1 //===- InstCombineCalls.cpp -----------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the visitCall and visitInvoke functions.
11 //
12 //===----------------------------------------------------------------------===//
14 #include "InstCombine.h"
15 #include "llvm/ADT/Statistic.h"
16 #include "llvm/Analysis/MemoryBuiltins.h"
17 #include "llvm/IR/CallSite.h"
18 #include "llvm/IR/DataLayout.h"
19 #include "llvm/IR/Dominators.h"
20 #include "llvm/IR/PatternMatch.h"
21 #include "llvm/IR/Statepoint.h"
22 #include "llvm/Transforms/Utils/BuildLibCalls.h"
23 #include "llvm/Transforms/Utils/Local.h"
24 #include "llvm/Transforms/Utils/SimplifyLibCalls.h"
25 using namespace llvm;
26 using namespace PatternMatch;
28 #define DEBUG_TYPE "instcombine"
30 STATISTIC(NumSimplified, "Number of library calls simplified");
32 /// getPromotedType - Return the specified type promoted as it would be to pass
33 /// though a va_arg area.
34 static Type *getPromotedType(Type *Ty) {
35 if (IntegerType* ITy = dyn_cast<IntegerType>(Ty)) {
36 if (ITy->getBitWidth() < 32)
37 return Type::getInt32Ty(Ty->getContext());
38 }
39 return Ty;
40 }
42 /// reduceToSingleValueType - Given an aggregate type which ultimately holds a
43 /// single scalar element, like {{{type}}} or [1 x type], return type.
44 static Type *reduceToSingleValueType(Type *T) {
45 while (!T->isSingleValueType()) {
46 if (StructType *STy = dyn_cast<StructType>(T)) {
47 if (STy->getNumElements() == 1)
48 T = STy->getElementType(0);
49 else
50 break;
51 } else if (ArrayType *ATy = dyn_cast<ArrayType>(T)) {
52 if (ATy->getNumElements() == 1)
53 T = ATy->getElementType();
54 else
55 break;
56 } else
57 break;
58 }
60 return T;
61 }
63 Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
64 unsigned DstAlign = getKnownAlignment(MI->getArgOperand(0), DL, AC, MI, DT);
65 unsigned SrcAlign = getKnownAlignment(MI->getArgOperand(1), DL, AC, MI, DT);
66 unsigned MinAlign = std::min(DstAlign, SrcAlign);
67 unsigned CopyAlign = MI->getAlignment();
69 if (CopyAlign < MinAlign) {
70 MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
71 MinAlign, false));
72 return MI;
73 }
75 // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with
76 // load/store.
77 ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getArgOperand(2));
78 if (!MemOpLength) return nullptr;
80 // Source and destination pointer types are always "i8*" for intrinsic. See
81 // if the size is something we can handle with a single primitive load/store.
82 // A single load+store correctly handles overlapping memory in the memmove
83 // case.
84 uint64_t Size = MemOpLength->getLimitedValue();
85 assert(Size && "0-sized memory transferring should be removed already.");
87 if (Size > 8 || (Size&(Size-1)))
88 return nullptr; // If not 1/2/4/8 bytes, exit.
90 // Use an integer load+store unless we can find something better.
91 unsigned SrcAddrSp =
92 cast<PointerType>(MI->getArgOperand(1)->getType())->getAddressSpace();
93 unsigned DstAddrSp =
94 cast<PointerType>(MI->getArgOperand(0)->getType())->getAddressSpace();
96 IntegerType* IntType = IntegerType::get(MI->getContext(), Size<<3);
97 Type *NewSrcPtrTy = PointerType::get(IntType, SrcAddrSp);
98 Type *NewDstPtrTy = PointerType::get(IntType, DstAddrSp);
100 // Memcpy forces the use of i8* for the source and destination. That means
101 // that if you're using memcpy to move one double around, you'll get a cast
102 // from double* to i8*. We'd much rather use a double load+store rather than
103 // an i64 load+store, here because this improves the odds that the source or
104 // dest address will be promotable. See if we can find a better type than the
105 // integer datatype.
106 Value *StrippedDest = MI->getArgOperand(0)->stripPointerCasts();
107 MDNode *CopyMD = nullptr;
108 if (StrippedDest != MI->getArgOperand(0)) {
109 Type *SrcETy = cast<PointerType>(StrippedDest->getType())
110 ->getElementType();
111 if (DL && SrcETy->isSized() && DL->getTypeStoreSize(SrcETy) == Size) {
112 // The SrcETy might be something like {{{double}}} or [1 x double]. Rip
113 // down through these levels if so.
114 SrcETy = reduceToSingleValueType(SrcETy);
116 if (SrcETy->isSingleValueType()) {
117 NewSrcPtrTy = PointerType::get(SrcETy, SrcAddrSp);
118 NewDstPtrTy = PointerType::get(SrcETy, DstAddrSp);
120 // If the memcpy has metadata describing the members, see if we can
121 // get the TBAA tag describing our copy.
122 if (MDNode *M = MI->getMetadata(LLVMContext::MD_tbaa_struct)) {
123 if (M->getNumOperands() == 3 && M->getOperand(0) &&
124 mdconst::hasa<ConstantInt>(M->getOperand(0)) &&
125 mdconst::extract<ConstantInt>(M->getOperand(0))->isNullValue() &&
126 M->getOperand(1) &&
127 mdconst::hasa<ConstantInt>(M->getOperand(1)) &&
128 mdconst::extract<ConstantInt>(M->getOperand(1))->getValue() ==
129 Size &&
130 M->getOperand(2) && isa<MDNode>(M->getOperand(2)))
131 CopyMD = cast<MDNode>(M->getOperand(2));
132 }
133 }
134 }
135 }
137 // If the memcpy/memmove provides better alignment info than we can
138 // infer, use it.
139 SrcAlign = std::max(SrcAlign, CopyAlign);
140 DstAlign = std::max(DstAlign, CopyAlign);
142 Value *Src = Builder->CreateBitCast(MI->getArgOperand(1), NewSrcPtrTy);
143 Value *Dest = Builder->CreateBitCast(MI->getArgOperand(0), NewDstPtrTy);
144 LoadInst *L = Builder->CreateLoad(Src, MI->isVolatile());
145 L->setAlignment(SrcAlign);
146 if (CopyMD)
147 L->setMetadata(LLVMContext::MD_tbaa, CopyMD);
148 StoreInst *S = Builder->CreateStore(L, Dest, MI->isVolatile());
149 S->setAlignment(DstAlign);
150 if (CopyMD)
151 S->setMetadata(LLVMContext::MD_tbaa, CopyMD);
153 // Set the size of the copy to 0, it will be deleted on the next iteration.
154 MI->setArgOperand(2, Constant::getNullValue(MemOpLength->getType()));
155 return MI;
156 }
158 Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
159 unsigned Alignment = getKnownAlignment(MI->getDest(), DL, AC, MI, DT);
160 if (MI->getAlignment() < Alignment) {
161 MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
162 Alignment, false));
163 return MI;
164 }
166 // Extract the length and alignment and fill if they are constant.
167 ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength());
168 ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
169 if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8))
170 return nullptr;
171 uint64_t Len = LenC->getLimitedValue();
172 Alignment = MI->getAlignment();
173 assert(Len && "0-sized memory setting should be removed already.");
175 // memset(s,c,n) -> store s, c (for n=1,2,4,8)
176 if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) {
177 Type *ITy = IntegerType::get(MI->getContext(), Len*8); // n=1 -> i8.
179 Value *Dest = MI->getDest();
180 unsigned DstAddrSp = cast<PointerType>(Dest->getType())->getAddressSpace();
181 Type *NewDstPtrTy = PointerType::get(ITy, DstAddrSp);
182 Dest = Builder->CreateBitCast(Dest, NewDstPtrTy);
184 // Alignment 0 is identity for alignment 1 for memset, but not store.
185 if (Alignment == 0) Alignment = 1;
187 // Extract the fill value and store.
188 uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL;
189 StoreInst *S = Builder->CreateStore(ConstantInt::get(ITy, Fill), Dest,
190 MI->isVolatile());
191 S->setAlignment(Alignment);
193 // Set the size of the copy to 0, it will be deleted on the next iteration.
194 MI->setLength(Constant::getNullValue(LenC->getType()));
195 return MI;
196 }
198 return nullptr;
199 }
201 /// visitCallInst - CallInst simplification. This mostly only handles folding
202 /// of intrinsic instructions. For normal calls, it allows visitCallSite to do
203 /// the heavy lifting.
204 ///
205 Instruction *InstCombiner::visitCallInst(CallInst &CI) {
206 if (isFreeCall(&CI, TLI))
207 return visitFree(CI);
209 // If the caller function is nounwind, mark the call as nounwind, even if the
210 // callee isn't.
211 if (CI.getParent()->getParent()->doesNotThrow() &&
212 !CI.doesNotThrow()) {
213 CI.setDoesNotThrow();
214 return &CI;
215 }
217 IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI);
218 if (!II) return visitCallSite(&CI);
220 // Intrinsics cannot occur in an invoke, so handle them here instead of in
221 // visitCallSite.
222 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) {
223 bool Changed = false;
225 // memmove/cpy/set of zero bytes is a noop.
226 if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) {
227 if (NumBytes->isNullValue())
228 return EraseInstFromFunction(CI);
230 if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes))
231 if (CI->getZExtValue() == 1) {
232 // Replace the instruction with just byte operations. We would
233 // transform other cases to loads/stores, but we don't know if
234 // alignment is sufficient.
235 }
236 }
238 // No other transformations apply to volatile transfers.
239 if (MI->isVolatile())
240 return nullptr;
242 // If we have a memmove and the source operation is a constant global,
243 // then the source and dest pointers can't alias, so we can change this
244 // into a call to memcpy.
