1//===------ SimplifyLibCalls.cpp - Library calls simplifier ---------------===//
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 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.
14//
15//===----------------------------------------------------------------------===//
16
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/ValueTracking.h"
22#include "llvm/IR/DataLayout.h"
23#include "llvm/IR/DiagnosticInfo.h"
24#include "llvm/IR/Function.h"
25#include "llvm/IR/IRBuilder.h"
26#include "llvm/IR/IntrinsicInst.h"
27#include "llvm/IR/Intrinsics.h"
28#include "llvm/IR/LLVMContext.h"
29#include "llvm/IR/Module.h"
30#include "llvm/Support/Allocator.h"
31#include "llvm/Support/CommandLine.h"
32#include "llvm/Target/TargetLibraryInfo.h"
33#include "llvm/Transforms/Utils/BuildLibCalls.h"
34
35using namespace llvm;
36
37static cl::opt<bool>
38ColdErrorCalls("error-reporting-is-cold",  cl::init(true),
39  cl::Hidden, cl::desc("Treat error-reporting calls as cold"));
40
41/// This class is the abstract base class for the set of optimizations that
42/// corresponds to one library call.
43namespace {
44class LibCallOptimization {
45protected:
46  Function *Caller;
47  const DataLayout *DL;
48  const TargetLibraryInfo *TLI;
49  const LibCallSimplifier *LCS;
50  LLVMContext* Context;
51public:
52  LibCallOptimization() { }
53  virtual ~LibCallOptimization() {}
54
55  /// callOptimizer - This pure virtual method is implemented by base classes to
56  /// do various optimizations.  If this returns null then no transformation was
57  /// performed.  If it returns CI, then it transformed the call and CI is to be
58  /// deleted.  If it returns something else, replace CI with the new value and
59  /// delete CI.
60  virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B)
61    =0;
62
63  /// ignoreCallingConv - Returns false if this transformation could possibly
64  /// change the calling convention.
65  virtual bool ignoreCallingConv() { return false; }
66
67  Value *optimizeCall(CallInst *CI, const DataLayout *DL,
68                      const TargetLibraryInfo *TLI,
69                      const LibCallSimplifier *LCS, IRBuilder<> &B) {
70    Caller = CI->getParent()->getParent();
71    this->DL = DL;
72    this->TLI = TLI;
73    this->LCS = LCS;
74    if (CI->getCalledFunction())
75      Context = &CI->getCalledFunction()->getContext();
76
77    // We never change the calling convention.
78    if (!ignoreCallingConv() && CI->getCallingConv() != llvm::CallingConv::C)
79      return nullptr;
80
81    return callOptimizer(CI->getCalledFunction(), CI, B);
82  }
83};
84
85//===----------------------------------------------------------------------===//
86// Helper Functions
87//===----------------------------------------------------------------------===//
88
89/// isOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
90/// value is equal or not-equal to zero.
91static bool isOnlyUsedInZeroEqualityComparison(Value *V) {
92  for (User *U : V->users()) {
93    if (ICmpInst *IC = dyn_cast<ICmpInst>(U))
94      if (IC->isEquality())
95        if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
96          if (C->isNullValue())
97            continue;
98    // Unknown instruction.
99    return false;
100  }
101  return true;
102}
103
104/// isOnlyUsedInEqualityComparison - Return true if it is only used in equality
105/// comparisons with With.
106static bool isOnlyUsedInEqualityComparison(Value *V, Value *With) {
107  for (User *U : V->users()) {
108    if (ICmpInst *IC = dyn_cast<ICmpInst>(U))
109      if (IC->isEquality() && IC->getOperand(1) == With)
110        continue;
111    // Unknown instruction.
112    return false;
113  }
114  return true;
115}
116
117static bool callHasFloatingPointArgument(const CallInst *CI) {
118  for (CallInst::const_op_iterator it = CI->op_begin(), e = CI->op_end();
119       it != e; ++it) {
120    if ((*it)->getType()->isFloatingPointTy())
121      return true;
122  }
123  return false;
124}
125
126/// \brief Check whether the overloaded unary floating point function
127/// corresponing to \a Ty is available.
128static bool hasUnaryFloatFn(const TargetLibraryInfo *TLI, Type *Ty,
129                            LibFunc::Func DoubleFn, LibFunc::Func FloatFn,
130                            LibFunc::Func LongDoubleFn) {
131  switch (Ty->getTypeID()) {
132  case Type::FloatTyID:
133    return TLI->has(FloatFn);
134  case Type::DoubleTyID:
135    return TLI->has(DoubleFn);
136  default:
137    return TLI->has(LongDoubleFn);
138  }
139}
140
141//===----------------------------------------------------------------------===//
142// Fortified Library Call Optimizations
143//===----------------------------------------------------------------------===//
144
145struct FortifiedLibCallOptimization : public LibCallOptimization {
146protected:
147  virtual bool isFoldable(unsigned SizeCIOp, unsigned SizeArgOp,
148			  bool isString) const = 0;
149};
150
151struct InstFortifiedLibCallOptimization : public FortifiedLibCallOptimization {
152  CallInst *CI;
153
154  bool isFoldable(unsigned SizeCIOp, unsigned SizeArgOp,
155                  bool isString) const override {
156    if (CI->getArgOperand(SizeCIOp) == CI->getArgOperand(SizeArgOp))
157      return true;
158    if (ConstantInt *SizeCI =
159                           dyn_cast<ConstantInt>(CI->getArgOperand(SizeCIOp))) {
160      if (SizeCI->isAllOnesValue())
161        return true;
162      if (isString) {
163        uint64_t Len = GetStringLength(CI->getArgOperand(SizeArgOp));
164        // If the length is 0 we don't know how long it is and so we can't
165        // remove the check.
166        if (Len == 0) return false;
167        return SizeCI->getZExtValue() >= Len;
168      }
169      if (ConstantInt *Arg = dyn_cast<ConstantInt>(
170                                                  CI->getArgOperand(SizeArgOp)))
171        return SizeCI->getZExtValue() >= Arg->getZExtValue();
172    }
173    return false;
174  }
175};
176
177struct MemCpyChkOpt : public InstFortifiedLibCallOptimization {
178  Value *callOptimizer(Function *Callee, CallInst *CI,
179                       IRBuilder<> &B) override {
180    this->CI = CI;
181    FunctionType *FT = Callee->getFunctionType();
182    LLVMContext &Context = CI->getParent()->getContext();
183
184    // Check if this has the right signature.
185    if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
186        !FT->getParamType(0)->isPointerTy() ||
187        !FT->getParamType(1)->isPointerTy() ||
188        FT->getParamType(2) != DL->getIntPtrType(Context) ||
189        FT->getParamType(3) != DL->getIntPtrType(Context))
190      return nullptr;
191
192    if (isFoldable(3, 2, false)) {
193      B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
194                     CI->getArgOperand(2), 1);
195      return CI->getArgOperand(0);
196    }
197    return nullptr;
198  }
199};
200
201struct MemMoveChkOpt : public InstFortifiedLibCallOptimization {
202  Value *callOptimizer(Function *Callee, CallInst *CI,
203                       IRBuilder<> &B) override {
204    this->CI = CI;
205    FunctionType *FT = Callee->getFunctionType();
206    LLVMContext &Context = CI->getParent()->getContext();
207
208    // Check if this has the right signature.
209    if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
210        !FT->getParamType(0)->isPointerTy() ||
211        !FT->getParamType(1)->isPointerTy() ||
212        FT->getParamType(2) != DL->getIntPtrType(Context) ||
213        FT->getParamType(3) != DL->getIntPtrType(Context))
214      return nullptr;
215
216    if (isFoldable(3, 2, false)) {
217      B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
218                      CI->getArgOperand(2), 1);
219      return CI->getArgOperand(0);
220    }
221    return nullptr;
222  }
223};
224
225struct MemSetChkOpt : public InstFortifiedLibCallOptimization {
226  Value *callOptimizer(Function *Callee, CallInst *CI,
227                       IRBuilder<> &B) override {
228    this->CI = CI;
229    FunctionType *FT = Callee->getFunctionType();
230    LLVMContext &Context = CI->getParent()->getContext();
231
232    // Check if this has the right signature.
233    if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
234        !FT->getParamType(0)->isPointerTy() ||
235        !FT->getParamType(1)->isIntegerTy() ||
236        FT->getParamType(2) != DL->getIntPtrType(Context) ||
237        FT->getParamType(3) != DL->getIntPtrType(Context))
238      return nullptr;
239
240    if (isFoldable(3, 2, false)) {
241      Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(),
242                                   false);
243      B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
244      return CI->getArgOperand(0);
245    }
246    return nullptr;
247  }
248};
249
250struct StrCpyChkOpt : public InstFortifiedLibCallOptimization {
251  Value *callOptimizer(Function *Callee, CallInst *CI,
252                       IRBuilder<> &B) override {
253    this->CI = CI;
254    StringRef Name = Callee->getName();
255    FunctionType *FT = Callee->getFunctionType();
256    LLVMContext &Context = CI->getParent()->getContext();
257
258    // Check if this has the right signature.
259    if (FT->getNumParams() != 3 ||
260        FT->getReturnType() != FT->getParamType(0) ||
261        FT->getParamType(0) != FT->getParamType(1) ||
262        FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
263        FT->getParamType(2) != DL->getIntPtrType(Context))
264      return nullptr;
265
266    Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
267    if (Dst == Src)      // __strcpy_chk(x,x)  -> x
268      return Src;
269
270    // If a) we don't have any length information, or b) we know this will
271    // fit then just lower to a plain strcpy. Otherwise we'll keep our
272    // strcpy_chk call which may fail at runtime if the size is too long.
273    // TODO: It might be nice to get a maximum length out of the possible
274    // string lengths for varying.
275    if (isFoldable(2, 1, true)) {
276      Value *Ret = EmitStrCpy(Dst, Src, B, DL, TLI, Name.substr(2, 6));
277      return Ret;
278    } else {
279      // Maybe we can stil fold __strcpy_chk to __memcpy_chk.
280      uint64_t Len = GetStringLength(Src);
281      if (Len == 0) return nullptr;
282
283      // This optimization require DataLayout.
284      if (!DL) return nullptr;
285
286      Value *Ret =
287	EmitMemCpyChk(Dst, Src,
288                      ConstantInt::get(DL->getIntPtrType(Context), Len),
289                      CI->getArgOperand(2), B, DL, TLI);
290      return Ret;
291    }
292    return nullptr;
293  }
294};
295
296struct StpCpyChkOpt : public InstFortifiedLibCallOptimization {
297  Value *callOptimizer(Function *Callee, CallInst *CI,
298                       IRBuilder<> &B) override {
299    this->CI = CI;
300    StringRef Name = Callee->getName();
301    FunctionType *FT = Callee->getFunctionType();
302    LLVMContext &Context = CI->getParent()->getContext();
303
304    // Check if this has the right signature.
305    if (FT->getNumParams() != 3 ||
306        FT->getReturnType() != FT->getParamType(0) ||
307        FT->getParamType(0) != FT->getParamType(1) ||
308        FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
309        FT->getParamType(2) != DL->getIntPtrType(FT->getParamType(0)))
310      return nullptr;
311
312    Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
313    if (Dst == Src) {  // stpcpy(x,x)  -> x+strlen(x)
314      Value *StrLen = EmitStrLen(Src, B, DL, TLI);
315      return StrLen ? B.CreateInBoundsGEP(Dst, StrLen) : nullptr;
316    }
317
318    // If a) we don't have any length information, or b) we know this will
319    // fit then just lower to a plain stpcpy. Otherwise we'll keep our
320    // stpcpy_chk call which may fail at runtime if the size is too long.
321    // TODO: It might be nice to get a maximum length out of the possible
322    // string lengths for varying.
