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 /// EmitStrCpy - Emit a call to the strcpy function to the builder, for the
85 /// specified pointer arguments.
86 Value *EmitStrCpy(Value *Dst, Value *Src, IRBuilder<> &B);
88 /// EmitMemCpy - Emit a call to the memcpy function to the builder. This
89 /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
90 Value *EmitMemCpy(Value *Dst, Value *Src, Value *Len,
91 unsigned Align, IRBuilder<> &B);
93 /// EmitMemMove - Emit a call to the memmove function to the builder. This
94 /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
95 Value *EmitMemMove(Value *Dst, Value *Src, Value *Len,
96 unsigned Align, IRBuilder<> &B);
98 /// EmitMemChr - Emit a call to the memchr function. This assumes that Ptr is
99 /// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
100 Value *EmitMemChr(Value *Ptr, Value *Val, Value *Len, IRBuilder<> &B);
102 /// EmitMemCmp - Emit a call to the memcmp function.
103 Value *EmitMemCmp(Value *Ptr1, Value *Ptr2, Value *Len, IRBuilder<> &B);
105 /// EmitMemSet - Emit a call to the memset function
106 Value *EmitMemSet(Value *Dst, Value *Val, Value *Len, IRBuilder<> &B);
108 /// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name'
109 /// (e.g. 'floor'). This function is known to take a single of type matching
110 /// 'Op' and returns one value with the same type. If 'Op' is a long double,
111 /// 'l' is added as the suffix of name, if 'Op' is a float, we add a 'f'
113 Value *EmitUnaryFloatFnCall(Value *Op, const char *Name, IRBuilder<> &B,
114 const AttrListPtr &Attrs);
116 /// EmitPutChar - Emit a call to the putchar function. This assumes that Char
118 Value *EmitPutChar(Value *Char, IRBuilder<> &B);
120 /// EmitPutS - Emit a call to the puts function. This assumes that Str is
122 void EmitPutS(Value *Str, IRBuilder<> &B);
124 /// EmitFPutC - Emit a call to the fputc function. This assumes that Char is
125 /// an i32, and File is a pointer to FILE.
126 void EmitFPutC(Value *Char, Value *File, IRBuilder<> &B);
128 /// EmitFPutS - Emit a call to the puts function. Str is required to be a
129 /// pointer and File is a pointer to FILE.
130 void EmitFPutS(Value *Str, Value *File, IRBuilder<> &B);
132 /// EmitFWrite - Emit a call to the fwrite function. This assumes that Ptr is
133 /// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
134 void EmitFWrite(Value *Ptr, Value *Size, Value *File, IRBuilder<> &B);
137 } // End anonymous namespace.
139 /// CastToCStr - Return V if it is an i8*, otherwise cast it to i8*.
140 Value *LibCallOptimization::CastToCStr(Value *V, IRBuilder<> &B) {
141 return B.CreateBitCast(V, Type::getInt8PtrTy(*Context), "cstr");
144 /// EmitStrLen - Emit a call to the strlen function to the builder, for the
145 /// specified pointer. This always returns an integer value of size intptr_t.
146 Value *LibCallOptimization::EmitStrLen(Value *Ptr, IRBuilder<> &B) {
147 Module *M = Caller->getParent();
148 AttributeWithIndex AWI[2];
149 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
150 AWI[1] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
151 Attribute::NoUnwind);
153 Constant *StrLen =M->getOrInsertFunction("strlen", AttrListPtr::get(AWI, 2),
154 TD->getIntPtrType(*Context),
155 Type::getInt8PtrTy(*Context),
157 CallInst *CI = B.CreateCall(StrLen, CastToCStr(Ptr, B), "strlen");
158 if (const Function *F = dyn_cast<Function>(StrLen->stripPointerCasts()))
159 CI->setCallingConv(F->getCallingConv());
164 /// EmitStrChr - Emit a call to the strchr function to the builder, for the
165 /// specified pointer and character. Ptr is required to be some pointer type,
166 /// and the return value has 'i8*' type.
167 Value *LibCallOptimization::EmitStrChr(Value *Ptr, char C, IRBuilder<> &B) {
168 Module *M = Caller->getParent();
169 AttributeWithIndex AWI =
170 AttributeWithIndex::get(~0u, Attribute::ReadOnly | Attribute::NoUnwind);
172 const Type *I8Ptr = Type::getInt8PtrTy(*Context);
173 const Type *I32Ty = Type::getInt32Ty(*Context);
174 Constant *StrChr = M->getOrInsertFunction("strchr", AttrListPtr::get(&AWI, 1),
175 I8Ptr, I8Ptr, I32Ty, NULL);
176 CallInst *CI = B.CreateCall2(StrChr, CastToCStr(Ptr, B),
177 ConstantInt::get(I32Ty, C), "strchr");
178 if (const Function *F = dyn_cast<Function>(StrChr->stripPointerCasts()))
179 CI->setCallingConv(F->getCallingConv());
183 /// EmitStrCpy - Emit a call to the strcpy function to the builder, for the
184 /// specified pointer arguments.
185 Value *LibCallOptimization::EmitStrCpy(Value *Dst, Value *Src, IRBuilder<> &B) {
186 Module *M = Caller->getParent();
187 AttributeWithIndex AWI[2];
188 AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
189 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
190 const Type *I8Ptr = Type::getInt8PtrTy(*Context);
191 Value *StrCpy = M->getOrInsertFunction("strcpy", AttrListPtr::get(AWI, 2),
192 I8Ptr, I8Ptr, I8Ptr, NULL);
193 CallInst *CI = B.CreateCall2(StrCpy, CastToCStr(Dst, B), CastToCStr(Src, B),
195 if (const Function *F = dyn_cast<Function>(StrCpy->stripPointerCasts()))
196 CI->setCallingConv(F->getCallingConv());
200 /// EmitMemCpy - Emit a call to the memcpy function to the builder. This always
201 /// expects that the size has type 'intptr_t' and Dst/Src are pointers.
202 Value *LibCallOptimization::EmitMemCpy(Value *Dst, Value *Src, Value *Len,
203 unsigned Align, IRBuilder<> &B) {
204 Module *M = Caller->getParent();
205 const Type *Ty = Len->getType();
206 Value *MemCpy = Intrinsic::getDeclaration(M, Intrinsic::memcpy, &Ty, 1);
207 Dst = CastToCStr(Dst, B);
208 Src = CastToCStr(Src, B);
209 return B.CreateCall4(MemCpy, Dst, Src, Len,
210 ConstantInt::get(Type::getInt32Ty(*Context), Align));
213 /// EmitMemMove - Emit a call to the memmove function to the builder. This
214 /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
215 Value *LibCallOptimization::EmitMemMove(Value *Dst, Value *Src, Value *Len,
216 unsigned Align, IRBuilder<> &B) {
217 Module *M = Caller->getParent();
218 const Type *Ty = TD->getIntPtrType(*Context);
219 Value *MemMove = Intrinsic::getDeclaration(M, Intrinsic::memmove, &Ty, 1);
220 Dst = CastToCStr(Dst, B);
221 Src = CastToCStr(Src, B);
222 Value *A = ConstantInt::get(Type::getInt32Ty(*Context), Align);
223 return B.CreateCall4(MemMove, Dst, Src, Len, A);
226 /// EmitMemChr - Emit a call to the memchr function. This assumes that Ptr is
227 /// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
228 Value *LibCallOptimization::EmitMemChr(Value *Ptr, Value *Val,
229 Value *Len, IRBuilder<> &B) {
230 Module *M = Caller->getParent();
231 AttributeWithIndex AWI;
232 AWI = AttributeWithIndex::get(~0u, Attribute::ReadOnly | Attribute::NoUnwind);
234 Value *MemChr = M->getOrInsertFunction("memchr", AttrListPtr::get(&AWI, 1),
235 Type::getInt8PtrTy(*Context),
236 Type::getInt8PtrTy(*Context),
237 Type::getInt32Ty(*Context),
238 TD->getIntPtrType(*Context),
240 CallInst *CI = B.CreateCall3(MemChr, CastToCStr(Ptr, B), Val, Len, "memchr");
242 if (const Function *F = dyn_cast<Function>(MemChr->stripPointerCasts()))
243 CI->setCallingConv(F->getCallingConv());
248 /// EmitMemCmp - Emit a call to the memcmp function.
249 Value *LibCallOptimization::EmitMemCmp(Value *Ptr1, Value *Ptr2,
250 Value *Len, IRBuilder<> &B) {
251 Module *M = Caller->getParent();
252 AttributeWithIndex AWI[3];
253 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
254 AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
255 AWI[2] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
256 Attribute::NoUnwind);
258 Value *MemCmp = M->getOrInsertFunction("memcmp", AttrListPtr::get(AWI, 3),
259 Type::getInt32Ty(*Context),
260 Type::getInt8PtrTy(*Context),
261 Type::getInt8PtrTy(*Context),
262 TD->getIntPtrType(*Context), NULL);
263 CallInst *CI = B.CreateCall3(MemCmp, CastToCStr(Ptr1, B), CastToCStr(Ptr2, B),
266 if (const Function *F = dyn_cast<Function>(MemCmp->stripPointerCasts()))
267 CI->setCallingConv(F->getCallingConv());
272 /// EmitMemSet - Emit a call to the memset function
273 Value *LibCallOptimization::EmitMemSet(Value *Dst, Value *Val,
274 Value *Len, IRBuilder<> &B) {
275 Module *M = Caller->getParent();
276 Intrinsic::ID IID = Intrinsic::memset;
278 Tys[0] = Len->getType();
279 Value *MemSet = Intrinsic::getDeclaration(M, IID, Tys, 1);
280 Value *Align = ConstantInt::get(Type::getInt32Ty(*Context), 1);
281 return B.CreateCall4(MemSet, CastToCStr(Dst, B), Val, Len, Align);
284 /// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
285 /// 'floor'). This function is known to take a single of type matching 'Op' and
286 /// returns one value with the same type. If 'Op' is a long double, 'l' is
287 /// added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
288 Value *LibCallOptimization::EmitUnaryFloatFnCall(Value *Op, const char *Name,
290 const AttrListPtr &Attrs) {
292 if (!Op->getType()->isDoubleTy()) {
293 // If we need to add a suffix, copy into NameBuffer.
