Re: [PATCH] trivial: the memset operation on a automatic array variable should be optimized out by data initialization

[rae l]

On 6/19/07, Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
> Denis Cheng wrote:
> > From: Denis Cheng <crquan@xxxxxxxxx>
> >
> > the explicit memset call could be optimized out by data initialization,
> > thus all the fill working can be done by the compiler implicitly.
> >
>
> How does the generated code change?  Does gcc do something stupid like
> statically allocate a prototype structure full of zeros, and then memcpy
> it in?  Or does it generate a series of explicit assignments for each
> member?  Or does it generate a memset anyway?
>
> Seems to me that this gives gcc the opportunity to be more stupid, and
> the only right answer is what we're doing anyway.
>
>     J
Technically speaking, C standard guarantees the data be initialized correctly;
just from the point view of code style, let the compiler selects how
to initialize will be better, this could let the compiler has more
optimization points.

--
Denis Cheng
Linux Application Developer
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/