323    if (isFoldable(2, 1, true)) {
324      Value *Ret = EmitStrCpy(Dst, Src, B, DL, TLI, Name.substr(2, 6));
325      return Ret;
326    } else {
327      // Maybe we can stil fold __stpcpy_chk to __memcpy_chk.
328      uint64_t Len = GetStringLength(Src);
329      if (Len == 0) return nullptr;
330
331      // This optimization require DataLayout.
332      if (!DL) return nullptr;
333
334      Type *PT = FT->getParamType(0);
335      Value *LenV = ConstantInt::get(DL->getIntPtrType(PT), Len);
336      Value *DstEnd = B.CreateGEP(Dst,
337                                  ConstantInt::get(DL->getIntPtrType(PT),
338                                                   Len - 1));
339      if (!EmitMemCpyChk(Dst, Src, LenV, CI->getArgOperand(2), B, DL, TLI))
340        return nullptr;
341      return DstEnd;
342    }
343    return nullptr;
344  }
345};
346
347struct StrNCpyChkOpt : public InstFortifiedLibCallOptimization {
348  Value *callOptimizer(Function *Callee, CallInst *CI,
349                       IRBuilder<> &B) override {
350    this->CI = CI;
351    StringRef Name = Callee->getName();
352    FunctionType *FT = Callee->getFunctionType();
353    LLVMContext &Context = CI->getParent()->getContext();
354
355    // Check if this has the right signature.
356    if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
357        FT->getParamType(0) != FT->getParamType(1) ||
358        FT->getParamType(0) != Type::getInt8PtrTy(Context) ||
359        !FT->getParamType(2)->isIntegerTy() ||
360        FT->getParamType(3) != DL->getIntPtrType(Context))
361      return nullptr;
362
363    if (isFoldable(3, 2, false)) {
364      Value *Ret = EmitStrNCpy(CI->getArgOperand(0), CI->getArgOperand(1),
365                               CI->getArgOperand(2), B, DL, TLI,
366                               Name.substr(2, 7));
367      return Ret;
368    }
369    return nullptr;
370  }
371};
372
373//===----------------------------------------------------------------------===//
374// String and Memory Library Call Optimizations
375//===----------------------------------------------------------------------===//
376
377struct StrCatOpt : public LibCallOptimization {
378  Value *callOptimizer(Function *Callee, CallInst *CI,
379                       IRBuilder<> &B) override {
380    // Verify the "strcat" function prototype.
381    FunctionType *FT = Callee->getFunctionType();
382    if (FT->getNumParams() != 2 ||
383        FT->getReturnType() != B.getInt8PtrTy() ||
384        FT->getParamType(0) != FT->getReturnType() ||
385        FT->getParamType(1) != FT->getReturnType())
386      return nullptr;
387
388    // Extract some information from the instruction
389    Value *Dst = CI->getArgOperand(0);
390    Value *Src = CI->getArgOperand(1);
391
392    // See if we can get the length of the input string.
393    uint64_t Len = GetStringLength(Src);
394    if (Len == 0) return nullptr;
395    --Len;  // Unbias length.
396
397    // Handle the simple, do-nothing case: strcat(x, "") -> x
398    if (Len == 0)
399      return Dst;
400
401    // These optimizations require DataLayout.
402    if (!DL) return nullptr;
403
404    return emitStrLenMemCpy(Src, Dst, Len, B);
405  }
406
407  Value *emitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len,
408                          IRBuilder<> &B) {
409    // We need to find the end of the destination string.  That's where the
410    // memory is to be moved to. We just generate a call to strlen.
411    Value *DstLen = EmitStrLen(Dst, B, DL, TLI);
412    if (!DstLen)
413      return nullptr;
414
415    // Now that we have the destination's length, we must index into the
416    // destination's pointer to get the actual memcpy destination (end of
417    // the string .. we're concatenating).
418    Value *CpyDst = B.CreateGEP(Dst, DstLen, "endptr");
419
420    // We have enough information to now generate the memcpy call to do the
421    // concatenation for us.  Make a memcpy to copy the nul byte with align = 1.
422    B.CreateMemCpy(CpyDst, Src,
423                   ConstantInt::get(DL->getIntPtrType(*Context), Len + 1), 1);
424    return Dst;
425  }
426};
427
428struct StrNCatOpt : public StrCatOpt {
429  Value *callOptimizer(Function *Callee, CallInst *CI,
430                       IRBuilder<> &B) override {
431    // Verify the "strncat" function prototype.
432    FunctionType *FT = Callee->getFunctionType();
433    if (FT->getNumParams() != 3 ||
434        FT->getReturnType() != B.getInt8PtrTy() ||
435        FT->getParamType(0) != FT->getReturnType() ||
436        FT->getParamType(1) != FT->getReturnType() ||
437        !FT->getParamType(2)->isIntegerTy())
438      return nullptr;
439
440    // Extract some information from the instruction
441    Value *Dst = CI->getArgOperand(0);
442    Value *Src = CI->getArgOperand(1);
443    uint64_t Len;
444
445    // We don't do anything if length is not constant
446    if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
447      Len = LengthArg->getZExtValue();
448    else
449      return nullptr;
450
451    // See if we can get the length of the input string.
452    uint64_t SrcLen = GetStringLength(Src);
453    if (SrcLen == 0) return nullptr;
454    --SrcLen;  // Unbias length.
455
456    // Handle the simple, do-nothing cases:
457    // strncat(x, "", c) -> x
458    // strncat(x,  c, 0) -> x
459    if (SrcLen == 0 || Len == 0) return Dst;
460
461    // These optimizations require DataLayout.
462    if (!DL) return nullptr;
463
464    // We don't optimize this case
465    if (Len < SrcLen) return nullptr;
466
467    // strncat(x, s, c) -> strcat(x, s)
468    // s is constant so the strcat can be optimized further
469    return emitStrLenMemCpy(Src, Dst, SrcLen, B);
470  }
471};
472
473struct StrChrOpt : public LibCallOptimization {
474  Value *callOptimizer(Function *Callee, CallInst *CI,
475                       IRBuilder<> &B) override {
476    // Verify the "strchr" function prototype.
477    FunctionType *FT = Callee->getFunctionType();
478    if (FT->getNumParams() != 2 ||
479        FT->getReturnType() != B.getInt8PtrTy() ||
480        FT->getParamType(0) != FT->getReturnType() ||
481        !FT->getParamType(1)->isIntegerTy(32))
482      return nullptr;
483
484    Value *SrcStr = CI->getArgOperand(0);
485
486    // If the second operand is non-constant, see if we can compute the length
487    // of the input string and turn this into memchr.
488    ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
489    if (!CharC) {
490      // These optimizations require DataLayout.
491      if (!DL) return nullptr;
492
493      uint64_t Len = GetStringLength(SrcStr);
494      if (Len == 0 || !FT->getParamType(1)->isIntegerTy(32))// memchr needs i32.
495        return nullptr;
496
497      return EmitMemChr(SrcStr, CI->getArgOperand(1), // include nul.
498                        ConstantInt::get(DL->getIntPtrType(*Context), Len),
499                        B, DL, TLI);
500    }
501
502    // Otherwise, the character is a constant, see if the first argument is
503    // a string literal.  If so, we can constant fold.
504    StringRef Str;
505    if (!getConstantStringInfo(SrcStr, Str)) {
506      if (DL && CharC->isZero()) // strchr(p, 0) -> p + strlen(p)
507        return B.CreateGEP(SrcStr, EmitStrLen(SrcStr, B, DL, TLI), "strchr");
508      return nullptr;
509    }
510
511    // Compute the offset, make sure to handle the case when we're searching for
512    // zero (a weird way to spell strlen).
513    size_t I = (0xFF & CharC->getSExtValue()) == 0 ?
514        Str.size() : Str.find(CharC->getSExtValue());
515    if (I == StringRef::npos) // Didn't find the char.  strchr returns null.
516      return Constant::getNullValue(CI->getType());
517
518    // strchr(s+n,c)  -> gep(s+n+i,c)
519    return B.CreateGEP(SrcStr, B.getInt64(I), "strchr");
520  }
521};
522
523struct StrRChrOpt : public LibCallOptimization {
524  Value *callOptimizer(Function *Callee, CallInst *CI,
525                       IRBuilder<> &B) override {
526    // Verify the "strrchr" function prototype.
527    FunctionType *FT = Callee->getFunctionType();
528    if (FT->getNumParams() != 2 ||
529        FT->getReturnType() != B.getInt8PtrTy() ||
530        FT->getParamType(0) != FT->getReturnType() ||
531        !FT->getParamType(1)->isIntegerTy(32))
532      return nullptr;
533
534    Value *SrcStr = CI->getArgOperand(0);
535    ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
536
537    // Cannot fold anything if we're not looking for a constant.
538    if (!CharC)
539      return nullptr;
540
541    StringRef Str;
542    if (!getConstantStringInfo(SrcStr, Str)) {
543      // strrchr(s, 0) -> strchr(s, 0)
544      if (DL && CharC->isZero())
545        return EmitStrChr(SrcStr, '\0', B, DL, TLI);
546      return nullptr;
547    }
548
549    // Compute the offset.
550    size_t I = (0xFF & CharC->getSExtValue()) == 0 ?
551        Str.size() : Str.rfind(CharC->getSExtValue());
552    if (I == StringRef::npos) // Didn't find the char. Return null.
553      return Constant::getNullValue(CI->getType());
554
555    // strrchr(s+n,c) -> gep(s+n+i,c)
556    return B.CreateGEP(SrcStr, B.getInt64(I), "strrchr");
557  }
558};
559
560struct StrCmpOpt : public LibCallOptimization {
561  Value *callOptimizer(Function *Callee, CallInst *CI,
562                       IRBuilder<> &B) override {
563    // Verify the "strcmp" function prototype.
564    FunctionType *FT = Callee->getFunctionType();
565    if (FT->getNumParams() != 2 ||
566        !FT->getReturnType()->isIntegerTy(32) ||
567        FT->getParamType(0) != FT->getParamType(1) ||
568        FT->getParamType(0) != B.getInt8PtrTy())
569      return nullptr;
570
571    Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
572    if (Str1P == Str2P)      // strcmp(x,x)  -> 0
573      return ConstantInt::get(CI->getType(), 0);
574
575    StringRef Str1, Str2;
576    bool HasStr1 = getConstantStringInfo(Str1P, Str1);
577    bool HasStr2 = getConstantStringInfo(Str2P, Str2);
578
579    // strcmp(x, y)  -> cnst  (if both x and y are constant strings)
580    if (HasStr1 && HasStr2)
581      return ConstantInt::get(CI->getType(), Str1.compare(Str2));
582
583    if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x
584      return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
585                                      CI->getType()));
586
587    if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
588      return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
589
590    // strcmp(P, "x") -> memcmp(P, "x", 2)
591    uint64_t Len1 = GetStringLength(Str1P);
592    uint64_t Len2 = GetStringLength(Str2P);
593    if (Len1 && Len2) {
594      // These optimizations require DataLayout.
595      if (!DL) return nullptr;
596
597      return EmitMemCmp(Str1P, Str2P,
598                        ConstantInt::get(DL->getIntPtrType(*Context),
599                        std::min(Len1, Len2)), B, DL, TLI);
600    }
601
602    return nullptr;
603  }
604};
605
606struct StrNCmpOpt : public LibCallOptimization {
607  Value *callOptimizer(Function *Callee, CallInst *CI,
608                       IRBuilder<> &B) override {
609    // Verify the "strncmp" function prototype.
610    FunctionType *FT = Callee->getFunctionType();
611    if (FT->getNumParams() != 3 ||
612        !FT->getReturnType()->isIntegerTy(32) ||
613        FT->getParamType(0) != FT->getParamType(1) ||
614        FT->getParamType(0) != B.getInt8PtrTy() ||
615        !FT->getParamType(2)->isIntegerTy())
616      return nullptr;
617
618    Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
619    if (Str1P == Str2P)      // strncmp(x,x,n)  -> 0
620      return ConstantInt::get(CI->getType(), 0);
621
622    // Get the length argument if it is constant.
