1 //===------ SimplifyLibCalls.cpp - Library calls simplifier ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is a utility pass used for testing the InstructionSimplify analysis.
11 // The analysis is applied to every instruction, and if it simplifies then the
12 // instruction is replaced by the simplification. If you are looking for a pass
13 // that performs serious instruction folding, use the instcombine pass instead.
15 //===----------------------------------------------------------------------===//
17 #include "llvm/Transforms/Utils/SimplifyLibCalls.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/Analysis/TargetLibraryInfo.h"
22 #include "llvm/Analysis/ValueTracking.h"
23 #include "llvm/IR/DataLayout.h"
24 #include "llvm/IR/DiagnosticInfo.h"
25 #include "llvm/IR/Function.h"
26 #include "llvm/IR/IRBuilder.h"
27 #include "llvm/IR/IntrinsicInst.h"
28 #include "llvm/IR/Intrinsics.h"
29 #include "llvm/IR/LLVMContext.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/PatternMatch.h"
32 #include "llvm/Support/Allocator.h"
33 #include "llvm/Support/CommandLine.h"
34 #include "llvm/Transforms/Utils/BuildLibCalls.h"
35 #include "llvm/Transforms/Utils/Local.h"
38 using namespace PatternMatch;
41 ColdErrorCalls("error-reporting-is-cold", cl::init(true), cl::Hidden,
42 cl::desc("Treat error-reporting calls as cold"));
45 EnableUnsafeFPShrink("enable-double-float-shrink", cl::Hidden,
47 cl::desc("Enable unsafe double to float "
48 "shrinking for math lib calls"));
51 //===----------------------------------------------------------------------===//
53 //===----------------------------------------------------------------------===//
55 static bool ignoreCallingConv(LibFunc::Func Func) {
56 return Func == LibFunc::abs || Func == LibFunc::labs ||
57 Func == LibFunc::llabs || Func == LibFunc::strlen;
60 /// isOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
61 /// value is equal or not-equal to zero.
62 static bool isOnlyUsedInZeroEqualityComparison(Value *V) {
63 for (User *U : V->users()) {
64 if (ICmpInst *IC = dyn_cast<ICmpInst>(U))
66 if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
69 // Unknown instruction.
75 /// isOnlyUsedInEqualityComparison - Return true if it is only used in equality
76 /// comparisons with With.
77 static bool isOnlyUsedInEqualityComparison(Value *V, Value *With) {
78 for (User *U : V->users()) {
79 if (ICmpInst *IC = dyn_cast<ICmpInst>(U))
80 if (IC->isEquality() && IC->getOperand(1) == With)
82 // Unknown instruction.
88 static bool callHasFloatingPointArgument(const CallInst *CI) {
89 return std::any_of(CI->op_begin(), CI->op_end(), [](const Use &OI) {
90 return OI->getType()->isFloatingPointTy();
94 /// \brief Check whether the overloaded unary floating point function
95 /// corresponding to \a Ty is available.
96 static bool hasUnaryFloatFn(const TargetLibraryInfo *TLI, Type *Ty,
97 LibFunc::Func DoubleFn, LibFunc::Func FloatFn,
98 LibFunc::Func LongDoubleFn) {
99 switch (Ty->getTypeID()) {
100 case Type::FloatTyID:
101 return TLI->has(FloatFn);
102 case Type::DoubleTyID:
103 return TLI->has(DoubleFn);
105 return TLI->has(LongDoubleFn);
109 /// \brief Check whether we can use unsafe floating point math for
110 /// the function passed as input.
111 static bool canUseUnsafeFPMath(Function *F) {
113 // FIXME: For finer-grain optimization, we need intrinsics to have the same
114 // fast-math flag decorations that are applied to FP instructions. For now,
115 // we have to rely on the function-level unsafe-fp-math attribute to do this
116 // optimization because there's no other way to express that the call can be
118 if (F->hasFnAttribute("unsafe-fp-math")) {
119 Attribute Attr = F->getFnAttribute("unsafe-fp-math");
120 if (Attr.getValueAsString() == "true")
126 /// \brief Returns whether \p F matches the signature expected for the
127 /// string/memory copying library function \p Func.
128 /// Acceptable functions are st[rp][n]?cpy, memove, memcpy, and memset.
129 /// Their fortified (_chk) counterparts are also accepted.
130 static bool checkStringCopyLibFuncSignature(Function *F, LibFunc::Func Func) {
131 const DataLayout &DL = F->getParent()->getDataLayout();
132 FunctionType *FT = F->getFunctionType();
133 LLVMContext &Context = F->getContext();
134 Type *PCharTy = Type::getInt8PtrTy(Context);
135 Type *SizeTTy = DL.getIntPtrType(Context);
136 unsigned NumParams = FT->getNumParams();
138 // All string libfuncs return the same type as the first parameter.
139 if (FT->getReturnType() != FT->getParamType(0))
144 llvm_unreachable("Can't check signature for non-string-copy libfunc.");
145 case LibFunc::stpncpy_chk:
146 case LibFunc::strncpy_chk:
147 --NumParams; // fallthrough
148 case LibFunc::stpncpy:
149 case LibFunc::strncpy: {
150 if (NumParams != 3 || FT->getParamType(0) != FT->getParamType(1) ||
151 FT->getParamType(0) != PCharTy || !FT->getParamType(2)->isIntegerTy())
155 case LibFunc::strcpy_chk:
156 case LibFunc::stpcpy_chk:
157 --NumParams; // fallthrough
158 case LibFunc::stpcpy:
159 case LibFunc::strcpy: {
160 if (NumParams != 2 || FT->getParamType(0) != FT->getParamType(1) ||
161 FT->getParamType(0) != PCharTy)
165 case LibFunc::memmove_chk:
166 case LibFunc::memcpy_chk:
167 --NumParams; // fallthrough
168 case LibFunc::memmove:
169 case LibFunc::memcpy: {
170 if (NumParams != 3 || !FT->getParamType(0)->isPointerTy() ||
171 !FT->getParamType(1)->isPointerTy() || FT->getParamType(2) != SizeTTy)
175 case LibFunc::memset_chk:
176 --NumParams; // fallthrough
177 case LibFunc::memset: {
178 if (NumParams != 3 || !FT->getParamType(0)->isPointerTy() ||
179 !FT->getParamType(1)->isIntegerTy() || FT->getParamType(2) != SizeTTy)
184 // If this is a fortified libcall, the last parameter is a size_t.
185 if (NumParams == FT->getNumParams() - 1)
186 return FT->getParamType(FT->getNumParams() - 1) == SizeTTy;
190 //===----------------------------------------------------------------------===//
191 // String and Memory Library Call Optimizations
192 //===----------------------------------------------------------------------===//
194 Value *LibCallSimplifier::optimizeStrCat(CallInst *CI, IRBuilder<> &B) {
195 Function *Callee = CI->getCalledFunction();
196 // Verify the "strcat" function prototype.
197 FunctionType *FT = Callee->getFunctionType();
198 if (FT->getNumParams() != 2||
199 FT->getReturnType() != B.getInt8PtrTy() ||
200 FT->getParamType(0) != FT->getReturnType() ||
201 FT->getParamType(1) != FT->getReturnType())
204 // Extract some information from the instruction
205 Value *Dst = CI->getArgOperand(0);
206 Value *Src = CI->getArgOperand(1);
208 // See if we can get the length of the input string.
209 uint64_t Len = GetStringLength(Src);
212 --Len; // Unbias length.
214 // Handle the simple, do-nothing case: strcat(x, "") -> x
218 return emitStrLenMemCpy(Src, Dst, Len, B);
221 Value *LibCallSimplifier::emitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len,
223 // We need to find the end of the destination string. That's where the
224 // memory is to be moved to. We just generate a call to strlen.
225 Value *DstLen = EmitStrLen(Dst, B, DL, TLI);
229 // Now that we have the destination's length, we must index into the
230 // destination's pointer to get the actual memcpy destination (end of
231 // the string .. we're concatenating).
232 Value *CpyDst = B.CreateGEP(B.getInt8Ty(), Dst, DstLen, "endptr");
234 // We have enough information to now generate the memcpy call to do the
235 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
236 B.CreateMemCpy(CpyDst, Src,
237 ConstantInt::get(DL.getIntPtrType(Src->getContext()), Len + 1),
242 Value *LibCallSimplifier::optimizeStrNCat(CallInst *CI, IRBuilder<> &B) {
243 Function *Callee = CI->getCalledFunction();
244 // Verify the "strncat" function prototype.
245 FunctionType *FT = Callee->getFunctionType();
246 if (FT->getNumParams() != 3 || FT->getReturnType() != B.getInt8PtrTy() ||
247 FT->getParamType(0) != FT->getReturnType() ||
248 FT->getParamType(1) != FT->getReturnType() ||
249 !FT->getParamType(2)->isIntegerTy())
252 // Extract some information from the instruction
253 Value *Dst = CI->getArgOperand(0);
254 Value *Src = CI->getArgOperand(1);
257 // We don't do anything if length is not constant
258 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
259 Len = LengthArg->getZExtValue();
263 // See if we can get the length of the input string.
264 uint64_t SrcLen = GetStringLength(Src);
267 --SrcLen; // Unbias length.
269 // Handle the simple, do-nothing cases:
270 // strncat(x, "", c) -> x
271 // strncat(x, c, 0) -> x
272 if (SrcLen == 0 || Len == 0)
275 // We don't optimize this case
279 // strncat(x, s, c) -> strcat(x, s)
280 // s is constant so the strcat can be optimized further
281 return emitStrLenMemCpy(Src, Dst, SrcLen, B);
284 Value *LibCallSimplifier::optimizeStrChr(CallInst *CI, IRBuilder<> &B) {
285 Function *Callee = CI->getCalledFunction();
286 // Verify the "strchr" function prototype.
287 FunctionType *FT = Callee->getFunctionType();
288 if (FT->getNumParams() != 2 || FT->getReturnType() != B.getInt8PtrTy() ||
289 FT->getParamType(0) != FT->getReturnType() ||
290 !FT->getParamType(1)->isIntegerTy(32))
293 Value *SrcStr = CI->getArgOperand(0);
295 // If the second operand is non-constant, see if we can compute the length
296 // of the input string and turn this into memchr.
297 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
299 uint64_t Len = GetStringLength(SrcStr);
300 if (Len == 0 || !FT->getParamType(1)->isIntegerTy(32)) // memchr needs i32.
303 return EmitMemChr(SrcStr, CI->getArgOperand(1), // include nul.
304 ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len),
308 // Otherwise, the character is a constant, see if the first argument is
309 // a string literal. If so, we can constant fold.
311 if (!getConstantStringInfo(SrcStr, Str)) {
312 if (CharC->isZero()) // strchr(p, 0) -> p + strlen(p)
313 return B.CreateGEP(B.getInt8Ty(), SrcStr, EmitStrLen(SrcStr, B, DL, TLI), "strchr");
317 // Compute the offset, make sure to handle the case when we're searching for
318 // zero (a weird way to spell strlen).
319 size_t I = (0xFF & CharC->getSExtValue()) == 0
321 : Str.find(CharC->getSExtValue());
322 if (I == StringRef::npos) // Didn't find the char. strchr returns null.
323 return Constant::getNullValue(CI->getType());
325 // strchr(s+n,c) -> gep(s+n+i,c)
326 return B.CreateGEP(B.getInt8Ty(), SrcStr, B.getInt64(I), "strchr");
329 Value *LibCallSimplifier::optimizeStrRChr(CallInst *CI, IRBuilder<> &B) {
330 Function *Callee = CI->getCalledFunction();
331 // Verify the "strrchr" function prototype.
