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/IRBuilder.h"
22 #include "llvm/Intrinsics.h"
23 #include "llvm/LLVMContext.h"
24 #include "llvm/Module.h"
25 #include "llvm/Pass.h"
26 #include "llvm/ADT/STLExtras.h"
27 #include "llvm/ADT/SmallPtrSet.h"
28 #include "llvm/ADT/Statistic.h"
29 #include "llvm/ADT/StringMap.h"
30 #include "llvm/Analysis/ValueTracking.h"
31 #include "llvm/Support/CommandLine.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/DataLayout.h"
35 #include "llvm/Target/TargetLibraryInfo.h"
36 #include "llvm/Config/config.h" // FIXME: Shouldn't depend on host!
39 STATISTIC(NumSimplified, "Number of library calls simplified");
40 STATISTIC(NumAnnotated, "Number of attributes added to library functions");
42 static cl::opt<bool> UnsafeFPShrink("enable-double-float-shrink", cl::Hidden,
44 cl::desc("Enable unsafe double to float "
45 "shrinking for math lib calls"));
46 //===----------------------------------------------------------------------===//
47 // Optimizer Base Class
48 //===----------------------------------------------------------------------===//
50 /// This class is the abstract base class for the set of optimizations that
51 /// corresponds to one library call.
53 class LibCallOptimization {
57 const TargetLibraryInfo *TLI;
60 LibCallOptimization() { }
61 virtual ~LibCallOptimization() {}
63 /// CallOptimizer - This pure virtual method is implemented by base classes to
64 /// do various optimizations. If this returns null then no transformation was
65 /// performed. If it returns CI, then it transformed the call and CI is to be
66 /// deleted. If it returns something else, replace CI with the new value and
68 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B)
71 Value *OptimizeCall(CallInst *CI, const DataLayout *TD,
72 const TargetLibraryInfo *TLI, IRBuilder<> &B) {
73 Caller = CI->getParent()->getParent();
76 if (CI->getCalledFunction())
77 Context = &CI->getCalledFunction()->getContext();
79 // We never change the calling convention.
80 if (CI->getCallingConv() != llvm::CallingConv::C)
83 return CallOptimizer(CI->getCalledFunction(), CI, B);
86 } // End anonymous namespace.
89 //===----------------------------------------------------------------------===//
91 //===----------------------------------------------------------------------===//
93 /// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
94 /// value is equal or not-equal to zero.
95 static bool IsOnlyUsedInZeroEqualityComparison(Value *V) {
96 for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
98 if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
100 if (Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
101 if (C->isNullValue())
103 // Unknown instruction.
109 static bool CallHasFloatingPointArgument(const CallInst *CI) {
110 for (CallInst::const_op_iterator it = CI->op_begin(), e = CI->op_end();
112 if ((*it)->getType()->isFloatingPointTy())
118 /// IsOnlyUsedInEqualityComparison - Return true if it is only used in equality
119 /// comparisons with With.
120 static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) {
121 for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
123 if (ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
124 if (IC->isEquality() && IC->getOperand(1) == With)
126 // Unknown instruction.
132 //===----------------------------------------------------------------------===//
133 // String and Memory LibCall Optimizations
134 //===----------------------------------------------------------------------===//
137 //===---------------------------------------===//
138 // 'strchr' Optimizations
140 struct StrChrOpt : public LibCallOptimization {
141 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
142 // Verify the "strchr" function prototype.
143 FunctionType *FT = Callee->getFunctionType();
144 if (FT->getNumParams() != 2 ||
145 FT->getReturnType() != B.getInt8PtrTy() ||
146 FT->getParamType(0) != FT->getReturnType() ||
147 !FT->getParamType(1)->isIntegerTy(32))
150 Value *SrcStr = CI->getArgOperand(0);
152 // If the second operand is non-constant, see if we can compute the length
153 // of the input string and turn this into memchr.
154 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
156 // These optimizations require DataLayout.
159 uint64_t Len = GetStringLength(SrcStr);
160 if (Len == 0 || !FT->getParamType(1)->isIntegerTy(32))// memchr needs i32.
163 return EmitMemChr(SrcStr, CI->getArgOperand(1), // include nul.
164 ConstantInt::get(TD->getIntPtrType(*Context), Len),
168 // Otherwise, the character is a constant, see if the first argument is
169 // a string literal. If so, we can constant fold.
171 if (!getConstantStringInfo(SrcStr, Str))
174 // Compute the offset, make sure to handle the case when we're searching for
175 // zero (a weird way to spell strlen).
176 size_t I = CharC->getSExtValue() == 0 ?
177 Str.size() : Str.find(CharC->getSExtValue());
178 if (I == StringRef::npos) // Didn't find the char. strchr returns null.
179 return Constant::getNullValue(CI->getType());
181 // strchr(s+n,c) -> gep(s+n+i,c)
182 return B.CreateGEP(SrcStr, B.getInt64(I), "strchr");
186 //===---------------------------------------===//
187 // 'strrchr' Optimizations
189 struct StrRChrOpt : public LibCallOptimization {
190 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
191 // Verify the "strrchr" function prototype.
192 FunctionType *FT = Callee->getFunctionType();
193 if (FT->getNumParams() != 2 ||
194 FT->getReturnType() != B.getInt8PtrTy() ||
195 FT->getParamType(0) != FT->getReturnType() ||
196 !FT->getParamType(1)->isIntegerTy(32))
199 Value *SrcStr = CI->getArgOperand(0);
200 ConstantInt *CharC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
202 // Cannot fold anything if we're not looking for a constant.
207 if (!getConstantStringInfo(SrcStr, Str)) {
208 // strrchr(s, 0) -> strchr(s, 0)
209 if (TD && CharC->isZero())
210 return EmitStrChr(SrcStr, '\0', B, TD, TLI);
214 // Compute the offset.
215 size_t I = CharC->getSExtValue() == 0 ?
216 Str.size() : Str.rfind(CharC->getSExtValue());
217 if (I == StringRef::npos) // Didn't find the char. Return null.
218 return Constant::getNullValue(CI->getType());
220 // strrchr(s+n,c) -> gep(s+n+i,c)
221 return B.CreateGEP(SrcStr, B.getInt64(I), "strrchr");
225 //===---------------------------------------===//
226 // 'strcmp' Optimizations
228 struct StrCmpOpt : public LibCallOptimization {
229 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
230 // Verify the "strcmp" function prototype.
231 FunctionType *FT = Callee->getFunctionType();
232 if (FT->getNumParams() != 2 ||
233 !FT->getReturnType()->isIntegerTy(32) ||
234 FT->getParamType(0) != FT->getParamType(1) ||
235 FT->getParamType(0) != B.getInt8PtrTy())
238 Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
239 if (Str1P == Str2P) // strcmp(x,x) -> 0
240 return ConstantInt::get(CI->getType(), 0);
242 StringRef Str1, Str2;
243 bool HasStr1 = getConstantStringInfo(Str1P, Str1);
244 bool HasStr2 = getConstantStringInfo(Str2P, Str2);
246 // strcmp(x, y) -> cnst (if both x and y are constant strings)
247 if (HasStr1 && HasStr2)
248 return ConstantInt::get(CI->getType(), Str1.compare(Str2));
250 if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x
251 return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
254 if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x
255 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
257 // strcmp(P, "x") -> memcmp(P, "x", 2)
258 uint64_t Len1 = GetStringLength(Str1P);
259 uint64_t Len2 = GetStringLength(Str2P);
261 // These optimizations require DataLayout.
264 return EmitMemCmp(Str1P, Str2P,
265 ConstantInt::get(TD->getIntPtrType(*Context),
266 std::min(Len1, Len2)), B, TD, TLI);
273 //===---------------------------------------===//
274 // 'strncmp' Optimizations
276 struct StrNCmpOpt : public LibCallOptimization {
277 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
278 // Verify the "strncmp" function prototype.
279 FunctionType *FT = Callee->getFunctionType();
280 if (FT->getNumParams() != 3 ||
281 !FT->getReturnType()->isIntegerTy(32) ||
282 FT->getParamType(0) != FT->getParamType(1) ||
283 FT->getParamType(0) != B.getInt8PtrTy() ||
284 !FT->getParamType(2)->isIntegerTy())
287 Value *Str1P = CI->getArgOperand(0), *Str2P = CI->getArgOperand(1);
288 if (Str1P == Str2P) // strncmp(x,x,n) -> 0
289 return ConstantInt::get(CI->getType(), 0);
291 // Get the length argument if it is constant.
293 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
294 Length = LengthArg->getZExtValue();
298 if (Length == 0) // strncmp(x,y,0) -> 0
299 return ConstantInt::get(CI->getType(), 0);
301 if (TD && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1)
302 return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, TD, TLI);
304 StringRef Str1, Str2;
305 bool HasStr1 = getConstantStringInfo(Str1P, Str1);
306 bool HasStr2 = getConstantStringInfo(Str2P, Str2);
308 // strncmp(x, y) -> cnst (if both x and y are constant strings)
309 if (HasStr1 && HasStr2) {
310 StringRef SubStr1 = Str1.substr(0, Length);
311 StringRef SubStr2 = Str2.substr(0, Length);
312 return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2));
315 if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> -*x
316 return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"),
319 if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x
320 return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType());
327 //===---------------------------------------===//
328 // 'strcpy' Optimizations
330 struct StrCpyOpt : public LibCallOptimization {
331 bool OptChkCall; // True if it's optimizing a __strcpy_chk libcall.
333 StrCpyOpt(bool c) : OptChkCall(c) {}
335 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
336 // Verify the "strcpy" function prototype.
337 unsigned NumParams = OptChkCall ? 3 : 2;
338 FunctionType *FT = Callee->getFunctionType();
339 if (FT->getNumParams() != NumParams ||
340 FT->getReturnType() != FT->getParamType(0) ||
341 FT->getParamType(0) != FT->getParamType(1) ||
342 FT->getParamType(0) != B.getInt8PtrTy())
345 Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
346 if (Dst == Src) // strcpy(x,x) -> x
349 // These optimizations require DataLayout.
352 // See if we can get the length of the input string.
353 uint64_t Len = GetStringLength(Src);
354 if (Len == 0) return 0;
356 // We have enough information to now generate the memcpy call to do the
357 // concatenation for us. Make a memcpy to copy the nul byte with align = 1.
