1 //===- SimplifyLibCalls.cpp - Optimize specific well-known library calls --===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a simple pass that applies a variety of small
11 // optimizations for calls to specific well-known function calls (e.g. runtime
12 // library functions). Any optimization that takes the very simple form
13 // "replace call to library function with simpler code that provides the same
14 // result" belongs in this file.
16 //===----------------------------------------------------------------------===//
18 #define DEBUG_TYPE "simplify-libcalls"
19 #include "llvm/Transforms/Scalar.h"
20 #include "llvm/Intrinsics.h"
21 #include "llvm/LLVMContext.h"
22 #include "llvm/Module.h"
23 #include "llvm/Pass.h"
24 #include "llvm/Support/IRBuilder.h"
25 #include "llvm/Analysis/ValueTracking.h"
26 #include "llvm/Target/TargetData.h"
27 #include "llvm/ADT/SmallPtrSet.h"
28 #include "llvm/ADT/StringMap.h"
29 #include "llvm/ADT/Statistic.h"
30 #include "llvm/ADT/STLExtras.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/raw_ostream.h"
33 #include "llvm/Config/config.h"
36 STATISTIC(NumSimplified, "Number of library calls simplified");
37 STATISTIC(NumAnnotated, "Number of attributes added to library functions");
39 //===----------------------------------------------------------------------===//
40 // Optimizer Base Class
41 //===----------------------------------------------------------------------===//
43 /// This class is the abstract base class for the set of optimizations that
44 /// corresponds to one library call.
46 class LibCallOptimization {
52 LibCallOptimization() { }
53 virtual ~LibCallOptimization() {}
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
60 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B)
63 Value *OptimizeCall(CallInst *CI, const TargetData *TD, IRBuilder<> &B) {
64 Caller = CI->getParent()->getParent();
66 if (CI->getCalledFunction())
67 Context = &CI->getCalledFunction()->getContext();
68 return CallOptimizer(CI->getCalledFunction(), CI, B);
71 /// CastToCStr - Return V if it is an i8*, otherwise cast it to i8*.
72 Value *CastToCStr(Value *V, IRBuilder<> &B);
74 /// EmitStrLen - Emit a call to the strlen function to the builder, for the
75 /// specified pointer. Ptr is required to be some pointer type, and the
76 /// return value has 'intptr_t' type.
77 Value *EmitStrLen(Value *Ptr, IRBuilder<> &B);
79 /// EmitStrChr - Emit a call to the strchr function to the builder, for the
80 /// specified pointer and character. Ptr is required to be some pointer type,
81 /// and the return value has 'i8*' type.
82 Value *EmitStrChr(Value *Ptr, char C, IRBuilder<> &B);
84 /// EmitMemCpy - Emit a call to the memcpy function to the builder. This
85 /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
86 Value *EmitMemCpy(Value *Dst, Value *Src, Value *Len,
87 unsigned Align, IRBuilder<> &B);
89 /// EmitMemMove - Emit a call to the memmove function to the builder. This
90 /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
91 Value *EmitMemMove(Value *Dst, Value *Src, Value *Len,
92 unsigned Align, IRBuilder<> &B);
94 /// EmitMemChr - Emit a call to the memchr function. This assumes that Ptr is
95 /// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
96 Value *EmitMemChr(Value *Ptr, Value *Val, Value *Len, IRBuilder<> &B);
98 /// EmitMemCmp - Emit a call to the memcmp function.
99 Value *EmitMemCmp(Value *Ptr1, Value *Ptr2, Value *Len, IRBuilder<> &B);
101 /// EmitMemSet - Emit a call to the memset function
102 Value *EmitMemSet(Value *Dst, Value *Val, Value *Len, IRBuilder<> &B);
104 /// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
105 /// 'floor'). This function is known to take a single of type matching 'Op'
106 /// and returns one value with the same type. If 'Op' is a long double, 'l'
107 /// is added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
108 Value *EmitUnaryFloatFnCall(Value *Op, const char *Name, IRBuilder<> &B,
109 const AttrListPtr &Attrs);
111 /// EmitPutChar - Emit a call to the putchar function. This assumes that Char
113 Value *EmitPutChar(Value *Char, IRBuilder<> &B);
115 /// EmitPutS - Emit a call to the puts function. This assumes that Str is
117 void EmitPutS(Value *Str, IRBuilder<> &B);
119 /// EmitFPutC - Emit a call to the fputc function. This assumes that Char is
120 /// an i32, and File is a pointer to FILE.
121 void EmitFPutC(Value *Char, Value *File, IRBuilder<> &B);
123 /// EmitFPutS - Emit a call to the puts function. Str is required to be a
124 /// pointer and File is a pointer to FILE.
125 void EmitFPutS(Value *Str, Value *File, IRBuilder<> &B);
127 /// EmitFWrite - Emit a call to the fwrite function. This assumes that Ptr is
128 /// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
129 void EmitFWrite(Value *Ptr, Value *Size, Value *File, IRBuilder<> &B);
132 } // End anonymous namespace.
134 /// CastToCStr - Return V if it is an i8*, otherwise cast it to i8*.
135 Value *LibCallOptimization::CastToCStr(Value *V, IRBuilder<> &B) {
136 return B.CreateBitCast(V, Type::getInt8PtrTy(*Context), "cstr");
139 /// EmitStrLen - Emit a call to the strlen function to the builder, for the
140 /// specified pointer. This always returns an integer value of size intptr_t.
141 Value *LibCallOptimization::EmitStrLen(Value *Ptr, IRBuilder<> &B) {
142 Module *M = Caller->getParent();
143 AttributeWithIndex AWI[2];
144 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
145 AWI[1] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
146 Attribute::NoUnwind);
148 Constant *StrLen =M->getOrInsertFunction("strlen", AttrListPtr::get(AWI, 2),
149 TD->getIntPtrType(*Context),
150 Type::getInt8PtrTy(*Context),
152 CallInst *CI = B.CreateCall(StrLen, CastToCStr(Ptr, B), "strlen");
153 if (const Function *F = dyn_cast<Function>(StrLen->stripPointerCasts()))
154 CI->setCallingConv(F->getCallingConv());
159 /// EmitStrChr - Emit a call to the strchr function to the builder, for the
160 /// specified pointer and character. Ptr is required to be some pointer type,
161 /// and the return value has 'i8*' type.
162 Value *LibCallOptimization::EmitStrChr(Value *Ptr, char C, IRBuilder<> &B) {
163 Module *M = Caller->getParent();
164 AttributeWithIndex AWI =
165 AttributeWithIndex::get(~0u, Attribute::ReadOnly | Attribute::NoUnwind);
167 const Type *I8Ptr = Type::getInt8PtrTy(*Context);
168 const Type *I32Ty = Type::getInt32Ty(*Context);
169 Constant *StrChr = M->getOrInsertFunction("strchr", AttrListPtr::get(&AWI, 1),
170 I8Ptr, I8Ptr, I32Ty, NULL);
171 CallInst *CI = B.CreateCall2(StrChr, CastToCStr(Ptr, B),
172 ConstantInt::get(I32Ty, C), "strchr");
173 if (const Function *F = dyn_cast<Function>(StrChr->stripPointerCasts()))
174 CI->setCallingConv(F->getCallingConv());
179 /// EmitMemCpy - Emit a call to the memcpy function to the builder. This always
180 /// expects that the size has type 'intptr_t' and Dst/Src are pointers.
181 Value *LibCallOptimization::EmitMemCpy(Value *Dst, Value *Src, Value *Len,
182 unsigned Align, IRBuilder<> &B) {
183 Module *M = Caller->getParent();
184 const Type *Ty = Len->getType();
185 Value *MemCpy = Intrinsic::getDeclaration(M, Intrinsic::memcpy, &Ty, 1);
186 Dst = CastToCStr(Dst, B);
187 Src = CastToCStr(Src, B);
188 return B.CreateCall4(MemCpy, Dst, Src, Len,
189 ConstantInt::get(Type::getInt32Ty(*Context), Align));
192 /// EmitMemMove - Emit a call to the memmove function to the builder. This
193 /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
194 Value *LibCallOptimization::EmitMemMove(Value *Dst, Value *Src, Value *Len,
195 unsigned Align, IRBuilder<> &B) {
196 Module *M = Caller->getParent();
197 const Type *Ty = TD->getIntPtrType(*Context);
198 Value *MemMove = Intrinsic::getDeclaration(M, Intrinsic::memmove, &Ty, 1);
199 Dst = CastToCStr(Dst, B);
200 Src = CastToCStr(Src, B);
201 Value *A = ConstantInt::get(Type::getInt32Ty(*Context), Align);
202 return B.CreateCall4(MemMove, Dst, Src, Len, A);
205 /// EmitMemChr - Emit a call to the memchr function. This assumes that Ptr is
206 /// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
207 Value *LibCallOptimization::EmitMemChr(Value *Ptr, Value *Val,
208 Value *Len, IRBuilder<> &B) {
209 Module *M = Caller->getParent();
210 AttributeWithIndex AWI;
211 AWI = AttributeWithIndex::get(~0u, Attribute::ReadOnly | Attribute::NoUnwind);
213 Value *MemChr = M->getOrInsertFunction("memchr", AttrListPtr::get(&AWI, 1),
214 Type::getInt8PtrTy(*Context),
215 Type::getInt8PtrTy(*Context),
216 Type::getInt32Ty(*Context),
217 TD->getIntPtrType(*Context),
219 CallInst *CI = B.CreateCall3(MemChr, CastToCStr(Ptr, B), Val, Len, "memchr");
221 if (const Function *F = dyn_cast<Function>(MemChr->stripPointerCasts()))
222 CI->setCallingConv(F->getCallingConv());
227 /// EmitMemCmp - Emit a call to the memcmp function.
228 Value *LibCallOptimization::EmitMemCmp(Value *Ptr1, Value *Ptr2,
229 Value *Len, IRBuilder<> &B) {
230 Module *M = Caller->getParent();
231 AttributeWithIndex AWI[3];
232 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
233 AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
234 AWI[2] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
235 Attribute::NoUnwind);
237 Value *MemCmp = M->getOrInsertFunction("memcmp", AttrListPtr::get(AWI, 3),
238 Type::getInt32Ty(*Context),
239 Type::getInt8PtrTy(*Context),
240 Type::getInt8PtrTy(*Context),
241 TD->getIntPtrType(*Context), NULL);
242 CallInst *CI = B.CreateCall3(MemCmp, CastToCStr(Ptr1, B), CastToCStr(Ptr2, B),
245 if (const Function *F = dyn_cast<Function>(MemCmp->stripPointerCasts()))
246 CI->setCallingConv(F->getCallingConv());
251 /// EmitMemSet - Emit a call to the memset function
252 Value *LibCallOptimization::EmitMemSet(Value *Dst, Value *Val,
253 Value *Len, IRBuilder<> &B) {
254 Module *M = Caller->getParent();
255 Intrinsic::ID IID = Intrinsic::memset;
257 Tys[0] = Len->getType();
258 Value *MemSet = Intrinsic::getDeclaration(M, IID, Tys, 1);
259 Value *Align = ConstantInt::get(Type::getInt32Ty(*Context), 1);
260 return B.CreateCall4(MemSet, CastToCStr(Dst, B), Val, Len, Align);
263 /// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
264 /// 'floor'). This function is known to take a single of type matching 'Op' and
265 /// returns one value with the same type. If 'Op' is a long double, 'l' is
266 /// added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
267 Value *LibCallOptimization::EmitUnaryFloatFnCall(Value *Op, const char *Name,
269 const AttrListPtr &Attrs) {
271 if (!Op->getType()->isDoubleTy()) {
272 // If we need to add a suffix, copy into NameBuffer.
273 unsigned NameLen = strlen(Name);
274 assert(NameLen < sizeof(NameBuffer)-2);
275 memcpy(NameBuffer, Name, NameLen);
276 if (Op->getType()->isFloatTy())
277 NameBuffer[NameLen] = 'f'; // floorf
279 NameBuffer[NameLen] = 'l'; // floorl
280 NameBuffer[NameLen+1] = 0;
284 Module *M = Caller->getParent();
285 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
286 Op->getType(), NULL);
287 CallInst *CI = B.CreateCall(Callee, Op, Name);
288 CI->setAttributes(Attrs);
289 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
290 CI->setCallingConv(F->getCallingConv());
295 /// EmitPutChar - Emit a call to the putchar function. This assumes that Char
297 Value *LibCallOptimization::EmitPutChar(Value *Char, IRBuilder<> &B) {
298 Module *M = Caller->getParent();
299 Value *PutChar = M->getOrInsertFunction("putchar", Type::getInt32Ty(*Context),
300 Type::getInt32Ty(*Context), NULL);
301 CallInst *CI = B.CreateCall(PutChar,
302 B.CreateIntCast(Char,
303 Type::getInt32Ty(*Context),
308 if (const Function *F = dyn_cast<Function>(PutChar->stripPointerCasts()))
309 CI->setCallingConv(F->getCallingConv());
313 /// EmitPutS - Emit a call to the puts function. This assumes that Str is
315 void LibCallOptimization::EmitPutS(Value *Str, IRBuilder<> &B) {
316 Module *M = Caller->getParent();
317 AttributeWithIndex AWI[2];
318 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
319 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
321 Value *PutS = M->getOrInsertFunction("puts", AttrListPtr::get(AWI, 2),
322 Type::getInt32Ty(*Context),
323 Type::getInt8PtrTy(*Context),
325 CallInst *CI = B.CreateCall(PutS, CastToCStr(Str, B), "puts");
326 if (const Function *F = dyn_cast<Function>(PutS->stripPointerCasts()))
327 CI->setCallingConv(F->getCallingConv());
331 /// EmitFPutC - Emit a call to the fputc function. This assumes that Char is
332 /// an integer and File is a pointer to FILE.
333 void LibCallOptimization::EmitFPutC(Value *Char, Value *File, IRBuilder<> &B) {
334 Module *M = Caller->getParent();
335 AttributeWithIndex AWI[2];
336 AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
337 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
339 if (isa<PointerType>(File->getType()))
340 F = M->getOrInsertFunction("fputc", AttrListPtr::get(AWI, 2),
341 Type::getInt32Ty(*Context),
342 Type::getInt32Ty(*Context), File->getType(),
345 F = M->getOrInsertFunction("fputc",
346 Type::getInt32Ty(*Context),
347 Type::getInt32Ty(*Context),
348 File->getType(), NULL);
349 Char = B.CreateIntCast(Char, Type::getInt32Ty(*Context), /*isSigned*/true,
351 CallInst *CI = B.CreateCall2(F, Char, File, "fputc");
353 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
354 CI->setCallingConv(Fn->getCallingConv());
357 /// EmitFPutS - Emit a call to the puts function. Str is required to be a
358 /// pointer and File is a pointer to FILE.
359 void LibCallOptimization::EmitFPutS(Value *Str, Value *File, IRBuilder<> &B) {
360 Module *M = Caller->getParent();
361 AttributeWithIndex AWI[3];
362 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
363 AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
364 AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
366 if (isa<PointerType>(File->getType()))
367 F = M->getOrInsertFunction("fputs", AttrListPtr::get(AWI, 3),
368 Type::getInt32Ty(*Context),
369 Type::getInt8PtrTy(*Context),
370 File->getType(), NULL);
372 F = M->getOrInsertFunction("fputs", Type::getInt32Ty(*Context),
373 Type::getInt8PtrTy(*Context),
374 File->getType(), NULL);
375 CallInst *CI = B.CreateCall2(F, CastToCStr(Str, B), File, "fputs");
377 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
378 CI->setCallingConv(Fn->getCallingConv());
381 /// EmitFWrite - Emit a call to the fwrite function. This assumes that Ptr is
382 /// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
383 void LibCallOptimization::EmitFWrite(Value *Ptr, Value *Size, Value *File,
385 Module *M = Caller->getParent();
386 AttributeWithIndex AWI[3];
387 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
388 AWI[1] = AttributeWithIndex::get(4, Attribute::NoCapture);
389 AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
391 if (isa<PointerType>(File->getType()))
392 F = M->getOrInsertFunction("fwrite", AttrListPtr::get(AWI, 3),
393 TD->getIntPtrType(*Context),
394 Type::getInt8PtrTy(*Context),
395 TD->getIntPtrType(*Context),
396 TD->getIntPtrType(*Context),
397 File->getType(), NULL);
399 F = M->getOrInsertFunction("fwrite", TD->getIntPtrType(*Context),
400 Type::getInt8PtrTy(*Context),
401 TD->getIntPtrType(*Context),
402 TD->getIntPtrType(*Context),
403 File->getType(), NULL);
404 CallInst *CI = B.CreateCall4(F, CastToCStr(Ptr, B), Size,
405 ConstantInt::get(TD->getIntPtrType(*Context), 1), File);
407 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
408 CI->setCallingConv(Fn->getCallingConv());
411 //===----------------------------------------------------------------------===//
413 //===----------------------------------------------------------------------===//
415 /// GetStringLengthH - If we can compute the length of the string pointed to by
416 /// the specified pointer, return 'len+1'. If we can't, return 0.
417 static uint64_t GetStringLengthH(Value *V, SmallPtrSet<PHINode*, 32> &PHIs) {
418 // Look through noop bitcast instructions.
419 if (BitCastInst *BCI = dyn_cast<BitCastInst>(V))
420 return GetStringLengthH(BCI->getOperand(0), PHIs);
422 // If this is a PHI node, there are two cases: either we have already seen it
424 if (PHINode *PN = dyn_cast<PHINode>(V)) {
425 if (!PHIs.insert(PN))
426 return ~0ULL; // already in the set.
428 // If it was new, see if all the input strings are the same length.
429 uint64_t LenSoFar = ~0ULL;
430 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
431 uint64_t Len = GetStringLengthH(PN->getIncomingValue(i), PHIs);
432 if (Len == 0) return 0; // Unknown length -> unknown.
434 if (Len == ~0ULL) continue;
436 if (Len != LenSoFar && LenSoFar != ~0ULL)
437 return 0; // Disagree -> unknown.
441 // Success, all agree.
445 // strlen(select(c,x,y)) -> strlen(x) ^ strlen(y)
446 if (SelectInst *SI = dyn_cast<SelectInst>(V)) {
447 uint64_t Len1 = GetStringLengthH(SI->getTrueValue(), PHIs);
448 if (Len1 == 0) return 0;
449 uint64_t Len2 = GetStringLengthH(SI->getFalseValue(), PHIs);
450 if (Len2 == 0) return 0;
451 if (Len1 == ~0ULL) return Len2;
452 if (Len2 == ~0ULL) return Len1;
453 if (Len1 != Len2) return 0;
457 // If the value is not a GEP instruction nor a constant expression with a
458 // GEP instruction, then return unknown.
460 if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) {
462 } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
463 if (CE->getOpcode() != Instruction::GetElementPtr)
470 // Make sure the GEP has exactly three arguments.
471 if (GEP->getNumOperands() != 3)
474 // Check to make sure that the first operand of the GEP is an integer and
475 // has value 0 so that we are sure we're indexing into the initializer.
476 if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
482 // If the second index isn't a ConstantInt, then this is a variable index
483 // into the array. If this occurs, we can't say anything meaningful about
485 uint64_t StartIdx = 0;
486 if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(2)))
487 StartIdx = CI->getZExtValue();
491 // The GEP instruction, constant or instruction, must reference a global
492 // variable that is a constant and is initialized. The referenced constant
493 // initializer is the array that we'll use for optimization.
494 GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0));
495 if (!GV || !GV->isConstant() || !GV->hasInitializer() ||
496 GV->mayBeOverridden())
498 Constant *GlobalInit = GV->getInitializer();
500 // Handle the ConstantAggregateZero case, which is a degenerate case. The
501 // initializer is constant zero so the length of the string must be zero.
502 if (isa<ConstantAggregateZero>(GlobalInit))
503 return 1; // Len = 0 offset by 1.
505 // Must be a Constant Array
506 ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit);
508 Array->getType()->getElementType() != Type::getInt8Ty(V->getContext()))
511 // Get the number of elements in the array
512 uint64_t NumElts = Array->getType()->getNumElements();
514 // Traverse the constant array from StartIdx (derived above) which is
515 // the place the GEP refers to in the array.
516 for (unsigned i = StartIdx; i != NumElts; ++i) {
517 Constant *Elt = Array->getOperand(i);
518 ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
519 if (!CI) // This array isn't suitable, non-int initializer.
522 return i-StartIdx+1; // We found end of string, success!
525 return 0; // The array isn't null terminated, conservatively return 'unknown'.
528 /// GetStringLength - If we can compute the length of the string pointed to by
529 /// the specified pointer, return 'len+1'. If we can't, return 0.
530 static uint64_t GetStringLength(Value *V) {
531 if (!isa<PointerType>(V->getType())) return 0;
533 SmallPtrSet<PHINode*, 32> PHIs;
534 uint64_t Len = GetStringLengthH(V, PHIs);
535 // If Len is ~0ULL, we had an infinite phi cycle: this is dead code, so return
536 // an empty string as a length.
537 return Len == ~0ULL ? 1 : Len;
540 /// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
541 /// value is equal or not-equal to zero.
542 static bool IsOnlyUsedInZeroEqualityComparison(Value *V) {
543 for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
545 if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
546 if (IC->isEquality())
547 if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
548 if (C->isNullValue())
550 // Unknown instruction.
556 //===----------------------------------------------------------------------===//
557 // String and Memory LibCall Optimizations
558 //===----------------------------------------------------------------------===//
560 //===---------------------------------------===//
561 // 'strcat' Optimizations
563 struct StrCatOpt : public LibCallOptimization {
564 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
565 // Verify the "strcat" function prototype.
566 const FunctionType *FT = Callee->getFunctionType();
567 if (FT->getNumParams() != 2 ||
568 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
569 FT->getParamType(0) != FT->getReturnType() ||
570 FT->getParamType(1) != FT->getReturnType())
573 // Extract some information from the instruction
574 Value *Dst = CI->getOperand(1);
575 Value *Src = CI->getOperand(2);
577 // See if we can get the length of the input string.
