[U-Boot] [PATCH] arm: add 64-64 bit divider

Marek Vasut marek.vasut at gmail.com
Wed Aug 31 17:33:59 CEST 2011


On Wednesday, August 31, 2011 05:27:46 PM Mike Frysinger wrote:
> On Wednesday, August 31, 2011 11:11:00 Marek Vasut wrote:
> > On Wednesday, August 31, 2011 04:32:52 PM Mike Frysinger wrote:
> > > On Wednesday, August 31, 2011 06:38:50 Che-Liang Chiou wrote:
> > > > This patch adds a 64-64 bit divider that supports ARMv4 and above.
> > > 
> > > why ?  if you're doing 64 bit divides, chances are you're doing
> > > something fundamentally wrong.  perhaps you should fix that instead.
> > 
> > Oh come on Mike, what about too big NAND memories ?
> 
> Linux hasnt had a problem supporting large NAND without a 64bit divide
> routine.  why are we special ?

Because someone (?) has to fix the code that uses do_div() ;-)

> 
> > > this is also why we have the do_div() helper macro.
> > > 
> > > so until your changelog documents the actual *reason* for this patch:
> > > NAK
> > 
> > The reason is likely it's faster.
> 
> let's see actual #'s

True, will you make the measurements? ;-)

Still, I'd stick with the plain-C version, it doesn't matter I guess.

Cheers
> -mike


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