359 !EmitMemCpyChk(Dst, Src,
360 ConstantInt::get(TD->getIntPtrType(*Context), Len),
361 CI->getArgOperand(2), B, TD, TLI))
362 B.CreateMemCpy(Dst, Src,
363 ConstantInt::get(TD->getIntPtrType(*Context), Len), 1);
368 //===---------------------------------------===//
369 // 'stpcpy' Optimizations
371 struct StpCpyOpt: public LibCallOptimization {
372 bool OptChkCall; // True if it's optimizing a __stpcpy_chk libcall.
374 StpCpyOpt(bool c) : OptChkCall(c) {}
376 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
377 // Verify the "stpcpy" function prototype.
378 unsigned NumParams = OptChkCall ? 3 : 2;
379 FunctionType *FT = Callee->getFunctionType();
380 if (FT->getNumParams() != NumParams ||
381 FT->getReturnType() != FT->getParamType(0) ||
382 FT->getParamType(0) != FT->getParamType(1) ||
383 FT->getParamType(0) != B.getInt8PtrTy())
386 // These optimizations require DataLayout.
389 Value *Dst = CI->getArgOperand(0), *Src = CI->getArgOperand(1);
390 if (Dst == Src) { // stpcpy(x,x) -> x+strlen(x)
391 Value *StrLen = EmitStrLen(Src, B, TD, TLI);
392 return StrLen ? B.CreateInBoundsGEP(Dst, StrLen) : 0;
395 // See if we can get the length of the input string.
396 uint64_t Len = GetStringLength(Src);
397 if (Len == 0) return 0;
399 Value *LenV = ConstantInt::get(TD->getIntPtrType(*Context), Len);
400 Value *DstEnd = B.CreateGEP(Dst,
401 ConstantInt::get(TD->getIntPtrType(*Context),
404 // We have enough information to now generate the memcpy call to do the
405 // copy for us. Make a memcpy to copy the nul byte with align = 1.
406 if (!OptChkCall || !EmitMemCpyChk(Dst, Src, LenV, CI->getArgOperand(2), B,
408 B.CreateMemCpy(Dst, Src, LenV, 1);
413 //===---------------------------------------===//
414 // 'strncpy' Optimizations
416 struct StrNCpyOpt : public LibCallOptimization {
417 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
418 FunctionType *FT = Callee->getFunctionType();
419 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
420 FT->getParamType(0) != FT->getParamType(1) ||
421 FT->getParamType(0) != B.getInt8PtrTy() ||
422 !FT->getParamType(2)->isIntegerTy())
425 Value *Dst = CI->getArgOperand(0);
426 Value *Src = CI->getArgOperand(1);
427 Value *LenOp = CI->getArgOperand(2);
429 // See if we can get the length of the input string.
430 uint64_t SrcLen = GetStringLength(Src);
431 if (SrcLen == 0) return 0;
435 // strncpy(x, "", y) -> memset(x, '\0', y, 1)
436 B.CreateMemSet(Dst, B.getInt8('\0'), LenOp, 1);
441 if (ConstantInt *LengthArg = dyn_cast<ConstantInt>(LenOp))
442 Len = LengthArg->getZExtValue();
446 if (Len == 0) return Dst; // strncpy(x, y, 0) -> x
448 // These optimizations require DataLayout.
451 // Let strncpy handle the zero padding
452 if (Len > SrcLen+1) return 0;
454 // strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant]
455 B.CreateMemCpy(Dst, Src,
456 ConstantInt::get(TD->getIntPtrType(*Context), Len), 1);
462 //===---------------------------------------===//
463 // 'strlen' Optimizations
465 struct StrLenOpt : public LibCallOptimization {
466 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
467 FunctionType *FT = Callee->getFunctionType();
468 if (FT->getNumParams() != 1 ||
469 FT->getParamType(0) != B.getInt8PtrTy() ||
470 !FT->getReturnType()->isIntegerTy())
473 Value *Src = CI->getArgOperand(0);
475 // Constant folding: strlen("xyz") -> 3
476 if (uint64_t Len = GetStringLength(Src))
477 return ConstantInt::get(CI->getType(), Len-1);
479 // strlen(x) != 0 --> *x != 0
480 // strlen(x) == 0 --> *x == 0
481 if (IsOnlyUsedInZeroEqualityComparison(CI))
482 return B.CreateZExt(B.CreateLoad(Src, "strlenfirst"), CI->getType());
488 //===---------------------------------------===//
489 // 'strpbrk' Optimizations
491 struct StrPBrkOpt : public LibCallOptimization {
492 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
493 FunctionType *FT = Callee->getFunctionType();
494 if (FT->getNumParams() != 2 ||
495 FT->getParamType(0) != B.getInt8PtrTy() ||
496 FT->getParamType(1) != FT->getParamType(0) ||
497 FT->getReturnType() != FT->getParamType(0))
501 bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
502 bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
504 // strpbrk(s, "") -> NULL
505 // strpbrk("", s) -> NULL
506 if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
507 return Constant::getNullValue(CI->getType());
510 if (HasS1 && HasS2) {
511 size_t I = S1.find_first_of(S2);
512 if (I == std::string::npos) // No match.
513 return Constant::getNullValue(CI->getType());
515 return B.CreateGEP(CI->getArgOperand(0), B.getInt64(I), "strpbrk");
518 // strpbrk(s, "a") -> strchr(s, 'a')
519 if (TD && HasS2 && S2.size() == 1)
520 return EmitStrChr(CI->getArgOperand(0), S2[0], B, TD, TLI);
526 //===---------------------------------------===//
527 // 'strto*' Optimizations. This handles strtol, strtod, strtof, strtoul, etc.
529 struct StrToOpt : public LibCallOptimization {
530 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
531 FunctionType *FT = Callee->getFunctionType();
532 if ((FT->getNumParams() != 2 && FT->getNumParams() != 3) ||
533 !FT->getParamType(0)->isPointerTy() ||
534 !FT->getParamType(1)->isPointerTy())
537 Value *EndPtr = CI->getArgOperand(1);
538 if (isa<ConstantPointerNull>(EndPtr)) {
539 // With a null EndPtr, this function won't capture the main argument.
540 // It would be readonly too, except that it still may write to errno.
541 Attributes::Builder B;
542 B.addAttribute(Attributes::NoCapture);
543 CI->addAttribute(1, Attributes::get(B));
550 //===---------------------------------------===//
551 // 'strspn' Optimizations
553 struct StrSpnOpt : public LibCallOptimization {
554 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
555 FunctionType *FT = Callee->getFunctionType();
556 if (FT->getNumParams() != 2 ||
557 FT->getParamType(0) != B.getInt8PtrTy() ||
558 FT->getParamType(1) != FT->getParamType(0) ||
559 !FT->getReturnType()->isIntegerTy())
563 bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
564 bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
566 // strspn(s, "") -> 0
567 // strspn("", s) -> 0
568 if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
569 return Constant::getNullValue(CI->getType());
572 if (HasS1 && HasS2) {
573 size_t Pos = S1.find_first_not_of(S2);
574 if (Pos == StringRef::npos) Pos = S1.size();
575 return ConstantInt::get(CI->getType(), Pos);
582 //===---------------------------------------===//
583 // 'strcspn' Optimizations
585 struct StrCSpnOpt : public LibCallOptimization {
586 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
587 FunctionType *FT = Callee->getFunctionType();
588 if (FT->getNumParams() != 2 ||
589 FT->getParamType(0) != B.getInt8PtrTy() ||
590 FT->getParamType(1) != FT->getParamType(0) ||
591 !FT->getReturnType()->isIntegerTy())
595 bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
596 bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
598 // strcspn("", s) -> 0
599 if (HasS1 && S1.empty())
600 return Constant::getNullValue(CI->getType());
603 if (HasS1 && HasS2) {
604 size_t Pos = S1.find_first_of(S2);
605 if (Pos == StringRef::npos) Pos = S1.size();
606 return ConstantInt::get(CI->getType(), Pos);
609 // strcspn(s, "") -> strlen(s)
610 if (TD && HasS2 && S2.empty())
611 return EmitStrLen(CI->getArgOperand(0), B, TD, TLI);
617 //===---------------------------------------===//
618 // 'strstr' Optimizations
620 struct StrStrOpt : public LibCallOptimization {
621 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
622 FunctionType *FT = Callee->getFunctionType();
623 if (FT->getNumParams() != 2 ||
624 !FT->getParamType(0)->isPointerTy() ||
625 !FT->getParamType(1)->isPointerTy() ||
626 !FT->getReturnType()->isPointerTy())
629 // fold strstr(x, x) -> x.
630 if (CI->getArgOperand(0) == CI->getArgOperand(1))
631 return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
633 // fold strstr(a, b) == a -> strncmp(a, b, strlen(b)) == 0
634 if (TD && IsOnlyUsedInEqualityComparison(CI, CI->getArgOperand(0))) {
635 Value *StrLen = EmitStrLen(CI->getArgOperand(1), B, TD, TLI);
638 Value *StrNCmp = EmitStrNCmp(CI->getArgOperand(0), CI->getArgOperand(1),
642 for (Value::use_iterator UI = CI->use_begin(), UE = CI->use_end();
644 ICmpInst *Old = cast<ICmpInst>(*UI++);
645 Value *Cmp = B.CreateICmp(Old->getPredicate(), StrNCmp,
646 ConstantInt::getNullValue(StrNCmp->getType()),
648 Old->replaceAllUsesWith(Cmp);
649 Old->eraseFromParent();
654 // See if either input string is a constant string.
655 StringRef SearchStr, ToFindStr;
656 bool HasStr1 = getConstantStringInfo(CI->getArgOperand(0), SearchStr);
657 bool HasStr2 = getConstantStringInfo(CI->getArgOperand(1), ToFindStr);
659 // fold strstr(x, "") -> x.
660 if (HasStr2 && ToFindStr.empty())
661 return B.CreateBitCast(CI->getArgOperand(0), CI->getType());
663 // If both strings are known, constant fold it.
664 if (HasStr1 && HasStr2) {
665 std::string::size_type Offset = SearchStr.find(ToFindStr);
667 if (Offset == StringRef::npos) // strstr("foo", "bar") -> null
668 return Constant::getNullValue(CI->getType());
670 // strstr("abcd", "bc") -> gep((char*)"abcd", 1)
671 Value *Result = CastToCStr(CI->getArgOperand(0), B);
672 Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
673 return B.CreateBitCast(Result, CI->getType());
676 // fold strstr(x, "y") -> strchr(x, 'y').
