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/Transforms/Utils/BuildLibCalls.h"
21 #include "llvm/Intrinsics.h"
22 #include "llvm/LLVMContext.h"
23 #include "llvm/Module.h"
24 #include "llvm/Pass.h"
25 #include "llvm/Support/IRBuilder.h"
26 #include "llvm/Analysis/ValueTracking.h"
27 #include "llvm/Target/TargetData.h"
28 #include "llvm/ADT/SmallPtrSet.h"
29 #include "llvm/ADT/StringMap.h"
30 #include "llvm/ADT/Statistic.h"
31 #include "llvm/ADT/STLExtras.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/Config/config.h"
37 STATISTIC(NumSimplified, "Number of library calls simplified");
38 STATISTIC(NumAnnotated, "Number of attributes added to library functions");
40 //===----------------------------------------------------------------------===//
41 // Optimizer Base Class
42 //===----------------------------------------------------------------------===//
44 /// This class is the abstract base class for the set of optimizations that
45 /// corresponds to one library call.
47 class LibCallOptimization {
53 LibCallOptimization() { }
54 virtual ~LibCallOptimization() {}
56 /// CallOptimizer - This pure virtual method is implemented by base classes to
57 /// do various optimizations. If this returns null then no transformation was
58 /// performed. If it returns CI, then it transformed the call and CI is to be
59 /// deleted. If it returns something else, replace CI with the new value and
61 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B)
64 Value *OptimizeCall(CallInst *CI, const TargetData *TD, IRBuilder<> &B) {
65 Caller = CI->getParent()->getParent();
67 if (CI->getCalledFunction())
68 Context = &CI->getCalledFunction()->getContext();
70 // We never change the calling convention.
71 if (CI->getCallingConv() != llvm::CallingConv::C)
74 return CallOptimizer(CI->getCalledFunction(), CI, B);
77 } // End anonymous namespace.
80 //===----------------------------------------------------------------------===//
82 //===----------------------------------------------------------------------===//
84 /// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
85 /// value is equal or not-equal to zero.
86 static bool IsOnlyUsedInZeroEqualityComparison(Value *V) {
87 for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
89 if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
91 if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
94 // Unknown instruction.
100 /// IsOnlyUsedInEqualityComparison - Return true if it is only used in equality
101 /// comparisons with With.
102 static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) {
103 for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
105 if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
106 if (IC->isEquality() && IC->getOperand(1) == With)
108 // Unknown instruction.
114 //===----------------------------------------------------------------------===//
115 // String and Memory LibCall Optimizations
116 //===----------------------------------------------------------------------===//
118 //===---------------------------------------===//
119 // 'strcat' Optimizations
121 struct StrCatOpt : public LibCallOptimization {
122 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
123 // Verify the "strcat" function prototype.
124 const FunctionType *FT = Callee->getFunctionType();
125 if (FT->getNumParams() != 2 ||
126 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
127 FT->getParamType(0) != FT->getReturnType() ||
128 FT->getParamType(1) != FT->getReturnType())
131 // Extract some information from the instruction
132 Value *Dst = CI->getArgOperand(0);
133 Value *Src = CI->getArgOperand(1);
135 // See if we can get the length of the input string.
136 uint64_t Len = GetStringLength(Src);
137 if (Len == 0) return 0;
138 --Len; // Unbias length.
140 // Handle the simple, do-nothing case: strcat(x, "") -> x
144 // These optimizations require TargetData.
147 EmitStrLenMemCpy(Src, Dst, Len, B);
151 void EmitStrLenMemCpy(Value *Src, Value *Dst, uint64_t Len, IRBuilder<> &B) {
152 // We need to find the end of the destination string. That's where the
153 // memory is to be moved to. We just generate a call to strlen.
154 Value *DstLen = EmitStrLen(Dst, B, TD);
156 // Now that we have the destination's length, we must index into the
157 // destination's pointer to get the actual memcpy destination (end of
158 // the string .. we're concatenating).
159 Value *CpyDst = B.CreateGEP(Dst, DstLen, "endptr");
161 // We have enough information to now generate the memcpy call to do the
162 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
163 EmitMemCpy(CpyDst, Src,
164 ConstantInt::get(TD->getIntPtrType(*Context), Len+1),
169 //===---------------------------------------===//
170 // 'strncat' Optimizations
172 struct StrNCatOpt : public StrCatOpt {
173 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
174 // Verify the "strncat" function prototype.
175 const FunctionType *FT = Callee->getFunctionType();
176 if (FT->getNumParams() != 3 ||
177 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
178 FT->getParamType(0) != FT->getReturnType() ||
179 FT->getParamType(1) != FT->getReturnType() ||
180 !FT->getParamType(2)->isIntegerTy())
183 // Extract some information from the instruction
184 Value *Dst = CI->getArgOperand(0);
185 Value *Src = CI->getArgOperand(1);
188 // We don't do anything if length is not constant
189 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
190 Len = LengthArg->getZExtValue();
194 // See if we can get the length of the input string.
195 uint64_t SrcLen = GetStringLength(Src);
196 if (SrcLen == 0) return 0;
197 --SrcLen; // Unbias length.
199 // Handle the simple, do-nothing cases:
200 // strncat(x, "", c) -> x
201 // strncat(x, c, 0) -> x
202 if (SrcLen == 0 || Len == 0) return Dst;
204 // These optimizations require TargetData.
207 // We don't optimize this case
208 if (Len < SrcLen) return 0;
210 // strncat(x, s, c) -> strcat(x, s)
211 // s is constant so the strcat can be optimized further
212 EmitStrLenMemCpy(Src, Dst, SrcLen, B);
217 //===---------------------------------------===//
218 // 'strchr' Optimizations
220 struct StrChrOpt : public LibCallOptimization {
221 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
222 // Verify the "strchr" function prototype.
223 const FunctionType *FT = Callee->getFunctionType();
224 if (FT->getNumParams() != 2 ||
225 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
226 FT->getParamType(0) != FT->getReturnType() ||
227 !FT->getParamType(1)->isIntegerTy(32))
230 Value *SrcStr = CI->getArgOperand(0);
232 // If the second operand is non-constant, see if we can compute the length
233 // of the input string and turn this into memchr.
234 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
236 // These optimizations require TargetData.
239 uint64_t Len = GetStringLength(SrcStr);
240 if (Len == 0 || !FT->getParamType(1)->isIntegerTy(32))// memchr needs i32.
243 return EmitMemChr(SrcStr, CI->getArgOperand(1), // include nul.
244 ConstantInt::get(TD->getIntPtrType(*Context), Len),
248 // Otherwise, the character is a constant, see if the first argument is
249 // a string literal. If so, we can constant fold.
251 if (!GetConstantStringInfo(SrcStr, Str))
254 // strchr can find the nul character.
257 // Compute the offset.
258 size_t I = Str.find(CharC->getSExtValue());
259 if (I == std::string::npos) // Didn't find the char. strchr returns null.
260 return Constant::getNullValue(CI->getType());
262 // strchr(s+n,c) -> gep(s+n+i,c)
263 Value *Idx = ConstantInt::get(Type::getInt64Ty(*Context), I);
264 return B.CreateGEP(SrcStr, Idx, "strchr");
268 //===---------------------------------------===//
269 // 'strrchr' Optimizations
271 struct StrRChrOpt : public LibCallOptimization {
272 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
273 // Verify the "strrchr" function prototype.
274 const FunctionType *FT = Callee->getFunctionType();
275 if (FT->getNumParams() != 2 ||
276 FT->getReturnType() != Type::getInt8PtrTy(*Context) ||
277 FT->getParamType(0) != FT->getReturnType() ||
278 !FT->getParamType(1)->isIntegerTy(32))
281 Value *SrcStr = CI->getArgOperand(0);
282 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
284 // Cannot fold anything if we're not looking for a constant.
289 if (!GetConstantStringInfo(SrcStr, Str)) {
290 // strrchr(s, 0) -> strchr(s, 0)
291 if (TD && CharC->isZero())
292 return EmitStrChr(SrcStr, '\0', B, TD);
296 // strrchr can find the nul character.
299 // Compute the offset.
300 size_t I = Str.rfind(CharC->getSExtValue());
301 if (I == std::string::npos) // Didn't find the char. Return null.
302 return Constant::getNullValue(CI->getType());
304 // strrchr(s+n,c) -> gep(s+n+i,c)
305 Value *Idx = ConstantInt::get(Type::getInt64Ty(*Context), I);
306 return B.CreateGEP(SrcStr, Idx, "strrchr");
310 //===---------------------------------------===//
311 // 'strcmp' Optimizations
313 struct StrCmpOpt : public LibCallOptimization {
314 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
315 // Verify the "strcmp" function prototype.
