Hi!
On Wed, Oct 30, 2019 at 11:34:42AM +0800, Jiufu Guo wrote:
> In this patch, loop unroll adjust hook is introduced for powerpc. In this
> hook,
> we can do target related hueristic adjustment. For this patch, we tunned for
> O2 to unroll small loops with small unroll factor (2 times), for other
> optimization, default unroll factor is used.
> 2019-10-30 Jiufu Guo <guoji...@linux.ibm.com>
>
> PR tree-optimization/88760
I think this should be "target"? (Change it in bugzilla if you change it
here, of course).
> * config/rs6000/rs6000.c (rs6000_option_override_internal): Remove
> code which changes PARAM_MAX_UNROLL_TIMES and PARAM_MAX_UNROLLED_INSNS.
> (TARGET_LOOP_UNROLL_ADJUST): Add loop unroll adjust hook.
> (rs6000_loop_unroll_adjust): New hook for loop unroll adjust. Unrolling
> small loop 2 times for -O2.
(Two spaces after a full stop).
> +/* This target hook implementation for TARGET_LOOP_UNROLL_ADJUST calculates
> + a new heristic number struct loop *loop should be unrolled. */
"heuristic".
Argument names are written in ALL CAPS, and repeating the type is useless
here (you can see it just a few lines down). But anyway, everything else
here just says things like
/* Implement targetm.loop_unroll_adjust. */
so just do that?
> +static unsigned
> +rs6000_loop_unroll_adjust (unsigned nunroll, struct loop * loop)
> +{
> + /* For -O2, we only unroll small loops with small unroll factor. */
> + if (optimize == 2)
> + {
> + /* If the loop contains few insns, treated it as small loops.
> + TODO: Uing 10 hard code for now. Continue to refine, For example,
> + if loop constians only 1-2 insns, we may unroll more times(4).
> + And we may use PARAM to control kinds of loop size. */
That first line has no new information. So maybe something like
/* TODO: This is hardcoded to 10 right now. It can be refined, for
example we may want to unroll very small loops more times (4 perhaps).
We also should use a PARAM for this. */
Okay for trunk like that. Thanks!
Segher
