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 /// EmitMemCpy - Emit a call to the memcpy function to the builder. This
80 /// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
81 Value *EmitMemCpy(Value *Dst, Value *Src, Value *Len,
82 unsigned Align, IRBuilder<> &B);
84 /// EmitMemChr - Emit a call to the memchr function. This assumes that Ptr is
85 /// a pointer, Val is an i32 value, and Len is an 'intptr_t' value.
86 Value *EmitMemChr(Value *Ptr, Value *Val, Value *Len, IRBuilder<> &B);
88 /// EmitMemCmp - Emit a call to the memcmp function.
89 Value *EmitMemCmp(Value *Ptr1, Value *Ptr2, Value *Len, IRBuilder<> &B);
91 /// EmitMemSet - Emit a call to the memset function
92 Value *EmitMemSet(Value *Dst, Value *Val, Value *Len, IRBuilder<> &B);
94 /// EmitUnaryFloatFnCall - Emit a call to the unary function named 'Name' (e.g.
95 /// 'floor'). This function is known to take a single of type matching 'Op'
96 /// and returns one value with the same type. If 'Op' is a long double, 'l'
97 /// is added as the suffix of name, if 'Op' is a float, we add a 'f' suffix.
98 Value *EmitUnaryFloatFnCall(Value *Op, const char *Name, IRBuilder<> &B,
99 const AttrListPtr &Attrs);
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, PointerType::getUnqual(Type::getInt8Ty(*Context)), "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),
140 TD->getIntPtrType(*Context),
141 PointerType::getUnqual(Type::getInt8Ty(*Context)),
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::getInt32Ty(*Context), 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 PointerType::getUnqual(Type::getInt8Ty(*Context)),
173 PointerType::getUnqual(Type::getInt8Ty(*Context)),
174 Type::getInt32Ty(*Context), TD->getIntPtrType(*Context),
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),
195 Type::getInt32Ty(*Context),
196 PointerType::getUnqual(Type::getInt8Ty(*Context)),
197 PointerType::getUnqual(Type::getInt8Ty(*Context)),
198 TD->getIntPtrType(*Context), 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::getInt32Ty(*Context), 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,
226 const AttrListPtr &Attrs) {
228 if (Op->getType() != Type::getDoubleTy(*Context)) {
229 // If we need to add a suffix, copy into NameBuffer.
230 unsigned NameLen = strlen(Name);
231 assert(NameLen < sizeof(NameBuffer)-2);
232 memcpy(NameBuffer, Name, NameLen);
233 if (Op->getType() == Type::getFloatTy(*Context))
234 NameBuffer[NameLen] = 'f'; // floorf
236 NameBuffer[NameLen] = 'l'; // floorl
237 NameBuffer[NameLen+1] = 0;
241 Module *M = Caller->getParent();
242 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
243 Op->getType(), NULL);
244 CallInst *CI = B.CreateCall(Callee, Op, Name);
245 CI->setAttributes(Attrs);
246 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
247 CI->setCallingConv(F->getCallingConv());
252 /// EmitPutChar - Emit a call to the putchar function. This assumes that Char
254 void LibCallOptimization::EmitPutChar(Value *Char, IRBuilder<> &B) {
255 Module *M = Caller->getParent();
256 Value *PutChar = M->getOrInsertFunction("putchar", Type::getInt32Ty(*Context),
257 Type::getInt32Ty(*Context), NULL);
258 CallInst *CI = B.CreateCall(PutChar,
259 B.CreateIntCast(Char, Type::getInt32Ty(*Context), "chari"),
262 if (const Function *F = dyn_cast<Function>(PutChar->stripPointerCasts()))
263 CI->setCallingConv(F->getCallingConv());
266 /// EmitPutS - Emit a call to the puts function. This assumes that Str is
268 void LibCallOptimization::EmitPutS(Value *Str, IRBuilder<> &B) {
269 Module *M = Caller->getParent();
270 AttributeWithIndex AWI[2];
271 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
272 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
274 Value *PutS = M->getOrInsertFunction("puts", AttrListPtr::get(AWI, 2),
275 Type::getInt32Ty(*Context),
276 PointerType::getUnqual(Type::getInt8Ty(*Context)),
278 CallInst *CI = B.CreateCall(PutS, CastToCStr(Str, B), "puts");
279 if (const Function *F = dyn_cast<Function>(PutS->stripPointerCasts()))
280 CI->setCallingConv(F->getCallingConv());
284 /// EmitFPutC - Emit a call to the fputc function. This assumes that Char is
285 /// an integer and File is a pointer to FILE.
286 void LibCallOptimization::EmitFPutC(Value *Char, Value *File, IRBuilder<> &B) {
287 Module *M = Caller->getParent();
288 AttributeWithIndex AWI[2];
289 AWI[0] = AttributeWithIndex::get(2, Attribute::NoCapture);
290 AWI[1] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
292 if (isa<PointerType>(File->getType()))
293 F = M->getOrInsertFunction("fputc", AttrListPtr::get(AWI, 2), Type::getInt32Ty(*Context),
294 Type::getInt32Ty(*Context), File->getType(), NULL);
296 F = M->getOrInsertFunction("fputc", Type::getInt32Ty(*Context), Type::getInt32Ty(*Context),
297 File->getType(), NULL);
298 Char = B.CreateIntCast(Char, Type::getInt32Ty(*Context), "chari");
299 CallInst *CI = B.CreateCall2(F, Char, File, "fputc");
301 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
302 CI->setCallingConv(Fn->getCallingConv());
305 /// EmitFPutS - Emit a call to the puts function. Str is required to be a
306 /// pointer and File is a pointer to FILE.
307 void LibCallOptimization::EmitFPutS(Value *Str, Value *File, IRBuilder<> &B) {
308 Module *M = Caller->getParent();
309 AttributeWithIndex AWI[3];
310 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
311 AWI[1] = AttributeWithIndex::get(2, Attribute::NoCapture);
312 AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
314 if (isa<PointerType>(File->getType()))
315 F = M->getOrInsertFunction("fputs", AttrListPtr::get(AWI, 3), Type::getInt32Ty(*Context),
316 PointerType::getUnqual(Type::getInt8Ty(*Context)),
317 File->getType(), NULL);
319 F = M->getOrInsertFunction("fputs", Type::getInt32Ty(*Context),
320 PointerType::getUnqual(Type::getInt8Ty(*Context)),
321 File->getType(), NULL);
322 CallInst *CI = B.CreateCall2(F, CastToCStr(Str, B), File, "fputs");
324 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
325 CI->setCallingConv(Fn->getCallingConv());
328 /// EmitFWrite - Emit a call to the fwrite function. This assumes that Ptr is
329 /// a pointer, Size is an 'intptr_t', and File is a pointer to FILE.
330 void LibCallOptimization::EmitFWrite(Value *Ptr, Value *Size, Value *File,
332 Module *M = Caller->getParent();
333 AttributeWithIndex AWI[3];
334 AWI[0] = AttributeWithIndex::get(1, Attribute::NoCapture);
335 AWI[1] = AttributeWithIndex::get(4, Attribute::NoCapture);
336 AWI[2] = AttributeWithIndex::get(~0u, Attribute::NoUnwind);
338 if (isa<PointerType>(File->getType()))
339 F = M->getOrInsertFunction("fwrite", AttrListPtr::get(AWI, 3),
340 TD->getIntPtrType(*Context),
341 PointerType::getUnqual(Type::getInt8Ty(*Context)),
342 TD->getIntPtrType(*Context), TD->getIntPtrType(*Context),
343 File->getType(), NULL);
345 F = M->getOrInsertFunction("fwrite", TD->getIntPtrType(*Context),
346 PointerType::getUnqual(Type::getInt8Ty(*Context)),
347 TD->getIntPtrType(*Context), TD->getIntPtrType(*Context),
348 File->getType(), NULL);
349 CallInst *CI = B.CreateCall4(F, CastToCStr(Ptr, B), Size,
350 ConstantInt::get(TD->getIntPtrType(*Context), 1), File);
352 if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
353 CI->setCallingConv(Fn->getCallingConv());
356 //===----------------------------------------------------------------------===//
358 //===----------------------------------------------------------------------===//
360 /// GetStringLengthH - If we can compute the length of the string pointed to by
361 /// the specified pointer, return 'len+1'. If we can't, return 0.
362 static uint64_t GetStringLengthH(Value *V, SmallPtrSet<PHINode*, 32> &PHIs) {
363 // Look through noop bitcast instructions.
364 if (BitCastInst *BCI = dyn_cast<BitCastInst>(V))
365 return GetStringLengthH(BCI->getOperand(0), PHIs);
367 // If this is a PHI node, there are two cases: either we have already seen it
369 if (PHINode *PN = dyn_cast<PHINode>(V)) {
370 if (!PHIs.insert(PN))
371 return ~0ULL; // already in the set.
373 // If it was new, see if all the input strings are the same length.
374 uint64_t LenSoFar = ~0ULL;
375 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
376 uint64_t Len = GetStringLengthH(PN->getIncomingValue(i), PHIs);
377 if (Len == 0) return 0; // Unknown length -> unknown.
379 if (Len == ~0ULL) continue;
381 if (Len != LenSoFar && LenSoFar != ~0ULL)
382 return 0; // Disagree -> unknown.
386 // Success, all agree.