294 unsigned NameLen = strlen(Name);
295 assert(NameLen < sizeof(NameBuffer)-2);
296 memcpy(NameBuffer, Name, NameLen);
297 if (Op->getType()->isFloatTy())
298 NameBuffer[NameLen] = 'f'; // floorf
300 NameBuffer[NameLen] = 'l'; // floorl
301 NameBuffer[NameLen+1] = 0;
305 Module *M = Caller->getParent();
306 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
307 Op->getType(), NULL);
308 CallInst *CI = B.CreateCall(Callee, Op, Name);
309 CI->setAttributes(Attrs);
310 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
311 CI->setCallingConv(F->getCallingConv());
316 /// EmitPutChar - Emit a call to the putchar function. This assumes that Char
318 Value *LibCallOptimization::EmitPutChar(Value *Char, IRBuilder<> &B) {
319 Module *M = Caller->getParent();
320 Value *PutChar = M->getOrInsertFunction("putchar", Type::getInt32Ty(*Context),
321 Type::getInt32Ty(*Context), NULL);
322 CallInst *CI = B.CreateCall(PutChar,
323 B.CreateIntCast(Char,
324 Type::getInt32Ty(*Context),
329 if (const Function *F = dyn_cast<Function>(PutChar->stripPointerCasts()))
330 CI->setCallingConv(F->getCallingConv());
334 /// EmitPutS - Emit a call to the puts function. This assumes that Str is
336 void LibCallOptimization::EmitPutS(Value *Str, IRBuilder<> &B) {
337 Module *M = Caller->getParent();
338 AttributeWithIndex AWI[2];
339 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
340 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
342 Value *PutS = M->getOrInsertFunction("puts", AttrListPtr::get(AWI, 2),
343 Type::getInt32Ty(*Context),
344 Type::getInt8PtrTy(*Context),
346 CallInst *CI = B.CreateCall(PutS, CastToCStr(Str, B), "puts");
347 if (const Function *F = dyn_cast<Function>(PutS->stripPointerCasts()))
348 CI->setCallingConv(F->getCallingConv());
352 /// EmitFPutC - Emit a call to the fputc function. This assumes that Char is
353 /// an integer and File is a pointer to FILE.
354 void LibCallOptimization::EmitFPutC(Value *Char, Value *File, IRBuilder<> &B) {
355 Module *M = Caller->getParent();
356 AttributeWithIndex AWI[2];
357 AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
358 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
360 if (isa<PointerType>(File->getType()))
361 F = M->getOrInsertFunction("fputc", AttrListPtr::get(AWI, 2),
362 Type::getInt32Ty(*Context),
363 Type::getInt32Ty(*Context), File->getType(),
366 F = M->getOrInsertFunction("fputc",
367 Type::getInt32Ty(*Context),
368 Type::getInt32Ty(*Context),
369 File->getType(), NULL);
370 Char = B.CreateIntCast(Char, Type::getInt32Ty(*Context), /*isSigned*/true,
372 CallInst *CI = B.CreateCall2(F, Char, File, "fputc");
374 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
375 CI->setCallingConv(Fn->getCallingConv());
378 /// EmitFPutS - Emit a call to the puts function. Str is required to be a
379 /// pointer and File is a pointer to FILE.
380 void LibCallOptimization::EmitFPutS(Value *Str, Value *File, IRBuilder<> &B) {
381 Module *M = Caller->getParent();
382 AttributeWithIndex AWI[3];
383 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
384 AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
385 AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
387 if (isa<PointerType>(File->getType()))
388 F = M->getOrInsertFunction("fputs", AttrListPtr::get(AWI, 3),
389 Type::getInt32Ty(*Context),
390 Type::getInt8PtrTy(*Context),
391 File->getType(), NULL);
393 F = M->getOrInsertFunction("fputs", Type::getInt32Ty(*Context),
394 Type::getInt8PtrTy(*Context),
395 File->getType(), NULL);
396 CallInst *CI = B.CreateCall2(F, CastToCStr(Str, B), File, "fputs");
398 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
399 CI->setCallingConv(Fn->getCallingConv());
402 /// EmitFWrite - Emit a call to the fwrite function. This assumes that Ptr is
403 /// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
404 void LibCallOptimization::EmitFWrite(Value *Ptr, Value *Size, Value *File,
406 Module *M = Caller->getParent();
407 AttributeWithIndex AWI[3];
408 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
409 AWI[1] = AttributeWithIndex::get(4, Attribute::NoCapture);
410 AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
412 if (isa<PointerType>(File->getType()))
413 F = M->getOrInsertFunction("fwrite", AttrListPtr::get(AWI, 3),
414 TD->getIntPtrType(*Context),
415 Type::getInt8PtrTy(*Context),
416 TD->getIntPtrType(*Context),
417 TD->getIntPtrType(*Context),
418 File->getType(), NULL);
420 F = M->getOrInsertFunction("fwrite", TD->getIntPtrType(*Context),
421 Type::getInt8PtrTy(*Context),
422 TD->getIntPtrType(*Context),
423 TD->getIntPtrType(*Context),
424 File->getType(), NULL);
425 CallInst *CI = B.CreateCall4(F, CastToCStr(Ptr, B), Size,
426 ConstantInt::get(TD->getIntPtrType(*Context), 1), File);
428 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
429 CI->setCallingConv(Fn->getCallingConv());
432 //===----------------------------------------------------------------------===//
434 //===----------------------------------------------------------------------===//
436 /// GetStringLengthH - If we can compute the length of the string pointed to by
437 /// the specified pointer, return 'len+1'. If we can't, return 0.
438 static uint64_t GetStringLengthH(Value *V, SmallPtrSet<PHINode*, 32> &PHIs) {
439 // Look through noop bitcast instructions.
440 if (BitCastInst *BCI = dyn_cast<BitCastInst>(V))
441 return GetStringLengthH(BCI->getOperand(0), PHIs);
443 // If this is a PHI node, there are two cases: either we have already seen it
445 if (PHINode *PN = dyn_cast<PHINode>(V)) {
446 if (!PHIs.insert(PN))
447 return ~0ULL; // already in the set.
449 // If it was new, see if all the input strings are the same length.
450 uint64_t LenSoFar = ~0ULL;
451 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
452 uint64_t Len = GetStringLengthH(PN->getIncomingValue(i), PHIs);
453 if (Len == 0) return 0; // Unknown length -> unknown.
455 if (Len == ~0ULL) continue;
457 if (Len != LenSoFar && LenSoFar != ~0ULL)
458 return 0; // Disagree -> unknown.
462 // Success, all agree.
466 // strlen(select(c,x,y)) -> strlen(x) ^ strlen(y)
467 if (SelectInst *SI = dyn_cast<SelectInst>(V)) {
468 uint64_t Len1 = GetStringLengthH(SI->getTrueValue(), PHIs);
469 if (Len1 == 0) return 0;
470 uint64_t Len2 = GetStringLengthH(SI->getFalseValue(), PHIs);
471 if (Len2 == 0) return 0;
472 if (Len1 == ~0ULL) return Len2;
473 if (Len2 == ~0ULL) return Len1;
474 if (Len1 != Len2) return 0;
478 // If the value is not a GEP instruction nor a constant expression with a
479 // GEP instruction, then return unknown.
481 if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) {
483 } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
484 if (CE->getOpcode() != Instruction::GetElementPtr)
491 // Make sure the GEP has exactly three arguments.
492 if (GEP->getNumOperands() != 3)
495 // Check to make sure that the first operand of the GEP is an integer and
496 // has value 0 so that we are sure we're indexing into the initializer.
497 if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
503 // If the second index isn't a ConstantInt, then this is a variable index
504 // into the array. If this occurs, we can't say anything meaningful about
506 uint64_t StartIdx = 0;
507 if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(2)))
508 StartIdx = CI->getZExtValue();
512 // The GEP instruction, constant or instruction, must reference a global
513 // variable that is a constant and is initialized. The referenced constant
514 // initializer is the array that we'll use for optimization.
515 GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0));
516 if (!GV || !GV->isConstant() || !GV->hasInitializer() ||
517 GV->mayBeOverridden())
519 Constant *GlobalInit = GV->getInitializer();
521 // Handle the ConstantAggregateZero case, which is a degenerate case. The
522 // initializer is constant zero so the length of the string must be zero.
523 if (isa<ConstantAggregateZero>(GlobalInit))
524 return 1; // Len = 0 offset by 1.
526 // Must be a Constant Array
527 ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit);
528 if (!Array || !Array->getType()->getElementType()->isInteger(8))
531 // Get the number of elements in the array
532 uint64_t NumElts = Array->getType()->getNumElements();
534 // Traverse the constant array from StartIdx (derived above) which is
535 // the place the GEP refers to in the array.
536 for (unsigned i = StartIdx; i != NumElts; ++i) {
537 Constant *Elt = Array->getOperand(i);
538 ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
539 if (!CI) // This array isn't suitable, non-int initializer.
542 return i-StartIdx+1; // We found end of string, success!
545 return 0; // The array isn't null terminated, conservatively return 'unknown'.
548 /// GetStringLength - If we can compute the length of the string pointed to by
549 /// the specified pointer, return 'len+1'. If we can't, return 0.
550 static uint64_t GetStringLength(Value *V) {
551 if (!isa<PointerType>(V->getType())) return 0;
553 SmallPtrSet<PHINode*, 32> PHIs;
554 uint64_t Len = GetStringLengthH(V, PHIs);
555 // If Len is ~0ULL, we had an infinite phi cycle: this is dead code, so return
556 // an empty string as a length.
557 return Len == ~0ULL ? 1 : Len;
560 /// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
561 /// value is equal or not-equal to zero.
562 static bool IsOnlyUsedInZeroEqualityComparison(Value *V) {
563 for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
565 if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
566 if (IC->isEquality())
567 if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
568 if (C->isNullValue())
570 // Unknown instruction.
576 //===----------------------------------------------------------------------===//
577 // String and Memory LibCall Optimizations
578 //===----------------------------------------------------------------------===//
580 //===---------------------------------------===//
581 // 'strcat' Optimizations
583 struct StrCatOpt : public LibCallOptimization {
584 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
585 // Verify the "strcat" function prototype.
586 const FunctionType *FT = Callee->getFunctionType();
587 if (FT->getNumParams() != 2 ||
588 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
589 FT->getParamType(0) != FT->getReturnType() ||
590 FT->getParamType(1) != FT->getReturnType())
593 // Extract some information from the instruction
594 Value *Dst = CI->getOperand(1);
595 Value *Src = CI->getOperand(2);
597 // See if we can get the length of the input string.
598 uint64_t Len = GetStringLength(Src);
599 if (Len == 0) return 0;
600 --Len; // Unbias length.
602 // Handle the simple, do-nothing case: strcat(x, "") -> x
606 // These optimizations require TargetData.
609 EmitStrLenMemCpy(Src, Dst, Len, B);
613 void EmitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len, IRBuilder<> &B) {
614 // We need to find the end of the destination string. That's where the
615 // memory is to be moved to. We just generate a call to strlen.
616 Value *DstLen = EmitStrLen(Dst, B);
618 // Now that we have the destination's length, we must index into the
619 // destination's pointer to get the actual memcpy destination (end of
620 // the string .. we're concatenating).
621 Value *CpyDst = B.CreateGEP(Dst, DstLen, "endptr");
623 // We have enough information to now generate the memcpy call to do the
624 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
625 EmitMemCpy(CpyDst, Src,
626 ConstantInt::get(TD->getIntPtrType(*Context), Len+1), 1, B);
630 //===---------------------------------------===//
631 // 'strncat' Optimizations
633 struct StrNCatOpt : public StrCatOpt {
634 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
635 // Verify the "strncat" function prototype.
