xref: /llvm-project/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp (revision f71cb9dbb739bb58ce7e52e49fe384ff2ff11687)
1 //===-- PPCTargetTransformInfo.cpp - PPC 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 "PPCTargetTransformInfo.h"
10 #include "llvm/Analysis/CodeMetrics.h"
11 #include "llvm/Analysis/TargetLibraryInfo.h"
12 #include "llvm/Analysis/TargetTransformInfo.h"
13 #include "llvm/CodeGen/BasicTTIImpl.h"
14 #include "llvm/CodeGen/TargetLowering.h"
15 #include "llvm/CodeGen/TargetSchedule.h"
16 #include "llvm/IR/IntrinsicsPowerPC.h"
17 #include "llvm/IR/ProfDataUtils.h"
18 #include "llvm/Support/CommandLine.h"
19 #include "llvm/Transforms/InstCombine/InstCombiner.h"
20 #include "llvm/Transforms/Utils/Local.h"
21 #include <optional>
22 
23 using namespace llvm;
24 
25 #define DEBUG_TYPE "ppctti"
26 
27 static cl::opt<bool> VecMaskCost("ppc-vec-mask-cost",
28 cl::desc("add masking cost for i1 vectors"), cl::init(true), cl::Hidden);
29 
30 static cl::opt<bool> DisablePPCConstHoist("disable-ppc-constant-hoisting",
31 cl::desc("disable constant hoisting on PPC"), cl::init(false), cl::Hidden);
32 
33 static cl::opt<bool>
34 EnablePPCColdCC("ppc-enable-coldcc", cl::Hidden, cl::init(false),
35                 cl::desc("Enable using coldcc calling conv for cold "
36                          "internal functions"));
37 
38 static cl::opt<bool>
39 LsrNoInsnsCost("ppc-lsr-no-insns-cost", cl::Hidden, cl::init(false),
40                cl::desc("Do not add instruction count to lsr cost model"));
41 
42 // The latency of mtctr is only justified if there are more than 4
43 // comparisons that will be removed as a result.
44 static cl::opt<unsigned>
45 SmallCTRLoopThreshold("min-ctr-loop-threshold", cl::init(4), cl::Hidden,
46                       cl::desc("Loops with a constant trip count smaller than "
47                                "this value will not use the count register."));
48 
49 //===----------------------------------------------------------------------===//
50 //
51 // PPC cost model.
52 //
53 //===----------------------------------------------------------------------===//
54 
55 TargetTransformInfo::PopcntSupportKind
56 PPCTTIImpl::getPopcntSupport(unsigned TyWidth) {
57   assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2");
58   if (ST->hasPOPCNTD() != PPCSubtarget::POPCNTD_Unavailable && TyWidth <= 64)
59     return ST->hasPOPCNTD() == PPCSubtarget::POPCNTD_Slow ?
60              TTI::PSK_SlowHardware : TTI::PSK_FastHardware;
61   return TTI::PSK_Software;
62 }
63 
64 std::optional<Instruction *>
65 PPCTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const {
66   Intrinsic::ID IID = II.getIntrinsicID();
67   switch (IID) {
68   default:
69     break;
70   case Intrinsic::ppc_altivec_lvx:
71   case Intrinsic::ppc_altivec_lvxl:
72     // Turn PPC lvx -> load if the pointer is known aligned.
73     if (getOrEnforceKnownAlignment(
74             II.getArgOperand(0), Align(16), IC.getDataLayout(), &II,
75             &IC.getAssumptionCache(), &IC.getDominatorTree()) >= 16) {
76       Value *Ptr = II.getArgOperand(0);
77       return new LoadInst(II.getType(), Ptr, "", false, Align(16));
78     }
79     break;
80   case Intrinsic::ppc_vsx_lxvw4x:
81   case Intrinsic::ppc_vsx_lxvd2x: {
82     // Turn PPC VSX loads into normal loads.
83     Value *Ptr = II.getArgOperand(0);
84     return new LoadInst(II.getType(), Ptr, Twine(""), false, Align(1));
85   }
86   case Intrinsic::ppc_altivec_stvx:
87   case Intrinsic::ppc_altivec_stvxl:
88     // Turn stvx -> store if the pointer is known aligned.
89     if (getOrEnforceKnownAlignment(
90             II.getArgOperand(1), Align(16), IC.getDataLayout(), &II,
91             &IC.getAssumptionCache(), &IC.getDominatorTree()) >= 16) {
92       Value *Ptr = II.getArgOperand(1);
93       return new StoreInst(II.getArgOperand(0), Ptr, false, Align(16));
94     }
95     break;
96   case Intrinsic::ppc_vsx_stxvw4x:
97   case Intrinsic::ppc_vsx_stxvd2x: {
98     // Turn PPC VSX stores into normal stores.
99     Value *Ptr = II.getArgOperand(1);
100     return new StoreInst(II.getArgOperand(0), Ptr, false, Align(1));
101   }
102   case Intrinsic::ppc_altivec_vperm:
103     // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
104     // Note that ppc_altivec_vperm has a big-endian bias, so when creating
105     // a vectorshuffle for little endian, we must undo the transformation
106     // performed on vec_perm in altivec.h.  That is, we must complement
107     // the permutation mask with respect to 31 and reverse the order of
108     // V1 and V2.
109     if (Constant *Mask = dyn_cast<Constant>(II.getArgOperand(2))) {
110       assert(cast<FixedVectorType>(Mask->getType())->getNumElements() == 16 &&
111              "Bad type for intrinsic!");
112 
113       // Check that all of the elements are integer constants or undefs.
114       bool AllEltsOk = true;
115       for (unsigned i = 0; i != 16; ++i) {
116         Constant *Elt = Mask->getAggregateElement(i);
117         if (!Elt || !(isa<ConstantInt>(Elt) || isa<UndefValue>(Elt))) {
118           AllEltsOk = false;
119           break;
120         }
121       }
122 
123       if (AllEltsOk) {
124         // Cast the input vectors to byte vectors.
125         Value *Op0 =
126             IC.Builder.CreateBitCast(II.getArgOperand(0), Mask->getType());
127         Value *Op1 =
128             IC.Builder.CreateBitCast(II.getArgOperand(1), Mask->getType());
129         Value *Result = UndefValue::get(Op0->getType());
130 
131         // Only extract each element once.