623    uint64_t Length;
624    if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
625      Length = LengthArg->getZExtValue();
626    else
627      return nullptr;
628
629    if (Length == 0) // strncmp(x,y,0)   -> 0
630      return ConstantInt::get(CI->getType(), 0);
631
632    if (DL && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
633      return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, DL, TLI);
634
635    StringRef Str1, Str2;
636    bool HasStr1 = getConstantStringInfo(Str1P, Str1);
637    bool HasStr2 = getConstantStringInfo(Str2P, Str2);
638
639    // strncmp(x, y)  -> cnst  (if both x and y are constant strings)
640    if (HasStr1 && HasStr2) {
641      StringRef SubStr1 = Str1.substr(0, Length);
642      StringRef SubStr2 = Str2.substr(0, Length);
643      return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2));
644    }
645
646    if (HasStr1 && Str1.empty())  // strncmp("", x, n) -> -*x
647      return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
648                                      CI->getType()));
649
650    if (HasStr2 && Str2.empty())  // strncmp(x, "", n) -> *x
651      return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
652
653    return nullptr;
654  }
655};
656
657struct StrCpyOpt : public LibCallOptimization {
658  Value *callOptimizer(Function *Callee, CallInst *CI,
659                       IRBuilder<> &B) override {
660    // Verify the "strcpy" function prototype.
661    FunctionType *FT = Callee->getFunctionType();
662    if (FT->getNumParams() != 2 ||
663        FT->getReturnType() != FT->getParamType(0) ||
664        FT->getParamType(0) != FT->getParamType(1) ||
665        FT->getParamType(0) != B.getInt8PtrTy())
666      return nullptr;
667
668    Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
669    if (Dst == Src)      // strcpy(x,x)  -> x
670      return Src;
671
672    // These optimizations require DataLayout.
673    if (!DL) return nullptr;
674
675    // See if we can get the length of the input string.
676    uint64_t Len = GetStringLength(Src);
677    if (Len == 0) return nullptr;
678
679    // We have enough information to now generate the memcpy call to do the
680    // copy for us.  Make a memcpy to copy the nul byte with align = 1.
681    B.CreateMemCpy(Dst, Src,
682		   ConstantInt::get(DL->getIntPtrType(*Context), Len), 1);
683    return Dst;
684  }
685};
686
687struct StpCpyOpt: public LibCallOptimization {
688  Value *callOptimizer(Function *Callee, CallInst *CI,
689                       IRBuilder<> &B) override {
690    // Verify the "stpcpy" function prototype.
691    FunctionType *FT = Callee->getFunctionType();
692    if (FT->getNumParams() != 2 ||
693        FT->getReturnType() != FT->getParamType(0) ||
694        FT->getParamType(0) != FT->getParamType(1) ||
695        FT->getParamType(0) != B.getInt8PtrTy())
696      return nullptr;
697
698    // These optimizations require DataLayout.
699    if (!DL) return nullptr;
700
701    Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
702    if (Dst == Src) {  // stpcpy(x,x)  -> x+strlen(x)
703      Value *StrLen = EmitStrLen(Src, B, DL, TLI);
704      return StrLen ? B.CreateInBoundsGEP(Dst, StrLen) : nullptr;
705    }
706
707    // See if we can get the length of the input string.
708    uint64_t Len = GetStringLength(Src);
709    if (Len == 0) return nullptr;
710
711    Type *PT = FT->getParamType(0);
712    Value *LenV = ConstantInt::get(DL->getIntPtrType(PT), Len);
713    Value *DstEnd = B.CreateGEP(Dst,
714                                ConstantInt::get(DL->getIntPtrType(PT),
715                                                 Len - 1));
716
717    // We have enough information to now generate the memcpy call to do the
718    // copy for us.  Make a memcpy to copy the nul byte with align = 1.
719    B.CreateMemCpy(Dst, Src, LenV, 1);
720    return DstEnd;
721  }
722};
723
724struct StrNCpyOpt : public LibCallOptimization {
725  Value *callOptimizer(Function *Callee, CallInst *CI,
726                       IRBuilder<> &B) override {
727    FunctionType *FT = Callee->getFunctionType();
728    if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
729        FT->getParamType(0) != FT->getParamType(1) ||
730        FT->getParamType(0) != B.getInt8PtrTy() ||
731        !FT->getParamType(2)->isIntegerTy())
732      return nullptr;
733
734    Value *Dst = CI->getArgOperand(0);
735    Value *Src = CI->getArgOperand(1);
736    Value *LenOp = CI->getArgOperand(2);
737
738    // See if we can get the length of the input string.
739    uint64_t SrcLen = GetStringLength(Src);
740    if (SrcLen == 0) return nullptr;
741    --SrcLen;
742
743    if (SrcLen == 0) {
744      // strncpy(x, "", y) -> memset(x, '\0', y, 1)
745      B.CreateMemSet(Dst, B.getInt8('\0'), LenOp, 1);
746      return Dst;
747    }
748
749    uint64_t Len;
750    if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
751      Len = LengthArg->getZExtValue();
752    else
753      return nullptr;
754
755    if (Len == 0) return Dst; // strncpy(x, y, 0) -> x
756
757    // These optimizations require DataLayout.
758    if (!DL) return nullptr;
759
760    // Let strncpy handle the zero padding
761    if (Len > SrcLen+1) return nullptr;
762
763    Type *PT = FT->getParamType(0);
764    // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
765    B.CreateMemCpy(Dst, Src,
766                   ConstantInt::get(DL->getIntPtrType(PT), Len), 1);
767
768    return Dst;
769  }
770};
771
772struct StrLenOpt : public LibCallOptimization {
773  bool ignoreCallingConv() override { return true; }
774  Value *callOptimizer(Function *Callee, CallInst *CI,
775                       IRBuilder<> &B) override {
776    FunctionType *FT = Callee->getFunctionType();
777    if (FT->getNumParams() != 1 ||
778        FT->getParamType(0) != B.getInt8PtrTy() ||
779        !FT->getReturnType()->isIntegerTy())
780      return nullptr;
781
782    Value *Src = CI->getArgOperand(0);
783
784    // Constant folding: strlen("xyz") -> 3
785    if (uint64_t Len = GetStringLength(Src))
786      return ConstantInt::get(CI->getType(), Len-1);
787
788    // strlen(x?"foo":"bars") --> x ? 3 : 4
789    if (SelectInst *SI = dyn_cast<SelectInst>(Src)) {
790      uint64_t LenTrue = GetStringLength(SI->getTrueValue());
791      uint64_t LenFalse = GetStringLength(SI->getFalseValue());
792      if (LenTrue && LenFalse) {
793        emitOptimizationRemark(*Context, "simplify-libcalls", *Caller,
794                               SI->getDebugLoc(),
795                               "folded strlen(select) to select of constants");
796        return B.CreateSelect(SI->getCondition(),
797                              ConstantInt::get(CI->getType(), LenTrue-1),
798                              ConstantInt::get(CI->getType(), LenFalse-1));
799      }
800    }
801
802    // strlen(x) != 0 --> *x != 0
803    // strlen(x) == 0 --> *x == 0
804    if (isOnlyUsedInZeroEqualityComparison(CI))
805      return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
806
807    return nullptr;
808  }
809};
810
811struct StrPBrkOpt : public LibCallOptimization {
812  Value *callOptimizer(Function *Callee, CallInst *CI,
813                       IRBuilder<> &B) override {
814    FunctionType *FT = Callee->getFunctionType();
815    if (FT->getNumParams() != 2 ||
816        FT->getParamType(0) != B.getInt8PtrTy() ||
817        FT->getParamType(1) != FT->getParamType(0) ||
818        FT->getReturnType() != FT->getParamType(0))
819      return nullptr;
820
821    StringRef S1, S2;
822    bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
823    bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
824
825    // strpbrk(s, "") -> NULL
826    // strpbrk("", s) -> NULL
827    if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
828      return Constant::getNullValue(CI->getType());
829
830    // Constant folding.
831    if (HasS1 && HasS2) {
832      size_t I = S1.find_first_of(S2);
833      if (I == StringRef::npos) // No match.
834        return Constant::getNullValue(CI->getType());
835
836      return B.CreateGEP(CI->getArgOperand(0), B.getInt64(I), "strpbrk");
837    }
838
839    // strpbrk(s, "a") -> strchr(s, 'a')
840    if (DL && HasS2 && S2.size() == 1)
841      return EmitStrChr(CI->getArgOperand(0), S2[0], B, DL, TLI);
842
843    return nullptr;
844  }
845};
846
847struct StrToOpt : public LibCallOptimization {
848  Value *callOptimizer(Function *Callee, CallInst *CI,
849                       IRBuilder<> &B) override {
850    FunctionType *FT = Callee->getFunctionType();
851    if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
852        !FT->getParamType(0)->isPointerTy() ||
853        !FT->getParamType(1)->isPointerTy())
854      return nullptr;
855
856    Value *EndPtr = CI->getArgOperand(1);
857    if (isa<ConstantPointerNull>(EndPtr)) {
858      // With a null EndPtr, this function won't capture the main argument.
859      // It would be readonly too, except that it still may write to errno.
860      CI->addAttribute(1, Attribute::NoCapture);
861    }
862
863    return nullptr;
864  }
865};
866
867struct StrSpnOpt : public LibCallOptimization {
868  Value *callOptimizer(Function *Callee, CallInst *CI,
869                       IRBuilder<> &B) override {
870    FunctionType *FT = Callee->getFunctionType();
871    if (FT->getNumParams() != 2 ||
872        FT->getParamType(0) != B.getInt8PtrTy() ||
873        FT->getParamType(1) != FT->getParamType(0) ||
874        !FT->getReturnType()->isIntegerTy())
875      return nullptr;
876
877    StringRef S1, S2;
878    bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
879    bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
880
881    // strspn(s, "") -> 0
882    // strspn("", s) -> 0
883    if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
884      return Constant::getNullValue(CI->getType());
885
886    // Constant folding.
887    if (HasS1 && HasS2) {
888      size_t Pos = S1.find_first_not_of(S2);
889      if (Pos == StringRef::npos) Pos = S1.size();
890      return ConstantInt::get(CI->getType(), Pos);
891    }
892
893    return nullptr;
894  }
895};
896
897struct StrCSpnOpt : public LibCallOptimization {
898  Value *callOptimizer(Function *Callee, CallInst *CI,
899                       IRBuilder<> &B) override {
900    FunctionType *FT = Callee->getFunctionType();
901    if (FT->getNumParams() != 2 ||
902        FT->getParamType(0) != B.getInt8PtrTy() ||
903        FT->getParamType(1) != FT->getParamType(0) ||
904        !FT->getReturnType()->isIntegerTy())
905      return nullptr;
906
907    StringRef S1, S2;
908    bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
909    bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
910
911    // strcspn("", s) -> 0
912    if (HasS1 && S1.empty())
913      return Constant::getNullValue(CI->getType());
914
915    // Constant folding.
916    if (HasS1 && HasS2) {
917      size_t Pos = S1.find_first_of(S2);
918      if (Pos == StringRef::npos) Pos = S1.size();
919      return ConstantInt::get(CI->getType(), Pos);
920    }
921
922    // strcspn(s, "") -> strlen(s)
923    if (DL && HasS2 && S2.empty())
924      return EmitStrLen(CI->getArgOperand(0), B, DL, TLI);
925
926    return nullptr;
927  }
928};
929
930struct StrStrOpt : public LibCallOptimization {
931  Value *callOptimizer(Function *Callee, CallInst *CI,
932                       IRBuilder<> &B) override {
933    FunctionType *FT = Callee->getFunctionType();
934    if (FT->getNumParams() != 2 ||
935        !FT->getParamType(0)->isPointerTy() ||
936        !FT->getParamType(1)->isPointerTy() ||
937        !FT->getReturnType()->isPointerTy())
938      return nullptr;
939
940    // fold strstr(x, x) -> x.
