• Paul D. Anderson (21/21) Mar 13 2012 I'm working on a decimal arithmetic project and I need 128 bit
• =?UTF-8?B?QWxleCBSw7hubmUgUGV0ZXJzZW4=?= (5/24) Mar 13 2012 The D language specifies 128-bit integers: cent and ucent. They just
• Manu (4/34) Mar 14 2012 Why aren't they implemented in a library for the time being at least, so
• Daniel Murphy (7/9) Mar 14 2012 The obvious answer is because nobody's done it yet.
• Andrei Alexandrescu (5/16) Mar 15 2012 My suggestion is to focus on fixed arbitrary-sized integers in Phobos,
• bearophile (8/11) Mar 15 2012 I think library-defined fixed arbitrary-sized integers and
• Daniel Murphy (4/8) Mar 15 2012 Yeah. A lot of the BigInt code can probably be adapted, if someone want...
• Paul D. Anderson (7/21) Mar 15 2012 I was really only checking to see if anyone had already
• Jonathan M Davis (8/15) Mar 14 2012 I believe that what it really comes down to is that cent and ucent were ...
• =?UTF-8?B?QWxleCBSw7hubmUgUGV0ZXJzZW4=?= (9/24) Mar 14 2012 There aren't really any platforms that natively support 128-bit
• Jonathan M Davis (5/33) Mar 14 2012 long long is 128 bits on 64-bit Linux. That's what I meant by support. 3...
• Daniel Murphy (3/4) Mar 14 2012 Are you sure about this? I think we already had this discussion...
• James Miller (5/11) Mar 14 2012 Same discussion, different topic. I think the one before was sparked
• Jonathan M Davis (4/10) Mar 14 2012 If it isn't, then whatever that discussion was obviously didn't stick in...
• Daniel Murphy (6/17) Mar 14 2012 long double (aka real, a much better name) is 128 bits (including paddin...
• bearophile (5/9) Mar 14 2012 You are able to support 128 bit numbers even on a 16 bit system

"Paul D. Anderson" <paul.d.removethis.anderson comcast.andthis.net> writes:

I'm working on a decimal arithmetic project and I need 128 bit 
integers in order to implement the decimal128 type. (The decimal 
value is stored in 128 bits; the coefficient field is 114 bits, 
to hold values with 34 decimal digits.)

I could use BigInt (but that's overkill) or I could code them up 
myself, which I'm willing to do if no alternative exists. But 
surely someone has already created this type, either as part of a 
larger project or as some kind of test problem, etc. Or perhaps 
someone would like to tackle it as a project of their own.

I specifically need unsigned 128 bit integers, but both signed 
and unsigned versions would probably have more general 
applications. Better yet, if it checked for overflow, like 
Andrei's CheckedInt class in TDPL, it would be more immediately 
useful.

This could also be the basis for a general fixed-size integer 
type, where the size is specified: CheckedInt!128, CheckedInt!96, 
etc. I recall having seen something like this mentioned in this 
forum.

So has anyone already done this? Does anyone want to take it on?

Thanks,

Paul

=?UTF-8?B?QWxleCBSw7hubmUgUGV0ZXJzZW4=?= <xtzgzorex gmail.com> writes:

On 14-03-2012 01:34, Paul D. Anderson wrote:
 I'm working on a decimal arithmetic project and I need 128 bit integers
 in order to implement the decimal128 type. (The decimal value is stored
 in 128 bits; the coefficient field is 114 bits, to hold values with 34
 decimal digits.)

 I could use BigInt (but that's overkill) or I could code them up myself,
 which I'm willing to do if no alternative exists. But surely someone has
 already created this type, either as part of a larger project or as some
 kind of test problem, etc. Or perhaps someone would like to tackle it as
 a project of their own.

 I specifically need unsigned 128 bit integers, but both signed and
 unsigned versions would probably have more general applications. Better
 yet, if it checked for overflow, like Andrei's CheckedInt class in TDPL,
 it would be more immediately useful.

 This could also be the basis for a general fixed-size integer type,
 where the size is specified: CheckedInt!128, CheckedInt!96, etc. I
 recall having seen something like this mentioned in this forum.

 So has anyone already done this? Does anyone want to take it on?

 Thanks,

 Paul

The D language specifies 128-bit integers: cent and ucent. They just 
aren't implemented yet...

-- 
- Alex

Manu <turkeyman gmail.com> writes:

On 14 March 2012 02:37, Alex R=C3=B8nne Petersen <xtzgzorex gmail.com> wrot=
e:

 On 14-03-2012 01:34, Paul D. Anderson wrote:

 I'm working on a decimal arithmetic project and I need 128 bit integers
 in order to implement the decimal128 type. (The decimal value is stored
 in 128 bits; the coefficient field is 114 bits, to hold values with 34
 decimal digits.)

 I could use BigInt (but that's overkill) or I could code them up myself,
 which I'm willing to do if no alternative exists. But surely someone has
 already created this type, either as part of a larger project or as some
 kind of test problem, etc. Or perhaps someone would like to tackle it as
 a project of their own.

