On Wed, May 4, 2016 at 12:52 AM, Bernd Schmidt <bschm...@redhat.com> wrote: > On 05/03/2016 11:26 PM, David Edelsohn wrote: >> >> Optimizations enabled by default at -O2 should show an overall net >> benefit -- that is the general justification that we have used in the >> past. I request that this change be reverted until more compelling >> evidence of benefit is presented. > > > Shrug. Done. I was going to look at adding some more smarts to it to clean > up after the register allocator; I guess I shan't bother. > > I must say I find the argumentation about the fallout not compelling. It's a > normal consequence of development work, and by enabling it at -O2, we have > found: > * a Linux kernel bug > * a rs6000 testsuite bug > * some i386.md issues that can cause performance problems > * and a compare-debug problem in regrename itself. > All of these are _good_ things. If we don't want to run into such issues > we'll have to cease all development work. > I'll still submit final versions of the fixes for the i386 and compare-debug > issues.
I agree with you here, enabling at -O2 was fine. Reverting will have regressed PR38825 again (curiously also some SSE scheduling issue). Thus I wonder if regrename could be integrated with sched2 itself. Richard. > > Bernd
