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, CI->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, CI->getAttributes());
1040 Value *FAbs = EmitUnaryFloatFnCall(Sqrt, "fabs", B, CI->getAttributes());
1041 Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf, "tmp");
1042 Value *Sel = B.CreateSelect(FCmp, Inf, FAbs, "tmp");
1046 if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
1048 if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
1049 return B.CreateFMul(Op1, Op1, "pow2");
1050 if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
1051 return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0),
1057 //===---------------------------------------===//
1058 // 'exp2' Optimizations
1060 struct Exp2Opt : public LibCallOptimization {
1061 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1062 const FunctionType *FT = Callee->getFunctionType();
1063 // Just make sure this has 1 argument of FP type, which matches the
1065 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1066 !FT->getParamType(0)->isFloatingPoint())
1069 Value *Op = CI->getOperand(1);
1070 // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
1071 // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
1072 Value *LdExpArg = 0;
1073 if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
1074 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
1075 LdExpArg = B.CreateSExt(OpC->getOperand(0), Type::getInt32Ty(*Context), "tmp");
1076 } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
1077 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
1078 LdExpArg = B.CreateZExt(OpC->getOperand(0), Type::getInt32Ty(*Context), "tmp");
1083 if (Op->getType() == Type::getFloatTy(*Context))
1085 else if (Op->getType() == Type::getDoubleTy(*Context))
1090 Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
1091 if (Op->getType() != Type::getFloatTy(*Context))
1092 One = ConstantExpr::getFPExtend(One, Op->getType());
1094 Module *M = Caller->getParent();
1095 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
1096 Op->getType(), Type::getInt32Ty(*Context),NULL);
1097 CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
1098 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
1099 CI->setCallingConv(F->getCallingConv());
1107 //===---------------------------------------===//
1108 // Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
1110 struct UnaryDoubleFPOpt : public LibCallOptimization {
1111 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1112 const FunctionType *FT = Callee->getFunctionType();
1113 if (FT->getNumParams() != 1 || FT->getReturnType() != Type::getDoubleTy(*Context) ||
1114 FT->getParamType(0) != Type::getDoubleTy(*Context))
1117 // If this is something like 'floor((double)floatval)', convert to floorf.
1118 FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getOperand(1));
1119 if (Cast == 0 || Cast->getOperand(0)->getType() != Type::getFloatTy(*Context))
1122 // floor((double)floatval) -> (double)floorf(floatval)
1123 Value *V = Cast->getOperand(0);
1124 V = EmitUnaryFloatFnCall(V, Callee->getName().data(), B, CI->getAttributes());
1125 return B.CreateFPExt(V, Type::getDoubleTy(*Context));
1129 //===----------------------------------------------------------------------===//
1130 // Integer Optimizations
1131 //===----------------------------------------------------------------------===//
1133 //===---------------------------------------===//
1134 // 'ffs*' Optimizations
1136 struct FFSOpt : public LibCallOptimization {
1137 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1138 const FunctionType *FT = Callee->getFunctionType();
1139 // Just make sure this has 2 arguments of the same FP type, which match the
1141 if (FT->getNumParams() != 1 || FT->getReturnType() != Type::getInt32Ty(*Context) ||
1142 !isa<IntegerType>(FT->getParamType(0)))
1145 Value *Op = CI->getOperand(1);
1148 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
1149 if (CI->getValue() == 0) // ffs(0) -> 0.
1150 return Constant::getNullValue(CI->getType());
1151 return ConstantInt::get(Type::getInt32Ty(*Context), // ffs(c) -> cttz(c)+1
1152 CI->getValue().countTrailingZeros()+1);
1155 // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
1156 const Type *ArgType = Op->getType();
1157 Value *F = Intrinsic::getDeclaration(Callee->getParent(),
1158 Intrinsic::cttz, &ArgType, 1);
1159 Value *V = B.CreateCall(F, Op, "cttz");
1160 V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1), "tmp");
1161 V = B.CreateIntCast(V, Type::getInt32Ty(*Context), false, "tmp");
1163 Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType), "tmp");
1164 return B.CreateSelect(Cond, V, ConstantInt::get(Type::getInt32Ty(*Context), 0));
1168 //===---------------------------------------===//
1169 // 'isdigit' Optimizations
1171 struct IsDigitOpt : public LibCallOptimization {
1172 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1173 const FunctionType *FT = Callee->getFunctionType();
1174 // We require integer(i32)
1175 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1176 FT->getParamType(0) != Type::getInt32Ty(*Context))
1179 // isdigit(c) -> (c-'0') <u 10
1180 Value *Op = CI->getOperand(1);
1181 Op = B.CreateSub(Op, ConstantInt::get(Type::getInt32Ty(*Context), '0'),
1183 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 10),
1185 return B.CreateZExt(Op, CI->getType());
1189 //===---------------------------------------===//
1190 // 'isascii' Optimizations
1192 struct IsAsciiOpt : public LibCallOptimization {
1193 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1194 const FunctionType *FT = Callee->getFunctionType();
1195 // We require integer(i32)
1196 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1197 FT->getParamType(0) != Type::getInt32Ty(*Context))
1200 // isascii(c) -> c <u 128
1201 Value *Op = CI->getOperand(1);
1202 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 128),
1204 return B.CreateZExt(Op, CI->getType());
1208 //===---------------------------------------===//
1209 // 'abs', 'labs', 'llabs' Optimizations
1211 struct AbsOpt : public LibCallOptimization {
1212 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1213 const FunctionType *FT = Callee->getFunctionType();
1214 // We require integer(integer) where the types agree.
