT, MVT::nxv8i8,  MVT::nxv8f16, 1 },
1776 
1777     // Complex, from nxv4f16.
1778     { ISD::FP_TO_SINT, MVT::nxv4i64, MVT::nxv4f16, 4 },
1779     { ISD::FP_TO_SINT, MVT::nxv4i32, MVT::nxv4f16, 1 },
1780     { ISD::FP_TO_SINT, MVT::nxv4i16, MVT::nxv4f16, 1 },
1781     { ISD::FP_TO_SINT, MVT::nxv4i8,  MVT::nxv4f16, 1 },
1782     { ISD::FP_TO_UINT, MVT::nxv4i64, MVT::nxv4f16, 4 },
1783     { ISD::FP_TO_UINT, MVT::nxv4i32, MVT::nxv4f16, 1 },
1784     { ISD::FP_TO_UINT, MVT::nxv4i16, MVT::nxv4f16, 1 },
1785     { ISD::FP_TO_UINT, MVT::nxv4i8,  MVT::nxv4f16, 1 },
1786 
1787     // Complex, from nxv2f16.
1788     { ISD::FP_TO_SINT, MVT::nxv2i64, MVT::nxv2f16, 1 },
1789     { ISD::FP_TO_SINT, MVT::nxv2i32, MVT::nxv2f16, 1 },
1790     { ISD::FP_TO_SINT, MVT::nxv2i16, MVT::nxv2f16, 1 },
1791     { ISD::FP_TO_SINT, MVT::nxv2i8,  MVT::nxv2f16, 1 },
1792     { ISD::FP_TO_UINT, MVT::nxv2i64, MVT::nxv2f16, 1 },
1793     { ISD::FP_TO_UINT, MVT::nxv2i32, MVT::nxv2f16, 1 },
1794     { ISD::FP_TO_UINT, MVT::nxv2i16, MVT::nxv2f16, 1 },
1795     { ISD::FP_TO_UINT, MVT::nxv2i8,  MVT::nxv2f16, 1 },
1796 
1797     // Truncate from nxvmf32 to nxvmf16.
1798     { ISD::FP_ROUND, MVT::nxv2f16, MVT::nxv2f32, 1 },
1799     { ISD::FP_ROUND, MVT::nxv4f16, MVT::nxv4f32, 1 },
1800     { ISD::FP_ROUND, MVT::nxv8f16, MVT::nxv8f32, 3 },
1801 
1802     // Truncate from nxvmf64 to nxvmf16.
1803     { ISD::FP_ROUND, MVT::nxv2f16, MVT::nxv2f64, 1 },
1804     { ISD::FP_ROUND, MVT::nxv4f16, MVT::nxv4f64, 3 },
1805     { ISD::FP_ROUND, MVT::nxv8f16, MVT::nxv8f64, 7 },
1806 
1807     // Truncate from nxvmf64 to nxvmf32.
1808     { ISD::FP_ROUND, MVT::nxv2f32, MVT::nxv2f64, 1 },
1809     { ISD::FP_ROUND, MVT::nxv4f32, MVT::nxv4f64, 3 },
1810     { ISD::FP_ROUND, MVT::nxv8f32, MVT::nxv8f64, 6 },
1811 
1812     // Extend from nxvmf16 to nxvmf32.
1813     { ISD::FP_EXTEND, MVT::nxv2f32, MVT::nxv2f16, 1},
1814     { ISD::FP_EXTEND, MVT::nxv4f32, MVT::nxv4f16, 1},
1815     { ISD::FP_EXTEND, MVT::nxv8f32, MVT::nxv8f16, 2},
1816 
1817     // Extend from nxvmf16 to nxvmf64.
1818     { ISD::FP_EXTEND, MVT::nxv2f64, MVT::nxv2f16, 1},
1819     { ISD::FP_EXTEND, MVT::nxv4f64, MVT::nxv4f16, 2},
1820     { ISD::FP_EXTEND, MVT::nxv8f64, MVT::nxv8f16, 4},
1821 
1822     // Extend from nxvmf32 to nxvmf64.
1823     { ISD::FP_EXTEND, MVT::nxv2f64, MVT::nxv2f32, 1},
1824     { ISD::FP_EXTEND, MVT::nxv4f64, MVT::nxv4f32, 2},
1825     { ISD::FP_EXTEND, MVT::nxv8f64, MVT::nxv8f32, 6},
1826 
1827     // Bitcasts from float to integer
1828     { ISD::BITCAST, MVT::nxv2f16, MVT::nxv2i16, 0 },
1829     { ISD::BITCAST, MVT::nxv4f16, MVT::nxv4i16, 0 },
1830     { ISD::BITCAST, MVT::nxv2f32, MVT::nxv2i32, 0 },
1831 
1832     // Bitcasts from integer to float
1833     { ISD::BITCAST, MVT::nxv2i16, MVT::nxv2f16, 0 },
1834     { ISD::BITCAST, MVT::nxv4i16, MVT::nxv4f16, 0 },
1835     { ISD::BITCAST, MVT::nxv2i32, MVT::nxv2f32, 0 },
1836   };
1837 
1838   if (const auto *Entry = ConvertCostTableLookup(ConversionTbl, ISD,
1839                                                  DstTy.getSimpleVT(),
1840                                                  SrcTy.getSimpleVT()))
1841     return AdjustCost(Entry->Cost);
1842 
1843   static const TypeConversionCostTblEntry FP16Tbl[] = {
1844       {ISD::FP_TO_SINT, MVT::v4i8, MVT::v4f16, 1}, // fcvtzs
1845       {ISD::FP_TO_UINT, MVT::v4i8, MVT::v4f16, 1},
1846       {ISD::FP_TO_SINT, MVT::v4i16, MVT::v4f16, 1}, // fcvtzs
1847       {ISD::FP_TO_UINT, MVT::v4i16, MVT::v4f16, 1},
1848       {ISD::FP_TO_SINT, MVT::v4i32, MVT::v4f16, 2}, // fcvtl+fcvtzs
1849       {ISD::FP_TO_UINT, MVT::v4i32, MVT::v4f16, 2},
1850       {ISD::FP_TO_SINT, MVT::v8i8, MVT::v8f16, 2}, // fcvtzs+xtn
1851       {ISD::FP_TO_UINT, MVT::v8i8, MVT::v8f16, 2},
1852       {ISD::FP_TO_SINT, MVT::v8i16, MVT::v8f16, 1}, // fcvtzs
1853       {ISD::FP_TO_UINT, MVT::v8i16, MVT::v8f16, 1},
1854       {ISD::FP_TO_SINT, MVT::v8i32, MVT::v8f16, 4}, // 2*fcvtl+2*fcvtzs
1855       {ISD::FP_TO_UINT, MVT::v8i32, MVT::v8f16, 4},
1856       {ISD::FP_TO_SINT, MVT::v16i8, MVT::v16f16, 3}, // 2*fcvtzs+xtn
1857       {ISD::FP_TO_UINT, MVT::v16i8, MVT::v16f16, 3},
1858       {ISD::FP_TO_SINT, MVT::v16i16, MVT::v16f16, 2}, // 2*fcvtzs
1859       {ISD::FP_TO_UINT, MVT::v16i16, MVT::v16f16, 2},
1860       {ISD::FP_TO_SINT, MVT::v16i32, MVT::v16f16, 8}, // 4*fcvtl+4*fcvtzs
1861       {ISD::FP_TO_UINT, MVT::v16i32, MVT::v16f16, 8},
1862       {ISD::UINT_TO_FP, MVT::v8f16, MVT::v8i8, 2},   // ushll + ucvtf
1863       {ISD::SINT_TO_FP, MVT::v8f16, MVT::v8i8, 2},   // sshll + scvtf
1864       {ISD::UINT_TO_FP, MVT::v16f16, MVT::v16i8, 4}, // 2 * ushl(2) + 2 * ucvtf
1865       {ISD::SINT_TO_FP, MVT::v16f16, MVT::v16i8, 4}, // 2 * sshl(2) + 2 * scvtf
1866   };
1867 
1868   if (ST->hasFullFP16())
1869     if (const auto *Entry = ConvertCostTableLookup(
1870             FP16Tbl, ISD, DstTy.getSimpleVT(), SrcTy.getSimpleVT()))
1871       return AdjustCost(Entry->Cost);
1872 
1873   return AdjustCost(
1874       BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I));
1875 }
1876 
1877 InstructionCost AArch64TTIImpl::getExtractWithExtendCost(unsigned Opcode,
1878                                                          Type *Dst,
1879                                                          VectorType *VecTy,
1880                                                          unsigned Index) {
1881 
1882   // Make sure we were given a valid extend opcode.
1883   assert((Opcode == Instruction::SExt || Opcode == Instruction::ZExt) &&
1884          "Invalid opcode");
1885 
1886   // We are extending an element we extract from a vector, so the source type
1887   // of the extend is the element type of the vector.
