On 03/23/2017 08:58 AM, Segher Boessenkool wrote:
The algorithm fwprop uses never reconsiders a possible propagation,
although it could succeed if the def (in the def-use to propagate)
has changed. This causes fwprop to do infinite propagations, like
in the scenario in the PR, where we end up
On Fri, Mar 24, 2017 at 12:54:35PM +0100, Richard Biener wrote:
> > I have implemented the "retry things" as well fwiw, but a) it is too
> > big and invasive for stage 4, and b) it kind of sucks, needs more
> > work, even more invasive. The workaround is cheap and solves the
> > immediate
On 03/24/2017 05:54 AM, Richard Biener wrote:
On Fri, Mar 24, 2017 at 10:39 AM, Segher Boessenkool
wrote:
On Fri, Mar 24, 2017 at 09:13:59AM +0100, Richard Biener wrote:
https://gcc.gnu.org/ml/gcc-patches/2017-02/msg01485.html
?
What about it? That suggestion
On Fri, Mar 24, 2017 at 10:39 AM, Segher Boessenkool
wrote:
> On Fri, Mar 24, 2017 at 09:13:59AM +0100, Richard Biener wrote:
>> >> https://gcc.gnu.org/ml/gcc-patches/2017-02/msg01485.html
>> >>
>> >> ?
>> >
>> > What about it? That suggestion would make fwprop do
On Fri, Mar 24, 2017 at 09:13:59AM +0100, Richard Biener wrote:
> >> https://gcc.gnu.org/ml/gcc-patches/2017-02/msg01485.html
> >>
> >> ?
> >
> > What about it? That suggestion would make fwprop do *less* useful work,
> > while in principle the problem is that it *already* does not enough!
>
>
On Thu, Mar 23, 2017 at 4:45 PM, Segher Boessenkool
wrote:
> On Thu, Mar 23, 2017 at 04:16:56PM +0100, Richard Biener wrote:
>> On Thu, Mar 23, 2017 at 3:58 PM, Segher Boessenkool
>> wrote:
>> > The algorithm fwprop uses never reconsiders a
On Thu, Mar 23, 2017 at 04:16:56PM +0100, Richard Biener wrote:
> On Thu, Mar 23, 2017 at 3:58 PM, Segher Boessenkool
> wrote:
> > The algorithm fwprop uses never reconsiders a possible propagation,
> > although it could succeed if the def (in the def-use to propagate)
On Thu, Mar 23, 2017 at 3:58 PM, Segher Boessenkool
wrote:
> The algorithm fwprop uses never reconsiders a possible propagation,
> although it could succeed if the def (in the def-use to propagate)
> has changed. This causes fwprop to do infinite propagations, like
>
The algorithm fwprop uses never reconsiders a possible propagation,
although it could succeed if the def (in the def-use to propagate)
has changed. This causes fwprop to do infinite propagations, like
in the scenario in the PR, where we end up with effectively
B = A
A = B
D = A
where only