revert my strstr optimization, I'm told it breaks x86-64 bootstrap.

[oota-llvm.git] / lib / Transforms / Scalar / SimplifyLibCalls.cpp

diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 89602985c871faaec4d47bf9097ff2b5cabf92b1..6fd884bbd6da346398f351c1b18139bcf749118f 100644 (file)
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -76,11 +76,6 @@ public:
   /// 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,
@@ -156,26 +151,6 @@ Value *LibCallOptimization::EmitStrLen(Value *Ptr, IRBuilder<> &B) {
   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,
@@ -915,7 +890,7 @@ struct StrLenOpt : public LibCallOptimization {
 };
 
 //===---------------------------------------===//
-// 'strto*' Optimizations.  This handles strtol, strtod, strtof, strtoul, etc.
+// 'strto*' Optimizations
 
 struct StrToOpt : public LibCallOptimization {
   virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
@@ -935,52 +910,6 @@ struct StrToOpt : public LibCallOptimization {
   }
 };
 
-//===---------------------------------------===//
-// '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 CI->getOperand(1);
-    
-    // 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", 2)
-      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
@@ -1746,8 +1675,8 @@ namespace {
     // String and Memory LibCall Optimizations
     StrCatOpt StrCat; StrNCatOpt StrNCat; StrChrOpt StrChr; StrCmpOpt StrCmp;
     StrNCmpOpt StrNCmp; StrCpyOpt StrCpy; StrNCpyOpt StrNCpy; StrLenOpt StrLen;
-    StrToOpt StrTo; StrStrOpt StrStr;
-    MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
+    StrToOpt StrTo; MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove;
+    MemSetOpt MemSet;
     // Math Library Optimizations
     PowOpt Pow; Exp2Opt Exp2; UnaryDoubleFPOpt UnaryDoubleFP;
     // Integer Optimizations
@@ -1809,7 +1738,6 @@ void SimplifyLibCalls::InitOptimizations() {
   Optimizations["strtoll"] = &StrTo;
   Optimizations["strtold"] = &StrTo;
   Optimizations["strtoull"] = &StrTo;
-  Optimizations["strstr"] = &StrStr;
   Optimizations["memcmp"] = &MemCmp;
   Optimizations["memcpy"] = &MemCpy;
   Optimizations["memmove"] = &MemMove;
@@ -2716,6 +2644,12 @@ bool SimplifyLibCalls::doInitialization(Module &M) {
 //   * 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
 //