1 //===-- SystemZTargetTransformInfo.cpp - SystemZ-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 // This file implements a TargetTransformInfo analysis pass specific to the
10 // SystemZ target machine. It uses the target's detailed information to provide
11 // more precise answers to certain TTI queries, while letting the target
12 // independent and default TTI implementations handle the rest.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "SystemZTargetTransformInfo.h"
17 #include "llvm/Analysis/TargetTransformInfo.h"
18 #include "llvm/CodeGen/BasicTTIImpl.h"
19 #include "llvm/CodeGen/CostTable.h"
20 #include "llvm/CodeGen/TargetLowering.h"
21 #include "llvm/IR/IntrinsicInst.h"
22 #include "llvm/Support/Debug.h"
23 using namespace llvm;
24 
25 #define DEBUG_TYPE "systemztti"
26 
27 //===----------------------------------------------------------------------===//
28 //
29 // SystemZ cost model.
30 //
31 //===----------------------------------------------------------------------===//
32 
33 InstructionCost SystemZTTIImpl::getIntImmCost(const APInt &Imm, Type *Ty,
34                                               TTI::TargetCostKind CostKind) {
35   assert(Ty->isIntegerTy());
36 
37   unsigned BitSize = Ty->getPrimitiveSizeInBits();
38   // There is no cost model for constants with a bit size of 0. Return TCC_Free
39   // here, so that constant hoisting will ignore this constant.
40   if (BitSize == 0)
41     return TTI::TCC_Free;
42   // No cost model for operations on integers larger than 64 bit implemented yet.
43   if (BitSize > 64)
44     return TTI::TCC_Free;
45 
46   if (Imm == 0)
47     return TTI::TCC_Free;
48 
49   if (Imm.getBitWidth() <= 64) {
50     // Constants loaded via lgfi.
51     if (isInt<32>(Imm.getSExtValue()))
52       return TTI::TCC_Basic;
53     // Constants loaded via llilf.
54     if (isUInt<32>(Imm.getZExtValue()))
55       return TTI::TCC_Basic;
56     // Constants loaded via llihf:
57     if ((Imm.getZExtValue() & 0xffffffff) == 0)
58       return TTI::TCC_Basic;
59 
60     return 2 * TTI::TCC_Basic;
61   }
62 
63   return 4 * TTI::TCC_Basic;
64 }
65 
66 InstructionCost SystemZTTIImpl::getIntImmCostInst(unsigned Opcode, unsigned Idx,
67                                                   const APInt &Imm, Type *Ty,
68                                                   TTI::TargetCostKind CostKind,
69                                                   Instruction *Inst) {
70   assert(Ty->isIntegerTy());
71 
72   unsigned BitSize = Ty->getPrimitiveSizeInBits();
73   // There is no cost model for constants with a bit size of 0. Return TCC_Free
74   // here, so that constant hoisting will ignore this constant.
75   if (BitSize == 0)
76     return TTI::TCC_Free;
77   // No cost model for operations on integers larger than 64 bit implemented yet.
78   if (BitSize > 64)
79     return TTI::TCC_Free;
80 
81   switch (Opcode) {
82   default:
83     return TTI::TCC_Free;
84   case Instruction::GetElementPtr:
85     // Always hoist the base address of a GetElementPtr. This prevents the
86     // creation of new constants for every base constant that gets constant
87     // folded with the offset.
88     if (Idx == 0)
89       return 2 * TTI::TCC_Basic;
90     return TTI::TCC_Free;
91   case Instruction::Store:
92     if (Idx == 0 && Imm.getBitWidth() <= 64) {
93       // Any 8-bit immediate store can by implemented via mvi.
94       if (BitSize == 8)
95         return TTI::TCC_Free;
96       // 16-bit immediate values can be stored via mvhhi/mvhi/mvghi.
97       if (isInt<16>(Imm.getSExtValue()))
98         return TTI::TCC_Free;
99     }
100     break;
101   case Instruction::ICmp:
102     if (Idx == 1 && Imm.getBitWidth() <= 64) {
103       // Comparisons against signed 32-bit immediates implemented via cgfi.
104       if (isInt<32>(Imm.getSExtValue()))
105         return TTI::TCC_Free;
106       // Comparisons against unsigned 32-bit immediates implemented via clgfi.
107       if (isUInt<32>(Imm.getZExtValue()))
108         return TTI::TCC_Free;
109     }
110     break;
111   case Instruction::Add:
112   case Instruction::Sub:
113     if (Idx == 1 && Imm.getBitWidth() <= 64) {
114       // We use algfi/slgfi to add/subtract 32-bit unsigned immediates.
115       if (isUInt<32>(Imm.getZExtValue()))
116         return TTI::TCC_Free;
117       // Or their negation, by swapping addition vs. subtraction.
118       if (isUInt<32>(-Imm.getSExtValue()))
119         return TTI::TCC_Free;
120     }
121     break;
122   case Instruction::Mul:
123     if (Idx == 1 && Imm.getBitWidth() <= 64) {
124       // We use msgfi to multiply by 32-bit signed immediates.
125       if (isInt<32>(Imm.getSExtValue()))
126         return TTI::TCC_Free;
127     }
128     break;
129   case Instruction::Or:
130   case Instruction::Xor:
131     if (Idx == 1 && Imm.getBitWidth() <= 64) {
132       // Masks supported by oilf/xilf.
133       if (isUInt<32>(Imm.getZExtValue()))
134         return TTI::TCC_Free;
135       // Masks supported by oihf/xihf.
136       if ((Imm.getZExtValue() & 0xffffffff) == 0)
137         return TTI::TCC_Free;
138     }
139     break;
140   case Instruction::And:
141     if (Idx == 1 && Imm.getBitWidth() <= 64) {
142       // Any 32-bit AND operation can by implemented via nilf.
143       if (BitSize <= 32)
144         return TTI::TCC_Free;
145       // 64-bit masks supported by nilf.
146       if (isUInt<32>(~Imm.getZExtValue()))
147         return TTI::TCC_Free;
148       // 64-bit masks supported by nilh.
149       if ((Imm.getZExtValue() & 0xffffffff) == 0xffffffff)
150         return TTI::TCC_Free;
151       // Some 64-bit AND operations can be implemented via risbg.
152       const SystemZInstrInfo *TII = ST->getInstrInfo();
153       unsigned Start, End;
154       if (TII->isRxSBGMask(Imm.getZExtValue(), BitSize, Start, End))
155         return TTI::TCC_Free;
156     }
157     break;
158   case Instruction::Shl:
159   case Instruction::LShr:
160   case Instruction::AShr:
161     // Always return TCC_Free for the shift value of a shift instruction.