390 // strlen(select(c,x,y)) -> strlen(x) ^ strlen(y)
391 if (SelectInst *SI = dyn_cast<SelectInst>(V)) {
392 uint64_t Len1 = GetStringLengthH(SI->getTrueValue(), PHIs);
393 if (Len1 == 0) return 0;
394 uint64_t Len2 = GetStringLengthH(SI->getFalseValue(), PHIs);
395 if (Len2 == 0) return 0;
396 if (Len1 == ~0ULL) return Len2;
397 if (Len2 == ~0ULL) return Len1;
398 if (Len1 != Len2) return 0;
402 // If the value is not a GEP instruction nor a constant expression with a
403 // GEP instruction, then return unknown.
405 if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) {
407 } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
408 if (CE->getOpcode() != Instruction::GetElementPtr)
415 // Make sure the GEP has exactly three arguments.
416 if (GEP->getNumOperands() != 3)
419 // Check to make sure that the first operand of the GEP is an integer and
420 // has value 0 so that we are sure we're indexing into the initializer.
421 if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
427 // If the second index isn't a ConstantInt, then this is a variable index
428 // into the array. If this occurs, we can't say anything meaningful about
430 uint64_t StartIdx = 0;
431 if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(2)))
432 StartIdx = CI->getZExtValue();
436 // The GEP instruction, constant or instruction, must reference a global
437 // variable that is a constant and is initialized. The referenced constant
438 // initializer is the array that we'll use for optimization.
439 GlobalVariable* GV = dyn_cast<GlobalVariable>(GEP->getOperand(0));
440 if (!GV || !GV->isConstant() || !GV->hasInitializer() ||
441 GV->mayBeOverridden())
443 Constant *GlobalInit = GV->getInitializer();
445 // Handle the ConstantAggregateZero case, which is a degenerate case. The
446 // initializer is constant zero so the length of the string must be zero.
447 if (isa<ConstantAggregateZero>(GlobalInit))
448 return 1; // Len = 0 offset by 1.
450 // Must be a Constant Array
451 ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit);
453 Array->getType()->getElementType() != Type::getInt8Ty(V->getContext()))
456 // Get the number of elements in the array
457 uint64_t NumElts = Array->getType()->getNumElements();
459 // Traverse the constant array from StartIdx (derived above) which is
460 // the place the GEP refers to in the array.
461 for (unsigned i = StartIdx; i != NumElts; ++i) {
462 Constant *Elt = Array->getOperand(i);
463 ConstantInt *CI = dyn_cast<ConstantInt>(Elt);
464 if (!CI) // This array isn't suitable, non-int initializer.
467 return i-StartIdx+1; // We found end of string, success!
470 return 0; // The array isn't null terminated, conservatively return 'unknown'.
473 /// GetStringLength - If we can compute the length of the string pointed to by
474 /// the specified pointer, return 'len+1'. If we can't, return 0.
475 static uint64_t GetStringLength(Value *V) {
476 if (!isa<PointerType>(V->getType())) return 0;
478 SmallPtrSet<PHINode*, 32> PHIs;
479 uint64_t Len = GetStringLengthH(V, PHIs);
480 // If Len is ~0ULL, we had an infinite phi cycle: this is dead code, so return
481 // an empty string as a length.
482 return Len == ~0ULL ? 1 : Len;
485 /// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
486 /// value is equal or not-equal to zero.
487 static bool IsOnlyUsedInZeroEqualityComparison(Value *V) {
488 for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
490 if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
491 if (IC->isEquality())
492 if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
493 if (C->isNullValue())
495 // Unknown instruction.
501 //===----------------------------------------------------------------------===//
502 // String and Memory LibCall Optimizations
503 //===----------------------------------------------------------------------===//
505 //===---------------------------------------===//
506 // 'strcat' Optimizations
508 struct StrCatOpt : public LibCallOptimization {
509 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
510 // Verify the "strcat" function prototype.
511 const FunctionType *FT = Callee->getFunctionType();
512 if (FT->getNumParams() != 2 ||
513 FT->getReturnType() != PointerType::getUnqual(Type::getInt8Ty(*Context)) ||
514 FT->getParamType(0) != FT->getReturnType() ||
515 FT->getParamType(1) != FT->getReturnType())
518 // Extract some information from the instruction
519 Value *Dst = CI->getOperand(1);
520 Value *Src = CI->getOperand(2);
522 // See if we can get the length of the input string.
523 uint64_t Len = GetStringLength(Src);
524 if (Len == 0) return 0;
525 --Len; // Unbias length.
527 // Handle the simple, do-nothing case: strcat(x, "") -> x
531 // These optimizations require TargetData.
534 EmitStrLenMemCpy(Src, Dst, Len, B);
538 void EmitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len, IRBuilder<> &B) {
539 // We need to find the end of the destination string. That's where the
540 // memory is to be moved to. We just generate a call to strlen.
541 Value *DstLen = EmitStrLen(Dst, B);
543 // Now that we have the destination's length, we must index into the
544 // destination's pointer to get the actual memcpy destination (end of
545 // the string .. we're concatenating).
546 Value *CpyDst = B.CreateGEP(Dst, DstLen, "endptr");
548 // We have enough information to now generate the memcpy call to do the
549 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
550 EmitMemCpy(CpyDst, Src,
551 ConstantInt::get(TD->getIntPtrType(*Context), Len+1), 1, B);
555 //===---------------------------------------===//
556 // 'strncat' Optimizations
558 struct StrNCatOpt : public StrCatOpt {
559 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
560 // Verify the "strncat" function prototype.
561 const FunctionType *FT = Callee->getFunctionType();
562 if (FT->getNumParams() != 3 ||
563 FT->getReturnType() != PointerType::getUnqual(Type::getInt8Ty(*Context)) ||
564 FT->getParamType(0) != FT->getReturnType() ||
565 FT->getParamType(1) != FT->getReturnType() ||
566 !isa<IntegerType>(FT->getParamType(2)))
569 // Extract some information from the instruction
570 Value *Dst = CI->getOperand(1);
571 Value *Src = CI->getOperand(2);
574 // We don't do anything if length is not constant
575 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
576 Len = LengthArg->getZExtValue();
580 // See if we can get the length of the input string.
581 uint64_t SrcLen = GetStringLength(Src);
582 if (SrcLen == 0) return 0;
583 --SrcLen; // Unbias length.
585 // Handle the simple, do-nothing cases:
586 // strncat(x, "", c) -> x
587 // strncat(x, c, 0) -> x
588 if (SrcLen == 0 || Len == 0) return Dst;
590 // These optimizations require TargetData.
593 // We don't optimize this case
594 if (Len < SrcLen) return 0;
596 // strncat(x, s, c) -> strcat(x, s)
597 // s is constant so the strcat can be optimized further
598 EmitStrLenMemCpy(Src, Dst, SrcLen, B);
603 //===---------------------------------------===//
604 // 'strchr' Optimizations
606 struct StrChrOpt : public LibCallOptimization {
607 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
608 // Verify the "strchr" function prototype.
609 const FunctionType *FT = Callee->getFunctionType();
610 if (FT->getNumParams() != 2 ||
611 FT->getReturnType() != PointerType::getUnqual(Type::getInt8Ty(*Context)) ||
612 FT->getParamType(0) != FT->getReturnType())
615 Value *SrcStr = CI->getOperand(1);
617 // If the second operand is non-constant, see if we can compute the length
618 // of the input string and turn this into memchr.
619 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getOperand(2));
621 // These optimizations require TargetData.
624 uint64_t Len = GetStringLength(SrcStr);
625 if (Len == 0 || FT->getParamType(1) != Type::getInt32Ty(*Context)) // memchr needs i32.
628 return EmitMemChr(SrcStr, CI->getOperand(2), // include nul.
629 ConstantInt::get(TD->getIntPtrType(*Context), Len), B);
632 // Otherwise, the character is a constant, see if the first argument is
633 // a string literal. If so, we can constant fold.
635 if (!GetConstantStringInfo(SrcStr, Str))
638 // strchr can find the nul character.
640 char CharValue = CharC->getSExtValue();
642 // Compute the offset.
645 if (i == Str.size()) // Didn't find the char. strchr returns null.
646 return Constant::getNullValue(CI->getType());
647 // Did we find our match?
648 if (Str[i] == CharValue)
653 // strchr(s+n,c) -> gep(s+n+i,c)
654 Value *Idx = ConstantInt::get(Type::getInt64Ty(*Context), i);
655 return B.CreateGEP(SrcStr, Idx, "strchr");
659 //===---------------------------------------===//
660 // 'strcmp' Optimizations
662 struct StrCmpOpt : public LibCallOptimization {
663 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
664 // Verify the "strcmp" function prototype.
665 const FunctionType *FT = Callee->getFunctionType();
666 if (FT->getNumParams() != 2 || FT->getReturnType() != Type::getInt32Ty(*Context) ||
667 FT->getParamType(0) != FT->getParamType(1) ||
668 FT->getParamType(0) != PointerType::getUnqual(Type::getInt8Ty(*Context)))
671 Value *Str1P = CI->getOperand(1), *Str2P = CI->getOperand(2);
672 if (Str1P == Str2P) // strcmp(x,x) -> 0
673 return ConstantInt::get(CI->getType(), 0);
675 std::string Str1, Str2;
676 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
677 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
679 if (HasStr1 && Str1.empty()) // strcmp("", x) -> *x
680 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
682 if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
683 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
685 // strcmp(x, y) -> cnst (if both x and y are constant strings)
686 if (HasStr1 && HasStr2)
687 return ConstantInt::get(CI->getType(),
688 strcmp(Str1.c_str(),Str2.c_str()));
690 // strcmp(P, "x") -> memcmp(P, "x", 2)
691 uint64_t Len1 = GetStringLength(Str1P);
692 uint64_t Len2 = GetStringLength(Str2P);
694 // These optimizations require TargetData.