941    if (CI->getArgOperand(0) == CI->getArgOperand(1))
942      return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
943
944    // fold strstr(a, b) == a -> strncmp(a, b, strlen(b)) == 0
945    if (DL && isOnlyUsedInEqualityComparison(CI, CI->getArgOperand(0))) {
946      Value *StrLen = EmitStrLen(CI->getArgOperand(1), B, DL, TLI);
947      if (!StrLen)
948        return nullptr;
949      Value *StrNCmp = EmitStrNCmp(CI->getArgOperand(0), CI->getArgOperand(1),
950                                   StrLen, B, DL, TLI);
951      if (!StrNCmp)
952        return nullptr;
953      for (auto UI = CI->user_begin(), UE = CI->user_end(); UI != UE;) {
954        ICmpInst *Old = cast<ICmpInst>(*UI++);
955        Value *Cmp = B.CreateICmp(Old->getPredicate(), StrNCmp,
956                                  ConstantInt::getNullValue(StrNCmp->getType()),
957                                  "cmp");
958        LCS->replaceAllUsesWith(Old, Cmp);
959      }
960      return CI;
961    }
962
963    // See if either input string is a constant string.
964    StringRef SearchStr, ToFindStr;
965    bool HasStr1 = getConstantStringInfo(CI->getArgOperand(0), SearchStr);
966    bool HasStr2 = getConstantStringInfo(CI->getArgOperand(1), ToFindStr);
967
968    // fold strstr(x, "") -> x.
969    if (HasStr2 && ToFindStr.empty())
970      return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
971
972    // If both strings are known, constant fold it.
973    if (HasStr1 && HasStr2) {
974      size_t Offset = SearchStr.find(ToFindStr);
975
976      if (Offset == StringRef::npos) // strstr("foo", "bar") -> null
977        return Constant::getNullValue(CI->getType());
978
979      // strstr("abcd", "bc") -> gep((char*)"abcd", 1)
980      Value *Result = CastToCStr(CI->getArgOperand(0), B);
981      Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
982      return B.CreateBitCast(Result, CI->getType());
983    }
984
985    // fold strstr(x, "y") -> strchr(x, 'y').
986    if (HasStr2 && ToFindStr.size() == 1) {
987      Value *StrChr= EmitStrChr(CI->getArgOperand(0), ToFindStr[0], B, DL, TLI);
988      return StrChr ? B.CreateBitCast(StrChr, CI->getType()) : nullptr;
989    }
990    return nullptr;
991  }
992};
993
994struct MemCmpOpt : public LibCallOptimization {
995  Value *callOptimizer(Function *Callee, CallInst *CI,
996                       IRBuilder<> &B) override {
997    FunctionType *FT = Callee->getFunctionType();
998    if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() ||
999        !FT->getParamType(1)->isPointerTy() ||
1000        !FT->getReturnType()->isIntegerTy(32))
1001      return nullptr;
1002
1003    Value *LHS = CI->getArgOperand(0), *RHS = CI->getArgOperand(1);
1004
1005    if (LHS == RHS)  // memcmp(s,s,x) -> 0
1006      return Constant::getNullValue(CI->getType());
1007
1008    // Make sure we have a constant length.
1009    ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
1010    if (!LenC) return nullptr;
1011    uint64_t Len = LenC->getZExtValue();
1012
1013    if (Len == 0) // memcmp(s1,s2,0) -> 0
1014      return Constant::getNullValue(CI->getType());
1015
1016    // memcmp(S1,S2,1) -> *(unsigned char*)LHS - *(unsigned char*)RHS
1017    if (Len == 1) {
1018      Value *LHSV = B.CreateZExt(B.CreateLoad(CastToCStr(LHS, B), "lhsc"),
1019                                 CI->getType(), "lhsv");
1020      Value *RHSV = B.CreateZExt(B.CreateLoad(CastToCStr(RHS, B), "rhsc"),
1021                                 CI->getType(), "rhsv");
1022      return B.CreateSub(LHSV, RHSV, "chardiff");
1023    }
1024
1025    // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
1026    StringRef LHSStr, RHSStr;
1027    if (getConstantStringInfo(LHS, LHSStr) &&
1028        getConstantStringInfo(RHS, RHSStr)) {
1029      // Make sure we're not reading out-of-bounds memory.
1030      if (Len > LHSStr.size() || Len > RHSStr.size())
1031        return nullptr;
1032      // Fold the memcmp and normalize the result.  This way we get consistent
1033      // results across multiple platforms.
1034      uint64_t Ret = 0;
1035      int Cmp = memcmp(LHSStr.data(), RHSStr.data(), Len);
1036      if (Cmp < 0)
1037        Ret = -1;
1038      else if (Cmp > 0)
1039        Ret = 1;
1040      return ConstantInt::get(CI->getType(), Ret);
1041    }
1042
1043    return nullptr;
1044  }
1045};
1046
1047struct MemCpyOpt : public LibCallOptimization {
1048  Value *callOptimizer(Function *Callee, CallInst *CI,
1049                       IRBuilder<> &B) override {
1050    // These optimizations require DataLayout.
1051    if (!DL) return nullptr;
1052
1053    FunctionType *FT = Callee->getFunctionType();
1054    if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1055        !FT->getParamType(0)->isPointerTy() ||
1056        !FT->getParamType(1)->isPointerTy() ||
1057        FT->getParamType(2) != DL->getIntPtrType(*Context))
1058      return nullptr;
1059
1060    // memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
1061    B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
1062                   CI->getArgOperand(2), 1);
1063    return CI->getArgOperand(0);
1064  }
1065};
1066
1067struct MemMoveOpt : public LibCallOptimization {
1068  Value *callOptimizer(Function *Callee, CallInst *CI,
1069                       IRBuilder<> &B) override {
1070    // These optimizations require DataLayout.
1071    if (!DL) return nullptr;
1072
1073    FunctionType *FT = Callee->getFunctionType();
1074    if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1075        !FT->getParamType(0)->isPointerTy() ||
1076        !FT->getParamType(1)->isPointerTy() ||
1077        FT->getParamType(2) != DL->getIntPtrType(*Context))
1078      return nullptr;
1079
1080    // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
1081    B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
1082                    CI->getArgOperand(2), 1);
1083    return CI->getArgOperand(0);
1084  }
1085};
1086
1087struct MemSetOpt : public LibCallOptimization {
1088  Value *callOptimizer(Function *Callee, CallInst *CI,
1089                       IRBuilder<> &B) override {
1090    // These optimizations require DataLayout.
1091    if (!DL) return nullptr;
1092
1093    FunctionType *FT = Callee->getFunctionType();
1094    if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1095        !FT->getParamType(0)->isPointerTy() ||
1096        !FT->getParamType(1)->isIntegerTy() ||
1097        FT->getParamType(2) != DL->getIntPtrType(FT->getParamType(0)))
1098      return nullptr;
1099
1100    // memset(p, v, n) -> llvm.memset(p, v, n, 1)
1101    Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
1102    B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
1103    return CI->getArgOperand(0);
1104  }
1105};
1106
1107//===----------------------------------------------------------------------===//
1108// Math Library Optimizations
1109//===----------------------------------------------------------------------===//
1110
1111//===----------------------------------------------------------------------===//
1112// Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
1113
1114struct UnaryDoubleFPOpt : public LibCallOptimization {
1115  bool CheckRetType;
1116  UnaryDoubleFPOpt(bool CheckReturnType): CheckRetType(CheckReturnType) {}
1117  Value *callOptimizer(Function *Callee, CallInst *CI,
1118                       IRBuilder<> &B) override {
1119    FunctionType *FT = Callee->getFunctionType();
1120    if (FT->getNumParams() != 1 || !FT->getReturnType()->isDoubleTy() ||
1121        !FT->getParamType(0)->isDoubleTy())
1122      return nullptr;
1123
1124    if (CheckRetType) {
1125      // Check if all the uses for function like 'sin' are converted to float.
1126      for (User *U : CI->users()) {
1127        FPTruncInst *Cast = dyn_cast<FPTruncInst>(U);
1128        if (!Cast || !Cast->getType()->isFloatTy())
1129          return nullptr;
1130      }
1131    }
1132
1133    // If this is something like 'floor((double)floatval)', convert to floorf.
1134    FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getArgOperand(0));
1135    if (!Cast || !Cast->getOperand(0)->getType()->isFloatTy())
1136      return nullptr;
1137
1138    // floor((double)floatval) -> (double)floorf(floatval)
1139    Value *V = Cast->getOperand(0);
1140    V = EmitUnaryFloatFnCall(V, Callee->getName(), B, Callee->getAttributes());
1141    return B.CreateFPExt(V, B.getDoubleTy());
1142  }
1143};
1144
1145// Double -> Float Shrinking Optimizations for Binary Functions like 'fmin/fmax'
1146struct BinaryDoubleFPOpt : public LibCallOptimization {
1147  bool CheckRetType;
1148  BinaryDoubleFPOpt(bool CheckReturnType): CheckRetType(CheckReturnType) {}
1149  Value *callOptimizer(Function *Callee, CallInst *CI,
1150                       IRBuilder<> &B) override {
1151    FunctionType *FT = Callee->getFunctionType();
1152    // Just make sure this has 2 arguments of the same FP type, which match the
1153    // result type.
1154    if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1155        FT->getParamType(0) != FT->getParamType(1) ||
1156        !FT->getParamType(0)->isFloatingPointTy())
1157      return nullptr;
1158
1159    if (CheckRetType) {
1160      // Check if all the uses for function like 'fmin/fmax' are converted to
1161      // float.
1162      for (User *U : CI->users()) {
1163        FPTruncInst *Cast = dyn_cast<FPTruncInst>(U);
1164        if (!Cast || !Cast->getType()->isFloatTy())
1165          return nullptr;
1166      }
1167    }
1168
1169    // If this is something like 'fmin((double)floatval1, (double)floatval2)',
1170    // we convert it to fminf.
1171    FPExtInst *Cast1 = dyn_cast<FPExtInst>(CI->getArgOperand(0));
1172    FPExtInst *Cast2 = dyn_cast<FPExtInst>(CI->getArgOperand(1));
1173    if (!Cast1 || !Cast1->getOperand(0)->getType()->isFloatTy() ||
1174        !Cast2 || !Cast2->getOperand(0)->getType()->isFloatTy())
1175      return nullptr;
1176
1177    // fmin((double)floatval1, (double)floatval2)
1178    //                      -> (double)fmin(floatval1, floatval2)
1179    Value *V = nullptr;
1180    Value *V1 = Cast1->getOperand(0);
1181    Value *V2 = Cast2->getOperand(0);
1182    V = EmitBinaryFloatFnCall(V1, V2, Callee->getName(), B,
1183                              Callee->getAttributes());
1184    return B.CreateFPExt(V, B.getDoubleTy());
1185  }
1186};
1187
1188struct UnsafeFPLibCallOptimization : public LibCallOptimization {
1189  bool UnsafeFPShrink;
1190  UnsafeFPLibCallOptimization(bool UnsafeFPShrink) {
1191    this->UnsafeFPShrink = UnsafeFPShrink;
1192  }
1193};
1194
1195struct CosOpt : public UnsafeFPLibCallOptimization {
1196  CosOpt(bool UnsafeFPShrink) : UnsafeFPLibCallOptimization(UnsafeFPShrink) {}
1197  Value *callOptimizer(Function *Callee, CallInst *CI,
1198                       IRBuilder<> &B) override {
1199    Value *Ret = nullptr;
1200    if (UnsafeFPShrink && Callee->getName() == "cos" &&
1201        TLI->has(LibFunc::cosf)) {
1202      UnaryDoubleFPOpt UnsafeUnaryDoubleFP(true);
1203      Ret = UnsafeUnaryDoubleFP.callOptimizer(Callee, CI, B);
1204    }
1205
1206    FunctionType *FT = Callee->getFunctionType();
1207    // Just make sure this has 1 argument of FP type, which matches the
1208    // result type.