162     if (Idx == 1)
163       return TTI::TCC_Free;
164     break;
165   case Instruction::UDiv:
166   case Instruction::SDiv:
167   case Instruction::URem:
168   case Instruction::SRem:
169   case Instruction::Trunc:
170   case Instruction::ZExt:
171   case Instruction::SExt:
172   case Instruction::IntToPtr:
173   case Instruction::PtrToInt:
174   case Instruction::BitCast:
175   case Instruction::PHI:
176   case Instruction::Call:
177   case Instruction::Select:
178   case Instruction::Ret:
179   case Instruction::Load:
180     break;
181   }
182 
183   return SystemZTTIImpl::getIntImmCost(Imm, Ty, CostKind);
184 }
185 
186 InstructionCost
187 SystemZTTIImpl::getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx,
188                                     const APInt &Imm, Type *Ty,
189                                     TTI::TargetCostKind CostKind) {
190   assert(Ty->isIntegerTy());
191 
192   unsigned BitSize = Ty->getPrimitiveSizeInBits();
193   // There is no cost model for constants with a bit size of 0. Return TCC_Free
194   // here, so that constant hoisting will ignore this constant.
195   if (BitSize == 0)
196     return TTI::TCC_Free;
197   // No cost model for operations on integers larger than 64 bit implemented yet.
198   if (BitSize > 64)
199     return TTI::TCC_Free;
200 
201   switch (IID) {
202   default:
203     return TTI::TCC_Free;
204   case Intrinsic::sadd_with_overflow:
205   case Intrinsic::uadd_with_overflow:
206   case Intrinsic::ssub_with_overflow:
207   case Intrinsic::usub_with_overflow:
208     // These get expanded to include a normal addition/subtraction.
209     if (Idx == 1 && Imm.getBitWidth() <= 64) {
210       if (isUInt<32>(Imm.getZExtValue()))
211         return TTI::TCC_Free;
212       if (isUInt<32>(-Imm.getSExtValue()))
213         return TTI::TCC_Free;
214     }
215     break;
216   case Intrinsic::smul_with_overflow:
217   case Intrinsic::umul_with_overflow:
218     // These get expanded to include a normal multiplication.
219     if (Idx == 1 && Imm.getBitWidth() <= 64) {
220       if (isInt<32>(Imm.getSExtValue()))
221         return TTI::TCC_Free;
222     }
223     break;
224   case Intrinsic::experimental_stackmap:
225     if ((Idx < 2) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue())))
226       return TTI::TCC_Free;
227     break;
228   case Intrinsic::experimental_patchpoint_void:
229   case Intrinsic::experimental_patchpoint_i64:
230     if ((Idx < 4) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue())))
231       return TTI::TCC_Free;
232     break;
233   }
234   return SystemZTTIImpl::getIntImmCost(Imm, Ty, CostKind);
235 }
236 
237 TargetTransformInfo::PopcntSupportKind
238 SystemZTTIImpl::getPopcntSupport(unsigned TyWidth) {
239   assert(isPowerOf2_32(TyWidth) && "Type width must be power of 2");
240   if (ST->hasPopulationCount() && TyWidth <= 64)
241     return TTI::PSK_FastHardware;
242   return TTI::PSK_Software;
243 }
244 
245 void SystemZTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
246                                              TTI::UnrollingPreferences &UP) {
247   // Find out if L contains a call, what the machine instruction count
248   // estimate is, and how many stores there are.
249   bool HasCall = false;
250   InstructionCost NumStores = 0;
251   for (auto &BB : L->blocks())
252     for (auto &I : *BB) {
253       if (isa<CallInst>(&I) || isa<InvokeInst>(&I)) {
254         if (const Function *F = cast<CallBase>(I).getCalledFunction()) {
255           if (isLoweredToCall(F))
256             HasCall = true;
257           if (F->getIntrinsicID() == Intrinsic::memcpy ||
258               F->getIntrinsicID() == Intrinsic::memset)
259             NumStores++;
260         } else { // indirect call.
261           HasCall = true;
262         }
263       }
264       if (isa<StoreInst>(&I)) {
265         Type *MemAccessTy = I.getOperand(0)->getType();
266         NumStores += getMemoryOpCost(Instruction::Store, MemAccessTy, None, 0,
267                                      TTI::TCK_RecipThroughput);
268       }
269     }
270 
271   // The z13 processor will run out of store tags if too many stores
272   // are fed into it too quickly. Therefore make sure there are not
273   // too many stores in the resulting unrolled loop.
274   unsigned const NumStoresVal = *NumStores.getValue();
275   unsigned const Max = (NumStoresVal ? (12 / NumStoresVal) : UINT_MAX);
276 
277   if (HasCall) {
278     // Only allow full unrolling if loop has any calls.
279     UP.FullUnrollMaxCount = Max;
280     UP.MaxCount = 1;
281     return;
282   }
283 
284   UP.MaxCount = Max;
285   if (UP.MaxCount <= 1)
286     return;
287 
288   // Allow partial and runtime trip count unrolling.
289   UP.Partial = UP.Runtime = true;
290 
291   UP.PartialThreshold = 75;
292   UP.DefaultUnrollRuntimeCount = 4;
293 
294   // Allow expensive instructions in the pre-header of the loop.
295   UP.AllowExpensiveTripCount = true;
296 
297   UP.Force = true;
298 }
299 
300 void SystemZTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
301                                            TTI::PeelingPreferences &PP) {
302   BaseT::getPeelingPreferences(L, SE, PP);
303 }
304 
305 bool SystemZTTIImpl::isLSRCostLess(TargetTransformInfo::LSRCost &C1,
306                                    TargetTransformInfo::LSRCost &C2) {
307   // SystemZ specific: check instruction count (first), and don't care about
308   // ImmCost, since offsets are checked explicitly.
309   return std::tie(C1.Insns, C1.NumRegs, C1.AddRecCost,
310                   C1.NumIVMuls, C1.NumBaseAdds,
311                   C1.ScaleCost, C1.SetupCost) <
312     std::tie(C2.Insns, C2.NumRegs, C2.AddRecCost,
313              C2.NumIVMuls, C2.NumBaseAdds,
314              C2.ScaleCost, C2.SetupCost);
315 }
316 
317 unsigned SystemZTTIImpl::getNumberOfRegisters(unsigned ClassID) const {
318   bool Vector = (ClassID == 1);
319   if (!Vector)
320     // Discount the stack pointer.  Also leave out %r0, since it can't
321     // be used in an address.