677 if (HasStr2 && ToFindStr.size() == 1) {
678 Value *StrChr= EmitStrChr(CI->getArgOperand(0), ToFindStr[0], B, TD, TLI);
679 return StrChr ? B.CreateBitCast(StrChr, CI->getType()) : 0;
686 //===---------------------------------------===//
687 // 'memcmp' Optimizations
689 struct MemCmpOpt : public LibCallOptimization {
690 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
691 FunctionType *FT = Callee->getFunctionType();
692 if (FT->getNumParams() != 3 || !FT->getParamType(0)->isPointerTy() ||
693 !FT->getParamType(1)->isPointerTy() ||
694 !FT->getReturnType()->isIntegerTy(32))
697 Value *LHS = CI->getArgOperand(0), *RHS = CI->getArgOperand(1);
699 if (LHS == RHS) // memcmp(s,s,x) -> 0
700 return Constant::getNullValue(CI->getType());
702 // Make sure we have a constant length.
703 ConstantInt *LenC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
705 uint64_t Len = LenC->getZExtValue();
707 if (Len == 0) // memcmp(s1,s2,0) -> 0
708 return Constant::getNullValue(CI->getType());
710 // memcmp(S1,S2,1) -> *(unsigned char*)LHS - *(unsigned char*)RHS
712 Value *LHSV = B.CreateZExt(B.CreateLoad(CastToCStr(LHS, B), "lhsc"),
713 CI->getType(), "lhsv");
714 Value *RHSV = B.CreateZExt(B.CreateLoad(CastToCStr(RHS, B), "rhsc"),
715 CI->getType(), "rhsv");
716 return B.CreateSub(LHSV, RHSV, "chardiff");
719 // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant)
720 StringRef LHSStr, RHSStr;
721 if (getConstantStringInfo(LHS, LHSStr) &&
722 getConstantStringInfo(RHS, RHSStr)) {
723 // Make sure we're not reading out-of-bounds memory.
724 if (Len > LHSStr.size() || Len > RHSStr.size())
726 uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len);
727 return ConstantInt::get(CI->getType(), Ret);
734 //===---------------------------------------===//
735 // 'memcpy' Optimizations
737 struct MemCpyOpt : public LibCallOptimization {
738 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
739 // These optimizations require DataLayout.
742 FunctionType *FT = Callee->getFunctionType();
743 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
744 !FT->getParamType(0)->isPointerTy() ||
745 !FT->getParamType(1)->isPointerTy() ||
746 FT->getParamType(2) != TD->getIntPtrType(*Context))
749 // memcpy(x, y, n) -> llvm.memcpy(x, y, n, 1)
750 B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
751 CI->getArgOperand(2), 1);
752 return CI->getArgOperand(0);
756 //===---------------------------------------===//
757 // 'memmove' Optimizations
759 struct MemMoveOpt : public LibCallOptimization {
760 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
761 // These optimizations require DataLayout.
764 FunctionType *FT = Callee->getFunctionType();
765 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
766 !FT->getParamType(0)->isPointerTy() ||
767 !FT->getParamType(1)->isPointerTy() ||
768 FT->getParamType(2) != TD->getIntPtrType(*Context))
771 // memmove(x, y, n) -> llvm.memmove(x, y, n, 1)
772 B.CreateMemMove(CI->getArgOperand(0), CI->getArgOperand(1),
773 CI->getArgOperand(2), 1);
774 return CI->getArgOperand(0);
778 //===---------------------------------------===//
779 // 'memset' Optimizations
781 struct MemSetOpt : public LibCallOptimization {
782 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
783 // These optimizations require DataLayout.
786 FunctionType *FT = Callee->getFunctionType();
787 if (FT->getNumParams() != 3 || FT->getReturnType() != FT->getParamType(0) ||
788 !FT->getParamType(0)->isPointerTy() ||
789 !FT->getParamType(1)->isIntegerTy() ||
790 FT->getParamType(2) != TD->getIntPtrType(*Context))
793 // memset(p, v, n) -> llvm.memset(p, v, n, 1)
794 Value *Val = B.CreateIntCast(CI->getArgOperand(1), B.getInt8Ty(), false);
795 B.CreateMemSet(CI->getArgOperand(0), Val, CI->getArgOperand(2), 1);
796 return CI->getArgOperand(0);
800 //===----------------------------------------------------------------------===//
801 // Math Library Optimizations
802 //===----------------------------------------------------------------------===//
804 //===---------------------------------------===//
805 // Double -> Float Shrinking Optimizations for Unary Functions like 'floor'
807 struct UnaryDoubleFPOpt : public LibCallOptimization {
809 UnaryDoubleFPOpt(bool CheckReturnType): CheckRetType(CheckReturnType) {}
810 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
811 FunctionType *FT = Callee->getFunctionType();
812 if (FT->getNumParams() != 1 || !FT->getReturnType()->isDoubleTy() ||
813 !FT->getParamType(0)->isDoubleTy())
817 // Check if all the uses for function like 'sin' are converted to float.
818 for (Value::use_iterator UseI = CI->use_begin(); UseI != CI->use_end();
820 FPTruncInst *Cast = dyn_cast<FPTruncInst>(*UseI);
821 if (Cast == 0 || !Cast->getType()->isFloatTy())
826 // If this is something like 'floor((double)floatval)', convert to floorf.
827 FPExtInst *Cast = dyn_cast<FPExtInst>(CI->getArgOperand(0));
828 if (Cast == 0 || !Cast->getOperand(0)->getType()->isFloatTy())
831 // floor((double)floatval) -> (double)floorf(floatval)
832 Value *V = Cast->getOperand(0);
833 V = EmitUnaryFloatFnCall(V, Callee->getName(), B, Callee->getAttributes());
834 return B.CreateFPExt(V, B.getDoubleTy());
838 //===---------------------------------------===//
839 // 'cos*' Optimizations
840 struct CosOpt : public LibCallOptimization {
841 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
843 if (UnsafeFPShrink && Callee->getName() == "cos" &&
844 TLI->has(LibFunc::cosf)) {
845 UnaryDoubleFPOpt UnsafeUnaryDoubleFP(true);
846 Ret = UnsafeUnaryDoubleFP.CallOptimizer(Callee, CI, B);
849 FunctionType *FT = Callee->getFunctionType();
850 // Just make sure this has 1 argument of FP type, which matches the
852 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
853 !FT->getParamType(0)->isFloatingPointTy())
857 Value *Op1 = CI->getArgOperand(0);
858 if (BinaryOperator::isFNeg(Op1)) {
859 BinaryOperator *BinExpr = cast<BinaryOperator>(Op1);
860 return B.CreateCall(Callee, BinExpr->getOperand(1), "cos");
866 //===---------------------------------------===//
867 // 'pow*' Optimizations
869 struct PowOpt : public LibCallOptimization {
870 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
872 if (UnsafeFPShrink && Callee->getName() == "pow" &&
873 TLI->has(LibFunc::powf)) {
874 UnaryDoubleFPOpt UnsafeUnaryDoubleFP(true);
875 Ret = UnsafeUnaryDoubleFP.CallOptimizer(Callee, CI, B);
878 FunctionType *FT = Callee->getFunctionType();
879 // Just make sure this has 2 arguments of the same FP type, which match the
881 if (FT->getNumParams() != 2 || FT->getReturnType() != FT->getParamType(0) ||
882 FT->getParamType(0) != FT->getParamType(1) ||
883 !FT->getParamType(0)->isFloatingPointTy())
886 Value *Op1 = CI->getArgOperand(0), *Op2 = CI->getArgOperand(1);
887 if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
888 if (Op1C->isExactlyValue(1.0)) // pow(1.0, x) -> 1.0
890 if (Op1C->isExactlyValue(2.0)) // pow(2.0, x) -> exp2(x)
891 return EmitUnaryFloatFnCall(Op2, "exp2", B, Callee->getAttributes());
894 ConstantFP *Op2C = dyn_cast<ConstantFP>(Op2);
895 if (Op2C == 0) return Ret;
897 if (Op2C->getValueAPF().isZero()) // pow(x, 0.0) -> 1.0
898 return ConstantFP::get(CI->getType(), 1.0);
900 if (Op2C->isExactlyValue(0.5)) {
901 // Expand pow(x, 0.5) to (x == -infinity ? +infinity : fabs(sqrt(x))).
902 // This is faster than calling pow, and still handles negative zero
903 // and negative infinity correctly.
904 // TODO: In fast-math mode, this could be just sqrt(x).
905 // TODO: In finite-only mode, this could be just fabs(sqrt(x)).
906 Value *Inf = ConstantFP::getInfinity(CI->getType());
907 Value *NegInf = ConstantFP::getInfinity(CI->getType(), true);
908 Value *Sqrt = EmitUnaryFloatFnCall(Op1, "sqrt", B,
909 Callee->getAttributes());
910 Value *FAbs = EmitUnaryFloatFnCall(Sqrt, "fabs", B,
911 Callee->getAttributes());
912 Value *FCmp = B.CreateFCmpOEQ(Op1, NegInf);
913 Value *Sel = B.CreateSelect(FCmp, Inf, FAbs);
917 if (Op2C->isExactlyValue(1.0)) // pow(x, 1.0) -> x
919 if (Op2C->isExactlyValue(2.0)) // pow(x, 2.0) -> x*x
920 return B.CreateFMul(Op1, Op1, "pow2");
921 if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
922 return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0),
928 //===---------------------------------------===//
929 // 'exp2' Optimizations
931 struct Exp2Opt : public LibCallOptimization {
932 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
934 if (UnsafeFPShrink && Callee->getName() == "exp2" &&
935 TLI->has(LibFunc::exp2)) {
936 UnaryDoubleFPOpt UnsafeUnaryDoubleFP(true);
937 Ret = UnsafeUnaryDoubleFP.CallOptimizer(Callee, CI, B);
940 FunctionType *FT = Callee->getFunctionType();
941 // Just make sure this has 1 argument of FP type, which matches the
943 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
944 !FT->getParamType(0)->isFloatingPointTy())
947 Value *Op = CI->getArgOperand(0);
948 // Turn exp2(sitofp(x)) -> ldexp(1.0, sext(x)) if sizeof(x) <= 32
949 // Turn exp2(uitofp(x)) -> ldexp(1.0, zext(x)) if sizeof(x) < 32
951 if (SIToFPInst *OpC = dyn_cast<SIToFPInst>(Op)) {
952 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() <= 32)
953 LdExpArg = B.CreateSExt(OpC->getOperand(0), B.getInt32Ty());
954 } else if (UIToFPInst *OpC = dyn_cast<UIToFPInst>(Op)) {
955 if (OpC->getOperand(0)->getType()->getPrimitiveSizeInBits() < 32)
956 LdExpArg = B.CreateZExt(OpC->getOperand(0), B.getInt32Ty());
961 if (Op->getType()->isFloatTy())
963 else if (Op->getType()->isDoubleTy())
968 Constant *One = ConstantFP::get(*Context, APFloat(1.0f));
969 if (!Op->getType()->isFloatTy())
970 One = ConstantExpr::getFPExtend(One, Op->getType());
972 Module *M = Caller->getParent();
973 Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
975 B.getInt32Ty(), NULL);
976 CallInst *CI = B.CreateCall2(Callee, One, LdExpArg);
977 if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
978 CI->setCallingConv(F->getCallingConv());
986 //===----------------------------------------------------------------------===//
987 // Integer Optimizations
988 //===----------------------------------------------------------------------===//
990 //===---------------------------------------===//
991 // 'ffs*' Optimizations
993 struct FFSOpt : public LibCallOptimization {
994 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
995 FunctionType *FT = Callee->getFunctionType();
996 // Just make sure this has 2 arguments of the same FP type, which match the
998 if (FT->getNumParams() != 1 ||
999 !FT->getReturnType()->isIntegerTy(32) ||
1000 !FT->getParamType(0)->isIntegerTy())
1003 Value *Op = CI->getArgOperand(0);
1006 if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
1007 if (CI->getValue() == 0) // ffs(0) -> 0.