132         Value *ExtractedElts[32];
133         memset(ExtractedElts, 0, sizeof(ExtractedElts));
134 
135         for (unsigned i = 0; i != 16; ++i) {
136           if (isa<UndefValue>(Mask->getAggregateElement(i)))
137             continue;
138           unsigned Idx =
139               cast<ConstantInt>(Mask->getAggregateElement(i))->getZExtValue();
140           Idx &= 31; // Match the hardware behavior.
141           if (DL.isLittleEndian())
142             Idx = 31 - Idx;
143 
144           if (!ExtractedElts[Idx]) {
145             Value *Op0ToUse = (DL.isLittleEndian()) ? Op1 : Op0;
146             Value *Op1ToUse = (DL.isLittleEndian()) ? Op0 : Op1;
147             ExtractedElts[Idx] = IC.Builder.CreateExtractElement(
148                 Idx < 16 ? Op0ToUse : Op1ToUse, IC.Builder.getInt32(Idx & 15));
149           }
150 
151           // Insert this value into the result vector.
152           Result = IC.Builder.CreateInsertElement(Result, ExtractedElts[Idx],
153                                                   IC.Builder.getInt32(i));
154         }
155         return CastInst::Create(Instruction::BitCast, Result, II.getType());
156       }
157     }
158     break;
159   }
160   return std::nullopt;
161 }
162 
163 InstructionCost PPCTTIImpl::getIntImmCost(const APInt &Imm, Type *Ty,
164                                           TTI::TargetCostKind CostKind) {
165   if (DisablePPCConstHoist)
166     return BaseT::getIntImmCost(Imm, Ty, CostKind);
167 
168   assert(Ty->isIntegerTy());
169 
170   unsigned BitSize = Ty->getPrimitiveSizeInBits();
171   if (BitSize == 0)
172     return ~0U;
173 
174   if (Imm == 0)
175     return TTI::TCC_Free;
176 
177   if (Imm.getBitWidth() <= 64) {
178     if (isInt<16>(Imm.getSExtValue()))
179       return TTI::TCC_Basic;
180 
181     if (isInt<32>(Imm.getSExtValue())) {
182       // A constant that can be materialized using lis.
183       if ((Imm.getZExtValue() & 0xFFFF) == 0)
184         return TTI::TCC_Basic;
185 
186       return 2 * TTI::TCC_Basic;
187     }
188   }
189 
190   return 4 * TTI::TCC_Basic;
191 }
192 
193 InstructionCost PPCTTIImpl::getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx,
194                                                 const APInt &Imm, Type *Ty,
195                                                 TTI::TargetCostKind CostKind) {
196   if (DisablePPCConstHoist)
197     return BaseT::getIntImmCostIntrin(IID, Idx, Imm, Ty, CostKind);
198 
199   assert(Ty->isIntegerTy());
200 
201   unsigned BitSize = Ty->getPrimitiveSizeInBits();
202   if (BitSize == 0)
203     return ~0U;
204 
205   switch (IID) {
206   default:
207     return TTI::TCC_Free;
208   case Intrinsic::sadd_with_overflow:
209   case Intrinsic::uadd_with_overflow:
210   case Intrinsic::ssub_with_overflow:
211   case Intrinsic::usub_with_overflow:
212     if ((Idx == 1) && Imm.getBitWidth() <= 64 && isInt<16>(Imm.getSExtValue()))
213       return TTI::TCC_Free;
214     break;
215   case Intrinsic::experimental_stackmap:
216     if ((Idx < 2) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue())))
217       return TTI::TCC_Free;
218     break;
219   case Intrinsic::experimental_patchpoint_void:
220   case Intrinsic::experimental_patchpoint:
221     if ((Idx < 4) || (Imm.getBitWidth() <= 64 && isInt<64>(Imm.getSExtValue())))
222       return TTI::TCC_Free;
223     break;
224   }
225   return PPCTTIImpl::getIntImmCost(Imm, Ty, CostKind);
226 }
227 
228 InstructionCost PPCTTIImpl::getIntImmCostInst(unsigned Opcode, unsigned Idx,
229                                               const APInt &Imm, Type *Ty,
230                                               TTI::TargetCostKind CostKind,
231                                               Instruction *Inst) {
232   if (DisablePPCConstHoist)
233     return BaseT::getIntImmCostInst(Opcode, Idx, Imm, Ty, CostKind, Inst);
234 
235   assert(Ty->isIntegerTy());
236 
237   unsigned BitSize = Ty->getPrimitiveSizeInBits();
238   if (BitSize == 0)
239     return ~0U;
240 
241   unsigned ImmIdx = ~0U;
242   bool ShiftedFree = false, RunFree = false, UnsignedFree = false,
243        ZeroFree = false;
244   switch (Opcode) {
245   default:
246     return TTI::TCC_Free;
247   case Instruction::GetElementPtr:
248     // Always hoist the base address of a GetElementPtr. This prevents the
249     // creation of new constants for every base constant that gets constant
250     // folded with the offset.
251     if (Idx == 0)
252       return 2 * TTI::TCC_Basic;
253     return TTI::TCC_Free;
254   case Instruction::And:
255     RunFree = true; // (for the rotate-and-mask instructions)
256     [[fallthrough]];
257   case Instruction::Add:
258   case Instruction::Or:
259   case Instruction::Xor:
260     ShiftedFree = true;
261     [[fallthrough]];
262   case Instruction::Sub:
263   case Instruction::Mul:
264   case Instruction::Shl:
265   case Instruction::LShr:
266   case Instruction::AShr:
267     ImmIdx = 1;
268     break;
269   case Instruction::ICmp:
270     UnsignedFree = true;
271     ImmIdx = 1;
272     // Zero comparisons can use record-form instructions.
