| /* |
| 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. |
| */ |
| |
| #include "../SDL_internal.h" |
| |
| /* This file contains a portable memcpy manipulation function for SDL */ |
| |
| void * |
| SDL_memcpy(SDL_OUT_BYTECAP(len) void *dst, SDL_IN_BYTECAP(len) const void *src, size_t len) |
| { |
| #ifdef __GNUC__ |
| /* Presumably this is well tuned for speed. |
| On my machine this is twice as fast as the C code below. |
| */ |
| return __builtin_memcpy(dst, src, len); |
| #elif defined(HAVE_MEMCPY) |
| return memcpy(dst, src, len); |
| #elif defined(HAVE_BCOPY) |
| bcopy(src, dst, len); |
| return dst; |
| #else |
| /* GCC 4.9.0 with -O3 will generate movaps instructions with the loop |
| using Uint32* pointers, so we need to make sure the pointers are |
| aligned before we loop using them. |
| */ |
| if (((uintptr_t)src & 0x3) || ((uintptr_t)dst & 0x3)) { |
| /* Do an unaligned byte copy */ |
| Uint8 *srcp1 = (Uint8 *)src; |
| Uint8 *dstp1 = (Uint8 *)dst; |
| |
| while (len--) { |
| *dstp1++ = *srcp1++; |
| } |
| } else { |
| size_t left = (len % 4); |
| Uint32 *srcp4, *dstp4; |
| Uint8 *srcp1, *dstp1; |
| |
| srcp4 = (Uint32 *) src; |
| dstp4 = (Uint32 *) dst; |
| len /= 4; |
| while (len--) { |
| *dstp4++ = *srcp4++; |
| } |
| |
| srcp1 = (Uint8 *) srcp4; |
| dstp1 = (Uint8 *) dstp4; |
| switch (left) { |
| case 3: |
| *dstp1++ = *srcp1++; |
| case 2: |
| *dstp1++ = *srcp1++; |
| case 1: |
| *dstp1++ = *srcp1++; |
| } |
| } |
| return dst; |
| #endif /* __GNUC__ */ |
| } |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |