https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89412
--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
Middle-end wants to create a subreg of BLKmode:
#3 0x0000000000cd5899 in simplify_gen_subreg
(outermode=outermode@entry=E_DCmode, op=op@entry=0x7fffea778240,
innermode=E_BLKmode, byte=byte@entry=...)
at ../../git/gcc/gcc/simplify-rtx.c:6709
6709 newx = simplify_subreg (outermode, op, innermode, byte);
(gdb) p outermode
$1 = E_DCmode
(gdb) p innermode
$2 = E_BLKmode
(gdb) p debug_rtx (op)
(mem/c:BLK (symbol_ref:SI ("d") [flags 0x2] <var_decl 0x7ffff7ffbab0 d>) [3 d+0
S16 A32])
