[ADT] Simplify and optimize StringSwitch

This change improves incremental rebuild performance on dual Xeon 8168
machines by 54%. This change also improves run time code gen by not
forcing the case values to be lvalues.

llvm-svn: 326109
This commit is contained in:
David Zarzycki 2018-02-26 18:41:26 +00:00
parent a456db3ea3
commit d15f31936a
3 changed files with 82 additions and 107 deletions

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@ -855,6 +855,10 @@ namespace llvm {
/// constexpr StringLiteral S("test");
///
class StringLiteral : public StringRef {
private:
constexpr StringLiteral(const char *Str, size_t N) : StringRef(Str, N) {
}
public:
template <size_t N>
constexpr StringLiteral(const char (&Str)[N])
@ -867,6 +871,12 @@ namespace llvm {
#endif
: StringRef(Str, N - 1) {
}
// Explicit construction for strings like "foo\0bar".
template <size_t N>
static constexpr StringLiteral withInnerNUL(const char (&Str)[N]) {
return StringLiteral(Str, N - 1);
}
};
/// @name StringRef Comparison Operators

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@ -42,16 +42,16 @@ namespace llvm {
template<typename T, typename R = T>
class StringSwitch {
/// \brief The string we are matching.
StringRef Str;
const StringRef Str;
/// \brief The pointer to the result of this switch statement, once known,
/// null before that.
const T *Result;
Optional<T> Result;
public:
LLVM_ATTRIBUTE_ALWAYS_INLINE
explicit StringSwitch(StringRef S)
: Str(S), Result(nullptr) { }
: Str(S), Result() { }
// StringSwitch is not copyable.
StringSwitch(const StringSwitch &) = delete;
@ -61,196 +61,159 @@ public:
*this = std::move(other);
}
StringSwitch &operator=(StringSwitch &&other) {
Str = other.Str;
Result = other.Result;
Str = std::move(other.Str);
Result = std::move(other.Result);
return *this;
}
~StringSwitch() = default;
// Case-sensitive case matchers
template<unsigned N>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch& Case(const char (&S)[N], const T& Value) {
assert(N);
if (!Result && N-1 == Str.size() &&
(N == 1 || std::memcmp(S, Str.data(), N-1) == 0)) {
Result = &Value;
StringSwitch &Case(StringLiteral S, T Value) {
if (!Result && Str == S) {
Result = std::move(Value);
}
return *this;
}
template<unsigned N>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch& EndsWith(const char (&S)[N], const T &Value) {
assert(N);
if (!Result && Str.size() >= N-1 &&
(N == 1 || std::memcmp(S, Str.data() + Str.size() + 1 - N, N-1) == 0)) {
Result = &Value;
StringSwitch& EndsWith(StringLiteral S, T Value) {
if (!Result && Str.endswith(S)) {
Result = std::move(Value);
}
return *this;
}
template<unsigned N>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch& StartsWith(const char (&S)[N], const T &Value) {
assert(N);
if (!Result && Str.size() >= N-1 &&
(N == 1 || std::memcmp(S, Str.data(), N-1) == 0)) {
Result = &Value;
StringSwitch& StartsWith(StringLiteral S, T Value) {
if (!Result && Str.startswith(S)) {
Result = std::move(Value);
}
return *this;
}
template<unsigned N0, unsigned N1>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const T& Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, T Value) {
return Case(S0, Value).Case(S1, Value);
}
template<unsigned N0, unsigned N1, unsigned N2>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const char (&S2)[N2], const T& Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, StringLiteral S2,
T Value) {
return Case(S0, Value).Cases(S1, S2, Value);
}