1888   auto *Src = VecTy->getElementType();
1889 
1890   // Sign- and zero-extends are for integer types only.
1891   assert(isa<IntegerType>(Dst) && isa<IntegerType>(Src) && "Invalid type");
1892 
1893   // Get the cost for the extract. We compute the cost (if any) for the extend
1894   // below.
1895   InstructionCost Cost =
1896       getVectorInstrCost(Instruction::ExtractElement, VecTy, Index);
1897 
1898   // Legalize the types.
1899   auto VecLT = TLI->getTypeLegalizationCost(DL, VecTy);
1900   auto DstVT = TLI->getValueType(DL, Dst);
1901   auto SrcVT = TLI->getValueType(DL, Src);
1902   TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
1903 
1904   // If the resulting type is still a vector and the destination type is legal,
1905   // we may get the extension for free. If not, get the default cost for the
1906   // extend.
1907   if (!VecLT.second.isVector() || !TLI->isTypeLegal(DstVT))
1908     return Cost + getCastInstrCost(Opcode, Dst, Src, TTI::CastContextHint::None,
1909                                    CostKind);
1910 
1911   // The destination type should be larger than the element type. If not, get
1912   // the default cost for the extend.
1913   if (DstVT.getFixedSizeInBits() < SrcVT.getFixedSizeInBits())
1914     return Cost + getCastInstrCost(Opcode, Dst, Src, TTI::CastContextHint::None,
1915                                    CostKind);
1916 
1917   switch (Opcode) {
1918   default:
1919     llvm_unreachable("Opcode should be either SExt or ZExt");
1920 
1921   // For sign-extends, we only need a smov, which performs the extension
1922   // automatically.
1923   case Instruction::SExt:
1924     return Cost;
1925 
1926   // For zero-extends, the extend is performed automatically by a umov unless
1927   // the destination type is i64 and the element type is i8 or i16.
1928   case Instruction::ZExt:
1929     if (DstVT.getSizeInBits() != 64u || SrcVT.getSizeInBits() == 32u)
1930       return Cost;
1931   }
1932 
1933   // If we are unable to perform the extend for free, get the default cost.
1934   return Cost + getCastInstrCost(Opcode, Dst, Src, TTI::CastContextHint::None,
1935                                  CostKind);
1936 }
1937 
1938 InstructionCost AArch64TTIImpl::getCFInstrCost(unsigned Opcode,
1939                                                TTI::TargetCostKind CostKind,
1940                                                const Instruction *I) {
1941   if (CostKind != TTI::TCK_RecipThroughput)
1942     return Opcode == Instruction::PHI ? 0 : 1;
1943   assert(CostKind == TTI::TCK_RecipThroughput && "unexpected CostKind");
1944   // Branches are assumed to be predicted.
1945   return 0;
1946 }
1947 
1948 InstructionCost AArch64TTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
1949                                                    unsigned Index) {
1950   assert(Val->isVectorTy() && "This must be a vector type");
1951 
1952   if (Index != -1U) {
1953     // Legalize the type.
1954     std::pair<InstructionCost, MVT> LT = TLI->getTypeLegalizationCost(DL, Val);
1955 
1956     // This type is legalized to a scalar type.
1957     if (!LT.second.isVector())
1958       return 0;
1959 
1960     // The type may be split. For fixed-width vectors we can normalize the
1961     // index to the new type.
1962     if (LT.second.isFixedLengthVector()) {
1963       unsigned Width = LT.second.getVectorNumElements();
1964       Index = Index % Width;
1965     }
1966 
1967     // The element at index zero is already inside the vector.
1968     if (Index == 0)
1969       return 0;
1970   }
1971 
1972   // All other insert/extracts cost this much.
1973   return ST->getVectorInsertExtractBaseCost();
1974 }
1975 
1976 InstructionCost AArch64TTIImpl::getArithmeticInstrCost(
1977     unsigned Opcode, Type *Ty, TTI::TargetCostKind CostKind,
1978     TTI::OperandValueKind Opd1Info, TTI::OperandValueKind Opd2Info,
1979     TTI::OperandValueProperties Opd1PropInfo,
1980     TTI::OperandValueProperties Opd2PropInfo, ArrayRef<const Value *> Args,
1981     const Instruction *CxtI) {
1982   // TODO: Handle more cost kinds.
1983   if (CostKind != TTI::TCK_RecipThroughput)
1984     return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Opd1Info,
1985                                          Opd2Info, Opd1PropInfo,
1986                                          Opd2PropInfo, Args, CxtI);
1987 
1988   // Legalize the type.
1989   std::pair<InstructionCost, MVT> LT = TLI->getTypeLegalizationCost(DL, Ty);
1990   int ISD = TLI->InstructionOpcodeToISD(Opcode);
1991 
1992   switch (ISD) {
1993   default:
1994     return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Opd1Info,
1995                                          Opd2Info, Opd1PropInfo, Opd2PropInfo);
1996   case ISD::SDIV:
1997     if (Opd2Info == TargetTransformInfo::OK_UniformConstantValue &&
1998         Opd2PropInfo == TargetTransformInfo::OP_PowerOf2) {
1999       // On AArch64, scalar signed division by constants power-of-two are
2000       // normally expanded to the sequence ADD + CMP + SELECT + SRA.
2001       // The OperandValue properties many not be same as that of previous
2002       // operation; conservatively assume OP_None.
2003       InstructionCost Cost = getArithmeticInstrCost(
2004           Instruction::Add, Ty, CostKind, Opd1Info, Opd2Info,
2005           TargetTransformInfo::OP_None, TargetTransformInfo::OP_None);
2006       Cost += getArithmeticInstrCost(Instruction::Sub, Ty, CostKind, Opd1Info,
2007                                      Opd2Info, TargetTransformInfo::OP_None,
2008                                      TargetTransformInfo::OP_None);
2009       Cost += getArithmeticInstrCost(
2010           Instruction::Select, Ty, CostKind, Opd1Info, Opd2Info,
2011           TargetTransformInfo::OP_None, TargetTransformInfo::OP_None);
2012       Cost += getArithmeticInstrCost(Instruction::AShr, Ty, CostKind, Opd1Info,
2013                                      Opd2Info, TargetTransformInfo::OP_None,
2014                                      TargetTransformInfo::OP_None);
2015       return Cost;
2016     }
2017     LLVM_FALLTHROUGH;
2018   case ISD::UDIV: {
2019     if (Opd2Info == TargetTransformInfo::OK_UniformConstantValue) {
2020       auto VT = TLI->getValueType(DL, Ty);
2021       if (TLI->isOperationLegalOrCustom(ISD::MULHU, VT)) {
2022         // Vector signed division by constant are expanded to the
2023         // sequence MULHS + ADD/SUB + SRA + SRL + ADD, and unsigned division
2024         // to MULHS + SUB + SRL + ADD + SRL.
2025         InstructionCost MulCost = getArithmeticInstrCost(
2026             Instruction::Mul, Ty, CostKind, Opd1Info, Opd2Info,
2027             TargetTransformInfo::OP_None, TargetTransformInfo::OP_None);
2028         InstructionCost AddCost = getArithmeticInstrCost(
2029             Instruction::Add, Ty, CostKind, Opd1Info, Opd2Info,
2030             TargetTransformInfo::OP_None, TargetTransformInfo::OP_None);
2031         InstructionCost ShrCost = getArithmeticInstrCost(
2032             Instruction::AShr, Ty, CostKind, Opd1Info, Opd2Info,
2033             TargetTransformInfo::OP_None, TargetTransformInfo::OP_None);
2034         return MulCost * 2 + AddCost * 2 + ShrCost * 2 + 1;
2035       }
2036     }
2037 
2038     InstructionCost Cost = BaseT::getArithmeticInstrCost(
2039         Opcode, Ty, CostKind, Opd1Info, Opd2Info, Opd1PropInfo, Opd2PropInfo);
2040     if (Ty->isVectorTy()) {
2041       // On AArch64, vector divisions are not supported natively and are
2042       // expanded into scalar divisions of each pair of elements.
2043       Cost += getArithmeticInstrCost(Instruction::ExtractElement, Ty, CostKind,
2044                                      Opd1Info, Opd2Info, Opd1PropInfo,
2045                                      Opd2PropInfo);
2046       Cost += getArithmeticInstrCost(Instruction::InsertElement, Ty, CostKind,
2047                                      Opd1Info, Opd2Info, Opd1PropInfo,
2048                                      Opd2PropInfo);
2049       // TODO: if one of the arguments is scalar, then it's not necessary to
2050       // double the cost of handling the vector elements.
2051       Cost += Cost;
2052     }
2053     return Cost;
2054   }
2055   case ISD::MUL:
2056     // Since we do not have a MUL.2d instruction, a mul <2 x i64> is expensive
2057     // as elements are extracted from the vectors and the muls scalarized.
