[libc-commits] [libc] 26c17f4 - [libc][NFC] Simplify op_generic
Guillaume Chatelet via libc-commits
libc-commits at lists.llvm.org
Fri Apr 7 04:58:52 PDT 2023
Author: Guillaume Chatelet
Date: 2023-04-07T11:58:38Z
New Revision: 26c17f4b60013e688a9ce764c4c4b088c0e5dcb9
URL: https://github.com/llvm/llvm-project/commit/26c17f4b60013e688a9ce764c4c4b088c0e5dcb9
DIFF: https://github.com/llvm/llvm-project/commit/26c17f4b60013e688a9ce764c4c4b088c0e5dcb9.diff
LOG: [libc][NFC] Simplify op_generic
Added:
Modified:
libc/src/string/memory_utils/op_generic.h
Removed:
################################################################################
diff --git a/libc/src/string/memory_utils/op_generic.h b/libc/src/string/memory_utils/op_generic.h
index 0a4a7cb2c93bb..fd63ac67d005a 100644
--- a/libc/src/string/memory_utils/op_generic.h
+++ b/libc/src/string/memory_utils/op_generic.h
@@ -35,95 +35,96 @@
namespace __llvm_libc::generic {
-// Implements generic load, store, splat and set for unsigned integral types.
-template <typename T> struct ScalarType {
- static_assert(cpp::is_integral_v<T> && !cpp::is_signed_v<T>);
- using Type = T;
- static constexpr size_t SIZE = sizeof(Type);
-
- LIBC_INLINE static Type load(CPtr src) {
- return ::__llvm_libc::load<Type>(src);
- }
- LIBC_INLINE static void store(Ptr dst, Type value) {
- ::__llvm_libc::store<Type>(dst, value);
- }
- LIBC_INLINE static Type splat(uint8_t value) {
- return Type(~0) / Type(0xFF) * Type(value);
- }
- LIBC_INLINE static void set(Ptr dst, uint8_t value) {
- store(dst, splat(value));
- }
+// Compiler types using the vector attributes.
+using uint8x1_t = uint8_t __attribute__((__vector_size__(1)));
+using uint8x2_t = uint8_t __attribute__((__vector_size__(2)));
+using uint8x4_t = uint8_t __attribute__((__vector_size__(4)));
+using uint8x8_t = uint8_t __attribute__((__vector_size__(8)));
+using uint8x16_t = uint8_t __attribute__((__vector_size__(16)));
+using uint8x32_t = uint8_t __attribute__((__vector_size__(32)));
+using uint8x64_t = uint8_t __attribute__((__vector_size__(64)));
+
+// We accept three types of values as elements for generic operations:
+// - scalar : unsigned integral types
+// - vector : compiler types using the vector attributes
+// - array : a cpp::array<T, N> where T is itself either a scalar or a vector.
+// The following traits help discriminate between these cases.
+
+template <typename T>
+constexpr bool is_scalar_v = cpp::is_integral_v<T> && cpp::is_unsigned_v<T>;
+
+template <typename T>
+constexpr bool is_vector_v =
+ cpp::details::is_unqualified_any_of<T, uint8x1_t, uint8x2_t, uint8x4_t,
+ uint8x8_t, uint8x16_t, uint8x32_t,
+ uint8x64_t>();
+
+template <class T> struct is_array : cpp::false_type {};
+template <class T, size_t N> struct is_array<cpp::array<T, N>> {
+ static constexpr bool value = is_scalar_v<T> || is_vector_v<T>;
};
+template <typename T> constexpr bool is_array_v = is_array<T>::value;
-// GCC can only take literals as __vector_size__ argument so we have to use
-// template specialization.
