@node posix_memalign
@subsection @code{posix_memalign}
@findex posix_memalign

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/functions/posix_memalign.html}

Gnulib module: posix_memalign
@mindex posix_memalign

Although this function is superseded by @code{aligned_alloc},
it is more portable to older systems that do not support C11.
@xref{aligned_alloc}.

Portability problems fixed by Gnulib:
@itemize
@item
This function returns a null pointer if the size argument is zero:
AIX 7.3.
@item
This function produces misaligned results on some platforms:
OpenBSD 6.1.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
This function is missing on some platforms:
Mac OS X 10.5, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.1.
@item
If the alignment and size are absurdly large, this function crashes:
@c https://sourceware.org/bugzilla/show_bug.cgi?id=32301
glibc 2.40.
@end itemize

@mindex aligned-malloc
The Gnulib module @code{aligned-malloc} provides functions for
allocating and freeing blocks of suitably aligned memory.

@mindex pagealign_alloc
The Gnulib module @code{pagealign_alloc} provides a similar API for
allocating and freeing blocks of memory aligned on a system page boundary.
