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Decimal Floating Point

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  Decimal Floating Point Fabian Russell <fr314159@gmail.com> - 2021-09-10 06:35 -0700
    Re: Decimal Floating Point "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-10 08:17 -0700
      Re: Decimal Floating Point scott@slp53.sl.home (Scott Lurndal) - 2021-09-10 15:44 +0000
        Re: Decimal Floating Point James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-10 12:06 -0400
          Re: Decimal Floating Point Manfred <noname@add.invalid> - 2021-09-10 18:09 +0200
            Re: Decimal Floating Point Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-09-10 16:23 +0000
            Re: Decimal Floating Point James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-10 12:37 -0400
          Re: Decimal Floating Point Fabian Russell <fr314159@gmail.com> - 2021-09-10 09:38 -0700
            Re: Decimal Floating Point James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-10 12:58 -0400
          Re: Decimal Floating Point Eli the Bearded <*@eli.users.panix.com> - 2021-09-10 18:11 +0000
            Re: Decimal Floating Point Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-10 12:13 -0700
              Re: Decimal Floating Point Fabian Russell <fr314159@gmail.com> - 2021-09-10 14:52 -0700
              Re: Decimal Floating Point Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-09-11 07:09 -0700
            Re: Decimal Floating Point James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-10 23:23 -0400
          Re: Decimal Floating Point scott@slp53.sl.home (Scott Lurndal) - 2021-09-10 19:04 +0000
            Re: Decimal Floating Point James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-10 23:23 -0400
              Re: Decimal Floating Point Manfred <noname@add.invalid> - 2021-09-18 19:20 +0200
                Re: Decimal Floating Point James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-20 00:16 -0400
      Re: Decimal Floating Point Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-10 11:14 -0700
        Re: Decimal Floating Point Bart <bc@freeuk.com> - 2021-09-10 23:50 +0100
          Re: Decimal Floating Point David Brown <david.brown@hesbynett.no> - 2021-09-11 20:22 +0200
            Re: Decimal Floating Point Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-11 15:37 -0700
              Re: Decimal Floating Point David Brown <david.brown@hesbynett.no> - 2021-09-12 12:58 +0200
        Re: Decimal Floating Point Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-10 17:36 -0700
    Re: Decimal Floating Point Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-10 18:04 +0200
    Re: Decimal Floating Point Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-10 18:06 +0200
      Re: Decimal Floating Point Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2021-09-10 09:37 -0700
        Re: Decimal Floating Point Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-10 20:43 +0200
      Re: Decimal Floating Point "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-10 09:52 -0700
        Re: Decimal Floating Point Fabian Russell <fr314159@gmail.com> - 2021-09-10 10:08 -0700
          Re: Decimal Floating Point antispam@math.uni.wroc.pl - 2021-09-11 00:36 +0000
      Re: Decimal Floating Point scott@slp53.sl.home (Scott Lurndal) - 2021-09-10 19:07 +0000
        Re: Decimal Floating Point Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-11 06:31 +0200
          Re: Decimal Floating Point Siri Cruise <chine.bleu@yahoo.com> - 2021-09-10 23:29 -0700
            Re: Decimal Floating Point Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-11 16:31 +0200
              Re: Decimal Floating Point Barry Schwarz <schwarzb@delq.com> - 2021-09-11 10:04 -0700
              Re: Decimal Floating Point James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-11 15:08 -0400
                Re: Decimal Floating Point Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-11 15:39 -0700
                  Re: Decimal Floating Point Richard Damon <Richard@Damon-Family.org> - 2021-09-11 19:28 -0400
    Re: Decimal Floating Point Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-10 11:21 -0700
    Re: Decimal Floating Point Philipp Klaus Krause <pkk@spth.de> - 2021-09-10 23:29 +0200
    Re: Decimal Floating Point Kaz Kylheku <563-365-8930@kylheku.com> - 2021-09-11 16:59 +0000
      Re: Decimal Floating Point Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-11 16:05 -0700
        Re: Decimal Floating Point Kaz Kylheku <563-365-8930@kylheku.com> - 2021-09-14 16:25 +0000
    Re: Decimal Floating Point "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-12 13:08 -0700
    Re: Decimal Floating Point Thomas David Rivers <rivers@dignus.com> - 2021-09-13 22:23 -0400

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#162688 — Decimal Floating Point

Decimal floating point was standardized as IEEE758-2008 and new C types
were defined: _Decimal128, _Decimal64, and _Decimal32.

