I read somewhere (won't say where ;-)) that someone is annoyed by D "pretending that "real" is an 80-bit type".  Is it not?  real.sizeof sure seems to return 10 for me.

--bb

Bill Baxter wrote:
> I read somewhere (won't say where ;-)) that someone is annoyed by D "pretending that "real" is an 80-bit type".  Is it not?  real.sizeof sure seems to return 10 for me.

It is with DMD.  I'm not sure if GDC uses 80 or 64-bit reals on the x86.


Sean

Bill Baxter wrote:

> I read somewhere (won't say where ;-)) that someone is annoyed by D "pretending that "real" is an 80-bit type".  Is it not?  real.sizeof sure seems to return 10 for me.

It's an 80-bit type on all (make that "both") DMD platforms...
It varies on the platforms and architectures that GDC supports.

"int" is a fixed 32-bit type, everywhere. "real" varies in size.
It's 80-bit on Intel, 64 bits on PowerPC and 128 bits on SPARC ?

It's defined as the "largest hardware implemented" float type.
Basically since it maps directly onto the "long double" C type.

--anders

PS. real.sizeof varies between Intel too, due to padding.
    But it should be the same x87 format of the registers.

    GDC manual says: "On Win32, GDC allocates 12 bytes for
    the real type, while DMD allocates 10 bytes."

That all sounds perfectly reasonable.  So why would that make it onto someone's "top D peeves" list?

--bb

Anders F Björklund wrote:
> Bill Baxter wrote:
> 
>> I read somewhere (won't say where ;-)) that someone is annoyed by D "pretending that "real" is an 80-bit type".  Is it not?  real.sizeof sure seems to return 10 for me.
> 
> 
> It's an 80-bit type on all (make that "both") DMD platforms...
> It varies on the platforms and architectures that GDC supports.
> 
> "int" is a fixed 32-bit type, everywhere. "real" varies in size.
> It's 80-bit on Intel, 64 bits on PowerPC and 128 bits on SPARC ?
> 
> It's defined as the "largest hardware implemented" float type.
> Basically since it maps directly onto the "long double" C type.
> 
> --anders
> 
> PS. real.sizeof varies between Intel too, due to padding.
>     But it should be the same x87 format of the registers.
> 
>     GDC manual says: "On Win32, GDC allocates 12 bytes for
>     the real type, while DMD allocates 10 bytes."

Perhaps they think that "real" should always be a 64-bit type?  There are a few different ways that statement could be interpreted.

Bill Baxter wrote:
> That all sounds perfectly reasonable.  So why would that make it onto someone's "top D peeves" list?
> 
> --bb
> 
> Anders F Björklund wrote:
>> Bill Baxter wrote:
>>
>>> I read somewhere (won't say where ;-)) that someone is annoyed by D "pretending that "real" is an 80-bit type".  Is it not?  real.sizeof sure seems to return 10 for me.
>>
>>
>> It's an 80-bit type on all (make that "both") DMD platforms...
>> It varies on the platforms and architectures that GDC supports.
>>
>> "int" is a fixed 32-bit type, everywhere. "real" varies in size.
>> It's 80-bit on Intel, 64 bits on PowerPC and 128 bits on SPARC ?
>>
>> It's defined as the "largest hardware implemented" float type.
>> Basically since it maps directly onto the "long double" C type.
>>
>> --anders
>>
>> PS. real.sizeof varies between Intel too, due to padding.
>>     But it should be the same x87 format of the registers.
>>
>>     GDC manual says: "On Win32, GDC allocates 12 bytes for
>>     the real type, while DMD allocates 10 bytes."

Sean Kelly wrote:
> Perhaps they think that "real" should always be a 64-bit type?  There are a few different ways that statement could be interpreted.

Or they're just mathematical purists who don't think a type named 'real' should have finite precision and range :p.
Of course, then they'd have to complain about 'int' being limited to -2^31..2^31-1 too.
And let's not get into ireal and creal...

Bill Baxter wrote:

>>> I read somewhere (won't say where ;-)) that someone is annoyed by D "pretending that "real" is an 80-bit type".  Is it not?  real.sizeof sure seems to return 10 for me.

>> "int" is a fixed 32-bit type, everywhere. "real" varies in size.

> That all sounds perfectly reasonable.  So why would that make it onto someone's "top D peeves" list?

In my case it's on my pet peeves list because of the "it's 10 for me".
So you have hardcoded assertions that real.sizeof > double.sizeof...

Kinda like the "if (Win32) else //linux ;", it's making assumptions.
They are valid for DMD, but break for GDC - and make porting harder ?

But most of all I dislike the "imaginary real" and the "complex real".
(see http://www.digitalmars.com/d/archives/digitalmars/D/18061.html)

Since it's not going to change anyway, I'm OK with coping with it...
But still think the 16-bit and 128-bit types would have been nice ?

--anders

Anders F Björklund wrote:
> Bill Baxter wrote:
> 
> In my case it's on my pet peeves list because of the "it's 10 for me".
> So you have hardcoded assertions that real.sizeof > double.sizeof...
> 
> Kinda like the "if (Win32) else //linux ;", it's making assumptions.
> They are valid for DMD, but break for GDC - and make porting harder ?
> 
> But most of all I dislike the "imaginary real" and the "complex real".
> (see http://www.digitalmars.com/d/archives/digitalmars/D/18061.html)
> 
> Since it's not going to change anyway, I'm OK with coping with it...
> But still think the 16-bit and 128-bit types would have been nice ?

I see.  So really it's nothing particular to D.  More with D users, and even then, users making assumptions about platforms is far from unique to D.  Glad to know it's nothing seriously wrong with D's 80-bit math on platforms that have it.

--bb

Anders F Björklund wrote:
> Bill Baxter wrote:
> 
>>>> I read somewhere (won't say where ;-)) that someone is annoyed by D "pretending that "real" is an 80-bit type".  Is it not?  real.sizeof sure seems to return 10 for me.
> 
>>> "int" is a fixed 32-bit type, everywhere. "real" varies in size.
> 
>> That all sounds perfectly reasonable.  So why would that make it onto someone's "top D peeves" list?
> 
> In my case it's on my pet peeves list because of the "it's 10 for me".
> So you have hardcoded assertions that real.sizeof > double.sizeof...
> 
> Kinda like the "if (Win32) else //linux ;", it's making assumptions.
> They are valid for DMD, but break for GDC - and make porting harder ?
> 
> But most of all I dislike the "imaginary real" and the "complex real".
> (see http://www.digitalmars.com/d/archives/digitalmars/D/18061.html)
> 
> Since it's not going to change anyway, I'm OK with coping with it...
> But still think the 16-bit and 128-bit types would have been nice ?

It is a bit weird that D has 'cent' and 'ucent' as reserved words, but not 'quadruple'.

"Don Clugston" <dac@nospam.com.au> wrote in message news:em43j6$7tl$1@digitaldaemon.com...

> It is a bit weird that D has 'cent' and 'ucent' as reserved words, but not 'quadruple'.

I'd hope it'd be just "quad" :S  "quadruple" is a little lengthy.