Re: PATCH [10/n]: Prepare x32: PR rtl-optimization/49114: Reload failed to handle (set reg:X (plus:X (subreg:X (reg:Y) 0) (const

["H.J. Lu" <hjl.tools@gmail.com>]

On Mon, Jun 27, 2011 at 3:08 PM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> H.J. Lu wrote:
>
>> reload generates:
>>
>> (insn 914 912 0 (set (reg:SI 0 ax)
>>         (plus:SI (subreg:SI (reg/v/f:DI 182 [ b ]) 0)
>>             (const_int 8 [0x8]))) 248 {*lea_1_x32}
>>      (nil))
>>
>> from
>>
>> insn = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
>
> Interesting.  The pseudo should have been replaced by the
> hard register (reg:DI 1) during the preceding call to
>      op0 = find_replacement (&XEXP (in, 0));
> (since reload 0 should have pushed a replacement record.)
>
> Interestingly enough, in the final output that replacement *is*
> performed in the REG_EQUIV note:
>
> (insn 1023 1022 1024 34 (set (reg:SI 1 dx)
>        (plus:SI (reg:SI 1 dx)
>            (const_int 8 [0x8]))) spooles.c:291 248 {*lea_1_x32}
>     (expr_list:REG_EQUIV (plus:SI (subreg:SI (reg:DI 1 dx) 0)
>            (const_int 8 [0x8]))
>        (nil)))
>
> which is why I hadn't expected this to be a problem here.
>
> Can you try to find out why the find_replacement doesn't work
> with your test case?
>

I will investigate.  Could (reg:SI 1 dx) vs  (subreg:SI (reg:DI 1 dx) 0)
a problem?


-- 
H.J.