Gcc has many built-in functions (via libgcc) to handle decimal FP:

https://gcc.gnu.org/onlinedocs/gccint/Decimal-float-library-routines.html

However, what puzzles me is that C has not yet incorporated the decimal
FP types so that the ordinary binary operators, such as "+ - * /" can operate
directly on them.  Rather, to add two _Decimal_64 values, x, y, for example,
one must use the function __bid_adddd3(x, y) instead of x + y.

Why bother to include the new types yet now allow them to be used
arithmetically like all other standard numeric types?

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#162693

On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
> Decimal floating point was standardized as IEEE758-2008 and new C types 
> were defined: _Decimal128, _Decimal64, and _Decimal32.

Can you cite a reference for that? The latest draft of the C standard that I
currently have access to is n2176.pdf, a draft version of the standard that
eventually got approved as C2017. I found no mention of those types in that
document.

> Gcc has many built-in functions (via libgcc) to handle decimal FP: 
> 
> https://gcc.gnu.org/onlinedocs/gccint/Decimal-float-library-routines.html 
> 
> However, what puzzles me is that C has not yet incorporated the decimal 
> FP types so that the ordinary binary operators, such as "+ - * /" can operate 
> directly on them. Rather, to add two _Decimal_64 values, x, y, for example, 
> one must use the function __bid_adddd3(x, y) instead of x + y. 
> 
> Why bother to include the new types yet now allow them to be used 
> arithmetically like all other standard numeric types?

This appears to be a gcc extension to C; as such, the best place to get good
answers to your question would be a forum devoted to gcc.

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#162696

"james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:
>On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
>> Decimal floating point was standardized as IEEE758-2008 and new C types 
>> were defined: _Decimal128, _Decimal64, and _Decimal32.
>
>Can you cite a reference for that? The latest draft of the C standard that I
>currently have access to is n2176.pdf, a draft version of the standard that
>eventually got approved as C2017. I found no mention of those types in that
>document.

I believe Fabian was referring to the IEEE standard, not the C standard.

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#162698

On 9/10/21 11:44 AM, Scott Lurndal wrote:
> "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:
>> On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
>>> Decimal floating point was standardized as IEEE758-2008 and new C types 
>>> were defined: _Decimal128, _Decimal64, and _Decimal32.
>>
>> Can you cite a reference for that? The latest draft of the C standard that I
>> currently have access to is n2176.pdf, a draft version of the standard that
>> eventually got approved as C2017. I found no mention of those types in that
>> document.
> 
> I believe Fabian was referring to the IEEE standard, not the C standard.

Yes, but because they are not in the C standard, they're not C standard
types, which means that the best place to ask questions about them is
not this newsgroup.

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#162700

On 9/10/2021 6:06 PM, James Kuyper wrote:
> On 9/10/21 11:44 AM, Scott Lurndal wrote:
>> "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:
>>> On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
>>>> Decimal floating point was standardized as IEEE758-2008 and new C types
>>>> were defined: _Decimal128, _Decimal64, and _Decimal32.
>>>
>>> Can you cite a reference for that? The latest draft of the C standard that I
>>> currently have access to is n2176.pdf, a draft version of the standard that
>>> eventually got approved as C2017. I found no mention of those types in that
>>> document.
>>
>> I believe Fabian was referring to the IEEE standard, not the C standard.
> 
> Yes, but because they are not in the C standard, they're not C standard
> types, which means that the best place to ask questions about them is
> not this newsgroup.
> 

He wrote "C types"..

