xref: /freebsd/contrib/llvm-project/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp (revision c57c26179033f64c2011a2d2a904ee3fa62e826a)
1 //===- InstCombineCalls.cpp -----------------------------------------------===//
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 the visitCall, visitInvoke, and visitCallBr functions.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "InstCombineInternal.h"
14 #include "llvm/ADT/APFloat.h"
15 #include "llvm/ADT/APInt.h"
16 #include "llvm/ADT/APSInt.h"
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/ADT/STLFunctionalExtras.h"
19 #include "llvm/ADT/SmallBitVector.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/Analysis/AliasAnalysis.h"
23 #include "llvm/Analysis/AssumeBundleQueries.h"
24 #include "llvm/Analysis/AssumptionCache.h"
25 #include "llvm/Analysis/InstructionSimplify.h"
26 #include "llvm/Analysis/Loads.h"
27 #include "llvm/Analysis/MemoryBuiltins.h"
28 #include "llvm/Analysis/ValueTracking.h"
29 #include "llvm/Analysis/VectorUtils.h"
30 #include "llvm/IR/AttributeMask.h"
31 #include "llvm/IR/Attributes.h"
32 #include "llvm/IR/BasicBlock.h"
33 #include "llvm/IR/Constant.h"
34 #include "llvm/IR/Constants.h"
35 #include "llvm/IR/DataLayout.h"
36 #include "llvm/IR/DebugInfo.h"
37 #include "llvm/IR/DerivedTypes.h"
38 #include "llvm/IR/Function.h"
39 #include "llvm/IR/GlobalVariable.h"
40 #include "llvm/IR/InlineAsm.h"
41 #include "llvm/IR/InstrTypes.h"
42 #include "llvm/IR/Instruction.h"
43 #include "llvm/IR/Instructions.h"
44 #include "llvm/IR/IntrinsicInst.h"
45 #include "llvm/IR/Intrinsics.h"
46 #include "llvm/IR/IntrinsicsAArch64.h"
47 #include "llvm/IR/IntrinsicsAMDGPU.h"
48 #include "llvm/IR/IntrinsicsARM.h"
49 #include "llvm/IR/IntrinsicsHexagon.h"
50 #include "llvm/IR/LLVMContext.h"
51 #include "llvm/IR/Metadata.h"
52 #include "llvm/IR/PatternMatch.h"
53 #include "llvm/IR/Statepoint.h"
54 #include "llvm/IR/Type.h"
55 #include "llvm/IR/User.h"
56 #include "llvm/IR/Value.h"
57 #include "llvm/IR/ValueHandle.h"
58 #include "llvm/Support/AtomicOrdering.h"
59 #include "llvm/Support/Casting.h"
60 #include "llvm/Support/CommandLine.h"
61 #include "llvm/Support/Compiler.h"
62 #include "llvm/Support/Debug.h"
63 #include "llvm/Support/ErrorHandling.h"
64 #include "llvm/Support/KnownBits.h"
65 #include "llvm/Support/MathExtras.h"
66 #include "llvm/Support/raw_ostream.h"
67 #include "llvm/Transforms/InstCombine/InstCombiner.h"
68 #include "llvm/Transforms/Utils/AssumeBundleBuilder.h"
69 #include "llvm/Transforms/Utils/Local.h"
70 #include "llvm/Transforms/Utils/SimplifyLibCalls.h"
71 #include <algorithm>
72 #include <cassert>
73 #include <cstdint>
74 #include <optional>
75 #include <utility>
76 #include <vector>
77 
78 #define DEBUG_TYPE "instcombine"
79 #include "llvm/Transforms/Utils/InstructionWorklist.h"
80 
81 using namespace llvm;
82 using namespace PatternMatch;
83 
84 STATISTIC(NumSimplified, "Number of library calls simplified");
85 
86 static cl::opt<unsigned> GuardWideningWindow(
87     "instcombine-guard-widening-window",
88     cl::init(3),
89     cl::desc("How wide an instruction window to bypass looking for "
90              "another guard"));
91 
92 /// Return the specified type promoted as it would be to pass though a va_arg
93 /// area.
94 static Type *getPromotedType(Type *Ty) {
95   if (IntegerType* ITy = dyn_cast<IntegerType>(Ty)) {
96     if (ITy->getBitWidth() < 32)
97       return Type::getInt32Ty(Ty->getContext());
98   }
99   return Ty;
100 }
101 
102 /// Recognize a memcpy/memmove from a trivially otherwise unused alloca.
103 /// TODO: This should probably be integrated with visitAllocSites, but that
104 /// requires a deeper change to allow either unread or unwritten objects.
105 static bool hasUndefSource(AnyMemTransferInst *MI) {
106   auto *Src = MI->getRawSource();
107   while (isa<GetElementPtrInst>(Src) || isa<BitCastInst>(Src)) {
108     if (!Src->hasOneUse())
109       return false;
110     Src = cast<Instruction>(Src)->getOperand(0);
111   }
112   return isa<AllocaInst>(Src) && Src->hasOneUse();
113 }
114 
115 Instruction *InstCombinerImpl::SimplifyAnyMemTransfer(AnyMemTransferInst *MI) {
116   Align DstAlign = getKnownAlignment(MI->getRawDest(), DL, MI, &AC, &DT);
117   MaybeAlign CopyDstAlign = MI->getDestAlign();
118   if (!CopyDstAlign || *CopyDstAlign < DstAlign) {
119     MI->setDestAlignment(DstAlign);
120     return MI;
121   }
122 
123   Align SrcAlign = getKnownAlignment(MI->getRawSource(), DL, MI, &AC, &DT);
124   MaybeAlign CopySrcAlign = MI->getSourceAlign();
125   if (!CopySrcAlign || *CopySrcAlign < SrcAlign) {
126     MI->setSourceAlignment(SrcAlign);
127     return MI;
128   }
129 
130   // If we have a store to a location which is known constant, we can conclude
131   // that the store must be storing the constant value (else the memory
132   // wouldn't be constant), and this must be a noop.
133   if (!isModSet(AA->getModRefInfoMask(MI->getDest()))) {
134     // Set the size of the copy to 0, it will be deleted on the next iteration.
135     MI->setLength(Constant::getNullValue(MI->getLength()->getType()));
136     return MI;
137   }
138 
139   // If the source is provably undef, the memcpy/memmove doesn't do anything
140   // (unless the transfer is volatile).
141   if (hasUndefSource(MI) && !MI->isVolatile()) {
142     // Set the size of the copy to 0, it will be deleted on the next iteration.
143     MI->setLength(Constant::getNullValue(MI->getLength()->getType()));
144     return MI;
145   }
146 
147   // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with
148   // load/store.
149   ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getLength());
150   if (!MemOpLength) return nullptr;
151 
152   // Source and destination pointer types are always "i8*" for intrinsic.  See
153   // if the size is something we can handle with a single primitive load/store.
154   // A single load+store correctly handles overlapping memory in the memmove
155   // case.
156   uint64_t Size = MemOpLength->getLimitedValue();
157   assert(Size && "0-sized memory transferring should be removed already.");
158 
159   if (Size > 8 || (Size&(Size-1)))
160     return nullptr;  // If not 1/2/4/8 bytes, exit.
161 
162   // If it is an atomic and alignment is less than the size then we will
163   // introduce the unaligned memory access which will be later transformed
164   // into libcall in CodeGen. This is not evident performance gain so disable
165   // it now.
166   if (isa<AtomicMemTransferInst>(MI))
167     if (*CopyDstAlign < Size || *CopySrcAlign < Size)
168       return nullptr;
169 
170   // Use an integer load+store unless we can find something better.
171   IntegerType* IntType = IntegerType::get(MI->getContext(), Size<<3);
172 
173   // If the memcpy has metadata describing the members, see if we can get the
174   // TBAA tag describing our copy.
175   AAMDNodes AACopyMD = MI->getAAMetadata();
176 
177   if (MDNode *M = AACopyMD.TBAAStruct) {
178     AACopyMD.TBAAStruct = nullptr;
179     if (M->getNumOperands() == 3 && M->getOperand(0) &&
180         mdconst::hasa<ConstantInt>(M->getOperand(0)) &&
181         mdconst::extract<ConstantInt>(M->getOperand(0))->isZero() &&
182         M->getOperand(1) &&
183         mdconst::hasa<ConstantInt>(M->getOperand(1)) &&
184         mdconst::extract<ConstantInt>(M->getOperand(1))->getValue() ==
185         Size &&
186         M->getOperand(2) && isa<MDNode>(M->getOperand(2)))
187       AACopyMD.TBAA = cast<MDNode>(M->getOperand(2));
188   }
189 
190   Value *Src = MI->getArgOperand(1);
191   Value *Dest = MI->getArgOperand(0);
192   LoadInst *L = Builder.CreateLoad(IntType, Src);
193   // Alignment from the mem intrinsic will be better, so use it.
194   L->setAlignment(*CopySrcAlign);
195   L->setAAMetadata(AACopyMD);
196   MDNode *LoopMemParallelMD =
197     MI->getMetadata(LLVMContext::MD_mem_parallel_loop_access);
198   if (LoopMemParallelMD)
199     L->setMetadata(LLVMContext::MD_mem_parallel_loop_access, LoopMemParallelMD);
200   MDNode *AccessGroupMD = MI->getMetadata(LLVMContext::MD_access_group);
201   if (AccessGroupMD)
202     L->setMetadata(LLVMContext::MD_access_group, AccessGroupMD);
203 
204   StoreInst *S = Builder.CreateStore(L, Dest);
205   // Alignment from the mem intrinsic will be better, so use it.
206   S->setAlignment(*CopyDstAlign);
207   S->setAAMetadata(AACopyMD);
208   if (LoopMemParallelMD)
209     S->setMetadata(LLVMContext::MD_mem_parallel_loop_access, LoopMemParallelMD);
210   if (AccessGroupMD)
211     S->setMetadata(LLVMContext::MD_access_group, AccessGroupMD);
212   S->copyMetadata(*MI, LLVMContext::MD_DIAssignID);
213 
214   if (auto *MT = dyn_cast<MemTransferInst>(MI)) {
215     // non-atomics can be volatile
216     L->setVolatile(MT->isVolatile());
217     S->setVolatile(MT->isVolatile());
218   }
219   if (isa<AtomicMemTransferInst>(MI)) {
220     // atomics have to be unordered
221     L->setOrdering(AtomicOrdering::Unordered);
222     S->setOrdering(AtomicOrdering::Unordered);
223   }
224 
225   // Set the size of the copy to 0, it will be deleted on the next iteration.
226   MI->setLength(Constant::getNullValue(MemOpLength->getType()));
227   return MI;
228 }
229 
230 Instruction *InstCombinerImpl::SimplifyAnyMemSet(AnyMemSetInst *MI) {
231   const Align KnownAlignment =
232       getKnownAlignment(MI->getDest(), DL, MI, &AC, &DT);
233   MaybeAlign MemSetAlign = MI->getDestAlign();
234   if (!MemSetAlign || *MemSetAlign < KnownAlignment) {
235     MI->setDestAlignment(KnownAlignment);
236     return MI;
237   }
238 
239   // If we have a store to a location which is known constant, we can conclude
240   // that the store must be storing the constant value (else the memory
241   // wouldn't be constant), and this must be a noop.
242   if (!isModSet(AA->getModRefInfoMask(MI->getDest()))) {
243     // Set the size of the copy to 0, it will be deleted on the next iteration.
244     MI->setLength(Constant::getNullValue(MI->getLength()->getType()));
245     return MI;
246   }
247 
248   // Remove memset with an undef value.
249   // FIXME: This is technically incorrect because it might overwrite a poison
250   // value. Change to PoisonValue once #52930 is resolved.
251   if (isa<UndefValue>(MI->getValue())) {
252     // Set the size of the copy to 0, it will be deleted on the next iteration.
253     MI->setLength(Constant::getNullValue(MI->getLength()->getType()));
254     return MI;
255   }
256 
257   // Extract the length and alignment and fill if they are constant.
258   ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength());
259   ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
260   if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8))
261     return nullptr;
262   const uint64_t Len = LenC->getLimitedValue();
263   assert(Len && "0-sized memory setting should be removed already.");
264   const Align Alignment = MI->getDestAlign().valueOrOne();
265 
266   // If it is an atomic and alignment is less than the size then we will
267   // introduce the unaligned memory access which will be later transformed
268   // into libcall in CodeGen. This is not evident performance gain so disable
269   // it now.
270   if (isa<AtomicMemSetInst>(MI))
271     if (Alignment < Len)
272       return nullptr;
273 
274   // memset(s,c,n) -> store s, c (for n=1,2,4,8)
275   if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) {
276     Type *ITy = IntegerType::get(MI->getContext(), Len*8);  // n=1 -> i8.
277 
278     Value *Dest = MI->getDest();
279 
280     // Extract the fill value and store.
281     const uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL;
282     Constant *FillVal = ConstantInt::get(ITy, Fill);
283     StoreInst *S = Builder.CreateStore(FillVal, Dest, MI->isVolatile());
284     S->copyMetadata(*MI, LLVMContext::MD_DIAssignID);
285     auto replaceOpForAssignmentMarkers = [FillC, FillVal](auto *DbgAssign) {
286       if (llvm::is_contained(DbgAssign->location_ops(), FillC))
287         DbgAssign->replaceVariableLocationOp(FillC, FillVal);
288     };
289     for_each(at::getAssignmentMarkers(S), replaceOpForAssignmentMarkers);
290     for_each(at::getDPVAssignmentMarkers(S), replaceOpForAssignmentMarkers);
291 
292     S->setAlignment(Alignment);
293     if (isa<AtomicMemSetInst>(MI))
294       S->setOrdering(AtomicOrdering::Unordered);
295 
296     // Set the size of the copy to 0, it will be deleted on the next iteration.
297     MI->setLength(Constant::getNullValue(LenC->getType()));
298     return MI;
299   }
300 
301   return nullptr;
302 }
303 
304 // TODO, Obvious Missing Transforms:
305 // * Narrow width by halfs excluding zero/undef lanes
306 Value *InstCombinerImpl::simplifyMaskedLoad(IntrinsicInst &II) {
307   Value *LoadPtr = II.getArgOperand(0);
308   const Align Alignment =
309       cast<ConstantInt>(II.getArgOperand(1))->getAlignValue();
310 
311   // If the mask is all ones or undefs, this is a plain vector load of the 1st
312   // argument.
313   if (maskIsAllOneOrUndef(II.getArgOperand(2))) {
314     LoadInst *L = Builder.CreateAlignedLoad(II.getType(), LoadPtr, Alignment,
315                                             "unmaskedload");
316     L->copyMetadata(II);
317     return L;
318   }
319 
320   // If we can unconditionally load from this address, replace with a
321   // load/select idiom. TODO: use DT for context sensitive query
322   if (isDereferenceablePointer(LoadPtr, II.getType(),
323                                II.getModule()->getDataLayout(), &II, &AC)) {
324     LoadInst *LI = Builder.CreateAlignedLoad(II.getType(), LoadPtr, Alignment,
325                                              "unmaskedload");
326     LI->copyMetadata(II);
327     return Builder.CreateSelect(II.getArgOperand(2), LI, II.getArgOperand(3));
328   }
329 
330   return nullptr;
331 }
332 
333 // TODO, Obvious Missing Transforms:
334 // * Single constant active lane -> store
335 // * Narrow width by halfs excluding zero/undef lanes
336 Instruction *InstCombinerImpl::simplifyMaskedStore(IntrinsicInst &II) {
337   auto *ConstMask = dyn_cast<Constant>(II.getArgOperand(3));
338   if (!ConstMask)
339     return nullptr;
340 
341   // If the mask is all zeros, this instruction does nothing.
342   if (ConstMask->isNullValue())
343     return eraseInstFromFunction(II);
344 
345   // If the mask is all ones, this is a plain vector store of the 1st argument.
346   if (ConstMask->isAllOnesValue()) {
347     Value *StorePtr = II.getArgOperand(1);
348     Align Alignment = cast<ConstantInt>(II.getArgOperand(2))->getAlignValue();
349     StoreInst *S =
350         new StoreInst(II.getArgOperand(0), StorePtr, false, Alignment);
351     S->copyMetadata(II);
352     return S;
353   }
354 
355   if (isa<ScalableVectorType>(ConstMask->getType()))
356     return nullptr;
357 
358   // Use masked off lanes to simplify operands via SimplifyDemandedVectorElts
359   APInt DemandedElts = possiblyDemandedEltsInMask(ConstMask);
360   APInt PoisonElts(DemandedElts.getBitWidth(), 0);
361   if (Value *V = SimplifyDemandedVectorElts(II.getOperand(0), DemandedElts,
362                                             PoisonElts))
363     return replaceOperand(II, 0, V);
364 
365   return nullptr;
366 }
367 
368 // TODO, Obvious Missing Transforms:
369 // * Single constant active lane load -> load
370 // * Dereferenceable address & few lanes -> scalarize speculative load/selects
371 // * Adjacent vector addresses -> masked.load
372 // * Narrow width by halfs excluding zero/undef lanes
373 // * Vector incrementing address -> vector masked load
374 Instruction *InstCombinerImpl::simplifyMaskedGather(IntrinsicInst &II) {
375   auto *ConstMask = dyn_cast<Constant>(II.getArgOperand(2));
376   if (!ConstMask)
377     return nullptr;
378 
379   // Vector splat address w/known mask -> scalar load
380   // Fold the gather to load the source vector first lane
381   // because it is reloading the same value each time
382   if (ConstMask->isAllOnesValue())
383     if (auto *SplatPtr = getSplatValue(II.getArgOperand(0))) {
384       auto *VecTy = cast<VectorType>(II.getType());
385       const Align Alignment =
386           cast<ConstantInt>(II.getArgOperand(1))->getAlignValue();
387       LoadInst *L = Builder.CreateAlignedLoad(VecTy->getElementType(), SplatPtr,
388                                               Alignment, "load.scalar");
389       Value *Shuf =
390           Builder.CreateVectorSplat(VecTy->getElementCount(), L, "broadcast");
391       return replaceInstUsesWith(II, cast<Instruction>(Shuf));
392     }
393 
394   return nullptr;
395 }
396 
397 // TODO, Obvious Missing Transforms:
398 // * Single constant active lane -> store
399 // * Adjacent vector addresses -> masked.store
400 // * Narrow store width by halfs excluding zero/undef lanes
401 // * Vector incrementing address -> vector masked store
402 Instruction *InstCombinerImpl::simplifyMaskedScatter(IntrinsicInst &II) {
403   auto *ConstMask = dyn_cast<Constant>(II.getArgOperand(3));
404   if (!ConstMask)
405     return nullptr;
406 
407   // If the mask is all zeros, a scatter does nothing.
408   if (ConstMask->isNullValue())
409     return eraseInstFromFunction(II);
410 
411   // Vector splat address -> scalar store
412   if (auto *SplatPtr = getSplatValue(II.getArgOperand(1))) {
413     // scatter(splat(value), splat(ptr), non-zero-mask) -> store value, ptr
414     if (auto *SplatValue = getSplatValue(II.getArgOperand(0))) {
415       if (maskContainsAllOneOrUndef(ConstMask)) {
416         Align Alignment =
417             cast<ConstantInt>(II.getArgOperand(2))->getAlignValue();
418         StoreInst *S = new StoreInst(SplatValue, SplatPtr, /*IsVolatile=*/false,
419                                      Alignment);
420         S->copyMetadata(II);
421         return S;
422       }
423     }
424     // scatter(vector, splat(ptr), splat(true)) -> store extract(vector,
425     // lastlane), ptr
426     if (ConstMask->isAllOnesValue()) {
427       Align Alignment = cast<ConstantInt>(II.getArgOperand(2))->getAlignValue();
428       VectorType *WideLoadTy = cast<VectorType>(II.getArgOperand(1)->getType());
429       ElementCount VF = WideLoadTy->getElementCount();
430       Value *RunTimeVF = Builder.CreateElementCount(Builder.getInt32Ty(), VF);
431       Value *LastLane = Builder.CreateSub(RunTimeVF, Builder.getInt32(1));
432       Value *Extract =
433           Builder.CreateExtractElement(II.getArgOperand(0), LastLane);
434       StoreInst *S =
435           new StoreInst(Extract, SplatPtr, /*IsVolatile=*/false, Alignment);
436       S->copyMetadata(II);
437       return S;
438     }
439   }
440   if (isa<ScalableVectorType>(ConstMask->getType()))
441     return nullptr;
442 
443   // Use masked off lanes to simplify operands via SimplifyDemandedVectorElts
444   APInt DemandedElts = possiblyDemandedEltsInMask(ConstMask);
445   APInt PoisonElts(DemandedElts.getBitWidth(), 0);
446   if (Value *V = SimplifyDemandedVectorElts(II.getOperand(0), DemandedElts,
447                                             PoisonElts))
448     return replaceOperand(II, 0, V);
449   if (Value *V = SimplifyDemandedVectorElts(II.getOperand(1), DemandedElts,
450                                             PoisonElts))
451     return replaceOperand(II, 1, V);
452 
453   return nullptr;
454 }
455 
456 /// This function transforms launder.invariant.group and strip.invariant.group
457 /// like:
458 /// launder(launder(%x)) -> launder(%x)       (the result is not the argument)
459 /// launder(strip(%x)) -> launder(%x)
460 /// strip(strip(%x)) -> strip(%x)             (the result is not the argument)
461 /// strip(launder(%x)) -> strip(%x)
462 /// This is legal because it preserves the most recent information about
463 /// the presence or absence of invariant.group.
464 static Instruction *simplifyInvariantGroupIntrinsic(IntrinsicInst &II,
465                                                     InstCombinerImpl &IC) {
466   auto *Arg = II.getArgOperand(0);
467   auto *StrippedArg = Arg->stripPointerCasts();
468   auto *StrippedInvariantGroupsArg = StrippedArg;
469   while (auto *Intr = dyn_cast<IntrinsicInst>(StrippedInvariantGroupsArg)) {
470     if (Intr->getIntrinsicID() != Intrinsic::launder_invariant_group &&
471         Intr->getIntrinsicID() != Intrinsic::strip_invariant_group)
472       break;
473     StrippedInvariantGroupsArg = Intr->getArgOperand(0)->stripPointerCasts();
474   }
475   if (StrippedArg == StrippedInvariantGroupsArg)
476     return nullptr; // No launders/strips to remove.
477 
478   Value *Result = nullptr;
479 
480   if (II.getIntrinsicID() == Intrinsic::launder_invariant_group)
481     Result = IC.Builder.CreateLaunderInvariantGroup(StrippedInvariantGroupsArg);
482   else if (II.getIntrinsicID() == Intrinsic::strip_invariant_group)
483     Result = IC.Builder.CreateStripInvariantGroup(StrippedInvariantGroupsArg);
484   else
485     llvm_unreachable(
486         "simplifyInvariantGroupIntrinsic only handles launder and strip");
487   if (Result->getType()->getPointerAddressSpace() !=
488       II.getType()->getPointerAddressSpace())
489     Result = IC.Builder.CreateAddrSpaceCast(Result, II.getType());
490 
491   return cast<Instruction>(Result);
492 }
493 
494 static Instruction *foldCttzCtlz(IntrinsicInst &II, InstCombinerImpl &IC) {
495   assert((II.getIntrinsicID() == Intrinsic::cttz ||
496           II.getIntrinsicID() == Intrinsic::ctlz) &&
497          "Expected cttz or ctlz intrinsic");
498   bool IsTZ = II.getIntrinsicID() == Intrinsic::cttz;
499   Value *Op0 = II.getArgOperand(0);
500   Value *Op1 = II.getArgOperand(1);
501   Value *X;
502   // ctlz(bitreverse(x)) -> cttz(x)
503   // cttz(bitreverse(x)) -> ctlz(x)
504   if (match(Op0, m_BitReverse(m_Value(X)))) {
505     Intrinsic::ID ID = IsTZ ? Intrinsic::ctlz : Intrinsic::cttz;
506     Function *F = Intrinsic::getDeclaration(II.getModule(), ID, II.getType());
507     return CallInst::Create(F, {X, II.getArgOperand(1)});
508   }
509 
510   if (II.getType()->isIntOrIntVectorTy(1)) {
511     // ctlz/cttz i1 Op0 --> not Op0
512     if (match(Op1, m_Zero()))
513       return BinaryOperator::CreateNot(Op0);
514     // If zero is poison, then the input can be assumed to be "true", so the
515     // instruction simplifies to "false".
516     assert(match(Op1, m_One()) && "Expected ctlz/cttz operand to be 0 or 1");
517     return IC.replaceInstUsesWith(II, ConstantInt::getNullValue(II.getType()));
518   }
519 
520   Constant *C;
521 
522   if (IsTZ) {
523     // cttz(-x) -> cttz(x)
524     if (match(Op0, m_Neg(m_Value(X))))
525       return IC.replaceOperand(II, 0, X);
526 
527     // cttz(-x & x) -> cttz(x)
528     if (match(Op0, m_c_And(m_Neg(m_Value(X)), m_Deferred(X))))
529       return IC.replaceOperand(II, 0, X);
530 
531     // cttz(sext(x)) -> cttz(zext(x))
532     if (match(Op0, m_OneUse(m_SExt(m_Value(X))))) {
533       auto *Zext = IC.Builder.CreateZExt(X, II.getType());
534       auto *CttzZext =
535           IC.Builder.CreateBinaryIntrinsic(Intrinsic::cttz, Zext, Op1);
536       return IC.replaceInstUsesWith(II, CttzZext);
537     }
538 
539     // Zext doesn't change the number of trailing zeros, so narrow:
540     // cttz(zext(x)) -> zext(cttz(x)) if the 'ZeroIsPoison' parameter is 'true'.
