https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116734
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
init-regs adds the set to 0 for the output:
adding initialization in st_update_array_templ of reg 119 at in block 8 for
insn 75.
scanning new insn with uid = 168.
scanning new insn with uid = 169.
(insn 167 129 75 8 (set (reg:SI 119)
(const_int 0 [0])) "t.cc":51:31 39 {*movsi_internal3}
(expr_list:REG_EQUIV (const_int 0 [0])
(nil)))
(insn 75 167 76 8 (parallel [
(reg:SI 119)
(reg:SI 118)
(mem/v:SI (reg/v/f:SI 69 [ buffer ]) [-1 S4 A32])
(reg:SI 118)
(reg:SI 148)
(const_int 0 [0])
(const_int 32773 [0x8005])
(const_int 0 [0])
(clobber (reg:SI 157))
]) "t.cc":51:31 86 {atomic_compare_and_swapsi}
(expr_list:REG_UNUSED (reg:SI 157)
(nil)))