 I specifically need unsigned 128 bit integers, but both signed and
 unsigned versions would probably have more general applications. Better
 yet, if it checked for overflow, like Andrei's CheckedInt class in TDPL,
 it would be more immediately useful.

 This could also be the basis for a general fixed-size integer type,
 where the size is specified: CheckedInt!128, CheckedInt!96, etc. I
 recall having seen something like this mentioned in this forum.

 So has anyone already done this? Does anyone want to take it on?

 Thanks,

 Paul

 The D language specifies 128-bit integers: cent and ucent. They just
 aren't implemented yet...


Why aren't they implemented in a library for the time being at least, so
code can compile and work?

"Daniel Murphy" <yebblies nospamgmail.com> writes:

"Manu" <turkeyman gmail.com> wrote in message 
news:mailman.657.1331715447.4860.digitalmars-d puremagic.com...

 Why aren't they implemented in a library for the time being at least, so 
 code can compile and work?

The obvious answer is because nobody's done it yet.

I have a branch that partially implements ucent in the dmd backend 
(somewhere in my fork on github), but it will likely be at least a month 
before I have time to work on it again.  It looks like it will be pretty 
easy on 64 bit. 

Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:

On 3/15/12 1:42 AM, Daniel Murphy wrote:
 "Manu"<turkeyman gmail.com>  wrote in message
 news:mailman.657.1331715447.4860.digitalmars-d puremagic.com...

 Why aren't they implemented in a library for the time being at least, so
 code can compile and work?

 The obvious answer is because nobody's done it yet.

 I have a branch that partially implements ucent in the dmd backend
 (somewhere in my fork on github), but it will likely be at least a month
 before I have time to work on it again.  It looks like it will be pretty
 easy on 64 bit.

My suggestion is to focus on fixed arbitrary-sized integers in Phobos, 
and then add optimizations for 64-bit integers on architectures that 
support it.

Andrei

"bearophile" <bearophileHUGS lycos.com> writes:

Andrei Alexandrescu:

 My suggestion is to focus on fixed arbitrary-sized integers in 
 Phobos, and then add optimizations for 64-bit integers on 
 architectures that support it.

I think library-defined fixed arbitrary-sized integers and 
built-in cent/ucent types are both useful to have. One doesn't 
fully replace the other. cent/ucent is more efficient (even on 32 
bit systems), while FixedInt is more flexible.

But both are low-priority.

Bye,
bearophile

"Daniel Murphy" <yebblies nospamgmail.com> writes:

"Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in message 
news:jjt1lh$pfb$1 digitalmars.com...
 My suggestion is to focus on fixed arbitrary-sized integers in Phobos, and 
 then add optimizations for 64-bit integers on architectures that support 
 it.

 Andrei

Yeah.  A lot of the BigInt code can probably be adapted, if someone wants to 
give it a go. 

"Paul D. Anderson" <paul.d.removethis.anderson comcast.andthis.net> writes:

On Thursday, 15 March 2012 at 15:39:47 UTC, Daniel Murphy wrote:
 "Andrei Alexandrescu" <SeeWebsiteForEmail erdani.org> wrote in 
 message
 news:jjt1lh$pfb$1 digitalmars.com...
 My suggestion is to focus on fixed arbitrary-sized integers in 
 Phobos, and then add optimizations for 64-bit integers on 
 architectures that support it.

 Andrei

 Yeah.  A lot of the BigInt code can probably be adapted, if 
 someone wants to
 give it a go.

I was really only checking to see if anyone had already 
implemented 128-bit integers. It seems like the answer is no, but 
Daniel may have some code.

It looks like the quickest solution is for me to do it myself. 
I'll let you all know when it's ready.

Paul

"Jonathan M Davis" <jmdavisProg gmx.com> writes:

On Wednesday, March 14, 2012 10:57:03 Manu wrote:
 On 14 March 2012 02:37, Alex Rønne Petersen <xtzgzorex gmail.com> wrote:
 On 14-03-2012 01:34, Paul D. Anderson wrote:
 The D language specifies 128-bit integers: cent and ucent. They just
 aren't implemented yet...

 
 Why aren't they implemented in a library for the time being at least, so
 code can compile and work?

I believe that what it really comes down to is that cent and ucent were set 
aside just in case they would be needed with no specific plans to do anything 
with them. So, they'll probably be implemented eventually, but they're 
definitely not a priority. And if you really need larger integers, then there's 
BigInt. Prior to the 64-bit ports of dmd (which are fairly recent), dmd wasn't 
even on any architectures that supported 128 bit integers anyway.

- Jonathan M Davis

=?UTF-8?B?QWxleCBSw7hubmUgUGV0ZXJzZW4=?= <xtzgzorex gmail.com> writes:

On 14-03-2012 17:49, Jonathan M Davis wrote:
 On Wednesday, March 14, 2012 10:57:03 Manu wrote:
 On 14 March 2012 02:37, Alex Rønne Petersen<xtzgzorex gmail.com>  wrote:
 On 14-03-2012 01:34, Paul D. Anderson wrote:
 The D language specifies 128-bit integers: cent and ucent. They just
 aren't implemented yet...

