[Bug libgomp/102838] [12 regression] Several tests SEGV in gomp_loop_ull_init

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102838

--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Ah, bet Solaris aligned_alloc relies on:
"the value of size shall be an integral multiple of alignment"
(glibc aligned_alloc doesn't).
Does memalign or posix_memalign rely on that too, or just aligned_alloc?
If just aligned_alloc, we could do incrementally:
2021-11-17  Jakub Jelinek  <jakub@redhat.com>

        PR libgomp/102838
        * alloc.c (gomp_aligned_alloc): Prefer _aligned_alloc over
        memalign over posix_memalign over aligned_alloc over fallback
        with malloc instead of aligned_alloc over _aligned_alloc over
        posix_memalign over memalign over fallback with malloc.  For
        aligned_alloc, round up size up to multiple of al.

--- libgomp/alloc.c.jj  2021-01-04 10:25:56.157037659 +0100
+++ libgomp/alloc.c     2021-11-17 13:32:25.246271672 +0100
@@ -65,18 +65,24 @@ gomp_aligned_alloc (size_t al, size_t si
   void *ret;
   if (al < sizeof (void *))
     al = sizeof (void *);
-#ifdef HAVE_ALIGNED_ALLOC
-  ret = aligned_alloc (al, size);
-#elif defined(HAVE__ALIGNED_MALLOC)
+#ifdef HAVE__ALIGNED_MALLOC
   ret = _aligned_malloc (size, al);
-#elif defined(HAVE_POSIX_MEMALIGN)
-  if (posix_memalign (&ret, al, size) != 0)
-    ret = NULL;
 #elif defined(HAVE_MEMALIGN)
   {
     extern void *memalign (size_t, size_t);
     ret = memalign (al, size);
   }
+#elif defined(HAVE_POSIX_MEMALIGN)
+  if (posix_memalign (&ret, al, size) != 0)
+    ret = NULL;
+#lif defined(HAVE_ALIGNED_ALLOC)
+  {
+    size_t sz = (size + al - 1) & ~(al - 1);
+    if (__builtin_expect (sz >= size, 1))
+      ret = aligned_alloc (al, sz);
+    else
+      ret = NULL;
+  }
 #else
   ret = NULL;
   if ((al & (al - 1)) == 0 && size)