> On Apr 21, 2017, at 5:41 AM, James Greenhalgh <james.greenha...@arm.com> > wrote: > > On Tue, Apr 18, 2017 at 05:38:48PM -0500, Bill Schmidt wrote: >> Hi, >> >> While investigating a performance issue, I happened to notice that vectorized >> COND_EXPRs were not contributing to the vectorizer cost model. This patch >> addresses that. >> >> Bootstrapped and tested on powerpc64le-unknown-linux-gnu. Is this ok for >> trunk, or should it wait for GCC 8? > > Hi Bill, > > I had a similar patch sitting in my tree waiting for GCC 8, with a few > differences. The main one is that you don't record the cost of the > vector conditional itself, only of the then/else branches. > > I've attached what I was working on. In my patch I first generalize > vect_model_simple_cost to fix the FORNOW: Assuming maximum 2 args per > stmts, and to cost the broadcast as a broadcast rather than a vector > statiement as the conditionals need a judgement on the prologue cost > of 4 args. That means taking an extra argument for the number of arguments > a statement needs to cost which in turn means updating the rest of the > functions which call vect_model_simple_cost. > > I haven't hacked on the vector cost model before, and your patch acheieves > the main part of what I was looking to do, but if you think any parts of > this are still valuable after your change, I'd be happy to rebase it once > the branch opens.
This looks great to me as well! Since Richard is happy with your patch, please just go ahead with it and I'll withdraw mine. It's good that you're adding this additional flexibility to the cost model. Thanks! Bill > > My patch was bootstrapped and tested on aarch64-none-linux-gnu with no > issues, with a ChangeLog which looks like: > > gcc/ > > 2017-04-21 James Greenhalgh <james.greenha...@arm.com> > > * tree-vect-stmts.c (vect_model_simple_cost): Model the cost > of all arguments to a statement as scalar_to_vec operations. > (vectorizable_call): Adjust call to vect_model_simple_cost for > new parameter. > (vectorizable_conversion): Likewise. > (vectorizable_assignment): Likewise. > (vectorizable_shift): Likewise. > (vectorizable_operation): Likewise. > (vectorizable_comparison): Likewise. > (vect_is_simple_cond): Record the def types for operands. > (vectorizable_condition): Likewise, call vect_model_simple_cost. > * tree-vectorizer.h (vect_model_simple_cost): Add new parameter > for statement argument count. > > Thanks, > James > > <0001-Patch-Expand-vector-cost-model-to-cover-vectorizable.patch>
