Re: new module 'aligned-malloc'

[Paul Eggert]

On 7/21/20 8:51 AM, Florian Weimer wrote:
> The official aligned_alloc produces pointers compatible with free.
> This module cannot do that.

I don't see why not, at least on platforms of interest to Gnulib. On systems 
that provide no native way to do an aligned allocation, we merely keep calling 
malloc with suitable arguments until we get a pointer that is suitably aligned. 
We then free all the unsuitable storage we allocated along the way, and return 
the good pointer.

Of course this would not be as efficient as a native aligned_alloc would be, but 
it should be good enough for portability to nonstandard platforms, for many 
applications anyway - and that is the Gnulib Way.

Eventually I hope even Microsoft will figure out how to do aligned allocation, 
and even if my hope is dashed that's OK, our code will still work.

There is a real advantage to using aligned_alloc instead of some nonstandard 
allocate/free pair. With aligned_alloc you can hand pointers off to other code 
that expects to use 'free' (and there is a lot of such code out there).