1008 return Constant::getNullValue(CI->getType());
1009 // ffs(c) -> cttz(c)+1
1010 return B.getInt32(CI->getValue().countTrailingZeros() + 1);
1013 // ffs(x) -> x != 0 ? (i32)llvm.cttz(x)+1 : 0
1014 Type *ArgType = Op->getType();
1015 Value *F = Intrinsic::getDeclaration(Callee->getParent(),
1016 Intrinsic::cttz, ArgType);
1017 Value *V = B.CreateCall2(F, Op, B.getFalse(), "cttz");
1018 V = B.CreateAdd(V, ConstantInt::get(V->getType(), 1));
1019 V = B.CreateIntCast(V, B.getInt32Ty(), false);
1021 Value *Cond = B.CreateICmpNE(Op, Constant::getNullValue(ArgType));
1022 return B.CreateSelect(Cond, V, B.getInt32(0));
1026 //===---------------------------------------===//
1027 // 'isdigit' Optimizations
1029 struct IsDigitOpt : public LibCallOptimization {
1030 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1031 FunctionType *FT = Callee->getFunctionType();
1032 // We require integer(i32)
1033 if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1034 !FT->getParamType(0)->isIntegerTy(32))
1037 // isdigit(c) -> (c-'0') <u 10
1038 Value *Op = CI->getArgOperand(0);
1039 Op = B.CreateSub(Op, B.getInt32('0'), "isdigittmp");
1040 Op = B.CreateICmpULT(Op, B.getInt32(10), "isdigit");
1041 return B.CreateZExt(Op, CI->getType());
1045 //===---------------------------------------===//
1046 // 'isascii' Optimizations
1048 struct IsAsciiOpt : public LibCallOptimization {
1049 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1050 FunctionType *FT = Callee->getFunctionType();
1051 // We require integer(i32)
1052 if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1053 !FT->getParamType(0)->isIntegerTy(32))
1056 // isascii(c) -> c <u 128
1057 Value *Op = CI->getArgOperand(0);
1058 Op = B.CreateICmpULT(Op, B.getInt32(128), "isascii");
1059 return B.CreateZExt(Op, CI->getType());
1063 //===---------------------------------------===//
1064 // 'abs', 'labs', 'llabs' Optimizations
1066 struct AbsOpt : public LibCallOptimization {
1067 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1068 FunctionType *FT = Callee->getFunctionType();
1069 // We require integer(integer) where the types agree.
1070 if (FT->getNumParams() != 1 || !FT->getReturnType()->isIntegerTy() ||
1071 FT->getParamType(0) != FT->getReturnType())
1074 // abs(x) -> x >s -1 ? x : -x
1075 Value *Op = CI->getArgOperand(0);
1076 Value *Pos = B.CreateICmpSGT(Op, Constant::getAllOnesValue(Op->getType()),
1078 Value *Neg = B.CreateNeg(Op, "neg");
1079 return B.CreateSelect(Pos, Op, Neg);
1084 //===---------------------------------------===//
1085 // 'toascii' Optimizations
1087 struct ToAsciiOpt : public LibCallOptimization {
1088 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1089 FunctionType *FT = Callee->getFunctionType();
1090 // We require i32(i32)
1091 if (FT->getNumParams() != 1 || FT->getReturnType() != FT->getParamType(0) ||
1092 !FT->getParamType(0)->isIntegerTy(32))
1095 // isascii(c) -> c & 0x7f
1096 return B.CreateAnd(CI->getArgOperand(0),
1097 ConstantInt::get(CI->getType(),0x7F));
1101 //===----------------------------------------------------------------------===//
1102 // Formatting and IO Optimizations
1103 //===----------------------------------------------------------------------===//
1105 //===---------------------------------------===//
1106 // 'printf' Optimizations
1108 struct PrintFOpt : public LibCallOptimization {
1109 Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI,
1111 // Check for a fixed format string.
1112 StringRef FormatStr;
1113 if (!getConstantStringInfo(CI->getArgOperand(0), FormatStr))
1116 // Empty format string -> noop.
1117 if (FormatStr.empty()) // Tolerate printf's declared void.
1118 return CI->use_empty() ? (Value*)CI :
1119 ConstantInt::get(CI->getType(), 0);
1121 // Do not do any of the following transformations if the printf return value
1122 // is used, in general the printf return value is not compatible with either
1123 // putchar() or puts().
1124 if (!CI->use_empty())
1127 // printf("x") -> putchar('x'), even for '%'.
1128 if (FormatStr.size() == 1) {
1129 Value *Res = EmitPutChar(B.getInt32(FormatStr[0]), B, TD, TLI);
1130 if (CI->use_empty() || !Res) return Res;
1131 return B.CreateIntCast(Res, CI->getType(), true);
1134 // printf("foo\n") --> puts("foo")
1135 if (FormatStr[FormatStr.size()-1] == '\n' &&
1136 FormatStr.find('%') == std::string::npos) { // no format characters.
1137 // Create a string literal with no \n on it. We expect the constant merge
1138 // pass to be run after this pass, to merge duplicate strings.
1139 FormatStr = FormatStr.drop_back();
1140 Value *GV = B.CreateGlobalString(FormatStr, "str");
1141 Value *NewCI = EmitPutS(GV, B, TD, TLI);
1142 return (CI->use_empty() || !NewCI) ?
1144 ConstantInt::get(CI->getType(), FormatStr.size()+1);
1147 // Optimize specific format strings.
1148 // printf("%c", chr) --> putchar(chr)
1149 if (FormatStr == "%c" && CI->getNumArgOperands() > 1 &&
1150 CI->getArgOperand(1)->getType()->isIntegerTy()) {
1151 Value *Res = EmitPutChar(CI->getArgOperand(1), B, TD, TLI);
1153 if (CI->use_empty() || !Res) return Res;
1154 return B.CreateIntCast(Res, CI->getType(), true);
1157 // printf("%s\n", str) --> puts(str)
1158 if (FormatStr == "%s\n" && CI->getNumArgOperands() > 1 &&
1159 CI->getArgOperand(1)->getType()->isPointerTy()) {
1160 return EmitPutS(CI->getArgOperand(1), B, TD, TLI);
1165 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1166 // Require one fixed pointer argument and an integer/void result.
1167 FunctionType *FT = Callee->getFunctionType();
1168 if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
1169 !(FT->getReturnType()->isIntegerTy() ||
1170 FT->getReturnType()->isVoidTy()))
1173 if (Value *V = OptimizeFixedFormatString(Callee, CI, B)) {
1177 // printf(format, ...) -> iprintf(format, ...) if no floating point
1179 if (TLI->has(LibFunc::iprintf) && !CallHasFloatingPointArgument(CI)) {
1180 Module *M = B.GetInsertBlock()->getParent()->getParent();
1181 Constant *IPrintFFn =
1182 M->getOrInsertFunction("iprintf", FT, Callee->getAttributes());
1183 CallInst *New = cast<CallInst>(CI->clone());
1184 New->setCalledFunction(IPrintFFn);
1192 //===---------------------------------------===//
1193 // 'sprintf' Optimizations
1195 struct SPrintFOpt : public LibCallOptimization {
1196 Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI,
1198 // Check for a fixed format string.
1199 StringRef FormatStr;
1200 if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
1203 // If we just have a format string (nothing else crazy) transform it.
1204 if (CI->getNumArgOperands() == 2) {
1205 // Make sure there's no % in the constant array. We could try to handle
1206 // %% -> % in the future if we cared.
1207 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1208 if (FormatStr[i] == '%')
1209 return 0; // we found a format specifier, bail out.
1211 // These optimizations require DataLayout.
1214 // sprintf(str, fmt) -> llvm.memcpy(str, fmt, strlen(fmt)+1, 1)
1215 B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(1),
1216 ConstantInt::get(TD->getIntPtrType(*Context), // Copy the
1217 FormatStr.size() + 1), 1); // nul byte.
1218 return ConstantInt::get(CI->getType(), FormatStr.size());
1221 // The remaining optimizations require the format string to be "%s" or "%c"
1222 // and have an extra operand.
1223 if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1224 CI->getNumArgOperands() < 3)
1227 // Decode the second character of the format string.
1228 if (FormatStr[1] == 'c') {
1229 // sprintf(dst, "%c", chr) --> *(i8*)dst = chr; *((i8*)dst+1) = 0
1230 if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return 0;
1231 Value *V = B.CreateTrunc(CI->getArgOperand(2), B.getInt8Ty(), "char");
1232 Value *Ptr = CastToCStr(CI->getArgOperand(0), B);
1233 B.CreateStore(V, Ptr);
1234 Ptr = B.CreateGEP(Ptr, B.getInt32(1), "nul");
1235 B.CreateStore(B.getInt8(0), Ptr);
1237 return ConstantInt::get(CI->getType(), 1);
1240 if (FormatStr[1] == 's') {
1241 // These optimizations require DataLayout.