316 const FunctionType *FT = Callee->getFunctionType();
317 if (FT->getNumParams() != 2 ||
318 !FT->getReturnType()->isIntegerTy(32) ||
319 FT->getParamType(0) != FT->getParamType(1) ||
320 FT->getParamType(0) != Type::getInt8PtrTy(*Context))
323 Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
324 if (Str1P == Str2P) // strcmp(x,x) -> 0
325 return ConstantInt::get(CI->getType(), 0);
327 std::string Str1, Str2;
328 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
329 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
331 if (HasStr1 && Str1.empty()) // strcmp("", x) -> *x
332 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
334 if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
335 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
337 // strcmp(x, y) -> cnst (if both x and y are constant strings)
338 if (HasStr1 && HasStr2)
339 return ConstantInt::get(CI->getType(),
340 strcmp(Str1.c_str(),Str2.c_str()));
342 // strcmp(P, "x") -> memcmp(P, "x", 2)
343 uint64_t Len1 = GetStringLength(Str1P);
344 uint64_t Len2 = GetStringLength(Str2P);
346 // These optimizations require TargetData.
349 return EmitMemCmp(Str1P, Str2P,
350 ConstantInt::get(TD->getIntPtrType(*Context),
351 std::min(Len1, Len2)), B, TD);
358 //===---------------------------------------===//
359 // 'strncmp' Optimizations
361 struct StrNCmpOpt : public LibCallOptimization {
362 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
363 // Verify the "strncmp" function prototype.
364 const FunctionType *FT = Callee->getFunctionType();
365 if (FT->getNumParams() != 3 ||
366 !FT->getReturnType()->isIntegerTy(32) ||
367 FT->getParamType(0) != FT->getParamType(1) ||
368 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
369 !FT->getParamType(2)->isIntegerTy())
372 Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
373 if (Str1P == Str2P) // strncmp(x,x,n) -> 0
374 return ConstantInt::get(CI->getType(), 0);
376 // Get the length argument if it is constant.
378 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
379 Length = LengthArg->getZExtValue();
383 if (Length == 0) // strncmp(x,y,0) -> 0
384 return ConstantInt::get(CI->getType(), 0);
386 if (TD && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
387 return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, TD);
389 std::string Str1, Str2;
390 bool HasStr1 = GetConstantStringInfo(Str1P, Str1);
391 bool HasStr2 = GetConstantStringInfo(Str2P, Str2);
393 if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> *x
394 return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType());
396 if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x
397 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
399 // strncmp(x, y) -> cnst (if both x and y are constant strings)
400 if (HasStr1 && HasStr2)
401 return ConstantInt::get(CI->getType(),
402 strncmp(Str1.c_str(), Str2.c_str(), Length));
408 //===---------------------------------------===//
409 // 'strcpy' Optimizations
411 struct StrCpyOpt : public LibCallOptimization {
412 bool OptChkCall; // True if it's optimizing a __strcpy_chk libcall.
414 StrCpyOpt(bool c) : OptChkCall(c) {}
416 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
417 // Verify the "strcpy" function prototype.
418 unsigned NumParams = OptChkCall ? 3 : 2;
419 const FunctionType *FT = Callee->getFunctionType();
420 if (FT->getNumParams() != NumParams ||
421 FT->getReturnType() != FT->getParamType(0) ||
422 FT->getParamType(0) != FT->getParamType(1) ||
423 FT->getParamType(0) != Type::getInt8PtrTy(*Context))
426 Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
427 if (Dst == Src) // strcpy(x,x) -> x
430 // These optimizations require TargetData.
433 // See if we can get the length of the input string.
434 uint64_t Len = GetStringLength(Src);
435 if (Len == 0) return 0;
437 // We have enough information to now generate the memcpy call to do the
438 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
440 EmitMemCpyChk(Dst, Src,
441 ConstantInt::get(TD->getIntPtrType(*Context), Len),
442 CI->getArgOperand(2), B, TD);
445 ConstantInt::get(TD->getIntPtrType(*Context), Len),
451 //===---------------------------------------===//
452 // 'strncpy' Optimizations
454 struct StrNCpyOpt : public LibCallOptimization {
455 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
456 const FunctionType *FT = Callee->getFunctionType();
457 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
458 FT->getParamType(0) != FT->getParamType(1) ||
459 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
460 !FT->getParamType(2)->isIntegerTy())
463 Value *Dst = CI->getArgOperand(0);
464 Value *Src = CI->getArgOperand(1);
465 Value *LenOp = CI->getArgOperand(2);
467 // See if we can get the length of the input string.
468 uint64_t SrcLen = GetStringLength(Src);
469 if (SrcLen == 0) return 0;
473 // strncpy(x, "", y) -> memset(x, '\0', y, 1)
474 EmitMemSet(Dst, ConstantInt::get(Type::getInt8Ty(*Context), '\0'),
475 LenOp, false, B, TD);
480 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
481 Len = LengthArg->getZExtValue();
485 if (Len == 0) return Dst; // strncpy(x, y, 0) -> x
487 // These optimizations require TargetData.
490 // Let strncpy handle the zero padding
491 if (Len > SrcLen+1) return 0;
493 // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
495 ConstantInt::get(TD->getIntPtrType(*Context), Len),
502 //===---------------------------------------===//
503 // 'strlen' Optimizations
505 struct StrLenOpt : public LibCallOptimization {
506 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
507 const FunctionType *FT = Callee->getFunctionType();
508 if (FT->getNumParams() != 1 ||
509 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
510 !FT->getReturnType()->isIntegerTy())
513 Value *Src = CI->getArgOperand(0);
515 // Constant folding: strlen("xyz") -> 3
516 if (uint64_t Len = GetStringLength(Src))
517 return ConstantInt::get(CI->getType(), Len-1);
519 // strlen(x) != 0 --> *x != 0
520 // strlen(x) == 0 --> *x == 0
521 if (IsOnlyUsedInZeroEqualityComparison(CI))
522 return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
528 //===---------------------------------------===//
529 // 'strpbrk' Optimizations
531 struct StrPBrkOpt : public LibCallOptimization {
532 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
533 const FunctionType *FT = Callee->getFunctionType();
534 if (FT->getNumParams() != 2 ||
535 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
536 FT->getParamType(1) != FT->getParamType(0) ||
537 FT->getReturnType() != FT->getParamType(0))
541 bool HasS1 = GetConstantStringInfo(CI->getArgOperand(0), S1);
542 bool HasS2 = GetConstantStringInfo(CI->getArgOperand(1), S2);
544 // strpbrk(s, "") -> NULL
545 // strpbrk("", s) -> NULL
546 if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
547 return Constant::getNullValue(CI->getType());
550 if (HasS1 && HasS2) {
551 size_t I = S1.find_first_of(S2);
552 if (I == std::string::npos) // No match.
553 return Constant::getNullValue(CI->getType());
555 Value *Idx = ConstantInt::get(Type::getInt64Ty(*Context), I);
556 return B.CreateGEP(CI->getArgOperand(0), Idx, "strpbrk");
559 // strpbrk(s, "a") -> strchr(s, 'a')
560 if (TD && HasS2 && S2.size() == 1)
561 return EmitStrChr(CI->getArgOperand(0), S2[0], B, TD);
567 //===---------------------------------------===//
568 // 'strto*' Optimizations. This handles strtol, strtod, strtof, strtoul, etc.
570 struct StrToOpt : public LibCallOptimization {
571 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
572 const FunctionType *FT = Callee->getFunctionType();
573 if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
574 !FT->getParamType(0)->isPointerTy() ||
575 !FT->getParamType(1)->isPointerTy())
578 Value *EndPtr = CI->getArgOperand(1);
579 if (isa<ConstantPointerNull>(EndPtr)) {
580 CI->setOnlyReadsMemory();
581 CI->addAttribute(1, Attribute::NoCapture);
588 //===---------------------------------------===//
589 // 'strspn' Optimizations
591 struct StrSpnOpt : public LibCallOptimization {
592 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
593 const FunctionType *FT = Callee->getFunctionType();
594 if (FT->getNumParams() != 2 ||
595 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
596 FT->getParamType(1) != FT->getParamType(0) ||
597 !FT->getReturnType()->isIntegerTy())
601 bool HasS1 = GetConstantStringInfo(CI->getArgOperand(0), S1);
602 bool HasS2 = GetConstantStringInfo(CI->getArgOperand(1), S2);
604 // strspn(s, "") -> 0
605 // strspn("", s) -> 0
606 if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
607 return Constant::getNullValue(CI->getType());
611 return ConstantInt::get(CI->getType(), strspn(S1.c_str(), S2.c_str()));
617 //===---------------------------------------===//
618 // 'strcspn' Optimizations
620 struct StrCSpnOpt : public LibCallOptimization {
621 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
622 const FunctionType *FT = Callee->getFunctionType();
623 if (FT->getNumParams() != 2 ||
624 FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
625 FT->getParamType(1) != FT->getParamType(0) ||
626 !FT->getReturnType()->isIntegerTy())
630 bool HasS1 = GetConstantStringInfo(CI->getArgOperand(0), S1);
631 bool HasS2 = GetConstantStringInfo(CI->getArgOperand(1), S2);
633 // strcspn("", s) -> 0
634 if (HasS1 && S1.empty())
635 return Constant::getNullValue(CI->getType());
639 return ConstantInt::get(CI->getType(), strcspn(S1.c_str(), S2.c_str()));
641 // strcspn(s, "") -> strlen(s)
642 if (TD && HasS2 && S2.empty())
643 return EmitStrLen(CI->getArgOperand(0), B, TD);
649 //===---------------------------------------===//
650 // 'strstr' Optimizations
652 struct StrStrOpt : public LibCallOptimization {
653 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
654 const FunctionType *FT = Callee->getFunctionType();
655 if (FT->getNumParams() != 2 ||
656 !FT->getParamType(0)->isPointerTy() ||
657 !FT->getParamType(1)->isPointerTy() ||
658 !FT->getReturnType()->isPointerTy())
661 // fold strstr(x, x) -> x.