273     [[fallthrough]];
274   case Instruction::Select:
275     ZeroFree = true;
276     break;
277   case Instruction::PHI:
278   case Instruction::Call:
279   case Instruction::Ret:
280   case Instruction::Load:
281   case Instruction::Store:
282     break;
283   }
284 
285   if (ZeroFree && Imm == 0)
286     return TTI::TCC_Free;
287 
288   if (Idx == ImmIdx && Imm.getBitWidth() <= 64) {
289     if (isInt<16>(Imm.getSExtValue()))
290       return TTI::TCC_Free;
291 
292     if (RunFree) {
293       if (Imm.getBitWidth() <= 32 &&
294           (isShiftedMask_32(Imm.getZExtValue()) ||
295            isShiftedMask_32(~Imm.getZExtValue())))
296         return TTI::TCC_Free;
297 
298       if (ST->isPPC64() &&
299           (isShiftedMask_64(Imm.getZExtValue()) ||
300            isShiftedMask_64(~Imm.getZExtValue())))
301         return TTI::TCC_Free;
302     }
303 
304     if (UnsignedFree && isUInt<16>(Imm.getZExtValue()))
305       return TTI::TCC_Free;
306 
307     if (ShiftedFree && (Imm.getZExtValue() & 0xFFFF) == 0)
308       return TTI::TCC_Free;
309   }
310 
311   return PPCTTIImpl::getIntImmCost(Imm, Ty, CostKind);
312 }
313 
314 // Check if the current Type is an MMA vector type. Valid MMA types are
315 // v256i1 and v512i1 respectively.
316 static bool isMMAType(Type *Ty) {
317   return Ty->isVectorTy() && (Ty->getScalarSizeInBits() == 1) &&
318          (Ty->getPrimitiveSizeInBits() > 128);
319 }
320 
321 InstructionCost PPCTTIImpl::getInstructionCost(const User *U,
322                                                ArrayRef<const Value *> Operands,
323                                                TTI::TargetCostKind CostKind) {
324   // We already implement getCastInstrCost and getMemoryOpCost where we perform
325   // the vector adjustment there.
326   if (isa<CastInst>(U) || isa<LoadInst>(U) || isa<StoreInst>(U))
327     return BaseT::getInstructionCost(U, Operands, CostKind);
328 
329   if (U->getType()->isVectorTy()) {
330     // Instructions that need to be split should cost more.
331     std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(U->getType());
332     return LT.first * BaseT::getInstructionCost(U, Operands, CostKind);
333   }
334 
335   return BaseT::getInstructionCost(U, Operands, CostKind);
336 }
337 
338 bool PPCTTIImpl::isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE,
339                                           AssumptionCache &AC,
340                                           TargetLibraryInfo *LibInfo,
341                                           HardwareLoopInfo &HWLoopInfo) {
342   const PPCTargetMachine &TM = ST->getTargetMachine();
343   TargetSchedModel SchedModel;
344   SchedModel.init(ST);
345 
346   // Do not convert small short loops to CTR loop.
347   unsigned ConstTripCount = SE.getSmallConstantTripCount(L);
348   if (ConstTripCount && ConstTripCount < SmallCTRLoopThreshold) {
349     SmallPtrSet<const Value *, 32> EphValues;
350     CodeMetrics::collectEphemeralValues(L, &AC, EphValues);
351     CodeMetrics Metrics;
352     for (BasicBlock *BB : L->blocks())
353       Metrics.analyzeBasicBlock(BB, *this, EphValues);
354     // 6 is an approximate latency for the mtctr instruction.
355     if (Metrics.NumInsts <= (6 * SchedModel.getIssueWidth()))
356       return false;
357   }
358 
359   // Check that there is no hardware loop related intrinsics in the loop.
360   for (auto *BB : L->getBlocks())
361     for (auto &I : *BB)
362       if (auto *Call = dyn_cast<IntrinsicInst>(&I))
363         if (Call->getIntrinsicID() == Intrinsic::set_loop_iterations ||
364             Call->getIntrinsicID() == Intrinsic::loop_decrement)
365           return false;
366 
367   SmallVector<BasicBlock*, 4> ExitingBlocks;
368   L->getExitingBlocks(ExitingBlocks);
369 
370   // If there is an exit edge known to be frequently taken,
371   // we should not transform this loop.
372   for (auto &BB : ExitingBlocks) {
373     Instruction *TI = BB->getTerminator();
374     if (!TI) continue;
375 
376     if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
377       uint64_t TrueWeight = 0, FalseWeight = 0;
378       if (!BI->isConditional() ||
379           !extractBranchWeights(*BI, TrueWeight, FalseWeight))
380         continue;
381 
382       // If the exit path is more frequent than the loop path,
383       // we return here without further analysis for this loop.
384       bool TrueIsExit = !L->contains(BI->getSuccessor(0));
385       if (( TrueIsExit && FalseWeight < TrueWeight) ||
386           (!TrueIsExit && FalseWeight > TrueWeight))
387         return false;
388     }
389   }
390 
391   LLVMContext &C = L->getHeader()->getContext();
392   HWLoopInfo.CountType = TM.isPPC64() ?
393     Type::getInt64Ty(C) : Type::getInt32Ty(C);
394   HWLoopInfo.LoopDecrement = ConstantInt::get(HWLoopInfo.CountType, 1);
395   return true;
396 }
397 
398 void PPCTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
399                                          TTI::UnrollingPreferences &UP,
400                                          OptimizationRemarkEmitter *ORE) {
401   if (ST->getCPUDirective() == PPC::DIR_A2) {
402     // The A2 is in-order with a deep pipeline, and concatenation unrolling
403     // helps expose latency-hiding opportunities to the instruction scheduler.
404     UP.Partial = UP.Runtime = true;
405 
406     // We unroll a lot on the A2 (hundreds of instructions), and the benefits
407     // often outweigh the cost of a division to compute the trip count.
408     UP.AllowExpensiveTripCount = true;
409   }
410 
411   BaseT::getUnrollingPreferences(L, SE, UP, ORE);
412 }
413 
414 void PPCTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
415                                        TTI::PeelingPreferences &PP) {
416   BaseT::getPeelingPreferences(L, SE, PP);
417 }
418 // This function returns true to allow using coldcc calling convention.
419 // Returning true results in coldcc being used for functions which are cold at
420 // all call sites when the callers of the functions are not calling any other
421 // non coldcc functions.
422 bool PPCTTIImpl::useColdCCForColdCall(Function &F) {
423   return EnablePPCColdCC;
424 }
425 
426 bool PPCTTIImpl::enableAggressiveInterleaving(bool LoopHasReductions) {
427   // On the A2, always unroll aggressively.
