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). For example, a call to the function "exit(3)" that
13 // occurs within the main() function can be transformed into a simple "return 3"
14 // instruction. Any optimization that takes this form (replace call to library
15 // function with simpler code that provides the same result) belongs in this
18 //===----------------------------------------------------------------------===//
20 #define DEBUG_TYPE "simplify-libcalls"
21 #include "llvm/Transforms/Scalar.h"
22 #include "llvm/Intrinsics.h"
23 #include "llvm/LLVMContext.h"
24 #include "llvm/Module.h"
25 #include "llvm/Pass.h"
26 #include "llvm/Support/IRBuilder.h"
27 #include "llvm/Analysis/ValueTracking.h"
28 #include "llvm/Target/TargetData.h"
29 #include "llvm/ADT/SmallPtrSet.h"
30 #include "llvm/ADT/StringMap.h"
31 #include "llvm/ADT/Statistic.h"
32 #include "llvm/Support/Compiler.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Config/config.h"
37 STATISTIC(NumSimplified, "Number of library calls simplified");
38 STATISTIC(NumAnnotated, "Number of attributes added to library functions");
40 //===----------------------------------------------------------------------===//
41 // Optimizer Base Class
42 //===----------------------------------------------------------------------===//
44 /// This class is the abstract base class for the set of optimizations that
45 /// corresponds to one library call.
47 class VISIBILITY_HIDDEN LibCallOptimization {
53 LibCallOptimization() { }
54 virtual ~LibCallOptimization() {}
56 /// CallOptimizer - This pure virtual method is implemented by base classes to
57 /// do various optimizations. If this returns null then no transformation was
58 /// performed. If it returns CI, then it transformed the call and CI is to be
59 /// deleted. If it returns something else, replace CI with the new value and
61 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B)
64 Value *OptimizeCall(CallInst *CI, const TargetData &TD, IRBuilder<> &B) {
65 Caller = CI->getParent()->getParent();
67 if (CI->getCalledFunction())
68 Context = &CI->getCalledFunction()->getContext();
69 return CallOptimizer(CI->getCalledFunction(), CI, B);
72 /// CastToCStr - Return V if it is an i8*, otherwise cast it to i8*.
73 Value *CastToCStr(Value *V, IRBuilder<> &B);
75 /// EmitStrLen - Emit a call to the strlen function to the builder, for the
76 /// specified pointer. Ptr is required to be some pointer type, and the
77 /// return value has 'intptr_t' type.
78 Value *EmitStrLen(Value *Ptr, IRBuilder<> &B);
80 /// EmitMemCpy - Emit a call to the memcpy function to the builder. This
81 /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
82 Value *EmitMemCpy(Value *Dst, Value *Src, Value *Len,
83 unsigned Align, IRBuilder<> &B);
85 /// EmitMemChr - Emit a call to the memchr function. This assumes that Ptr is
86 /// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
87 Value *EmitMemChr(Value *Ptr, Value *Val, Value *Len, IRBuilder<> &B);
89 /// EmitMemCmp - Emit a call to the memcmp function.
90 Value *EmitMemCmp(Value *Ptr1, Value *Ptr2, Value *Len, IRBuilder<> &B);
92 /// EmitMemSet - Emit a call to the memset function
93 Value *EmitMemSet(Value *Dst, Value *Val, Value *Len, IRBuilder<> &B);
95 /// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
96 /// 'floor'). This function is known to take a single of type matching 'Op'
97 /// and returns one value with the same type. If 'Op' is a long double, 'l'
98 /// is added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
99 Value *EmitUnaryFloatFnCall(Value *Op, const char *Name, IRBuilder<> &B);
101 /// EmitPutChar - Emit a call to the putchar function. This assumes that Char
103 void EmitPutChar(Value *Char, IRBuilder<> &B);
105 /// EmitPutS - Emit a call to the puts function. This assumes that Str is
107 void EmitPutS(Value *Str, IRBuilder<> &B);
109 /// EmitFPutC - Emit a call to the fputc function. This assumes that Char is
110 /// an i32, and File is a pointer to FILE.
111 void EmitFPutC(Value *Char, Value *File, IRBuilder<> &B);
113 /// EmitFPutS - Emit a call to the puts function. Str is required to be a
114 /// pointer and File is a pointer to FILE.
115 void EmitFPutS(Value *Str, Value *File, IRBuilder<> &B);
117 /// EmitFWrite - Emit a call to the fwrite function. This assumes that Ptr is
118 /// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
119 void EmitFWrite(Value *Ptr, Value *Size, Value *File, IRBuilder<> &B);
122 } // End anonymous namespace.
124 /// CastToCStr - Return V if it is an i8*, otherwise cast it to i8*.
125 Value *LibCallOptimization::CastToCStr(Value *V, IRBuilder<> &B) {
127 B.CreateBitCast(V, Context->getPointerTypeUnqual(Type::Int8Ty), "cstr");
130 /// EmitStrLen - Emit a call to the strlen function to the builder, for the
131 /// specified pointer. This always returns an integer value of size intptr_t.
132 Value *LibCallOptimization::EmitStrLen(Value *Ptr, IRBuilder<> &B) {
133 Module *M = Caller->getParent();
134 AttributeWithIndex AWI[2];
135 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
136 AWI[1] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
137 Attribute::NoUnwind);
139 Constant *StrLen =M->getOrInsertFunction("strlen", AttrListPtr::get(AWI, 2),
141 Context->getPointerTypeUnqual(Type::Int8Ty),
143 CallInst *CI = B.CreateCall(StrLen, CastToCStr(Ptr, B), "strlen");
144 if (const Function *F = dyn_cast<Function>(StrLen->stripPointerCasts()))
145 CI->setCallingConv(F->getCallingConv());
150 /// EmitMemCpy - Emit a call to the memcpy function to the builder. This always
151 /// expects that the size has type 'intptr_t' and Dst/Src are pointers.
152 Value *LibCallOptimization::EmitMemCpy(Value *Dst, Value *Src, Value *Len,
153 unsigned Align, IRBuilder<> &B) {
154 Module *M = Caller->getParent();
155 Intrinsic::ID IID = Intrinsic::memcpy;
157 Tys[0] = Len->getType();
158 Value *MemCpy = Intrinsic::getDeclaration(M, IID, Tys, 1);
159 return B.CreateCall4(MemCpy, CastToCStr(Dst, B), CastToCStr(Src, B), Len,
160 ConstantInt::get(Type::Int32Ty, Align));
163 /// EmitMemChr - Emit a call to the memchr function. This assumes that Ptr is
164 /// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
165 Value *LibCallOptimization::EmitMemChr(Value *Ptr, Value *Val,
166 Value *Len, IRBuilder<> &B) {
167 Module *M = Caller->getParent();
168 AttributeWithIndex AWI;
169 AWI = AttributeWithIndex::get(~0u, Attribute::ReadOnly | Attribute::NoUnwind);
171 Value *MemChr = M->getOrInsertFunction("memchr", AttrListPtr::get(&AWI, 1),
172 Context->getPointerTypeUnqual(Type::Int8Ty),
173 Context->getPointerTypeUnqual(Type::Int8Ty),
174 Type::Int32Ty, TD->getIntPtrType(),
176 CallInst *CI = B.CreateCall3(MemChr, CastToCStr(Ptr, B), Val, Len, "memchr");
178 if (const Function *F = dyn_cast<Function>(MemChr->stripPointerCasts()))
179 CI->setCallingConv(F->getCallingConv());
184 /// EmitMemCmp - Emit a call to the memcmp function.
185 Value *LibCallOptimization::EmitMemCmp(Value *Ptr1, Value *Ptr2,
186 Value *Len, IRBuilder<> &B) {
187 Module *M = Caller->getParent();
188 AttributeWithIndex AWI[3];
189 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
190 AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
191 AWI[2] = AttributeWithIndex::get(~0u, Attribute::ReadOnly |
192 Attribute::NoUnwind);
194 Value *MemCmp = M->getOrInsertFunction("memcmp", AttrListPtr::get(AWI, 3),
196 Context->getPointerTypeUnqual(Type::Int8Ty),
197 Context->getPointerTypeUnqual(Type::Int8Ty),
198 TD->getIntPtrType(), NULL);
199 CallInst *CI = B.CreateCall3(MemCmp, CastToCStr(Ptr1, B), CastToCStr(Ptr2, B),
202 if (const Function *F = dyn_cast<Function>(MemCmp->stripPointerCasts()))
203 CI->setCallingConv(F->getCallingConv());
208 /// EmitMemSet - Emit a call to the memset function
209 Value *LibCallOptimization::EmitMemSet(Value *Dst, Value *Val,
210 Value *Len, IRBuilder<> &B) {
211 Module *M = Caller->getParent();
212 Intrinsic::ID IID = Intrinsic::memset;
214 Tys[0] = Len->getType();
215 Value *MemSet = Intrinsic::getDeclaration(M, IID, Tys, 1);
216 Value *Align = ConstantInt::get(Type::Int32Ty, 1);
217 return B.CreateCall4(MemSet, CastToCStr(Dst, B), Val, Len, Align);
220 /// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
221 /// 'floor'). This function is known to take a single of type matching 'Op' and
222 /// returns one value with the same type. If 'Op' is a long double, 'l' is
223 /// added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
224 Value *LibCallOptimization::EmitUnaryFloatFnCall(Value *Op, const char *Name,
227 if (Op->getType() != Type::DoubleTy) {
228 // If we need to add a suffix, copy into NameBuffer.
229 unsigned NameLen = strlen(Name);
230 assert(NameLen < sizeof(NameBuffer)-2);
231 memcpy(NameBuffer, Name, NameLen);
232 if (Op->getType() == Type::FloatTy)
233 NameBuffer[NameLen] = 'f'; // floorf
235 NameBuffer[NameLen] = 'l'; // floorl
236 NameBuffer[NameLen+1] = 0;
240 Module *M = Caller->getParent();
241 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
242 Op->getType(), NULL);
243 CallInst *CI = B.CreateCall(Callee, Op, Name);
245 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
246 CI->setCallingConv(F->getCallingConv());
251 /// EmitPutChar - Emit a call to the putchar function. This assumes that Char
253 void LibCallOptimization::EmitPutChar(Value *Char, IRBuilder<> &B) {
254 Module *M = Caller->getParent();
255 Value *PutChar = M->getOrInsertFunction("putchar", Type::Int32Ty,
256 Type::Int32Ty, NULL);
257 CallInst *CI = B.CreateCall(PutChar,
258 B.CreateIntCast(Char, Type::Int32Ty, "chari"),
261 if (const Function *F = dyn_cast<Function>(PutChar->stripPointerCasts()))
262 CI->setCallingConv(F->getCallingConv());
265 /// EmitPutS - Emit a call to the puts function. This assumes that Str is
267 void LibCallOptimization::EmitPutS(Value *Str, IRBuilder<> &B) {
268 Module *M = Caller->getParent();
269 AttributeWithIndex AWI[2];
270 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
271 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
273 Value *PutS = M->getOrInsertFunction("puts", AttrListPtr::get(AWI, 2),
275 Context->getPointerTypeUnqual(Type::Int8Ty),
277 CallInst *CI = B.CreateCall(PutS, CastToCStr(Str, B), "puts");
278 if (const Function *F = dyn_cast<Function>(PutS->stripPointerCasts()))
279 CI->setCallingConv(F->getCallingConv());
283 /// EmitFPutC - Emit a call to the fputc function. This assumes that Char is
284 /// an integer and File is a pointer to FILE.
285 void LibCallOptimization::EmitFPutC(Value *Char, Value *File, IRBuilder<> &B) {
286 Module *M = Caller->getParent();
287 AttributeWithIndex AWI[2];
288 AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
289 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
291 if (isa<PointerType>(File->getType()))
292 F = M->getOrInsertFunction("fputc", AttrListPtr::get(AWI, 2), Type::Int32Ty,
293 Type::Int32Ty, File->getType(), NULL);
295 F = M->getOrInsertFunction("fputc", Type::Int32Ty, Type::Int32Ty,
296 File->getType(), NULL);
297 Char = B.CreateIntCast(Char, Type::Int32Ty, "chari");
298 CallInst *CI = B.CreateCall2(F, Char, File, "fputc");
300 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
301 CI->setCallingConv(Fn->getCallingConv());
304 /// EmitFPutS - Emit a call to the puts function. Str is required to be a
305 /// pointer and File is a pointer to FILE.
306 void LibCallOptimization::EmitFPutS(Value *Str, Value *File, IRBuilder<> &B) {
307 Module *M = Caller->getParent();
308 AttributeWithIndex AWI[3];
309 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
310 AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
311 AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
313 if (isa<PointerType>(File->getType()))
314 F = M->getOrInsertFunction("fputs", AttrListPtr::get(AWI, 3), Type::Int32Ty,
315 Context->getPointerTypeUnqual(Type::Int8Ty),
316 File->getType(), NULL);
318 F = M->getOrInsertFunction("fputs", Type::Int32Ty,
319 Context->getPointerTypeUnqual(Type::Int8Ty),
320 File->getType(), NULL);
321 CallInst *CI = B.CreateCall2(F, CastToCStr(Str, B), File, "fputs");
323 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
324 CI->setCallingConv(Fn->getCallingConv());
327 /// EmitFWrite - Emit a call to the fwrite function. This assumes that Ptr is
328 /// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
329 void LibCallOptimization::EmitFWrite(Value *Ptr, Value *Size, Value *File,
331 Module *M = Caller->getParent();
332 AttributeWithIndex AWI[3];
333 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
334 AWI[1] = AttributeWithIndex::get(4, Attribute::NoCapture);
335 AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
337 if (isa<PointerType>(File->getType()))
338 F = M->getOrInsertFunction("fwrite", AttrListPtr::get(AWI, 3),
340 Context->getPointerTypeUnqual(Type::Int8Ty),
341 TD->getIntPtrType(), TD->getIntPtrType(),
342 File->getType(), NULL);
344 F = M->getOrInsertFunction("fwrite", TD->getIntPtrType(),
345 Context->getPointerTypeUnqual(Type::Int8Ty),
346 TD->getIntPtrType(), TD->getIntPtrType(),
347 File->getType(), NULL);
348 CallInst *CI = B.CreateCall4(F, CastToCStr(Ptr, B), Size,
349 ConstantInt::get(TD->getIntPtrType(), 1), File);
351 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
352 CI->setCallingConv(Fn->getCallingConv());
355 //===----------------------------------------------------------------------===//
357 //===----------------------------------------------------------------------===//
359 /// GetStringLengthH - If we can compute the length of the string pointed to by
360 /// the specified pointer, return 'len+1'. If we can't, return 0.
361 static uint64_t GetStringLengthH(Value *V, SmallPtrSet<PHINode*, 32> &PHIs) {
362 // Look through noop bitcast instructions.
363 if (BitCastInst *BCI = dyn_cast<BitCastInst>(V))
364 return GetStringLengthH(BCI->getOperand(0), PHIs);
366 // If this is a PHI node, there are two cases: either we have already seen it
368 if (PHINode *PN = dyn_cast<PHINode>(V)) {
369 if (!PHIs.insert(PN))
370 return ~0ULL; // already in the set.
372 // If it was new, see if all the input strings are the same length.
373 uint64_t LenSoFar = ~0ULL;
374 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
375 uint64_t Len = GetStringLengthH(PN->getIncomingValue(i), PHIs);
376 if (Len == 0) return 0; // Unknown length -> unknown.
378 if (Len == ~0ULL) continue;
380 if (Len != LenSoFar && LenSoFar != ~0ULL)
381 return 0; // Disagree -> unknown.
385 // Success, all agree.
389 // strlen(select(c,x,y)) -> strlen(x) ^ strlen(y)
390 if (SelectInst *SI = dyn_cast<SelectInst>(V)) {
391 uint64_t Len1 = GetStringLengthH(SI->getTrueValue(), PHIs);
392 if (Len1 == 0) return 0;
393 uint64_t Len2 = GetStringLengthH(SI->getFalseValue(), PHIs);
394 if (Len2 == 0) return 0;
395 if (Len1 == ~0ULL) return Len2;
396 if (Len2 == ~0ULL) return Len1;
397 if (Len1 != Len2) return 0;
401 // If the value is not a GEP instruction nor a constant expression with a
402 // GEP instruction, then return unknown.
404 if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) {
406 } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
407 if (CE->getOpcode() != Instruction::GetElementPtr)
414 // Make sure the GEP has exactly three arguments.
415 if (GEP->getNumOperands() != 3)
418 // Check to make sure that the first operand of the GEP is an integer and
419 // has value 0 so that we are sure we're indexing into the initializer.
420 if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
426 // If the second index isn't a ConstantInt, then this is a variable index
427 // into the array. If this occurs, we can't say anything meaningful about
429 uint64_t StartIdx = 0;
430 if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(2)))
431 StartIdx = CI->getZExtValue();
435 // The GEP instruction, constant or instruction, must reference a global
436 // variable that is a constant and is initialized. The referenced constant
437 // initializer is the array that we'll use for optimization.
438 GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0));
439 if (!GV || !GV->isConstant() || !GV->hasInitializer())
441 Constant *GlobalInit = GV->getInitializer();
443 // Handle the ConstantAggregateZero case, which is a degenerate case. The
444 // initializer is constant zero so the length of the string must be zero.
445 if (isa<ConstantAggregateZero>(GlobalInit))
446 return 1; // Len = 0 offset by 1.
448 // Must be a Constant Array
449 ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit);
450 if (!Array || Array->getType()->getElementType() != Type::Int8Ty)
453 // Get the number of elements in the array
454 uint64_t NumElts = Array->getType()->getNumElements();
456 // Traverse the constant array from StartIdx (derived above) which is
457 // the place the GEP refers to in the array.
458 for (unsigned i = StartIdx; i != NumElts; ++i) {
459 Constant *Elt = Array->getOperand(i);
460 ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
461 if (!CI) // This array isn't suitable, non-int initializer.
464 return i-StartIdx+1; // We found end of string, success!
467 return 0; // The array isn't null terminated, conservatively return 'unknown'.
470 /// GetStringLength - If we can compute the length of the string pointed to by
471 /// the specified pointer, return 'len+1'. If we can't, return 0.
472 static uint64_t GetStringLength(Value *V) {
473 if (!isa<PointerType>(V->getType())) return 0;
475 SmallPtrSet<PHINode*, 32> PHIs;
476 uint64_t Len = GetStringLengthH(V, PHIs);
477 // If Len is ~0ULL, we had an infinite phi cycle: this is dead code, so return
478 // an empty string as a length.
479 return Len == ~0ULL ? 1 : Len;
482 /// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
483 /// value is equal or not-equal to zero.
484 static bool IsOnlyUsedInZeroEqualityComparison(Value *V) {
485 for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
487 if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
488 if (IC->isEquality())
489 if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
490 if (C->isNullValue())
492 // Unknown instruction.
498 //===----------------------------------------------------------------------===//
499 // Miscellaneous LibCall Optimizations
500 //===----------------------------------------------------------------------===//
503 //===---------------------------------------===//
504 // 'exit' Optimizations
506 /// ExitOpt - int main() { exit(4); } --> int main() { return 4; }
507 struct VISIBILITY_HIDDEN ExitOpt : public LibCallOptimization {
508 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
509 // Verify we have a reasonable prototype for exit.
510 if (Callee->arg_size() == 0 || !CI->use_empty())
513 // Verify the caller is main, and that the result type of main matches the
514 // argument type of exit.
515 if (Caller->getName() != "main" || !Caller->hasExternalLinkage() ||
516 Caller->getReturnType() != CI->getOperand(1)->getType())
519 TerminatorInst *OldTI = CI->getParent()->getTerminator();
521 // Create the return after the call.
522 ReturnInst *RI = B.CreateRet(CI->getOperand(1));
524 // Drop all successor phi node entries.
525 for (unsigned i = 0, e = OldTI->getNumSuccessors(); i != e; ++i)
526 OldTI->getSuccessor(i)->removePredecessor(CI->getParent());
528 // Erase all instructions from after our return instruction until the end of
530 BasicBlock::iterator FirstDead = RI; ++FirstDead;
531 CI->getParent()->getInstList().erase(FirstDead, CI->getParent()->end());
536 //===----------------------------------------------------------------------===//
537 // String and Memory LibCall Optimizations
538 //===----------------------------------------------------------------------===//
540 //===---------------------------------------===//
541 // 'strcat' Optimizations
543 struct VISIBILITY_HIDDEN StrCatOpt : public LibCallOptimization {
544 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
545 // Verify the "strcat" function prototype.
546 const FunctionType *FT = Callee->getFunctionType();
547 if (FT->getNumParams() != 2 ||
548 FT->getReturnType() != Context->getPointerTypeUnqual(Type::Int8Ty) ||
549 FT->getParamType(0) != FT->getReturnType() ||
550 FT->getParamType(1) != FT->getReturnType())
553 // Extract some information from the instruction
554 Value *Dst = CI->getOperand(1);
555 Value *Src = CI->getOperand(2);
557 // See if we can get the length of the input string.