332 FunctionType *FT = Callee->getFunctionType();
333 if (FT->getNumParams() != 2 || FT->getReturnType() != B.getInt8PtrTy() ||
334 FT->getParamType(0) != FT->getReturnType() ||
335 !FT->getParamType(1)->isIntegerTy(32))
338 Value *SrcStr = CI->getArgOperand(0);
339 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
341 // Cannot fold anything if we're not looking for a constant.
346 if (!getConstantStringInfo(SrcStr, Str)) {
347 // strrchr(s, 0) -> strchr(s, 0)
349 return EmitStrChr(SrcStr, '\0', B, TLI);
353 // Compute the offset.
354 size_t I = (0xFF & CharC->getSExtValue()) == 0
356 : Str.rfind(CharC->getSExtValue());
357 if (I == StringRef::npos) // Didn't find the char. Return null.
358 return Constant::getNullValue(CI->getType());
360 // strrchr(s+n,c) -> gep(s+n+i,c)
361 return B.CreateGEP(B.getInt8Ty(), SrcStr, B.getInt64(I), "strrchr");
364 Value *LibCallSimplifier::optimizeStrCmp(CallInst *CI, IRBuilder<> &B) {
365 Function *Callee = CI->getCalledFunction();
366 // Verify the "strcmp" function prototype.
367 FunctionType *FT = Callee->getFunctionType();
368 if (FT->getNumParams() != 2 || !FT->getReturnType()->isIntegerTy(32) ||
369 FT->getParamType(0) != FT->getParamType(1) ||
370 FT->getParamType(0) != B.getInt8PtrTy())
373 Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
374 if (Str1P == Str2P) // strcmp(x,x) -> 0
375 return ConstantInt::get(CI->getType(), 0);
377 StringRef Str1, Str2;
378 bool HasStr1 = getConstantStringInfo(Str1P, Str1);
379 bool HasStr2 = getConstantStringInfo(Str2P, Str2);
381 // strcmp(x, y) -> cnst (if both x and y are constant strings)
382 if (HasStr1 && HasStr2)
383 return ConstantInt::get(CI->getType(), Str1.compare(Str2));
385 if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x
387 B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType()));
389 if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
390 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
392 // strcmp(P, "x") -> memcmp(P, "x", 2)
393 uint64_t Len1 = GetStringLength(Str1P);
394 uint64_t Len2 = GetStringLength(Str2P);
396 return EmitMemCmp(Str1P, Str2P,
397 ConstantInt::get(DL.getIntPtrType(CI->getContext()),
398 std::min(Len1, Len2)),
405 Value *LibCallSimplifier::optimizeStrNCmp(CallInst *CI, IRBuilder<> &B) {
406 Function *Callee = CI->getCalledFunction();
407 // Verify the "strncmp" function prototype.
408 FunctionType *FT = Callee->getFunctionType();
409 if (FT->getNumParams() != 3 || !FT->getReturnType()->isIntegerTy(32) ||
410 FT->getParamType(0) != FT->getParamType(1) ||
411 FT->getParamType(0) != B.getInt8PtrTy() ||
412 !FT->getParamType(2)->isIntegerTy())
415 Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
416 if (Str1P == Str2P) // strncmp(x,x,n) -> 0
417 return ConstantInt::get(CI->getType(), 0);
419 // Get the length argument if it is constant.
421 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
422 Length = LengthArg->getZExtValue();
426 if (Length == 0) // strncmp(x,y,0) -> 0
427 return ConstantInt::get(CI->getType(), 0);
429 if (Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
430 return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, DL, TLI);
432 StringRef Str1, Str2;
433 bool HasStr1 = getConstantStringInfo(Str1P, Str1);
434 bool HasStr2 = getConstantStringInfo(Str2P, Str2);
436 // strncmp(x, y) -> cnst (if both x and y are constant strings)
437 if (HasStr1 && HasStr2) {
438 StringRef SubStr1 = Str1.substr(0, Length);
439 StringRef SubStr2 = Str2.substr(0, Length);
440 return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2));
443 if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> -*x
445 B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType()));
447 if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x
448 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
453 Value *LibCallSimplifier::optimizeStrCpy(CallInst *CI, IRBuilder<> &B) {
454 Function *Callee = CI->getCalledFunction();
456 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::strcpy))
459 Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
460 if (Dst == Src) // strcpy(x,x) -> x
463 // See if we can get the length of the input string.
464 uint64_t Len = GetStringLength(Src);
468 // We have enough information to now generate the memcpy call to do the
469 // copy for us. Make a memcpy to copy the nul byte with align = 1.
470 B.CreateMemCpy(Dst, Src,
471 ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len), 1);
475 Value *LibCallSimplifier::optimizeStpCpy(CallInst *CI, IRBuilder<> &B) {
476 Function *Callee = CI->getCalledFunction();
477 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::stpcpy))
480 Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
481 if (Dst == Src) { // stpcpy(x,x) -> x+strlen(x)
482 Value *StrLen = EmitStrLen(Src, B, DL, TLI);
483 return StrLen ? B.CreateInBoundsGEP(B.getInt8Ty(), Dst, StrLen) : nullptr;
486 // See if we can get the length of the input string.
487 uint64_t Len = GetStringLength(Src);
491 Type *PT = Callee->getFunctionType()->getParamType(0);
492 Value *LenV = ConstantInt::get(DL.getIntPtrType(PT), Len);
494 B.CreateGEP(B.getInt8Ty(), Dst, ConstantInt::get(DL.getIntPtrType(PT), Len - 1));
496 // We have enough information to now generate the memcpy call to do the
497 // copy for us. Make a memcpy to copy the nul byte with align = 1.
498 B.CreateMemCpy(Dst, Src, LenV, 1);
502 Value *LibCallSimplifier::optimizeStrNCpy(CallInst *CI, IRBuilder<> &B) {
503 Function *Callee = CI->getCalledFunction();
504 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::strncpy))
507 Value *Dst = CI->getArgOperand(0);
508 Value *Src = CI->getArgOperand(1);
509 Value *LenOp = CI->getArgOperand(2);
511 // See if we can get the length of the input string.
512 uint64_t SrcLen = GetStringLength(Src);
518 // strncpy(x, "", y) -> memset(x, '\0', y, 1)
519 B.CreateMemSet(Dst, B.getInt8('\0'), LenOp, 1);
524 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
525 Len = LengthArg->getZExtValue();
530 return Dst; // strncpy(x, y, 0) -> x
532 // Let strncpy handle the zero padding
533 if (Len > SrcLen + 1)
536 Type *PT = Callee->getFunctionType()->getParamType(0);
537 // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
538 B.CreateMemCpy(Dst, Src, ConstantInt::get(DL.getIntPtrType(PT), Len), 1);
543 Value *LibCallSimplifier::optimizeStrLen(CallInst *CI, IRBuilder<> &B) {
544 Function *Callee = CI->getCalledFunction();
545 FunctionType *FT = Callee->getFunctionType();
546 if (FT->getNumParams() != 1 || FT->getParamType(0) != B.getInt8PtrTy() ||
547 !FT->getReturnType()->isIntegerTy())
550 Value *Src = CI->getArgOperand(0);
552 // Constant folding: strlen("xyz") -> 3
553 if (uint64_t Len = GetStringLength(Src))
554 return ConstantInt::get(CI->getType(), Len - 1);
556 // strlen(x?"foo":"bars") --> x ? 3 : 4
557 if (SelectInst *SI = dyn_cast<SelectInst>(Src)) {
558 uint64_t LenTrue = GetStringLength(SI->getTrueValue());
559 uint64_t LenFalse = GetStringLength(SI->getFalseValue());
560 if (LenTrue && LenFalse) {
561 Function *Caller = CI->getParent()->getParent();
562 emitOptimizationRemark(CI->getContext(), "simplify-libcalls", *Caller,
564 "folded strlen(select) to select of constants");
565 return B.CreateSelect(SI->getCondition(),
566 ConstantInt::get(CI->getType(), LenTrue - 1),
567 ConstantInt::get(CI->getType(), LenFalse - 1));
571 // strlen(x) != 0 --> *x != 0
572 // strlen(x) == 0 --> *x == 0
573 if (isOnlyUsedInZeroEqualityComparison(CI))
574 return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
579 Value *LibCallSimplifier::optimizeStrPBrk(CallInst *CI, IRBuilder<> &B) {
580 Function *Callee = CI->getCalledFunction();
581 FunctionType *FT = Callee->getFunctionType();
582 if (FT->getNumParams() != 2 || FT->getParamType(0) != B.getInt8PtrTy() ||
583 FT->getParamType(1) != FT->getParamType(0) ||
584 FT->getReturnType() != FT->getParamType(0))
588 bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
589 bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
591 // strpbrk(s, "") -> nullptr
592 // strpbrk("", s) -> nullptr
593 if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
594 return Constant::getNullValue(CI->getType());
597 if (HasS1 && HasS2) {
598 size_t I = S1.find_first_of(S2);
599 if (I == StringRef::npos) // No match.
600 return Constant::getNullValue(CI->getType());
602 return B.CreateGEP(B.getInt8Ty(), CI->getArgOperand(0), B.getInt64(I), "strpbrk");
605 // strpbrk(s, "a") -> strchr(s, 'a')
606 if (HasS2 && S2.size() == 1)
607 return EmitStrChr(CI->getArgOperand(0), S2[0], B, TLI);
612 Value *LibCallSimplifier::optimizeStrTo(CallInst *CI, IRBuilder<> &B) {
613 Function *Callee = CI->getCalledFunction();
614 FunctionType *FT = Callee->getFunctionType();
615 if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
616 !FT->getParamType(0)->isPointerTy() ||
617 !FT->getParamType(1)->isPointerTy())
620 Value *EndPtr = CI->getArgOperand(1);
621 if (isa<ConstantPointerNull>(EndPtr)) {
622 // With a null EndPtr, this function won't capture the main argument.
623 // It would be readonly too, except that it still may write to errno.
624 CI->addAttribute(1, Attribute::NoCapture);
630 Value *LibCallSimplifier::optimizeStrSpn(CallInst *CI, IRBuilder<> &B) {
631 Function *Callee = CI->getCalledFunction();
632 FunctionType *FT = Callee->getFunctionType();
633 if (FT->getNumParams() != 2 || FT->getParamType(0) != B.getInt8PtrTy() ||
634 FT->getParamType(1) != FT->getParamType(0) ||
635 !FT->getReturnType()->isIntegerTy())
639 bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
640 bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
642 // strspn(s, "") -> 0
643 // strspn("", s) -> 0
644 if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
645 return Constant::getNullValue(CI->getType());
648 if (HasS1 && HasS2) {
649 size_t Pos = S1.find_first_not_of(S2);
650 if (Pos == StringRef::npos)
652 return ConstantInt::get(CI->getType(), Pos);
658 Value *LibCallSimplifier::optimizeStrCSpn(CallInst *CI, IRBuilder<> &B) {
659 Function *Callee = CI->getCalledFunction();
660 FunctionType *FT = Callee->getFunctionType();
661 if (FT->getNumParams() != 2 || FT->getParamType(0) != B.getInt8PtrTy() ||
662 FT->getParamType(1) != FT->getParamType(0) ||
663 !FT->getReturnType()->isIntegerTy())
667 bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
668 bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
670 // strcspn("", s) -> 0
671 if (HasS1 && S1.empty())
672 return Constant::getNullValue(CI->getType());
675 if (HasS1 && HasS2) {
676 size_t Pos = S1.find_first_of(S2);
677 if (Pos == StringRef::npos)
679 return ConstantInt::get(CI->getType(), Pos);
682 // strcspn(s, "") -> strlen(s)
683 if (HasS2 && S2.empty())
684 return EmitStrLen(CI->getArgOperand(0), B, DL, TLI);
689 Value *LibCallSimplifier::optimizeStrStr(CallInst *CI, IRBuilder<> &B) {
690 Function *Callee = CI->getCalledFunction();
691 FunctionType *FT = Callee->getFunctionType();
692 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
693 !FT->getParamType(1)->isPointerTy() ||
694 !FT->getReturnType()->isPointerTy())
697 // fold strstr(x, x) -> x.
