On Mon, 9 Nov 2020, Martin Jambor wrote:
> Hi,
>
> This patch adds loop iteration macros FOR_EACH_ENCLOSED_LOOP and
> FOR_EACH_ENCLOSED_LOOP_FN which can loop only over inner loops of a
> given loop.
>
> The patch is required for a follow-up patch which enables loop
> invariant motion to only work on a selected loop. I have bootstrapped
> and tested the two patches on x86_64-linux and aarch64-linux. OK for
> trunk once the follow-up patch is accepted too?
OK for trunk.
Thanks,
Richard.
> Thanks,
>
> Martin
>
>
> gcc/ChangeLog:
>
> 2020-10-29 Martin Jambor <mjam...@suse.cz>
>
> * cfgloop.h (loop_iterator::loop_iterator): Add parameter to the
> constructor, make it iterate over sub-loops if non-NULL.
> (FOR_EACH_LOOP): Pass extra NULL to loop_iterator::loop_iterator.
> (FOR_EACH_LOOP_FN): Likewise.
> (FOR_EACH_ENCLOSED_LOOP): New macro.
> (FOR_EACH_ENCLOSED_LOOP_FN): Likewise.
> ---
> gcc/cfgloop.h | 44 ++++++++++++++++++++++++++++++++------------
> 1 file changed, 32 insertions(+), 12 deletions(-)
>
> diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
> index d14689dc31f..e8ffa5b2964 100644
> --- a/gcc/cfgloop.h
> +++ b/gcc/cfgloop.h
> @@ -663,7 +663,7 @@ enum li_flags
> class loop_iterator
> {
> public:
> - loop_iterator (function *fn, loop_p *loop, unsigned flags);
> + loop_iterator (function *fn, loop_p top, loop_p *loop, unsigned flags);
>
> inline loop_p next ();
>
> @@ -693,8 +693,15 @@ loop_iterator::next ()
> return NULL;
> }
>
> +/* Constructor to set up iteration over loops. FN is the function in which
> the
> + loop tree resides. If TOP is NULL iterate over all loops in the function,
> + otherwise iterate only over sub-loops of TOP (including TOP). LOOP points
> + to the iteration pointer in the iteration. FLAGS modify the iteration as
> + described in enum li_flags. */
> +
> inline
> -loop_iterator::loop_iterator (function *fn, loop_p *loop, unsigned flags)
> +loop_iterator::loop_iterator (function *fn, loop_p top, loop_p *loop,
> + unsigned flags)
> {
> class loop *aloop;
> unsigned i;
> @@ -716,13 +723,16 @@ loop_iterator::loop_iterator (function *fn, loop_p
> *loop, unsigned flags)
> for (i = 0; vec_safe_iterate (loops_for_fn (fn)->larray, i, &aloop);
> i++)
> if (aloop != NULL
> && aloop->inner == NULL
> - && aloop->num >= mn)
> + && aloop->num >= mn
> + && (!top || flow_loop_nested_p (top, aloop)))
> this->to_visit.quick_push (aloop->num);
> }
> else if (flags & LI_FROM_INNERMOST)
> {
> + if (!top)
> + top = loops_for_fn (fn)->tree_root;
> /* Push the loops to LI->TO_VISIT in postorder. */
> - for (aloop = loops_for_fn (fn)->tree_root;
> + for (aloop = top;
> aloop->inner != NULL;
> aloop = aloop->inner)
> continue;
> @@ -732,15 +742,15 @@ loop_iterator::loop_iterator (function *fn, loop_p
> *loop, unsigned flags)
> if (aloop->num >= mn)
> this->to_visit.quick_push (aloop->num);
>
> - if (aloop->next)
> + if (aloop == top)
> + break;
> + else if (aloop->next)
> {
> for (aloop = aloop->next;
> aloop->inner != NULL;
> aloop = aloop->inner)
> continue;
> }
> - else if (!loop_outer (aloop))
> - break;
> else
> aloop = loop_outer (aloop);
> }
> @@ -748,7 +758,7 @@ loop_iterator::loop_iterator (function *fn, loop_p *loop,
> unsigned flags)
> else
> {
> /* Push the loops to LI->TO_VISIT in preorder. */
> - aloop = loops_for_fn (fn)->tree_root;
> + aloop = top ? top : loops_for_fn (fn)->tree_root;
> while (1)
> {
> if (aloop->num >= mn)
> @@ -758,9 +768,9 @@ loop_iterator::loop_iterator (function *fn, loop_p *loop,
> unsigned flags)
> aloop = aloop->inner;
> else
> {
> - while (aloop != NULL && aloop->next == NULL)
> + while (aloop != top && aloop->next == NULL)
> aloop = loop_outer (aloop);
> - if (aloop == NULL)
> + if (aloop == top)
> break;
> aloop = aloop->next;
> }
> @@ -771,12 +781,22 @@ loop_iterator::loop_iterator (function *fn, loop_p
> *loop, unsigned flags)
> }
>
> #define FOR_EACH_LOOP(LOOP, FLAGS) \
> - for (loop_iterator li(cfun, &(LOOP), FLAGS); \
> + for (loop_iterator li(cfun, NULL, &(LOOP), FLAGS); \
> (LOOP); \
> (LOOP) = li.next ())
>
> #define FOR_EACH_LOOP_FN(FN, LOOP, FLAGS) \
> - for (loop_iterator li(FN, &(LOOP), FLAGS); \
> + for (loop_iterator li(FN, NULL, &(LOOP), FLAGS); \
> + (LOOP); \
> + (LOOP) = li.next ())
> +
> +#define FOR_EACH_ENCLOSED_LOOP(TOP, LOOP, FLAGS) \
> + for (loop_iterator li(cfun, TOP, &(LOOP), FLAGS); \
> + (LOOP); \
> + (LOOP) = li.next ())
> +
> +#define FOR_EACH_ENCLOSED_LOOP_FN(FN, TOP, LOOP, FLAGS) \
> + for (loop_iterator li(FN, TOP, &(LOOP), FLAGS); \
> (LOOP); \
> (LOOP) = li.next ())
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imend