558 uint64_t Len = GetStringLength(Src);
559 if (Len == 0) return 0;
560 --Len; // Unbias length.
562 // Handle the simple, do-nothing case: strcat(x, "") -> x
566 EmitStrLenMemCpy(Src, Dst, Len, B);
570 void EmitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len, IRBuilder<> &B) {
571 // We need to find the end of the destination string. That's where the
572 // memory is to be moved to. We just generate a call to strlen.
573 Value *DstLen = EmitStrLen(Dst, B);
575 // Now that we have the destination's length, we must index into the
576 // destination's pointer to get the actual memcpy destination (end of
577 // the string .. we're concatenating).
578 Value *CpyDst = B.CreateGEP(Dst, DstLen, "endptr");
580 // We have enough information to now generate the memcpy call to do the
581 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
582 EmitMemCpy(CpyDst, Src,
583 ConstantInt::get(TD->getIntPtrType(), Len+1), 1, B);
587 //===---------------------------------------===//
588 // 'strncat' Optimizations
590 struct VISIBILITY_HIDDEN StrNCatOpt : public StrCatOpt {
591 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
592 // Verify the "strncat" function prototype.
593 const FunctionType *FT = Callee->getFunctionType();
594 if (FT->getNumParams() != 3 ||
595 FT->getReturnType() != Context->getPointerTypeUnqual(Type::Int8Ty) ||
596 FT->getParamType(0) != FT->getReturnType() ||
597 FT->getParamType(1) != FT->getReturnType() ||
598 !isa<IntegerType>(FT->getParamType(2)))
601 // Extract some information from the instruction
602 Value *Dst = CI->getOperand(1);
603 Value *Src = CI->getOperand(2);
606 // We don't do anything if length is not constant
607 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
608 Len = LengthArg->getZExtValue();
612 // See if we can get the length of the input string.
613 uint64_t SrcLen = GetStringLength(Src);
614 if (SrcLen == 0) return 0;
615 --SrcLen; // Unbias length.
617 // Handle the simple, do-nothing cases:
618 // strncat(x, "", c) -> x
619 // strncat(x, c, 0) -> x
620 if (SrcLen == 0 || Len == 0) return Dst;
622 // We don't optimize this case
623 if (Len < SrcLen) return 0;
625 // strncat(x, s, c) -> strcat(x, s)
626 // s is constant so the strcat can be optimized further
627 EmitStrLenMemCpy(Src, Dst, SrcLen, B);
632 //===---------------------------------------===//
633 // 'strchr' Optimizations
635 struct VISIBILITY_HIDDEN StrChrOpt : public LibCallOptimization {
636 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
637 // Verify the "strchr" function prototype.
638 const FunctionType *FT = Callee->getFunctionType();
639 if (FT->getNumParams() != 2 ||
640 FT->getReturnType() != Context->getPointerTypeUnqual(Type::Int8Ty) ||
641 FT->getParamType(0) != FT->getReturnType())
644 Value *SrcStr = CI->getOperand(1);
646 // If the second operand is non-constant, see if we can compute the length
647 // of the input string and turn this into memchr.
648 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getOperand(2));
650 uint64_t Len = GetStringLength(SrcStr);
651 if (Len == 0 || FT->getParamType(1) != Type::Int32Ty) // memchr needs i32.
654 return EmitMemChr(SrcStr, CI->getOperand(2), // include nul.
655 ConstantInt::get(TD->getIntPtrType(), Len), B);
658 // Otherwise, the character is a constant, see if the first argument is
659 // a string literal. If so, we can constant fold.
661 if (!GetConstantStringInfo(SrcStr, Str))
664 // strchr can find the nul character.
666 char CharValue = CharC->getSExtValue();
668 // Compute the offset.
671 if (i == Str.size()) // Didn't find the char. strchr returns null.
672 return Context->getNullValue(CI->getType());
673 // Did we find our match?
674 if (Str[i] == CharValue)
679 // strchr(s+n,c) -> gep(s+n+i,c)
680 Value *Idx = ConstantInt::get(Type::Int64Ty, i);
681 return B.CreateGEP(SrcStr, Idx, "strchr");
685 //===---------------------------------------===//
686 // 'strcmp' Optimizations
688 struct VISIBILITY_HIDDEN StrCmpOpt : public LibCallOptimization {
689 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
690 // Verify the "strcmp" function prototype.
691 const FunctionType *FT = Callee->getFunctionType();
692 if (FT->getNumParams() != 2 || FT->getReturnType() != Type::Int32Ty ||
693 FT->getParamType(0) != FT->getParamType(1) ||
694 FT->getParamType(0) != Context->getPointerTypeUnqual(Type::Int8Ty))
697 Value *Str1P = CI->getOperand(1), *Str2P = CI->getOperand(2);
698 if (Str1P == Str2P) // strcmp(x,x) -> 0
699 return ConstantInt::get(CI->getType(), 0);
701 std::string Str1, Str2;
702 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
703 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
705 if (HasStr1 && Str1.empty()) // strcmp("", x) -> *x
706 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
708 if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
709 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
711 // strcmp(x, y) -> cnst (if both x and y are constant strings)
712 if (HasStr1 && HasStr2)
713 return ConstantInt::get(CI->getType(),
714 strcmp(Str1.c_str(),Str2.c_str()));
716 // strcmp(P, "x") -> memcmp(P, "x", 2)
717 uint64_t Len1 = GetStringLength(Str1P);
718 uint64_t Len2 = GetStringLength(Str2P);
720 return EmitMemCmp(Str1P, Str2P,
721 ConstantInt::get(TD->getIntPtrType(),
722 std::min(Len1, Len2)), B);
729 //===---------------------------------------===//
730 // 'strncmp' Optimizations
732 struct VISIBILITY_HIDDEN StrNCmpOpt : public LibCallOptimization {
733 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
734 // Verify the "strncmp" function prototype.
735 const FunctionType *FT = Callee->getFunctionType();
736 if (FT->getNumParams() != 3 || FT->getReturnType() != Type::Int32Ty ||
737 FT->getParamType(0) != FT->getParamType(1) ||
738 FT->getParamType(0) != Context->getPointerTypeUnqual(Type::Int8Ty) ||
739 !isa<IntegerType>(FT->getParamType(2)))
742 Value *Str1P = CI->getOperand(1), *Str2P = CI->getOperand(2);
743 if (Str1P == Str2P) // strncmp(x,x,n) -> 0
744 return ConstantInt::get(CI->getType(), 0);
746 // Get the length argument if it is constant.
748 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
749 Length = LengthArg->getZExtValue();
753 if (Length == 0) // strncmp(x,y,0) -> 0
754 return ConstantInt::get(CI->getType(), 0);
756 std::string Str1, Str2;
757 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
758 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
760 if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> *x
761 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
763 if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x
764 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
766 // strncmp(x, y) -> cnst (if both x and y are constant strings)
767 if (HasStr1 && HasStr2)
768 return ConstantInt::get(CI->getType(),
769 strncmp(Str1.c_str(), Str2.c_str(), Length));
775 //===---------------------------------------===//
776 // 'strcpy' Optimizations
778 struct VISIBILITY_HIDDEN StrCpyOpt : public LibCallOptimization {
779 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
780 // Verify the "strcpy" function prototype.
781 const FunctionType *FT = Callee->getFunctionType();
782 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
783 FT->getParamType(0) != FT->getParamType(1) ||
784 FT->getParamType(0) != Context->getPointerTypeUnqual(Type::Int8Ty))
787 Value *Dst = CI->getOperand(1), *Src = CI->getOperand(2);
788 if (Dst == Src) // strcpy(x,x) -> x
791 // See if we can get the length of the input string.
792 uint64_t Len = GetStringLength(Src);
793 if (Len == 0) return 0;
795 // We have enough information to now generate the memcpy call to do the
796 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
798 ConstantInt::get(TD->getIntPtrType(), Len), 1, B);
803 //===---------------------------------------===//
804 // 'strncpy' Optimizations
806 struct VISIBILITY_HIDDEN StrNCpyOpt : public LibCallOptimization {
807 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
808 const FunctionType *FT = Callee->getFunctionType();
809 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
810 FT->getParamType(0) != FT->getParamType(1) ||
811 FT->getParamType(0) != Context->getPointerTypeUnqual(Type::Int8Ty) ||
812 !isa<IntegerType>(FT->getParamType(2)))
815 Value *Dst = CI->getOperand(1);
816 Value *Src = CI->getOperand(2);
817 Value *LenOp = CI->getOperand(3);
819 // See if we can get the length of the input string.
820 uint64_t SrcLen = GetStringLength(Src);
821 if (SrcLen == 0) return 0;
825 // strncpy(x, "", y) -> memset(x, '\0', y, 1)
826 EmitMemSet(Dst, ConstantInt::get(Type::Int8Ty, '\0'), LenOp, B);
831 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
832 Len = LengthArg->getZExtValue();
836 if (Len == 0) return Dst; // strncpy(x, y, 0) -> x
838 // Let strncpy handle the zero padding
839 if (Len > SrcLen+1) return 0;
841 // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
843 ConstantInt::get(TD->getIntPtrType(), Len), 1, B);
849 //===---------------------------------------===//
850 // 'strlen' Optimizations
852 struct VISIBILITY_HIDDEN StrLenOpt : public LibCallOptimization {
853 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
854 const FunctionType *FT = Callee->getFunctionType();
855 if (FT->getNumParams() != 1 ||
856 FT->getParamType(0) != Context->getPointerTypeUnqual(Type::Int8Ty) ||
857 !isa<IntegerType>(FT->getReturnType()))
860 Value *Src = CI->getOperand(1);
862 // Constant folding: strlen("xyz") -> 3
863 if (uint64_t Len = GetStringLength(Src))
864 return ConstantInt::get(CI->getType(), Len-1);
866 // Handle strlen(p) != 0.
867 if (!IsOnlyUsedInZeroEqualityComparison(CI)) return 0;
869 // strlen(x) != 0 --> *x != 0
870 // strlen(x) == 0 --> *x == 0
871 return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
875 //===---------------------------------------===//
876 // 'strto*' Optimizations
878 struct VISIBILITY_HIDDEN StrToOpt : public LibCallOptimization {
879 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
880 const FunctionType *FT = Callee->getFunctionType();
881 if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
882 !isa<PointerType>(FT->getParamType(0)) ||
883 !isa<PointerType>(FT->getParamType(1)))
886 Value *EndPtr = CI->getOperand(2);
887 if (isa<ConstantPointerNull>(EndPtr)) {
888 CI->setOnlyReadsMemory();
889 CI->addAttribute(1, Attribute::NoCapture);
897 //===---------------------------------------===//
898 // 'memcmp' Optimizations
900 struct VISIBILITY_HIDDEN MemCmpOpt : public LibCallOptimization {
901 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
902 const FunctionType *FT = Callee->getFunctionType();
903 if (FT->getNumParams() != 3 || !isa<PointerType>(FT->getParamType(0)) ||
904 !isa<PointerType>(FT->getParamType(1)) ||
905 FT->getReturnType() != Type::Int32Ty)
908 Value *LHS = CI->getOperand(1), *RHS = CI->getOperand(2);
910 if (LHS == RHS) // memcmp(s,s,x) -> 0
911 return Context->getNullValue(CI->getType());
913 // Make sure we have a constant length.
