From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Kettenis To: Andrew Cagney Cc: gdb-patches@sources.redhat.com, binutils@sources.redhat.com Subject: Re: [rfc] Add some more floatformat types .... Date: Thu, 16 Aug 2001 16:55:00 -0000 Message-id: References: <3B76164B.9060908@cygnus.com> <3B7C1287.9080906@cygnus.com> X-SW-Source: 2001-08/msg00199.html Andrew Cagney writes: > > The attached adds the floatformats: > > > > floatformat_i387_ext80; > > floatformat_i387_ext96; > > > > Explicitly sized x86 float formats. > > > > Depending on where/how it is stored, > > an i386 extended could use 80 (10 bytes) > > or 96 (12 bytes). Andrew, I thought I (implicitly) raised some objections to this change. See http://sources.redhat.com/ml/gdb/2001-07/msg00401.html To clarify things a bit: The ISA (that stands for Istruction Set Architecture doesn't it) defines a single 80-bit extended floating point format. On top of that floating point format most ABI's build a a 96-bit extended floating point type (e.g. GCC's `long double'). I'd like GDB to somehow maintain this concept, by *not* introducing the floatformat_i387_ext80 and floatformat_i387_ext96 types you propose. Instead we should make the distinction at the builtin_type_* level. By making the 80-bit and 96-bit builtin_type_* variants share the same underlying floatformat_* variable, we can easiliy check whether two floating point formats on the ABI level share the same encoding on the ISA level. Something similar might hold for IA-64. The other two fixes seem obvious to me. Mark