1209    if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1210        !FT->getParamType(0)->isFloatingPointTy())
1211      return Ret;
1212
1213    // cos(-x) -> cos(x)
1214    Value *Op1 = CI->getArgOperand(0);
1215    if (BinaryOperator::isFNeg(Op1)) {
1216      BinaryOperator *BinExpr = cast<BinaryOperator>(Op1);
1217      return B.CreateCall(Callee, BinExpr->getOperand(1), "cos");
1218    }
1219    return Ret;
1220  }
1221};
1222
1223struct PowOpt : public UnsafeFPLibCallOptimization {
1224  PowOpt(bool UnsafeFPShrink) : UnsafeFPLibCallOptimization(UnsafeFPShrink) {}
1225  Value *callOptimizer(Function *Callee, CallInst *CI,
1226                       IRBuilder<> &B) override {
1227    Value *Ret = nullptr;
1228    if (UnsafeFPShrink && Callee->getName() == "pow" &&
1229        TLI->has(LibFunc::powf)) {
1230      UnaryDoubleFPOpt UnsafeUnaryDoubleFP(true);
1231      Ret = UnsafeUnaryDoubleFP.callOptimizer(Callee, CI, B);
1232    }
1233
1234    FunctionType *FT = Callee->getFunctionType();
1235    // Just make sure this has 2 arguments of the same FP type, which match the
1236    // result type.
1237    if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1238        FT->getParamType(0) != FT->getParamType(1) ||
1239        !FT->getParamType(0)->isFloatingPointTy())
1240      return Ret;
1241
1242    Value *Op1 = CI->getArgOperand(0), *Op2 = CI->getArgOperand(1);
1243    if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
1244      // pow(1.0, x) -> 1.0
1245      if (Op1C->isExactlyValue(1.0))
1246        return Op1C;
1247      // pow(2.0, x) -> exp2(x)
1248      if (Op1C->isExactlyValue(2.0) &&
1249          hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp2, LibFunc::exp2f,
1250                          LibFunc::exp2l))
1251        return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
1252      // pow(10.0, x) -> exp10(x)
1253      if (Op1C->isExactlyValue(10.0) &&
1254          hasUnaryFloatFn(TLI, Op1->getType(), LibFunc::exp10, LibFunc::exp10f,
1255                          LibFunc::exp10l))
1256        return EmitUnaryFloatFnCall(Op2, TLI->getName(LibFunc::exp10), B,
1257                                    Callee->getAttributes());
1258    }
1259
1260    ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
1261    if (!Op2C) return Ret;
1262
1263    if (Op2C->getValueAPF().isZero())  // pow(x, 0.0) -> 1.0
1264      return ConstantFP::get(CI->getType(), 1.0);
1265
1266    if (Op2C->isExactlyValue(0.5) &&
1267        hasUnaryFloatFn(TLI, Op2->getType(), LibFunc::sqrt, LibFunc::sqrtf,
1268                        LibFunc::sqrtl) &&
1269        hasUnaryFloatFn(TLI, Op2->getType(), LibFunc::fabs, LibFunc::fabsf,
1270                        LibFunc::fabsl)) {
1271      // Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
1272      // This is faster than calling pow, and still handles negative zero
1273      // and negative infinity correctly.
1274      // TODO: In fast-math mode, this could be just sqrt(x).
1275      // TODO: In finite-only mode, this could be just fabs(sqrt(x)).
1276      Value *Inf = ConstantFP::getInfinity(CI->getType());
1277      Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
1278      Value *Sqrt = EmitUnaryFloatFnCall(Op1, "sqrt", B,
1279                                         Callee->getAttributes());
1280      Value *FAbs = EmitUnaryFloatFnCall(Sqrt, "fabs", B,
1281                                         Callee->getAttributes());
1282      Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf);
1283      Value *Sel = B.CreateSelect(FCmp, Inf, FAbs);
1284      return Sel;
1285    }
1286
1287    if (Op2C->isExactlyValue(1.0))  // pow(x, 1.0) -> x
1288      return Op1;
1289    if (Op2C->isExactlyValue(2.0))  // pow(x, 2.0) -> x*x
1290      return B.CreateFMul(Op1, Op1, "pow2");
1291    if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
1292      return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0),
1293                          Op1, "powrecip");
1294    return nullptr;
1295  }
1296};
1297
1298struct Exp2Opt : public UnsafeFPLibCallOptimization {
1299  Exp2Opt(bool UnsafeFPShrink) : UnsafeFPLibCallOptimization(UnsafeFPShrink) {}
1300  Value *callOptimizer(Function *Callee, CallInst *CI,
1301                       IRBuilder<> &B) override {
1302    Value *Ret = nullptr;
1303    if (UnsafeFPShrink && Callee->getName() == "exp2" &&
1304        TLI->has(LibFunc::exp2f)) {
1305      UnaryDoubleFPOpt UnsafeUnaryDoubleFP(true);
1306      Ret = UnsafeUnaryDoubleFP.callOptimizer(Callee, CI, B);
1307    }
1308
1309    FunctionType *FT = Callee->getFunctionType();
1310    // Just make sure this has 1 argument of FP type, which matches the
1311    // result type.
1312    if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1313        !FT->getParamType(0)->isFloatingPointTy())
1314      return Ret;
1315
1316    Value *Op = CI->getArgOperand(0);
1317    // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x))  if sizeof(x) <= 32
1318    // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x))  if sizeof(x) < 32
1319    LibFunc::Func LdExp = LibFunc::ldexpl;
1320    if (Op->getType()->isFloatTy())
1321      LdExp = LibFunc::ldexpf;
1322    else if (Op->getType()->isDoubleTy())
1323      LdExp = LibFunc::ldexp;
1324
1325    if (TLI->has(LdExp)) {
1326      Value *LdExpArg = nullptr;
1327      if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
1328        if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
1329          LdExpArg = B.CreateSExt(OpC->getOperand(0), B.getInt32Ty());
1330      } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
1331        if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
1332          LdExpArg = B.CreateZExt(OpC->getOperand(0), B.getInt32Ty());
1333      }
1334
1335      if (LdExpArg) {
1336        Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
1337        if (!Op->getType()->isFloatTy())
1338          One = ConstantExpr::getFPExtend(One, Op->getType());
1339
1340        Module *M = Caller->getParent();
1341        Value *Callee =
1342            M->getOrInsertFunction(TLI->getName(LdExp), Op->getType(),
1343                                   Op->getType(), B.getInt32Ty(), NULL);
1344        CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
1345        if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
1346          CI->setCallingConv(F->getCallingConv());
1347
1348        return CI;
1349      }
1350    }
1351    return Ret;
1352  }
1353};
1354
1355struct SinCosPiOpt : public LibCallOptimization {
1356  SinCosPiOpt() {}
1357
1358  Value *callOptimizer(Function *Callee, CallInst *CI,
1359                       IRBuilder<> &B) override {
1360    // Make sure the prototype is as expected, otherwise the rest of the
1361    // function is probably invalid and likely to abort.
1362    if (!isTrigLibCall(CI))
1363      return nullptr;
1364
1365    Value *Arg = CI->getArgOperand(0);
1366    SmallVector<CallInst *, 1> SinCalls;
1367    SmallVector<CallInst *, 1> CosCalls;
1368    SmallVector<CallInst *, 1> SinCosCalls;
1369
1370    bool IsFloat = Arg->getType()->isFloatTy();
1371
1372    // Look for all compatible sinpi, cospi and sincospi calls with the same
1373    // argument. If there are enough (in some sense) we can make the
1374    // substitution.
1375    for (User *U : Arg->users())
1376      classifyArgUse(U, CI->getParent(), IsFloat, SinCalls, CosCalls,
1377                     SinCosCalls);
1378
1379    // It's only worthwhile if both sinpi and cospi are actually used.
1380    if (SinCosCalls.empty() && (SinCalls.empty() || CosCalls.empty()))
1381      return nullptr;
1382
1383    Value *Sin, *Cos, *SinCos;
1384    insertSinCosCall(B, CI->getCalledFunction(), Arg, IsFloat, Sin, Cos,
1385                     SinCos);
1386
1387    replaceTrigInsts(SinCalls, Sin);
1388    replaceTrigInsts(CosCalls, Cos);
1389    replaceTrigInsts(SinCosCalls, SinCos);
1390
1391    return nullptr;
1392  }
1393
1394  bool isTrigLibCall(CallInst *CI) {
1395    Function *Callee = CI->getCalledFunction();
1396    FunctionType *FT = Callee->getFunctionType();
1397
1398    // We can only hope to do anything useful if we can ignore things like errno
1399    // and floating-point exceptions.
1400    bool AttributesSafe = CI->hasFnAttr(Attribute::NoUnwind) &&
1401                          CI->hasFnAttr(Attribute::ReadNone);
1402
1403    // Other than that we need float(float) or double(double)
1404    return AttributesSafe && FT->getNumParams() == 1 &&
1405           FT->getReturnType() == FT->getParamType(0) &&
1406           (FT->getParamType(0)->isFloatTy() ||
1407            FT->getParamType(0)->isDoubleTy());
1408  }
1409
1410  void classifyArgUse(Value *Val, BasicBlock *BB, bool IsFloat,
1411                      SmallVectorImpl<CallInst *> &SinCalls,
1412                      SmallVectorImpl<CallInst *> &CosCalls,
1413                      SmallVectorImpl<CallInst *> &SinCosCalls) {
1414    CallInst *CI = dyn_cast<CallInst>(Val);
1415
1416    if (!CI)
1417      return;
1418
1419    Function *Callee = CI->getCalledFunction();
1420    StringRef FuncName = Callee->getName();
1421    LibFunc::Func Func;
1422    if (!TLI->getLibFunc(FuncName, Func) || !TLI->has(Func) ||
1423        !isTrigLibCall(CI))
1424      return;
1425
1426    if (IsFloat) {
1427      if (Func == LibFunc::sinpif)
1428        SinCalls.push_back(CI);
1429      else if (Func == LibFunc::cospif)
1430        CosCalls.push_back(CI);
1431      else if (Func == LibFunc::sincospif_stret)
1432        SinCosCalls.push_back(CI);
1433    } else {
1434      if (Func == LibFunc::sinpi)
1435        SinCalls.push_back(CI);
1436      else if (Func == LibFunc::cospi)
1437        CosCalls.push_back(CI);
1438      else if (Func == LibFunc::sincospi_stret)
1439        SinCosCalls.push_back(CI);
1440    }
1441  }
1442
1443  void replaceTrigInsts(SmallVectorImpl<CallInst*> &Calls, Value *Res) {
1444    for (SmallVectorImpl<CallInst*>::iterator I = Calls.begin(),
1445           E = Calls.end();
1446         I != E; ++I) {
1447      LCS->replaceAllUsesWith(*I, Res);
1448    }
1449  }
1450
1451  void insertSinCosCall(IRBuilder<> &B, Function *OrigCallee, Value *Arg,
1452                        bool UseFloat, Value *&Sin, Value *&Cos,
1453                        Value *&SinCos) {
1454    Type *ArgTy = Arg->getType();
1455    Type *ResTy;
1456    StringRef Name;
1457
1458    Triple T(OrigCallee->getParent()->getTargetTriple());
1459    if (UseFloat) {
1460      Name = "__sincospif_stret";
1461
1462      assert(T.getArch() != Triple::x86 && "x86 messy and unsupported for now");
1463      // x86_64 can't use {float, float} since that would be returned in both
1464      // xmm0 and xmm1, which isn't what a real struct would do.
