Velocity Reviews > How to redefine arithmetic operators.

# How to redefine arithmetic operators.

Raghu
Guest
Posts: n/a

 11-29-2005
Hello all,

I need your help on how to redefine teh function of arithmetic operators in
C.

for example : if there is an equation c = a/b;

i want to execute my own algorithm for division operator.
I am compelled to use the native C , instead of calling functions or using
macros for doing arithmetic operations.
I mean i was compelled not to use c =MYDIV(a,b) or somewthing like that.

This i needeed to simulate floating point unit of MPC5554 on PC.In MPC the
way the rounding , overflow,errors dealt is different from those used in P4
or AMD.

so i need to simulate the floating point arithmetic of MPC5554 , when i want
to simualte the code designed for it.
I hope i could able express my question clearly.

Thanks and Best Regards
Raghu.

Marc Boyer
Guest
Posts: n/a

 11-29-2005
Le 29-11-2005, Raghu <(E-Mail Removed)> a écrit*:
> I need your help on how to redefine teh function of arithmetic operators in
> C.
>
> for example : if there is an equation c = a/b;
>
> i want to execute my own algorithm for division operator.
> I am compelled to use the native C , instead of calling functions or using
> macros for doing arithmetic operations.
> I mean i was compelled not to use c =MYDIV(a,b) or somewthing like that.

The difference between c=MYDIV(a,b) and c=a/b is only 'syntaxic
sugar'.
If you really need to overload operators, you can do it in C++,
but there is no way to do it in C.

Marc Boyer

jacob navia
Guest
Posts: n/a

 11-29-2005
Raghu a écrit :
> Hello all,
>
> I need your help on how to redefine teh function of arithmetic operators in
> C.
>
> for example : if there is an equation c = a/b;
>
> i want to execute my own algorithm for division operator.
> I am compelled to use the native C , instead of calling functions or using
> macros for doing arithmetic operations.
> I mean i was compelled not to use c =MYDIV(a,b) or somewthing like that.
>
> This i needeed to simulate floating point unit of MPC5554 on PC.In MPC the
> way the rounding , overflow,errors dealt is different from those used in P4
> or AMD.
>
> so i need to simulate the floating point arithmetic of MPC5554 , when i want
> to simualte the code designed for it.
> I hope i could able express my question clearly.
>
>
> Thanks and Best Regards
> Raghu.
>
>
>

I am afraid to start a new flame war here, but if you accept
to use *non-standard* C, the lcc-win32 compiler allows you to

Of course this is an extension, but it is compatible with the standard.
No new keywords are used.

http://www.cs.virinia.edu/~lcc-win32

Keith Thompson
Guest
Posts: n/a

 11-29-2005
jacob navia <(E-Mail Removed)> writes:
> Raghu a écrit :
>> I need your help on how to redefine teh function of arithmetic
>> operators in
>> C.
>> for example : if there is an equation c = a/b;

[snip]
>>

> I am afraid to start a new flame war here, but if you accept
> to use *non-standard* C, the lcc-win32 compiler allows you to
>
> Of course this is an extension, but it is compatible with the
> standard. No new keywords are used.

In what sense is this "without leaving the framework of C"?

it, you can do without it (with ordinary function calls).

C-like language supported by lcc-win32, and others. Standard C itself
does not. (And of course lcc-win32, as the name implies, is limited
to 32-bit Windows systems; see comp.compilers.lcc for more
information.)

Note that a conforming implementation may have extensions (including
additional library functions), provided they do not alter the behavior
of any strictly conforming program, so lcc-win32 may still qualify as
a C compiler.

--
Keith Thompson (The_Other_Keith) http://www.velocityreviews.com/forums/(E-Mail Removed) <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

jacob navia
Guest
Posts: n/a

 11-29-2005
Keith Thompson a écrit :
>
> You don't really *need* operator overloading; anything you can do with
> it, you can do without it (with ordinary function calls).

This is of course true.

It is just a matter of measure.

Consider this:
qfloat a;
qfloat q = (sqrt(a+1)/sqrt(a-1))*(cos(a+1)/cos(a-1));

compared with:

tmp2 = sqrtq(tmp1);
tmp3 = qsub(a,1);
tmp4 = sqrt(tmp3);
tmp5 = qdiv(tmp1,tmp3);
tmp6 = cosq(tmp1);
tmp7 = cosq(tmp3);
tmp8 = qdiv(tmp6,tmp7);
result = qmul(tmp8,tmp5);

This does the *same* stuff but which expression would
you prefer???

And above all, which expression would you like to MAINTAIN?

But sugar is an essential component of meals !!!

Of course you can abuse it, (as you can abuse *real* sugar!)
but for *many* applications is the only way to go!

Being able to define new types of numbers is one of them.
Otherwise, the C syntax is totally awkward.

jacob

Randy Howard
Guest
Posts: n/a

 11-29-2005
jacob navia wrote
(in article <438c2df2\$0\$29185\$(E-Mail Removed)>):

> I am afraid to start a new flame war here,

Actually, you seem to revel in it.

