Reviewing my review :)
Richard Sandiford <richard.sandif...@arm.com> writes:
>> +
>> + for (auto def : info->defs ())
>> + {
>> + auto set = dyn_cast<set_info *> (def);
>> + if (set && set->has_any_uses ())
>> + {
>> + for (auto use : set->all_uses())
>
> Nit: has_any_uses isn't necessary: the inner loop will simply do nothing
> in that case. Also, we can/should restrict the scan to non-debug uses.
>
> This can then be:
>
> for (auto def : info->defs ())
> if (auto set = dyn_cast<set_info *> (def))
> for (auto use : set->nondebug_insn_uses())
I forgot the space before "()" in the line above.
>
>> + {
>> + if (use->insn ()->is_artificial ())
>> + return false;
>> +
>> + insn_info *info = use->insn ();
>> +
>> + if (info
>> + && info->rtl ()
>
> This test shouldn't be necessary.
>
>> + && info->is_real ())
>> + {
>> + rtx_insn *rtl_insn = info->rtl ();
>> + rtx set = single_set (rtl_insn);
>> +
>> + if (set == NULL_RTX)
>> + return false;
>> +
>> + rtx op0 = SET_SRC (set);
>> + if (GET_CODE (op0) != UNSPEC)
>> + return false;
> [...]
> Also, using single_set means that the function still lets through
> parallels of two sets in which the sources are unspecs. Is that
> intentional?
I got this wrong, sorry. You return false for non-single_set,
so that particular problem doesn't arise. But why do we want to
reject uses of registers that are set by parallel sets?
Thanks,
Richard
