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0ad/source/lib/sysdep/rtl/gcc/gcc.cpp

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C++

/* Copyright (c) 2010 Wildfire Games
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "precompiled.h"
#include "lib/sysdep/rtl.h"
#include "lib/bits.h"
// Linux has posix_memalign, AFAIK our other gcc platforms do not have it.
#define HAVE_POSIX_MEMALIGN OS_LINUX
#if HAVE_POSIX_MEMALIGN
void* rtl_AllocateAligned(size_t size, size_t alignment)
{
void *ptr;
int ret = posix_memalign(&ptr, alignment, size);
if (ret) {
// TODO: report error?
return NULL;
}
return ptr;
}
void rtl_FreeAligned(void* alignedPointer)
{
free(alignedPointer);
}
#else // Fallback aligned allocation using malloc
void* rtl_AllocateAligned(size_t size, size_t align)
{
// This ensures we have enough extra space to store the original pointer,
// and produce an aligned buffer, assuming the platform malloc ensures at
// least sizeof(void*) alignment.
if (align < 2*sizeof(void*))
align = 2*sizeof(void*);
void* const malloc_ptr = malloc(size + align);
if (!malloc_ptr)
return NULL;
// Round malloc_ptr up to the next aligned address, leaving some unused
// space before the pointer we'll return. The minimum alignment above
// ensures we'll have at least sizeof(void*) extra space.
void* const aligned_ptr =
(void *)(round_down(uintptr_t(malloc_ptr), uintptr_t(align)) + align);
// Just make sure we did the right thing with all the alignment hacks above.
debug_assert(((void**)aligned_ptr) - 1 >= malloc_ptr);
// Store the original pointer which will have to be sent to free().
((void **)aligned_ptr)[-1] = malloc_ptr;
return aligned_ptr;
}
void rtl_FreeAligned(void* alignedPointer)
{
if (alignedPointer)
free(((void**)alignedPointer)[-1]);
}
#endif