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