From: Rich Felker <dalias@libc.org>
To: musl@lists.openwall.com
Subject: Re: [PATCH] optimize explicit_bzero for size
Date: Thu, 28 Jun 2018 16:21:28 -0400 [thread overview]
Message-ID: <20180628202128.GJ1392@brightrain.aerifal.cx> (raw)
In-Reply-To: <CA+XhMqwKjgoUnhNnRUOp0UkeFV_2yLLTQKkBTTHC=xVHPEan3w@mail.gmail.com>
On Thu, Jun 28, 2018 at 08:42:13PM +0100, David CARLIER wrote:
> On Thu, 28 Jun 2018 at 20:36, Rich Felker <dalias@libc.org> wrote:
> >
> > On Thu, Jun 28, 2018 at 08:57:29PM +0300, Alexander Monakov wrote:
> > > Avoid saving/restoring the incoming argument by reusing memset return value.
> > > ---
>
> Why not even though I m wondering if this saving/restoring really
> occurs/instruction really generated with last compilers.
> Prefer Alexander's version otherwise :-)
It necessarily has to because of ABI. Any register you could use to
save the value before making an external call is a register whose old
value you would have to save before using it, so no matter what you
do, something has to get spilled to the stack and thus a stack frame
has to be created.
Rich
prev parent reply other threads:[~2018-06-28 20:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-28 17:57 Alexander Monakov
2018-06-28 19:35 ` Rich Felker
2018-06-28 19:42 ` David CARLIER
2018-06-28 20:21 ` Rich Felker [this message]
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