322     return 14;
323   if (ST->hasVector())
324     return 32;
325   return 0;
326 }
327 
328 TypeSize
329 SystemZTTIImpl::getRegisterBitWidth(TargetTransformInfo::RegisterKind K) const {
330   switch (K) {
331   case TargetTransformInfo::RGK_Scalar:
332     return TypeSize::getFixed(64);
333   case TargetTransformInfo::RGK_FixedWidthVector:
334     return TypeSize::getFixed(ST->hasVector() ? 128 : 0);
335   case TargetTransformInfo::RGK_ScalableVector:
336     return TypeSize::getScalable(0);
337   }
338 
339   llvm_unreachable("Unsupported register kind");
340 }
341 
342 unsigned SystemZTTIImpl::getMinPrefetchStride(unsigned NumMemAccesses,
343                                               unsigned NumStridedMemAccesses,
344                                               unsigned NumPrefetches,
345                                               bool HasCall) const {
346   // Don't prefetch a loop with many far apart accesses.
347   if (NumPrefetches > 16)
348     return UINT_MAX;
349 
350   // Emit prefetch instructions for smaller strides in cases where we think
351   // the hardware prefetcher might not be able to keep up.
352   if (NumStridedMemAccesses > 32 && !HasCall &&
353       (NumMemAccesses - NumStridedMemAccesses) * 32 <= NumStridedMemAccesses)
354     return 1;
355 
356   return ST->hasMiscellaneousExtensions3() ? 8192 : 2048;
357 }
358 
359 bool SystemZTTIImpl::hasDivRemOp(Type *DataType, bool IsSigned) {
360   EVT VT = TLI->getValueType(DL, DataType);
361   return (VT.isScalarInteger() && TLI->isTypeLegal(VT));
362 }
363 
364 // Return the bit size for the scalar type or vector element
365 // type. getScalarSizeInBits() returns 0 for a pointer type.
366 static unsigned getScalarSizeInBits(Type *Ty) {
367   unsigned Size =
368     (Ty->isPtrOrPtrVectorTy() ? 64U : Ty->getScalarSizeInBits());
369   assert(Size > 0 && "Element must have non-zero size.");
370   return Size;
371 }
372 
373 // getNumberOfParts() calls getTypeLegalizationCost() which splits the vector
374 // type until it is legal. This would e.g. return 4 for <6 x i64>, instead of
375 // 3.
376 static unsigned getNumVectorRegs(Type *Ty) {
377   auto *VTy = cast<FixedVectorType>(Ty);
378   unsigned WideBits = getScalarSizeInBits(Ty) * VTy->getNumElements();
379   assert(WideBits > 0 && "Could not compute size of vector");
380   return ((WideBits % 128U) ? ((WideBits / 128U) + 1) : (WideBits / 128U));
381 }
382 
383 InstructionCost SystemZTTIImpl::getArithmeticInstrCost(
384     unsigned Opcode, Type *Ty, TTI::TargetCostKind CostKind,
385     TTI::OperandValueKind Op1Info, TTI::OperandValueKind Op2Info,
386     TTI::OperandValueProperties Opd1PropInfo,
387     TTI::OperandValueProperties Opd2PropInfo, ArrayRef<const Value *> Args,
388     const Instruction *CxtI) {
389 
390   // TODO: Handle more cost kinds.
391   if (CostKind != TTI::TCK_RecipThroughput)
392     return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Op1Info,
393                                          Op2Info, Opd1PropInfo,
394                                          Opd2PropInfo, Args, CxtI);
395 
396   // TODO: return a good value for BB-VECTORIZER that includes the
397   // immediate loads, which we do not want to count for the loop
398   // vectorizer, since they are hopefully hoisted out of the loop. This
399   // would require a new parameter 'InLoop', but not sure if constant
400   // args are common enough to motivate this.
401 
402   unsigned ScalarBits = Ty->getScalarSizeInBits();
403 
404   // There are thre cases of division and remainder: Dividing with a register
405   // needs a divide instruction. A divisor which is a power of two constant
406   // can be implemented with a sequence of shifts. Any other constant needs a
407   // multiply and shifts.
408   const unsigned DivInstrCost = 20;
409   const unsigned DivMulSeqCost = 10;
410   const unsigned SDivPow2Cost = 4;
411 
412   bool SignedDivRem =
413       Opcode == Instruction::SDiv || Opcode == Instruction::SRem;
414   bool UnsignedDivRem =
415       Opcode == Instruction::UDiv || Opcode == Instruction::URem;
416 
417   // Check for a constant divisor.
418   bool DivRemConst = false;
419   bool DivRemConstPow2 = false;
420   if ((SignedDivRem || UnsignedDivRem) && Args.size() == 2) {
421     if (const Constant *C = dyn_cast<Constant>(Args[1])) {
422       const ConstantInt *CVal =
423           (C->getType()->isVectorTy()
424                ? dyn_cast_or_null<const ConstantInt>(C->getSplatValue())
425                : dyn_cast<const ConstantInt>(C));
426       if (CVal != nullptr &&
427           (CVal->getValue().isPowerOf2() || (-CVal->getValue()).isPowerOf2()))
428         DivRemConstPow2 = true;
429       else
430         DivRemConst = true;
431     }
432   }
433 
434   if (!Ty->isVectorTy()) {
435     // These FP operations are supported with a dedicated instruction for
436     // float, double and fp128 (base implementation assumes float generally
437     // costs 2).
438     if (Opcode == Instruction::FAdd || Opcode == Instruction::FSub ||
439         Opcode == Instruction::FMul || Opcode == Instruction::FDiv)
440       return 1;
441 
442     // There is no native support for FRem.
443     if (Opcode == Instruction::FRem)
444       return LIBCALL_COST;
445 
446     // Give discount for some combined logical operations if supported.
447     if (Args.size() == 2 && ST->hasMiscellaneousExtensions3()) {
448       if (Opcode == Instruction::Xor) {
449         for (const Value *A : Args) {
450           if (const Instruction *I = dyn_cast<Instruction>(A))
451             if (I->hasOneUse() &&
452                 (I->getOpcode() == Instruction::And ||
453                  I->getOpcode() == Instruction::Or ||
454                  I->getOpcode() == Instruction::Xor))
455               return 0;
456         }
457       }
458       else if (Opcode == Instruction::Or || Opcode == Instruction::And) {
459         for (const Value *A : Args) {
460           if (const Instruction *I = dyn_cast<Instruction>(A))
461             if (I->hasOneUse() && I->getOpcode() == Instruction::Xor)
462               return 0;
463         }
464       }
465     }
466 
467     // Or requires one instruction, although it has custom handling for i64.
468     if (Opcode == Instruction::Or)
469       return 1;
470 
471     if (Opcode == Instruction::Xor && ScalarBits == 1) {
472       if (ST->hasLoadStoreOnCond2())
473         return 5; // 2 * (li 0; loc 1); xor
474       return 7; // 2 * ipm sequences ; xor ; shift ; compare
475     }
476 
477     if (DivRemConstPow2)
478       return (SignedDivRem ? SDivPow2Cost : 1);
479     if (DivRemConst)
480       return DivMulSeqCost;
481     if (SignedDivRem || UnsignedDivRem)
482       return DivInstrCost;
483   }
484   else if (ST->hasVector()) {
485     auto *VTy = cast<FixedVectorType>(Ty);
486     unsigned VF = VTy->getNumElements();
487     unsigned NumVectors = getNumVectorRegs(Ty);
488 
489     // These vector operations are custom handled, but are still supported
490     // with one instruction per vector, regardless of element size.
