Hi,
On Mon, Jan 24, 2022 at 08:34:39PM +0100, Jakub Jelinek wrote:
> The following patch uses DW_ATE_GNU_{,complex_}float128 (new extensions
> equal to corresponding HP extensions) instead of DW_ATE_float,
> another possibility would be DW_ATE_GNU_precision attribute on the
> DW_TAG_base_type that would for these multiple 16-byte float cases
> (or always) emit a precision (113 for binary128, 106 for double double),
> yet another one is what Ulrich mentions in his slides
> (DW_AT_GNU_encoding_variant {0,1}).
>
> I didn't get any responses to my dwarf discuss mails yet, on IRC
> Jason preferred a DW_AT_encoding change while Mark prefered
> DW_AT_GNU_precision. In any case, all of these are just GNU extensions,
> if/when DWARF standardizes something else, we can use it for -gdwarf-6
> or later.
When we try to standardize this (in DWARF6) then I think I prefer
having a separate attribute which specifies the precision, just like
we already use DW_AT_byte_size to specify the size. That might also
help with the different float16 encodings.
But if we need a solution now (for gcc12) then using a new DW_ATE_GNU
extension seems more practical.
Cheers,
Mark
