[PATCH] savage: Avoid unnecessary float calculation in video display

[Tormod Volden]

On Sat, Sep 17, 2011 at 1:03 PM, walter harms wrote:
>>      if (S3_MOBILE_TWISTER_SERIES(psav->Chipset)
>> -        && psav->FPExpansion) {
>> -        drw_w = (((float)(drw_w * psav->XExp1)/(float)psav->XExp2)+1);
>> -        drw_h = (float)(drw_h * psav->YExp1)/(float)psav->YExp2+1;
>> -        dstBox->x1 = (float)(dstBox->x1 * psav->XExp1)/(float)psav->XExp2;
>> -        dstBox->y1 = (float)(dstBox->y1 * psav->YExp1)/(float)psav->YExp2;
>> +     && psav->FPExpansion) {
>> +     drw_w = (drw_w * psav->XExp1) / psav->XExp2 + 1;
>> +     drw_h = (drw_h * psav->YExp1) / psav->YExp2 + 1;
>
> to improve readability i would suggest a writing like this:
>
>        scale=  psav->XExp1/psav->XExp2;
>        drw_w = 1+  drw_w *scale ;
>        drw_h = 1+  drw_h *scale ;

Hi Walter,

Thanks for your review and comments. Note that the scale is different
for x and y so it would need two scale variables in your example. I
don't want to put too much effort into beautifying the code, just make
the "Old" and "New" chipset code path match.

>
> the price of float is small these days  ...

This driver is not for today's hardware :) Yes, I guess there is no
visible performance win, but it makes the code more consistent and
readable.

Cheers,
Tormod