245 if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) {
246 if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource()))
247 if (GVSrc->isConstant()) {
248 Module *M = CI.getParent()->getParent()->getParent();
249 Intrinsic::ID MemCpyID = Intrinsic::memcpy;
250 Type *Tys[3] = { CI.getArgOperand(0)->getType(),
251 CI.getArgOperand(1)->getType(),
252 CI.getArgOperand(2)->getType() };
253 CI.setCalledFunction(Intrinsic::getDeclaration(M, MemCpyID, Tys));
254 Changed = true;
255 }
256 }
258 if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
259 // memmove(x,x,size) -> noop.
260 if (MTI->getSource() == MTI->getDest())
261 return EraseInstFromFunction(CI);
262 }
264 // If we can determine a pointer alignment that is bigger than currently
265 // set, update the alignment.
266 if (isa<MemTransferInst>(MI)) {
267 if (Instruction *I = SimplifyMemTransfer(MI))
268 return I;
269 } else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) {
270 if (Instruction *I = SimplifyMemSet(MSI))
271 return I;
272 }
274 if (Changed) return II;
275 }
277 switch (II->getIntrinsicID()) {
278 default: break;
279 case Intrinsic::objectsize: {
280 uint64_t Size;
281 if (getObjectSize(II->getArgOperand(0), Size, DL, TLI))
282 return ReplaceInstUsesWith(CI, ConstantInt::get(CI.getType(), Size));
283 return nullptr;
284 }
285 case Intrinsic::bswap: {
286 Value *IIOperand = II->getArgOperand(0);
287 Value *X = nullptr;
289 // bswap(bswap(x)) -> x
290 if (match(IIOperand, m_BSwap(m_Value(X))))
291 return ReplaceInstUsesWith(CI, X);
293 // bswap(trunc(bswap(x))) -> trunc(lshr(x, c))
294 if (match(IIOperand, m_Trunc(m_BSwap(m_Value(X))))) {
295 unsigned C = X->getType()->getPrimitiveSizeInBits() -
296 IIOperand->getType()->getPrimitiveSizeInBits();
297 Value *CV = ConstantInt::get(X->getType(), C);
298 Value *V = Builder->CreateLShr(X, CV);
299 return new TruncInst(V, IIOperand->getType());
300 }
301 break;
302 }
304 case Intrinsic::powi:
305 if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
306 // powi(x, 0) -> 1.0
307 if (Power->isZero())
308 return ReplaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0));
309 // powi(x, 1) -> x
310 if (Power->isOne())
311 return ReplaceInstUsesWith(CI, II->getArgOperand(0));
312 // powi(x, -1) -> 1/x
313 if (Power->isAllOnesValue())
314 return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0),
315 II->getArgOperand(0));
316 }
317 break;
318 case Intrinsic::cttz: {
319 // If all bits below the first known one are known zero,
320 // this value is constant.
321 IntegerType *IT = dyn_cast<IntegerType>(II->getArgOperand(0)->getType());
322 // FIXME: Try to simplify vectors of integers.
323 if (!IT) break;
324 uint32_t BitWidth = IT->getBitWidth();
325 APInt KnownZero(BitWidth, 0);
326 APInt KnownOne(BitWidth, 0);
327 computeKnownBits(II->getArgOperand(0), KnownZero, KnownOne, 0, II);
328 unsigned TrailingZeros = KnownOne.countTrailingZeros();
329 APInt Mask(APInt::getLowBitsSet(BitWidth, TrailingZeros));
330 if ((Mask & KnownZero) == Mask)
331 return ReplaceInstUsesWith(CI, ConstantInt::get(IT,
332 APInt(BitWidth, TrailingZeros)));
334 }
335 break;
336 case Intrinsic::ctlz: {
337 // If all bits above the first known one are known zero,
338 // this value is constant.
339 IntegerType *IT = dyn_cast<IntegerType>(II->getArgOperand(0)->getType());
340 // FIXME: Try to simplify vectors of integers.
341 if (!IT) break;
342 uint32_t BitWidth = IT->getBitWidth();
343 APInt KnownZero(BitWidth, 0);
344 APInt KnownOne(BitWidth, 0);
345 computeKnownBits(II->getArgOperand(0), KnownZero, KnownOne, 0, II);
346 unsigned LeadingZeros = KnownOne.countLeadingZeros();
347 APInt Mask(APInt::getHighBitsSet(BitWidth, LeadingZeros));
348 if ((Mask & KnownZero) == Mask)
349 return ReplaceInstUsesWith(CI, ConstantInt::get(IT,
350 APInt(BitWidth, LeadingZeros)));
352 }
353 break;
354 case Intrinsic::uadd_with_overflow: {
355 Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1);
356 OverflowResult OR = computeOverflowForUnsignedAdd(LHS, RHS, II);
357 if (OR == OverflowResult::NeverOverflows)
358 return CreateOverflowTuple(II, Builder->CreateNUWAdd(LHS, RHS), false);
359 if (OR == OverflowResult::AlwaysOverflows)
360 return CreateOverflowTuple(II, Builder->CreateAdd(LHS, RHS), true);
361 }
362 // FALL THROUGH uadd into sadd
363 case Intrinsic::sadd_with_overflow:
364 // Canonicalize constants into the RHS.
365 if (isa<Constant>(II->getArgOperand(0)) &&
366 !isa<Constant>(II->getArgOperand(1))) {
367 Value *LHS = II->getArgOperand(0);
368 II->setArgOperand(0, II->getArgOperand(1));
369 II->setArgOperand(1, LHS);
370 return II;
371 }
373 // X + undef -> undef
374 if (isa<UndefValue>(II->getArgOperand(1)))
375 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
377 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
378 // X + 0 -> {X, false}
379 if (RHS->isZero()) {
380 return CreateOverflowTuple(II, II->getArgOperand(0), false,
381 /*ReUseName*/false);
382 }
383 }
385 // We can strength reduce reduce this signed add into a regular add if we
386 // can prove that it will never overflow.
387 if (II->getIntrinsicID() == Intrinsic::sadd_with_overflow) {
388 Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1);
389 if (WillNotOverflowSignedAdd(LHS, RHS, II)) {
390 return CreateOverflowTuple(II, Builder->CreateNSWAdd(LHS, RHS), false);
391 }
392 }
394 break;
395 case Intrinsic::usub_with_overflow:
396 case Intrinsic::ssub_with_overflow: {
397 Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1);
398 // undef - X -> undef
399 // X - undef -> undef
400 if (isa<UndefValue>(LHS) || isa<UndefValue>(RHS))
401 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
403 if (ConstantInt *ConstRHS = dyn_cast<ConstantInt>(RHS)) {
404 // X - 0 -> {X, false}
405 if (ConstRHS->isZero()) {
406 return CreateOverflowTuple(II, LHS, false, /*ReUseName*/false);
407 }
408 }
409 if (II->getIntrinsicID() == Intrinsic::ssub_with_overflow) {
410 if (WillNotOverflowSignedSub(LHS, RHS, II)) {
411 return CreateOverflowTuple(II, Builder->CreateNSWSub(LHS, RHS), false);
412 }
413 } else {
414 if (WillNotOverflowUnsignedSub(LHS, RHS, II)) {
415 return CreateOverflowTuple(II, Builder->CreateNUWSub(LHS, RHS), false);
416 }
417 }
418 break;
419 }
420 case Intrinsic::umul_with_overflow: {
421 Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1);
422 OverflowResult OR = computeOverflowForUnsignedMul(LHS, RHS, II);
423 if (OR == OverflowResult::NeverOverflows)
424 return CreateOverflowTuple(II, Builder->CreateNUWMul(LHS, RHS), false);
425 if (OR == OverflowResult::AlwaysOverflows)
426 return CreateOverflowTuple(II, Builder->CreateMul(LHS, RHS), true);
427 } // FALL THROUGH
428 case Intrinsic::smul_with_overflow:
429 // Canonicalize constants into the RHS.
430 if (isa<Constant>(II->getArgOperand(0)) &&
431 !isa<Constant>(II->getArgOperand(1))) {
432 Value *LHS = II->getArgOperand(0);
433 II->setArgOperand(0, II->getArgOperand(1));
434 II->setArgOperand(1, LHS);
435 return II;
436 }
438 // X * undef -> undef
439 if (isa<UndefValue>(II->getArgOperand(1)))
440 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
442 if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
443 // X*0 -> {0, false}
444 if (RHSI->isZero())
445 return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType()));
447 // X * 1 -> {X, false}
448 if (RHSI->equalsInt(1)) {
449 return CreateOverflowTuple(II, II->getArgOperand(0), false,
450 /*ReUseName*/false);
451 }
452 }
453 if (II->getIntrinsicID() == Intrinsic::smul_with_overflow) {
454 Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1);
455 if (WillNotOverflowSignedMul(LHS, RHS, II)) {
456 return CreateOverflowTuple(II, Builder->CreateNSWMul(LHS, RHS), false);
457 }
458 }
459 break;
460 case Intrinsic::minnum:
461 case Intrinsic::maxnum: {
462 Value *Arg0 = II->getArgOperand(0);
463 Value *Arg1 = II->getArgOperand(1);
465 // fmin(x, x) -> x
466 if (Arg0 == Arg1)
467 return ReplaceInstUsesWith(CI, Arg0);
469 const ConstantFP *C0 = dyn_cast<ConstantFP>(Arg0);
470 const ConstantFP *C1 = dyn_cast<ConstantFP>(Arg1);
472 // Canonicalize constants into the RHS.
473 if (C0 && !C1) {
474 II->setArgOperand(0, Arg1);
475 II->setArgOperand(1, Arg0);
476 return II;
477 }
479 // fmin(x, nan) -> x
480 if (C1 && C1->isNaN())
481 return ReplaceInstUsesWith(CI, Arg0);
483 // This is the value because if undef were NaN, we would return the other
484 // value and cannot return a NaN unless both operands are.