1465      ResTy = T.getArch() == Triple::x86_64
1466                  ? static_cast<Type *>(VectorType::get(ArgTy, 2))
1467                  : static_cast<Type *>(StructType::get(ArgTy, ArgTy, NULL));
1468    } else {
1469      Name = "__sincospi_stret";
1470      ResTy = StructType::get(ArgTy, ArgTy, NULL);
1471    }
1472
1473    Module *M = OrigCallee->getParent();
1474    Value *Callee = M->getOrInsertFunction(Name, OrigCallee->getAttributes(),
1475                                           ResTy, ArgTy, NULL);
1476
1477    if (Instruction *ArgInst = dyn_cast<Instruction>(Arg)) {
1478      // If the argument is an instruction, it must dominate all uses so put our
1479      // sincos call there.
1480      BasicBlock::iterator Loc = ArgInst;
1481      B.SetInsertPoint(ArgInst->getParent(), ++Loc);
1482    } else {
1483      // Otherwise (e.g. for a constant) the beginning of the function is as
1484      // good a place as any.
1485      BasicBlock &EntryBB = B.GetInsertBlock()->getParent()->getEntryBlock();
1486      B.SetInsertPoint(&EntryBB, EntryBB.begin());
1487    }
1488
1489    SinCos = B.CreateCall(Callee, Arg, "sincospi");
1490
1491    if (SinCos->getType()->isStructTy()) {
1492      Sin = B.CreateExtractValue(SinCos, 0, "sinpi");
1493      Cos = B.CreateExtractValue(SinCos, 1, "cospi");
1494    } else {
1495      Sin = B.CreateExtractElement(SinCos, ConstantInt::get(B.getInt32Ty(), 0),
1496                                   "sinpi");
1497      Cos = B.CreateExtractElement(SinCos, ConstantInt::get(B.getInt32Ty(), 1),
1498                                   "cospi");
1499    }
1500  }
1501
1502};
1503
1504//===----------------------------------------------------------------------===//
1505// Integer Library Call Optimizations
1506//===----------------------------------------------------------------------===//
1507
1508struct FFSOpt : public LibCallOptimization {
1509  Value *callOptimizer(Function *Callee, CallInst *CI,
1510                       IRBuilder<> &B) override {
1511    FunctionType *FT = Callee->getFunctionType();
1512    // Just make sure this has 2 arguments of the same FP type, which match the
1513    // result type.
1514    if (FT->getNumParams() != 1 ||
1515        !FT->getReturnType()->isIntegerTy(32) ||
1516        !FT->getParamType(0)->isIntegerTy())
1517      return nullptr;
1518
1519    Value *Op = CI->getArgOperand(0);
1520
1521    // Constant fold.
1522    if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
1523      if (CI->isZero()) // ffs(0) -> 0.
1524        return B.getInt32(0);
1525      // ffs(c) -> cttz(c)+1
1526      return B.getInt32(CI->getValue().countTrailingZeros() + 1);
1527    }
1528
1529    // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
1530    Type *ArgType = Op->getType();
1531    Value *F = Intrinsic::getDeclaration(Callee->getParent(),
1532                                         Intrinsic::cttz, ArgType);
1533    Value *V = B.CreateCall2(F, Op, B.getFalse(), "cttz");
1534    V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1));
1535    V = B.CreateIntCast(V, B.getInt32Ty(), false);
1536
1537    Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType));
1538    return B.CreateSelect(Cond, V, B.getInt32(0));
1539  }
1540};
1541
1542struct AbsOpt : public LibCallOptimization {
1543  bool ignoreCallingConv() override { return true; }
1544  Value *callOptimizer(Function *Callee, CallInst *CI,
1545                       IRBuilder<> &B) override {
1546    FunctionType *FT = Callee->getFunctionType();
1547    // We require integer(integer) where the types agree.
1548    if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1549        FT->getParamType(0) != FT->getReturnType())
1550      return nullptr;
1551
1552    // abs(x) -> x >s -1 ? x : -x
1553    Value *Op = CI->getArgOperand(0);
1554    Value *Pos = B.CreateICmpSGT(Op, Constant::getAllOnesValue(Op->getType()),
1555                                 "ispos");
1556    Value *Neg = B.CreateNeg(Op, "neg");
1557    return B.CreateSelect(Pos, Op, Neg);
1558  }
1559};
1560
1561struct IsDigitOpt : public LibCallOptimization {
1562  Value *callOptimizer(Function *Callee, CallInst *CI,
1563                       IRBuilder<> &B) override {
1564    FunctionType *FT = Callee->getFunctionType();
1565    // We require integer(i32)
1566    if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1567        !FT->getParamType(0)->isIntegerTy(32))
1568      return nullptr;
1569
1570    // isdigit(c) -> (c-'0') <u 10
1571    Value *Op = CI->getArgOperand(0);
1572    Op = B.CreateSub(Op, B.getInt32('0'), "isdigittmp");
1573    Op = B.CreateICmpULT(Op, B.getInt32(10), "isdigit");
1574    return B.CreateZExt(Op, CI->getType());
1575  }
1576};
1577
1578struct IsAsciiOpt : public LibCallOptimization {
1579  Value *callOptimizer(Function *Callee, CallInst *CI,
1580                       IRBuilder<> &B) override {
1581    FunctionType *FT = Callee->getFunctionType();
1582    // We require integer(i32)
1583    if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1584        !FT->getParamType(0)->isIntegerTy(32))
1585      return nullptr;
1586
1587    // isascii(c) -> c <u 128
1588    Value *Op = CI->getArgOperand(0);
1589    Op = B.CreateICmpULT(Op, B.getInt32(128), "isascii");
1590    return B.CreateZExt(Op, CI->getType());
1591  }
1592};
1593
1594struct ToAsciiOpt : public LibCallOptimization {
1595  Value *callOptimizer(Function *Callee, CallInst *CI,
1596                       IRBuilder<> &B) override {
1597    FunctionType *FT = Callee->getFunctionType();
1598    // We require i32(i32)
1599    if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1600        !FT->getParamType(0)->isIntegerTy(32))
1601      return nullptr;
1602
1603    // toascii(c) -> c & 0x7f
1604    return B.CreateAnd(CI->getArgOperand(0),
1605                       ConstantInt::get(CI->getType(),0x7F));
1606  }
1607};
1608
1609//===----------------------------------------------------------------------===//
1610// Formatting and IO Library Call Optimizations
1611//===----------------------------------------------------------------------===//
1612
1613struct ErrorReportingOpt : public LibCallOptimization {
1614  ErrorReportingOpt(int S = -1) : StreamArg(S) {}
1615
1616  Value *callOptimizer(Function *Callee, CallInst *CI,
1617                       IRBuilder<> &) override {
1618    // Error reporting calls should be cold, mark them as such.
1619    // This applies even to non-builtin calls: it is only a hint and applies to
1620    // functions that the frontend might not understand as builtins.
1621
1622    // This heuristic was suggested in:
1623    // Improving Static Branch Prediction in a Compiler
1624    // Brian L. Deitrich, Ben-Chung Cheng, Wen-mei W. Hwu
1625    // Proceedings of PACT'98, Oct. 1998, IEEE
1626
1627    if (!CI->hasFnAttr(Attribute::Cold) && isReportingError(Callee, CI)) {
1628      CI->addAttribute(AttributeSet::FunctionIndex, Attribute::Cold);
1629    }
1630
1631    return nullptr;
1632  }
1633
1634protected:
1635  bool isReportingError(Function *Callee, CallInst *CI) {
1636    if (!ColdErrorCalls)
1637      return false;
1638
1639    if (!Callee || !Callee->isDeclaration())
1640      return false;
1641
1642    if (StreamArg < 0)
1643      return true;
1644
1645    // These functions might be considered cold, but only if their stream
1646    // argument is stderr.
1647
1648    if (StreamArg >= (int) CI->getNumArgOperands())
1649      return false;
1650    LoadInst *LI = dyn_cast<LoadInst>(CI->getArgOperand(StreamArg));
1651    if (!LI)
1652      return false;
1653    GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getPointerOperand());
1654    if (!GV || !GV->isDeclaration())
1655      return false;
1656    return GV->getName() == "stderr";
1657  }
1658
1659  int StreamArg;
1660};
1661
1662struct PrintFOpt : public LibCallOptimization {
1663  Value *optimizeFixedFormatString(Function *Callee, CallInst *CI,
1664                                   IRBuilder<> &B) {
1665    // Check for a fixed format string.
1666    StringRef FormatStr;
1667    if (!getConstantStringInfo(CI->getArgOperand(0), FormatStr))
1668      return nullptr;
1669
1670    // Empty format string -> noop.
1671    if (FormatStr.empty())  // Tolerate printf's declared void.
1672      return CI->use_empty() ? (Value*)CI :
1673                               ConstantInt::get(CI->getType(), 0);
1674
1675    // Do not do any of the following transformations if the printf return value
1676    // is used, in general the printf return value is not compatible with either
1677    // putchar() or puts().
1678    if (!CI->use_empty())
1679      return nullptr;
1680
1681    // printf("x") -> putchar('x'), even for '%'.
1682    if (FormatStr.size() == 1) {
1683      Value *Res = EmitPutChar(B.getInt32(FormatStr[0]), B, DL, TLI);
1684      if (CI->use_empty() || !Res) return Res;
1685      return B.CreateIntCast(Res, CI->getType(), true);
1686    }
1687
1688    // printf("foo\n") --> puts("foo")
1689    if (FormatStr[FormatStr.size()-1] == '\n' &&
1690        FormatStr.find('%') == StringRef::npos) { // No format characters.
1691      // Create a string literal with no \n on it.  We expect the constant merge
1692      // pass to be run after this pass, to merge duplicate strings.
1693      FormatStr = FormatStr.drop_back();
1694      Value *GV = B.CreateGlobalString(FormatStr, "str");
1695      Value *NewCI = EmitPutS(GV, B, DL, TLI);
1696      return (CI->use_empty() || !NewCI) ?
1697              NewCI :
1698              ConstantInt::get(CI->getType(), FormatStr.size()+1);
1699    }
1700
1701    // Optimize specific format strings.
1702    // printf("%c", chr) --> putchar(chr)
1703    if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
1704        CI->getArgOperand(1)->getType()->isIntegerTy()) {
1705      Value *Res = EmitPutChar(CI->getArgOperand(1), B, DL, TLI);
1706
1707      if (CI->use_empty() || !Res) return Res;
1708      return B.CreateIntCast(Res, CI->getType(), true);
1709    }
1710
1711    // printf("%s\n", str) --> puts(str)
1712    if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
1713        CI->getArgOperand(1)->getType()->isPointerTy()) {
1714      return EmitPutS(CI->getArgOperand(1), B, DL, TLI);
1715    }
1716    return nullptr;
1717  }
1718
1719  Value *callOptimizer(Function *Callee, CallInst *CI,
1720                       IRBuilder<> &B) override {
1721    // Require one fixed pointer argument and an integer/void result.
1722    FunctionType *FT = Callee->getFunctionType();
1723    if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
1724        !(FT->getReturnType()->isIntegerTy() ||
1725          FT->getReturnType()->isVoidTy()))
1726      return nullptr;
1727
1728    if (Value *V = optimizeFixedFormatString(Callee, CI, B)) {
1729      return V;
1730    }
1731
1732    // printf(format, ...) -> iprintf(format, ...) if no floating point
1733    // arguments.
1734    if (TLI->has(LibFunc::iprintf) && !callHasFloatingPointArgument(CI)) {
1735      Module *M = B.GetInsertBlock()->getParent()->getParent();
1736      Constant *IPrintFFn =
1737        M->getOrInsertFunction("iprintf", FT, Callee->getAttributes());
1738      CallInst *New = cast<CallInst>(CI->clone());
1739      New->setCalledFunction(IPrintFFn);
1740      B.Insert(New);
1741      return New;
1742    }
1743    return nullptr;
1744  }
1745};
1746
1747struct SPrintFOpt : public LibCallOptimization {
1748  Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI,
1749                                   IRBuilder<> &B) {
1750    // Check for a fixed format string.