914 ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getOperand(3));
916 uint64_t Len = LenC->getZExtValue();
918 if (Len == 0) // memcmp(s1,s2,0) -> 0
919 return Context->getNullValue(CI->getType());
921 if (Len == 1) { // memcmp(S1,S2,1) -> *LHS - *RHS
922 Value *LHSV = B.CreateLoad(CastToCStr(LHS, B), "lhsv");
923 Value *RHSV = B.CreateLoad(CastToCStr(RHS, B), "rhsv");
924 return B.CreateSExt(B.CreateSub(LHSV, RHSV, "chardiff"), CI->getType());
927 // memcmp(S1,S2,2) != 0 -> (*(short*)LHS ^ *(short*)RHS) != 0
928 // memcmp(S1,S2,4) != 0 -> (*(int*)LHS ^ *(int*)RHS) != 0
929 if ((Len == 2 || Len == 4) && IsOnlyUsedInZeroEqualityComparison(CI)) {
930 const Type *PTy = Context->getPointerTypeUnqual(Len == 2 ?
931 Type::Int16Ty : Type::Int32Ty);
932 LHS = B.CreateBitCast(LHS, PTy, "tmp");
933 RHS = B.CreateBitCast(RHS, PTy, "tmp");
934 LoadInst *LHSV = B.CreateLoad(LHS, "lhsv");
935 LoadInst *RHSV = B.CreateLoad(RHS, "rhsv");
936 LHSV->setAlignment(1); RHSV->setAlignment(1); // Unaligned loads.
937 return B.CreateZExt(B.CreateXor(LHSV, RHSV, "shortdiff"), CI->getType());
944 //===---------------------------------------===//
945 // 'memcpy' Optimizations
947 struct VISIBILITY_HIDDEN MemCpyOpt : public LibCallOptimization {
948 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
949 const FunctionType *FT = Callee->getFunctionType();
950 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
951 !isa<PointerType>(FT->getParamType(0)) ||
952 !isa<PointerType>(FT->getParamType(1)) ||
953 FT->getParamType(2) != TD->getIntPtrType())
956 // memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
957 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3), 1, B);
958 return CI->getOperand(1);
962 //===---------------------------------------===//
963 // 'memmove' Optimizations
965 struct VISIBILITY_HIDDEN MemMoveOpt : public LibCallOptimization {
966 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
967 const FunctionType *FT = Callee->getFunctionType();
968 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
969 !isa<PointerType>(FT->getParamType(0)) ||
970 !isa<PointerType>(FT->getParamType(1)) ||
971 FT->getParamType(2) != TD->getIntPtrType())
974 // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
975 Module *M = Caller->getParent();
976 Intrinsic::ID IID = Intrinsic::memmove;
978 Tys[0] = TD->getIntPtrType();
979 Value *MemMove = Intrinsic::getDeclaration(M, IID, Tys, 1);
980 Value *Dst = CastToCStr(CI->getOperand(1), B);
981 Value *Src = CastToCStr(CI->getOperand(2), B);
982 Value *Size = CI->getOperand(3);
983 Value *Align = ConstantInt::get(Type::Int32Ty, 1);
984 B.CreateCall4(MemMove, Dst, Src, Size, Align);
985 return CI->getOperand(1);
989 //===---------------------------------------===//
990 // 'memset' Optimizations
992 struct VISIBILITY_HIDDEN MemSetOpt : public LibCallOptimization {
993 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
994 const FunctionType *FT = Callee->getFunctionType();
995 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
996 !isa<PointerType>(FT->getParamType(0)) ||
997 !isa<IntegerType>(FT->getParamType(1)) ||
998 FT->getParamType(2) != TD->getIntPtrType())
1001 // memset(p, v, n) -> llvm.memset(p, v, n, 1)
1002 Value *Val = B.CreateIntCast(CI->getOperand(2), Type::Int8Ty, false);
1003 EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B);
1004 return CI->getOperand(1);
1008 //===----------------------------------------------------------------------===//
1009 // Math Library Optimizations
1010 //===----------------------------------------------------------------------===//
1012 //===---------------------------------------===//
1013 // 'pow*' Optimizations
1015 struct VISIBILITY_HIDDEN PowOpt : public LibCallOptimization {
1016 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1017 const FunctionType *FT = Callee->getFunctionType();
1018 // Just make sure this has 2 arguments of the same FP type, which match the
1020 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1021 FT->getParamType(0) != FT->getParamType(1) ||
1022 !FT->getParamType(0)->isFloatingPoint())
1025 Value *Op1 = CI->getOperand(1), *Op2 = CI->getOperand(2);
1026 if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
1027 if (Op1C->isExactlyValue(1.0)) // pow(1.0, x) -> 1.0
1029 if (Op1C->isExactlyValue(2.0)) // pow(2.0, x) -> exp2(x)
1030 return EmitUnaryFloatFnCall(Op2, "exp2", B);
1033 ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
1034 if (Op2C == 0) return 0;
1036 if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
1037 return Context->getConstantFP(CI->getType(), 1.0);
1039 if (Op2C->isExactlyValue(0.5)) {
1040 // FIXME: This is not safe for -0.0 and -inf. This can only be done when
1041 // 'unsafe' math optimizations are allowed.
1042 // x pow(x, 0.5) sqrt(x)
1043 // ---------------------------------------------
1047 // pow(x, 0.5) -> sqrt(x)
1048 return B.CreateCall(get_sqrt(), Op1, "sqrt");
1052 if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
1054 if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
1055 return B.CreateFMul(Op1, Op1, "pow2");
1056 if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
1057 return B.CreateFDiv(Context->getConstantFP(CI->getType(), 1.0),
1063 //===---------------------------------------===//
1064 // 'exp2' Optimizations
1066 struct VISIBILITY_HIDDEN Exp2Opt : public LibCallOptimization {
1067 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1068 const FunctionType *FT = Callee->getFunctionType();
1069 // Just make sure this has 1 argument of FP type, which matches the
1071 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1072 !FT->getParamType(0)->isFloatingPoint())
1075 Value *Op = CI->getOperand(1);
1076 // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
1077 // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
1078 Value *LdExpArg = 0;
1079 if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
1080 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
1081 LdExpArg = B.CreateSExt(OpC->getOperand(0), Type::Int32Ty, "tmp");
1082 } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
1083 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
1084 LdExpArg = B.CreateZExt(OpC->getOperand(0), Type::Int32Ty, "tmp");
1089 if (Op->getType() == Type::FloatTy)
1091 else if (Op->getType() == Type::DoubleTy)
1096 Constant *One = Context->getConstantFP(APFloat(1.0f));
1097 if (Op->getType() != Type::FloatTy)
1098 One = Context->getConstantExprFPExtend(One, Op->getType());
1100 Module *M = Caller->getParent();
1101 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
1102 Op->getType(), Type::Int32Ty,NULL);
1103 CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
1104 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
1105 CI->setCallingConv(F->getCallingConv());
1113 //===---------------------------------------===//
1114 // Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
1116 struct VISIBILITY_HIDDEN UnaryDoubleFPOpt : public LibCallOptimization {
1117 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1118 const FunctionType *FT = Callee->getFunctionType();
1119 if (FT->getNumParams() != 1 || FT->getReturnType() != Type::DoubleTy ||
1120 FT->getParamType(0) != Type::DoubleTy)
1123 // If this is something like 'floor((double)floatval)', convert to floorf.
1124 FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getOperand(1));
1125 if (Cast == 0 || Cast->getOperand(0)->getType() != Type::FloatTy)
1128 // floor((double)floatval) -> (double)floorf(floatval)
1129 Value *V = Cast->getOperand(0);
1130 V = EmitUnaryFloatFnCall(V, Callee->getName().data(), B);
1131 return B.CreateFPExt(V, Type::DoubleTy);
1135 //===----------------------------------------------------------------------===//
1136 // Integer Optimizations
1137 //===----------------------------------------------------------------------===//
1139 //===---------------------------------------===//
1140 // 'ffs*' Optimizations
1142 struct VISIBILITY_HIDDEN FFSOpt : public LibCallOptimization {
1143 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1144 const FunctionType *FT = Callee->getFunctionType();
1145 // Just make sure this has 2 arguments of the same FP type, which match the
1147 if (FT->getNumParams() != 1 || FT->getReturnType() != Type::Int32Ty ||
1148 !isa<IntegerType>(FT->getParamType(0)))
1151 Value *Op = CI->getOperand(1);
1154 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
1155 if (CI->getValue() == 0) // ffs(0) -> 0.
1156 return Context->getNullValue(CI->getType());
1157 return ConstantInt::get(Type::Int32Ty, // ffs(c) -> cttz(c)+1
1158 CI->getValue().countTrailingZeros()+1);
1161 // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
1162 const Type *ArgType = Op->getType();
1163 Value *F = Intrinsic::getDeclaration(Callee->getParent(),
1164 Intrinsic::cttz, &ArgType, 1);
1165 Value *V = B.CreateCall(F, Op, "cttz");
1166 V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1), "tmp");
1167 V = B.CreateIntCast(V, Type::Int32Ty, false, "tmp");
1169 Value *Cond = B.CreateICmpNE(Op, Context->getNullValue(ArgType), "tmp");
1170 return B.CreateSelect(Cond, V, ConstantInt::get(Type::Int32Ty, 0));
1174 //===---------------------------------------===//
1175 // 'isdigit' Optimizations
1177 struct VISIBILITY_HIDDEN IsDigitOpt : public LibCallOptimization {
1178 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1179 const FunctionType *FT = Callee->getFunctionType();
1180 // We require integer(i32)
1181 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1182 FT->getParamType(0) != Type::Int32Ty)
1185 // isdigit(c) -> (c-'0') <u 10
1186 Value *Op = CI->getOperand(1);
1187 Op = B.CreateSub(Op, ConstantInt::get(Type::Int32Ty, '0'),
1189 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::Int32Ty, 10),
1191 return B.CreateZExt(Op, CI->getType());
1195 //===---------------------------------------===//
1196 // 'isascii' Optimizations
1198 struct VISIBILITY_HIDDEN IsAsciiOpt : public LibCallOptimization {
1199 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1200 const FunctionType *FT = Callee->getFunctionType();
1201 // We require integer(i32)
1202 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1203 FT->getParamType(0) != Type::Int32Ty)
1206 // isascii(c) -> c <u 128
1207 Value *Op = CI->getOperand(1);
1208 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::Int32Ty, 128),
1210 return B.CreateZExt(Op, CI->getType());
1214 //===---------------------------------------===//
1215 // 'abs', 'labs', 'llabs' Optimizations
1217 struct VISIBILITY_HIDDEN AbsOpt : public LibCallOptimization {
1218 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1219 const FunctionType *FT = Callee->getFunctionType();
1220 // We require integer(integer) where the types agree.