541     if (match(Op0, m_OneUse(m_ZExt(m_Value(X)))) && match(Op1, m_One())) {
542       auto *Cttz = IC.Builder.CreateBinaryIntrinsic(Intrinsic::cttz, X,
543                                                     IC.Builder.getTrue());
544       auto *ZextCttz = IC.Builder.CreateZExt(Cttz, II.getType());
545       return IC.replaceInstUsesWith(II, ZextCttz);
546     }
547 
548     // cttz(abs(x)) -> cttz(x)
549     // cttz(nabs(x)) -> cttz(x)
550     Value *Y;
551     SelectPatternFlavor SPF = matchSelectPattern(Op0, X, Y).Flavor;
552     if (SPF == SPF_ABS || SPF == SPF_NABS)
553       return IC.replaceOperand(II, 0, X);
554 
555     if (match(Op0, m_Intrinsic<Intrinsic::abs>(m_Value(X))))
556       return IC.replaceOperand(II, 0, X);
557 
558     // cttz(shl(%const, %val), 1) --> add(cttz(%const, 1), %val)
559     if (match(Op0, m_Shl(m_ImmConstant(C), m_Value(X))) &&
560         match(Op1, m_One())) {
561       Value *ConstCttz =
562           IC.Builder.CreateBinaryIntrinsic(Intrinsic::cttz, C, Op1);
563       return BinaryOperator::CreateAdd(ConstCttz, X);
564     }
565 
566     // cttz(lshr exact (%const, %val), 1) --> sub(cttz(%const, 1), %val)
567     if (match(Op0, m_Exact(m_LShr(m_ImmConstant(C), m_Value(X)))) &&
568         match(Op1, m_One())) {
569       Value *ConstCttz =
570           IC.Builder.CreateBinaryIntrinsic(Intrinsic::cttz, C, Op1);
571       return BinaryOperator::CreateSub(ConstCttz, X);
572     }
573   } else {
574     // ctlz(lshr(%const, %val), 1) --> add(ctlz(%const, 1), %val)
575     if (match(Op0, m_LShr(m_ImmConstant(C), m_Value(X))) &&
576         match(Op1, m_One())) {
577       Value *ConstCtlz =
578           IC.Builder.CreateBinaryIntrinsic(Intrinsic::ctlz, C, Op1);
579       return BinaryOperator::CreateAdd(ConstCtlz, X);
580     }
581 
582     // ctlz(shl nuw (%const, %val), 1) --> sub(ctlz(%const, 1), %val)
583     if (match(Op0, m_NUWShl(m_ImmConstant(C), m_Value(X))) &&
584         match(Op1, m_One())) {
585       Value *ConstCtlz =
586           IC.Builder.CreateBinaryIntrinsic(Intrinsic::ctlz, C, Op1);
587       return BinaryOperator::CreateSub(ConstCtlz, X);
588     }
589   }
590 
591   KnownBits Known = IC.computeKnownBits(Op0, 0, &II);
592 
593   // Create a mask for bits above (ctlz) or below (cttz) the first known one.
594   unsigned PossibleZeros = IsTZ ? Known.countMaxTrailingZeros()
595                                 : Known.countMaxLeadingZeros();
596   unsigned DefiniteZeros = IsTZ ? Known.countMinTrailingZeros()
597                                 : Known.countMinLeadingZeros();
598 
599   // If all bits above (ctlz) or below (cttz) the first known one are known
600   // zero, this value is constant.
601   // FIXME: This should be in InstSimplify because we're replacing an
602   // instruction with a constant.
603   if (PossibleZeros == DefiniteZeros) {
604     auto *C = ConstantInt::get(Op0->getType(), DefiniteZeros);
605     return IC.replaceInstUsesWith(II, C);
606   }
607 
608   // If the input to cttz/ctlz is known to be non-zero,
609   // then change the 'ZeroIsPoison' parameter to 'true'
610   // because we know the zero behavior can't affect the result.
611   if (!Known.One.isZero() ||
612       isKnownNonZero(Op0, IC.getDataLayout(), 0, &IC.getAssumptionCache(), &II,
613                      &IC.getDominatorTree())) {
614     if (!match(II.getArgOperand(1), m_One()))
615       return IC.replaceOperand(II, 1, IC.Builder.getTrue());
616   }
617 
618   // Add range metadata since known bits can't completely reflect what we know.
619   auto *IT = cast<IntegerType>(Op0->getType()->getScalarType());
620   if (IT && IT->getBitWidth() != 1 && !II.getMetadata(LLVMContext::MD_range)) {
621     Metadata *LowAndHigh[] = {
622         ConstantAsMetadata::get(ConstantInt::get(IT, DefiniteZeros)),
623         ConstantAsMetadata::get(ConstantInt::get(IT, PossibleZeros + 1))};
624     II.setMetadata(LLVMContext::MD_range,
625                    MDNode::get(II.getContext(), LowAndHigh));
626     return &II;
627   }
628 
629   return nullptr;
630 }
631 
632 static Instruction *foldCtpop(IntrinsicInst &II, InstCombinerImpl &IC) {
633   assert(II.getIntrinsicID() == Intrinsic::ctpop &&
634          "Expected ctpop intrinsic");
635   Type *Ty = II.getType();
636   unsigned BitWidth = Ty->getScalarSizeInBits();
637   Value *Op0 = II.getArgOperand(0);
638   Value *X, *Y;
639 
640   // ctpop(bitreverse(x)) -> ctpop(x)
641   // ctpop(bswap(x)) -> ctpop(x)
642   if (match(Op0, m_BitReverse(m_Value(X))) || match(Op0, m_BSwap(m_Value(X))))
643     return IC.replaceOperand(II, 0, X);
644 
645   // ctpop(rot(x)) -> ctpop(x)
646   if ((match(Op0, m_FShl(m_Value(X), m_Value(Y), m_Value())) ||
647        match(Op0, m_FShr(m_Value(X), m_Value(Y), m_Value()))) &&
648       X == Y)
649     return IC.replaceOperand(II, 0, X);
650 
651   // ctpop(x | -x) -> bitwidth - cttz(x, false)
652   if (Op0->hasOneUse() &&
653       match(Op0, m_c_Or(m_Value(X), m_Neg(m_Deferred(X))))) {
654     Function *F =
655         Intrinsic::getDeclaration(II.getModule(), Intrinsic::cttz, Ty);
656     auto *Cttz = IC.Builder.CreateCall(F, {X, IC.Builder.getFalse()});
657     auto *Bw = ConstantInt::get(Ty, APInt(BitWidth, BitWidth));
658     return IC.replaceInstUsesWith(II, IC.Builder.CreateSub(Bw, Cttz));
659   }
660 
661   // ctpop(~x & (x - 1)) -> cttz(x, false)
662   if (match(Op0,
663             m_c_And(m_Not(m_Value(X)), m_Add(m_Deferred(X), m_AllOnes())))) {
664     Function *F =
665         Intrinsic::getDeclaration(II.getModule(), Intrinsic::cttz, Ty);
666     return CallInst::Create(F, {X, IC.Builder.getFalse()});
667   }
668 
669   // Zext doesn't change the number of set bits, so narrow:
670   // ctpop (zext X) --> zext (ctpop X)
671   if (match(Op0, m_OneUse(m_ZExt(m_Value(X))))) {
672     Value *NarrowPop = IC.Builder.CreateUnaryIntrinsic(Intrinsic::ctpop, X);
673     return CastInst::Create(Instruction::ZExt, NarrowPop, Ty);
674   }
675 
676   KnownBits Known(BitWidth);
677   IC.computeKnownBits(Op0, Known, 0, &II);
678 
679   // If all bits are zero except for exactly one fixed bit, then the result
680   // must be 0 or 1, and we can get that answer by shifting to LSB:
681   // ctpop (X & 32) --> (X & 32) >> 5
682   // TODO: Investigate removing this as its likely unnecessary given the below
683   // `isKnownToBeAPowerOfTwo` check.
684   if ((~Known.Zero).isPowerOf2())
685     return BinaryOperator::CreateLShr(
686         Op0, ConstantInt::get(Ty, (~Known.Zero).exactLogBase2()));
687 
688   // More generally we can also handle non-constant power of 2 patterns such as
689   // shl/shr(Pow2, X), (X & -X), etc... by transforming:
690   // ctpop(Pow2OrZero) --> icmp ne X, 0
691   if (IC.isKnownToBeAPowerOfTwo(Op0, /* OrZero */ true))
692     return CastInst::Create(Instruction::ZExt,
693                             IC.Builder.CreateICmp(ICmpInst::ICMP_NE, Op0,
694                                                   Constant::getNullValue(Ty)),
695                             Ty);
696 
697   // Add range metadata since known bits can't completely reflect what we know.
698   auto *IT = cast<IntegerType>(Ty->getScalarType());
699   unsigned MinCount = Known.countMinPopulation();
700   unsigned MaxCount = Known.countMaxPopulation();
701   if (IT->getBitWidth() != 1 && !II.getMetadata(LLVMContext::MD_range)) {
702     Metadata *LowAndHigh[] = {
703         ConstantAsMetadata::get(ConstantInt::get(IT, MinCount)),
704         ConstantAsMetadata::get(ConstantInt::get(IT, MaxCount + 1))};
705     II.setMetadata(LLVMContext::MD_range,
706                    MDNode::get(II.getContext(), LowAndHigh));
707     return &II;
708   }
709 
710   return nullptr;
711 }
712 
713 /// Convert a table lookup to shufflevector if the mask is constant.
714 /// This could benefit tbl1 if the mask is { 7,6,5,4,3,2,1,0 }, in
715 /// which case we could lower the shufflevector with rev64 instructions
716 /// as it's actually a byte reverse.
717 static Value *simplifyNeonTbl1(const IntrinsicInst &II,
718                                InstCombiner::BuilderTy &Builder) {
719   // Bail out if the mask is not a constant.
720   auto *C = dyn_cast<Constant>(II.getArgOperand(1));
721   if (!C)
722     return nullptr;
723 
724   auto *VecTy = cast<FixedVectorType>(II.getType());
725   unsigned NumElts = VecTy->getNumElements();
726 
727   // Only perform this transformation for <8 x i8> vector types.
728   if (!VecTy->getElementType()->isIntegerTy(8) || NumElts != 8)
729     return nullptr;
730 
731   int Indexes[8];
732 
733   for (unsigned I = 0; I < NumElts; ++I) {
734     Constant *COp = C->getAggregateElement(I);
735 
736     if (!COp || !isa<ConstantInt>(COp))
737       return nullptr;
738 
739     Indexes[I] = cast<ConstantInt>(COp)->getLimitedValue();
740 
741     // Make sure the mask indices are in range.
742     if ((unsigned)Indexes[I] >= NumElts)
743       return nullptr;
744   }
745 
746   auto *V1 = II.getArgOperand(0);
747   auto *V2 = Constant::getNullValue(V1->getType());
748   return Builder.CreateShuffleVector(V1, V2, ArrayRef(Indexes));
749 }
750 
751 // Returns true iff the 2 intrinsics have the same operands, limiting the
752 // comparison to the first NumOperands.
753 static bool haveSameOperands(const IntrinsicInst &I, const IntrinsicInst &E,
754                              unsigned NumOperands) {
755   assert(I.arg_size() >= NumOperands && "Not enough operands");
756   assert(E.arg_size() >= NumOperands && "Not enough operands");
757   for (unsigned i = 0; i < NumOperands; i++)
758     if (I.getArgOperand(i) != E.getArgOperand(i))
759       return false;
760   return true;
761 }
762 
763 // Remove trivially empty start/end intrinsic ranges, i.e. a start
764 // immediately followed by an end (ignoring debuginfo or other
765 // start/end intrinsics in between). As this handles only the most trivial
766 // cases, tracking the nesting level is not needed:
767 //
768 //   call @llvm.foo.start(i1 0)
769 //   call @llvm.foo.start(i1 0) ; This one won't be skipped: it will be removed
770 //   call @llvm.foo.end(i1 0)
771 //   call @llvm.foo.end(i1 0) ; &I
772 static bool
773 removeTriviallyEmptyRange(IntrinsicInst &EndI, InstCombinerImpl &IC,
774                           std::function<bool(const IntrinsicInst &)> IsStart) {
775   // We start from the end intrinsic and scan backwards, so that InstCombine
776   // has already processed (and potentially removed) all the instructions
777   // before the end intrinsic.
778   BasicBlock::reverse_iterator BI(EndI), BE(EndI.getParent()->rend());
779   for (; BI != BE; ++BI) {
780     if (auto *I = dyn_cast<IntrinsicInst>(&*BI)) {
781       if (I->isDebugOrPseudoInst() ||
782           I->getIntrinsicID() == EndI.getIntrinsicID())
783         continue;
784       if (IsStart(*I)) {
785         if (haveSameOperands(EndI, *I, EndI.arg_size())) {
786           IC.eraseInstFromFunction(*I);
787           IC.eraseInstFromFunction(EndI);
788           return true;
789         }
790         // Skip start intrinsics that don't pair with this end intrinsic.
791         continue;
792       }
793     }
794     break;
795   }
796 
797   return false;
798 }
799 
800 Instruction *InstCombinerImpl::visitVAEndInst(VAEndInst &I) {
801   removeTriviallyEmptyRange(I, *this, [](const IntrinsicInst &I) {
802     return I.getIntrinsicID() == Intrinsic::vastart ||
803            I.getIntrinsicID() == Intrinsic::vacopy;
804   });
805   return nullptr;
806 }
807 
808 static CallInst *canonicalizeConstantArg0ToArg1(CallInst &Call) {
809   assert(Call.arg_size() > 1 && "Need at least 2 args to swap");
810   Value *Arg0 = Call.getArgOperand(0), *Arg1 = Call.getArgOperand(1);
811   if (isa<Constant>(Arg0) && !isa<Constant>(Arg1)) {
812     Call.setArgOperand(0, Arg1);
813     Call.setArgOperand(1, Arg0);
814     return &Call;
815   }
816   return nullptr;
817 }
818 
819 /// Creates a result tuple for an overflow intrinsic \p II with a given
820 /// \p Result and a constant \p Overflow value.
821 static Instruction *createOverflowTuple(IntrinsicInst *II, Value *Result,
822                                         Constant *Overflow) {
823   Constant *V[] = {PoisonValue::get(Result->getType()), Overflow};
824   StructType *ST = cast<StructType>(II->getType());
825   Constant *Struct = ConstantStruct::get(ST, V);
826   return InsertValueInst::Create(Struct, Result, 0);
827 }
828 
829 Instruction *
830 InstCombinerImpl::foldIntrinsicWithOverflowCommon(IntrinsicInst *II) {
831   WithOverflowInst *WO = cast<WithOverflowInst>(II);
832   Value *OperationResult = nullptr;
833   Constant *OverflowResult = nullptr;
834   if (OptimizeOverflowCheck(WO->getBinaryOp(), WO->isSigned(), WO->getLHS(),
835                             WO->getRHS(), *WO, OperationResult, OverflowResult))
836     return createOverflowTuple(WO, OperationResult, OverflowResult);
837   return nullptr;
838 }
839 
840 static bool inputDenormalIsIEEE(const Function &F, const Type *Ty) {
841   Ty = Ty->getScalarType();
842   return F.getDenormalMode(Ty->getFltSemantics()).Input == DenormalMode::IEEE;
843 }
844 
845 static bool inputDenormalIsDAZ(const Function &F, const Type *Ty) {
846   Ty = Ty->getScalarType();
847   return F.getDenormalMode(Ty->getFltSemantics()).inputsAreZero();
848 }
849 
850 /// \returns the compare predicate type if the test performed by
851 /// llvm.is.fpclass(x, \p Mask) is equivalent to fcmp o__ x, 0.0 with the
852 /// floating-point environment assumed for \p F for type \p Ty
853 static FCmpInst::Predicate fpclassTestIsFCmp0(FPClassTest Mask,
854                                               const Function &F, Type *Ty) {
855   switch (static_cast<unsigned>(Mask)) {
856   case fcZero:
857     if (inputDenormalIsIEEE(F, Ty))
858       return FCmpInst::FCMP_OEQ;
859     break;
860   case fcZero | fcSubnormal:
861     if (inputDenormalIsDAZ(F, Ty))
862       return FCmpInst::FCMP_OEQ;
863     break;
864   case fcPositive | fcNegZero:
865     if (inputDenormalIsIEEE(F, Ty))
866       return FCmpInst::FCMP_OGE;
867     break;
868   case fcPositive | fcNegZero | fcNegSubnormal:
869     if (inputDenormalIsDAZ(F, Ty))
870       return FCmpInst::FCMP_OGE;
871     break;
872   case fcPosSubnormal | fcPosNormal | fcPosInf:
873     if (inputDenormalIsIEEE(F, Ty))
874       return FCmpInst::FCMP_OGT;
875     break;
876   case fcNegative | fcPosZero:
877     if (inputDenormalIsIEEE(F, Ty))
878       return FCmpInst::FCMP_OLE;
879     break;
880   case fcNegative | fcPosZero | fcPosSubnormal:
881     if (inputDenormalIsDAZ(F, Ty))
882       return FCmpInst::FCMP_OLE;
883     break;
884   case fcNegSubnormal | fcNegNormal | fcNegInf:
885     if (inputDenormalIsIEEE(F, Ty))
886       return FCmpInst::FCMP_OLT;
887     break;
888   case fcPosNormal | fcPosInf:
889     if (inputDenormalIsDAZ(F, Ty))
890       return FCmpInst::FCMP_OGT;
891     break;
892   case fcNegNormal | fcNegInf:
893     if (inputDenormalIsDAZ(F, Ty))
894       return FCmpInst::FCMP_OLT;
895     break;
896   case ~fcZero & ~fcNan:
897     if (inputDenormalIsIEEE(F, Ty))
898       return FCmpInst::FCMP_ONE;
899     break;
900   case ~(fcZero | fcSubnormal) & ~fcNan:
901     if (inputDenormalIsDAZ(F, Ty))
902       return FCmpInst::FCMP_ONE;
903     break;
904   default:
905     break;
906   }
907 
908   return FCmpInst::BAD_FCMP_PREDICATE;
909 }
910 
911 Instruction *InstCombinerImpl::foldIntrinsicIsFPClass(IntrinsicInst &II) {
912   Value *Src0 = II.getArgOperand(0);
913   Value *Src1 = II.getArgOperand(1);
914   const ConstantInt *CMask = cast<ConstantInt>(Src1);
915   FPClassTest Mask = static_cast<FPClassTest>(CMask->getZExtValue());
916   const bool IsUnordered = (Mask & fcNan) == fcNan;
917   const bool IsOrdered = (Mask & fcNan) == fcNone;
918   const FPClassTest OrderedMask = Mask & ~fcNan;
919   const FPClassTest OrderedInvertedMask = ~OrderedMask & ~fcNan;
920 
921   const bool IsStrict = II.isStrictFP();
922 
923   Value *FNegSrc;
924   if (match(Src0, m_FNeg(m_Value(FNegSrc)))) {
925     // is.fpclass (fneg x), mask -> is.fpclass x, (fneg mask)
926 
927     II.setArgOperand(1, ConstantInt::get(Src1->getType(), fneg(Mask)));
928     return replaceOperand(II, 0, FNegSrc);
929   }
930 
931   Value *FAbsSrc;
932   if (match(Src0, m_FAbs(m_Value(FAbsSrc)))) {
933     II.setArgOperand(1, ConstantInt::get(Src1->getType(), inverse_fabs(Mask)));
934     return replaceOperand(II, 0, FAbsSrc);
935   }
936 
937   if ((OrderedMask == fcInf || OrderedInvertedMask == fcInf) &&
938       (IsOrdered || IsUnordered) && !IsStrict) {
939     // is.fpclass(x, fcInf) -> fcmp oeq fabs(x), +inf
940     // is.fpclass(x, ~fcInf) -> fcmp one fabs(x), +inf
941     // is.fpclass(x, fcInf|fcNan) -> fcmp ueq fabs(x), +inf
942     // is.fpclass(x, ~(fcInf|fcNan)) -> fcmp une fabs(x), +inf
943     Constant *Inf = ConstantFP::getInfinity(Src0->getType());
944     FCmpInst::Predicate Pred =
945         IsUnordered ? FCmpInst::FCMP_UEQ : FCmpInst::FCMP_OEQ;
946     if (OrderedInvertedMask == fcInf)
947       Pred = IsUnordered ? FCmpInst::FCMP_UNE : FCmpInst::FCMP_ONE;
948 
949     Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, Src0);
950     Value *CmpInf = Builder.CreateFCmp(Pred, Fabs, Inf);
951     CmpInf->takeName(&II);
952     return replaceInstUsesWith(II, CmpInf);
953   }
954 
955   if ((OrderedMask == fcPosInf || OrderedMask == fcNegInf) &&
956       (IsOrdered || IsUnordered) && !IsStrict) {
957     // is.fpclass(x, fcPosInf) -> fcmp oeq x, +inf
958     // is.fpclass(x, fcNegInf) -> fcmp oeq x, -inf
959     // is.fpclass(x, fcPosInf|fcNan) -> fcmp ueq x, +inf
960     // is.fpclass(x, fcNegInf|fcNan) -> fcmp ueq x, -inf
961     Constant *Inf =
962         ConstantFP::getInfinity(Src0->getType(), OrderedMask == fcNegInf);
963     Value *EqInf = IsUnordered ? Builder.CreateFCmpUEQ(Src0, Inf)
964                                : Builder.CreateFCmpOEQ(Src0, Inf);
965 
966     EqInf->takeName(&II);
967     return replaceInstUsesWith(II, EqInf);
968   }
969 
970   if ((OrderedInvertedMask == fcPosInf || OrderedInvertedMask == fcNegInf) &&
971       (IsOrdered || IsUnordered) && !IsStrict) {
972     // is.fpclass(x, ~fcPosInf) -> fcmp one x, +inf
973     // is.fpclass(x, ~fcNegInf) -> fcmp one x, -inf
974     // is.fpclass(x, ~fcPosInf|fcNan) -> fcmp une x, +inf
975     // is.fpclass(x, ~fcNegInf|fcNan) -> fcmp une x, -inf
976     Constant *Inf = ConstantFP::getInfinity(Src0->getType(),
977                                             OrderedInvertedMask == fcNegInf);
978     Value *NeInf = IsUnordered ? Builder.CreateFCmpUNE(Src0, Inf)
979                                : Builder.CreateFCmpONE(Src0, Inf);
980     NeInf->takeName(&II);
981     return replaceInstUsesWith(II, NeInf);
982   }
983 
984   if (Mask == fcNan && !IsStrict) {
985     // Equivalent of isnan. Replace with standard fcmp if we don't care about FP
986     // exceptions.
987     Value *IsNan =
988         Builder.CreateFCmpUNO(Src0, ConstantFP::getZero(Src0->getType()));
989     IsNan->takeName(&II);
990     return replaceInstUsesWith(II, IsNan);
991   }
992 
993   if (Mask == (~fcNan & fcAllFlags) && !IsStrict) {
994     // Equivalent of !isnan. Replace with standard fcmp.
995     Value *FCmp =
996         Builder.CreateFCmpORD(Src0, ConstantFP::getZero(Src0->getType()));
997     FCmp->takeName(&II);
998     return replaceInstUsesWith(II, FCmp);
999   }
1000 
1001   FCmpInst::Predicate PredType = FCmpInst::BAD_FCMP_PREDICATE;
1002 
1003   // Try to replace with an fcmp with 0
1004   //
1005   // is.fpclass(x, fcZero) -> fcmp oeq x, 0.0
1006   // is.fpclass(x, fcZero | fcNan) -> fcmp ueq x, 0.0
1007   // is.fpclass(x, ~fcZero & ~fcNan) -> fcmp one x, 0.0
1008   // is.fpclass(x, ~fcZero) -> fcmp une x, 0.0
1009   //
1010   // is.fpclass(x, fcPosSubnormal | fcPosNormal | fcPosInf) -> fcmp ogt x, 0.0
1011   // is.fpclass(x, fcPositive | fcNegZero) -> fcmp oge x, 0.0
1012   //
1013   // is.fpclass(x, fcNegSubnormal | fcNegNormal | fcNegInf) -> fcmp olt x, 0.0
1014   // is.fpclass(x, fcNegative | fcPosZero) -> fcmp ole x, 0.0
1015   //
1016   if (!IsStrict && (IsOrdered || IsUnordered) &&
1017       (PredType = fpclassTestIsFCmp0(OrderedMask, *II.getFunction(),
1018                                      Src0->getType())) !=
1019           FCmpInst::BAD_FCMP_PREDICATE) {
1020     Constant *Zero = ConstantFP::getZero(Src0->getType());
1021     // Equivalent of == 0.
1022     Value *FCmp = Builder.CreateFCmp(
1023         IsUnordered ? FCmpInst::getUnorderedPredicate(PredType) : PredType,
1024         Src0, Zero);
1025 
1026     FCmp->takeName(&II);
1027     return replaceInstUsesWith(II, FCmp);
1028   }
1029 
1030   KnownFPClass Known = computeKnownFPClass(Src0, Mask, &II);
1031 
1032   // Clear test bits we know must be false from the source value.
1033   // fp_class (nnan x), qnan|snan|other -> fp_class (nnan x), other
1034   // fp_class (ninf x), ninf|pinf|other -> fp_class (ninf x), other
1035   if ((Mask & Known.KnownFPClasses) != Mask) {
1036     II.setArgOperand(
1037         1, ConstantInt::get(Src1->getType(), Mask & Known.KnownFPClasses));
1038     return &II;
1039   }
1040 
1041   // If none of the tests which can return false are possible, fold to true.
1042   // fp_class (nnan x), ~(qnan|snan) -> true
1043   // fp_class (ninf x), ~(ninf|pinf) -> true
1044   if (Mask == Known.KnownFPClasses)
1045     return replaceInstUsesWith(II, ConstantInt::get(II.getType(), true));
1046 
1047   return nullptr;
1048 }
1049 
1050 static std::optional<bool> getKnownSign(Value *Op, Instruction *CxtI,
1051                                    const DataLayout &DL, AssumptionCache *AC,
1052                                    DominatorTree *DT) {
1053   KnownBits Known = computeKnownBits(Op, DL, 0, AC, CxtI, DT);
1054   if (Known.isNonNegative())
1055     return false;
1056   if (Known.isNegative())
1057     return true;
1058 
1059   Value *X, *Y;
1060   if (match(Op, m_NSWSub(m_Value(X), m_Value(Y))))
1061     return isImpliedByDomCondition(ICmpInst::ICMP_SLT, X, Y, CxtI, DL);
1062 
1063   return isImpliedByDomCondition(
1064       ICmpInst::ICMP_SLT, Op, Constant::getNullValue(Op->getType()), CxtI, DL);
1065 }
1066 
1067 static std::optional<bool> getKnownSignOrZero(Value *Op, Instruction *CxtI,
1068                                               const DataLayout &DL,
1069                                               AssumptionCache *AC,
1070                                               DominatorTree *DT) {
1071   if (std::optional<bool> Sign = getKnownSign(Op, CxtI, DL, AC, DT))
1072     return Sign;
1073 
1074   Value *X, *Y;
1075   if (match(Op, m_NSWSub(m_Value(X), m_Value(Y))))
1076     return isImpliedByDomCondition(ICmpInst::ICMP_SLE, X, Y, CxtI, DL);
1077 
1078   return std::nullopt;
1079 }
1080 
1081 /// Return true if two values \p Op0 and \p Op1 are known to have the same sign.