698 if (CI->getArgOperand(0) == CI->getArgOperand(1))
699 return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
701 // fold strstr(a, b) == a -> strncmp(a, b, strlen(b)) == 0
702 if (isOnlyUsedInEqualityComparison(CI, CI->getArgOperand(0))) {
703 Value *StrLen = EmitStrLen(CI->getArgOperand(1), B, DL, TLI);
706 Value *StrNCmp = EmitStrNCmp(CI->getArgOperand(0), CI->getArgOperand(1),
710 for (auto UI = CI->user_begin(), UE = CI->user_end(); UI != UE;) {
711 ICmpInst *Old = cast<ICmpInst>(*UI++);
713 B.CreateICmp(Old->getPredicate(), StrNCmp,
714 ConstantInt::getNullValue(StrNCmp->getType()), "cmp");
715 replaceAllUsesWith(Old, Cmp);
720 // See if either input string is a constant string.
721 StringRef SearchStr, ToFindStr;
722 bool HasStr1 = getConstantStringInfo(CI->getArgOperand(0), SearchStr);
723 bool HasStr2 = getConstantStringInfo(CI->getArgOperand(1), ToFindStr);
725 // fold strstr(x, "") -> x.
726 if (HasStr2 && ToFindStr.empty())
727 return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
729 // If both strings are known, constant fold it.
730 if (HasStr1 && HasStr2) {
731 size_t Offset = SearchStr.find(ToFindStr);
733 if (Offset == StringRef::npos) // strstr("foo", "bar") -> null
734 return Constant::getNullValue(CI->getType());
736 // strstr("abcd", "bc") -> gep((char*)"abcd", 1)
737 Value *Result = CastToCStr(CI->getArgOperand(0), B);
738 Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
739 return B.CreateBitCast(Result, CI->getType());
742 // fold strstr(x, "y") -> strchr(x, 'y').
743 if (HasStr2 && ToFindStr.size() == 1) {
744 Value *StrChr = EmitStrChr(CI->getArgOperand(0), ToFindStr[0], B, TLI);
745 return StrChr ? B.CreateBitCast(StrChr, CI->getType()) : nullptr;
750 Value *LibCallSimplifier::optimizeMemChr(CallInst *CI, IRBuilder<> &B) {
751 Function *Callee = CI->getCalledFunction();
752 FunctionType *FT = Callee->getFunctionType();
753 if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() ||
754 !FT->getParamType(1)->isIntegerTy(32) ||
755 !FT->getParamType(2)->isIntegerTy() ||
756 !FT->getReturnType()->isPointerTy())
759 Value *SrcStr = CI->getArgOperand(0);
760 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
761 ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
763 // memchr(x, y, 0) -> null
764 if (LenC && LenC->isNullValue())
765 return Constant::getNullValue(CI->getType());
767 // From now on we need at least constant length and string.
769 if (!LenC || !getConstantStringInfo(SrcStr, Str, 0, /*TrimAtNul=*/false))
772 // Truncate the string to LenC. If Str is smaller than LenC we will still only
773 // scan the string, as reading past the end of it is undefined and we can just
774 // return null if we don't find the char.
775 Str = Str.substr(0, LenC->getZExtValue());
777 // If the char is variable but the input str and length are not we can turn
778 // this memchr call into a simple bit field test. Of course this only works
779 // when the return value is only checked against null.
781 // It would be really nice to reuse switch lowering here but we can't change
782 // the CFG at this point.
784 // memchr("\r\n", C, 2) != nullptr -> (C & ((1 << '\r') | (1 << '\n'))) != 0
785 // after bounds check.
786 if (!CharC && !Str.empty() && isOnlyUsedInZeroEqualityComparison(CI)) {
788 *std::max_element(reinterpret_cast<const unsigned char *>(Str.begin()),
789 reinterpret_cast<const unsigned char *>(Str.end()));
791 // Make sure the bit field we're about to create fits in a register on the
793 // FIXME: On a 64 bit architecture this prevents us from using the
794 // interesting range of alpha ascii chars. We could do better by emitting
795 // two bitfields or shifting the range by 64 if no lower chars are used.
796 if (!DL.fitsInLegalInteger(Max + 1))
799 // For the bit field use a power-of-2 type with at least 8 bits to avoid
800 // creating unnecessary illegal types.
801 unsigned char Width = NextPowerOf2(std::max((unsigned char)7, Max));
803 // Now build the bit field.
804 APInt Bitfield(Width, 0);
806 Bitfield.setBit((unsigned char)C);
807 Value *BitfieldC = B.getInt(Bitfield);
809 // First check that the bit field access is within bounds.
810 Value *C = B.CreateZExtOrTrunc(CI->getArgOperand(1), BitfieldC->getType());
811 Value *Bounds = B.CreateICmp(ICmpInst::ICMP_ULT, C, B.getIntN(Width, Width),
814 // Create code that checks if the given bit is set in the field.
815 Value *Shl = B.CreateShl(B.getIntN(Width, 1ULL), C);
816 Value *Bits = B.CreateIsNotNull(B.CreateAnd(Shl, BitfieldC), "memchr.bits");
818 // Finally merge both checks and cast to pointer type. The inttoptr
819 // implicitly zexts the i1 to intptr type.
820 return B.CreateIntToPtr(B.CreateAnd(Bounds, Bits, "memchr"), CI->getType());
823 // Check if all arguments are constants. If so, we can constant fold.
827 // Compute the offset.
828 size_t I = Str.find(CharC->getSExtValue() & 0xFF);
829 if (I == StringRef::npos) // Didn't find the char. memchr returns null.
830 return Constant::getNullValue(CI->getType());
832 // memchr(s+n,c,l) -> gep(s+n+i,c)
833 return B.CreateGEP(B.getInt8Ty(), SrcStr, B.getInt64(I), "memchr");
836 Value *LibCallSimplifier::optimizeMemCmp(CallInst *CI, IRBuilder<> &B) {
837 Function *Callee = CI->getCalledFunction();
838 FunctionType *FT = Callee->getFunctionType();
839 if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() ||
840 !FT->getParamType(1)->isPointerTy() ||
841 !FT->getReturnType()->isIntegerTy(32))
844 Value *LHS = CI->getArgOperand(0), *RHS = CI->getArgOperand(1);
846 if (LHS == RHS) // memcmp(s,s,x) -> 0
847 return Constant::getNullValue(CI->getType());
849 // Make sure we have a constant length.
850 ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
853 uint64_t Len = LenC->getZExtValue();
855 if (Len == 0) // memcmp(s1,s2,0) -> 0
856 return Constant::getNullValue(CI->getType());
858 // memcmp(S1,S2,1) -> *(unsigned char*)LHS - *(unsigned char*)RHS
860 Value *LHSV = B.CreateZExt(B.CreateLoad(CastToCStr(LHS, B), "lhsc"),
861 CI->getType(), "lhsv");
862 Value *RHSV = B.CreateZExt(B.CreateLoad(CastToCStr(RHS, B), "rhsc"),
863 CI->getType(), "rhsv");
864 return B.CreateSub(LHSV, RHSV, "chardiff");
867 // memcmp(S1,S2,N/8)==0 -> (*(intN_t*)S1 != *(intN_t*)S2)==0
868 if (DL.isLegalInteger(Len * 8) && isOnlyUsedInZeroEqualityComparison(CI)) {
870 IntegerType *IntType = IntegerType::get(CI->getContext(), Len * 8);
871 unsigned PrefAlignment = DL.getPrefTypeAlignment(IntType);
873 if (getKnownAlignment(LHS, DL, CI) >= PrefAlignment &&
874 getKnownAlignment(RHS, DL, CI) >= PrefAlignment) {
877 IntType->getPointerTo(LHS->getType()->getPointerAddressSpace());
879 IntType->getPointerTo(RHS->getType()->getPointerAddressSpace());
881 Value *LHSV = B.CreateLoad(B.CreateBitCast(LHS, LHSPtrTy, "lhsc"), "lhsv");
882 Value *RHSV = B.CreateLoad(B.CreateBitCast(RHS, RHSPtrTy, "rhsc"), "rhsv");
884 return B.CreateZExt(B.CreateICmpNE(LHSV, RHSV), CI->getType(), "memcmp");
888 // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
889 StringRef LHSStr, RHSStr;
890 if (getConstantStringInfo(LHS, LHSStr) &&
891 getConstantStringInfo(RHS, RHSStr)) {
892 // Make sure we're not reading out-of-bounds memory.
893 if (Len > LHSStr.size() || Len > RHSStr.size())
895 // Fold the memcmp and normalize the result. This way we get consistent
896 // results across multiple platforms.
898 int Cmp = memcmp(LHSStr.data(), RHSStr.data(), Len);
903 return ConstantInt::get(CI->getType(), Ret);
909 Value *LibCallSimplifier::optimizeMemCpy(CallInst *CI, IRBuilder<> &B) {
910 Function *Callee = CI->getCalledFunction();
912 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memcpy))
915 // memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
916 B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
917 CI->getArgOperand(2), 1);
918 return CI->getArgOperand(0);
921 Value *LibCallSimplifier::optimizeMemMove(CallInst *CI, IRBuilder<> &B) {
922 Function *Callee = CI->getCalledFunction();
924 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memmove))
927 // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
928 B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
929 CI->getArgOperand(2), 1);
930 return CI->getArgOperand(0);
933 Value *LibCallSimplifier::optimizeMemSet(CallInst *CI, IRBuilder<> &B) {
934 Function *Callee = CI->getCalledFunction();
936 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memset))
939 // memset(p, v, n) -> llvm.memset(p, v, n, 1)
940 Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
941 B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
942 return CI->getArgOperand(0);
945 //===----------------------------------------------------------------------===//
946 // Math Library Optimizations
947 //===----------------------------------------------------------------------===//
949 /// Return a variant of Val with float type.
950 /// Currently this works in two cases: If Val is an FPExtension of a float
951 /// value to something bigger, simply return the operand.
952 /// If Val is a ConstantFP but can be converted to a float ConstantFP without
953 /// loss of precision do so.
954 static Value *valueHasFloatPrecision(Value *Val) {
955 if (FPExtInst *Cast = dyn_cast<FPExtInst>(Val)) {
956 Value *Op = Cast->getOperand(0);
957 if (Op->getType()->isFloatTy())
960 if (ConstantFP *Const = dyn_cast<ConstantFP>(Val)) {
961 APFloat F = Const->getValueAPF();
963 (void)F.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven,
966 return ConstantFP::get(Const->getContext(), F);
971 //===----------------------------------------------------------------------===//
972 // Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
974 Value *LibCallSimplifier::optimizeUnaryDoubleFP(CallInst *CI, IRBuilder<> &B,
976 Function *Callee = CI->getCalledFunction();
977 FunctionType *FT = Callee->getFunctionType();
978 if (FT->getNumParams() != 1 || !FT->getReturnType()->isDoubleTy() ||
979 !FT->getParamType(0)->isDoubleTy())
983 // Check if all the uses for function like 'sin' are converted to float.
