lkml.org 
[lkml]   [2001]   [Apr]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: which gcc version?
On Thu, Apr 05, 2001 at 07:39:14PM +0530, Manoj Sontakke wrote:
> hi
>
> On Thu, 5 Apr 2001, Alexander Viro wrote:
> > On Thu, 5 Apr 2001, Manoj Sontakke wrote:
> >
> > > Hi
> > > I am getting linker error "undefined reference to __divdi3".
> > > This is because c = a/b; where a,b,c are of type "long long"
> > > I understand this is gcc problem.
> > > I am doing this on a pentium with gcc -v = egcs-2.91.66
> >
> > Don't do it in the kernel. It has nothing to gcc version.
>
> Addition and subtraction works fine. The problem is with multiplication
> and division. I am doing this to avoid floating point calculation and
> doing fixed point calculation. The rage is large enough to need "long
> long" Any other way to achieve this?

How arbitrary is the divisor ?
Not by change a power-of-two ?

If it is arbitrary, how large ?
The printk() contains support routine doing longlong/int
division when a) speed is *not* important, b) divisor is
sufficiently small, and I think c) divisor is positive.

When you look at that code, you should begin to grasp,
what kind of monster is the longlong/longlong code at -lgcc ...
(and why gcc doesn't produce inline code for it.)

> thanks
> manoj

/Matti Aarnio
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:24    [W:0.062 / U:2.408 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site