On 23/07/2024 11:39, Richard Biener wrote:
On Tue, 23 Jul 2024, Jakub Jelinek wrote:
Hi!
Richi suggested to mention the PR116029 bug in 11.5.0 caveats as we can't
fix that anymore.
Here is a patch for that, which attempts to describe (my limited
understanding of) the issue.
As TARGET_CPU_generic is now 64, when config.gcc doesn't set
TARGET_CPU_DEFAULT, we end up with TARGET_CPU_DEFAULT
(64 | (AARCH64_CPU_DEFAULT_FLAGS << 6))
which is treated as I think
TARGET_CPU_cortexa34 | ((AARCH64_CPU_DEFAULT_FLAGS | AARCH64_FL_SIMD) << 6))
Ok for wwwdocs?
OK, but please give arm folks the chance to review this.
Richard.
diff --git a/htdocs/gcc-11/changes.html b/htdocs/gcc-11/changes.html
index e010cd08..26189772 100644
--- a/htdocs/gcc-11/changes.html
+++ b/htdocs/gcc-11/changes.html
@@ -1164,5 +1164,20 @@ known to be fixed in the 11.5 release. This list might
not be
complete (that is, it is possible that some PRs that have been fixed
are not listed here).</p>
+<h3>Caveats</h3>
+
+<h4>aarch64</h4>
+<ul>
+ <li>
+ Due to a late introduced bug if the compiler is configured without
+ explicit <code>--with-arch=</code>, <code>--with=cpu=</code> and/or
+ <code>--with-tune=</code> configure options the compiler without
+ explicit <code>-march=</code> etc. options might act as if asked
+ for <code>cortex-a34</code>. This can be fixed by appling manually the
+ <a href="https://gcc.gnu.org/r12-8060";>r12-8060</a> commit on top
+ of GCC 11.5.0. See <a href="https://gcc.gnu.org/PR116029";>PR116029</a>
+ for more details.
Possibly add that 11.4 and earlier are not affected? 'late' is not very
specific as to when the bug appeared and people using earlier versions
might see this and be confused.
Otherwise, LGTM.
R.
+ </li>
+</ul>
</body>
</html>
Jakub
