[Bug target/109661] [13/14 Regression] ICE in aarch64_function_arg_alignment when building erlang

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109661

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Untested fix:

2023-04-28  Jakub Jelinek  <jakub@redhat.com>

        PR target/109661
        * config/aarch64/aarch64.cc (aarch64_function_arg_alignment): For
        ENUMERAL_TYPEs use alignment of TYPE_MAIN_VARIANT (TREE_TYPE (type))
        rather than TYPE_MAIN_VARIANT (type).

        * g++.dg/other/pr109661.C: New test.

--- gcc/config/aarch64/aarch64.cc.jj    2023-04-24 14:54:45.558075512 +0200
+++ gcc/config/aarch64/aarch64.cc       2023-04-28 10:37:58.013311653 +0200
@@ -7487,6 +7487,9 @@ aarch64_function_arg_alignment (machine_

   if (!AGGREGATE_TYPE_P (type))
     {
+      /* For enumeral types use the underlying type if possible.  */
+      if (TREE_CODE (type) == ENUMERAL_TYPE && TREE_TYPE (type))
+       type = TREE_TYPE (type);
       /* The ABI alignment is the natural alignment of the type, without
         any attributes applied.  Normally this is the alignment of the
         TYPE_MAIN_VARIANT, but not always; see PR108910 for a counterexample.
--- gcc/testsuite/g++.dg/other/pr109661.C.jj    2023-04-28 10:41:21.169350306
+0200
+++ gcc/testsuite/g++.dg/other/pr109661.C       2023-04-28 10:40:46.246859362
+0200
@@ -0,0 +1,12 @@
+// PR target/109661
+// { dg-do compile { target c++11 } }
+// { dg-options "-w" } */
+
+typedef unsigned long U __attribute__ ((aligned (128)));
+typedef enum : U { V = 0 } W;
+
+U
+foo (U a, W b)
+{
+  return a + U (b);
+}

The question is if it is an ABI change from GCC 12 or not (GCC 13 ICEs on it,
so ABI doesn't matter).