src/gallium/auxiliary/os/os_memory_aligned.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2008-2010 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 /*
  30  * Memory alignment wrappers.
  31  */
  32
  33
  34 #ifndef _OS_MEMORY_H_
  35 #error "Must not be included directly. Include os_memory.h instead"
  36 #endif
  37
  38
  39 #include "pipe/p_compiler.h"
  40
  41
  42 /**
  43  * Return memory on given byte alignment
  44  */
  45 static INLINE void *
  46 os_malloc_aligned(size_t size, size_t alignment)
  47 {
  48    char *ptr, *buf;
  49
  50    ptr = (char *) os_malloc(size + alignment + sizeof(void *));
  51    if (!ptr)
  52       return NULL;
  53
  54    buf = (char *)(((uintptr_t)ptr + sizeof(void *) + alignment - 1) & ~((uintptr_t)(alignment - 1)));
  55    *(char **)(buf - sizeof(void *)) = ptr;
  56
  57    return buf;
  58 }
  59
  60
  61 /**
  62  * Free memory returned by align_malloc().
  63  */
  64 static INLINE void
  65 os_free_aligned(void *ptr)
  66 {
  67    if (ptr) {
  68       void **cubbyHole = (void **) ((char *) ptr - sizeof(void *));
  69       void *realAddr = *cubbyHole;
  70       os_free(realAddr);
  71    }
  72 }