578 uint64_t Len = GetStringLength(Src);
579 if (Len == 0) return 0;
580 --Len; // Unbias length.
582 // Handle the simple, do-nothing case: strcat(x, "") -> x
586 // These optimizations require TargetData.
589 EmitStrLenMemCpy(Src, Dst, Len, B);
593 void EmitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len, IRBuilder<> &B) {
594 // We need to find the end of the destination string. That's where the
595 // memory is to be moved to. We just generate a call to strlen.
596 Value *DstLen = EmitStrLen(Dst, B);
598 // Now that we have the destination's length, we must index into the
599 // destination's pointer to get the actual memcpy destination (end of
600 // the string .. we're concatenating).
601 Value *CpyDst = B.CreateGEP(Dst, DstLen, "endptr");
603 // We have enough information to now generate the memcpy call to do the
604 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
605 EmitMemCpy(CpyDst, Src,
606 ConstantInt::get(TD->getIntPtrType(*Context), Len+1), 1, B);
610 //===---------------------------------------===//
611 // 'strncat' Optimizations
613 struct StrNCatOpt : public StrCatOpt {
614 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
615 // Verify the "strncat" function prototype.
616 const FunctionType *FT = Callee->getFunctionType();
617 if (FT->getNumParams() != 3 ||
618 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
619 FT->getParamType(0) != FT->getReturnType() ||
620 FT->getParamType(1) != FT->getReturnType() ||
621 !isa<IntegerType>(FT->getParamType(2)))
624 // Extract some information from the instruction
625 Value *Dst = CI->getOperand(1);
626 Value *Src = CI->getOperand(2);
629 // We don't do anything if length is not constant
630 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
631 Len = LengthArg->getZExtValue();
635 // See if we can get the length of the input string.
636 uint64_t SrcLen = GetStringLength(Src);
637 if (SrcLen == 0) return 0;
638 --SrcLen; // Unbias length.
640 // Handle the simple, do-nothing cases:
641 // strncat(x, "", c) -> x
642 // strncat(x, c, 0) -> x
643 if (SrcLen == 0 || Len == 0) return Dst;
645 // These optimizations require TargetData.
648 // We don't optimize this case
649 if (Len < SrcLen) return 0;
651 // strncat(x, s, c) -> strcat(x, s)
652 // s is constant so the strcat can be optimized further
653 EmitStrLenMemCpy(Src, Dst, SrcLen, B);
658 //===---------------------------------------===//
659 // 'strchr' Optimizations
661 struct StrChrOpt : public LibCallOptimization {
662 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
663 // Verify the "strchr" function prototype.
664 const FunctionType *FT = Callee->getFunctionType();
665 if (FT->getNumParams() != 2 ||
666 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
667 FT->getParamType(0) != FT->getReturnType())
670 Value *SrcStr = CI->getOperand(1);
672 // If the second operand is non-constant, see if we can compute the length
673 // of the input string and turn this into memchr.
674 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getOperand(2));
676 // These optimizations require TargetData.
679 uint64_t Len = GetStringLength(SrcStr);
681 FT->getParamType(1) != Type::getInt32Ty(*Context)) // memchr needs i32.
684 return EmitMemChr(SrcStr, CI->getOperand(2), // include nul.
685 ConstantInt::get(TD->getIntPtrType(*Context), Len), B);
688 // Otherwise, the character is a constant, see if the first argument is
689 // a string literal. If so, we can constant fold.
691 if (!GetConstantStringInfo(SrcStr, Str))
694 // strchr can find the nul character.
696 char CharValue = CharC->getSExtValue();
698 // Compute the offset.
701 if (i == Str.size()) // Didn't find the char. strchr returns null.
702 return Constant::getNullValue(CI->getType());
703 // Did we find our match?
704 if (Str[i] == CharValue)
709 // strchr(s+n,c) -> gep(s+n+i,c)
710 Value *Idx = ConstantInt::get(Type::getInt64Ty(*Context), i);
711 return B.CreateGEP(SrcStr, Idx, "strchr");
715 //===---------------------------------------===//
716 // 'strcmp' Optimizations
718 struct StrCmpOpt : public LibCallOptimization {
719 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
720 // Verify the "strcmp" function prototype.
721 const FunctionType *FT = Callee->getFunctionType();
722 if (FT->getNumParams() != 2 ||
723 FT->getReturnType() != Type::getInt32Ty(*Context) ||
724 FT->getParamType(0) != FT->getParamType(1) ||
725 FT->getParamType(0) != Type::getInt8PtrTy(*Context))
728 Value *Str1P = CI->getOperand(1), *Str2P = CI->getOperand(2);
729 if (Str1P == Str2P) // strcmp(x,x) -> 0
730 return ConstantInt::get(CI->getType(), 0);
732 std::string Str1, Str2;
733 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
734 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
736 if (HasStr1 && Str1.empty()) // strcmp("", x) -> *x
737 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
739 if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
740 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
742 // strcmp(x, y) -> cnst (if both x and y are constant strings)
743 if (HasStr1 && HasStr2)
744 return ConstantInt::get(CI->getType(),
745 strcmp(Str1.c_str(),Str2.c_str()));
747 // strcmp(P, "x") -> memcmp(P, "x", 2)
748 uint64_t Len1 = GetStringLength(Str1P);
749 uint64_t Len2 = GetStringLength(Str2P);
751 // These optimizations require TargetData.
754 return EmitMemCmp(Str1P, Str2P,
755 ConstantInt::get(TD->getIntPtrType(*Context),
756 std::min(Len1, Len2)), B);
763 //===---------------------------------------===//
764 // 'strncmp' Optimizations
766 struct StrNCmpOpt : public LibCallOptimization {
767 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
768 // Verify the "strncmp" function prototype.
769 const FunctionType *FT = Callee->getFunctionType();
770 if (FT->getNumParams() != 3 ||
771 FT->getReturnType() != Type::getInt32Ty(*Context) ||
772 FT->getParamType(0) != FT->getParamType(1) ||
773 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
774 !isa<IntegerType>(FT->getParamType(2)))
777 Value *Str1P = CI->getOperand(1), *Str2P = CI->getOperand(2);
778 if (Str1P == Str2P) // strncmp(x,x,n) -> 0
779 return ConstantInt::get(CI->getType(), 0);
781 // Get the length argument if it is constant.
783 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
784 Length = LengthArg->getZExtValue();
788 if (Length == 0) // strncmp(x,y,0) -> 0
789 return ConstantInt::get(CI->getType(), 0);
791 std::string Str1, Str2;
792 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
793 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
795 if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> *x
796 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
798 if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x
799 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
801 // strncmp(x, y) -> cnst (if both x and y are constant strings)
802 if (HasStr1 && HasStr2)
803 return ConstantInt::get(CI->getType(),
804 strncmp(Str1.c_str(), Str2.c_str(), Length));
810 //===---------------------------------------===//
811 // 'strcpy' Optimizations
813 struct StrCpyOpt : public LibCallOptimization {
814 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
815 // Verify the "strcpy" function prototype.
816 const FunctionType *FT = Callee->getFunctionType();
817 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
818 FT->getParamType(0) != FT->getParamType(1) ||
819 FT->getParamType(0) != Type::getInt8PtrTy(*Context))
822 Value *Dst = CI->getOperand(1), *Src = CI->getOperand(2);
823 if (Dst == Src) // strcpy(x,x) -> x
826 // These optimizations require TargetData.
829 // See if we can get the length of the input string.
830 uint64_t Len = GetStringLength(Src);
831 if (Len == 0) return 0;
833 // We have enough information to now generate the memcpy call to do the
834 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
836 ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B);
841 //===---------------------------------------===//
842 // 'strncpy' Optimizations
844 struct StrNCpyOpt : public LibCallOptimization {
845 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
846 const FunctionType *FT = Callee->getFunctionType();
847 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
848 FT->getParamType(0) != FT->getParamType(1) ||
849 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
850 !isa<IntegerType>(FT->getParamType(2)))
853 Value *Dst = CI->getOperand(1);
854 Value *Src = CI->getOperand(2);
855 Value *LenOp = CI->getOperand(3);
857 // See if we can get the length of the input string.
858 uint64_t SrcLen = GetStringLength(Src);
859 if (SrcLen == 0) return 0;
863 // strncpy(x, "", y) -> memset(x, '\0', y, 1)
864 EmitMemSet(Dst, ConstantInt::get(Type::getInt8Ty(*Context), '\0'), LenOp,
870 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
871 Len = LengthArg->getZExtValue();
875 if (Len == 0) return Dst; // strncpy(x, y, 0) -> x
877 // These optimizations require TargetData.
880 // Let strncpy handle the zero padding
881 if (Len > SrcLen+1) return 0;
883 // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
885 ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B);
891 //===---------------------------------------===//
892 // 'strlen' Optimizations
894 struct StrLenOpt : public LibCallOptimization {
895 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
896 const FunctionType *FT = Callee->getFunctionType();
897 if (FT->getNumParams() != 1 ||
898 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
899 !isa<IntegerType>(FT->getReturnType()))
902 Value *Src = CI->getOperand(1);
904 // Constant folding: strlen("xyz") -> 3
905 if (uint64_t Len = GetStringLength(Src))
906 return ConstantInt::get(CI->getType(), Len-1);
908 // strlen(x) != 0 --> *x != 0
909 // strlen(x) == 0 --> *x == 0
910 if (IsOnlyUsedInZeroEqualityComparison(CI))
911 return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
916 //===---------------------------------------===//
917 // 'strto*' Optimizations. This handles strtol, strtod, strtof, strtoul, etc.
919 struct StrToOpt : public LibCallOptimization {
920 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
921 const FunctionType *FT = Callee->getFunctionType();
922 if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
923 !isa<PointerType>(FT->getParamType(0)) ||
924 !isa<PointerType>(FT->getParamType(1)))
927 Value *EndPtr = CI->getOperand(2);
928 if (isa<ConstantPointerNull>(EndPtr)) {
929 CI->setOnlyReadsMemory();
930 CI->addAttribute(1, Attribute::NoCapture);
937 //===---------------------------------------===//
938 // 'strstr' Optimizations
940 struct StrStrOpt : public LibCallOptimization {
941 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
942 const FunctionType *FT = Callee->getFunctionType();
943 if (FT->getNumParams() != 2 ||
944 !isa<PointerType>(FT->getParamType(0)) ||
945 !isa<PointerType>(FT->getParamType(1)) ||
946 !isa<PointerType>(FT->getReturnType()))
949 // fold strstr(x, x) -> x.
950 if (CI->getOperand(1) == CI->getOperand(2))
951 return B.CreateBitCast(CI->getOperand(1), CI->getType());
953 // See if either input string is a constant string.
954 std::string SearchStr, ToFindStr;
955 bool HasStr1 = GetConstantStringInfo(CI->getOperand(1), SearchStr);
956 bool HasStr2 = GetConstantStringInfo(CI->getOperand(2), ToFindStr);
958 // fold strstr(x, "") -> x.
959 if (HasStr2 && ToFindStr.empty())
960 return B.CreateBitCast(CI->getOperand(1), CI->getType());
962 // If both strings are known, constant fold it.