1215 if (FT->getNumParams() != 1 || !isa<IntegerType>(FT->getReturnType()) ||
1216 FT->getParamType(0) != FT->getReturnType())
1219 // abs(x) -> x >s -1 ? x : -x
1220 Value *Op = CI->getOperand(1);
1221 Value *Pos = B.CreateICmpSGT(Op,
1222 Constant::getAllOnesValue(Op->getType()),
1224 Value *Neg = B.CreateNeg(Op, "neg");
1225 return B.CreateSelect(Pos, Op, Neg);
1230 //===---------------------------------------===//
1231 // 'toascii' Optimizations
1233 struct ToAsciiOpt : public LibCallOptimization {
1234 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1235 const FunctionType *FT = Callee->getFunctionType();
1236 // We require i32(i32)
1237 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1238 FT->getParamType(0) != Type::getInt32Ty(*Context))
1241 // isascii(c) -> c & 0x7f
1242 return B.CreateAnd(CI->getOperand(1),
1243 ConstantInt::get(CI->getType(),0x7F));
1247 //===----------------------------------------------------------------------===//
1248 // Formatting and IO Optimizations
1249 //===----------------------------------------------------------------------===//
1251 //===---------------------------------------===//
1252 // 'printf' Optimizations
1254 struct PrintFOpt : public LibCallOptimization {
1255 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1256 // Require one fixed pointer argument and an integer/void result.
1257 const FunctionType *FT = Callee->getFunctionType();
1258 if (FT->getNumParams() < 1 || !isa<PointerType>(FT->getParamType(0)) ||
1259 !(isa<IntegerType>(FT->getReturnType()) ||
1260 FT->getReturnType() == Type::getVoidTy(*Context)))
1263 // Check for a fixed format string.
1264 std::string FormatStr;
1265 if (!GetConstantStringInfo(CI->getOperand(1), FormatStr))
1268 // Empty format string -> noop.
1269 if (FormatStr.empty()) // Tolerate printf's declared void.
1270 return CI->use_empty() ? (Value*)CI :
1271 ConstantInt::get(CI->getType(), 0);
1273 // printf("x") -> putchar('x'), even for '%'.
1274 if (FormatStr.size() == 1) {
1275 EmitPutChar(ConstantInt::get(Type::getInt32Ty(*Context), FormatStr[0]), B);
1276 return CI->use_empty() ? (Value*)CI :
1277 ConstantInt::get(CI->getType(), 1);
1280 // printf("foo\n") --> puts("foo")
1281 if (FormatStr[FormatStr.size()-1] == '\n' &&
1282 FormatStr.find('%') == std::string::npos) { // no format characters.
1283 // Create a string literal with no \n on it. We expect the constant merge
1284 // pass to be run after this pass, to merge duplicate strings.
1285 FormatStr.erase(FormatStr.end()-1);
1286 Constant *C = ConstantArray::get(*Context, FormatStr, true);
1287 C = new GlobalVariable(*Callee->getParent(), C->getType(), true,
1288 GlobalVariable::InternalLinkage, C, "str");
1290 return CI->use_empty() ? (Value*)CI :
1291 ConstantInt::get(CI->getType(), FormatStr.size()+1);
1294 // Optimize specific format strings.
1295 // printf("%c", chr) --> putchar(*(i8*)dst)
1296 if (FormatStr == "%c" && CI->getNumOperands() > 2 &&
1297 isa<IntegerType>(CI->getOperand(2)->getType())) {
1298 EmitPutChar(CI->getOperand(2), B);
1299 return CI->use_empty() ? (Value*)CI :
1300 ConstantInt::get(CI->getType(), 1);
1303 // printf("%s\n", str) --> puts(str)
1304 if (FormatStr == "%s\n" && CI->getNumOperands() > 2 &&
1305 isa<PointerType>(CI->getOperand(2)->getType()) &&
1307 EmitPutS(CI->getOperand(2), B);
1314 //===---------------------------------------===//
1315 // 'sprintf' Optimizations
1317 struct SPrintFOpt : public LibCallOptimization {
1318 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1319 // Require two fixed pointer arguments and an integer result.
1320 const FunctionType *FT = Callee->getFunctionType();
1321 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1322 !isa<PointerType>(FT->getParamType(1)) ||
1323 !isa<IntegerType>(FT->getReturnType()))
1326 // Check for a fixed format string.
1327 std::string FormatStr;
1328 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1331 // If we just have a format string (nothing else crazy) transform it.
1332 if (CI->getNumOperands() == 3) {
1333 // Make sure there's no % in the constant array. We could try to handle
1334 // %% -> % in the future if we cared.
1335 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1336 if (FormatStr[i] == '%')
1337 return 0; // we found a format specifier, bail out.
1339 // These optimizations require TargetData.
1342 // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1343 EmitMemCpy(CI->getOperand(1), CI->getOperand(2), // Copy the nul byte.
