On Tue, Oct 17, 2017 at 9:45 AM, Eric Botcazou <ebotca...@adacore.com> wrote: > Hi, > > add_autoinc_candidates begins with this test: > > /* If we insert the increment in any position other than the standard > ones, we must ensure that it is incremented once per iteration. > It must not be in an inner nested loop, or one side of an if > statement. */ > if (use_bb->loop_father != data->current_loop > || !dominated_by_p (CDI_DOMINATORS, data->current_loop->latch, use_bb) > || stmt_could_throw_p (use->stmt) > || !cst_and_fits_in_hwi (step)) > return; > > This means that, for languages supporting non-call exceptions like Ada, no > auto-inc candidates will be added for a simple iteration over an array in most > cases since stmt_could_throw_p returns true. I don't think that's necessary, > or else it would also be necessary to test gimple_could_trap_p, which would > have the same effect for all languages. Note that add_autoinc_candidates is > only invoked for USE_ADDRESS use types: > > /* At last, add auto-incremental candidates. Make such variables > important since other iv uses with same base object may be based > on it. */ > if (use != NULL && use->type == USE_ADDRESS) > add_autoinc_candidates (data, iv->base, iv->step, true, use); > > So the attached patch replaces it with stmt_can_throw_internal (which is the > predicate used to compute the flow of control) as e.g. in the vectorizer. > > Bootstrapped/regtested on PowerPC64/Linux, OK for the mainline?
Ok. Richard. > > 2017-10-17 Eric Botcazou <ebotca...@adacore.com> > > * tree-ssa-loop-ivopts.c (add_autoinc_candidates): Bail out only if > the use statement can throw internally. > > -- > Eric Botcazou
