mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-12-03 17:02:03 +00:00
[ADT] Add Bitfield utilities
Context:
--------
There are places in LLVM where we need to pack typed fields into opaque values.
For instance, the `XXXInst` classes in `llvm/include/llvm/IR/Instructions.h` that extract informations from `Value::SubclassData` via `getSubclassDataFromInstruction()`.
The bit twiddling is done manually: this impairs readability and prevent consistent handling of out of range values (e.g. 435b458ad0/llvm/include/llvm/IR/Instructions.h (L564))
More importantly, the bit pattern is scattered throughout the implementation making it hard to pack additionnal fields or check for overlapping bits.
Design decisions:
-----------------
The Bitfield structs are to be declared together so it is clear which bits are used or not.
The code is designed with simplicity in mind, hence a few limitations:
- Storage is limited to a single integer,
- Enum values have to be `unsigned`,
- Storage type has to be `unsigned`,
- There are no automatic detection of overlapping fields (packed bitfield declaration should help though),
- The interface is C like so `storage` needs to be passed in everytime (code is simpler and lifetime considerations more obvious)
RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-June/142196.html
Differential Revision: https://reviews.llvm.org/D81580
This commit is contained in:
Guillaume Chatelet
parent
1d4b51e294
commit
9871a892f8
282
include/llvm/ADT/Bitfields.h
Normal file
282
include/llvm/ADT/Bitfields.h
Normal file
@ -0,0 +1,282 @@
|
||||
//===-- llvm/ADT/Bitfield.h - Get and Set bits in an integer ---*- C++ -*--===//
|
||||
//
|
||||
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
||||
// See https://llvm.org/LICENSE.txt for license information.
|
||||
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
///
|
||||
/// \file
|
||||
/// This file implements methods to test, set and extract typed bits from packed
|
||||
/// unsigned integers.
|
||||
///
|
||||
/// Why not C++ bitfields?
|
||||
/// ----------------------
|
||||
/// C++ bitfields do not offer control over the bit layout nor consistent
|
||||
/// behavior when it comes to out of range values.
|
||||
/// For instance, the layout is implementation defined and adjacent bits may be
|
||||
/// packed together but are not required to. This is problematic when storage is
|
||||
/// sparse and data must be stored in a particular integer type.
|
||||
///
|
||||
/// The methods provided in this file ensures precise control over the
|
||||
/// layout/storage as well as protection against out of range values.
|
||||
///
|
||||
/// Usage example
|
||||
/// -------------
|
||||
/// \code{.cpp}
|
||||
/// uint8_t Storage = 0;
|
||||
///
|
||||
/// // Store and retrieve a single bit as bool.
|
||||
/// using Bool = Bitfield::Element<bool, 0, 1>;
|
||||
/// Bitfield::set<Bool>(Storage, true);
|
||||
/// EXPECT_EQ(Storage, 0b00000001);
|
||||
/// // ^
|
||||
/// EXPECT_EQ(Bitfield::get<Bool>(Storage), true);
|
||||
///
|
||||
/// // Store and retrieve a 2 bit typed enum.
|
||||
/// // Note: enum underlying type must be unsigned.
|
||||
/// enum class SuitEnum : uint8_t { CLUBS, DIAMONDS, HEARTS, SPADES };
|
||||
/// // Note: enum maximum value needs to be passed in as last parameter.
|
||||
/// using Suit = Bitfield::Element<SuitEnum, 1, 2, SuitEnum::SPADES>;
|
||||
/// Bitfield::set<Suit>(Storage, SuitEnum::HEARTS);
|
||||
/// EXPECT_EQ(Storage, 0b00000101);
|
||||
/// // ^^
|
||||
/// EXPECT_EQ(Bitfield::get<Suit>(Storage), SuitEnum::HEARTS);
|
||||
///
|
||||
/// // Store and retrieve a 5 bit value as unsigned.
|
||||
/// using Value = Bitfield::Element<unsigned, 3, 5>;
|
||||
/// Bitfield::set<Value>(Storage, 10);
|
||||
/// EXPECT_EQ(Storage, 0b01010101);
|
||||
/// // ^^^^^
|
||||
/// EXPECT_EQ(Bitfield::get<Value>(Storage), 10U);
|
||||
///
|
||||
/// // Interpret the same 5 bit value as signed.