1344 ConstantInt::get(TD->getIntPtrType(*Context), FormatStr.size()+1),1,B);
1345 return ConstantInt::get(CI->getType(), FormatStr.size());
1348 // The remaining optimizations require the format string to be "%s" or "%c"
1349 // and have an extra operand.
1350 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1353 // Decode the second character of the format string.
1354 if (FormatStr[1] == 'c') {
1355 // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1356 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1357 Value *V = B.CreateTrunc(CI->getOperand(3), Type::getInt8Ty(*Context), "char");
1358 Value *Ptr = CastToCStr(CI->getOperand(1), B);
1359 B.CreateStore(V, Ptr);
1360 Ptr = B.CreateGEP(Ptr, ConstantInt::get(Type::getInt32Ty(*Context), 1), "nul");
1361 B.CreateStore(Constant::getNullValue(Type::getInt8Ty(*Context)), Ptr);
1363 return ConstantInt::get(CI->getType(), 1);
1366 if (FormatStr[1] == 's') {
1367 // These optimizations require TargetData.
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 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 FPutsOpt : public LibCallOptimization {
1425 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1426 // These optimizations require TargetData.
1429 // Require two pointers. Also, we can't optimize if return value is used.
1430 const FunctionType *FT = Callee->getFunctionType();
1431 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1432 !isa<PointerType>(FT->getParamType(1)) ||
1436 // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1437 uint64_t Len = GetStringLength(CI->getOperand(1));
1439 EmitFWrite(CI->getOperand(1),
1440 ConstantInt::get(TD->getIntPtrType(*Context), Len-1),
1441 CI->getOperand(2), B);
1442 return CI; // Known to have no uses (see above).
1446 //===---------------------------------------===//
1447 // 'fprintf' Optimizations
1449 struct FPrintFOpt : public LibCallOptimization {
1450 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1451 // Require two fixed paramters as pointers and integer result.
1452 const FunctionType *FT = Callee->getFunctionType();
1453 if (FT->getNumParams() != 2 || !isa<PointerType>(FT->getParamType(0)) ||
1454 !isa<PointerType>(FT->getParamType(1)) ||
1455 !isa<IntegerType>(FT->getReturnType()))
1458 // All the optimizations depend on the format string.
1459 std::string FormatStr;
1460 if (!GetConstantStringInfo(CI->getOperand(2), FormatStr))
1463 // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1464 if (CI->getNumOperands() == 3) {
1465 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1466 if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1467 return 0; // We found a format specifier.
1469 // These optimizations require TargetData.
1472 EmitFWrite(CI->getOperand(2), ConstantInt::get(TD->getIntPtrType(*Context),
1474 CI->getOperand(1), B);
1475 return ConstantInt::get(CI->getType(), FormatStr.size());
1478 // The remaining optimizations require the format string to be "%s" or "%c"
1479 // and have an extra operand.
1480 if (FormatStr.size() != 2 || FormatStr[0] != '%' || CI->getNumOperands() <4)
1483 // Decode the second character of the format string.
1484 if (FormatStr[1] == 'c') {
1485 // fprintf(F, "%c", chr) --> *(i8*)dst = chr
1486 if (!isa<IntegerType>(CI->getOperand(3)->getType())) return 0;
1487 EmitFPutC(CI->getOperand(3), CI->getOperand(1), B);
1488 return ConstantInt::get(CI->getType(), 1);
1491 if (FormatStr[1] == 's') {
1492 // fprintf(F, "%s", str) -> fputs(str, F)
1493 if (!isa<PointerType>(CI->getOperand(3)->getType()) || !CI->use_empty())
1495 EmitFPutS(CI->getOperand(3), CI->getOperand(1), B);
1502 } // end anonymous namespace.
1504 //===----------------------------------------------------------------------===//
1505 // SimplifyLibCalls Pass Implementation
1506 //===----------------------------------------------------------------------===//
1509 /// This pass optimizes well known library functions from libc and libm.
1511 class SimplifyLibCalls : public FunctionPass {
1512 StringMap<LibCallOptimization*> Optimizations;
1513 // String and Memory LibCall Optimizations
1514 StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
1515 StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
1516 StrToOpt StrTo; MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove;
1518 // Math Library Optimizations
1519 PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
1520 // Integer Optimizations
1521 FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
1523 // Formatting and IO Optimizations
1524 SPrintFOpt SPrintF; PrintFOpt PrintF;
1525 FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
1527 bool Modified; // This is only used by doInitialization.
1529 static char ID; // Pass identification
1530 SimplifyLibCalls() : FunctionPass(&ID) {}
1532 void InitOptimizations();
1533 bool runOnFunction(Function &F);
1535 void setDoesNotAccessMemory(Function &F);
1536 void setOnlyReadsMemory(Function &F);
1537 void setDoesNotThrow(Function &F);
1538 void setDoesNotCapture(Function &F, unsigned n);
1539 void setDoesNotAlias(Function &F, unsigned n);
1540 bool doInitialization(Module &M);
1542 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1545 char SimplifyLibCalls::ID = 0;
1546 } // end anonymous namespace.
1548 static RegisterPass<SimplifyLibCalls>
1549 X("simplify-libcalls", "Simplify well-known library calls");
1551 // Public interface to the Simplify LibCalls pass.
