[Bug tree-optimization/84824] DCE fails to remove dead code of std::function constructor

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84824

--- Comment #12 from rguenther at suse dot de <rguenther at suse dot de> ---
On Fri, 16 Mar 2018, manjian2006 at gmail dot com wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84824
> 
> --- Comment #11 from linzj <manjian2006 at gmail dot com> ---
> This patch makes the printf clobber/use set correct. But it doesn't seem like
> much help.

I think that in itself doesn't help much, but I didn't look too closely.