Subversion Repositories openrisc_2011-10-31

/*

FUNCTION

<<vec_malloc>>, <<vec_realloc>>, <<vec_free>>---manage vector memory

INDEX

        vec_malloc

INDEX

        vec_realloc

INDEX

        vec_free

INDEX

        _vec_malloc_r

INDEX

        _vec_realloc_r

INDEX

        _vec_free_r

ANSI_SYNOPSIS

        #include <stdlib.h>

        void *vec_malloc(size_t <[nbytes]>);

        void *vec_realloc(void *<[aptr]>, size_t <[nbytes]>);

        void vec_free(void *<[aptr]>);

        void *_vec_malloc_r(void *<[reent]>, size_t <[nbytes]>);

        void *_vec_realloc_r(void *<[reent]>,

                         void *<[aptr]>, size_t <[nbytes]>);

        void _vec_free_r(void *<[reent]>, void *<[aptr]>);

TRAD_SYNOPSIS

        #include <stdlib.h>

        char *vec_malloc(<[nbytes]>)

        size_t <[nbytes]>;

        char *vec_realloc(<[aptr]>, <[nbytes]>)

        char *<[aptr]>;

        size_t <[nbytes]>;

        void vec_free(<[aptr]>)

        char *<[aptr]>;

        char *_vec_malloc_r(<[reent]>,<[nbytes]>)

        char *<[reent]>;

        size_t <[nbytes]>;

        char *_vec_realloc_r(<[reent]>, <[aptr]>, <[nbytes]>)

        char *<[reent]>;

        char *<[aptr]>;

        size_t <[nbytes]>;

        void _vec_free_r(<[reent]>, <[aptr]>)

        char *<[reent]>;

        char *<[aptr]>;

DESCRIPTION

These functions manage a pool of system memory that is 16-byte aligned..

Use <<vec_malloc>> to request allocation of an object with at least

<[nbytes]> bytes of storage available and is 16-byte aligned.  If the space is

available, <<vec_malloc>> returns a pointer to a newly allocated block as its result.

If you already have a block of storage allocated by <<vec_malloc>>, but

you no longer need all the space allocated to it, you can make it

smaller by calling <<vec_realloc>> with both the object pointer and the

new desired size as arguments.  <<vec_realloc>> guarantees that the

contents of the smaller object match the beginning of the original object.

Similarly, if you need more space for an object, use <<vec_realloc>> to

request the larger size; again, <<vec_realloc>> guarantees that the

beginning of the new, larger object matches the contents of the

original object.

When you no longer need an object originally allocated by <<vec_malloc>>

or <<vec_realloc>> (or the related function <<vec_calloc>>), return it to the

memory storage pool by calling <<vec_free>> with the address of the object

as the argument.  You can also use <<vec_realloc>> for this purpose by

calling it with <<0>> as the <[nbytes]> argument.

The alternate functions <<_vec_malloc_r>>, <<_vec_realloc_r>>, <<_vec_free_r>>,

are reentrant versions.  The extra argument <[reent]> is a pointer to a reentrancy

structure.

If you have multiple threads of execution which may call any of these

routines, or if any of these routines may be called reentrantly, then

you must provide implementations of the <<__vec_malloc_lock>> and

<<__vec_malloc_unlock>> functions for your system.  See the documentation

for those functions.

These functions operate by calling the function <<_sbrk_r>> or

<<sbrk>>, which allocates space.  You may need to provide one of these

functions for your system.  <<_sbrk_r>> is called with a positive

value to allocate more space, and with a negative value to release

previously allocated space if it is no longer required.

@xref{Stubs}.

RETURNS

<<vec_malloc>> returns a pointer to the newly allocated space, if

successful; otherwise it returns <<NULL>>.  If your application needs

to generate empty objects, you may use <<vec_malloc(0)>> for this purpose.

<<vec_realloc>> returns a pointer to the new block of memory, or <<NULL>>

if a new block could not be allocated.  <<NULL>> is also the result

when you use `<<vec_realloc(<[aptr]>,0)>>' (which has the same effect as

`<<vec_free(<[aptr]>)>>').  You should always check the result of

<<vec_realloc>>; successful vec_reallocation is not guaranteed even when

you request a smaller object.

<<vec_free>> does not return a result.

PORTABILITY

<<vec_malloc>>, <<vec_realloc>>, and <<vec_free>> are all extensions

specified in the AltiVec Programming Interface Manual.

Supporting OS subroutines required: <<sbrk>>.  */

#include <_ansi.h>

#include <reent.h>

#include <stdlib.h>

#include <malloc.h>

#ifndef _REENT_ONLY

_PTR

_DEFUN (vec_malloc, (nbytes),

        size_t nbytes)          /* get a block */

{

  return _memalign_r (_REENT, 16, nbytes);

}

#endif