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
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+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);
+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) {
+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
}
+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
}
+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
}
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