Messages in this thread | | | Date | Mon, 21 Jan 2008 10:15:12 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] x86_64: check if Tom2 is enabled |
| |
Cyrill Gorcunov wrote: > [Andi Kleen - Mon, Jan 21, 2008 at 07:03:27PM +0100] > | > | > is it possible to change 'l' and 'h' to 'low' and 'high'? > | > 'cause 'l' does look like '1' (one) number... > | > | It would be fine for me for someone to implement safe_rdtscll() and get rid > | of l and h everywhere. IMHO all the l and h accesses of MSRs are just harder > | to read and error prone over the ll 64bit variants. > | > | But I didn't want to add it just for this. > | > > clear enough, thanks >
Actually, I think it depends on the specific MSR - some use the halves for different data, whereas others treat it as a large 64-bit object.
Ironically enough, the way the MSR interfaces were carried into the 64-bit world makes the situation worse on 64 bits; edx:eax is the common way to represent a 64-bit value on 32 bits.
-hpa
| |