2058     // As getScalarizationOverhead is a bit too pessimistic, we estimate the
2059     // cost for a i64 vector directly here, which is:
2060     // - four 2-cost i64 extracts,
2061     // - two 2-cost i64 inserts, and
2062     // - two 1-cost muls.
2063     // So, for a v2i64 with LT.First = 1 the cost is 14, and for a v4i64 with
2064     // LT.first = 2 the cost is 28. If both operands are extensions it will not
2065     // need to scalarize so the cost can be cheaper (smull or umull).
2066     if (LT.second != MVT::v2i64 || isWideningInstruction(Ty, Opcode, Args))
2067       return LT.first;
2068     return LT.first * 14;
2069   case ISD::ADD:
2070   case ISD::XOR:
2071   case ISD::OR:
2072   case ISD::AND:
2073   case ISD::SRL:
2074   case ISD::SRA:
2075   case ISD::SHL:
2076     // These nodes are marked as 'custom' for combining purposes only.
2077     // We know that they are legal. See LowerAdd in ISelLowering.
2078     return LT.first;
2079 
2080   case ISD::FADD:
2081   case ISD::FSUB:
2082   case ISD::FMUL:
2083   case ISD::FDIV:
2084   case ISD::FNEG:
2085     // These nodes are marked as 'custom' just to lower them to SVE.
2086     // We know said lowering will incur no additional cost.
2087     if (!Ty->getScalarType()->isFP128Ty())
2088       return 2 * LT.first;
2089 
2090     return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Opd1Info,
2091                                          Opd2Info, Opd1PropInfo, Opd2PropInfo);
2092   }
2093 }
2094 
2095 InstructionCost AArch64TTIImpl::getAddressComputationCost(Type *Ty,
2096                                                           ScalarEvolution *SE,
2097                                                           const SCEV *Ptr) {
2098   // Address computations in vectorized code with non-consecutive addresses will
2099   // likely result in more instructions compared to scalar code where the
2100   // computation can more often be merged into the index mode. The resulting
2101   // extra micro-ops can significantly decrease throughput.
2102   unsigned NumVectorInstToHideOverhead = 10;
2103   int MaxMergeDistance = 64;
2104 
2105   if (Ty->isVectorTy() && SE &&
2106       !BaseT::isConstantStridedAccessLessThan(SE, Ptr, MaxMergeDistance + 1))
2107     return NumVectorInstToHideOverhead;
2108 
2109   // In many cases the address computation is not merged into the instruction
2110   // addressing mode.
2111   return 1;
2112 }
2113 
2114 InstructionCost AArch64TTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
2115                                                    Type *CondTy,
2116                                                    CmpInst::Predicate VecPred,
2117                                                    TTI::TargetCostKind CostKind,
2118                                                    const Instruction *I) {
2119   // TODO: Handle other cost kinds.
2120   if (CostKind != TTI::TCK_RecipThroughput)
2121     return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, CostKind,
2122                                      I);
2123 
2124   int ISD = TLI->InstructionOpcodeToISD(Opcode);
2125   // We don't lower some vector selects well that are wider than the register
2126   // width.
2127   if (isa<FixedVectorType>(ValTy) && ISD == ISD::SELECT) {
2128     // We would need this many instructions to hide the scalarization happening.
2129     const int AmortizationCost = 20;
2130 
2131     // If VecPred is not set, check if we can get a predicate from the context
2132     // instruction, if its type matches the requested ValTy.
2133     if (VecPred == CmpInst::BAD_ICMP_PREDICATE && I && I->getType() == ValTy) {
2134       CmpInst::Predicate CurrentPred;
2135       if (match(I, m_Select(m_Cmp(CurrentPred, m_Value(), m_Value()), m_Value(),
2136                             m_Value())))
2137         VecPred = CurrentPred;
2138     }
2139     // Check if we have a compare/select chain that can be lowered using
2140     // a (F)CMxx & BFI pair.
2141     if (CmpInst::isIntPredicate(VecPred) || VecPred == CmpInst::FCMP_OLE ||
2142         VecPred == CmpInst::FCMP_OLT || VecPred == CmpInst::FCMP_OGT ||
2143         VecPred == CmpInst::FCMP_OGE || VecPred == CmpInst::FCMP_OEQ ||
2144         VecPred == CmpInst::FCMP_UNE) {
2145       static const auto ValidMinMaxTys = {
2146           MVT::v8i8,  MVT::v16i8, MVT::v4i16, MVT::v8i16, MVT::v2i32,
2147           MVT::v4i32, MVT::v2i64, MVT::v2f32, MVT::v4f32, MVT::v2f64};
2148       static const auto ValidFP16MinMaxTys = {MVT::v4f16, MVT::v8f16};
2149 
2150       auto LT = TLI->getTypeLegalizationCost(DL, ValTy);
2151       if (any_of(ValidMinMaxTys, [&LT](MVT M) { return M == LT.second; }) ||
2152           (ST->hasFullFP16() &&
2153            any_of(ValidFP16MinMaxTys, [&LT](MVT M) { return M == LT.second; })))
2154         return LT.first;
2155     }
2156 
2157     static const TypeConversionCostTblEntry
2158     VectorSelectTbl[] = {
2159       { ISD::SELECT, MVT::v16i1, MVT::v16i16, 16 },
2160       { ISD::SELECT, MVT::v8i1, MVT::v8i32, 8 },
2161       { ISD::SELECT, MVT::v16i1, MVT::v16i32, 16 },
2162       { ISD::SELECT, MVT::v4i1, MVT::v4i64, 4 * AmortizationCost },
2163       { ISD::SELECT, MVT::v8i1, MVT::v8i64, 8 * AmortizationCost },
2164       { ISD::SELECT, MVT::v16i1, MVT::v16i64, 16 * AmortizationCost }
2165     };
2166 
2167     EVT SelCondTy = TLI->getValueType(DL, CondTy);
2168     EVT SelValTy = TLI->getValueType(DL, ValTy);
2169     if (SelCondTy.isSimple() && SelValTy.isSimple()) {
2170       if (const auto *Entry = ConvertCostTableLookup(VectorSelectTbl, ISD,
2171                                                      SelCondTy.getSimpleVT(),
2172                                                      SelValTy.getSimpleVT()))
2173         return Entry->Cost;
2174     }
2175   }
2176   // The base case handles scalable vectors fine for now, since it treats the
2177   // cost as 1 * legalization cost.
2178   return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, CostKind, I);
2179 }
2180 
2181 AArch64TTIImpl::TTI::MemCmpExpansionOptions
2182 AArch64TTIImpl::enableMemCmpExpansion(bool OptSize, bool IsZeroCmp) const {
2183   TTI::MemCmpExpansionOptions Options;
2184   if (ST->requiresStrictAlign()) {
2185     // TODO: Add cost modeling for strict align. Misaligned loads expand to
2186     // a bunch of instructions when strict align is enabled.
2187     return Options;
2188   }
2189   Options.AllowOverlappingLoads = true;
2190   Options.MaxNumLoads = TLI->getMaxExpandSizeMemcmp(OptSize);
2191   Options.NumLoadsPerBlock = Options.MaxNumLoads;
2192   // TODO: Though vector loads usually perform well on AArch64, in some targets
2193   // they may wake up the FP unit, which raises the power consumption.  Perhaps
2194   // they could be used with no holds barred (-O3).
2195   Options.LoadSizes = {8, 4, 2, 1};
2196   return Options;
2197 }
2198 
2199 bool AArch64TTIImpl::prefersVectorizedAddressing() const {
2200   return ST->hasSVE();
2201 }
2202 
2203 InstructionCost
2204 AArch64TTIImpl::getMaskedMemoryOpCost(unsigned Opcode, Type *Src,
2205                                       Align Alignment, unsigned AddressSpace,
2206                                       TTI::TargetCostKind CostKind) {
2207   if (useNeonVector(Src))
2208     return BaseT::getMaskedMemoryOpCost(Opcode, Src, Alignment, AddressSpace,
2209                                         CostKind);
2210   auto LT = TLI->getTypeLegalizationCost(DL, Src);
2211   if (!LT.first.isValid())
2212     return InstructionCost::getInvalid();
2213 
2214   // The code-generator is currently not able to handle scalable vectors
2215   // of <vscale x 1 x eltty> yet, so return an invalid cost to avoid selecting
2216   // it. This change will be removed when code-generation for these types is
2217   // sufficiently reliable.
