[Bug rtl-optimization/68641] undefined variables implicitly considered to be zero

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68641

--- Comment #4 from rguenther at suse dot de <rguenther at suse dot de> ---
On Wed, 2 Dec 2015, ebotcazou at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68641
> 
> Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
> 
>            What    |Removed                     |Added
> ----------------------------------------------------------------------------
>            Severity|normal                      |enhancement
> 
> --- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> The whole reasoning looks fairly dubious to me, the optimizer is free to do
> whatever it wants on undefined behavior and requests that the generated code
> behaves identically at all optimization levels on it have little merit IMO.

True, just that we avoid uninitialized regs at -O1+ but not on -O0
makes this one valid.

OTOH I'd just use it as an excuse to drop init-regs.c ...