636 const FunctionType *FT = Callee->getFunctionType();
637 if (FT->getNumParams() != 3 ||
638 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
639 FT->getParamType(0) != FT->getReturnType() ||
640 FT->getParamType(1) != FT->getReturnType() ||
641 !isa<IntegerType>(FT->getParamType(2)))
644 // Extract some information from the instruction
645 Value *Dst = CI->getOperand(1);
646 Value *Src = CI->getOperand(2);
649 // We don't do anything if length is not constant
650 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
651 Len = LengthArg->getZExtValue();
655 // See if we can get the length of the input string.
656 uint64_t SrcLen = GetStringLength(Src);
657 if (SrcLen == 0) return 0;
658 --SrcLen; // Unbias length.
660 // Handle the simple, do-nothing cases:
661 // strncat(x, "", c) -> x
662 // strncat(x, c, 0) -> x
663 if (SrcLen == 0 || Len == 0) return Dst;
665 // These optimizations require TargetData.
668 // We don't optimize this case
669 if (Len < SrcLen) return 0;
671 // strncat(x, s, c) -> strcat(x, s)
672 // s is constant so the strcat can be optimized further
673 EmitStrLenMemCpy(Src, Dst, SrcLen, B);
678 //===---------------------------------------===//
679 // 'strchr' Optimizations
681 struct StrChrOpt : public LibCallOptimization {
682 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
683 // Verify the "strchr" function prototype.
684 const FunctionType *FT = Callee->getFunctionType();
685 if (FT->getNumParams() != 2 ||
686 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
687 FT->getParamType(0) != FT->getReturnType())
690 Value *SrcStr = CI->getOperand(1);
692 // If the second operand is non-constant, see if we can compute the length
693 // of the input string and turn this into memchr.
694 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getOperand(2));
696 // These optimizations require TargetData.
699 uint64_t Len = GetStringLength(SrcStr);
700 if (Len == 0 || !FT->getParamType(1)->isInteger(32)) // memchr needs i32.
703 return EmitMemChr(SrcStr, CI->getOperand(2), // include nul.
704 ConstantInt::get(TD->getIntPtrType(*Context), Len), B);
707 // Otherwise, the character is a constant, see if the first argument is
708 // a string literal. If so, we can constant fold.
710 if (!GetConstantStringInfo(SrcStr, Str))
713 // strchr can find the nul character.
715 char CharValue = CharC->getSExtValue();
717 // Compute the offset.
720 if (i == Str.size()) // Didn't find the char. strchr returns null.
721 return Constant::getNullValue(CI->getType());
722 // Did we find our match?
723 if (Str[i] == CharValue)
728 // strchr(s+n,c) -> gep(s+n+i,c)
729 Value *Idx = ConstantInt::get(Type::getInt64Ty(*Context), i);
730 return B.CreateGEP(SrcStr, Idx, "strchr");
734 //===---------------------------------------===//
735 // 'strcmp' Optimizations
737 struct StrCmpOpt : public LibCallOptimization {
738 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
739 // Verify the "strcmp" function prototype.
740 const FunctionType *FT = Callee->getFunctionType();
741 if (FT->getNumParams() != 2 ||
742 !FT->getReturnType()->isInteger(32) ||
743 FT->getParamType(0) != FT->getParamType(1) ||
744 FT->getParamType(0) != Type::getInt8PtrTy(*Context))
747 Value *Str1P = CI->getOperand(1), *Str2P = CI->getOperand(2);
748 if (Str1P == Str2P) // strcmp(x,x) -> 0
749 return ConstantInt::get(CI->getType(), 0);
751 std::string Str1, Str2;
752 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
753 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
755 if (HasStr1 && Str1.empty()) // strcmp("", x) -> *x
756 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
758 if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
759 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
761 // strcmp(x, y) -> cnst (if both x and y are constant strings)
762 if (HasStr1 && HasStr2)
763 return ConstantInt::get(CI->getType(),
764 strcmp(Str1.c_str(),Str2.c_str()));
766 // strcmp(P, "x") -> memcmp(P, "x", 2)
767 uint64_t Len1 = GetStringLength(Str1P);
768 uint64_t Len2 = GetStringLength(Str2P);
770 // These optimizations require TargetData.
773 return EmitMemCmp(Str1P, Str2P,
774 ConstantInt::get(TD->getIntPtrType(*Context),
775 std::min(Len1, Len2)), B);
782 //===---------------------------------------===//
783 // 'strncmp' Optimizations
785 struct StrNCmpOpt : public LibCallOptimization {
786 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
787 // Verify the "strncmp" function prototype.
788 const FunctionType *FT = Callee->getFunctionType();
789 if (FT->getNumParams() != 3 ||
790 !FT->getReturnType()->isInteger(32) ||
791 FT->getParamType(0) != FT->getParamType(1) ||
792 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
793 !isa<IntegerType>(FT->getParamType(2)))
796 Value *Str1P = CI->getOperand(1), *Str2P = CI->getOperand(2);
797 if (Str1P == Str2P) // strncmp(x,x,n) -> 0
798 return ConstantInt::get(CI->getType(), 0);
800 // Get the length argument if it is constant.
802 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
803 Length = LengthArg->getZExtValue();
807 if (Length == 0) // strncmp(x,y,0) -> 0
808 return ConstantInt::get(CI->getType(), 0);
810 std::string Str1, Str2;
811 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
812 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
814 if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> *x
815 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
817 if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x
818 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
820 // strncmp(x, y) -> cnst (if both x and y are constant strings)
821 if (HasStr1 && HasStr2)
822 return ConstantInt::get(CI->getType(),
823 strncmp(Str1.c_str(), Str2.c_str(), Length));
829 //===---------------------------------------===//
830 // 'strcpy' Optimizations
832 struct StrCpyOpt : public LibCallOptimization {
833 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
834 // Verify the "strcpy" function prototype.
835 const FunctionType *FT = Callee->getFunctionType();
836 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
837 FT->getParamType(0) != FT->getParamType(1) ||
838 FT->getParamType(0) != Type::getInt8PtrTy(*Context))
841 Value *Dst = CI->getOperand(1), *Src = CI->getOperand(2);
842 if (Dst == Src) // strcpy(x,x) -> x
845 // These optimizations require TargetData.
848 // See if we can get the length of the input string.
849 uint64_t Len = GetStringLength(Src);
850 if (Len == 0) return 0;
852 // We have enough information to now generate the memcpy call to do the
853 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
855 ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B);
860 //===---------------------------------------===//
861 // 'strncpy' Optimizations
863 struct StrNCpyOpt : public LibCallOptimization {
864 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
865 const FunctionType *FT = Callee->getFunctionType();
866 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
867 FT->getParamType(0) != FT->getParamType(1) ||
868 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
869 !isa<IntegerType>(FT->getParamType(2)))
872 Value *Dst = CI->getOperand(1);
873 Value *Src = CI->getOperand(2);
874 Value *LenOp = CI->getOperand(3);
876 // See if we can get the length of the input string.
877 uint64_t SrcLen = GetStringLength(Src);
878 if (SrcLen == 0) return 0;
882 // strncpy(x, "", y) -> memset(x, '\0', y, 1)
883 EmitMemSet(Dst, ConstantInt::get(Type::getInt8Ty(*Context), '\0'), LenOp,
889 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
890 Len = LengthArg->getZExtValue();
894 if (Len == 0) return Dst; // strncpy(x, y, 0) -> x
896 // These optimizations require TargetData.
899 // Let strncpy handle the zero padding
900 if (Len > SrcLen+1) return 0;
902 // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
904 ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B);
910 //===---------------------------------------===//
911 // 'strlen' Optimizations
913 struct StrLenOpt : public LibCallOptimization {
914 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
915 const FunctionType *FT = Callee->getFunctionType();
916 if (FT->getNumParams() != 1 ||
917 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
918 !isa<IntegerType>(FT->getReturnType()))
921 Value *Src = CI->getOperand(1);
923 // Constant folding: strlen("xyz") -> 3
924 if (uint64_t Len = GetStringLength(Src))
925 return ConstantInt::get(CI->getType(), Len-1);
927 // strlen(x) != 0 --> *x != 0
928 // strlen(x) == 0 --> *x == 0
929 if (IsOnlyUsedInZeroEqualityComparison(CI))
930 return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
935 //===---------------------------------------===//
936 // 'strto*' Optimizations. This handles strtol, strtod, strtof, strtoul, etc.
938 struct StrToOpt : public LibCallOptimization {
939 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
940 const FunctionType *FT = Callee->getFunctionType();
941 if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
942 !isa<PointerType>(FT->getParamType(0)) ||
943 !isa<PointerType>(FT->getParamType(1)))
946 Value *EndPtr = CI->getOperand(2);
947 if (isa<ConstantPointerNull>(EndPtr)) {
948 CI->setOnlyReadsMemory();
949 CI->addAttribute(1, Attribute::NoCapture);
956 //===---------------------------------------===//
957 // 'strstr' Optimizations
959 struct StrStrOpt : public LibCallOptimization {
960 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
961 const FunctionType *FT = Callee->getFunctionType();
962 if (FT->getNumParams() != 2 ||
963 !isa<PointerType>(FT->getParamType(0)) ||
964 !isa<PointerType>(FT->getParamType(1)) ||
965 !isa<PointerType>(FT->getReturnType()))
968 // fold strstr(x, x) -> x.
969 if (CI->getOperand(1) == CI->getOperand(2))
970 return B.CreateBitCast(CI->getOperand(1), CI->getType());
972 // See if either input string is a constant string.
973 std::string SearchStr, ToFindStr;
974 bool HasStr1 = GetConstantStringInfo(CI->getOperand(1), SearchStr);
975 bool HasStr2 = GetConstantStringInfo(CI->getOperand(2), ToFindStr);
977 // fold strstr(x, "") -> x.
978 if (HasStr2 && ToFindStr.empty())
979 return B.CreateBitCast(CI->getOperand(1), CI->getType());
981 // If both strings are known, constant fold it.
982 if (HasStr1 && HasStr2) {
983 std::string::size_type Offset = SearchStr.find(ToFindStr);
985 if (Offset == std::string::npos) // strstr("foo", "bar") -> null
986 return Constant::getNullValue(CI->getType());
988 // strstr("abcd", "bc") -> gep((char*)"abcd", 1)
989 Value *Result = CastToCStr(CI->getOperand(1), B);
990 Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
991 return B.CreateBitCast(Result, CI->getType());
994 // fold strstr(x, "y") -> strchr(x, 'y').
995 if (HasStr2 && ToFindStr.size() == 1)
996 return B.CreateBitCast(EmitStrChr(CI->getOperand(1), ToFindStr[0], B),
1003 //===---------------------------------------===//
1004 // 'memcmp' Optimizations
1006 struct MemCmpOpt : public LibCallOptimization {
1007 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1008 const FunctionType *FT = Callee->getFunctionType();
1009 if (FT->getNumParams() != 3 || !isa<PointerType>(FT->getParamType(0)) ||
1010 !isa<PointerType>(FT->getParamType(1)) ||
1011 !FT->getReturnType()->isInteger(32))
1014 Value *LHS = CI->getOperand(1), *RHS = CI->getOperand(2);
1016 if (LHS == RHS) // memcmp(s,s,x) -> 0
1017 return Constant::getNullValue(CI->getType());
1019 // Make sure we have a constant length.
