This is the mail archive of the
mailing list for the glibc project.
Re: Adding __float128 (i.e TS 18661-3)
- From: Steven Munroe <munroesj at linux dot vnet dot ibm dot com>
- To: Joseph Myers <joseph at codesourcery dot com>
- Cc: "Paul E. Murphy" <murphyp at linux dot vnet dot ibm dot com>, "libc-alpha at sourceware dot org" <libc-alpha at sourceware dot org>, Steve Munroe <sjmunroe at us dot ibm dot com>, Tulio Magno Quites Machado Filho <tuliom at linux dot vnet dot ibm dot com>
- Date: Tue, 07 Jun 2016 15:32:11 -0500
- Subject: Re: Adding __float128 (i.e TS 18661-3)
- Authentication-results: sourceware.org; auth=none
- References: <572BB6DF dot 7090709 at linux dot vnet dot ibm dot com> <alpine dot DEB dot 2 dot 20 dot 1605052236310 dot 24016 at digraph dot polyomino dot org dot uk>
- Reply-to: munroesj at linux dot vnet dot ibm dot com
On Thu, 2016-05-05 at 23:35 +0000, Joseph Myers wrote:
> On Thu, 5 May 2016, Paul E. Murphy wrote:
> > As Joseph pointed out earlier in  and  we can't hack and slash our
> > way into supporting this, but IMO, the consensus driven model doesn't
> > encourage a large upfront design, as interested parties only seem to
> > show up at the tail end (during patch submissions). I think we need
> > consensus on what the end result will look like, and what steps will
> > get us there.
> and later could run for more.
> > My proposed design for source structure is:
> > * sysdeps/ieee754/f128/ holds all the __float128
> > (e.g sysdeps/ieee754/f64x-ibm for a _Float64x type based off ibm128)
> _Float64x cannot be based on ibm128; it must have IEEE semantics. It
> could be an alias for __float128, or for x86 extended (I don't see any
> circumstances in which it would be anything else).
Yes it seems that _Float64x are specifically defined to enclusively
cover x86 80-bit and seems to exclude the IBM long double.
I assume that you object to using a standard "extented" type in a none
How about using an "extendable" type unique to IBM long double.
Thankfully Mike Meissner enable both __float128 and __ibm128 in GCC-6.1:
Is this acceptable?