428   if (ST->getCPUDirective() == PPC::DIR_A2)
429     return true;
430 
431   return LoopHasReductions;
432 }
433 
434 PPCTTIImpl::TTI::MemCmpExpansionOptions
435 PPCTTIImpl::enableMemCmpExpansion(bool OptSize, bool IsZeroCmp) const {
436   TTI::MemCmpExpansionOptions Options;
437   Options.LoadSizes = {8, 4, 2, 1};
438   Options.MaxNumLoads = TLI->getMaxExpandSizeMemcmp(OptSize);
439   return Options;
440 }
441 
442 bool PPCTTIImpl::enableInterleavedAccessVectorization() {
443   return true;
444 }
445 
446 unsigned PPCTTIImpl::getNumberOfRegisters(unsigned ClassID) const {
447   assert(ClassID == GPRRC || ClassID == FPRRC ||
448          ClassID == VRRC || ClassID == VSXRC);
449   if (ST->hasVSX()) {
450     assert(ClassID == GPRRC || ClassID == VSXRC || ClassID == VRRC);
451     return ClassID == VSXRC ? 64 : 32;
452   }
453   assert(ClassID == GPRRC || ClassID == FPRRC || ClassID == VRRC);
454   return 32;
455 }
456 
457 unsigned PPCTTIImpl::getRegisterClassForType(bool Vector, Type *Ty) const {
458   if (Vector)
459     return ST->hasVSX() ? VSXRC : VRRC;
460   else if (Ty && (Ty->getScalarType()->isFloatTy() ||
461                   Ty->getScalarType()->isDoubleTy()))
462     return ST->hasVSX() ? VSXRC : FPRRC;
463   else if (Ty && (Ty->getScalarType()->isFP128Ty() ||
464                   Ty->getScalarType()->isPPC_FP128Ty()))
465     return VRRC;
466   else if (Ty && Ty->getScalarType()->isHalfTy())
467     return VSXRC;
468   else
469     return GPRRC;
470 }
471 
472 const char* PPCTTIImpl::getRegisterClassName(unsigned ClassID) const {
473 
474   switch (ClassID) {
475     default:
476       llvm_unreachable("unknown register class");
477       return "PPC::unknown register class";
478     case GPRRC:       return "PPC::GPRRC";
479     case FPRRC:       return "PPC::FPRRC";
480     case VRRC:        return "PPC::VRRC";
481     case VSXRC:       return "PPC::VSXRC";
482   }
483 }
484 
485 TypeSize
486 PPCTTIImpl::getRegisterBitWidth(TargetTransformInfo::RegisterKind K) const {
487   switch (K) {
488   case TargetTransformInfo::RGK_Scalar:
489     return TypeSize::getFixed(ST->isPPC64() ? 64 : 32);
490   case TargetTransformInfo::RGK_FixedWidthVector:
491     return TypeSize::getFixed(ST->hasAltivec() ? 128 : 0);
492   case TargetTransformInfo::RGK_ScalableVector:
493     return TypeSize::getScalable(0);
494   }
495 
496   llvm_unreachable("Unsupported register kind");
497 }
498 
499 unsigned PPCTTIImpl::getCacheLineSize() const {
500   // Starting with P7 we have a cache line size of 128.
501   unsigned Directive = ST->getCPUDirective();
502   // Assume that Future CPU has the same cache line size as the others.
503   if (Directive == PPC::DIR_PWR7 || Directive == PPC::DIR_PWR8 ||
504       Directive == PPC::DIR_PWR9 || Directive == PPC::DIR_PWR10 ||
505       Directive == PPC::DIR_PWR11 || Directive == PPC::DIR_PWR_FUTURE)
506     return 128;
507 
508   // On other processors return a default of 64 bytes.
509   return 64;
510 }
511 
512 unsigned PPCTTIImpl::getPrefetchDistance() const {
513   return 300;
514 }
515 
516 unsigned PPCTTIImpl::getMaxInterleaveFactor(ElementCount VF) {
517   unsigned Directive = ST->getCPUDirective();
518   // The 440 has no SIMD support, but floating-point instructions
519   // have a 5-cycle latency, so unroll by 5x for latency hiding.
520   if (Directive == PPC::DIR_440)
521     return 5;
522 
523   // The A2 has no SIMD support, but floating-point instructions
524   // have a 6-cycle latency, so unroll by 6x for latency hiding.
525   if (Directive == PPC::DIR_A2)
526     return 6;
527 
528   // FIXME: For lack of any better information, do no harm...
529   if (Directive == PPC::DIR_E500mc || Directive == PPC::DIR_E5500)
530     return 1;
531 
532   // For P7 and P8, floating-point instructions have a 6-cycle latency and
533   // there are two execution units, so unroll by 12x for latency hiding.
534   // FIXME: the same for P9 as previous gen until POWER9 scheduling is ready
535   // FIXME: the same for P10 as previous gen until POWER10 scheduling is ready
536   // Assume that future is the same as the others.
537   if (Directive == PPC::DIR_PWR7 || Directive == PPC::DIR_PWR8 ||
538       Directive == PPC::DIR_PWR9 || Directive == PPC::DIR_PWR10 ||
539       Directive == PPC::DIR_PWR11 || Directive == PPC::DIR_PWR_FUTURE)
540     return 12;
541 
542   // For most things, modern systems have two execution units (and
543   // out-of-order execution).
544   return 2;
545 }
546 
547 // Returns a cost adjustment factor to adjust the cost of vector instructions
548 // on targets which there is overlap between the vector and scalar units,
549 // thereby reducing the overall throughput of vector code wrt. scalar code.
550 // An invalid instruction cost is returned if the type is an MMA vector type.
551 InstructionCost PPCTTIImpl::vectorCostAdjustmentFactor(unsigned Opcode,
552                                                        Type *Ty1, Type *Ty2) {
553   // If the vector type is of an MMA type (v256i1, v512i1), an invalid
554   // instruction cost is returned. This is to signify to other cost computing
555   // functions to return the maximum instruction cost in order to prevent any
556   // opportunities for the optimizer to produce MMA types within the IR.
557   if (isMMAType(Ty1))
558     return InstructionCost::getInvalid();
559 
560   if (!ST->vectorsUseTwoUnits() || !Ty1->isVectorTy())
561     return InstructionCost(1);
562 
563   std::pair<InstructionCost, MVT> LT1 = getTypeLegalizationCost(Ty1);
564   // If type legalization involves splitting the vector, we don't want to
565   // double the cost at every step - only the last step.
