------- Comment #11 from dberlin at gcc dot gnu dot org 2006-03-21 16:57
-------
Subject: Re: Missed jump threading
optimization
On Tue, 2006-03-21 at 15:57 +0000, law at redhat dot com wrote:
>
> ------- Comment #9 from law at redhat dot com 2006-03-21 15:57 -------
> We've got zero chance of threading the jump in this case until the
> partially redundant load from "i" is removed.
>
> Daniel -- there's a pretty obvious redundant load from the global
> variable "i" in this testcase. I haven't investigated why PRE
> is missing this obvious redundancy.
It doesn't deal with loads from global variables because we need to
place a value number on each "instance" that occurs in the program, but
can't easily because they are all shared.
I will get to it eventually.
>
> Jeff
>
>
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18046