1221 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1222 FT->getParamType(0) != FT->getReturnType())
1225 // abs(x) -> x >s -1 ? x : -x
1226 Value *Op = CI->getOperand(1);
1227 Value *Pos = B.CreateICmpSGT(Op,
1228 Context->getAllOnesValue(Op->getType()),
1230 Value *Neg = B.CreateNeg(Op, "neg");
1231 return B.CreateSelect(Pos, Op, Neg);
1236 //===---------------------------------------===//
1237 // 'toascii' Optimizations
1239 struct VISIBILITY_HIDDEN ToAsciiOpt : public LibCallOptimization {
1240 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1241 const FunctionType *FT = Callee->getFunctionType();
1242 // We require i32(i32)
1243 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1244 FT->getParamType(0) != Type::Int32Ty)
1247 // isascii(c) -> c & 0x7f
1248 return B.CreateAnd(CI->getOperand(1),
1249 ConstantInt::get(CI->getType(),0x7F));
1253 //===----------------------------------------------------------------------===//
1254 // Formatting and IO Optimizations
1255 //===----------------------------------------------------------------------===//
1257 //===---------------------------------------===//
1258 // 'printf' Optimizations
1260 struct VISIBILITY_HIDDEN PrintFOpt : public LibCallOptimization {
1261 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1262 // Require one fixed pointer argument and an integer/void result.
1263 const FunctionType *FT = Callee->getFunctionType();
1264 if (FT->getNumParams() < 1 || !isa<PointerType>(FT->getParamType(0)) ||
1265 !(isa<IntegerType>(FT->getReturnType()) ||
1266 FT->getReturnType() == Type::VoidTy))
1269 // Check for a fixed format string.
1270 std::string FormatStr;
1271 if (!GetConstantStringInfo(CI->getOperand(1), FormatStr))
1274 // Empty format string -> noop.
1275 if (FormatStr.empty()) // Tolerate printf's declared void.
1276 return CI->use_empty() ? (Value*)CI :
1277 ConstantInt::get(CI->getType(), 0);
1279 // printf("x") -> putchar('x'), even for '%'.
1280 if (FormatStr.size() == 1) {
1281 EmitPutChar(ConstantInt::get(Type::Int32Ty, FormatStr[0]), B);
1282 return CI->use_empty() ? (Value*)CI :
1283 ConstantInt::get(CI->getType(), 1);
1286 // printf("foo\n") --> puts("foo")
1287 if (FormatStr[FormatStr.size()-1] == '\n' &&
1288 FormatStr.find('%') == std::string::npos) { // no format characters.
1289 // Create a string literal with no \n on it. We expect the constant merge
1290 // pass to be run after this pass, to merge duplicate strings.
1291 FormatStr.erase(FormatStr.end()-1);
1292 Constant *C = Context->getConstantArray(FormatStr, true);
1293 C = new GlobalVariable(*Callee->getParent(), C->getType(), true,
1294 GlobalVariable::InternalLinkage, C, "str");
1296 return CI->use_empty() ? (Value*)CI :
1297 ConstantInt::get(CI->getType(), FormatStr.size()+1);
1300 // Optimize specific format strings.
1301 // printf("%c", chr) --> putchar(*(i8*)dst)
1302 if (FormatStr == "%c" && CI->getNumOperands() > 2 &&
1303 isa<IntegerType>(CI->getOperand(2)->getType())) {
1304 EmitPutChar(CI->getOperand(2), B);
1305 return CI->use_empty() ? (Value*)CI :
1306 ConstantInt::get(CI->getType(), 1);
1309 // printf("%s\n", str) --> puts(str)
1310 if (FormatStr == "%s\n" && CI->getNumOperands() > 2 &&
1311 isa<PointerType>(CI->getOperand(2)->getType()) &&
1313 EmitPutS(CI->getOperand(2), B);
1320 //===---------------------------------------===//
1321 // 'sprintf' Optimizations
1323 struct VISIBILITY_HIDDEN SPrintFOpt : public LibCallOptimization {
1324 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1325 // Require two fixed pointer arguments and an integer result.
1326 const FunctionType *FT = Callee->getFunctionType();
1327 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1328 !isa<PointerType>(FT->getParamType(1)) ||
1329 !isa<IntegerType>(FT->getReturnType()))
1332 // Check for a fixed format string.
1333 std::string FormatStr;
1334 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1337 // If we just have a format string (nothing else crazy) transform it.
1338 if (CI->getNumOperands() == 3) {
1339 // Make sure there's no % in the constant array. We could try to handle
1340 // %% -> % in the future if we cared.
1341 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1342 if (FormatStr[i] == '%')
1343 return 0; // we found a format specifier, bail out.
1345 // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1346 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), // Copy the nul byte.
1347 ConstantInt::get(TD->getIntPtrType(), FormatStr.size()+1),1,B);
1348 return ConstantInt::get(CI->getType(), FormatStr.size());
1351 // The remaining optimizations require the format string to be "%s" or "%c"
1352 // and have an extra operand.
1353 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1356 // Decode the second character of the format string.
1357 if (FormatStr[1] == 'c') {
1358 // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1359 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1360 Value *V = B.CreateTrunc(CI->getOperand(3), Type::Int8Ty, "char");
1361 Value *Ptr = CastToCStr(CI->getOperand(1), B);
1362 B.CreateStore(V, Ptr);
1363 Ptr = B.CreateGEP(Ptr, ConstantInt::get(Type::Int32Ty, 1), "nul");
1364 B.CreateStore(Context->getNullValue(Type::Int8Ty), Ptr);
1366 return ConstantInt::get(CI->getType(), 1);
1369 if (FormatStr[1] == 's') {
1370 // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1371 if (!isa<PointerType>(CI->getOperand(3)->getType())) return 0;
1373 Value *Len = EmitStrLen(CI->getOperand(3), B);
1374 Value *IncLen = B.CreateAdd(Len,
1375 ConstantInt::get(Len->getType(), 1),
1377 EmitMemCpy(CI->getOperand(1), CI->getOperand(3), IncLen, 1, B);
1379 // The sprintf result is the unincremented number of bytes in the string.
1380 return B.CreateIntCast(Len, CI->getType(), false);
1386 //===---------------------------------------===//
1387 // 'fwrite' Optimizations
1389 struct VISIBILITY_HIDDEN FWriteOpt : public LibCallOptimization {
1390 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1391 // Require a pointer, an integer, an integer, a pointer, returning integer.
1392 const FunctionType *FT = Callee->getFunctionType();
1393 if (FT->getNumParams() != 4 || !isa<PointerType>(FT->getParamType(0)) ||
1394 !isa<IntegerType>(FT->getParamType(1)) ||
1395 !isa<IntegerType>(FT->getParamType(2)) ||
1396 !isa<PointerType>(FT->getParamType(3)) ||
1397 !isa<IntegerType>(FT->getReturnType()))
1400 // Get the element size and count.
1401 ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getOperand(2));
1402 ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getOperand(3));
1403 if (!SizeC || !CountC) return 0;
1404 uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
1406 // If this is writing zero records, remove the call (it's a noop).
1408 return ConstantInt::get(CI->getType(), 0);
1410 // If this is writing one byte, turn it into fputc.
1411 if (Bytes == 1) { // fwrite(S,1,1,F) -> fputc(S[0],F)
1412 Value *Char = B.CreateLoad(CastToCStr(CI->getOperand(1), B), "char");
1413 EmitFPutC(Char, CI->getOperand(4), B);
1414 return ConstantInt::get(CI->getType(), 1);
1421 //===---------------------------------------===//
1422 // 'fputs' Optimizations
1424 struct VISIBILITY_HIDDEN FPutsOpt : public LibCallOptimization {
1425 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1426 // Require two pointers. Also, we can't optimize if return value is used.
1427 const FunctionType *FT = Callee->getFunctionType();
1428 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1429 !isa<PointerType>(FT->getParamType(1)) ||
1433 // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1434 uint64_t Len = GetStringLength(CI->getOperand(1));
1436 EmitFWrite(CI->getOperand(1),
1437 ConstantInt::get(TD->getIntPtrType(), Len-1),
1438 CI->getOperand(2), B);
1439 return CI; // Known to have no uses (see above).
1443 //===---------------------------------------===//
1444 // 'fprintf' Optimizations
1446 struct VISIBILITY_HIDDEN FPrintFOpt : public LibCallOptimization {
1447 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1448 // Require two fixed paramters as pointers and integer result.
1449 const FunctionType *FT = Callee->getFunctionType();
1450 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1451 !isa<PointerType>(FT->getParamType(1)) ||
1452 !isa<IntegerType>(FT->getReturnType()))
1455 // All the optimizations depend on the format string.
1456 std::string FormatStr;
1457 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1460 // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1461 if (CI->getNumOperands() == 3) {
1462 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1463 if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1464 return 0; // We found a format specifier.
1466 EmitFWrite(CI->getOperand(2), ConstantInt::get(TD->getIntPtrType(),
1468 CI->getOperand(1), B);
1469 return ConstantInt::get(CI->getType(), FormatStr.size());
1472 // The remaining optimizations require the format string to be "%s" or "%c"
1473 // and have an extra operand.
1474 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1477 // Decode the second character of the format string.
1478 if (FormatStr[1] == 'c') {
1479 // fprintf(F, "%c", chr) --> *(i8*)dst = chr
1480 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1481 EmitFPutC(CI->getOperand(3), CI->getOperand(1), B);
1482 return ConstantInt::get(CI->getType(), 1);
1485 if (FormatStr[1] == 's') {
1486 // fprintf(F, "%s", str) -> fputs(str, F)
1487 if (!isa<PointerType>(CI->getOperand(3)->getType()) || !CI->use_empty())
1489 EmitFPutS(CI->getOperand(3), CI->getOperand(1), B);
1496 } // end anonymous namespace.
