lkml.org 
[lkml]   [1999]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Can and should the kernel HZ value be changed?
On Thu, Jan 07, 1999 at 01:13:16PM -0500, Richard B. Johnson wrote:
> On Thu, 7 Jan 1999, Chris Wedgwood wrote:
> > Oh -- and gcc sucks rocks at geenrate long long code. Not helped by
> > the fact ia32 is a horribly register starved processor.
>
> Not so. Long long stuff is as good as anyone should expect on a 32-bit
> machine. It's a lot better than 680xx stuff I've seen from compilers.

> [code example]

I've used GCC's long long stuff, and found it acceptable but not great.
I was about to write about how terrible it is, but I just tried some
tests and found the code to be quite acceptable.

There are some optimisations it's not at all good at, but on the whole
it's ok. I have written time critical code which uses long long for a
few things, where appropriate. Then again, I did tweak the compiler to
produce better code in the cases triggered by my program.

Just don't expect to divide two long longs efficiently -- the ia32
doesn't have good hardware support for that, which is why it's out of
line.

-- Jamie

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

\
 
 \ /
  Last update: 2005-03-22 13:49    [W:0.030 / U:0.480 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site