1020 ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getOperand(3));
1021 if (!LenC) return 0;
1022 uint64_t Len = LenC->getZExtValue();
1024 if (Len == 0) // memcmp(s1,s2,0) -> 0
1025 return Constant::getNullValue(CI->getType());
1027 if (Len == 1) { // memcmp(S1,S2,1) -> *LHS - *RHS
1028 Value *LHSV = B.CreateLoad(CastToCStr(LHS, B), "lhsv");
1029 Value *RHSV = B.CreateLoad(CastToCStr(RHS, B), "rhsv");
1030 return B.CreateSExt(B.CreateSub(LHSV, RHSV, "chardiff"), CI->getType());
1033 // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
1034 std::string LHSStr, RHSStr;
1035 if (GetConstantStringInfo(LHS, LHSStr) &&
1036 GetConstantStringInfo(RHS, RHSStr)) {
1037 // Make sure we're not reading out-of-bounds memory.
1038 if (Len > LHSStr.length() || Len > RHSStr.length())
1040 uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len);
1041 return ConstantInt::get(CI->getType(), Ret);
1048 //===---------------------------------------===//
1049 // 'memcpy' Optimizations
1051 struct MemCpyOpt : public LibCallOptimization {
1052 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1053 // These optimizations require TargetData.
1056 const FunctionType *FT = Callee->getFunctionType();
1057 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1058 !isa<PointerType>(FT->getParamType(0)) ||
1059 !isa<PointerType>(FT->getParamType(1)) ||
1060 FT->getParamType(2) != TD->getIntPtrType(*Context))
1063 // memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
1064 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3), 1, B);
1065 return CI->getOperand(1);
1069 //===---------------------------------------===//
1070 // 'memmove' Optimizations
1072 struct MemMoveOpt : public LibCallOptimization {
1073 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1074 // These optimizations require TargetData.
1077 const FunctionType *FT = Callee->getFunctionType();
1078 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1079 !isa<PointerType>(FT->getParamType(0)) ||
1080 !isa<PointerType>(FT->getParamType(1)) ||
1081 FT->getParamType(2) != TD->getIntPtrType(*Context))
1084 // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
1085 EmitMemMove(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3), 1, B);
1086 return CI->getOperand(1);
1090 //===---------------------------------------===//
1091 // 'memset' Optimizations
1093 struct MemSetOpt : public LibCallOptimization {
1094 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1095 // These optimizations require TargetData.
1098 const FunctionType *FT = Callee->getFunctionType();
1099 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1100 !isa<PointerType>(FT->getParamType(0)) ||
1101 !isa<IntegerType>(FT->getParamType(1)) ||
1102 FT->getParamType(2) != TD->getIntPtrType(*Context))
1105 // memset(p, v, n) -> llvm.memset(p, v, n, 1)
1106 Value *Val = B.CreateIntCast(CI->getOperand(2), Type::getInt8Ty(*Context),
1108 EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B);
1109 return CI->getOperand(1);
1113 //===----------------------------------------------------------------------===//
1114 // Object Size Checking Optimizations
1115 //===----------------------------------------------------------------------===//
1117 //===---------------------------------------===//
1118 // 'memcpy_chk' Optimizations
1120 struct MemCpyChkOpt : public LibCallOptimization {
1121 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1122 // These optimizations require TargetData.
1125 const FunctionType *FT = Callee->getFunctionType();
1126 if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
1127 !isa<PointerType>(FT->getParamType(0)) ||
1128 !isa<PointerType>(FT->getParamType(1)) ||
1129 !isa<IntegerType>(FT->getParamType(3)) ||
1130 FT->getParamType(2) != TD->getIntPtrType(*Context))
1133 ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
1136 if (SizeCI->isAllOnesValue()) {
1137 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3), 1, B);
1138 return CI->getOperand(1);
1145 //===---------------------------------------===//
1146 // 'memset_chk' Optimizations
1148 struct MemSetChkOpt : public LibCallOptimization {
1149 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1150 // These optimizations require TargetData.
1153 const FunctionType *FT = Callee->getFunctionType();
1154 if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
1155 !isa<PointerType>(FT->getParamType(0)) ||
1156 !isa<IntegerType>(FT->getParamType(1)) ||
1157 !isa<IntegerType>(FT->getParamType(3)) ||
1158 FT->getParamType(2) != TD->getIntPtrType(*Context))
1161 ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
1164 if (SizeCI->isAllOnesValue()) {
1165 Value *Val = B.CreateIntCast(CI->getOperand(2), Type::getInt8Ty(*Context),
1167 EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B);
1168 return CI->getOperand(1);
1175 //===---------------------------------------===//
1176 // 'memmove_chk' Optimizations
1178 struct MemMoveChkOpt : public LibCallOptimization {
1179 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1180 // These optimizations require TargetData.
1183 const FunctionType *FT = Callee->getFunctionType();
1184 if (FT->getNumParams() != 4 || FT->getReturnType() != FT->getParamType(0) ||
1185 !isa<PointerType>(FT->getParamType(0)) ||
1186 !isa<PointerType>(FT->getParamType(1)) ||
1187 !isa<IntegerType>(FT->getParamType(3)) ||
1188 FT->getParamType(2) != TD->getIntPtrType(*Context))
1191 ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(4));
1194 if (SizeCI->isAllOnesValue()) {
1195 EmitMemMove(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3),
1197 return CI->getOperand(1);
1204 struct StrCpyChkOpt : public LibCallOptimization {
1205 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1206 // These optimizations require TargetData.
1209 const FunctionType *FT = Callee->getFunctionType();
1210 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
1211 !isa<PointerType>(FT->getParamType(0)) ||
1212 !isa<PointerType>(FT->getParamType(1)) ||
1213 !isa<IntegerType>(FT->getParamType(2)))
1216 ConstantInt *SizeCI = dyn_cast<ConstantInt>(CI->getOperand(3));
1220 // We don't have any length information, just lower to a plain strcpy.
1221 if (SizeCI->isAllOnesValue())
1222 return EmitStrCpy(CI->getOperand(1), CI->getOperand(2), B);
1229 //===----------------------------------------------------------------------===//
1230 // Math Library Optimizations
1231 //===----------------------------------------------------------------------===//
1233 //===---------------------------------------===//
1234 // 'pow*' Optimizations
1236 struct PowOpt : public LibCallOptimization {
1237 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1238 const FunctionType *FT = Callee->getFunctionType();
1239 // Just make sure this has 2 arguments of the same FP type, which match the
1241 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1242 FT->getParamType(0) != FT->getParamType(1) ||
1243 !FT->getParamType(0)->isFloatingPoint())
1246 Value *Op1 = CI->getOperand(1), *Op2 = CI->getOperand(2);
1247 if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
1248 if (Op1C->isExactlyValue(1.0)) // pow(1.0, x) -> 1.0
1250 if (Op1C->isExactlyValue(2.0)) // pow(2.0, x) -> exp2(x)
1251 return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
1254 ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
1255 if (Op2C == 0) return 0;
1257 if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
1258 return ConstantFP::get(CI->getType(), 1.0);
1260 if (Op2C->isExactlyValue(0.5)) {
1261 // Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
1262 // This is faster than calling pow, and still handles negative zero
1263 // and negative infinite correctly.
1264 // TODO: In fast-math mode, this could be just sqrt(x).
1265 // TODO: In finite-only mode, this could be just fabs(sqrt(x)).
1266 Value *Inf = ConstantFP::getInfinity(CI->getType());
1267 Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
1268 Value *Sqrt = EmitUnaryFloatFnCall(Op1, "sqrt", B,
1269 Callee->getAttributes());
1270 Value *FAbs = EmitUnaryFloatFnCall(Sqrt, "fabs", B,
1271 Callee->getAttributes());
1272 Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf, "tmp");
1273 Value *Sel = B.CreateSelect(FCmp, Inf, FAbs, "tmp");
1277 if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
1279 if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
1280 return B.CreateFMul(Op1, Op1, "pow2");
1281 if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
1282 return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0),
1288 //===---------------------------------------===//
1289 // 'exp2' Optimizations
1291 struct Exp2Opt : public LibCallOptimization {
1292 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1293 const FunctionType *FT = Callee->getFunctionType();
1294 // Just make sure this has 1 argument of FP type, which matches the
1296 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1297 !FT->getParamType(0)->isFloatingPoint())
1300 Value *Op = CI->getOperand(1);
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 Value *LdExpArg = 0;
1304 if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
1305 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
1306 LdExpArg = B.CreateSExt(OpC->getOperand(0),
1307 Type::getInt32Ty(*Context), "tmp");
1308 } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
1309 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
1310 LdExpArg = B.CreateZExt(OpC->getOperand(0),
1311 Type::getInt32Ty(*Context), "tmp");
1316 if (Op->getType()->isFloatTy())
1318 else if (Op->getType()->isDoubleTy())
1323 Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
1324 if (!Op->getType()->isFloatTy())
1325 One = ConstantExpr::getFPExtend(One, Op->getType());
1327 Module *M = Caller->getParent();
1328 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
1330 Type::getInt32Ty(*Context),NULL);
1331 CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
1332 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
1333 CI->setCallingConv(F->getCallingConv());
1341 //===---------------------------------------===//
1342 // Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
1344 struct UnaryDoubleFPOpt : public LibCallOptimization {
1345 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1346 const FunctionType *FT = Callee->getFunctionType();
1347 if (FT->getNumParams() != 1 || !FT->getReturnType()->isDoubleTy() ||
1348 !FT->getParamType(0)->isDoubleTy())
1351 // If this is something like 'floor((double)floatval)', convert to floorf.
1352 FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getOperand(1));
1353 if (Cast == 0 || !Cast->getOperand(0)->getType()->isFloatTy())
1356 // floor((double)floatval) -> (double)floorf(floatval)
1357 Value *V = Cast->getOperand(0);
1358 V = EmitUnaryFloatFnCall(V, Callee->getName().data(), B,
1359 Callee->getAttributes());
1360 return B.CreateFPExt(V, Type::getDoubleTy(*Context));
1364 //===----------------------------------------------------------------------===//
1365 // Integer Optimizations
1366 //===----------------------------------------------------------------------===//
1368 //===---------------------------------------===//
1369 // 'ffs*' Optimizations
1371 struct FFSOpt : public LibCallOptimization {
1372 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1373 const FunctionType *FT = Callee->getFunctionType();
1374 // Just make sure this has 2 arguments of the same FP type, which match the
1376 if (FT->getNumParams() != 1 ||
1377 !FT->getReturnType()->isInteger(32) ||
1378 !isa<IntegerType>(FT->getParamType(0)))
1381 Value *Op = CI->getOperand(1);
1384 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
1385 if (CI->getValue() == 0) // ffs(0) -> 0.
