instcombine: Migrate strpbrk optimizations
This patch migrates the strpbrk optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167105 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 658e7c3..1aac8c5 100644
--- a/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -717,6 +717,41 @@
}
};
+struct StrPBrkOpt : 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() != FT->getParamType(0))
+ return 0;
+
+ StringRef S1, S2;
+ bool HasS1 = getConstantStringInfo(CI->getArgOperand(0), S1);
+ bool HasS2 = getConstantStringInfo(CI->getArgOperand(1), S2);
+
+ // strpbrk(s, "") -> NULL
+ // strpbrk("", s) -> NULL
+ if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
+ return Constant::getNullValue(CI->getType());
+
+ // Constant folding.
+ if (HasS1 && HasS2) {
+ size_t I = S1.find_first_of(S2);
+ if (I == std::string::npos) // No match.
+ return Constant::getNullValue(CI->getType());
+
+ return B.CreateGEP(CI->getArgOperand(0), B.getInt64(I), "strpbrk");
+ }
+
+ // strpbrk(s, "a") -> strchr(s, 'a')
+ if (TD && HasS2 && S2.size() == 1)
+ return EmitStrChr(CI->getArgOperand(0), S2[0], B, TD, TLI);
+
+ return 0;
+ }
+};
+
} // End anonymous namespace.
namespace llvm {
@@ -745,6 +780,7 @@
StpCpyOpt StpCpy;
StrNCpyOpt StrNCpy;
StrLenOpt StrLen;
+ StrPBrkOpt StrPBrk;
void initOptimizations();
public:
@@ -777,6 +813,7 @@
Optimizations["stpcpy"] = &StpCpy;
Optimizations["strncpy"] = &StrNCpy;
Optimizations["strlen"] = &StrLen;
+ Optimizations["strpbrk"] = &StrPBrk;
}
Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {