[RS6000] Fix -m32 -Os lossage

[David Edelsohn]

On Thu, Feb 12, 2015 at 7:33 AM, Alan Modra <amodra@gmail.com> wrote:
> Fixes -Os breakage showing up as 3 testsuite fails like the following,
> caused by add<mode>3 losing r0 as a valid source reg.
>
> insn does not satisfy its constraints:
> (insn 98 97 99 2 (set (reg:SI 11 11)
>         (plus:SI (reg:SI 0 0)
>             (const_int 80 [0x50]))) /src/gcc-current/gcc/testsuite/gcc.target/powerpc/savres.c:112 80 {*addsi3}
>      (expr_list:REG_DEAD (reg:SI 0 0)
>         (nil)))
>
> Bootstrap and regression test in progress.
>
>         * config/rs6000/rs6000.c (rs6000_emit_epilogue): Use addsi3_carry
>         or adddi3_carry when restoring frame_reg_rtx from r0 after restvr.

Okay.

Thanks for catching this.

- David