2218   if (cast<VectorType>(Src)->getElementCount() == ElementCount::getScalable(1))
2219     return InstructionCost::getInvalid();
2220 
2221   return LT.first * 2;
2222 }
2223 
2224 static unsigned getSVEGatherScatterOverhead(unsigned Opcode) {
2225   return Opcode == Instruction::Load ? SVEGatherOverhead : SVEScatterOverhead;
2226 }
2227 
2228 InstructionCost AArch64TTIImpl::getGatherScatterOpCost(
2229     unsigned Opcode, Type *DataTy, const Value *Ptr, bool VariableMask,
2230     Align Alignment, TTI::TargetCostKind CostKind, const Instruction *I) {
2231   if (useNeonVector(DataTy))
2232     return BaseT::getGatherScatterOpCost(Opcode, DataTy, Ptr, VariableMask,
2233                                          Alignment, CostKind, I);
2234   auto *VT = cast<VectorType>(DataTy);
2235   auto LT = TLI->getTypeLegalizationCost(DL, DataTy);
2236   if (!LT.first.isValid())
2237     return InstructionCost::getInvalid();
2238 
2239   // The code-generator is currently not able to handle scalable vectors
2240   // of <vscale x 1 x eltty> yet, so return an invalid cost to avoid selecting
2241   // it. This change will be removed when code-generation for these types is
2242   // sufficiently reliable.
2243   if (cast<VectorType>(DataTy)->getElementCount() ==
2244       ElementCount::getScalable(1))
2245     return InstructionCost::getInvalid();
2246 
2247   ElementCount LegalVF = LT.second.getVectorElementCount();
2248   InstructionCost MemOpCost =
2249       getMemoryOpCost(Opcode, VT->getElementType(), Alignment, 0, CostKind, I);
2250   // Add on an overhead cost for using gathers/scatters.
2251   // TODO: At the moment this is applied unilaterally for all CPUs, but at some
2252   // point we may want a per-CPU overhead.
2253   MemOpCost *= getSVEGatherScatterOverhead(Opcode);
2254   return LT.first * MemOpCost * getMaxNumElements(LegalVF);
2255 }
2256 
2257 bool AArch64TTIImpl::useNeonVector(const Type *Ty) const {
2258   return isa<FixedVectorType>(Ty) && !ST->useSVEForFixedLengthVectors();
2259 }
2260 
2261 InstructionCost AArch64TTIImpl::getMemoryOpCost(unsigned Opcode, Type *Ty,
2262                                                 MaybeAlign Alignment,
2263                                                 unsigned AddressSpace,
2264                                                 TTI::TargetCostKind CostKind,
2265                                                 const Instruction *I) {
2266   EVT VT = TLI->getValueType(DL, Ty, true);
2267   // Type legalization can't handle structs
2268   if (VT == MVT::Other)
2269     return BaseT::getMemoryOpCost(Opcode, Ty, Alignment, AddressSpace,
2270                                   CostKind);
2271 
2272   auto LT = TLI->getTypeLegalizationCost(DL, Ty);
2273   if (!LT.first.isValid())
2274     return InstructionCost::getInvalid();
2275 
2276   // The code-generator is currently not able to handle scalable vectors
2277   // of <vscale x 1 x eltty> yet, so return an invalid cost to avoid selecting
2278   // it. This change will be removed when code-generation for these types is
2279   // sufficiently reliable.
2280   if (auto *VTy = dyn_cast<ScalableVectorType>(Ty))
2281     if (VTy->getElementCount() == ElementCount::getScalable(1))
2282       return InstructionCost::getInvalid();
2283 
2284   // TODO: consider latency as well for TCK_SizeAndLatency.
2285   if (CostKind == TTI::TCK_CodeSize || CostKind == TTI::TCK_SizeAndLatency)
2286     return LT.first;
2287 
2288   if (CostKind != TTI::TCK_RecipThroughput)
2289     return 1;
2290 
2291   if (ST->isMisaligned128StoreSlow() && Opcode == Instruction::Store &&
2292       LT.second.is128BitVector() && (!Alignment || *Alignment < Align(16))) {
2293     // Unaligned stores are extremely inefficient. We don't split all
2294     // unaligned 128-bit stores because the negative impact that has shown in
2295     // practice on inlined block copy code.
2296     // We make such stores expensive so that we will only vectorize if there
2297     // are 6 other instructions getting vectorized.
2298     const int AmortizationCost = 6;
2299 
2300     return LT.first * 2 * AmortizationCost;
2301   }
2302 
2303   // Check truncating stores and extending loads.
2304   if (useNeonVector(Ty) &&
2305       Ty->getScalarSizeInBits() != LT.second.getScalarSizeInBits()) {
2306     // v4i8 types are lowered to scalar a load/store and sshll/xtn.
2307     if (VT == MVT::v4i8)
2308       return 2;
2309     // Otherwise we need to scalarize.
2310     return cast<FixedVectorType>(Ty)->getNumElements() * 2;
2311   }
2312 
2313   return LT.first;
2314 }
2315 
2316 InstructionCost AArch64TTIImpl::getInterleavedMemoryOpCost(
2317     unsigned Opcode, Type *VecTy, unsigned Factor, ArrayRef<unsigned> Indices,
2318     Align Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind,
2319     bool UseMaskForCond, bool UseMaskForGaps) {
2320   assert(Factor >= 2 && "Invalid interleave factor");
2321   auto *VecVTy = cast<FixedVectorType>(VecTy);
2322 
2323   if (!UseMaskForCond && !UseMaskForGaps &&
2324       Factor <= TLI->getMaxSupportedInterleaveFactor()) {
2325     unsigned NumElts = VecVTy->getNumElements();
2326     auto *SubVecTy =
2327         FixedVectorType::get(VecTy->getScalarType(), NumElts / Factor);
2328 
2329     // ldN/stN only support legal vector types of size 64 or 128 in bits.
2330     // Accesses having vector types that are a multiple of 128 bits can be
2331     // matched to more than one ldN/stN instruction.
2332     bool UseScalable;
2333     if (NumElts % Factor == 0 &&
2334         TLI->isLegalInterleavedAccessType(SubVecTy, DL, UseScalable))
2335       return Factor * TLI->getNumInterleavedAccesses(SubVecTy, DL, UseScalable);
2336   }
2337 
2338   return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices,
2339                                            Alignment, AddressSpace, CostKind,
2340                                            UseMaskForCond, UseMaskForGaps);
2341 }
2342 
2343 InstructionCost
2344 AArch64TTIImpl::getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) {
2345   InstructionCost Cost = 0;
2346   TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
2347   for (auto *I : Tys) {
2348     if (!I->isVectorTy())
2349       continue;
2350     if (I->getScalarSizeInBits() * cast<FixedVectorType>(I)->getNumElements() ==
2351         128)
2352       Cost += getMemoryOpCost(Instruction::Store, I, Align(128), 0, CostKind) +
2353               getMemoryOpCost(Instruction::Load, I, Align(128), 0, CostKind);
2354   }
2355   return Cost;
2356 }
2357 
2358 unsigned AArch64TTIImpl::getMaxInterleaveFactor(unsigned VF) {
2359   return ST->getMaxInterleaveFactor();
2360 }
2361 
2362 // For Falkor, we want to avoid having too many strided loads in a loop since
2363 // that can exhaust the HW prefetcher resources.  We adjust the unroller
2364 // MaxCount preference below to attempt to ensure unrolling doesn't create too
2365 // many strided loads.
2366 static void
2367 getFalkorUnrollingPreferences(Loop *L, ScalarEvolution &SE,
2368                               TargetTransformInfo::UnrollingPreferences &UP) {
2369   enum { MaxStridedLoads = 7 };
2370   auto countStridedLoads = [](Loop *L, ScalarEvolution &SE) {
2371     int StridedLoads = 0;
2372     // FIXME? We could make this more precise by looking at the CFG and
2373     // e.g. not counting loads in each side of an if-then-else diamond.
2374     for (const auto BB : L->blocks()) {
2375       for (auto &I : *BB) {
2376         LoadInst *LMemI = dyn_cast<LoadInst>(&I);
2377         if (!LMemI)
2378           continue;
2379 
2380         Value *PtrValue = LMemI->getPointerOperand();
2381         if (L->isLoopInvariant(PtrValue))
2382           continue;
2383 
2384         const SCEV *LSCEV = SE.getSCEV(PtrValue);
2385         const SCEVAddRecExpr *LSCEVAddRec = dyn_cast<SCEVAddRecExpr>(LSCEV);
2386         if (!LSCEVAddRec || !LSCEVAddRec->isAffine())
2387           continue;
2388 
2389         // FIXME? We could take pairing of unrolled load copies into account
2390         // by looking at the AddRec, but we would probably have to limit this
2391         // to loops with no stores or other memory optimization barriers.
2392         ++StridedLoads;
2393         // We've seen enough strided loads that seeing more won't make a
2394         // difference.
