Commit bcd88ef7 authored by Meador Inge's avatar Meador Inge
Browse files

instcombine: Migrate strcspn optimizations 

This patch migrates the strcspn optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167675
parent 91b014cd

llvm/lib/Transforms/Scalar/SimplifyLibCalls.cpp

+1 −37
Original line number Diff line number Diff line
@@ -118,41 +118,6 @@ static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) { 
//===----------------------------------------------------------------------===//



namespace {

//===---------------------------------------===//

// 'strcspn' Optimizations



struct StrCSpnOpt : 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()->isIntegerTy())

      return 0;



    StringRef 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) {

      size_t Pos = S1.find_first_of(S2);

      if (Pos == StringRef::npos) Pos = S1.size();

      return ConstantInt::get(CI->getType(), Pos);

    }



    // strcspn(s, "") -> strlen(s)

    if (TD && HasS2 && S2.empty())

      return EmitStrLen(CI->getArgOperand(0), B, TD, TLI);



    return 0;

  }

};



//===---------------------------------------===//

// 'strstr' Optimizations
@@ -1005,7 +970,7 @@ namespace { 


    StringMap<LibCallOptimization*> Optimizations;

    // String and Memory LibCall Optimizations

    StrCSpnOpt StrCSpn; StrStrOpt StrStr;

    StrStrOpt StrStr;

    MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;

    // Math Library Optimizations

    CosOpt Cos; PowOpt Pow; Exp2Opt Exp2;
@@ -1073,7 +1038,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2, 
/// we know.

void SimplifyLibCalls::InitOptimizations() {

  // String and Memory LibCall Optimizations

  Optimizations["strcspn"] = &StrCSpn;

  Optimizations["strstr"] = &StrStr;

  Optimizations["memcmp"] = &MemCmp;

  AddOpt(LibFunc::memcpy, &MemCpy);

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

+34 −0
Original line number Diff line number Diff line
@@ -801,6 +801,38 @@ struct StrSpnOpt : public LibCallOptimization { 
  }

};



struct StrCSpnOpt : 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()->isIntegerTy())

      return 0;



    StringRef 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) {

      size_t Pos = S1.find_first_of(S2);

      if (Pos == StringRef::npos) Pos = S1.size();

      return ConstantInt::get(CI->getType(), Pos);

    }



    // strcspn(s, "") -> strlen(s)

    if (TD && HasS2 && S2.empty())

      return EmitStrLen(CI->getArgOperand(0), B, TD, TLI);



    return 0;

  }

};



} // End anonymous namespace.



namespace llvm {
@@ -832,6 +864,7 @@ class LibCallSimplifierImpl { 
  StrPBrkOpt StrPBrk;

  StrToOpt StrTo;

  StrSpnOpt StrSpn;

  StrCSpnOpt StrCSpn;



  void initOptimizations();

  void addOpt(LibFunc::Func F, LibCallOptimization* Opt);
@@ -874,6 +907,7 @@ void LibCallSimplifierImpl::initOptimizations() { 
  addOpt(LibFunc::strtold, &StrTo);

  addOpt(LibFunc::strtoull, &StrTo);

  addOpt(LibFunc::strspn, &StrSpn);

  addOpt(LibFunc::strcspn, &StrCSpn);

}



Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {

llvm/test/Transforms/InstCombine/disable-simplify-libcalls.ll

+9 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ declare i64 @strtol(i8*, i8**, i32) 
declare i64 @strtoll(i8*, i8**, i32)

declare i64 @strtoul(i8*, i8**, i32)

declare i64 @strtoull(i8*, i8**, i32)

declare i64 @strcspn(i8*, i8*)



define double @t1(double %x) {

; CHECK: @t1
@@ -225,3 +226,11 @@ define i64 @t24(i8** %y) { 
  ret i64 %ret

; CHECK: call i64 @strtoull

}



define i64 @t25(i8* %y) {

; CHECK: @t25

  %x = getelementptr [1 x i8]* @empty, i32 0, i32 0

  %ret = call i64 @strcspn(i8* %x, i8* %y)

  ret i64 %ret

; CHECK: call i64 @strcspn

}

llvm/test/Transforms/InstCombine/strcspn-1.ll

0 → 100644
+57 −0
Original line number Diff line number Diff line 
; Test that the strcspn library call simplifier works correctly.

;

; RUN: opt < %s -instcombine -S | FileCheck %s



target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"



@abcba = constant [6 x i8] c"abcba\00"

@abc = constant [4 x i8] c"abc\00"

@null = constant [1 x i8] zeroinitializer



declare i64 @strcspn(i8*, i8*)



; Check strcspn(s, "") -> strlen(s).



define i64 @test_simplify1(i8* %str) {

; CHECK: @test_simplify1

  %pat = getelementptr [1 x i8]* @null, i32 0, i32 0



  %ret = call i64 @strcspn(i8* %str, i8* %pat)

; CHECK-NEXT: [[VAR:%[a-z]+]] = call i64 @strlen(i8* %str)

  ret i64 %ret

; CHECK-NEXT: ret i64 [[VAR]]

}



; Check strcspn("", s) -> 0.



define i64 @test_simplify2(i8* %pat) {

; CHECK: @test_simplify2

  %str = getelementptr [1 x i8]* @null, i32 0, i32 0



  %ret = call i64 @strcspn(i8* %str, i8* %pat)

  ret i64 %ret

; CHECK-NEXT: ret i64 0

}



; Check strcspn(s1, s2), where s1 and s2 are constants.



define i64 @test_simplify3() {

; CHECK: @test_simplify3

  %str = getelementptr [6 x i8]* @abcba, i32 0, i32 0

  %pat = getelementptr [4 x i8]* @abc, i32 0, i32 0



  %ret = call i64 @strcspn(i8* %str, i8* %pat)

  ret i64 %ret

; CHECK-NEXT: ret i64 0

}



; Check cases that shouldn't be simplified.



define i64 @test_no_simplify1(i8* %str, i8* %pat) {

; CHECK: @test_no_simplify1



  %ret = call i64 @strcspn(i8* %str, i8* %pat)

; CHECK-NEXT: %ret = call i64 @strcspn(i8* %str, i8* %pat)

  ret i64 %ret

; CHECK-NEXT: ret i64 %ret

}

llvm/test/Transforms/InstCombine/strcspn-2.ll

0 → 100644
+21 −0
Original line number Diff line number Diff line 
; Test that the strcspn library call simplifier works correctly.

;

; RUN: opt < %s -instcombine -S | FileCheck %s



target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"



@null = constant [1 x i8] zeroinitializer



declare double @strcspn(i8*, i8*)



; Check that strcspn functions with the wrong prototype aren't simplified.



define double @test_no_simplify1(i8* %pat) {

; CHECK: @test_no_simplify1

  %str = getelementptr [1 x i8]* @null, i32 0, i32 0



  %ret = call double @strcspn(i8* %str, i8* %pat)

; CHECK-NEXT: call double @strcspn

  ret double %ret

; CHECK-NEXT: ret double %ret

}