1552 FunctionPass *llvm::createSimplifyLibCallsPass() {
1553 return new SimplifyLibCalls();
1556 /// Optimizations - Populate the Optimizations map with all the optimizations
1558 void SimplifyLibCalls::InitOptimizations() {
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 = getAnalysisIfAvailable<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 LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
1661 // Set the builder to the instruction after the call.
1662 Builder.SetInsertPoint(BB, I);
1664 // Try to optimize this call.
1665 Value *Result = LCO->OptimizeCall(CI, TD, Builder);
1666 if (Result == 0) continue;
1668 DEBUG(errs() << "SimplifyLibCalls simplified: " << *CI;
1669 errs() << " into: " << *Result << "\n");
1671 // Something changed!
1675 // Inspect the instruction after the call (which was potentially just
1679 if (CI != Result && !CI->use_empty()) {
1680 CI->replaceAllUsesWith(Result);
1681 if (!Result->hasName())
1682 Result->takeName(CI);
1684 CI->eraseFromParent();
1690 // Utility methods for doInitialization.
1692 void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
1693 if (!F.doesNotAccessMemory()) {
1694 F.setDoesNotAccessMemory();
1699 void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
1700 if (!F.onlyReadsMemory()) {
1701 F.setOnlyReadsMemory();
1706 void SimplifyLibCalls::setDoesNotThrow(Function &F) {
1707 if (!F.doesNotThrow()) {
1708 F.setDoesNotThrow();
1713 void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
1714 if (!F.doesNotCapture(n)) {
1715 F.setDoesNotCapture(n);
1720 void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
1721 if (!F.doesNotAlias(n)) {
1722 F.setDoesNotAlias(n);
1728 /// doInitialization - Add attributes to well-known functions.
1730 bool SimplifyLibCalls::doInitialization(Module &M) {
1732 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
1734 if (!F.isDeclaration())
1740 const FunctionType *FTy = F.getFunctionType();
1742 StringRef Name = F.getName();
1745 if (Name == "strlen") {
1746 if (FTy->getNumParams() != 1 ||
1747 !isa<PointerType>(FTy->getParamType(0)))
1749 setOnlyReadsMemory(F);
1751 setDoesNotCapture(F, 1);
1752 } else if (Name == "strcpy" ||
1758 Name == "strtoul" ||
1759 Name == "strtoll" ||
1760 Name == "strtold" ||
1761 Name == "strncat" ||
1762 Name == "strncpy" ||
1763 Name == "strtoull") {
1764 if (FTy->getNumParams() < 2 ||
1765 !isa<PointerType>(FTy->getParamType(1)))
1768 setDoesNotCapture(F, 2);
1769 } else if (Name == "strxfrm") {
1770 if (FTy->getNumParams() != 3 ||
1771 !isa<PointerType>(FTy->getParamType(0)) ||
1772 !isa<PointerType>(FTy->getParamType(1)))
1775 setDoesNotCapture(F, 1);
1776 setDoesNotCapture(F, 2);
1777 } else if (Name == "strcmp" ||
1779 Name == "strncmp" ||
1780 Name ==" strcspn" ||
1781 Name == "strcoll" ||
1782 Name == "strcasecmp" ||
1783 Name == "strncasecmp") {
1784 if (FTy->getNumParams() < 2 ||
1785 !isa<PointerType>(FTy->getParamType(0)) ||
1786 !isa<PointerType>(FTy->getParamType(1)))
1788 setOnlyReadsMemory(F);
1790 setDoesNotCapture(F, 1);
1791 setDoesNotCapture(F, 2);
1792 } else if (Name == "strstr" ||
1793 Name == "strpbrk") {
1794 if (FTy->getNumParams() != 2 ||
1795 !isa<PointerType>(FTy->getParamType(1)))
1797 setOnlyReadsMemory(F);
1799 setDoesNotCapture(F, 2);
1800 } else if (Name == "strtok" ||
1801 Name == "strtok_r") {
1802 if (FTy->getNumParams() < 2 ||
1803 !isa<PointerType>(FTy->getParamType(1)))
1806 setDoesNotCapture(F, 2);
1807 } else if (Name == "scanf" ||
1809 Name == "setvbuf") {
1810 if (FTy->getNumParams() < 1 ||
1811 !isa<PointerType>(FTy->getParamType(0)))
1814 setDoesNotCapture(F, 1);
1815 } else if (Name == "strdup" ||
1816 Name == "strndup") {
1817 if (FTy->getNumParams() < 1 ||
1818 !isa<PointerType>(FTy->getReturnType()) ||
1819 !isa<PointerType>(FTy->getParamType(0)))
1822 setDoesNotAlias(F, 0);
1823 setDoesNotCapture(F, 1);
1824 } else if (Name == "stat" ||
1826 Name == "sprintf" ||
1827 Name == "statvfs") {
1828 if (FTy->getNumParams() < 2 ||
1829 !isa<PointerType>(FTy->getParamType(0)) ||
1830 !isa<PointerType>(FTy->getParamType(1)))
1833 setDoesNotCapture(F, 1);
1834 setDoesNotCapture(F, 2);
1835 } else if (Name == "snprintf") {
1836 if (FTy->getNumParams() != 3 ||
1837 !isa<PointerType>(FTy->getParamType(0)) ||
1838 !isa<PointerType>(FTy->getParamType(2)))
1841 setDoesNotCapture(F, 1);
1842 setDoesNotCapture(F, 3);
1843 } else if (Name == "setitimer") {
1844 if (FTy->getNumParams() != 3 ||
1845 !isa<PointerType>(FTy->getParamType(1)) ||
1846 !isa<PointerType>(FTy->getParamType(2)))
1849 setDoesNotCapture(F, 2);
1850 setDoesNotCapture(F, 3);
1851 } else if (Name == "system") {
1852 if (FTy->getNumParams() != 1 ||
1853 !isa<PointerType>(FTy->getParamType(0)))
1855 // May throw; "system" is a valid pthread cancellation point.