|
||||
/// using SignedValue = Bitfield::Element<int, 3, 5>;
|
||||
/// Bitfield::set<SignedValue>(Storage, -2);
|
||||
/// EXPECT_EQ(Storage, 0b11110101);
|
||||
/// // ^^^^^
|
||||
/// EXPECT_EQ(Bitfield::get<SignedValue>(Storage), -2);
|
||||
///
|
||||
/// // Ability to efficiently test if a field is non zero.
|
||||
/// EXPECT_TRUE(Bitfield::test<Value>(Storage));
|
||||
///
|
||||
/// // Alter Storage changes value.
|
||||
/// Storage = 0;
|
||||
/// EXPECT_EQ(Bitfield::get<Bool>(Storage), false);
|
||||
/// EXPECT_EQ(Bitfield::get<Suit>(Storage), SuitEnum::CLUBS);
|
||||
/// EXPECT_EQ(Bitfield::get<Value>(Storage), 0U);
|
||||
/// EXPECT_EQ(Bitfield::get<SignedValue>(Storage), 0);
|
||||
///
|
||||
/// Storage = 255;
|
||||
/// EXPECT_EQ(Bitfield::get<Bool>(Storage), true);
|
||||
/// EXPECT_EQ(Bitfield::get<Suit>(Storage), SuitEnum::SPADES);
|
||||
/// EXPECT_EQ(Bitfield::get<Value>(Storage), 31U);
|
||||
/// EXPECT_EQ(Bitfield::get<SignedValue>(Storage), -1);
|
||||
/// \endcode
|
||||
///
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#ifndef LLVM_ADT_BITFIELDS_H
|
||||
#define LLVM_ADT_BITFIELDS_H
|
||||
|
||||
#include <cassert>
|
||||
#include <climits> // CHAR_BIT
|
||||
#include <cstddef> // size_t
|
||||
#include <cstdint> // uintXX_t
|
||||
#include <limits> // numeric_limits
|
||||
#include <type_traits>
|
||||
|
||||
namespace llvm {
|
||||
|
||||
namespace bitfields_details {
|
||||
|
||||
/// A struct defining useful bit patterns for n-bits integer types.
|
||||
template <typename T, unsigned Bits> struct BitPatterns {
|
||||
/// Bit patterns are forged using the equivalent `Unsigned` type because of
|
||||
/// undefined operations over signed types (e.g. Bitwise shift operators).
|
||||
/// Moreover same size casting from unsigned to signed is well defined but not
|
||||
/// the other way around.
|
||||
using Unsigned = typename std::make_unsigned<T>::type;
|
||||
static_assert(sizeof(Unsigned) == sizeof(T), "Types must have same size");
|
||||
|
||||
static constexpr unsigned TypeBits = sizeof(Unsigned) * CHAR_BIT;
|
||||
static_assert(TypeBits >= Bits, "n-bit must fit in T");
|
||||
|
||||
/// e.g. with TypeBits == 8 and Bits == 6.
|
||||
static constexpr Unsigned AllZeros = Unsigned(0); // 00000000
|
||||
static constexpr Unsigned AllOnes = ~Unsigned(0); // 11111111
|
||||
static constexpr Unsigned Umin = AllZeros; // 00000000
|
||||
static constexpr Unsigned Umax = AllOnes >> (TypeBits - Bits); // 00111111
|
||||
static constexpr Unsigned SignBitMask = Unsigned(1) << (Bits - 1); // 00100000
|
||||
static constexpr Unsigned Smax = Umax >> 1U; // 00011111
|
||||
static constexpr Unsigned Smin = ~Smax; // 11100000
|
||||
static constexpr Unsigned SignExtend = Smin << 1U; // 11000000
|
||||
};
|
||||
|
||||
/// `Compressor` is used to manipulate the bits of a (possibly signed) integer
|
||||
/// type so it can be packed and unpacked into a `bits` sized integer,
|
||||
/// `Compressor` is specialized on signed-ness so no runtime cost is incurred.
|
||||
/// The `pack` method also checks that the passed in `UserValue` is valid.