984 for (User *U : CI->users()) {
985 FPTruncInst *Cast = dyn_cast<FPTruncInst>(U);
986 if (!Cast || !Cast->getType()->isFloatTy())
991 // If this is something like 'floor((double)floatval)', convert to floorf.
992 Value *V = valueHasFloatPrecision(CI->getArgOperand(0));
996 // floor((double)floatval) -> (double)floorf(floatval)
997 if (Callee->isIntrinsic()) {
998 Module *M = CI->getParent()->getParent()->getParent();
999 Intrinsic::ID IID = Callee->getIntrinsicID();
1000 Function *F = Intrinsic::getDeclaration(M, IID, B.getFloatTy());
1001 V = B.CreateCall(F, V);
1003 // The call is a library call rather than an intrinsic.
1004 V = EmitUnaryFloatFnCall(V, Callee->getName(), B, Callee->getAttributes());
1007 return B.CreateFPExt(V, B.getDoubleTy());
1010 // Double -> Float Shrinking Optimizations for Binary Functions like 'fmin/fmax'
1011 Value *LibCallSimplifier::optimizeBinaryDoubleFP(CallInst *CI, IRBuilder<> &B) {
1012 Function *Callee = CI->getCalledFunction();
1013 FunctionType *FT = Callee->getFunctionType();
1014 // Just make sure this has 2 arguments of the same FP type, which match the
1016 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1017 FT->getParamType(0) != FT->getParamType(1) ||
1018 !FT->getParamType(0)->isFloatingPointTy())
1021 // If this is something like 'fmin((double)floatval1, (double)floatval2)',
1022 // or fmin(1.0, (double)floatval), then we convert it to fminf.
1023 Value *V1 = valueHasFloatPrecision(CI->getArgOperand(0));
1026 Value *V2 = valueHasFloatPrecision(CI->getArgOperand(1));
1030 // fmin((double)floatval1, (double)floatval2)
1031 // -> (double)fminf(floatval1, floatval2)
1032 // TODO: Handle intrinsics in the same way as in optimizeUnaryDoubleFP().
1033 Value *V = EmitBinaryFloatFnCall(V1, V2, Callee->getName(), B,
1034 Callee->getAttributes());
1035 return B.CreateFPExt(V, B.getDoubleTy());
1038 Value *LibCallSimplifier::optimizeCos(CallInst *CI, IRBuilder<> &B) {
1039 Function *Callee = CI->getCalledFunction();
1040 Value *Ret = nullptr;
1041 StringRef Name = Callee->getName();
1042 if (UnsafeFPShrink && Name == "cos" && hasFloatVersion(Name))
1043 Ret = optimizeUnaryDoubleFP(CI, B, true);
1045 FunctionType *FT = Callee->getFunctionType();
1046 // Just make sure this has 1 argument of FP type, which matches the
1048 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1049 !FT->getParamType(0)->isFloatingPointTy())
1052 // cos(-x) -> cos(x)
1053 Value *Op1 = CI->getArgOperand(0);
1054 if (BinaryOperator::isFNeg(Op1)) {
1055 BinaryOperator *BinExpr = cast<BinaryOperator>(Op1);
1056 return B.CreateCall(Callee, BinExpr->getOperand(1), "cos");
1061 Value *LibCallSimplifier::optimizePow(CallInst *CI, IRBuilder<> &B) {
1062 Function *Callee = CI->getCalledFunction();
1063 Value *Ret = nullptr;
1064 StringRef Name = Callee->getName();
1065 if (UnsafeFPShrink && Name == "pow" && hasFloatVersion(Name))
1066 Ret = optimizeUnaryDoubleFP(CI, B, true);
1068 FunctionType *FT = Callee->getFunctionType();
1069 // Just make sure this has 2 arguments of the same FP type, which match the
1071 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1072 FT->getParamType(0) != FT->getParamType(1) ||
1073 !FT->getParamType(0)->isFloatingPointTy())
1076 Value *Op1 = CI->getArgOperand(0), *Op2 = CI->getArgOperand(1);
1077 if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
1078 // pow(1.0, x) -> 1.0
1079 if (Op1C->isExactlyValue(1.0))
1081 // pow(2.0, x) -> exp2(x)
1082 if (Op1C->isExactlyValue(2.0) &&
1083 hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp2, LibFunc::exp2f,
1085 return EmitUnaryFloatFnCall(Op2, TLI->getName(LibFunc::exp2), B,
1086 Callee->getAttributes());
1087 // pow(10.0, x) -> exp10(x)
1088 if (Op1C->isExactlyValue(10.0) &&
1089 hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp10, LibFunc::exp10f,
1091 return EmitUnaryFloatFnCall(Op2, TLI->getName(LibFunc::exp10), B,
1092 Callee->getAttributes());
1095 bool unsafeFPMath = canUseUnsafeFPMath(CI->getParent()->getParent());
1097 // pow(exp(x), y) -> exp(x*y)
1098 // pow(exp2(x), y) -> exp2(x * y)
1099 // We enable these only under fast-math. Besides rounding
1100 // differences the transformation changes overflow and
1101 // underflow behavior quite dramatically.
1102 // Example: x = 1000, y = 0.001.
1103 // pow(exp(x), y) = pow(inf, 0.001) = inf, whereas exp(x*y) = exp(1).
1105 if (auto *OpC = dyn_cast<CallInst>(Op1)) {
1106 IRBuilder<>::FastMathFlagGuard Guard(B);
1108 FMF.setUnsafeAlgebra();
1109 B.SetFastMathFlags(FMF);
1112 Function *OpCCallee = OpC->getCalledFunction();
1113 if (OpCCallee && TLI->getLibFunc(OpCCallee->getName(), Func) &&
1114 TLI->has(Func) && (Func == LibFunc::exp || Func == LibFunc::exp2))
1115 return EmitUnaryFloatFnCall(
1116 B.CreateFMul(OpC->getArgOperand(0), Op2, "mul"),
1117 OpCCallee->getName(), B, OpCCallee->getAttributes());
1121 ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
1125 if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
1126 return ConstantFP::get(CI->getType(), 1.0);
1128 if (Op2C->isExactlyValue(0.5) &&
1129 hasUnaryFloatFn(TLI, Op2->getType(), LibFunc::sqrt, LibFunc::sqrtf,
1131 hasUnaryFloatFn(TLI, Op2->getType(), LibFunc::fabs, LibFunc::fabsf,
1134 // In -ffast-math, pow(x, 0.5) -> sqrt(x).
1136 return EmitUnaryFloatFnCall(Op1, TLI->getName(LibFunc::sqrt), B,
1137 Callee->getAttributes());
1139 // Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
1140 // This is faster than calling pow, and still handles negative zero
1141 // and negative infinity correctly.
1142 // TODO: In finite-only mode, this could be just fabs(sqrt(x)).
1143 Value *Inf = ConstantFP::getInfinity(CI->getType());
1144 Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
1145 Value *Sqrt = EmitUnaryFloatFnCall(Op1, "sqrt", B, Callee->getAttributes());
1147 EmitUnaryFloatFnCall(Sqrt, "fabs", B, Callee->getAttributes());
1148 Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf);
1149 Value *Sel = B.CreateSelect(FCmp, Inf, FAbs);
1153 if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
1155 if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
1156 return B.CreateFMul(Op1, Op1, "pow2");
1157 if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
1158 return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0), Op1, "powrecip");
1162 Value *LibCallSimplifier::optimizeExp2(CallInst *CI, IRBuilder<> &B) {
1163 Function *Callee = CI->getCalledFunction();
1164 Function *Caller = CI->getParent()->getParent();
1165 Value *Ret = nullptr;
1166 StringRef Name = Callee->getName();
1167 if (UnsafeFPShrink && Name == "exp2" && hasFloatVersion(Name))
1168 Ret = optimizeUnaryDoubleFP(CI, B, true);
1170 FunctionType *FT = Callee->getFunctionType();
1171 // Just make sure this has 1 argument of FP type, which matches the
1173 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1174 !FT->getParamType(0)->isFloatingPointTy())
1177 Value *Op = CI->getArgOperand(0);
1178 // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
1179 // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
1180 LibFunc::Func LdExp = LibFunc::ldexpl;
1181 if (Op->getType()->isFloatTy())
1182 LdExp = LibFunc::ldexpf;
1183 else if (Op->getType()->isDoubleTy())
1184 LdExp = LibFunc::ldexp;
1186 if (TLI->has(LdExp)) {
1187 Value *LdExpArg = nullptr;
1188 if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
1189 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
1190 LdExpArg = B.CreateSExt(OpC->getOperand(0), B.getInt32Ty());
1191 } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
1192 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
1193 LdExpArg = B.CreateZExt(OpC->getOperand(0), B.getInt32Ty());
1197 Constant *One = ConstantFP::get(CI->getContext(), APFloat(1.0f));
1198 if (!Op->getType()->isFloatTy())
1199 One = ConstantExpr::getFPExtend(One, Op->getType());
1201 Module *M = Caller->getParent();
1203 M->getOrInsertFunction(TLI->getName(LdExp), Op->getType(),
1204 Op->getType(), B.getInt32Ty(), nullptr);
1205 CallInst *CI = B.CreateCall(Callee, {One, LdExpArg});
1206 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
1207 CI->setCallingConv(F->getCallingConv());
1215 Value *LibCallSimplifier::optimizeFabs(CallInst *CI, IRBuilder<> &B) {
1216 Function *Callee = CI->getCalledFunction();
1217 Value *Ret = nullptr;
1218 StringRef Name = Callee->getName();
1219 if (Name == "fabs" && hasFloatVersion(Name))
1220 Ret = optimizeUnaryDoubleFP(CI, B, false);
1222 FunctionType *FT = Callee->getFunctionType();
1223 // Make sure this has 1 argument of FP type which matches the result type.
1224 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1225 !FT->getParamType(0)->isFloatingPointTy())
1228 Value *Op = CI->getArgOperand(0);
1229 if (Instruction *I = dyn_cast<Instruction>(Op)) {
1230 // Fold fabs(x * x) -> x * x; any squared FP value must already be positive.
1231 if (I->getOpcode() == Instruction::FMul)
1232 if (I->getOperand(0) == I->getOperand(1))
1238 Value *LibCallSimplifier::optimizeFMinFMax(CallInst *CI, IRBuilder<> &B) {
1239 // If we can shrink the call to a float function rather than a double
1240 // function, do that first.
1241 Function *Callee = CI->getCalledFunction();
1242 StringRef Name = Callee->getName();
1243 if ((Name == "fmin" && hasFloatVersion(Name)) ||
1244 (Name == "fmax" && hasFloatVersion(Name))) {
1245 Value *Ret = optimizeBinaryDoubleFP(CI, B);
1250 // Make sure this has 2 arguments of FP type which match the result type.
1251 FunctionType *FT = Callee->getFunctionType();
1252 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1253 FT->getParamType(0) != FT->getParamType(1) ||
1254 !FT->getParamType(0)->isFloatingPointTy())
1257 IRBuilder<>::FastMathFlagGuard Guard(B);
1259 Function *F = CI->getParent()->getParent();
1260 if (canUseUnsafeFPMath(F)) {
1261 // Unsafe algebra sets all fast-math-flags to true.