1082 static bool signBitMustBeTheSame(Value *Op0, Value *Op1, Instruction *CxtI,
1083                                  const DataLayout &DL, AssumptionCache *AC,
1084                                  DominatorTree *DT) {
1085   std::optional<bool> Known1 = getKnownSign(Op1, CxtI, DL, AC, DT);
1086   if (!Known1)
1087     return false;
1088   std::optional<bool> Known0 = getKnownSign(Op0, CxtI, DL, AC, DT);
1089   if (!Known0)
1090     return false;
1091   return *Known0 == *Known1;
1092 }
1093 
1094 /// Try to canonicalize min/max(X + C0, C1) as min/max(X, C1 - C0) + C0. This
1095 /// can trigger other combines.
1096 static Instruction *moveAddAfterMinMax(IntrinsicInst *II,
1097                                        InstCombiner::BuilderTy &Builder) {
1098   Intrinsic::ID MinMaxID = II->getIntrinsicID();
1099   assert((MinMaxID == Intrinsic::smax || MinMaxID == Intrinsic::smin ||
1100           MinMaxID == Intrinsic::umax || MinMaxID == Intrinsic::umin) &&
1101          "Expected a min or max intrinsic");
1102 
1103   // TODO: Match vectors with undef elements, but undef may not propagate.
1104   Value *Op0 = II->getArgOperand(0), *Op1 = II->getArgOperand(1);
1105   Value *X;
1106   const APInt *C0, *C1;
1107   if (!match(Op0, m_OneUse(m_Add(m_Value(X), m_APInt(C0)))) ||
1108       !match(Op1, m_APInt(C1)))
1109     return nullptr;
1110 
1111   // Check for necessary no-wrap and overflow constraints.
1112   bool IsSigned = MinMaxID == Intrinsic::smax || MinMaxID == Intrinsic::smin;
1113   auto *Add = cast<BinaryOperator>(Op0);
1114   if ((IsSigned && !Add->hasNoSignedWrap()) ||
1115       (!IsSigned && !Add->hasNoUnsignedWrap()))
1116     return nullptr;
1117 
1118   // If the constant difference overflows, then instsimplify should reduce the
1119   // min/max to the add or C1.
1120   bool Overflow;
1121   APInt CDiff =
1122       IsSigned ? C1->ssub_ov(*C0, Overflow) : C1->usub_ov(*C0, Overflow);
1123   assert(!Overflow && "Expected simplify of min/max");
1124 
1125   // min/max (add X, C0), C1 --> add (min/max X, C1 - C0), C0
1126   // Note: the "mismatched" no-overflow setting does not propagate.
1127   Constant *NewMinMaxC = ConstantInt::get(II->getType(), CDiff);
1128   Value *NewMinMax = Builder.CreateBinaryIntrinsic(MinMaxID, X, NewMinMaxC);
1129   return IsSigned ? BinaryOperator::CreateNSWAdd(NewMinMax, Add->getOperand(1))
1130                   : BinaryOperator::CreateNUWAdd(NewMinMax, Add->getOperand(1));
1131 }
1132 /// Match a sadd_sat or ssub_sat which is using min/max to clamp the value.
1133 Instruction *InstCombinerImpl::matchSAddSubSat(IntrinsicInst &MinMax1) {
1134   Type *Ty = MinMax1.getType();
1135 
1136   // We are looking for a tree of:
1137   // max(INT_MIN, min(INT_MAX, add(sext(A), sext(B))))
1138   // Where the min and max could be reversed
1139   Instruction *MinMax2;
1140   BinaryOperator *AddSub;
1141   const APInt *MinValue, *MaxValue;
1142   if (match(&MinMax1, m_SMin(m_Instruction(MinMax2), m_APInt(MaxValue)))) {
1143     if (!match(MinMax2, m_SMax(m_BinOp(AddSub), m_APInt(MinValue))))
1144       return nullptr;
1145   } else if (match(&MinMax1,
1146                    m_SMax(m_Instruction(MinMax2), m_APInt(MinValue)))) {
1147     if (!match(MinMax2, m_SMin(m_BinOp(AddSub), m_APInt(MaxValue))))
1148       return nullptr;
1149   } else
1150     return nullptr;
1151 
1152   // Check that the constants clamp a saturate, and that the new type would be
1153   // sensible to convert to.
1154   if (!(*MaxValue + 1).isPowerOf2() || -*MinValue != *MaxValue + 1)
1155     return nullptr;
1156   // In what bitwidth can this be treated as saturating arithmetics?
1157   unsigned NewBitWidth = (*MaxValue + 1).logBase2() + 1;
1158   // FIXME: This isn't quite right for vectors, but using the scalar type is a
1159   // good first approximation for what should be done there.
1160   if (!shouldChangeType(Ty->getScalarType()->getIntegerBitWidth(), NewBitWidth))
1161     return nullptr;
1162 
1163   // Also make sure that the inner min/max and the add/sub have one use.
1164   if (!MinMax2->hasOneUse() || !AddSub->hasOneUse())
1165     return nullptr;
1166 
1167   // Create the new type (which can be a vector type)
1168   Type *NewTy = Ty->getWithNewBitWidth(NewBitWidth);
1169 
1170   Intrinsic::ID IntrinsicID;
1171   if (AddSub->getOpcode() == Instruction::Add)
1172     IntrinsicID = Intrinsic::sadd_sat;
1173   else if (AddSub->getOpcode() == Instruction::Sub)
1174     IntrinsicID = Intrinsic::ssub_sat;
1175   else
1176     return nullptr;
1177 
1178   // The two operands of the add/sub must be nsw-truncatable to the NewTy. This
1179   // is usually achieved via a sext from a smaller type.
1180   if (ComputeMaxSignificantBits(AddSub->getOperand(0), 0, AddSub) >
1181           NewBitWidth ||
1182       ComputeMaxSignificantBits(AddSub->getOperand(1), 0, AddSub) > NewBitWidth)
1183     return nullptr;
1184 
1185   // Finally create and return the sat intrinsic, truncated to the new type
1186   Function *F = Intrinsic::getDeclaration(MinMax1.getModule(), IntrinsicID, NewTy);
1187   Value *AT = Builder.CreateTrunc(AddSub->getOperand(0), NewTy);
1188   Value *BT = Builder.CreateTrunc(AddSub->getOperand(1), NewTy);
1189   Value *Sat = Builder.CreateCall(F, {AT, BT});
1190   return CastInst::Create(Instruction::SExt, Sat, Ty);
1191 }
1192 
1193 
1194 /// If we have a clamp pattern like max (min X, 42), 41 -- where the output
1195 /// can only be one of two possible constant values -- turn that into a select
1196 /// of constants.
1197 static Instruction *foldClampRangeOfTwo(IntrinsicInst *II,
1198                                         InstCombiner::BuilderTy &Builder) {
1199   Value *I0 = II->getArgOperand(0), *I1 = II->getArgOperand(1);
1200   Value *X;
1201   const APInt *C0, *C1;
1202   if (!match(I1, m_APInt(C1)) || !I0->hasOneUse())
1203     return nullptr;
1204 
1205   CmpInst::Predicate Pred = CmpInst::BAD_ICMP_PREDICATE;
1206   switch (II->getIntrinsicID()) {
1207   case Intrinsic::smax:
1208     if (match(I0, m_SMin(m_Value(X), m_APInt(C0))) && *C0 == *C1 + 1)
1209       Pred = ICmpInst::ICMP_SGT;
1210     break;
1211   case Intrinsic::smin:
1212     if (match(I0, m_SMax(m_Value(X), m_APInt(C0))) && *C1 == *C0 + 1)
1213       Pred = ICmpInst::ICMP_SLT;
1214     break;
1215   case Intrinsic::umax:
1216     if (match(I0, m_UMin(m_Value(X), m_APInt(C0))) && *C0 == *C1 + 1)
1217       Pred = ICmpInst::ICMP_UGT;
1218     break;
1219   case Intrinsic::umin:
1220     if (match(I0, m_UMax(m_Value(X), m_APInt(C0))) && *C1 == *C0 + 1)
1221       Pred = ICmpInst::ICMP_ULT;
1222     break;
1223   default:
1224     llvm_unreachable("Expected min/max intrinsic");
1225   }
1226   if (Pred == CmpInst::BAD_ICMP_PREDICATE)
1227     return nullptr;
1228 
1229   // max (min X, 42), 41 --> X > 41 ? 42 : 41
1230   // min (max X, 42), 43 --> X < 43 ? 42 : 43
1231   Value *Cmp = Builder.CreateICmp(Pred, X, I1);
1232   return SelectInst::Create(Cmp, ConstantInt::get(II->getType(), *C0), I1);
1233 }
1234 
1235 /// If this min/max has a constant operand and an operand that is a matching
1236 /// min/max with a constant operand, constant-fold the 2 constant operands.
1237 static Value *reassociateMinMaxWithConstants(IntrinsicInst *II,
1238                                              IRBuilderBase &Builder) {
1239   Intrinsic::ID MinMaxID = II->getIntrinsicID();
1240   auto *LHS = dyn_cast<IntrinsicInst>(II->getArgOperand(0));
1241   if (!LHS || LHS->getIntrinsicID() != MinMaxID)
1242     return nullptr;
1243 
1244   Constant *C0, *C1;
1245   if (!match(LHS->getArgOperand(1), m_ImmConstant(C0)) ||
1246       !match(II->getArgOperand(1), m_ImmConstant(C1)))
1247     return nullptr;
1248 
1249   // max (max X, C0), C1 --> max X, (max C0, C1) --> max X, NewC
1250   ICmpInst::Predicate Pred = MinMaxIntrinsic::getPredicate(MinMaxID);
1251   Value *CondC = Builder.CreateICmp(Pred, C0, C1);
1252   Value *NewC = Builder.CreateSelect(CondC, C0, C1);
1253   return Builder.CreateIntrinsic(MinMaxID, II->getType(),
1254                                  {LHS->getArgOperand(0), NewC});
1255 }
1256 
1257 /// If this min/max has a matching min/max operand with a constant, try to push
1258 /// the constant operand into this instruction. This can enable more folds.
1259 static Instruction *
1260 reassociateMinMaxWithConstantInOperand(IntrinsicInst *II,
1261                                        InstCombiner::BuilderTy &Builder) {
1262   // Match and capture a min/max operand candidate.
1263   Value *X, *Y;
1264   Constant *C;
1265   Instruction *Inner;
1266   if (!match(II, m_c_MaxOrMin(m_OneUse(m_CombineAnd(
1267                                   m_Instruction(Inner),
1268                                   m_MaxOrMin(m_Value(X), m_ImmConstant(C)))),
1269                               m_Value(Y))))
1270     return nullptr;
1271 
1272   // The inner op must match. Check for constants to avoid infinite loops.
1273   Intrinsic::ID MinMaxID = II->getIntrinsicID();
1274   auto *InnerMM = dyn_cast<IntrinsicInst>(Inner);
1275   if (!InnerMM || InnerMM->getIntrinsicID() != MinMaxID ||
1276       match(X, m_ImmConstant()) || match(Y, m_ImmConstant()))
1277     return nullptr;
1278 
1279   // max (max X, C), Y --> max (max X, Y), C
1280   Function *MinMax =
1281       Intrinsic::getDeclaration(II->getModule(), MinMaxID, II->getType());
1282   Value *NewInner = Builder.CreateBinaryIntrinsic(MinMaxID, X, Y);
1283   NewInner->takeName(Inner);
1284   return CallInst::Create(MinMax, {NewInner, C});
1285 }
1286 
1287 /// Reduce a sequence of min/max intrinsics with a common operand.
1288 static Instruction *factorizeMinMaxTree(IntrinsicInst *II) {
1289   // Match 3 of the same min/max ops. Example: umin(umin(), umin()).
1290   auto *LHS = dyn_cast<IntrinsicInst>(II->getArgOperand(0));
1291   auto *RHS = dyn_cast<IntrinsicInst>(II->getArgOperand(1));
1292   Intrinsic::ID MinMaxID = II->getIntrinsicID();
1293   if (!LHS || !RHS || LHS->getIntrinsicID() != MinMaxID ||
1294       RHS->getIntrinsicID() != MinMaxID ||
1295       (!LHS->hasOneUse() && !RHS->hasOneUse()))
1296     return nullptr;
1297 
1298   Value *A = LHS->getArgOperand(0);
1299   Value *B = LHS->getArgOperand(1);
1300   Value *C = RHS->getArgOperand(0);
1301   Value *D = RHS->getArgOperand(1);
1302 
1303   // Look for a common operand.
1304   Value *MinMaxOp = nullptr;
1305   Value *ThirdOp = nullptr;
1306   if (LHS->hasOneUse()) {
1307     // If the LHS is only used in this chain and the RHS is used outside of it,
1308     // reuse the RHS min/max because that will eliminate the LHS.
1309     if (D == A || C == A) {
1310       // min(min(a, b), min(c, a)) --> min(min(c, a), b)
1311       // min(min(a, b), min(a, d)) --> min(min(a, d), b)
1312       MinMaxOp = RHS;
1313       ThirdOp = B;
1314     } else if (D == B || C == B) {
1315       // min(min(a, b), min(c, b)) --> min(min(c, b), a)
1316       // min(min(a, b), min(b, d)) --> min(min(b, d), a)
1317       MinMaxOp = RHS;
1318       ThirdOp = A;
1319     }
1320   } else {
1321     assert(RHS->hasOneUse() && "Expected one-use operand");
1322     // Reuse the LHS. This will eliminate the RHS.
1323     if (D == A || D == B) {
1324       // min(min(a, b), min(c, a)) --> min(min(a, b), c)
1325       // min(min(a, b), min(c, b)) --> min(min(a, b), c)
1326       MinMaxOp = LHS;
1327       ThirdOp = C;
1328     } else if (C == A || C == B) {
1329       // min(min(a, b), min(b, d)) --> min(min(a, b), d)
1330       // min(min(a, b), min(c, b)) --> min(min(a, b), d)
1331       MinMaxOp = LHS;
1332       ThirdOp = D;
1333     }
1334   }
1335 
1336   if (!MinMaxOp || !ThirdOp)
1337     return nullptr;
1338 
1339   Module *Mod = II->getModule();
1340   Function *MinMax = Intrinsic::getDeclaration(Mod, MinMaxID, II->getType());
1341   return CallInst::Create(MinMax, { MinMaxOp, ThirdOp });
1342 }
1343 
1344 /// If all arguments of the intrinsic are unary shuffles with the same mask,
1345 /// try to shuffle after the intrinsic.
1346 static Instruction *
1347 foldShuffledIntrinsicOperands(IntrinsicInst *II,
1348                               InstCombiner::BuilderTy &Builder) {
1349   // TODO: This should be extended to handle other intrinsics like fshl, ctpop,
1350   //       etc. Use llvm::isTriviallyVectorizable() and related to determine
1351   //       which intrinsics are safe to shuffle?
1352   switch (II->getIntrinsicID()) {
1353   case Intrinsic::smax:
1354   case Intrinsic::smin:
1355   case Intrinsic::umax:
1356   case Intrinsic::umin:
1357   case Intrinsic::fma:
1358   case Intrinsic::fshl:
1359   case Intrinsic::fshr:
1360     break;
1361   default:
1362     return nullptr;
1363   }
1364 
1365   Value *X;
1366   ArrayRef<int> Mask;
1367   if (!match(II->getArgOperand(0),
1368              m_Shuffle(m_Value(X), m_Undef(), m_Mask(Mask))))
1369     return nullptr;
1370 
1371   // At least 1 operand must have 1 use because we are creating 2 instructions.
1372   if (none_of(II->args(), [](Value *V) { return V->hasOneUse(); }))
1373     return nullptr;
1374 
1375   // See if all arguments are shuffled with the same mask.
1376   SmallVector<Value *, 4> NewArgs(II->arg_size());
1377   NewArgs[0] = X;
1378   Type *SrcTy = X->getType();
1379   for (unsigned i = 1, e = II->arg_size(); i != e; ++i) {
1380     if (!match(II->getArgOperand(i),
1381                m_Shuffle(m_Value(X), m_Undef(), m_SpecificMask(Mask))) ||
1382         X->getType() != SrcTy)
1383       return nullptr;
1384     NewArgs[i] = X;
1385   }
1386 
1387   // intrinsic (shuf X, M), (shuf Y, M), ... --> shuf (intrinsic X, Y, ...), M
1388   Instruction *FPI = isa<FPMathOperator>(II) ? II : nullptr;
1389   Value *NewIntrinsic =
1390       Builder.CreateIntrinsic(II->getIntrinsicID(), SrcTy, NewArgs, FPI);
1391   return new ShuffleVectorInst(NewIntrinsic, Mask);
1392 }
1393 
1394 /// Fold the following cases and accepts bswap and bitreverse intrinsics:
1395 ///   bswap(logic_op(bswap(x), y)) --> logic_op(x, bswap(y))
1396 ///   bswap(logic_op(bswap(x), bswap(y))) --> logic_op(x, y) (ignores multiuse)
1397 template <Intrinsic::ID IntrID>
1398 static Instruction *foldBitOrderCrossLogicOp(Value *V,
1399                                              InstCombiner::BuilderTy &Builder) {
1400   static_assert(IntrID == Intrinsic::bswap || IntrID == Intrinsic::bitreverse,
1401                 "This helper only supports BSWAP and BITREVERSE intrinsics");
1402 
1403   Value *X, *Y;
1404   // Find bitwise logic op. Check that it is a BinaryOperator explicitly so we
1405   // don't match ConstantExpr that aren't meaningful for this transform.
1406   if (match(V, m_OneUse(m_BitwiseLogic(m_Value(X), m_Value(Y)))) &&
1407       isa<BinaryOperator>(V)) {
1408     Value *OldReorderX, *OldReorderY;
1409     BinaryOperator::BinaryOps Op = cast<BinaryOperator>(V)->getOpcode();
1410 
1411     // If both X and Y are bswap/bitreverse, the transform reduces the number
1412     // of instructions even if there's multiuse.
1413     // If only one operand is bswap/bitreverse, we need to ensure the operand
1414     // have only one use.
1415     if (match(X, m_Intrinsic<IntrID>(m_Value(OldReorderX))) &&
1416         match(Y, m_Intrinsic<IntrID>(m_Value(OldReorderY)))) {
1417       return BinaryOperator::Create(Op, OldReorderX, OldReorderY);
1418     }
1419 
1420     if (match(X, m_OneUse(m_Intrinsic<IntrID>(m_Value(OldReorderX))))) {
1421       Value *NewReorder = Builder.CreateUnaryIntrinsic(IntrID, Y);
1422       return BinaryOperator::Create(Op, OldReorderX, NewReorder);
1423     }
1424 
1425     if (match(Y, m_OneUse(m_Intrinsic<IntrID>(m_Value(OldReorderY))))) {
1426       Value *NewReorder = Builder.CreateUnaryIntrinsic(IntrID, X);
1427       return BinaryOperator::Create(Op, NewReorder, OldReorderY);
1428     }
1429   }
1430   return nullptr;
1431 }
1432 
1433 /// CallInst simplification. This mostly only handles folding of intrinsic
1434 /// instructions. For normal calls, it allows visitCallBase to do the heavy
1435 /// lifting.
1436 Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
1437   // Don't try to simplify calls without uses. It will not do anything useful,
1438   // but will result in the following folds being skipped.
1439   if (!CI.use_empty()) {
1440     SmallVector<Value *, 4> Args;
1441     Args.reserve(CI.arg_size());
1442     for (Value *Op : CI.args())
1443       Args.push_back(Op);
1444     if (Value *V = simplifyCall(&CI, CI.getCalledOperand(), Args,
1445                                 SQ.getWithInstruction(&CI)))
1446       return replaceInstUsesWith(CI, V);
1447   }
1448 
1449   if (Value *FreedOp = getFreedOperand(&CI, &TLI))
1450     return visitFree(CI, FreedOp);
1451 
1452   // If the caller function (i.e. us, the function that contains this CallInst)
1453   // is nounwind, mark the call as nounwind, even if the callee isn't.
1454   if (CI.getFunction()->doesNotThrow() && !CI.doesNotThrow()) {
1455     CI.setDoesNotThrow();
1456     return &CI;
1457   }
1458 
1459   IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI);
1460   if (!II) return visitCallBase(CI);
1461 
1462   // For atomic unordered mem intrinsics if len is not a positive or
1463   // not a multiple of element size then behavior is undefined.
1464   if (auto *AMI = dyn_cast<AtomicMemIntrinsic>(II))
1465     if (ConstantInt *NumBytes = dyn_cast<ConstantInt>(AMI->getLength()))
1466       if (NumBytes->isNegative() ||
1467           (NumBytes->getZExtValue() % AMI->getElementSizeInBytes() != 0)) {
1468         CreateNonTerminatorUnreachable(AMI);
1469         assert(AMI->getType()->isVoidTy() &&
1470                "non void atomic unordered mem intrinsic");
1471         return eraseInstFromFunction(*AMI);
1472       }
1473 
1474   // Intrinsics cannot occur in an invoke or a callbr, so handle them here
1475   // instead of in visitCallBase.
1476   if (auto *MI = dyn_cast<AnyMemIntrinsic>(II)) {
1477     bool Changed = false;
1478 
1479     // memmove/cpy/set of zero bytes is a noop.
1480     if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) {
1481       if (NumBytes->isNullValue())
1482         return eraseInstFromFunction(CI);
1483     }
1484 
1485     // No other transformations apply to volatile transfers.
1486     if (auto *M = dyn_cast<MemIntrinsic>(MI))
1487       if (M->isVolatile())
1488         return nullptr;
1489 
1490     // If we have a memmove and the source operation is a constant global,
1491     // then the source and dest pointers can't alias, so we can change this
1492     // into a call to memcpy.
1493     if (auto *MMI = dyn_cast<AnyMemMoveInst>(MI)) {
1494       if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource()))
1495         if (GVSrc->isConstant()) {
1496           Module *M = CI.getModule();
1497           Intrinsic::ID MemCpyID =
1498               isa<AtomicMemMoveInst>(MMI)
1499                   ? Intrinsic::memcpy_element_unordered_atomic
1500                   : Intrinsic::memcpy;
1501           Type *Tys[3] = { CI.getArgOperand(0)->getType(),
1502                            CI.getArgOperand(1)->getType(),
1503                            CI.getArgOperand(2)->getType() };
1504           CI.setCalledFunction(Intrinsic::getDeclaration(M, MemCpyID, Tys));
1505           Changed = true;
1506         }
1507     }
1508 
1509     if (AnyMemTransferInst *MTI = dyn_cast<AnyMemTransferInst>(MI)) {
1510       // memmove(x,x,size) -> noop.
1511       if (MTI->getSource() == MTI->getDest())
1512         return eraseInstFromFunction(CI);
1513     }
1514 
1515     // If we can determine a pointer alignment that is bigger than currently
1516     // set, update the alignment.
1517     if (auto *MTI = dyn_cast<AnyMemTransferInst>(MI)) {
1518       if (Instruction *I = SimplifyAnyMemTransfer(MTI))
1519         return I;
1520     } else if (auto *MSI = dyn_cast<AnyMemSetInst>(MI)) {
1521       if (Instruction *I = SimplifyAnyMemSet(MSI))
1522         return I;
1523     }
1524 
1525     if (Changed) return II;
1526   }
1527 
1528   // For fixed width vector result intrinsics, use the generic demanded vector
1529   // support.
1530   if (auto *IIFVTy = dyn_cast<FixedVectorType>(II->getType())) {
1531     auto VWidth = IIFVTy->getNumElements();
1532     APInt PoisonElts(VWidth, 0);
1533     APInt AllOnesEltMask(APInt::getAllOnes(VWidth));
1534     if (Value *V = SimplifyDemandedVectorElts(II, AllOnesEltMask, PoisonElts)) {
1535       if (V != II)
1536         return replaceInstUsesWith(*II, V);
1537       return II;
1538     }
1539   }
1540 
1541   if (II->isCommutative()) {
1542     if (auto Pair = matchSymmetricPair(II->getOperand(0), II->getOperand(1))) {
1543       replaceOperand(*II, 0, Pair->first);
1544       replaceOperand(*II, 1, Pair->second);
1545       return II;
1546     }
1547 
1548     if (CallInst *NewCall = canonicalizeConstantArg0ToArg1(CI))
1549       return NewCall;
1550   }
1551 
1552   // Unused constrained FP intrinsic calls may have declared side effect, which
1553   // prevents it from being removed. In some cases however the side effect is
1554   // actually absent. To detect this case, call SimplifyConstrainedFPCall. If it
1555   // returns a replacement, the call may be removed.
1556   if (CI.use_empty() && isa<ConstrainedFPIntrinsic>(CI)) {
1557     if (simplifyConstrainedFPCall(&CI, SQ.getWithInstruction(&CI)))
1558       return eraseInstFromFunction(CI);
1559   }
1560 
1561   Intrinsic::ID IID = II->getIntrinsicID();
1562   switch (IID) {
1563   case Intrinsic::objectsize: {
1564     SmallVector<Instruction *> InsertedInstructions;
1565     if (Value *V = lowerObjectSizeCall(II, DL, &TLI, AA, /*MustSucceed=*/false,
1566                                        &InsertedInstructions)) {
1567       for (Instruction *Inserted : InsertedInstructions)
1568         Worklist.add(Inserted);
1569       return replaceInstUsesWith(CI, V);
1570     }
1571     return nullptr;
1572   }
1573   case Intrinsic::abs: {
1574     Value *IIOperand = II->getArgOperand(0);
1575     bool IntMinIsPoison = cast<Constant>(II->getArgOperand(1))->isOneValue();
1576 
1577     // abs(-x) -> abs(x)
1578     // TODO: Copy nsw if it was present on the neg?