662 if (CI->getArgOperand(0) == CI->getArgOperand(1))
663 return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
665 // fold strstr(a, b) == a -> strncmp(a, b, strlen(b)) == 0
666 if (TD && IsOnlyUsedInEqualityComparison(CI, CI->getArgOperand(0))) {
667 Value *StrLen = EmitStrLen(CI->getArgOperand(1), B, TD);
668 Value *StrNCmp = EmitStrNCmp(CI->getArgOperand(0), CI->getArgOperand(1),
670 for (Value::use_iterator UI = CI->use_begin(), UE = CI->use_end();
672 ICmpInst *Old = cast<ICmpInst>(*UI++);
673 Value *Cmp = B.CreateICmp(Old->getPredicate(), StrNCmp,
674 ConstantInt::getNullValue(StrNCmp->getType()),
676 Old->replaceAllUsesWith(Cmp);
677 Old->eraseFromParent();
682 // See if either input string is a constant string.
683 std::string SearchStr, ToFindStr;
684 bool HasStr1 = GetConstantStringInfo(CI->getArgOperand(0), SearchStr);
685 bool HasStr2 = GetConstantStringInfo(CI->getArgOperand(1), ToFindStr);
687 // fold strstr(x, "") -> x.
688 if (HasStr2 && ToFindStr.empty())
689 return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
691 // If both strings are known, constant fold it.
692 if (HasStr1 && HasStr2) {
693 std::string::size_type Offset = SearchStr.find(ToFindStr);
695 if (Offset == std::string::npos) // strstr("foo", "bar") -> null
696 return Constant::getNullValue(CI->getType());
698 // strstr("abcd", "bc") -> gep((char*)"abcd", 1)
699 Value *Result = CastToCStr(CI->getArgOperand(0), B);
700 Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
701 return B.CreateBitCast(Result, CI->getType());
704 // fold strstr(x, "y") -> strchr(x, 'y').
705 if (HasStr2 && ToFindStr.size() == 1)
706 return B.CreateBitCast(EmitStrChr(CI->getArgOperand(0),
707 ToFindStr[0], B, TD), CI->getType());
713 //===---------------------------------------===//
714 // 'memcmp' Optimizations
716 struct MemCmpOpt : public LibCallOptimization {
717 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
718 const FunctionType *FT = Callee->getFunctionType();
719 if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() ||
720 !FT->getParamType(1)->isPointerTy() ||
721 !FT->getReturnType()->isIntegerTy(32))
724 Value *LHS = CI->getArgOperand(0), *RHS = CI->getArgOperand(1);
726 if (LHS == RHS) // memcmp(s,s,x) -> 0
727 return Constant::getNullValue(CI->getType());
729 // Make sure we have a constant length.
730 ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
732 uint64_t Len = LenC->getZExtValue();
734 if (Len == 0) // memcmp(s1,s2,0) -> 0
735 return Constant::getNullValue(CI->getType());
737 // memcmp(S1,S2,1) -> *(unsigned char*)LHS - *(unsigned char*)RHS
739 Value *LHSV = B.CreateZExt(B.CreateLoad(CastToCStr(LHS, B), "lhsc"),
740 CI->getType(), "lhsv");
741 Value *RHSV = B.CreateZExt(B.CreateLoad(CastToCStr(RHS, B), "rhsc"),
742 CI->getType(), "rhsv");
743 return B.CreateSub(LHSV, RHSV, "chardiff");
746 // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
747 std::string LHSStr, RHSStr;
748 if (GetConstantStringInfo(LHS, LHSStr) &&
749 GetConstantStringInfo(RHS, RHSStr)) {
750 // Make sure we're not reading out-of-bounds memory.
751 if (Len > LHSStr.length() || Len > RHSStr.length())
753 uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len);
754 return ConstantInt::get(CI->getType(), Ret);
761 //===---------------------------------------===//
762 // 'memcpy' Optimizations
764 struct MemCpyOpt : public LibCallOptimization {
765 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
766 // These optimizations require TargetData.
769 const FunctionType *FT = Callee->getFunctionType();
770 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
771 !FT->getParamType(0)->isPointerTy() ||
772 !FT->getParamType(1)->isPointerTy() ||
773 FT->getParamType(2) != TD->getIntPtrType(*Context))
776 // memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
777 EmitMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
778 CI->getArgOperand(2), 1, false, B, TD);
779 return CI->getArgOperand(0);
783 //===---------------------------------------===//
784 // 'memmove' Optimizations
786 struct MemMoveOpt : public LibCallOptimization {
787 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
788 // These optimizations require TargetData.
791 const FunctionType *FT = Callee->getFunctionType();
792 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
793 !FT->getParamType(0)->isPointerTy() ||
794 !FT->getParamType(1)->isPointerTy() ||
795 FT->getParamType(2) != TD->getIntPtrType(*Context))
798 // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
799 EmitMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
800 CI->getArgOperand(2), 1, false, B, TD);
801 return CI->getArgOperand(0);
805 //===---------------------------------------===//
806 // 'memset' Optimizations
808 struct MemSetOpt : public LibCallOptimization {
809 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
810 // These optimizations require TargetData.
813 const FunctionType *FT = Callee->getFunctionType();
814 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
815 !FT->getParamType(0)->isPointerTy() ||
816 !FT->getParamType(1)->isIntegerTy() ||
817 FT->getParamType(2) != TD->getIntPtrType(*Context))
820 // memset(p, v, n) -> llvm.memset(p, v, n, 1)
821 Value *Val = B.CreateIntCast(CI->getArgOperand(1),
822 Type::getInt8Ty(*Context), false);
823 EmitMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), false, B, TD);
824 return CI->getArgOperand(0);
828 //===----------------------------------------------------------------------===//
829 // Math Library Optimizations
830 //===----------------------------------------------------------------------===//
832 //===---------------------------------------===//
833 // 'pow*' Optimizations
835 struct PowOpt : public LibCallOptimization {
836 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
837 const FunctionType *FT = Callee->getFunctionType();
838 // Just make sure this has 2 arguments of the same FP type, which match the
840 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
841 FT->getParamType(0) != FT->getParamType(1) ||
842 !FT->getParamType(0)->isFloatingPointTy())
845 Value *Op1 = CI->getArgOperand(0), *Op2 = CI->getArgOperand(1);
846 if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
847 if (Op1C->isExactlyValue(1.0)) // pow(1.0, x) -> 1.0
849 if (Op1C->isExactlyValue(2.0)) // pow(2.0, x) -> exp2(x)
850 return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
853 ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
854 if (Op2C == 0) return 0;
856 if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
857 return ConstantFP::get(CI->getType(), 1.0);
859 if (Op2C->isExactlyValue(0.5)) {
860 // Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
861 // This is faster than calling pow, and still handles negative zero
862 // and negative infinite correctly.
863 // TODO: In fast-math mode, this could be just sqrt(x).
864 // TODO: In finite-only mode, this could be just fabs(sqrt(x)).
865 Value *Inf = ConstantFP::getInfinity(CI->getType());
866 Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
867 Value *Sqrt = EmitUnaryFloatFnCall(Op1, "sqrt", B,
868 Callee->getAttributes());
869 Value *FAbs = EmitUnaryFloatFnCall(Sqrt, "fabs", B,
870 Callee->getAttributes());
871 Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf, "tmp");
872 Value *Sel = B.CreateSelect(FCmp, Inf, FAbs, "tmp");
876 if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
878 if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
879 return B.CreateFMul(Op1, Op1, "pow2");
880 if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
881 return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0),
887 //===---------------------------------------===//
888 // 'exp2' Optimizations
890 struct Exp2Opt : public LibCallOptimization {
891 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
892 const FunctionType *FT = Callee->getFunctionType();
893 // Just make sure this has 1 argument of FP type, which matches the
895 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
896 !FT->getParamType(0)->isFloatingPointTy())
899 Value *Op = CI->getArgOperand(0);
900 // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
901 // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
903 if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
904 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
905 LdExpArg = B.CreateSExt(OpC->getOperand(0),
906 Type::getInt32Ty(*Context), "tmp");
907 } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
908 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
909 LdExpArg = B.CreateZExt(OpC->getOperand(0),
910 Type::getInt32Ty(*Context), "tmp");
915 if (Op->getType()->isFloatTy())
917 else if (Op->getType()->isDoubleTy())
922 Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
923 if (!Op->getType()->isFloatTy())
924 One = ConstantExpr::getFPExtend(One, Op->getType());
926 Module *M = Caller->getParent();
927 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
929 Type::getInt32Ty(*Context),NULL);
930 CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
931 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
932 CI->setCallingConv(F->getCallingConv());
940 //===---------------------------------------===//
941 // Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
943 struct UnaryDoubleFPOpt : public LibCallOptimization {
944 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
945 const FunctionType *FT = Callee->getFunctionType();
946 if (FT->getNumParams() != 1 || !FT->getReturnType()->isDoubleTy() ||
947 !FT->getParamType(0)->isDoubleTy())
950 // If this is something like 'floor((double)floatval)', convert to floorf.