2395         if (StridedLoads > MaxStridedLoads / 2)
2396           return StridedLoads;
2397       }
2398     }
2399     return StridedLoads;
2400   };
2401 
2402   int StridedLoads = countStridedLoads(L, SE);
2403   LLVM_DEBUG(dbgs() << "falkor-hwpf: detected " << StridedLoads
2404                     << " strided loads\n");
2405   // Pick the largest power of 2 unroll count that won't result in too many
2406   // strided loads.
2407   if (StridedLoads) {
2408     UP.MaxCount = 1 << Log2_32(MaxStridedLoads / StridedLoads);
2409     LLVM_DEBUG(dbgs() << "falkor-hwpf: setting unroll MaxCount to "
2410                       << UP.MaxCount << '\n');
2411   }
2412 }
2413 
2414 void AArch64TTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
2415                                              TTI::UnrollingPreferences &UP,
2416                                              OptimizationRemarkEmitter *ORE) {
2417   // Enable partial unrolling and runtime unrolling.
2418   BaseT::getUnrollingPreferences(L, SE, UP, ORE);
2419 
2420   UP.UpperBound = true;
2421 
2422   // For inner loop, it is more likely to be a hot one, and the runtime check
2423   // can be promoted out from LICM pass, so the overhead is less, let's try
2424   // a larger threshold to unroll more loops.
2425   if (L->getLoopDepth() > 1)
2426     UP.PartialThreshold *= 2;
2427 
2428   // Disable partial & runtime unrolling on -Os.
2429   UP.PartialOptSizeThreshold = 0;
2430 
2431   if (ST->getProcFamily() == AArch64Subtarget::Falkor &&
2432       EnableFalkorHWPFUnrollFix)
2433     getFalkorUnrollingPreferences(L, SE, UP);
2434 
2435   // Scan the loop: don't unroll loops with calls as this could prevent
2436   // inlining. Don't unroll vector loops either, as they don't benefit much from
2437   // unrolling.
2438   for (auto *BB : L->getBlocks()) {
2439     for (auto &I : *BB) {
2440       // Don't unroll vectorised loop.
2441       if (I.getType()->isVectorTy())
2442         return;
2443 
2444       if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
2445         if (const Function *F = cast<CallBase>(I).getCalledFunction()) {
2446           if (!isLoweredToCall(F))
2447             continue;
2448         }
2449         return;
2450       }
2451     }
2452   }
2453 
2454   // Enable runtime unrolling for in-order models
2455   // If mcpu is omitted, getProcFamily() returns AArch64Subtarget::Others, so by
2456   // checking for that case, we can ensure that the default behaviour is
2457   // unchanged
2458   if (ST->getProcFamily() != AArch64Subtarget::Others &&
2459       !ST->getSchedModel().isOutOfOrder()) {
2460     UP.Runtime = true;
2461     UP.Partial = true;
2462     UP.UnrollRemainder = true;
2463     UP.DefaultUnrollRuntimeCount = 4;
2464 
2465     UP.UnrollAndJam = true;
2466     UP.UnrollAndJamInnerLoopThreshold = 60;
2467   }
2468 }
2469 
2470 void AArch64TTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
2471                                            TTI::PeelingPreferences &PP) {
2472   BaseT::getPeelingPreferences(L, SE, PP);
2473 }
2474 
2475 Value *AArch64TTIImpl::getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
2476                                                          Type *ExpectedType) {
2477   switch (Inst->getIntrinsicID()) {
2478   default:
2479     return nullptr;
2480   case Intrinsic::aarch64_neon_st2:
2481   case Intrinsic::aarch64_neon_st3:
2482   case Intrinsic::aarch64_neon_st4: {
2483     // Create a struct type
2484     StructType *ST = dyn_cast<StructType>(ExpectedType);
2485     if (!ST)
2486       return nullptr;
2487     unsigned NumElts = Inst->arg_size() - 1;
2488     if (ST->getNumElements() != NumElts)
2489       return nullptr;
2490     for (unsigned i = 0, e = NumElts; i != e; ++i) {
2491       if (Inst->getArgOperand(i)->getType() != ST->getElementType(i))
2492         return nullptr;
2493     }
2494     Value *Res = UndefValue::get(ExpectedType);
2495     IRBuilder<> Builder(Inst);
2496     for (unsigned i = 0, e = NumElts; i != e; ++i) {
2497       Value *L = Inst->getArgOperand(i);
2498       Res = Builder.CreateInsertValue(Res, L, i);
2499     }
2500     return Res;
2501   }
2502   case Intrinsic::aarch64_neon_ld2:
2503   case Intrinsic::aarch64_neon_ld3:
2504   case Intrinsic::aarch64_neon_ld4:
2505     if (Inst->getType() == ExpectedType)
2506       return Inst;
2507     return nullptr;
2508   }
2509 }
2510 
2511 bool AArch64TTIImpl::getTgtMemIntrinsic(IntrinsicInst *Inst,
2512                                         MemIntrinsicInfo &Info) {
2513   switch (Inst->getIntrinsicID()) {
2514   default:
2515     break;
2516   case Intrinsic::aarch64_neon_ld2:
2517   case Intrinsic::aarch64_neon_ld3:
2518   case Intrinsic::aarch64_neon_ld4:
2519     Info.ReadMem = true;
2520     Info.WriteMem = false;
2521     Info.PtrVal = Inst->getArgOperand(0);
2522     break;
2523   case Intrinsic::aarch64_neon_st2:
2524   case Intrinsic::aarch64_neon_st3:
2525   case Intrinsic::aarch64_neon_st4:
2526     Info.ReadMem = false;
2527     Info.WriteMem = true;
2528     Info.PtrVal = Inst->getArgOperand(Inst->arg_size() - 1);
2529     break;
2530   }
2531 
2532   switch (Inst->getIntrinsicID()) {
2533   default:
2534     return false;
2535   case Intrinsic::aarch64_neon_ld2:
2536   case Intrinsic::aarch64_neon_st2:
2537     Info.MatchingId = VECTOR_LDST_TWO_ELEMENTS;
2538     break;
2539   case Intrinsic::aarch64_neon_ld3:
2540   case Intrinsic::aarch64_neon_st3:
2541     Info.MatchingId = VECTOR_LDST_THREE_ELEMENTS;
2542     break;
2543   case Intrinsic::aarch64_neon_ld4:
2544   case Intrinsic::aarch64_neon_st4:
2545     Info.MatchingId = VECTOR_LDST_FOUR_ELEMENTS;
2546     break;
2547   }
2548   return true;
2549 }
2550 
2551 /// See if \p I should be considered for address type promotion. We check if \p
2552 /// I is a sext with right type and used in memory accesses. If it used in a
2553 /// "complex" getelementptr, we allow it to be promoted without finding other
2554 /// sext instructions that sign extended the same initial value. A getelementptr
2555 /// is considered as "complex" if it has more than 2 operands.
2556 bool AArch64TTIImpl::shouldConsiderAddressTypePromotion(
2557     const Instruction &I, bool &AllowPromotionWithoutCommonHeader) {
2558   bool Considerable = false;
2559   AllowPromotionWithoutCommonHeader = false;
2560   if (!isa<SExtInst>(&I))
2561     return false;
2562   Type *ConsideredSExtType =
2563       Type::getInt64Ty(I.getParent()->getParent()->getContext());
2564   if (I.getType() != ConsideredSExtType)
2565     return false;
2566   // See if the sext is the one with the right type and used in at least one
2567   // GetElementPtrInst.
2568   for (const User *U : I.users()) {
2569     if (const GetElementPtrInst *GEPInst = dyn_cast<GetElementPtrInst>(U)) {
2570       Considerable = true;
2571       // A getelementptr is considered as "complex" if it has more than 2
2572       // operands. We will promote a SExt used in such complex GEP as we
2573       // expect some computation to be merged if they are done on 64 bits.