-template <size_t Size> struct VectorValueType {};
-template <> struct VectorValueType<1> {
- using type = uint8_t __attribute__((__vector_size__(1)));
-};
-template <> struct VectorValueType<2> {
- using type = uint8_t __attribute__((__vector_size__(2)));
-};
-template <> struct VectorValueType<4> {
- using type = uint8_t __attribute__((__vector_size__(4)));
-};
-template <> struct VectorValueType<8> {
- using type = uint8_t __attribute__((__vector_size__(8)));
-};
-template <> struct VectorValueType<16> {
- using type = uint8_t __attribute__((__vector_size__(16)));
-};
-template <> struct VectorValueType<32> {
- using type = uint8_t __attribute__((__vector_size__(32)));
-};
-template <> struct VectorValueType<64> {
- using type = uint8_t __attribute__((__vector_size__(64)));
-};
+template <typename T>
+constexpr bool is_element_type_v =
+ is_scalar_v<T> || is_vector_v<T> || is_array_v<T>;
-// Implements generic load, store, splat and set for vector types.
-template <size_t Size> struct VectorType {
- using Type = typename VectorValueType<Size>::type;
- static constexpr size_t SIZE = Size;
- LIBC_INLINE static Type load(CPtr src) {
- return ::__llvm_libc::load<Type>(src);
+//
+template <class T> struct array_size {};
+template <class T, size_t N>
+struct array_size<cpp::array<T, N>> : cpp::integral_constant<size_t, N> {};
+template <typename T> constexpr size_t array_size_v = array_size<T>::value;
+
+// Generic operations for the above type categories.
+
+template <typename T> T load(CPtr src) {
+ static_assert(is_element_type_v<T>);
+ if constexpr (is_scalar_v<T> || is_vector_v<T>) {
+ return ::__llvm_libc::load<T>(src);
+ } else if constexpr (is_array_v<T>) {
+ using value_type = typename T::value_type;
+ T Value;
+ for (size_t I = 0; I < array_size_v<T>; ++I)
+ Value[I] = load<value_type>(src + (I * sizeof(value_type)));
+ return Value;
}
- LIBC_INLINE static void store(Ptr dst, Type value) {
- ::__llvm_libc::store<Type>(dst, value);
+}
+
+template <typename T> void store(Ptr dst, T value) {
+ static_assert(is_element_type_v<T>);
+ if constexpr (is_scalar_v<T> || is_vector_v<T>) {
+ ::__llvm_libc::store<T>(dst, value);
+ } else if constexpr (is_array_v<T>) {
+ using value_type = typename T::value_type;
+ for (size_t I = 0; I < array_size_v<T>; ++I)
+ store<value_type>(dst + (I * sizeof(value_type)), value[I]);
}
- LIBC_INLINE static Type splat(uint8_t value) {
- Type Out;
+}
+
+template <typename T> T splat(uint8_t value) {
+ static_assert(is_scalar_v<T> || is_vector_v<T>);
+ if constexpr (is_scalar_v<T>)
+ return T(~0) / T(0xFF) * T(value);
+ else if constexpr (is_vector_v<T>) {
+ T Out;
// This for loop is optimized out for vector types.
- for (size_t i = 0; i < Size; ++i)
+ for (size_t i = 0; i < sizeof(T); ++i)
Out[i] = static_cast<uint8_t>(value);
return Out;
}
- LIBC_INLINE static void set(Ptr dst, uint8_t value) {
- store(dst, splat(value));
- }
-};
+}
-// Implements load, store and set for sizes not natively supported by the
-// platform. SubType is either ScalarType or VectorType.