1751    StringRef FormatStr;
1752    if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
1753      return nullptr;
1754
1755    // If we just have a format string (nothing else crazy) transform it.
1756    if (CI->getNumArgOperands() == 2) {
1757      // Make sure there's no % in the constant array.  We could try to handle
1758      // %% -> % in the future if we cared.
1759      for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1760        if (FormatStr[i] == '%')
1761          return nullptr; // we found a format specifier, bail out.
1762
1763      // These optimizations require DataLayout.
1764      if (!DL) return nullptr;
1765
1766      // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1767      B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
1768                     ConstantInt::get(DL->getIntPtrType(*Context), // Copy the
1769                                      FormatStr.size() + 1), 1);   // nul byte.
1770      return ConstantInt::get(CI->getType(), FormatStr.size());
1771    }
1772
1773    // The remaining optimizations require the format string to be "%s" or "%c"
1774    // and have an extra operand.
1775    if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1776        CI->getNumArgOperands() < 3)
1777      return nullptr;
1778
1779    // Decode the second character of the format string.
1780    if (FormatStr[1] == 'c') {
1781      // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1782      if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return nullptr;
1783      Value *V = B.CreateTrunc(CI->getArgOperand(2), B.getInt8Ty(), "char");
1784      Value *Ptr = CastToCStr(CI->getArgOperand(0), B);
1785      B.CreateStore(V, Ptr);
1786      Ptr = B.CreateGEP(Ptr, B.getInt32(1), "nul");
1787      B.CreateStore(B.getInt8(0), Ptr);
1788
1789      return ConstantInt::get(CI->getType(), 1);
1790    }
1791
1792    if (FormatStr[1] == 's') {
1793      // These optimizations require DataLayout.
1794      if (!DL) return nullptr;
1795
1796      // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1797      if (!CI->getArgOperand(2)->getType()->isPointerTy()) return nullptr;
1798
1799      Value *Len = EmitStrLen(CI->getArgOperand(2), B, DL, TLI);
1800      if (!Len)
1801        return nullptr;
1802      Value *IncLen = B.CreateAdd(Len,
1803                                  ConstantInt::get(Len->getType(), 1),
1804                                  "leninc");
1805      B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(2), IncLen, 1);
1806
1807      // The sprintf result is the unincremented number of bytes in the string.
1808      return B.CreateIntCast(Len, CI->getType(), false);
1809    }
1810    return nullptr;
1811  }
1812
1813  Value *callOptimizer(Function *Callee, CallInst *CI,
1814                       IRBuilder<> &B) override {
1815    // Require two fixed pointer arguments and an integer result.
1816    FunctionType *FT = Callee->getFunctionType();
1817    if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1818        !FT->getParamType(1)->isPointerTy() ||
1819        !FT->getReturnType()->isIntegerTy())
1820      return nullptr;
1821
1822    if (Value *V = OptimizeFixedFormatString(Callee, CI, B)) {
1823      return V;
1824    }
1825
1826    // sprintf(str, format, ...) -> siprintf(str, format, ...) if no floating
1827    // point arguments.
1828    if (TLI->has(LibFunc::siprintf) && !callHasFloatingPointArgument(CI)) {
1829      Module *M = B.GetInsertBlock()->getParent()->getParent();
1830      Constant *SIPrintFFn =
1831        M->getOrInsertFunction("siprintf", FT, Callee->getAttributes());
1832      CallInst *New = cast<CallInst>(CI->clone());
1833      New->setCalledFunction(SIPrintFFn);
1834      B.Insert(New);
1835      return New;
1836    }
1837    return nullptr;
1838  }
1839};
1840
1841struct FPrintFOpt : public LibCallOptimization {
1842  Value *optimizeFixedFormatString(Function *Callee, CallInst *CI,
1843                                   IRBuilder<> &B) {
1844    ErrorReportingOpt ER(/* StreamArg = */ 0);
1845    (void) ER.callOptimizer(Callee, CI, B);
1846
1847    // All the optimizations depend on the format string.
1848    StringRef FormatStr;
1849    if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
1850      return nullptr;
1851
1852    // Do not do any of the following transformations if the fprintf return
1853    // value is used, in general the fprintf return value is not compatible
1854    // with fwrite(), fputc() or fputs().
1855    if (!CI->use_empty())
1856      return nullptr;
1857
1858    // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1859    if (CI->getNumArgOperands() == 2) {
1860      for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1861        if (FormatStr[i] == '%')  // Could handle %% -> % if we cared.
1862          return nullptr; // We found a format specifier.
1863
1864      // These optimizations require DataLayout.
1865      if (!DL) return nullptr;
1866
1867      return EmitFWrite(CI->getArgOperand(1),
1868                        ConstantInt::get(DL->getIntPtrType(*Context),
1869                                         FormatStr.size()),
1870                        CI->getArgOperand(0), B, DL, TLI);
1871    }
1872
1873    // The remaining optimizations require the format string to be "%s" or "%c"
1874    // and have an extra operand.
1875    if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1876        CI->getNumArgOperands() < 3)
1877      return nullptr;
1878
1879    // Decode the second character of the format string.
1880    if (FormatStr[1] == 'c') {
1881      // fprintf(F, "%c", chr) --> fputc(chr, F)
1882      if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return nullptr;
1883      return EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, DL, TLI);
1884    }
1885
1886    if (FormatStr[1] == 's') {
1887      // fprintf(F, "%s", str) --> fputs(str, F)
1888      if (!CI->getArgOperand(2)->getType()->isPointerTy())
1889        return nullptr;
1890      return EmitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, DL, TLI);
1891    }
1892    return nullptr;
1893  }
1894
1895  Value *callOptimizer(Function *Callee, CallInst *CI,
1896                       IRBuilder<> &B) override {
1897    // Require two fixed paramters as pointers and integer result.
1898    FunctionType *FT = Callee->getFunctionType();
1899    if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1900        !FT->getParamType(1)->isPointerTy() ||
1901        !FT->getReturnType()->isIntegerTy())
1902      return nullptr;
1903
1904    if (Value *V = optimizeFixedFormatString(Callee, CI, B)) {
1905      return V;
1906    }
1907
1908    // fprintf(stream, format, ...) -> fiprintf(stream, format, ...) if no
1909    // floating point arguments.
1910    if (TLI->has(LibFunc::fiprintf) && !callHasFloatingPointArgument(CI)) {
1911      Module *M = B.GetInsertBlock()->getParent()->getParent();
1912      Constant *FIPrintFFn =
1913        M->getOrInsertFunction("fiprintf", FT, Callee->getAttributes());
1914      CallInst *New = cast<CallInst>(CI->clone());
1915      New->setCalledFunction(FIPrintFFn);
1916      B.Insert(New);
1917      return New;
1918    }
1919    return nullptr;
1920  }
1921};
1922
1923struct FWriteOpt : public LibCallOptimization {
1924  Value *callOptimizer(Function *Callee, CallInst *CI,
1925                       IRBuilder<> &B) override {
1926    ErrorReportingOpt ER(/* StreamArg = */ 3);
1927    (void) ER.callOptimizer(Callee, CI, B);
1928
1929    // Require a pointer, an integer, an integer, a pointer, returning integer.
1930    FunctionType *FT = Callee->getFunctionType();
1931    if (FT->getNumParams() != 4 || !FT->getParamType(0)->isPointerTy() ||
1932        !FT->getParamType(1)->isIntegerTy() ||
1933        !FT->getParamType(2)->isIntegerTy() ||
1934        !FT->getParamType(3)->isPointerTy() ||
1935        !FT->getReturnType()->isIntegerTy())
1936      return nullptr;
1937
1938    // Get the element size and count.
1939    ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
1940    ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
1941    if (!SizeC || !CountC) return nullptr;
1942    uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
1943
1944    // If this is writing zero records, remove the call (it's a noop).
1945    if (Bytes == 0)
1946      return ConstantInt::get(CI->getType(), 0);
1947
1948    // If this is writing one byte, turn it into fputc.
1949    // This optimisation is only valid, if the return value is unused.
1950    if (Bytes == 1 && CI->use_empty()) {  // fwrite(S,1,1,F) -> fputc(S[0],F)
1951      Value *Char = B.CreateLoad(CastToCStr(CI->getArgOperand(0), B), "char");
1952      Value *NewCI = EmitFPutC(Char, CI->getArgOperand(3), B, DL, TLI);
1953      return NewCI ? ConstantInt::get(CI->getType(), 1) : nullptr;
1954    }
1955
1956    return nullptr;
1957  }
1958};
1959
1960struct FPutsOpt : public LibCallOptimization {
1961  Value *callOptimizer(Function *Callee, CallInst *CI,
1962                       IRBuilder<> &B) override {
1963    ErrorReportingOpt ER(/* StreamArg = */ 1);
1964    (void) ER.callOptimizer(Callee, CI, B);
1965
1966    // These optimizations require DataLayout.
1967    if (!DL) return nullptr;
1968
1969    // Require two pointers.  Also, we can't optimize if return value is used.
1970    FunctionType *FT = Callee->getFunctionType();
1971    if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1972        !FT->getParamType(1)->isPointerTy() ||
1973        !CI->use_empty())
1974      return nullptr;
1975
1976    // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1977    uint64_t Len = GetStringLength(CI->getArgOperand(0));
1978    if (!Len) return nullptr;
1979    // Known to have no uses (see above).
1980    return EmitFWrite(CI->getArgOperand(0),
1981                      ConstantInt::get(DL->getIntPtrType(*Context), Len-1),
1982                      CI->getArgOperand(1), B, DL, TLI);
1983  }
1984};
1985
1986struct PutsOpt : public LibCallOptimization {
1987  Value *callOptimizer(Function *Callee, CallInst *CI,
1988                       IRBuilder<> &B) override {
1989    // Require one fixed pointer argument and an integer/void result.
1990    FunctionType *FT = Callee->getFunctionType();
1991    if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
1992        !(FT->getReturnType()->isIntegerTy() ||
1993          FT->getReturnType()->isVoidTy()))
1994      return nullptr;
1995
1996    // Check for a constant string.
1997    StringRef Str;
1998    if (!getConstantStringInfo(CI->getArgOperand(0), Str))
1999      return nullptr;
2000
2001    if (Str.empty() && CI->use_empty()) {
2002      // puts("") -> putchar('\n')
2003      Value *Res = EmitPutChar(B.getInt32('\n'), B, DL, TLI);
2004      if (CI->use_empty() || !Res) return Res;
2005      return B.CreateIntCast(Res, CI->getType(), true);
2006    }
2007
2008    return nullptr;
2009  }
2010};
2011
2012} // End anonymous namespace.
2013
2014namespace llvm {
2015
2016class LibCallSimplifierImpl {
2017  const DataLayout *DL;
2018  const TargetLibraryInfo *TLI;
2019  const LibCallSimplifier *LCS;
2020  bool UnsafeFPShrink;
2021
2022  // Math library call optimizations.
2023  CosOpt Cos;
2024  PowOpt Pow;
2025  Exp2Opt Exp2;
2026public:
2027  LibCallSimplifierImpl(const DataLayout *DL, const TargetLibraryInfo *TLI,
2028                        const LibCallSimplifier *LCS,
2029                        bool UnsafeFPShrink = false)
2030    : Cos(UnsafeFPShrink), Pow(UnsafeFPShrink), Exp2(UnsafeFPShrink) {
2031    this->DL = DL;
2032    this->TLI = TLI;
2033    this->LCS = LCS;
2034    this->UnsafeFPShrink = UnsafeFPShrink;
2035  }
2036
2037  Value *optimizeCall(CallInst *CI);
2038  LibCallOptimization *lookupOptimization(CallInst *CI);
2039  bool hasFloatVersion(StringRef FuncName);
2040};
2041
2042bool LibCallSimplifierImpl::hasFloatVersion(StringRef FuncName) {
2043  LibFunc::Func Func;
2044  SmallString<20> FloatFuncName = FuncName;
2045  FloatFuncName += 'f';
2046  if (TLI->getLibFunc(FloatFuncName, Func))
2047    return TLI->has(Func);
2048  return false;
2049}
2050
2051// Fortified library call optimizations.