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#162702

On Fri, 10 Sep 2021 18:09:48 +0200, Manfred wrote:

> On 9/10/2021 6:06 PM, James Kuyper wrote:
>> On 9/10/21 11:44 AM, Scott Lurndal wrote:
>>> "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:
>>>> On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
>>>>> Decimal floating point was standardized as IEEE758-2008 and new C types
>>>>> were defined: _Decimal128, _Decimal64, and _Decimal32.
>>>>
>>>> Can you cite a reference for that? The latest draft of the C standard that I
>>>> currently have access to is n2176.pdf, a draft version of the standard that
>>>> eventually got approved as C2017. I found no mention of those types in that
>>>> document.
>>>
>>> I believe Fabian was referring to the IEEE standard, not the C standard.
>> 
>> Yes, but because they are not in the C standard, they're not C standard
>> types, which means that the best place to ask questions about them is
>> not this newsgroup.
>> 
> 
> He wrote "C types"..

Yes? So?

The IEEE doesn't have overriding authority over the ISO C standard, and /anybody/
can "define" a new "C type". But /defining/ such a thing, and /making it part
of the standard/ are two completely different things.

Microsoft /defined/ "far" as a C storage class specifier, but "far" isn't part of
the ISO C standard language.

Gnome /defined/ "GtkWidget" as a C object, but "GtkWidget" isn't part of the ISO
C standard language.

A number of the regulars here in comp.lang.c have /defined/ various enhancements
to the C language, ranging from garbage-collection to string-handling to OO primitives,
but none of these /defined/ enhancements are part of the ISO C standard language.

All in all, third party declarations of new "standard" features are just so much
smoke and wind, /until/ the ISO standardization committee enshrines them in the
C language standard. At best, those new "standard" features are just optional
libraries and/or modifications to compilers that also happen to support the C
language.

-- 
Lew Pitcher
"In Skills, We Trust"

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#162705

On 9/10/21 12:09 PM, Manfred wrote:
> On 9/10/2021 6:06 PM, James Kuyper wrote:
>> On 9/10/21 11:44 AM, Scott Lurndal wrote:
>>> "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:
>>>> On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
>>>>> Decimal floating point was standardized as IEEE758-2008 and new C types
>>>>> were defined: _Decimal128, _Decimal64, and _Decimal32.
>>>>
>>>> Can you cite a reference for that? The latest draft of the C standard that I
>>>> currently have access to is n2176.pdf, a draft version of the standard that
>>>> eventually got approved as C2017. I found no mention of those types in that
>>>> document.
>>>
>>> I believe Fabian was referring to the IEEE standard, not the C standard.
>>
>> Yes, but because they are not in the C standard, they're not C standard
>> types, which means that the best place to ask questions about them is
>> not this newsgroup.
>>
> 
> He wrote "C types"..

Yes. Despite the fact that he described them as C types, they are not C
standard types, so the best place to discuss them is elsewhere. If
they're defined by the IEEE758-2008, they should be discussed in a forum
appropriate to that standard. If they're defined by gcc, they should be
discussed in a gcc forum. Discuss them anywhere else, and you're less
likely to find people who can intelligently discuss them. Unfortunately,
that won't stop people from trying to discuss them - but due to a
shortage of people who are sufficiently familiar with those types, any
errors perpetrated by people who aren't sufficiently familiar with them
may go unchallenged if you post your question in the wrong forum.

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#162706

On Friday, September 10, 2021 at 12:06:29 PM UTC-4, james...@alumni.caltech.edu wrote:

> Yes, but because they are not in the C standard, they're not C standard 
> types, 
>

I now understand.  I am more interested is using these new types rather than understanding
their origin.

But are the decFP types being considered for inclusion in the C standard?

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#162709

On 9/10/21 12:38 PM, Fabian Russell wrote:
> On Friday, September 10, 2021 at 12:06:29 PM UTC-4, james...@alumni.caltech.edu wrote:
> 
>> Yes, but because they are not in the C standard, they're not C standard 
>> types, 
>>
> 
> I now understand.  I am more interested is using these new types rather than understanding
> their origin.
> 
> But are the decFP types being considered for inclusion in the C standard?