|
||||
template <typename T, unsigned Bits, bool = std::is_unsigned<T>::value>
|
||||
struct Compressor {
|
||||
static_assert(std::is_unsigned<T>::value, "T is unsigned");
|
||||
using BP = BitPatterns<T, Bits>;
|
||||
|
||||
static T pack(T UserValue, T UserMaxValue) {
|
||||
assert(UserValue <= UserMaxValue && "value is too big");
|
||||
assert(UserValue <= BP::Umax && "value is too big");
|
||||
return UserValue;
|
||||
}
|
||||
|
||||
static T unpack(T StorageValue) { return StorageValue; }
|
||||
};
|
||||
|
||||
template <typename T, unsigned Bits> struct Compressor<T, Bits, false> {
|
||||
static_assert(std::is_signed<T>::value, "T is signed");
|
||||
using BP = BitPatterns<T, Bits>;
|
||||
|
||||
static T pack(T UserValue, T UserMaxValue) {
|
||||
assert(UserValue <= UserMaxValue && "value is too big");
|
||||
assert(UserValue <= T(BP::Smax) && "value is too big");
|
||||
assert(UserValue >= T(BP::Smin) && "value is too small");
|
||||
if (UserValue < 0)
|
||||
UserValue &= ~BP::SignExtend;
|
||||
return UserValue;
|
||||
}
|
||||
|
||||
static T unpack(T StorageValue) {
|
||||
if (StorageValue >= T(BP::SignBitMask))
|
||||
StorageValue |= BP::SignExtend;
|
||||
return StorageValue;
|
||||
}
|
||||
};
|
||||
|
||||
/// Impl is where Bifield description and Storage are put together to interact
|
||||
/// with values.
|
||||
template <typename Bitfield, typename StorageType> struct Impl {
|
||||
static_assert(std::is_unsigned<StorageType>::value,
|
||||
"Storage must be unsigned");
|
||||
using IntegerType = typename Bitfield::IntegerType;
|
||||
using C = Compressor<IntegerType, Bitfield::Bits>;
|
||||
using BP = BitPatterns<StorageType, Bitfield::Bits>;
|
||||
|
||||
static constexpr size_t StorageBits = sizeof(StorageType) * CHAR_BIT;
|
||||
static_assert(Bitfield::FirstBit <= StorageBits, "Data must fit in mask");
|
||||
static_assert(Bitfield::LastBit <= StorageBits, "Data must fit in mask");
|
||||
static constexpr StorageType Mask = BP::Umax << Bitfield::Shift;
|
||||
|
||||
/// Checks `UserValue` is within bounds and packs it between `FirstBit` and
|
||||
/// `LastBit` of `Packed` leaving the rest unchanged.
|
||||
static void update(StorageType &Packed, IntegerType UserValue) {
|
||||
const StorageType StorageValue = C::pack(UserValue, Bitfield::UserMaxValue);
|
||||
Packed &= ~Mask;
|
||||
Packed |= StorageValue << Bitfield::Shift;
|
||||
}
|
||||
|
||||
/// Interprets bits between `FirstBit` and `LastBit` of `Packed` as
|
||||
/// an`IntegerType`.
|
||||
static IntegerType extract(StorageType Packed) {
|
||||
const StorageType StorageValue = (Packed & Mask) >> Bitfield::Shift;
|
||||
return C::unpack(StorageValue);
|
||||
}
|
||||
|
||||
/// Interprets bits between `FirstBit` and `LastBit` of `Packed` as
|
||||
/// an`IntegerType`.
|
||||
static StorageType test(StorageType Packed) { return Packed & Mask; }
|
||||
};
|
||||
|
||||
/// `Bitfield` deals with the following type:
|
||||
/// - unsigned enums
|
||||
/// - signed and unsigned integer
|
||||
/// - `bool`
|
||||
/// Internally though we only manipulate integer with well defined and
|
||||
/// consistent semantic, this excludes typed enums and `bool` that are replaced
|
||||
/// with their unsigned counterparts. The correct type is restored in the public
|
||||
/// API.
|
||||
template <typename T, bool = std::is_enum<T>::value>
|
||||
struct ResolveUnderlyingType {
|
||||
using type = typename std::underlying_type<T>::type;
|
||||
};
|
||||
template <typename T> struct ResolveUnderlyingType<T, false> {
|
||||
using type = T;
|
||||
};
|
||||
template <> struct ResolveUnderlyingType<bool, false> {
|
||||
/// In case sizeof(bool) != 1, replace `void` by an additionnal
|
||||
/// std::conditional.
|
||||
using type = std::conditional<sizeof(bool) == 1, uint8_t, void>::type;
|
||||
};
|
||||
|
||||
} // namespace bitfields_details
|
||||
|
||||
/// Holds functions to get, set or test bitfields.