963 if (HasStr1 && HasStr2) {
964 std::string::size_type Offset = SearchStr.find(ToFindStr);
966 if (Offset == std::string::npos) // strstr("foo", "bar") -> null
967 return Constant::getNullValue(CI->getType());
969 // strstr("abcd", "bc") -> gep((char*)"abcd", 1)
970 Value *Result = CastToCStr(CI->getOperand(1), B);
971 Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
972 return B.CreateBitCast(Result, CI->getType());
975 // fold strstr(x, "y") -> strchr(x, 'y').
976 if (HasStr2 && ToFindStr.size() == 1)
977 return B.CreateBitCast(EmitStrChr(CI->getOperand(1), ToFindStr[0], B),
984 //===---------------------------------------===//
985 // 'memcmp' Optimizations
987 struct MemCmpOpt : public LibCallOptimization {
988 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
989 const FunctionType *FT = Callee->getFunctionType();
990 if (FT->getNumParams() != 3 || !isa<PointerType>(FT->getParamType(0)) ||
991 !isa<PointerType>(FT->getParamType(1)) ||
992 FT->getReturnType() != Type::getInt32Ty(*Context))
995 Value *LHS = CI->getOperand(1), *RHS = CI->getOperand(2);
997 if (LHS == RHS) // memcmp(s,s,x) -> 0
998 return Constant::getNullValue(CI->getType());
1000 // Make sure we have a constant length.
1001 ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getOperand(3));
1002 if (!LenC) return 0;
1003 uint64_t Len = LenC->getZExtValue();
1005 if (Len == 0) // memcmp(s1,s2,0) -> 0
1006 return Constant::getNullValue(CI->getType());
1008 if (Len == 1) { // memcmp(S1,S2,1) -> *LHS - *RHS
1009 Value *LHSV = B.CreateLoad(CastToCStr(LHS, B), "lhsv");
1010 Value *RHSV = B.CreateLoad(CastToCStr(RHS, B), "rhsv");
1011 return B.CreateSExt(B.CreateSub(LHSV, RHSV, "chardiff"), CI->getType());
1014 // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
1015 std::string LHSStr, RHSStr;
1016 if (GetConstantStringInfo(LHS, LHSStr) &&
1017 GetConstantStringInfo(RHS, RHSStr)) {
1018 // Make sure we're not reading out-of-bounds memory.
1019 if (Len > LHSStr.length() || Len > RHSStr.length())
1021 uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len);
1022 return ConstantInt::get(CI->getType(), Ret);
1029 //===---------------------------------------===//
1030 // 'memcpy' Optimizations
1032 struct MemCpyOpt : public LibCallOptimization {
1033 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1034 // These optimizations require TargetData.
1037 const FunctionType *FT = Callee->getFunctionType();
1038 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1039 !isa<PointerType>(FT->getParamType(0)) ||
1040 !isa<PointerType>(FT->getParamType(1)) ||
1041 FT->getParamType(2) != TD->getIntPtrType(*Context))
1044 // memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
1045 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3), 1, B);
1046 return CI->getOperand(1);
1050 //===---------------------------------------===//
1051 // 'memmove' Optimizations
1053 struct MemMoveOpt : public LibCallOptimization {
1054 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1055 // These optimizations require TargetData.
1058 const FunctionType *FT = Callee->getFunctionType();
1059 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1060 !isa<PointerType>(FT->getParamType(0)) ||
1061 !isa<PointerType>(FT->getParamType(1)) ||
1062 FT->getParamType(2) != TD->getIntPtrType(*Context))
1065 // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
1066 EmitMemMove(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3), 1, B);
1067 return CI->getOperand(1);
1071 //===---------------------------------------===//
1072 // 'memset' Optimizations
1074 struct MemSetOpt : public LibCallOptimization {
1075 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1076 // These optimizations require TargetData.
1079 const FunctionType *FT = Callee->getFunctionType();
1080 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1081 !isa<PointerType>(FT->getParamType(0)) ||
1082 !isa<IntegerType>(FT->getParamType(1)) ||
1083 FT->getParamType(2) != TD->getIntPtrType(*Context))
1086 // memset(p, v, n) -> llvm.memset(p, v, n, 1)
1087 Value *Val = B.CreateIntCast(CI->getOperand(2), Type::getInt8Ty(*Context),
1089 EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B);
1090 return CI->getOperand(1);
1094 //===----------------------------------------------------------------------===//
1095 // Object Size Checking Optimizations
1096 //===----------------------------------------------------------------------===//
1098 //===---------------------------------------===//
1101 struct SizeOpt : public LibCallOptimization {
1102 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1103 // TODO: We can do more with this, but delaying to here should be no change
1105 ConstantInt *Const = dyn_cast<ConstantInt>(CI->getOperand(2));
1107 if (!Const) return 0;
1109 const Type *Ty = Callee->getFunctionType()->getReturnType();
1111 if (Const->getZExtValue() == 0)
1112 return Constant::getAllOnesValue(Ty);
1114 return ConstantInt::get(Ty, 0);
1119 //===---------------------------------------===//
1120 // 'memcpy_chk' Optimizations
1122 struct MemCpyChkOpt : public LibCallOptimization {
1123 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1124 // These optimizations require TargetData.
1127 const FunctionType *FT = Callee->getFunctionType();
1128 if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
1129 !isa<PointerType>(FT->getParamType(0)) ||
1130 !isa<PointerType>(FT->getParamType(1)) ||
1131 !isa<IntegerType>(FT->getParamType(3)) ||
1132 FT->getParamType(2) != TD->getIntPtrType(*Context))
1135 ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
1138 if (SizeCI->isAllOnesValue()) {
1139 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3), 1, B);
1140 return CI->getOperand(1);
1147 //===---------------------------------------===//
1148 // 'memset_chk' Optimizations
1150 struct MemSetChkOpt : public LibCallOptimization {
1151 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1152 // These optimizations require TargetData.
1155 const FunctionType *FT = Callee->getFunctionType();
1156 if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
1157 !isa<PointerType>(FT->getParamType(0)) ||
1158 !isa<IntegerType>(FT->getParamType(1)) ||
1159 !isa<IntegerType>(FT->getParamType(3)) ||
1160 FT->getParamType(2) != TD->getIntPtrType(*Context))
1163 ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
1166 if (SizeCI->isAllOnesValue()) {
1167 Value *Val = B.CreateIntCast(CI->getOperand(2), Type::getInt8Ty(*Context),
1169 EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B);
1170 return CI->getOperand(1);
1177 //===---------------------------------------===//
1178 // 'memmove_chk' Optimizations
1180 struct MemMoveChkOpt : public LibCallOptimization {
1181 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1182 // These optimizations require TargetData.
1185 const FunctionType *FT = Callee->getFunctionType();
1186 if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
1187 !isa<PointerType>(FT->getParamType(0)) ||
1188 !isa<PointerType>(FT->getParamType(1)) ||
1189 !isa<IntegerType>(FT->getParamType(3)) ||
1190 FT->getParamType(2) != TD->getIntPtrType(*Context))
1193 ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
1196 if (SizeCI->isAllOnesValue()) {
1197 EmitMemMove(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
1199 return CI->getOperand(1);
1206 //===----------------------------------------------------------------------===//
1207 // Math Library Optimizations
1208 //===----------------------------------------------------------------------===//
1210 //===---------------------------------------===//
1211 // 'pow*' Optimizations
1213 struct PowOpt : public LibCallOptimization {
1214 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1215 const FunctionType *FT = Callee->getFunctionType();
1216 // Just make sure this has 2 arguments of the same FP type, which match the
1218 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1219 FT->getParamType(0) != FT->getParamType(1) ||
1220 !FT->getParamType(0)->isFloatingPoint())
1223 Value *Op1 = CI->getOperand(1), *Op2 = CI->getOperand(2);
1224 if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
1225 if (Op1C->isExactlyValue(1.0)) // pow(1.0, x) -> 1.0
1227 if (Op1C->isExactlyValue(2.0)) // pow(2.0, x) -> exp2(x)
1228 return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
1231 ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
1232 if (Op2C == 0) return 0;
1234 if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
1235 return ConstantFP::get(CI->getType(), 1.0);
1237 if (Op2C->isExactlyValue(0.5)) {
1238 // Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
1239 // This is faster than calling pow, and still handles negative zero
1240 // and negative infinite correctly.
1241 // TODO: In fast-math mode, this could be just sqrt(x).
1242 // TODO: In finite-only mode, this could be just fabs(sqrt(x)).
1243 Value *Inf = ConstantFP::getInfinity(CI->getType());
1244 Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
1245 Value *Sqrt = EmitUnaryFloatFnCall(Op1, "sqrt", B,
1246 Callee->getAttributes());
1247 Value *FAbs = EmitUnaryFloatFnCall(Sqrt, "fabs", B,
1248 Callee->getAttributes());
1249 Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf, "tmp");
1250 Value *Sel = B.CreateSelect(FCmp, Inf, FAbs, "tmp");
1254 if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
1256 if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
1257 return B.CreateFMul(Op1, Op1, "pow2");
1258 if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
1259 return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0),
1265 //===---------------------------------------===//
1266 // 'exp2' Optimizations
1268 struct Exp2Opt : public LibCallOptimization {
1269 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1270 const FunctionType *FT = Callee->getFunctionType();
1271 // Just make sure this has 1 argument of FP type, which matches the
1273 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1274 !FT->getParamType(0)->isFloatingPoint())
1277 Value *Op = CI->getOperand(1);
1278 // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
1279 // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
1280 Value *LdExpArg = 0;
1281 if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
1282 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
1283 LdExpArg = B.CreateSExt(OpC->getOperand(0),
1284 Type::getInt32Ty(*Context), "tmp");
1285 } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
1286 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
1287 LdExpArg = B.CreateZExt(OpC->getOperand(0),
1288 Type::getInt32Ty(*Context), "tmp");
1293 if (Op->getType()->isFloatTy())
1295 else if (Op->getType()->isDoubleTy())
1300 Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
1301 if (!Op->getType()->isFloatTy())
1302 One = ConstantExpr::getFPExtend(One, Op->getType());
1304 Module *M = Caller->getParent();
1305 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
1307 Type::getInt32Ty(*Context),NULL);
1308 CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
1309 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
1310 CI->setCallingConv(F->getCallingConv());
1318 //===---------------------------------------===//
1319 // Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
1321 struct UnaryDoubleFPOpt : public LibCallOptimization {
1322 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1323 const FunctionType *FT = Callee->getFunctionType();
1324 if (FT->getNumParams() != 1 || !FT->getReturnType()->isDoubleTy() ||
1325 !FT->getParamType(0)->isDoubleTy())
1328 // If this is something like 'floor((double)floatval)', convert to floorf.