951 FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getArgOperand(0));
952 if (Cast == 0 || !Cast->getOperand(0)->getType()->isFloatTy())
955 // floor((double)floatval) -> (double)floorf(floatval)
956 Value *V = Cast->getOperand(0);
957 V = EmitUnaryFloatFnCall(V, Callee->getName().data(), B,
958 Callee->getAttributes());
959 return B.CreateFPExt(V, Type::getDoubleTy(*Context));
963 //===----------------------------------------------------------------------===//
964 // Integer Optimizations
965 //===----------------------------------------------------------------------===//
967 //===---------------------------------------===//
968 // 'ffs*' Optimizations
970 struct FFSOpt : public LibCallOptimization {
971 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
972 const FunctionType *FT = Callee->getFunctionType();
973 // Just make sure this has 2 arguments of the same FP type, which match the
975 if (FT->getNumParams() != 1 ||
976 !FT->getReturnType()->isIntegerTy(32) ||
977 !FT->getParamType(0)->isIntegerTy())
980 Value *Op = CI->getArgOperand(0);
983 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
984 if (CI->getValue() == 0) // ffs(0) -> 0.
985 return Constant::getNullValue(CI->getType());
986 return ConstantInt::get(Type::getInt32Ty(*Context), // ffs(c) -> cttz(c)+1
987 CI->getValue().countTrailingZeros()+1);
990 // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
991 const Type *ArgType = Op->getType();
992 Value *F = Intrinsic::getDeclaration(Callee->getParent(),
993 Intrinsic::cttz, &ArgType, 1);
994 Value *V = B.CreateCall(F, Op, "cttz");
995 V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1), "tmp");
996 V = B.CreateIntCast(V, Type::getInt32Ty(*Context), false, "tmp");
998 Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType), "tmp");
999 return B.CreateSelect(Cond, V,
1000 ConstantInt::get(Type::getInt32Ty(*Context), 0));
1004 //===---------------------------------------===//
1005 // 'isdigit' Optimizations
1007 struct IsDigitOpt : public LibCallOptimization {
1008 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1009 const FunctionType *FT = Callee->getFunctionType();
1010 // We require integer(i32)
1011 if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1012 !FT->getParamType(0)->isIntegerTy(32))
1015 // isdigit(c) -> (c-'0') <u 10
1016 Value *Op = CI->getArgOperand(0);
1017 Op = B.CreateSub(Op, ConstantInt::get(Type::getInt32Ty(*Context), '0'),
1019 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 10),
1021 return B.CreateZExt(Op, CI->getType());
1025 //===---------------------------------------===//
1026 // 'isascii' Optimizations
1028 struct IsAsciiOpt : public LibCallOptimization {
1029 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1030 const FunctionType *FT = Callee->getFunctionType();
1031 // We require integer(i32)
1032 if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1033 !FT->getParamType(0)->isIntegerTy(32))
1036 // isascii(c) -> c <u 128
1037 Value *Op = CI->getArgOperand(0);
1038 Op = B.CreateICmpULT(Op, ConstantInt::get(Type::getInt32Ty(*Context), 128),
1040 return B.CreateZExt(Op, CI->getType());
1044 //===---------------------------------------===//
1045 // 'abs', 'labs', 'llabs' Optimizations
1047 struct AbsOpt : public LibCallOptimization {
1048 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1049 const FunctionType *FT = Callee->getFunctionType();
1050 // We require integer(integer) where the types agree.
1051 if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1052 FT->getParamType(0) != FT->getReturnType())
1055 // abs(x) -> x >s -1 ? x : -x
1056 Value *Op = CI->getArgOperand(0);
1057 Value *Pos = B.CreateICmpSGT(Op,
1058 Constant::getAllOnesValue(Op->getType()),
1060 Value *Neg = B.CreateNeg(Op, "neg");
1061 return B.CreateSelect(Pos, Op, Neg);
1066 //===---------------------------------------===//
1067 // 'toascii' Optimizations
1069 struct ToAsciiOpt : public LibCallOptimization {
1070 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1071 const FunctionType *FT = Callee->getFunctionType();
1072 // We require i32(i32)
1073 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1074 !FT->getParamType(0)->isIntegerTy(32))
1077 // isascii(c) -> c & 0x7f
1078 return B.CreateAnd(CI->getArgOperand(0),
1079 ConstantInt::get(CI->getType(),0x7F));
1083 //===----------------------------------------------------------------------===//
1084 // Formatting and IO Optimizations
1085 //===----------------------------------------------------------------------===//
1087 //===---------------------------------------===//
1088 // 'printf' Optimizations
1090 struct PrintFOpt : public LibCallOptimization {
1091 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1092 // Require one fixed pointer argument and an integer/void result.
1093 const FunctionType *FT = Callee->getFunctionType();
1094 if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
1095 !(FT->getReturnType()->isIntegerTy() ||
1096 FT->getReturnType()->isVoidTy()))
1099 // Check for a fixed format string.
1100 std::string FormatStr;
1101 if (!GetConstantStringInfo(CI->getArgOperand(0), FormatStr))
1104 // Empty format string -> noop.
1105 if (FormatStr.empty()) // Tolerate printf's declared void.
1106 return CI->use_empty() ? (Value*)CI :
1107 ConstantInt::get(CI->getType(), 0);
1109 // printf("x") -> putchar('x'), even for '%'. Return the result of putchar
1110 // in case there is an error writing to stdout.
1111 if (FormatStr.size() == 1) {
1112 Value *Res = EmitPutChar(ConstantInt::get(Type::getInt32Ty(*Context),
1113 FormatStr[0]), B, TD);
1114 if (CI->use_empty()) return CI;
1115 return B.CreateIntCast(Res, CI->getType(), true);
1118 // printf("foo\n") --> puts("foo")
1119 if (FormatStr[FormatStr.size()-1] == '\n' &&
1120 FormatStr.find('%') == std::string::npos) { // no format characters.
1121 // Create a string literal with no \n on it. We expect the constant merge
1122 // pass to be run after this pass, to merge duplicate strings.
1123 FormatStr.erase(FormatStr.end()-1);
1124 Constant *C = ConstantArray::get(*Context, FormatStr, true);
1125 C = new GlobalVariable(*Callee->getParent(), C->getType(), true,
1126 GlobalVariable::InternalLinkage, C, "str");
1128 return CI->use_empty() ? (Value*)CI :
1129 ConstantInt::get(CI->getType(), FormatStr.size()+1);
1132 // Optimize specific format strings.
1133 // printf("%c", chr) --> putchar(chr)
1134 if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
1135 CI->getArgOperand(1)->getType()->isIntegerTy()) {
1136 Value *Res = EmitPutChar(CI->getArgOperand(1), B, TD);
1138 if (CI->use_empty()) return CI;
1139 return B.CreateIntCast(Res, CI->getType(), true);
1142 // printf("%s\n", str) --> puts(str)
1143 if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
1144 CI->getArgOperand(1)->getType()->isPointerTy() &&
1146 EmitPutS(CI->getArgOperand(1), B, TD);
1153 //===---------------------------------------===//
1154 // 'sprintf' Optimizations
1156 struct SPrintFOpt : public LibCallOptimization {
1157 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1158 // Require two fixed pointer arguments and an integer result.
1159 const FunctionType *FT = Callee->getFunctionType();
1160 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1161 !FT->getParamType(1)->isPointerTy() ||
1162 !FT->getReturnType()->isIntegerTy())
1165 // Check for a fixed format string.
1166 std::string FormatStr;
1167 if (!GetConstantStringInfo(CI->getArgOperand(1), FormatStr))
1170 // If we just have a format string (nothing else crazy) transform it.
1171 if (CI->getNumArgOperands() == 2) {
1172 // Make sure there's no % in the constant array. We could try to handle
1173 // %% -> % in the future if we cared.
1174 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1175 if (FormatStr[i] == '%')
1176 return 0; // we found a format specifier, bail out.
1178 // These optimizations require TargetData.
1181 // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1182 EmitMemCpy(CI->getArgOperand(0), CI->getArgOperand(1), // Copy the
1183 ConstantInt::get(TD->getIntPtrType(*Context), // nul byte.
1184 FormatStr.size() + 1), 1, false, B, TD);
1185 return ConstantInt::get(CI->getType(), FormatStr.size());
1188 // The remaining optimizations require the format string to be "%s" or "%c"
1189 // and have an extra operand.
1190 if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1191 CI->getNumArgOperands() < 3)
1194 // Decode the second character of the format string.
1195 if (FormatStr[1] == 'c') {
1196 // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1197 if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return 0;
1198 Value *V = B.CreateTrunc(CI->getArgOperand(2),
1199 Type::getInt8Ty(*Context), "char");
1200 Value *Ptr = CastToCStr(CI->getArgOperand(0), B);
1201 B.CreateStore(V, Ptr);
1202 Ptr = B.CreateGEP(Ptr, ConstantInt::get(Type::getInt32Ty(*Context), 1),
1204 B.CreateStore(Constant::getNullValue(Type::getInt8Ty(*Context)), Ptr);
1206 return ConstantInt::get(CI->getType(), 1);
1209 if (FormatStr[1] == 's') {
1210 // These optimizations require TargetData.