1262 FMF.setUnsafeAlgebra();
1264 // At a minimum, no-nans-fp-math must be true.
1265 Attribute Attr = F->getFnAttribute("no-nans-fp-math");
1266 if (Attr.getValueAsString() != "true")
1268 // No-signed-zeros is implied by the definitions of fmax/fmin themselves:
1269 // "Ideally, fmax would be sensitive to the sign of zero, for example
1270 // fmax(-0. 0, +0. 0) would return +0; however, implementation in software
1271 // might be impractical."
1272 FMF.setNoSignedZeros();
1275 B.SetFastMathFlags(FMF);
1277 // We have a relaxed floating-point environment. We can ignore NaN-handling
1278 // and transform to a compare and select. We do not have to consider errno or
1279 // exceptions, because fmin/fmax do not have those.
1280 Value *Op0 = CI->getArgOperand(0);
1281 Value *Op1 = CI->getArgOperand(1);
1282 Value *Cmp = Callee->getName().startswith("fmin") ?
1283 B.CreateFCmpOLT(Op0, Op1) : B.CreateFCmpOGT(Op0, Op1);
1284 return B.CreateSelect(Cmp, Op0, Op1);
1287 Value *LibCallSimplifier::optimizeSqrt(CallInst *CI, IRBuilder<> &B) {
1288 Function *Callee = CI->getCalledFunction();
1290 Value *Ret = nullptr;
1291 if (TLI->has(LibFunc::sqrtf) && (Callee->getName() == "sqrt" ||
1292 Callee->getIntrinsicID() == Intrinsic::sqrt))
1293 Ret = optimizeUnaryDoubleFP(CI, B, true);
1294 if (!canUseUnsafeFPMath(CI->getParent()->getParent()))
1297 Value *Op = CI->getArgOperand(0);
1298 if (Instruction *I = dyn_cast<Instruction>(Op)) {
1299 if (I->getOpcode() == Instruction::FMul && I->hasUnsafeAlgebra()) {
1300 // We're looking for a repeated factor in a multiplication tree,
1301 // so we can do this fold: sqrt(x * x) -> fabs(x);
1302 // or this fold: sqrt(x * x * y) -> fabs(x) * sqrt(y).
1303 Value *Op0 = I->getOperand(0);
1304 Value *Op1 = I->getOperand(1);
1305 Value *RepeatOp = nullptr;
1306 Value *OtherOp = nullptr;
1308 // Simple match: the operands of the multiply are identical.
1311 // Look for a more complicated pattern: one of the operands is itself
1312 // a multiply, so search for a common factor in that multiply.
1313 // Note: We don't bother looking any deeper than this first level or for
1314 // variations of this pattern because instcombine's visitFMUL and/or the
1315 // reassociation pass should give us this form.
1316 Value *OtherMul0, *OtherMul1;
1317 if (match(Op0, m_FMul(m_Value(OtherMul0), m_Value(OtherMul1)))) {
1318 // Pattern: sqrt((x * y) * z)
1319 if (OtherMul0 == OtherMul1) {
1320 // Matched: sqrt((x * x) * z)
1321 RepeatOp = OtherMul0;
1327 // Fast math flags for any created instructions should match the sqrt
1329 // FIXME: We're not checking the sqrt because it doesn't have
1330 // fast-math-flags (see earlier comment).
1331 IRBuilder<>::FastMathFlagGuard Guard(B);
1332 B.SetFastMathFlags(I->getFastMathFlags());
1333 // If we found a repeated factor, hoist it out of the square root and
1334 // replace it with the fabs of that factor.
1335 Module *M = Callee->getParent();
1336 Type *ArgType = Op->getType();
1337 Value *Fabs = Intrinsic::getDeclaration(M, Intrinsic::fabs, ArgType);
1338 Value *FabsCall = B.CreateCall(Fabs, RepeatOp, "fabs");
1340 // If we found a non-repeated factor, we still need to get its square
1341 // root. We then multiply that by the value that was simplified out
1342 // of the square root calculation.
1343 Value *Sqrt = Intrinsic::getDeclaration(M, Intrinsic::sqrt, ArgType);
1344 Value *SqrtCall = B.CreateCall(Sqrt, OtherOp, "sqrt");
1345 return B.CreateFMul(FabsCall, SqrtCall);
1354 Value *LibCallSimplifier::optimizeTan(CallInst *CI, IRBuilder<> &B) {
1355 Function *Callee = CI->getCalledFunction();
1356 Value *Ret = nullptr;
1357 StringRef Name = Callee->getName();
1358 if (UnsafeFPShrink && Name == "tan" && hasFloatVersion(Name))
1359 Ret = optimizeUnaryDoubleFP(CI, B, true);
1360 FunctionType *FT = Callee->getFunctionType();
1362 // Just make sure this has 1 argument of FP type, which matches the
1364 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1365 !FT->getParamType(0)->isFloatingPointTy())
1368 if (!canUseUnsafeFPMath(CI->getParent()->getParent()))
1370 Value *Op1 = CI->getArgOperand(0);
1371 auto *OpC = dyn_cast<CallInst>(Op1);
1375 // tan(atan(x)) -> x
1376 // tanf(atanf(x)) -> x
1377 // tanl(atanl(x)) -> x
1379 Function *F = OpC->getCalledFunction();
1380 if (F && TLI->getLibFunc(F->getName(), Func) && TLI->has(Func) &&
1381 ((Func == LibFunc::atan && Callee->getName() == "tan") ||
1382 (Func == LibFunc::atanf && Callee->getName() == "tanf") ||
1383 (Func == LibFunc::atanl && Callee->getName() == "tanl")))
1384 Ret = OpC->getArgOperand(0);
1388 static bool isTrigLibCall(CallInst *CI);
1389 static void insertSinCosCall(IRBuilder<> &B, Function *OrigCallee, Value *Arg,
1390 bool UseFloat, Value *&Sin, Value *&Cos,
1393 Value *LibCallSimplifier::optimizeSinCosPi(CallInst *CI, IRBuilder<> &B) {
1395 // Make sure the prototype is as expected, otherwise the rest of the
1396 // function is probably invalid and likely to abort.
1397 if (!isTrigLibCall(CI))
1400 Value *Arg = CI->getArgOperand(0);
1401 SmallVector<CallInst *, 1> SinCalls;
1402 SmallVector<CallInst *, 1> CosCalls;
1403 SmallVector<CallInst *, 1> SinCosCalls;
1405 bool IsFloat = Arg->getType()->isFloatTy();
1407 // Look for all compatible sinpi, cospi and sincospi calls with the same
1408 // argument. If there are enough (in some sense) we can make the
1410 for (User *U : Arg->users())
1411 classifyArgUse(U, CI->getParent(), IsFloat, SinCalls, CosCalls,
1414 // It's only worthwhile if both sinpi and cospi are actually used.
1415 if (SinCosCalls.empty() && (SinCalls.empty() || CosCalls.empty()))
1418 Value *Sin, *Cos, *SinCos;
1419 insertSinCosCall(B, CI->getCalledFunction(), Arg, IsFloat, Sin, Cos, SinCos);
1421 replaceTrigInsts(SinCalls, Sin);
1422 replaceTrigInsts(CosCalls, Cos);
1423 replaceTrigInsts(SinCosCalls, SinCos);
1428 static bool isTrigLibCall(CallInst *CI) {
1429 Function *Callee = CI->getCalledFunction();
1430 FunctionType *FT = Callee->getFunctionType();
1432 // We can only hope to do anything useful if we can ignore things like errno
1433 // and floating-point exceptions.
1434 bool AttributesSafe =
1435 CI->hasFnAttr(Attribute::NoUnwind) && CI->hasFnAttr(Attribute::ReadNone);
1437 // Other than that we need float(float) or double(double)
1438 return AttributesSafe && FT->getNumParams() == 1 &&
1439 FT->getReturnType() == FT->getParamType(0) &&
1440 (FT->getParamType(0)->isFloatTy() ||
1441 FT->getParamType(0)->isDoubleTy());
1445 LibCallSimplifier::classifyArgUse(Value *Val, BasicBlock *BB, bool IsFloat,
1446 SmallVectorImpl<CallInst *> &SinCalls,
1447 SmallVectorImpl<CallInst *> &CosCalls,
1448 SmallVectorImpl<CallInst *> &SinCosCalls) {
1449 CallInst *CI = dyn_cast<CallInst>(Val);
1454 Function *Callee = CI->getCalledFunction();
1456 if (!Callee || !TLI->getLibFunc(Callee->getName(), Func) || !TLI->has(Func) ||
1461 if (Func == LibFunc::sinpif)
1462 SinCalls.push_back(CI);
1463 else if (Func == LibFunc::cospif)
1464 CosCalls.push_back(CI);
1465 else if (Func == LibFunc::sincospif_stret)
1466 SinCosCalls.push_back(CI);
1468 if (Func == LibFunc::sinpi)
1469 SinCalls.push_back(CI);
1470 else if (Func == LibFunc::cospi)
1471 CosCalls.push_back(CI);
1472 else if (Func == LibFunc::sincospi_stret)
1473 SinCosCalls.push_back(CI);
1477 void LibCallSimplifier::replaceTrigInsts(SmallVectorImpl<CallInst *> &Calls,
1479 for (CallInst *C : Calls)
1480 replaceAllUsesWith(C, Res);
1483 void insertSinCosCall(IRBuilder<> &B, Function *OrigCallee, Value *Arg,
1484 bool UseFloat, Value *&Sin, Value *&Cos, Value *&SinCos) {
1485 Type *ArgTy = Arg->getType();
1489 Triple T(OrigCallee->getParent()->getTargetTriple());
1491 Name = "__sincospif_stret";
1493 assert(T.getArch() != Triple::x86 && "x86 messy and unsupported for now");
1494 // x86_64 can't use {float, float} since that would be returned in both
1495 // xmm0 and xmm1, which isn't what a real struct would do.
1496 ResTy = T.getArch() == Triple::x86_64
1497 ? static_cast<Type *>(VectorType::get(ArgTy, 2))
1498 : static_cast<Type *>(StructType::get(ArgTy, ArgTy, nullptr));
1500 Name = "__sincospi_stret";
1501 ResTy = StructType::get(ArgTy, ArgTy, nullptr);
1504 Module *M = OrigCallee->getParent();
1505 Value *Callee = M->getOrInsertFunction(Name, OrigCallee->getAttributes(),
1506 ResTy, ArgTy, nullptr);
1508 if (Instruction *ArgInst = dyn_cast<Instruction>(Arg)) {
1509 // If the argument is an instruction, it must dominate all uses so put our
1510 // sincos call there.
1511 B.SetInsertPoint(ArgInst->getParent(), ++ArgInst->getIterator());
1513 // Otherwise (e.g. for a constant) the beginning of the function is as
1514 // good a place as any.