485 //
486 // fmin(undef, x) -> x
487 if (isa<UndefValue>(Arg0))
488 return ReplaceInstUsesWith(CI, Arg1);
490 // fmin(x, undef) -> x
491 if (isa<UndefValue>(Arg1))
492 return ReplaceInstUsesWith(CI, Arg0);
494 Value *X = nullptr;
495 Value *Y = nullptr;
496 if (II->getIntrinsicID() == Intrinsic::minnum) {
497 // fmin(x, fmin(x, y)) -> fmin(x, y)
498 // fmin(y, fmin(x, y)) -> fmin(x, y)
499 if (match(Arg1, m_FMin(m_Value(X), m_Value(Y)))) {
500 if (Arg0 == X || Arg0 == Y)
501 return ReplaceInstUsesWith(CI, Arg1);
502 }
504 // fmin(fmin(x, y), x) -> fmin(x, y)
505 // fmin(fmin(x, y), y) -> fmin(x, y)
506 if (match(Arg0, m_FMin(m_Value(X), m_Value(Y)))) {
507 if (Arg1 == X || Arg1 == Y)
508 return ReplaceInstUsesWith(CI, Arg0);
509 }
511 // TODO: fmin(nnan x, inf) -> x
512 // TODO: fmin(nnan ninf x, flt_max) -> x
513 if (C1 && C1->isInfinity()) {
514 // fmin(x, -inf) -> -inf
515 if (C1->isNegative())
516 return ReplaceInstUsesWith(CI, Arg1);
517 }
518 } else {
519 assert(II->getIntrinsicID() == Intrinsic::maxnum);
520 // fmax(x, fmax(x, y)) -> fmax(x, y)
521 // fmax(y, fmax(x, y)) -> fmax(x, y)
522 if (match(Arg1, m_FMax(m_Value(X), m_Value(Y)))) {
523 if (Arg0 == X || Arg0 == Y)
524 return ReplaceInstUsesWith(CI, Arg1);
525 }
527 // fmax(fmax(x, y), x) -> fmax(x, y)
528 // fmax(fmax(x, y), y) -> fmax(x, y)
529 if (match(Arg0, m_FMax(m_Value(X), m_Value(Y)))) {
530 if (Arg1 == X || Arg1 == Y)
531 return ReplaceInstUsesWith(CI, Arg0);
532 }
534 // TODO: fmax(nnan x, -inf) -> x
535 // TODO: fmax(nnan ninf x, -flt_max) -> x
536 if (C1 && C1->isInfinity()) {
537 // fmax(x, inf) -> inf
538 if (!C1->isNegative())
539 return ReplaceInstUsesWith(CI, Arg1);
540 }
541 }
542 break;
543 }
544 case Intrinsic::ppc_altivec_lvx:
545 case Intrinsic::ppc_altivec_lvxl:
546 // Turn PPC lvx -> load if the pointer is known aligned.
547 if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, DL, AC, II, DT) >=
548 16) {
549 Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
550 PointerType::getUnqual(II->getType()));
551 return new LoadInst(Ptr);
552 }
553 break;
554 case Intrinsic::ppc_vsx_lxvw4x:
555 case Intrinsic::ppc_vsx_lxvd2x: {
556 // Turn PPC VSX loads into normal loads.
557 Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
558 PointerType::getUnqual(II->getType()));
559 return new LoadInst(Ptr, Twine(""), false, 1);
560 }
561 case Intrinsic::ppc_altivec_stvx:
562 case Intrinsic::ppc_altivec_stvxl:
563 // Turn stvx -> store if the pointer is known aligned.
564 if (getOrEnforceKnownAlignment(II->getArgOperand(1), 16, DL, AC, II, DT) >=
565 16) {
566 Type *OpPtrTy =
567 PointerType::getUnqual(II->getArgOperand(0)->getType());
568 Value *Ptr = Builder->CreateBitCast(II->getArgOperand(1), OpPtrTy);
569 return new StoreInst(II->getArgOperand(0), Ptr);
570 }
571 break;
572 case Intrinsic::ppc_vsx_stxvw4x:
573 case Intrinsic::ppc_vsx_stxvd2x: {
574 // Turn PPC VSX stores into normal stores.
575 Type *OpPtrTy = PointerType::getUnqual(II->getArgOperand(0)->getType());
576 Value *Ptr = Builder->CreateBitCast(II->getArgOperand(1), OpPtrTy);
577 return new StoreInst(II->getArgOperand(0), Ptr, false, 1);
578 }
579 case Intrinsic::x86_sse_storeu_ps:
580 case Intrinsic::x86_sse2_storeu_pd:
581 case Intrinsic::x86_sse2_storeu_dq:
582 // Turn X86 storeu -> store if the pointer is known aligned.
583 if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, DL, AC, II, DT) >=
584 16) {
585 Type *OpPtrTy =
586 PointerType::getUnqual(II->getArgOperand(1)->getType());
587 Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0), OpPtrTy);
588 return new StoreInst(II->getArgOperand(1), Ptr);
589 }
590 break;
592 case Intrinsic::x86_sse_cvtss2si:
593 case Intrinsic::x86_sse_cvtss2si64:
594 case Intrinsic::x86_sse_cvttss2si:
595 case Intrinsic::x86_sse_cvttss2si64:
596 case Intrinsic::x86_sse2_cvtsd2si:
597 case Intrinsic::x86_sse2_cvtsd2si64:
598 case Intrinsic::x86_sse2_cvttsd2si:
599 case Intrinsic::x86_sse2_cvttsd2si64: {
600 // These intrinsics only demand the 0th element of their input vectors. If
601 // we can simplify the input based on that, do so now.
602 unsigned VWidth =
603 cast<VectorType>(II->getArgOperand(0)->getType())->getNumElements();
604 APInt DemandedElts(VWidth, 1);
605 APInt UndefElts(VWidth, 0);
606 if (Value *V = SimplifyDemandedVectorElts(II->getArgOperand(0),
607 DemandedElts, UndefElts)) {
608 II->setArgOperand(0, V);
609 return II;
610 }
611 break;
612 }
614 // Constant fold <A x Bi> << Ci.
615 // FIXME: We don't handle _dq because it's a shift of an i128, but is
616 // represented in the IR as <2 x i64>. A per element shift is wrong.
617 case Intrinsic::x86_sse2_psll_d:
618 case Intrinsic::x86_sse2_psll_q:
619 case Intrinsic::x86_sse2_psll_w:
620 case Intrinsic::x86_sse2_pslli_d:
621 case Intrinsic::x86_sse2_pslli_q:
622 case Intrinsic::x86_sse2_pslli_w:
623 case Intrinsic::x86_avx2_psll_d:
624 case Intrinsic::x86_avx2_psll_q:
625 case Intrinsic::x86_avx2_psll_w:
626 case Intrinsic::x86_avx2_pslli_d:
627 case Intrinsic::x86_avx2_pslli_q:
628 case Intrinsic::x86_avx2_pslli_w:
629 case Intrinsic::x86_sse2_psrl_d:
630 case Intrinsic::x86_sse2_psrl_q:
631 case Intrinsic::x86_sse2_psrl_w:
632 case Intrinsic::x86_sse2_psrli_d:
633 case Intrinsic::x86_sse2_psrli_q:
634 case Intrinsic::x86_sse2_psrli_w:
635 case Intrinsic::x86_avx2_psrl_d:
636 case Intrinsic::x86_avx2_psrl_q:
637 case Intrinsic::x86_avx2_psrl_w:
638 case Intrinsic::x86_avx2_psrli_d:
639 case Intrinsic::x86_avx2_psrli_q:
640 case Intrinsic::x86_avx2_psrli_w: {
641 // Simplify if count is constant. To 0 if >= BitWidth,
642 // otherwise to shl/lshr.
643 auto CDV = dyn_cast<ConstantDataVector>(II->getArgOperand(1));
644 auto CInt = dyn_cast<ConstantInt>(II->getArgOperand(1));
645 if (!CDV && !CInt)
646 break;
647 ConstantInt *Count;
648 if (CDV)
649 Count = cast<ConstantInt>(CDV->getElementAsConstant(0));
650 else
651 Count = CInt;
653 auto Vec = II->getArgOperand(0);
654 auto VT = cast<VectorType>(Vec->getType());
655 if (Count->getZExtValue() >
656 VT->getElementType()->getPrimitiveSizeInBits() - 1)
657 return ReplaceInstUsesWith(
658 CI, ConstantAggregateZero::get(Vec->getType()));
660 bool isPackedShiftLeft = true;
661 switch (II->getIntrinsicID()) {
662 default : break;
663 case Intrinsic::x86_sse2_psrl_d:
664 case Intrinsic::x86_sse2_psrl_q:
665 case Intrinsic::x86_sse2_psrl_w:
666 case Intrinsic::x86_sse2_psrli_d:
667 case Intrinsic::x86_sse2_psrli_q:
668 case Intrinsic::x86_sse2_psrli_w:
669 case Intrinsic::x86_avx2_psrl_d:
670 case Intrinsic::x86_avx2_psrl_q:
671 case Intrinsic::x86_avx2_psrl_w:
672 case Intrinsic::x86_avx2_psrli_d:
673 case Intrinsic::x86_avx2_psrli_q:
674 case Intrinsic::x86_avx2_psrli_w: isPackedShiftLeft = false; break;
675 }
677 unsigned VWidth = VT->getNumElements();
678 // Get a constant vector of the same type as the first operand.
679 auto VTCI = ConstantInt::get(VT->getElementType(), Count->getZExtValue());
680 if (isPackedShiftLeft)
681 return BinaryOperator::CreateShl(Vec,
682 Builder->CreateVectorSplat(VWidth, VTCI));
684 return BinaryOperator::CreateLShr(Vec,
685 Builder->CreateVectorSplat(VWidth, VTCI));
686 }
688 case Intrinsic::x86_sse41_pmovsxbw:
689 case Intrinsic::x86_sse41_pmovsxwd:
690 case Intrinsic::x86_sse41_pmovsxdq:
691 case Intrinsic::x86_sse41_pmovzxbw:
692 case Intrinsic::x86_sse41_pmovzxwd:
693 case Intrinsic::x86_sse41_pmovzxdq: {
694 // pmov{s|z}x ignores the upper half of their input vectors.