2574       if (GEPInst->getNumOperands() > 2) {
2575         AllowPromotionWithoutCommonHeader = true;
2576         break;
2577       }
2578     }
2579   }
2580   return Considerable;
2581 }
2582 
2583 bool AArch64TTIImpl::isLegalToVectorizeReduction(
2584     const RecurrenceDescriptor &RdxDesc, ElementCount VF) const {
2585   if (!VF.isScalable())
2586     return true;
2587 
2588   Type *Ty = RdxDesc.getRecurrenceType();
2589   if (Ty->isBFloatTy() || !isElementTypeLegalForScalableVector(Ty))
2590     return false;
2591 
2592   switch (RdxDesc.getRecurrenceKind()) {
2593   case RecurKind::Add:
2594   case RecurKind::FAdd:
2595   case RecurKind::And:
2596   case RecurKind::Or:
2597   case RecurKind::Xor:
2598   case RecurKind::SMin:
2599   case RecurKind::SMax:
2600   case RecurKind::UMin:
2601   case RecurKind::UMax:
2602   case RecurKind::FMin:
2603   case RecurKind::FMax:
2604   case RecurKind::SelectICmp:
2605   case RecurKind::SelectFCmp:
2606   case RecurKind::FMulAdd:
2607     return true;
2608   default:
2609     return false;
2610   }
2611 }
2612 
2613 InstructionCost
2614 AArch64TTIImpl::getMinMaxReductionCost(VectorType *Ty, VectorType *CondTy,
2615                                        bool IsUnsigned,
2616                                        TTI::TargetCostKind CostKind) {
2617   std::pair<InstructionCost, MVT> LT = TLI->getTypeLegalizationCost(DL, Ty);
2618 
2619   if (LT.second.getScalarType() == MVT::f16 && !ST->hasFullFP16())
2620     return BaseT::getMinMaxReductionCost(Ty, CondTy, IsUnsigned, CostKind);
2621 
2622   assert((isa<ScalableVectorType>(Ty) == isa<ScalableVectorType>(CondTy)) &&
2623          "Both vector needs to be equally scalable");
2624 
2625   InstructionCost LegalizationCost = 0;
2626   if (LT.first > 1) {
2627     Type *LegalVTy = EVT(LT.second).getTypeForEVT(Ty->getContext());
2628     unsigned MinMaxOpcode =
2629         Ty->isFPOrFPVectorTy()
2630             ? Intrinsic::maxnum
2631             : (IsUnsigned ? Intrinsic::umin : Intrinsic::smin);
2632     IntrinsicCostAttributes Attrs(MinMaxOpcode, LegalVTy, {LegalVTy, LegalVTy});
2633     LegalizationCost = getIntrinsicInstrCost(Attrs, CostKind) * (LT.first - 1);
2634   }
2635 
2636   return LegalizationCost + /*Cost of horizontal reduction*/ 2;
2637 }
2638 
2639 InstructionCost AArch64TTIImpl::getArithmeticReductionCostSVE(
2640     unsigned Opcode, VectorType *ValTy, TTI::TargetCostKind CostKind) {
2641   std::pair<InstructionCost, MVT> LT = TLI->getTypeLegalizationCost(DL, ValTy);
2642   InstructionCost LegalizationCost = 0;
2643   if (LT.first > 1) {
2644     Type *LegalVTy = EVT(LT.second).getTypeForEVT(ValTy->getContext());
2645     LegalizationCost = getArithmeticInstrCost(Opcode, LegalVTy, CostKind);
2646     LegalizationCost *= LT.first - 1;
2647   }
2648 
2649   int ISD = TLI->InstructionOpcodeToISD(Opcode);
2650   assert(ISD && "Invalid opcode");
2651   // Add the final reduction cost for the legal horizontal reduction
2652   switch (ISD) {
2653   case ISD::ADD:
2654   case ISD::AND:
2655   case ISD::OR:
2656   case ISD::XOR:
2657   case ISD::FADD:
2658     return LegalizationCost + 2;
2659   default:
2660     return InstructionCost::getInvalid();
2661   }
2662 }
2663 
2664 InstructionCost
2665 AArch64TTIImpl::getArithmeticReductionCost(unsigned Opcode, VectorType *ValTy,
2666                                            Optional<FastMathFlags> FMF,
2667                                            TTI::TargetCostKind CostKind) {
2668   if (TTI::requiresOrderedReduction(FMF)) {
2669     if (auto *FixedVTy = dyn_cast<FixedVectorType>(ValTy)) {
2670       InstructionCost BaseCost =
2671           BaseT::getArithmeticReductionCost(Opcode, ValTy, FMF, CostKind);
2672       // Add on extra cost to reflect the extra overhead on some CPUs. We still
2673       // end up vectorizing for more computationally intensive loops.
2674       return BaseCost + FixedVTy->getNumElements();
2675     }
2676 
2677     if (Opcode != Instruction::FAdd)
2678       return InstructionCost::getInvalid();
2679 
2680     auto *VTy = cast<ScalableVectorType>(ValTy);
2681     InstructionCost Cost =
2682         getArithmeticInstrCost(Opcode, VTy->getScalarType(), CostKind);
2683     Cost *= getMaxNumElements(VTy->getElementCount());
2684     return Cost;
2685   }
2686 
2687   if (isa<ScalableVectorType>(ValTy))
2688     return getArithmeticReductionCostSVE(Opcode, ValTy, CostKind);
2689 
2690   std::pair<InstructionCost, MVT> LT = TLI->getTypeLegalizationCost(DL, ValTy);
2691   MVT MTy = LT.second;
2692   int ISD = TLI->InstructionOpcodeToISD(Opcode);
2693   assert(ISD && "Invalid opcode");
2694 
2695   // Horizontal adds can use the 'addv' instruction. We model the cost of these
2696   // instructions as twice a normal vector add, plus 1 for each legalization
2697   // step (LT.first). This is the only arithmetic vector reduction operation for
2698   // which we have an instruction.
2699   // OR, XOR and AND costs should match the codegen from:
2700   // OR: llvm/test/CodeGen/AArch64/reduce-or.ll
2701   // XOR: llvm/test/CodeGen/AArch64/reduce-xor.ll
2702   // AND: llvm/test/CodeGen/AArch64/reduce-and.ll
2703   static const CostTblEntry CostTblNoPairwise[]{
2704       {ISD::ADD, MVT::v8i8,   2},
2705       {ISD::ADD, MVT::v16i8,  2},
2706       {ISD::ADD, MVT::v4i16,  2},
2707       {ISD::ADD, MVT::v8i16,  2},
2708       {ISD::ADD, MVT::v4i32,  2},
2709       {ISD::OR,  MVT::v8i8,  15},
2710       {ISD::OR,  MVT::v16i8, 17},
2711       {ISD::OR,  MVT::v4i16,  7},
2712       {ISD::OR,  MVT::v8i16,  9},
2713       {ISD::OR,  MVT::v2i32,  3},
2714       {ISD::OR,  MVT::v4i32,  5},
2715       {ISD::OR,  MVT::v2i64,  3},
2716       {ISD::XOR, MVT::v8i8,  15},
2717       {ISD::XOR, MVT::v16i8, 17},
2718       {ISD::XOR, MVT::v4i16,  7},
2719       {ISD::XOR, MVT::v8i16,  9},
2720       {ISD::XOR, MVT::v2i32,  3},
2721       {ISD::XOR, MVT::v4i32,  5},
2722       {ISD::XOR, MVT::v2i64,  3},
2723       {ISD::AND, MVT::v8i8,  15},
2724       {ISD::AND, MVT::v16i8, 17},
2725       {ISD::AND, MVT::v4i16,  7},
2726       {ISD::AND, MVT::v8i16,  9},
2727       {ISD::AND, MVT::v2i32,  3},
2728       {ISD::AND, MVT::v4i32,  5},
2729       {ISD::AND, MVT::v2i64,  3},
2730   };
2731   switch (ISD) {
2732   default:
2733     break;
2734   case ISD::ADD:
2735     if (const auto *Entry = CostTableLookup(CostTblNoPairwise, ISD, MTy))
2736       return (LT.first - 1) + Entry->Cost;
2737     break;
2738   case ISD::XOR:
2739   case ISD::AND:
2740   case ISD::OR:
2741     const auto *Entry = CostTableLookup(CostTblNoPairwise, ISD, MTy);
2742     if (!Entry)
2743       break;
2744     auto *ValVTy = cast<FixedVectorType>(ValTy);
2745     if (!ValVTy->getElementType()->isIntegerTy(1) &&
2746         MTy.getVectorNumElements() <= ValVTy->getNumElements() &&
2747         isPowerOf2_32(ValVTy->getNumElements())) {
2748       InstructionCost ExtraCost = 0;
2749       if (LT.first != 1) {
2750         // Type needs to be split, so there is an extra cost of LT.first - 1
2751         // arithmetic ops.
2752         auto *Ty = FixedVectorType::get(ValTy->getElementType(),
2753                                         MTy.getVectorNumElements());
2754         ExtraCost = getArithmeticInstrCost(Opcode, Ty, CostKind);
2755         ExtraCost *= LT.first - 1;
2756       }
2757       return Entry->Cost + ExtraCost;
2758     }
2759     break;
2760   }
2761   return BaseT::getArithmeticReductionCost(Opcode, ValTy, FMF, CostKind);
2762 }
2763 
2764 InstructionCost AArch64TTIImpl::getSpliceCost(VectorType *Tp, int Index) {
2765   static const CostTblEntry ShuffleTbl[] = {
2766       { TTI::SK_Splice, MVT::nxv16i8,  1 },
2767       { TTI::SK_Splice, MVT::nxv8i16,  1 },
2768       { TTI::SK_Splice, MVT::nxv4i32,  1 },
2769       { TTI::SK_Splice, MVT::nxv2i64,  1 },
2770       { TTI::SK_Splice, MVT::nxv2f16,  1 },
2771       { TTI::SK_Splice, MVT::nxv4f16,  1 },
2772       { TTI::SK_Splice, MVT::nxv8f16,  1 },
2773       { TTI::SK_Splice, MVT::nxv2bf16, 1 },
2774       { TTI::SK_Splice, MVT::nxv4bf16, 1 },
2775       { TTI::SK_Splice, MVT::nxv8bf16, 1 },
2776       { TTI::SK_Splice, MVT::nxv2f32,  1 },
2777       { TTI::SK_Splice, MVT::nxv4f32,  1 },
2778       { TTI::SK_Splice, MVT::nxv2f64,  1 },
2779   };
2780 
2781   std::pair<InstructionCost, MVT> LT = TLI->getTypeLegalizationCost(DL, Tp);
2782   Type *LegalVTy = EVT(LT.second).getTypeForEVT(Tp->getContext());
2783   TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput;
2784   EVT PromotedVT = LT.second.getScalarType() == MVT::i1
2785                        ? TLI->getPromotedVTForPredicate(EVT(LT.second))
2786                        : LT.second;
2787   Type *PromotedVTy = EVT(PromotedVT).getTypeForEVT(Tp->getContext());
2788   InstructionCost LegalizationCost = 0;
2789   if (Index < 0) {
2790     LegalizationCost =
2791         getCmpSelInstrCost(Instruction::ICmp, PromotedVTy, PromotedVTy,
2792                            CmpInst::BAD_ICMP_PREDICATE, CostKind) +
2793         getCmpSelInstrCost(Instruction::Select, PromotedVTy, LegalVTy,
2794                            CmpInst::BAD_ICMP_PREDICATE, CostKind);
2795   }
2796 
2797   // Predicated splice are promoted when lowering. See AArch64ISelLowering.cpp
2798   // Cost performed on a promoted type.
2799   if (LT.second.getScalarType() == MVT::i1) {
2800     LegalizationCost +=
2801         getCastInstrCost(Instruction::ZExt, PromotedVTy, LegalVTy,
2802                          TTI::CastContextHint::None, CostKind) +
2803         getCastInstrCost(Instruction::Trunc, LegalVTy, PromotedVTy,
2804                          TTI::CastContextHint::None, CostKind);
2805   }
2806   const auto *Entry =
2807       CostTableLookup(ShuffleTbl, TTI::SK_Splice, PromotedVT.getSimpleVT());
2808   assert(Entry && "Illegal Type for Splice");
2809   LegalizationCost += Entry->Cost;
2810   return LegalizationCost * LT.first;
2811 }
2812 
2813 InstructionCost AArch64TTIImpl::getShuffleCost(TTI::ShuffleKind Kind,
2814                                                VectorType *Tp,
2815                                                ArrayRef<int> Mask, int Index,
2816                                                VectorType *SubTp,
2817                                                ArrayRef<const Value *> Args) {
2818   std::pair<InstructionCost, MVT> LT = TLI->getTypeLegalizationCost(DL, Tp);
2819   // If we have a Mask, and the LT is being legalized somehow, split the Mask
2820   // into smaller vectors and sum the cost of each shuffle.
2821   if (!Mask.empty() && isa<FixedVectorType>(Tp) && LT.second.isVector() &&
2822       Tp->getScalarSizeInBits() == LT.second.getScalarSizeInBits() &&
2823       cast<FixedVectorType>(Tp)->getNumElements() >
2824           LT.second.getVectorNumElements() &&
2825       !Index && !SubTp) {
2826     unsigned TpNumElts = cast<FixedVectorType>(Tp)->getNumElements();
2827     assert(Mask.size() == TpNumElts && "Expected Mask and Tp size to match!");
2828     unsigned LTNumElts = LT.second.getVectorNumElements();
2829     unsigned NumVecs = (TpNumElts + LTNumElts - 1) / LTNumElts;
2830     VectorType *NTp =
2831         VectorType::get(Tp->getScalarType(), LT.second.getVectorElementCount());
2832     InstructionCost Cost;
2833     for (unsigned N = 0; N < NumVecs; N++) {
2834       SmallVector<int> NMask;
2835       // Split the existing mask into chunks of size LTNumElts. Track the source
2836       // sub-vectors to ensure the result has at most 2 inputs.
2837       unsigned Source1, Source2;
2838       unsigned NumSources = 0;
2839       for (unsigned E = 0; E < LTNumElts; E++) {
2840         int MaskElt = (N * LTNumElts + E < TpNumElts) ? Mask[N * LTNumElts + E]
2841                                                       : UndefMaskElem;
2842         if (MaskElt < 0) {
2843           NMask.push_back(UndefMaskElem);
2844           continue;
2845         }
2846 
2847         // Calculate which source from the input this comes from and whether it
2848         // is new to us.
2849         unsigned Source = MaskElt / LTNumElts;
2850         if (NumSources == 0) {
2851           Source1 = Source;
2852           NumSources = 1;
2853         } else if (NumSources == 1 && Source != Source1) {
2854           Source2 = Source;
2855           NumSources = 2;
2856         } else if (NumSources >= 2 && Source != Source1 && Source != Source2) {
2857           NumSources++;
2858         }
2859 
2860         // Add to the new mask. For the NumSources>2 case these are not correct,
2861         // but are only used for the modular lane number.
2862         if (Source == Source1)
2863           NMask.push_back(MaskElt % LTNumElts);
2864         else if (Source == Source2)
2865           NMask.push_back(MaskElt % LTNumElts + LTNumElts);
2866         else
2867           NMask.push_back(MaskElt % LTNumElts);
2868       }
2869       // If the sub-mask has at most 2 input sub-vectors then re-cost it using
2870       // getShuffleCost. If not then cost it using the worst case.
2871       if (NumSources <= 2)
2872         Cost += getShuffleCost(NumSources <= 1 ? TTI::SK_PermuteSingleSrc
2873                                                : TTI::SK_PermuteTwoSrc,
2874                                NTp, NMask, 0, nullptr, Args);
2875       else if (any_of(enumerate(NMask), [&](const auto &ME) {
2876                  return ME.value() % LTNumElts == ME.index();
2877                }))
2878         Cost += LTNumElts - 1;
2879       else
2880         Cost += LTNumElts;
2881     }
2882     return Cost;
2883   }
2884 
2885   Kind = improveShuffleKindFromMask(Kind, Mask);
2886 
2887   // Check for broadcast loads.
2888   if (Kind == TTI::SK_Broadcast) {
2889     bool IsLoad = !Args.empty() && isa<LoadInst>(Args[0]);
2890     if (IsLoad && LT.second.isVector() &&
2891         isLegalBroadcastLoad(Tp->getElementType(),
2892                              LT.second.getVectorElementCount()))
2893       return 0; // broadcast is handled by ld1r
2894   }
2895 
2896   // If we have 4 elements for the shuffle and a Mask, get the cost straight
2897   // from the perfect shuffle tables.
2898   if (Mask.size() == 4 && Tp->getElementCount() == ElementCount::getFixed(4) &&
2899       (Tp->getScalarSizeInBits() == 16 || Tp->getScalarSizeInBits() == 32) &&
2900       all_of(Mask, [](int E) { return E < 8; }))
2901     return getPerfectShuffleCost(Mask);
2902 
2903   if (Kind == TTI::SK_Broadcast || Kind == TTI::SK_Transpose ||
2904       Kind == TTI::SK_Select || Kind == TTI::SK_PermuteSingleSrc ||
2905       Kind == TTI::SK_Reverse) {
2906 
2907     static const CostTblEntry ShuffleTbl[] = {
2908       // Broadcast shuffle kinds can be performed with 'dup'.
2909       { TTI::SK_Broadcast, MVT::v8i8,  1 },
2910       { TTI::SK_Broadcast, MVT::v16i8, 1 },
2911       { TTI::SK_Broadcast, MVT::v4i16, 1 },
2912       { TTI::SK_Broadcast, MVT::v8i16, 1 },
2913       { TTI::SK_Broadcast, MVT::v2i32, 1 },
2914       { TTI::SK_Broadcast, MVT::v4i32, 1 },
2915       { TTI::SK_Broadcast, MVT::v2i64, 1 },
2916       { TTI::SK_Broadcast, MVT::v2f32, 1 },
2917       { TTI::SK_Broadcast, MVT::v4f32, 1 },
2918       { TTI::SK_Broadcast, MVT::v2f64, 1 },
2919       // Transpose shuffle kinds can be performed with 'trn1/trn2' and
2920       // 'zip1/zip2' instructions.