697 return EmitMemCmp(Str1P, Str2P,
698 ConstantInt::get(TD->getIntPtrType(*Context),
699 std::min(Len1, Len2)), B);
706 //===---------------------------------------===//
707 // 'strncmp' Optimizations
709 struct StrNCmpOpt : public LibCallOptimization {
710 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
711 // Verify the "strncmp" function prototype.
712 const FunctionType *FT = Callee->getFunctionType();
713 if (FT->getNumParams() != 3 || FT->getReturnType() != Type::getInt32Ty(*Context) ||
714 FT->getParamType(0) != FT->getParamType(1) ||
715 FT->getParamType(0) != PointerType::getUnqual(Type::getInt8Ty(*Context)) ||
716 !isa<IntegerType>(FT->getParamType(2)))
719 Value *Str1P = CI->getOperand(1), *Str2P = CI->getOperand(2);
720 if (Str1P == Str2P) // strncmp(x,x,n) -> 0
721 return ConstantInt::get(CI->getType(), 0);
723 // Get the length argument if it is constant.
725 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getOperand(3)))
726 Length = LengthArg->getZExtValue();
730 if (Length == 0) // strncmp(x,y,0) -> 0
731 return ConstantInt::get(CI->getType(), 0);
733 std::string Str1, Str2;
734 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
735 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
737 if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> *x
738 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
740 if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x
741 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
743 // strncmp(x, y) -> cnst (if both x and y are constant strings)
744 if (HasStr1 && HasStr2)
745 return ConstantInt::get(CI->getType(),
746 strncmp(Str1.c_str(), Str2.c_str(), Length));
752 //===---------------------------------------===//
753 // 'strcpy' Optimizations
755 struct StrCpyOpt : public LibCallOptimization {
756 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
757 // Verify the "strcpy" function prototype.
758 const FunctionType *FT = Callee->getFunctionType();
759 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
760 FT->getParamType(0) != FT->getParamType(1) ||
761 FT->getParamType(0) != PointerType::getUnqual(Type::getInt8Ty(*Context)))
764 Value *Dst = CI->getOperand(1), *Src = CI->getOperand(2);
765 if (Dst == Src) // strcpy(x,x) -> x
768 // These optimizations require TargetData.
771 // See if we can get the length of the input string.
772 uint64_t Len = GetStringLength(Src);
773 if (Len == 0) return 0;
775 // We have enough information to now generate the memcpy call to do the
776 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
778 ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B);
783 //===---------------------------------------===//
784 // 'strncpy' Optimizations
786 struct StrNCpyOpt : public LibCallOptimization {
787 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
788 const FunctionType *FT = Callee->getFunctionType();
789 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
790 FT->getParamType(0) != FT->getParamType(1) ||
791 FT->getParamType(0) != PointerType::getUnqual(Type::getInt8Ty(*Context)) ||
792 !isa<IntegerType>(FT->getParamType(2)))
795 Value *Dst = CI->getOperand(1);
796 Value *Src = CI->getOperand(2);
797 Value *LenOp = CI->getOperand(3);
799 // See if we can get the length of the input string.
800 uint64_t SrcLen = GetStringLength(Src);
801 if (SrcLen == 0) return 0;
805 // strncpy(x, "", y) -> memset(x, '\0', y, 1)
806 EmitMemSet(Dst, ConstantInt::get(Type::getInt8Ty(*Context), '\0'), LenOp, B);
811 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
812 Len = LengthArg->getZExtValue();
816 if (Len == 0) return Dst; // strncpy(x, y, 0) -> x
818 // These optimizations require TargetData.
821 // Let strncpy handle the zero padding
822 if (Len > SrcLen+1) return 0;
824 // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
826 ConstantInt::get(TD->getIntPtrType(*Context), Len), 1, B);
832 //===---------------------------------------===//
833 // 'strlen' Optimizations
835 struct StrLenOpt : public LibCallOptimization {
836 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
837 const FunctionType *FT = Callee->getFunctionType();
838 if (FT->getNumParams() != 1 ||
839 FT->getParamType(0) != PointerType::getUnqual(Type::getInt8Ty(*Context)) ||
840 !isa<IntegerType>(FT->getReturnType()))
843 Value *Src = CI->getOperand(1);
845 // Constant folding: strlen("xyz") -> 3
846 if (uint64_t Len = GetStringLength(Src))
847 return ConstantInt::get(CI->getType(), Len-1);
849 // Handle strlen(p) != 0.
850 if (!IsOnlyUsedInZeroEqualityComparison(CI)) return 0;
852 // strlen(x) != 0 --> *x != 0
853 // strlen(x) == 0 --> *x == 0
854 return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
858 //===---------------------------------------===//
859 // 'strto*' Optimizations
861 struct StrToOpt : public LibCallOptimization {
862 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
863 const FunctionType *FT = Callee->getFunctionType();
864 if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
865 !isa<PointerType>(FT->getParamType(0)) ||
866 !isa<PointerType>(FT->getParamType(1)))
869 Value *EndPtr = CI->getOperand(2);
870 if (isa<ConstantPointerNull>(EndPtr)) {
871 CI->setOnlyReadsMemory();
872 CI->addAttribute(1, Attribute::NoCapture);
880 //===---------------------------------------===//
881 // 'memcmp' Optimizations
883 struct MemCmpOpt : public LibCallOptimization {
884 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
885 const FunctionType *FT = Callee->getFunctionType();
886 if (FT->getNumParams() != 3 || !isa<PointerType>(FT->getParamType(0)) ||
887 !isa<PointerType>(FT->getParamType(1)) ||
888 FT->getReturnType() != Type::getInt32Ty(*Context))
891 Value *LHS = CI->getOperand(1), *RHS = CI->getOperand(2);
893 if (LHS == RHS) // memcmp(s,s,x) -> 0
894 return Constant::getNullValue(CI->getType());
896 // Make sure we have a constant length.
897 ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getOperand(3));
899 uint64_t Len = LenC->getZExtValue();
901 if (Len == 0) // memcmp(s1,s2,0) -> 0
902 return Constant::getNullValue(CI->getType());
904 if (Len == 1) { // memcmp(S1,S2,1) -> *LHS - *RHS
905 Value *LHSV = B.CreateLoad(CastToCStr(LHS, B), "lhsv");
906 Value *RHSV = B.CreateLoad(CastToCStr(RHS, B), "rhsv");
907 return B.CreateSExt(B.CreateSub(LHSV, RHSV, "chardiff"), CI->getType());
910 // memcmp(S1,S2,2) != 0 -> (*(short*)LHS ^ *(short*)RHS) != 0
911 // memcmp(S1,S2,4) != 0 -> (*(int*)LHS ^ *(int*)RHS) != 0
912 if ((Len == 2 || Len == 4) && IsOnlyUsedInZeroEqualityComparison(CI)) {
913 const Type *PTy = PointerType::getUnqual(Len == 2 ?
914 Type::getInt16Ty(*Context) : Type::getInt32Ty(*Context));
915 LHS = B.CreateBitCast(LHS, PTy, "tmp");
916 RHS = B.CreateBitCast(RHS, PTy, "tmp");
917 LoadInst *LHSV = B.CreateLoad(LHS, "lhsv");
918 LoadInst *RHSV = B.CreateLoad(RHS, "rhsv");
919 LHSV->setAlignment(1); RHSV->setAlignment(1); // Unaligned loads.
920 return B.CreateZExt(B.CreateXor(LHSV, RHSV, "shortdiff"), CI->getType());
927 //===---------------------------------------===//
928 // 'memcpy' Optimizations
930 struct MemCpyOpt : public LibCallOptimization {
931 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
932 // These optimizations require TargetData.
935 const FunctionType *FT = Callee->getFunctionType();
936 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
937 !isa<PointerType>(FT->getParamType(0)) ||
938 !isa<PointerType>(FT->getParamType(1)) ||
939 FT->getParamType(2) != TD->getIntPtrType(*Context))
942 // memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
943 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), CI->getOperand(3), 1, B);
944 return CI->getOperand(1);
948 //===---------------------------------------===//
949 // 'memmove' Optimizations
951 struct MemMoveOpt : public LibCallOptimization {
952 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
953 // These optimizations require TargetData.
956 const FunctionType *FT = Callee->getFunctionType();
957 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
958 !isa<PointerType>(FT->getParamType(0)) ||
959 !isa<PointerType>(FT->getParamType(1)) ||
960 FT->getParamType(2) != TD->getIntPtrType(*Context))
963 // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
964 Module *M = Caller->getParent();
965 Intrinsic::ID IID = Intrinsic::memmove;
967 Tys[0] = TD->getIntPtrType(*Context);
968 Value *MemMove = Intrinsic::getDeclaration(M, IID, Tys, 1);
969 Value *Dst = CastToCStr(CI->getOperand(1), B);
970 Value *Src = CastToCStr(CI->getOperand(2), B);
971 Value *Size = CI->getOperand(3);
972 Value *Align = ConstantInt::get(Type::getInt32Ty(*Context), 1);
973 B.CreateCall4(MemMove, Dst, Src, Size, Align);
974 return CI->getOperand(1);
978 //===---------------------------------------===//
979 // 'memset' Optimizations
981 struct MemSetOpt : public LibCallOptimization {
982 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
983 // These optimizations require TargetData.