1498 //===----------------------------------------------------------------------===//
1499 // SimplifyLibCalls Pass Implementation
1500 //===----------------------------------------------------------------------===//
1503 /// This pass optimizes well known library functions from libc and libm.
1505 class VISIBILITY_HIDDEN SimplifyLibCalls : public FunctionPass {
1506 StringMap<LibCallOptimization*> Optimizations;
1507 // Miscellaneous LibCall Optimizations
1509 // String and Memory LibCall Optimizations
1510 StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
1511 StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
1512 StrToOpt StrTo; MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove;
1514 // Math Library Optimizations
1515 PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
1516 // Integer Optimizations
1517 FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
1519 // Formatting and IO Optimizations
1520 SPrintFOpt SPrintF; PrintFOpt PrintF;
1521 FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
1523 bool Modified; // This is only used by doInitialization.
1525 static char ID; // Pass identification
1526 SimplifyLibCalls() : FunctionPass(&ID) {}
1528 void InitOptimizations();
1529 bool runOnFunction(Function &F);
1531 void setDoesNotAccessMemory(Function &F);
1532 void setOnlyReadsMemory(Function &F);
1533 void setDoesNotThrow(Function &F);
1534 void setDoesNotCapture(Function &F, unsigned n);
1535 void setDoesNotAlias(Function &F, unsigned n);
1536 bool doInitialization(Module &M);
1538 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1539 AU.addRequired<TargetData>();
1542 char SimplifyLibCalls::ID = 0;
1543 } // end anonymous namespace.
1545 static RegisterPass<SimplifyLibCalls>
1546 X("simplify-libcalls", "Simplify well-known library calls");
1548 // Public interface to the Simplify LibCalls pass.
1549 FunctionPass *llvm::createSimplifyLibCallsPass() {
1550 return new SimplifyLibCalls();
1553 /// Optimizations - Populate the Optimizations map with all the optimizations
1555 void SimplifyLibCalls::InitOptimizations() {
1556 // Miscellaneous LibCall Optimizations
1557 Optimizations["exit"] = &Exit;
1559 // String and Memory LibCall Optimizations
1560 Optimizations["strcat"] = &StrCat;
1561 Optimizations["strncat"] = &StrNCat;
1562 Optimizations["strchr"] = &StrChr;
1563 Optimizations["strcmp"] = &StrCmp;
1564 Optimizations["strncmp"] = &StrNCmp;
1565 Optimizations["strcpy"] = &StrCpy;
1566 Optimizations["strncpy"] = &StrNCpy;
1567 Optimizations["strlen"] = &StrLen;
1568 Optimizations["strtol"] = &StrTo;
1569 Optimizations["strtod"] = &StrTo;
1570 Optimizations["strtof"] = &StrTo;
1571 Optimizations["strtoul"] = &StrTo;
1572 Optimizations["strtoll"] = &StrTo;
1573 Optimizations["strtold"] = &StrTo;
1574 Optimizations["strtoull"] = &StrTo;
1575 Optimizations["memcmp"] = &MemCmp;
1576 Optimizations["memcpy"] = &MemCpy;
1577 Optimizations["memmove"] = &MemMove;
1578 Optimizations["memset"] = &MemSet;
1580 // Math Library Optimizations
1581 Optimizations["powf"] = &Pow;
1582 Optimizations["pow"] = &Pow;
1583 Optimizations["powl"] = &Pow;
1584 Optimizations["llvm.pow.f32"] = &Pow;
1585 Optimizations["llvm.pow.f64"] = &Pow;
1586 Optimizations["llvm.pow.f80"] = &Pow;
1587 Optimizations["llvm.pow.f128"] = &Pow;
1588 Optimizations["llvm.pow.ppcf128"] = &Pow;
1589 Optimizations["exp2l"] = &Exp2;
1590 Optimizations["exp2"] = &Exp2;
1591 Optimizations["exp2f"] = &Exp2;
1592 Optimizations["llvm.exp2.ppcf128"] = &Exp2;
1593 Optimizations["llvm.exp2.f128"] = &Exp2;
1594 Optimizations["llvm.exp2.f80"] = &Exp2;
1595 Optimizations["llvm.exp2.f64"] = &Exp2;
1596 Optimizations["llvm.exp2.f32"] = &Exp2;
1599 Optimizations["floor"] = &UnaryDoubleFP;
1602 Optimizations["ceil"] = &UnaryDoubleFP;
1605 Optimizations["round"] = &UnaryDoubleFP;
1608 Optimizations["rint"] = &UnaryDoubleFP;
1610 #ifdef HAVE_NEARBYINTF
1611 Optimizations["nearbyint"] = &UnaryDoubleFP;
1614 // Integer Optimizations
1615 Optimizations["ffs"] = &FFS;
1616 Optimizations["ffsl"] = &FFS;
1617 Optimizations["ffsll"] = &FFS;
1618 Optimizations["abs"] = &Abs;
1619 Optimizations["labs"] = &Abs;
1620 Optimizations["llabs"] = &Abs;
1621 Optimizations["isdigit"] = &IsDigit;
1622 Optimizations["isascii"] = &IsAscii;
1623 Optimizations["toascii"] = &ToAscii;
1625 // Formatting and IO Optimizations
1626 Optimizations["sprintf"] = &SPrintF;
1627 Optimizations["printf"] = &PrintF;
1628 Optimizations["fwrite"] = &FWrite;
1629 Optimizations["fputs"] = &FPuts;
1630 Optimizations["fprintf"] = &FPrintF;
1634 /// runOnFunction - Top level algorithm.
1636 bool SimplifyLibCalls::runOnFunction(Function &F) {
1637 if (Optimizations.empty())
1638 InitOptimizations();
1640 const TargetData &TD = getAnalysis<TargetData>();
1642 IRBuilder<> Builder(F.getContext());
1644 bool Changed = false;
1645 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1646 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
1647 // Ignore non-calls.
1648 CallInst *CI = dyn_cast<CallInst>(I++);
1651 // Ignore indirect calls and calls to non-external functions.
1652 Function *Callee = CI->getCalledFunction();
1653 if (Callee == 0 || !Callee->isDeclaration() ||
1654 !(Callee->hasExternalLinkage() || Callee->hasDLLImportLinkage()))
1657 // Ignore unknown calls.
1658 const char *CalleeName = Callee->getNameStart();
1659 StringMap<LibCallOptimization*>::iterator OMI =
1660 Optimizations.find(StringRef(CalleeName, Callee->getNameLen()));
1661 if (OMI == Optimizations.end()) continue;
1663 // Set the builder to the instruction after the call.
1664 Builder.SetInsertPoint(BB, I);
1666 // Try to optimize this call.
1667 Value *Result = OMI->second->OptimizeCall(CI, TD, Builder);
1668 if (Result == 0) continue;
1670 DEBUG(DOUT << "SimplifyLibCalls simplified: " << *CI;
1671 DOUT << " into: " << *Result << "\n");
1673 // Something changed!
1677 // Inspect the instruction after the call (which was potentially just
1681 if (CI != Result && !CI->use_empty()) {
1682 CI->replaceAllUsesWith(Result);
1683 if (!Result->hasName())
1684 Result->takeName(CI);
1686 CI->eraseFromParent();
1692 // Utility methods for doInitialization.
1694 void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
1695 if (!F.doesNotAccessMemory()) {
1696 F.setDoesNotAccessMemory();
1701 void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
1702 if (!F.onlyReadsMemory()) {
1703 F.setOnlyReadsMemory();
1708 void SimplifyLibCalls::setDoesNotThrow(Function &F) {
1709 if (!F.doesNotThrow()) {
1710 F.setDoesNotThrow();
1715 void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
1716 if (!F.doesNotCapture(n)) {
1717 F.setDoesNotCapture(n);
1722 void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
1723 if (!F.doesNotAlias(n)) {
1724 F.setDoesNotAlias(n);
1730 /// doInitialization - Add attributes to well-known functions.
1732 bool SimplifyLibCalls::doInitialization(Module &M) {
1734 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
1736 if (!F.isDeclaration())
1742 const FunctionType *FTy = F.getFunctionType();
1744 StringRef Name = F.getName();
1747 if (Name == "strlen") {
1748 if (FTy->getNumParams() != 1 ||
1749 !isa<PointerType>(FTy->getParamType(0)))
1751 setOnlyReadsMemory(F);
1753 setDoesNotCapture(F, 1);
1754 } else if (Name == "strcpy" ||
1760 Name == "strtoul" ||
1761 Name == "strtoll" ||
1762 Name == "strtold" ||
1763 Name == "strncat" ||
1764 Name == "strncpy" ||
1765 Name == "strtoull") {
1766 if (FTy->getNumParams() < 2 ||
1767 !isa<PointerType>(FTy->getParamType(1)))
1770 setDoesNotCapture(F, 2);
1771 } else if (Name == "strxfrm") {
1772 if (FTy->getNumParams() != 3 ||
1773 !isa<PointerType>(FTy->getParamType(0)) ||
1774 !isa<PointerType>(FTy->getParamType(1)))
1777 setDoesNotCapture(F, 1);
1778 setDoesNotCapture(F, 2);
1779 } else if (Name == "strcmp" ||
1781 Name == "strncmp" ||
1782 Name ==" strcspn" ||
1783 Name == "strcoll" ||
1784 Name == "strcasecmp" ||
1785 Name == "strncasecmp") {
1786 if (FTy->getNumParams() < 2 ||
1787 !isa<PointerType>(FTy->getParamType(0)) ||
1788 !isa<PointerType>(FTy->getParamType(1)))
1790 setOnlyReadsMemory(F);
1792 setDoesNotCapture(F, 1);
1793 setDoesNotCapture(F, 2);
1794 } else if (Name == "strstr" ||
1795 Name == "strpbrk") {
1796 if (FTy->getNumParams() != 2 ||
1797 !isa<PointerType>(FTy->getParamType(1)))
1799 setOnlyReadsMemory(F);
1801 setDoesNotCapture(F, 2);
1802 } else if (Name == "strtok" ||
1803 Name == "strtok_r") {
1804 if (FTy->getNumParams() < 2 ||
1805 !isa<PointerType>(FTy->getParamType(1)))
1808 setDoesNotCapture(F, 2);
1809 } else if (Name == "scanf" ||
1811 Name == "setvbuf") {
1812 if (FTy->getNumParams() < 1 ||
1813 !isa<PointerType>(FTy->getParamType(0)))
1816 setDoesNotCapture(F, 1);
1817 } else if (Name == "strdup" ||
1818 Name == "strndup") {
1819 if (FTy->getNumParams() < 1 ||
1820 !isa<PointerType>(FTy->getReturnType()) ||
1821 !isa<PointerType>(FTy->getParamType(0)))
1824 setDoesNotAlias(F, 0);
1825 setDoesNotCapture(F, 1);
1826 } else if (Name == "stat" ||
1828 Name == "sprintf" ||
1829 Name == "statvfs") {
1830 if (FTy->getNumParams() < 2 ||
1831 !isa<PointerType>(FTy->getParamType(0)) ||
1832 !isa<PointerType>(FTy->getParamType(1)))
1835 setDoesNotCapture(F, 1);
1836 setDoesNotCapture(F, 2);
1837 } else if (Name == "snprintf") {
1838 if (FTy->getNumParams() != 3 ||
1839 !isa<PointerType>(FTy->getParamType(0)) ||
1840 !isa<PointerType>(FTy->getParamType(2)))
1843 setDoesNotCapture(F, 1);
1844 setDoesNotCapture(F, 3);
1845 } else if (Name == "setitimer") {
1846 if (FTy->getNumParams() != 3 ||
1847 !isa<PointerType>(FTy->getParamType(1)) ||
1848 !isa<PointerType>(FTy->getParamType(2)))
1851 setDoesNotCapture(F, 2);
1852 setDoesNotCapture(F, 3);
1853 } else if (Name == "system") {
1854 if (FTy->getNumParams() != 1 ||
1855 !isa<PointerType>(FTy->getParamType(0)))
1857 // May throw; "system" is a valid pthread cancellation point.