|
||||
struct Bitfield {
|
||||
/// Describes an element of a Bitfield. This type is then used with the
|
||||
/// Bitfield static member functions.
|
||||
/// \param T, the type of the field once in unpacked form,
|
||||
/// \param Offset, the position of the first bit,
|
||||
/// \param Size, the size of the field,
|
||||
/// \param MaxValue, For enums the maximum enum allowed.
|
||||
template <typename T, unsigned Offset, unsigned Size,
|
||||
T MaxValue = std::is_enum<T>::value
|
||||
? T(0) // coupled with static_assert below
|
||||
: std::numeric_limits<T>::max()>
|
||||
struct Element {
|
||||
using Type = T;
|
||||
using IntegerType =
|
||||
typename bitfields_details::ResolveUnderlyingType<T>::type;
|
||||
static constexpr unsigned Shift = Offset;
|
||||
static constexpr unsigned Bits = Size;
|
||||
static constexpr unsigned FirstBit = Offset;
|
||||
static constexpr unsigned LastBit = Shift + Bits;
|
||||
|
||||
private:
|
||||
template <typename, typename> friend struct bitfields_details::Impl;
|
||||
|
||||
static_assert(Bits > 0, "Bits must be non zero");
|
||||
static constexpr size_t TypeBits = sizeof(IntegerType) * CHAR_BIT;
|
||||
static_assert(Bits <= TypeBits, "Bits may not be greater than T size");
|
||||
static_assert(!std::is_enum<T>::value || MaxValue != T(0),
|
||||
"Enum Bitfields must provide a MaxValue");
|
||||
static_assert(!std::is_enum<T>::value ||
|
||||
std::is_unsigned<IntegerType>::value,
|
||||
"Enum must be unsigned");
|
||||
static_assert(std::is_integral<IntegerType>::value &&
|
||||
std::numeric_limits<IntegerType>::is_integer,
|
||||
"IntegerType must be an integer type");
|
||||
|
||||
static constexpr IntegerType UserMaxValue =
|
||||
static_cast<IntegerType>(MaxValue);
|
||||
};
|
||||
|
||||
/// Unpacks the field from the `Packed` value.
|
||||
template <typename Bitfield, typename StorageType>
|
||||
static typename Bitfield::Type get(StorageType Packed) {
|
||||
using I = bitfields_details::Impl<Bitfield, StorageType>;
|
||||
return static_cast<typename Bitfield::Type>(I::extract(Packed));
|
||||
}
|
||||
|
||||
/// Return a non-zero value if the field is non-zero.
|
||||
/// It is more efficient than `getField`.
|
||||
template <typename Bitfield, typename StorageType>
|
||||
static StorageType test(StorageType Packed) {
|
||||
using I = bitfields_details::Impl<Bitfield, StorageType>;
|
||||
return I::test(Packed);
|
||||
}
|
||||
|
||||
/// Sets the typed value in the provided `Packed` value.
|
||||
/// The method will asserts if the provided value is too big to fit in.
|
||||
template <typename Bitfield, typename StorageType>
|
||||
static void set(StorageType &Packed, typename Bitfield::Type Value) {
|
||||
using I = bitfields_details::Impl<Bitfield, StorageType>;
|
||||
I::update(Packed, static_cast<typename Bitfield::IntegerType>(Value));
|
||||
}
|
||||
|
||||
/// Returns whether the two bitfields share common bits.
|
||||
template <typename A, typename B> static constexpr bool isOverlapping() {
|
||||
return A::LastBit > B::FirstBit && B::LastBit > A::FirstBit;
|
||||
}
|
||||
};
|
||||
|
||||
} // namespace llvm
|
||||
|
||||
#endif // LLVM_ADT_BITFIELDS_H
|
||||
244
unittests/ADT/BitFieldsTest.cpp
Normal file
244
unittests/ADT/BitFieldsTest.cpp
Normal file
@ -0,0 +1,244 @@
|
||||
//===- llvm/unittests/ADT/BitFieldsTest.cpp - BitFields unit tests --------===//
|
||||
//
|
||||
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
||||
// See https://llvm.org/LICENSE.txt for license information.
|
||||
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "llvm/ADT/Bitfields.h"
|
||||
#include "gtest/gtest.h"
|
||||
|
||||
using namespace llvm;
|
||||
|
||||
namespace {
|
||||
|
||||
TEST(BitfieldsTest, Example) {
|
||||
uint8_t Storage = 0;
|
||||
|
||||
// Store and retrieve a single bit as bool.