986 const FunctionType *FT = Callee->getFunctionType();
987 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
988 !isa<PointerType>(FT->getParamType(0)) ||
989 !isa<IntegerType>(FT->getParamType(1)) ||
990 FT->getParamType(2) != TD->getIntPtrType(*Context))
993 // memset(p, v, n) -> llvm.memset(p, v, n, 1)
994 Value *Val = B.CreateIntCast(CI->getOperand(2), Type::getInt8Ty(*Context), false);
995 EmitMemSet(CI->getOperand(1), Val, CI->getOperand(3), B);
996 return CI->getOperand(1);
1000 //===----------------------------------------------------------------------===//
1001 // Math Library Optimizations
1002 //===----------------------------------------------------------------------===//
1004 //===---------------------------------------===//
1005 // 'pow*' Optimizations
1007 struct PowOpt : public LibCallOptimization {
1008 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1009 const FunctionType *FT = Callee->getFunctionType();
1010 // Just make sure this has 2 arguments of the same FP type, which match the
1012 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
1013 FT->getParamType(0) != FT->getParamType(1) ||
1014 !FT->getParamType(0)->isFloatingPoint())
1017 Value *Op1 = CI->getOperand(1), *Op2 = CI->getOperand(2);
1018 if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
1019 if (Op1C->isExactlyValue(1.0)) // pow(1.0, x) -> 1.0
1021 if (Op1C->isExactlyValue(2.0)) // pow(2.0, x) -> exp2(x)
1022 return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
1025 ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
1026 if (Op2C == 0) return 0;
1028 if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
1029 return ConstantFP::get(CI->getType(), 1.0);
1031 if (Op2C->isExactlyValue(0.5)) {
1032 // Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
1033 // This is faster than calling pow, and still handles negative zero
1034 // and negative infinite correctly.
1035 // TODO: In fast-math mode, this could be just sqrt(x).
1036 // TODO: In finite-only mode, this could be just fabs(sqrt(x)).
1037 Value *Inf = ConstantFP::getInfinity(CI->getType());
1038 Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
1039 Value *Sqrt = EmitUnaryFloatFnCall(Op1, "sqrt", B,
1040 Callee->getAttributes());
1041 Value *FAbs = EmitUnaryFloatFnCall(Sqrt, "fabs", B,
1042 Callee->getAttributes());
1043 Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf, "tmp");
1044 Value *Sel = B.CreateSelect(FCmp, Inf, FAbs, "tmp");
1048 if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
1050 if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
1051 return B.CreateFMul(Op1, Op1, "pow2");
1052 if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
1053 return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0),
1059 //===---------------------------------------===//
1060 // 'exp2' Optimizations
1062 struct Exp2Opt : public LibCallOptimization {
1063 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1064 const FunctionType *FT = Callee->getFunctionType();
1065 // Just make sure this has 1 argument of FP type, which matches the
1067 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1068 !FT->getParamType(0)->isFloatingPoint())
1071 Value *Op = CI->getOperand(1);
1072 // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
1073 // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
1074 Value *LdExpArg = 0;
1075 if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
1076 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
1077 LdExpArg = B.CreateSExt(OpC->getOperand(0), Type::getInt32Ty(*Context), "tmp");
1078 } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
1079 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
1080 LdExpArg = B.CreateZExt(OpC->getOperand(0), Type::getInt32Ty(*Context), "tmp");
1085 if (Op->getType() == Type::getFloatTy(*Context))
1087 else if (Op->getType() == Type::getDoubleTy(*Context))
1092 Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
1093 if (Op->getType() != Type::getFloatTy(*Context))
1094 One = ConstantExpr::getFPExtend(One, Op->getType());
1096 Module *M = Caller->getParent();
1097 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
1098 Op->getType(), Type::getInt32Ty(*Context),NULL);
1099 CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
1100 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
1101 CI->setCallingConv(F->getCallingConv());
1109 //===---------------------------------------===//
1110 // Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
1112 struct UnaryDoubleFPOpt : public LibCallOptimization {
1113 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1114 const FunctionType *FT = Callee->getFunctionType();
1115 if (FT->getNumParams() != 1 || FT->getReturnType() != Type::getDoubleTy(*Context) ||
1116 FT->getParamType(0) != Type::getDoubleTy(*Context))
1119 // If this is something like 'floor((double)floatval)', convert to floorf.
1120 FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getOperand(1));
1121 if (Cast == 0 || Cast->getOperand(0)->getType() != Type::getFloatTy(*Context))
1124 // floor((double)floatval) -> (double)floorf(floatval)
1125 Value *V = Cast->getOperand(0);
1126 V = EmitUnaryFloatFnCall(V, Callee->getName().data(), B,
1127 Callee->getAttributes());
1128 return B.CreateFPExt(V, Type::getDoubleTy(*Context));
1132 //===----------------------------------------------------------------------===//
1133 // Integer Optimizations
1134 //===----------------------------------------------------------------------===//
1136 //===---------------------------------------===//
1137 // 'ffs*' Optimizations
1139 struct FFSOpt : public LibCallOptimization {
1140 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1141 const FunctionType *FT = Callee->getFunctionType();
1142 // Just make sure this has 2 arguments of the same FP type, which match the
1144 if (FT->getNumParams() != 1 || FT->getReturnType() != Type::getInt32Ty(*Context) ||
1145 !isa<IntegerType>(FT->getParamType(0)))
1148 Value *Op = CI->getOperand(1);
1151 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
1152 if (CI->getValue() == 0) // ffs(0) -> 0.
1153 return Constant::getNullValue(CI->getType());
1154 return ConstantInt::get(Type::getInt32Ty(*Context), // ffs(c) -> cttz(c)+1
1155 CI->getValue().countTrailingZeros()+1);
1158 // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
1159 const Type *ArgType = Op->getType();
1160 Value *F = Intrinsic::getDeclaration(Callee->getParent(),
1161 Intrinsic::cttz, &ArgType, 1);
1162 Value *V = B.CreateCall(F, Op, "cttz");
1163 V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1), "tmp");
1164 V = B.CreateIntCast(V, Type::getInt32Ty(*Context), false, "tmp");
1166 Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType), "tmp");
1167 return B.CreateSelect(Cond, V, ConstantInt::get(Type::getInt32Ty(*Context), 0));
1171 //===---------------------------------------===//
1172 // 'isdigit' Optimizations
1174 struct IsDigitOpt : public LibCallOptimization {
1175 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1176 const FunctionType *FT = Callee->getFunctionType();
1177 // We require integer(i32)
1178 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1179 FT->getParamType(0) != Type::getInt32Ty(*Context))
1182 // isdigit(c) -> (c-'0') <u 10
1183 Value *Op = CI->getOperand(1);
1184 Op = B.CreateSub(Op, ConstantInt::get(Type::getInt32Ty(*Context), '0'),
1186 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 10),
1188 return B.CreateZExt(Op, CI->getType());
1192 //===---------------------------------------===//
1193 // 'isascii' Optimizations
1195 struct IsAsciiOpt : public LibCallOptimization {
1196 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1197 const FunctionType *FT = Callee->getFunctionType();
1198 // We require integer(i32)
1199 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1200 FT->getParamType(0) != Type::getInt32Ty(*Context))
1203 // isascii(c) -> c <u 128
1204 Value *Op = CI->getOperand(1);
1205 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 128),
1207 return B.CreateZExt(Op, CI->getType());
1211 //===---------------------------------------===//
1212 // 'abs', 'labs', 'llabs' Optimizations
1214 struct AbsOpt : public LibCallOptimization {
1215 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1216 const FunctionType *FT = Callee->getFunctionType();
1217 // We require integer(integer) where the types agree.
1218 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1219 FT->getParamType(0) != FT->getReturnType())
1222 // abs(x) -> x >s -1 ? x : -x
1223 Value *Op = CI->getOperand(1);
1224 Value *Pos = B.CreateICmpSGT(Op,
1225 Constant::getAllOnesValue(Op->getType()),
1227 Value *Neg = B.CreateNeg(Op, "neg");
1228 return B.CreateSelect(Pos, Op, Neg);
1233 //===---------------------------------------===//
1234 // 'toascii' Optimizations
1236 struct ToAsciiOpt : public LibCallOptimization {
1237 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1238 const FunctionType *FT = Callee->getFunctionType();
1239 // We require i32(i32)
1240 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1241 FT->getParamType(0) != Type::getInt32Ty(*Context))
1244 // isascii(c) -> c & 0x7f
1245 return B.CreateAnd(CI->getOperand(1),
1246 ConstantInt::get(CI->getType(),0x7F));
1250 //===----------------------------------------------------------------------===//
1251 // Formatting and IO Optimizations
1252 //===----------------------------------------------------------------------===//
1254 //===---------------------------------------===//
1255 // 'printf' Optimizations
1257 struct PrintFOpt : public LibCallOptimization {
1258 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1259 // Require one fixed pointer argument and an integer/void result.
1260 const FunctionType *FT = Callee->getFunctionType();
1261 if (FT->getNumParams() < 1 || !isa<PointerType>(FT->getParamType(0)) ||
1262 !(isa<IntegerType>(FT->getReturnType()) ||
1263 FT->getReturnType() == Type::getVoidTy(*Context)))
1266 // Check for a fixed format string.
1267 std::string FormatStr;
1268 if (!GetConstantStringInfo(CI->getOperand(1), FormatStr))
1271 // Empty format string -> noop.
1272 if (FormatStr.empty()) // Tolerate printf's declared void.
1273 return CI->use_empty() ? (Value*)CI :
1274 ConstantInt::get(CI->getType(), 0);
1276 // printf("x") -> putchar('x'), even for '%'.
1277 if (FormatStr.size() == 1) {
1278 EmitPutChar(ConstantInt::get(Type::getInt32Ty(*Context), FormatStr[0]), B);
1279 return CI->use_empty() ? (Value*)CI :
1280 ConstantInt::get(CI->getType(), 1);
1283 // printf("foo\n") --> puts("foo")
1284 if (FormatStr[FormatStr.size()-1] == '\n' &&
1285 FormatStr.find('%') == std::string::npos) { // no format characters.
1286 // Create a string literal with no \n on it. We expect the constant merge
1287 // pass to be run after this pass, to merge duplicate strings.
1288 FormatStr.erase(FormatStr.end()-1);
1289 Constant *C = ConstantArray::get(*Context, FormatStr, true);
1290 C = new GlobalVariable(*Callee->getParent(), C->getType(), true,
1291 GlobalVariable::InternalLinkage, C, "str");
1293 return CI->use_empty() ? (Value*)CI :
1294 ConstantInt::get(CI->getType(), FormatStr.size()+1);
1297 // Optimize specific format strings.
1298 // printf("%c", chr) --> putchar(*(i8*)dst)
1299 if (FormatStr == "%c" && CI->getNumOperands() > 2 &&
1300 isa<IntegerType>(CI->getOperand(2)->getType())) {
1301 EmitPutChar(CI->getOperand(2), B);
1302 return CI->use_empty() ? (Value*)CI :
1303 ConstantInt::get(CI->getType(), 1);
1306 // printf("%s\n", str) --> puts(str)
1307 if (FormatStr == "%s\n" && CI->getNumOperands() > 2 &&
1308 isa<PointerType>(CI->getOperand(2)->getType()) &&
1310 EmitPutS(CI->getOperand(2), B);
1317 //===---------------------------------------===//
1318 // 'sprintf' Optimizations
1320 struct SPrintFOpt : public LibCallOptimization {
1321 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1322 // Require two fixed pointer arguments and an integer result.
1323 const FunctionType *FT = Callee->getFunctionType();
1324 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1325 !isa<PointerType>(FT->getParamType(1)) ||
1326 !isa<IntegerType>(FT->getReturnType()))
1329 // Check for a fixed format string.
1330 std::string FormatStr;
1331 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1334 // If we just have a format string (nothing else crazy) transform it.
1335 if (CI->getNumOperands() == 3) {
1336 // Make sure there's no % in the constant array. We could try to handle
1337 // %% -> % in the future if we cared.
1338 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1339 if (FormatStr[i] == '%')
1340 return 0; // we found a format specifier, bail out.
1342 // These optimizations require TargetData.
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(*Context), 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::getInt8Ty(*Context), "char");
1361 Value *Ptr = CastToCStr(CI->getOperand(1), B);
1362 B.CreateStore(V, Ptr);
1363 Ptr = B.CreateGEP(Ptr, ConstantInt::get(Type::getInt32Ty(*Context), 1), "nul");
1364 B.CreateStore(Constant::getNullValue(Type::getInt8Ty(*Context)), Ptr);
1366 return ConstantInt::get(CI->getType(), 1);
1369 if (FormatStr[1] == 's') {
1370 // These optimizations require TargetData.
1373 // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1374 if (!isa<PointerType>(CI->getOperand(3)->getType())) return 0;
1376 Value *Len = EmitStrLen(CI->getOperand(3), B);
1377 Value *IncLen = B.CreateAdd(Len,
1378 ConstantInt::get(Len->getType(), 1),
1380 EmitMemCpy(CI->getOperand(1), CI->getOperand(3), IncLen, 1, B);
1382 // The sprintf result is the unincremented number of bytes in the string.
1383 return B.CreateIntCast(Len, CI->getType(), false);
1389 //===---------------------------------------===//
1390 // 'fwrite' Optimizations
1392 struct FWriteOpt : public LibCallOptimization {
1393 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1394 // Require a pointer, an integer, an integer, a pointer, returning integer.
1395 const FunctionType *FT = Callee->getFunctionType();
1396 if (FT->getNumParams() != 4 || !isa<PointerType>(FT->getParamType(0)) ||
1397 !isa<IntegerType>(FT->getParamType(1)) ||
1398 !isa<IntegerType>(FT->getParamType(2)) ||
1399 !isa<PointerType>(FT->getParamType(3)) ||
1400 !isa<IntegerType>(FT->getReturnType()))
1403 // Get the element size and count.
1404 ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getOperand(2));
1405 ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getOperand(3));
1406 if (!SizeC || !CountC) return 0;
1407 uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
1409 // If this is writing zero records, remove the call (it's a noop).
1411 return ConstantInt::get(CI->getType(), 0);
1413 // If this is writing one byte, turn it into fputc.
1414 if (Bytes == 1) { // fwrite(S,1,1,F) -> fputc(S[0],F)
1415 Value *Char = B.CreateLoad(CastToCStr(CI->getOperand(1), B), "char");
1416 EmitFPutC(Char, CI->getOperand(4), B);
1417 return ConstantInt::get(CI->getType(), 1);
1424 //===---------------------------------------===//
1425 // 'fputs' Optimizations
1427 struct FPutsOpt : public LibCallOptimization {
1428 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1429 // These optimizations require TargetData.
1432 // Require two pointers. Also, we can't optimize if return value is used.
1433 const FunctionType *FT = Callee->getFunctionType();
1434 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1435 !isa<PointerType>(FT->getParamType(1)) ||
1439 // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1440 uint64_t Len = GetStringLength(CI->getOperand(1));
1442 EmitFWrite(CI->getOperand(1),
1443 ConstantInt::get(TD->getIntPtrType(*Context), Len-1),
1444 CI->getOperand(2), B);
1445 return CI; // Known to have no uses (see above).
1449 //===---------------------------------------===//
1450 // 'fprintf' Optimizations
1452 struct FPrintFOpt : public LibCallOptimization {
1453 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1454 // Require two fixed paramters as pointers and integer result.
1455 const FunctionType *FT = Callee->getFunctionType();
1456 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1457 !isa<PointerType>(FT->getParamType(1)) ||
1458 !isa<IntegerType>(FT->getReturnType()))
1461 // All the optimizations depend on the format string.
1462 std::string FormatStr;
1463 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1466 // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1467 if (CI->getNumOperands() == 3) {
1468 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1469 if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1470 return 0; // We found a format specifier.
1472 // These optimizations require TargetData.
1475 EmitFWrite(CI->getOperand(2), ConstantInt::get(TD->getIntPtrType(*Context),
1477 CI->getOperand(1), B);
1478 return ConstantInt::get(CI->getType(), FormatStr.size());
1481 // The remaining optimizations require the format string to be "%s" or "%c"
1482 // and have an extra operand.
1483 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1486 // Decode the second character of the format string.
1487 if (FormatStr[1] == 'c') {
1488 // fprintf(F, "%c", chr) --> *(i8*)dst = chr
1489 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1490 EmitFPutC(CI->getOperand(3), CI->getOperand(1), B);
1491 return ConstantInt::get(CI->getType(), 1);
1494 if (FormatStr[1] == 's') {
1495 // fprintf(F, "%s", str) -> fputs(str, F)
1496 if (!isa<PointerType>(CI->getOperand(3)->getType()) || !CI->use_empty())
1498 EmitFPutS(CI->getOperand(3), CI->getOperand(1), B);
1505 } // end anonymous namespace.
1507 //===----------------------------------------------------------------------===//
1508 // SimplifyLibCalls Pass Implementation
1509 //===----------------------------------------------------------------------===//
1512 /// This pass optimizes well known library functions from libc and libm.
1514 class SimplifyLibCalls : public FunctionPass {
1515 StringMap<LibCallOptimization*> Optimizations;
1516 // String and Memory LibCall Optimizations
1517 StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
1518 StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
1519 StrToOpt StrTo; MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove;
1521 // Math Library Optimizations
1522 PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
1523 // Integer Optimizations
1524 FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
1526 // Formatting and IO Optimizations
1527 SPrintFOpt SPrintF; PrintFOpt PrintF;
1528 FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
1530 bool Modified; // This is only used by doInitialization.
1532 static char ID; // Pass identification
1533 SimplifyLibCalls() : FunctionPass(&ID) {}
1535 void InitOptimizations();
1536 bool runOnFunction(Function &F);
1538 void setDoesNotAccessMemory(Function &F);
1539 void setOnlyReadsMemory(Function &F);
1540 void setDoesNotThrow(Function &F);
1541 void setDoesNotCapture(Function &F, unsigned n);
1542 void setDoesNotAlias(Function &F, unsigned n);
1543 bool doInitialization(Module &M);
1545 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1548 char SimplifyLibCalls::ID = 0;
1549 } // end anonymous namespace.
1551 static RegisterPass<SimplifyLibCalls>
1552 X("simplify-libcalls", "Simplify well-known library calls");
1554 // Public interface to the Simplify LibCalls pass.
