On 21/11/2023 16:49, Richard Sandiford wrote:
> Richard Sandiford <richard.sandif...@arm.com> writes:
> > Alex Coplan <alex.cop...@arm.com> writes:
> >> This adds some helpers to access-utils.h for removing accesses from an
> >> access_array. This is needed by the upcoming aarch64 load/store pair
> >> fusion pass.
> >>
> >> Bootstrapped/regtested as a series on aarch64-linux-gnu, OK for trunk?
> >>
> >> gcc/ChangeLog:
> >>
> >> * rtl-ssa/access-utils.h (filter_accesses): New.
> >> (remove_regno_access): New.
> >> (check_remove_regno_access): New.
> >> ---
> >> gcc/rtl-ssa/access-utils.h | 42 ++++++++++++++++++++++++++++++++++++++
> >> 1 file changed, 42 insertions(+)
> >>
> >> diff --git a/gcc/rtl-ssa/access-utils.h b/gcc/rtl-ssa/access-utils.h
> >> index f078625babf..31259d742d9 100644
> >> --- a/gcc/rtl-ssa/access-utils.h
> >> +++ b/gcc/rtl-ssa/access-utils.h
> >> @@ -78,6 +78,48 @@ drop_memory_access (T accesses)
> >> return T (arr.begin (), accesses.size () - 1);
> >> }
> >>
> >> +// Filter ACCESSES to return an access_array of only those accesses that
> >> +// satisfy PREDICATE. Alocate the new array above WATERMARK.
> >> +template<typename T, typename FilterPredicate>
> >> +inline T
> >> +filter_accesses (obstack_watermark &watermark,
> >> + T accesses,
> >> + FilterPredicate predicate)
> >> +{
> >> + access_array_builder builder (watermark);
> >> + builder.reserve (accesses.size ());
> >> + auto it = accesses.begin ();
> >> + auto end = accesses.end ();
> >> + for (; it != end; it++)
> >> + if (predicate (*it))
> >> + builder.quick_push (*it);
> >
> > It looks like the last five lines could be simplified to:
> >
> > for (access_info *access : accesses)
> > if (!predicate (access))
> > builder.quick_push (access);
So I implemented these changes, but I found that I had to use auto
instead of access_info * for the type of access in the for loop.
That allows callers to use the most specific/derived type for the
parameter in the predicate (e.g. use `use_info *` for an array of uses).
Is it OK with that change? I've attached a revised patch.
Bootstrapped/regtested on aarch64-linux-gnu.
Thanks,
Alex
>
> Oops, I meant:
>
> if (predicate (access))
>
> of course :)
diff --git a/gcc/rtl-ssa/access-utils.h b/gcc/rtl-ssa/access-utils.h
index f078625babf..9a62addfd2a 100644
--- a/gcc/rtl-ssa/access-utils.h
+++ b/gcc/rtl-ssa/access-utils.h
@@ -78,6 +78,46 @@ drop_memory_access (T accesses)
return T (arr.begin (), accesses.size () - 1);
}
+// Filter ACCESSES to return an access_array of only those accesses that
+// satisfy PREDICATE. Alocate the new array above WATERMARK.
+template<typename T, typename FilterPredicate>
+inline T
+filter_accesses (obstack_watermark &watermark,
+ T accesses,
+ FilterPredicate predicate)
+{
+ access_array_builder builder (watermark);
+ builder.reserve (accesses.size ());
+ for (auto access : accesses)
+ if (predicate (access))
+ builder.quick_push (access);
+ return T (builder.finish ());
+}
+
+// Given an array of ACCESSES, remove any access with regno REGNO.
+// Allocate the new access array above WM.
+template<typename T>
+inline T
+remove_regno_access (obstack_watermark &watermark,
+ T accesses, unsigned int regno)
+{
+ using Access = decltype (accesses[0]);
+ auto pred = [regno](Access a) { return a->regno () != regno; };
+ return filter_accesses (watermark, accesses, pred);
+}
+
+// As above, but additionally check that we actually did remove an access.
+template<typename T>
+inline T
+check_remove_regno_access (obstack_watermark &watermark,
+ T accesses, unsigned regno)
+{
+ auto orig_size = accesses.size ();
+ auto result = remove_regno_access (watermark, accesses, regno);
+ gcc_assert (result.size () < orig_size);
+ return result;
+}
+
// If sorted array ACCESSES includes a reference to REGNO, return the
// access, otherwise return null.
template<typename T>
diff --git a/gcc/rtl-ssa/accesses.cc b/gcc/rtl-ssa/accesses.cc
index 76d70fd8bd3..9ec0e6be071 100644
--- a/gcc/rtl-ssa/accesses.cc
+++ b/gcc/rtl-ssa/accesses.cc
@@ -1597,16 +1597,14 @@ access_array
rtl_ssa::remove_note_accesses_base (obstack_watermark &watermark,
access_array accesses)
{
+ auto predicate = [](access_info *a) {
+ return !a->only_occurs_in_notes ();
+ };
+
for (access_info *access : accesses)
if (access->only_occurs_in_notes ())
- {
- access_array_builder builder (watermark);
- builder.reserve (accesses.size ());
- for (access_info *access2 : accesses)
- if (!access2->only_occurs_in_notes ())
- builder.quick_push (access2);
- return builder.finish ();
- }
+ return filter_accesses (watermark, accesses, predicate);
+
return accesses;
}
