diff options
Diffstat (limited to 'lib/Transforms/Utils/SimplifyLibCalls.cpp')
-rw-r--r-- | lib/Transforms/Utils/SimplifyLibCalls.cpp | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp index f0d5491f90..74d4e22fa4 100644 --- a/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -801,6 +801,38 @@ struct StrSpnOpt : public LibCallOptimization { } }; +struct StrCSpnOpt : public LibCallOptimization { + virtual Value *callOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) { + FunctionType *FT = Callee->getFunctionType(); + if (FT->getNumParams() != 2 || + FT->getParamType(0) != B.getInt8PtrTy() || + FT->getParamType(1) != FT->getParamType(0) || + !FT->getReturnType()->isIntegerTy()) + return 0; + + StringRef S1, S2; + bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1); + bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2); + + // strcspn("", s) -> 0 + if (HasS1 && S1.empty()) + return Constant::getNullValue(CI->getType()); + + // Constant folding. + if (HasS1 && HasS2) { + size_t Pos = S1.find_first_of(S2); + if (Pos == StringRef::npos) Pos = S1.size(); + return ConstantInt::get(CI->getType(), Pos); + } + + // strcspn(s, "") -> strlen(s) + if (TD && HasS2 && S2.empty()) + return EmitStrLen(CI->getArgOperand(0), B, TD, TLI); + + return 0; + } +}; + } // End anonymous namespace. namespace llvm { @@ -832,6 +864,7 @@ class LibCallSimplifierImpl { StrPBrkOpt StrPBrk; StrToOpt StrTo; StrSpnOpt StrSpn; + StrCSpnOpt StrCSpn; void initOptimizations(); void addOpt(LibFunc::Func F, LibCallOptimization* Opt); @@ -874,6 +907,7 @@ void LibCallSimplifierImpl::initOptimizations() { addOpt(LibFunc::strtold, &StrTo); addOpt(LibFunc::strtoull, &StrTo); addOpt(LibFunc::strspn, &StrSpn); + addOpt(LibFunc::strcspn, &StrCSpn); } Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) { |