1555 FunctionPass *llvm::createSimplifyLibCallsPass() {
1556 return new SimplifyLibCalls();
1559 /// Optimizations - Populate the Optimizations map with all the optimizations
1561 void SimplifyLibCalls::InitOptimizations() {
1562 // String and Memory LibCall Optimizations
1563 Optimizations["strcat"] = &StrCat;
1564 Optimizations["strncat"] = &StrNCat;
1565 Optimizations["strchr"] = &StrChr;
1566 Optimizations["strcmp"] = &StrCmp;
1567 Optimizations["strncmp"] = &StrNCmp;
1568 Optimizations["strcpy"] = &StrCpy;
1569 Optimizations["strncpy"] = &StrNCpy;
1570 Optimizations["strlen"] = &StrLen;
1571 Optimizations["strtol"] = &StrTo;
1572 Optimizations["strtod"] = &StrTo;
1573 Optimizations["strtof"] = &StrTo;
1574 Optimizations["strtoul"] = &StrTo;
1575 Optimizations["strtoll"] = &StrTo;
1576 Optimizations["strtold"] = &StrTo;
1577 Optimizations["strtoull"] = &StrTo;
1578 Optimizations["memcmp"] = &MemCmp;
1579 Optimizations["memcpy"] = &MemCpy;
1580 Optimizations["memmove"] = &MemMove;
1581 Optimizations["memset"] = &MemSet;
1583 // Math Library Optimizations
1584 Optimizations["powf"] = &Pow;
1585 Optimizations["pow"] = &Pow;
1586 Optimizations["powl"] = &Pow;
1587 Optimizations["llvm.pow.f32"] = &Pow;
1588 Optimizations["llvm.pow.f64"] = &Pow;
1589 Optimizations["llvm.pow.f80"] = &Pow;
1590 Optimizations["llvm.pow.f128"] = &Pow;
1591 Optimizations["llvm.pow.ppcf128"] = &Pow;
1592 Optimizations["exp2l"] = &Exp2;
1593 Optimizations["exp2"] = &Exp2;
1594 Optimizations["exp2f"] = &Exp2;
1595 Optimizations["llvm.exp2.ppcf128"] = &Exp2;
1596 Optimizations["llvm.exp2.f128"] = &Exp2;
1597 Optimizations["llvm.exp2.f80"] = &Exp2;
1598 Optimizations["llvm.exp2.f64"] = &Exp2;
1599 Optimizations["llvm.exp2.f32"] = &Exp2;
1602 Optimizations["floor"] = &UnaryDoubleFP;
1605 Optimizations["ceil"] = &UnaryDoubleFP;
1608 Optimizations["round"] = &UnaryDoubleFP;
1611 Optimizations["rint"] = &UnaryDoubleFP;
1613 #ifdef HAVE_NEARBYINTF
1614 Optimizations["nearbyint"] = &UnaryDoubleFP;
1617 // Integer Optimizations
1618 Optimizations["ffs"] = &FFS;
1619 Optimizations["ffsl"] = &FFS;
1620 Optimizations["ffsll"] = &FFS;
1621 Optimizations["abs"] = &Abs;
1622 Optimizations["labs"] = &Abs;
1623 Optimizations["llabs"] = &Abs;
1624 Optimizations["isdigit"] = &IsDigit;
1625 Optimizations["isascii"] = &IsAscii;
1626 Optimizations["toascii"] = &ToAscii;
1628 // Formatting and IO Optimizations
1629 Optimizations["sprintf"] = &SPrintF;
1630 Optimizations["printf"] = &PrintF;
1631 Optimizations["fwrite"] = &FWrite;
1632 Optimizations["fputs"] = &FPuts;
1633 Optimizations["fprintf"] = &FPrintF;
1637 /// runOnFunction - Top level algorithm.
1639 bool SimplifyLibCalls::runOnFunction(Function &F) {
1640 if (Optimizations.empty())
1641 InitOptimizations();
1643 const TargetData *TD = getAnalysisIfAvailable<TargetData>();
1645 IRBuilder<> Builder(F.getContext());
1647 bool Changed = false;
1648 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1649 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
1650 // Ignore non-calls.
1651 CallInst *CI = dyn_cast<CallInst>(I++);
1654 // Ignore indirect calls and calls to non-external functions.
1655 Function *Callee = CI->getCalledFunction();
1656 if (Callee == 0 || !Callee->isDeclaration() ||
1657 !(Callee->hasExternalLinkage() || Callee->hasDLLImportLinkage()))
1660 // Ignore unknown calls.
1661 LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
1664 // Set the builder to the instruction after the call.
1665 Builder.SetInsertPoint(BB, I);
1667 // Try to optimize this call.
1668 Value *Result = LCO->OptimizeCall(CI, TD, Builder);
1669 if (Result == 0) continue;
1671 DEBUG(errs() << "SimplifyLibCalls simplified: " << *CI;
1672 errs() << " into: " << *Result << "\n");
1674 // Something changed!
1678 // Inspect the instruction after the call (which was potentially just
1682 if (CI != Result && !CI->use_empty()) {
1683 CI->replaceAllUsesWith(Result);
1684 if (!Result->hasName())
1685 Result->takeName(CI);
1687 CI->eraseFromParent();
1693 // Utility methods for doInitialization.
1695 void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
1696 if (!F.doesNotAccessMemory()) {
1697 F.setDoesNotAccessMemory();
1702 void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
1703 if (!F.onlyReadsMemory()) {
1704 F.setOnlyReadsMemory();
1709 void SimplifyLibCalls::setDoesNotThrow(Function &F) {
1710 if (!F.doesNotThrow()) {
1711 F.setDoesNotThrow();
1716 void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
1717 if (!F.doesNotCapture(n)) {
1718 F.setDoesNotCapture(n);
1723 void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
1724 if (!F.doesNotAlias(n)) {
1725 F.setDoesNotAlias(n);
1731 /// doInitialization - Add attributes to well-known functions.
1733 bool SimplifyLibCalls::doInitialization(Module &M) {
1735 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
1737 if (!F.isDeclaration())
1743 const FunctionType *FTy = F.getFunctionType();
1745 StringRef Name = F.getName();
1748 if (Name == "strlen") {
1749 if (FTy->getNumParams() != 1 ||
1750 !isa<PointerType>(FTy->getParamType(0)))
1752 setOnlyReadsMemory(F);
1754 setDoesNotCapture(F, 1);
1755 } else if (Name == "strcpy" ||
1761 Name == "strtoul" ||
1762 Name == "strtoll" ||
1763 Name == "strtold" ||
1764 Name == "strncat" ||
1765 Name == "strncpy" ||
1766 Name == "strtoull") {
1767 if (FTy->getNumParams() < 2 ||
1768 !isa<PointerType>(FTy->getParamType(1)))
1771 setDoesNotCapture(F, 2);
1772 } else if (Name == "strxfrm") {
1773 if (FTy->getNumParams() != 3 ||
1774 !isa<PointerType>(FTy->getParamType(0)) ||
1775 !isa<PointerType>(FTy->getParamType(1)))
1778 setDoesNotCapture(F, 1);
1779 setDoesNotCapture(F, 2);
1780 } else if (Name == "strcmp" ||
1782 Name == "strncmp" ||
1783 Name ==" strcspn" ||
1784 Name == "strcoll" ||
1785 Name == "strcasecmp" ||
1786 Name == "strncasecmp") {
1787 if (FTy->getNumParams() < 2 ||
1788 !isa<PointerType>(FTy->getParamType(0)) ||
1789 !isa<PointerType>(FTy->getParamType(1)))
1791 setOnlyReadsMemory(F);
1793 setDoesNotCapture(F, 1);
1794 setDoesNotCapture(F, 2);
1795 } else if (Name == "strstr" ||
1796 Name == "strpbrk") {
1797 if (FTy->getNumParams() != 2 ||
1798 !isa<PointerType>(FTy->getParamType(1)))
1800 setOnlyReadsMemory(F);
1802 setDoesNotCapture(F, 2);
1803 } else if (Name == "strtok" ||
1804 Name == "strtok_r") {
1805 if (FTy->getNumParams() < 2 ||
1806 !isa<PointerType>(FTy->getParamType(1)))
1809 setDoesNotCapture(F, 2);
1810 } else if (Name == "scanf" ||
1812 Name == "setvbuf") {
1813 if (FTy->getNumParams() < 1 ||
1814 !isa<PointerType>(FTy->getParamType(0)))
1817 setDoesNotCapture(F, 1);
1818 } else if (Name == "strdup" ||
1819 Name == "strndup") {
1820 if (FTy->getNumParams() < 1 ||
1821 !isa<PointerType>(FTy->getReturnType()) ||
1822 !isa<PointerType>(FTy->getParamType(0)))
1825 setDoesNotAlias(F, 0);
1826 setDoesNotCapture(F, 1);
1827 } else if (Name == "stat" ||
1829 Name == "sprintf" ||
1830 Name == "statvfs") {
1831 if (FTy->getNumParams() < 2 ||
1832 !isa<PointerType>(FTy->getParamType(0)) ||
1833 !isa<PointerType>(FTy->getParamType(1)))
1836 setDoesNotCapture(F, 1);
1837 setDoesNotCapture(F, 2);
1838 } else if (Name == "snprintf") {
1839 if (FTy->getNumParams() != 3 ||
1840 !isa<PointerType>(FTy->getParamType(0)) ||
1841 !isa<PointerType>(FTy->getParamType(2)))
1844 setDoesNotCapture(F, 1);
1845 setDoesNotCapture(F, 3);
1846 } else if (Name == "setitimer") {
1847 if (FTy->getNumParams() != 3 ||
1848 !isa<PointerType>(FTy->getParamType(1)) ||
1849 !isa<PointerType>(FTy->getParamType(2)))
1852 setDoesNotCapture(F, 2);
1853 setDoesNotCapture(F, 3);
1854 } else if (Name == "system") {
1855 if (FTy->getNumParams() != 1 ||
1856 !isa<PointerType>(FTy->getParamType(0)))
1858 // May throw; "system" is a valid pthread cancellation point.
