Re: [PATCH 5/6] IIO:hwmon interface client driver.

[Russell King - ARM Linux]

On Mon, Oct 24, 2011 at 04:58:49PM +0100, Jonathan Cameron wrote:
> On 10/24/11 16:39, Guenter Roeck wrote:
> > Is div_s64 really necessary, or would
> > 
> > 		result = (long)val * (long)scaleint +
> > 			DIV_ROUND_CLOSEST((s64)val * (s64)scalepart,
> > 					 1000000000LL);
> > 
> > work as well ?
> Not if you want it to compile on arm v5 by the look of it.
> 
> ERROR: "__aeabi_ldivmod" [drivers/staging/iio/iio_hwmon.ko] undefined!

You know, div64 is there to deal with the case of _sanely_ dividing
a 64-bit number by a 32-bit number - there should be absolutely no
question about _not_ using it if that's the operation you are wanting
to perform.

Expecting gcc to do a better job without using div64 is just asking for
bad code on 32-bit platforms.
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