1329 FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getOperand(1));
1330 if (Cast == 0 || !Cast->getOperand(0)->getType()->isFloatTy())
1333 // floor((double)floatval) -> (double)floorf(floatval)
1334 Value *V = Cast->getOperand(0);
1335 V = EmitUnaryFloatFnCall(V, Callee->getName().data(), B,
1336 Callee->getAttributes());
1337 return B.CreateFPExt(V, Type::getDoubleTy(*Context));
1341 //===----------------------------------------------------------------------===//
1342 // Integer Optimizations
1343 //===----------------------------------------------------------------------===//
1345 //===---------------------------------------===//
1346 // 'ffs*' Optimizations
1348 struct FFSOpt : public LibCallOptimization {
1349 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1350 const FunctionType *FT = Callee->getFunctionType();
1351 // Just make sure this has 2 arguments of the same FP type, which match the
1353 if (FT->getNumParams() != 1 ||
1354 FT->getReturnType() != Type::getInt32Ty(*Context) ||
1355 !isa<IntegerType>(FT->getParamType(0)))
1358 Value *Op = CI->getOperand(1);
1361 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
1362 if (CI->getValue() == 0) // ffs(0) -> 0.
1363 return Constant::getNullValue(CI->getType());
1364 return ConstantInt::get(Type::getInt32Ty(*Context), // ffs(c) -> cttz(c)+1
1365 CI->getValue().countTrailingZeros()+1);
1368 // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
1369 const Type *ArgType = Op->getType();
1370 Value *F = Intrinsic::getDeclaration(Callee->getParent(),
1371 Intrinsic::cttz, &ArgType, 1);
1372 Value *V = B.CreateCall(F, Op, "cttz");
1373 V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1), "tmp");
1374 V = B.CreateIntCast(V, Type::getInt32Ty(*Context), false, "tmp");
1376 Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType), "tmp");
1377 return B.CreateSelect(Cond, V,
1378 ConstantInt::get(Type::getInt32Ty(*Context), 0));
1382 //===---------------------------------------===//
1383 // 'isdigit' Optimizations
1385 struct IsDigitOpt : public LibCallOptimization {
1386 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1387 const FunctionType *FT = Callee->getFunctionType();
1388 // We require integer(i32)
1389 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1390 FT->getParamType(0) != Type::getInt32Ty(*Context))
1393 // isdigit(c) -> (c-'0') <u 10
1394 Value *Op = CI->getOperand(1);
1395 Op = B.CreateSub(Op, ConstantInt::get(Type::getInt32Ty(*Context), '0'),
1397 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 10),
1399 return B.CreateZExt(Op, CI->getType());
1403 //===---------------------------------------===//
1404 // 'isascii' Optimizations
1406 struct IsAsciiOpt : public LibCallOptimization {
1407 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1408 const FunctionType *FT = Callee->getFunctionType();
1409 // We require integer(i32)
1410 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1411 FT->getParamType(0) != Type::getInt32Ty(*Context))
1414 // isascii(c) -> c <u 128
1415 Value *Op = CI->getOperand(1);
1416 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 128),
1418 return B.CreateZExt(Op, CI->getType());
1422 //===---------------------------------------===//
1423 // 'abs', 'labs', 'llabs' Optimizations
1425 struct AbsOpt : public LibCallOptimization {
1426 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1427 const FunctionType *FT = Callee->getFunctionType();
1428 // We require integer(integer) where the types agree.
1429 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1430 FT->getParamType(0) != FT->getReturnType())
1433 // abs(x) -> x >s -1 ? x : -x
1434 Value *Op = CI->getOperand(1);
1435 Value *Pos = B.CreateICmpSGT(Op,
1436 Constant::getAllOnesValue(Op->getType()),
1438 Value *Neg = B.CreateNeg(Op, "neg");
1439 return B.CreateSelect(Pos, Op, Neg);
1444 //===---------------------------------------===//
1445 // 'toascii' Optimizations
1447 struct ToAsciiOpt : public LibCallOptimization {
1448 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1449 const FunctionType *FT = Callee->getFunctionType();
1450 // We require i32(i32)
1451 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1452 FT->getParamType(0) != Type::getInt32Ty(*Context))
1455 // isascii(c) -> c & 0x7f
1456 return B.CreateAnd(CI->getOperand(1),
1457 ConstantInt::get(CI->getType(),0x7F));
1461 //===----------------------------------------------------------------------===//
1462 // Formatting and IO Optimizations
1463 //===----------------------------------------------------------------------===//
1465 //===---------------------------------------===//
1466 // 'printf' Optimizations
1468 struct PrintFOpt : public LibCallOptimization {
1469 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1470 // Require one fixed pointer argument and an integer/void result.
1471 const FunctionType *FT = Callee->getFunctionType();
1472 if (FT->getNumParams() < 1 || !isa<PointerType>(FT->getParamType(0)) ||
1473 !(isa<IntegerType>(FT->getReturnType()) ||
1474 FT->getReturnType()->isVoidTy()))
1477 // Check for a fixed format string.
1478 std::string FormatStr;
1479 if (!GetConstantStringInfo(CI->getOperand(1), FormatStr))
1482 // Empty format string -> noop.
1483 if (FormatStr.empty()) // Tolerate printf's declared void.
1484 return CI->use_empty() ? (Value*)CI :
1485 ConstantInt::get(CI->getType(), 0);
1487 // printf("x") -> putchar('x'), even for '%'. Return the result of putchar
1488 // in case there is an error writing to stdout.
1489 if (FormatStr.size() == 1) {
1490 Value *Res = EmitPutChar(ConstantInt::get(Type::getInt32Ty(*Context),
1492 if (CI->use_empty()) return CI;
1493 return B.CreateIntCast(Res, CI->getType(), true);
1496 // printf("foo\n") --> puts("foo")
1497 if (FormatStr[FormatStr.size()-1] == '\n' &&
1498 FormatStr.find('%') == std::string::npos) { // no format characters.
1499 // Create a string literal with no \n on it. We expect the constant merge
1500 // pass to be run after this pass, to merge duplicate strings.
1501 FormatStr.erase(FormatStr.end()-1);
1502 Constant *C = ConstantArray::get(*Context, FormatStr, true);
1503 C = new GlobalVariable(*Callee->getParent(), C->getType(), true,
1504 GlobalVariable::InternalLinkage, C, "str");
1506 return CI->use_empty() ? (Value*)CI :
1507 ConstantInt::get(CI->getType(), FormatStr.size()+1);
1510 // Optimize specific format strings.
1511 // printf("%c", chr) --> putchar(*(i8*)dst)
1512 if (FormatStr == "%c" && CI->getNumOperands() > 2 &&
1513 isa<IntegerType>(CI->getOperand(2)->getType())) {
1514 Value *Res = EmitPutChar(CI->getOperand(2), B);
1516 if (CI->use_empty()) return CI;
1517 return B.CreateIntCast(Res, CI->getType(), true);
1520 // printf("%s\n", str) --> puts(str)
1521 if (FormatStr == "%s\n" && CI->getNumOperands() > 2 &&
1522 isa<PointerType>(CI->getOperand(2)->getType()) &&
1524 EmitPutS(CI->getOperand(2), B);
1531 //===---------------------------------------===//
1532 // 'sprintf' Optimizations
1534 struct SPrintFOpt : public LibCallOptimization {
1535 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1536 // Require two fixed pointer arguments and an integer result.
1537 const FunctionType *FT = Callee->getFunctionType();
1538 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1539 !isa<PointerType>(FT->getParamType(1)) ||
1540 !isa<IntegerType>(FT->getReturnType()))
1543 // Check for a fixed format string.
1544 std::string FormatStr;
1545 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1548 // If we just have a format string (nothing else crazy) transform it.
1549 if (CI->getNumOperands() == 3) {
1550 // Make sure there's no % in the constant array. We could try to handle
1551 // %% -> % in the future if we cared.
1552 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1553 if (FormatStr[i] == '%')
1554 return 0; // we found a format specifier, bail out.
1556 // These optimizations require TargetData.
1559 // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1560 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), // Copy the nul byte.
1561 ConstantInt::get(TD->getIntPtrType(*Context), FormatStr.size()+1),1,B);
1562 return ConstantInt::get(CI->getType(), FormatStr.size());
1565 // The remaining optimizations require the format string to be "%s" or "%c"
1566 // and have an extra operand.
1567 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1570 // Decode the second character of the format string.
1571 if (FormatStr[1] == 'c') {
1572 // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1573 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1574 Value *V = B.CreateTrunc(CI->getOperand(3),
1575 Type::getInt8Ty(*Context), "char");
1576 Value *Ptr = CastToCStr(CI->getOperand(1), B);
1577 B.CreateStore(V, Ptr);
1578 Ptr = B.CreateGEP(Ptr, ConstantInt::get(Type::getInt32Ty(*Context), 1),
1580 B.CreateStore(Constant::getNullValue(Type::getInt8Ty(*Context)), Ptr);
1582 return ConstantInt::get(CI->getType(), 1);
1585 if (FormatStr[1] == 's') {
1586 // These optimizations require TargetData.
1589 // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1590 if (!isa<PointerType>(CI->getOperand(3)->getType())) return 0;
1592 Value *Len = EmitStrLen(CI->getOperand(3), B);
1593 Value *IncLen = B.CreateAdd(Len,
1594 ConstantInt::get(Len->getType(), 1),
1596 EmitMemCpy(CI->getOperand(1), CI->getOperand(3), IncLen, 1, B);
1598 // The sprintf result is the unincremented number of bytes in the string.
1599 return B.CreateIntCast(Len, CI->getType(), false);
1605 //===---------------------------------------===//
1606 // 'fwrite' Optimizations
1608 struct FWriteOpt : public LibCallOptimization {
1609 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1610 // Require a pointer, an integer, an integer, a pointer, returning integer.
1611 const FunctionType *FT = Callee->getFunctionType();
1612 if (FT->getNumParams() != 4 || !isa<PointerType>(FT->getParamType(0)) ||
1613 !isa<IntegerType>(FT->getParamType(1)) ||
1614 !isa<IntegerType>(FT->getParamType(2)) ||
1615 !isa<PointerType>(FT->getParamType(3)) ||
1616 !isa<IntegerType>(FT->getReturnType()))
1619 // Get the element size and count.
1620 ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getOperand(2));
1621 ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getOperand(3));
1622 if (!SizeC || !CountC) return 0;
1623 uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
1625 // If this is writing zero records, remove the call (it's a noop).
1627 return ConstantInt::get(CI->getType(), 0);
1629 // If this is writing one byte, turn it into fputc.
1630 if (Bytes == 1) { // fwrite(S,1,1,F) -> fputc(S[0],F)
1631 Value *Char = B.CreateLoad(CastToCStr(CI->getOperand(1), B), "char");
1632 EmitFPutC(Char, CI->getOperand(4), B);
1633 return ConstantInt::get(CI->getType(), 1);
1640 //===---------------------------------------===//
1641 // 'fputs' Optimizations
1643 struct FPutsOpt : public LibCallOptimization {
1644 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1645 // These optimizations require TargetData.
1648 // Require two pointers. Also, we can't optimize if return value is used.
1649 const FunctionType *FT = Callee->getFunctionType();
1650 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1651 !isa<PointerType>(FT->getParamType(1)) ||
1655 // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1656 uint64_t Len = GetStringLength(CI->getOperand(1));
1658 EmitFWrite(CI->getOperand(1),
1659 ConstantInt::get(TD->getIntPtrType(*Context), Len-1),
1660 CI->getOperand(2), B);
1661 return CI; // Known to have no uses (see above).