1244 // sprintf(dest, "%s", str) -> llvm.memcpy(dest, str, strlen(str)+1, 1)
1245 if (!CI->getArgOperand(2)->getType()->isPointerTy()) return 0;
1247 Value *Len = EmitStrLen(CI->getArgOperand(2), B, TD, TLI);
1250 Value *IncLen = B.CreateAdd(Len,
1251 ConstantInt::get(Len->getType(), 1),
1253 B.CreateMemCpy(CI->getArgOperand(0), CI->getArgOperand(2), IncLen, 1);
1255 // The sprintf result is the unincremented number of bytes in the string.
1256 return B.CreateIntCast(Len, CI->getType(), false);
1261 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1262 // Require two fixed pointer arguments and an integer result.
1263 FunctionType *FT = Callee->getFunctionType();
1264 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1265 !FT->getParamType(1)->isPointerTy() ||
1266 !FT->getReturnType()->isIntegerTy())
1269 if (Value *V = OptimizeFixedFormatString(Callee, CI, B)) {
1273 // sprintf(str, format, ...) -> siprintf(str, format, ...) if no floating
1275 if (TLI->has(LibFunc::siprintf) && !CallHasFloatingPointArgument(CI)) {
1276 Module *M = B.GetInsertBlock()->getParent()->getParent();
1277 Constant *SIPrintFFn =
1278 M->getOrInsertFunction("siprintf", FT, Callee->getAttributes());
1279 CallInst *New = cast<CallInst>(CI->clone());
1280 New->setCalledFunction(SIPrintFFn);
1288 //===---------------------------------------===//
1289 // 'fwrite' Optimizations
1291 struct FWriteOpt : public LibCallOptimization {
1292 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1293 // Require a pointer, an integer, an integer, a pointer, returning integer.
1294 FunctionType *FT = Callee->getFunctionType();
1295 if (FT->getNumParams() != 4 || !FT->getParamType(0)->isPointerTy() ||
1296 !FT->getParamType(1)->isIntegerTy() ||
1297 !FT->getParamType(2)->isIntegerTy() ||
1298 !FT->getParamType(3)->isPointerTy() ||
1299 !FT->getReturnType()->isIntegerTy())
1302 // Get the element size and count.
1303 ConstantInt *SizeC = dyn_cast<ConstantInt>(CI->getArgOperand(1));
1304 ConstantInt *CountC = dyn_cast<ConstantInt>(CI->getArgOperand(2));
1305 if (!SizeC || !CountC) return 0;
1306 uint64_t Bytes = SizeC->getZExtValue()*CountC->getZExtValue();
1308 // If this is writing zero records, remove the call (it's a noop).
1310 return ConstantInt::get(CI->getType(), 0);
1312 // If this is writing one byte, turn it into fputc.
1313 // This optimisation is only valid, if the return value is unused.
1314 if (Bytes == 1 && CI->use_empty()) { // fwrite(S,1,1,F) -> fputc(S[0],F)
1315 Value *Char = B.CreateLoad(CastToCStr(CI->getArgOperand(0), B), "char");
1316 Value *NewCI = EmitFPutC(Char, CI->getArgOperand(3), B, TD, TLI);
1317 return NewCI ? ConstantInt::get(CI->getType(), 1) : 0;
1324 //===---------------------------------------===//
1325 // 'fputs' Optimizations
1327 struct FPutsOpt : public LibCallOptimization {
1328 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1329 // These optimizations require DataLayout.
1332 // Require two pointers. Also, we can't optimize if return value is used.
1333 FunctionType *FT = Callee->getFunctionType();
1334 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1335 !FT->getParamType(1)->isPointerTy() ||
1339 // fputs(s,F) --> fwrite(s,1,strlen(s),F)
1340 uint64_t Len = GetStringLength(CI->getArgOperand(0));
1342 // Known to have no uses (see above).
1343 return EmitFWrite(CI->getArgOperand(0),
1344 ConstantInt::get(TD->getIntPtrType(*Context), Len-1),
1345 CI->getArgOperand(1), B, TD, TLI);
1349 //===---------------------------------------===//
1350 // 'fprintf' Optimizations
1352 struct FPrintFOpt : public LibCallOptimization {
1353 Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI,
1355 // All the optimizations depend on the format string.
1356 StringRef FormatStr;
1357 if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr))
1360 // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
1361 if (CI->getNumArgOperands() == 2) {
1362 for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
1363 if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
1364 return 0; // We found a format specifier.
1366 // These optimizations require DataLayout.
1369 Value *NewCI = EmitFWrite(CI->getArgOperand(1),
1370 ConstantInt::get(TD->getIntPtrType(*Context),
1372 CI->getArgOperand(0), B, TD, TLI);
1373 return NewCI ? ConstantInt::get(CI->getType(), FormatStr.size()) : 0;
1376 // The remaining optimizations require the format string to be "%s" or "%c"
1377 // and have an extra operand.
1378 if (FormatStr.size() != 2 || FormatStr[0] != '%' ||
1379 CI->getNumArgOperands() < 3)
1382 // Decode the second character of the format string.
1383 if (FormatStr[1] == 'c') {
1384 // fprintf(F, "%c", chr) --> fputc(chr, F)
1385 if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return 0;
1386 Value *NewCI = EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B,
1388 return NewCI ? ConstantInt::get(CI->getType(), 1) : 0;
1391 if (FormatStr[1] == 's') {
1392 // fprintf(F, "%s", str) --> fputs(str, F)
1393 if (!CI->getArgOperand(2)->getType()->isPointerTy() || !CI->use_empty())
1395 return EmitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, TD, TLI);
1400 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1401 // Require two fixed paramters as pointers and integer result.
1402 FunctionType *FT = Callee->getFunctionType();
1403 if (FT->getNumParams() != 2 || !FT->getParamType(0)->isPointerTy() ||
1404 !FT->getParamType(1)->isPointerTy() ||
1405 !FT->getReturnType()->isIntegerTy())
1408 if (Value *V = OptimizeFixedFormatString(Callee, CI, B)) {
1412 // fprintf(stream, format, ...) -> fiprintf(stream, format, ...) if no
1413 // floating point arguments.
1414 if (TLI->has(LibFunc::fiprintf) && !CallHasFloatingPointArgument(CI)) {
1415 Module *M = B.GetInsertBlock()->getParent()->getParent();
1416 Constant *FIPrintFFn =
1417 M->getOrInsertFunction("fiprintf", FT, Callee->getAttributes());
1418 CallInst *New = cast<CallInst>(CI->clone());
1419 New->setCalledFunction(FIPrintFFn);
1427 //===---------------------------------------===//
1428 // 'puts' Optimizations
1430 struct PutsOpt : public LibCallOptimization {
1431 virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
1432 // Require one fixed pointer argument and an integer/void result.
1433 FunctionType *FT = Callee->getFunctionType();
1434 if (FT->getNumParams() < 1 || !FT->getParamType(0)->isPointerTy() ||
1435 !(FT->getReturnType()->isIntegerTy() ||
1436 FT->getReturnType()->isVoidTy()))
1439 // Check for a constant string.
1441 if (!getConstantStringInfo(CI->getArgOperand(0), Str))
1444 if (Str.empty() && CI->use_empty()) {
1445 // puts("") -> putchar('\n')
1446 Value *Res = EmitPutChar(B.getInt32('\n'), B, TD, TLI);
1447 if (CI->use_empty() || !Res) return Res;
1448 return B.CreateIntCast(Res, CI->getType(), true);
1455 } // end anonymous namespace.
1457 //===----------------------------------------------------------------------===//
1458 // SimplifyLibCalls Pass Implementation
1459 //===----------------------------------------------------------------------===//
1462 /// This pass optimizes well known library functions from libc and libm.
1464 class SimplifyLibCalls : public FunctionPass {
1465 TargetLibraryInfo *TLI;
1467 StringMap<LibCallOptimization*> Optimizations;
1468 // String and Memory LibCall Optimizations
1469 StrChrOpt StrChr; StrRChrOpt StrRChr;
1470 StrCmpOpt StrCmp; StrNCmpOpt StrNCmp;
1471 StrCpyOpt StrCpy; StrCpyOpt StrCpyChk;
1472 StpCpyOpt StpCpy; StpCpyOpt StpCpyChk;
1474 StrLenOpt StrLen; StrPBrkOpt StrPBrk;
1475 StrToOpt StrTo; StrSpnOpt StrSpn; StrCSpnOpt StrCSpn; StrStrOpt StrStr;
1476 MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
1477 // Math Library Optimizations
1478 CosOpt Cos; PowOpt Pow; Exp2Opt Exp2;
1479 UnaryDoubleFPOpt UnaryDoubleFP, UnsafeUnaryDoubleFP;
1480 // Integer Optimizations
1481 FFSOpt FFS; AbsOpt Abs; IsDigitOpt IsDigit; IsAsciiOpt IsAscii;
1483 // Formatting and IO Optimizations
1484 SPrintFOpt SPrintF; PrintFOpt PrintF;
1485 FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
1488 bool Modified; // This is only used by doInitialization.
1490 static char ID; // Pass identification
1491 SimplifyLibCalls() : FunctionPass(ID), StrCpy(false), StrCpyChk(true),
1492 StpCpy(false), StpCpyChk(true),
1493 UnaryDoubleFP(false), UnsafeUnaryDoubleFP(true) {
1494 initializeSimplifyLibCallsPass(*PassRegistry::getPassRegistry());
1496 void AddOpt(LibFunc::Func F, LibCallOptimization* Opt);
1497 void AddOpt(LibFunc::Func F1, LibFunc::Func F2, LibCallOptimization* Opt);
1499 void InitOptimizations();
1500 bool runOnFunction(Function &F);
1502 void setDoesNotAccessMemory(Function &F);
1503 void setOnlyReadsMemory(Function &F);
1504 void setDoesNotThrow(Function &F);
1505 void setDoesNotCapture(Function &F, unsigned n);
1506 void setDoesNotAlias(Function &F, unsigned n);
1507 bool doInitialization(Module &M);
1509 void inferPrototypeAttributes(Function &F);
1510 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
1511 AU.addRequired<TargetLibraryInfo>();
1514 } // end anonymous namespace.