I have heard rumors to that effect.

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#162712

In comp.lang.c, James Kuyper  <jameskuyper@alumni.caltech.edu> wrote:
> On 9/10/21 11:44 AM, Scott Lurndal wrote:
>> I believe Fabian was referring to the IEEE standard, not the C standard.
> Yes, but because they are not in the C standard, they're not C standard
> types, which means that the best place to ask questions about them is
> not this newsgroup.

I'm reading this in comp.lang.c and I look at the Newsgroups header and
don't see a crosspost to comp.std.c so I'm wondering why you believe
"not C Standard ... not this newsgroup".

Elijah
------
comp.std.c seems to be the only active comp.std.* group

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#162719

Eli the Bearded <*@eli.users.panix.com> writes:
> In comp.lang.c, James Kuyper  <jameskuyper@alumni.caltech.edu> wrote:
>> On 9/10/21 11:44 AM, Scott Lurndal wrote:
>>> I believe Fabian was referring to the IEEE standard, not the C standard.
>> Yes, but because they are not in the C standard, they're not C standard
>> types, which means that the best place to ask questions about them is
>> not this newsgroup.
>
> I'm reading this in comp.lang.c and I look at the Newsgroups header and
> don't see a crosspost to comp.std.c so I'm wondering why you believe
> "not C Standard ... not this newsgroup".

Because the general (though not universal) consensus is that comp.lang.c
is for discussion of the C language as defined by the standard, and
comp.std.c is for discussion of the standard itself as a document.

As it happens, decimal floating-point *is* part of the latest draft
standard, so it's topical here.  Not everyone in the discussion was
aware of that.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

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#162724

On Friday, September 10, 2021 at 3:13:34 PM UTC-4, Keith Thompson wrote:

> Because the general (though not universal) consensus is that comp.lang.c 
> is for discussion of the C language as defined by the standard,
>

Do pardon me.  I was under the impression that comp.lang.c was for discussions
of the C programming language and issues of C programming.

In any case, I just want to point out that standards-conformant decFP hardware can
exist as shown by this product for ordinary PCs:

http://www.silminds.com/index.php?option=com_content&task=view&id=51&Itemid=36

The web page also lists some of the areas where decFP is applicable and if the C language
is to adequately service the future then decFP has to be made a part of the standard.

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#162733

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

> Eli the Bearded <*@eli.users.panix.com> writes:
>
>> In comp.lang.c, James Kuyper  <jameskuyper@alumni.caltech.edu> wrote:
>>
>>> On 9/10/21 11:44 AM, Scott Lurndal wrote:
>>>
>>>> I believe Fabian was referring to the IEEE standard, not the C
>>>> standard.
>>>
>>> Yes, but because they are not in the C standard, they're not C
>>> standard types, which means that the best place to ask questions
>>> about them is not this newsgroup.
>>
>> I'm reading this in comp.lang.c and I look at the Newsgroups header
>> and don't see a crosspost to comp.std.c so I'm wondering why you
>> believe "not C Standard ... not this newsgroup".
>
> Because the general (though not universal) consensus is that
> comp.lang.c is for discussion of the C language as defined by
> the standard,

I believe that is a minority view.  First off the newsgroup
(albeit with a different name) predates the existence of any ISO
or ANSI standard.  Second, and probably more important, most of
the discussion that actually takes place is about using the C
language rather than about the language per se.  Even if a
program is written in "standard C", it can reasonably lead to
questions outside the ISO standard proper, because C allows
extensions, and because tools (compilers, linkers, etc) come into
play when trying to write C code, and I think also some other
causes.  Furthermore I think there is at least tacit agreement
among most participants here that these kinds of questions are
appropriate to be brought up in the newsgroup, even if better
answers might (and I emphasize might) be available in another
venue.

What comp.lang.c is definitely NOT for is subjects that are
primarily concerned with languages other than C.  Almost everyone
(other than trolls) adheres to this principle, with a small
number of repeat offender exceptions.