695 unsigned VWidth =
696 cast<VectorType>(II->getArgOperand(0)->getType())->getNumElements();
697 unsigned LowHalfElts = VWidth / 2;
698 APInt InputDemandedElts(APInt::getBitsSet(VWidth, 0, LowHalfElts));
699 APInt UndefElts(VWidth, 0);
700 if (Value *TmpV = SimplifyDemandedVectorElts(II->getArgOperand(0),
701 InputDemandedElts,
702 UndefElts)) {
703 II->setArgOperand(0, TmpV);
704 return II;
705 }
706 break;
707 }
709 case Intrinsic::x86_sse4a_insertqi: {
710 // insertqi x, y, 64, 0 can just copy y's lower bits and leave the top
711 // ones undef
712 // TODO: eventually we should lower this intrinsic to IR
713 if (auto CIWidth = dyn_cast<ConstantInt>(II->getArgOperand(2))) {
714 if (auto CIStart = dyn_cast<ConstantInt>(II->getArgOperand(3))) {
715 unsigned Index = CIStart->getZExtValue();
716 // From AMD documentation: "a value of zero in the field length is
717 // defined as length of 64".
718 unsigned Length = CIWidth->equalsInt(0) ? 64 : CIWidth->getZExtValue();
720 // From AMD documentation: "If the sum of the bit index + length field
721 // is greater than 64, the results are undefined".
723 // Note that both field index and field length are 8-bit quantities.
724 // Since variables 'Index' and 'Length' are unsigned values
725 // obtained from zero-extending field index and field length
726 // respectively, their sum should never wrap around.
727 if ((Index + Length) > 64)
728 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
730 if (Length == 64 && Index == 0) {
731 Value *Vec = II->getArgOperand(1);
732 Value *Undef = UndefValue::get(Vec->getType());
733 const uint32_t Mask[] = { 0, 2 };
734 return ReplaceInstUsesWith(
735 CI,
736 Builder->CreateShuffleVector(
737 Vec, Undef, ConstantDataVector::get(
738 II->getContext(), makeArrayRef(Mask))));
740 } else if (auto Source =
741 dyn_cast<IntrinsicInst>(II->getArgOperand(0))) {
742 if (Source->hasOneUse() &&
743 Source->getArgOperand(1) == II->getArgOperand(1)) {
744 // If the source of the insert has only one use and it's another
745 // insert (and they're both inserting from the same vector), try to
746 // bundle both together.
747 auto CISourceWidth =
748 dyn_cast<ConstantInt>(Source->getArgOperand(2));
749 auto CISourceStart =
750 dyn_cast<ConstantInt>(Source->getArgOperand(3));
751 if (CISourceStart && CISourceWidth) {
752 unsigned Start = CIStart->getZExtValue();
753 unsigned Width = CIWidth->getZExtValue();
754 unsigned End = Start + Width;
755 unsigned SourceStart = CISourceStart->getZExtValue();
756 unsigned SourceWidth = CISourceWidth->getZExtValue();
757 unsigned SourceEnd = SourceStart + SourceWidth;
758 unsigned NewStart, NewWidth;
759 bool ShouldReplace = false;
760 if (Start <= SourceStart && SourceStart <= End) {
761 NewStart = Start;
762 NewWidth = std::max(End, SourceEnd) - NewStart;
763 ShouldReplace = true;
764 } else if (SourceStart <= Start && Start <= SourceEnd) {
765 NewStart = SourceStart;
766 NewWidth = std::max(SourceEnd, End) - NewStart;
767 ShouldReplace = true;
768 }
770 if (ShouldReplace) {
771 Constant *ConstantWidth = ConstantInt::get(
772 II->getArgOperand(2)->getType(), NewWidth, false);
773 Constant *ConstantStart = ConstantInt::get(
774 II->getArgOperand(3)->getType(), NewStart, false);
775 Value *Args[4] = { Source->getArgOperand(0),
776 II->getArgOperand(1), ConstantWidth,
777 ConstantStart };
778 Module *M = CI.getParent()->getParent()->getParent();
779 Value *F =
780 Intrinsic::getDeclaration(M, Intrinsic::x86_sse4a_insertqi);
781 return ReplaceInstUsesWith(CI, Builder->CreateCall(F, Args));
782 }
783 }
784 }
785 }
786 }
787 }
788 break;
789 }
791 case Intrinsic::x86_sse41_pblendvb:
792 case Intrinsic::x86_sse41_blendvps:
793 case Intrinsic::x86_sse41_blendvpd:
794 case Intrinsic::x86_avx_blendv_ps_256:
795 case Intrinsic::x86_avx_blendv_pd_256:
796 case Intrinsic::x86_avx2_pblendvb: {
797 // Convert blendv* to vector selects if the mask is constant.
798 // This optimization is convoluted because the intrinsic is defined as
799 // getting a vector of floats or doubles for the ps and pd versions.
800 // FIXME: That should be changed.
801 Value *Mask = II->getArgOperand(2);
802 if (auto C = dyn_cast<ConstantDataVector>(Mask)) {
803 auto Tyi1 = Builder->getInt1Ty();
804 auto SelectorType = cast<VectorType>(Mask->getType());
805 auto EltTy = SelectorType->getElementType();
806 unsigned Size = SelectorType->getNumElements();
807 unsigned BitWidth =
808 EltTy->isFloatTy()
809 ? 32
810 : (EltTy->isDoubleTy() ? 64 : EltTy->getIntegerBitWidth());
811 assert((BitWidth == 64 || BitWidth == 32 || BitWidth == 8) &&
812 "Wrong arguments for variable blend intrinsic");
813 SmallVector<Constant *, 32> Selectors;
814 for (unsigned I = 0; I < Size; ++I) {
815 // The intrinsics only read the top bit
816 uint64_t Selector;
817 if (BitWidth == 8)
818 Selector = C->getElementAsInteger(I);
819 else
820 Selector = C->getElementAsAPFloat(I).bitcastToAPInt().getZExtValue();
821 Selectors.push_back(ConstantInt::get(Tyi1, Selector >> (BitWidth - 1)));
822 }
823 auto NewSelector = ConstantVector::get(Selectors);
824 return SelectInst::Create(NewSelector, II->getArgOperand(1),
825 II->getArgOperand(0), "blendv");
826 } else {
827 break;
828 }
829 }
831 case Intrinsic::x86_avx_vpermilvar_ps:
832 case Intrinsic::x86_avx_vpermilvar_ps_256:
833 case Intrinsic::x86_avx_vpermilvar_pd:
834 case Intrinsic::x86_avx_vpermilvar_pd_256: {
835 // Convert vpermil* to shufflevector if the mask is constant.
836 Value *V = II->getArgOperand(1);
837 unsigned Size = cast<VectorType>(V->getType())->getNumElements();
838 assert(Size == 8 || Size == 4 || Size == 2);
839 uint32_t Indexes[8];
840 if (auto C = dyn_cast<ConstantDataVector>(V)) {
841 // The intrinsics only read one or two bits, clear the rest.
842 for (unsigned I = 0; I < Size; ++I) {
843 uint32_t Index = C->getElementAsInteger(I) & 0x3;
844 if (II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd ||
845 II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd_256)
846 Index >>= 1;
847 Indexes[I] = Index;
848 }
849 } else if (isa<ConstantAggregateZero>(V)) {
850 for (unsigned I = 0; I < Size; ++I)
851 Indexes[I] = 0;
852 } else {
853 break;
854 }
855 // The _256 variants are a bit trickier since the mask bits always index
856 // into the corresponding 128 half. In order to convert to a generic
857 // shuffle, we have to make that explicit.
858 if (II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_ps_256 ||
859 II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd_256) {
860 for (unsigned I = Size / 2; I < Size; ++I)
861 Indexes[I] += Size / 2;
862 }
863 auto NewC =
864 ConstantDataVector::get(V->getContext(), makeArrayRef(Indexes, Size));
865 auto V1 = II->getArgOperand(0);
866 auto V2 = UndefValue::get(V1->getType());
867 auto Shuffle = Builder->CreateShuffleVector(V1, V2, NewC);
868 return ReplaceInstUsesWith(CI, Shuffle);
869 }
871 case Intrinsic::ppc_altivec_vperm:
872 // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
873 // Note that ppc_altivec_vperm has a big-endian bias, so when creating
874 // a vectorshuffle for little endian, we must undo the transformation
875 // performed on vec_perm in altivec.h. That is, we must complement
876 // the permutation mask with respect to 31 and reverse the order of
877 // V1 and V2.
878 if (Constant *Mask = dyn_cast<Constant>(II->getArgOperand(2))) {
879 assert(Mask->getType()->getVectorNumElements() == 16 &&
880 "Bad type for intrinsic!");
882 // Check that all of the elements are integer constants or undefs.
883 bool AllEltsOk = true;
884 for (unsigned i = 0; i != 16; ++i) {
885 Constant *Elt = Mask->getAggregateElement(i);
886 if (!Elt || !(isa<ConstantInt>(Elt) || isa<UndefValue>(Elt))) {
887 AllEltsOk = false;
888 break;
889 }
890 }
892 if (AllEltsOk) {
893 // Cast the input vectors to byte vectors.
894 Value *Op0 = Builder->CreateBitCast(II->getArgOperand(0),
895 Mask->getType());
896 Value *Op1 = Builder->CreateBitCast(II->getArgOperand(1),
897 Mask->getType());
898 Value *Result = UndefValue::get(Op0->getType());
900 // Only extract each element once.
