[llvm-commits] [llvm] r91486 - in /llvm/trunk: lib/Transforms/Scalar/SimplifyLibCalls.cpp test/Transforms/SimplifyLibCalls/StrStr.ll

Chris Lattner sabre at nondot.org
Tue Dec 15 16:46:02 PST 2009


Author: lattner
Date: Tue Dec 15 18:46:02 2009
New Revision: 91486

URL: http://llvm.org/viewvc/llvm-project?rev=91486&view=rev
Log:
revert my strstr optimization, I'm told it breaks x86-64 bootstrap.

Will reapply with a fix when I get a chance.

Modified:
    llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp
    llvm/trunk/test/Transforms/SimplifyLibCalls/StrStr.ll

Modified: llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp?rev=91486&r1=91485&r2=91486&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SimplifyLibCalls.cpp Tue Dec 15 18:46:02 2009
@@ -76,11 +76,6 @@
   /// 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 @@
   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 @@
 };
 
 //===---------------------------------------===//
-// '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 @@
   }
 };
 
-//===---------------------------------------===//
-// '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 @@
     // 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 @@
   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 @@
 //   * 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
 //

Modified: llvm/trunk/test/Transforms/SimplifyLibCalls/StrStr.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyLibCalls/StrStr.ll?rev=91486&r1=91485&r2=91486&view=diff

==============================================================================
--- llvm/trunk/test/Transforms/SimplifyLibCalls/StrStr.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyLibCalls/StrStr.ll Tue Dec 15 18:46:02 2009
@@ -1,48 +0,0 @@
-; RUN: opt < %s -simplify-libcalls -S | FileCheck %s
-; PR5783
-
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32"
-target triple = "i386-apple-darwin9.0"
-
- at .str = private constant [1 x i8] zeroinitializer ; <[1 x i8]*> [#uses=1]
- at .str1 = private constant [2 x i8] c"a\00"        ; <[2 x i8]*> [#uses=1]
- at .str2 = private constant [6 x i8] c"abcde\00"    ; <[6 x i8]*> [#uses=1]
- at .str3 = private constant [4 x i8] c"bcd\00"      ; <[4 x i8]*> [#uses=1]
-
-define i8* @test1(i8* %P) nounwind readonly {
-entry:
-  %call = tail call i8* @strstr(i8* %P, i8* getelementptr inbounds ([1 x i8]* @.str, i32 0, i32 0)) nounwind ; <i8*> [#uses=1]
-  ret i8* %call
-; strstr(P, "") -> P
-; CHECK: @test1
-; CHECK: ret i8* %P
-}
-
-declare i8* @strstr(i8*, i8* nocapture) nounwind readonly
-
-define i8* @test2(i8* %P) nounwind readonly {
-entry:
-  %call = tail call i8* @strstr(i8* %P, i8* getelementptr inbounds ([2 x i8]* @.str1, i32 0, i32 0)) nounwind ; <i8*> [#uses=1]
-  ret i8* %call
-; strstr(P, "a") -> strchr(P, 'a')
-; CHECK: @test2
-; CHECK: @strchr(i8* %P, i32 97)
-}
-
-define i8* @test3(i8* nocapture %P) nounwind readonly {
-entry:
-  %call = tail call i8* @strstr(i8* getelementptr inbounds ([6 x i8]* @.str2, i32 0, i32 0), i8* getelementptr inbounds ([4 x i8]* @.str3, i32 0, i32 0)) nounwind ; <i8*> [#uses=1]
-  ret i8* %call
-; strstr("abcde", "bcd") -> "abcde"+1
-; CHECK: @test3
-; CHECK: getelementptr inbounds ([6 x i8]* @.str2, i32 0, i64 1)
-}
-
-define i8* @test4(i8* %P) nounwind readonly {
-entry:
-  %call = tail call i8* @strstr(i8* %P, i8* %P) nounwind ; <i8*> [#uses=1]
-  ret i8* %call
-; strstr(P, P) -> P
-; CHECK: @test4
-; CHECK: ret i8* %P
-}





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