I think it might be better to introduce a new parameter for max peel insn at O2 (e.g, call it MAX_O2_COMPLETELY_PEEL_INSN or MAX_DEFAULT_...), and use the same logic in your patch to override the MAX_COMPLETELY_PEELED_INSN parameter at O2).
By so doing, we don't need to have a hard coded factor of 2. In the longer run, we really need better cost/benefit analysis, but that is independent. David On Tue, Jan 21, 2014 at 1:49 PM, Sriraman Tallam <tmsri...@google.com> wrote: > Hi, > > Currently, tree unrolling pass(cunroll) does not allow any code > size growth in O2 mode. Code size growth is permitted only if O3 or > funroll-loops/fpeel-loops is used. I have created a patch to allow > partial code size increase in O2 mode. With funroll-loops the maximum > allowed code growth is 400 unrolled insns. I have set it to 200 > unrolled insns in O2 mode. This patch improves an image processing > benchmark by 20%. It improves most benchmarks by 1-2%. The code size > increase is <1% for all the benchmarks except the image processing > benchmark which increases by 6% (perf improves by 20%). > > I am working on getting this patch reviewed for trunk. Here is > the disussion on this: > http://gcc.gnu.org/ml/gcc-patches/2013-11/msg02643.html I have > incorporated the comments on making the patch simpler. I will > follow-up on that patch to trunk by also getting data on limiting > complete peeling with O2. > > Is this ok for the google branch? > > Thanks > Sri