901 Value *ExtractedElts[32];
902 memset(ExtractedElts, 0, sizeof(ExtractedElts));
904 for (unsigned i = 0; i != 16; ++i) {
905 if (isa<UndefValue>(Mask->getAggregateElement(i)))
906 continue;
907 unsigned Idx =
908 cast<ConstantInt>(Mask->getAggregateElement(i))->getZExtValue();
909 Idx &= 31; // Match the hardware behavior.
910 if (DL && DL->isLittleEndian())
911 Idx = 31 - Idx;
913 if (!ExtractedElts[Idx]) {
914 Value *Op0ToUse = (DL && DL->isLittleEndian()) ? Op1 : Op0;
915 Value *Op1ToUse = (DL && DL->isLittleEndian()) ? Op0 : Op1;
916 ExtractedElts[Idx] =
917 Builder->CreateExtractElement(Idx < 16 ? Op0ToUse : Op1ToUse,
918 Builder->getInt32(Idx&15));
919 }
921 // Insert this value into the result vector.
922 Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx],
923 Builder->getInt32(i));
924 }
925 return CastInst::Create(Instruction::BitCast, Result, CI.getType());
926 }
927 }
928 break;
930 case Intrinsic::arm_neon_vld1:
931 case Intrinsic::arm_neon_vld2:
932 case Intrinsic::arm_neon_vld3:
933 case Intrinsic::arm_neon_vld4:
934 case Intrinsic::arm_neon_vld2lane:
935 case Intrinsic::arm_neon_vld3lane:
936 case Intrinsic::arm_neon_vld4lane:
937 case Intrinsic::arm_neon_vst1:
938 case Intrinsic::arm_neon_vst2:
939 case Intrinsic::arm_neon_vst3:
940 case Intrinsic::arm_neon_vst4:
941 case Intrinsic::arm_neon_vst2lane:
942 case Intrinsic::arm_neon_vst3lane:
943 case Intrinsic::arm_neon_vst4lane: {
944 unsigned MemAlign = getKnownAlignment(II->getArgOperand(0), DL, AC, II, DT);
945 unsigned AlignArg = II->getNumArgOperands() - 1;
946 ConstantInt *IntrAlign = dyn_cast<ConstantInt>(II->getArgOperand(AlignArg));
947 if (IntrAlign && IntrAlign->getZExtValue() < MemAlign) {
948 II->setArgOperand(AlignArg,
949 ConstantInt::get(Type::getInt32Ty(II->getContext()),
950 MemAlign, false));
951 return II;
952 }
953 break;
954 }
956 case Intrinsic::arm_neon_vmulls:
957 case Intrinsic::arm_neon_vmullu:
958 case Intrinsic::aarch64_neon_smull:
959 case Intrinsic::aarch64_neon_umull: {
960 Value *Arg0 = II->getArgOperand(0);
961 Value *Arg1 = II->getArgOperand(1);
963 // Handle mul by zero first:
964 if (isa<ConstantAggregateZero>(Arg0) || isa<ConstantAggregateZero>(Arg1)) {
965 return ReplaceInstUsesWith(CI, ConstantAggregateZero::get(II->getType()));
966 }
968 // Check for constant LHS & RHS - in this case we just simplify.
969 bool Zext = (II->getIntrinsicID() == Intrinsic::arm_neon_vmullu ||
970 II->getIntrinsicID() == Intrinsic::aarch64_neon_umull);
971 VectorType *NewVT = cast<VectorType>(II->getType());
972 if (Constant *CV0 = dyn_cast<Constant>(Arg0)) {
973 if (Constant *CV1 = dyn_cast<Constant>(Arg1)) {
974 CV0 = ConstantExpr::getIntegerCast(CV0, NewVT, /*isSigned=*/!Zext);
975 CV1 = ConstantExpr::getIntegerCast(CV1, NewVT, /*isSigned=*/!Zext);
977 return ReplaceInstUsesWith(CI, ConstantExpr::getMul(CV0, CV1));
978 }
980 // Couldn't simplify - canonicalize constant to the RHS.
981 std::swap(Arg0, Arg1);
982 }
984 // Handle mul by one:
985 if (Constant *CV1 = dyn_cast<Constant>(Arg1))
986 if (ConstantInt *Splat =
987 dyn_cast_or_null<ConstantInt>(CV1->getSplatValue()))
988 if (Splat->isOne())
989 return CastInst::CreateIntegerCast(Arg0, II->getType(),
990 /*isSigned=*/!Zext);
992 break;
993 }
995 case Intrinsic::AMDGPU_rcp: {
996 if (const ConstantFP *C = dyn_cast<ConstantFP>(II->getArgOperand(0))) {
997 const APFloat &ArgVal = C->getValueAPF();
998 APFloat Val(ArgVal.getSemantics(), 1.0);
999 APFloat::opStatus Status = Val.divide(ArgVal,
1000 APFloat::rmNearestTiesToEven);
1001 // Only do this if it was exact and therefore not dependent on the
1002 // rounding mode.
1003 if (Status == APFloat::opOK)
1004 return ReplaceInstUsesWith(CI, ConstantFP::get(II->getContext(), Val));
1005 }
1007 break;
1008 }
1009 case Intrinsic::stackrestore: {
1010 // If the save is right next to the restore, remove the restore. This can
1011 // happen when variable allocas are DCE'd.
1012 if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getArgOperand(0))) {
1013 if (SS->getIntrinsicID() == Intrinsic::stacksave) {
1014 BasicBlock::iterator BI = SS;
1015 if (&*++BI == II)
1016 return EraseInstFromFunction(CI);
1017 }
1018 }
1020 // Scan down this block to see if there is another stack restore in the
1021 // same block without an intervening call/alloca.
1022 BasicBlock::iterator BI = II;
1023 TerminatorInst *TI = II->getParent()->getTerminator();
1024 bool CannotRemove = false;
1025 for (++BI; &*BI != TI; ++BI) {
1026 if (isa<AllocaInst>(BI)) {
1027 CannotRemove = true;
1028 break;
1029 }
1030 if (CallInst *BCI = dyn_cast<CallInst>(BI)) {
1031 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) {
1032 // If there is a stackrestore below this one, remove this one.
1033 if (II->getIntrinsicID() == Intrinsic::stackrestore)
1034 return EraseInstFromFunction(CI);
1035 // Otherwise, ignore the intrinsic.
1036 } else {
1037 // If we found a non-intrinsic call, we can't remove the stack
1038 // restore.
1039 CannotRemove = true;
1040 break;
1041 }
1042 }
1043 }
1045 // If the stack restore is in a return, resume, or unwind block and if there
1046 // are no allocas or calls between the restore and the return, nuke the
1047 // restore.
1048 if (!CannotRemove && (isa<ReturnInst>(TI) || isa<ResumeInst>(TI)))
1049 return EraseInstFromFunction(CI);
1050 break;
1051 }
1052 case Intrinsic::assume: {
1053 // Canonicalize assume(a && b) -> assume(a); assume(b);
1054 // Note: New assumption intrinsics created here are registered by
1055 // the InstCombineIRInserter object.
1056 Value *IIOperand = II->getArgOperand(0), *A, *B,
1057 *AssumeIntrinsic = II->getCalledValue();
1058 if (match(IIOperand, m_And(m_Value(A), m_Value(B)))) {
1059 Builder->CreateCall(AssumeIntrinsic, A, II->getName());
1060 Builder->CreateCall(AssumeIntrinsic, B, II->getName());
1061 return EraseInstFromFunction(*II);
1062 }
1063 // assume(!(a || b)) -> assume(!a); assume(!b);
1064 if (match(IIOperand, m_Not(m_Or(m_Value(A), m_Value(B))))) {
1065 Builder->CreateCall(AssumeIntrinsic, Builder->CreateNot(A),
1066 II->getName());
1067 Builder->CreateCall(AssumeIntrinsic, Builder->CreateNot(B),
1068 II->getName());
1069 return EraseInstFromFunction(*II);
1070 }
1072 // assume( (load addr) != null ) -> add 'nonnull' metadata to load
1073 // (if assume is valid at the load)
1074 if (ICmpInst* ICmp = dyn_cast<ICmpInst>(IIOperand)) {
1075 Value *LHS = ICmp->getOperand(0);
1076 Value *RHS = ICmp->getOperand(1);
1077 if (ICmpInst::ICMP_NE == ICmp->getPredicate() &&
1078 isa<LoadInst>(LHS) &&
1079 isa<Constant>(RHS) &&
1080 RHS->getType()->isPointerTy() &&
1081 cast<Constant>(RHS)->isNullValue()) {
1082 LoadInst* LI = cast<LoadInst>(LHS);
1083 if (isValidAssumeForContext(II, LI, DL, DT)) {
1084 MDNode *MD = MDNode::get(II->getContext(), None);
1085 LI->setMetadata(LLVMContext::MD_nonnull, MD);
1086 return EraseInstFromFunction(*II);
1087 }
1088 }
1089 // TODO: apply nonnull return attributes to calls and invokes
1090 // TODO: apply range metadata for range check patterns?
1091 }
1092 // If there is a dominating assume with the same condition as this one,
1093 // then this one is redundant, and should be removed.
1094 APInt KnownZero(1, 0), KnownOne(1, 0);
1095 computeKnownBits(IIOperand, KnownZero, KnownOne, 0, II);
1096 if (KnownOne.isAllOnesValue())
1097 return EraseInstFromFunction(*II);
1099 break;
1100 }
1101 case Intrinsic::experimental_gc_relocate: {
1102 // Translate facts known about a pointer before relocating into
1103 // facts about the relocate value, while being careful to
1104 // preserve relocation semantics.
1105 GCRelocateOperands Operands(II);
1106 Value *DerivedPtr = Operands.derivedPtr();
1108 // Remove the relocation if unused, note that this check is required
1109 // to prevent the cases below from looping forever.
