Dorit, So it is correct to say that any loop that is vectorized is removed from consideration for these other loop optimizations? I ask because I am wondering if I should be testing these new loop optimizations at -O2 in order to see their full effect (without vectorization inhibiting their use). Jack
On Wed, Aug 13, 2008 at 05:08:53PM +0300, Dorit Nuzman wrote: > > Can anyone explain the relationship between the current vectorization > > optimizations in the gcc trunk compiler and the new -floop-strip-mine, > > -floop-interchange and -floop-block loop optimizations? Which takes > > precedence and does one set block the other in any way? I would hope > > that the new loop optimizations simply redefine the loops that are then > > processed for vectorization so that both sets of optimizations can > > be in effect at the same time. Thanks in advance for any clarifications > > on how these optimizations interact with each other. > > There's currently no interaction between the Graphite optimizations and > vectorization. I don't know what considerations/cost-model Graphite uses > before applying its optimizations, but vectorization is not one of them. We > are now starting to look into teaching Graphite to take into account > factors that affect the applicability and profitability of vectorization, > but this work is in a very initial stage. > > dorit > > > Jack