Add constant folding for strspn and strcspn to SimplifyLibCalls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115116 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index c4787c8..81460bc 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -584,6 +584,67 @@
};
//===---------------------------------------===//
+// 'strspn' Optimizations
+
+struct StrSpnOpt : public LibCallOptimization {
+ virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ const FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 2 ||
+ FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
+ FT->getParamType(1) != FT->getParamType(0) ||
+ !FT->getReturnType()->isIntegerTy())
+ return 0;
+
+ std::string S1, S2;
+ bool HasS1 = GetConstantStringInfo(CI->getArgOperand(0), S1);
+ bool HasS2 = GetConstantStringInfo(CI->getArgOperand(1), S2);
+
+ // strspn(s, "") -> 0
+ // strspn("", s) -> 0
+ if ((HasS1 && S1.empty()) || (HasS2 && S2.empty()))
+ return Constant::getNullValue(CI->getType());
+
+ // Constant folding.
+ if (HasS1 && HasS2)
+ return ConstantInt::get(CI->getType(), strspn(S1.c_str(), S2.c_str()));
+
+ return 0;
+ }
+};
+
+//===---------------------------------------===//
+// 'strcspn' Optimizations
+
+struct StrCSpnOpt : public LibCallOptimization {
+ virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ const FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 2 ||
+ FT->getParamType(0) != Type::getInt8PtrTy(*Context) ||
+ FT->getParamType(1) != FT->getParamType(0) ||
+ !FT->getReturnType()->isIntegerTy())
+ return 0;
+
+ std::string 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()));
+
+ // strcspn(s, "") -> strlen(s)
+ if (TD && HasS2 && S2.empty())
+ return EmitStrLen(CI->getArgOperand(0), B, TD);
+
+ return 0;
+ }
+};
+
+//===---------------------------------------===//
// 'strstr' Optimizations
struct StrStrOpt : public LibCallOptimization {
@@ -1297,7 +1358,7 @@
StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrRChrOpt StrRChr;
StrCmpOpt StrCmp; StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrCpyOpt StrCpyChk;
StrNCpyOpt StrNCpy; StrLenOpt StrLen; StrPBrkOpt StrPBrk;
- StrToOpt StrTo; StrStrOpt StrStr;
+ StrToOpt StrTo; StrSpnOpt StrSpn; StrCSpnOpt StrCSpn; StrStrOpt StrStr;
MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
// Math Library Optimizations
PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
@@ -1357,6 +1418,8 @@
Optimizations["strtoll"] = &StrTo;
Optimizations["strtold"] = &StrTo;
Optimizations["strtoull"] = &StrTo;
+ Optimizations["strspn"] = &StrSpn;
+ Optimizations["strcspn"] = &StrCSpn;
Optimizations["strstr"] = &StrStr;
Optimizations["memcmp"] = &MemCmp;
Optimizations["memcpy"] = &MemCpy;
@@ -2250,14 +2313,6 @@
// * stpcpy(str, "literal") ->
// llvm.memcpy(str,"literal",strlen("literal")+1,1)
//
-// strspn, strcspn:
-// * strspn(s,a) -> const_int (if both args are constant)
-// * strspn("",a) -> 0
-// * strspn(s,"") -> 0
-// * strcspn(s,a) -> const_int (if both args are constant)
-// * strcspn("",a) -> 0
-// * strcspn(s,"") -> strlen(a)
-//
// tan, tanf, tanl:
// * tan(atan(x)) -> x
//