1110 if (II->use_empty())
1111 return EraseInstFromFunction(*II);
1113 // Undef is undef, even after relocation.
1114 // TODO: provide a hook for this in GCStrategy. This is clearly legal for
1115 // most practical collectors, but there was discussion in the review thread
1116 // about whether it was legal for all possible collectors.
1117 if (isa<UndefValue>(DerivedPtr))
1118 return ReplaceInstUsesWith(*II, DerivedPtr);
1120 // The relocation of null will be null for most any collector.
1121 // TODO: provide a hook for this in GCStrategy. There might be some weird
1122 // collector this property does not hold for.
1123 if (isa<ConstantPointerNull>(DerivedPtr))
1124 return ReplaceInstUsesWith(*II, DerivedPtr);
1126 // isKnownNonNull -> nonnull attribute
1127 if (isKnownNonNull(DerivedPtr))
1128 II->addAttribute(AttributeSet::ReturnIndex, Attribute::NonNull);
1130 // TODO: dereferenceable -> deref attribute
1132 // TODO: bitcast(relocate(p)) -> relocate(bitcast(p))
1133 // Canonicalize on the type from the uses to the defs
1135 // TODO: relocate((gep p, C, C2, ...)) -> gep(relocate(p), C, C2, ...)
1136 }
1137 }
1139 return visitCallSite(II);
1140 }
1142 // InvokeInst simplification
1143 //
1144 Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) {
1145 return visitCallSite(&II);
1146 }
1148 /// isSafeToEliminateVarargsCast - If this cast does not affect the value
1149 /// passed through the varargs area, we can eliminate the use of the cast.
1150 static bool isSafeToEliminateVarargsCast(const CallSite CS,
1151 const CastInst * const CI,
1152 const DataLayout * const DL,
1153 const int ix) {
1154 if (!CI->isLosslessCast())
1155 return false;
1157 // If this is a GC intrinsic, avoid munging types. We need types for
1158 // statepoint reconstruction in SelectionDAG.
1159 // TODO: This is probably something which should be expanded to all
1160 // intrinsics since the entire point of intrinsics is that
1161 // they are understandable by the optimizer.
1162 if (isStatepoint(CS) || isGCRelocate(CS) || isGCResult(CS))
1163 return false;
1165 // The size of ByVal or InAlloca arguments is derived from the type, so we
1166 // can't change to a type with a different size. If the size were
1167 // passed explicitly we could avoid this check.
1168 if (!CS.isByValOrInAllocaArgument(ix))
1169 return true;
1171 Type* SrcTy =
1172 cast<PointerType>(CI->getOperand(0)->getType())->getElementType();
1173 Type* DstTy = cast<PointerType>(CI->getType())->getElementType();
1174 if (!SrcTy->isSized() || !DstTy->isSized())
1175 return false;
1176 if (!DL || DL->getTypeAllocSize(SrcTy) != DL->getTypeAllocSize(DstTy))
1177 return false;
1178 return true;
1179 }
1181 // Try to fold some different type of calls here.
1182 // Currently we're only working with the checking functions, memcpy_chk,
1183 // mempcpy_chk, memmove_chk, memset_chk, strcpy_chk, stpcpy_chk, strncpy_chk,
1184 // strcat_chk and strncat_chk.
1185 Instruction *InstCombiner::tryOptimizeCall(CallInst *CI, const DataLayout *DL) {
1186 if (!CI->getCalledFunction()) return nullptr;
1188 auto InstCombineRAUW = [this](Instruction *From, Value *With) {
1189 ReplaceInstUsesWith(*From, With);
1190 };
1191 LibCallSimplifier Simplifier(DL, TLI, InstCombineRAUW);
1192 if (Value *With = Simplifier.optimizeCall(CI)) {
1193 ++NumSimplified;
1194 return CI->use_empty() ? CI : ReplaceInstUsesWith(*CI, With);
1195 }
1197 return nullptr;
1198 }
1200 static IntrinsicInst *FindInitTrampolineFromAlloca(Value *TrampMem) {
1201 // Strip off at most one level of pointer casts, looking for an alloca. This
1202 // is good enough in practice and simpler than handling any number of casts.
1203 Value *Underlying = TrampMem->stripPointerCasts();
1204 if (Underlying != TrampMem &&
1205 (!Underlying->hasOneUse() || Underlying->user_back() != TrampMem))
1206 return nullptr;
1207 if (!isa<AllocaInst>(Underlying))
1208 return nullptr;
1210 IntrinsicInst *InitTrampoline = nullptr;
1211 for (User *U : TrampMem->users()) {
1212 IntrinsicInst *II = dyn_cast<IntrinsicInst>(U);
1213 if (!II)
1214 return nullptr;
1215 if (II->getIntrinsicID() == Intrinsic::init_trampoline) {
1216 if (InitTrampoline)
1217 // More than one init_trampoline writes to this value. Give up.
1218 return nullptr;
1219 InitTrampoline = II;
1220 continue;
1221 }
1222 if (II->getIntrinsicID() == Intrinsic::adjust_trampoline)
1223 // Allow any number of calls to adjust.trampoline.
1224 continue;
1225 return nullptr;
1226 }
1228 // No call to init.trampoline found.
1229 if (!InitTrampoline)
1230 return nullptr;
1232 // Check that the alloca is being used in the expected way.
1233 if (InitTrampoline->getOperand(0) != TrampMem)
1234 return nullptr;
1236 return InitTrampoline;
1237 }
1239 static IntrinsicInst *FindInitTrampolineFromBB(IntrinsicInst *AdjustTramp,
1240 Value *TrampMem) {
1241 // Visit all the previous instructions in the basic block, and try to find a
1242 // init.trampoline which has a direct path to the adjust.trampoline.
1243 for (BasicBlock::iterator I = AdjustTramp,
1244 E = AdjustTramp->getParent()->begin(); I != E; ) {
1245 Instruction *Inst = --I;
1246 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
1247 if (II->getIntrinsicID() == Intrinsic::init_trampoline &&
1248 II->getOperand(0) == TrampMem)
1249 return II;
1250 if (Inst->mayWriteToMemory())
1251 return nullptr;
1252 }
1253 return nullptr;
1254 }
1256 // Given a call to llvm.adjust.trampoline, find and return the corresponding
1257 // call to llvm.init.trampoline if the call to the trampoline can be optimized
1258 // to a direct call to a function. Otherwise return NULL.
1259 //
1260 static IntrinsicInst *FindInitTrampoline(Value *Callee) {
1261 Callee = Callee->stripPointerCasts();
1262 IntrinsicInst *AdjustTramp = dyn_cast<IntrinsicInst>(Callee);
1263 if (!AdjustTramp ||
1264 AdjustTramp->getIntrinsicID() != Intrinsic::adjust_trampoline)
1265 return nullptr;
1267 Value *TrampMem = AdjustTramp->getOperand(0);
1269 if (IntrinsicInst *IT = FindInitTrampolineFromAlloca(TrampMem))
1270 return IT;
1271 if (IntrinsicInst *IT = FindInitTrampolineFromBB(AdjustTramp, TrampMem))
1272 return IT;
1273 return nullptr;
1274 }
1276 // visitCallSite - Improvements for call and invoke instructions.
1277 //
1278 Instruction *InstCombiner::visitCallSite(CallSite CS) {
1279 if (isAllocLikeFn(CS.getInstruction(), TLI))
1280 return visitAllocSite(*CS.getInstruction());
1282 bool Changed = false;
1284 // If the callee is a pointer to a function, attempt to move any casts to the
1285 // arguments of the call/invoke.
1286 Value *Callee = CS.getCalledValue();
1287 if (!isa<Function>(Callee) && transformConstExprCastCall(CS))
1288 return nullptr;
1290 if (Function *CalleeF = dyn_cast<Function>(Callee))
1291 // If the call and callee calling conventions don't match, this call must
1292 // be unreachable, as the call is undefined.
1293 if (CalleeF->getCallingConv() != CS.getCallingConv() &&
1294 // Only do this for calls to a function with a body. A prototype may
1295 // not actually end up matching the implementation's calling conv for a
1296 // variety of reasons (e.g. it may be written in assembly).
1297 !CalleeF->isDeclaration()) {
1298 Instruction *OldCall = CS.getInstruction();
1299 new StoreInst(ConstantInt::getTrue(Callee->getContext()),
1300 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
1301 OldCall);
1302 // If OldCall does not return void then replaceAllUsesWith undef.
1303 // This allows ValueHandlers and custom metadata to adjust itself.
1304 if (!OldCall->getType()->isVoidTy())
1305 ReplaceInstUsesWith(*OldCall, UndefValue::get(OldCall->getType()));
1306 if (isa<CallInst>(OldCall))
1307 return EraseInstFromFunction(*OldCall);
1309 // We cannot remove an invoke, because it would change the CFG, just
1310 // change the callee to a null pointer.
1311 cast<InvokeInst>(OldCall)->setCalledFunction(
1312 Constant::getNullValue(CalleeF->getType()));
1313 return nullptr;
1314 }
1316 if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
1317 // If CS does not return void then replaceAllUsesWith undef.
1318 // This allows ValueHandlers and custom metadata to adjust itself.
1319 if (!CS.getInstruction()->getType()->isVoidTy())
1320 ReplaceInstUsesWith(*CS.getInstruction(),
1321 UndefValue::get(CS.getInstruction()->getType()));
1323 if (isa<InvokeInst>(CS.getInstruction())) {
1324 // Can't remove an invoke because we cannot change the CFG.
1325 return nullptr;
1326 }
1328 // This instruction is not reachable, just remove it. We insert a store to
1329 // undef so that we know that this code is not reachable, despite the fact
1330 // that we can't modify the CFG here.