1386 return Constant::getNullValue(CI->getType());
1387 return ConstantInt::get(Type::getInt32Ty(*Context), // ffs(c) -> cttz(c)+1
1388 CI->getValue().countTrailingZeros()+1);
1391 // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
1392 const Type *ArgType = Op->getType();
1393 Value *F = Intrinsic::getDeclaration(Callee->getParent(),
1394 Intrinsic::cttz, &ArgType, 1);
1395 Value *V = B.CreateCall(F, Op, "cttz");
1396 V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1), "tmp");
1397 V = B.CreateIntCast(V, Type::getInt32Ty(*Context), false, "tmp");
1399 Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType), "tmp");
1400 return B.CreateSelect(Cond, V,
1401 ConstantInt::get(Type::getInt32Ty(*Context), 0));
1405 //===---------------------------------------===//
1406 // 'isdigit' Optimizations
1408 struct IsDigitOpt : public LibCallOptimization {
1409 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1410 const FunctionType *FT = Callee->getFunctionType();
1411 // We require integer(i32)
1412 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1413 !FT->getParamType(0)->isInteger(32))
1416 // isdigit(c) -> (c-'0') <u 10
1417 Value *Op = CI->getOperand(1);
1418 Op = B.CreateSub(Op, ConstantInt::get(Type::getInt32Ty(*Context), '0'),
1420 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 10),
1422 return B.CreateZExt(Op, CI->getType());
1426 //===---------------------------------------===//
1427 // 'isascii' Optimizations
1429 struct IsAsciiOpt : public LibCallOptimization {
1430 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1431 const FunctionType *FT = Callee->getFunctionType();
1432 // We require integer(i32)
1433 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1434 !FT->getParamType(0)->isInteger(32))
1437 // isascii(c) -> c <u 128
1438 Value *Op = CI->getOperand(1);
1439 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 128),
1441 return B.CreateZExt(Op, CI->getType());
1445 //===---------------------------------------===//
1446 // 'abs', 'labs', 'llabs' Optimizations
1448 struct AbsOpt : public LibCallOptimization {
1449 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1450 const FunctionType *FT = Callee->getFunctionType();
1451 // We require integer(integer) where the types agree.
1452 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1453 FT->getParamType(0) != FT->getReturnType())
1456 // abs(x) -> x >s -1 ? x : -x
1457 Value *Op = CI->getOperand(1);
1458 Value *Pos = B.CreateICmpSGT(Op,
1459 Constant::getAllOnesValue(Op->getType()),
1461 Value *Neg = B.CreateNeg(Op, "neg");
1462 return B.CreateSelect(Pos, Op, Neg);
1467 //===---------------------------------------===//
1468 // 'toascii' Optimizations
1470 struct ToAsciiOpt : public LibCallOptimization {
1471 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1472 const FunctionType *FT = Callee->getFunctionType();
1473 // We require i32(i32)
1474 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1475 !FT->getParamType(0)->isInteger(32))
1478 // isascii(c) -> c & 0x7f
1479 return B.CreateAnd(CI->getOperand(1),
1480 ConstantInt::get(CI->getType(),0x7F));
1484 //===----------------------------------------------------------------------===//
1485 // Formatting and IO Optimizations
1486 //===----------------------------------------------------------------------===//
1488 //===---------------------------------------===//
1489 // 'printf' Optimizations
1491 struct PrintFOpt : public LibCallOptimization {
1492 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1493 // Require one fixed pointer argument and an integer/void result.
1494 const FunctionType *FT = Callee->getFunctionType();
1495 if (FT->getNumParams() < 1 || !isa<PointerType>(FT->getParamType(0)) ||
1496 !(isa<IntegerType>(FT->getReturnType()) ||
1497 FT->getReturnType()->isVoidTy()))
1500 // Check for a fixed format string.
1501 std::string FormatStr;
1502 if (!GetConstantStringInfo(CI->getOperand(1), FormatStr))
1505 // Empty format string -> noop.
1506 if (FormatStr.empty()) // Tolerate printf's declared void.
1507 return CI->use_empty() ? (Value*)CI :
1508 ConstantInt::get(CI->getType(), 0);
1510 // printf("x") -> putchar('x'), even for '%'. Return the result of putchar
1511 // in case there is an error writing to stdout.
1512 if (FormatStr.size() == 1) {
1513 Value *Res = EmitPutChar(ConstantInt::get(Type::getInt32Ty(*Context),
1515 if (CI->use_empty()) return CI;
1516 return B.CreateIntCast(Res, CI->getType(), true);
1519 // printf("foo\n") --> puts("foo")
1520 if (FormatStr[FormatStr.size()-1] == '\n' &&
1521 FormatStr.find('%') == std::string::npos) { // no format characters.
1522 // Create a string literal with no \n on it. We expect the constant merge
1523 // pass to be run after this pass, to merge duplicate strings.
1524 FormatStr.erase(FormatStr.end()-1);
1525 Constant *C = ConstantArray::get(*Context, FormatStr, true);
1526 C = new GlobalVariable(*Callee->getParent(), C->getType(), true,
1527 GlobalVariable::InternalLinkage, C, "str");
1529 return CI->use_empty() ? (Value*)CI :
1530 ConstantInt::get(CI->getType(), FormatStr.size()+1);
1533 // Optimize specific format strings.
1534 // printf("%c", chr) --> putchar(*(i8*)dst)
1535 if (FormatStr == "%c" && CI->getNumOperands() > 2 &&
1536 isa<IntegerType>(CI->getOperand(2)->getType())) {
1537 Value *Res = EmitPutChar(CI->getOperand(2), B);
1539 if (CI->use_empty()) return CI;
1540 return B.CreateIntCast(Res, CI->getType(), true);
1543 // printf("%s\n", str) --> puts(str)
1544 if (FormatStr == "%s\n" && CI->getNumOperands() > 2 &&
1545 isa<PointerType>(CI->getOperand(2)->getType()) &&
1547 EmitPutS(CI->getOperand(2), B);
1554 //===---------------------------------------===//
1555 // 'sprintf' Optimizations
1557 struct SPrintFOpt : public LibCallOptimization {
1558 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1559 // Require two fixed pointer arguments and an integer result.
1560 const FunctionType *FT = Callee->getFunctionType();
1561 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1562 !isa<PointerType>(FT->getParamType(1)) ||
1563 !isa<IntegerType>(FT->getReturnType()))
1566 // Check for a fixed format string.
1567 std::string FormatStr;
1568 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1571 // If we just have a format string (nothing else crazy) transform it.
1572 if (CI->getNumOperands() == 3) {
1573 // Make sure there's no % in the constant array. We could try to handle
1574 // %% -> % in the future if we cared.
1575 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1576 if (FormatStr[i] == '%')
1577 return 0; // we found a format specifier, bail out.
1579 // These optimizations require TargetData.
1582 // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1583 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), // Copy the nul byte.
1585 (TD->getIntPtrType(*Context), FormatStr.size()+1),1,B);
1586 return ConstantInt::get(CI->getType(), FormatStr.size());
1589 // The remaining optimizations require the format string to be "%s" or "%c"
1590 // and have an extra operand.
1591 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1594 // Decode the second character of the format string.
1595 if (FormatStr[1] == 'c') {
1596 // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1597 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1598 Value *V = B.CreateTrunc(CI->getOperand(3),
1599 Type::getInt8Ty(*Context), "char");
1600 Value *Ptr = CastToCStr(CI->getOperand(1), B);
1601 B.CreateStore(V, Ptr);
1602 Ptr = B.CreateGEP(Ptr, ConstantInt::get(Type::getInt32Ty(*Context), 1),
1604 B.CreateStore(Constant::getNullValue(Type::getInt8Ty(*Context)), Ptr);
1606 return ConstantInt::get(CI->getType(), 1);
1609 if (FormatStr[1] == 's') {
1610 // These optimizations require TargetData.
1613 // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1614 if (!isa<PointerType>(CI->getOperand(3)->getType())) return 0;
1616 Value *Len = EmitStrLen(CI->getOperand(3), B);
1617 Value *IncLen = B.CreateAdd(Len,
1618 ConstantInt::get(Len->getType(), 1),
1620 EmitMemCpy(CI->getOperand(1), CI->getOperand(3), IncLen, 1, B);
1622 // The sprintf result is the unincremented number of bytes in the string.
1623 return B.CreateIntCast(Len, CI->getType(), false);
1629 //===---------------------------------------===//
1630 // 'fwrite' Optimizations
1632 struct FWriteOpt : public LibCallOptimization {
1633 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1634 // Require a pointer, an integer, an integer, a pointer, returning integer.
1635 const FunctionType *FT = Callee->getFunctionType();
1636 if (FT->getNumParams() != 4 || !isa<PointerType>(FT->getParamType(0)) ||
1637 !isa<IntegerType>(FT->getParamType(1)) ||
1638 !isa<IntegerType>(FT->getParamType(2)) ||
1639 !isa<PointerType>(FT->getParamType(3)) ||
1640 !isa<IntegerType>(FT->getReturnType()))
1643 // Get the element size and count.
1644 ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getOperand(2));
1645 ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getOperand(3));
1646 if (!SizeC || !CountC) return 0;
1647 uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
1649 // If this is writing zero records, remove the call (it's a noop).
1651 return ConstantInt::get(CI->getType(), 0);
1653 // If this is writing one byte, turn it into fputc.
1654 if (Bytes == 1) { // fwrite(S,1,1,F) -> fputc(S[0],F)
1655 Value *Char = B.CreateLoad(CastToCStr(CI->getOperand(1), B), "char");
1656 EmitFPutC(Char, CI->getOperand(4), B);
1657 return ConstantInt::get(CI->getType(), 1);
1664 //===---------------------------------------===//
1665 // 'fputs' Optimizations
1667 struct FPutsOpt : public LibCallOptimization {
1668 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1669 // These optimizations require TargetData.
1672 // Require two pointers. Also, we can't optimize if return value is used.
1673 const FunctionType *FT = Callee->getFunctionType();
1674 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1675 !isa<PointerType>(FT->getParamType(1)) ||
1679 // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1680 uint64_t Len = GetStringLength(CI->getOperand(1));
1682 EmitFWrite(CI->getOperand(1),
1683 ConstantInt::get(TD->getIntPtrType(*Context), Len-1),
1684 CI->getOperand(2), B);
1685 return CI; // Known to have no uses (see above).
1689 //===---------------------------------------===//
1690 // 'fprintf' Optimizations
1692 struct FPrintFOpt : public LibCallOptimization {
1693 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1694 // Require two fixed paramters as pointers and integer result.
1695 const FunctionType *FT = Callee->getFunctionType();
1696 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1697 !isa<PointerType>(FT->getParamType(1)) ||
1698 !isa<IntegerType>(FT->getReturnType()))
1701 // All the optimizations depend on the format string.
1702 std::string FormatStr;
1703 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1706 // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1707 if (CI->getNumOperands() == 3) {
1708 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1709 if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1710 return 0; // We found a format specifier.
1712 // These optimizations require TargetData.
1715 EmitFWrite(CI->getOperand(2),
1716 ConstantInt::get(TD->getIntPtrType(*Context),
1718 CI->getOperand(1), B);
1719 return ConstantInt::get(CI->getType(), FormatStr.size());
1722 // The remaining optimizations require the format string to be "%s" or "%c"
1723 // and have an extra operand.
1724 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1727 // Decode the second character of the format string.
1728 if (FormatStr[1] == 'c') {
1729 // fprintf(F, "%c", chr) --> *(i8*)dst = chr
1730 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1731 EmitFPutC(CI->getOperand(3), CI->getOperand(1), B);
1732 return ConstantInt::get(CI->getType(), 1);
1735 if (FormatStr[1] == 's') {
1736 // fprintf(F, "%s", str) -> fputs(str, F)
1737 if (!isa<PointerType>(CI->getOperand(3)->getType()) || !CI->use_empty())
1739 EmitFPutS(CI->getOperand(3), CI->getOperand(1), B);
1746 } // end anonymous namespace.
1748 //===----------------------------------------------------------------------===//
1749 // SimplifyLibCalls Pass Implementation
1750 //===----------------------------------------------------------------------===//
1753 /// This pass optimizes well known library functions from libc and libm.
1755 class SimplifyLibCalls : public FunctionPass {
1756 StringMap<LibCallOptimization*> Optimizations;
1757 // String and Memory LibCall Optimizations
1758 StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
1759 StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
1760 StrToOpt StrTo; StrStrOpt StrStr;
1761 MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
1762 // Math Library Optimizations
1763 PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
1764 // Integer Optimizations
1765 FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
1767 // Formatting and IO Optimizations
1768 SPrintFOpt SPrintF; PrintFOpt PrintF;
1769 FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
1771 // Object Size Checking
1772 MemCpyChkOpt MemCpyChk; MemSetChkOpt MemSetChk; MemMoveChkOpt MemMoveChk;
1773 StrCpyChkOpt StrCpyChk;
1775 bool Modified; // This is only used by doInitialization.
1777 static char ID; // Pass identification
1778 SimplifyLibCalls() : FunctionPass(&ID) {}
1780 void InitOptimizations();
1781 bool runOnFunction(Function &F);
1783 void setDoesNotAccessMemory(Function &F);
1784 void setOnlyReadsMemory(Function &F);
1785 void setDoesNotThrow(Function &F);
1786 void setDoesNotCapture(Function &F, unsigned n);
1787 void setDoesNotAlias(Function &F, unsigned n);
1788 bool doInitialization(Module &M);
1790 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1793 char SimplifyLibCalls::ID = 0;
1794 } // end anonymous namespace.
1796 static RegisterPass<SimplifyLibCalls>
1797 X("simplify-libcalls", "Simplify well-known library calls");
1799 // Public interface to the Simplify LibCalls pass.
1800 FunctionPass *llvm::createSimplifyLibCallsPass() {
1801 return new SimplifyLibCalls();
1804 /// Optimizations - Populate the Optimizations map with all the optimizations
1806 void SimplifyLibCalls::InitOptimizations() {
1807 // String and Memory LibCall Optimizations
1808 Optimizations["strcat"] = &StrCat;
1809 Optimizations["strncat"] = &StrNCat;
1810 Optimizations["strchr"] = &StrChr;
1811 Optimizations["strcmp"] = &StrCmp;
1812 Optimizations["strncmp"] = &StrNCmp;
1813 Optimizations["strcpy"] = &StrCpy;
1814 Optimizations["strncpy"] = &StrNCpy;
1815 Optimizations["strlen"] = &StrLen;
1816 Optimizations["strtol"] = &StrTo;
1817 Optimizations["strtod"] = &StrTo;
1818 Optimizations["strtof"] = &StrTo;
1819 Optimizations["strtoul"] = &StrTo;
1820 Optimizations["strtoll"] = &StrTo;
1821 Optimizations["strtold"] = &StrTo;
1822 Optimizations["strtoull"] = &StrTo;
1823 Optimizations["strstr"] = &StrStr;
1824 Optimizations["memcmp"] = &MemCmp;
1825 Optimizations["memcpy"] = &MemCpy;
1826 Optimizations["memmove"] = &MemMove;
1827 Optimizations["memset"] = &MemSet;
1829 // Math Library Optimizations
1830 Optimizations["powf"] = &Pow;
1831 Optimizations["pow"] = &Pow;
1832 Optimizations["powl"] = &Pow;
1833 Optimizations["llvm.pow.f32"] = &Pow;
1834 Optimizations["llvm.pow.f64"] = &Pow;
1835 Optimizations["llvm.pow.f80"] = &Pow;
1836 Optimizations["llvm.pow.f128"] = &Pow;
1837 Optimizations["llvm.pow.ppcf128"] = &Pow;
1838 Optimizations["exp2l"] = &Exp2;
1839 Optimizations["exp2"] = &Exp2;
1840 Optimizations["exp2f"] = &Exp2;
1841 Optimizations["llvm.exp2.ppcf128"] = &Exp2;
1842 Optimizations["llvm.exp2.f128"] = &Exp2;
1843 Optimizations["llvm.exp2.f80"] = &Exp2;
1844 Optimizations["llvm.exp2.f64"] = &Exp2;
1845 Optimizations["llvm.exp2.f32"] = &Exp2;
1848 Optimizations["floor"] = &UnaryDoubleFP;
1851 Optimizations["ceil"] = &UnaryDoubleFP;
1854 Optimizations["round"] = &UnaryDoubleFP;
1857 Optimizations["rint"] = &UnaryDoubleFP;
1859 #ifdef HAVE_NEARBYINTF
1860 Optimizations["nearbyint"] = &UnaryDoubleFP;
1863 // Integer Optimizations
1864 Optimizations["ffs"] = &FFS;
1865 Optimizations["ffsl"] = &FFS;
1866 Optimizations["ffsll"] = &FFS;
1867 Optimizations["abs"] = &Abs;
1868 Optimizations["labs"] = &Abs;
1869 Optimizations["llabs"] = &Abs;
1870 Optimizations["isdigit"] = &IsDigit;
1871 Optimizations["isascii"] = &IsAscii;
1872 Optimizations["toascii"] = &ToAscii;
1874 // Formatting and IO Optimizations
1875 Optimizations["sprintf"] = &SPrintF;
1876 Optimizations["printf"] = &PrintF;
1877 Optimizations["fwrite"] = &FWrite;
1878 Optimizations["fputs"] = &FPuts;
1879 Optimizations["fprintf"] = &FPrintF;
1881 // Object Size Checking
1882 Optimizations["__memcpy_chk"] = &MemCpyChk;
1883 Optimizations["__memset_chk"] = &MemSetChk;
1884 Optimizations["__memmove_chk"] = &MemMoveChk;
1885 Optimizations["__strcpy_chk"] = &StrCpyChk;
1889 /// runOnFunction - Top level algorithm.
1891 bool SimplifyLibCalls::runOnFunction(Function &F) {
1892 if (Optimizations.empty())
1893 InitOptimizations();
1895 const TargetData *TD = getAnalysisIfAvailable<TargetData>();
1897 IRBuilder<> Builder(F.getContext());
1899 bool Changed = false;
1900 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1901 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
1902 // Ignore non-calls.
1903 CallInst *CI = dyn_cast<CallInst>(I++);
1906 // Ignore indirect calls and calls to non-external functions.
1907 Function *Callee = CI->getCalledFunction();
1908 if (Callee == 0 || !Callee->isDeclaration() ||
1909 !(Callee->hasExternalLinkage() || Callee->hasDLLImportLinkage()))
1912 // Ignore unknown calls.
1913 LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
1916 // Set the builder to the instruction after the call.
1917 Builder.SetInsertPoint(BB, I);
1919 // Try to optimize this call.
1920 Value *Result = LCO->OptimizeCall(CI, TD, Builder);
1921 if (Result == 0) continue;
1923 DEBUG(dbgs() << "SimplifyLibCalls simplified: " << *CI;
1924 dbgs() << " into: " << *Result << "\n");
1926 // Something changed!
1930 // Inspect the instruction after the call (which was potentially just
1934 if (CI != Result && !CI->use_empty()) {
1935 CI->replaceAllUsesWith(Result);
1936 if (!Result->hasName())
1937 Result->takeName(CI);
1939 CI->eraseFromParent();
1945 // Utility methods for doInitialization.
1947 void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
1948 if (!F.doesNotAccessMemory()) {
1949 F.setDoesNotAccessMemory();
1954 void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
1955 if (!F.onlyReadsMemory()) {
1956 F.setOnlyReadsMemory();
1961 void SimplifyLibCalls::setDoesNotThrow(Function &F) {
1962 if (!F.doesNotThrow()) {
1963 F.setDoesNotThrow();
1968 void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
1969 if (!F.doesNotCapture(n)) {
1970 F.setDoesNotCapture(n);
1975 void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
1976 if (!F.doesNotAlias(n)) {
1977 F.setDoesNotAlias(n);
1983 /// doInitialization - Add attributes to well-known functions.
