diff options
author | Fox Caminiti <fox@foxcam.net> | 2022-12-22 13:29:02 -0500 |
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committer | Fox Caminiti <fox@foxcam.net> | 2022-12-22 13:29:02 -0500 |
commit | 375c120d30456738897c4bd775e38aa1db7d239c (patch) | |
tree | 5b365a6233cf736db15fa52fcfac4ba80a986217 /dependencies/SDL/SDL_bits.h | |
parent | 4854647d659f75ac6cf4575b61d1dcfd25865791 (diff) |
v3.1
Diffstat (limited to 'dependencies/SDL/SDL_bits.h')
-rw-r--r-- | dependencies/SDL/SDL_bits.h | 126 |
1 files changed, 0 insertions, 126 deletions
diff --git a/dependencies/SDL/SDL_bits.h b/dependencies/SDL/SDL_bits.h deleted file mode 100644 index 22cb853..0000000 --- a/dependencies/SDL/SDL_bits.h +++ /dev/null @@ -1,126 +0,0 @@ -/* - Simple DirectMedia Layer - Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org> - - This software is provided 'as-is', without any express or implied - warranty. In no event will the authors be held liable for any damages - arising from the use of this software. - - Permission is granted to anyone to use this software for any purpose, - including commercial applications, and to alter it and redistribute it - freely, subject to the following restrictions: - - 1. The origin of this software must not be misrepresented; you must not - claim that you wrote the original software. If you use this software - in a product, an acknowledgment in the product documentation would be - appreciated but is not required. - 2. Altered source versions must be plainly marked as such, and must not be - misrepresented as being the original software. - 3. This notice may not be removed or altered from any source distribution. -*/ - -/** - * \file SDL_bits.h - * - * Functions for fiddling with bits and bitmasks. - */ - -#ifndef SDL_bits_h_ -#define SDL_bits_h_ - -#include "SDL_stdinc.h" - -#include "begin_code.h" -/* Set up for C function definitions, even when using C++ */ -#ifdef __cplusplus -extern "C" { -#endif - -/** - * \file SDL_bits.h - */ - -/** - * Get the index of the most significant bit. Result is undefined when called - * with 0. This operation can also be stated as "count leading zeroes" and - * "log base 2". - * - * \return the index of the most significant bit, or -1 if the value is 0. - */ -#if defined(__WATCOMC__) && defined(__386__) -extern __inline int _SDL_bsr_watcom(Uint32); -#pragma aux _SDL_bsr_watcom = \ - "bsr eax, eax" \ - parm [eax] nomemory \ - value [eax] \ - modify exact [eax] nomemory; -#endif - -SDL_FORCE_INLINE int -SDL_MostSignificantBitIndex32(Uint32 x) -{ -#if defined(__GNUC__) && (__GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) - /* Count Leading Zeroes builtin in GCC. - * http://gcc.gnu.org/onlinedocs/gcc-4.3.4/gcc/Other-Builtins.html - */ - if (x == 0) { - return -1; - } - return 31 - __builtin_clz(x); -#elif defined(__WATCOMC__) && defined(__386__) - if (x == 0) { - return -1; - } - return _SDL_bsr_watcom(x); -#elif defined(_MSC_VER) - unsigned long index; - if (_BitScanReverse(&index, x)) { - return index; - } - return -1; -#else - /* Based off of Bit Twiddling Hacks by Sean Eron Anderson - * <seander@cs.stanford.edu>, released in the public domain. - * http://graphics.stanford.edu/~seander/bithacks.html#IntegerLog - */ - const Uint32 b[] = {0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000}; - const int S[] = {1, 2, 4, 8, 16}; - - int msbIndex = 0; - int i; - - if (x == 0) { - return -1; - } - - for (i = 4; i >= 0; i--) - { - if (x & b[i]) - { - x >>= S[i]; - msbIndex |= S[i]; - } - } - - return msbIndex; -#endif -} - -SDL_FORCE_INLINE SDL_bool -SDL_HasExactlyOneBitSet32(Uint32 x) -{ - if (x && !(x & (x - 1))) { - return SDL_TRUE; - } - return SDL_FALSE; -} - -/* Ends C function definitions when using C++ */ -#ifdef __cplusplus -} -#endif -#include "close_code.h" - -#endif /* SDL_bits_h_ */ - -/* vi: set ts=4 sw=4 expandtab: */ |