566   if (LT1.first != 1 || !LT1.second.isVector())
567     return InstructionCost(1);
568 
569   int ISD = TLI->InstructionOpcodeToISD(Opcode);
570   if (TLI->isOperationExpand(ISD, LT1.second))
571     return InstructionCost(1);
572 
573   if (Ty2) {
574     std::pair<InstructionCost, MVT> LT2 = getTypeLegalizationCost(Ty2);
575     if (LT2.first != 1 || !LT2.second.isVector())
576       return InstructionCost(1);
577   }
578 
579   return InstructionCost(2);
580 }
581 
582 InstructionCost PPCTTIImpl::getArithmeticInstrCost(
583     unsigned Opcode, Type *Ty, TTI::TargetCostKind CostKind,
584     TTI::OperandValueInfo Op1Info, TTI::OperandValueInfo Op2Info,
585     ArrayRef<const Value *> Args,
586     const Instruction *CxtI) {
587   assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode");
588 
589   InstructionCost CostFactor = vectorCostAdjustmentFactor(Opcode, Ty, nullptr);
590   if (!CostFactor.isValid())
591     return InstructionCost::getMax();
592 
593   // TODO: Handle more cost kinds.
594   if (CostKind != TTI::TCK_RecipThroughput)
595     return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Op1Info,
596                                          Op2Info, Args, CxtI);
597 
598   // Fallback to the default implementation.
599   InstructionCost Cost = BaseT::getArithmeticInstrCost(
600       Opcode, Ty, CostKind, Op1Info, Op2Info);
601   return Cost * CostFactor;
602 }
603 
604 InstructionCost PPCTTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp,
605                                            ArrayRef<int> Mask,
606                                            TTI::TargetCostKind CostKind,
607                                            int Index, Type *SubTp,
608                                            ArrayRef<const Value *> Args,
609                                            const Instruction *CxtI) {
610 
611   InstructionCost CostFactor =
612       vectorCostAdjustmentFactor(Instruction::ShuffleVector, Tp, nullptr);
613   if (!CostFactor.isValid())
614     return InstructionCost::getMax();
615 
616   // Legalize the type.
617   std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Tp);
618 
619   // PPC, for both Altivec/VSX, support cheap arbitrary permutations
620   // (at least in the sense that there need only be one non-loop-invariant
621   // instruction). We need one such shuffle instruction for each actual
622   // register (this is not true for arbitrary shuffles, but is true for the
623   // structured types of shuffles covered by TTI::ShuffleKind).
624   return LT.first * CostFactor;
625 }
626 
627 InstructionCost PPCTTIImpl::getCFInstrCost(unsigned Opcode,
628                                            TTI::TargetCostKind CostKind,
629                                            const Instruction *I) {
630   if (CostKind != TTI::TCK_RecipThroughput)
631     return Opcode == Instruction::PHI ? 0 : 1;
632   // Branches are assumed to be predicted.
633   return 0;
634 }
635 
636 InstructionCost PPCTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst,
637                                              Type *Src,
638                                              TTI::CastContextHint CCH,
639                                              TTI::TargetCostKind CostKind,
640                                              const Instruction *I) {
641   assert(TLI->InstructionOpcodeToISD(Opcode) && "Invalid opcode");
642 
643   InstructionCost CostFactor = vectorCostAdjustmentFactor(Opcode, Dst, Src);
644   if (!CostFactor.isValid())
645     return InstructionCost::getMax();
646 
647   InstructionCost Cost =
648       BaseT::getCastInstrCost(Opcode, Dst, Src, CCH, CostKind, I);
649   Cost *= CostFactor;
650   // TODO: Allow non-throughput costs that aren't binary.
651   if (CostKind != TTI::TCK_RecipThroughput)
652     return Cost == 0 ? 0 : 1;
653   return Cost;
654 }
655 
656 InstructionCost PPCTTIImpl::getCmpSelInstrCost(
657     unsigned Opcode, Type *ValTy, Type *CondTy, CmpInst::Predicate VecPred,
658     TTI::TargetCostKind CostKind, TTI::OperandValueInfo Op1Info,
659     TTI::OperandValueInfo Op2Info, const Instruction *I) {
660   InstructionCost CostFactor =
661       vectorCostAdjustmentFactor(Opcode, ValTy, nullptr);
662   if (!CostFactor.isValid())
663     return InstructionCost::getMax();
664 
665   InstructionCost Cost = BaseT::getCmpSelInstrCost(
666       Opcode, ValTy, CondTy, VecPred, CostKind, Op1Info, Op2Info, I);
667   // TODO: Handle other cost kinds.
668   if (CostKind != TTI::TCK_RecipThroughput)
669     return Cost;
670   return Cost * CostFactor;
671 }
672 
673 InstructionCost PPCTTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
674                                                TTI::TargetCostKind CostKind,
675                                                unsigned Index, Value *Op0,
676                                                Value *Op1) {
677   assert(Val->isVectorTy() && "This must be a vector type");
678 
679   int ISD = TLI->InstructionOpcodeToISD(Opcode);
680   assert(ISD && "Invalid opcode");
681 
682   InstructionCost CostFactor = vectorCostAdjustmentFactor(Opcode, Val, nullptr);
683   if (!CostFactor.isValid())
684     return InstructionCost::getMax();
685 
686   InstructionCost Cost =
687       BaseT::getVectorInstrCost(Opcode, Val, CostKind, Index, Op0, Op1);
688   Cost *= CostFactor;
689 
690   if (ST->hasVSX() && Val->getScalarType()->isDoubleTy()) {
691     // Double-precision scalars are already located in index #0 (or #1 if LE).
692     if (ISD == ISD::EXTRACT_VECTOR_ELT &&
693         Index == (ST->isLittleEndian() ? 1 : 0))
694       return 0;
695 
696     return Cost;
697 
698   } else if (Val->getScalarType()->isIntegerTy()) {
699     unsigned EltSize = Val->getScalarSizeInBits();
700     // Computing on 1 bit values requires extra mask or compare operations.
701     unsigned MaskCostForOneBitSize = (VecMaskCost && EltSize == 1) ? 1 : 0;
702     // Computing on non const index requires extra mask or compare operations.
703     unsigned MaskCostForIdx = (Index != -1U) ? 0 : 1;
704     if (ST->hasP9Altivec()) {
705       // P10 has vxform insert which can handle non const index. The
706       // MaskCostForIdx is for masking the index.