491     if (Opcode == Instruction::Shl || Opcode == Instruction::LShr ||
492         Opcode == Instruction::AShr) {
493       return NumVectors;
494     }
495 
496     if (DivRemConstPow2)
497       return (NumVectors * (SignedDivRem ? SDivPow2Cost : 1));
498     if (DivRemConst) {
499       SmallVector<Type *> Tys(Args.size(), Ty);
500       return VF * DivMulSeqCost + getScalarizationOverhead(VTy, Args, Tys);
501     }
502     if ((SignedDivRem || UnsignedDivRem) && VF > 4)
503       // Temporary hack: disable high vectorization factors with integer
504       // division/remainder, which will get scalarized and handled with
505       // GR128 registers. The mischeduler is not clever enough to avoid
506       // spilling yet.
507       return 1000;
508 
509     // These FP operations are supported with a single vector instruction for
510     // double (base implementation assumes float generally costs 2). For
511     // FP128, the scalar cost is 1, and there is no overhead since the values
512     // are already in scalar registers.
513     if (Opcode == Instruction::FAdd || Opcode == Instruction::FSub ||
514         Opcode == Instruction::FMul || Opcode == Instruction::FDiv) {
515       switch (ScalarBits) {
516       case 32: {
517         // The vector enhancements facility 1 provides v4f32 instructions.
518         if (ST->hasVectorEnhancements1())
519           return NumVectors;
520         // Return the cost of multiple scalar invocation plus the cost of
521         // inserting and extracting the values.
522         InstructionCost ScalarCost =
523             getArithmeticInstrCost(Opcode, Ty->getScalarType(), CostKind);
524         SmallVector<Type *> Tys(Args.size(), Ty);
525         InstructionCost Cost =
526             (VF * ScalarCost) + getScalarizationOverhead(VTy, Args, Tys);
527         // FIXME: VF 2 for these FP operations are currently just as
528         // expensive as for VF 4.
529         if (VF == 2)
530           Cost *= 2;
531         return Cost;
532       }
533       case 64:
534       case 128:
535         return NumVectors;
536       default:
537         break;
538       }
539     }
540 
541     // There is no native support for FRem.
542     if (Opcode == Instruction::FRem) {
543       SmallVector<Type *> Tys(Args.size(), Ty);
544       unsigned Cost =
545           (VF * LIBCALL_COST) + getScalarizationOverhead(VTy, Args, Tys);
546       // FIXME: VF 2 for float is currently just as expensive as for VF 4.
547       if (VF == 2 && ScalarBits == 32)
548         Cost *= 2;
549       return Cost;
550     }
551   }
552 
553   // Fallback to the default implementation.
554   return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Op1Info, Op2Info,
555                                        Opd1PropInfo, Opd2PropInfo, Args, CxtI);
556 }
557 
558 InstructionCost SystemZTTIImpl::getShuffleCost(TTI::ShuffleKind Kind,
559                                                VectorType *Tp,
560                                                ArrayRef<int> Mask, int Index,
561                                                VectorType *SubTp) {
562   if (ST->hasVector()) {
563     unsigned NumVectors = getNumVectorRegs(Tp);
564 
565     // TODO: Since fp32 is expanded, the shuffle cost should always be 0.
566 
567     // FP128 values are always in scalar registers, so there is no work
568     // involved with a shuffle, except for broadcast. In that case register
569     // moves are done with a single instruction per element.
570     if (Tp->getScalarType()->isFP128Ty())
571       return (Kind == TargetTransformInfo::SK_Broadcast ? NumVectors - 1 : 0);
572 
573     switch (Kind) {
574     case  TargetTransformInfo::SK_ExtractSubvector:
575       // ExtractSubvector Index indicates start offset.
576 
577       // Extracting a subvector from first index is a noop.
578       return (Index == 0 ? 0 : NumVectors);
579 
580     case TargetTransformInfo::SK_Broadcast:
581       // Loop vectorizer calls here to figure out the extra cost of
582       // broadcasting a loaded value to all elements of a vector. Since vlrep
583       // loads and replicates with a single instruction, adjust the returned
584       // value.
585       return NumVectors - 1;
586 
587     default:
588 
589       // SystemZ supports single instruction permutation / replication.
590       return NumVectors;
591     }
592   }
593 
594   return BaseT::getShuffleCost(Kind, Tp, Mask, Index, SubTp);
595 }
596 
597 // Return the log2 difference of the element sizes of the two vector types.
598 static unsigned getElSizeLog2Diff(Type *Ty0, Type *Ty1) {
599   unsigned Bits0 = Ty0->getScalarSizeInBits();
600   unsigned Bits1 = Ty1->getScalarSizeInBits();
601 
602   if (Bits1 >  Bits0)
603     return (Log2_32(Bits1) - Log2_32(Bits0));
604 
605   return (Log2_32(Bits0) - Log2_32(Bits1));
606 }
607 
608 // Return the number of instructions needed to truncate SrcTy to DstTy.
609 unsigned SystemZTTIImpl::
610 getVectorTruncCost(Type *SrcTy, Type *DstTy) {
611   assert (SrcTy->isVectorTy() && DstTy->isVectorTy());
612   assert(SrcTy->getPrimitiveSizeInBits().getFixedSize() >
613              DstTy->getPrimitiveSizeInBits().getFixedSize() &&
614          "Packing must reduce size of vector type.");
615   assert(cast<FixedVectorType>(SrcTy)->getNumElements() ==
616              cast<FixedVectorType>(DstTy)->getNumElements() &&
617          "Packing should not change number of elements.");
618 
619   // TODO: Since fp32 is expanded, the extract cost should always be 0.
620 
621   unsigned NumParts = getNumVectorRegs(SrcTy);
622   if (NumParts <= 2)
623     // Up to 2 vector registers can be truncated efficiently with pack or
624     // permute. The latter requires an immediate mask to be loaded, which
625     // typically gets hoisted out of a loop.  TODO: return a good value for
626     // BB-VECTORIZER that includes the immediate loads, which we do not want
627     // to count for the loop vectorizer.
628     return 1;
629 
630   unsigned Cost = 0;
631   unsigned Log2Diff = getElSizeLog2Diff(SrcTy, DstTy);
632   unsigned VF = cast<FixedVectorType>(SrcTy)->getNumElements();
633   for (unsigned P = 0; P < Log2Diff; ++P) {
634     if (NumParts > 1)
635       NumParts /= 2;
636     Cost += NumParts;
637   }
638 
639   // Currently, a general mix of permutes and pack instructions is output by
640   // isel, which follow the cost computation above except for this case which
641   // is one instruction less:
642   if (VF == 8 && SrcTy->getScalarSizeInBits() == 64 &&
643       DstTy->getScalarSizeInBits() == 8)
644     Cost--;
645 
646   return Cost;
647 }
648 
649 // Return the cost of converting a vector bitmask produced by a compare
650 // (SrcTy), to the type of the select or extend instruction (DstTy).
651 unsigned SystemZTTIImpl::
652 getVectorBitmaskConversionCost(Type *SrcTy, Type *DstTy) {
653   assert (SrcTy->isVectorTy() && DstTy->isVectorTy() &&
654           "Should only be called with vector types.");
655 
656   unsigned PackCost = 0;
657   unsigned SrcScalarBits = SrcTy->getScalarSizeInBits();
658   unsigned DstScalarBits = DstTy->getScalarSizeInBits();
659   unsigned Log2Diff = getElSizeLog2Diff(SrcTy, DstTy);
660   if (SrcScalarBits > DstScalarBits)
661     // The bitmask will be truncated.
662     PackCost = getVectorTruncCost(SrcTy, DstTy);
663   else if (SrcScalarBits < DstScalarBits) {
664     unsigned DstNumParts = getNumVectorRegs(DstTy);
665     // Each vector select needs its part of the bitmask unpacked.
666     PackCost = Log2Diff * DstNumParts;
667     // Extra cost for moving part of mask before unpacking.
668     PackCost += DstNumParts - 1;
669   }
670 
671   return PackCost;
672 }
673 
674 // Return the type of the compared operands. This is needed to compute the
675 // cost for a Select / ZExt or SExt instruction.
676 static Type *getCmpOpsType(const Instruction *I, unsigned VF = 1) {
677   Type *OpTy = nullptr;
678   if (CmpInst *CI = dyn_cast<CmpInst>(I->getOperand(0)))
679     OpTy = CI->getOperand(0)->getType();
680   else if (Instruction *LogicI = dyn_cast<Instruction>(I->getOperand(0)))
681     if (LogicI->getNumOperands() == 2)
682       if (CmpInst *CI0 = dyn_cast<CmpInst>(LogicI->getOperand(0)))
683         if (isa<CmpInst>(LogicI->getOperand(1)))
684           OpTy = CI0->getOperand(0)->getType();
685 
686   if (OpTy != nullptr) {
687     if (VF == 1) {
688       assert (!OpTy->isVectorTy() && "Expected scalar type");
689       return OpTy;
690     }
691     // Return the potentially vectorized type based on 'I' and 'VF'.  'I' may
692     // be either scalar or already vectorized with a same or lesser VF.
693     Type *ElTy = OpTy->getScalarType();
694     return FixedVectorType::get(ElTy, VF);
695   }
696 
697   return nullptr;
698 }
699 
700 // Get the cost of converting a boolean vector to a vector with same width
701 // and element size as Dst, plus the cost of zero extending if needed.
702 unsigned SystemZTTIImpl::
703 getBoolVecToIntConversionCost(unsigned Opcode, Type *Dst,
704                               const Instruction *I) {
705   auto *DstVTy = cast<FixedVectorType>(Dst);
706   unsigned VF = DstVTy->getNumElements();
707   unsigned Cost = 0;
708   // If we know what the widths of the compared operands, get any cost of
709   // converting it to match Dst. Otherwise assume same widths.
710   Type *CmpOpTy = ((I != nullptr) ? getCmpOpsType(I, VF) : nullptr);
711   if (CmpOpTy != nullptr)
712     Cost = getVectorBitmaskConversionCost(CmpOpTy, Dst);
713   if (Opcode == Instruction::ZExt || Opcode == Instruction::UIToFP)
714     // One 'vn' per dst vector with an immediate mask.
715     Cost += getNumVectorRegs(Dst);
716   return Cost;
717 }
718 
719 InstructionCost SystemZTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst,
720                                                  Type *Src,
721                                                  TTI::CastContextHint CCH,
722                                                  TTI::TargetCostKind CostKind,
723                                                  const Instruction *I) {
724   // FIXME: Can the logic below also be used for these cost kinds?
725   if (CostKind == TTI::TCK_CodeSize || CostKind == TTI::TCK_SizeAndLatency) {
726     auto BaseCost = BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I);
727     return BaseCost == 0 ? BaseCost : 1;
728   }
729 
730   unsigned DstScalarBits = Dst->getScalarSizeInBits();
731   unsigned SrcScalarBits = Src->getScalarSizeInBits();
732 
733   if (!Src->isVectorTy()) {
734     assert (!Dst->isVectorTy());
735 
736     if (Opcode == Instruction::SIToFP || Opcode == Instruction::UIToFP) {
737       if (SrcScalarBits >= 32 ||
738           (I != nullptr && isa<LoadInst>(I->getOperand(0))))
739         return 1;
740       return SrcScalarBits > 1 ? 2 /*i8/i16 extend*/ : 5 /*branch seq.*/;
741     }
742 
743     if ((Opcode == Instruction::ZExt || Opcode == Instruction::SExt) &&
744         Src->isIntegerTy(1)) {
745       if (ST->hasLoadStoreOnCond2())
746         return 2; // li 0; loc 1
747 
748       // This should be extension of a compare i1 result, which is done with
749       // ipm and a varying sequence of instructions.
750       unsigned Cost = 0;
751       if (Opcode == Instruction::SExt)
752         Cost = (DstScalarBits < 64 ? 3 : 4);
753       if (Opcode == Instruction::ZExt)
754         Cost = 3;
755       Type *CmpOpTy = ((I != nullptr) ? getCmpOpsType(I) : nullptr);
756       if (CmpOpTy != nullptr && CmpOpTy->isFloatingPointTy())
757         // If operands of an fp-type was compared, this costs +1.
758         Cost++;
759       return Cost;
760     }
761   }
762   else if (ST->hasVector()) {
763     // Vector to scalar cast.
764     auto *SrcVecTy = cast<FixedVectorType>(Src);
765     auto *DstVecTy = dyn_cast<FixedVectorType>(Dst);
766     if (!DstVecTy) {
767       // TODO: tune vector-to-scalar cast.
768       return BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I);
769     }
770     unsigned VF = SrcVecTy->getNumElements();
771     unsigned NumDstVectors = getNumVectorRegs(Dst);
772     unsigned NumSrcVectors = getNumVectorRegs(Src);
773 
774     if (Opcode == Instruction::Trunc) {
775       if (Src->getScalarSizeInBits() == Dst->getScalarSizeInBits())
776         return 0; // Check for NOOP conversions.
