"Values optmized out" and http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36303

[Ian Lance Taylor]

Faraz Ahmed <faraz.shaikh@gmail.com> writes:

> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36303
>
> In reference to the above bug, gcc optimized some code under the -O2
> option. If the assembly described in the bug is a standard behaviour
> of -O2 then one can close this bug. Can someone please confirm this to
> be a bug, or a valid -O2 optimization that won't be fixed.

There are known deficiencies in gcc's current location list
information.  There are two independent projects under way to address
this:

http://gcc.gnu.org/wiki/Var_Tracking_Assignments
http://gcc.gnu.org/wiki/AndrewMacLeod (DEBUGLOCUS on that page)

With luck one of those will eventually be committed to mainline and will
address this issue.

Ian