> -----Original Message-----
> From: gcc-ow...@gcc.gnu.org [mailto:gcc-ow...@gcc.gnu.org] On Behalf Of Paulo
> Matos
> Sent: 19 December 2012 17:00
> To: gcc@gcc.gnu.org
> Subject: cselib_record_set breaks due to auto_inc_dec
>
> Hi,
>
> After pro and epilogue pass I have the following epilogue insn:
> (insn/f 20 19 21 2 (parallel [
> (set (mem:DI (plus:SI (reg:SI 26 r26)
> (reg/f:SI 57 r57)) [0 S8 A8])
> (reg:DI 57 r57))
> (set (reg/f:SI 57 r57)
> (plus:SI (reg:SI 26 r26)
> (reg/f:SI 57 r57)))
> ]) bdra_main.i:2 -1
> (expr_list:REG_DEAD (reg:SI 26 r26)
> (expr_list:REG_FRAME_RELATED_EXPR (set (mem:DI (pre_modify:SI
> (reg/f:SI 57 r57)
> (plus:SI (reg/f:SI 57 r57)
> (const_int -8208 [0xffffffffffffdff0]))) [0 S8
> A8])
> (reg:DI 57 r57))
> (nil))))
[snip]
>
> Has anyone come across this before?
>
To add to what I said before, a bit of investigation shows that for_each_rtx,
called from for_each_inc_dec (in rtlanal.c), iterates over all expressions in
insn, including (in the above case):
(expr_list:REG_DEAD (reg:SI 26 r26)
(expr_list:REG_FRAME_RELATED_EXPR (set (mem:DI (pre_modify:SI
(reg/f:SI 57 r57)
(plus:SI (reg/f:SI 57 r57)
(const_int -8208 [0xffffffffffffdff0]))) [0 S8
A8])
(reg:DI 57 r57))
(nil))))
This doesn't look sensible to me (but I might be overlooking a reason why we
want to do so) in the context of cselib_record_sets, however, I think
cselib_record_sets should instead have the patch applied:
- for_each_inc_dec (&insn, cselib_record_autoinc_cb, &data);
+ for_each_inc_dec (&body, cselib_record_autoinc_cb, &data);
What do you think?
--
Paulo Matos