1579     Value *X;
1580     if (match(IIOperand, m_Neg(m_Value(X))))
1581       return replaceOperand(*II, 0, X);
1582     if (match(IIOperand, m_Select(m_Value(), m_Value(X), m_Neg(m_Deferred(X)))))
1583       return replaceOperand(*II, 0, X);
1584     if (match(IIOperand, m_Select(m_Value(), m_Neg(m_Value(X)), m_Deferred(X))))
1585       return replaceOperand(*II, 0, X);
1586 
1587     if (std::optional<bool> Known =
1588             getKnownSignOrZero(IIOperand, II, DL, &AC, &DT)) {
1589       // abs(x) -> x if x >= 0 (include abs(x-y) --> x - y where x >= y)
1590       // abs(x) -> x if x > 0 (include abs(x-y) --> x - y where x > y)
1591       if (!*Known)
1592         return replaceInstUsesWith(*II, IIOperand);
1593 
1594       // abs(x) -> -x if x < 0
1595       // abs(x) -> -x if x < = 0 (include abs(x-y) --> y - x where x <= y)
1596       if (IntMinIsPoison)
1597         return BinaryOperator::CreateNSWNeg(IIOperand);
1598       return BinaryOperator::CreateNeg(IIOperand);
1599     }
1600 
1601     // abs (sext X) --> zext (abs X*)
1602     // Clear the IsIntMin (nsw) bit on the abs to allow narrowing.
1603     if (match(IIOperand, m_OneUse(m_SExt(m_Value(X))))) {
1604       Value *NarrowAbs =
1605           Builder.CreateBinaryIntrinsic(Intrinsic::abs, X, Builder.getFalse());
1606       return CastInst::Create(Instruction::ZExt, NarrowAbs, II->getType());
1607     }
1608 
1609     // Match a complicated way to check if a number is odd/even:
1610     // abs (srem X, 2) --> and X, 1
1611     const APInt *C;
1612     if (match(IIOperand, m_SRem(m_Value(X), m_APInt(C))) && *C == 2)
1613       return BinaryOperator::CreateAnd(X, ConstantInt::get(II->getType(), 1));
1614 
1615     break;
1616   }
1617   case Intrinsic::umin: {
1618     Value *I0 = II->getArgOperand(0), *I1 = II->getArgOperand(1);
1619     // umin(x, 1) == zext(x != 0)
1620     if (match(I1, m_One())) {
1621       assert(II->getType()->getScalarSizeInBits() != 1 &&
1622              "Expected simplify of umin with max constant");
1623       Value *Zero = Constant::getNullValue(I0->getType());
1624       Value *Cmp = Builder.CreateICmpNE(I0, Zero);
1625       return CastInst::Create(Instruction::ZExt, Cmp, II->getType());
1626     }
1627     [[fallthrough]];
1628   }
1629   case Intrinsic::umax: {
1630     Value *I0 = II->getArgOperand(0), *I1 = II->getArgOperand(1);
1631     Value *X, *Y;
1632     if (match(I0, m_ZExt(m_Value(X))) && match(I1, m_ZExt(m_Value(Y))) &&
1633         (I0->hasOneUse() || I1->hasOneUse()) && X->getType() == Y->getType()) {
1634       Value *NarrowMaxMin = Builder.CreateBinaryIntrinsic(IID, X, Y);
1635       return CastInst::Create(Instruction::ZExt, NarrowMaxMin, II->getType());
1636     }
1637     Constant *C;
1638     if (match(I0, m_ZExt(m_Value(X))) && match(I1, m_Constant(C)) &&
1639         I0->hasOneUse()) {
1640       if (Constant *NarrowC = getLosslessUnsignedTrunc(C, X->getType())) {
1641         Value *NarrowMaxMin = Builder.CreateBinaryIntrinsic(IID, X, NarrowC);
1642         return CastInst::Create(Instruction::ZExt, NarrowMaxMin, II->getType());
1643       }
1644     }
1645     // If both operands of unsigned min/max are sign-extended, it is still ok
1646     // to narrow the operation.
1647     [[fallthrough]];
1648   }
1649   case Intrinsic::smax:
1650   case Intrinsic::smin: {
1651     Value *I0 = II->getArgOperand(0), *I1 = II->getArgOperand(1);
1652     Value *X, *Y;
1653     if (match(I0, m_SExt(m_Value(X))) && match(I1, m_SExt(m_Value(Y))) &&
1654         (I0->hasOneUse() || I1->hasOneUse()) && X->getType() == Y->getType()) {
1655       Value *NarrowMaxMin = Builder.CreateBinaryIntrinsic(IID, X, Y);
1656       return CastInst::Create(Instruction::SExt, NarrowMaxMin, II->getType());
1657     }
1658 
1659     Constant *C;
1660     if (match(I0, m_SExt(m_Value(X))) && match(I1, m_Constant(C)) &&
1661         I0->hasOneUse()) {
1662       if (Constant *NarrowC = getLosslessSignedTrunc(C, X->getType())) {
1663         Value *NarrowMaxMin = Builder.CreateBinaryIntrinsic(IID, X, NarrowC);
1664         return CastInst::Create(Instruction::SExt, NarrowMaxMin, II->getType());
1665       }
1666     }
1667 
1668     // umin(i1 X, i1 Y) -> and i1 X, Y
1669     // smax(i1 X, i1 Y) -> and i1 X, Y
1670     if ((IID == Intrinsic::umin || IID == Intrinsic::smax) &&
1671         II->getType()->isIntOrIntVectorTy(1)) {
1672       return BinaryOperator::CreateAnd(I0, I1);
1673     }
1674 
1675     // umax(i1 X, i1 Y) -> or i1 X, Y
1676     // smin(i1 X, i1 Y) -> or i1 X, Y
1677     if ((IID == Intrinsic::umax || IID == Intrinsic::smin) &&
1678         II->getType()->isIntOrIntVectorTy(1)) {
1679       return BinaryOperator::CreateOr(I0, I1);
1680     }
1681 
1682     if (IID == Intrinsic::smax || IID == Intrinsic::smin) {
1683       // smax (neg nsw X), (neg nsw Y) --> neg nsw (smin X, Y)
1684       // smin (neg nsw X), (neg nsw Y) --> neg nsw (smax X, Y)
1685       // TODO: Canonicalize neg after min/max if I1 is constant.
1686       if (match(I0, m_NSWNeg(m_Value(X))) && match(I1, m_NSWNeg(m_Value(Y))) &&
1687           (I0->hasOneUse() || I1->hasOneUse())) {
1688         Intrinsic::ID InvID = getInverseMinMaxIntrinsic(IID);
1689         Value *InvMaxMin = Builder.CreateBinaryIntrinsic(InvID, X, Y);
1690         return BinaryOperator::CreateNSWNeg(InvMaxMin);
1691       }
1692     }
1693 
1694     // (umax X, (xor X, Pow2))
1695     //      -> (or X, Pow2)
1696     // (umin X, (xor X, Pow2))
1697     //      -> (and X, ~Pow2)
1698     // (smax X, (xor X, Pos_Pow2))
1699     //      -> (or X, Pos_Pow2)
1700     // (smin X, (xor X, Pos_Pow2))
1701     //      -> (and X, ~Pos_Pow2)
1702     // (smax X, (xor X, Neg_Pow2))
1703     //      -> (and X, ~Neg_Pow2)
1704     // (smin X, (xor X, Neg_Pow2))
1705     //      -> (or X, Neg_Pow2)
1706     if ((match(I0, m_c_Xor(m_Specific(I1), m_Value(X))) ||
1707          match(I1, m_c_Xor(m_Specific(I0), m_Value(X)))) &&
1708         isKnownToBeAPowerOfTwo(X, /* OrZero */ true)) {
1709       bool UseOr = IID == Intrinsic::smax || IID == Intrinsic::umax;
1710       bool UseAndN = IID == Intrinsic::smin || IID == Intrinsic::umin;
1711 
1712       if (IID == Intrinsic::smax || IID == Intrinsic::smin) {
1713         auto KnownSign = getKnownSign(X, II, DL, &AC, &DT);
1714         if (KnownSign == std::nullopt) {
1715           UseOr = false;
1716           UseAndN = false;
1717         } else if (*KnownSign /* true is Signed. */) {
1718           UseOr ^= true;
1719           UseAndN ^= true;
1720           Type *Ty = I0->getType();
1721           // Negative power of 2 must be IntMin. It's possible to be able to
1722           // prove negative / power of 2 without actually having known bits, so
1723           // just get the value by hand.
1724           X = Constant::getIntegerValue(
1725               Ty, APInt::getSignedMinValue(Ty->getScalarSizeInBits()));
1726         }
1727       }
1728       if (UseOr)
1729         return BinaryOperator::CreateOr(I0, X);
1730       else if (UseAndN)
1731         return BinaryOperator::CreateAnd(I0, Builder.CreateNot(X));
1732     }
1733 
1734     // If we can eliminate ~A and Y is free to invert:
1735     // max ~A, Y --> ~(min A, ~Y)
1736     //
1737     // Examples:
1738     // max ~A, ~Y --> ~(min A, Y)
1739     // max ~A, C --> ~(min A, ~C)
1740     // max ~A, (max ~Y, ~Z) --> ~min( A, (min Y, Z))
1741     auto moveNotAfterMinMax = [&](Value *X, Value *Y) -> Instruction * {
1742       Value *A;
1743       if (match(X, m_OneUse(m_Not(m_Value(A)))) &&
1744           !isFreeToInvert(A, A->hasOneUse())) {
1745         if (Value *NotY = getFreelyInverted(Y, Y->hasOneUse(), &Builder)) {
1746           Intrinsic::ID InvID = getInverseMinMaxIntrinsic(IID);
1747           Value *InvMaxMin = Builder.CreateBinaryIntrinsic(InvID, A, NotY);
1748           return BinaryOperator::CreateNot(InvMaxMin);
1749         }
1750       }
1751       return nullptr;
1752     };
1753 
1754     if (Instruction *I = moveNotAfterMinMax(I0, I1))
1755       return I;
1756     if (Instruction *I = moveNotAfterMinMax(I1, I0))
1757       return I;
1758 
1759     if (Instruction *I = moveAddAfterMinMax(II, Builder))
1760       return I;
1761 
1762     // smax(X, -X) --> abs(X)
1763     // smin(X, -X) --> -abs(X)
1764     // umax(X, -X) --> -abs(X)
1765     // umin(X, -X) --> abs(X)
1766     if (isKnownNegation(I0, I1)) {
1767       // We can choose either operand as the input to abs(), but if we can
1768       // eliminate the only use of a value, that's better for subsequent
1769       // transforms/analysis.
1770       if (I0->hasOneUse() && !I1->hasOneUse())
1771         std::swap(I0, I1);
1772 
1773       // This is some variant of abs(). See if we can propagate 'nsw' to the abs
1774       // operation and potentially its negation.
1775       bool IntMinIsPoison = isKnownNegation(I0, I1, /* NeedNSW */ true);
1776       Value *Abs = Builder.CreateBinaryIntrinsic(
1777           Intrinsic::abs, I0,
1778           ConstantInt::getBool(II->getContext(), IntMinIsPoison));
1779 
1780       // We don't have a "nabs" intrinsic, so negate if needed based on the
1781       // max/min operation.
1782       if (IID == Intrinsic::smin || IID == Intrinsic::umax)
1783         Abs = Builder.CreateNeg(Abs, "nabs", /* NUW */ false, IntMinIsPoison);
1784       return replaceInstUsesWith(CI, Abs);
1785     }
1786 
1787     if (Instruction *Sel = foldClampRangeOfTwo(II, Builder))
1788       return Sel;
1789 
1790     if (Instruction *SAdd = matchSAddSubSat(*II))
1791       return SAdd;
1792 
1793     if (Value *NewMinMax = reassociateMinMaxWithConstants(II, Builder))
1794       return replaceInstUsesWith(*II, NewMinMax);
1795 
1796     if (Instruction *R = reassociateMinMaxWithConstantInOperand(II, Builder))
1797       return R;
1798 
1799     if (Instruction *NewMinMax = factorizeMinMaxTree(II))
1800        return NewMinMax;
1801 
1802     // Try to fold minmax with constant RHS based on range information
1803     const APInt *RHSC;
1804     if (match(I1, m_APIntAllowUndef(RHSC))) {
1805       ICmpInst::Predicate Pred =
1806           ICmpInst::getNonStrictPredicate(MinMaxIntrinsic::getPredicate(IID));
1807       bool IsSigned = MinMaxIntrinsic::isSigned(IID);
1808       ConstantRange LHS_CR = computeConstantRangeIncludingKnownBits(
1809           I0, IsSigned, SQ.getWithInstruction(II));
1810       if (!LHS_CR.isFullSet()) {
1811         if (LHS_CR.icmp(Pred, *RHSC))
1812           return replaceInstUsesWith(*II, I0);
1813         if (LHS_CR.icmp(ICmpInst::getSwappedPredicate(Pred), *RHSC))
1814           return replaceInstUsesWith(*II,
1815                                      ConstantInt::get(II->getType(), *RHSC));
1816       }
1817     }
1818 
1819     break;
1820   }
1821   case Intrinsic::bitreverse: {
1822     Value *IIOperand = II->getArgOperand(0);
1823     // bitrev (zext i1 X to ?) --> X ? SignBitC : 0
1824     Value *X;
1825     if (match(IIOperand, m_ZExt(m_Value(X))) &&
1826         X->getType()->isIntOrIntVectorTy(1)) {
1827       Type *Ty = II->getType();
1828       APInt SignBit = APInt::getSignMask(Ty->getScalarSizeInBits());
1829       return SelectInst::Create(X, ConstantInt::get(Ty, SignBit),
1830                                 ConstantInt::getNullValue(Ty));
1831     }
1832 
1833     if (Instruction *crossLogicOpFold =
1834         foldBitOrderCrossLogicOp<Intrinsic::bitreverse>(IIOperand, Builder))
1835       return crossLogicOpFold;
1836 
1837     break;
1838   }
1839   case Intrinsic::bswap: {
1840     Value *IIOperand = II->getArgOperand(0);
1841 
1842     // Try to canonicalize bswap-of-logical-shift-by-8-bit-multiple as
1843     // inverse-shift-of-bswap:
1844     // bswap (shl X, Y) --> lshr (bswap X), Y
1845     // bswap (lshr X, Y) --> shl (bswap X), Y
1846     Value *X, *Y;
1847     if (match(IIOperand, m_OneUse(m_LogicalShift(m_Value(X), m_Value(Y))))) {
1848       // The transform allows undef vector elements, so try a constant match
1849       // first. If knownbits can handle that case, that clause could be removed.
1850       unsigned BitWidth = IIOperand->getType()->getScalarSizeInBits();
1851       const APInt *C;
1852       if ((match(Y, m_APIntAllowUndef(C)) && (*C & 7) == 0) ||
1853           MaskedValueIsZero(Y, APInt::getLowBitsSet(BitWidth, 3))) {
1854         Value *NewSwap = Builder.CreateUnaryIntrinsic(Intrinsic::bswap, X);
1855         BinaryOperator::BinaryOps InverseShift =
1856             cast<BinaryOperator>(IIOperand)->getOpcode() == Instruction::Shl
1857                 ? Instruction::LShr
1858                 : Instruction::Shl;
1859         return BinaryOperator::Create(InverseShift, NewSwap, Y);
1860       }
1861     }
1862 
1863     KnownBits Known = computeKnownBits(IIOperand, 0, II);
1864     uint64_t LZ = alignDown(Known.countMinLeadingZeros(), 8);
1865     uint64_t TZ = alignDown(Known.countMinTrailingZeros(), 8);
1866     unsigned BW = Known.getBitWidth();
1867 
1868     // bswap(x) -> shift(x) if x has exactly one "active byte"
1869     if (BW - LZ - TZ == 8) {
1870       assert(LZ != TZ && "active byte cannot be in the middle");
1871       if (LZ > TZ)  // -> shl(x) if the "active byte" is in the low part of x
1872         return BinaryOperator::CreateNUWShl(
1873             IIOperand, ConstantInt::get(IIOperand->getType(), LZ - TZ));
1874       // -> lshr(x) if the "active byte" is in the high part of x
1875       return BinaryOperator::CreateExactLShr(
1876             IIOperand, ConstantInt::get(IIOperand->getType(), TZ - LZ));
1877     }
1878 
1879     // bswap(trunc(bswap(x))) -> trunc(lshr(x, c))
1880     if (match(IIOperand, m_Trunc(m_BSwap(m_Value(X))))) {
1881       unsigned C = X->getType()->getScalarSizeInBits() - BW;
1882       Value *CV = ConstantInt::get(X->getType(), C);
1883       Value *V = Builder.CreateLShr(X, CV);
1884       return new TruncInst(V, IIOperand->getType());
1885     }
1886 
1887     if (Instruction *crossLogicOpFold =
1888             foldBitOrderCrossLogicOp<Intrinsic::bswap>(IIOperand, Builder)) {
1889       return crossLogicOpFold;
1890     }
1891 
1892     // Try to fold into bitreverse if bswap is the root of the expression tree.
1893     if (Instruction *BitOp = matchBSwapOrBitReverse(*II, /*MatchBSwaps*/ false,
1894                                                     /*MatchBitReversals*/ true))
1895       return BitOp;
1896     break;
1897   }
1898   case Intrinsic::masked_load:
1899     if (Value *SimplifiedMaskedOp = simplifyMaskedLoad(*II))
1900       return replaceInstUsesWith(CI, SimplifiedMaskedOp);
1901     break;
1902   case Intrinsic::masked_store:
1903     return simplifyMaskedStore(*II);
1904   case Intrinsic::masked_gather:
1905     return simplifyMaskedGather(*II);
1906   case Intrinsic::masked_scatter:
1907     return simplifyMaskedScatter(*II);
1908   case Intrinsic::launder_invariant_group:
1909   case Intrinsic::strip_invariant_group:
1910     if (auto *SkippedBarrier = simplifyInvariantGroupIntrinsic(*II, *this))
1911       return replaceInstUsesWith(*II, SkippedBarrier);
1912     break;
1913   case Intrinsic::powi:
1914     if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
1915       // 0 and 1 are handled in instsimplify
1916       // powi(x, -1) -> 1/x
1917       if (Power->isMinusOne())
1918         return BinaryOperator::CreateFDivFMF(ConstantFP::get(CI.getType(), 1.0),
1919                                              II->getArgOperand(0), II);
1920       // powi(x, 2) -> x*x
1921       if (Power->equalsInt(2))
1922         return BinaryOperator::CreateFMulFMF(II->getArgOperand(0),
1923                                              II->getArgOperand(0), II);
1924 
1925       if (!Power->getValue()[0]) {
1926         Value *X;
1927         // If power is even:
1928         // powi(-x, p) -> powi(x, p)
1929         // powi(fabs(x), p) -> powi(x, p)
1930         // powi(copysign(x, y), p) -> powi(x, p)
1931         if (match(II->getArgOperand(0), m_FNeg(m_Value(X))) ||
1932             match(II->getArgOperand(0), m_FAbs(m_Value(X))) ||
1933             match(II->getArgOperand(0),
1934                   m_Intrinsic<Intrinsic::copysign>(m_Value(X), m_Value())))
1935           return replaceOperand(*II, 0, X);
1936       }
1937     }
1938     break;
1939 
1940   case Intrinsic::cttz:
1941   case Intrinsic::ctlz:
1942     if (auto *I = foldCttzCtlz(*II, *this))
1943       return I;
1944     break;
1945 
1946   case Intrinsic::ctpop:
1947     if (auto *I = foldCtpop(*II, *this))
1948       return I;
1949     break;
1950 
1951   case Intrinsic::fshl:
1952   case Intrinsic::fshr: {
1953     Value *Op0 = II->getArgOperand(0), *Op1 = II->getArgOperand(1);
1954     Type *Ty = II->getType();
1955     unsigned BitWidth = Ty->getScalarSizeInBits();
1956     Constant *ShAmtC;
1957     if (match(II->getArgOperand(2), m_ImmConstant(ShAmtC))) {
1958       // Canonicalize a shift amount constant operand to modulo the bit-width.
1959       Constant *WidthC = ConstantInt::get(Ty, BitWidth);
1960       Constant *ModuloC =
1961           ConstantFoldBinaryOpOperands(Instruction::URem, ShAmtC, WidthC, DL);
1962       if (!ModuloC)
1963         return nullptr;
1964       if (ModuloC != ShAmtC)
1965         return replaceOperand(*II, 2, ModuloC);
1966 
1967       assert(ConstantExpr::getICmp(ICmpInst::ICMP_UGT, WidthC, ShAmtC) ==
1968                  ConstantInt::getTrue(CmpInst::makeCmpResultType(Ty)) &&
1969              "Shift amount expected to be modulo bitwidth");
1970 
1971       // Canonicalize funnel shift right by constant to funnel shift left. This
1972       // is not entirely arbitrary. For historical reasons, the backend may
1973       // recognize rotate left patterns but miss rotate right patterns.
1974       if (IID == Intrinsic::fshr) {
1975         // fshr X, Y, C --> fshl X, Y, (BitWidth - C)
1976         Constant *LeftShiftC = ConstantExpr::getSub(WidthC, ShAmtC);
1977         Module *Mod = II->getModule();
1978         Function *Fshl = Intrinsic::getDeclaration(Mod, Intrinsic::fshl, Ty);
1979         return CallInst::Create(Fshl, { Op0, Op1, LeftShiftC });
1980       }
1981       assert(IID == Intrinsic::fshl &&
1982              "All funnel shifts by simple constants should go left");
1983 
1984       // fshl(X, 0, C) --> shl X, C
1985       // fshl(X, undef, C) --> shl X, C
1986       if (match(Op1, m_ZeroInt()) || match(Op1, m_Undef()))
1987         return BinaryOperator::CreateShl(Op0, ShAmtC);
1988 
1989       // fshl(0, X, C) --> lshr X, (BW-C)
1990       // fshl(undef, X, C) --> lshr X, (BW-C)
1991       if (match(Op0, m_ZeroInt()) || match(Op0, m_Undef()))
1992         return BinaryOperator::CreateLShr(Op1,
1993                                           ConstantExpr::getSub(WidthC, ShAmtC));
1994 
1995       // fshl i16 X, X, 8 --> bswap i16 X (reduce to more-specific form)
1996       if (Op0 == Op1 && BitWidth == 16 && match(ShAmtC, m_SpecificInt(8))) {
1997         Module *Mod = II->getModule();
1998         Function *Bswap = Intrinsic::getDeclaration(Mod, Intrinsic::bswap, Ty);
1999         return CallInst::Create(Bswap, { Op0 });
2000       }
2001       if (Instruction *BitOp =
2002               matchBSwapOrBitReverse(*II, /*MatchBSwaps*/ true,
2003                                      /*MatchBitReversals*/ true))
2004         return BitOp;
2005     }
2006 
2007     // Left or right might be masked.
2008     if (SimplifyDemandedInstructionBits(*II))
2009       return &CI;
2010 
2011     // The shift amount (operand 2) of a funnel shift is modulo the bitwidth,
2012     // so only the low bits of the shift amount are demanded if the bitwidth is
2013     // a power-of-2.
2014     if (!isPowerOf2_32(BitWidth))
2015       break;
2016     APInt Op2Demanded = APInt::getLowBitsSet(BitWidth, Log2_32_Ceil(BitWidth));
2017     KnownBits Op2Known(BitWidth);
2018     if (SimplifyDemandedBits(II, 2, Op2Demanded, Op2Known))
2019       return &CI;
2020     break;
2021   }
2022   case Intrinsic::ptrmask: {
2023     unsigned BitWidth = DL.getPointerTypeSizeInBits(II->getType());
2024     KnownBits Known(BitWidth);
2025     if (SimplifyDemandedInstructionBits(*II, Known))
2026       return II;
2027 
2028     Value *InnerPtr, *InnerMask;
2029     bool Changed = false;
2030     // Combine:
2031     // (ptrmask (ptrmask p, A), B)
2032     //    -> (ptrmask p, (and A, B))
2033     if (match(II->getArgOperand(0),
2034               m_OneUse(m_Intrinsic<Intrinsic::ptrmask>(m_Value(InnerPtr),
2035                                                        m_Value(InnerMask))))) {
2036       assert(II->getArgOperand(1)->getType() == InnerMask->getType() &&
2037              "Mask types must match");
2038       // TODO: If InnerMask == Op1, we could copy attributes from inner
2039       // callsite -> outer callsite.
2040       Value *NewMask = Builder.CreateAnd(II->getArgOperand(1), InnerMask);
2041       replaceOperand(CI, 0, InnerPtr);
2042       replaceOperand(CI, 1, NewMask);
2043       Changed = true;
2044     }
2045 
2046     // See if we can deduce non-null.
2047     if (!CI.hasRetAttr(Attribute::NonNull) &&
2048         (Known.isNonZero() ||
2049          isKnownNonZero(II, DL, /*Depth*/ 0, &AC, II, &DT))) {
2050       CI.addRetAttr(Attribute::NonNull);
2051       Changed = true;
2052     }
2053 
2054     unsigned NewAlignmentLog =
2055         std::min(Value::MaxAlignmentExponent,
2056                  std::min(BitWidth - 1, Known.countMinTrailingZeros()));
2057     // Known bits will capture if we had alignment information associated with
2058     // the pointer argument.