1516 char SimplifyLibCalls::ID = 0;
1518 INITIALIZE_PASS_BEGIN(SimplifyLibCalls, "simplify-libcalls",
1519 "Simplify well-known library calls", false, false)
1520 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
1521 INITIALIZE_PASS_END(SimplifyLibCalls, "simplify-libcalls",
1522 "Simplify well-known library calls", false, false)
1524 // Public interface to the Simplify LibCalls pass.
1525 FunctionPass *llvm::createSimplifyLibCallsPass() {
1526 return new SimplifyLibCalls();
1529 void SimplifyLibCalls::AddOpt(LibFunc::Func F, LibCallOptimization* Opt) {
1531 Optimizations[TLI->getName(F)] = Opt;
1534 void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2,
1535 LibCallOptimization* Opt) {
1536 if (TLI->has(F1) && TLI->has(F2))
1537 Optimizations[TLI->getName(F1)] = Opt;
1540 /// Optimizations - Populate the Optimizations map with all the optimizations
1542 void SimplifyLibCalls::InitOptimizations() {
1543 // String and Memory LibCall Optimizations
1544 Optimizations["strchr"] = &StrChr;
1545 Optimizations["strrchr"] = &StrRChr;
1546 Optimizations["strcmp"] = &StrCmp;
1547 Optimizations["strncmp"] = &StrNCmp;
1548 Optimizations["strcpy"] = &StrCpy;
1549 Optimizations["strncpy"] = &StrNCpy;
1550 Optimizations["stpcpy"] = &StpCpy;
1551 Optimizations["strlen"] = &StrLen;
1552 Optimizations["strpbrk"] = &StrPBrk;
1553 Optimizations["strtol"] = &StrTo;
1554 Optimizations["strtod"] = &StrTo;
1555 Optimizations["strtof"] = &StrTo;
1556 Optimizations["strtoul"] = &StrTo;
1557 Optimizations["strtoll"] = &StrTo;
1558 Optimizations["strtold"] = &StrTo;
1559 Optimizations["strtoull"] = &StrTo;
1560 Optimizations["strspn"] = &StrSpn;
1561 Optimizations["strcspn"] = &StrCSpn;
1562 Optimizations["strstr"] = &StrStr;
1563 Optimizations["memcmp"] = &MemCmp;
1564 AddOpt(LibFunc::memcpy, &MemCpy);
1565 Optimizations["memmove"] = &MemMove;
1566 AddOpt(LibFunc::memset, &MemSet);
1568 // _chk variants of String and Memory LibCall Optimizations.
1569 Optimizations["__strcpy_chk"] = &StrCpyChk;
1570 Optimizations["__stpcpy_chk"] = &StpCpyChk;
1572 // Math Library Optimizations
1573 Optimizations["cosf"] = &Cos;
1574 Optimizations["cos"] = &Cos;
1575 Optimizations["cosl"] = &Cos;
1576 Optimizations["powf"] = &Pow;
1577 Optimizations["pow"] = &Pow;
1578 Optimizations["powl"] = &Pow;
1579 Optimizations["llvm.pow.f32"] = &Pow;
1580 Optimizations["llvm.pow.f64"] = &Pow;
1581 Optimizations["llvm.pow.f80"] = &Pow;
1582 Optimizations["llvm.pow.f128"] = &Pow;
1583 Optimizations["llvm.pow.ppcf128"] = &Pow;
1584 Optimizations["exp2l"] = &Exp2;
1585 Optimizations["exp2"] = &Exp2;
1586 Optimizations["exp2f"] = &Exp2;
1587 Optimizations["llvm.exp2.ppcf128"] = &Exp2;
1588 Optimizations["llvm.exp2.f128"] = &Exp2;
1589 Optimizations["llvm.exp2.f80"] = &Exp2;
1590 Optimizations["llvm.exp2.f64"] = &Exp2;
1591 Optimizations["llvm.exp2.f32"] = &Exp2;
1593 AddOpt(LibFunc::ceil, LibFunc::ceilf, &UnaryDoubleFP);
1594 AddOpt(LibFunc::fabs, LibFunc::fabsf, &UnaryDoubleFP);
1595 AddOpt(LibFunc::floor, LibFunc::floorf, &UnaryDoubleFP);
1596 AddOpt(LibFunc::rint, LibFunc::rintf, &UnaryDoubleFP);
1597 AddOpt(LibFunc::round, LibFunc::roundf, &UnaryDoubleFP);
1598 AddOpt(LibFunc::nearbyint, LibFunc::nearbyintf, &UnaryDoubleFP);
1599 AddOpt(LibFunc::trunc, LibFunc::truncf, &UnaryDoubleFP);
1601 if(UnsafeFPShrink) {
1602 AddOpt(LibFunc::acos, LibFunc::acosf, &UnsafeUnaryDoubleFP);
1603 AddOpt(LibFunc::acosh, LibFunc::acoshf, &UnsafeUnaryDoubleFP);
1604 AddOpt(LibFunc::asin, LibFunc::asinf, &UnsafeUnaryDoubleFP);
1605 AddOpt(LibFunc::asinh, LibFunc::asinhf, &UnsafeUnaryDoubleFP);
1606 AddOpt(LibFunc::atan, LibFunc::atanf, &UnsafeUnaryDoubleFP);
1607 AddOpt(LibFunc::atanh, LibFunc::atanhf, &UnsafeUnaryDoubleFP);
1608 AddOpt(LibFunc::cbrt, LibFunc::cbrtf, &UnsafeUnaryDoubleFP);
1609 AddOpt(LibFunc::cosh, LibFunc::coshf, &UnsafeUnaryDoubleFP);
1610 AddOpt(LibFunc::exp, LibFunc::expf, &UnsafeUnaryDoubleFP);
1611 AddOpt(LibFunc::exp10, LibFunc::exp10f, &UnsafeUnaryDoubleFP);
1612 AddOpt(LibFunc::expm1, LibFunc::expm1f, &UnsafeUnaryDoubleFP);
1613 AddOpt(LibFunc::log, LibFunc::logf, &UnsafeUnaryDoubleFP);
1614 AddOpt(LibFunc::log10, LibFunc::log10f, &UnsafeUnaryDoubleFP);
1615 AddOpt(LibFunc::log1p, LibFunc::log1pf, &UnsafeUnaryDoubleFP);
1616 AddOpt(LibFunc::log2, LibFunc::log2f, &UnsafeUnaryDoubleFP);
1617 AddOpt(LibFunc::logb, LibFunc::logbf, &UnsafeUnaryDoubleFP);
1618 AddOpt(LibFunc::sin, LibFunc::sinf, &UnsafeUnaryDoubleFP);
1619 AddOpt(LibFunc::sinh, LibFunc::sinhf, &UnsafeUnaryDoubleFP);
1620 AddOpt(LibFunc::sqrt, LibFunc::sqrtf, &UnsafeUnaryDoubleFP);
1621 AddOpt(LibFunc::tan, LibFunc::tanf, &UnsafeUnaryDoubleFP);
1622 AddOpt(LibFunc::tanh, LibFunc::tanhf, &UnsafeUnaryDoubleFP);
1625 // Integer Optimizations
1626 Optimizations["ffs"] = &FFS;
1627 Optimizations["ffsl"] = &FFS;
1628 Optimizations["ffsll"] = &FFS;
1629 Optimizations["abs"] = &Abs;
1630 Optimizations["labs"] = &Abs;
1631 Optimizations["llabs"] = &Abs;
1632 Optimizations["isdigit"] = &IsDigit;
1633 Optimizations["isascii"] = &IsAscii;
1634 Optimizations["toascii"] = &ToAscii;
1636 // Formatting and IO Optimizations
1637 Optimizations["sprintf"] = &SPrintF;
1638 Optimizations["printf"] = &PrintF;
1639 AddOpt(LibFunc::fwrite, &FWrite);
1640 AddOpt(LibFunc::fputs, &FPuts);
1641 Optimizations["fprintf"] = &FPrintF;
1642 Optimizations["puts"] = &Puts;
1646 /// runOnFunction - Top level algorithm.
1648 bool SimplifyLibCalls::runOnFunction(Function &F) {
1649 TLI = &getAnalysis<TargetLibraryInfo>();
1651 if (Optimizations.empty())
1652 InitOptimizations();
1654 const DataLayout *TD = getAnalysisIfAvailable<DataLayout>();
1656 IRBuilder<> Builder(F.getContext());
1658 bool Changed = false;
1659 for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
1660 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
1661 // Ignore non-calls.
1662 CallInst *CI = dyn_cast<CallInst>(I++);
1665 // Ignore indirect calls and calls to non-external functions.
1666 Function *Callee = CI->getCalledFunction();
1667 if (Callee == 0 || !Callee->isDeclaration() ||
1668 !(Callee->hasExternalLinkage() || Callee->hasDLLImportLinkage()))
1671 // Ignore unknown calls.
1672 LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
1675 // Set the builder to the instruction after the call.
1676 Builder.SetInsertPoint(BB, I);
1678 // Use debug location of CI for all new instructions.
1679 Builder.SetCurrentDebugLocation(CI->getDebugLoc());
1681 // Try to optimize this call.
1682 Value *Result = LCO->OptimizeCall(CI, TD, TLI, Builder);
1683 if (Result == 0) continue;
1685 DEBUG(dbgs() << "SimplifyLibCalls simplified: " << *CI;
1686 dbgs() << " into: " << *Result << "\n");
1688 // Something changed!
1692 // Inspect the instruction after the call (which was potentially just
1696 if (CI != Result && !CI->use_empty()) {
1697 CI->replaceAllUsesWith(Result);
1698 if (!Result->hasName())
1699 Result->takeName(CI);
1701 CI->eraseFromParent();
1707 // Utility methods for doInitialization.
1709 void SimplifyLibCalls::setDoesNotAccessMemory(Function &F) {
1710 if (!F.doesNotAccessMemory()) {
1711 F.setDoesNotAccessMemory();
1716 void SimplifyLibCalls::setOnlyReadsMemory(Function &F) {
1717 if (!F.onlyReadsMemory()) {
1718 F.setOnlyReadsMemory();
1723 void SimplifyLibCalls::setDoesNotThrow(Function &F) {
1724 if (!F.doesNotThrow()) {
1725 F.setDoesNotThrow();
1730 void SimplifyLibCalls::setDoesNotCapture(Function &F, unsigned n) {
1731 if (!F.doesNotCapture(n)) {
1732 F.setDoesNotCapture(n);
1737 void SimplifyLibCalls::setDoesNotAlias(Function &F, unsigned n) {
1738 if (!F.doesNotAlias(n)) {
1739 F.setDoesNotAlias(n);
1746 void SimplifyLibCalls::inferPrototypeAttributes(Function &F) {
1747 FunctionType *FTy = F.getFunctionType();
1749 StringRef Name = F.getName();
1752 if (Name == "strlen") {
1753 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
1755 setOnlyReadsMemory(F);
1757 setDoesNotCapture(F, 1);
1758 } else if (Name == "strchr" ||
1759 Name == "strrchr") {
1760 if (FTy->getNumParams() != 2 ||
1761 !FTy->getParamType(0)->isPointerTy() ||
1762 !FTy->getParamType(1)->isIntegerTy())
1764 setOnlyReadsMemory(F);
1766 } else if (Name == "strcpy" ||
1772 Name == "strtoul" ||
1773 Name == "strtoll" ||
1774 Name == "strtold" ||
1775 Name == "strncat" ||
1776 Name == "strncpy" ||
1777 Name == "stpncpy" ||
1778 Name == "strtoull") {
1779 if (FTy->getNumParams() < 2 ||
1780 !FTy->getParamType(1)->isPointerTy())
1783 setDoesNotCapture(F, 2);
1784 } else if (Name == "strxfrm") {
1785 if (FTy->getNumParams() != 3 ||
1786 !FTy->getParamType(0)->isPointerTy() ||
1787 !FTy->getParamType(1)->isPointerTy())
1790 setDoesNotCapture(F, 1);
1791 setDoesNotCapture(F, 2);
1792 } else if (Name == "strcmp" ||
1794 Name == "strncmp" ||
1795 Name == "strcspn" ||
1796 Name == "strcoll" ||
1797 Name == "strcasecmp" ||
1798 Name == "strncasecmp") {
1799 if (FTy->getNumParams() < 2 ||
1800 !FTy->getParamType(0)->isPointerTy() ||
1801 !FTy->getParamType(1)->isPointerTy())
1803 setOnlyReadsMemory(F);
1805 setDoesNotCapture(F, 1);
1806 setDoesNotCapture(F, 2);
1807 } else if (Name == "strstr" ||
1808 Name == "strpbrk") {
1809 if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
1811 setOnlyReadsMemory(F);
1813 setDoesNotCapture(F, 2);
1814 } else if (Name == "strtok" ||
1815 Name == "strtok_r") {
1816 if (FTy->getNumParams() < 2 || !FTy->getParamType(1)->isPointerTy())
1819 setDoesNotCapture(F, 2);
1820 } else if (Name == "scanf" ||
1822 Name == "setvbuf") {
1823 if (FTy->getNumParams() < 1 || !FTy->getParamType(0)->isPointerTy())
1826 setDoesNotCapture(F, 1);
1827 } else if (Name == "strdup" ||
1828 Name == "strndup") {
1829 if (FTy->getNumParams() < 1 || !FTy->getReturnType()->isPointerTy() ||
1830 !FTy->getParamType(0)->isPointerTy())
1833 setDoesNotAlias(F, 0);
1834 setDoesNotCapture(F, 1);
1835 } else if (Name == "stat" ||
1837 Name == "sprintf" ||
1838 Name == "statvfs") {
1839 if (FTy->getNumParams() < 2 ||
1840 !FTy->getParamType(0)->isPointerTy() ||
1841 !FTy->getParamType(1)->isPointerTy())
1844 setDoesNotCapture(F, 1);
1845 setDoesNotCapture(F, 2);
1846 } else if (Name == "snprintf") {
1847 if (FTy->getNumParams() != 3 ||
1848 !FTy->getParamType(0)->isPointerTy() ||
1849 !FTy->getParamType(2)->isPointerTy())
1852 setDoesNotCapture(F, 1);
1853 setDoesNotCapture(F, 3);
1854 } else if (Name == "setitimer") {
1855 if (FTy->getNumParams() != 3 ||
1856 !FTy->getParamType(1)->isPointerTy() ||
1857 !FTy->getParamType(2)->isPointerTy())
1860 setDoesNotCapture(F, 2);
1861 setDoesNotCapture(F, 3);
1862 } else if (Name == "system") {
1863 if (FTy->getNumParams() != 1 ||
1864 !FTy->getParamType(0)->isPointerTy())
1866 // May throw; "system" is a valid pthread cancellation point.
1867 setDoesNotCapture(F, 1);
1871 if (Name == "malloc") {
1872 if (FTy->getNumParams() != 1 ||
1873 !FTy->getReturnType()->isPointerTy())
1876 setDoesNotAlias(F, 0);
1877 } else if (Name == "memcmp") {
1878 if (FTy->getNumParams() != 3 ||
1879 !FTy->getParamType(0)->isPointerTy() ||
1880 !FTy->getParamType(1)->isPointerTy())
1882 setOnlyReadsMemory(F);
1884 setDoesNotCapture(F, 1);
1885 setDoesNotCapture(F, 2);
1886 } else if (Name == "memchr" ||
1887 Name == "memrchr") {
1888 if (FTy->getNumParams() != 3)
1890 setOnlyReadsMemory(F);
1892 } else if (Name == "modf" ||
1896 Name == "memccpy" ||
1897 Name == "memmove") {
1898 if (FTy->getNumParams() < 2 ||
1899 !FTy->getParamType(1)->isPointerTy())
1902 setDoesNotCapture(F, 2);
1903 } else if (Name == "memalign") {
1904 if (!FTy->getReturnType()->isPointerTy())
1906 setDoesNotAlias(F, 0);
1907 } else if (Name == "mkdir" ||
1909 if (FTy->getNumParams() == 0 ||
1910 !FTy->getParamType(0)->isPointerTy())
1913 setDoesNotCapture(F, 1);
1917 if (Name == "realloc") {
1918 if (FTy->getNumParams() != 2 ||
1919 !FTy->getParamType(0)->isPointerTy() ||
1920 !FTy->getReturnType()->isPointerTy())
1923 setDoesNotAlias(F, 0);
1924 setDoesNotCapture(F, 1);
1925 } else if (Name == "read") {
1926 if (FTy->getNumParams() != 3 ||
1927 !FTy->getParamType(1)->isPointerTy())
1929 // May throw; "read" is a valid pthread cancellation point.
1930 setDoesNotCapture(F, 2);
1931 } else if (Name == "rmdir" ||
1934 Name == "realpath") {
1935 if (FTy->getNumParams() < 1 ||
1936 !FTy->getParamType(0)->isPointerTy())
1939 setDoesNotCapture(F, 1);
1940 } else if (Name == "rename" ||
1941 Name == "readlink") {
1942 if (FTy->getNumParams() < 2 ||
1943 !FTy->getParamType(0)->isPointerTy() ||
1944 !FTy->getParamType(1)->isPointerTy())
1947 setDoesNotCapture(F, 1);
1948 setDoesNotCapture(F, 2);
1952 if (Name == "write") {
1953 if (FTy->getNumParams() != 3 || !FTy->getParamType(1)->isPointerTy())
1955 // May throw; "write" is a valid pthread cancellation point.
1956 setDoesNotCapture(F, 2);
1960 if (Name == "bcopy") {
1961 if (FTy->getNumParams() != 3 ||
1962 !FTy->getParamType(0)->isPointerTy() ||
1963 !FTy->getParamType(1)->isPointerTy())
1966 setDoesNotCapture(F, 1);
1967 setDoesNotCapture(F, 2);
1968 } else if (Name == "bcmp") {
1969 if (FTy->getNumParams() != 3 ||
1970 !FTy->getParamType(0)->isPointerTy() ||
1971 !FTy->getParamType(1)->isPointerTy())
1974 setOnlyReadsMemory(F);
1975 setDoesNotCapture(F, 1);
1976 setDoesNotCapture(F, 2);
1977 } else if (Name == "bzero") {
1978 if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
1981 setDoesNotCapture(F, 1);
1985 if (Name == "calloc") {
1986 if (FTy->getNumParams() != 2 ||
1987 !FTy->getReturnType()->isPointerTy())
1990 setDoesNotAlias(F, 0);
1991 } else if (Name == "chmod" ||
1993 Name == "ctermid" ||
1994 Name == "clearerr" ||
1995 Name == "closedir") {
1996 if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
1999 setDoesNotCapture(F, 1);
2003 if (Name == "atoi" ||
2007 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2010 setOnlyReadsMemory(F);
2011 setDoesNotCapture(F, 1);
2012 } else if (Name == "access") {
2013 if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
2016 setDoesNotCapture(F, 1);
2020 if (Name == "fopen") {
2021 if (FTy->getNumParams() != 2 ||
2022 !FTy->getReturnType()->isPointerTy() ||
2023 !FTy->getParamType(0)->isPointerTy() ||
2024 !FTy->getParamType(1)->isPointerTy())
2027 setDoesNotAlias(F, 0);
2028 setDoesNotCapture(F, 1);
2029 setDoesNotCapture(F, 2);
2030 } else if (Name == "fdopen") {
2031 if (FTy->getNumParams() != 2 ||
2032 !FTy->getReturnType()->isPointerTy() ||
2033 !FTy->getParamType(1)->isPointerTy())
2036 setDoesNotAlias(F, 0);
2037 setDoesNotCapture(F, 2);
2038 } else if (Name == "feof" ||
2048 Name == "fsetpos" ||
2049 Name == "flockfile" ||
2050 Name == "funlockfile" ||
2051 Name == "ftrylockfile") {
2052 if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
2055 setDoesNotCapture(F, 1);
2056 } else if (Name == "ferror") {
2057 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2060 setDoesNotCapture(F, 1);
2061 setOnlyReadsMemory(F);
2062 } else if (Name == "fputc" ||
2067 Name == "fstatvfs") {
2068 if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
2071 setDoesNotCapture(F, 2);
2072 } else if (Name == "fgets") {
2073 if (FTy->getNumParams() != 3 ||
2074 !FTy->getParamType(0)->isPointerTy() ||
2075 !FTy->getParamType(2)->isPointerTy())
2078 setDoesNotCapture(F, 3);
2079 } else if (Name == "fread" ||
2081 if (FTy->getNumParams() != 4 ||
2082 !FTy->getParamType(0)->isPointerTy() ||
2083 !FTy->getParamType(3)->isPointerTy())
2086 setDoesNotCapture(F, 1);
2087 setDoesNotCapture(F, 4);
2088 } else if (Name == "fputs" ||
2090 Name == "fprintf" ||
2091 Name == "fgetpos") {
2092 if (FTy->getNumParams() < 2 ||
2093 !FTy->getParamType(0)->isPointerTy() ||
2094 !FTy->getParamType(1)->isPointerTy())
2097 setDoesNotCapture(F, 1);
2098 setDoesNotCapture(F, 2);
2102 if (Name == "getc" ||
2103 Name == "getlogin_r" ||
2104 Name == "getc_unlocked") {
2105 if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
2108 setDoesNotCapture(F, 1);
2109 } else if (Name == "getenv") {
2110 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2113 setOnlyReadsMemory(F);
2114 setDoesNotCapture(F, 1);
2115 } else if (Name == "gets" ||
2116 Name == "getchar") {
2118 } else if (Name == "getitimer") {
2119 if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
2122 setDoesNotCapture(F, 2);
2123 } else if (Name == "getpwnam") {
2124 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2127 setDoesNotCapture(F, 1);
2131 if (Name == "ungetc") {
2132 if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
2135 setDoesNotCapture(F, 2);
2136 } else if (Name == "uname" ||
2138 Name == "unsetenv") {
2139 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2142 setDoesNotCapture(F, 1);
2143 } else if (Name == "utime" ||
2145 if (FTy->getNumParams() != 2 ||
2146 !FTy->getParamType(0)->isPointerTy() ||
2147 !FTy->getParamType(1)->isPointerTy())
2150 setDoesNotCapture(F, 1);
2151 setDoesNotCapture(F, 2);
2155 if (Name == "putc") {
2156 if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
2159 setDoesNotCapture(F, 2);
2160 } else if (Name == "puts" ||
2163 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2166 setDoesNotCapture(F, 1);
2167 } else if (Name == "pread" ||
2169 if (FTy->getNumParams() != 4 || !FTy->getParamType(1)->isPointerTy())
2171 // May throw; these are valid pthread cancellation points.