1213 // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1214 if (!CI->getArgOperand(2)->getType()->isPointerTy()) return 0;
1216 Value *Len = EmitStrLen(CI->getArgOperand(2), B, TD);
1217 Value *IncLen = B.CreateAdd(Len,
1218 ConstantInt::get(Len->getType(), 1),
1220 EmitMemCpy(CI->getArgOperand(0), CI->getArgOperand(2),
1221 IncLen, 1, false, B, TD);
1223 // The sprintf result is the unincremented number of bytes in the string.
1224 return B.CreateIntCast(Len, CI->getType(), false);
1230 //===---------------------------------------===//
1231 // 'fwrite' Optimizations
1233 struct FWriteOpt : public LibCallOptimization {
1234 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1235 // Require a pointer, an integer, an integer, a pointer, returning integer.
1236 const FunctionType *FT = Callee->getFunctionType();
1237 if (FT->getNumParams() != 4 || !FT->getParamType(0)->isPointerTy() ||
1238 !FT->getParamType(1)->isIntegerTy() ||
1239 !FT->getParamType(2)->isIntegerTy() ||
1240 !FT->getParamType(3)->isPointerTy() ||
1241 !FT->getReturnType()->isIntegerTy())
1244 // Get the element size and count.
1245 ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
1246 ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
1247 if (!SizeC || !CountC) return 0;
1248 uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
1250 // If this is writing zero records, remove the call (it's a noop).
1252 return ConstantInt::get(CI->getType(), 0);
1254 // If this is writing one byte, turn it into fputc.
1255 if (Bytes == 1) { // fwrite(S,1,1,F) -> fputc(S[0],F)
1256 Value *Char = B.CreateLoad(CastToCStr(CI->getArgOperand(0), B), "char");
1257 EmitFPutC(Char, CI->getArgOperand(3), B, TD);
1258 return ConstantInt::get(CI->getType(), 1);
1265 //===---------------------------------------===//
1266 // 'fputs' Optimizations
1268 struct FPutsOpt : public LibCallOptimization {
1269 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1270 // These optimizations require TargetData.
1273 // Require two pointers. Also, we can't optimize if return value is used.
1274 const FunctionType *FT = Callee->getFunctionType();
1275 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1276 !FT->getParamType(1)->isPointerTy() ||
1280 // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1281 uint64_t Len = GetStringLength(CI->getArgOperand(0));
1283 EmitFWrite(CI->getArgOperand(0),
1284 ConstantInt::get(TD->getIntPtrType(*Context), Len-1),
1285 CI->getArgOperand(1), B, TD);
1286 return CI; // Known to have no uses (see above).
1290 //===---------------------------------------===//
1291 // 'fprintf' Optimizations
1293 struct FPrintFOpt : public LibCallOptimization {
1294 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1295 // Require two fixed paramters as pointers and integer result.
1296 const FunctionType *FT = Callee->getFunctionType();
1297 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1298 !FT->getParamType(1)->isPointerTy() ||
1299 !FT->getReturnType()->isIntegerTy())
1302 // All the optimizations depend on the format string.
1303 std::string FormatStr;
1304 if (!GetConstantStringInfo(CI->getArgOperand(1), FormatStr))
1307 // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1308 if (CI->getNumArgOperands() == 2) {
1309 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1310 if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1311 return 0; // We found a format specifier.
1313 // These optimizations require TargetData.
1316 EmitFWrite(CI->getArgOperand(1),
1317 ConstantInt::get(TD->getIntPtrType(*Context),
1319 CI->getArgOperand(0), B, TD);
1320 return ConstantInt::get(CI->getType(), FormatStr.size());
1323 // The remaining optimizations require the format string to be "%s" or "%c"
1324 // and have an extra operand.
1325 if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1326 CI->getNumArgOperands() < 3)
1329 // Decode the second character of the format string.
1330 if (FormatStr[1] == 'c') {
1331 // fprintf(F, "%c", chr) --> fputc(chr, F)
1332 if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return 0;
1333 EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, TD);
1334 return ConstantInt::get(CI->getType(), 1);
1337 if (FormatStr[1] == 's') {
1338 // fprintf(F, "%s", str) --> fputs(str, F)
1339 if (!CI->getArgOperand(2)->getType()->isPointerTy() || !CI->use_empty())
1341 EmitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, TD);
1348 //===---------------------------------------===//
1349 // 'puts' Optimizations
1351 struct PutsOpt : public LibCallOptimization {
1352 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1353 // Require one fixed pointer argument and an integer/void result.
1354 const FunctionType *FT = Callee->getFunctionType();
1355 if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
1356 !(FT->getReturnType()->isIntegerTy() ||
1357 FT->getReturnType()->isVoidTy()))
1360 // Check for a constant string.
1362 if (!GetConstantStringInfo(CI->getArgOperand(0), Str))
1366 // puts("") -> putchar('\n')
1367 Value *Res = EmitPutChar(B.getInt32('\n'), B, TD);
1368 if (CI->use_empty()) return CI;
1369 return B.CreateIntCast(Res, CI->getType(), true);
1376 } // end anonymous namespace.
1378 //===----------------------------------------------------------------------===//
1379 // SimplifyLibCalls Pass Implementation
1380 //===----------------------------------------------------------------------===//
1383 /// This pass optimizes well known library functions from libc and libm.
1385 class SimplifyLibCalls : public FunctionPass {
1386 StringMap<LibCallOptimization*> Optimizations;
1387 // String and Memory LibCall Optimizations
1388 StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrRChrOpt StrRChr;
1389 StrCmpOpt StrCmp; StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrCpyOpt StrCpyChk;
1390 StrNCpyOpt StrNCpy; StrLenOpt StrLen; StrPBrkOpt StrPBrk;
1391 StrToOpt StrTo; StrSpnOpt StrSpn; StrCSpnOpt StrCSpn; StrStrOpt StrStr;
1392 MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
1393 // Math Library Optimizations
1394 PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
1395 // Integer Optimizations
1396 FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
1398 // Formatting and IO Optimizations
1399 SPrintFOpt SPrintF; PrintFOpt PrintF;
1400 FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
1403 bool Modified; // This is only used by doInitialization.
1405 static char ID; // Pass identification
1406 SimplifyLibCalls() : FunctionPass(ID), StrCpy(false), StrCpyChk(true) {
1407 initializeSimplifyLibCallsPass(*PassRegistry::getPassRegistry());
1409 void InitOptimizations();
1410 bool runOnFunction(Function &F);
1412 void setDoesNotAccessMemory(Function &F);
1413 void setOnlyReadsMemory(Function &F);
1414 void setDoesNotThrow(Function &F);
1415 void setDoesNotCapture(Function &F, unsigned n);
1416 void setDoesNotAlias(Function &F, unsigned n);
1417 bool doInitialization(Module &M);
1419 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1422 char SimplifyLibCalls::ID = 0;
1423 } // end anonymous namespace.
1425 INITIALIZE_PASS(SimplifyLibCalls, "simplify-libcalls",
1426 "Simplify well-known library calls", false, false)
1428 // Public interface to the Simplify LibCalls pass.
1429 FunctionPass *llvm::createSimplifyLibCallsPass() {
1430 return new SimplifyLibCalls();
1433 /// Optimizations - Populate the Optimizations map with all the optimizations
1435 void SimplifyLibCalls::InitOptimizations() {
1436 // String and Memory LibCall Optimizations
1437 Optimizations["strcat"] = &StrCat;
1438 Optimizations["strncat"] = &StrNCat;
1439 Optimizations["strchr"] = &StrChr;
1440 Optimizations["strrchr"] = &StrRChr;
1441 Optimizations["strcmp"] = &StrCmp;
1442 Optimizations["strncmp"] = &StrNCmp;
1443 Optimizations["strcpy"] = &StrCpy;
1444 Optimizations["strncpy"] = &StrNCpy;
1445 Optimizations["strlen"] = &StrLen;
1446 Optimizations["strpbrk"] = &StrPBrk;
1447 Optimizations["strtol"] = &StrTo;
1448 Optimizations["strtod"] = &StrTo;
1449 Optimizations["strtof"] = &StrTo;
1450 Optimizations["strtoul"] = &StrTo;
1451 Optimizations["strtoll"] = &StrTo;
1452 Optimizations["strtold"] = &StrTo;
1453 Optimizations["strtoull"] = &StrTo;
1454 Optimizations["strspn"] = &StrSpn;
1455 Optimizations["strcspn"] = &StrCSpn;
1456 Optimizations["strstr"] = &StrStr;
1457 Optimizations["memcmp"] = &MemCmp;
1458 Optimizations["memcpy"] = &MemCpy;
1459 Optimizations["memmove"] = &MemMove;
1460 Optimizations["memset"] = &MemSet;
1462 // _chk variants of String and Memory LibCall Optimizations.