1856 setDoesNotCapture(F, 1);
1860 if (Name == "malloc") {
1861 if (FTy->getNumParams() != 1 ||
1862 !isa<PointerType>(FTy->getReturnType()))
1865 setDoesNotAlias(F, 0);
1866 } else if (Name == "memcmp") {
1867 if (FTy->getNumParams() != 3 ||
1868 !isa<PointerType>(FTy->getParamType(0)) ||
1869 !isa<PointerType>(FTy->getParamType(1)))
1871 setOnlyReadsMemory(F);
1873 setDoesNotCapture(F, 1);
1874 setDoesNotCapture(F, 2);
1875 } else if (Name == "memchr" ||
1876 Name == "memrchr") {
1877 if (FTy->getNumParams() != 3)
1879 setOnlyReadsMemory(F);
1881 } else if (Name == "modf" ||
1885 Name == "memccpy" ||
1886 Name == "memmove") {
1887 if (FTy->getNumParams() < 2 ||
1888 !isa<PointerType>(FTy->getParamType(1)))
1891 setDoesNotCapture(F, 2);
1892 } else if (Name == "memalign") {
1893 if (!isa<PointerType>(FTy->getReturnType()))
1895 setDoesNotAlias(F, 0);
1896 } else if (Name == "mkdir" ||
1898 if (FTy->getNumParams() == 0 ||
1899 !isa<PointerType>(FTy->getParamType(0)))
1902 setDoesNotCapture(F, 1);
1906 if (Name == "realloc") {
1907 if (FTy->getNumParams() != 2 ||
1908 !isa<PointerType>(FTy->getParamType(0)) ||
1909 !isa<PointerType>(FTy->getReturnType()))
1912 setDoesNotAlias(F, 0);
1913 setDoesNotCapture(F, 1);
1914 } else if (Name == "read") {
1915 if (FTy->getNumParams() != 3 ||
1916 !isa<PointerType>(FTy->getParamType(1)))
1918 // May throw; "read" is a valid pthread cancellation point.
1919 setDoesNotCapture(F, 2);
1920 } else if (Name == "rmdir" ||
1923 Name == "realpath") {
1924 if (FTy->getNumParams() < 1 ||
1925 !isa<PointerType>(FTy->getParamType(0)))
1928 setDoesNotCapture(F, 1);
1929 } else if (Name == "rename" ||
1930 Name == "readlink") {
1931 if (FTy->getNumParams() < 2 ||
1932 !isa<PointerType>(FTy->getParamType(0)) ||
1933 !isa<PointerType>(FTy->getParamType(1)))
1936 setDoesNotCapture(F, 1);
1937 setDoesNotCapture(F, 2);
1941 if (Name == "write") {
1942 if (FTy->getNumParams() != 3 ||
1943 !isa<PointerType>(FTy->getParamType(1)))
1945 // May throw; "write" is a valid pthread cancellation point.
1946 setDoesNotCapture(F, 2);
1950 if (Name == "bcopy") {
1951 if (FTy->getNumParams() != 3 ||
1952 !isa<PointerType>(FTy->getParamType(0)) ||
1953 !isa<PointerType>(FTy->getParamType(1)))
1956 setDoesNotCapture(F, 1);
1957 setDoesNotCapture(F, 2);
1958 } else if (Name == "bcmp") {
1959 if (FTy->getNumParams() != 3 ||
1960 !isa<PointerType>(FTy->getParamType(0)) ||
1961 !isa<PointerType>(FTy->getParamType(1)))
1964 setOnlyReadsMemory(F);
1965 setDoesNotCapture(F, 1);
1966 setDoesNotCapture(F, 2);
1967 } else if (Name == "bzero") {
1968 if (FTy->getNumParams() != 2 ||
1969 !isa<PointerType>(FTy->getParamType(0)))
1972 setDoesNotCapture(F, 1);
1976 if (Name == "calloc") {
1977 if (FTy->getNumParams() != 2 ||
1978 !isa<PointerType>(FTy->getReturnType()))
1981 setDoesNotAlias(F, 0);
1982 } else if (Name == "chmod" ||
1984 Name == "ctermid" ||
1985 Name == "clearerr" ||
1986 Name == "closedir") {
1987 if (FTy->getNumParams() == 0 ||
1988 !isa<PointerType>(FTy->getParamType(0)))
1991 setDoesNotCapture(F, 1);
1995 if (Name == "atoi" ||
1999 if (FTy->getNumParams() != 1 ||
2000 !isa<PointerType>(FTy->getParamType(0)))
2003 setOnlyReadsMemory(F);
2004 setDoesNotCapture(F, 1);
2005 } else if (Name == "access") {
2006 if (FTy->getNumParams() != 2 ||
2007 !isa<PointerType>(FTy->getParamType(0)))
2010 setDoesNotCapture(F, 1);
2014 if (Name == "fopen") {
2015 if (FTy->getNumParams() != 2 ||
2016 !isa<PointerType>(FTy->getReturnType()) ||