1665 //===---------------------------------------===//
1666 // 'fprintf' Optimizations
1668 struct FPrintFOpt : public LibCallOptimization {
1669 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1670 // Require two fixed paramters as pointers and integer result.
1671 const FunctionType *FT = Callee->getFunctionType();
1672 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1673 !isa<PointerType>(FT->getParamType(1)) ||
1674 !isa<IntegerType>(FT->getReturnType()))
1677 // All the optimizations depend on the format string.
1678 std::string FormatStr;
1679 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1682 // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1683 if (CI->getNumOperands() == 3) {
1684 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1685 if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1686 return 0; // We found a format specifier.
1688 // These optimizations require TargetData.
1691 EmitFWrite(CI->getOperand(2), ConstantInt::get(TD->getIntPtrType(*Context),
1693 CI->getOperand(1), B);
1694 return ConstantInt::get(CI->getType(), FormatStr.size());
1697 // The remaining optimizations require the format string to be "%s" or "%c"
1698 // and have an extra operand.
1699 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1702 // Decode the second character of the format string.
1703 if (FormatStr[1] == 'c') {
1704 // fprintf(F, "%c", chr) --> *(i8*)dst = chr
1705 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1706 EmitFPutC(CI->getOperand(3), CI->getOperand(1), B);
1707 return ConstantInt::get(CI->getType(), 1);
1710 if (FormatStr[1] == 's') {
1711 // fprintf(F, "%s", str) -> fputs(str, F)
1712 if (!isa<PointerType>(CI->getOperand(3)->getType()) || !CI->use_empty())
1714 EmitFPutS(CI->getOperand(3), CI->getOperand(1), B);
1721 } // end anonymous namespace.
1723 //===----------------------------------------------------------------------===//
1724 // SimplifyLibCalls Pass Implementation
1725 //===----------------------------------------------------------------------===//
1728 /// This pass optimizes well known library functions from libc and libm.
1730 class SimplifyLibCalls : public FunctionPass {
1731 StringMap<LibCallOptimization*> Optimizations;
1732 // String and Memory LibCall Optimizations
1733 StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
1734 StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
1735 StrToOpt StrTo; StrStrOpt StrStr;
1736 MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
1737 // Math Library Optimizations
1738 PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
1739 // Integer Optimizations
1740 FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
1742 // Formatting and IO Optimizations
1743 SPrintFOpt SPrintF; PrintFOpt PrintF;
1744 FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
1746 // Object Size Checking
1748 MemCpyChkOpt MemCpyChk; MemSetChkOpt MemSetChk; MemMoveChkOpt MemMoveChk;
1750 bool Modified; // This is only used by doInitialization.
1752 static char ID; // Pass identification
1753 SimplifyLibCalls() : FunctionPass(&ID) {}
1755 void InitOptimizations();
1756 bool runOnFunction(Function &F);
1758 void setDoesNotAccessMemory(Function &F);
1759 void setOnlyReadsMemory(Function &F);
1760 void setDoesNotThrow(Function &F);
1761 void setDoesNotCapture(Function &F, unsigned n);
1762 void setDoesNotAlias(Function &F, unsigned n);
1763 bool doInitialization(Module &M);
1765 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1768 char SimplifyLibCalls::ID = 0;
1769 } // end anonymous namespace.
1771 static RegisterPass<SimplifyLibCalls>
1772 X("simplify-libcalls", "Simplify well-known library calls");
1774 // Public interface to the Simplify LibCalls pass.
1775 FunctionPass *llvm::createSimplifyLibCallsPass() {
1776 return new SimplifyLibCalls();
1779 /// Optimizations - Populate the Optimizations map with all the optimizations
1781 void SimplifyLibCalls::InitOptimizations() {
1782 // String and Memory LibCall Optimizations
1783 Optimizations["strcat"] = &StrCat;
1784 Optimizations["strncat"] = &StrNCat;
1785 Optimizations["strchr"] = &StrChr;
1786 Optimizations["strcmp"] = &StrCmp;
1787 Optimizations["strncmp"] = &StrNCmp;
1788 Optimizations["strcpy"] = &StrCpy;
1789 Optimizations["strncpy"] = &StrNCpy;
1790 Optimizations["strlen"] = &StrLen;
1791 Optimizations["strtol"] = &StrTo;
1792 Optimizations["strtod"] = &StrTo;
1793 Optimizations["strtof"] = &StrTo;
1794 Optimizations["strtoul"] = &StrTo;
1795 Optimizations["strtoll"] = &StrTo;
1796 Optimizations["strtold"] = &StrTo;
1797 Optimizations["strtoull"] = &StrTo;
1798 Optimizations["strstr"] = &StrStr;
1799 Optimizations["memcmp"] = &MemCmp;
1800 Optimizations["memcpy"] = &MemCpy;
1801 Optimizations["memmove"] = &MemMove;
1802 Optimizations["memset"] = &MemSet;
1804 // Math Library Optimizations
1805 Optimizations["powf"] = &Pow;
1806 Optimizations["pow"] = &Pow;
1807 Optimizations["powl"] = &Pow;
1808 Optimizations["llvm.pow.f32"] = &Pow;
1809 Optimizations["llvm.pow.f64"] = &Pow;
1810 Optimizations["llvm.pow.f80"] = &Pow;
1811 Optimizations["llvm.pow.f128"] = &Pow;
1812 Optimizations["llvm.pow.ppcf128"] = &Pow;
1813 Optimizations["exp2l"] = &Exp2;
1814 Optimizations["exp2"] = &Exp2;
1815 Optimizations["exp2f"] = &Exp2;
1816 Optimizations["llvm.exp2.ppcf128"] = &Exp2;
1817 Optimizations["llvm.exp2.f128"] = &Exp2;
1818 Optimizations["llvm.exp2.f80"] = &Exp2;
1819 Optimizations["llvm.exp2.f64"] = &Exp2;
1820 Optimizations["llvm.exp2.f32"] = &Exp2;
1823 Optimizations["floor"] = &UnaryDoubleFP;
1826 Optimizations["ceil"] = &UnaryDoubleFP;
1829 Optimizations["round"] = &UnaryDoubleFP;
1832 Optimizations["rint"] = &UnaryDoubleFP;
1834 #ifdef HAVE_NEARBYINTF
1835 Optimizations["nearbyint"] = &UnaryDoubleFP;
1838 // Integer Optimizations
1839 Optimizations["ffs"] = &FFS;
1840 Optimizations["ffsl"] = &FFS;
1841 Optimizations["ffsll"] = &FFS;
1842 Optimizations["abs"] = &Abs;
1843 Optimizations["labs"] = &Abs;
1844 Optimizations["llabs"] = &Abs;
1845 Optimizations["isdigit"] = &IsDigit;
1846 Optimizations["isascii"] = &IsAscii;
1847 Optimizations["toascii"] = &ToAscii;
1849 // Formatting and IO Optimizations
1850 Optimizations["sprintf"] = &SPrintF;
1851 Optimizations["printf"] = &PrintF;
1852 Optimizations["fwrite"] = &FWrite;
1853 Optimizations["fputs"] = &FPuts;
1854 Optimizations["fprintf"] = &FPrintF;
1856 // Object Size Checking
1857 Optimizations["llvm.objectsize.i32"] = &ObjectSize;
1858 Optimizations["llvm.objectsize.i64"] = &ObjectSize;
1859 Optimizations["__memcpy_chk"] = &MemCpyChk;
1860 Optimizations["__memset_chk"] = &MemSetChk;
1861 Optimizations["__memmove_chk"] = &MemMoveChk;
1865 /// runOnFunction - Top level algorithm.
1867 bool SimplifyLibCalls::runOnFunction(Function &F) {
1868 if (Optimizations.empty())
1869 InitOptimizations();
1871 const TargetData *TD = getAnalysisIfAvailable<TargetData>();
1873 IRBuilder<> Builder(F.getContext());
1875 bool Changed = false;
1876 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1877 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
1878 // Ignore non-calls.
1879 CallInst *CI = dyn_cast<CallInst>(I++);
1882 // Ignore indirect calls and calls to non-external functions.
1883 Function *Callee = CI->getCalledFunction();
1884 if (Callee == 0 || !Callee->isDeclaration() ||
1885 !(Callee->hasExternalLinkage() || Callee->hasDLLImportLinkage()))
1888 // Ignore unknown calls.
1889 LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
1892 // Set the builder to the instruction after the call.
1893 Builder.SetInsertPoint(BB, I);
1895 // Try to optimize this call.
1896 Value *Result = LCO->OptimizeCall(CI, TD, Builder);
1897 if (Result == 0) continue;
1899 DEBUG(errs() << "SimplifyLibCalls simplified: " << *CI;
1900 errs() << " into: " << *Result << "\n");
1902 // Something changed!
1906 // Inspect the instruction after the call (which was potentially just
1910 if (CI != Result && !CI->use_empty()) {
1911 CI->replaceAllUsesWith(Result);
1912 if (!Result->hasName())
1913 Result->takeName(CI);
1915 CI->eraseFromParent();
1921 // Utility methods for doInitialization.
1923 void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
1924 if (!F.doesNotAccessMemory()) {
1925 F.setDoesNotAccessMemory();
1930 void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
1931 if (!F.onlyReadsMemory()) {
1932 F.setOnlyReadsMemory();
1937 void SimplifyLibCalls::setDoesNotThrow(Function &F) {
1938 if (!F.doesNotThrow()) {
1939 F.setDoesNotThrow();
1944 void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
1945 if (!F.doesNotCapture(n)) {
1946 F.setDoesNotCapture(n);
1951 void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
1952 if (!F.doesNotAlias(n)) {
1953 F.setDoesNotAlias(n);
1959 /// doInitialization - Add attributes to well-known functions.