1859 setDoesNotCapture(F, 1);
1863 if (Name == "malloc") {
1864 if (FTy->getNumParams() != 1 ||
1865 !isa<PointerType>(FTy->getReturnType()))
1868 setDoesNotAlias(F, 0);
1869 } else if (Name == "memcmp") {
1870 if (FTy->getNumParams() != 3 ||
1871 !isa<PointerType>(FTy->getParamType(0)) ||
1872 !isa<PointerType>(FTy->getParamType(1)))
1874 setOnlyReadsMemory(F);
1876 setDoesNotCapture(F, 1);
1877 setDoesNotCapture(F, 2);
1878 } else if (Name == "memchr" ||
1879 Name == "memrchr") {
1880 if (FTy->getNumParams() != 3)
1882 setOnlyReadsMemory(F);
1884 } else if (Name == "modf" ||
1888 Name == "memccpy" ||
1889 Name == "memmove") {
1890 if (FTy->getNumParams() < 2 ||
1891 !isa<PointerType>(FTy->getParamType(1)))
1894 setDoesNotCapture(F, 2);
1895 } else if (Name == "memalign") {
1896 if (!isa<PointerType>(FTy->getReturnType()))
1898 setDoesNotAlias(F, 0);
1899 } else if (Name == "mkdir" ||
1901 if (FTy->getNumParams() == 0 ||
1902 !isa<PointerType>(FTy->getParamType(0)))
1905 setDoesNotCapture(F, 1);
1909 if (Name == "realloc") {
1910 if (FTy->getNumParams() != 2 ||
1911 !isa<PointerType>(FTy->getParamType(0)) ||
1912 !isa<PointerType>(FTy->getReturnType()))
1915 setDoesNotAlias(F, 0);
1916 setDoesNotCapture(F, 1);
1917 } else if (Name == "read") {
1918 if (FTy->getNumParams() != 3 ||
1919 !isa<PointerType>(FTy->getParamType(1)))
1921 // May throw; "read" is a valid pthread cancellation point.
1922 setDoesNotCapture(F, 2);
1923 } else if (Name == "rmdir" ||
1926 Name == "realpath") {
1927 if (FTy->getNumParams() < 1 ||
1928 !isa<PointerType>(FTy->getParamType(0)))
1931 setDoesNotCapture(F, 1);
1932 } else if (Name == "rename" ||
1933 Name == "readlink") {
1934 if (FTy->getNumParams() < 2 ||
1935 !isa<PointerType>(FTy->getParamType(0)) ||
1936 !isa<PointerType>(FTy->getParamType(1)))
1939 setDoesNotCapture(F, 1);
1940 setDoesNotCapture(F, 2);
1944 if (Name == "write") {
1945 if (FTy->getNumParams() != 3 ||
1946 !isa<PointerType>(FTy->getParamType(1)))
1948 // May throw; "write" is a valid pthread cancellation point.
1949 setDoesNotCapture(F, 2);
1953 if (Name == "bcopy") {
1954 if (FTy->getNumParams() != 3 ||
1955 !isa<PointerType>(FTy->getParamType(0)) ||
1956 !isa<PointerType>(FTy->getParamType(1)))
1959 setDoesNotCapture(F, 1);
1960 setDoesNotCapture(F, 2);
1961 } else if (Name == "bcmp") {
1962 if (FTy->getNumParams() != 3 ||
1963 !isa<PointerType>(FTy->getParamType(0)) ||
1964 !isa<PointerType>(FTy->getParamType(1)))
1967 setOnlyReadsMemory(F);
1968 setDoesNotCapture(F, 1);
1969 setDoesNotCapture(F, 2);
1970 } else if (Name == "bzero") {
1971 if (FTy->getNumParams() != 2 ||
1972 !isa<PointerType>(FTy->getParamType(0)))
1975 setDoesNotCapture(F, 1);
1979 if (Name == "calloc") {
1980 if (FTy->getNumParams() != 2 ||
1981 !isa<PointerType>(FTy->getReturnType()))
1984 setDoesNotAlias(F, 0);
1985 } else if (Name == "chmod" ||
1987 Name == "ctermid" ||
1988 Name == "clearerr" ||
1989 Name == "closedir") {
1990 if (FTy->getNumParams() == 0 ||
1991 !isa<PointerType>(FTy->getParamType(0)))
1994 setDoesNotCapture(F, 1);
1998 if (Name == "atoi" ||
2002 if (FTy->getNumParams() != 1 ||
2003 !isa<PointerType>(FTy->getParamType(0)))
2006 setOnlyReadsMemory(F);
2007 setDoesNotCapture(F, 1);
2008 } else if (Name == "access") {
2009 if (FTy->getNumParams() != 2 ||
2010 !isa<PointerType>(FTy->getParamType(0)))
2013 setDoesNotCapture(F, 1);
2017 if (Name == "fopen") {
2018 if (FTy->getNumParams() != 2 ||
2019 !isa<PointerType>(FTy->getReturnType()) ||
2020 !isa<PointerType>(FTy->getParamType(0)) ||
2021 !isa<PointerType>(FTy->getParamType(1)))
2024 setDoesNotAlias(F, 0);
2025 setDoesNotCapture(F, 1);
2026 setDoesNotCapture(F, 2);
2027 } else if (Name == "fdopen") {
2028 if (FTy->getNumParams() != 2 ||
2029 !isa<PointerType>(FTy->getReturnType()) ||
2030 !isa<PointerType>(FTy->getParamType(1)))
2033 setDoesNotAlias(F, 0);
2034 setDoesNotCapture(F, 2);
2035 } else if (Name == "feof" ||
2045 Name == "fsetpos" ||
2046 Name == "flockfile" ||
2047 Name == "funlockfile" ||
2048 Name == "ftrylockfile") {
2049 if (FTy->getNumParams() == 0 ||
2050 !isa<PointerType>(FTy->getParamType(0)))
2053 setDoesNotCapture(F, 1);
2054 } else if (Name == "ferror") {
2055 if (FTy->getNumParams() != 1 ||
2056 !isa<PointerType>(FTy->getParamType(0)))
2059 setDoesNotCapture(F, 1);
2060 setOnlyReadsMemory(F);
2061 } else if (Name == "fputc" ||
2066 Name == "fstatvfs") {
2067 if (FTy->getNumParams() != 2 ||
2068 !isa<PointerType>(FTy->getParamType(1)))
2071 setDoesNotCapture(F, 2);
2072 } else if (Name == "fgets") {
2073 if (FTy->getNumParams() != 3 ||
2074 !isa<PointerType>(FTy->getParamType(0)) ||
2075 !isa<PointerType>(FTy->getParamType(2)))
2078 setDoesNotCapture(F, 3);
2079 } else if (Name == "fread" ||
2081 if (FTy->getNumParams() != 4 ||
2082 !isa<PointerType>(FTy->getParamType(0)) ||
2083 !isa<PointerType>(FTy->getParamType(3)))
2086 setDoesNotCapture(F, 1);
2087 setDoesNotCapture(F, 4);
2088 } else if (Name == "fputs" ||
2090 Name == "fprintf" ||
2091 Name == "fgetpos") {
2092 if (FTy->getNumParams() < 2 ||
2093 !isa<PointerType>(FTy->getParamType(0)) ||
2094 !isa<PointerType>(FTy->getParamType(1)))
2097 setDoesNotCapture(F, 1);
2098 setDoesNotCapture(F, 2);
2102 if (Name == "getc" ||
2103 Name == "getlogin_r" ||
2104 Name == "getc_unlocked") {
2105 if (FTy->getNumParams() == 0 ||
2106 !isa<PointerType>(FTy->getParamType(0)))
2109 setDoesNotCapture(F, 1);
2110 } else if (Name == "getenv") {
2111 if (FTy->getNumParams() != 1 ||
2112 !isa<PointerType>(FTy->getParamType(0)))
2115 setOnlyReadsMemory(F);
2116 setDoesNotCapture(F, 1);
2117 } else if (Name == "gets" ||
2118 Name == "getchar") {
2120 } else if (Name == "getitimer") {
2121 if (FTy->getNumParams() != 2 ||
2122 !isa<PointerType>(FTy->getParamType(1)))
2125 setDoesNotCapture(F, 2);
2126 } else if (Name == "getpwnam") {
2127 if (FTy->getNumParams() != 1 ||
2128 !isa<PointerType>(FTy->getParamType(0)))
2131 setDoesNotCapture(F, 1);
2135 if (Name == "ungetc") {
2136 if (FTy->getNumParams() != 2 ||
2137 !isa<PointerType>(FTy->getParamType(1)))
2140 setDoesNotCapture(F, 2);
2141 } else if (Name == "uname" ||
2143 Name == "unsetenv") {
2144 if (FTy->getNumParams() != 1 ||
2145 !isa<PointerType>(FTy->getParamType(0)))
2148 setDoesNotCapture(F, 1);
2149 } else if (Name == "utime" ||
2151 if (FTy->getNumParams() != 2 ||
2152 !isa<PointerType>(FTy->getParamType(0)) ||
2153 !isa<PointerType>(FTy->getParamType(1)))
2156 setDoesNotCapture(F, 1);
2157 setDoesNotCapture(F, 2);
2161 if (Name == "putc") {
2162 if (FTy->getNumParams() != 2 ||
2163 !isa<PointerType>(FTy->getParamType(1)))
2166 setDoesNotCapture(F, 2);
2167 } else if (Name == "puts" ||
2170 if (FTy->getNumParams() != 1 ||
2171 !isa<PointerType>(FTy->getParamType(0)))
2174 setDoesNotCapture(F, 1);
2175 } else if (Name == "pread" ||
2177 if (FTy->getNumParams() != 4 ||
2178 !isa<PointerType>(FTy->getParamType(1)))
2180 // May throw; these are valid pthread cancellation points.
