[Bug tree-optimization/34723] Summing variable should be initialized to the first member before the loop

[ubizjak at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34723

Uroš Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-12-13
                 CC|                            |law at redhat dot com
     Ever confirmed|0                           |1

--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Uroš Bizjak from comment #0)

> Note that gcc-4.3 initializes summation variable to zero, where gcc-4.2
> initializes summation variable to first array member, saving one loop
> iteration.

Reconfirmed on 4.9.

I'm adding Jeff to CC for his opinon on Andrew's "jump threading used to mess
up the loop" observation from comment #1.