2059     if (NewAlignmentLog > Log2(CI.getRetAlign().valueOrOne())) {
2060       CI.addRetAttr(Attribute::getWithAlignment(
2061           CI.getContext(), Align(uint64_t(1) << NewAlignmentLog)));
2062       Changed = true;
2063     }
2064     if (Changed)
2065       return &CI;
2066     break;
2067   }
2068   case Intrinsic::uadd_with_overflow:
2069   case Intrinsic::sadd_with_overflow: {
2070     if (Instruction *I = foldIntrinsicWithOverflowCommon(II))
2071       return I;
2072 
2073     // Given 2 constant operands whose sum does not overflow:
2074     // uaddo (X +nuw C0), C1 -> uaddo X, C0 + C1
2075     // saddo (X +nsw C0), C1 -> saddo X, C0 + C1
2076     Value *X;
2077     const APInt *C0, *C1;
2078     Value *Arg0 = II->getArgOperand(0);
2079     Value *Arg1 = II->getArgOperand(1);
2080     bool IsSigned = IID == Intrinsic::sadd_with_overflow;
2081     bool HasNWAdd = IsSigned ? match(Arg0, m_NSWAdd(m_Value(X), m_APInt(C0)))
2082                              : match(Arg0, m_NUWAdd(m_Value(X), m_APInt(C0)));
2083     if (HasNWAdd && match(Arg1, m_APInt(C1))) {
2084       bool Overflow;
2085       APInt NewC =
2086           IsSigned ? C1->sadd_ov(*C0, Overflow) : C1->uadd_ov(*C0, Overflow);
2087       if (!Overflow)
2088         return replaceInstUsesWith(
2089             *II, Builder.CreateBinaryIntrinsic(
2090                      IID, X, ConstantInt::get(Arg1->getType(), NewC)));
2091     }
2092     break;
2093   }
2094 
2095   case Intrinsic::umul_with_overflow:
2096   case Intrinsic::smul_with_overflow:
2097   case Intrinsic::usub_with_overflow:
2098     if (Instruction *I = foldIntrinsicWithOverflowCommon(II))
2099       return I;
2100     break;
2101 
2102   case Intrinsic::ssub_with_overflow: {
2103     if (Instruction *I = foldIntrinsicWithOverflowCommon(II))
2104       return I;
2105 
2106     Constant *C;
2107     Value *Arg0 = II->getArgOperand(0);
2108     Value *Arg1 = II->getArgOperand(1);
2109     // Given a constant C that is not the minimum signed value
2110     // for an integer of a given bit width:
2111     //
2112     // ssubo X, C -> saddo X, -C
2113     if (match(Arg1, m_Constant(C)) && C->isNotMinSignedValue()) {
2114       Value *NegVal = ConstantExpr::getNeg(C);
2115       // Build a saddo call that is equivalent to the discovered
2116       // ssubo call.
2117       return replaceInstUsesWith(
2118           *II, Builder.CreateBinaryIntrinsic(Intrinsic::sadd_with_overflow,
2119                                              Arg0, NegVal));
2120     }
2121 
2122     break;
2123   }
2124 
2125   case Intrinsic::uadd_sat:
2126   case Intrinsic::sadd_sat:
2127   case Intrinsic::usub_sat:
2128   case Intrinsic::ssub_sat: {
2129     SaturatingInst *SI = cast<SaturatingInst>(II);
2130     Type *Ty = SI->getType();
2131     Value *Arg0 = SI->getLHS();
2132     Value *Arg1 = SI->getRHS();
2133 
2134     // Make use of known overflow information.
2135     OverflowResult OR = computeOverflow(SI->getBinaryOp(), SI->isSigned(),
2136                                         Arg0, Arg1, SI);
2137     switch (OR) {
2138       case OverflowResult::MayOverflow:
2139         break;
2140       case OverflowResult::NeverOverflows:
2141         if (SI->isSigned())
2142           return BinaryOperator::CreateNSW(SI->getBinaryOp(), Arg0, Arg1);
2143         else
2144           return BinaryOperator::CreateNUW(SI->getBinaryOp(), Arg0, Arg1);
2145       case OverflowResult::AlwaysOverflowsLow: {
2146         unsigned BitWidth = Ty->getScalarSizeInBits();
2147         APInt Min = APSInt::getMinValue(BitWidth, !SI->isSigned());
2148         return replaceInstUsesWith(*SI, ConstantInt::get(Ty, Min));
2149       }
2150       case OverflowResult::AlwaysOverflowsHigh: {
2151         unsigned BitWidth = Ty->getScalarSizeInBits();
2152         APInt Max = APSInt::getMaxValue(BitWidth, !SI->isSigned());
2153         return replaceInstUsesWith(*SI, ConstantInt::get(Ty, Max));
2154       }
2155     }
2156 
2157     // ssub.sat(X, C) -> sadd.sat(X, -C) if C != MIN
2158     Constant *C;
2159     if (IID == Intrinsic::ssub_sat && match(Arg1, m_Constant(C)) &&
2160         C->isNotMinSignedValue()) {
2161       Value *NegVal = ConstantExpr::getNeg(C);
2162       return replaceInstUsesWith(
2163           *II, Builder.CreateBinaryIntrinsic(
2164               Intrinsic::sadd_sat, Arg0, NegVal));
2165     }
2166 
2167     // sat(sat(X + Val2) + Val) -> sat(X + (Val+Val2))
2168     // sat(sat(X - Val2) - Val) -> sat(X - (Val+Val2))
2169     // if Val and Val2 have the same sign
2170     if (auto *Other = dyn_cast<IntrinsicInst>(Arg0)) {
2171       Value *X;
2172       const APInt *Val, *Val2;
2173       APInt NewVal;
2174       bool IsUnsigned =
2175           IID == Intrinsic::uadd_sat || IID == Intrinsic::usub_sat;
2176       if (Other->getIntrinsicID() == IID &&
2177           match(Arg1, m_APInt(Val)) &&
2178           match(Other->getArgOperand(0), m_Value(X)) &&
2179           match(Other->getArgOperand(1), m_APInt(Val2))) {
2180         if (IsUnsigned)
2181           NewVal = Val->uadd_sat(*Val2);
2182         else if (Val->isNonNegative() == Val2->isNonNegative()) {
2183           bool Overflow;
2184           NewVal = Val->sadd_ov(*Val2, Overflow);
2185           if (Overflow) {
2186             // Both adds together may add more than SignedMaxValue
2187             // without saturating the final result.
2188             break;
2189           }
2190         } else {
2191           // Cannot fold saturated addition with different signs.
2192           break;
2193         }
2194 
2195         return replaceInstUsesWith(
2196             *II, Builder.CreateBinaryIntrinsic(
2197                      IID, X, ConstantInt::get(II->getType(), NewVal)));
2198       }
2199     }
2200     break;
2201   }
2202 
2203   case Intrinsic::minnum:
2204   case Intrinsic::maxnum:
2205   case Intrinsic::minimum:
2206   case Intrinsic::maximum: {
2207     Value *Arg0 = II->getArgOperand(0);
2208     Value *Arg1 = II->getArgOperand(1);
2209     Value *X, *Y;
2210     if (match(Arg0, m_FNeg(m_Value(X))) && match(Arg1, m_FNeg(m_Value(Y))) &&
2211         (Arg0->hasOneUse() || Arg1->hasOneUse())) {
2212       // If both operands are negated, invert the call and negate the result:
2213       // min(-X, -Y) --> -(max(X, Y))
2214       // max(-X, -Y) --> -(min(X, Y))
2215       Intrinsic::ID NewIID;
2216       switch (IID) {
2217       case Intrinsic::maxnum:
2218         NewIID = Intrinsic::minnum;
2219         break;
2220       case Intrinsic::minnum:
2221         NewIID = Intrinsic::maxnum;
2222         break;
2223       case Intrinsic::maximum:
2224         NewIID = Intrinsic::minimum;
2225         break;
2226       case Intrinsic::minimum:
2227         NewIID = Intrinsic::maximum;
2228         break;
2229       default:
2230         llvm_unreachable("unexpected intrinsic ID");
2231       }
2232       Value *NewCall = Builder.CreateBinaryIntrinsic(NewIID, X, Y, II);
2233       Instruction *FNeg = UnaryOperator::CreateFNeg(NewCall);
2234       FNeg->copyIRFlags(II);
2235       return FNeg;
2236     }
2237 
2238     // m(m(X, C2), C1) -> m(X, C)
2239     const APFloat *C1, *C2;
2240     if (auto *M = dyn_cast<IntrinsicInst>(Arg0)) {
2241       if (M->getIntrinsicID() == IID && match(Arg1, m_APFloat(C1)) &&
2242           ((match(M->getArgOperand(0), m_Value(X)) &&
2243             match(M->getArgOperand(1), m_APFloat(C2))) ||
2244            (match(M->getArgOperand(1), m_Value(X)) &&
2245             match(M->getArgOperand(0), m_APFloat(C2))))) {
2246         APFloat Res(0.0);
2247         switch (IID) {
2248         case Intrinsic::maxnum:
2249           Res = maxnum(*C1, *C2);
2250           break;
2251         case Intrinsic::minnum:
2252           Res = minnum(*C1, *C2);
2253           break;
2254         case Intrinsic::maximum:
2255           Res = maximum(*C1, *C2);
2256           break;
2257         case Intrinsic::minimum:
2258           Res = minimum(*C1, *C2);
2259           break;
2260         default:
2261           llvm_unreachable("unexpected intrinsic ID");
2262         }
2263         Instruction *NewCall = Builder.CreateBinaryIntrinsic(
2264             IID, X, ConstantFP::get(Arg0->getType(), Res), II);
2265         // TODO: Conservatively intersecting FMF. If Res == C2, the transform
2266         //       was a simplification (so Arg0 and its original flags could
2267         //       propagate?)
2268         NewCall->andIRFlags(M);
2269         return replaceInstUsesWith(*II, NewCall);
2270       }
2271     }
2272 
2273     // m((fpext X), (fpext Y)) -> fpext (m(X, Y))
2274     if (match(Arg0, m_OneUse(m_FPExt(m_Value(X)))) &&
2275         match(Arg1, m_OneUse(m_FPExt(m_Value(Y)))) &&
2276         X->getType() == Y->getType()) {
2277       Value *NewCall =
2278           Builder.CreateBinaryIntrinsic(IID, X, Y, II, II->getName());
2279       return new FPExtInst(NewCall, II->getType());
2280     }
2281 
2282     // max X, -X --> fabs X
2283     // min X, -X --> -(fabs X)
2284     // TODO: Remove one-use limitation? That is obviously better for max.
2285     //       It would be an extra instruction for min (fnabs), but that is
2286     //       still likely better for analysis and codegen.
2287     if ((match(Arg0, m_OneUse(m_FNeg(m_Value(X)))) && Arg1 == X) ||
2288         (match(Arg1, m_OneUse(m_FNeg(m_Value(X)))) && Arg0 == X)) {
2289       Value *R = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, X, II);
2290       if (IID == Intrinsic::minimum || IID == Intrinsic::minnum)
2291         R = Builder.CreateFNegFMF(R, II);
2292       return replaceInstUsesWith(*II, R);
2293     }
2294 
2295     break;
2296   }
2297   case Intrinsic::matrix_multiply: {
2298     // Optimize negation in matrix multiplication.
2299 
2300     // -A * -B -> A * B
2301     Value *A, *B;
2302     if (match(II->getArgOperand(0), m_FNeg(m_Value(A))) &&
2303         match(II->getArgOperand(1), m_FNeg(m_Value(B)))) {
2304       replaceOperand(*II, 0, A);
2305       replaceOperand(*II, 1, B);
2306       return II;
2307     }
2308 
2309     Value *Op0 = II->getOperand(0);
2310     Value *Op1 = II->getOperand(1);
2311     Value *OpNotNeg, *NegatedOp;
2312     unsigned NegatedOpArg, OtherOpArg;
2313     if (match(Op0, m_FNeg(m_Value(OpNotNeg)))) {
2314       NegatedOp = Op0;
2315       NegatedOpArg = 0;
2316       OtherOpArg = 1;
2317     } else if (match(Op1, m_FNeg(m_Value(OpNotNeg)))) {
2318       NegatedOp = Op1;
2319       NegatedOpArg = 1;
2320       OtherOpArg = 0;
2321     } else
2322       // Multiplication doesn't have a negated operand.
2323       break;
2324 
2325     // Only optimize if the negated operand has only one use.
2326     if (!NegatedOp->hasOneUse())
2327       break;
2328 
2329     Value *OtherOp = II->getOperand(OtherOpArg);
2330     VectorType *RetTy = cast<VectorType>(II->getType());
2331     VectorType *NegatedOpTy = cast<VectorType>(NegatedOp->getType());
2332     VectorType *OtherOpTy = cast<VectorType>(OtherOp->getType());
2333     ElementCount NegatedCount = NegatedOpTy->getElementCount();
2334     ElementCount OtherCount = OtherOpTy->getElementCount();
2335     ElementCount RetCount = RetTy->getElementCount();
2336     // (-A) * B -> A * (-B), if it is cheaper to negate B and vice versa.
2337     if (ElementCount::isKnownGT(NegatedCount, OtherCount) &&
2338         ElementCount::isKnownLT(OtherCount, RetCount)) {
2339       Value *InverseOtherOp = Builder.CreateFNeg(OtherOp);
2340       replaceOperand(*II, NegatedOpArg, OpNotNeg);
2341       replaceOperand(*II, OtherOpArg, InverseOtherOp);
2342       return II;
2343     }
2344     // (-A) * B -> -(A * B), if it is cheaper to negate the result
2345     if (ElementCount::isKnownGT(NegatedCount, RetCount)) {
2346       SmallVector<Value *, 5> NewArgs(II->args());
2347       NewArgs[NegatedOpArg] = OpNotNeg;
2348       Instruction *NewMul =
2349           Builder.CreateIntrinsic(II->getType(), IID, NewArgs, II);
2350       return replaceInstUsesWith(*II, Builder.CreateFNegFMF(NewMul, II));
2351     }
2352     break;
2353   }
2354   case Intrinsic::fmuladd: {
2355     // Canonicalize fast fmuladd to the separate fmul + fadd.
2356     if (II->isFast()) {
2357       BuilderTy::FastMathFlagGuard Guard(Builder);
2358       Builder.setFastMathFlags(II->getFastMathFlags());
2359       Value *Mul = Builder.CreateFMul(II->getArgOperand(0),
2360                                       II->getArgOperand(1));
2361       Value *Add = Builder.CreateFAdd(Mul, II->getArgOperand(2));
2362       Add->takeName(II);
2363       return replaceInstUsesWith(*II, Add);
2364     }
2365 
2366     // Try to simplify the underlying FMul.
2367     if (Value *V = simplifyFMulInst(II->getArgOperand(0), II->getArgOperand(1),
2368                                     II->getFastMathFlags(),
2369                                     SQ.getWithInstruction(II))) {
2370       auto *FAdd = BinaryOperator::CreateFAdd(V, II->getArgOperand(2));
2371       FAdd->copyFastMathFlags(II);
2372       return FAdd;
2373     }
2374 
2375     [[fallthrough]];
2376   }
2377   case Intrinsic::fma: {
2378     // fma fneg(x), fneg(y), z -> fma x, y, z
2379     Value *Src0 = II->getArgOperand(0);
2380     Value *Src1 = II->getArgOperand(1);
2381     Value *X, *Y;
2382     if (match(Src0, m_FNeg(m_Value(X))) && match(Src1, m_FNeg(m_Value(Y)))) {
2383       replaceOperand(*II, 0, X);
2384       replaceOperand(*II, 1, Y);
2385       return II;
2386     }
2387 
2388     // fma fabs(x), fabs(x), z -> fma x, x, z
2389     if (match(Src0, m_FAbs(m_Value(X))) &&
2390         match(Src1, m_FAbs(m_Specific(X)))) {
2391       replaceOperand(*II, 0, X);
2392       replaceOperand(*II, 1, X);
2393       return II;
2394     }
2395 
2396     // Try to simplify the underlying FMul. We can only apply simplifications
2397     // that do not require rounding.
2398     if (Value *V = simplifyFMAFMul(II->getArgOperand(0), II->getArgOperand(1),
2399                                    II->getFastMathFlags(),
2400                                    SQ.getWithInstruction(II))) {
2401       auto *FAdd = BinaryOperator::CreateFAdd(V, II->getArgOperand(2));
2402       FAdd->copyFastMathFlags(II);
2403       return FAdd;
2404     }
2405 
2406     // fma x, y, 0 -> fmul x, y
2407     // This is always valid for -0.0, but requires nsz for +0.0 as
2408     // -0.0 + 0.0 = 0.0, which would not be the same as the fmul on its own.
2409     if (match(II->getArgOperand(2), m_NegZeroFP()) ||
2410         (match(II->getArgOperand(2), m_PosZeroFP()) &&
2411          II->getFastMathFlags().noSignedZeros()))
2412       return BinaryOperator::CreateFMulFMF(Src0, Src1, II);
2413 
2414     break;
2415   }
2416   case Intrinsic::copysign: {
2417     Value *Mag = II->getArgOperand(0), *Sign = II->getArgOperand(1);
2418     if (SignBitMustBeZero(Sign, DL, &TLI)) {
2419       // If we know that the sign argument is positive, reduce to FABS:
2420       // copysign Mag, +Sign --> fabs Mag
2421       Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, Mag, II);
2422       return replaceInstUsesWith(*II, Fabs);
2423     }
2424     // TODO: There should be a ValueTracking sibling like SignBitMustBeOne.
2425     const APFloat *C;
2426     if (match(Sign, m_APFloat(C)) && C->isNegative()) {
2427       // If we know that the sign argument is negative, reduce to FNABS:
2428       // copysign Mag, -Sign --> fneg (fabs Mag)
2429       Value *Fabs = Builder.CreateUnaryIntrinsic(Intrinsic::fabs, Mag, II);
2430       return replaceInstUsesWith(*II, Builder.CreateFNegFMF(Fabs, II));
2431     }
2432 
2433     // Propagate sign argument through nested calls:
2434     // copysign Mag, (copysign ?, X) --> copysign Mag, X
2435     Value *X;
2436     if (match(Sign, m_Intrinsic<Intrinsic::copysign>(m_Value(), m_Value(X))))
2437       return replaceOperand(*II, 1, X);
2438 
2439     // Peek through changes of magnitude's sign-bit. This call rewrites those:
2440     // copysign (fabs X), Sign --> copysign X, Sign
2441     // copysign (fneg X), Sign --> copysign X, Sign
2442     if (match(Mag, m_FAbs(m_Value(X))) || match(Mag, m_FNeg(m_Value(X))))
2443       return replaceOperand(*II, 0, X);
2444 
2445     break;
2446   }
2447   case Intrinsic::fabs: {
2448     Value *Cond, *TVal, *FVal;
2449     if (match(II->getArgOperand(0),
2450               m_Select(m_Value(Cond), m_Value(TVal), m_Value(FVal)))) {
2451       // fabs (select Cond, TrueC, FalseC) --> select Cond, AbsT, AbsF
2452       if (isa<Constant>(TVal) && isa<Constant>(FVal)) {
2453         CallInst *AbsT = Builder.CreateCall(II->getCalledFunction(), {TVal});
2454         CallInst *AbsF = Builder.CreateCall(II->getCalledFunction(), {FVal});
2455         return SelectInst::Create(Cond, AbsT, AbsF);
2456       }
2457       // fabs (select Cond, -FVal, FVal) --> fabs FVal
2458       if (match(TVal, m_FNeg(m_Specific(FVal))))
2459         return replaceOperand(*II, 0, FVal);
2460       // fabs (select Cond, TVal, -TVal) --> fabs TVal
2461       if (match(FVal, m_FNeg(m_Specific(TVal))))
2462         return replaceOperand(*II, 0, TVal);
2463     }
2464 
2465     Value *Magnitude, *Sign;
2466     if (match(II->getArgOperand(0),
2467               m_CopySign(m_Value(Magnitude), m_Value(Sign)))) {
2468       // fabs (copysign x, y) -> (fabs x)
2469       CallInst *AbsSign =
2470           Builder.CreateCall(II->getCalledFunction(), {Magnitude});
2471       AbsSign->copyFastMathFlags(II);
2472       return replaceInstUsesWith(*II, AbsSign);
2473     }
2474 
2475     [[fallthrough]];
2476   }
2477   case Intrinsic::ceil:
2478   case Intrinsic::floor:
2479   case Intrinsic::round:
2480   case Intrinsic::roundeven:
2481   case Intrinsic::nearbyint:
2482   case Intrinsic::rint:
2483   case Intrinsic::trunc: {
2484     Value *ExtSrc;
2485     if (match(II->getArgOperand(0), m_OneUse(m_FPExt(m_Value(ExtSrc))))) {
2486       // Narrow the call: intrinsic (fpext x) -> fpext (intrinsic x)
2487       Value *NarrowII = Builder.CreateUnaryIntrinsic(IID, ExtSrc, II);
2488       return new FPExtInst(NarrowII, II->getType());
2489     }
2490     break;
2491   }
2492   case Intrinsic::cos:
2493   case Intrinsic::amdgcn_cos: {
2494     Value *X;
2495     Value *Src = II->getArgOperand(0);
2496     if (match(Src, m_FNeg(m_Value(X))) || match(Src, m_FAbs(m_Value(X)))) {
2497       // cos(-x) -> cos(x)
2498       // cos(fabs(x)) -> cos(x)
2499       return replaceOperand(*II, 0, X);
2500     }
2501     break;
2502   }
2503   case Intrinsic::sin: {
2504     Value *X;
2505     if (match(II->getArgOperand(0), m_OneUse(m_FNeg(m_Value(X))))) {
2506       // sin(-x) --> -sin(x)
2507       Value *NewSin = Builder.CreateUnaryIntrinsic(Intrinsic::sin, X, II);
2508       Instruction *FNeg = UnaryOperator::CreateFNeg(NewSin);
2509       FNeg->copyFastMathFlags(II);
2510       return FNeg;
2511     }
2512     break;
2513   }
2514   case Intrinsic::ldexp: {
2515     // ldexp(ldexp(x, a), b) -> ldexp(x, a + b)
2516     //
2517     // The danger is if the first ldexp would overflow to infinity or underflow
2518     // to zero, but the combined exponent avoids it. We ignore this with
2519     // reassoc.
2520     //
2521     // It's also safe to fold if we know both exponents are >= 0 or <= 0 since
2522     // it would just double down on the overflow/underflow which would occur
2523     // anyway.
2524     //
2525     // TODO: Could do better if we had range tracking for the input value
2526     // exponent. Also could broaden sign check to cover == 0 case.
2527     Value *Src = II->getArgOperand(0);
2528     Value *Exp = II->getArgOperand(1);
2529     Value *InnerSrc;
2530     Value *InnerExp;
2531     if (match(Src, m_OneUse(m_Intrinsic<Intrinsic::ldexp>(
2532                        m_Value(InnerSrc), m_Value(InnerExp)))) &&
2533         Exp->getType() == InnerExp->getType()) {
2534       FastMathFlags FMF = II->getFastMathFlags();
2535       FastMathFlags InnerFlags = cast<FPMathOperator>(Src)->getFastMathFlags();
2536 
2537       if ((FMF.allowReassoc() && InnerFlags.allowReassoc()) ||
2538           signBitMustBeTheSame(Exp, InnerExp, II, DL, &AC, &DT)) {
2539         // TODO: Add nsw/nuw probably safe if integer type exceeds exponent
2540         // width.
2541         Value *NewExp = Builder.CreateAdd(InnerExp, Exp);
2542         II->setArgOperand(1, NewExp);
2543         II->setFastMathFlags(InnerFlags); // Or the inner flags.
2544         return replaceOperand(*II, 0, InnerSrc);
2545       }
2546     }
2547 
2548     break;
2549   }
2550   case Intrinsic::ptrauth_auth:
2551   case Intrinsic::ptrauth_resign: {
2552     // (sign|resign) + (auth|resign) can be folded by omitting the middle
2553     // sign+auth component if the key and discriminator match.
2554     bool NeedSign = II->getIntrinsicID() == Intrinsic::ptrauth_resign;
2555     Value *Key = II->getArgOperand(1);
2556     Value *Disc = II->getArgOperand(2);
2557 
2558     // AuthKey will be the key we need to end up authenticating against in
2559     // whatever we replace this sequence with.
2560     Value *AuthKey = nullptr, *AuthDisc = nullptr, *BasePtr;
2561     if (auto CI = dyn_cast<CallBase>(II->getArgOperand(0))) {
2562       BasePtr = CI->getArgOperand(0);
2563       if (CI->getIntrinsicID() == Intrinsic::ptrauth_sign) {
2564         if (CI->getArgOperand(1) != Key || CI->getArgOperand(2) != Disc)
2565           break;
2566       } else if (CI->getIntrinsicID() == Intrinsic::ptrauth_resign) {
2567         if (CI->getArgOperand(3) != Key || CI->getArgOperand(4) != Disc)
2568           break;
2569         AuthKey = CI->getArgOperand(1);
2570         AuthDisc = CI->getArgOperand(2);
2571       } else
2572         break;
2573     } else
2574       break;
2575 
2576     unsigned NewIntrin;
2577     if (AuthKey && NeedSign) {
2578       // resign(0,1) + resign(1,2) = resign(0, 2)
2579       NewIntrin = Intrinsic::ptrauth_resign;
2580     } else if (AuthKey) {
2581       // resign(0,1) + auth(1) = auth(0)
2582       NewIntrin = Intrinsic::ptrauth_auth;
2583     } else if (NeedSign) {
2584       // sign(0) + resign(0, 1) = sign(1)
2585       NewIntrin = Intrinsic::ptrauth_sign;
2586     } else {
2587       // sign(0) + auth(0) = nop
2588       replaceInstUsesWith(*II, BasePtr);
2589       eraseInstFromFunction(*II);
2590       return nullptr;
2591     }
2592 
2593     SmallVector<Value *, 4> CallArgs;
2594     CallArgs.push_back(BasePtr);
2595     if (AuthKey) {
2596       CallArgs.push_back(AuthKey);
2597       CallArgs.push_back(AuthDisc);
2598     }
2599 
2600     if (NeedSign) {
2601       CallArgs.push_back(II->getArgOperand(3));
2602       CallArgs.push_back(II->getArgOperand(4));
2603     }
2604 
2605     Function *NewFn = Intrinsic::getDeclaration(II->getModule(), NewIntrin);
2606     return CallInst::Create(NewFn, CallArgs);
2607   }
2608   case Intrinsic::arm_neon_vtbl1:
2609   case Intrinsic::aarch64_neon_tbl1:
2610     if (Value *V = simplifyNeonTbl1(*II, Builder))
2611       return replaceInstUsesWith(*II, V);
2612     break;
2613 
2614   case Intrinsic::arm_neon_vmulls:
2615   case Intrinsic::arm_neon_vmullu:
2616   case Intrinsic::aarch64_neon_smull:
2617   case Intrinsic::aarch64_neon_umull: {
2618     Value *Arg0 = II->getArgOperand(0);
2619     Value *Arg1 = II->getArgOperand(1);
2620 
2621     // Handle mul by zero first:
2622     if (isa<ConstantAggregateZero>(Arg0) || isa<ConstantAggregateZero>(Arg1)) {
2623       return replaceInstUsesWith(CI, ConstantAggregateZero::get(II->getType()));
2624     }
2625 
2626     // Check for constant LHS & RHS - in this case we just simplify.
