[Bug target/99548] Help me! Lost the fight against the compiler.

["pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99548

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|rtl-optimization            |target

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
For aarch64 we get:
        ldp     x4, x3, [x1]
        mov     x7, 38
        ldp     x6, x5, [x2]
        ldr     x8, [x1, 16]
        add     x6, x4, x6
        cmp     x4, x6
        adc     x5, x3, x5
        cmp     x3, x5
        ldr     x3, [x1, 24]
        ldp     x4, x1, [x2, 16]
        adc     x4, x8, x4
        cmp     x8, x4
        adc     x1, x3, x1
        cmp     x3, x1
        csetm   x2, cs
        and     x2, x2, x7
        add     x2, x2, x6
        cmp     x2, x6
        cinc    x6, x5, ls
        cmp     x6, x5
        cinc    x5, x4, ls
        cmp     x5, x4
        cinc    x3, x1, ls
        cmp     x3, x1
        csetm   x1, ls
        and     x1, x1, x7
        add     x1, x1, x2
        str     x1, [x0]
        cmp     x1, x2
        cinc    x1, x6, ls
        str     x1, [x0, 8]
        cmp     x1, x6
        cinc    x1, x5, ls
        cmp     x1, x5
        cinc    x3, x3, ls
        stp     x1, x3, [x0, 16]
        ret
There is only one missing optimization there really:
        csetm   x1, ls
        and     x1, x1, x7
Should be turned into:
csel x1, x7, xzw, ls
Which is repeated a few times.

It looks like x86_64 has other issues.