Messages in this thread |  | | Date | Mon, 11 Feb 2019 20:10:39 +0300 | From | Alexey Dobriyan <> | Subject | Re: [PATCH v-1] x86_64: new and improved memset() + question |
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On Mon, Feb 11, 2019 at 01:47:16PM +0100, Ingo Molnar wrote: > * Alexey Dobriyan <adobriyan@gmail.com> wrote:
> > QUESTION: is it possible to tell gcc "this function is semantically > > equivalent to memset(3) so make high level optimizations but call it > > when it is necessary"? I suspect the answer is "no" :-\ > > No idea ... > > > TODO: > > CONFIG_FORTIFY_SOURCE is enabled by distros > > benchmarks > > testing > > more comments > > check with memset_io() so that no surprises pop up > > I'd only like to make happy noises here to make sure you continue with > this work - it does look promising. :-)
Thanks, Ingo.
This is really the core of the problem: once memset() becomes something other than
static inline void *memset(void *p, int c, size_t len) { return __builtin_memset(p, c, len); }
GCC starts pretending that it doesn't know what memset() is and all those advertised space savings go to hell.
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