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#162729

On 9/10/21 2:11 PM, Eli the Bearded wrote:
> In comp.lang.c, James Kuyper  <jameskuyper@alumni.caltech.edu> wrote:
>> On 9/10/21 11:44 AM, Scott Lurndal wrote:
>>> I believe Fabian was referring to the IEEE standard, not the C standard.
>> Yes, but because they are not in the C standard, they're not C standard
>> types, which means that the best place to ask questions about them is
>> not this newsgroup.
> 
> I'm reading this in comp.lang.c and I look at the Newsgroups header and
> don't see a crosspost to comp.std.c so I'm wondering why you believe
> "not C Standard ... not this newsgroup".

comp.std.c is for discussions of the standard for the C language.
comp.lang.c is for discussion of the language defined by that standard.
Comp.lang.c is unmoderated, and has no official charter, having been
created before charters were required. Therefore, it's perfectly
feasible to post questions about association football here, if you want.
You won't be violating any official rules by doing so. However, as a
simple practical matter, if your question is relevant to a specific
compiler, a specific operating system, or a particular library, you'll
get better answers by posting questions in a forum more tightly focused
on that compiler, operating system, or library than this newsgroup is.

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#162717

James Kuyper <jameskuyper@alumni.caltech.edu> writes:
>On 9/10/21 11:44 AM, Scott Lurndal wrote:
>> "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:
>>> On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
>>>> Decimal floating point was standardized as IEEE758-2008 and new C types 
>>>> were defined: _Decimal128, _Decimal64, and _Decimal32.
>>>
>>> Can you cite a reference for that? The latest draft of the C standard that I
>>> currently have access to is n2176.pdf, a draft version of the standard that
>>> eventually got approved as C2017. I found no mention of those types in that
>>> document.
>> 
>> I believe Fabian was referring to the IEEE standard, not the C standard.
>
>Yes, but because they are not in the C standard, they're not C standard
>types, which means that the best place to ask questions about them is
>not this newsgroup.

I disagree.  This is comp.lang.c, not comp.lang.std.c.

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#162730

On 9/10/21 3:04 PM, Scott Lurndal wrote:
> James Kuyper <jameskuyper@alumni.caltech.edu> writes:
...
>> Yes, but because they are not in the C standard, they're not C standard
>> types, which means that the best place to ask questions about them is
>> not this newsgroup.
> 
> I disagree.  This is comp.lang.c, not comp.lang.std.c.

That doesn't change anything - you'll get better responses to a question
about GnuC in a forum specific to GnuC, and you'll get better answers to
a question about Visual C in a forum devoted to Visual C, you'll get
better answers to questions about tcc are in a forum devoted to tcc,
etc. The only questions where this is the best place to get an answer
are questions that are not specific to any particular compiler - which
is pretty much the same as standard C.

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#162761

On 9/11/2021 5:23 AM, James Kuyper wrote:
> On 9/10/21 3:04 PM, Scott Lurndal wrote:
>> James Kuyper <jameskuyper@alumni.caltech.edu> writes:
> ...
>>> Yes, but because they are not in the C standard, they're not C standard
>>> types, which means that the best place to ask questions about them is
>>> not this newsgroup.
>>
>> I disagree.  This is comp.lang.c, not comp.lang.std.c.
> 
> That doesn't change anything - you'll get better responses to a question
> about GnuC in a forum specific to GnuC, and you'll get better answers to
> a question about Visual C in a forum devoted to Visual C, you'll get
> better answers to questions about tcc are in a forum devoted to tcc,
> etc. The only questions where this is the best place to get an answer
> are questions that are not specific to any particular compiler - which
> is pretty much the same as standard C.
> 

I am not going to make a lot of fuzz about this, however one 
consideration seems relevant:

You keep saying "you'll get better answers...", now while this obviously 
depends on topicality (although I don't agree entirely with your 
definition of this newsgroup), it also depends on the activity of the 
posters involved.
Considering that most of the Usenet is dead thanks to spammers, trolls, 
and, last in order, migration to other platforms, while this newsgroup 
is still somewhat active, this gives a better chance to get a good 
answer here, where there is a fair number of competent people, rather 
than from a group that might be more specific, but just inactive.