1858 setDoesNotCapture(F, 1);
1862 if (Name == "memcmp") {
1863 if (FTy->getNumParams() != 3 ||
1864 !isa<PointerType>(FTy->getParamType(0)) ||
1865 !isa<PointerType>(FTy->getParamType(1)))
1867 setOnlyReadsMemory(F);
1869 setDoesNotCapture(F, 1);
1870 setDoesNotCapture(F, 2);
1871 } else if (Name == "memchr" ||
1872 Name == "memrchr") {
1873 if (FTy->getNumParams() != 3)
1875 setOnlyReadsMemory(F);
1877 } else if (Name == "modf" ||
1881 Name == "memccpy" ||
1882 Name == "memmove") {
1883 if (FTy->getNumParams() < 2 ||
1884 !isa<PointerType>(FTy->getParamType(1)))
1887 setDoesNotCapture(F, 2);
1888 } else if (Name == "memalign") {
1889 if (!isa<PointerType>(FTy->getReturnType()))
1891 setDoesNotAlias(F, 0);
1892 } else if (Name == "mkdir" ||
1894 if (FTy->getNumParams() == 0 ||
1895 !isa<PointerType>(FTy->getParamType(0)))
1898 setDoesNotCapture(F, 1);
1902 if (Name == "realloc") {
1903 if (FTy->getNumParams() != 2 ||
1904 !isa<PointerType>(FTy->getParamType(0)) ||
1905 !isa<PointerType>(FTy->getReturnType()))
1908 setDoesNotAlias(F, 0);
1909 setDoesNotCapture(F, 1);
1910 } else if (Name == "read") {
1911 if (FTy->getNumParams() != 3 ||
1912 !isa<PointerType>(FTy->getParamType(1)))
1914 // May throw; "read" is a valid pthread cancellation point.
1915 setDoesNotCapture(F, 2);
1916 } else if (Name == "rmdir" ||
1919 Name == "realpath") {
1920 if (FTy->getNumParams() < 1 ||
1921 !isa<PointerType>(FTy->getParamType(0)))
1924 setDoesNotCapture(F, 1);
1925 } else if (Name == "rename" ||
1926 Name == "readlink") {
1927 if (FTy->getNumParams() < 2 ||
1928 !isa<PointerType>(FTy->getParamType(0)) ||
1929 !isa<PointerType>(FTy->getParamType(1)))
1932 setDoesNotCapture(F, 1);
1933 setDoesNotCapture(F, 2);
1937 if (Name == "write") {
1938 if (FTy->getNumParams() != 3 ||
1939 !isa<PointerType>(FTy->getParamType(1)))
1941 // May throw; "write" is a valid pthread cancellation point.
1942 setDoesNotCapture(F, 2);
1946 if (Name == "bcopy") {
1947 if (FTy->getNumParams() != 3 ||
1948 !isa<PointerType>(FTy->getParamType(0)) ||
1949 !isa<PointerType>(FTy->getParamType(1)))
1952 setDoesNotCapture(F, 1);
1953 setDoesNotCapture(F, 2);
1954 } else if (Name == "bcmp") {
1955 if (FTy->getNumParams() != 3 ||
1956 !isa<PointerType>(FTy->getParamType(0)) ||
1957 !isa<PointerType>(FTy->getParamType(1)))
1960 setOnlyReadsMemory(F);
1961 setDoesNotCapture(F, 1);
1962 setDoesNotCapture(F, 2);
1963 } else if (Name == "bzero") {
1964 if (FTy->getNumParams() != 2 ||
1965 !isa<PointerType>(FTy->getParamType(0)))
1968 setDoesNotCapture(F, 1);
1972 if (Name == "calloc") {
1973 if (FTy->getNumParams() != 2 ||
1974 !isa<PointerType>(FTy->getReturnType()))
1977 setDoesNotAlias(F, 0);
1978 } else if (Name == "chmod" ||
1980 Name == "ctermid" ||
1981 Name == "clearerr" ||
1982 Name == "closedir") {
1983 if (FTy->getNumParams() == 0 ||
1984 !isa<PointerType>(FTy->getParamType(0)))
1987 setDoesNotCapture(F, 1);
1991 if (Name == "atoi" ||
1995 if (FTy->getNumParams() != 1 ||
1996 !isa<PointerType>(FTy->getParamType(0)))
1999 setOnlyReadsMemory(F);
2000 setDoesNotCapture(F, 1);
2001 } else if (Name == "access") {
2002 if (FTy->getNumParams() != 2 ||
2003 !isa<PointerType>(FTy->getParamType(0)))
2006 setDoesNotCapture(F, 1);
2010 if (Name == "fopen") {
2011 if (FTy->getNumParams() != 2 ||
2012 !isa<PointerType>(FTy->getReturnType()) ||
2013 !isa<PointerType>(FTy->getParamType(0)) ||
2014 !isa<PointerType>(FTy->getParamType(1)))
2017 setDoesNotAlias(F, 0);
2018 setDoesNotCapture(F, 1);
2019 setDoesNotCapture(F, 2);
2020 } else if (Name == "fdopen") {
2021 if (FTy->getNumParams() != 2 ||
2022 !isa<PointerType>(FTy->getReturnType()) ||
2023 !isa<PointerType>(FTy->getParamType(1)))
2026 setDoesNotAlias(F, 0);
2027 setDoesNotCapture(F, 2);
2028 } else if (Name == "feof" ||
2038 Name == "fsetpos" ||
2039 Name == "flockfile" ||
2040 Name == "funlockfile" ||
2041 Name == "ftrylockfile") {
2042 if (FTy->getNumParams() == 0 ||
2043 !isa<PointerType>(FTy->getParamType(0)))
2046 setDoesNotCapture(F, 1);
2047 } else if (Name == "ferror") {
2048 if (FTy->getNumParams() != 1 ||
2049 !isa<PointerType>(FTy->getParamType(0)))
2052 setDoesNotCapture(F, 1);
2053 setOnlyReadsMemory(F);
2054 } else if (Name == "fputc" ||
2059 Name == "fstatvfs") {
2060 if (FTy->getNumParams() != 2 ||
2061 !isa<PointerType>(FTy->getParamType(1)))
2064 setDoesNotCapture(F, 2);
2065 } else if (Name == "fgets") {
2066 if (FTy->getNumParams() != 3 ||
2067 !isa<PointerType>(FTy->getParamType(0)) ||
2068 !isa<PointerType>(FTy->getParamType(2)))
2071 setDoesNotCapture(F, 3);
2072 } else if (Name == "fread" ||
2074 if (FTy->getNumParams() != 4 ||
2075 !isa<PointerType>(FTy->getParamType(0)) ||
2076 !isa<PointerType>(FTy->getParamType(3)))
2079 setDoesNotCapture(F, 1);
2080 setDoesNotCapture(F, 4);
2081 } else if (Name == "fputs" ||
2083 Name == "fprintf" ||
2084 Name == "fgetpos") {
2085 if (FTy->getNumParams() < 2 ||
2086 !isa<PointerType>(FTy->getParamType(0)) ||
2087 !isa<PointerType>(FTy->getParamType(1)))
2090 setDoesNotCapture(F, 1);
2091 setDoesNotCapture(F, 2);
2095 if (Name == "getc" ||
2096 Name == "getlogin_r" ||
2097 Name == "getc_unlocked") {
2098 if (FTy->getNumParams() == 0 ||
2099 !isa<PointerType>(FTy->getParamType(0)))
2102 setDoesNotCapture(F, 1);
2103 } else if (Name == "getenv") {
2104 if (FTy->getNumParams() != 1 ||
2105 !isa<PointerType>(FTy->getParamType(0)))
2108 setOnlyReadsMemory(F);
2109 setDoesNotCapture(F, 1);
2110 } else if (Name == "gets" ||
2111 Name == "getchar") {
2113 } else if (Name == "getitimer") {
2114 if (FTy->getNumParams() != 2 ||
2115 !isa<PointerType>(FTy->getParamType(1)))
2118 setDoesNotCapture(F, 2);
2119 } else if (Name == "getpwnam") {
2120 if (FTy->getNumParams() != 1 ||
2121 !isa<PointerType>(FTy->getParamType(0)))
2124 setDoesNotCapture(F, 1);
2128 if (Name == "ungetc") {
2129 if (FTy->getNumParams() != 2 ||
2130 !isa<PointerType>(FTy->getParamType(1)))
2133 setDoesNotCapture(F, 2);
2134 } else if (Name == "uname" ||
2136 Name == "unsetenv") {
2137 if (FTy->getNumParams() != 1 ||
2138 !isa<PointerType>(FTy->getParamType(0)))
2141 setDoesNotCapture(F, 1);
2142 } else if (Name == "utime" ||
2144 if (FTy->getNumParams() != 2 ||
2145 !isa<PointerType>(FTy->getParamType(0)) ||
2146 !isa<PointerType>(FTy->getParamType(1)))
2149 setDoesNotCapture(F, 1);
2150 setDoesNotCapture(F, 2);
2154 if (Name == "putc") {
2155 if (FTy->getNumParams() != 2 ||
2156 !isa<PointerType>(FTy->getParamType(1)))
2159 setDoesNotCapture(F, 2);
2160 } else if (Name == "puts" ||
2163 if (FTy->getNumParams() != 1 ||
2164 !isa<PointerType>(FTy->getParamType(0)))
2167 setDoesNotCapture(F, 1);
2168 } else if (Name == "pread" ||
2170 if (FTy->getNumParams() != 4 ||
2171 !isa<PointerType>(FTy->getParamType(1)))
2173 // May throw; these are valid pthread cancellation points.