-template <typename SubType, size_t ArraySize> struct ArrayType {
- using Type = cpp::array<typename SubType::Type, ArraySize>;
- static constexpr size_t SizeOfElement = SubType::SIZE;
- static constexpr size_t SIZE = SizeOfElement * ArraySize;
- LIBC_INLINE static Type load(CPtr src) {
- Type Value;
- for (size_t I = 0; I < ArraySize; ++I)
- Value[I] = SubType::load(src + (I * SizeOfElement));
- return Value;
- }
- LIBC_INLINE static void store(Ptr dst, Type Value) {
- for (size_t I = 0; I < ArraySize; ++I)
- SubType::store(dst + (I * SizeOfElement), Value[I]);
+template <typename T> void set(Ptr dst, uint8_t value) {
+ static_assert(is_element_type_v<T>);
+ if constexpr (is_scalar_v<T> || is_vector_v<T>) {
+ store<T>(dst, splat<T>(value));
+ } else if constexpr (is_array_v<T>) {
+ using value_type = typename T::value_type;
+ const value_type Splat = splat<value_type>(value);
+ for (size_t I = 0; I < array_size_v<T>; ++I)
+ store<value_type>(dst + (I * sizeof(value_type)), Splat);
}
- LIBC_INLINE static void set(Ptr dst, uint8_t value) {
- const auto Splat = SubType::splat(value);
- for (size_t I = 0; I < ArraySize; ++I)
- SubType::store(dst + (I * SizeOfElement), Splat);
- }
-};
+}
static_assert((UINTPTR_MAX == 4294967295U) ||
(UINTPTR_MAX == 18446744073709551615UL),
@@ -134,20 +135,28 @@ static_assert((UINTPTR_MAX == 4294967295U) ||
#endif
namespace details {
-// Checks that each type's SIZE is sorted in strictly decreasing order.
-// i.e. First::SIZE > Second::SIZE > ... > Last::SIZE
+// Checks that each type is sorted in strictly decreasing order of size.
+// i.e. sizeof(First) > sizeof(Second) > ... > sizeof(Last)
+template <typename First> constexpr bool is_decreasing_size() {
+ return sizeof(First) == 1;
+}
template <typename First, typename Second, typename... Next>
constexpr bool is_decreasing_size() {
- if constexpr (sizeof...(Next) > 0) {
- return (First::SIZE > Second::SIZE) &&
- is_decreasing_size<Second, Next...>();
- } else {
- return First::SIZE > Second::SIZE;
- }
+ if constexpr (sizeof...(Next) > 0)
+ return sizeof(First) > sizeof(Second) && is_decreasing_size<Next...>();
+ else
+ return sizeof(First) > sizeof(Second) && is_decreasing_size<Second>();
}
-// Helper to test if a type is void.
-template <typename T> inline constexpr bool is_void_v = cpp::is_same_v<T, void>;
+template <size_t Size, typename... Ts> struct Largest;
+template <size_t Size> struct Largest<Size> {
+ using type = uint8_t;
+};
+template <size_t Size, typename T, typename... Ts>
+struct Largest<Size, T, Ts...> {
+ using next = Largest<Size, Ts...>;
+ using type = cpp::conditional_t<(Size >= sizeof(T)), T, typename next::type>;
+};
} // namespace details
@@ -160,26 +169,14 @@ template <typename T> inline constexpr bool is_void_v = cpp::is_same_v<T, void>;
// using ST = SupportedTypes<ScalarType<uint16_t>, ScalarType<uint8_t>>;
// using Type = ST::TypeFor<10>;
// static_assert(cpp:is_same_v<Type, ScalarType<uint16_t>>);
-template <typename First, typename Second, typename... Next>
-struct SupportedTypes {
- static_assert(details::is_decreasing_size<First, Second, Next...>());
- using MaxType = First;
- template <size_t Size>
- using TypeFor = cpp::conditional_t<
- (Size >= First::SIZE), First,
- typename SupportedTypes<Second, Next...>::template TypeFor<Size>>;
-};
+template <typename First, typename... Ts> struct SupportedTypes {
+ static_assert(details::is_decreasing_size<First, Ts...>());
-template <typename First, typename Second>
-struct SupportedTypes<First, Second> {
- static_assert(details::is_decreasing_size<First, Second>());
using MaxType = First;
template <size_t Size>
- using TypeFor = cpp::conditional_t<
- (Size >= First::SIZE), First,
- cpp::conditional_t<(Size >= Second::SIZE), Second, void>>;
+ using TypeFor = typename details::Largest<Size, First, Ts...>::type;
};
// Map from sizes to structures offering static load, store and splat methods.
@@ -189,19 +186,21 @@ struct SupportedTypes<First, Second> {
// Lists a generic native types to use for Memset and Memmove operations.
// TODO: Inject the native types within Memset and Memmove depending on the
// target architectures and derive MaxSize from it.
