This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCHv2, rs6000] Add minimum __float128 built-in support required for glibc
- From: Segher Boessenkool <segher at kernel dot crashing dot org>
- To: Bill Schmidt <wschmidt at linux dot vnet dot ibm dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, David Edelsohn <dje dot gcc at gmail dot com>
- Date: Fri, 24 Jun 2016 15:05:41 -0500
- Subject: Re: [PATCHv2, rs6000] Add minimum __float128 built-in support required for glibc
- Authentication-results: sourceware.org; auth=none
- References: <DEA68D1C-CC68-4458-986E-6DF38ABA37F5 at linux dot vnet dot ibm dot com> <20160623234928 dot GA15741 at gate dot crashing dot org> <FEA53047-7DCC-47E4-8DDF-91A9FC8BEE12 at linux dot vnet dot ibm dot com>
On Thu, Jun 23, 2016 at 07:33:34PM -0500, Bill Schmidt wrote:
> > For posterity:
> >
> > Use vspltisw A,N ; vsrw B,A,A ; vslo D,B,A to create in D:
> > N=-16 ffff_0000_0000_0000_0000_0000_0000_0000 (ieee128 -Inf)
> > N=-17 7fff_0000_0000_0000_0000_0000_0000_0000 (ieee128 +Inf)
>
> For the latter, it was N=-15 IIRC? Anyway -17 is an illegal value for vspltisw.
Yes, of course. Three insns is too much asm to do correctly! :-)
Segher