707       // P9 has insert for const index. A move-to VSR and a permute/insert.
708       // Assume vector operation cost for both (cost will be 2x on P9).
709       if (ISD == ISD::INSERT_VECTOR_ELT) {
710         if (ST->hasP10Vector())
711           return CostFactor + MaskCostForIdx;
712         else if (Index != -1U)
713           return 2 * CostFactor;
714       } else if (ISD == ISD::EXTRACT_VECTOR_ELT) {
715         // It's an extract.  Maybe we can do a cheap move-from VSR.
716         unsigned EltSize = Val->getScalarSizeInBits();
717         // P9 has both mfvsrd and mfvsrld for 64 bit integer.
718         if (EltSize == 64 && Index != -1U)
719           return 1;
720         else if (EltSize == 32) {
721           unsigned MfvsrwzIndex = ST->isLittleEndian() ? 2 : 1;
722           if (Index == MfvsrwzIndex)
723             return 1;
724 
725           // For other indexs like non const, P9 has vxform extract. The
726           // MaskCostForIdx is for masking the index.
727           return CostFactor + MaskCostForIdx;
728         }
729 
730         // We need a vector extract (or mfvsrld).  Assume vector operation cost.
731         // The cost of the load constant for a vector extract is disregarded
732         // (invariant, easily schedulable).
733         return CostFactor + MaskCostForOneBitSize + MaskCostForIdx;
734       }
735     } else if (ST->hasDirectMove() && Index != -1U) {
736       // Assume permute has standard cost.
737       // Assume move-to/move-from VSR have 2x standard cost.
738       if (ISD == ISD::INSERT_VECTOR_ELT)
739         return 3;
740       return 3 + MaskCostForOneBitSize;
741     }
742   }
743 
744   // Estimated cost of a load-hit-store delay.  This was obtained
745   // experimentally as a minimum needed to prevent unprofitable
746   // vectorization for the paq8p benchmark.  It may need to be
747   // raised further if other unprofitable cases remain.
748   unsigned LHSPenalty = 2;
749   if (ISD == ISD::INSERT_VECTOR_ELT)
750     LHSPenalty += 7;
751 
752   // Vector element insert/extract with Altivec is very expensive,
753   // because they require store and reload with the attendant
754   // processor stall for load-hit-store.  Until VSX is available,
755   // these need to be estimated as very costly.
756   if (ISD == ISD::EXTRACT_VECTOR_ELT ||
757       ISD == ISD::INSERT_VECTOR_ELT)
758     return LHSPenalty + Cost;
759 
760   return Cost;
761 }
762 
763 InstructionCost PPCTTIImpl::getMemoryOpCost(unsigned Opcode, Type *Src,
764                                             MaybeAlign Alignment,
765                                             unsigned AddressSpace,
766                                             TTI::TargetCostKind CostKind,
767                                             TTI::OperandValueInfo OpInfo,
768                                             const Instruction *I) {
769 
770   InstructionCost CostFactor = vectorCostAdjustmentFactor(Opcode, Src, nullptr);
771   if (!CostFactor.isValid())
772     return InstructionCost::getMax();
773 
774   if (TLI->getValueType(DL, Src,  true) == MVT::Other)
775     return BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace,
776                                   CostKind);
777   // Legalize the type.
778   std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(Src);
779   assert((Opcode == Instruction::Load || Opcode == Instruction::Store) &&
780          "Invalid Opcode");
781 
782   InstructionCost Cost =
783       BaseT::getMemoryOpCost(Opcode, Src, Alignment, AddressSpace, CostKind);
784   // TODO: Handle other cost kinds.
785   if (CostKind != TTI::TCK_RecipThroughput)
786     return Cost;
787 
788   Cost *= CostFactor;
789 
790   bool IsAltivecType = ST->hasAltivec() &&
791                        (LT.second == MVT::v16i8 || LT.second == MVT::v8i16 ||
792                         LT.second == MVT::v4i32 || LT.second == MVT::v4f32);
793   bool IsVSXType = ST->hasVSX() &&
794                    (LT.second == MVT::v2f64 || LT.second == MVT::v2i64);
795 
796   // VSX has 32b/64b load instructions. Legalization can handle loading of
797   // 32b/64b to VSR correctly and cheaply. But BaseT::getMemoryOpCost and
798   // PPCTargetLowering can't compute the cost appropriately. So here we
799   // explicitly check this case. There are also corresponding store
800   // instructions.
801   unsigned MemBits = Src->getPrimitiveSizeInBits();
802   unsigned SrcBytes = LT.second.getStoreSize();
803   if (ST->hasVSX() && IsAltivecType) {
804     if (MemBits == 64 || (ST->hasP8Vector() && MemBits == 32))
805       return 1;
806 
807     // Use lfiwax/xxspltw
808     Align AlignBytes = Alignment ? *Alignment : Align(1);
809     if (Opcode == Instruction::Load && MemBits == 32 && AlignBytes < SrcBytes)
810       return 2;
811   }
812 
813   // Aligned loads and stores are easy.
814   if (!SrcBytes || !Alignment || *Alignment >= SrcBytes)
815     return Cost;
816 
817   // If we can use the permutation-based load sequence, then this is also
818   // relatively cheap (not counting loop-invariant instructions): one load plus
819   // one permute (the last load in a series has extra cost, but we're
820   // neglecting that here). Note that on the P7, we could do unaligned loads
821   // for Altivec types using the VSX instructions, but that's more expensive
822   // than using the permutation-based load sequence. On the P8, that's no
823   // longer true.
824   if (Opcode == Instruction::Load && (!ST->hasP8Vector() && IsAltivecType) &&
825       *Alignment >= LT.second.getScalarType().getStoreSize())
826     return Cost + LT.first; // Add the cost of the permutations.
827 
828   // For VSX, we can do unaligned loads and stores on Altivec/VSX types. On the
829   // P7, unaligned vector loads are more expensive than the permutation-based
830   // load sequence, so that might be used instead, but regardless, the net cost
831   // is about the same (not counting loop-invariant instructions).
832   if (IsVSXType || (ST->hasVSX() && IsAltivecType))
833     return Cost;
834 
835   // Newer PPC supports unaligned memory access.
