[Bug target/101325] [12 Regression] arm: Wrong code with MVE vcmpeqq intrinsic since r12-671-gd083fbf72

[clyon at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101325

--- Comment #6 from Christophe Lyon <clyon at gcc dot gnu.org> ---
Before r12-671 before combine we have:
(insn 7 4 8 2 (set (reg:HI 117)
        (unspec:HI [
                (reg/v:V16QI 115 [ v ])
                (reg/v:V16QI 116 [ w ])
            ] VCMPEQQ_S)) "arm_mve.h":4210:10 3228 {mve_vcmpeqq_v16qi}
     (expr_list:REG_DEAD (reg/v:V16QI 116 [ w ])
        (expr_list:REG_DEAD (reg/v:V16QI 115 [ v ])
            (nil))))
(insn 8 7 14 2 (set (reg:SI 113 [ _5 ])
        (zero_extend:SI (reg:HI 117))) "arm_mve.h":4210:10 1019
{*thumb2_zero_extendhisi2_v6}
     (expr_list:REG_DEAD (reg:HI 117)
        (nil)))

After r12-671, we have:
(insn 7 4 8 2 (set (reg:HI 117)
        (eq:HI (reg/v:V16QI 115 [ v ])
            (reg/v:V16QI 116 [ w ]))) "arm_mve.h":4210:10 3173
{mve_vcmpeqq_v16qi}
     (expr_list:REG_DEAD (reg/v:V16QI 116 [ w ])
        (expr_list:REG_DEAD (reg/v:V16QI 115 [ v ])
            (nil))))
(insn 8 7 14 2 (set (reg:SI 113 [ _5 ])
        (zero_extend:SI (reg:HI 117))) "arm_mve.h":4210:10 1019
{*thumb2_zero_extendhisi2_v6}
     (expr_list:REG_DEAD (reg:HI 117)
        (nil)))