From e99dabc729f998d04fcd759528c8799df6fff4d4 Mon Sep 17 00:00:00 2001 From: Oleg Sikorskiy Date: Mon, 22 Mar 2021 21:25:06 +0300 Subject: [PATCH] AK: Implement bit_cast --- AK/BitCast.h | 43 ++++++++++++++++++++++++++++++++++++++ AK/Tests/CMakeLists.txt | 1 + AK/Tests/TestBitCast.cpp | 45 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 89 insertions(+) create mode 100644 AK/BitCast.h create mode 100644 AK/Tests/TestBitCast.cpp diff --git a/AK/BitCast.h b/AK/BitCast.h new file mode 100644 index 0000000000..475d5ac57e --- /dev/null +++ b/AK/BitCast.h @@ -0,0 +1,43 @@ +/* + * Copyright (c) 2021, the SerenityOS developers. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#pragma once + +namespace AK { + +template +inline T bit_cast(const U& a) +{ + static_assert(sizeof(T) == sizeof(U)); + + T result; + __builtin_memcpy(&result, &a, sizeof(T)); + return result; +} + +} + +using AK::bit_cast; diff --git a/AK/Tests/CMakeLists.txt b/AK/Tests/CMakeLists.txt index 3d5bc360a2..391bfbd0e0 100644 --- a/AK/Tests/CMakeLists.txt +++ b/AK/Tests/CMakeLists.txt @@ -9,6 +9,7 @@ set(AK_TEST_SOURCES TestBase64.cpp TestBinaryHeap.cpp TestBinarySearch.cpp + TestBitCast.cpp TestBitmap.cpp TestByteBuffer.cpp TestChecked.cpp diff --git a/AK/Tests/TestBitCast.cpp b/AK/Tests/TestBitCast.cpp new file mode 100644 index 0000000000..b251dbe9a1 --- /dev/null +++ b/AK/Tests/TestBitCast.cpp @@ -0,0 +1,45 @@ +/* + * Copyright (c) 2021, the SerenityOS developers. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include + +#include + +template +void check_cast_both_ways(const A& a, const B& b) +{ + EXPECT_EQ((bit_cast(b)), a); + EXPECT_EQ((bit_cast(a)), b); +} + +TEST_CASE(double_int_conversion) +{ + check_cast_both_ways(static_cast(0), 0.0); + check_cast_both_ways(static_cast(1) << 63, -0.0); + check_cast_both_ways(static_cast(0x4172f58bc0000000), 19880124.0); +} + +TEST_MAIN(BitCast)