[Bug rtl-optimization/68330] [6 Regression]: FAIL: gcc.target/alpha/pr42269-1.c scan-assembler-not addl on alpha-linux-gnu

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68330

--- Comment #3 from UroÅ Bizjak <ubizjak at gmail dot com> ---
(In reply to Segher Boessenkool from comment #2)
> Hrm, I don't think your analysis is entirely correct yet -- you say
> with the old compiler insn 19 is removed, but that sets reg 73 which
> is still used in insn 20.

For some reason, the transformation slightly mixes insn numbers:

(note 18 15 19 2 NOTE_INSN_DELETED)
(insn 19 18 20 2 (set (reg/v:DI 73 [ x ])
        (xor:DI (reg/v:DI 71 [ x ])
            (reg:DI 72 [ _4 ]))) pr42269.c:9 58 {xordi3}
     (expr_list:REG_DEAD (reg/v:DI 71 [ x ])
        (expr_list:REG_DEAD (reg:DI 72 [ _4 ])
            (nil))))
(insn 20 19 21 2 (set (reg:DI 91 [ x ])
        (zero_extend:DI (subreg/s/u:SI (reg/v:DI 73 [ x ]) 0))) pr42269.c:10 48
{zero_extendsidi2}
     (nil))