777       return getVectorTruncCost(Src, Dst);
778     }
779 
780     if (Opcode == Instruction::ZExt || Opcode == Instruction::SExt) {
781       if (SrcScalarBits >= 8) {
782         // ZExt/SExt will be handled with one unpack per doubling of width.
783         unsigned NumUnpacks = getElSizeLog2Diff(Src, Dst);
784 
785         // For types that spans multiple vector registers, some additional
786         // instructions are used to setup the unpacking.
787         unsigned NumSrcVectorOps =
788           (NumUnpacks > 1 ? (NumDstVectors - NumSrcVectors)
789                           : (NumDstVectors / 2));
790 
791         return (NumUnpacks * NumDstVectors) + NumSrcVectorOps;
792       }
793       else if (SrcScalarBits == 1)
794         return getBoolVecToIntConversionCost(Opcode, Dst, I);
795     }
796 
797     if (Opcode == Instruction::SIToFP || Opcode == Instruction::UIToFP ||
798         Opcode == Instruction::FPToSI || Opcode == Instruction::FPToUI) {
799       // TODO: Fix base implementation which could simplify things a bit here
800       // (seems to miss on differentiating on scalar/vector types).
801 
802       // Only 64 bit vector conversions are natively supported before z15.
803       if (DstScalarBits == 64 || ST->hasVectorEnhancements2()) {
804         if (SrcScalarBits == DstScalarBits)
805           return NumDstVectors;
806 
807         if (SrcScalarBits == 1)
808           return getBoolVecToIntConversionCost(Opcode, Dst, I) + NumDstVectors;
809       }
810 
811       // Return the cost of multiple scalar invocation plus the cost of
812       // inserting and extracting the values. Base implementation does not
813       // realize float->int gets scalarized.
814       InstructionCost ScalarCost = getCastInstrCost(
815           Opcode, Dst->getScalarType(), Src->getScalarType(), CCH, CostKind);
816       InstructionCost TotCost = VF * ScalarCost;
817       bool NeedsInserts = true, NeedsExtracts = true;
818       // FP128 registers do not get inserted or extracted.
819       if (DstScalarBits == 128 &&
820           (Opcode == Instruction::SIToFP || Opcode == Instruction::UIToFP))
821         NeedsInserts = false;
822       if (SrcScalarBits == 128 &&
823           (Opcode == Instruction::FPToSI || Opcode == Instruction::FPToUI))
824         NeedsExtracts = false;
825 
826       TotCost += getScalarizationOverhead(SrcVecTy, false, NeedsExtracts);
827       TotCost += getScalarizationOverhead(DstVecTy, NeedsInserts, false);
828 
829       // FIXME: VF 2 for float<->i32 is currently just as expensive as for VF 4.
830       if (VF == 2 && SrcScalarBits == 32 && DstScalarBits == 32)
831         TotCost *= 2;
832 
833       return TotCost;
834     }
835 
836     if (Opcode == Instruction::FPTrunc) {
837       if (SrcScalarBits == 128)  // fp128 -> double/float + inserts of elements.
838         return VF /*ldxbr/lexbr*/ +
839                getScalarizationOverhead(DstVecTy, true, false);
840       else // double -> float
841         return VF / 2 /*vledb*/ + std::max(1U, VF / 4 /*vperm*/);
842     }
843 
844     if (Opcode == Instruction::FPExt) {
845       if (SrcScalarBits == 32 && DstScalarBits == 64) {
846         // float -> double is very rare and currently unoptimized. Instead of
847         // using vldeb, which can do two at a time, all conversions are
848         // scalarized.
849         return VF * 2;
850       }
851       // -> fp128.  VF * lxdb/lxeb + extraction of elements.
852       return VF + getScalarizationOverhead(SrcVecTy, false, true);
853     }
854   }
855 
856   return BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I);
857 }
858 
859 // Scalar i8 / i16 operations will typically be made after first extending
860 // the operands to i32.
861 static unsigned getOperandsExtensionCost(const Instruction *I) {
862   unsigned ExtCost = 0;
863   for (Value *Op : I->operands())
864     // A load of i8 or i16 sign/zero extends to i32.
865     if (!isa<LoadInst>(Op) && !isa<ConstantInt>(Op))
866       ExtCost++;
867 
868   return ExtCost;
869 }
870 
871 InstructionCost SystemZTTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
872                                                    Type *CondTy,
873                                                    CmpInst::Predicate VecPred,
874                                                    TTI::TargetCostKind CostKind,
875                                                    const Instruction *I) {
876   if (CostKind != TTI::TCK_RecipThroughput)
877     return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, CostKind);
878 
879   if (!ValTy->isVectorTy()) {
880     switch (Opcode) {
881     case Instruction::ICmp: {
882       // A loaded value compared with 0 with multiple users becomes Load and
883       // Test. The load is then not foldable, so return 0 cost for the ICmp.
884       unsigned ScalarBits = ValTy->getScalarSizeInBits();
885       if (I != nullptr && ScalarBits >= 32)
886         if (LoadInst *Ld = dyn_cast<LoadInst>(I->getOperand(0)))
887           if (const ConstantInt *C = dyn_cast<ConstantInt>(I->getOperand(1)))
888             if (!Ld->hasOneUse() && Ld->getParent() == I->getParent() &&
889                 C->isZero())
890               return 0;
891 
892       unsigned Cost = 1;
893       if (ValTy->isIntegerTy() && ValTy->getScalarSizeInBits() <= 16)
894         Cost += (I != nullptr ? getOperandsExtensionCost(I) : 2);
895       return Cost;
896     }
897     case Instruction::Select:
898       if (ValTy->isFloatingPointTy())
899         return 4; // No load on condition for FP - costs a conditional jump.
900       return 1; // Load On Condition / Select Register.
901     }
902   }
903   else if (ST->hasVector()) {
904     unsigned VF = cast<FixedVectorType>(ValTy)->getNumElements();
905 
906     // Called with a compare instruction.
907     if (Opcode == Instruction::ICmp || Opcode == Instruction::FCmp) {
908       unsigned PredicateExtraCost = 0;
909       if (I != nullptr) {
910         // Some predicates cost one or two extra instructions.
911         switch (cast<CmpInst>(I)->getPredicate()) {
912         case CmpInst::Predicate::ICMP_NE:
913         case CmpInst::Predicate::ICMP_UGE:
914         case CmpInst::Predicate::ICMP_ULE:
915         case CmpInst::Predicate::ICMP_SGE:
916         case CmpInst::Predicate::ICMP_SLE:
917           PredicateExtraCost = 1;
918           break;
919         case CmpInst::Predicate::FCMP_ONE:
920         case CmpInst::Predicate::FCMP_ORD:
921         case CmpInst::Predicate::FCMP_UEQ:
922         case CmpInst::Predicate::FCMP_UNO:
923           PredicateExtraCost = 2;
924           break;
925         default:
926           break;
927         }
928       }
929 
930       // Float is handled with 2*vmr[lh]f + 2*vldeb + vfchdb for each pair of
931       // floats.  FIXME: <2 x float> generates same code as <4 x float>.
