From 90f1d8a5da6f962175af0a3ebedb76aeffa42694 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 31 Jan 2012 04:43:11 +0000 Subject: [PATCH] start moving SimplifyLibcalls over to getConstantStringInfo, which is dramatically more efficient than GetConstantStringInfo. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149352 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/SimplifyLibCalls.cpp | 102 +++++++++++---------- 1 file changed, 53 insertions(+), 49 deletions(-) diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index dcfcf1a8764..8935cc7839b 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -256,19 +256,18 @@ struct StrChrOpt : public LibCallOptimization { ConstantInt::get(TD->getIntPtrType(*Context), Len), B, TD); } - + // Otherwise, the character is a constant, see if the first argument is // a string literal. If so, we can constant fold. - std::string Str; - if (!GetConstantStringInfo(SrcStr, Str)) + StringRef Str; + if (!getConstantStringInfo(SrcStr, Str)) return 0; - // strchr can find the nul character. - Str += '\0'; - - // Compute the offset. - size_t I = Str.find(CharC->getSExtValue()); - if (I == std::string::npos) // Didn't find the char. strchr returns null. + // Compute the offset, make sure to handle the case when we're searching for + // zero (a weird way to spell strlen). + size_t I = CharC->getSExtValue() == 0 ? + Str.size() : Str.find(CharC->getSExtValue()); + if (I == StringRef::npos) // Didn't find the char. strchr returns null. return Constant::getNullValue(CI->getType()); // strchr(s+n,c) -> gep(s+n+i,c) @@ -296,20 +295,18 @@ struct StrRChrOpt : public LibCallOptimization { if (!CharC) return 0; - std::string Str; - if (!GetConstantStringInfo(SrcStr, Str)) { + StringRef Str; + if (!getConstantStringInfo(SrcStr, Str)) { // strrchr(s, 0) -> strchr(s, 0) if (TD && CharC->isZero()) return EmitStrChr(SrcStr, '\0', B, TD); return 0; } - // strrchr can find the nul character. - Str += '\0'; - // Compute the offset. - size_t I = Str.rfind(CharC->getSExtValue()); - if (I == std::string::npos) // Didn't find the char. Return null. + size_t I = CharC->getSExtValue() == 0 ? + Str.size() : Str.rfind(CharC->getSExtValue()); + if (I == StringRef::npos) // Didn't find the char. Return null. return Constant::getNullValue(CI->getType()); // strrchr(s+n,c) -> gep(s+n+i,c) @@ -334,14 +331,13 @@ struct StrCmpOpt : public LibCallOptimization { if (Str1P == Str2P) // strcmp(x,x) -> 0 return ConstantInt::get(CI->getType(), 0); - std::string Str1, Str2; - bool HasStr1 = GetConstantStringInfo(Str1P, Str1); - bool HasStr2 = GetConstantStringInfo(Str2P, Str2); + StringRef Str1, Str2; + bool HasStr1 = getConstantStringInfo(Str1P, Str1); + bool HasStr2 = getConstantStringInfo(Str2P, Str2); // strcmp(x, y) -> cnst (if both x and y are constant strings) if (HasStr1 && HasStr2) - return ConstantInt::get(CI->getType(), - StringRef(Str1).compare(Str2)); + return ConstantInt::get(CI->getType(), Str1.compare(Str2)); if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), @@ -397,14 +393,14 @@ struct StrNCmpOpt : public LibCallOptimization { if (TD && Length == 1) // strncmp(x,y,1) -> memcmp(x,y,1) return EmitMemCmp(Str1P, Str2P, CI->getArgOperand(2), B, TD); - std::string Str1, Str2; - bool HasStr1 = GetConstantStringInfo(Str1P, Str1); - bool HasStr2 = GetConstantStringInfo(Str2P, Str2); + StringRef Str1, Str2; + bool HasStr1 = getConstantStringInfo(Str1P, Str1); + bool HasStr2 = getConstantStringInfo(Str2P, Str2); // strncmp(x, y) -> cnst (if both x and y are constant strings) if (HasStr1 && HasStr2) { - StringRef SubStr1 = StringRef(Str1).substr(0, Length); - StringRef SubStr2 = StringRef(Str2).substr(0, Length); + StringRef SubStr1 = Str1.substr(0, Length); + StringRef SubStr2 = Str2.substr(0, Length); return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2)); } @@ -609,9 +605,9 @@ struct StrSpnOpt : public LibCallOptimization { !FT->getReturnType()->isIntegerTy()) return 0; - std::string S1, S2; - bool HasS1 = GetConstantStringInfo(CI->getArgOperand(0), S1); - bool