Re: quick question on 64-bit values with 32-bit inline assembly

["Maciej W. Rozycki" <macro@linux-mips.org>]

On Mon, 28 Jan 2008, M. Warner Losh wrote:

> : The architecture manual doesn't make a difference between 32-bit and
> : 64-bit for rdhwr.  My reading is the entire 64-bit would have to be
> : transfered.
> 
> Hmmm, the manual I have specifically calls out the difference...

 Concerning implementation-specific registers number 30 and 31 the MIPS64 
architecture manual states that if the register in question is 64-bit and 
64-bit operations are enabled then it is copied as is and otherwise it is 
sign-extended from the bit #31.  Note that the kernel mode implies 64-bit 
operations enabled.

  Maciej