template<unsigned N0, unsigned N1, unsigned N2, unsigned N3>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const char (&S2)[N2], const char (&S3)[N3],
const T& Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, T Value) {
return Case(S0, Value).Cases(S1, S2, S3, Value);
}
template<unsigned N0, unsigned N1, unsigned N2, unsigned N3, unsigned N4>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const char (&S2)[N2], const char (&S3)[N3],
const char (&S4)[N4], const T& Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, StringLiteral S4, T Value) {
return Case(S0, Value).Cases(S1, S2, S3, S4, Value);
}
template <unsigned N0, unsigned N1, unsigned N2, unsigned N3, unsigned N4,
unsigned N5>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const char (&S2)[N2], const char (&S3)[N3],
const char (&S4)[N4], const char (&S5)[N5],
const T &Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, StringLiteral S4, StringLiteral S5,
T Value) {
return Case(S0, Value).Cases(S1, S2, S3, S4, S5, Value);
}
template <unsigned N0, unsigned N1, unsigned N2, unsigned N3, unsigned N4,
unsigned N5, unsigned N6>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const char (&S2)[N2], const char (&S3)[N3],
const char (&S4)[N4], const char (&S5)[N5],
const char (&S6)[N6], const T &Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, StringLiteral S4, StringLiteral S5,
StringLiteral S6, T Value) {
return Case(S0, Value).Cases(S1, S2, S3, S4, S5, S6, Value);
}
template <unsigned N0, unsigned N1, unsigned N2, unsigned N3, unsigned N4,
unsigned N5, unsigned N6, unsigned N7>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const char (&S2)[N2], const char (&S3)[N3],
const char (&S4)[N4], const char (&S5)[N5],
const char (&S6)[N6], const char (&S7)[N7],
const T &Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, StringLiteral S4, StringLiteral S5,
StringLiteral S6, StringLiteral S7, T Value) {
return Case(S0, Value).Cases(S1, S2, S3, S4, S5, S6, S7, Value);
}
template <unsigned N0, unsigned N1, unsigned N2, unsigned N3, unsigned N4,
unsigned N5, unsigned N6, unsigned N7, unsigned N8>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const char (&S2)[N2], const char (&S3)[N3],
const char (&S4)[N4], const char (&S5)[N5],
const char (&S6)[N6], const char (&S7)[N7],
const char (&S8)[N8], const T &Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, StringLiteral S4, StringLiteral S5,
StringLiteral S6, StringLiteral S7, StringLiteral S8,
T Value) {
return Case(S0, Value).Cases(S1, S2, S3, S4, S5, S6, S7, S8, Value);
}
template <unsigned N0, unsigned N1, unsigned N2, unsigned N3, unsigned N4,
unsigned N5, unsigned N6, unsigned N7, unsigned N8, unsigned N9>
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &Cases(const char (&S0)[N0], const char (&S1)[N1],
const char (&S2)[N2], const char (&S3)[N3],
const char (&S4)[N4], const char (&S5)[N5],
const char (&S6)[N6], const char (&S7)[N7],
const char (&S8)[N8], const char (&S9)[N9],
const T &Value) {
StringSwitch &Cases(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, StringLiteral S4, StringLiteral S5,
StringLiteral S6, StringLiteral S7, StringLiteral S8,
StringLiteral S9, T Value) {
return Case(S0, Value).Cases(S1, S2, S3, S4, S5, S6, S7, S8, S9, Value);
}
// Case-insensitive case matchers.
template <unsigned N>
LLVM_ATTRIBUTE_ALWAYS_INLINE StringSwitch &CaseLower(const char (&S)[N],
const T &Value) {
if (!Result && Str.equals_lower(StringRef(S, N - 1)))
Result = &Value;
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &CaseLower(StringLiteral S, T Value) {