1985 bool SimplifyLibCalls::doInitialization(Module &M) {
1987 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
1989 if (!F.isDeclaration())
1995 const FunctionType *FTy = F.getFunctionType();
1997 StringRef Name = F.getName();
2000 if (Name == "strlen") {
2001 if (FTy->getNumParams() != 1 ||
2002 !isa<PointerType>(FTy->getParamType(0)))
2004 setOnlyReadsMemory(F);
2006 setDoesNotCapture(F, 1);
2007 } else if (Name == "strcpy" ||
2013 Name == "strtoul" ||
2014 Name == "strtoll" ||
2015 Name == "strtold" ||
2016 Name == "strncat" ||
2017 Name == "strncpy" ||
2018 Name == "strtoull") {
2019 if (FTy->getNumParams() < 2 ||
2020 !isa<PointerType>(FTy->getParamType(1)))
2023 setDoesNotCapture(F, 2);
2024 } else if (Name == "strxfrm") {
2025 if (FTy->getNumParams() != 3 ||
2026 !isa<PointerType>(FTy->getParamType(0)) ||
2027 !isa<PointerType>(FTy->getParamType(1)))
2030 setDoesNotCapture(F, 1);
2031 setDoesNotCapture(F, 2);
2032 } else if (Name == "strcmp" ||
2034 Name == "strncmp" ||
2035 Name ==" strcspn" ||
2036 Name == "strcoll" ||
2037 Name == "strcasecmp" ||
2038 Name == "strncasecmp") {
2039 if (FTy->getNumParams() < 2 ||
2040 !isa<PointerType>(FTy->getParamType(0)) ||
2041 !isa<PointerType>(FTy->getParamType(1)))
2043 setOnlyReadsMemory(F);
2045 setDoesNotCapture(F, 1);
2046 setDoesNotCapture(F, 2);
2047 } else if (Name == "strstr" ||
2048 Name == "strpbrk") {
2049 if (FTy->getNumParams() != 2 ||
2050 !isa<PointerType>(FTy->getParamType(1)))
2052 setOnlyReadsMemory(F);
2054 setDoesNotCapture(F, 2);
2055 } else if (Name == "strtok" ||
2056 Name == "strtok_r") {
2057 if (FTy->getNumParams() < 2 ||
2058 !isa<PointerType>(FTy->getParamType(1)))
2061 setDoesNotCapture(F, 2);
2062 } else if (Name == "scanf" ||
2064 Name == "setvbuf") {
2065 if (FTy->getNumParams() < 1 ||
2066 !isa<PointerType>(FTy->getParamType(0)))
2069 setDoesNotCapture(F, 1);
2070 } else if (Name == "strdup" ||
2071 Name == "strndup") {
2072 if (FTy->getNumParams() < 1 ||
2073 !isa<PointerType>(FTy->getReturnType()) ||
2074 !isa<PointerType>(FTy->getParamType(0)))
2077 setDoesNotAlias(F, 0);
2078 setDoesNotCapture(F, 1);
2079 } else if (Name == "stat" ||
2081 Name == "sprintf" ||
2082 Name == "statvfs") {
2083 if (FTy->getNumParams() < 2 ||
2084 !isa<PointerType>(FTy->getParamType(0)) ||
2085 !isa<PointerType>(FTy->getParamType(1)))
2088 setDoesNotCapture(F, 1);
2089 setDoesNotCapture(F, 2);
2090 } else if (Name == "snprintf") {
2091 if (FTy->getNumParams() != 3 ||
2092 !isa<PointerType>(FTy->getParamType(0)) ||
2093 !isa<PointerType>(FTy->getParamType(2)))
2096 setDoesNotCapture(F, 1);
2097 setDoesNotCapture(F, 3);
2098 } else if (Name == "setitimer") {
2099 if (FTy->getNumParams() != 3 ||
2100 !isa<PointerType>(FTy->getParamType(1)) ||
2101 !isa<PointerType>(FTy->getParamType(2)))
2104 setDoesNotCapture(F, 2);
2105 setDoesNotCapture(F, 3);
2106 } else if (Name == "system") {
2107 if (FTy->getNumParams() != 1 ||
2108 !isa<PointerType>(FTy->getParamType(0)))
2110 // May throw; "system" is a valid pthread cancellation point.
2111 setDoesNotCapture(F, 1);
2115 if (Name == "malloc") {
2116 if (FTy->getNumParams() != 1 ||
2117 !isa<PointerType>(FTy->getReturnType()))
2120 setDoesNotAlias(F, 0);
2121 } else if (Name == "memcmp") {
2122 if (FTy->getNumParams() != 3 ||
2123 !isa<PointerType>(FTy->getParamType(0)) ||
2124 !isa<PointerType>(FTy->getParamType(1)))
2126 setOnlyReadsMemory(F);
2128 setDoesNotCapture(F, 1);
2129 setDoesNotCapture(F, 2);
2130 } else if (Name == "memchr" ||
2131 Name == "memrchr") {
2132 if (FTy->getNumParams() != 3)
2134 setOnlyReadsMemory(F);
2136 } else if (Name == "modf" ||
2140 Name == "memccpy" ||
2141 Name == "memmove") {
2142 if (FTy->getNumParams() < 2 ||
2143 !isa<PointerType>(FTy->getParamType(1)))
2146 setDoesNotCapture(F, 2);
2147 } else if (Name == "memalign") {
2148 if (!isa<PointerType>(FTy->getReturnType()))
2150 setDoesNotAlias(F, 0);
2151 } else if (Name == "mkdir" ||
2153 if (FTy->getNumParams() == 0 ||
2154 !isa<PointerType>(FTy->getParamType(0)))
2157 setDoesNotCapture(F, 1);
2161 if (Name == "realloc") {
2162 if (FTy->getNumParams() != 2 ||
2163 !isa<PointerType>(FTy->getParamType(0)) ||
2164 !isa<PointerType>(FTy->getReturnType()))
2167 setDoesNotAlias(F, 0);
2168 setDoesNotCapture(F, 1);
2169 } else if (Name == "read") {
2170 if (FTy->getNumParams() != 3 ||
2171 !isa<PointerType>(FTy->getParamType(1)))
2173 // May throw; "read" is a valid pthread cancellation point.
2174 setDoesNotCapture(F, 2);
2175 } else if (Name == "rmdir" ||
2178 Name == "realpath") {
2179 if (FTy->getNumParams() < 1 ||
2180 !isa<PointerType>(FTy->getParamType(0)))
2183 setDoesNotCapture(F, 1);
2184 } else if (Name == "rename" ||
2185 Name == "readlink") {
2186 if (FTy->getNumParams() < 2 ||
2187 !isa<PointerType>(FTy->getParamType(0)) ||
2188 !isa<PointerType>(FTy->getParamType(1)))
2191 setDoesNotCapture(F, 1);
2192 setDoesNotCapture(F, 2);
2196 if (Name == "write") {
2197 if (FTy->getNumParams() != 3 ||
2198 !isa<PointerType>(FTy->getParamType(1)))
2200 // May throw; "write" is a valid pthread cancellation point.
2201 setDoesNotCapture(F, 2);
2205 if (Name == "bcopy") {
2206 if (FTy->getNumParams() != 3 ||
2207 !isa<PointerType>(FTy->getParamType(0)) ||
2208 !isa<PointerType>(FTy->getParamType(1)))
2211 setDoesNotCapture(F, 1);
2212 setDoesNotCapture(F, 2);
2213 } else if (Name == "bcmp") {
2214 if (FTy->getNumParams() != 3 ||
2215 !isa<PointerType>(FTy->getParamType(0)) ||
2216 !isa<PointerType>(FTy->getParamType(1)))
2219 setOnlyReadsMemory(F);
2220 setDoesNotCapture(F, 1);
2221 setDoesNotCapture(F, 2);
2222 } else if (Name == "bzero") {
2223 if (FTy->getNumParams() != 2 ||
2224 !isa<PointerType>(FTy->getParamType(0)))
2227 setDoesNotCapture(F, 1);
2231 if (Name == "calloc") {
2232 if (FTy->getNumParams() != 2 ||
2233 !isa<PointerType>(FTy->getReturnType()))
2236 setDoesNotAlias(F, 0);
2237 } else if (Name == "chmod" ||
2239 Name == "ctermid" ||
2240 Name == "clearerr" ||
2241 Name == "closedir") {
2242 if (FTy->getNumParams() == 0 ||
2243 !isa<PointerType>(FTy->getParamType(0)))
2246 setDoesNotCapture(F, 1);
2250 if (Name == "atoi" ||
2254 if (FTy->getNumParams() != 1 ||
2255 !isa<PointerType>(FTy->getParamType(0)))
2258 setOnlyReadsMemory(F);
2259 setDoesNotCapture(F, 1);
2260 } else if (Name == "access") {
2261 if (FTy->getNumParams() != 2 ||
2262 !isa<PointerType>(FTy->getParamType(0)))
2265 setDoesNotCapture(F, 1);
2269 if (Name == "fopen") {
2270 if (FTy->getNumParams() != 2 ||
2271 !isa<PointerType>(FTy->getReturnType()) ||
2272 !isa<PointerType>(FTy->getParamType(0)) ||
2273 !isa<PointerType>(FTy->getParamType(1)))
2276 setDoesNotAlias(F, 0);
2277 setDoesNotCapture(F, 1);
2278 setDoesNotCapture(F, 2);
2279 } else if (Name == "fdopen") {
2280 if (FTy->getNumParams() != 2 ||
2281 !isa<PointerType>(FTy->getReturnType()) ||
2282 !isa<PointerType>(FTy->getParamType(1)))
2285 setDoesNotAlias(F, 0);
2286 setDoesNotCapture(F, 2);
2287 } else if (Name == "feof" ||
2297 Name == "fsetpos" ||
2298 Name == "flockfile" ||
2299 Name == "funlockfile" ||
2300 Name == "ftrylockfile") {
2301 if (FTy->getNumParams() == 0 ||
2302 !isa<PointerType>(FTy->getParamType(0)))
2305 setDoesNotCapture(F, 1);
2306 } else if (Name == "ferror") {
2307 if (FTy->getNumParams() != 1 ||
2308 !isa<PointerType>(FTy->getParamType(0)))
2311 setDoesNotCapture(F, 1);
2312 setOnlyReadsMemory(F);
2313 } else if (Name == "fputc" ||
2318 Name == "fstatvfs") {
2319 if (FTy->getNumParams() != 2 ||
2320 !isa<PointerType>(FTy->getParamType(1)))
2323 setDoesNotCapture(F, 2);
2324 } else if (Name == "fgets") {
2325 if (FTy->getNumParams() != 3 ||
2326 !isa<PointerType>(FTy->getParamType(0)) ||
2327 !isa<PointerType>(FTy->getParamType(2)))
2330 setDoesNotCapture(F, 3);
2331 } else if (Name == "fread" ||
2333 if (FTy->getNumParams() != 4 ||
2334 !isa<PointerType>(FTy->getParamType(0)) ||
2335 !isa<PointerType>(FTy->getParamType(3)))
2338 setDoesNotCapture(F, 1);
2339 setDoesNotCapture(F, 4);
2340 } else if (Name == "fputs" ||
2342 Name == "fprintf" ||
2343 Name == "fgetpos") {
2344 if (FTy->getNumParams() < 2 ||
2345 !isa<PointerType>(FTy->getParamType(0)) ||
2346 !isa<PointerType>(FTy->getParamType(1)))
2349 setDoesNotCapture(F, 1);
2350 setDoesNotCapture(F, 2);
2354 if (Name == "getc" ||
2355 Name == "getlogin_r" ||
2356 Name == "getc_unlocked") {
2357 if (FTy->getNumParams() == 0 ||
2358 !isa<PointerType>(FTy->getParamType(0)))
2361 setDoesNotCapture(F, 1);
2362 } else if (Name == "getenv") {
2363 if (FTy->getNumParams() != 1 ||
2364 !isa<PointerType>(FTy->getParamType(0)))
2367 setOnlyReadsMemory(F);
2368 setDoesNotCapture(F, 1);
2369 } else if (Name == "gets" ||
2370 Name == "getchar") {
2372 } else if (Name == "getitimer") {
2373 if (FTy->getNumParams() != 2 ||
2374 !isa<PointerType>(FTy->getParamType(1)))
2377 setDoesNotCapture(F, 2);
2378 } else if (Name == "getpwnam") {
2379 if (FTy->getNumParams() != 1 ||
2380 !isa<PointerType>(FTy->getParamType(0)))
2383 setDoesNotCapture(F, 1);
2387 if (Name == "ungetc") {
2388 if (FTy->getNumParams() != 2 ||
2389 !isa<PointerType>(FTy->getParamType(1)))
2392 setDoesNotCapture(F, 2);
2393 } else if (Name == "uname" ||
2395 Name == "unsetenv") {
2396 if (FTy->getNumParams() != 1 ||
2397 !isa<PointerType>(FTy->getParamType(0)))
2400 setDoesNotCapture(F, 1);
2401 } else if (Name == "utime" ||
2403 if (FTy->getNumParams() != 2 ||
2404 !isa<PointerType>(FTy->getParamType(0)) ||
2405 !isa<PointerType>(FTy->getParamType(1)))
2408 setDoesNotCapture(F, 1);
2409 setDoesNotCapture(F, 2);
2413 if (Name == "putc") {
2414 if (FTy->getNumParams() != 2 ||
2415 !isa<PointerType>(FTy->getParamType(1)))
2418 setDoesNotCapture(F, 2);
2419 } else if (Name == "puts" ||
2422 if (FTy->getNumParams() != 1 ||
2423 !isa<PointerType>(FTy->getParamType(0)))
2426 setDoesNotCapture(F, 1);
2427 } else if (Name == "pread" ||
2429 if (FTy->getNumParams() != 4 ||
2430 !isa<PointerType>(FTy->getParamType(1)))
2432 // May throw; these are valid pthread cancellation points.
