[Bug tree-optimization/65968] Failure to remove casts, cause poor code generation

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65968

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-12-23
     Ever confirmed|0                           |1

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.

AARCH64 it is not as bad as x86_64 though:

With -UEASY:
.L2:
        ldr     q0, [x0]
        smull   v2.4s, v0.4h, v0.4h
        smull2  v0.4s, v0.8h, v0.8h
        xtn     v1.4h, v2.4s
        xtn2    v1.8h, v0.4s
        str     q1, [x0], 16
        cmp     x1, x0
        bne     .L2

With -DEASY:
.L2:
        ldr     q0, [x0]
        mul     v0.8h, v0.8h, v0.8h
        str     q0, [x0], 16
        cmp     x1, x0
        bne     .L2