instcombine: Migrate strcspn optimizations

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

llvm-svn: 167675
This commit is contained in:
Meador Inge 2012-11-10 15:16:48 +00:00
parent 91b014cd66
commit bcd88ef764
6 changed files with 122 additions and 62 deletions
llvm

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@ -118,41 +118,6 @@ static bool IsOnlyUsedInEqualityComparison(Value *V, Value *With) {
//===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===//
namespace { 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 // 'strstr' Optimizations
@ -1005,7 +970,7 @@ namespace {
StringMap<LibCallOptimization*> Optimizations; StringMap<LibCallOptimization*> Optimizations;
// String and Memory LibCall Optimizations // String and Memory LibCall Optimizations
StrCSpnOpt StrCSpn; StrStrOpt StrStr; StrStrOpt StrStr;
MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet; MemCmpOpt MemCmp; MemCpyOpt MemCpy; MemMoveOpt MemMove; MemSetOpt MemSet;
// Math Library Optimizations // Math Library Optimizations
CosOpt Cos; PowOpt Pow; Exp2Opt Exp2; CosOpt Cos; PowOpt Pow; Exp2Opt Exp2;
@ -1073,7 +1038,6 @@ void SimplifyLibCalls::AddOpt(LibFunc::Func F1, LibFunc::Func F2,
/// we know. /// we know.
void SimplifyLibCalls::InitOptimizations() { void SimplifyLibCalls::InitOptimizations() {
// String and Memory LibCall Optimizations // String and Memory LibCall Optimizations
Optimizations["strcspn"] = &StrCSpn;
Optimizations["strstr"] = &StrStr; Optimizations["strstr"] = &StrStr;
Optimizations["memcmp"] = &MemCmp; Optimizations["memcmp"] = &MemCmp;
AddOpt(LibFunc::memcpy, &MemCpy); AddOpt(LibFunc::memcpy, &MemCpy);

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@ -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. } // End anonymous namespace.
namespace llvm { namespace llvm {
@ -832,6 +864,7 @@ class LibCallSimplifierImpl {
StrPBrkOpt StrPBrk; StrPBrkOpt StrPBrk;
StrToOpt StrTo; StrToOpt StrTo;
StrSpnOpt StrSpn; StrSpnOpt StrSpn;
StrCSpnOpt StrCSpn;
void initOptimizations(); void initOptimizations();
void addOpt(LibFunc::Func F, LibCallOptimization* Opt); void addOpt(LibFunc::Func F, LibCallOptimization* Opt);
@ -874,6 +907,7 @@ void LibCallSimplifierImpl::initOptimizations() {
addOpt(LibFunc::strtold, &StrTo); addOpt(LibFunc::strtold, &StrTo);
addOpt(LibFunc::strtoull, &StrTo); addOpt(LibFunc::strtoull, &StrTo);
addOpt(LibFunc::strspn, &StrSpn); addOpt(LibFunc::strspn, &StrSpn);
addOpt(LibFunc::strcspn, &StrCSpn);
} }
Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) { Value *LibCallSimplifierImpl::optimizeCall(CallInst *CI) {

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@ -36,6 +36,7 @@ declare i64 @strtol(i8*, i8**, i32)
declare i64 @strtoll(i8*, i8**, i32) declare i64 @strtoll(i8*, i8**, i32)
declare i64 @strtoul(i8*, i8**, i32) declare i64 @strtoul(i8*, i8**, i32)
declare i64 @strtoull(i8*, i8**, i32) declare i64 @strtoull(i8*, i8**, i32)
declare i64 @strcspn(i8*, i8*)
define double @t1(double %x) { define double @t1(double %x) {
; CHECK: @t1 ; CHECK: @t1
@ -225,3 +226,11 @@ define i64 @t24(i8** %y) {
ret i64 %ret ret i64 %ret
; CHECK: call i64 @strtoull ; 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
}

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@ -0,0 +1,57 @@
; 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
}

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@ -0,0 +1,21 @@
; 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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@ -1,25 +0,0 @@
; RUN: opt < %s -simplify-libcalls -S | FileCheck %s
target datalayout = "-p:64:64:64"
@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*)
define i64 @testcspn(i8* %s1, i8* %s2) {
%abcba_p = getelementptr [6 x i8]* @abcba, i32 0, i32 0
%abc_p = getelementptr [4 x i8]* @abc, i32 0, i32 0
%null_p = getelementptr [1 x i8]* @null, i32 0, i32 0
%test1 = call i64 @strcspn(i8* %s1, i8* %null_p)
; CHECK: call i64 @strlen(i8* %s1)
%test2 = call i64 @strcspn(i8* %null_p, i8* %s2)
%test3 = call i64 @strcspn(i8* %abcba_p, i8* %abc_p)
; CHECK-NOT: call i64 @strcspn
%test4 = call i64 @strcspn(i8* %s1, i8* %s2)
; CHECK: call i64 @strcspn(i8* %s1, i8* %s2)
%add0 = add i64 %test1, %test3
; CHECK: add i64 %{{.+}}, 0
ret i64 %add0
}