932       unsigned CmpCostPerVector = (ValTy->getScalarType()->isFloatTy() ? 10 : 1);
933       unsigned NumVecs_cmp = getNumVectorRegs(ValTy);
934 
935       unsigned Cost = (NumVecs_cmp * (CmpCostPerVector + PredicateExtraCost));
936       return Cost;
937     }
938     else { // Called with a select instruction.
939       assert (Opcode == Instruction::Select);
940 
941       // We can figure out the extra cost of packing / unpacking if the
942       // instruction was passed and the compare instruction is found.
943       unsigned PackCost = 0;
944       Type *CmpOpTy = ((I != nullptr) ? getCmpOpsType(I, VF) : nullptr);
945       if (CmpOpTy != nullptr)
946         PackCost =
947           getVectorBitmaskConversionCost(CmpOpTy, ValTy);
948 
949       return getNumVectorRegs(ValTy) /*vsel*/ + PackCost;
950     }
951   }
952 
953   return BaseT::getCmpSelInstrCost(Opcode, ValTy, CondTy, VecPred, CostKind);
954 }
955 
956 InstructionCost SystemZTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
957                                                    unsigned Index) {
958   // vlvgp will insert two grs into a vector register, so only count half the
959   // number of instructions.
960   if (Opcode == Instruction::InsertElement && Val->isIntOrIntVectorTy(64))
961     return ((Index % 2 == 0) ? 1 : 0);
962 
963   if (Opcode == Instruction::ExtractElement) {
964     int Cost = ((getScalarSizeInBits(Val) == 1) ? 2 /*+test-under-mask*/ : 1);
965 
966     // Give a slight penalty for moving out of vector pipeline to FXU unit.
967     if (Index == 0 && Val->isIntOrIntVectorTy())
968       Cost += 1;
969 
970     return Cost;
971   }
972 
973   return BaseT::getVectorInstrCost(Opcode, Val, Index);
974 }
975 
976 // Check if a load may be folded as a memory operand in its user.
977 bool SystemZTTIImpl::
978 isFoldableLoad(const LoadInst *Ld, const Instruction *&FoldedValue) {
979   if (!Ld->hasOneUse())
980     return false;
981   FoldedValue = Ld;
982   const Instruction *UserI = cast<Instruction>(*Ld->user_begin());
983   unsigned LoadedBits = getScalarSizeInBits(Ld->getType());
984   unsigned TruncBits = 0;
985   unsigned SExtBits = 0;
986   unsigned ZExtBits = 0;
987   if (UserI->hasOneUse()) {
988     unsigned UserBits = UserI->getType()->getScalarSizeInBits();
989     if (isa<TruncInst>(UserI))
990       TruncBits = UserBits;
991     else if (isa<SExtInst>(UserI))
992       SExtBits = UserBits;
993     else if (isa<ZExtInst>(UserI))
994       ZExtBits = UserBits;
995   }
996   if (TruncBits || SExtBits || ZExtBits) {
997     FoldedValue = UserI;
998     UserI = cast<Instruction>(*UserI->user_begin());
999     // Load (single use) -> trunc/extend (single use) -> UserI
1000   }
1001   if ((UserI->getOpcode() == Instruction::Sub ||
1002        UserI->getOpcode() == Instruction::SDiv ||
1003        UserI->getOpcode() == Instruction::UDiv) &&
1004       UserI->getOperand(1) != FoldedValue)
1005     return false; // Not commutative, only RHS foldable.
1006   // LoadOrTruncBits holds the number of effectively loaded bits, but 0 if an
1007   // extension was made of the load.
1008   unsigned LoadOrTruncBits =
1009       ((SExtBits || ZExtBits) ? 0 : (TruncBits ? TruncBits : LoadedBits));
1010   switch (UserI->getOpcode()) {
1011   case Instruction::Add: // SE: 16->32, 16/32->64, z14:16->64. ZE: 32->64
1012   case Instruction::Sub:
1013   case Instruction::ICmp:
1014     if (LoadedBits == 32 && ZExtBits == 64)
1015       return true;
1016     LLVM_FALLTHROUGH;
1017   case Instruction::Mul: // SE: 16->32, 32->64, z14:16->64
1018     if (UserI->getOpcode() != Instruction::ICmp) {
1019       if (LoadedBits == 16 &&
1020           (SExtBits == 32 ||
1021            (SExtBits == 64 && ST->hasMiscellaneousExtensions2())))
1022         return true;
1023       if (LoadOrTruncBits == 16)
1024         return true;
1025     }
1026     LLVM_FALLTHROUGH;
1027   case Instruction::SDiv:// SE: 32->64
1028     if (LoadedBits == 32 && SExtBits == 64)
1029       return true;
1030     LLVM_FALLTHROUGH;
1031   case Instruction::UDiv:
1032   case Instruction::And:
1033   case Instruction::Or:
1034   case Instruction::Xor:
1035     // This also makes sense for float operations, but disabled for now due
1036     // to regressions.
1037     // case Instruction::FCmp:
1038     // case Instruction::FAdd:
1039     // case Instruction::FSub:
1040     // case Instruction::FMul:
1041     // case Instruction::FDiv:
1042 
1043     // All possible extensions of memory checked above.
1044 
1045     // Comparison between memory and immediate.
1046     if (UserI->getOpcode() == Instruction::ICmp)
1047       if (ConstantInt *CI = dyn_cast<ConstantInt>(UserI->getOperand(1)))
1048         if (CI->getValue().isIntN(16))
1049           return true;
1050     return (LoadOrTruncBits == 32 || LoadOrTruncBits == 64);
1051     break;
1052   }
1053   return false;
1054 }
1055 
1056 static bool isBswapIntrinsicCall(const Value *V) {
1057   if (const Instruction *I = dyn_cast<Instruction>(V))
1058     if (auto *CI = dyn_cast<CallInst>(I))
1059       if (auto *F = CI->getCalledFunction())
1060         if (F->getIntrinsicID() == Intrinsic::bswap)
1061           return true;
1062   return false;
1063 }
1064 
1065 InstructionCost SystemZTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src,
1066                                                 MaybeAlign Alignment,
1067                                                 unsigned AddressSpace,
1068                                                 TTI::TargetCostKind CostKind,
1069                                                 const Instruction *I) {
1070   assert(!Src->isVoidTy() && "Invalid type");
1071 
1072   // TODO: Handle other cost kinds.
1073   if (CostKind != TTI::TCK_RecipThroughput)
1074     return 1;
1075 
1076   if (!Src->isVectorTy() && Opcode == Instruction::Load && I != nullptr) {
1077     // Store the load or its truncated or extended value in FoldedValue.
