https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67946
--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
You should compile this with -mavx, otherwise x, y and z global variables get
expanded in BLKmode. So, we get:
(gdb) p code
$1 = PLUS_EXPR
(gdb) p op0
$2 = (rtx) 0x2aaab05a4918
(gdb) p debug_rtx (op0)
(mem/c:BLK (symbol_ref:DI ("z") [flags 0x2] <var_decl 0x2aaab058da20 z>) [1 z+0
S32 A256])
$3 = void
(gdb) p debug_rtx (op1)
(mem/c:BLK (symbol_ref:DI ("y") [flags 0x2] <var_decl 0x2aaab058d990 y>) [1 y+0
S32 A256])
