reapply my strstr optimization. I have reproduced the x86-64 bootstrap
miscompile (i386.o miscompares) but it happens both with and without
this patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91532 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 6fd884b..192bcbd 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -76,6 +76,11 @@
/// return value has 'intptr_t' type.
Value *EmitStrLen(Value *Ptr, IRBuilder<> &B);
+ /// EmitStrChr - Emit a call to the strchr function to the builder, for the
+ /// specified pointer and character. Ptr is required to be some pointer type,
+ /// and the return value has 'i8*' type.
+ Value *EmitStrChr(Value *Ptr, char C, IRBuilder<> &B);
+
/// EmitMemCpy - Emit a call to the memcpy function to the builder. This
/// always expects that the size has type 'intptr_t' and Dst/Src are pointers.
Value *EmitMemCpy(Value *Dst, Value *Src, Value *Len,
@@ -151,6 +156,26 @@
return CI;
}
+/// EmitStrChr - Emit a call to the strchr function to the builder, for the
+/// specified pointer and character. Ptr is required to be some pointer type,
+/// and the return value has 'i8*' type.
+Value *LibCallOptimization::EmitStrChr(Value *Ptr, char C, IRBuilder<> &B) {
+ Module *M = Caller->getParent();
+ AttributeWithIndex AWI =
+ AttributeWithIndex::get(~0u, Attribute::ReadOnly | Attribute::NoUnwind);
+
+ const Type *I8Ptr = Type::getInt8PtrTy(*Context);
+ const Type *I32Ty = Type::getInt32Ty(*Context);
+ Constant *StrChr = M->getOrInsertFunction("strchr", AttrListPtr::get(&AWI, 1),
+ I8Ptr, I8Ptr, I32Ty, NULL);
+ CallInst *CI = B.CreateCall2(StrChr, CastToCStr(Ptr, B),
+ ConstantInt::get(I32Ty, C), "strchr");
+ if (const Function *F = dyn_cast<Function>(StrChr->stripPointerCasts()))
+ CI->setCallingConv(F->getCallingConv());
+ return CI;
+}
+
+
/// EmitMemCpy - Emit a call to the memcpy function to the builder. This always
/// expects that the size has type 'intptr_t' and Dst/Src are pointers.
Value *LibCallOptimization::EmitMemCpy(Value *Dst, Value *Src, Value *Len,
@@ -890,7 +915,7 @@
};
//===---------------------------------------===//
-// 'strto*' Optimizations
+// 'strto*' Optimizations. This handles strtol, strtod, strtof, strtoul, etc.
struct StrToOpt : public LibCallOptimization {
virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
@@ -910,6 +935,52 @@
}
};
+//===---------------------------------------===//
+// 'strstr' Optimizations
+
+struct StrStrOpt : public LibCallOptimization {
+ virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ const FunctionType *FT = Callee->getFunctionType();
+ if (FT->getNumParams() != 2 ||
+ !isa<PointerType>(FT->getParamType(0)) ||
+ !isa<PointerType>(FT->getParamType(1)) ||
+ !isa<PointerType>(FT->getReturnType()))
+ return 0;
+
+ // fold strstr(x, x) -> x.
+ if (CI->getOperand(1) == CI->getOperand(2))
+ return B.CreateBitCast(CI->getOperand(1), CI->getType());
+
+ // See if either input string is a constant string.
+ std::string SearchStr, ToFindStr;
+ bool HasStr1 = GetConstantStringInfo(CI->getOperand(1), SearchStr);
+ bool HasStr2 = GetConstantStringInfo(CI->getOperand(2), ToFindStr);
+
+ // fold strstr(x, "") -> x.
+ if (HasStr2 && ToFindStr.empty())
+ return B.CreateBitCast(CI->getOperand(1), CI->getType());
+
+ // If both strings are known, constant fold it.
+ if (HasStr1 && HasStr2) {
+ std::string::size_type Offset = SearchStr.find(ToFindStr);
+
+ if (Offset == std::string::npos) // strstr("foo", "bar") -> null
+ return Constant::getNullValue(CI->getType());
+
+ // strstr("abcd", "bc") -> gep((char*)"abcd", 1)
+ Value *Result = CastToCStr(CI->getOperand(1), B);
+ Result = B.CreateConstInBoundsGEP1_64(Result, Offset, "strstr");
+ return B.CreateBitCast(Result, CI->getType());
+ }
+
+ // fold strstr(x, "y") -> strchr(x, 'y').
+ if (HasStr2 && ToFindStr.size() == 1)
+ return B.CreateBitCast(EmitStrChr(CI->getOperand(1), ToFindStr[0], B),
+ CI->getType());
+ return 0;
+ }
+};
+
//===---------------------------------------===//
// 'memcmp' Optimizations
@@ -1675,8 +1746,8 @@
// String and Memory LibCall Optimizations
StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
- StrToOpt StrTo; MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove;
- MemSetOpt MemSet;
+ StrToOpt StrTo; StrStrOpt StrStr;
+ MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
// Math Library Optimizations
PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
// Integer Optimizations
@@ -1738,6 +1809,7 @@
Optimizations["strtoll"] = &StrTo;
Optimizations["strtold"] = &StrTo;
Optimizations["strtoull"] = &StrTo;
+ Optimizations["strstr"] = &StrStr;
Optimizations["memcmp"] = &MemCmp;
Optimizations["memcpy"] = &MemCpy;
Optimizations["memmove"] = &MemMove;
@@ -2644,12 +2716,6 @@
// * strcspn("",a) -> 0
// * strcspn(s,"") -> strlen(a)
//
-// strstr: (PR5783)
-// * strstr(x,x) -> x
-// * strstr(x, "") -> x
-// * strstr(x, "a") -> strchr(x, 'a')
-// * strstr(s1,s2) -> result (if s1 and s2 are constant strings)
-//
// tan, tanf, tanl:
// * tan(atan(x)) -> x
//