2921       { TTI::SK_Transpose, MVT::v8i8,  1 },
2922       { TTI::SK_Transpose, MVT::v16i8, 1 },
2923       { TTI::SK_Transpose, MVT::v4i16, 1 },
2924       { TTI::SK_Transpose, MVT::v8i16, 1 },
2925       { TTI::SK_Transpose, MVT::v2i32, 1 },
2926       { TTI::SK_Transpose, MVT::v4i32, 1 },
2927       { TTI::SK_Transpose, MVT::v2i64, 1 },
2928       { TTI::SK_Transpose, MVT::v2f32, 1 },
2929       { TTI::SK_Transpose, MVT::v4f32, 1 },
2930       { TTI::SK_Transpose, MVT::v2f64, 1 },
2931       // Select shuffle kinds.
2932       // TODO: handle vXi8/vXi16.
2933       { TTI::SK_Select, MVT::v2i32, 1 }, // mov.
2934       { TTI::SK_Select, MVT::v4i32, 2 }, // rev+trn (or similar).
2935       { TTI::SK_Select, MVT::v2i64, 1 }, // mov.
2936       { TTI::SK_Select, MVT::v2f32, 1 }, // mov.
2937       { TTI::SK_Select, MVT::v4f32, 2 }, // rev+trn (or similar).
2938       { TTI::SK_Select, MVT::v2f64, 1 }, // mov.
2939       // PermuteSingleSrc shuffle kinds.
2940       { TTI::SK_PermuteSingleSrc, MVT::v2i32, 1 }, // mov.
2941       { TTI::SK_PermuteSingleSrc, MVT::v4i32, 3 }, // perfectshuffle worst case.
2942       { TTI::SK_PermuteSingleSrc, MVT::v2i64, 1 }, // mov.
2943       { TTI::SK_PermuteSingleSrc, MVT::v2f32, 1 }, // mov.
2944       { TTI::SK_PermuteSingleSrc, MVT::v4f32, 3 }, // perfectshuffle worst case.
2945       { TTI::SK_PermuteSingleSrc, MVT::v2f64, 1 }, // mov.
2946       { TTI::SK_PermuteSingleSrc, MVT::v4i16, 3 }, // perfectshuffle worst case.
2947       { TTI::SK_PermuteSingleSrc, MVT::v4f16, 3 }, // perfectshuffle worst case.
2948       { TTI::SK_PermuteSingleSrc, MVT::v4bf16, 3 }, // perfectshuffle worst case.
2949       { TTI::SK_PermuteSingleSrc, MVT::v8i16, 8 }, // constpool + load + tbl
2950       { TTI::SK_PermuteSingleSrc, MVT::v8f16, 8 }, // constpool + load + tbl
2951       { TTI::SK_PermuteSingleSrc, MVT::v8bf16, 8 }, // constpool + load + tbl
2952       { TTI::SK_PermuteSingleSrc, MVT::v8i8, 8 }, // constpool + load + tbl
2953       { TTI::SK_PermuteSingleSrc, MVT::v16i8, 8 }, // constpool + load + tbl
2954       // Reverse can be lowered with `rev`.
2955       { TTI::SK_Reverse, MVT::v2i32, 1 }, // mov.
2956       { TTI::SK_Reverse, MVT::v4i32, 2 }, // REV64; EXT
2957       { TTI::SK_Reverse, MVT::v2i64, 1 }, // mov.
2958       { TTI::SK_Reverse, MVT::v2f32, 1 }, // mov.
2959       { TTI::SK_Reverse, MVT::v4f32, 2 }, // REV64; EXT
2960       { TTI::SK_Reverse, MVT::v2f64, 1 }, // mov.
2961       { TTI::SK_Reverse, MVT::v8f16, 2 }, // REV64; EXT
2962       { TTI::SK_Reverse, MVT::v8i16, 2 }, // REV64; EXT
2963       { TTI::SK_Reverse, MVT::v16i8, 2 }, // REV64; EXT
2964       { TTI::SK_Reverse, MVT::v4f16, 1 }, // REV64
2965       { TTI::SK_Reverse, MVT::v4i16, 1 }, // REV64
2966       { TTI::SK_Reverse, MVT::v8i8, 1 }, // REV64
2967       // Broadcast shuffle kinds for scalable vectors
2968       { TTI::SK_Broadcast, MVT::nxv16i8,  1 },
2969       { TTI::SK_Broadcast, MVT::nxv8i16,  1 },
2970       { TTI::SK_Broadcast, MVT::nxv4i32,  1 },
2971       { TTI::SK_Broadcast, MVT::nxv2i64,  1 },
2972       { TTI::SK_Broadcast, MVT::nxv2f16,  1 },
2973       { TTI::SK_Broadcast, MVT::nxv4f16,  1 },
2974       { TTI::SK_Broadcast, MVT::nxv8f16,  1 },
2975       { TTI::SK_Broadcast, MVT::nxv2bf16, 1 },
2976       { TTI::SK_Broadcast, MVT::nxv4bf16, 1 },
2977       { TTI::SK_Broadcast, MVT::nxv8bf16, 1 },
2978       { TTI::SK_Broadcast, MVT::nxv2f32,  1 },
2979       { TTI::SK_Broadcast, MVT::nxv4f32,  1 },
2980       { TTI::SK_Broadcast, MVT::nxv2f64,  1 },
2981       { TTI::SK_Broadcast, MVT::nxv16i1,  1 },
2982       { TTI::SK_Broadcast, MVT::nxv8i1,   1 },
2983       { TTI::SK_Broadcast, MVT::nxv4i1,   1 },
2984       { TTI::SK_Broadcast, MVT::nxv2i1,   1 },
2985       // Handle the cases for vector.reverse with scalable vectors
2986       { TTI::SK_Reverse, MVT::nxv16i8,  1 },
2987       { TTI::SK_Reverse, MVT::nxv8i16,  1 },
2988       { TTI::SK_Reverse, MVT::nxv4i32,  1 },
2989       { TTI::SK_Reverse, MVT::nxv2i64,  1 },
2990       { TTI::SK_Reverse, MVT::nxv2f16,  1 },
2991       { TTI::SK_Reverse, MVT::nxv4f16,  1 },
2992       { TTI::SK_Reverse, MVT::nxv8f16,  1 },
2993       { TTI::SK_Reverse, MVT::nxv2bf16, 1 },
2994       { TTI::SK_Reverse, MVT::nxv4bf16, 1 },
2995       { TTI::SK_Reverse, MVT::nxv8bf16, 1 },
2996       { TTI::SK_Reverse, MVT::nxv2f32,  1 },
2997       { TTI::SK_Reverse, MVT::nxv4f32,  1 },
2998       { TTI::SK_Reverse, MVT::nxv2f64,  1 },
2999       { TTI::SK_Reverse, MVT::nxv16i1,  1 },
3000       { TTI::SK_Reverse, MVT::nxv8i1,   1 },
3001       { TTI::SK_Reverse, MVT::nxv4i1,   1 },
3002       { TTI::SK_Reverse, MVT::nxv2i1,   1 },
3003     };
3004     if (const auto *Entry = CostTableLookup(ShuffleTbl, Kind, LT.second))
3005       return LT.first * Entry->Cost;
3006   }
3007 
3008   if (Kind == TTI::SK_Splice && isa<ScalableVectorType>(Tp))
3009     return getSpliceCost(Tp, Index);
3010 
3011   // Inserting a subvector can often be done with either a D, S or H register
3012   // move, so long as the inserted vector is "aligned".
3013   if (Kind == TTI::SK_InsertSubvector && LT.second.isFixedLengthVector() &&
3014       LT.second.getSizeInBits() <= 128 && SubTp) {
3015     std::pair<InstructionCost, MVT> SubLT =
3016         TLI->getTypeLegalizationCost(DL, SubTp);
3017     if (SubLT.second.isVector()) {
3018       int NumElts = LT.second.getVectorNumElements();
3019       int NumSubElts = SubLT.second.getVectorNumElements();
3020       if ((Index % NumSubElts) == 0 && (NumElts % NumSubElts) == 0)
3021         return SubLT.first;
3022     }
3023   }
3024 
3025   return BaseT::getShuffleCost(Kind, Tp, Mask, Index, SubTp);
3026 }
3027 
3028 bool AArch64TTIImpl::preferPredicateOverEpilogue(
3029     Loop *L, LoopInfo *LI, ScalarEvolution &SE, AssumptionCache &AC,
3030     TargetLibraryInfo *TLI, DominatorTree *DT, LoopVectorizationLegality *LVL) {
3031   if (!ST->hasSVE() || TailFoldingKindLoc == TailFoldingKind::TFDisabled)
3032     return false;
3033 
3034   TailFoldingKind Required; // Defaults to 0.
3035   if (LVL->getReductionVars().size())
3036     Required.add(TailFoldingKind::TFReductions);
3037   if (LVL->getFirstOrderRecurrences().size())
3038     Required.add(TailFoldingKind::TFRecurrences);
3039   if (!Required)
3040     Required.add(TailFoldingKind::TFSimple);
3041 
3042   return (TailFoldingKindLoc & Required) == Required;
3043 }
3044