1515 BasicBlock &EntryBB = B.GetInsertBlock()->getParent()->getEntryBlock();
1516 B.SetInsertPoint(&EntryBB, EntryBB.begin());
1519 SinCos = B.CreateCall(Callee, Arg, "sincospi");
1521 if (SinCos->getType()->isStructTy()) {
1522 Sin = B.CreateExtractValue(SinCos, 0, "sinpi");
1523 Cos = B.CreateExtractValue(SinCos, 1, "cospi");
1525 Sin = B.CreateExtractElement(SinCos, ConstantInt::get(B.getInt32Ty(), 0),
1527 Cos = B.CreateExtractElement(SinCos, ConstantInt::get(B.getInt32Ty(), 1),
1532 //===----------------------------------------------------------------------===//
1533 // Integer Library Call Optimizations
1534 //===----------------------------------------------------------------------===//
1536 static bool checkIntUnaryReturnAndParam(Function *Callee) {
1537 FunctionType *FT = Callee->getFunctionType();
1538 return FT->getNumParams() == 1 && FT->getReturnType()->isIntegerTy(32) &&
1539 FT->getParamType(0)->isIntegerTy();
1542 Value *LibCallSimplifier::optimizeFFS(CallInst *CI, IRBuilder<> &B) {
1543 Function *Callee = CI->getCalledFunction();
1544 if (!checkIntUnaryReturnAndParam(Callee))
1546 Value *Op = CI->getArgOperand(0);
1549 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
1550 if (CI->isZero()) // ffs(0) -> 0.
1551 return B.getInt32(0);
1552 // ffs(c) -> cttz(c)+1
1553 return B.getInt32(CI->getValue().countTrailingZeros() + 1);
1556 // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
1557 Type *ArgType = Op->getType();
1559 Intrinsic::getDeclaration(Callee->getParent(), Intrinsic::cttz, ArgType);
1560 Value *V = B.CreateCall(F, {Op, B.getTrue()}, "cttz");
1561 V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1));
1562 V = B.CreateIntCast(V, B.getInt32Ty(), false);
1564 Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType));
1565 return B.CreateSelect(Cond, V, B.getInt32(0));
1568 Value *LibCallSimplifier::optimizeAbs(CallInst *CI, IRBuilder<> &B) {
1569 Function *Callee = CI->getCalledFunction();
1570 FunctionType *FT = Callee->getFunctionType();
1571 // We require integer(integer) where the types agree.
1572 if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1573 FT->getParamType(0) != FT->getReturnType())
1576 // abs(x) -> x >s -1 ? x : -x
1577 Value *Op = CI->getArgOperand(0);
1579 B.CreateICmpSGT(Op, Constant::getAllOnesValue(Op->getType()), "ispos");
1580 Value *Neg = B.CreateNeg(Op, "neg");
1581 return B.CreateSelect(Pos, Op, Neg);
1584 Value *LibCallSimplifier::optimizeIsDigit(CallInst *CI, IRBuilder<> &B) {
1585 if (!checkIntUnaryReturnAndParam(CI->getCalledFunction()))
1588 // isdigit(c) -> (c-'0') <u 10
1589 Value *Op = CI->getArgOperand(0);
1590 Op = B.CreateSub(Op, B.getInt32('0'), "isdigittmp");
1591 Op = B.CreateICmpULT(Op, B.getInt32(10), "isdigit");
1592 return B.CreateZExt(Op, CI->getType());
1595 Value *LibCallSimplifier::optimizeIsAscii(CallInst *CI, IRBuilder<> &B) {
1596 if (!checkIntUnaryReturnAndParam(CI->getCalledFunction()))
1599 // isascii(c) -> c <u 128
1600 Value *Op = CI->getArgOperand(0);
1601 Op = B.CreateICmpULT(Op, B.getInt32(128), "isascii");
1602 return B.CreateZExt(Op, CI->getType());
1605 Value *LibCallSimplifier::optimizeToAscii(CallInst *CI, IRBuilder<> &B) {
1606 if (!checkIntUnaryReturnAndParam(CI->getCalledFunction()))
1609 // toascii(c) -> c & 0x7f
1610 return B.CreateAnd(CI->getArgOperand(0),
1611 ConstantInt::get(CI->getType(), 0x7F));
1614 //===----------------------------------------------------------------------===//
1615 // Formatting and IO Library Call Optimizations
1616 //===----------------------------------------------------------------------===//
1618 static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg);
1620 Value *LibCallSimplifier::optimizeErrorReporting(CallInst *CI, IRBuilder<> &B,
1622 // Error reporting calls should be cold, mark them as such.
1623 // This applies even to non-builtin calls: it is only a hint and applies to
1624 // functions that the frontend might not understand as builtins.
1626 // This heuristic was suggested in:
1627 // Improving Static Branch Prediction in a Compiler
1628 // Brian L. Deitrich, Ben-Chung Cheng, Wen-mei W. Hwu
1629 // Proceedings of PACT'98, Oct. 1998, IEEE
1630 Function *Callee = CI->getCalledFunction();
1632 if (!CI->hasFnAttr(Attribute::Cold) &&
1633 isReportingError(Callee, CI, StreamArg)) {
1634 CI->addAttribute(AttributeSet::FunctionIndex, Attribute::Cold);
1640 static bool isReportingError(Function *Callee, CallInst *CI, int StreamArg) {
1641 if (!ColdErrorCalls || !Callee || !Callee->isDeclaration())
1647 // These functions might be considered cold, but only if their stream
1648 // argument is stderr.
1650 if (StreamArg >= (int)CI->getNumArgOperands())
1652 LoadInst *LI = dyn_cast<LoadInst>(CI->getArgOperand(StreamArg));
1655 GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getPointerOperand());
1656 if (!GV || !GV->isDeclaration())
1658 return GV->getName() == "stderr";
1661 Value *LibCallSimplifier::optimizePrintFString(CallInst *CI, IRBuilder<> &B) {
1662 // Check for a fixed format string.
1663 StringRef FormatStr;
1664 if (!getConstantStringInfo(CI->getArgOperand(0), FormatStr))
1667 // Empty format string -> noop.
1668 if (FormatStr.empty()) // Tolerate printf's declared void.
1669 return CI->use_empty() ? (Value *)CI : ConstantInt::get(CI->getType(), 0);
1671 // Do not do any of the following transformations if the printf return value
1672 // is used, in general the printf return value is not compatible with either
1673 // putchar() or puts().
1674 if (!CI->use_empty())
1677 // printf("x") -> putchar('x'), even for '%'.
1678 if (FormatStr.size() == 1) {
1679 Value *Res = EmitPutChar(B.getInt32(FormatStr[0]), B, TLI);
1680 if (CI->use_empty() || !Res)
1682 return B.CreateIntCast(Res, CI->getType(), true);
1685 // printf("foo\n") --> puts("foo")
1686 if (FormatStr[FormatStr.size() - 1] == '\n' &&
1687 FormatStr.find('%') == StringRef::npos) { // No format characters.
1688 // Create a string literal with no \n on it. We expect the constant merge
1689 // pass to be run after this pass, to merge duplicate strings.
1690 FormatStr = FormatStr.drop_back();
1691 Value *GV = B.CreateGlobalString(FormatStr, "str");
1692 Value *NewCI = EmitPutS(GV, B, TLI);
1693 return (CI->use_empty() || !NewCI)
1695 : ConstantInt::get(CI->getType(), FormatStr.size() + 1);
1698 // Optimize specific format strings.
1699 // printf("%c", chr) --> putchar(chr)
1700 if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
1701 CI->getArgOperand(1)->getType()->isIntegerTy()) {
1702 Value *Res = EmitPutChar(CI->getArgOperand(1), B, TLI);
1704 if (CI->use_empty() || !Res)
1706 return B.CreateIntCast(Res, CI->getType(), true);
1709 // printf("%s\n", str) --> puts(str)
1710 if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
1711 CI->getArgOperand(1)->getType()->isPointerTy()) {
1712 return EmitPutS(CI->getArgOperand(1), B, TLI);
1717 Value *LibCallSimplifier::optimizePrintF(CallInst *CI, IRBuilder<> &B) {
1719 Function *Callee = CI->getCalledFunction();
1720 // Require one fixed pointer argument and an integer/void result.
1721 FunctionType *FT = Callee->getFunctionType();
1722 if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
1723 !(FT->getReturnType()->isIntegerTy() || FT->getReturnType()->isVoidTy()))
1726 if (Value *V = optimizePrintFString(CI, B)) {
1730 // printf(format, ...) -> iprintf(format, ...) if no floating point
1732 if (TLI->has(LibFunc::iprintf) && !callHasFloatingPointArgument(CI)) {
1733 Module *M = B.GetInsertBlock()->getParent()->getParent();
1734 Constant *IPrintFFn =
1735 M->getOrInsertFunction("iprintf", FT, Callee->getAttributes());
1736 CallInst *New = cast<CallInst>(CI->clone());
1737 New->setCalledFunction(IPrintFFn);
1744 Value *LibCallSimplifier::optimizeSPrintFString(CallInst *CI, IRBuilder<> &B) {
1745 // Check for a fixed format string.
1746 StringRef FormatStr;
1747 if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
1750 // If we just have a format string (nothing else crazy) transform it.
1751 if (CI->getNumArgOperands() == 2) {
1752 // Make sure there's no % in the constant array. We could try to handle
1753 // %% -> % in the future if we cared.
1754 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1755 if (FormatStr[i] == '%')
1756 return nullptr; // we found a format specifier, bail out.
1758 // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1759 B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
1760 ConstantInt::get(DL.getIntPtrType(CI->getContext()),
1761 FormatStr.size() + 1),
1762 1); // Copy the null byte.
1763 return ConstantInt::get(CI->getType(), FormatStr.size());
1766 // The remaining optimizations require the format string to be "%s" or "%c"
1767 // and have an extra operand.
1768 if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1769 CI->getNumArgOperands() < 3)
1772 // Decode the second character of the format string.
1773 if (FormatStr[1] == 'c') {
1774 // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1775 if (!CI->getArgOperand(2)->getType()->isIntegerTy())
1777 Value *V = B.CreateTrunc(CI->getArgOperand(2), B.getInt8Ty(), "char");
1778 Value *Ptr = CastToCStr(CI->getArgOperand(0), B);
1779 B.CreateStore(V, Ptr);
1780 Ptr = B.CreateGEP(B.getInt8Ty(), Ptr, B.getInt32(1), "nul");
1781 B.CreateStore(B.getInt8(0), Ptr);
1783 return ConstantInt::get(CI->getType(), 1);
1786 if (FormatStr[1] == 's') {
1787 // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1788 if (!CI->getArgOperand(2)->getType()->isPointerTy())
1791 Value *Len = EmitStrLen(CI->getArgOperand(2), B, DL, TLI);
1795 B.CreateAdd(Len, ConstantInt::get(Len->getType(), 1), "leninc");
1796 B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(2), IncLen, 1);
1798 // The sprintf result is the unincremented number of bytes in the string.
1799 return B.CreateIntCast(Len, CI->getType(), false);
1804 Value *LibCallSimplifier::optimizeSPrintF(CallInst *CI, IRBuilder<> &B) {
1805 Function *Callee = CI->getCalledFunction();
1806 // Require two fixed pointer arguments and an integer result.
1807 FunctionType *FT = Callee->getFunctionType();
1808 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1809 !FT->getParamType(1)->isPointerTy() ||
1810 !FT->getReturnType()->isIntegerTy())
1813 if (Value *V = optimizeSPrintFString(CI, B)) {
1817 // sprintf(str, format, ...) -> siprintf(str, format, ...) if no floating
1819 if (TLI->has(LibFunc::siprintf) && !callHasFloatingPointArgument(CI)) {
1820 Module *M = B.GetInsertBlock()->getParent()->getParent();
1821 Constant *SIPrintFFn =
1822 M->getOrInsertFunction("siprintf", FT, Callee->getAttributes());
1823 CallInst *New = cast<CallInst>(CI->clone());
1824 New->setCalledFunction(SIPrintFFn);
1831 Value *LibCallSimplifier::optimizeFPrintFString(CallInst *CI, IRBuilder<> &B) {
1832 optimizeErrorReporting(CI, B, 0);
1834 // All the optimizations depend on the format string.
