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Date: Sat, 5 Mar 2016 09:14:57 +0300 (MSK)
From: Alexander Monakov <>
Subject: Re: [RFC PATCH] micro-optimize __procfdname

On Sat, 5 Mar 2016, Rich Felker wrote:
> > make it really obvious that __procfdname_impl fills in reverse; it might be a
> > very minor size optimization. I don't mind dropping this add adjusting buf
> > with '+= procfdbufsize - 1' in the callee.
> Yes, making it obvious what's going on is nice too.

I'm going to keep that adjustment in the macro for now, then.

> Actually it would be even nicer if we could use a compound literal
> inside the macro as the buffer, but that would pessimize with
> unnecessary initialization and eliminate a lot of the code-size
> benefit, I think.

Yep, I did consider that and arrived to a similar conclusion. Well, there's an
option of using alloca as long as no use is in a loop, but that's a bit uglier,
and as I recall it wasn't optimized to a static stack allocation.

I forgot to ask before, shouldn't __procfdname_impl have a visibility

And likewise for other internal functions.  There are some internal functions
without hidden/internal visibility annotation, visible outside of
That seems unintended and slightly harmful.


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