2181 setDoesNotCapture(F, 2);
2182 } else if (Name == "putchar") {
2184 } else if (Name == "popen") {
2185 if (FTy->getNumParams() != 2 ||
2186 !isa<PointerType>(FTy->getReturnType()) ||
2187 !isa<PointerType>(FTy->getParamType(0)) ||
2188 !isa<PointerType>(FTy->getParamType(1)))
2191 setDoesNotAlias(F, 0);
2192 setDoesNotCapture(F, 1);
2193 setDoesNotCapture(F, 2);
2194 } else if (Name == "pclose") {
2195 if (FTy->getNumParams() != 1 ||
2196 !isa<PointerType>(FTy->getParamType(0)))
2199 setDoesNotCapture(F, 1);
2203 if (Name == "vscanf") {
2204 if (FTy->getNumParams() != 2 ||
2205 !isa<PointerType>(FTy->getParamType(1)))
2208 setDoesNotCapture(F, 1);
2209 } else if (Name == "vsscanf" ||
2210 Name == "vfscanf") {
2211 if (FTy->getNumParams() != 3 ||
2212 !isa<PointerType>(FTy->getParamType(1)) ||
2213 !isa<PointerType>(FTy->getParamType(2)))
2216 setDoesNotCapture(F, 1);
2217 setDoesNotCapture(F, 2);
2218 } else if (Name == "valloc") {
2219 if (!isa<PointerType>(FTy->getReturnType()))
2222 setDoesNotAlias(F, 0);
2223 } else if (Name == "vprintf") {
2224 if (FTy->getNumParams() != 2 ||
2225 !isa<PointerType>(FTy->getParamType(0)))
2228 setDoesNotCapture(F, 1);
2229 } else if (Name == "vfprintf" ||
2230 Name == "vsprintf") {
2231 if (FTy->getNumParams() != 3 ||
2232 !isa<PointerType>(FTy->getParamType(0)) ||
2233 !isa<PointerType>(FTy->getParamType(1)))
2236 setDoesNotCapture(F, 1);
2237 setDoesNotCapture(F, 2);
2238 } else if (Name == "vsnprintf") {
2239 if (FTy->getNumParams() != 4 ||
2240 !isa<PointerType>(FTy->getParamType(0)) ||
2241 !isa<PointerType>(FTy->getParamType(2)))
2244 setDoesNotCapture(F, 1);
2245 setDoesNotCapture(F, 3);
2249 if (Name == "open") {
2250 if (FTy->getNumParams() < 2 ||
2251 !isa<PointerType>(FTy->getParamType(0)))
2253 // May throw; "open" is a valid pthread cancellation point.
2254 setDoesNotCapture(F, 1);
2255 } else if (Name == "opendir") {
2256 if (FTy->getNumParams() != 1 ||
2257 !isa<PointerType>(FTy->getReturnType()) ||
2258 !isa<PointerType>(FTy->getParamType(0)))
2261 setDoesNotAlias(F, 0);
2262 setDoesNotCapture(F, 1);
2266 if (Name == "tmpfile") {
2267 if (!isa<PointerType>(FTy->getReturnType()))
2270 setDoesNotAlias(F, 0);
2271 } else if (Name == "times") {
2272 if (FTy->getNumParams() != 1 ||
2273 !isa<PointerType>(FTy->getParamType(0)))
2276 setDoesNotCapture(F, 1);
2280 if (Name == "htonl" ||
2283 setDoesNotAccessMemory(F);
2287 if (Name == "ntohl" ||
2290 setDoesNotAccessMemory(F);
2294 if (Name == "lstat") {
2295 if (FTy->getNumParams() != 2 ||
2296 !isa<PointerType>(FTy->getParamType(0)) ||
2297 !isa<PointerType>(FTy->getParamType(1)))
2300 setDoesNotCapture(F, 1);
2301 setDoesNotCapture(F, 2);
2302 } else if (Name == "lchown") {
2303 if (FTy->getNumParams() != 3 ||
2304 !isa<PointerType>(FTy->getParamType(0)))
2307 setDoesNotCapture(F, 1);
2311 if (Name == "qsort") {
2312 if (FTy->getNumParams() != 4 ||
2313 !isa<PointerType>(FTy->getParamType(3)))
2315 // May throw; places call through function pointer.
2316 setDoesNotCapture(F, 4);
2320 if (Name == "__strdup" ||
2321 Name == "__strndup") {
2322 if (FTy->getNumParams() < 1 ||
2323 !isa<PointerType>(FTy->getReturnType()) ||
2324 !isa<PointerType>(FTy->getParamType(0)))
2327 setDoesNotAlias(F, 0);
2328 setDoesNotCapture(F, 1);
2329 } else if (Name == "__strtok_r") {
2330 if (FTy->getNumParams() != 3 ||
2331 !isa<PointerType>(FTy->getParamType(1)))
2334 setDoesNotCapture(F, 2);
2335 } else if (Name == "_IO_getc") {
2336 if (FTy->getNumParams() != 1 ||
2337 !isa<PointerType>(FTy->getParamType(0)))
2340 setDoesNotCapture(F, 1);
2341 } else if (Name == "_IO_putc") {
2342 if (FTy->getNumParams() != 2 ||
2343 !isa<PointerType>(FTy->getParamType(1)))
2346 setDoesNotCapture(F, 2);
2350 if (Name == "\1__isoc99_scanf") {
2351 if (FTy->getNumParams() < 1 ||
2352 !isa<PointerType>(FTy->getParamType(0)))
2355 setDoesNotCapture(F, 1);
2356 } else if (Name == "\1stat64" ||
2357 Name == "\1lstat64" ||
2358 Name == "\1statvfs64" ||
2359 Name == "\1__isoc99_sscanf") {
2360 if (FTy->getNumParams() < 1 ||
2361 !isa<PointerType>(FTy->getParamType(0)) ||
2362 !isa<PointerType>(FTy->getParamType(1)))
2365 setDoesNotCapture(F, 1);
2366 setDoesNotCapture(F, 2);
2367 } else if (Name == "\1fopen64") {
2368 if (FTy->getNumParams() != 2 ||
2369 !isa<PointerType>(FTy->getReturnType()) ||
2370 !isa<PointerType>(FTy->getParamType(0)) ||
2371 !isa<PointerType>(FTy->getParamType(1)))
2374 setDoesNotAlias(F, 0);
2375 setDoesNotCapture(F, 1);
2376 setDoesNotCapture(F, 2);
2377 } else if (Name == "\1fseeko64" ||
2378 Name == "\1ftello64") {
2379 if (FTy->getNumParams() == 0 ||
2380 !isa<PointerType>(FTy->getParamType(0)))
2383 setDoesNotCapture(F, 1);
2384 } else if (Name == "\1tmpfile64") {
2385 if (!isa<PointerType>(FTy->getReturnType()))
2388 setDoesNotAlias(F, 0);
2389 } else if (Name == "\1fstat64" ||
2390 Name == "\1fstatvfs64") {
2391 if (FTy->getNumParams() != 2 ||
2392 !isa<PointerType>(FTy->getParamType(1)))
2395 setDoesNotCapture(F, 2);
2396 } else if (Name == "\1open64") {
2397 if (FTy->getNumParams() < 2 ||
2398 !isa<PointerType>(FTy->getParamType(0)))
2400 // May throw; "open" is a valid pthread cancellation point.
2401 setDoesNotCapture(F, 1);
2410 // Additional cases that we need to add to this file:
2413 // * cbrt(expN(X)) -> expN(x/3)
2414 // * cbrt(sqrt(x)) -> pow(x,1/6)
2415 // * cbrt(sqrt(x)) -> pow(x,1/9)
2418 // * cos(-x) -> cos(x)
2421 // * exp(log(x)) -> x
2424 // * log(exp(x)) -> x
2425 // * log(x**y) -> y*log(x)
2426 // * log(exp(y)) -> y*log(e)
2427 // * log(exp2(y)) -> y*log(2)
2428 // * log(exp10(y)) -> y*log(10)
2429 // * log(sqrt(x)) -> 0.5*log(x)
2430 // * log(pow(x,y)) -> y*log(x)
2432 // lround, lroundf, lroundl:
2433 // * lround(cnst) -> cnst'
2436 // * memcmp(x,y,l) -> cnst
2437 // (if all arguments are constant and strlen(x) <= l and strlen(y) <= l)
2440 // * pow(exp(x),y) -> exp(x*y)
2441 // * pow(sqrt(x),y) -> pow(x,y*0.5)
2442 // * pow(pow(x,y),z)-> pow(x,y*z)
2445 // * puts("") -> putchar("\n")
2447 // round, roundf, roundl:
2448 // * round(cnst) -> cnst'
2451 // * signbit(cnst) -> cnst'
2452 // * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2454 // sqrt, sqrtf, sqrtl:
2455 // * sqrt(expN(x)) -> expN(x*0.5)
2456 // * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2457 // * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2460 // * stpcpy(str, "literal") ->
2461 // llvm.memcpy(str,"literal",strlen("literal")+1,1)
2463 // * strrchr(s,c) -> reverse_offset_of_in(c,s)
2464 // (if c is a constant integer and s is a constant string)
2465 // * strrchr(s1,0) -> strchr(s1,0)
2468 // * strpbrk(s,a) -> offset_in_for(s,a)
2469 // (if s and a are both constant strings)
2470 // * strpbrk(s,"") -> 0
2471 // * strpbrk(s,a) -> strchr(s,a[0]) (if a is constant string of length 1)
2474 // * strspn(s,a) -> const_int (if both args are constant)
2475 // * strspn("",a) -> 0
2476 // * strspn(s,"") -> 0
2477 // * strcspn(s,a) -> const_int (if both args are constant)
2478 // * strcspn("",a) -> 0
2479 // * strcspn(s,"") -> strlen(a)
2482 // * strstr(x,x) -> x
2483 // * strstr(s1,s2) -> offset_of_s2_in(s1)
2484 // (if s1 and s2 are constant strings)
2487 // * tan(atan(x)) -> x
2489 // trunc, truncf, truncl:
2490 // * trunc(cnst) -> cnst'