diff --git a/src/common/bit_field.h b/src/common/bit_field.h index e27c93907..02266c7b9 100644 --- a/src/common/bit_field.h +++ b/src/common/bit_field.h @@ -34,6 +34,7 @@ #include #include #include "common/common_funcs.h" +#include "common/swap.h" /* * Abstract bitfield class @@ -108,7 +109,7 @@ * symptoms. */ #pragma pack(1) -template +template struct BitField { private: // UnderlyingType is T for non-enum types and the underlying type of T if @@ -121,6 +122,8 @@ private: // We store the value as the unsigned type to avoid undefined behaviour on value shifting using StorageType = std::make_unsigned_t; + using StorageTypeWithEndian = typename AddEndian::type; + public: BitField& operator=(const BitField&) = default; @@ -168,7 +171,7 @@ public: } FORCE_INLINE void Assign(const T& value) { - storage = (storage & ~mask) | FormatValue(value); + storage = (static_cast(storage) & ~mask) | FormatValue(value); } FORCE_INLINE T Value() const { @@ -180,7 +183,7 @@ public: } private: - StorageType storage; + StorageTypeWithEndian storage; static_assert(bits + position <= 8 * sizeof(T), "Bitfield out of range"); @@ -196,3 +199,6 @@ private: static_assert(std::is_trivially_copyable>::value, "BitField must be trivially copyable"); #endif + +template +using BitFieldBE = BitField; diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt index f048714a7..0cb36a2ce 100644 --- a/src/tests/CMakeLists.txt +++ b/src/tests/CMakeLists.txt @@ -1,4 +1,5 @@ add_executable(tests + common/bit_field.cpp common/param_package.cpp core/arm/arm_test_common.cpp core/arm/arm_test_common.h diff --git a/src/tests/common/bit_field.cpp b/src/tests/common/bit_field.cpp new file mode 100644 index 000000000..8ca1889f9 --- /dev/null +++ b/src/tests/common/bit_field.cpp @@ -0,0 +1,90 @@ +// Copyright 2019 Citra Emulator Project +// Licensed under GPLv2 or any later version +// Refer to the license.txt file included. + +#include +#include +#include +#include +#include "common/bit_field.h" + +TEST_CASE("BitField", "[common]") { + enum class TestEnum : u32 { + A = 0b10111101, + B = 0b10101110, + C = 0b00001111, + }; + + union LEBitField { + u32_le raw; + BitField<0, 6, u32> a; + BitField<6, 4, s32> b; + BitField<10, 8, TestEnum> c; + BitField<18, 14, u32> d; + } le_bitfield; + + union BEBitField { + u32_be raw; + BitFieldBE<0, 6, u32> a; + BitFieldBE<6, 4, s32> b; + BitFieldBE<10, 8, TestEnum> c; + BitFieldBE<18, 14, u32> d; + } be_bitfield; + + static_assert(sizeof(LEBitField) == sizeof(u32)); + static_assert(sizeof(BEBitField) == sizeof(u32)); + static_assert(std::is_trivially_copyable_v); + static_assert(std::is_trivially_copyable_v); + + std::array raw{{ + 0b01101100, + 0b11110110, + 0b10111010, + 0b11101100, + }}; + + std::memcpy(&le_bitfield, &raw, sizeof(raw)); + std::memcpy(&be_bitfield, &raw, sizeof(raw)); + + // bit fields: 11101100101110'10111101'1001'101100 + REQUIRE(le_bitfield.raw == 0b11101100'10111010'11110110'01101100); + REQUIRE(le_bitfield.a == 0b101100); + REQUIRE(le_bitfield.b == -7); // 1001 as two's complement + REQUIRE(le_bitfield.c == TestEnum::A); + REQUIRE(le_bitfield.d == 0b11101100101110); + + le_bitfield.a.Assign(0b000111); + le_bitfield.b.Assign(-1); + le_bitfield.c.Assign(TestEnum::C); + le_bitfield.d.Assign(0b01010101010101); + std::memcpy(&raw, &le_bitfield, sizeof(raw)); + // bit fields: 01010101010101'00001111'1111'000111 + REQUIRE(le_bitfield.raw == 0b01010101'01010100'00111111'11000111); + REQUIRE(raw == std::array{{ + 0b11000111, + 0b00111111, + 0b01010100, + 0b01010101, + }}); + + // bit fields: 01101100111101'10101110'1011'101100 + REQUIRE(be_bitfield.raw == 0b01101100'11110110'10111010'11101100); + REQUIRE(be_bitfield.a == 0b101100); + REQUIRE(be_bitfield.b == -5); // 1011 as two's complement + REQUIRE(be_bitfield.c == TestEnum::B); + REQUIRE(be_bitfield.d == 0b01101100111101); + + be_bitfield.a.Assign(0b000111); + be_bitfield.b.Assign(-1); + be_bitfield.c.Assign(TestEnum::C); + be_bitfield.d.Assign(0b01010101010101); + std::memcpy(&raw, &be_bitfield, sizeof(raw)); + // bit fields: 01010101010101'00001111'1111'000111 + REQUIRE(be_bitfield.raw == 0b01010101'01010100'00111111'11000111); + REQUIRE(raw == std::array{{ + 0b01010101, + 0b01010100, + 0b00111111, + 0b11000111, + }}); +}