 Why aren't they implemented in a library for the time being at least, so
 code can compile and work?

 I believe that what it really comes down to is that cent and ucent were set
 aside just in case they would be needed with no specific plans to do anything
 with them. So, they'll probably be implemented eventually, but they're
 definitely not a priority. And if you really need larger integers, then there's
 BigInt. Prior to the 64-bit ports of dmd (which are fairly recent), dmd wasn't
 even on any architectures that supported 128 bit integers anyway.

 - Jonathan M Davis

There aren't really any platforms that natively support 128-bit 
integers, even today. The most "support" you'll get is SIMD-like 
extensions, but those aren't necessarily useful for implementing 128-bit 
integers.

So, most likely, the compiler would just have to unroll 128-bit 
operations just as it does for 64-bit operations on 32-bit targets.

-- 
- Alex

"Jonathan M Davis" <jmdavisProg gmx.com> writes:

On Wednesday, March 14, 2012 17:51:49 Alex Rønne Petersen wrote:
 On 14-03-2012 17:49, Jonathan M Davis wrote:
 On Wednesday, March 14, 2012 10:57:03 Manu wrote:
 On 14 March 2012 02:37, Alex Rønne Petersen<xtzgzorex gmail.com> wrote:
 On 14-03-2012 01:34, Paul D. Anderson wrote:
 The D language specifies 128-bit integers: cent and ucent. They just
 aren't implemented yet...

 
 Why aren't they implemented in a library for the time being at least, so
 code can compile and work?

 
 I believe that what it really comes down to is that cent and ucent were
 set
 aside just in case they would be needed with no specific plans to do
 anything with them. So, they'll probably be implemented eventually, but
 they're definitely not a priority. And if you really need larger
 integers, then there's BigInt. Prior to the 64-bit ports of dmd (which
 are fairly recent), dmd wasn't even on any architectures that supported
 128 bit integers anyway.
 
 - Jonathan M Davis

 
 There aren't really any platforms that natively support 128-bit
 integers, even today. The most "support" you'll get is SIMD-like
 extensions, but those aren't necessarily useful for implementing 128-bit
 integers.
 
 So, most likely, the compiler would just have to unroll 128-bit
 operations just as it does for 64-bit operations on 32-bit targets.

long long is 128 bits on 64-bit Linux. That's what I meant by support. 32-bit 
doesn't have that with any C type on any platform that I know of. I have no 
idea how it's implemented though.

- Jonathan M Davis

"Daniel Murphy" <yebblies nospamgmail.com> writes:

"Jonathan M Davis" <jmdavisProg gmx.com> wrote in message 
news:mailman.666.1331749219.4860.digitalmars-d puremagic.com...
 long long is 128 bits on 64-bit Linux.

Are you sure about this?  I think we already had this discussion... 

James Miller <james aatch.net> writes:

On 15 March 2012 13:55, Daniel Murphy <yebblies nospamgmail.com> wrote:
 "Jonathan M Davis" <jmdavisProg gmx.com> wrote in message
 news:mailman.666.1331749219.4860.digitalmars-d puremagic.com...
 long long is 128 bits on 64-bit Linux.

 Are you sure about this? =C2=A0I think we already had this discussion...

Same discussion, different topic. I think the one before was sparked
by size_t issues.

--
James Miller

Jonathan M Davis <jmdavisProg gmx.com> writes:

On Thursday, March 15, 2012 11:55:46 Daniel Murphy wrote:
 "Jonathan M Davis" <jmdavisProg gmx.com> wrote in message
 news:mailman.666.1331749219.4860.digitalmars-d puremagic.com...
 
 long long is 128 bits on 64-bit Linux.

 
 Are you sure about this?  I think we already had this discussion...

If it isn't, then whatever that discussion was obviously didn't stick in my 
head.

- Jonathan M Davis

"Daniel Murphy" <yebblies nospamgmail.com> writes:

"Jonathan M Davis" <jmdavisProg gmx.com> wrote in message 
news:mailman.685.1331774722.4860.digitalmars-d puremagic.com...
 On Thursday, March 15, 2012 11:55:46 Daniel Murphy wrote:
 "Jonathan M Davis" <jmdavisProg gmx.com> wrote in message
 news:mailman.666.1331749219.4860.digitalmars-d puremagic.com...

 long long is 128 bits on 64-bit Linux.

 Are you sure about this?  I think we already had this discussion...

 If it isn't, then whatever that discussion was obviously didn't stick in 
 my
 head.

 - Jonathan M Davis

long double (aka real, a much better name) is 128 bits (including padding) 
on some platforms/compilers, I'm pretty sure long long is 64 bits in every 
x86-64 memory model.  Some compilers do however support 128 bit integer 
types on some platforms. 

"bearophile" <bearophileHUGS lycos.com> writes:

Jonathan M Davis:

 Prior to the 64-bit ports of dmd (which are fairly recent), dmd 
 wasn't
 even on any architectures that supported 128 bit integers 
 anyway.

You are able to support 128 bit numbers even on a 16 bit system 
:-)

Bye,
bearophile