On Sun, Sep 2, 2012 at 1:46 PM, Uros Bizjak <ubiz...@gmail.com> wrote:
> On Sun, Sep 2, 2012 at 1:38 PM, Steven Bosscher <stevenb....@gmail.com> wrote:
>> On Sun, Sep 2, 2012 at 1:22 PM, Uros Bizjak <ubiz...@gmail.com> wrote:
>>> Hello!
>>>
>>> Attached patch prevents compute_bb_for_insn to calculate BB for
>>> barrier RTXes. This is in fact the same approach all other
>>> *_bb_for_insn use.
>
>> What is happening for you, is that you're seeing a BARRIER between
>> BB_HEAD(bb) and BB_END(bb), which is not possible. The barrier is
>> mis-placed.
>
> Please see how the dump looks:
>
> (insn 12 11 28 3 (set (reg:SI 1 dx [63])
> (const_int 2 [0x2])) pr54455.c:5 65 {*movsi_internal}
> (nil))
> (note 28 12 29 3 NOTE_INSN_EPILOGUE_BEG)
> (insn/f 29 28 30 3 (set (reg/f:DI 6 bp)
> (mem:DI (post_inc:DI (reg/f:DI 7 sp)) [0 S8 A8])) pr54455.c:13 -1
> (expr_list:REG_CFA_DEF_CFA (plus:DI (reg/f:DI 7 sp)
> (const_int 8 [0x8]))
> (nil)))
> (jump_insn 30 29 31 3 (simple_return) pr54455.c:13 -1
> (nil)
> -> simple_return)
> (barrier 31 30 15)
> (note 15 31 21 ("lab") NOTE_INSN_DELETED_LABEL 3)
> (note 21 15 24 NOTE_INSN_DELETED)
> (note 24 21 0 NOTE_INSN_DELETED)
>
> Please note that we have a bunch of notes at the end, and barrier
> above them. There are no active insns between barrer and BB_END. Where
> should this RTX go?
It doesn't have to be the barrier that has to move. It could also be
that the barrier is inserted in the right place but BB_END wasn't
updated to point to the jump insn.
Ciao!
Steven