836   if (TLI->allowsMisalignedMemoryAccesses(LT.second, 0))
837     return Cost;
838 
839   // PPC in general does not support unaligned loads and stores. They'll need
840   // to be decomposed based on the alignment factor.
841 
842   // Add the cost of each scalar load or store.
843   assert(Alignment);
844   Cost += LT.first * ((SrcBytes / Alignment->value()) - 1);
845 
846   // For a vector type, there is also scalarization overhead (only for
847   // stores, loads are expanded using the vector-load + permutation sequence,
848   // which is much less expensive).
849   if (Src->isVectorTy() && Opcode == Instruction::Store)
850     for (int i = 0, e = cast<FixedVectorType>(Src)->getNumElements(); i < e;
851          ++i)
852       Cost += getVectorInstrCost(Instruction::ExtractElement, Src, CostKind, i,
853                                  nullptr, nullptr);
854 
855   return Cost;
856 }
857 
858 InstructionCost PPCTTIImpl::getInterleavedMemoryOpCost(
859     unsigned Opcode, Type *VecTy, unsigned Factor, ArrayRef<unsigned> Indices,
860     Align Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind,
861     bool UseMaskForCond, bool UseMaskForGaps) {
862   InstructionCost CostFactor =
863       vectorCostAdjustmentFactor(Opcode, VecTy, nullptr);
864   if (!CostFactor.isValid())
865     return InstructionCost::getMax();
866 
867   if (UseMaskForCond || UseMaskForGaps)
868     return BaseT::getInterleavedMemoryOpCost(Opcode, VecTy, Factor, Indices,
869                                              Alignment, AddressSpace, CostKind,
870                                              UseMaskForCond, UseMaskForGaps);
871 
872   assert(isa<VectorType>(VecTy) &&
873          "Expect a vector type for interleaved memory op");
874 
875   // Legalize the type.
876   std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(VecTy);
877 
878   // Firstly, the cost of load/store operation.
879   InstructionCost Cost = getMemoryOpCost(Opcode, VecTy, MaybeAlign(Alignment),
880                                          AddressSpace, CostKind);
881 
882   // PPC, for both Altivec/VSX, support cheap arbitrary permutations
883   // (at least in the sense that there need only be one non-loop-invariant
884   // instruction). For each result vector, we need one shuffle per incoming
885   // vector (except that the first shuffle can take two incoming vectors
886   // because it does not need to take itself).
887   Cost += Factor*(LT.first-1);
888 
889   return Cost;
890 }
891 
892 InstructionCost
893 PPCTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
894                                   TTI::TargetCostKind CostKind) {
895   return BaseT::getIntrinsicInstrCost(ICA, CostKind);
896 }
897 
898 bool PPCTTIImpl::areTypesABICompatible(const Function *Caller,
899                                        const Function *Callee,
900                                        const ArrayRef<Type *> &Types) const {
901 
902   // We need to ensure that argument promotion does not
903   // attempt to promote pointers to MMA types (__vector_pair
904   // and __vector_quad) since these types explicitly cannot be
905   // passed as arguments. Both of these types are larger than
906   // the 128-bit Altivec vectors and have a scalar size of 1 bit.
907   if (!BaseT::areTypesABICompatible(Caller, Callee, Types))
908     return false;
909 
910   return llvm::none_of(Types, [](Type *Ty) {
911     if (Ty->isSized())
912       return Ty->isIntOrIntVectorTy(1) && Ty->getPrimitiveSizeInBits() > 128;
913     return false;
914   });
915 }
916 
917 bool PPCTTIImpl::canSaveCmp(Loop *L, BranchInst **BI, ScalarEvolution *SE,
918                             LoopInfo *LI, DominatorTree *DT,
919                             AssumptionCache *AC, TargetLibraryInfo *LibInfo) {
920   // Process nested loops first.
921   for (Loop *I : *L)
922     if (canSaveCmp(I, BI, SE, LI, DT, AC, LibInfo))
923       return false; // Stop search.
924 
925   HardwareLoopInfo HWLoopInfo(L);
926 
927   if (!HWLoopInfo.canAnalyze(*LI))
928     return false;
929 
930   if (!isHardwareLoopProfitable(L, *SE, *AC, LibInfo, HWLoopInfo))
931     return false;
932 
933   if (!HWLoopInfo.isHardwareLoopCandidate(*SE, *LI, *DT))
934     return false;
935 
936   *BI = HWLoopInfo.ExitBranch;
937   return true;
938 }
939 
940 bool PPCTTIImpl::isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
941                                const TargetTransformInfo::LSRCost &C2) {
942   // PowerPC default behaviour here is "instruction number 1st priority".
943   // If LsrNoInsnsCost is set, call default implementation.
944   if (!LsrNoInsnsCost)
945     return std::tie(C1.Insns, C1.NumRegs, C1.AddRecCost, C1.NumIVMuls,
946                     C1.NumBaseAdds, C1.ScaleCost, C1.ImmCost, C1.SetupCost) <
947            std::tie(C2.Insns, C2.NumRegs, C2.AddRecCost, C2.NumIVMuls,
948                     C2.NumBaseAdds, C2.ScaleCost, C2.ImmCost, C2.SetupCost);
949   else
950     return TargetTransformInfoImplBase::isLSRCostLess(C1, C2);
951 }
952 
953 bool PPCTTIImpl::isNumRegsMajorCostOfLSR() {
954   return false;
955 }
956 
957 bool PPCTTIImpl::shouldBuildRelLookupTables() const {
958   const PPCTargetMachine &TM = ST->getTargetMachine();
959   // XCOFF hasn't implemented lowerRelativeReference, disable non-ELF for now.
960   if (!TM.isELFv2ABI())
961     return false;
962   return BaseT::shouldBuildRelLookupTables();
963 }
964 
965 bool PPCTTIImpl::getTgtMemIntrinsic(IntrinsicInst *Inst,
966                                     MemIntrinsicInfo &Info) {
967   switch (Inst->getIntrinsicID()) {
968   case Intrinsic::ppc_altivec_lvx:
969   case Intrinsic::ppc_altivec_lvxl:
970   case Intrinsic::ppc_altivec_lvebx:
971   case Intrinsic::ppc_altivec_lvehx:
972   case Intrinsic::ppc_altivec_lvewx:
973   case Intrinsic::ppc_vsx_lxvd2x:
974   case Intrinsic::ppc_vsx_lxvw4x:
975   case Intrinsic::ppc_vsx_lxvd2x_be:
976   case Intrinsic::ppc_vsx_lxvw4x_be:
977   case Intrinsic::ppc_vsx_lxvl:
978   case Intrinsic::ppc_vsx_lxvll:
979   case Intrinsic::ppc_vsx_lxvp: {
980     Info.PtrVal = Inst->getArgOperand(0);
981     Info.ReadMem = true;
982     Info.WriteMem = false;
983     return true;
984   }
985   case Intrinsic::ppc_altivec_stvx:
986   case Intrinsic::ppc_altivec_stvxl:
987   case Intrinsic::ppc_altivec_stvebx:
988   case Intrinsic::ppc_altivec_stvehx:
989   case Intrinsic::ppc_altivec_stvewx:
990   case Intrinsic::ppc_vsx_stxvd2x:
991   case Intrinsic::ppc_vsx_stxvw4x:
992   case Intrinsic::ppc_vsx_stxvd2x_be:
993   case Intrinsic::ppc_vsx_stxvw4x_be:
994   case Intrinsic::ppc_vsx_stxvl:
995   case Intrinsic::ppc_vsx_stxvll:
996   case Intrinsic::ppc_vsx_stxvp: {
997     Info.PtrVal = Inst->getArgOperand(1);
998     Info.ReadMem = false;
999     Info.WriteMem = true;
1000     return true;
1001   }
1002   case Intrinsic::ppc_stbcx:
1003   case Intrinsic::ppc_sthcx:
1004   case Intrinsic::ppc_stdcx:
1005   case Intrinsic::ppc_stwcx: {
1006     Info.PtrVal = Inst->getArgOperand(0);
1007     Info.ReadMem = false;
1008     Info.WriteMem = true;
1009     return true;
1010   }
1011   default:
1012     break;
1013   }
1014 
1015   return false;
1016 }
1017 
1018 bool PPCTTIImpl::hasActiveVectorLength(unsigned Opcode, Type *DataType,
1019                                        Align Alignment) const {
1020   // Only load and stores instructions can have variable vector length on Power.
1021   if (Opcode != Instruction::Load && Opcode != Instruction::Store)
1022     return false;
1023   // Loads/stores with length instructions use bits 0-7 of the GPR operand and
1024   // therefore cannot be used in 32-bit mode.
1025   if ((!ST->hasP9Vector() && !ST->hasP10Vector()) || !ST->isPPC64())
1026     return false;
1027   if (isa<FixedVectorType>(DataType)) {
1028     unsigned VecWidth = DataType->getPrimitiveSizeInBits();
1029     return VecWidth == 128;
1030   }
1031   Type *ScalarTy = DataType->getScalarType();
1032 
1033   if (ScalarTy->isPointerTy())
1034     return true;
1035 
1036   if (ScalarTy->isFloatTy() || ScalarTy->isDoubleTy())
1037     return true;
1038 
1039   if (!ScalarTy->isIntegerTy())
1040     return false;
1041 
1042   unsigned IntWidth = ScalarTy->getIntegerBitWidth();
1043   return IntWidth == 8 || IntWidth == 16 || IntWidth == 32 || IntWidth == 64;
1044 }
1045 
1046 InstructionCost PPCTTIImpl::getVPMemoryOpCost(unsigned Opcode, Type *Src,
1047                                               Align Alignment,
1048                                               unsigned AddressSpace,
1049                                               TTI::TargetCostKind CostKind,
1050                                               const Instruction *I) {
1051   InstructionCost Cost = BaseT::getVPMemoryOpCost(Opcode, Src, Alignment,
1052                                                   AddressSpace, CostKind, I);
1053   if (TLI->getValueType(DL, Src, true) == MVT::Other)
1054     return Cost;
1055   // TODO: Handle other cost kinds.
1056   if (CostKind != TTI::TCK_RecipThroughput)
1057     return Cost;
1058 
1059   assert((Opcode == Instruction::Load || Opcode == Instruction::Store) &&
1060          "Invalid Opcode");
1061 
1062   auto *SrcVTy = dyn_cast<FixedVectorType>(Src);
1063   assert(SrcVTy && "Expected a vector type for VP memory operations");
1064 
1065   if (hasActiveVectorLength(Opcode, Src, Alignment)) {
1066     std::pair<InstructionCost, MVT> LT = getTypeLegalizationCost(SrcVTy);
1067 
1068     InstructionCost CostFactor =
1069         vectorCostAdjustmentFactor(Opcode, Src, nullptr);
1070     if (!CostFactor.isValid())
1071       return InstructionCost::getMax();
1072 
1073     InstructionCost Cost = LT.first * CostFactor;
1074     assert(Cost.isValid() && "Expected valid cost");
1075 
1076     // On P9 but not on P10, if the op is misaligned then it will cause a
1077     // pipeline flush. Otherwise the VSX masked memops cost the same as unmasked
1078     // ones.
1079     const Align DesiredAlignment(16);
1080     if (Alignment >= DesiredAlignment || ST->getCPUDirective() != PPC::DIR_PWR9)
1081       return Cost;
1082 
1083     // Since alignment may be under estimated, we try to compute the probability
1084     // that the actual address is aligned to the desired boundary. For example
1085     // an 8-byte aligned load is assumed to be actually 16-byte aligned half the
1086     // time, while a 4-byte aligned load has a 25% chance of being 16-byte
1087     // aligned.
1088     float AlignmentProb = ((float)Alignment.value()) / DesiredAlignment.value();
1089     float MisalignmentProb = 1.0 - AlignmentProb;
1090     return (MisalignmentProb * P9PipelineFlushEstimate) +
1091            (AlignmentProb * *Cost.getValue());
1092   }
1093 
1094   // Usually we should not get to this point, but the following is an attempt to
1095   // model the cost of legalization. Currently we can only lower intrinsics with
1096   // evl but no mask, on Power 9/10. Otherwise, we must scalarize.
1097   return getMaskedMemoryOpCost(Opcode, Src, Alignment, AddressSpace, CostKind);
1098 }
1099 
1100 bool PPCTTIImpl::supportsTailCallFor(const CallBase *CB) const {
1101   return TLI->supportsTailCallFor(CB);
1102 }
1103