This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: Adding __float128 (i.e TS 18661-3)
- From: Joseph Myers <joseph at codesourcery dot com>
- To: Steven Munroe <munroesj at linux dot vnet dot ibm 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: Wed, 8 Jun 2016 12:33:01 +0000
- 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> <1465331531 dot 18737 dot 28 dot camel at oc7878010663> <alpine dot DEB dot 2 dot 20 dot 1606072103460 dot 9812 at digraph dot polyomino dot org dot uk> <1465336580 dot 18737 dot 42 dot camel at oc7878010663> <alpine dot DEB dot 2 dot 20 dot 1606072207170 dot 9812 at digraph dot polyomino dot org dot uk> <1465343325 dot 18737 dot 62 dot camel at oc7878010663>
On Tue, 7 Jun 2016, Steven Munroe wrote:
> And we would like to avoid compile errors due to missing compiler
> options and associated type randomization.
Compile errors are fine - they make the problem obvious. What should be
avoided is cases where code quietly gets built with the wrong type without
producing errors, but does the wrong thing at runtime. (And there are a
range of possible solutions to avoid that, including e.g. #error for the
wrong long double format in a header used in the ldbl-128ibm code.)
> Separately we do use the printf plugin API to support _Decimal Float and
> vector printf and provide these to Linux on Power customers. It is fair
> to assume that we would provide a 'Q' format plugin for early adopters
> of __float128.
Sure, and if people want to use scanf like that I think it would be
reasonable to add scanf hooks support similar to the printf hooks support.
--
Joseph S. Myers
joseph@codesourcery.com