Re: [PATCH 1/3] Refactor to allow internal_fn's

["Andre Vieira (lists)" <andre.simoesdiasvieira@arm.com>]

On 03/05/2023 12:55, Richard Biener wrote:
> On Fri, 28 Apr 2023, Andre Vieira (lists) wrote:
> 
>> Hi,
>>
>> I'm posting the patches separately now with ChangeLogs.
>>
>> I made the suggested changes and tried to simplify the code a bit further.
>> Where internal to tree-vect-stmts I changed most functions to use code_helper
>> to avoid having to check at places we didn't need to. I was trying to simplify
>> things further by also modifying supportable_half_widening_operation and
>> supportable_convert_operation but the result of that was that I ended up
>> moving the code to cast to tree code inside them rather than at the call site
>> and it didn't look simpler, so I left those. Though if we did make those
>> changes we'd no longer need to keep around the tc1 variable in
>> vectorizable_conversion... Let me know what you think.
> 
> I see that
> 
> -  else if (CONVERT_EXPR_CODE_P (code)
> +  else if (CONVERT_EXPR_CODE_P (code.safe_as_tree_code ())
> 
> is convenient (as much as I dislike safe_as_tree_code).  Isn't
> the following
> 
> -  if (!CONVERT_EXPR_CODE_P (code))
> +  if (!CONVERT_EXPR_CODE_P ((tree_code) code))
>       return false;
For some reason I thought the code could only reach here if code was a 
tree code, but I guess if we have an ifn and the modes aren't the same 
as the wide_vectype it would fall to this, which for an ifn this would 
fail. I am wondering whether it needs to though, the multi-step widening 
should also work for ifn's no? We'd need to adapt it, to not use c1, c2 
but hi, lo in case of ifn I guess.. and then use a different optab look 
up too?

Though I'm thinking, maybe this should be a follow-up and just not have 
that 'feature' for now. The feature being, supporting multi-step 
conversion for new widening IFN's.