|
||||
using Bool = Bitfield::Element<bool, 0, 1>;
|
||||
Bitfield::set<Bool>(Storage, true);
|
||||
EXPECT_EQ(Storage, 0b00000001);
|
||||
// ^
|
||||
EXPECT_EQ(Bitfield::get<Bool>(Storage), true);
|
||||
|
||||
// Store and retrieve a 2 bit typed enum.
|
||||
// Note: enum underlying type must be unsigned.
|
||||
enum class SuitEnum : uint8_t { CLUBS, DIAMONDS, HEARTS, SPADES };
|
||||
// Note: enum maximum value needs to be passed in as last parameter.
|
||||
using Suit = Bitfield::Element<SuitEnum, 1, 2, SuitEnum::SPADES>;
|
||||
Bitfield::set<Suit>(Storage, SuitEnum::HEARTS);
|
||||
EXPECT_EQ(Storage, 0b00000101);
|
||||
// ^^
|
||||
EXPECT_EQ(Bitfield::get<Suit>(Storage), SuitEnum::HEARTS);
|
||||
|
||||
// Store and retrieve a 5 bit value as unsigned.
|
||||
using Value = Bitfield::Element<unsigned, 3, 5>;
|
||||
Bitfield::set<Value>(Storage, 10);
|
||||
EXPECT_EQ(Storage, 0b01010101);
|
||||
// ^^^^^
|
||||
EXPECT_EQ(Bitfield::get<Value>(Storage), 10U);
|
||||
|
||||
// Interpret the same 5 bit value as signed.
|
||||
using SignedValue = Bitfield::Element<int, 3, 5>;
|
||||
Bitfield::set<SignedValue>(Storage, -2);
|
||||
EXPECT_EQ(Storage, 0b11110101);
|
||||
// ^^^^^
|
||||
EXPECT_EQ(Bitfield::get<SignedValue>(Storage), -2);
|
||||
|
||||
// Ability to efficiently test if a field is non zero.
|
||||
EXPECT_TRUE(Bitfield::test<Value>(Storage));
|
||||
|
||||
// Alter Storage changes value.
|
||||
Storage = 0;
|
||||
EXPECT_EQ(Bitfield::get<Bool>(Storage), false);
|
||||
EXPECT_EQ(Bitfield::get<Suit>(Storage), SuitEnum::CLUBS);
|
||||
EXPECT_EQ(Bitfield::get<Value>(Storage), 0U);
|
||||
EXPECT_EQ(Bitfield::get<SignedValue>(Storage), 0);
|
||||
|
||||
Storage = 255;
|
||||
EXPECT_EQ(Bitfield::get<Bool>(Storage), true);
|
||||
EXPECT_EQ(Bitfield::get<Suit>(Storage), SuitEnum::SPADES);
|
||||
EXPECT_EQ(Bitfield::get<Value>(Storage), 31U);
|
||||
EXPECT_EQ(Bitfield::get<SignedValue>(Storage), -1);
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, FirstBit) {
|
||||
uint8_t Storage = 0;
|
||||
using FirstBit = Bitfield::Element<bool, 0, 1>;
|
||||
// Set true
|
||||
Bitfield::set<FirstBit>(Storage, true);
|
||||
EXPECT_EQ(Bitfield::get<FirstBit>(Storage), true);
|
||||
EXPECT_EQ(Storage, 0x1ULL);
|
||||
// Set false
|
||||
Bitfield::set<FirstBit>(Storage, false);
|
||||
EXPECT_EQ(Bitfield::get<FirstBit>(Storage), false);
|
||||
EXPECT_EQ(Storage, 0x0ULL);
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, SecondBit) {
|
||||
uint8_t Storage = 0;
|
||||
using SecondBit = Bitfield::Element<bool, 1, 1>;
|
||||
// Set true
|
||||
Bitfield::set<SecondBit>(Storage, true);
|
||||
EXPECT_EQ(Bitfield::get<SecondBit>(Storage), true);
|
||||
EXPECT_EQ(Storage, 0x2ULL);
|
||||
// Set false
|
||||
Bitfield::set<SecondBit>(Storage, false);
|
||||
EXPECT_EQ(Bitfield::get<SecondBit>(Storage), false);
|
||||
EXPECT_EQ(Storage, 0x0ULL);
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, LastBit) {
|
||||
uint8_t Storage = 0;
|
||||