1835 StringRef FormatStr;
1836 if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
1839 // Do not do any of the following transformations if the fprintf return
1840 // value is used, in general the fprintf return value is not compatible
1841 // with fwrite(), fputc() or fputs().
1842 if (!CI->use_empty())
1845 // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1846 if (CI->getNumArgOperands() == 2) {
1847 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1848 if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1849 return nullptr; // We found a format specifier.
1852 CI->getArgOperand(1),
1853 ConstantInt::get(DL.getIntPtrType(CI->getContext()), FormatStr.size()),
1854 CI->getArgOperand(0), B, DL, TLI);
1857 // The remaining optimizations require the format string to be "%s" or "%c"
1858 // and have an extra operand.
1859 if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1860 CI->getNumArgOperands() < 3)
1863 // Decode the second character of the format string.
1864 if (FormatStr[1] == 'c') {
1865 // fprintf(F, "%c", chr) --> fputc(chr, F)
1866 if (!CI->getArgOperand(2)->getType()->isIntegerTy())
1868 return EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, TLI);
1871 if (FormatStr[1] == 's') {
1872 // fprintf(F, "%s", str) --> fputs(str, F)
1873 if (!CI->getArgOperand(2)->getType()->isPointerTy())
1875 return EmitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, TLI);
1880 Value *LibCallSimplifier::optimizeFPrintF(CallInst *CI, IRBuilder<> &B) {
1881 Function *Callee = CI->getCalledFunction();
1882 // Require two fixed paramters as pointers and integer result.
1883 FunctionType *FT = Callee->getFunctionType();
1884 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1885 !FT->getParamType(1)->isPointerTy() ||
1886 !FT->getReturnType()->isIntegerTy())
1889 if (Value *V = optimizeFPrintFString(CI, B)) {
1893 // fprintf(stream, format, ...) -> fiprintf(stream, format, ...) if no
1894 // floating point arguments.
1895 if (TLI->has(LibFunc::fiprintf) && !callHasFloatingPointArgument(CI)) {
1896 Module *M = B.GetInsertBlock()->getParent()->getParent();
1897 Constant *FIPrintFFn =
1898 M->getOrInsertFunction("fiprintf", FT, Callee->getAttributes());
1899 CallInst *New = cast<CallInst>(CI->clone());
1900 New->setCalledFunction(FIPrintFFn);
1907 Value *LibCallSimplifier::optimizeFWrite(CallInst *CI, IRBuilder<> &B) {
1908 optimizeErrorReporting(CI, B, 3);
1910 Function *Callee = CI->getCalledFunction();
1911 // Require a pointer, an integer, an integer, a pointer, returning integer.
1912 FunctionType *FT = Callee->getFunctionType();
1913 if (FT->getNumParams() != 4 || !FT->getParamType(0)->isPointerTy() ||
1914 !FT->getParamType(1)->isIntegerTy() ||
1915 !FT->getParamType(2)->isIntegerTy() ||
1916 !FT->getParamType(3)->isPointerTy() ||
1917 !FT->getReturnType()->isIntegerTy())
1920 // Get the element size and count.
1921 ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
1922 ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
1923 if (!SizeC || !CountC)
1925 uint64_t Bytes = SizeC->getZExtValue() * CountC->getZExtValue();
1927 // If this is writing zero records, remove the call (it's a noop).
1929 return ConstantInt::get(CI->getType(), 0);
1931 // If this is writing one byte, turn it into fputc.
1932 // This optimisation is only valid, if the return value is unused.
1933 if (Bytes == 1 && CI->use_empty()) { // fwrite(S,1,1,F) -> fputc(S[0],F)
1934 Value *Char = B.CreateLoad(CastToCStr(CI->getArgOperand(0), B), "char");
1935 Value *NewCI = EmitFPutC(Char, CI->getArgOperand(3), B, TLI);
1936 return NewCI ? ConstantInt::get(CI->getType(), 1) : nullptr;
1942 Value *LibCallSimplifier::optimizeFPuts(CallInst *CI, IRBuilder<> &B) {
1943 optimizeErrorReporting(CI, B, 1);
1945 Function *Callee = CI->getCalledFunction();
1947 // Require two pointers. Also, we can't optimize if return value is used.
1948 FunctionType *FT = Callee->getFunctionType();
1949 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1950 !FT->getParamType(1)->isPointerTy() || !CI->use_empty())
1953 // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1954 uint64_t Len = GetStringLength(CI->getArgOperand(0));
1958 // Known to have no uses (see above).
1960 CI->getArgOperand(0),
1961 ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len - 1),
1962 CI->getArgOperand(1), B, DL, TLI);
1965 Value *LibCallSimplifier::optimizePuts(CallInst *CI, IRBuilder<> &B) {
1966 Function *Callee = CI->getCalledFunction();
1967 // Require one fixed pointer argument and an integer/void result.
1968 FunctionType *FT = Callee->getFunctionType();
1969 if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
1970 !(FT->getReturnType()->isIntegerTy() || FT->getReturnType()->isVoidTy()))
1973 // Check for a constant string.
1975 if (!getConstantStringInfo(CI->getArgOperand(0), Str))
1978 if (Str.empty() && CI->use_empty()) {
1979 // puts("") -> putchar('\n')
1980 Value *Res = EmitPutChar(B.getInt32('\n'), B, TLI);
1981 if (CI->use_empty() || !Res)
1983 return B.CreateIntCast(Res, CI->getType(), true);
1989 bool LibCallSimplifier::hasFloatVersion(StringRef FuncName) {
1991 SmallString<20> FloatFuncName = FuncName;
1992 FloatFuncName += 'f';
1993 if (TLI->getLibFunc(FloatFuncName, Func))
1994 return TLI->has(Func);
1998 Value *LibCallSimplifier::optimizeStringMemoryLibCall(CallInst *CI,
1999 IRBuilder<> &Builder) {
2001 Function *Callee = CI->getCalledFunction();
2002 StringRef FuncName = Callee->getName();
2004 // Check for string/memory library functions.
2005 if (TLI->getLibFunc(FuncName, Func) && TLI->has(Func)) {
2006 // Make sure we never change the calling convention.
2007 assert((ignoreCallingConv(Func) ||
2008 CI->getCallingConv() == llvm::CallingConv::C) &&
2009 "Optimizing string/memory libcall would change the calling convention");
2011 case LibFunc::strcat:
2012 return optimizeStrCat(CI, Builder);
2013 case LibFunc::strncat:
2014 return optimizeStrNCat(CI, Builder);
2015 case LibFunc::strchr:
2016 return optimizeStrChr(CI, Builder);
2017 case LibFunc::strrchr:
2018 return optimizeStrRChr(CI, Builder);
2019 case LibFunc::strcmp:
2020 return optimizeStrCmp(CI, Builder);
2021 case LibFunc::strncmp:
2022 return optimizeStrNCmp(CI, Builder);
2023 case LibFunc::strcpy:
2024 return optimizeStrCpy(CI, Builder);
2025 case LibFunc::stpcpy:
2026 return optimizeStpCpy(CI, Builder);
2027 case LibFunc::strncpy:
2028 return optimizeStrNCpy(CI, Builder);
2029 case LibFunc::strlen:
2030 return optimizeStrLen(CI, Builder);
2031 case LibFunc::strpbrk:
2032 return optimizeStrPBrk(CI, Builder);
2033 case LibFunc::strtol:
2034 case LibFunc::strtod:
2035 case LibFunc::strtof:
2036 case LibFunc::strtoul:
2037 case LibFunc::strtoll:
2038 case LibFunc::strtold:
2039 case LibFunc::strtoull:
2040 return optimizeStrTo(CI, Builder);
2041 case LibFunc::strspn:
2042 return optimizeStrSpn(CI, Builder);
2043 case LibFunc::strcspn:
2044 return optimizeStrCSpn(CI, Builder);
2045 case LibFunc::strstr:
2046 return optimizeStrStr(CI, Builder);
2047 case LibFunc::memchr:
2048 return optimizeMemChr(CI, Builder);
2049 case LibFunc::memcmp:
2050 return optimizeMemCmp(CI, Builder);
2051 case LibFunc::memcpy:
2052 return optimizeMemCpy(CI, Builder);
2053 case LibFunc::memmove:
2054 return optimizeMemMove(CI, Builder);
2055 case LibFunc::memset:
2056 return optimizeMemSet(CI, Builder);
2064 Value *LibCallSimplifier::optimizeCall(CallInst *CI) {
2065 if (CI->isNoBuiltin())
2069 Function *Callee = CI->getCalledFunction();
2070 StringRef FuncName = Callee->getName();
2071 IRBuilder<> Builder(CI);
2072 bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C;
2074 // Command-line parameter overrides function attribute.
2075 if (EnableUnsafeFPShrink.getNumOccurrences() > 0)
2076 UnsafeFPShrink = EnableUnsafeFPShrink;
2077 else if (canUseUnsafeFPMath(Callee))
2078 UnsafeFPShrink = true;
2080 // First, check for intrinsics.
2081 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI)) {
2082 if (!isCallingConvC)
2084 switch (II->getIntrinsicID()) {
2085 case Intrinsic::pow:
2086 return optimizePow(CI, Builder);
2087 case Intrinsic::exp2:
2088 return optimizeExp2(CI, Builder);
2089 case Intrinsic::fabs:
2090 return optimizeFabs(CI, Builder);
2091 case Intrinsic::sqrt:
2092 return optimizeSqrt(CI, Builder);
2098 // Also try to simplify calls to fortified library functions.
2099 if (Value *SimplifiedFortifiedCI = FortifiedSimplifier.optimizeCall(CI)) {
2100 // Try to further simplify the result.
2101 CallInst *SimplifiedCI = dyn_cast<CallInst>(SimplifiedFortifiedCI);
2102 if (SimplifiedCI && SimplifiedCI->getCalledFunction()) {
2103 // Use an IR Builder from SimplifiedCI if available instead of CI
2104 // to guarantee we reach all uses we might replace later on.
2105 IRBuilder<> TmpBuilder(SimplifiedCI);
2106 if (Value *V = optimizeStringMemoryLibCall(SimplifiedCI, TmpBuilder)) {
2107 // If we were able to further simplify, remove the now redundant call.
2108 SimplifiedCI->replaceAllUsesWith(V);
2109 SimplifiedCI->eraseFromParent();
2113 return SimplifiedFortifiedCI;
2116 // Then check for known library functions.
2117 if (TLI->getLibFunc(FuncName, Func) && TLI->has(Func)) {
2118 // We never change the calling convention.
