On Fri, Apr 21, 2017 at 12:41 PM, 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. > > My patch was bootstrapped and tested on aarch64-none-linux-gnu with no > issues, with a ChangeLog which looks like:
Looks good to me as well. Thanks, Richard. > 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 >
