gcc/config/i386/gmm_malloc.h

   1 /* Copyright (C) 2004 Free Software Foundation, Inc.
   2
   3    This file is part of GCC.
   4
   5    GCC is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    GCC is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with GCC; see the file COPYING.  If not, write to
  17    the Free Software Foundation, 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 /* As a special exception, if you include this header file into source
  21    files compiled by GCC, this header file does not by itself cause
  22    the resulting executable to be covered by the GNU General Public
  23    License.  This exception does not however invalidate any other
  24    reasons why the executable file might be covered by the GNU General
  25    Public License.  */
  26
  27 #ifndef _MM_MALLOC_H_INCLUDED
  28 #define _MM_MALLOC_H_INCLUDED
  29
  30 #include <stdlib.h>
  31 #include <errno.h>
  32
  33 static __inline__ void*
  34 _mm_malloc (size_t size, size_t align)
  35 {
  36   void * malloc_ptr;
  37   void * aligned_ptr;
  38
  39   /* Error if align is not a power of two.  */
  40   if (align & (align - 1))
  41     {
  42       errno = EINVAL;
  43       return ((void*) 0);
  44     }
  45
  46   if (size == 0)
  47     return ((void *) 0);
  48
  49  /* Assume malloc'd pointer is aligned at least to sizeof (void*).
  50     If necessary, add another sizeof (void*) to store the value
  51     returned by malloc. Effectively this enforces a minimum alignment
  52     of sizeof double. */
  53     if (align < 2 * sizeof (void *))
  54       align = 2 * sizeof (void *);
  55
  56   malloc_ptr = malloc (size + align);
  57   if (!malloc_ptr)
  58     return ((void *) 0);
  59
  60   /* Align  We have at least sizeof (void *) space below malloc'd ptr. */
  61   aligned_ptr = (void *) (((size_t) malloc_ptr + align)
  62                           & ~((size_t) (align) - 1));
  63
  64   /* Store the original pointer just before p.  */
  65   ((void **) aligned_ptr) [-1] = malloc_ptr;
  66
  67   return aligned_ptr;
  68 }
  69
  70 static __inline__ void
  71 _mm_free (void * aligned_ptr)
  72 {
  73   if (aligned_ptr)
  74     free (((void **) aligned_ptr) [-1]);
  75 }
  76
  77 #endif /* _MM_MALLOC_H_INCLUDED */