2172 setDoesNotCapture(F, 2);
2173 } else if (Name == "putchar") {
2175 } else if (Name == "popen") {
2176 if (FTy->getNumParams() != 2 ||
2177 !FTy->getReturnType()->isPointerTy() ||
2178 !FTy->getParamType(0)->isPointerTy() ||
2179 !FTy->getParamType(1)->isPointerTy())
2182 setDoesNotAlias(F, 0);
2183 setDoesNotCapture(F, 1);
2184 setDoesNotCapture(F, 2);
2185 } else if (Name == "pclose") {
2186 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2189 setDoesNotCapture(F, 1);
2193 if (Name == "vscanf") {
2194 if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
2197 setDoesNotCapture(F, 1);
2198 } else if (Name == "vsscanf" ||
2199 Name == "vfscanf") {
2200 if (FTy->getNumParams() != 3 ||
2201 !FTy->getParamType(1)->isPointerTy() ||
2202 !FTy->getParamType(2)->isPointerTy())
2205 setDoesNotCapture(F, 1);
2206 setDoesNotCapture(F, 2);
2207 } else if (Name == "valloc") {
2208 if (!FTy->getReturnType()->isPointerTy())
2211 setDoesNotAlias(F, 0);
2212 } else if (Name == "vprintf") {
2213 if (FTy->getNumParams() != 2 || !FTy->getParamType(0)->isPointerTy())
2216 setDoesNotCapture(F, 1);
2217 } else if (Name == "vfprintf" ||
2218 Name == "vsprintf") {
2219 if (FTy->getNumParams() != 3 ||
2220 !FTy->getParamType(0)->isPointerTy() ||
2221 !FTy->getParamType(1)->isPointerTy())
2224 setDoesNotCapture(F, 1);
2225 setDoesNotCapture(F, 2);
2226 } else if (Name == "vsnprintf") {
2227 if (FTy->getNumParams() != 4 ||
2228 !FTy->getParamType(0)->isPointerTy() ||
2229 !FTy->getParamType(2)->isPointerTy())
2232 setDoesNotCapture(F, 1);
2233 setDoesNotCapture(F, 3);
2237 if (Name == "open") {
2238 if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
2240 // May throw; "open" is a valid pthread cancellation point.
2241 setDoesNotCapture(F, 1);
2242 } else if (Name == "opendir") {
2243 if (FTy->getNumParams() != 1 ||
2244 !FTy->getReturnType()->isPointerTy() ||
2245 !FTy->getParamType(0)->isPointerTy())
2248 setDoesNotAlias(F, 0);
2249 setDoesNotCapture(F, 1);
2253 if (Name == "tmpfile") {
2254 if (!FTy->getReturnType()->isPointerTy())
2257 setDoesNotAlias(F, 0);
2258 } else if (Name == "times") {
2259 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2262 setDoesNotCapture(F, 1);
2266 if (Name == "htonl" ||
2269 setDoesNotAccessMemory(F);
2273 if (Name == "ntohl" ||
2276 setDoesNotAccessMemory(F);
2280 if (Name == "lstat") {
2281 if (FTy->getNumParams() != 2 ||
2282 !FTy->getParamType(0)->isPointerTy() ||
2283 !FTy->getParamType(1)->isPointerTy())
2286 setDoesNotCapture(F, 1);
2287 setDoesNotCapture(F, 2);
2288 } else if (Name == "lchown") {
2289 if (FTy->getNumParams() != 3 || !FTy->getParamType(0)->isPointerTy())
2292 setDoesNotCapture(F, 1);
2296 if (Name == "qsort") {
2297 if (FTy->getNumParams() != 4 || !FTy->getParamType(3)->isPointerTy())
2299 // May throw; places call through function pointer.
2300 setDoesNotCapture(F, 4);
2304 if (Name == "__strdup" ||
2305 Name == "__strndup") {
2306 if (FTy->getNumParams() < 1 ||
2307 !FTy->getReturnType()->isPointerTy() ||
2308 !FTy->getParamType(0)->isPointerTy())
2311 setDoesNotAlias(F, 0);
2312 setDoesNotCapture(F, 1);
2313 } else if (Name == "__strtok_r") {
2314 if (FTy->getNumParams() != 3 ||
2315 !FTy->getParamType(1)->isPointerTy())
2318 setDoesNotCapture(F, 2);
2319 } else if (Name == "_IO_getc") {
2320 if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
2323 setDoesNotCapture(F, 1);
2324 } else if (Name == "_IO_putc") {
2325 if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
2328 setDoesNotCapture(F, 2);
2332 if (Name == "\1__isoc99_scanf") {
2333 if (FTy->getNumParams() < 1 ||
2334 !FTy->getParamType(0)->isPointerTy())
2337 setDoesNotCapture(F, 1);
2338 } else if (Name == "\1stat64" ||
2339 Name == "\1lstat64" ||
2340 Name == "\1statvfs64" ||
2341 Name == "\1__isoc99_sscanf") {
2342 if (FTy->getNumParams() < 1 ||
2343 !FTy->getParamType(0)->isPointerTy() ||
2344 !FTy->getParamType(1)->isPointerTy())
2347 setDoesNotCapture(F, 1);
2348 setDoesNotCapture(F, 2);
2349 } else if (Name == "\1fopen64") {
2350 if (FTy->getNumParams() != 2 ||
2351 !FTy->getReturnType()->isPointerTy() ||
2352 !FTy->getParamType(0)->isPointerTy() ||
2353 !FTy->getParamType(1)->isPointerTy())
2356 setDoesNotAlias(F, 0);
2357 setDoesNotCapture(F, 1);
2358 setDoesNotCapture(F, 2);
2359 } else if (Name == "\1fseeko64" ||
2360 Name == "\1ftello64") {
2361 if (FTy->getNumParams() == 0 || !FTy->getParamType(0)->isPointerTy())
2364 setDoesNotCapture(F, 1);
2365 } else if (Name == "\1tmpfile64") {
2366 if (!FTy->getReturnType()->isPointerTy())
2369 setDoesNotAlias(F, 0);
2370 } else if (Name == "\1fstat64" ||
2371 Name == "\1fstatvfs64") {
2372 if (FTy->getNumParams() != 2 || !FTy->getParamType(1)->isPointerTy())
2375 setDoesNotCapture(F, 2);
2376 } else if (Name == "\1open64") {
2377 if (FTy->getNumParams() < 2 || !FTy->getParamType(0)->isPointerTy())
2379 // May throw; "open" is a valid pthread cancellation point.
2380 setDoesNotCapture(F, 1);
2386 /// doInitialization - Add attributes to well-known functions.
2388 bool SimplifyLibCalls::doInitialization(Module &M) {
2390 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
2392 if (F.isDeclaration() && F.hasName())
2393 inferPrototypeAttributes(F);
2399 // Additional cases that we need to add to this file:
2402 // * cbrt(expN(X)) -> expN(x/3)
2403 // * cbrt(sqrt(x)) -> pow(x,1/6)
2404 // * cbrt(sqrt(x)) -> pow(x,1/9)
2407 // * exp(log(x)) -> x
2410 // * log(exp(x)) -> x
2411 // * log(x**y) -> y*log(x)
2412 // * log(exp(y)) -> y*log(e)
2413 // * log(exp2(y)) -> y*log(2)
2414 // * log(exp10(y)) -> y*log(10)
2415 // * log(sqrt(x)) -> 0.5*log(x)
2416 // * log(pow(x,y)) -> y*log(x)
2418 // lround, lroundf, lroundl:
2419 // * lround(cnst) -> cnst'
2422 // * pow(exp(x),y) -> exp(x*y)
2423 // * pow(sqrt(x),y) -> pow(x,y*0.5)
2424 // * pow(pow(x,y),z)-> pow(x,y*z)
2426 // round, roundf, roundl:
2427 // * round(cnst) -> cnst'
2430 // * signbit(cnst) -> cnst'
2431 // * signbit(nncst) -> 0 (if pstv is a non-negative constant)
2433 // sqrt, sqrtf, sqrtl:
2434 // * sqrt(expN(x)) -> expN(x*0.5)
2435 // * sqrt(Nroot(x)) -> pow(x,1/(2*N))
2436 // * sqrt(pow(x,y)) -> pow(|x|,y*0.5)
2439 // * strchr(p, 0) -> strlen(p)
2441 // * tan(atan(x)) -> x
2443 // trunc, truncf, truncl:
2444 // * trunc(cnst) -> cnst'