1961 bool SimplifyLibCalls::doInitialization(Module &M) {
1963 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
1965 if (!F.isDeclaration())
1971 const FunctionType *FTy = F.getFunctionType();
1973 StringRef Name = F.getName();
1976 if (Name == "strlen") {
1977 if (FTy->getNumParams() != 1 ||
1978 !isa<PointerType>(FTy->getParamType(0)))
1980 setOnlyReadsMemory(F);
1982 setDoesNotCapture(F, 1);
1983 } else if (Name == "strcpy" ||
1989 Name == "strtoul" ||
1990 Name == "strtoll" ||
1991 Name == "strtold" ||
1992 Name == "strncat" ||
1993 Name == "strncpy" ||
1994 Name == "strtoull") {
1995 if (FTy->getNumParams() < 2 ||
1996 !isa<PointerType>(FTy->getParamType(1)))
1999 setDoesNotCapture(F, 2);
2000 } else if (Name == "strxfrm") {
2001 if (FTy->getNumParams() != 3 ||
2002 !isa<PointerType>(FTy->getParamType(0)) ||
2003 !isa<PointerType>(FTy->getParamType(1)))
2006 setDoesNotCapture(F, 1);
2007 setDoesNotCapture(F, 2);
2008 } else if (Name == "strcmp" ||
2010 Name == "strncmp" ||
2011 Name ==" strcspn" ||
2012 Name == "strcoll" ||
2013 Name == "strcasecmp" ||
2014 Name == "strncasecmp") {
2015 if (FTy->getNumParams() < 2 ||
2016 !isa<PointerType>(FTy->getParamType(0)) ||
2017 !isa<PointerType>(FTy->getParamType(1)))
2019 setOnlyReadsMemory(F);
2021 setDoesNotCapture(F, 1);
2022 setDoesNotCapture(F, 2);
2023 } else if (Name == "strstr" ||
2024 Name == "strpbrk") {
2025 if (FTy->getNumParams() != 2 ||
2026 !isa<PointerType>(FTy->getParamType(1)))
2028 setOnlyReadsMemory(F);
2030 setDoesNotCapture(F, 2);
2031 } else if (Name == "strtok" ||
2032 Name == "strtok_r") {
2033 if (FTy->getNumParams() < 2 ||
2034 !isa<PointerType>(FTy->getParamType(1)))
2037 setDoesNotCapture(F, 2);
2038 } else if (Name == "scanf" ||
2040 Name == "setvbuf") {
2041 if (FTy->getNumParams() < 1 ||
2042 !isa<PointerType>(FTy->getParamType(0)))
2045 setDoesNotCapture(F, 1);
2046 } else if (Name == "strdup" ||
2047 Name == "strndup") {
2048 if (FTy->getNumParams() < 1 ||
2049 !isa<PointerType>(FTy->getReturnType()) ||
2050 !isa<PointerType>(FTy->getParamType(0)))
2053 setDoesNotAlias(F, 0);
2054 setDoesNotCapture(F, 1);
2055 } else if (Name == "stat" ||
2057 Name == "sprintf" ||
2058 Name == "statvfs") {
2059 if (FTy->getNumParams() < 2 ||
2060 !isa<PointerType>(FTy->getParamType(0)) ||
2061 !isa<PointerType>(FTy->getParamType(1)))
2064 setDoesNotCapture(F, 1);
2065 setDoesNotCapture(F, 2);
2066 } else if (Name == "snprintf") {
2067 if (FTy->getNumParams() != 3 ||
2068 !isa<PointerType>(FTy->getParamType(0)) ||
2069 !isa<PointerType>(FTy->getParamType(2)))
2072 setDoesNotCapture(F, 1);
2073 setDoesNotCapture(F, 3);
2074 } else if (Name == "setitimer") {
2075 if (FTy->getNumParams() != 3 ||
2076 !isa<PointerType>(FTy->getParamType(1)) ||
2077 !isa<PointerType>(FTy->getParamType(2)))
2080 setDoesNotCapture(F, 2);
2081 setDoesNotCapture(F, 3);
2082 } else if (Name == "system") {
2083 if (FTy->getNumParams() != 1 ||
2084 !isa<PointerType>(FTy->getParamType(0)))
2086 // May throw; "system" is a valid pthread cancellation point.
2087 setDoesNotCapture(F, 1);
2091 if (Name == "malloc") {
2092 if (FTy->getNumParams() != 1 ||
2093 !isa<PointerType>(FTy->getReturnType()))
2096 setDoesNotAlias(F, 0);
2097 } else if (Name == "memcmp") {
2098 if (FTy->getNumParams() != 3 ||
2099 !isa<PointerType>(FTy->getParamType(0)) ||
2100 !isa<PointerType>(FTy->getParamType(1)))
2102 setOnlyReadsMemory(F);
2104 setDoesNotCapture(F, 1);
2105 setDoesNotCapture(F, 2);
2106 } else if (Name == "memchr" ||
2107 Name == "memrchr") {
2108 if (FTy->getNumParams() != 3)
2110 setOnlyReadsMemory(F);
2112 } else if (Name == "modf" ||
2116 Name == "memccpy" ||
2117 Name == "memmove") {
2118 if (FTy->getNumParams() < 2 ||
2119 !isa<PointerType>(FTy->getParamType(1)))
2122 setDoesNotCapture(F, 2);
2123 } else if (Name == "memalign") {
2124 if (!isa<PointerType>(FTy->getReturnType()))
2126 setDoesNotAlias(F, 0);
2127 } else if (Name == "mkdir" ||
2129 if (FTy->getNumParams() == 0 ||
2130 !isa<PointerType>(FTy->getParamType(0)))
2133 setDoesNotCapture(F, 1);
2137 if (Name == "realloc") {
2138 if (FTy->getNumParams() != 2 ||
2139 !isa<PointerType>(FTy->getParamType(0)) ||
2140 !isa<PointerType>(FTy->getReturnType()))
2143 setDoesNotAlias(F, 0);
2144 setDoesNotCapture(F, 1);
2145 } else if (Name == "read") {
2146 if (FTy->getNumParams() != 3 ||
2147 !isa<PointerType>(FTy->getParamType(1)))
2149 // May throw; "read" is a valid pthread cancellation point.
2150 setDoesNotCapture(F, 2);
2151 } else if (Name == "rmdir" ||
2154 Name == "realpath") {
2155 if (FTy->getNumParams() < 1 ||
2156 !isa<PointerType>(FTy->getParamType(0)))
2159 setDoesNotCapture(F, 1);
2160 } else if (Name == "rename" ||
2161 Name == "readlink") {
2162 if (FTy->getNumParams() < 2 ||
2163 !isa<PointerType>(FTy->getParamType(0)) ||
2164 !isa<PointerType>(FTy->getParamType(1)))
2167 setDoesNotCapture(F, 1);
2168 setDoesNotCapture(F, 2);
2172 if (Name == "write") {
2173 if (FTy->getNumParams() != 3 ||
2174 !isa<PointerType>(FTy->getParamType(1)))
2176 // May throw; "write" is a valid pthread cancellation point.
2177 setDoesNotCapture(F, 2);
2181 if (Name == "bcopy") {
2182 if (FTy->getNumParams() != 3 ||
2183 !isa<PointerType>(FTy->getParamType(0)) ||
2184 !isa<PointerType>(FTy->getParamType(1)))
2187 setDoesNotCapture(F, 1);
2188 setDoesNotCapture(F, 2);
2189 } else if (Name == "bcmp") {
2190 if (FTy->getNumParams() != 3 ||
2191 !isa<PointerType>(FTy->getParamType(0)) ||
2192 !isa<PointerType>(FTy->getParamType(1)))
2195 setOnlyReadsMemory(F);
2196 setDoesNotCapture(F, 1);
2197 setDoesNotCapture(F, 2);
2198 } else if (Name == "bzero") {
2199 if (FTy->getNumParams() != 2 ||
2200 !isa<PointerType>(FTy->getParamType(0)))
2203 setDoesNotCapture(F, 1);
2207 if (Name == "calloc") {
2208 if (FTy->getNumParams() != 2 ||
2209 !isa<PointerType>(FTy->getReturnType()))
2212 setDoesNotAlias(F, 0);
2213 } else if (Name == "chmod" ||
2215 Name == "ctermid" ||
2216 Name == "clearerr" ||
2217 Name == "closedir") {
2218 if (FTy->getNumParams() == 0 ||
2219 !isa<PointerType>(FTy->getParamType(0)))
2222 setDoesNotCapture(F, 1);
2226 if (Name == "atoi" ||
2230 if (FTy->getNumParams() != 1 ||
2231 !isa<PointerType>(FTy->getParamType(0)))
2234 setOnlyReadsMemory(F);
2235 setDoesNotCapture(F, 1);
2236 } else if (Name == "access") {
2237 if (FTy->getNumParams() != 2 ||
2238 !isa<PointerType>(FTy->getParamType(0)))
2241 setDoesNotCapture(F, 1);
2245 if (Name == "fopen") {
2246 if (FTy->getNumParams() != 2 ||
2247 !isa<PointerType>(FTy->getReturnType()) ||
2248 !isa<PointerType>(FTy->getParamType(0)) ||
2249 !isa<PointerType>(FTy->getParamType(1)))
2252 setDoesNotAlias(F, 0);
2253 setDoesNotCapture(F, 1);
2254 setDoesNotCapture(F, 2);
2255 } else if (Name == "fdopen") {
2256 if (FTy->getNumParams() != 2 ||
2257 !isa<PointerType>(FTy->getReturnType()) ||
2258 !isa<PointerType>(FTy->getParamType(1)))
2261 setDoesNotAlias(F, 0);
2262 setDoesNotCapture(F, 2);
2263 } else if (Name == "feof" ||
2273 Name == "fsetpos" ||
2274 Name == "flockfile" ||
2275 Name == "funlockfile" ||
2276 Name == "ftrylockfile") {
2277 if (FTy->getNumParams() == 0 ||
2278 !isa<PointerType>(FTy->getParamType(0)))
2281 setDoesNotCapture(F, 1);
2282 } else if (Name == "ferror") {
2283 if (FTy->getNumParams() != 1 ||
2284 !isa<PointerType>(FTy->getParamType(0)))
2287 setDoesNotCapture(F, 1);
2288 setOnlyReadsMemory(F);
2289 } else if (Name == "fputc" ||
2294 Name == "fstatvfs") {
2295 if (FTy->getNumParams() != 2 ||
2296 !isa<PointerType>(FTy->getParamType(1)))
2299 setDoesNotCapture(F, 2);
2300 } else if (Name == "fgets") {
2301 if (FTy->getNumParams() != 3 ||
2302 !isa<PointerType>(FTy->getParamType(0)) ||
2303 !isa<PointerType>(FTy->getParamType(2)))
2306 setDoesNotCapture(F, 3);
2307 } else if (Name == "fread" ||
2309 if (FTy->getNumParams() != 4 ||
2310 !isa<PointerType>(FTy->getParamType(0)) ||
2311 !isa<PointerType>(FTy->getParamType(3)))
2314 setDoesNotCapture(F, 1);
2315 setDoesNotCapture(F, 4);
2316 } else if (Name == "fputs" ||
2318 Name == "fprintf" ||
2319 Name == "fgetpos") {
2320 if (FTy->getNumParams() < 2 ||
2321 !isa<PointerType>(FTy->getParamType(0)) ||
2322 !isa<PointerType>(FTy->getParamType(1)))
2325 setDoesNotCapture(F, 1);
2326 setDoesNotCapture(F, 2);
2330 if (Name == "getc" ||
2331 Name == "getlogin_r" ||
2332 Name == "getc_unlocked") {
2333 if (FTy->getNumParams() == 0 ||
2334 !isa<PointerType>(FTy->getParamType(0)))
2337 setDoesNotCapture(F, 1);
2338 } else if (Name == "getenv") {
2339 if (FTy->getNumParams() != 1 ||
2340 !isa<PointerType>(FTy->getParamType(0)))
2343 setOnlyReadsMemory(F);
2344 setDoesNotCapture(F, 1);
2345 } else if (Name == "gets" ||
2346 Name == "getchar") {
2348 } else if (Name == "getitimer") {
2349 if (FTy->getNumParams() != 2 ||
2350 !isa<PointerType>(FTy->getParamType(1)))
2353 setDoesNotCapture(F, 2);
2354 } else if (Name == "getpwnam") {
2355 if (FTy->getNumParams() != 1 ||
2356 !isa<PointerType>(FTy->getParamType(0)))
2359 setDoesNotCapture(F, 1);
2363 if (Name == "ungetc") {
2364 if (FTy->getNumParams() != 2 ||
2365 !isa<PointerType>(FTy->getParamType(1)))
2368 setDoesNotCapture(F, 2);
2369 } else if (Name == "uname" ||
2371 Name == "unsetenv") {
2372 if (FTy->getNumParams() != 1 ||
2373 !isa<PointerType>(FTy->getParamType(0)))
2376 setDoesNotCapture(F, 1);
2377 } else if (Name == "utime" ||
2379 if (FTy->getNumParams() != 2 ||
2380 !isa<PointerType>(FTy->getParamType(0)) ||
2381 !isa<PointerType>(FTy->getParamType(1)))
2384 setDoesNotCapture(F, 1);
2385 setDoesNotCapture(F, 2);
2389 if (Name == "putc") {
2390 if (FTy->getNumParams() != 2 ||
2391 !isa<PointerType>(FTy->getParamType(1)))
2394 setDoesNotCapture(F, 2);
2395 } else if (Name == "puts" ||
2398 if (FTy->getNumParams() != 1 ||
2399 !isa<PointerType>(FTy->getParamType(0)))
2402 setDoesNotCapture(F, 1);
2403 } else if (Name == "pread" ||
2405 if (FTy->getNumParams() != 4 ||
2406 !isa<PointerType>(FTy->getParamType(1)))
2408 // May throw; these are valid pthread cancellation points.