1463 Optimizations["__strcpy_chk"] = &StrCpyChk;
1465 // Math Library Optimizations
1466 Optimizations["powf"] = &Pow;
1467 Optimizations["pow"] = &Pow;
1468 Optimizations["powl"] = &Pow;
1469 Optimizations["llvm.pow.f32"] = &Pow;
1470 Optimizations["llvm.pow.f64"] = &Pow;
1471 Optimizations["llvm.pow.f80"] = &Pow;
1472 Optimizations["llvm.pow.f128"] = &Pow;
1473 Optimizations["llvm.pow.ppcf128"] = &Pow;
1474 Optimizations["exp2l"] = &Exp2;
1475 Optimizations["exp2"] = &Exp2;
1476 Optimizations["exp2f"] = &Exp2;
1477 Optimizations["llvm.exp2.ppcf128"] = &Exp2;
1478 Optimizations["llvm.exp2.f128"] = &Exp2;
1479 Optimizations["llvm.exp2.f80"] = &Exp2;
1480 Optimizations["llvm.exp2.f64"] = &Exp2;
1481 Optimizations["llvm.exp2.f32"] = &Exp2;
1484 Optimizations["floor"] = &UnaryDoubleFP;
1487 Optimizations["ceil"] = &UnaryDoubleFP;
1490 Optimizations["round"] = &UnaryDoubleFP;
1493 Optimizations["rint"] = &UnaryDoubleFP;
1495 #ifdef HAVE_NEARBYINTF
1496 Optimizations["nearbyint"] = &UnaryDoubleFP;
1499 // Integer Optimizations
1500 Optimizations["ffs"] = &FFS;
1501 Optimizations["ffsl"] = &FFS;
1502 Optimizations["ffsll"] = &FFS;
1503 Optimizations["abs"] = &Abs;
1504 Optimizations["labs"] = &Abs;
1505 Optimizations["llabs"] = &Abs;
1506 Optimizations["isdigit"] = &IsDigit;
1507 Optimizations["isascii"] = &IsAscii;
1508 Optimizations["toascii"] = &ToAscii;
1510 // Formatting and IO Optimizations
1511 Optimizations["sprintf"] = &SPrintF;
1512 Optimizations["printf"] = &PrintF;
1513 Optimizations["fwrite"] = &FWrite;
1514 Optimizations["fputs"] = &FPuts;
1515 Optimizations["fprintf"] = &FPrintF;
1516 Optimizations["puts"] = &Puts;
1520 /// runOnFunction - Top level algorithm.
1522 bool SimplifyLibCalls::runOnFunction(Function &F) {
1523 if (Optimizations.empty())
1524 InitOptimizations();
1526 const TargetData *TD = getAnalysisIfAvailable<TargetData>();
1528 IRBuilder<> Builder(F.getContext());
1530 bool Changed = false;
1531 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1532 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
1533 // Ignore non-calls.
1534 CallInst *CI = dyn_cast<CallInst>(I++);
1537 // Ignore indirect calls and calls to non-external functions.
1538 Function *Callee = CI->getCalledFunction();
1539 if (Callee == 0 || !Callee->isDeclaration() ||
1540 !(Callee->hasExternalLinkage() || Callee->hasDLLImportLinkage()))
1543 // Ignore unknown calls.
1544 LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
1547 // Set the builder to the instruction after the call.
1548 Builder.SetInsertPoint(BB, I);
1550 // Try to optimize this call.
1551 Value *Result = LCO->OptimizeCall(CI, TD, Builder);
1552 if (Result == 0) continue;
1554 DEBUG(dbgs() << "SimplifyLibCalls simplified: " << *CI;
1555 dbgs() << " into: " << *Result << "\n");
1557 // Something changed!
1561 // Inspect the instruction after the call (which was potentially just
1565 if (CI != Result && !CI->use_empty()) {
1566 CI->replaceAllUsesWith(Result);
1567 if (!Result->hasName())
1568 Result->takeName(CI);
1570 CI->eraseFromParent();
1576 // Utility methods for doInitialization.
1578 void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
1579 if (!F.doesNotAccessMemory()) {
1580 F.setDoesNotAccessMemory();
1585 void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
1586 if (!F.onlyReadsMemory()) {
1587 F.setOnlyReadsMemory();
1592 void SimplifyLibCalls::setDoesNotThrow(Function &F) {
1593 if (!F.doesNotThrow()) {
1594 F.setDoesNotThrow();
1599 void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
1600 if (!F.doesNotCapture(n)) {
1601 F.setDoesNotCapture(n);
1606 void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
1607 if (!F.doesNotAlias(n)) {
1608 F.setDoesNotAlias(n);
1614 /// doInitialization - Add attributes to well-known functions.
1616 bool SimplifyLibCalls::doInitialization(Module &M) {
1618 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
1620 if (!F.isDeclaration())
1626 const FunctionType *FTy = F.getFunctionType();
1628 StringRef Name = F.getName();
1631 if (Name == "strlen") {
1632 if (FTy->getNumParams() != 1 ||
1633 !FTy->getParamType(0)->isPointerTy())
1635 setOnlyReadsMemory(F);
1637 setDoesNotCapture(F, 1);
1638 } else if (Name == "strchr" ||
1639 Name == "strrchr") {
1640 if (FTy->getNumParams() != 2 ||
1641 !FTy->getParamType(0)->isPointerTy() ||
1642 !FTy->getParamType(1)->isIntegerTy())
1644 setOnlyReadsMemory(F);
1646 } else if (Name == "strcpy" ||
1652 Name == "strtoul" ||
1653 Name == "strtoll" ||
1654 Name == "strtold" ||
1655 Name == "strncat" ||
1656 Name == "strncpy" ||
1657 Name == "strtoull") {
1658 if (FTy->getNumParams() < 2 ||
1659 !FTy->getParamType(1)->isPointerTy())
1662 setDoesNotCapture(F, 2);
1663 } else if (Name == "strxfrm") {
1664 if (FTy->getNumParams() != 3 ||
1665 !FTy->getParamType(0)->isPointerTy() ||
1666 !FTy->getParamType(1)->isPointerTy())
1669 setDoesNotCapture(F, 1);
1670 setDoesNotCapture(F, 2);
1671 } else if (Name == "strcmp" ||
1673 Name == "strncmp" ||
1674 Name == "strcspn" ||
1675 Name == "strcoll" ||
1676 Name == "strcasecmp" ||
1677 Name == "strncasecmp") {
1678 if (FTy->getNumParams() < 2 ||
1679 !FTy->getParamType(0)->isPointerTy() ||
1680 !FTy->getParamType(1)->isPointerTy())
1682 setOnlyReadsMemory(F);
1684 setDoesNotCapture(F, 1);
1685 setDoesNotCapture(F, 2);
1686 } else if (Name == "strstr" ||
1687 Name == "strpbrk") {
1688 if (FTy->getNumParams() != 2 ||
1689 !FTy->getParamType(1)->isPointerTy())
1691 setOnlyReadsMemory(F);
1693 setDoesNotCapture(F, 2);
1694 } else if (Name == "strtok" ||
1695 Name == "strtok_r") {
1696 if (FTy->getNumParams() < 2 ||
1697 !FTy->getParamType(1)->isPointerTy())
1700 setDoesNotCapture(F, 2);
1701 } else if (Name == "scanf" ||
1703 Name == "setvbuf") {
1704 if (FTy->getNumParams() < 1 ||
1705 !FTy->getParamType(0)->isPointerTy())
1708 setDoesNotCapture(F, 1);
1709 } else if (Name == "strdup" ||
1710 Name == "strndup") {
1711 if (FTy->getNumParams() < 1 ||
1712 !FTy->getReturnType()->isPointerTy() ||
1713 !FTy->getParamType(0)->isPointerTy())
1716 setDoesNotAlias(F, 0);
1717 setDoesNotCapture(F, 1);
1718 } else if (Name == "stat" ||
1720 Name == "sprintf" ||
1721 Name == "statvfs") {
1722 if (FTy->getNumParams() < 2 ||
1723 !FTy->getParamType(0)->isPointerTy() ||
1724 !FTy->getParamType(1)->isPointerTy())
1727 setDoesNotCapture(F, 1);
1728 setDoesNotCapture(F, 2);
1729 } else if (Name == "snprintf") {
1730 if (FTy->getNumParams() != 3 ||
1731 !FTy->getParamType(0)->isPointerTy() ||
1732 !FTy->getParamType(2)->isPointerTy())
1735 setDoesNotCapture(F, 1);
1736 setDoesNotCapture(F, 3);
1737 } else if (Name == "setitimer") {
1738 if (FTy->getNumParams() != 3 ||
1739 !FTy->getParamType(1)->isPointerTy() ||
1740 !FTy->getParamType(2)->isPointerTy())
1743 setDoesNotCapture(F, 2);
1744 setDoesNotCapture(F, 3);
1745 } else if (Name == "system") {
1746 if (FTy->getNumParams() != 1 ||
1747 !FTy->getParamType(0)->isPointerTy())
1749 // May throw; "system" is a valid pthread cancellation point.