-using NativeTypeMap =
- SupportedTypes<VectorType<64>, //
- VectorType<32>, //
- VectorType<16>,
+using NativeTypeMap = SupportedTypes<uint8x64_t, //
+ uint8x32_t, //
+ uint8x16_t,
#if defined(LLVM_LIBC_HAS_UINT64)
- ScalarType<uint64_t>, // Not available on 32bit
+ uint64_t, // Not available on 32bit
#endif
- ScalarType<uint32_t>, //
- ScalarType<uint16_t>, //
- ScalarType<uint8_t>>;
+ uint32_t, //
+ uint16_t, //
+ uint8_t>;
namespace details {
+// Helper to test if a type is void.
+template <typename T> inline constexpr bool is_void_v = cpp::is_same_v<T, void>;
+
// In case the 'Size' is not supported we can fall back to a sequence of smaller
// operations using the largest natively supported type.
template <size_t Size, size_t MaxSize> static constexpr bool useArrayType() {
@@ -214,12 +213,11 @@ template <size_t Size, size_t MaxSize> static constexpr bool useArrayType() {
template <size_t Size, size_t MaxSize>
using getTypeFor = cpp::conditional_t<
useArrayType<Size, MaxSize>(),
- ArrayType<NativeTypeMap::TypeFor<MaxSize>, Size / MaxSize>,
+ cpp::array<NativeTypeMap::TypeFor<MaxSize>, Size / MaxSize>,
NativeTypeMap::TypeFor<Size>>;
} // namespace details
-
///////////////////////////////////////////////////////////////////////////////
// Memset
// The MaxSize template argument gives the maximum size handled natively by the
@@ -240,7 +238,7 @@ template <size_t Size, size_t MaxSize> struct Memset {
if constexpr (details::is_void_v<T>) {
deferred_static_assert("Unimplemented Size");
} else {
- T::set(dst, value);
+ set<T>(dst, value);
}
}
}
@@ -278,7 +276,7 @@ template <size_t Size, size_t MaxSize> struct Memmove {
if constexpr (details::is_void_v<T>) {
deferred_static_assert("Unimplemented Size");
} else {
- T::store(dst, T::load(src));
+ store<T>(dst, load<T>(src));
}
}
@@ -290,10 +288,10 @@ template <size_t Size, size_t MaxSize> struct Memmove {
// The load and store operations can be performed in any order as long as
// they are not interleaved. More investigations are needed to determine
// the best order.
- const auto head = T::load(src);
- const auto tail = T::load(src + offset);
- T::store(dst, head);
- T::store(dst + offset, tail);
+ const auto head = load<T>(src);
+ const auto tail = load<T>(src + offset);
+ store<T>(dst, head);
+ store<T>(dst + offset, tail);
}
}
@@ -373,14 +371,14 @@ template <size_t Size, size_t MaxSize> struct Memmove {
size_t count) {
static_assert(Size > 1, "a loop of size 1 does not need tail");
const size_t tail_offset = count - Size;
- const auto tail_value = T::load(src + tail_offset);
+ const auto tail_value = load<T>(src + tail_offset);
size_t offset = 0;
LIBC_LOOP_NOUNROLL
do {
block(dst + offset, src + offset);
offset += Size;
} while (offset < count - Size);
- T::store(dst + tail_offset, tail_value);
+ store<T>(dst + tail_offset, tail_value);
}
// Move backward suitable when dst > src. We load the head bytes before
@@ -400,14 +398,14 @@ template <size_t Size, size_t MaxSize> struct Memmove {
LIBC_INLINE static void loop_and_tail_backward(Ptr dst, CPtr src,
size_t count) {
static_assert(Size > 1, "a loop of size 1 does not need tail");
- const auto head_value = T::load(src);
+ const auto head_value = load<T>(src);
ptr
diff _t offset = count - Size;
LIBC_LOOP_NOUNROLL
do {
block(dst + offset, src + offset);
offset -= Size;
} while (offset >= 0);
- T::store(dst, head_value);
+ store<T>(dst, head_value);
}
};
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