Ping?
On 2012/6/1 06:24 PM, Chung-Lin Tang wrote:
> On 12/5/23 1:46 AM, Richard Henderson wrote:
>> On 05/18/12 03:48, Chung-Lin Tang wrote:
>>> @@ -2401,6 +2401,7 @@ scan_trace (dw_trace_info *trace)
>>> {
>>> /* Propagate across fallthru edges. */
>>> dwarf2out_flush_queued_reg_saves ();
>>> + def_cfa_1 (&this_cfa);
>>> maybe_record_trace_start (insn, NULL);
>>> break;
>>> }
>>> @@ -2455,6 +2456,18 @@ scan_trace (dw_trace_info *trace)
>>> cur_cfa = &this_cfa;
>>> continue;
>>> }
>>> + else
>>> + {
>>> + /* If ELT is a annulled branch-taken instruction (i.e.
>>> executed
>>> + only when branch is not taken), the args_size and CFA
>>> should
>>> + not change through the jump. */
>>> + create_trace_edges (control);
>>> +
>>> + /* Update and continue with the trace. */
>>> + add_cfi_insn = insn;
>>> + scan_insn_after (elt);
>>> + continue;
>>> + }
>>
>> I think the def_cfa_1 is misplaced. It should be immediately before
>> that last continue. That mirrors the sort of flow you get via the
>> other paths through the loop.
>
> Or possibly moved before the dwarf2out_flush_queued_reg_saves () call in
> the patch? (in the save_point_p () break case) Note I'm only saying
> this based on overall ordering of those two routine calls in the loop.
>
> Attached is a testcase (adapted from libgomp) that, with the SH epilogue
> unwind patch applied alone, produces the ICE I'm seeing (-O2
> -funwind-tables).
>
> This dwarf2 patch, with any of the three new def_cfa_1() call sites
> seems to solve it, though you might want to comment on which call site
> seems "correct"
>
> Thanks,
> Chung-Lin
