Committed as r274487 with approval in https://gcc.gnu.org/ml/gcc-patches/2019-08/msg00974.html
Index: gcc/builtins.c =================================================================== --- gcc/builtins.c (revision 274486) +++ gcc/builtins.c (revision 274487) @@ -5756,6 +5756,7 @@ expand_builtin_init_descriptor (tree exp) r_descr = expand_normal (t_descr); m_descr = gen_rtx_MEM (BLKmode, r_descr); MEM_NOTRAP_P (m_descr) = 1; + set_mem_align (m_descr, GET_MODE_ALIGNMENT (ptr_mode)); r_func = expand_normal (t_func); r_chain = expand_normal (t_chain); Index: gcc/ChangeLog =================================================================== --- gcc/ChangeLog (revision 274486) +++ gcc/ChangeLog (revision 274487) @@ -1,3 +1,7 @@ +2019-08-14 Bernd Edlinger <bernd.edlin...@hotmail.de> + + * builtins.c (expand_builtin_init_descriptor): Set memory alignment. + 2019-08-14 Martin Sebor <mse...@redhat.com> PR tree-optimization/91294 Thanks Bernd.