2017 !isa<PointerType>(FTy->getParamType(0)) ||
2018 !isa<PointerType>(FTy->getParamType(1)))
2021 setDoesNotAlias(F, 0);
2022 setDoesNotCapture(F, 1);
2023 setDoesNotCapture(F, 2);
2024 } else if (Name == "fdopen") {
2025 if (FTy->getNumParams() != 2 ||
2026 !isa<PointerType>(FTy->getReturnType()) ||
2027 !isa<PointerType>(FTy->getParamType(1)))
2030 setDoesNotAlias(F, 0);
2031 setDoesNotCapture(F, 2);
2032 } else if (Name == "feof" ||
2042 Name == "fsetpos" ||
2043 Name == "flockfile" ||
2044 Name == "funlockfile" ||
2045 Name == "ftrylockfile") {
2046 if (FTy->getNumParams() == 0 ||
2047 !isa<PointerType>(FTy->getParamType(0)))
2050 setDoesNotCapture(F, 1);
2051 } else if (Name == "ferror") {
2052 if (FTy->getNumParams() != 1 ||
2053 !isa<PointerType>(FTy->getParamType(0)))
2056 setDoesNotCapture(F, 1);
2057 setOnlyReadsMemory(F);
2058 } else if (Name == "fputc" ||
2063 Name == "fstatvfs") {
2064 if (FTy->getNumParams() != 2 ||
2065 !isa<PointerType>(FTy->getParamType(1)))
2068 setDoesNotCapture(F, 2);
2069 } else if (Name == "fgets") {
2070 if (FTy->getNumParams() != 3 ||
2071 !isa<PointerType>(FTy->getParamType(0)) ||
2072 !isa<PointerType>(FTy->getParamType(2)))
2075 setDoesNotCapture(F, 3);
2076 } else if (Name == "fread" ||
2078 if (FTy->getNumParams() != 4 ||
2079 !isa<PointerType>(FTy->getParamType(0)) ||
2080 !isa<PointerType>(FTy->getParamType(3)))
2083 setDoesNotCapture(F, 1);
2084 setDoesNotCapture(F, 4);
2085 } else if (Name == "fputs" ||
2087 Name == "fprintf" ||
2088 Name == "fgetpos") {
2089 if (FTy->getNumParams() < 2 ||
2090 !isa<PointerType>(FTy->getParamType(0)) ||
2091 !isa<PointerType>(FTy->getParamType(1)))
2094 setDoesNotCapture(F, 1);
2095 setDoesNotCapture(F, 2);
2099 if (Name == "getc" ||
2100 Name == "getlogin_r" ||
2101 Name == "getc_unlocked") {
2102 if (FTy->getNumParams() == 0 ||
2103 !isa<PointerType>(FTy->getParamType(0)))
2106 setDoesNotCapture(F, 1);
2107 } else if (Name == "getenv") {
2108 if (FTy->getNumParams() != 1 ||
2109 !isa<PointerType>(FTy->getParamType(0)))
2112 setOnlyReadsMemory(F);
2113 setDoesNotCapture(F, 1);
2114 } else if (Name == "gets" ||
2115 Name == "getchar") {
2117 } else if (Name == "getitimer") {
2118 if (FTy->getNumParams() != 2 ||
2119 !isa<PointerType>(FTy->getParamType(1)))
2122 setDoesNotCapture(F, 2);
2123 } else if (Name == "getpwnam") {
2124 if (FTy->getNumParams() != 1 ||
2125 !isa<PointerType>(FTy->getParamType(0)))
2128 setDoesNotCapture(F, 1);
2132 if (Name == "ungetc") {
2133 if (FTy->getNumParams() != 2 ||
2134 !isa<PointerType>(FTy->getParamType(1)))
2137 setDoesNotCapture(F, 2);
2138 } else if (Name == "uname" ||
2140 Name == "unsetenv") {
2141 if (FTy->getNumParams() != 1 ||
2142 !isa<PointerType>(FTy->getParamType(0)))
2145 setDoesNotCapture(F, 1);
2146 } else if (Name == "utime" ||
2148 if (FTy->getNumParams() != 2 ||
2149 !isa<PointerType>(FTy->getParamType(0)) ||
2150 !isa<PointerType>(FTy->getParamType(1)))
2153 setDoesNotCapture(F, 1);
2154 setDoesNotCapture(F, 2);
2158 if (Name == "putc") {
2159 if (FTy->getNumParams() != 2 ||
2160 !isa<PointerType>(FTy->getParamType(1)))
2163 setDoesNotCapture(F, 2);
2164 } else if (Name == "puts" ||
2167 if (FTy->getNumParams() != 1 ||
2168 !isa<PointerType>(FTy->getParamType(0)))
2171 setDoesNotCapture(F, 1);
2172 } else if (Name == "pread" ||
2174 if (FTy->getNumParams() != 4 ||
2175 !isa<PointerType>(FTy->getParamType(1)))
2177 // May throw; these are valid pthread cancellation points.
