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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

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