2174 setDoesNotCapture(F, 2);
2175 } else if (Name == "putchar") {
2177 } else if (Name == "popen") {
2178 if (FTy->getNumParams() != 2 ||
2179 !isa<PointerType>(FTy->getReturnType()) ||
2180 !isa<PointerType>(FTy->getParamType(0)) ||
2181 !isa<PointerType>(FTy->getParamType(1)))
2184 setDoesNotAlias(F, 0);
2185 setDoesNotCapture(F, 1);
2186 setDoesNotCapture(F, 2);
2187 } else if (Name == "pclose") {
2188 if (FTy->getNumParams() != 1 ||
2189 !isa<PointerType>(FTy->getParamType(0)))
2192 setDoesNotCapture(F, 1);
2196 if (Name == "vscanf") {
2197 if (FTy->getNumParams() != 2 ||
2198 !isa<PointerType>(FTy->getParamType(1)))
2201 setDoesNotCapture(F, 1);
2202 } else if (Name == "vsscanf" ||
2203 Name == "vfscanf") {
2204 if (FTy->getNumParams() != 3 ||
2205 !isa<PointerType>(FTy->getParamType(1)) ||
2206 !isa<PointerType>(FTy->getParamType(2)))
2209 setDoesNotCapture(F, 1);
2210 setDoesNotCapture(F, 2);
2211 } else if (Name == "valloc") {
2212 if (!isa<PointerType>(FTy->getReturnType()))
2215 setDoesNotAlias(F, 0);
2216 } else if (Name == "vprintf") {
2217 if (FTy->getNumParams() != 2 ||
2218 !isa<PointerType>(FTy->getParamType(0)))
2221 setDoesNotCapture(F, 1);
2222 } else if (Name == "vfprintf" ||
2223 Name == "vsprintf") {
2224 if (FTy->getNumParams() != 3 ||
2225 !isa<PointerType>(FTy->getParamType(0)) ||
2226 !isa<PointerType>(FTy->getParamType(1)))
2229 setDoesNotCapture(F, 1);
2230 setDoesNotCapture(F, 2);
2231 } else if (Name == "vsnprintf") {
2232 if (FTy->getNumParams() != 4 ||
2233 !isa<PointerType>(FTy->getParamType(0)) ||
2234 !isa<PointerType>(FTy->getParamType(2)))
2237 setDoesNotCapture(F, 1);
2238 setDoesNotCapture(F, 3);
2242 if (Name == "open") {
2243 if (FTy->getNumParams() < 2 ||
2244 !isa<PointerType>(FTy->getParamType(0)))
2246 // May throw; "open" is a valid pthread cancellation point.
2247 setDoesNotCapture(F, 1);
2248 } else if (Name == "opendir") {
2249 if (FTy->getNumParams() != 1 ||
2250 !isa<PointerType>(FTy->getReturnType()) ||
2251 !isa<PointerType>(FTy->getParamType(0)))
2254 setDoesNotAlias(F, 0);
2255 setDoesNotCapture(F, 1);
2259 if (Name == "tmpfile") {
2260 if (!isa<PointerType>(FTy->getReturnType()))
2263 setDoesNotAlias(F, 0);
2264 } else if (Name == "times") {
2265 if (FTy->getNumParams() != 1 ||
2266 !isa<PointerType>(FTy->getParamType(0)))
2269 setDoesNotCapture(F, 1);
2273 if (Name == "htonl" ||
2276 setDoesNotAccessMemory(F);
2280 if (Name == "ntohl" ||
2283 setDoesNotAccessMemory(F);
2287 if (Name == "lstat") {
2288 if (FTy->getNumParams() != 2 ||
2289 !isa<PointerType>(FTy->getParamType(0)) ||
2290 !isa<PointerType>(FTy->getParamType(1)))
2293 setDoesNotCapture(F, 1);
2294 setDoesNotCapture(F, 2);
2295 } else if (Name == "lchown") {
2296 if (FTy->getNumParams() != 3 ||
2297 !isa<PointerType>(FTy->getParamType(0)))
2300 setDoesNotCapture(F, 1);
2304 if (Name == "qsort") {
2305 if (FTy->getNumParams() != 4 ||
2306 !isa<PointerType>(FTy->getParamType(3)))
2308 // May throw; places call through function pointer.
2309 setDoesNotCapture(F, 4);
2313 if (Name == "__strdup" ||
2314 Name == "__strndup") {
2315 if (FTy->getNumParams() < 1 ||
2316 !isa<PointerType>(FTy->getReturnType()) ||
2317 !isa<PointerType>(FTy->getParamType(0)))
2320 setDoesNotAlias(F, 0);
2321 setDoesNotCapture(F, 1);
2322 } else if (Name == "__strtok_r") {
2323 if (FTy->getNumParams() != 3 ||
2324 !isa<PointerType>(FTy->getParamType(1)))
2327 setDoesNotCapture(F, 2);
2328 } else if (Name == "_IO_getc") {
2329 if (FTy->getNumParams() != 1 ||
2330 !isa<PointerType>(FTy->getParamType(0)))
2333 setDoesNotCapture(F, 1);
2334 } else if (Name == "_IO_putc") {
2335 if (FTy->getNumParams() != 2 ||
2336 !isa<PointerType>(FTy->getParamType(1)))
2339 setDoesNotCapture(F, 2);
2343 if (Name == "\1__isoc99_scanf") {
2344 if (FTy->getNumParams() < 1 ||
2345 !isa<PointerType>(FTy->getParamType(0)))
2348 setDoesNotCapture(F, 1);
2349 } else if (Name == "\1stat64" ||
2350 Name == "\1lstat64" ||
2351 Name == "\1statvfs64" ||
2352 Name == "\1__isoc99_sscanf") {
2353 if (FTy->getNumParams() < 1 ||
2354 !isa<PointerType>(FTy->getParamType(0)) ||
2355 !isa<PointerType>(FTy->getParamType(1)))
2358 setDoesNotCapture(F, 1);
2359 setDoesNotCapture(F, 2);
2360 } else if (Name == "\1fopen64") {
2361 if (FTy->getNumParams() != 2 ||
2362 !isa<PointerType>(FTy->getReturnType()) ||
2363 !isa<PointerType>(FTy->getParamType(0)) ||
2364 !isa<PointerType>(FTy->getParamType(1)))
2367 setDoesNotAlias(F, 0);
2368 setDoesNotCapture(F, 1);
2369 setDoesNotCapture(F, 2);
2370 } else if (Name == "\1fseeko64" ||
2371 Name == "\1ftello64") {
2372 if (FTy->getNumParams() == 0 ||
2373 !isa<PointerType>(FTy->getParamType(0)))
2376 setDoesNotCapture(F, 1);
2377 } else if (Name == "\1tmpfile64") {
2378 if (!isa<PointerType>(FTy->getReturnType()))
2381 setDoesNotAlias(F, 0);
2382 } else if (Name == "\1fstat64" ||
2383 Name == "\1fstatvfs64") {
2384 if (FTy->getNumParams() != 2 ||
2385 !isa<PointerType>(FTy->getParamType(1)))
2388 setDoesNotCapture(F, 2);
2389 } else if (Name == "\1open64") {
2390 if (FTy->getNumParams() < 2 ||
2391 !isa<PointerType>(FTy->getParamType(0)))
2393 // May throw; "open" is a valid pthread cancellation point.
2394 setDoesNotCapture(F, 1);
2403 // Additional cases that we need to add to this file:
2406 // * cbrt(expN(X)) -> expN(x/3)
2407 // * cbrt(sqrt(x)) -> pow(x,1/6)
2408 // * cbrt(sqrt(x)) -> pow(x,1/9)
2411 // * cos(-x) -> cos(x)
2414 // * exp(log(x)) -> x
2417 // * log(exp(x)) -> x
2418 // * log(x**y) -> y*log(x)
2419 // * log(exp(y)) -> y*log(e)
2420 // * log(exp2(y)) -> y*log(2)
2421 // * log(exp10(y)) -> y*log(10)
2422 // * log(sqrt(x)) -> 0.5*log(x)
2423 // * log(pow(x,y)) -> y*log(x)
2425 // lround, lroundf, lroundl:
2426 // * lround(cnst) -> cnst'
2429 // * memcmp(x,y,l) -> cnst
2430 // (if all arguments are constant and strlen(x) <= l and strlen(y) <= l)
2433 // * pow(exp(x),y) -> exp(x*y)
2434 // * pow(sqrt(x),y) -> pow(x,y*0.5)
2435 // * pow(pow(x,y),z)-> pow(x,y*z)
2438 // * puts("") -> putchar("\n")
2440 // round, roundf, roundl:
2441 // * round(cnst) -> cnst'
2444 // * signbit(cnst) -> cnst'
2445 // * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2447 // sqrt, sqrtf, sqrtl:
2448 // * sqrt(expN(x)) -> expN(x*0.5)
2449 // * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2450 // * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2453 // * stpcpy(str, "literal") ->
2454 // llvm.memcpy(str,"literal",strlen("literal")+1,1)
2456 // * strrchr(s,c) -> reverse_offset_of_in(c,s)
2457 // (if c is a constant integer and s is a constant string)
2458 // * strrchr(s1,0) -> strchr(s1,0)
2461 // * strpbrk(s,a) -> offset_in_for(s,a)
2462 // (if s and a are both constant strings)
2463 // * strpbrk(s,"") -> 0
2464 // * strpbrk(s,a) -> strchr(s,a[0]) (if a is constant string of length 1)
2467 // * strspn(s,a) -> const_int (if both args are constant)
2468 // * strspn("",a) -> 0
2469 // * strspn(s,"") -> 0
2470 // * strcspn(s,a) -> const_int (if both args are constant)
2471 // * strcspn("",a) -> 0
2472 // * strcspn(s,"") -> strlen(a)
2475 // * strstr(x,x) -> x
2476 // * strstr(s1,s2) -> offset_of_s2_in(s1)
2477 // (if s1 and s2 are constant strings)
2480 // * tan(atan(x)) -> x
2482 // trunc, truncf, truncl:
2483 // * trunc(cnst) -> cnst'