Port-vax archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: VAX RPB (Restart Parameter Block)



From: Roger Ivie <rivie%ridgenet.net@localhost>

>On Wed, 6 Feb 2013, Holm Tiffe wrote:
>> That's crazy, isn't it?
>> Never seen such an instruction on another architecture that just is testing
>> the least significant bit. Maybe that's useful for some shift operations,
>> but I think there are better commands for this.
>
>The interlocked queue instructions use the least-significant bit of the
>first longword of the queue header to manage the interlock.

Also, VMS system calls return success/failure in the LSB of R0.
So you actually use this instruction really a lot in practice.

John Wilson
D Bit


Home | Main Index | Thread Index | Old Index