On 11/24/2016 09:14 AM, Segher Boessenkool wrote:
On Thu, Nov 24, 2016 at 08:48:04AM -0700, Jeff Law wrote:
On 11/24/2016 07:53 AM, Segher Boessenkool wrote:
That we compare different kinds of costs (which really has no meaning at
all, it's a heuristic at best) in various places is a known problem, not
a regression.
But the problems with the costing system exhibit themselves as a code
quality regression. In the end that's what the end-users see -- a
regression in the quality of the code GCC generates.
Yes, exactly -- and I fear this all-encompassing change will cause just
such a regression for many users. Tests are running, will know more
later today (or tomorrow).
The PR is about a very specific problem; the patch is not. The patch
is not a bug fix. If we allow anything that "makes things better" in
stage 3, what make it different from stage 1 then?
So how would you suggest this be fixed right now? I'd really like to
get the regression addressed.
I would claim that Bernd's patch is right from a design and
implementation standpoint -- the issues are fallout from backend issues
and none looked terrible to me.
jeff