2178 setDoesNotCapture(F, 2);
2179 } else if (Name == "putchar") {
2181 } else if (Name == "popen") {
2182 if (FTy->getNumParams() != 2 ||
2183 !isa<PointerType>(FTy->getReturnType()) ||
2184 !isa<PointerType>(FTy->getParamType(0)) ||
2185 !isa<PointerType>(FTy->getParamType(1)))
2188 setDoesNotAlias(F, 0);
2189 setDoesNotCapture(F, 1);
2190 setDoesNotCapture(F, 2);
2191 } else if (Name == "pclose") {
2192 if (FTy->getNumParams() != 1 ||
2193 !isa<PointerType>(FTy->getParamType(0)))
2196 setDoesNotCapture(F, 1);
2200 if (Name == "vscanf") {
2201 if (FTy->getNumParams() != 2 ||
2202 !isa<PointerType>(FTy->getParamType(1)))
2205 setDoesNotCapture(F, 1);
2206 } else if (Name == "vsscanf" ||
2207 Name == "vfscanf") {
2208 if (FTy->getNumParams() != 3 ||
2209 !isa<PointerType>(FTy->getParamType(1)) ||
2210 !isa<PointerType>(FTy->getParamType(2)))
2213 setDoesNotCapture(F, 1);
2214 setDoesNotCapture(F, 2);
2215 } else if (Name == "valloc") {
2216 if (!isa<PointerType>(FTy->getReturnType()))
2219 setDoesNotAlias(F, 0);
2220 } else if (Name == "vprintf") {
2221 if (FTy->getNumParams() != 2 ||
2222 !isa<PointerType>(FTy->getParamType(0)))
2225 setDoesNotCapture(F, 1);
2226 } else if (Name == "vfprintf" ||
2227 Name == "vsprintf") {
2228 if (FTy->getNumParams() != 3 ||
2229 !isa<PointerType>(FTy->getParamType(0)) ||
2230 !isa<PointerType>(FTy->getParamType(1)))
2233 setDoesNotCapture(F, 1);
2234 setDoesNotCapture(F, 2);
2235 } else if (Name == "vsnprintf") {
2236 if (FTy->getNumParams() != 4 ||
2237 !isa<PointerType>(FTy->getParamType(0)) ||
2238 !isa<PointerType>(FTy->getParamType(2)))
2241 setDoesNotCapture(F, 1);
2242 setDoesNotCapture(F, 3);
2246 if (Name == "open") {
2247 if (FTy->getNumParams() < 2 ||
2248 !isa<PointerType>(FTy->getParamType(0)))
2250 // May throw; "open" is a valid pthread cancellation point.
2251 setDoesNotCapture(F, 1);
2252 } else if (Name == "opendir") {
2253 if (FTy->getNumParams() != 1 ||
2254 !isa<PointerType>(FTy->getReturnType()) ||
2255 !isa<PointerType>(FTy->getParamType(0)))
2258 setDoesNotAlias(F, 0);
2259 setDoesNotCapture(F, 1);
2263 if (Name == "tmpfile") {
2264 if (!isa<PointerType>(FTy->getReturnType()))
2267 setDoesNotAlias(F, 0);
2268 } else if (Name == "times") {
2269 if (FTy->getNumParams() != 1 ||
2270 !isa<PointerType>(FTy->getParamType(0)))
2273 setDoesNotCapture(F, 1);
2277 if (Name == "htonl" ||
2280 setDoesNotAccessMemory(F);
2284 if (Name == "ntohl" ||
2287 setDoesNotAccessMemory(F);
2291 if (Name == "lstat") {
2292 if (FTy->getNumParams() != 2 ||
2293 !isa<PointerType>(FTy->getParamType(0)) ||
2294 !isa<PointerType>(FTy->getParamType(1)))
2297 setDoesNotCapture(F, 1);
2298 setDoesNotCapture(F, 2);
2299 } else if (Name == "lchown") {
2300 if (FTy->getNumParams() != 3 ||
2301 !isa<PointerType>(FTy->getParamType(0)))
2304 setDoesNotCapture(F, 1);
2308 if (Name == "qsort") {
2309 if (FTy->getNumParams() != 4 ||
2310 !isa<PointerType>(FTy->getParamType(3)))
2312 // May throw; places call through function pointer.