> but if you accept to use *non-standard* C,

(thereby leaving the 'framework of C')

> the lcc-win32 compiler allows you to

Incorrect. You are using extensions so non-standard that they
ONLY work on a single compiler, for a single operating system.

Even the folks that use gcc extensions are far better off than
that, nevermind the POSIX crowd, which has it golden in
comparison.

> ... but it is compatible with the standard.

No, it isn't. Try compiling it on a compiler from anyone else.
So much for that theory.

--
"The power of accurate observation is called cynicism by those
who have not got it." - George Bernard Shaw

Jack Klein
Guest
Posts: n/a

 11-29-2005
On Tue, 29 Nov 2005 11:31:19 +0100, jacob navia
<(E-Mail Removed)> wrote in comp.lang.c:

> Raghu a écrit :
> > Hello all,
> >
> > I need your help on how to redefine teh function of arithmetic operators in
> > C.
> >
> > for example : if there is an equation c = a/b;
> >
> > i want to execute my own algorithm for division operator.
> > I am compelled to use the native C , instead of calling functions or using
> > macros for doing arithmetic operations.
> > I mean i was compelled not to use c =MYDIV(a,b) or somewthing like that.
> >
> > This i needeed to simulate floating point unit of MPC5554 on PC.In MPC the
> > way the rounding , overflow,errors dealt is different from those used in P4
> > or AMD.
> >
> > so i need to simulate the floating point arithmetic of MPC5554 , when i want
> > to simualte the code designed for it.
> > I hope i could able express my question clearly.
> >
> > Your help and advice is sought after at the earliest.
> >
> > Thanks and Best Regards
> > Raghu.
> >
> >
> >

> I am afraid to start a new flame war here, but if you accept
> to use *non-standard* C, the lcc-win32 compiler allows you to
>
> Of course this is an extension, but it is compatible with the standard.
> No new keywords are used.
>
> http://www.cs.virinia.edu/~lcc-win32

Jacob, as much as I admire lcc-win32, I was not aware that you had a
cross compiler that output PowerPC executables.

--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html
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alt.comp.lang.learn.c-c++
http://www.contrib.andrew.cmu.edu/~a...FAQ-acllc.html

Richard Bos
Guest
Posts: n/a

 11-29-2005
jacob navia <(E-Mail Removed)> wrote:

> Consider this:
> qfloat a;
> qfloat q = (sqrt(a+1)/sqrt(a-1))*(cos(a+1)/cos(a-1));
>
> compared with:

> This does the *same* stuff but which expression would
> you prefer???

Neither. I would prefer not to use superfluous not-C. Even more than
that I would prefer not-C not to be discussed here.

Richard

jacob navia
Guest
Posts: n/a

 11-29-2005
Jack Klein wrote:
> On Tue, 29 Nov 2005 11:31:19 +0100, jacob navia
> <(E-Mail Removed)> wrote in comp.lang.c:
>
>
>>Raghu a écrit :
>>
>>>Hello all,
>>>
>>>I need your help on how to redefine teh function of arithmetic operators in
>>>C.
>>>
>>>for example : if there is an equation c = a/b;
>>>
>>>i want to execute my own algorithm for division operator.
>>>I am compelled to use the native C , instead of calling functions or using
>>>macros for doing arithmetic operations.
>>>I mean i was compelled not to use c =MYDIV(a,b) or somewthing like that.
>>>
>>>This i needeed to simulate floating point unit of MPC5554 on PC.In MPC the
>>>way the rounding , overflow,errors dealt is different from those used in P4
>>>or AMD.
>>>
>>>so i need to simulate the floating point arithmetic of MPC5554 , when i want
>>>to simualte the code designed for it.
>>>I hope i could able express my question clearly.
>>>
>>>
>>>Thanks and Best Regards
>>>Raghu.
>>>
>>>
>>>

>>
>>I am afraid to start a new flame war here, but if you accept
>>to use *non-standard* C, the lcc-win32 compiler allows you to
>>
>>Of course this is an extension, but it is compatible with the standard.
>>No new keywords are used.
>>
>>http://www.cs.virinia.edu/~lcc-win32

>
>
> Jacob, as much as I admire lcc-win32, I was not aware that you had a
> cross compiler that output PowerPC executables.
>

AAAAArgh!!

You are right. My fault.

jacob

Kenny McCormack
Guest
Posts: n/a

 11-29-2005
In article <(E-Mail Removed)4all.nl>,
Richard Bos <(E-Mail Removed)> wrote:
>jacob navia <(E-Mail Removed)> wrote:
>
>> Consider this:
>> qfloat a;
>> qfloat q = (sqrt(a+1)/sqrt(a-1))*(cos(a+1)/cos(a-1));
>>
>> compared with:

>
>> This does the *same* stuff but which expression would
>> you prefer???

>
>Neither. I would prefer not to use superfluous not-C. Even more than
>that I would prefer not-C not to be discussed here.
>
>Richard

Because we all know how dangerous thoughts and words can be to an
established order.