2627     bool Zext = (IID == Intrinsic::arm_neon_vmullu ||
2628                  IID == Intrinsic::aarch64_neon_umull);
2629     VectorType *NewVT = cast<VectorType>(II->getType());
2630     if (Constant *CV0 = dyn_cast<Constant>(Arg0)) {
2631       if (Constant *CV1 = dyn_cast<Constant>(Arg1)) {
2632         Value *V0 = Builder.CreateIntCast(CV0, NewVT, /*isSigned=*/!Zext);
2633         Value *V1 = Builder.CreateIntCast(CV1, NewVT, /*isSigned=*/!Zext);
2634         return replaceInstUsesWith(CI, Builder.CreateMul(V0, V1));
2635       }
2636 
2637       // Couldn't simplify - canonicalize constant to the RHS.
2638       std::swap(Arg0, Arg1);
2639     }
2640 
2641     // Handle mul by one:
2642     if (Constant *CV1 = dyn_cast<Constant>(Arg1))
2643       if (ConstantInt *Splat =
2644               dyn_cast_or_null<ConstantInt>(CV1->getSplatValue()))
2645         if (Splat->isOne())
2646           return CastInst::CreateIntegerCast(Arg0, II->getType(),
2647                                              /*isSigned=*/!Zext);
2648 
2649     break;
2650   }
2651   case Intrinsic::arm_neon_aesd:
2652   case Intrinsic::arm_neon_aese:
2653   case Intrinsic::aarch64_crypto_aesd:
2654   case Intrinsic::aarch64_crypto_aese: {
2655     Value *DataArg = II->getArgOperand(0);
2656     Value *KeyArg  = II->getArgOperand(1);
2657 
2658     // Try to use the builtin XOR in AESE and AESD to eliminate a prior XOR
2659     Value *Data, *Key;
2660     if (match(KeyArg, m_ZeroInt()) &&
2661         match(DataArg, m_Xor(m_Value(Data), m_Value(Key)))) {
2662       replaceOperand(*II, 0, Data);
2663       replaceOperand(*II, 1, Key);
2664       return II;
2665     }
2666     break;
2667   }
2668   case Intrinsic::hexagon_V6_vandvrt:
2669   case Intrinsic::hexagon_V6_vandvrt_128B: {
2670     // Simplify Q -> V -> Q conversion.
2671     if (auto Op0 = dyn_cast<IntrinsicInst>(II->getArgOperand(0))) {
2672       Intrinsic::ID ID0 = Op0->getIntrinsicID();
2673       if (ID0 != Intrinsic::hexagon_V6_vandqrt &&
2674           ID0 != Intrinsic::hexagon_V6_vandqrt_128B)
2675         break;
2676       Value *Bytes = Op0->getArgOperand(1), *Mask = II->getArgOperand(1);
2677       uint64_t Bytes1 = computeKnownBits(Bytes, 0, Op0).One.getZExtValue();
2678       uint64_t Mask1 = computeKnownBits(Mask, 0, II).One.getZExtValue();
2679       // Check if every byte has common bits in Bytes and Mask.
2680       uint64_t C = Bytes1 & Mask1;
2681       if ((C & 0xFF) && (C & 0xFF00) && (C & 0xFF0000) && (C & 0xFF000000))
2682         return replaceInstUsesWith(*II, Op0->getArgOperand(0));
2683     }
2684     break;
2685   }
2686   case Intrinsic::stackrestore: {
2687     enum class ClassifyResult {
2688       None,
2689       Alloca,
2690       StackRestore,
2691       CallWithSideEffects,
2692     };
2693     auto Classify = [](const Instruction *I) {
2694       if (isa<AllocaInst>(I))
2695         return ClassifyResult::Alloca;
2696 
2697       if (auto *CI = dyn_cast<CallInst>(I)) {
2698         if (auto *II = dyn_cast<IntrinsicInst>(CI)) {
2699           if (II->getIntrinsicID() == Intrinsic::stackrestore)
2700             return ClassifyResult::StackRestore;
2701 
2702           if (II->mayHaveSideEffects())
2703             return ClassifyResult::CallWithSideEffects;
2704         } else {
2705           // Consider all non-intrinsic calls to be side effects
2706           return ClassifyResult::CallWithSideEffects;
2707         }
2708       }
2709 
2710       return ClassifyResult::None;
2711     };
2712 
2713     // If the stacksave and the stackrestore are in the same BB, and there is
2714     // no intervening call, alloca, or stackrestore of a different stacksave,
2715     // remove the restore. This can happen when variable allocas are DCE'd.
2716     if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getArgOperand(0))) {
2717       if (SS->getIntrinsicID() == Intrinsic::stacksave &&
2718           SS->getParent() == II->getParent()) {
2719         BasicBlock::iterator BI(SS);
2720         bool CannotRemove = false;
2721         for (++BI; &*BI != II; ++BI) {
2722           switch (Classify(&*BI)) {
2723           case ClassifyResult::None:
2724             // So far so good, look at next instructions.
2725             break;
2726 
2727           case ClassifyResult::StackRestore:
2728             // If we found an intervening stackrestore for a different
2729             // stacksave, we can't remove the stackrestore. Otherwise, continue.
2730             if (cast<IntrinsicInst>(*BI).getArgOperand(0) != SS)
2731               CannotRemove = true;
2732             break;
2733 
2734           case ClassifyResult::Alloca:
2735           case ClassifyResult::CallWithSideEffects:
2736             // If we found an alloca, a non-intrinsic call, or an intrinsic
2737             // call with side effects, we can't remove the stackrestore.
2738             CannotRemove = true;
2739             break;
2740           }
2741           if (CannotRemove)
2742             break;
2743         }
2744 
2745         if (!CannotRemove)
2746           return eraseInstFromFunction(CI);
2747       }
2748     }
2749 
2750     // Scan down this block to see if there is another stack restore in the
2751     // same block without an intervening call/alloca.
2752     BasicBlock::iterator BI(II);
2753     Instruction *TI = II->getParent()->getTerminator();
2754     bool CannotRemove = false;
2755     for (++BI; &*BI != TI; ++BI) {
2756       switch (Classify(&*BI)) {
2757       case ClassifyResult::None:
2758         // So far so good, look at next instructions.
2759         break;
2760 
2761       case ClassifyResult::StackRestore:
2762         // If there is a stackrestore below this one, remove this one.
2763         return eraseInstFromFunction(CI);
2764 
2765       case ClassifyResult::Alloca:
2766       case ClassifyResult::CallWithSideEffects:
2767         // If we found an alloca, a non-intrinsic call, or an intrinsic call
2768         // with side effects (such as llvm.stacksave and llvm.read_register),
2769         // we can't remove the stack restore.
2770         CannotRemove = true;
2771         break;
2772       }
2773       if (CannotRemove)
2774         break;
2775     }
2776 
2777     // If the stack restore is in a return, resume, or unwind block and if there
2778     // are no allocas or calls between the restore and the return, nuke the
2779     // restore.
2780     if (!CannotRemove && (isa<ReturnInst>(TI) || isa<ResumeInst>(TI)))
2781       return eraseInstFromFunction(CI);
2782     break;
2783   }
2784   case Intrinsic::lifetime_end:
2785     // Asan needs to poison memory to detect invalid access which is possible
2786     // even for empty lifetime range.
2787     if (II->getFunction()->hasFnAttribute(Attribute::SanitizeAddress) ||
2788         II->getFunction()->hasFnAttribute(Attribute::SanitizeMemory) ||
2789         II->getFunction()->hasFnAttribute(Attribute::SanitizeHWAddress))
2790       break;
2791 
2792     if (removeTriviallyEmptyRange(*II, *this, [](const IntrinsicInst &I) {
2793           return I.getIntrinsicID() == Intrinsic::lifetime_start;
2794         }))
2795       return nullptr;
2796     break;
2797   case Intrinsic::assume: {
2798     Value *IIOperand = II->getArgOperand(0);
2799     SmallVector<OperandBundleDef, 4> OpBundles;
2800     II->getOperandBundlesAsDefs(OpBundles);
2801 
2802     /// This will remove the boolean Condition from the assume given as
2803     /// argument and remove the assume if it becomes useless.
2804     /// always returns nullptr for use as a return values.
2805     auto RemoveConditionFromAssume = [&](Instruction *Assume) -> Instruction * {
2806       assert(isa<AssumeInst>(Assume));
2807       if (isAssumeWithEmptyBundle(*cast<AssumeInst>(II)))
2808         return eraseInstFromFunction(CI);
2809       replaceUse(II->getOperandUse(0), ConstantInt::getTrue(II->getContext()));
2810       return nullptr;
2811     };
2812     // Remove an assume if it is followed by an identical assume.
2813     // TODO: Do we need this? Unless there are conflicting assumptions, the
2814     // computeKnownBits(IIOperand) below here eliminates redundant assumes.
2815     Instruction *Next = II->getNextNonDebugInstruction();
2816     if (match(Next, m_Intrinsic<Intrinsic::assume>(m_Specific(IIOperand))))
2817       return RemoveConditionFromAssume(Next);
2818 
2819     // Canonicalize assume(a && b) -> assume(a); assume(b);
2820     // Note: New assumption intrinsics created here are registered by
2821     // the InstCombineIRInserter object.
2822     FunctionType *AssumeIntrinsicTy = II->getFunctionType();
2823     Value *AssumeIntrinsic = II->getCalledOperand();
2824     Value *A, *B;
2825     if (match(IIOperand, m_LogicalAnd(m_Value(A), m_Value(B)))) {
2826       Builder.CreateCall(AssumeIntrinsicTy, AssumeIntrinsic, A, OpBundles,
2827                          II->getName());
2828       Builder.CreateCall(AssumeIntrinsicTy, AssumeIntrinsic, B, II->getName());
2829       return eraseInstFromFunction(*II);
2830     }
2831     // assume(!(a || b)) -> assume(!a); assume(!b);
2832     if (match(IIOperand, m_Not(m_LogicalOr(m_Value(A), m_Value(B))))) {
2833       Builder.CreateCall(AssumeIntrinsicTy, AssumeIntrinsic,
2834                          Builder.CreateNot(A), OpBundles, II->getName());
2835       Builder.CreateCall(AssumeIntrinsicTy, AssumeIntrinsic,
2836                          Builder.CreateNot(B), II->getName());
2837       return eraseInstFromFunction(*II);
2838     }
2839 
2840     // assume( (load addr) != null ) -> add 'nonnull' metadata to load
2841     // (if assume is valid at the load)
2842     CmpInst::Predicate Pred;
2843     Instruction *LHS;
2844     if (match(IIOperand, m_ICmp(Pred, m_Instruction(LHS), m_Zero())) &&
2845         Pred == ICmpInst::ICMP_NE && LHS->getOpcode() == Instruction::Load &&
2846         LHS->getType()->isPointerTy() &&
2847         isValidAssumeForContext(II, LHS, &DT)) {
2848       MDNode *MD = MDNode::get(II->getContext(), std::nullopt);
2849       LHS->setMetadata(LLVMContext::MD_nonnull, MD);
2850       LHS->setMetadata(LLVMContext::MD_noundef, MD);
2851       return RemoveConditionFromAssume(II);
2852 
2853       // TODO: apply nonnull return attributes to calls and invokes
2854       // TODO: apply range metadata for range check patterns?
2855     }
2856 
2857     // Separate storage assumptions apply to the underlying allocations, not any
2858     // particular pointer within them. When evaluating the hints for AA purposes
2859     // we getUnderlyingObject them; by precomputing the answers here we can
2860     // avoid having to do so repeatedly there.
2861     for (unsigned Idx = 0; Idx < II->getNumOperandBundles(); Idx++) {
2862       OperandBundleUse OBU = II->getOperandBundleAt(Idx);
2863       if (OBU.getTagName() == "separate_storage") {
2864         assert(OBU.Inputs.size() == 2);
2865         auto MaybeSimplifyHint = [&](const Use &U) {
2866           Value *Hint = U.get();
2867           // Not having a limit is safe because InstCombine removes unreachable
2868           // code.
2869           Value *UnderlyingObject = getUnderlyingObject(Hint, /*MaxLookup*/ 0);
2870           if (Hint != UnderlyingObject)
2871             replaceUse(const_cast<Use &>(U), UnderlyingObject);
2872         };
2873         MaybeSimplifyHint(OBU.Inputs[0]);
2874         MaybeSimplifyHint(OBU.Inputs[1]);
2875       }
2876     }
2877 
2878     // Convert nonnull assume like:
2879     // %A = icmp ne i32* %PTR, null
2880     // call void @llvm.assume(i1 %A)
2881     // into
2882     // call void @llvm.assume(i1 true) [ "nonnull"(i32* %PTR) ]
2883     if (EnableKnowledgeRetention &&
2884         match(IIOperand, m_Cmp(Pred, m_Value(A), m_Zero())) &&
2885         Pred == CmpInst::ICMP_NE && A->getType()->isPointerTy()) {
2886       if (auto *Replacement = buildAssumeFromKnowledge(
2887               {RetainedKnowledge{Attribute::NonNull, 0, A}}, Next, &AC, &DT)) {
2888 
2889         Replacement->insertBefore(Next);
2890         AC.registerAssumption(Replacement);
2891         return RemoveConditionFromAssume(II);
2892       }
2893     }
2894 
2895     // Convert alignment assume like:
2896     // %B = ptrtoint i32* %A to i64
2897     // %C = and i64 %B, Constant
2898     // %D = icmp eq i64 %C, 0
2899     // call void @llvm.assume(i1 %D)
2900     // into
2901     // call void @llvm.assume(i1 true) [ "align"(i32* [[A]], i64  Constant + 1)]
2902     uint64_t AlignMask;
2903     if (EnableKnowledgeRetention &&
2904         match(IIOperand,
2905               m_Cmp(Pred, m_And(m_Value(A), m_ConstantInt(AlignMask)),
2906                     m_Zero())) &&
2907         Pred == CmpInst::ICMP_EQ) {
2908       if (isPowerOf2_64(AlignMask + 1)) {
2909         uint64_t Offset = 0;
2910         match(A, m_Add(m_Value(A), m_ConstantInt(Offset)));
2911         if (match(A, m_PtrToInt(m_Value(A)))) {
2912           /// Note: this doesn't preserve the offset information but merges
2913           /// offset and alignment.
2914           /// TODO: we can generate a GEP instead of merging the alignment with
2915           /// the offset.
2916           RetainedKnowledge RK{Attribute::Alignment,
2917                                (unsigned)MinAlign(Offset, AlignMask + 1), A};
2918           if (auto *Replacement =
2919                   buildAssumeFromKnowledge(RK, Next, &AC, &DT)) {
2920 
2921             Replacement->insertAfter(II);
2922             AC.registerAssumption(Replacement);
2923           }
2924           return RemoveConditionFromAssume(II);
2925         }
2926       }
2927     }
2928 
2929     /// Canonicalize Knowledge in operand bundles.
2930     if (EnableKnowledgeRetention && II->hasOperandBundles()) {
2931       for (unsigned Idx = 0; Idx < II->getNumOperandBundles(); Idx++) {
2932         auto &BOI = II->bundle_op_info_begin()[Idx];
2933         RetainedKnowledge RK =
2934           llvm::getKnowledgeFromBundle(cast<AssumeInst>(*II), BOI);
2935         if (BOI.End - BOI.Begin > 2)
2936           continue; // Prevent reducing knowledge in an align with offset since
2937                     // extracting a RetainedKnowledge from them looses offset
2938                     // information
2939         RetainedKnowledge CanonRK =
2940           llvm::simplifyRetainedKnowledge(cast<AssumeInst>(II), RK,
2941                                           &getAssumptionCache(),
2942                                           &getDominatorTree());
2943         if (CanonRK == RK)
2944           continue;
2945         if (!CanonRK) {
2946           if (BOI.End - BOI.Begin > 0) {
2947             Worklist.pushValue(II->op_begin()[BOI.Begin]);
2948             Value::dropDroppableUse(II->op_begin()[BOI.Begin]);
2949           }
2950           continue;
2951         }
2952         assert(RK.AttrKind == CanonRK.AttrKind);
2953         if (BOI.End - BOI.Begin > 0)
2954           II->op_begin()[BOI.Begin].set(CanonRK.WasOn);
2955         if (BOI.End - BOI.Begin > 1)
2956           II->op_begin()[BOI.Begin + 1].set(ConstantInt::get(
2957               Type::getInt64Ty(II->getContext()), CanonRK.ArgValue));
2958         if (RK.WasOn)
2959           Worklist.pushValue(RK.WasOn);
2960         return II;
2961       }
2962     }
2963 
2964     // If there is a dominating assume with the same condition as this one,
2965     // then this one is redundant, and should be removed.
2966     KnownBits Known(1);
2967     computeKnownBits(IIOperand, Known, 0, II);
2968     if (Known.isAllOnes() && isAssumeWithEmptyBundle(cast<AssumeInst>(*II)))
2969       return eraseInstFromFunction(*II);
2970 
2971     // assume(false) is unreachable.
2972     if (match(IIOperand, m_CombineOr(m_Zero(), m_Undef()))) {
2973       CreateNonTerminatorUnreachable(II);
2974       return eraseInstFromFunction(*II);
2975     }
2976 
2977     // Update the cache of affected values for this assumption (we might be
2978     // here because we just simplified the condition).
2979     AC.updateAffectedValues(cast<AssumeInst>(II));
2980     break;
2981   }
2982   case Intrinsic::experimental_guard: {
2983     // Is this guard followed by another guard?  We scan forward over a small
2984     // fixed window of instructions to handle common cases with conditions
2985     // computed between guards.
2986     Instruction *NextInst = II->getNextNonDebugInstruction();
2987     for (unsigned i = 0; i < GuardWideningWindow; i++) {
2988       // Note: Using context-free form to avoid compile time blow up
2989       if (!isSafeToSpeculativelyExecute(NextInst))
2990         break;
2991       NextInst = NextInst->getNextNonDebugInstruction();
2992     }
2993     Value *NextCond = nullptr;
2994     if (match(NextInst,
2995               m_Intrinsic<Intrinsic::experimental_guard>(m_Value(NextCond)))) {
2996       Value *CurrCond = II->getArgOperand(0);
2997 
2998       // Remove a guard that it is immediately preceded by an identical guard.
2999       // Otherwise canonicalize guard(a); guard(b) -> guard(a & b).
3000       if (CurrCond != NextCond) {
3001         Instruction *MoveI = II->getNextNonDebugInstruction();
3002         while (MoveI != NextInst) {
3003           auto *Temp = MoveI;
3004           MoveI = MoveI->getNextNonDebugInstruction();
3005           Temp->moveBefore(II);
3006         }
3007         replaceOperand(*II, 0, Builder.CreateAnd(CurrCond, NextCond));
3008       }
3009       eraseInstFromFunction(*NextInst);
3010       return II;
3011     }
3012     break;
3013   }
3014   case Intrinsic::vector_insert: {
3015     Value *Vec = II->getArgOperand(0);
3016     Value *SubVec = II->getArgOperand(1);
3017     Value *Idx = II->getArgOperand(2);
3018     auto *DstTy = dyn_cast<FixedVectorType>(II->getType());
3019     auto *VecTy = dyn_cast<FixedVectorType>(Vec->getType());
3020     auto *SubVecTy = dyn_cast<FixedVectorType>(SubVec->getType());
3021 
3022     // Only canonicalize if the destination vector, Vec, and SubVec are all
3023     // fixed vectors.
3024     if (DstTy && VecTy && SubVecTy) {
3025       unsigned DstNumElts = DstTy->getNumElements();
3026       unsigned VecNumElts = VecTy->getNumElements();
3027       unsigned SubVecNumElts = SubVecTy->getNumElements();
3028       unsigned IdxN = cast<ConstantInt>(Idx)->getZExtValue();
3029 
3030       // An insert that entirely overwrites Vec with SubVec is a nop.
3031       if (VecNumElts == SubVecNumElts)
3032         return replaceInstUsesWith(CI, SubVec);
3033 
3034       // Widen SubVec into a vector of the same width as Vec, since
3035       // shufflevector requires the two input vectors to be the same width.
3036       // Elements beyond the bounds of SubVec within the widened vector are
3037       // undefined.
3038       SmallVector<int, 8> WidenMask;
3039       unsigned i;
3040       for (i = 0; i != SubVecNumElts; ++i)
3041         WidenMask.push_back(i);
3042       for (; i != VecNumElts; ++i)
3043         WidenMask.push_back(PoisonMaskElem);
3044 
3045       Value *WidenShuffle = Builder.CreateShuffleVector(SubVec, WidenMask);
3046 
3047       SmallVector<int, 8> Mask;
3048       for (unsigned i = 0; i != IdxN; ++i)
3049         Mask.push_back(i);
3050       for (unsigned i = DstNumElts; i != DstNumElts + SubVecNumElts; ++i)
3051         Mask.push_back(i);
3052       for (unsigned i = IdxN + SubVecNumElts; i != DstNumElts; ++i)
3053         Mask.push_back(i);
3054 
3055       Value *Shuffle = Builder.CreateShuffleVector(Vec, WidenShuffle, Mask);
3056       return replaceInstUsesWith(CI, Shuffle);
3057     }
3058     break;
3059   }
3060   case Intrinsic::vector_extract: {
3061     Value *Vec = II->getArgOperand(0);
3062     Value *Idx = II->getArgOperand(1);
3063 
3064     Type *ReturnType = II->getType();
3065     // (extract_vector (insert_vector InsertTuple, InsertValue, InsertIdx),
3066     // ExtractIdx)
3067     unsigned ExtractIdx = cast<ConstantInt>(Idx)->getZExtValue();
3068     Value *InsertTuple, *InsertIdx, *InsertValue;
3069     if (match(Vec, m_Intrinsic<Intrinsic::vector_insert>(m_Value(InsertTuple),
3070                                                          m_Value(InsertValue),
3071                                                          m_Value(InsertIdx))) &&
3072         InsertValue->getType() == ReturnType) {
3073       unsigned Index = cast<ConstantInt>(InsertIdx)->getZExtValue();
3074       // Case where we get the same index right after setting it.
3075       // extract.vector(insert.vector(InsertTuple, InsertValue, Idx), Idx) -->
3076       // InsertValue
3077       if (ExtractIdx == Index)
3078         return replaceInstUsesWith(CI, InsertValue);
3079       // If we are getting a different index than what was set in the
3080       // insert.vector intrinsic. We can just set the input tuple to the one up
3081       // in the chain. extract.vector(insert.vector(InsertTuple, InsertValue,
3082       // InsertIndex), ExtractIndex)
3083       // --> extract.vector(InsertTuple, ExtractIndex)
3084       else
3085         return replaceOperand(CI, 0, InsertTuple);
3086     }
3087 
3088     auto *DstTy = dyn_cast<VectorType>(ReturnType);
3089     auto *VecTy = dyn_cast<VectorType>(Vec->getType());
3090 
3091     if (DstTy && VecTy) {
3092       auto DstEltCnt = DstTy->getElementCount();
3093       auto VecEltCnt = VecTy->getElementCount();
3094       unsigned IdxN = cast<ConstantInt>(Idx)->getZExtValue();
3095 
3096       // Extracting the entirety of Vec is a nop.
3097       if (DstEltCnt == VecTy->getElementCount()) {
3098         replaceInstUsesWith(CI, Vec);
3099         return eraseInstFromFunction(CI);
3100       }
3101 
3102       // Only canonicalize to shufflevector if the destination vector and
3103       // Vec are fixed vectors.