1750 setDoesNotCapture(F, 1);
1754 if (Name == "malloc") {
1755 if (FTy->getNumParams() != 1 ||
1756 !FTy->getReturnType()->isPointerTy())
1759 setDoesNotAlias(F, 0);
1760 } else if (Name == "memcmp") {
1761 if (FTy->getNumParams() != 3 ||
1762 !FTy->getParamType(0)->isPointerTy() ||
1763 !FTy->getParamType(1)->isPointerTy())
1765 setOnlyReadsMemory(F);
1767 setDoesNotCapture(F, 1);
1768 setDoesNotCapture(F, 2);
1769 } else if (Name == "memchr" ||
1770 Name == "memrchr") {
1771 if (FTy->getNumParams() != 3)
1773 setOnlyReadsMemory(F);
1775 } else if (Name == "modf" ||
1779 Name == "memccpy" ||
1780 Name == "memmove") {
1781 if (FTy->getNumParams() < 2 ||
1782 !FTy->getParamType(1)->isPointerTy())
1785 setDoesNotCapture(F, 2);
1786 } else if (Name == "memalign") {
1787 if (!FTy->getReturnType()->isPointerTy())
1789 setDoesNotAlias(F, 0);
1790 } else if (Name == "mkdir" ||
1792 if (FTy->getNumParams() == 0 ||
1793 !FTy->getParamType(0)->isPointerTy())
1796 setDoesNotCapture(F, 1);
1800 if (Name == "realloc") {
1801 if (FTy->getNumParams() != 2 ||
1802 !FTy->getParamType(0)->isPointerTy() ||
1803 !FTy->getReturnType()->isPointerTy())
1806 setDoesNotAlias(F, 0);
1807 setDoesNotCapture(F, 1);
1808 } else if (Name == "read") {
1809 if (FTy->getNumParams() != 3 ||
1810 !FTy->getParamType(1)->isPointerTy())
1812 // May throw; "read" is a valid pthread cancellation point.
1813 setDoesNotCapture(F, 2);
1814 } else if (Name == "rmdir" ||
1817 Name == "realpath") {
1818 if (FTy->getNumParams() < 1 ||
1819 !FTy->getParamType(0)->isPointerTy())
1822 setDoesNotCapture(F, 1);
1823 } else if (Name == "rename" ||
1824 Name == "readlink") {
1825 if (FTy->getNumParams() < 2 ||
1826 !FTy->getParamType(0)->isPointerTy() ||
1827 !FTy->getParamType(1)->isPointerTy())
1830 setDoesNotCapture(F, 1);
1831 setDoesNotCapture(F, 2);
1835 if (Name == "write") {
1836 if (FTy->getNumParams() != 3 ||
1837 !FTy->getParamType(1)->isPointerTy())
1839 // May throw; "write" is a valid pthread cancellation point.
1840 setDoesNotCapture(F, 2);
1844 if (Name == "bcopy") {
1845 if (FTy->getNumParams() != 3 ||
1846 !FTy->getParamType(0)->isPointerTy() ||
1847 !FTy->getParamType(1)->isPointerTy())
1850 setDoesNotCapture(F, 1);
1851 setDoesNotCapture(F, 2);
1852 } else if (Name == "bcmp") {
1853 if (FTy->getNumParams() != 3 ||
1854 !FTy->getParamType(0)->isPointerTy() ||
1855 !FTy->getParamType(1)->isPointerTy())
1858 setOnlyReadsMemory(F);
1859 setDoesNotCapture(F, 1);
1860 setDoesNotCapture(F, 2);
1861 } else if (Name == "bzero") {
1862 if (FTy->getNumParams() != 2 ||
1863 !FTy->getParamType(0)->isPointerTy())
1866 setDoesNotCapture(F, 1);
1870 if (Name == "calloc") {
1871 if (FTy->getNumParams() != 2 ||
1872 !FTy->getReturnType()->isPointerTy())
1875 setDoesNotAlias(F, 0);
1876 } else if (Name == "chmod" ||
1878 Name == "ctermid" ||
1879 Name == "clearerr" ||
1880 Name == "closedir") {
1881 if (FTy->getNumParams() == 0 ||
1882 !FTy->getParamType(0)->isPointerTy())
1885 setDoesNotCapture(F, 1);
1889 if (Name == "atoi" ||
1893 if (FTy->getNumParams() != 1 ||
1894 !FTy->getParamType(0)->isPointerTy())
1897 setOnlyReadsMemory(F);
1898 setDoesNotCapture(F, 1);
1899 } else if (Name == "access") {
1900 if (FTy->getNumParams() != 2 ||
1901 !FTy->getParamType(0)->isPointerTy())
1904 setDoesNotCapture(F, 1);
1908 if (Name == "fopen") {
1909 if (FTy->getNumParams() != 2 ||
1910 !FTy->getReturnType()->isPointerTy() ||
1911 !FTy->getParamType(0)->isPointerTy() ||
1912 !FTy->getParamType(1)->isPointerTy())
1915 setDoesNotAlias(F, 0);
1916 setDoesNotCapture(F, 1);
1917 setDoesNotCapture(F, 2);
1918 } else if (Name == "fdopen") {
1919 if (FTy->getNumParams() != 2 ||
1920 !FTy->getReturnType()->isPointerTy() ||
1921 !FTy->getParamType(1)->isPointerTy())
1924 setDoesNotAlias(F, 0);
1925 setDoesNotCapture(F, 2);
1926 } else if (Name == "feof" ||
1936 Name == "fsetpos" ||
1937 Name == "flockfile" ||
1938 Name == "funlockfile" ||
1939 Name == "ftrylockfile") {
1940 if (FTy->getNumParams() == 0 ||
1941 !FTy->getParamType(0)->isPointerTy())
1944 setDoesNotCapture(F, 1);
1945 } else if (Name == "ferror") {
1946 if (FTy->getNumParams() != 1 ||
1947 !FTy->getParamType(0)->isPointerTy())
1950 setDoesNotCapture(F, 1);
1951 setOnlyReadsMemory(F);
1952 } else if (Name == "fputc" ||
1957 Name == "fstatvfs") {
1958 if (FTy->getNumParams() != 2 ||
1959 !FTy->getParamType(1)->isPointerTy())
1962 setDoesNotCapture(F, 2);
1963 } else if (Name == "fgets") {
1964 if (FTy->getNumParams() != 3 ||
1965 !FTy->getParamType(0)->isPointerTy() ||
1966 !FTy->getParamType(2)->isPointerTy())
1969 setDoesNotCapture(F, 3);
1970 } else if (Name == "fread" ||
1972 if (FTy->getNumParams() != 4 ||
1973 !FTy->getParamType(0)->isPointerTy() ||
1974 !FTy->getParamType(3)->isPointerTy())
1977 setDoesNotCapture(F, 1);
1978 setDoesNotCapture(F, 4);
1979 } else if (Name == "fputs" ||
1981 Name == "fprintf" ||
1982 Name == "fgetpos") {
1983 if (FTy->getNumParams() < 2 ||
1984 !FTy->getParamType(0)->isPointerTy() ||
1985 !FTy->getParamType(1)->isPointerTy())
1988 setDoesNotCapture(F, 1);
1989 setDoesNotCapture(F, 2);
1993 if (Name == "getc" ||
1994 Name == "getlogin_r" ||
1995 Name == "getc_unlocked") {
1996 if (FTy->getNumParams() == 0 ||
1997 !FTy->getParamType(0)->isPointerTy())
2000 setDoesNotCapture(F, 1);
2001 } else if (Name == "getenv") {
2002 if (FTy->getNumParams() != 1 ||
2003 !FTy->getParamType(0)->isPointerTy())
2006 setOnlyReadsMemory(F);
2007 setDoesNotCapture(F, 1);
2008 } else if (Name == "gets" ||
2009 Name == "getchar") {
2011 } else if (Name == "getitimer") {
2012 if (FTy->getNumParams() != 2 ||
2013 !FTy->getParamType(1)->isPointerTy())
2016 setDoesNotCapture(F, 2);
2017 } else if (Name == "getpwnam") {
2018 if (FTy->getNumParams() != 1 ||
2019 !FTy->getParamType(0)->isPointerTy())
2022 setDoesNotCapture(F, 1);
2026 if (Name == "ungetc") {
2027 if (FTy->getNumParams() != 2 ||
2028 !FTy->getParamType(1)->isPointerTy())
2031 setDoesNotCapture(F, 2);
2032 } else if (Name == "uname" ||
2034 Name == "unsetenv") {
2035 if (FTy->getNumParams() != 1 ||
2036 !FTy->getParamType(0)->isPointerTy())
2039 setDoesNotCapture(F, 1);
2040 } else if (Name == "utime" ||
2042 if (FTy->getNumParams() != 2 ||
2043 !FTy->getParamType(0)->isPointerTy() ||
2044 !FTy->getParamType(1)->isPointerTy())
2047 setDoesNotCapture(F, 1);
2048 setDoesNotCapture(F, 2);
2052 if (Name == "putc") {
2053 if (FTy->getNumParams() != 2 ||
2054 !FTy->getParamType(1)->isPointerTy())
2057 setDoesNotCapture(F, 2);
2058 } else if (Name == "puts" ||
2061 if (FTy->getNumParams() != 1 ||
2062 !FTy->getParamType(0)->isPointerTy())
2065 setDoesNotCapture(F, 1);
2066 } else if (Name == "pread" ||
2068 if (FTy->getNumParams() != 4 ||
2069 !FTy->getParamType(1)->isPointerTy())
2071 // May throw; these are valid pthread cancellation points.