1078     const Instruction *FoldedValue = nullptr;
1079     if (isFoldableLoad(cast<LoadInst>(I), FoldedValue)) {
1080       const Instruction *UserI = cast<Instruction>(*FoldedValue->user_begin());
1081       assert (UserI->getNumOperands() == 2 && "Expected a binop.");
1082 
1083       // UserI can't fold two loads, so in that case return 0 cost only
1084       // half of the time.
1085       for (unsigned i = 0; i < 2; ++i) {
1086         if (UserI->getOperand(i) == FoldedValue)
1087           continue;
1088 
1089         if (Instruction *OtherOp = dyn_cast<Instruction>(UserI->getOperand(i))){
1090           LoadInst *OtherLoad = dyn_cast<LoadInst>(OtherOp);
1091           if (!OtherLoad &&
1092               (isa<TruncInst>(OtherOp) || isa<SExtInst>(OtherOp) ||
1093                isa<ZExtInst>(OtherOp)))
1094             OtherLoad = dyn_cast<LoadInst>(OtherOp->getOperand(0));
1095           if (OtherLoad && isFoldableLoad(OtherLoad, FoldedValue/*dummy*/))
1096             return i == 0; // Both operands foldable.
1097         }
1098       }
1099 
1100       return 0; // Only I is foldable in user.
1101     }
1102   }
1103 
1104   unsigned NumOps =
1105     (Src->isVectorTy() ? getNumVectorRegs(Src) : getNumberOfParts(Src));
1106 
1107   // Store/Load reversed saves one instruction.
1108   if (((!Src->isVectorTy() && NumOps == 1) || ST->hasVectorEnhancements2()) &&
1109       I != nullptr) {
1110     if (Opcode == Instruction::Load && I->hasOneUse()) {
1111       const Instruction *LdUser = cast<Instruction>(*I->user_begin());
1112       // In case of load -> bswap -> store, return normal cost for the load.
1113       if (isBswapIntrinsicCall(LdUser) &&
1114           (!LdUser->hasOneUse() || !isa<StoreInst>(*LdUser->user_begin())))
1115         return 0;
1116     }
1117     else if (const StoreInst *SI = dyn_cast<StoreInst>(I)) {
1118       const Value *StoredVal = SI->getValueOperand();
1119       if (StoredVal->hasOneUse() && isBswapIntrinsicCall(StoredVal))
1120         return 0;
1121     }
1122   }
1123 
1124   if (Src->getScalarSizeInBits() == 128)
1125     // 128 bit scalars are held in a pair of two 64 bit registers.
1126     NumOps *= 2;
1127 
1128   return  NumOps;
1129 }
1130 
1131 // The generic implementation of getInterleavedMemoryOpCost() is based on
1132 // adding costs of the memory operations plus all the extracts and inserts
1133 // needed for using / defining the vector operands. The SystemZ version does
1134 // roughly the same but bases the computations on vector permutations
1135 // instead.
1136 InstructionCost SystemZTTIImpl::getInterleavedMemoryOpCost(
1137     unsigned Opcode, Type *VecTy, unsigned Factor, ArrayRef<unsigned> Indices,
1138     Align Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind,
1139     bool UseMaskForCond, bool UseMaskForGaps) {
1140   if (UseMaskForCond || UseMaskForGaps)
1141     return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices,
1142                                              Alignment, AddressSpace, CostKind,
1143                                              UseMaskForCond, UseMaskForGaps);
1144   assert(isa<VectorType>(VecTy) &&
1145          "Expect a vector type for interleaved memory op");
1146 
1147   // Return the ceiling of dividing A by B.
1148   auto ceil = [](unsigned A, unsigned B) { return (A + B - 1) / B; };
1149 
1150   unsigned NumElts = cast<FixedVectorType>(VecTy)->getNumElements();
1151   assert(Factor > 1 && NumElts % Factor == 0 && "Invalid interleave factor");
1152   unsigned VF = NumElts / Factor;
1153   unsigned NumEltsPerVecReg = (128U / getScalarSizeInBits(VecTy));
1154   unsigned NumVectorMemOps = getNumVectorRegs(VecTy);
1155   unsigned NumPermutes = 0;
1156 
1157   if (Opcode == Instruction::Load) {
1158     // Loading interleave groups may have gaps, which may mean fewer
1159     // loads. Find out how many vectors will be loaded in total, and in how
1160     // many of them each value will be in.
1161     BitVector UsedInsts(NumVectorMemOps, false);
1162     std::vector<BitVector> ValueVecs(Factor, BitVector(NumVectorMemOps, false));
1163     for (unsigned Index : Indices)
1164       for (unsigned Elt = 0; Elt < VF; ++Elt) {
1165         unsigned Vec = (Index + Elt * Factor) / NumEltsPerVecReg;
1166         UsedInsts.set(Vec);
1167         ValueVecs[Index].set(Vec);
1168       }
1169     NumVectorMemOps = UsedInsts.count();
1170 
1171     for (unsigned Index : Indices) {
1172       // Estimate that each loaded source vector containing this Index
1173       // requires one operation, except that vperm can handle two input
1174       // registers first time for each dst vector.
1175       unsigned NumSrcVecs = ValueVecs[Index].count();
1176       unsigned NumDstVecs = ceil(VF * getScalarSizeInBits(VecTy), 128U);
1177       assert (NumSrcVecs >= NumDstVecs && "Expected at least as many sources");
1178       NumPermutes += std::max(1U, NumSrcVecs - NumDstVecs);
1179     }
1180   } else {
1181     // Estimate the permutes for each stored vector as the smaller of the
1182     // number of elements and the number of source vectors. Subtract one per
1183     // dst vector for vperm (S.A.).
1184     unsigned NumSrcVecs = std::min(NumEltsPerVecReg, Factor);
1185     unsigned NumDstVecs = NumVectorMemOps;
1186     assert (NumSrcVecs > 1 && "Expected at least two source vectors.");
1187     NumPermutes += (NumDstVecs * NumSrcVecs) - NumDstVecs;
1188   }
1189 
1190   // Cost of load/store operations and the permutations needed.
1191   return NumVectorMemOps + NumPermutes;
1192 }
1193 
1194 static int getVectorIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy) {
1195   if (RetTy->isVectorTy() && ID == Intrinsic::bswap)
1196     return getNumVectorRegs(RetTy); // VPERM
1197   return -1;
1198 }
1199 
1200 InstructionCost
1201 SystemZTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
1202                                       TTI::TargetCostKind CostKind) {
1203   InstructionCost Cost =
1204       getVectorIntrinsicInstrCost(ICA.getID(), ICA.getReturnType());
1205   if (Cost != -1)
1206     return Cost;
1207   return BaseT::getIntrinsicInstrCost(ICA, CostKind);
1208 }
1209