2052static MemCpyChkOpt MemCpyChk;
2053static MemMoveChkOpt MemMoveChk;
2054static MemSetChkOpt MemSetChk;
2055static StrCpyChkOpt StrCpyChk;
2056static StpCpyChkOpt StpCpyChk;
2057static StrNCpyChkOpt StrNCpyChk;
2058
2059// String library call optimizations.
2060static StrCatOpt StrCat;
2061static StrNCatOpt StrNCat;
2062static StrChrOpt StrChr;
2063static StrRChrOpt StrRChr;
2064static StrCmpOpt StrCmp;
2065static StrNCmpOpt StrNCmp;
2066static StrCpyOpt StrCpy;
2067static StpCpyOpt StpCpy;
2068static StrNCpyOpt StrNCpy;
2069static StrLenOpt StrLen;
2070static StrPBrkOpt StrPBrk;
2071static StrToOpt StrTo;
2072static StrSpnOpt StrSpn;
2073static StrCSpnOpt StrCSpn;
2074static StrStrOpt StrStr;
2075
2076// Memory library call optimizations.
2077static MemCmpOpt MemCmp;
2078static MemCpyOpt MemCpy;
2079static MemMoveOpt MemMove;
2080static MemSetOpt MemSet;
2081
2082// Math library call optimizations.
2083static UnaryDoubleFPOpt UnaryDoubleFP(false);
2084static BinaryDoubleFPOpt BinaryDoubleFP(false);
2085static UnaryDoubleFPOpt UnsafeUnaryDoubleFP(true);
2086static SinCosPiOpt SinCosPi;
2087
2088  // Integer library call optimizations.
2089static FFSOpt FFS;
2090static AbsOpt Abs;
2091static IsDigitOpt IsDigit;
2092static IsAsciiOpt IsAscii;
2093static ToAsciiOpt ToAscii;
2094
2095// Formatting and IO library call optimizations.
2096static ErrorReportingOpt ErrorReporting;
2097static ErrorReportingOpt ErrorReporting0(0);
2098static ErrorReportingOpt ErrorReporting1(1);
2099static PrintFOpt PrintF;
2100static SPrintFOpt SPrintF;
2101static FPrintFOpt FPrintF;
2102static FWriteOpt FWrite;
2103static FPutsOpt FPuts;
2104static PutsOpt Puts;
2105
2106LibCallOptimization *LibCallSimplifierImpl::lookupOptimization(CallInst *CI) {
2107  LibFunc::Func Func;
2108  Function *Callee = CI->getCalledFunction();
2109  StringRef FuncName = Callee->getName();
2110
2111  // Next check for intrinsics.
2112  if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI)) {
2113    switch (II->getIntrinsicID()) {
2114    case Intrinsic::pow:
2115       return &Pow;
2116    case Intrinsic::exp2:
2117       return &Exp2;
2118    default:
2119       return nullptr;
2120    }
2121  }
2122
2123  // Then check for known library functions.
2124  if (TLI->getLibFunc(FuncName, Func) && TLI->has(Func)) {
2125    switch (Func) {
2126      case LibFunc::strcat:
2127        return &StrCat;
2128      case LibFunc::strncat:
2129        return &StrNCat;
2130      case LibFunc::strchr:
2131        return &StrChr;
2132      case LibFunc::strrchr:
2133        return &StrRChr;
2134      case LibFunc::strcmp:
2135        return &StrCmp;
2136      case LibFunc::strncmp:
2137        return &StrNCmp;
2138      case LibFunc::strcpy:
2139        return &StrCpy;
2140      case LibFunc::stpcpy:
2141        return &StpCpy;
2142      case LibFunc::strncpy:
2143        return &StrNCpy;
2144      case LibFunc::strlen:
2145        return &StrLen;
2146      case LibFunc::strpbrk:
2147        return &StrPBrk;
2148      case LibFunc::strtol:
2149      case LibFunc::strtod:
2150      case LibFunc::strtof:
2151      case LibFunc::strtoul:
2152      case LibFunc::strtoll:
2153      case LibFunc::strtold:
2154      case LibFunc::strtoull:
2155        return &StrTo;
2156      case LibFunc::strspn:
2157        return &StrSpn;
2158      case LibFunc::strcspn:
2159        return &StrCSpn;
2160      case LibFunc::strstr:
2161        return &StrStr;
2162      case LibFunc::memcmp:
2163        return &MemCmp;
2164      case LibFunc::memcpy:
2165        return &MemCpy;
2166      case LibFunc::memmove:
2167        return &MemMove;
2168      case LibFunc::memset:
2169        return &MemSet;
2170      case LibFunc::cosf:
2171      case LibFunc::cos:
2172      case LibFunc::cosl:
2173        return &Cos;
2174      case LibFunc::sinpif:
2175      case LibFunc::sinpi:
2176      case LibFunc::cospif:
2177      case LibFunc::cospi:
2178        return &SinCosPi;
2179      case LibFunc::powf:
2180      case LibFunc::pow:
2181      case LibFunc::powl:
2182        return &Pow;
2183      case LibFunc::exp2l:
2184      case LibFunc::exp2:
2185      case LibFunc::exp2f:
2186        return &Exp2;
2187      case LibFunc::ffs:
2188      case LibFunc::ffsl:
2189      case LibFunc::ffsll:
2190        return &FFS;
2191      case LibFunc::abs:
2192      case LibFunc::labs:
2193      case LibFunc::llabs:
2194        return &Abs;
2195      case LibFunc::isdigit:
2196        return &IsDigit;
2197      case LibFunc::isascii:
2198        return &IsAscii;
2199      case LibFunc::toascii:
2200        return &ToAscii;
2201      case LibFunc::printf:
2202        return &PrintF;
2203      case LibFunc::sprintf:
2204        return &SPrintF;
2205      case LibFunc::fprintf:
2206        return &FPrintF;
2207      case LibFunc::fwrite:
2208        return &FWrite;
2209      case LibFunc::fputs:
2210        return &FPuts;
2211      case LibFunc::puts:
2212        return &Puts;
2213      case LibFunc::perror:
2214        return &ErrorReporting;
2215      case LibFunc::vfprintf:
2216      case LibFunc::fiprintf:
2217        return &ErrorReporting0;
2218      case LibFunc::fputc:
2219        return &ErrorReporting1;
2220      case LibFunc::ceil:
2221      case LibFunc::fabs:
2222      case LibFunc::floor:
2223      case LibFunc::rint:
2224      case LibFunc::round:
2225      case LibFunc::nearbyint:
2226      case LibFunc::trunc:
2227        if (hasFloatVersion(FuncName))
2228          return &UnaryDoubleFP;
2229        return nullptr;
2230      case LibFunc::acos:
2231      case LibFunc::acosh:
2232      case LibFunc::asin:
2233      case LibFunc::asinh:
2234      case LibFunc::atan:
2235      case LibFunc::atanh:
2236      case LibFunc::cbrt:
2237      case LibFunc::cosh:
2238      case LibFunc::exp:
2239      case LibFunc::exp10:
2240      case LibFunc::expm1:
2241      case LibFunc::log:
2242      case LibFunc::log10:
2243      case LibFunc::log1p:
2244      case LibFunc::log2:
2245      case LibFunc::logb:
2246      case LibFunc::sin:
2247      case LibFunc::sinh:
2248      case LibFunc::sqrt:
2249      case LibFunc::tan:
2250      case LibFunc::tanh:
2251        if (UnsafeFPShrink && hasFloatVersion(FuncName))
2252         return &UnsafeUnaryDoubleFP;
2253        return nullptr;
2254      case LibFunc::fmin:
2255      case LibFunc::fmax:
2256        if (hasFloatVersion(FuncName))
2257          return &BinaryDoubleFP;
2258        return nullptr;
2259      case LibFunc::memcpy_chk:
2260        return &MemCpyChk;
2261      default:
2262        return nullptr;
2263      }
2264  }
2265
2266  // Finally check for fortified library calls.
2267  if (FuncName.endswith("_chk")) {
2268    if (FuncName == "__memmove_chk")
2269      return &MemMoveChk;
2270    else if (FuncName == "__memset_chk")
2271      return &MemSetChk;
2272    else if (FuncName == "__strcpy_chk")
2273      return &StrCpyChk;
2274    else if (FuncName == "__stpcpy_chk")
2275      return &StpCpyChk;
2276    else if (FuncName == "__strncpy_chk")
2277      return &StrNCpyChk;
2278    else if (FuncName == "__stpncpy_chk")
2279      return &StrNCpyChk;
2280  }
2281
2282  return nullptr;
2283
2284}
2285
2286Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {
2287  LibCallOptimization *LCO = lookupOptimization(CI);
2288  if (LCO) {
2289    IRBuilder<> Builder(CI);
2290    return LCO->optimizeCall(CI, DL, TLI, LCS, Builder);
2291  }
2292  return nullptr;
2293}
2294
2295LibCallSimplifier::LibCallSimplifier(const DataLayout *DL,
2296                                     const TargetLibraryInfo *TLI,
2297                                     bool UnsafeFPShrink) {
2298  Impl = new LibCallSimplifierImpl(DL, TLI, this, UnsafeFPShrink);
2299}
2300
2301LibCallSimplifier::~LibCallSimplifier() {
2302  delete Impl;
2303}
2304
2305Value *LibCallSimplifier::optimizeCall(CallInst *CI) {
2306  if (CI->isNoBuiltin()) return nullptr;
2307  return Impl->optimizeCall(CI);
2308}
2309
2310void LibCallSimplifier::replaceAllUsesWith(Instruction *I, Value *With) const {
2311  I->replaceAllUsesWith(With);
2312  I->eraseFromParent();
2313}
2314
2315}
2316
2317// TODO:
2318//   Additional cases that we need to add to this file:
2319//
2320// cbrt:
2321//   * cbrt(expN(X))  -> expN(x/3)
2322//   * cbrt(sqrt(x))  -> pow(x,1/6)
2323//   * cbrt(sqrt(x))  -> pow(x,1/9)
2324//
2325// exp, expf, expl:
2326//   * exp(log(x))  -> x
2327//
2328// log, logf, logl:
2329//   * log(exp(x))   -> x
2330//   * log(x**y)     -> y*log(x)
2331//   * log(exp(y))   -> y*log(e)
2332//   * log(exp2(y))  -> y*log(2)
2333//   * log(exp10(y)) -> y*log(10)
2334//   * log(sqrt(x))  -> 0.5*log(x)
2335//   * log(pow(x,y)) -> y*log(x)
2336//
2337// lround, lroundf, lroundl:
2338//   * lround(cnst) -> cnst'
2339//
2340// pow, powf, powl:
2341//   * pow(exp(x),y)  -> exp(x*y)
2342//   * pow(sqrt(x),y) -> pow(x,y*0.5)
2343//   * pow(pow(x,y),z)-> pow(x,y*z)
2344//
2345// round, roundf, roundl:
2346//   * round(cnst) -> cnst'
2347//
2348// signbit:
2349//   * signbit(cnst) -> cnst'
2350//   * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2351//
2352// sqrt, sqrtf, sqrtl:
2353//   * sqrt(expN(x))  -> expN(x*0.5)
2354//   * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2355//   * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2356//
2357// tan, tanf, tanl:
2358//   * tan(atan(x)) -> x
2359//
2360// trunc, truncf, truncl:
2361//   * trunc(cnst) -> cnst'
2362//
2363//
2364