diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/SimplifyLibCalls.cpp | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp index e433e30ea8..fbb9465743 100644 --- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp +++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp @@ -338,16 +338,17 @@ struct StrCmpOpt : public LibCallOptimization { bool HasStr1 = GetConstantStringInfo(Str1P, Str1); bool HasStr2 = GetConstantStringInfo(Str2P, Str2); - if (HasStr1 && Str1.empty()) // strcmp("", x) -> *x - return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType()); - - if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x - return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType()); - // strcmp(x, y) -> cnst (if both x and y are constant strings) if (HasStr1 && HasStr2) return ConstantInt::get(CI->getType(), - strcmp(Str1.c_str(),Str2.c_str())); + StringRef(Str1).compare(Str2)); + + if (HasStr1 && Str1.empty()) // strcmp("", x) -> -*x + return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), + CI->getType())); + + if (HasStr2 && Str2.empty()) // strcmp(x,"") -> *x + return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType()); // strcmp(P, "x") -> memcmp(P, "x", 2) uint64_t Len1 = GetStringLength(Str1P); @@ -400,16 +401,20 @@ struct StrNCmpOpt : public LibCallOptimization { bool HasStr1 = GetConstantStringInfo(Str1P, Str1); bool HasStr2 = GetConstantStringInfo(Str2P, Str2); - if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> *x - return B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), CI->getType()); + // 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); + return ConstantInt::get(CI->getType(), SubStr1.compare(SubStr2)); + } + + if (HasStr1 && Str1.empty()) // strncmp("", x, n) -> -*x + return B.CreateNeg(B.CreateZExt(B.CreateLoad(Str2P, "strcmpload"), + CI->getType())); if (HasStr2 && Str2.empty()) // strncmp(x, "", n) -> *x return B.CreateZExt(B.CreateLoad(Str1P, "strcmpload"), CI->getType()); - // strncmp(x, y) -> cnst (if both x and y are constant strings) - if (HasStr1 && HasStr2) - return ConstantInt::get(CI->getType(), - strncmp(Str1.c_str(), Str2.c_str(), Length)); return 0; } }; |