using LastBit = Bitfield::Element<bool, 7, 1>;
|
||||
// Set true
|
||||
Bitfield::set<LastBit>(Storage, true);
|
||||
EXPECT_EQ(Bitfield::get<LastBit>(Storage), true);
|
||||
EXPECT_EQ(Storage, 0x80ULL);
|
||||
// Set false
|
||||
Bitfield::set<LastBit>(Storage, false);
|
||||
EXPECT_EQ(Bitfield::get<LastBit>(Storage), false);
|
||||
EXPECT_EQ(Storage, 0x0ULL);
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, LastBitUint64) {
|
||||
uint64_t Storage = 0;
|
||||
using LastBit = Bitfield::Element<bool, 63, 1>;
|
||||
// Set true
|
||||
Bitfield::set<LastBit>(Storage, true);
|
||||
EXPECT_EQ(Bitfield::get<LastBit>(Storage), true);
|
||||
EXPECT_EQ(Storage, 0x8000000000000000ULL);
|
||||
// Set false
|
||||
Bitfield::set<LastBit>(Storage, false);
|
||||
EXPECT_EQ(Bitfield::get<LastBit>(Storage), false);
|
||||
EXPECT_EQ(Storage, 0x0ULL);
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, Enum) {
|
||||
enum Enum : unsigned { Zero = 0, Two = 2, LAST = Two };
|
||||
|
||||
uint8_t Storage = 0;
|
||||
using OrderingField = Bitfield::Element<Enum, 1, 2, LAST>;
|
||||
EXPECT_EQ(Bitfield::get<OrderingField>(Storage), Zero);
|
||||
Bitfield::set<OrderingField>(Storage, Two);
|
||||
EXPECT_EQ(Bitfield::get<OrderingField>(Storage), Two);
|
||||
EXPECT_EQ(Storage, 0b00000100);
|
||||
// value 2 in ^^
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, EnumClass) {
|
||||
enum class Enum : unsigned { Zero = 0, Two = 2, LAST = Two };
|
||||
|
||||
uint8_t Storage = 0;
|
||||
using OrderingField = Bitfield::Element<Enum, 1, 2, Enum::LAST>;
|
||||
EXPECT_EQ(Bitfield::get<OrderingField>(Storage), Enum::Zero);
|
||||
Bitfield::set<OrderingField>(Storage, Enum::Two);
|
||||
EXPECT_EQ(Bitfield::get<OrderingField>(Storage), Enum::Two);
|
||||
EXPECT_EQ(Storage, 0b00000100);
|
||||
// value 2 in ^^
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, OneBitSigned) {
|
||||
uint8_t Storage = 0;
|
||||
using SignedField = Bitfield::Element<int, 1, 1>;
|
||||
EXPECT_EQ(Bitfield::get<SignedField>(Storage), 0);
|
||||
EXPECT_EQ(Storage, 0b00000000);
|
||||
// value 0 in ^
|
||||
Bitfield::set<SignedField>(Storage, -1);
|
||||
EXPECT_EQ(Bitfield::get<SignedField>(Storage), -1);
|
||||
EXPECT_EQ(Storage, 0b00000010);
|
||||
// value 1 in ^
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, TwoBitSigned) {
|
||||
uint8_t Storage = 0;
|
||||
using SignedField = Bitfield::Element<int, 1, 2>;
|
||||
EXPECT_EQ(Bitfield::get<SignedField>(Storage), 0);
|
||||
EXPECT_EQ(Storage, 0b00000000);
|
||||
// value 0 in ^^
|
||||
Bitfield::set<SignedField>(Storage, 1);
|
||||
EXPECT_EQ(Bitfield::get<SignedField>(Storage), 1);
|
||||
EXPECT_EQ(Storage, 0b00000010);
|
||||
// value 1 in ^^
|
||||
Bitfield::set<SignedField>(Storage, -1);
|
||||
EXPECT_EQ(Bitfield::get<SignedField>(Storage), -1);
|
||||
EXPECT_EQ(Storage, 0b00000110);
|
||||
// value -1 in ^^
|
||||
Bitfield::set<SignedField>(Storage, -2);
|
||||
EXPECT_EQ(Bitfield::get<SignedField>(Storage), -2);
|
||||
