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?
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 ())
--
2.29.2