2072 setDoesNotCapture(F, 2);
2073 } else if (Name == "putchar") {
2075 } else if (Name == "popen") {
2076 if (FTy->getNumParams() != 2 ||
2077 !FTy->getReturnType()->isPointerTy() ||
2078 !FTy->getParamType(0)->isPointerTy() ||
2079 !FTy->getParamType(1)->isPointerTy())
2082 setDoesNotAlias(F, 0);
2083 setDoesNotCapture(F, 1);
2084 setDoesNotCapture(F, 2);
2085 } else if (Name == "pclose") {
2086 if (FTy->getNumParams() != 1 ||
2087 !FTy->getParamType(0)->isPointerTy())
2090 setDoesNotCapture(F, 1);
2094 if (Name == "vscanf") {
2095 if (FTy->getNumParams() != 2 ||
2096 !FTy->getParamType(1)->isPointerTy())
2099 setDoesNotCapture(F, 1);
2100 } else if (Name == "vsscanf" ||
2101 Name == "vfscanf") {
2102 if (FTy->getNumParams() != 3 ||
2103 !FTy->getParamType(1)->isPointerTy() ||
2104 !FTy->getParamType(2)->isPointerTy())
2107 setDoesNotCapture(F, 1);
2108 setDoesNotCapture(F, 2);
2109 } else if (Name == "valloc") {
2110 if (!FTy->getReturnType()->isPointerTy())
2113 setDoesNotAlias(F, 0);
2114 } else if (Name == "vprintf") {
2115 if (FTy->getNumParams() != 2 ||
2116 !FTy->getParamType(0)->isPointerTy())
2119 setDoesNotCapture(F, 1);
2120 } else if (Name == "vfprintf" ||
2121 Name == "vsprintf") {
2122 if (FTy->getNumParams() != 3 ||
2123 !FTy->getParamType(0)->isPointerTy() ||
2124 !FTy->getParamType(1)->isPointerTy())
2127 setDoesNotCapture(F, 1);
2128 setDoesNotCapture(F, 2);
2129 } else if (Name == "vsnprintf") {
2130 if (FTy->getNumParams() != 4 ||
2131 !FTy->getParamType(0)->isPointerTy() ||
2132 !FTy->getParamType(2)->isPointerTy())
2135 setDoesNotCapture(F, 1);
2136 setDoesNotCapture(F, 3);
2140 if (Name == "open") {
2141 if (FTy->getNumParams() < 2 ||
2142 !FTy->getParamType(0)->isPointerTy())
2144 // May throw; "open" is a valid pthread cancellation point.
2145 setDoesNotCapture(F, 1);
2146 } else if (Name == "opendir") {
2147 if (FTy->getNumParams() != 1 ||
2148 !FTy->getReturnType()->isPointerTy() ||
2149 !FTy->getParamType(0)->isPointerTy())
2152 setDoesNotAlias(F, 0);
2153 setDoesNotCapture(F, 1);
2157 if (Name == "tmpfile") {
2158 if (!FTy->getReturnType()->isPointerTy())
2161 setDoesNotAlias(F, 0);
2162 } else if (Name == "times") {
2163 if (FTy->getNumParams() != 1 ||
2164 !FTy->getParamType(0)->isPointerTy())
2167 setDoesNotCapture(F, 1);
2171 if (Name == "htonl" ||
2174 setDoesNotAccessMemory(F);
2178 if (Name == "ntohl" ||
2181 setDoesNotAccessMemory(F);
2185 if (Name == "lstat") {
2186 if (FTy->getNumParams() != 2 ||
2187 !FTy->getParamType(0)->isPointerTy() ||
2188 !FTy->getParamType(1)->isPointerTy())
2191 setDoesNotCapture(F, 1);
2192 setDoesNotCapture(F, 2);
2193 } else if (Name == "lchown") {
2194 if (FTy->getNumParams() != 3 ||
2195 !FTy->getParamType(0)->isPointerTy())
2198 setDoesNotCapture(F, 1);
2202 if (Name == "qsort") {
2203 if (FTy->getNumParams() != 4 ||
2204 !FTy->getParamType(3)->isPointerTy())
2206 // May throw; places call through function pointer.
2207 setDoesNotCapture(F, 4);
2211 if (Name == "__strdup" ||
2212 Name == "__strndup") {
2213 if (FTy->getNumParams() < 1 ||
2214 !FTy->getReturnType()->isPointerTy() ||
2215 !FTy->getParamType(0)->isPointerTy())
2218 setDoesNotAlias(F, 0);
2219 setDoesNotCapture(F, 1);
2220 } else if (Name == "__strtok_r") {
2221 if (FTy->getNumParams() != 3 ||
2222 !FTy->getParamType(1)->isPointerTy())
2225 setDoesNotCapture(F, 2);
2226 } else if (Name == "_IO_getc") {
2227 if (FTy->getNumParams() != 1 ||
2228 !FTy->getParamType(0)->isPointerTy())
2231 setDoesNotCapture(F, 1);
2232 } else if (Name == "_IO_putc") {
2233 if (FTy->getNumParams() != 2 ||
2234 !FTy->getParamType(1)->isPointerTy())
2237 setDoesNotCapture(F, 2);
2241 if (Name == "\1__isoc99_scanf") {
2242 if (FTy->getNumParams() < 1 ||
2243 !FTy->getParamType(0)->isPointerTy())
2246 setDoesNotCapture(F, 1);
2247 } else if (Name == "\1stat64" ||
2248 Name == "\1lstat64" ||
2249 Name == "\1statvfs64" ||
2250 Name == "\1__isoc99_sscanf") {
2251 if (FTy->getNumParams() < 1 ||
2252 !FTy->getParamType(0)->isPointerTy() ||
2253 !FTy->getParamType(1)->isPointerTy())
2256 setDoesNotCapture(F, 1);
2257 setDoesNotCapture(F, 2);
2258 } else if (Name == "\1fopen64") {
2259 if (FTy->getNumParams() != 2 ||
2260 !FTy->getReturnType()->isPointerTy() ||
2261 !FTy->getParamType(0)->isPointerTy() ||
2262 !FTy->getParamType(1)->isPointerTy())
2265 setDoesNotAlias(F, 0);
2266 setDoesNotCapture(F, 1);
2267 setDoesNotCapture(F, 2);
2268 } else if (Name == "\1fseeko64" ||
2269 Name == "\1ftello64") {
2270 if (FTy->getNumParams() == 0 ||
2271 !FTy->getParamType(0)->isPointerTy())
2274 setDoesNotCapture(F, 1);
2275 } else if (Name == "\1tmpfile64") {
2276 if (!FTy->getReturnType()->isPointerTy())
2279 setDoesNotAlias(F, 0);
2280 } else if (Name == "\1fstat64" ||
2281 Name == "\1fstatvfs64") {
2282 if (FTy->getNumParams() != 2 ||
2283 !FTy->getParamType(1)->isPointerTy())
2286 setDoesNotCapture(F, 2);
2287 } else if (Name == "\1open64") {
2288 if (FTy->getNumParams() < 2 ||
2289 !FTy->getParamType(0)->isPointerTy())
2291 // May throw; "open" is a valid pthread cancellation point.
2292 setDoesNotCapture(F, 1);
2301 // Additional cases that we need to add to this file:
2304 // * cbrt(expN(X)) -> expN(x/3)
2305 // * cbrt(sqrt(x)) -> pow(x,1/6)
2306 // * cbrt(sqrt(x)) -> pow(x,1/9)
2309 // * cos(-x) -> cos(x)
2312 // * exp(log(x)) -> x
2315 // * log(exp(x)) -> x
2316 // * log(x**y) -> y*log(x)
2317 // * log(exp(y)) -> y*log(e)
2318 // * log(exp2(y)) -> y*log(2)
2319 // * log(exp10(y)) -> y*log(10)
2320 // * log(sqrt(x)) -> 0.5*log(x)
2321 // * log(pow(x,y)) -> y*log(x)
2323 // lround, lroundf, lroundl:
2324 // * lround(cnst) -> cnst'
2327 // * pow(exp(x),y) -> exp(x*y)
2328 // * pow(sqrt(x),y) -> pow(x,y*0.5)
2329 // * pow(pow(x,y),z)-> pow(x,y*z)
2331 // round, roundf, roundl:
2332 // * round(cnst) -> cnst'
2335 // * signbit(cnst) -> cnst'
2336 // * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2338 // sqrt, sqrtf, sqrtl:
2339 // * sqrt(expN(x)) -> expN(x*0.5)
2340 // * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2341 // * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2344 // * stpcpy(str, "literal") ->
2345 // llvm.memcpy(str,"literal",strlen("literal")+1,1)
2348 // * tan(atan(x)) -> x
2350 // trunc, truncf, truncl:
2351 // * trunc(cnst) -> cnst'