EXPECT_EQ(Storage, 0b00000100);
|
||||
// value -2 in ^^
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, isOverlapping) {
|
||||
// 01234567
|
||||
// A: --------
|
||||
// B: ---
|
||||
// C: ---
|
||||
// D: ---
|
||||
using A = Bitfield::Element<unsigned, 0, 8>;
|
||||
using B = Bitfield::Element<unsigned, 3, 3>;
|
||||
using C = Bitfield::Element<unsigned, 1, 3>;
|
||||
using D = Bitfield::Element<unsigned, 4, 3>;
|
||||
EXPECT_TRUE((Bitfield::isOverlapping<A, B>()));
|
||||
EXPECT_TRUE((Bitfield::isOverlapping<A, C>()));
|
||||
EXPECT_TRUE((Bitfield::isOverlapping<A, B>()));
|
||||
EXPECT_TRUE((Bitfield::isOverlapping<A, D>()));
|
||||
|
||||
EXPECT_TRUE((Bitfield::isOverlapping<B, C>()));
|
||||
EXPECT_TRUE((Bitfield::isOverlapping<B, D>()));
|
||||
EXPECT_FALSE((Bitfield::isOverlapping<C, D>()));
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, FullUint64) {
|
||||
uint64_t Storage = 0;
|
||||
using Value = Bitfield::Element<uint64_t, 0, 64>;
|
||||
Bitfield::set<Value>(Storage, -1ULL);
|
||||
EXPECT_EQ(Bitfield::get<Value>(Storage), -1ULL);
|
||||
Bitfield::set<Value>(Storage, 0ULL);
|
||||
EXPECT_EQ(Bitfield::get<Value>(Storage), 0ULL);
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, FullInt64) {
|
||||
uint64_t Storage = 0;
|
||||
using Value = Bitfield::Element<int64_t, 0, 64>;
|
||||
Bitfield::set<Value>(Storage, -1);
|
||||
EXPECT_EQ(Bitfield::get<Value>(Storage), -1);
|
||||
Bitfield::set<Value>(Storage, 0);
|
||||
EXPECT_EQ(Bitfield::get<Value>(Storage), 0);
|
||||
}
|
||||
|
||||
#ifdef EXPECT_DEBUG_DEATH
|
||||
|
||||
TEST(BitfieldsTest, ValueTooBigBool) {
|
||||
uint64_t Storage = 0;
|
||||
using A = Bitfield::Element<unsigned, 0, 1>;
|
||||
Bitfield::set<A>(Storage, true);
|
||||
Bitfield::set<A>(Storage, false);
|
||||
EXPECT_DEBUG_DEATH(Bitfield::set<A>(Storage, 2), "value is too big");
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, ValueTooBigInt) {
|
||||
uint64_t Storage = 0;
|
||||
using A = Bitfield::Element<unsigned, 0, 2>;
|
||||
Bitfield::set<A>(Storage, 3);
|
||||
EXPECT_DEBUG_DEATH(Bitfield::set<A>(Storage, 4), "value is too big");
|
||||
EXPECT_DEBUG_DEATH(Bitfield::set<A>(Storage, -1), "value is too big");
|
||||
}
|
||||
|
||||
TEST(BitfieldsTest, ValueTooBigBounded) {
|
||||
uint8_t Storage = 0;
|
||||
using A = Bitfield::Element<int, 1, 2>;
|
||||
Bitfield::set<A>(Storage, 1);
|
||||
Bitfield::set<A>(Storage, 0);
|
||||
Bitfield::set<A>(Storage, -1);
|
||||
Bitfield::set<A>(Storage, -2);
|
||||
EXPECT_DEBUG_DEATH(Bitfield::set<A>(Storage, 2), "value is too big");
|
||||
EXPECT_DEBUG_DEATH(Bitfield::set<A>(Storage, -3), "value is too small");
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
} // namespace
|
||||
@ -8,6 +8,7 @@ add_llvm_unittest(ADTTests
|
||||
APIntTest.cpp
|
||||
APSIntTest.cpp
|
||||
ArrayRefTest.cpp
|
||||
BitFieldsTest.cpp
|
||||
BitmaskEnumTest.cpp
|
||||
BitVectorTest.cpp
|
||||
BreadthFirstIteratorTest.cpp
|
||||
|
||||
Loading…
Reference in New Issue
Block a user