Re: EndianU32_NtoB
Re: EndianU32_NtoB
- Subject: Re: EndianU32_NtoB
- From: "Sean McBride" <email@hidden>
- Date: Fri, 30 Oct 2009 13:51:18 -0400
- Organization: Rogue Research Inc.
On 10/30/09 6:29 PM, gMail.com said:
>Cool. Thanks. I did the following, either when I read from the disk and when
>I write to the disk
>
>Read unsigned int in case of PPC
> outValue[i] = EndianU32_NtoB(inValue[i]);
>
>Write unsigned int in case of PPC
> outValue[i] = EndianU32_BtoN(inValue[i]);
>
>Read float in case of PPC
> EndianDouble_NtoB(outValue[i], inValue[i]);
>
>Write float in case of PPC
> EndianDouble_BtoN(outValue[i], inValue[i]);
That's fine.
>#define EndianDouble_BtoN(o,i)
>((Float64*)&o)[0]=CFConvertFloat64SwappedToHost(((CFSwappedFloat64*)&i)[0]);
>
>#define EndianDouble_NtoB(o,i)
>((CFSwappedFloat64*)&o)[0]=CFConvertFloat64HostToSwapped(((Float64*)&i)[0]);
Not sure about that. I think you might be breaking 'struct aliasing
rules'. What happens if you add the -Wstrict-aliasing warning flag?
That's why I suggested using a union. See also:
<http://cellperformance.beyond3d.com/articles/2006/06/understanding-
strict-aliasing.html>
--
____________________________________________________________
Sean McBride, B. Eng email@hidden
Rogue Research www.rogue-research.com
Mac Software Developer Montréal, Québec, Canada
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden