lkml.org 
[lkml]   [2015]   [May]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Compilers and RCU readers: Once more unto the breach!
On Wed, May 20, 2015 at 02:18:37PM +0100, David Howells wrote:
> Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:
>
> > > Additionally, what about the following code?
> > >
> > > char *x = y ? z : z;
> > >
> > > Does that extend a dependency chain from z to x? If so, I can imagine a
> > > CPU breaking that in practice.
> >
> > I am not seeing this. I would expect the compiler to optimize to
> > something like this:
> >
> > char *x = z;
>
> Why? What if y has a potential side-effect (say it makes a function call)?

I was thinking of "y" as a simple variable, but if it is something more
complex, then the compiler could do this, right?

char *x;

y;
x = z;

Thanx, Paul



\
 
 \ /
  Last update: 2015-05-20 16:01    [W:0.216 / U:0.612 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site