HasS2 = GetConstantStringInfo(CI->getArgOperand(1), S2); + StringRef S1, S2; + bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1); + bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2); // strspn(s, "") -> 0 // strspn("", s) -> 0 @@ -619,8 +615,11 @@ struct StrSpnOpt : public LibCallOptimization { return Constant::getNullValue(CI->getType()); // Constant folding. - if (HasS1 && HasS2) - return ConstantInt::get(CI->getType(), strspn(S1.c_str(), S2.c_str())); + if (HasS1 && HasS2) { + size_t Pos = S1.find_first_not_of(S2); + if (Pos == StringRef::npos) Pos = S1.size(); + return ConstantInt::get(CI->getType(), Pos); + } return 0; } @@ -638,17 +637,20 @@ struct StrCSpnOpt : public LibCallOptimization { !FT->getReturnType()->isIntegerTy()) return 0; - std::string S1, S2; - bool HasS1 = GetConstantStringInfo(CI->getArgOperand(0), S1); - bool HasS2 = GetConstantStringInfo(CI->getArgOperand(1), S2); + 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) - return ConstantInt::get(CI->getType(), strcspn(S1.c_str(), S2.c_str())); + 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()) @@ -756,11 +758,11 @@ struct MemCmpOpt : public LibCallOptimization { } // Constant folding: memcmp(x, y, l) -> cnst (all arguments are constant) - std::string LHSStr, RHSStr; - if (GetConstantStringInfo(LHS, LHSStr) && - GetConstantStringInfo(RHS, RHSStr)) { + StringRef LHSStr, RHSStr; + if (getConstantStringInfo(LHS, LHSStr) && + getConstantStringInfo(RHS, RHSStr)) { // Make sure we're not reading out-of-bounds memory. - if (Len > LHSStr.length() || Len > RHSStr.length()) + if (Len > LHSStr.size() || Len > RHSStr.size()) return 0; uint64_t Ret = memcmp(LHSStr.data(), RHSStr.data(), Len); return ConstantInt::get(CI->getType(), Ret); @@ -1116,8 +1118,8 @@ struct PrintFOpt : public LibCallOptimization { Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI, IRBuilder<> &B) { // Check for a fixed format string. - std::string FormatStr; - if (!GetConstantStringInfo(CI->getArgOperand(0), FormatStr)) + StringRef FormatStr; + if (!getConstantStringInfo(CI->getArgOperand(0), FormatStr)) return 0; // Empty format string -> noop. @@ -1143,7 +1145,7 @@ struct PrintFOpt : public LibCallOptimization { FormatStr.find('%') == std::string::npos) { // no format characters. // Create a string literal with no \n on it. We expect the constant merge // pass to be run after this pass, to merge duplicate strings. - FormatStr.erase(FormatStr.end()-1); + FormatStr = FormatStr.drop_back(); Value *GV = B.CreateGlobalString(FormatStr, "str"); EmitPutS(GV, B, TD); return CI->use_empty() ? (Value*)CI : @@ -1203,8 +1205,8 @@ struct SPrintFOpt : public LibCallOptimization { Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI, IRBuilder<> &B) { // Check for a fixed format string. - std::string FormatStr; - if (!GetConstantStringInfo(CI->getArgOperand(1), FormatStr)) + StringRef FormatStr; + if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr)) return 0; // If we just have a format string (nothing else crazy) transform it. @@ -1358,8 +1360,8 @@ struct FPrintFOpt : public LibCallOptimization { Value *OptimizeFixedFormatString(Function *Callee, CallInst *CI, IRBuilder<> &B) { // All the optimizations depend on the format string. - std::string FormatStr; - if (!GetConstantStringInfo(CI->getArgOperand(1), FormatStr)) + StringRef FormatStr; + if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr)) return 0; // fprintf(F, "foo") --> fwrite("foo", 3, 1, F) @@ -1442,8 +1444,8 @@ struct PutsOpt : public LibCallOptimization { return 0; // Check for a constant string. - std::string Str; - if (!GetConstantStringInfo(CI->getArgOperand(0), Str)) + StringRef Str; + if (!getConstantStringInfo(CI->getArgOperand(0), Str)) return 0; if (Str.empty() && CI->use_empty()) { @@ -2413,6 +2415,8 @@ bool SimplifyLibCalls::doInitialization(Module &M) { // * stpcpy(str, "literal") -> // llvm.memcpy(str,"literal",strlen("literal")+1,1) // +// strchr: +// * strchr(p, 0) -> strlen(p) // tan, tanf, tanl: // * tan(atan(x)) -> x // -- 2.34.1