1331 new StoreInst(ConstantInt::getTrue(Callee->getContext()),
1332 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
1333 CS.getInstruction());
1335 return EraseInstFromFunction(*CS.getInstruction());
1336 }
1338 if (IntrinsicInst *II = FindInitTrampoline(Callee))
1339 return transformCallThroughTrampoline(CS, II);
1341 PointerType *PTy = cast<PointerType>(Callee->getType());
1342 FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1343 if (FTy->isVarArg()) {
1344 int ix = FTy->getNumParams();
1345 // See if we can optimize any arguments passed through the varargs area of
1346 // the call.
1347 for (CallSite::arg_iterator I = CS.arg_begin() + FTy->getNumParams(),
1348 E = CS.arg_end(); I != E; ++I, ++ix) {
1349 CastInst *CI = dyn_cast<CastInst>(*I);
1350 if (CI && isSafeToEliminateVarargsCast(CS, CI, DL, ix)) {
1351 *I = CI->getOperand(0);
1352 Changed = true;
1353 }
1354 }
1355 }
1357 if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) {
1358 // Inline asm calls cannot throw - mark them 'nounwind'.
1359 CS.setDoesNotThrow();
1360 Changed = true;
1361 }
1363 // Try to optimize the call if possible, we require DataLayout for most of
1364 // this. None of these calls are seen as possibly dead so go ahead and
1365 // delete the instruction now.
1366 if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction())) {
1367 Instruction *I = tryOptimizeCall(CI, DL);
1368 // If we changed something return the result, etc. Otherwise let
1369 // the fallthrough check.
1370 if (I) return EraseInstFromFunction(*I);
1371 }
1373 return Changed ? CS.getInstruction() : nullptr;
1374 }
1376 // transformConstExprCastCall - If the callee is a constexpr cast of a function,
1377 // attempt to move the cast to the arguments of the call/invoke.
1378 //
1379 bool InstCombiner::transformConstExprCastCall(CallSite CS) {
1380 Function *Callee =
1381 dyn_cast<Function>(CS.getCalledValue()->stripPointerCasts());
1382 if (!Callee)
1383 return false;
1384 Instruction *Caller = CS.getInstruction();
1385 const AttributeSet &CallerPAL = CS.getAttributes();
1387 // Okay, this is a cast from a function to a different type. Unless doing so
1388 // would cause a type conversion of one of our arguments, change this call to
1389 // be a direct call with arguments casted to the appropriate types.
1390 //
1391 FunctionType *FT = Callee->getFunctionType();
1392 Type *OldRetTy = Caller->getType();
1393 Type *NewRetTy = FT->getReturnType();
1395 // Check to see if we are changing the return type...
1396 if (OldRetTy != NewRetTy) {
1398 if (NewRetTy->isStructTy())
1399 return false; // TODO: Handle multiple return values.
1401 if (!CastInst::isBitOrNoopPointerCastable(NewRetTy, OldRetTy, DL)) {
1402 if (Callee->isDeclaration())
1403 return false; // Cannot transform this return value.
1405 if (!Caller->use_empty() &&
1406 // void -> non-void is handled specially
1407 !NewRetTy->isVoidTy())
1408 return false; // Cannot transform this return value.
1409 }
1411 if (!CallerPAL.isEmpty() && !Caller->use_empty()) {
1412 AttrBuilder RAttrs(CallerPAL, AttributeSet::ReturnIndex);
1413 if (RAttrs.
1414 hasAttributes(AttributeFuncs::
1415 typeIncompatible(NewRetTy, AttributeSet::ReturnIndex),
1416 AttributeSet::ReturnIndex))
1417 return false; // Attribute not compatible with transformed value.
1418 }
1420 // If the callsite is an invoke instruction, and the return value is used by
1421 // a PHI node in a successor, we cannot change the return type of the call
1422 // because there is no place to put the cast instruction (without breaking
1423 // the critical edge). Bail out in this case.
1424 if (!Caller->use_empty())
1425 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller))
1426 for (User *U : II->users())
1427 if (PHINode *PN = dyn_cast<PHINode>(U))
1428 if (PN->getParent() == II->getNormalDest() ||
1429 PN->getParent() == II->getUnwindDest())
1430 return false;
1431 }
1433 unsigned NumActualArgs = CS.arg_size();
1434 unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
1436 // Prevent us turning:
1437 // declare void @takes_i32_inalloca(i32* inalloca)
1438 // call void bitcast (void (i32*)* @takes_i32_inalloca to void (i32)*)(i32 0)
1439 //
1440 // into:
1441 // call void @takes_i32_inalloca(i32* null)
1442 if (Callee->getAttributes().hasAttrSomewhere(Attribute::InAlloca))
1443 return false;
1445 CallSite::arg_iterator AI = CS.arg_begin();
1446 for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) {
1447 Type *ParamTy = FT->getParamType(i);
1448 Type *ActTy = (*AI)->getType();
1450 if (!CastInst::isBitOrNoopPointerCastable(ActTy, ParamTy, DL))
1451 return false; // Cannot transform this parameter value.
1453 if (AttrBuilder(CallerPAL.getParamAttributes(i + 1), i + 1).
1454 hasAttributes(AttributeFuncs::
1455 typeIncompatible(ParamTy, i + 1), i + 1))
1456 return false; // Attribute not compatible with transformed value.
1458 if (CS.isInAllocaArgument(i))
1459 return false; // Cannot transform to and from inalloca.
1461 // If the parameter is passed as a byval argument, then we have to have a
1462 // sized type and the sized type has to have the same size as the old type.
1463 if (ParamTy != ActTy &&
1464 CallerPAL.getParamAttributes(i + 1).hasAttribute(i + 1,
1465 Attribute::ByVal)) {
1466 PointerType *ParamPTy = dyn_cast<PointerType>(ParamTy);
1467 if (!ParamPTy || !ParamPTy->getElementType()->isSized() || !DL)
1468 return false;
1470 Type *CurElTy = ActTy->getPointerElementType();
1471 if (DL->getTypeAllocSize(CurElTy) !=
1472 DL->getTypeAllocSize(ParamPTy->getElementType()))
1473 return false;
1474 }
1475 }
1477 if (Callee->isDeclaration()) {
1478 // Do not delete arguments unless we have a function body.
1479 if (FT->getNumParams() < NumActualArgs && !FT->isVarArg())
1480 return false;
1482 // If the callee is just a declaration, don't change the varargsness of the
1483 // call. We don't want to introduce a varargs call where one doesn't
1484 // already exist.
1485 PointerType *APTy = cast<PointerType>(CS.getCalledValue()->getType());
1486 if (FT->isVarArg()!=cast<FunctionType>(APTy->getElementType())->isVarArg())
1487 return false;
1489 // If both the callee and the cast type are varargs, we still have to make
1490 // sure the number of fixed parameters are the same or we have the same
1491 // ABI issues as if we introduce a varargs call.
1492 if (FT->isVarArg() &&
1493 cast<FunctionType>(APTy->getElementType())->isVarArg() &&
1494 FT->getNumParams() !=
1495 cast<FunctionType>(APTy->getElementType())->getNumParams())
1496 return false;
1497 }
1499 if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
1500 !CallerPAL.isEmpty())
1501 // In this case we have more arguments than the new function type, but we
1502 // won't be dropping them. Check that these extra arguments have attributes
1503 // that are compatible with being a vararg call argument.
1504 for (unsigned i = CallerPAL.getNumSlots(); i; --i) {
1505 unsigned Index = CallerPAL.getSlotIndex(i - 1);
1506 if (Index <= FT->getNumParams())
1507 break;
1509 // Check if it has an attribute that's incompatible with varargs.
1510 AttributeSet PAttrs = CallerPAL.getSlotAttributes(i - 1);
1511 if (PAttrs.hasAttribute(Index, Attribute::StructRet))
1512 return false;
1513 }
1516 // Okay, we decided that this is a safe thing to do: go ahead and start
1517 // inserting cast instructions as necessary.
1518 std::vector<Value*> Args;
1519 Args.reserve(NumActualArgs);
1520 SmallVector<AttributeSet, 8> attrVec;
1521 attrVec.reserve(NumCommonArgs);
1523 // Get any return attributes.
1524 AttrBuilder RAttrs(CallerPAL, AttributeSet::ReturnIndex);
1526 // If the return value is not being used, the type may not be compatible
1527 // with the existing attributes. Wipe out any problematic attributes.
1528 RAttrs.
1529 removeAttributes(AttributeFuncs::
1530 typeIncompatible(NewRetTy, AttributeSet::ReturnIndex),
1531 AttributeSet::ReturnIndex);
1533 // Add the new return attributes.
1534 if (RAttrs.hasAttributes())
1535 attrVec.push_back(AttributeSet::get(Caller->getContext(),
1536 AttributeSet::ReturnIndex, RAttrs));
1538 AI = CS.arg_begin();
1539 for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) {
1540 Type *ParamTy = FT->getParamType(i);
1542 if ((*AI)->getType() == ParamTy) {
1543 Args.push_back(*AI);
1544 } else {
1545 Args.push_back(Builder->CreateBitOrPointerCast(*AI, ParamTy));
1546 }
1548 // Add any parameter attributes.
1549 AttrBuilder PAttrs(CallerPAL.getParamAttributes(i + 1), i + 1);
1550 if (PAttrs.hasAttributes())
1551 attrVec.push_back(AttributeSet::get(Caller->getContext(), i + 1,
1552 PAttrs));
1553 }
1555 // If the function takes more arguments than the call was taking, add them
1556 // now.
1557 for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i)
1558 Args.push_back(Constant::getNullValue(FT->getParamType(i)));
1560 // If we are removing arguments to the function, emit an obnoxious warning.
1561 if (FT->getNumParams() < NumActualArgs) {
1562 // TODO: if (!FT->isVarArg()) this call may be unreachable. PR14722
1563 if (FT->isVarArg()) {
1564 // Add all of the arguments in their promoted form to the arg list.
