On Dec 7, 2023, Alexandre Oliva <ol...@adacore.com> wrote:
> Thanks for raising the issue. Maybe there should be at least a comment
> there, and perhaps some asserts to check that pointer and reference
> types don't make to indirect_parms.
Document why attribute access doesn't need the same treatment as fn
spec, and check that the assumption behind it holds.
Regstrapped on x86_64-linux-gnu. Ok to install?
for gcc/ChangeLog
* ipa-strub.cc (pass_ipa_strub::execute): Check that we don't
add indirection to pointer parameters, and document attribute
access non-interactions.
---
gcc/ipa-strub.cc | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/gcc/ipa-strub.cc b/gcc/ipa-strub.cc
index 2afb7a455751d..8ec6824e8a802 100644
--- a/gcc/ipa-strub.cc
+++ b/gcc/ipa-strub.cc
@@ -2889,6 +2889,13 @@ pass_ipa_strub::execute (function *)
&& (tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (nparm)))
<= 4 * UNITS_PER_WORD))))
{
+ /* No point in indirecting pointer types. Presumably they
+ won't ever pass the size-based test above, but check the
+ assumption here, because getting this wrong would mess
+ with attribute access and possibly others. We deal with
+ fn spec below. */
+ gcc_checking_assert (!POINTER_TYPE_P (TREE_TYPE (nparm)));
+
indirect_nparms.add (nparm);
/* ??? Is there any case in which it is not safe to suggest the parms
@@ -2976,7 +2983,9 @@ pass_ipa_strub::execute (function *)
}
}
- /* ??? Maybe we could adjust it instead. */
+ /* ??? Maybe we could adjust it instead. Note we don't need
+ to mess with attribute access: pointer-typed parameters are
+ not modified, so they can remain unchanged. */
if (drop_fnspec)
remove_named_attribute_unsharing ("fn spec",
&TYPE_ATTRIBUTES (nftype));
--
Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
Free Software Activist GNU Toolchain Engineer
More tolerance and less prejudice are key for inclusion and diversity
Excluding neuro-others for not behaving ""normal"" is *not* inclusive