Obviously this doesn't mean that any question about programming should 
land here, but a question about feasibility or use of numeric C types 
(considerably more general than e.g. Gtk types) in the language doesn't 
seem odd to me - better than kicking off anything that is not (yet) in 
the standard; that doesn't seem helpful for the activity of the group, 
to my opinion.
You might have seen that recently there was a thread on comp.lang.c++ 
about rational numbers, also not part of the C++ standard, but which 
still led to some interesting follow-ups - again, better than kicking 
the thing off as "not standard"

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#162766

On 9/18/21 1:20 PM, Manfred wrote:
> On 9/11/2021 5:23 AM, James Kuyper wrote:
...
>> That doesn't change anything - you'll get better responses to a question
>> about GnuC in a forum specific to GnuC, and you'll get better answers to
>> a question about Visual C in a forum devoted to Visual C, you'll get
>> better answers to questions about tcc are in a forum devoted to tcc,
>> etc. The only questions where this is the best place to get an answer
>> are questions that are not specific to any particular compiler - which
>> is pretty much the same as standard C.
...
> You keep saying "you'll get better answers...", now while this obviously 
> depends on topicality (although I don't agree entirely with your 
> definition of this newsgroup), it also depends on the activity of the 
> posters involved.
> Considering that most of the Usenet is dead thanks to spammers, trolls, 
> and, last in order, migration to other platforms, while this newsgroup 
> is still somewhat active, this gives a better chance to get a good 
> answer here, where there is a fair number of competent people, rather 
> than from a group that might be more specific, but just inactive.

I was very careful to say "forum", not "usenet newsgroup". If there is
any particular compiler or operating system for which comp.lang.c is the
best available forum for discussing it, then it is almost completely
dead - if it were still alive, there would be a currently active forum
somewhere that would be a better place than here to get answers about it.
Now, that allows for the possibility that there might be some zombie
systems for which that is actually true - but neither Visual C++, GnuC,
Windows, nor POSIX are zombies. I'm not so sure about tcc.

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#162713

"james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:
> On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
>> Decimal floating point was standardized as IEEE758-2008 and new C types 
>> were defined: _Decimal128, _Decimal64, and _Decimal32.
>
> Can you cite a reference for that? The latest draft of the C standard that I
> currently have access to is n2176.pdf, a draft version of the standard that
> eventually got approved as C2017. I found no mention of those types in that
> document.

See n2596.pdf, a more recent draft of the C 202x standard.  Yes, decimal
floating-point is being proposed as an optional standard C feature.

http://www.open-std.org/JTC1/SC22/WG14/www/docs/n2176.pdf

[...]

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

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#162726

On 10/09/2021 19:14, Keith Thompson wrote:
> "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:
>> On Friday, September 10, 2021 at 9:35:09 AM UTC-4, Fabian Russell wrote:
>>> Decimal floating point was standardized as IEEE758-2008 and new C types
>>> were defined: _Decimal128, _Decimal64, and _Decimal32.
>>
>> Can you cite a reference for that? The latest draft of the C standard that I
>> currently have access to is n2176.pdf, a draft version of the standard that
>> eventually got approved as C2017. I found no mention of those types in that
>> document.
> 
> See n2596.pdf, a more recent draft of the C 202x standard.  Yes, decimal
> floating-point is being proposed as an optional standard C feature.

I should hope it's optional. I've been looking at the description of the 
bit-format:

https://en.wikipedia.org/wiki/Decimal64_floating-point_format

and couldn't make head or tail of it. I'm not sure if they could have 
made it any more complicated. Pity the people who have to do software 
emulations since hardware support is going to be scant.

(I've done my own decimal FP emulation, but I'm not constrained to 
32/64/128-bit values and my encoding is far simpler.)


> http://www.open-std.org/JTC1/SC22/WG14/www/docs/n2176.pdf
> 

(This link is password protected. None of the handful of rude words I 
typed in seemed to work.)

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