2433 setDoesNotCapture(F, 2);
2434 } else if (Name == "putchar") {
2436 } else if (Name == "popen") {
2437 if (FTy->getNumParams() != 2 ||
2438 !isa<PointerType>(FTy->getReturnType()) ||
2439 !isa<PointerType>(FTy->getParamType(0)) ||
2440 !isa<PointerType>(FTy->getParamType(1)))
2443 setDoesNotAlias(F, 0);
2444 setDoesNotCapture(F, 1);
2445 setDoesNotCapture(F, 2);
2446 } else if (Name == "pclose") {
2447 if (FTy->getNumParams() != 1 ||
2448 !isa<PointerType>(FTy->getParamType(0)))
2451 setDoesNotCapture(F, 1);
2455 if (Name == "vscanf") {
2456 if (FTy->getNumParams() != 2 ||
2457 !isa<PointerType>(FTy->getParamType(1)))
2460 setDoesNotCapture(F, 1);
2461 } else if (Name == "vsscanf" ||
2462 Name == "vfscanf") {
2463 if (FTy->getNumParams() != 3 ||
2464 !isa<PointerType>(FTy->getParamType(1)) ||
2465 !isa<PointerType>(FTy->getParamType(2)))
2468 setDoesNotCapture(F, 1);
2469 setDoesNotCapture(F, 2);
2470 } else if (Name == "valloc") {
2471 if (!isa<PointerType>(FTy->getReturnType()))
2474 setDoesNotAlias(F, 0);
2475 } else if (Name == "vprintf") {
2476 if (FTy->getNumParams() != 2 ||
2477 !isa<PointerType>(FTy->getParamType(0)))
2480 setDoesNotCapture(F, 1);
2481 } else if (Name == "vfprintf" ||
2482 Name == "vsprintf") {
2483 if (FTy->getNumParams() != 3 ||
2484 !isa<PointerType>(FTy->getParamType(0)) ||
2485 !isa<PointerType>(FTy->getParamType(1)))
2488 setDoesNotCapture(F, 1);
2489 setDoesNotCapture(F, 2);
2490 } else if (Name == "vsnprintf") {
2491 if (FTy->getNumParams() != 4 ||
2492 !isa<PointerType>(FTy->getParamType(0)) ||
2493 !isa<PointerType>(FTy->getParamType(2)))
2496 setDoesNotCapture(F, 1);
2497 setDoesNotCapture(F, 3);
2501 if (Name == "open") {
2502 if (FTy->getNumParams() < 2 ||
2503 !isa<PointerType>(FTy->getParamType(0)))
2505 // May throw; "open" is a valid pthread cancellation point.
2506 setDoesNotCapture(F, 1);
2507 } else if (Name == "opendir") {
2508 if (FTy->getNumParams() != 1 ||
2509 !isa<PointerType>(FTy->getReturnType()) ||
2510 !isa<PointerType>(FTy->getParamType(0)))
2513 setDoesNotAlias(F, 0);
2514 setDoesNotCapture(F, 1);
2518 if (Name == "tmpfile") {
2519 if (!isa<PointerType>(FTy->getReturnType()))
2522 setDoesNotAlias(F, 0);
2523 } else if (Name == "times") {
2524 if (FTy->getNumParams() != 1 ||
2525 !isa<PointerType>(FTy->getParamType(0)))
2528 setDoesNotCapture(F, 1);
2532 if (Name == "htonl" ||
2535 setDoesNotAccessMemory(F);
2539 if (Name == "ntohl" ||
2542 setDoesNotAccessMemory(F);
2546 if (Name == "lstat") {
2547 if (FTy->getNumParams() != 2 ||
2548 !isa<PointerType>(FTy->getParamType(0)) ||
2549 !isa<PointerType>(FTy->getParamType(1)))
2552 setDoesNotCapture(F, 1);
2553 setDoesNotCapture(F, 2);
2554 } else if (Name == "lchown") {
2555 if (FTy->getNumParams() != 3 ||
2556 !isa<PointerType>(FTy->getParamType(0)))
2559 setDoesNotCapture(F, 1);
2563 if (Name == "qsort") {
2564 if (FTy->getNumParams() != 4 ||
2565 !isa<PointerType>(FTy->getParamType(3)))
2567 // May throw; places call through function pointer.
2568 setDoesNotCapture(F, 4);
2572 if (Name == "__strdup" ||
2573 Name == "__strndup") {
2574 if (FTy->getNumParams() < 1 ||
2575 !isa<PointerType>(FTy->getReturnType()) ||
2576 !isa<PointerType>(FTy->getParamType(0)))
2579 setDoesNotAlias(F, 0);
2580 setDoesNotCapture(F, 1);
2581 } else if (Name == "__strtok_r") {
2582 if (FTy->getNumParams() != 3 ||
2583 !isa<PointerType>(FTy->getParamType(1)))
2586 setDoesNotCapture(F, 2);
2587 } else if (Name == "_IO_getc") {
2588 if (FTy->getNumParams() != 1 ||
2589 !isa<PointerType>(FTy->getParamType(0)))
2592 setDoesNotCapture(F, 1);
2593 } else if (Name == "_IO_putc") {
2594 if (FTy->getNumParams() != 2 ||
2595 !isa<PointerType>(FTy->getParamType(1)))
2598 setDoesNotCapture(F, 2);
2602 if (Name == "\1__isoc99_scanf") {
2603 if (FTy->getNumParams() < 1 ||
2604 !isa<PointerType>(FTy->getParamType(0)))
2607 setDoesNotCapture(F, 1);
2608 } else if (Name == "\1stat64" ||
2609 Name == "\1lstat64" ||
2610 Name == "\1statvfs64" ||
2611 Name == "\1__isoc99_sscanf") {
2612 if (FTy->getNumParams() < 1 ||
2613 !isa<PointerType>(FTy->getParamType(0)) ||
2614 !isa<PointerType>(FTy->getParamType(1)))
2617 setDoesNotCapture(F, 1);
2618 setDoesNotCapture(F, 2);
2619 } else if (Name == "\1fopen64") {
2620 if (FTy->getNumParams() != 2 ||
2621 !isa<PointerType>(FTy->getReturnType()) ||
2622 !isa<PointerType>(FTy->getParamType(0)) ||
2623 !isa<PointerType>(FTy->getParamType(1)))
2626 setDoesNotAlias(F, 0);
2627 setDoesNotCapture(F, 1);
2628 setDoesNotCapture(F, 2);
2629 } else if (Name == "\1fseeko64" ||
2630 Name == "\1ftello64") {
2631 if (FTy->getNumParams() == 0 ||
2632 !isa<PointerType>(FTy->getParamType(0)))
2635 setDoesNotCapture(F, 1);
2636 } else if (Name == "\1tmpfile64") {
2637 if (!isa<PointerType>(FTy->getReturnType()))
2640 setDoesNotAlias(F, 0);
2641 } else if (Name == "\1fstat64" ||
2642 Name == "\1fstatvfs64") {
2643 if (FTy->getNumParams() != 2 ||
2644 !isa<PointerType>(FTy->getParamType(1)))
2647 setDoesNotCapture(F, 2);
2648 } else if (Name == "\1open64") {
2649 if (FTy->getNumParams() < 2 ||
2650 !isa<PointerType>(FTy->getParamType(0)))
2652 // May throw; "open" is a valid pthread cancellation point.
2653 setDoesNotCapture(F, 1);
2662 // Additional cases that we need to add to this file:
2665 // * cbrt(expN(X)) -> expN(x/3)
2666 // * cbrt(sqrt(x)) -> pow(x,1/6)
2667 // * cbrt(sqrt(x)) -> pow(x,1/9)
2670 // * cos(-x) -> cos(x)
2673 // * exp(log(x)) -> x
2676 // * log(exp(x)) -> x
2677 // * log(x**y) -> y*log(x)
2678 // * log(exp(y)) -> y*log(e)
2679 // * log(exp2(y)) -> y*log(2)
2680 // * log(exp10(y)) -> y*log(10)
2681 // * log(sqrt(x)) -> 0.5*log(x)
2682 // * log(pow(x,y)) -> y*log(x)
2684 // lround, lroundf, lroundl:
2685 // * lround(cnst) -> cnst'
2688 // * pow(exp(x),y) -> exp(x*y)
2689 // * pow(sqrt(x),y) -> pow(x,y*0.5)
2690 // * pow(pow(x,y),z)-> pow(x,y*z)
2693 // * puts("") -> putchar("\n")
2695 // round, roundf, roundl:
2696 // * round(cnst) -> cnst'
2699 // * signbit(cnst) -> cnst'
2700 // * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2702 // sqrt, sqrtf, sqrtl:
2703 // * sqrt(expN(x)) -> expN(x*0.5)
2704 // * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2705 // * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2708 // * stpcpy(str, "literal") ->
2709 // llvm.memcpy(str,"literal",strlen("literal")+1,1)
2711 // * strrchr(s,c) -> reverse_offset_of_in(c,s)
2712 // (if c is a constant integer and s is a constant string)
2713 // * strrchr(s1,0) -> strchr(s1,0)
2716 // * strpbrk(s,a) -> offset_in_for(s,a)
2717 // (if s and a are both constant strings)
2718 // * strpbrk(s,"") -> 0
2719 // * strpbrk(s,a) -> strchr(s,a[0]) (if a is constant string of length 1)
2722 // * strspn(s,a) -> const_int (if both args are constant)
2723 // * strspn("",a) -> 0
2724 // * strspn(s,"") -> 0
2725 // * strcspn(s,a) -> const_int (if both args are constant)
2726 // * strcspn("",a) -> 0
2727 // * strcspn(s,"") -> strlen(a)
2730 // * tan(atan(x)) -> x
2732 // trunc, truncf, truncl:
2733 // * trunc(cnst) -> cnst'