2409 setDoesNotCapture(F, 2);
2410 } else if (Name == "putchar") {
2412 } else if (Name == "popen") {
2413 if (FTy->getNumParams() != 2 ||
2414 !isa<PointerType>(FTy->getReturnType()) ||
2415 !isa<PointerType>(FTy->getParamType(0)) ||
2416 !isa<PointerType>(FTy->getParamType(1)))
2419 setDoesNotAlias(F, 0);
2420 setDoesNotCapture(F, 1);
2421 setDoesNotCapture(F, 2);
2422 } else if (Name == "pclose") {
2423 if (FTy->getNumParams() != 1 ||
2424 !isa<PointerType>(FTy->getParamType(0)))
2427 setDoesNotCapture(F, 1);
2431 if (Name == "vscanf") {
2432 if (FTy->getNumParams() != 2 ||
2433 !isa<PointerType>(FTy->getParamType(1)))
2436 setDoesNotCapture(F, 1);
2437 } else if (Name == "vsscanf" ||
2438 Name == "vfscanf") {
2439 if (FTy->getNumParams() != 3 ||
2440 !isa<PointerType>(FTy->getParamType(1)) ||
2441 !isa<PointerType>(FTy->getParamType(2)))
2444 setDoesNotCapture(F, 1);
2445 setDoesNotCapture(F, 2);
2446 } else if (Name == "valloc") {
2447 if (!isa<PointerType>(FTy->getReturnType()))
2450 setDoesNotAlias(F, 0);
2451 } else if (Name == "vprintf") {
2452 if (FTy->getNumParams() != 2 ||
2453 !isa<PointerType>(FTy->getParamType(0)))
2456 setDoesNotCapture(F, 1);
2457 } else if (Name == "vfprintf" ||
2458 Name == "vsprintf") {
2459 if (FTy->getNumParams() != 3 ||
2460 !isa<PointerType>(FTy->getParamType(0)) ||
2461 !isa<PointerType>(FTy->getParamType(1)))
2464 setDoesNotCapture(F, 1);
2465 setDoesNotCapture(F, 2);
2466 } else if (Name == "vsnprintf") {
2467 if (FTy->getNumParams() != 4 ||
2468 !isa<PointerType>(FTy->getParamType(0)) ||
2469 !isa<PointerType>(FTy->getParamType(2)))
2472 setDoesNotCapture(F, 1);
2473 setDoesNotCapture(F, 3);
2477 if (Name == "open") {
2478 if (FTy->getNumParams() < 2 ||
2479 !isa<PointerType>(FTy->getParamType(0)))
2481 // May throw; "open" is a valid pthread cancellation point.
2482 setDoesNotCapture(F, 1);
2483 } else if (Name == "opendir") {
2484 if (FTy->getNumParams() != 1 ||
2485 !isa<PointerType>(FTy->getReturnType()) ||
2486 !isa<PointerType>(FTy->getParamType(0)))
2489 setDoesNotAlias(F, 0);
2490 setDoesNotCapture(F, 1);
2494 if (Name == "tmpfile") {
2495 if (!isa<PointerType>(FTy->getReturnType()))
2498 setDoesNotAlias(F, 0);
2499 } else if (Name == "times") {
2500 if (FTy->getNumParams() != 1 ||
2501 !isa<PointerType>(FTy->getParamType(0)))
2504 setDoesNotCapture(F, 1);
2508 if (Name == "htonl" ||
2511 setDoesNotAccessMemory(F);
2515 if (Name == "ntohl" ||
2518 setDoesNotAccessMemory(F);
2522 if (Name == "lstat") {
2523 if (FTy->getNumParams() != 2 ||
2524 !isa<PointerType>(FTy->getParamType(0)) ||
2525 !isa<PointerType>(FTy->getParamType(1)))
2528 setDoesNotCapture(F, 1);
2529 setDoesNotCapture(F, 2);
2530 } else if (Name == "lchown") {
2531 if (FTy->getNumParams() != 3 ||
2532 !isa<PointerType>(FTy->getParamType(0)))
2535 setDoesNotCapture(F, 1);
2539 if (Name == "qsort") {
2540 if (FTy->getNumParams() != 4 ||
2541 !isa<PointerType>(FTy->getParamType(3)))
2543 // May throw; places call through function pointer.
2544 setDoesNotCapture(F, 4);
2548 if (Name == "__strdup" ||
2549 Name == "__strndup") {
2550 if (FTy->getNumParams() < 1 ||
2551 !isa<PointerType>(FTy->getReturnType()) ||
2552 !isa<PointerType>(FTy->getParamType(0)))
2555 setDoesNotAlias(F, 0);
2556 setDoesNotCapture(F, 1);
2557 } else if (Name == "__strtok_r") {
2558 if (FTy->getNumParams() != 3 ||
2559 !isa<PointerType>(FTy->getParamType(1)))
2562 setDoesNotCapture(F, 2);
2563 } else if (Name == "_IO_getc") {
2564 if (FTy->getNumParams() != 1 ||
2565 !isa<PointerType>(FTy->getParamType(0)))
2568 setDoesNotCapture(F, 1);
2569 } else if (Name == "_IO_putc") {
2570 if (FTy->getNumParams() != 2 ||
2571 !isa<PointerType>(FTy->getParamType(1)))
2574 setDoesNotCapture(F, 2);
2578 if (Name == "\1__isoc99_scanf") {
2579 if (FTy->getNumParams() < 1 ||
2580 !isa<PointerType>(FTy->getParamType(0)))
2583 setDoesNotCapture(F, 1);
2584 } else if (Name == "\1stat64" ||
2585 Name == "\1lstat64" ||
2586 Name == "\1statvfs64" ||
2587 Name == "\1__isoc99_sscanf") {
2588 if (FTy->getNumParams() < 1 ||
2589 !isa<PointerType>(FTy->getParamType(0)) ||
2590 !isa<PointerType>(FTy->getParamType(1)))
2593 setDoesNotCapture(F, 1);
2594 setDoesNotCapture(F, 2);
2595 } else if (Name == "\1fopen64") {
2596 if (FTy->getNumParams() != 2 ||
2597 !isa<PointerType>(FTy->getReturnType()) ||
2598 !isa<PointerType>(FTy->getParamType(0)) ||
2599 !isa<PointerType>(FTy->getParamType(1)))
2602 setDoesNotAlias(F, 0);
2603 setDoesNotCapture(F, 1);
2604 setDoesNotCapture(F, 2);
2605 } else if (Name == "\1fseeko64" ||
2606 Name == "\1ftello64") {
2607 if (FTy->getNumParams() == 0 ||
2608 !isa<PointerType>(FTy->getParamType(0)))
2611 setDoesNotCapture(F, 1);
2612 } else if (Name == "\1tmpfile64") {
2613 if (!isa<PointerType>(FTy->getReturnType()))
2616 setDoesNotAlias(F, 0);
2617 } else if (Name == "\1fstat64" ||
2618 Name == "\1fstatvfs64") {
2619 if (FTy->getNumParams() != 2 ||
2620 !isa<PointerType>(FTy->getParamType(1)))
2623 setDoesNotCapture(F, 2);
2624 } else if (Name == "\1open64") {
2625 if (FTy->getNumParams() < 2 ||
2626 !isa<PointerType>(FTy->getParamType(0)))
2628 // May throw; "open" is a valid pthread cancellation point.
2629 setDoesNotCapture(F, 1);
2638 // Additional cases that we need to add to this file:
2641 // * cbrt(expN(X)) -> expN(x/3)
2642 // * cbrt(sqrt(x)) -> pow(x,1/6)
2643 // * cbrt(sqrt(x)) -> pow(x,1/9)
2646 // * cos(-x) -> cos(x)
2649 // * exp(log(x)) -> x
2652 // * log(exp(x)) -> x
2653 // * log(x**y) -> y*log(x)
2654 // * log(exp(y)) -> y*log(e)
2655 // * log(exp2(y)) -> y*log(2)
2656 // * log(exp10(y)) -> y*log(10)
2657 // * log(sqrt(x)) -> 0.5*log(x)
2658 // * log(pow(x,y)) -> y*log(x)
2660 // lround, lroundf, lroundl:
2661 // * lround(cnst) -> cnst'
2664 // * pow(exp(x),y) -> exp(x*y)
2665 // * pow(sqrt(x),y) -> pow(x,y*0.5)
2666 // * pow(pow(x,y),z)-> pow(x,y*z)
2669 // * puts("") -> putchar("\n")
2671 // round, roundf, roundl:
2672 // * round(cnst) -> cnst'
2675 // * signbit(cnst) -> cnst'
2676 // * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2678 // sqrt, sqrtf, sqrtl:
2679 // * sqrt(expN(x)) -> expN(x*0.5)
2680 // * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2681 // * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2684 // * stpcpy(str, "literal") ->
2685 // llvm.memcpy(str,"literal",strlen("literal")+1,1)
2687 // * strrchr(s,c) -> reverse_offset_of_in(c,s)
2688 // (if c is a constant integer and s is a constant string)
2689 // * strrchr(s1,0) -> strchr(s1,0)
2692 // * strpbrk(s,a) -> offset_in_for(s,a)
2693 // (if s and a are both constant strings)
2694 // * strpbrk(s,"") -> 0
2695 // * strpbrk(s,a) -> strchr(s,a[0]) (if a is constant string of length 1)
2698 // * strspn(s,a) -> const_int (if both args are constant)
2699 // * strspn("",a) -> 0
2700 // * strspn(s,"") -> 0
2701 // * strcspn(s,a) -> const_int (if both args are constant)
2702 // * strcspn("",a) -> 0
2703 // * strcspn(s,"") -> strlen(a)
2706 // * tan(atan(x)) -> x
2708 // trunc, truncf, truncl:
2709 // * trunc(cnst) -> cnst'