On Thu, Dec 01, 2011 at 11:39:36PM -0800, Teresa Johnson wrote: > To do this I leveraged the existing TARGET_LOOP_UNROLL_ADJUST target > hook, which was previously only defined for s390. I added one > additional call to this target hook, when unrolling for constant trip > count loops. Previously it was only called for runtime computed trip > counts. Andreas, can you comment on the effect for s390 of this > additional call of the target hook, since I can't measure that?
Limiting the unrolling of loops with constant iterations makes also sense for s390. However, the limitations are only relevant if it actually stays a loop. If the loop gets completely peeled into a sequential instruction stream there should be no limitation. But as I understand it this will be done by different code paths. So I think the change should be ok for s390 as well. It will take some time to get measurements on that. I'll try to keep that in mind until then. Bye, -Andreas-