2313 setDoesNotCapture(F, 4);
2317 if (Name == "__strdup" ||
2318 Name == "__strndup") {
2319 if (FTy->getNumParams() < 1 ||
2320 !isa<PointerType>(FTy->getReturnType()) ||
2321 !isa<PointerType>(FTy->getParamType(0)))
2324 setDoesNotAlias(F, 0);
2325 setDoesNotCapture(F, 1);
2326 } else if (Name == "__strtok_r") {
2327 if (FTy->getNumParams() != 3 ||
2328 !isa<PointerType>(FTy->getParamType(1)))
2331 setDoesNotCapture(F, 2);
2332 } else if (Name == "_IO_getc") {
2333 if (FTy->getNumParams() != 1 ||
2334 !isa<PointerType>(FTy->getParamType(0)))
2337 setDoesNotCapture(F, 1);
2338 } else if (Name == "_IO_putc") {
2339 if (FTy->getNumParams() != 2 ||
2340 !isa<PointerType>(FTy->getParamType(1)))
2343 setDoesNotCapture(F, 2);
2347 if (Name == "\1__isoc99_scanf") {
2348 if (FTy->getNumParams() < 1 ||
2349 !isa<PointerType>(FTy->getParamType(0)))
2352 setDoesNotCapture(F, 1);
2353 } else if (Name == "\1stat64" ||
2354 Name == "\1lstat64" ||
2355 Name == "\1statvfs64" ||
2356 Name == "\1__isoc99_sscanf") {
2357 if (FTy->getNumParams() < 1 ||
2358 !isa<PointerType>(FTy->getParamType(0)) ||
2359 !isa<PointerType>(FTy->getParamType(1)))
2362 setDoesNotCapture(F, 1);
2363 setDoesNotCapture(F, 2);
2364 } else if (Name == "\1fopen64") {
2365 if (FTy->getNumParams() != 2 ||
2366 !isa<PointerType>(FTy->getReturnType()) ||
2367 !isa<PointerType>(FTy->getParamType(0)) ||
2368 !isa<PointerType>(FTy->getParamType(1)))
2371 setDoesNotAlias(F, 0);
2372 setDoesNotCapture(F, 1);
2373 setDoesNotCapture(F, 2);
2374 } else if (Name == "\1fseeko64" ||
2375 Name == "\1ftello64") {
2376 if (FTy->getNumParams() == 0 ||
2377 !isa<PointerType>(FTy->getParamType(0)))
2380 setDoesNotCapture(F, 1);
2381 } else if (Name == "\1tmpfile64") {
2382 if (!isa<PointerType>(FTy->getReturnType()))
2385 setDoesNotAlias(F, 0);
2386 } else if (Name == "\1fstat64" ||
2387 Name == "\1fstatvfs64") {
2388 if (FTy->getNumParams() != 2 ||
2389 !isa<PointerType>(FTy->getParamType(1)))
2392 setDoesNotCapture(F, 2);
2393 } else if (Name == "\1open64") {
2394 if (FTy->getNumParams() < 2 ||
2395 !isa<PointerType>(FTy->getParamType(0)))
2397 // May throw; "open" is a valid pthread cancellation point.
2398 setDoesNotCapture(F, 1);
2407 // Additional cases that we need to add to this file:
2410 // * cbrt(expN(X)) -> expN(x/3)
2411 // * cbrt(sqrt(x)) -> pow(x,1/6)
2412 // * cbrt(sqrt(x)) -> pow(x,1/9)
2415 // * cos(-x) -> cos(x)
2418 // * exp(log(x)) -> x
2421 // * log(exp(x)) -> x
2422 // * log(x**y) -> y*log(x)
2423 // * log(exp(y)) -> y*log(e)
2424 // * log(exp2(y)) -> y*log(2)
2425 // * log(exp10(y)) -> y*log(10)
2426 // * log(sqrt(x)) -> 0.5*log(x)
2427 // * log(pow(x,y)) -> y*log(x)
2429 // lround, lroundf, lroundl:
2430 // * lround(cnst) -> cnst'
2433 // * memcmp(x,y,l) -> cnst
2434 // (if all arguments are constant and strlen(x) <= l and strlen(y) <= l)
2437 // * pow(exp(x),y) -> exp(x*y)
2438 // * pow(sqrt(x),y) -> pow(x,y*0.5)
2439 // * pow(pow(x,y),z)-> pow(x,y*z)
2442 // * puts("") -> putchar("\n")
2444 // round, roundf, roundl:
2445 // * round(cnst) -> cnst'
2448 // * signbit(cnst) -> cnst'
2449 // * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2451 // sqrt, sqrtf, sqrtl:
2452 // * sqrt(expN(x)) -> expN(x*0.5)
2453 // * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2454 // * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2457 // * stpcpy(str, "literal") ->
2458 // llvm.memcpy(str,"literal",strlen("literal")+1,1)
2460 // * strrchr(s,c) -> reverse_offset_of_in(c,s)
2461 // (if c is a constant integer and s is a constant string)
2462 // * strrchr(s1,0) -> strchr(s1,0)
2465 // * strpbrk(s,a) -> offset_in_for(s,a)
2466 // (if s and a are both constant strings)
2467 // * strpbrk(s,"") -> 0
2468 // * strpbrk(s,a) -> strchr(s,a[0]) (if a is constant string of length 1)
2471 // * strspn(s,a) -> const_int (if both args are constant)
2472 // * strspn("",a) -> 0
2473 // * strspn(s,"") -> 0
2474 // * strcspn(s,a) -> const_int (if both args are constant)
2475 // * strcspn("",a) -> 0
2476 // * strcspn(s,"") -> strlen(a)
2479 // * strstr(x,x) -> x
2480 // * strstr(s1,s2) -> offset_of_s2_in(s1)
2481 // (if s1 and s2 are constant strings)
2484 // * tan(atan(x)) -> x
2486 // trunc, truncf, truncl:
2487 // * trunc(cnst) -> cnst'