3104       if (VecEltCnt.isScalable() || DstEltCnt.isScalable())
3105         break;
3106 
3107       SmallVector<int, 8> Mask;
3108       for (unsigned i = 0; i != DstEltCnt.getKnownMinValue(); ++i)
3109         Mask.push_back(IdxN + i);
3110 
3111       Value *Shuffle = Builder.CreateShuffleVector(Vec, Mask);
3112       return replaceInstUsesWith(CI, Shuffle);
3113     }
3114     break;
3115   }
3116   case Intrinsic::experimental_vector_reverse: {
3117     Value *BO0, *BO1, *X, *Y;
3118     Value *Vec = II->getArgOperand(0);
3119     if (match(Vec, m_OneUse(m_BinOp(m_Value(BO0), m_Value(BO1))))) {
3120       auto *OldBinOp = cast<BinaryOperator>(Vec);
3121       if (match(BO0, m_VecReverse(m_Value(X)))) {
3122         // rev(binop rev(X), rev(Y)) --> binop X, Y
3123         if (match(BO1, m_VecReverse(m_Value(Y))))
3124           return replaceInstUsesWith(CI,
3125                                      BinaryOperator::CreateWithCopiedFlags(
3126                                          OldBinOp->getOpcode(), X, Y, OldBinOp,
3127                                          OldBinOp->getName(), II));
3128         // rev(binop rev(X), BO1Splat) --> binop X, BO1Splat
3129         if (isSplatValue(BO1))
3130           return replaceInstUsesWith(CI,
3131                                      BinaryOperator::CreateWithCopiedFlags(
3132                                          OldBinOp->getOpcode(), X, BO1,
3133                                          OldBinOp, OldBinOp->getName(), II));
3134       }
3135       // rev(binop BO0Splat, rev(Y)) --> binop BO0Splat, Y
3136       if (match(BO1, m_VecReverse(m_Value(Y))) && isSplatValue(BO0))
3137         return replaceInstUsesWith(CI, BinaryOperator::CreateWithCopiedFlags(
3138                                            OldBinOp->getOpcode(), BO0, Y,
3139                                            OldBinOp, OldBinOp->getName(), II));
3140     }
3141     // rev(unop rev(X)) --> unop X
3142     if (match(Vec, m_OneUse(m_UnOp(m_VecReverse(m_Value(X)))))) {
3143       auto *OldUnOp = cast<UnaryOperator>(Vec);
3144       auto *NewUnOp = UnaryOperator::CreateWithCopiedFlags(
3145           OldUnOp->getOpcode(), X, OldUnOp, OldUnOp->getName(), II);
3146       return replaceInstUsesWith(CI, NewUnOp);
3147     }
3148     break;
3149   }
3150   case Intrinsic::vector_reduce_or:
3151   case Intrinsic::vector_reduce_and: {
3152     // Canonicalize logical or/and reductions:
3153     // Or reduction for i1 is represented as:
3154     // %val = bitcast <ReduxWidth x i1> to iReduxWidth
3155     // %res = cmp ne iReduxWidth %val, 0
3156     // And reduction for i1 is represented as:
3157     // %val = bitcast <ReduxWidth x i1> to iReduxWidth
3158     // %res = cmp eq iReduxWidth %val, 11111
3159     Value *Arg = II->getArgOperand(0);
3160     Value *Vect;
3161     if (match(Arg, m_ZExtOrSExtOrSelf(m_Value(Vect)))) {
3162       if (auto *FTy = dyn_cast<FixedVectorType>(Vect->getType()))
3163         if (FTy->getElementType() == Builder.getInt1Ty()) {
3164           Value *Res = Builder.CreateBitCast(
3165               Vect, Builder.getIntNTy(FTy->getNumElements()));
3166           if (IID == Intrinsic::vector_reduce_and) {
3167             Res = Builder.CreateICmpEQ(
3168                 Res, ConstantInt::getAllOnesValue(Res->getType()));
3169           } else {
3170             assert(IID == Intrinsic::vector_reduce_or &&
3171                    "Expected or reduction.");
3172             Res = Builder.CreateIsNotNull(Res);
3173           }
3174           if (Arg != Vect)
3175             Res = Builder.CreateCast(cast<CastInst>(Arg)->getOpcode(), Res,
3176                                      II->getType());
3177           return replaceInstUsesWith(CI, Res);
3178         }
3179     }
3180     [[fallthrough]];
3181   }
3182   case Intrinsic::vector_reduce_add: {
3183     if (IID == Intrinsic::vector_reduce_add) {
3184       // Convert vector_reduce_add(ZExt(<n x i1>)) to
3185       // ZExtOrTrunc(ctpop(bitcast <n x i1> to in)).
3186       // Convert vector_reduce_add(SExt(<n x i1>)) to
3187       // -ZExtOrTrunc(ctpop(bitcast <n x i1> to in)).
3188       // Convert vector_reduce_add(<n x i1>) to
3189       // Trunc(ctpop(bitcast <n x i1> to in)).
3190       Value *Arg = II->getArgOperand(0);
3191       Value *Vect;
3192       if (match(Arg, m_ZExtOrSExtOrSelf(m_Value(Vect)))) {
3193         if (auto *FTy = dyn_cast<FixedVectorType>(Vect->getType()))
3194           if (FTy->getElementType() == Builder.getInt1Ty()) {
3195             Value *V = Builder.CreateBitCast(
3196                 Vect, Builder.getIntNTy(FTy->getNumElements()));
3197             Value *Res = Builder.CreateUnaryIntrinsic(Intrinsic::ctpop, V);
3198             if (Res->getType() != II->getType())
3199               Res = Builder.CreateZExtOrTrunc(Res, II->getType());
3200             if (Arg != Vect &&
3201                 cast<Instruction>(Arg)->getOpcode() == Instruction::SExt)
3202               Res = Builder.CreateNeg(Res);
3203             return replaceInstUsesWith(CI, Res);
3204           }
3205       }
3206     }
3207     [[fallthrough]];
3208   }
3209   case Intrinsic::vector_reduce_xor: {
3210     if (IID == Intrinsic::vector_reduce_xor) {
3211       // Exclusive disjunction reduction over the vector with
3212       // (potentially-extended) i1 element type is actually a
3213       // (potentially-extended) arithmetic `add` reduction over the original
3214       // non-extended value:
3215       //   vector_reduce_xor(?ext(<n x i1>))
3216       //     -->
3217       //   ?ext(vector_reduce_add(<n x i1>))
3218       Value *Arg = II->getArgOperand(0);
3219       Value *Vect;
3220       if (match(Arg, m_ZExtOrSExtOrSelf(m_Value(Vect)))) {
3221         if (auto *FTy = dyn_cast<FixedVectorType>(Vect->getType()))
3222           if (FTy->getElementType() == Builder.getInt1Ty()) {
3223             Value *Res = Builder.CreateAddReduce(Vect);
3224             if (Arg != Vect)
3225               Res = Builder.CreateCast(cast<CastInst>(Arg)->getOpcode(), Res,
3226                                        II->getType());
3227             return replaceInstUsesWith(CI, Res);
3228           }
3229       }
3230     }
3231     [[fallthrough]];
3232   }
3233   case Intrinsic::vector_reduce_mul: {
3234     if (IID == Intrinsic::vector_reduce_mul) {
3235       // Multiplicative reduction over the vector with (potentially-extended)
3236       // i1 element type is actually a (potentially zero-extended)
3237       // logical `and` reduction over the original non-extended value:
3238       //   vector_reduce_mul(?ext(<n x i1>))
3239       //     -->
3240       //   zext(vector_reduce_and(<n x i1>))
3241       Value *Arg = II->getArgOperand(0);
3242       Value *Vect;
3243       if (match(Arg, m_ZExtOrSExtOrSelf(m_Value(Vect)))) {
3244         if (auto *FTy = dyn_cast<FixedVectorType>(Vect->getType()))
3245           if (FTy->getElementType() == Builder.getInt1Ty()) {
3246             Value *Res = Builder.CreateAndReduce(Vect);
3247             if (Res->getType() != II->getType())
3248               Res = Builder.CreateZExt(Res, II->getType());
3249             return replaceInstUsesWith(CI, Res);
3250           }
3251       }
3252     }
3253     [[fallthrough]];
3254   }
3255   case Intrinsic::vector_reduce_umin:
3256   case Intrinsic::vector_reduce_umax: {
3257     if (IID == Intrinsic::vector_reduce_umin ||
3258         IID == Intrinsic::vector_reduce_umax) {
3259       // UMin/UMax reduction over the vector with (potentially-extended)
3260       // i1 element type is actually a (potentially-extended)
3261       // logical `and`/`or` reduction over the original non-extended value:
3262       //   vector_reduce_u{min,max}(?ext(<n x i1>))
3263       //     -->
3264       //   ?ext(vector_reduce_{and,or}(<n x i1>))
3265       Value *Arg = II->getArgOperand(0);
3266       Value *Vect;
3267       if (match(Arg, m_ZExtOrSExtOrSelf(m_Value(Vect)))) {
3268         if (auto *FTy = dyn_cast<FixedVectorType>(Vect->getType()))
3269           if (FTy->getElementType() == Builder.getInt1Ty()) {
3270             Value *Res = IID == Intrinsic::vector_reduce_umin
3271                              ? Builder.CreateAndReduce(Vect)
3272                              : Builder.CreateOrReduce(Vect);
3273             if (Arg != Vect)
3274               Res = Builder.CreateCast(cast<CastInst>(Arg)->getOpcode(), Res,
3275                                        II->getType());
3276             return replaceInstUsesWith(CI, Res);
3277           }
3278       }
3279     }
3280     [[fallthrough]];
3281   }
3282   case Intrinsic::vector_reduce_smin:
3283   case Intrinsic::vector_reduce_smax: {
3284     if (IID == Intrinsic::vector_reduce_smin ||
3285         IID == Intrinsic::vector_reduce_smax) {
3286       // SMin/SMax reduction over the vector with (potentially-extended)
3287       // i1 element type is actually a (potentially-extended)
3288       // logical `and`/`or` reduction over the original non-extended value:
3289       //   vector_reduce_s{min,max}(<n x i1>)
3290       //     -->
3291       //   vector_reduce_{or,and}(<n x i1>)
3292       // and
3293       //   vector_reduce_s{min,max}(sext(<n x i1>))
3294       //     -->
3295       //   sext(vector_reduce_{or,and}(<n x i1>))
3296       // and
3297       //   vector_reduce_s{min,max}(zext(<n x i1>))
3298       //     -->
3299       //   zext(vector_reduce_{and,or}(<n x i1>))
3300       Value *Arg = II->getArgOperand(0);
3301       Value *Vect;
3302       if (match(Arg, m_ZExtOrSExtOrSelf(m_Value(Vect)))) {
3303         if (auto *FTy = dyn_cast<FixedVectorType>(Vect->getType()))
3304           if (FTy->getElementType() == Builder.getInt1Ty()) {
3305             Instruction::CastOps ExtOpc = Instruction::CastOps::CastOpsEnd;
3306             if (Arg != Vect)
3307               ExtOpc = cast<CastInst>(Arg)->getOpcode();
3308             Value *Res = ((IID == Intrinsic::vector_reduce_smin) ==
3309                           (ExtOpc == Instruction::CastOps::ZExt))
3310                              ? Builder.CreateAndReduce(Vect)
3311                              : Builder.CreateOrReduce(Vect);
3312             if (Arg != Vect)
3313               Res = Builder.CreateCast(ExtOpc, Res, II->getType());
3314             return replaceInstUsesWith(CI, Res);
3315           }
3316       }
3317     }
3318     [[fallthrough]];
3319   }
3320   case Intrinsic::vector_reduce_fmax:
3321   case Intrinsic::vector_reduce_fmin:
3322   case Intrinsic::vector_reduce_fadd:
3323   case Intrinsic::vector_reduce_fmul: {
3324     bool CanBeReassociated = (IID != Intrinsic::vector_reduce_fadd &&
3325                               IID != Intrinsic::vector_reduce_fmul) ||
3326                              II->hasAllowReassoc();
3327     const unsigned ArgIdx = (IID == Intrinsic::vector_reduce_fadd ||
3328                              IID == Intrinsic::vector_reduce_fmul)
3329                                 ? 1
3330                                 : 0;
3331     Value *Arg = II->getArgOperand(ArgIdx);
3332     Value *V;
3333     ArrayRef<int> Mask;
3334     if (!isa<FixedVectorType>(Arg->getType()) || !CanBeReassociated ||
3335         !match(Arg, m_Shuffle(m_Value(V), m_Undef(), m_Mask(Mask))) ||
3336         !cast<ShuffleVectorInst>(Arg)->isSingleSource())
3337       break;
3338     int Sz = Mask.size();
3339     SmallBitVector UsedIndices(Sz);
3340     for (int Idx : Mask) {
3341       if (Idx == PoisonMaskElem || UsedIndices.test(Idx))
3342         break;
3343       UsedIndices.set(Idx);
3344     }
3345     // Can remove shuffle iff just shuffled elements, no repeats, undefs, or
3346     // other changes.
3347     if (UsedIndices.all()) {
3348       replaceUse(II->getOperandUse(ArgIdx), V);
3349       return nullptr;
3350     }
3351     break;
3352   }
3353   case Intrinsic::is_fpclass: {
3354     if (Instruction *I = foldIntrinsicIsFPClass(*II))
3355       return I;
3356     break;
3357   }
3358   default: {
3359     // Handle target specific intrinsics
3360     std::optional<Instruction *> V = targetInstCombineIntrinsic(*II);
3361     if (V)
3362       return *V;
3363     break;
3364   }
3365   }
3366 
3367   // Try to fold intrinsic into select operands. This is legal if:
3368   //  * The intrinsic is speculatable.
3369   //  * The select condition is not a vector, or the intrinsic does not
3370   //    perform cross-lane operations.
3371   switch (IID) {
3372   case Intrinsic::ctlz:
3373   case Intrinsic::cttz:
3374   case Intrinsic::ctpop:
3375   case Intrinsic::umin:
3376   case Intrinsic::umax:
3377   case Intrinsic::smin:
3378   case Intrinsic::smax:
3379   case Intrinsic::usub_sat:
3380   case Intrinsic::uadd_sat:
3381   case Intrinsic::ssub_sat:
3382   case Intrinsic::sadd_sat:
3383     for (Value *Op : II->args())
3384       if (auto *Sel = dyn_cast<SelectInst>(Op))
3385         if (Instruction *R = FoldOpIntoSelect(*II, Sel))
3386           return R;
3387     [[fallthrough]];
3388   default:
3389     break;
3390   }
3391 
3392   if (Instruction *Shuf = foldShuffledIntrinsicOperands(II, Builder))
3393     return Shuf;
3394 
3395   // Some intrinsics (like experimental_gc_statepoint) can be used in invoke
3396   // context, so it is handled in visitCallBase and we should trigger it.
3397   return visitCallBase(*II);
3398 }
3399 
3400 // Fence instruction simplification
3401 Instruction *InstCombinerImpl::visitFenceInst(FenceInst &FI) {
3402   auto *NFI = dyn_cast<FenceInst>(FI.getNextNonDebugInstruction());
3403   // This check is solely here to handle arbitrary target-dependent syncscopes.
3404   // TODO: Can remove if does not matter in practice.
3405   if (NFI && FI.isIdenticalTo(NFI))
3406     return eraseInstFromFunction(FI);
3407 
3408   // Returns true if FI1 is identical or stronger fence than FI2.
3409   auto isIdenticalOrStrongerFence = [](FenceInst *FI1, FenceInst *FI2) {
3410     auto FI1SyncScope = FI1->getSyncScopeID();
3411     // Consider same scope, where scope is global or single-thread.
3412     if (FI1SyncScope != FI2->getSyncScopeID() ||
3413         (FI1SyncScope != SyncScope::System &&
3414          FI1SyncScope != SyncScope::SingleThread))
3415       return false;
3416 
3417     return isAtLeastOrStrongerThan(FI1->getOrdering(), FI2->getOrdering());
3418   };
3419   if (NFI && isIdenticalOrStrongerFence(NFI, &FI))
3420     return eraseInstFromFunction(FI);
3421 
3422   if (auto *PFI = dyn_cast_or_null<FenceInst>(FI.getPrevNonDebugInstruction()))
3423     if (isIdenticalOrStrongerFence(PFI, &FI))
3424       return eraseInstFromFunction(FI);
3425   return nullptr;
3426 }
3427 
3428 // InvokeInst simplification
3429 Instruction *InstCombinerImpl::visitInvokeInst(InvokeInst &II) {
3430   return visitCallBase(II);
3431 }
3432 
3433 // CallBrInst simplification
3434 Instruction *InstCombinerImpl::visitCallBrInst(CallBrInst &CBI) {
3435   return visitCallBase(CBI);
3436 }
3437 
3438 Instruction *InstCombinerImpl::tryOptimizeCall(CallInst *CI) {
3439   if (!CI->getCalledFunction()) return nullptr;
3440 
3441   // Skip optimizing notail and musttail calls so
3442   // LibCallSimplifier::optimizeCall doesn't have to preserve those invariants.
3443   // LibCallSimplifier::optimizeCall should try to preseve tail calls though.
3444   if (CI->isMustTailCall() || CI->isNoTailCall())
3445     return nullptr;
3446 
3447   auto InstCombineRAUW = [this](Instruction *From, Value *With) {
3448     replaceInstUsesWith(*From, With);
3449   };
3450   auto InstCombineErase = [this](Instruction *I) {
3451     eraseInstFromFunction(*I);
3452   };
3453   LibCallSimplifier Simplifier(DL, &TLI, &AC, ORE, BFI, PSI, InstCombineRAUW,
3454                                InstCombineErase);
3455   if (Value *With = Simplifier.optimizeCall(CI, Builder)) {
3456     ++NumSimplified;
3457     return CI->use_empty() ? CI : replaceInstUsesWith(*CI, With);
3458   }
3459 
3460   return nullptr;
3461 }
3462 
3463 static IntrinsicInst *findInitTrampolineFromAlloca(Value *TrampMem) {
3464   // Strip off at most one level of pointer casts, looking for an alloca.  This
3465   // is good enough in practice and simpler than handling any number of casts.
3466   Value *Underlying = TrampMem->stripPointerCasts();
3467   if (Underlying != TrampMem &&
3468       (!Underlying->hasOneUse() || Underlying->user_back() != TrampMem))
3469     return nullptr;
3470   if (!isa<AllocaInst>(Underlying))
3471     return nullptr;
3472 
3473   IntrinsicInst *InitTrampoline = nullptr;
3474   for (User *U : TrampMem->users()) {
3475     IntrinsicInst *II = dyn_cast<IntrinsicInst>(U);
3476     if (!II)
3477       return nullptr;
3478     if (II->getIntrinsicID() == Intrinsic::init_trampoline) {
3479       if (InitTrampoline)
3480         // More than one init_trampoline writes to this value.  Give up.
3481         return nullptr;
3482       InitTrampoline = II;
3483       continue;
3484     }
3485     if (II->getIntrinsicID() == Intrinsic::adjust_trampoline)
3486       // Allow any number of calls to adjust.trampoline.
3487       continue;
3488     return nullptr;
3489   }
3490 
3491   // No call to init.trampoline found.
3492   if (!InitTrampoline)
3493     return nullptr;
3494 
3495   // Check that the alloca is being used in the expected way.
3496   if (InitTrampoline->getOperand(0) != TrampMem)
3497     return nullptr;
3498 
3499   return InitTrampoline;
3500 }
3501 
3502 static IntrinsicInst *findInitTrampolineFromBB(IntrinsicInst *AdjustTramp,
3503                                                Value *TrampMem) {
3504   // Visit all the previous instructions in the basic block, and try to find a
3505   // init.trampoline which has a direct path to the adjust.trampoline.
3506   for (BasicBlock::iterator I = AdjustTramp->getIterator(),
3507                             E = AdjustTramp->getParent()->begin();
3508        I != E;) {
3509     Instruction *Inst = &*--I;
3510     if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
3511       if (II->getIntrinsicID() == Intrinsic::init_trampoline &&
3512           II->getOperand(0) == TrampMem)
3513         return II;
3514     if (Inst->mayWriteToMemory())
3515       return nullptr;
3516   }
3517   return nullptr;
3518 }
3519 
3520 // Given a call to llvm.adjust.trampoline, find and return the corresponding
3521 // call to llvm.init.trampoline if the call to the trampoline can be optimized
3522 // to a direct call to a function.  Otherwise return NULL.
3523 static IntrinsicInst *findInitTrampoline(Value *Callee) {
3524   Callee = Callee->stripPointerCasts();
3525   IntrinsicInst *AdjustTramp = dyn_cast<IntrinsicInst>(Callee);
3526   if (!AdjustTramp ||
3527       AdjustTramp->getIntrinsicID() != Intrinsic::adjust_trampoline)
3528     return nullptr;
3529 
3530   Value *TrampMem = AdjustTramp->getOperand(0);
3531 
3532   if (IntrinsicInst *IT = findInitTrampolineFromAlloca(TrampMem))
3533     return IT;
3534   if (IntrinsicInst *IT = findInitTrampolineFromBB(AdjustTramp, TrampMem))
3535     return IT;
3536   return nullptr;
3537 }
3538 
3539 bool InstCombinerImpl::annotateAnyAllocSite(CallBase &Call,
3540                                             const TargetLibraryInfo *TLI) {
3541   // Note: We only handle cases which can't be driven from generic attributes
3542   // here.  So, for example, nonnull and noalias (which are common properties
3543   // of some allocation functions) are expected to be handled via annotation
3544   // of the respective allocator declaration with generic attributes.
3545   bool Changed = false;
3546 
3547   if (!Call.getType()->isPointerTy())
3548     return Changed;
3549 
3550   std::optional<APInt> Size = getAllocSize(&Call, TLI);
3551   if (Size && *Size != 0) {
3552     // TODO: We really should just emit deref_or_null here and then
3553     // let the generic inference code combine that with nonnull.
3554     if (Call.hasRetAttr(Attribute::NonNull)) {
3555       Changed = !Call.hasRetAttr(Attribute::Dereferenceable);
3556       Call.addRetAttr(Attribute::getWithDereferenceableBytes(
3557           Call.getContext(), Size->getLimitedValue()));
3558     } else {
3559       Changed = !Call.hasRetAttr(Attribute::DereferenceableOrNull);
3560       Call.addRetAttr(Attribute::getWithDereferenceableOrNullBytes(
3561           Call.getContext(), Size->getLimitedValue()));
3562     }
3563   }
3564 
3565   // Add alignment attribute if alignment is a power of two constant.
3566   Value *Alignment = getAllocAlignment(&Call, TLI);
3567   if (!Alignment)
3568     return Changed;
3569 
3570   ConstantInt *AlignOpC = dyn_cast<ConstantInt>(Alignment);
3571   if (AlignOpC && AlignOpC->getValue().ult(llvm::Value::MaximumAlignment)) {
3572     uint64_t AlignmentVal = AlignOpC->getZExtValue();
3573     if (llvm::isPowerOf2_64(AlignmentVal)) {
3574       Align ExistingAlign = Call.getRetAlign().valueOrOne();
3575       Align NewAlign = Align(AlignmentVal);
3576       if (NewAlign > ExistingAlign) {
3577         Call.addRetAttr(
3578             Attribute::getWithAlignment(Call.getContext(), NewAlign));
3579         Changed = true;
3580       }
3581     }
3582   }
3583   return Changed;
3584 }
3585 
3586 /// Improvements for call, callbr and invoke instructions.
3587 Instruction *InstCombinerImpl::visitCallBase(CallBase &Call) {
3588   bool Changed = annotateAnyAllocSite(Call, &TLI);
3589 
3590   // Mark any parameters that are known to be non-null with the nonnull
3591   // attribute.  This is helpful for inlining calls to functions with null
3592   // checks on their arguments.
3593   SmallVector<unsigned, 4> ArgNos;
3594   unsigned ArgNo = 0;
3595 
3596   for (Value *V : Call.args()) {
3597     if (V->getType()->isPointerTy() &&
3598         !Call.paramHasAttr(ArgNo, Attribute::NonNull) &&
3599         isKnownNonZero(V, DL, 0, &AC, &Call, &DT))
3600       ArgNos.push_back(ArgNo);
3601     ArgNo++;
3602   }
3603 
3604   assert(ArgNo == Call.arg_size() && "Call arguments not processed correctly.");
3605 
3606   if (!ArgNos.empty()) {
3607     AttributeList AS = Call.getAttributes();
3608     LLVMContext &Ctx = Call.getContext();
3609     AS = AS.addParamAttribute(Ctx, ArgNos,
3610                               Attribute::get(Ctx, Attribute::NonNull));
3611     Call.setAttributes(AS);
3612     Changed = true;
3613   }
3614 
3615   // If the callee is a pointer to a function, attempt to move any casts to the
3616   // arguments of the call/callbr/invoke.
3617   Value *Callee = Call.getCalledOperand();
3618   Function *CalleeF = dyn_cast<Function>(Callee);
3619   if ((!CalleeF || CalleeF->getFunctionType() != Call.getFunctionType()) &&
3620       transformConstExprCastCall(Call))
3621     return nullptr;
3622 
3623   if (CalleeF) {
3624     // Remove the convergent attr on calls when the callee is not convergent.
3625     if (Call.isConvergent() && !CalleeF->isConvergent() &&
3626         !CalleeF->isIntrinsic()) {
3627       LLVM_DEBUG(dbgs() << "Removing convergent attr from instr " << Call
3628                         << "\n");
3629       Call.setNotConvergent();
3630       return &Call;
3631     }
3632 
3633     // If the call and callee calling conventions don't match, and neither one
3634     // of the calling conventions is compatible with C calling convention
3635     // this call must be unreachable, as the call is undefined.
3636     if ((CalleeF->getCallingConv() != Call.getCallingConv() &&
3637          !(CalleeF->getCallingConv() == llvm::CallingConv::C &&
3638            TargetLibraryInfoImpl::isCallingConvCCompatible(&Call)) &&
3639          !(Call.getCallingConv() == llvm::CallingConv::C &&
3640            TargetLibraryInfoImpl::isCallingConvCCompatible(CalleeF))) &&
3641         // Only do this for calls to a function with a body.  A prototype may
3642         // not actually end up matching the implementation's calling conv for a
3643         // variety of reasons (e.g. it may be written in assembly).
3644         !CalleeF->isDeclaration()) {
3645       Instruction *OldCall = &Call;
3646       CreateNonTerminatorUnreachable(OldCall);
3647       // If OldCall does not return void then replaceInstUsesWith poison.
3648       // This allows ValueHandlers and custom metadata to adjust itself.
3649       if (!OldCall->getType()->isVoidTy())
3650         replaceInstUsesWith(*OldCall, PoisonValue::get(OldCall->getType()));
3651       if (isa<CallInst>(OldCall))
3652         return eraseInstFromFunction(*OldCall);
3653 
3654       // We cannot remove an invoke or a callbr, because it would change thexi
3655       // CFG, just change the callee to a null pointer.
3656       cast<CallBase>(OldCall)->setCalledFunction(
3657           CalleeF->getFunctionType(),
3658           Constant::getNullValue(CalleeF->getType()));
3659       return nullptr;
3660     }
3661   }
3662 
3663   // Calling a null function pointer is undefined if a null address isn't
3664   // dereferenceable.
3665   if ((isa<ConstantPointerNull>(Callee) &&
3666        !NullPointerIsDefined(Call.getFunction())) ||
3667       isa<UndefValue>(Callee)) {
3668     // If Call does not return void then replaceInstUsesWith poison.
3669     // This allows ValueHandlers and custom metadata to adjust itself.
3670     if (!Call.getType()->isVoidTy())
3671       replaceInstUsesWith(Call, PoisonValue::get(Call.getType()));
3672 
3673     if (Call.isTerminator()) {
3674       // Can't remove an invoke or callbr because we cannot change the CFG.
3675       return nullptr;
3676     }
3677 
3678     // This instruction is not reachable, just remove it.
3679     CreateNonTerminatorUnreachable(&Call);
3680     return eraseInstFromFunction(Call);
3681   }
3682 
3683   if (IntrinsicInst *II = findInitTrampoline(Callee))
3684     return transformCallThroughTrampoline(Call, *II);
3685 
3686   if (isa<InlineAsm>(Callee) && !Call.doesNotThrow()) {
3687     InlineAsm *IA = cast<InlineAsm>(Callee);
3688     if (!IA->canThrow()) {
3689       // Normal inline asm calls cannot throw - mark them
3690       // 'nounwind'.
