[Bug target/54829] bad optimization: sub followed by cmp w/ zero (x86 & ARM)

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54829

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-10-05
     Ever Confirmed|0                           |1
           Severity|normal                      |enhancement

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-10-05 23:39:56 UTC ---
Confirmed:
Trying 7 -> 8:
Failed to match this instruction:
(set (reg:CC 17 flags)
    (compare:CC (minus:DI (reg/v:DI 60 [ a ])
            (reg/v:DI 61 [ b ]))
        (const_int 0 [0])))