https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110206
--- Comment #4 from Uroš Bizjak <ubizjak at gmail dot com> ---
cprop1 pass does not consider paradoxical subreg and for (insn 22) claims that
it equals 8 elements of QImode:
(insn 21 19 22 4 (set (reg:V4QI 98)
(mem/u/c:V4QI (symbol_ref/u:DI ("*.LC1") [flags 0x2]) [0 S4 A32]))
"pr110206.c":12:42 1530 {*movv4qi_internal}
(expr_list:REG_EQUAL (const_vector:V4QI [
(const_int -52 [0xffffffffffffffcc]) repeated x4
])
(nil)))
(insn 22 21 23 4 (set (reg:V8HI 100)
(zero_extend:V8HI (vec_select:V8QI (subreg:V16QI (reg:V4QI 98) 0)
(parallel [
(const_int 0 [0])
(const_int 1 [0x1])
(const_int 2 [0x2])
(const_int 3 [0x3])
(const_int 4 [0x4])
(const_int 5 [0x5])
(const_int 6 [0x6])
(const_int 7 [0x7])
])))) "pr110206.c":12:42 7471 {sse4_1_zero_extendv8qiv8hi2}
(expr_list:REG_EQUAL (const_vector:V8HI [
(const_int 204 [0xcc]) repeated x8
])
(expr_list:REG_DEAD (reg:V4QI 98)
(nil))))
