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Re: Preliminary patch for PR23820 and PR24309
On 10/13/07, Sebastian Pop <sebpop@gmail.com> wrote:
> On 10/13/07, Richard Guenther <richard.guenther@gmail.com> wrote:
> > Huh? That patch should make zero difference.
> >
>
> However, it does. I double checked that without that patch ltrans-3
> fails, and with the patch it passes. Another sequence that works for
> ltrans-3 is duplicating DCE before VRP.
I checked as well and the dumps after these both passes are the same.
Also both passes are before loop-header copying. The difference it
seems to make is that DCE removes a forwarder block which it doesn't
do if it runs after VRP. For some reason.
Richard.