+ John Reagan who can (I hope) speak to the choice of using different ATE codes for distinguishing VAX/IEEE floats in OpenVMS. --paulor
> -----Original Message----- > From: Dwarf-Discuss <dwarf-discuss-boun...@lists.dwarfstd.org> On Behalf > Of Jakub Jelinek via Dwarf-Discuss > Sent: Monday, January 24, 2022 5:17 PM > To: Jason Merrill <ja...@redhat.com> > Cc: DWARF Discuss <dwarf-discuss@lists.dwarfstd.org> > Subject: Re: [Dwarf-Discuss] Multiple floating point types with the same > size but different encodings > > On Mon, Jan 24, 2022 at 04:52:38PM -0500, Jason Merrill wrote: > > DW_ATE seems natural, since that's how we express the encoding of a base > > type. OTOH, using DW_AT_precision would parallel DW_AT_digit_count for > > fixed-point encodings. My concern is that it would be possible to have > > multiple alternative encodings with the same precision, but perhaps > that's > > not sufficiently likely? > > Guess advantage of a special DW_ATE_* for it is that it is smaller, > DW_AT_encoding has to be specified either way, while we have > DW_FORM_implicit_const, that will take something at least in > .debug_abbrev. > The types we see used together right now (i.e. this double double vs. > quad IEEE or float16 vs. bfloat16) do differ in precisions. > There are some differences in some cases even with the same precision, > e.g. in NaNs (mips vs. rest), but those don't appear together, or the > VAX floats (but I think on a VAX one will see only those 3 floats there > and they have different precisions too (24, 53 and 56)). > > The special DW_ATE_* values would need to be in the user range though, > while DW_AT_precision could be something explained in DWARF6. > > Jakub _______________________________________________ Dwarf-Discuss mailing list Dwarf-Discuss@lists.dwarfstd.org http://lists.dwarfstd.org/listinfo.cgi/dwarf-discuss-dwarfstd.org