2119 if (!ignoreCallingConv(Func) && !isCallingConvC)
2121 if (Value *V = optimizeStringMemoryLibCall(CI, Builder))
2127 return optimizeCos(CI, Builder);
2128 case LibFunc::sinpif:
2129 case LibFunc::sinpi:
2130 case LibFunc::cospif:
2131 case LibFunc::cospi:
2132 return optimizeSinCosPi(CI, Builder);
2136 return optimizePow(CI, Builder);
2137 case LibFunc::exp2l:
2139 case LibFunc::exp2f:
2140 return optimizeExp2(CI, Builder);
2141 case LibFunc::fabsf:
2143 case LibFunc::fabsl:
2144 return optimizeFabs(CI, Builder);
2145 case LibFunc::sqrtf:
2147 case LibFunc::sqrtl:
2148 return optimizeSqrt(CI, Builder);
2151 case LibFunc::ffsll:
2152 return optimizeFFS(CI, Builder);
2155 case LibFunc::llabs:
2156 return optimizeAbs(CI, Builder);
2157 case LibFunc::isdigit:
2158 return optimizeIsDigit(CI, Builder);
2159 case LibFunc::isascii:
2160 return optimizeIsAscii(CI, Builder);
2161 case LibFunc::toascii:
2162 return optimizeToAscii(CI, Builder);
2163 case LibFunc::printf:
2164 return optimizePrintF(CI, Builder);
2165 case LibFunc::sprintf:
2166 return optimizeSPrintF(CI, Builder);
2167 case LibFunc::fprintf:
2168 return optimizeFPrintF(CI, Builder);
2169 case LibFunc::fwrite:
2170 return optimizeFWrite(CI, Builder);
2171 case LibFunc::fputs:
2172 return optimizeFPuts(CI, Builder);
2174 return optimizePuts(CI, Builder);
2178 return optimizeTan(CI, Builder);
2179 case LibFunc::perror:
2180 return optimizeErrorReporting(CI, Builder);
2181 case LibFunc::vfprintf:
2182 case LibFunc::fiprintf:
2183 return optimizeErrorReporting(CI, Builder, 0);
2184 case LibFunc::fputc:
2185 return optimizeErrorReporting(CI, Builder, 1);
2187 case LibFunc::floor:
2189 case LibFunc::round:
2190 case LibFunc::nearbyint:
2191 case LibFunc::trunc:
2192 if (hasFloatVersion(FuncName))
2193 return optimizeUnaryDoubleFP(CI, Builder, false);
2196 case LibFunc::acosh:
2198 case LibFunc::asinh:
2200 case LibFunc::atanh:
2204 case LibFunc::exp10:
2205 case LibFunc::expm1:
2207 case LibFunc::log10:
2208 case LibFunc::log1p:
2214 if (UnsafeFPShrink && hasFloatVersion(FuncName))
2215 return optimizeUnaryDoubleFP(CI, Builder, true);
2217 case LibFunc::copysign:
2218 if (hasFloatVersion(FuncName))
2219 return optimizeBinaryDoubleFP(CI, Builder);
2221 case LibFunc::fminf:
2223 case LibFunc::fminl:
2224 case LibFunc::fmaxf:
2226 case LibFunc::fmaxl:
2227 return optimizeFMinFMax(CI, Builder);
2235 LibCallSimplifier::LibCallSimplifier(
2236 const DataLayout &DL, const TargetLibraryInfo *TLI,
2237 function_ref<void(Instruction *, Value *)> Replacer)
2238 : FortifiedSimplifier(TLI), DL(DL), TLI(TLI), UnsafeFPShrink(false),
2239 Replacer(Replacer) {}
2241 void LibCallSimplifier::replaceAllUsesWith(Instruction *I, Value *With) {
2242 // Indirect through the replacer used in this instance.
2247 // Additional cases that we need to add to this file:
2250 // * cbrt(expN(X)) -> expN(x/3)
2251 // * cbrt(sqrt(x)) -> pow(x,1/6)
2252 // * cbrt(cbrt(x)) -> pow(x,1/9)
2255 // * exp(log(x)) -> x
2258 // * log(exp(x)) -> x
2259 // * log(x**y) -> y*log(x)
2260 // * log(exp(y)) -> y*log(e)
2261 // * log(exp2(y)) -> y*log(2)
2262 // * log(exp10(y)) -> y*log(10)
2263 // * log(sqrt(x)) -> 0.5*log(x)
2264 // * log(pow(x,y)) -> y*log(x)
2266 // lround, lroundf, lroundl:
2267 // * lround(cnst) -> cnst'
2270 // * pow(sqrt(x),y) -> pow(x,y*0.5)
2271 // * pow(pow(x,y),z)-> pow(x,y*z)
2273 // round, roundf, roundl:
2274 // * round(cnst) -> cnst'
2277 // * signbit(cnst) -> cnst'
2278 // * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2280 // sqrt, sqrtf, sqrtl:
2281 // * sqrt(expN(x)) -> expN(x*0.5)
2282 // * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2283 // * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2285 // trunc, truncf, truncl:
2286 // * trunc(cnst) -> cnst'
2290 //===----------------------------------------------------------------------===//
2291 // Fortified Library Call Optimizations
2292 //===----------------------------------------------------------------------===//
2294 bool FortifiedLibCallSimplifier::isFortifiedCallFoldable(CallInst *CI,
2298 if (CI->getArgOperand(ObjSizeOp) == CI->getArgOperand(SizeOp))
2300 if (ConstantInt *ObjSizeCI =
2301 dyn_cast<ConstantInt>(CI->getArgOperand(ObjSizeOp))) {
2302 if (ObjSizeCI->isAllOnesValue())
2304 // If the object size wasn't -1 (unknown), bail out if we were asked to.
2305 if (OnlyLowerUnknownSize)
2308 uint64_t Len = GetStringLength(CI->getArgOperand(SizeOp));
2309 // If the length is 0 we don't know how long it is and so we can't
2310 // remove the check.
2313 return ObjSizeCI->getZExtValue() >= Len;
2315 if (ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getArgOperand(SizeOp)))
2316 return ObjSizeCI->getZExtValue() >= SizeCI->getZExtValue();
2321 Value *FortifiedLibCallSimplifier::optimizeMemCpyChk(CallInst *CI, IRBuilder<> &B) {
2322 Function *Callee = CI->getCalledFunction();
2324 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memcpy_chk))
2327 if (isFortifiedCallFoldable(CI, 3, 2, false)) {
2328 B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
2329 CI->getArgOperand(2), 1);
2330 return CI->getArgOperand(0);
2335 Value *FortifiedLibCallSimplifier::optimizeMemMoveChk(CallInst *CI, IRBuilder<> &B) {
2336 Function *Callee = CI->getCalledFunction();
2338 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memmove_chk))
2341 if (isFortifiedCallFoldable(CI, 3, 2, false)) {
2342 B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
2343 CI->getArgOperand(2), 1);
2344 return CI->getArgOperand(0);
2349 Value *FortifiedLibCallSimplifier::optimizeMemSetChk(CallInst *CI, IRBuilder<> &B) {
2350 Function *Callee = CI->getCalledFunction();
2352 if (!checkStringCopyLibFuncSignature(Callee, LibFunc::memset_chk))
2355 if (isFortifiedCallFoldable(CI, 3, 2, false)) {
2356 Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
2357 B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
2358 return CI->getArgOperand(0);
2363 Value *FortifiedLibCallSimplifier::optimizeStrpCpyChk(CallInst *CI,
2365 LibFunc::Func Func) {
2366 Function *Callee = CI->getCalledFunction();
2367 StringRef Name = Callee->getName();
2368 const DataLayout &DL = CI->getModule()->getDataLayout();
2370 if (!checkStringCopyLibFuncSignature(Callee, Func))
2373 Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1),
2374 *ObjSize = CI->getArgOperand(2);
2376 // __stpcpy_chk(x,x,...) -> x+strlen(x)
2377 if (Func == LibFunc::stpcpy_chk && !OnlyLowerUnknownSize && Dst == Src) {
2378 Value *StrLen = EmitStrLen(Src, B, DL, TLI);
2379 return StrLen ? B.CreateInBoundsGEP(B.getInt8Ty(), Dst, StrLen) : nullptr;
2382 // If a) we don't have any length information, or b) we know this will
2383 // fit then just lower to a plain st[rp]cpy. Otherwise we'll keep our
2384 // st[rp]cpy_chk call which may fail at runtime if the size is too long.
2385 // TODO: It might be nice to get a maximum length out of the possible
2386 // string lengths for varying.
2387 if (isFortifiedCallFoldable(CI, 2, 1, true))
2388 return EmitStrCpy(Dst, Src, B, TLI, Name.substr(2, 6));
2390 if (OnlyLowerUnknownSize)
2393 // Maybe we can stil fold __st[rp]cpy_chk to __memcpy_chk.
2394 uint64_t Len = GetStringLength(Src);
2398 Type *SizeTTy = DL.getIntPtrType(CI->getContext());
2399 Value *LenV = ConstantInt::get(SizeTTy, Len);
2400 Value *Ret = EmitMemCpyChk(Dst, Src, LenV, ObjSize, B, DL, TLI);
2401 // If the function was an __stpcpy_chk, and we were able to fold it into
2402 // a __memcpy_chk, we still need to return the correct end pointer.
2403 if (Ret && Func == LibFunc::stpcpy_chk)
2404 return B.CreateGEP(B.getInt8Ty(), Dst, ConstantInt::get(SizeTTy, Len - 1));
2408 Value *FortifiedLibCallSimplifier::optimizeStrpNCpyChk(CallInst *CI,
2410 LibFunc::Func Func) {
2411 Function *Callee = CI->getCalledFunction();
2412 StringRef Name = Callee->getName();
2414 if (!checkStringCopyLibFuncSignature(Callee, Func))
2416 if (isFortifiedCallFoldable(CI, 3, 2, false)) {
2417 Value *Ret = EmitStrNCpy(CI->getArgOperand(0), CI->getArgOperand(1),
2418 CI->getArgOperand(2), B, TLI, Name.substr(2, 7));
2424 Value *FortifiedLibCallSimplifier::optimizeCall(CallInst *CI) {
2425 // FIXME: We shouldn't be changing "nobuiltin" or TLI unavailable calls here.
2426 // Some clang users checked for _chk libcall availability using:
2427 // __has_builtin(__builtin___memcpy_chk)
2428 // When compiling with -fno-builtin, this is always true.
2429 // When passing -ffreestanding/-mkernel, which both imply -fno-builtin, we
2430 // end up with fortified libcalls, which isn't acceptable in a freestanding
2431 // environment which only provides their non-fortified counterparts.
2433 // Until we change clang and/or teach external users to check for availability
2434 // differently, disregard the "nobuiltin" attribute and TLI::has.
2439 Function *Callee = CI->getCalledFunction();
2440 StringRef FuncName = Callee->getName();
2441 IRBuilder<> Builder(CI);
2442 bool isCallingConvC = CI->getCallingConv() == llvm::CallingConv::C;
2444 // First, check that this is a known library functions.
2445 if (!TLI->getLibFunc(FuncName, Func))
2448 // We never change the calling convention.
2449 if (!ignoreCallingConv(Func) && !isCallingConvC)
2453 case LibFunc::memcpy_chk:
2454 return optimizeMemCpyChk(CI, Builder);
2455 case LibFunc::memmove_chk:
2456 return optimizeMemMoveChk(CI, Builder);
2457 case LibFunc::memset_chk:
2458 return optimizeMemSetChk(CI, Builder);
2459 case LibFunc::stpcpy_chk:
2460 case LibFunc::strcpy_chk:
2461 return optimizeStrpCpyChk(CI, Builder, Func);
2462 case LibFunc::stpncpy_chk:
2463 case LibFunc::strncpy_chk:
2464 return optimizeStrpNCpyChk(CI, Builder, Func);
2471 FortifiedLibCallSimplifier::FortifiedLibCallSimplifier(
2472 const TargetLibraryInfo *TLI, bool OnlyLowerUnknownSize)
2473 : TLI(TLI), OnlyLowerUnknownSize(OnlyLowerUnknownSize) {}