1565 for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) {
1566 Type *PTy = getPromotedType((*AI)->getType());
1567 if (PTy != (*AI)->getType()) {
1568 // Must promote to pass through va_arg area!
1569 Instruction::CastOps opcode =
1570 CastInst::getCastOpcode(*AI, false, PTy, false);
1571 Args.push_back(Builder->CreateCast(opcode, *AI, PTy));
1572 } else {
1573 Args.push_back(*AI);
1574 }
1576 // Add any parameter attributes.
1577 AttrBuilder PAttrs(CallerPAL.getParamAttributes(i + 1), i + 1);
1578 if (PAttrs.hasAttributes())
1579 attrVec.push_back(AttributeSet::get(FT->getContext(), i + 1,
1580 PAttrs));
1581 }
1582 }
1583 }
1585 AttributeSet FnAttrs = CallerPAL.getFnAttributes();
1586 if (CallerPAL.hasAttributes(AttributeSet::FunctionIndex))
1587 attrVec.push_back(AttributeSet::get(Callee->getContext(), FnAttrs));
1589 if (NewRetTy->isVoidTy())
1590 Caller->setName(""); // Void type should not have a name.
1592 const AttributeSet &NewCallerPAL = AttributeSet::get(Callee->getContext(),
1593 attrVec);
1595 Instruction *NC;
1596 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
1597 NC = Builder->CreateInvoke(Callee, II->getNormalDest(),
1598 II->getUnwindDest(), Args);
1599 NC->takeName(II);
1600 cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv());
1601 cast<InvokeInst>(NC)->setAttributes(NewCallerPAL);
1602 } else {
1603 CallInst *CI = cast<CallInst>(Caller);
1604 NC = Builder->CreateCall(Callee, Args);
1605 NC->takeName(CI);
1606 if (CI->isTailCall())
1607 cast<CallInst>(NC)->setTailCall();
1608 cast<CallInst>(NC)->setCallingConv(CI->getCallingConv());
1609 cast<CallInst>(NC)->setAttributes(NewCallerPAL);
1610 }
1612 // Insert a cast of the return type as necessary.
1613 Value *NV = NC;
1614 if (OldRetTy != NV->getType() && !Caller->use_empty()) {
1615 if (!NV->getType()->isVoidTy()) {
1616 NV = NC = CastInst::CreateBitOrPointerCast(NC, OldRetTy);
1617 NC->setDebugLoc(Caller->getDebugLoc());
1619 // If this is an invoke instruction, we should insert it after the first
1620 // non-phi, instruction in the normal successor block.
1621 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
1622 BasicBlock::iterator I = II->getNormalDest()->getFirstInsertionPt();
1623 InsertNewInstBefore(NC, *I);
1624 } else {
1625 // Otherwise, it's a call, just insert cast right after the call.
1626 InsertNewInstBefore(NC, *Caller);
1627 }
1628 Worklist.AddUsersToWorkList(*Caller);
1629 } else {
1630 NV = UndefValue::get(Caller->getType());
1631 }
1632 }
1634 if (!Caller->use_empty())
1635 ReplaceInstUsesWith(*Caller, NV);
1636 else if (Caller->hasValueHandle()) {
1637 if (OldRetTy == NV->getType())
1638 ValueHandleBase::ValueIsRAUWd(Caller, NV);
1639 else
1640 // We cannot call ValueIsRAUWd with a different type, and the
1641 // actual tracked value will disappear.
1642 ValueHandleBase::ValueIsDeleted(Caller);
1643 }
1645 EraseInstFromFunction(*Caller);
1646 return true;
1647 }
1649 // transformCallThroughTrampoline - Turn a call to a function created by
1650 // init_trampoline / adjust_trampoline intrinsic pair into a direct call to the
1651 // underlying function.
1652 //
1653 Instruction *
1654 InstCombiner::transformCallThroughTrampoline(CallSite CS,
1655 IntrinsicInst *Tramp) {
1656 Value *Callee = CS.getCalledValue();
1657 PointerType *PTy = cast<PointerType>(Callee->getType());
1658 FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1659 const AttributeSet &Attrs = CS.getAttributes();
1661 // If the call already has the 'nest' attribute somewhere then give up -
1662 // otherwise 'nest' would occur twice after splicing in the chain.
1663 if (Attrs.hasAttrSomewhere(Attribute::Nest))
1664 return nullptr;
1666 assert(Tramp &&
1667 "transformCallThroughTrampoline called with incorrect CallSite.");
1669 Function *NestF =cast<Function>(Tramp->getArgOperand(1)->stripPointerCasts());
1670 PointerType *NestFPTy = cast<PointerType>(NestF->getType());
1671 FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType());
1673 const AttributeSet &NestAttrs = NestF->getAttributes();
1674 if (!NestAttrs.isEmpty()) {
1675 unsigned NestIdx = 1;
1676 Type *NestTy = nullptr;
1677 AttributeSet NestAttr;
1679 // Look for a parameter marked with the 'nest' attribute.
1680 for (FunctionType::param_iterator I = NestFTy->param_begin(),
1681 E = NestFTy->param_end(); I != E; ++NestIdx, ++I)
1682 if (NestAttrs.hasAttribute(NestIdx, Attribute::Nest)) {
1683 // Record the parameter type and any other attributes.
1684 NestTy = *I;
1685 NestAttr = NestAttrs.getParamAttributes(NestIdx);
1686 break;
1687 }
1689 if (NestTy) {
1690 Instruction *Caller = CS.getInstruction();
1691 std::vector<Value*> NewArgs;
1692 NewArgs.reserve(CS.arg_size() + 1);
1694 SmallVector<AttributeSet, 8> NewAttrs;
1695 NewAttrs.reserve(Attrs.getNumSlots() + 1);
1697 // Insert the nest argument into the call argument list, which may
1698 // mean appending it. Likewise for attributes.
1700 // Add any result attributes.
1701 if (Attrs.hasAttributes(AttributeSet::ReturnIndex))
1702 NewAttrs.push_back(AttributeSet::get(Caller->getContext(),
1703 Attrs.getRetAttributes()));
1705 {
1706 unsigned Idx = 1;
1707 CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
1708 do {
1709 if (Idx == NestIdx) {
1710 // Add the chain argument and attributes.
1711 Value *NestVal = Tramp->getArgOperand(2);
1712 if (NestVal->getType() != NestTy)
1713 NestVal = Builder->CreateBitCast(NestVal, NestTy, "nest");
1714 NewArgs.push_back(NestVal);
1715 NewAttrs.push_back(AttributeSet::get(Caller->getContext(),
1716 NestAttr));
1717 }
1719 if (I == E)
1720 break;
1722 // Add the original argument and attributes.
1723 NewArgs.push_back(*I);
1724 AttributeSet Attr = Attrs.getParamAttributes(Idx);
1725 if (Attr.hasAttributes(Idx)) {
1726 AttrBuilder B(Attr, Idx);
1727 NewAttrs.push_back(AttributeSet::get(Caller->getContext(),
1728 Idx + (Idx >= NestIdx), B));
1729 }
1731 ++Idx, ++I;
1732 } while (1);
1733 }
1735 // Add any function attributes.
1736 if (Attrs.hasAttributes(AttributeSet::FunctionIndex))
1737 NewAttrs.push_back(AttributeSet::get(FTy->getContext(),
1738 Attrs.getFnAttributes()));
1740 // The trampoline may have been bitcast to a bogus type (FTy).
1741 // Handle this by synthesizing a new function type, equal to FTy
1742 // with the chain parameter inserted.
1744 std::vector<Type*> NewTypes;
1745 NewTypes.reserve(FTy->getNumParams()+1);
1747 // Insert the chain's type into the list of parameter types, which may
1748 // mean appending it.
1749 {
1750 unsigned Idx = 1;
1751 FunctionType::param_iterator I = FTy->param_begin(),
1752 E = FTy->param_end();
1754 do {
1755 if (Idx == NestIdx)
1756 // Add the chain's type.
1757 NewTypes.push_back(NestTy);
1759 if (I == E)
1760 break;
1762 // Add the original type.
1763 NewTypes.push_back(*I);
1765 ++Idx, ++I;
1766 } while (1);
1767 }
1769 // Replace the trampoline call with a direct call. Let the generic
1770 // code sort out any function type mismatches.
1771 FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes,
1772 FTy->isVarArg());
1773 Constant *NewCallee =
1774 NestF->getType() == PointerType::getUnqual(NewFTy) ?
1775 NestF : ConstantExpr::getBitCast(NestF,
1776 PointerType::getUnqual(NewFTy));
1777 const AttributeSet &NewPAL =
1778 AttributeSet::get(FTy->getContext(), NewAttrs);
1780 Instruction *NewCaller;
1781 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
1782 NewCaller = InvokeInst::Create(NewCallee,
1783 II->getNormalDest(), II->getUnwindDest(),
1784 NewArgs);
1785 cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv());
1786 cast<InvokeInst>(NewCaller)->setAttributes(NewPAL);
1787 } else {
1788 NewCaller = CallInst::Create(NewCallee, NewArgs);
1789 if (cast<CallInst>(Caller)->isTailCall())
1790 cast<CallInst>(NewCaller)->setTailCall();
1791 cast<CallInst>(NewCaller)->
1792 setCallingConv(cast<CallInst>(Caller)->getCallingConv());
1793 cast<CallInst>(NewCaller)->setAttributes(NewPAL);
1794 }
1796 return NewCaller;
1797 }
1798 }
1800 // Replace the trampoline call with a direct call. Since there is no 'nest'
1801 // parameter, there is no need to adjust the argument list. Let the generic
1802 // code sort out any function type mismatches.
1803 Constant *NewCallee =
1804 NestF->getType() == PTy ? NestF :
1805 ConstantExpr::getBitCast(NestF, PTy);
1806 CS.setCalledFunction(NewCallee);
1807 return CS.getInstruction();
1808 }