if (!Result && Str.equals_lower(S))
Result = std::move(Value);
return *this;
}
template <unsigned N>
LLVM_ATTRIBUTE_ALWAYS_INLINE StringSwitch &EndsWithLower(const char (&S)[N],
const T &Value) {
if (!Result && Str.endswith_lower(StringRef(S, N - 1)))
Result = &Value;
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &EndsWithLower(StringLiteral S, T Value) {
if (!Result && Str.endswith_lower(S))
Result = Value;
return *this;
}
template <unsigned N>
LLVM_ATTRIBUTE_ALWAYS_INLINE StringSwitch &StartsWithLower(const char (&S)[N],
const T &Value) {
if (!Result && Str.startswith_lower(StringRef(S, N - 1)))
Result = &Value;
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &StartsWithLower(StringLiteral S, T Value) {
if (!Result && Str.startswith_lower(S))
Result = std::move(Value);
return *this;
}
template <unsigned N0, unsigned N1>
LLVM_ATTRIBUTE_ALWAYS_INLINE StringSwitch &
CasesLower(const char (&S0)[N0], const char (&S1)[N1], const T &Value) {
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &CasesLower(StringLiteral S0, StringLiteral S1, T Value) {
return CaseLower(S0, Value).CaseLower(S1, Value);
}
template <unsigned N0, unsigned N1, unsigned N2>
LLVM_ATTRIBUTE_ALWAYS_INLINE StringSwitch &
CasesLower(const char (&S0)[N0], const char (&S1)[N1], const char (&S2)[N2],
const T &Value) {
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &CasesLower(StringLiteral S0, StringLiteral S1, StringLiteral S2,
T Value) {
return CaseLower(S0, Value).CasesLower(S1, S2, Value);
}
template <unsigned N0, unsigned N1, unsigned N2, unsigned N3>
LLVM_ATTRIBUTE_ALWAYS_INLINE StringSwitch &
CasesLower(const char (&S0)[N0], const char (&S1)[N1], const char (&S2)[N2],
const char (&S3)[N3], const T &Value) {
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &CasesLower(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, T Value) {
return CaseLower(S0, Value).CasesLower(S1, S2, S3, Value);
}
template <unsigned N0, unsigned N1, unsigned N2, unsigned N3, unsigned N4>
LLVM_ATTRIBUTE_ALWAYS_INLINE StringSwitch &
CasesLower(const char (&S0)[N0], const char (&S1)[N1], const char (&S2)[N2],
const char (&S3)[N3], const char (&S4)[N4], const T &Value) {
LLVM_ATTRIBUTE_ALWAYS_INLINE
StringSwitch &CasesLower(StringLiteral S0, StringLiteral S1, StringLiteral S2,
StringLiteral S3, StringLiteral S4, T Value) {
return CaseLower(S0, Value).CasesLower(S1, S2, S3, S4, Value);
}
LLVM_NODISCARD
LLVM_ATTRIBUTE_ALWAYS_INLINE
R Default(const T &Value) const {
R Default(T Value) {
if (Result)
return *Result;
return std::move(*Result);
return Value;
}
LLVM_NODISCARD
LLVM_ATTRIBUTE_ALWAYS_INLINE
operator R() const {
operator R() {
assert(Result && "Fell off the end of a string-switch");
return *Result;
return std::move(*Result);
}
};

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@ -158,7 +158,8 @@ TEST(StringSwitchTest, Cases) {
auto Translate = [](StringRef S) {
return llvm::StringSwitch<OSType>(S)
.Cases("wind\0ws", "win32", "winnt", OSType::Windows)
.Cases(StringLiteral::withInnerNUL("wind\0ws"), "win32", "winnt",
OSType::Windows)
.Cases("linux", "unix", "*nix", "posix", OSType::Linux)
.Default(OSType::Unknown);
};
@ -184,7 +185,8 @@ TEST(StringSwitchTest, CasesLower) {
auto Translate = [](StringRef S) {
return llvm::StringSwitch<OSType>(S)
.CasesLower("wind\0ws", "win32", "winnt", OSType::Windows)
.CasesLower(StringLiteral::withInnerNUL("wind\0ws"), "win32", "winnt",
OSType::Windows)
.CasesLower("linux", "unix", "*nix", "posix", OSType::Linux)
.Default(OSType::Unknown);
};