3691       Call.setDoesNotThrow();
3692       Changed = true;
3693     }
3694   }
3695 
3696   // Try to optimize the call if possible, we require DataLayout for most of
3697   // this.  None of these calls are seen as possibly dead so go ahead and
3698   // delete the instruction now.
3699   if (CallInst *CI = dyn_cast<CallInst>(&Call)) {
3700     Instruction *I = tryOptimizeCall(CI);
3701     // If we changed something return the result, etc. Otherwise let
3702     // the fallthrough check.
3703     if (I) return eraseInstFromFunction(*I);
3704   }
3705 
3706   if (!Call.use_empty() && !Call.isMustTailCall())
3707     if (Value *ReturnedArg = Call.getReturnedArgOperand()) {
3708       Type *CallTy = Call.getType();
3709       Type *RetArgTy = ReturnedArg->getType();
3710       if (RetArgTy->canLosslesslyBitCastTo(CallTy))
3711         return replaceInstUsesWith(
3712             Call, Builder.CreateBitOrPointerCast(ReturnedArg, CallTy));
3713     }
3714 
3715   // Drop unnecessary kcfi operand bundles from calls that were converted
3716   // into direct calls.
3717   auto Bundle = Call.getOperandBundle(LLVMContext::OB_kcfi);
3718   if (Bundle && !Call.isIndirectCall()) {
3719     DEBUG_WITH_TYPE(DEBUG_TYPE "-kcfi", {
3720       if (CalleeF) {
3721         ConstantInt *FunctionType = nullptr;
3722         ConstantInt *ExpectedType = cast<ConstantInt>(Bundle->Inputs[0]);
3723 
3724         if (MDNode *MD = CalleeF->getMetadata(LLVMContext::MD_kcfi_type))
3725           FunctionType = mdconst::extract<ConstantInt>(MD->getOperand(0));
3726 
3727         if (FunctionType &&
3728             FunctionType->getZExtValue() != ExpectedType->getZExtValue())
3729           dbgs() << Call.getModule()->getName()
3730                  << ": warning: kcfi: " << Call.getCaller()->getName()
3731                  << ": call to " << CalleeF->getName()
3732                  << " using a mismatching function pointer type\n";
3733       }
3734     });
3735 
3736     return CallBase::removeOperandBundle(&Call, LLVMContext::OB_kcfi);
3737   }
3738 
3739   if (isRemovableAlloc(&Call, &TLI))
3740     return visitAllocSite(Call);
3741 
3742   // Handle intrinsics which can be used in both call and invoke context.
3743   switch (Call.getIntrinsicID()) {
3744   case Intrinsic::experimental_gc_statepoint: {
3745     GCStatepointInst &GCSP = *cast<GCStatepointInst>(&Call);
3746     SmallPtrSet<Value *, 32> LiveGcValues;
3747     for (const GCRelocateInst *Reloc : GCSP.getGCRelocates()) {
3748       GCRelocateInst &GCR = *const_cast<GCRelocateInst *>(Reloc);
3749 
3750       // Remove the relocation if unused.
3751       if (GCR.use_empty()) {
3752         eraseInstFromFunction(GCR);
3753         continue;
3754       }
3755 
3756       Value *DerivedPtr = GCR.getDerivedPtr();
3757       Value *BasePtr = GCR.getBasePtr();
3758 
3759       // Undef is undef, even after relocation.
3760       if (isa<UndefValue>(DerivedPtr) || isa<UndefValue>(BasePtr)) {
3761         replaceInstUsesWith(GCR, UndefValue::get(GCR.getType()));
3762         eraseInstFromFunction(GCR);
3763         continue;
3764       }
3765 
3766       if (auto *PT = dyn_cast<PointerType>(GCR.getType())) {
3767         // The relocation of null will be null for most any collector.
3768         // TODO: provide a hook for this in GCStrategy.  There might be some
3769         // weird collector this property does not hold for.
3770         if (isa<ConstantPointerNull>(DerivedPtr)) {
3771           // Use null-pointer of gc_relocate's type to replace it.
3772           replaceInstUsesWith(GCR, ConstantPointerNull::get(PT));
3773           eraseInstFromFunction(GCR);
3774           continue;
3775         }
3776 
3777         // isKnownNonNull -> nonnull attribute
3778         if (!GCR.hasRetAttr(Attribute::NonNull) &&
3779             isKnownNonZero(DerivedPtr, DL, 0, &AC, &Call, &DT)) {
3780           GCR.addRetAttr(Attribute::NonNull);
3781           // We discovered new fact, re-check users.
3782           Worklist.pushUsersToWorkList(GCR);
3783         }
3784       }
3785 
3786       // If we have two copies of the same pointer in the statepoint argument
3787       // list, canonicalize to one.  This may let us common gc.relocates.
3788       if (GCR.getBasePtr() == GCR.getDerivedPtr() &&
3789           GCR.getBasePtrIndex() != GCR.getDerivedPtrIndex()) {
3790         auto *OpIntTy = GCR.getOperand(2)->getType();
3791         GCR.setOperand(2, ConstantInt::get(OpIntTy, GCR.getBasePtrIndex()));
3792       }
3793 
3794       // TODO: bitcast(relocate(p)) -> relocate(bitcast(p))
3795       // Canonicalize on the type from the uses to the defs
3796 
3797       // TODO: relocate((gep p, C, C2, ...)) -> gep(relocate(p), C, C2, ...)
3798       LiveGcValues.insert(BasePtr);
3799       LiveGcValues.insert(DerivedPtr);
3800     }
3801     std::optional<OperandBundleUse> Bundle =
3802         GCSP.getOperandBundle(LLVMContext::OB_gc_live);
3803     unsigned NumOfGCLives = LiveGcValues.size();
3804     if (!Bundle || NumOfGCLives == Bundle->Inputs.size())
3805       break;
3806     // We can reduce the size of gc live bundle.
3807     DenseMap<Value *, unsigned> Val2Idx;
3808     std::vector<Value *> NewLiveGc;
3809     for (Value *V : Bundle->Inputs) {
3810       if (Val2Idx.count(V))
3811         continue;
3812       if (LiveGcValues.count(V)) {
3813         Val2Idx[V] = NewLiveGc.size();
3814         NewLiveGc.push_back(V);
3815       } else
3816         Val2Idx[V] = NumOfGCLives;
3817     }
3818     // Update all gc.relocates
3819     for (const GCRelocateInst *Reloc : GCSP.getGCRelocates()) {
3820       GCRelocateInst &GCR = *const_cast<GCRelocateInst *>(Reloc);
3821       Value *BasePtr = GCR.getBasePtr();
3822       assert(Val2Idx.count(BasePtr) && Val2Idx[BasePtr] != NumOfGCLives &&
3823              "Missed live gc for base pointer");
3824       auto *OpIntTy1 = GCR.getOperand(1)->getType();
3825       GCR.setOperand(1, ConstantInt::get(OpIntTy1, Val2Idx[BasePtr]));
3826       Value *DerivedPtr = GCR.getDerivedPtr();
3827       assert(Val2Idx.count(DerivedPtr) && Val2Idx[DerivedPtr] != NumOfGCLives &&
3828              "Missed live gc for derived pointer");
3829       auto *OpIntTy2 = GCR.getOperand(2)->getType();
3830       GCR.setOperand(2, ConstantInt::get(OpIntTy2, Val2Idx[DerivedPtr]));
3831     }
3832     // Create new statepoint instruction.
3833     OperandBundleDef NewBundle("gc-live", NewLiveGc);
3834     return CallBase::Create(&Call, NewBundle);
3835   }
3836   default: { break; }
3837   }
3838 
3839   return Changed ? &Call : nullptr;
3840 }
3841 
3842 /// If the callee is a constexpr cast of a function, attempt to move the cast to
3843 /// the arguments of the call/invoke.
3844 /// CallBrInst is not supported.
3845 bool InstCombinerImpl::transformConstExprCastCall(CallBase &Call) {
3846   auto *Callee =
3847       dyn_cast<Function>(Call.getCalledOperand()->stripPointerCasts());
3848   if (!Callee)
3849     return false;
3850 
3851   assert(!isa<CallBrInst>(Call) &&
3852          "CallBr's don't have a single point after a def to insert at");
3853 
3854   // If this is a call to a thunk function, don't remove the cast. Thunks are
3855   // used to transparently forward all incoming parameters and outgoing return
3856   // values, so it's important to leave the cast in place.
3857   if (Callee->hasFnAttribute("thunk"))
3858     return false;
3859 
3860   // If this is a call to a naked function, the assembly might be
3861   // using an argument, or otherwise rely on the frame layout,
3862   // the function prototype will mismatch.
3863   if (Callee->hasFnAttribute(Attribute::Naked))
3864     return false;
3865 
3866   // If this is a musttail call, the callee's prototype must match the caller's
3867   // prototype with the exception of pointee types. The code below doesn't
3868   // implement that, so we can't do this transform.
3869   // TODO: Do the transform if it only requires adding pointer casts.
3870   if (Call.isMustTailCall())
3871     return false;
3872 
3873   Instruction *Caller = &Call;
3874   const AttributeList &CallerPAL = Call.getAttributes();
3875 
3876   // Okay, this is a cast from a function to a different type.  Unless doing so
3877   // would cause a type conversion of one of our arguments, change this call to
3878   // be a direct call with arguments casted to the appropriate types.
3879   FunctionType *FT = Callee->getFunctionType();
3880   Type *OldRetTy = Caller->getType();
3881   Type *NewRetTy = FT->getReturnType();
3882 
3883   // Check to see if we are changing the return type...
3884   if (OldRetTy != NewRetTy) {
3885 
3886     if (NewRetTy->isStructTy())
3887       return false; // TODO: Handle multiple return values.
3888 
3889     if (!CastInst::isBitOrNoopPointerCastable(NewRetTy, OldRetTy, DL)) {
3890       if (Callee->isDeclaration())
3891         return false;   // Cannot transform this return value.
3892 
3893       if (!Caller->use_empty() &&
3894           // void -> non-void is handled specially
3895           !NewRetTy->isVoidTy())
3896         return false;   // Cannot transform this return value.
3897     }
3898 
3899     if (!CallerPAL.isEmpty() && !Caller->use_empty()) {
3900       AttrBuilder RAttrs(FT->getContext(), CallerPAL.getRetAttrs());
3901       if (RAttrs.overlaps(AttributeFuncs::typeIncompatible(NewRetTy)))
3902         return false;   // Attribute not compatible with transformed value.
3903     }
3904 
3905     // If the callbase is an invoke instruction, and the return value is
3906     // used by a PHI node in a successor, we cannot change the return type of
3907     // the call because there is no place to put the cast instruction (without
3908     // breaking the critical edge).  Bail out in this case.
3909     if (!Caller->use_empty()) {
3910       BasicBlock *PhisNotSupportedBlock = nullptr;
3911       if (auto *II = dyn_cast<InvokeInst>(Caller))
3912         PhisNotSupportedBlock = II->getNormalDest();
3913       if (PhisNotSupportedBlock)
3914         for (User *U : Caller->users())
3915           if (PHINode *PN = dyn_cast<PHINode>(U))
3916             if (PN->getParent() == PhisNotSupportedBlock)
3917               return false;
3918     }
3919   }
3920 
3921   unsigned NumActualArgs = Call.arg_size();
3922   unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
3923 
3924   // Prevent us turning:
3925   // declare void @takes_i32_inalloca(i32* inalloca)
3926   //  call void bitcast (void (i32*)* @takes_i32_inalloca to void (i32)*)(i32 0)
3927   //
3928   // into:
3929   //  call void @takes_i32_inalloca(i32* null)
3930   //
3931   //  Similarly, avoid folding away bitcasts of byval calls.
3932   if (Callee->getAttributes().hasAttrSomewhere(Attribute::InAlloca) ||
3933       Callee->getAttributes().hasAttrSomewhere(Attribute::Preallocated))
3934     return false;
3935 
3936   auto AI = Call.arg_begin();
3937   for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) {
3938     Type *ParamTy = FT->getParamType(i);
3939     Type *ActTy = (*AI)->getType();
3940 
3941     if (!CastInst::isBitOrNoopPointerCastable(ActTy, ParamTy, DL))
3942       return false;   // Cannot transform this parameter value.
3943 
3944     // Check if there are any incompatible attributes we cannot drop safely.
3945     if (AttrBuilder(FT->getContext(), CallerPAL.getParamAttrs(i))
3946             .overlaps(AttributeFuncs::typeIncompatible(
3947                 ParamTy, AttributeFuncs::ASK_UNSAFE_TO_DROP)))
3948       return false;   // Attribute not compatible with transformed value.
3949 
3950     if (Call.isInAllocaArgument(i) ||
3951         CallerPAL.hasParamAttr(i, Attribute::Preallocated))
3952       return false; // Cannot transform to and from inalloca/preallocated.
3953 
3954     if (CallerPAL.hasParamAttr(i, Attribute::SwiftError))
3955       return false;
3956 
3957     if (CallerPAL.hasParamAttr(i, Attribute::ByVal) !=
3958         Callee->getAttributes().hasParamAttr(i, Attribute::ByVal))
3959       return false; // Cannot transform to or from byval.
3960   }
3961 
3962   if (Callee->isDeclaration()) {
3963     // Do not delete arguments unless we have a function body.
3964     if (FT->getNumParams() < NumActualArgs && !FT->isVarArg())
3965       return false;
3966 
3967     // If the callee is just a declaration, don't change the varargsness of the
3968     // call.  We don't want to introduce a varargs call where one doesn't
3969     // already exist.
3970     if (FT->isVarArg() != Call.getFunctionType()->isVarArg())
3971       return false;
3972 
3973     // If both the callee and the cast type are varargs, we still have to make
3974     // sure the number of fixed parameters are the same or we have the same
3975     // ABI issues as if we introduce a varargs call.
3976     if (FT->isVarArg() && Call.getFunctionType()->isVarArg() &&
3977         FT->getNumParams() != Call.getFunctionType()->getNumParams())
3978       return false;
3979   }
3980 
3981   if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
3982       !CallerPAL.isEmpty()) {
3983     // In this case we have more arguments than the new function type, but we
3984     // won't be dropping them.  Check that these extra arguments have attributes
3985     // that are compatible with being a vararg call argument.
3986     unsigned SRetIdx;
3987     if (CallerPAL.hasAttrSomewhere(Attribute::StructRet, &SRetIdx) &&
3988         SRetIdx - AttributeList::FirstArgIndex >= FT->getNumParams())
3989       return false;
3990   }
3991 
3992   // Okay, we decided that this is a safe thing to do: go ahead and start
3993   // inserting cast instructions as necessary.
3994   SmallVector<Value *, 8> Args;
3995   SmallVector<AttributeSet, 8> ArgAttrs;
3996   Args.reserve(NumActualArgs);
3997   ArgAttrs.reserve(NumActualArgs);
3998 
3999   // Get any return attributes.
4000   AttrBuilder RAttrs(FT->getContext(), CallerPAL.getRetAttrs());
4001 
4002   // If the return value is not being used, the type may not be compatible
4003   // with the existing attributes.  Wipe out any problematic attributes.
4004   RAttrs.remove(AttributeFuncs::typeIncompatible(NewRetTy));
4005 
4006   LLVMContext &Ctx = Call.getContext();
4007   AI = Call.arg_begin();
4008   for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) {
4009     Type *ParamTy = FT->getParamType(i);
4010 
4011     Value *NewArg = *AI;
4012     if ((*AI)->getType() != ParamTy)
4013       NewArg = Builder.CreateBitOrPointerCast(*AI, ParamTy);
4014     Args.push_back(NewArg);
4015 
4016     // Add any parameter attributes except the ones incompatible with the new
4017     // type. Note that we made sure all incompatible ones are safe to drop.
4018     AttributeMask IncompatibleAttrs = AttributeFuncs::typeIncompatible(
4019         ParamTy, AttributeFuncs::ASK_SAFE_TO_DROP);
4020     ArgAttrs.push_back(
4021         CallerPAL.getParamAttrs(i).removeAttributes(Ctx, IncompatibleAttrs));
4022   }
4023 
4024   // If the function takes more arguments than the call was taking, add them
4025   // now.
4026   for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i) {
4027     Args.push_back(Constant::getNullValue(FT->getParamType(i)));
4028     ArgAttrs.push_back(AttributeSet());
4029   }
4030 
4031   // If we are removing arguments to the function, emit an obnoxious warning.
4032   if (FT->getNumParams() < NumActualArgs) {
4033     // TODO: if (!FT->isVarArg()) this call may be unreachable. PR14722
4034     if (FT->isVarArg()) {
4035       // Add all of the arguments in their promoted form to the arg list.
4036       for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) {
4037         Type *PTy = getPromotedType((*AI)->getType());
4038         Value *NewArg = *AI;
4039         if (PTy != (*AI)->getType()) {
4040           // Must promote to pass through va_arg area!
4041           Instruction::CastOps opcode =
4042             CastInst::getCastOpcode(*AI, false, PTy, false);
4043           NewArg = Builder.CreateCast(opcode, *AI, PTy);
4044         }
4045         Args.push_back(NewArg);
4046 
4047         // Add any parameter attributes.
4048         ArgAttrs.push_back(CallerPAL.getParamAttrs(i));
4049       }
4050     }
4051   }
4052 
4053   AttributeSet FnAttrs = CallerPAL.getFnAttrs();
4054 
4055   if (NewRetTy->isVoidTy())
4056     Caller->setName("");   // Void type should not have a name.
4057 
4058   assert((ArgAttrs.size() == FT->getNumParams() || FT->isVarArg()) &&
4059          "missing argument attributes");
4060   AttributeList NewCallerPAL = AttributeList::get(
4061       Ctx, FnAttrs, AttributeSet::get(Ctx, RAttrs), ArgAttrs);
4062 
4063   SmallVector<OperandBundleDef, 1> OpBundles;
4064   Call.getOperandBundlesAsDefs(OpBundles);
4065 
4066   CallBase *NewCall;
4067   if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
4068     NewCall = Builder.CreateInvoke(Callee, II->getNormalDest(),
4069                                    II->getUnwindDest(), Args, OpBundles);
4070   } else {
4071     NewCall = Builder.CreateCall(Callee, Args, OpBundles);
4072     cast<CallInst>(NewCall)->setTailCallKind(
4073         cast<CallInst>(Caller)->getTailCallKind());
4074   }
4075   NewCall->takeName(Caller);
4076   NewCall->setCallingConv(Call.getCallingConv());
4077   NewCall->setAttributes(NewCallerPAL);
4078 
4079   // Preserve prof metadata if any.
4080   NewCall->copyMetadata(*Caller, {LLVMContext::MD_prof});
4081 
4082   // Insert a cast of the return type as necessary.
4083   Instruction *NC = NewCall;
4084   Value *NV = NC;
4085   if (OldRetTy != NV->getType() && !Caller->use_empty()) {
4086     if (!NV->getType()->isVoidTy()) {
4087       NV = NC = CastInst::CreateBitOrPointerCast(NC, OldRetTy);
4088       NC->setDebugLoc(Caller->getDebugLoc());
4089 
4090       auto OptInsertPt = NewCall->getInsertionPointAfterDef();
4091       assert(OptInsertPt && "No place to insert cast");
4092       InsertNewInstBefore(NC, *OptInsertPt);
4093       Worklist.pushUsersToWorkList(*Caller);
4094     } else {
4095       NV = PoisonValue::get(Caller->getType());
4096     }
4097   }
4098 
4099   if (!Caller->use_empty())
4100     replaceInstUsesWith(*Caller, NV);
4101   else if (Caller->hasValueHandle()) {
4102     if (OldRetTy == NV->getType())
4103       ValueHandleBase::ValueIsRAUWd(Caller, NV);
4104     else
4105       // We cannot call ValueIsRAUWd with a different type, and the
4106       // actual tracked value will disappear.
4107       ValueHandleBase::ValueIsDeleted(Caller);
4108   }
4109 
4110   eraseInstFromFunction(*Caller);
4111   return true;
4112 }
4113 
4114 /// Turn a call to a function created by init_trampoline / adjust_trampoline
4115 /// intrinsic pair into a direct call to the underlying function.
4116 Instruction *
4117 InstCombinerImpl::transformCallThroughTrampoline(CallBase &Call,
4118                                                  IntrinsicInst &Tramp) {
4119   FunctionType *FTy = Call.getFunctionType();
4120   AttributeList Attrs = Call.getAttributes();
4121 
4122   // If the call already has the 'nest' attribute somewhere then give up -
4123   // otherwise 'nest' would occur twice after splicing in the chain.
4124   if (Attrs.hasAttrSomewhere(Attribute::Nest))
4125     return nullptr;
4126 
4127   Function *NestF = cast<Function>(Tramp.getArgOperand(1)->stripPointerCasts());
4128   FunctionType *NestFTy = NestF->getFunctionType();
4129 
4130   AttributeList NestAttrs = NestF->getAttributes();
4131   if (!NestAttrs.isEmpty()) {
4132     unsigned NestArgNo = 0;
4133     Type *NestTy = nullptr;
4134     AttributeSet NestAttr;
4135 
4136     // Look for a parameter marked with the 'nest' attribute.
4137     for (FunctionType::param_iterator I = NestFTy->param_begin(),
4138                                       E = NestFTy->param_end();
4139          I != E; ++NestArgNo, ++I) {
4140       AttributeSet AS = NestAttrs.getParamAttrs(NestArgNo);
4141       if (AS.hasAttribute(Attribute::Nest)) {
4142         // Record the parameter type and any other attributes.
4143         NestTy = *I;
4144         NestAttr = AS;
4145         break;
4146       }
4147     }
4148 
4149     if (NestTy) {
4150       std::vector<Value*> NewArgs;
4151       std::vector<AttributeSet> NewArgAttrs;
4152       NewArgs.reserve(Call.arg_size() + 1);
4153       NewArgAttrs.reserve(Call.arg_size());
4154 
4155       // Insert the nest argument into the call argument list, which may
4156       // mean appending it.  Likewise for attributes.
4157 
4158       {
4159         unsigned ArgNo = 0;
4160         auto I = Call.arg_begin(), E = Call.arg_end();
4161         do {
4162           if (ArgNo == NestArgNo) {
4163             // Add the chain argument and attributes.
4164             Value *NestVal = Tramp.getArgOperand(2);
4165             if (NestVal->getType() != NestTy)
4166               NestVal = Builder.CreateBitCast(NestVal, NestTy, "nest");
4167             NewArgs.push_back(NestVal);
4168             NewArgAttrs.push_back(NestAttr);
4169           }
4170 
4171           if (I == E)
4172             break;
4173 
4174           // Add the original argument and attributes.
4175           NewArgs.push_back(*I);
4176           NewArgAttrs.push_back(Attrs.getParamAttrs(ArgNo));
4177 
4178           ++ArgNo;
4179           ++I;
4180         } while (true);
4181       }
4182 
4183       // The trampoline may have been bitcast to a bogus type (FTy).
4184       // Handle this by synthesizing a new function type, equal to FTy
4185       // with the chain parameter inserted.
4186 
4187       std::vector<Type*> NewTypes;
4188       NewTypes.reserve(FTy->getNumParams()+1);
4189 
4190       // Insert the chain's type into the list of parameter types, which may
4191       // mean appending it.
4192       {
4193         unsigned ArgNo = 0;
4194         FunctionType::param_iterator I = FTy->param_begin(),
4195           E = FTy->param_end();
4196 
4197         do {
4198           if (ArgNo == NestArgNo)
4199             // Add the chain's type.
4200             NewTypes.push_back(NestTy);
4201 
4202           if (I == E)
4203             break;
4204 
4205           // Add the original type.
4206           NewTypes.push_back(*I);
4207 
4208           ++ArgNo;
4209           ++I;
4210         } while (true);
4211       }
4212 
4213       // Replace the trampoline call with a direct call.  Let the generic
4214       // code sort out any function type mismatches.
4215       FunctionType *NewFTy =
4216           FunctionType::get(FTy->getReturnType(), NewTypes, FTy->isVarArg());
4217       AttributeList NewPAL =
4218           AttributeList::get(FTy->getContext(), Attrs.getFnAttrs(),
4219                              Attrs.getRetAttrs(), NewArgAttrs);
4220 
4221       SmallVector<OperandBundleDef, 1> OpBundles;
4222       Call.getOperandBundlesAsDefs(OpBundles);
4223 
4224       Instruction *NewCaller;
4225       if (InvokeInst *II = dyn_cast<InvokeInst>(&Call)) {
4226         NewCaller = InvokeInst::Create(NewFTy, NestF, II->getNormalDest(),
4227                                        II->getUnwindDest(), NewArgs, OpBundles);
4228         cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv());
4229         cast<InvokeInst>(NewCaller)->setAttributes(NewPAL);
4230       } else if (CallBrInst *CBI = dyn_cast<CallBrInst>(&Call)) {
4231         NewCaller =
4232             CallBrInst::Create(NewFTy, NestF, CBI->getDefaultDest(),
4233                                CBI->getIndirectDests(), NewArgs, OpBundles);
4234         cast<CallBrInst>(NewCaller)->setCallingConv(CBI->getCallingConv());
4235         cast<CallBrInst>(NewCaller)->setAttributes(NewPAL);
4236       } else {
4237         NewCaller = CallInst::Create(NewFTy, NestF, NewArgs, OpBundles);
4238         cast<CallInst>(NewCaller)->setTailCallKind(
4239             cast<CallInst>(Call).getTailCallKind());
4240         cast<CallInst>(NewCaller)->setCallingConv(
4241             cast<CallInst>(Call).getCallingConv());
4242         cast<CallInst>(NewCaller)->setAttributes(NewPAL);
4243       }
4244       NewCaller->setDebugLoc(Call.getDebugLoc());
4245 
4246       return NewCaller;
4247     }
4248   }
4249 
4250   // Replace the trampoline call with a direct call.  Since there is no 'nest'
4251   // parameter, there is no need to adjust the argument list.  Let the generic
4252   // code sort out any function type mismatches.
4253   Call.setCalledFunction(FTy, NestF);
4254   return &Call;
4255 }
4256