[Info-vax] Listeners in VMS Basic, was: Re: Integrity iLO Configuration?

[Arne Vajhøj]

On 7/12/2021 1:11 PM, abrsvc wrote:
> On Monday, July 12, 2021 at 12:46:27 PM UTC-4, abrsvc wrote:
>> On Monday, July 12, 2021 at 12:43:13 PM UTC-4, abrsvc wrote:
>>> On Monday, July 12, 2021 at 12:28:37 PM UTC-4, Arne Vajhøj wrote:
>>>> On 7/12/2021 12:17 PM, abrsvc wrote:
>>>>> On Monday, July 12, 2021 at 11:02:35 AM UTC-4, Arne Vajhøj wrote:
>>>>>> On 7/12/2021 1:34 AM, Simon Clubley wrote:
>>>>>>> On 2021-07-10, abrsvc <dansabr... at yahoo.com> wrote:
>>>>>>>>> But I wonder why MOVZWL and not just MOVL!
>>>>>>>>
>>>>>>>> IRRC, the MOVZWL will take less memory since the immediate value will be smaller.
>>>>>>>
>>>>>>> It would be amusing if the more efficient sequences get translated
>>>>>>> to less efficient sequences on Alpha and above when using the Macro-32
>>>>>>> compiler and if a less efficient sequence on VAX actually translates
>>>>>>> to a more efficient sequence on Alpha and above. :-)
>>>>>> On Alpha both end up as:
>>>>>>
>>>>>> MOV 1, R0
>>>>>
>>>>> There is no "mov" on Alpha. What you will end up with is a load/store combination.

>>>> .entry z1,^m<r2,r3,r4,r5>
>>>> movl #1,r0
>>>> ret
>>>> .entry z2,^m<r2,r3,r4,r5>
>>>> movzwl #1,r0

>>>> gave me:
>>>>
>>>> .PSECT $CODE, QUAD, PIC, CON, REL,
>>>> LCL, SHR, EXE, RD, NOWRT
>>>> 0000 Z1::

>>>> 47E03400 0024 MOV 1, R0

>>>> 0050 Z2::

>>>> 47E03400 0074 MOV 1, R0

>>> I stand corrected, but not in the way you think. The MOV FP,SP is actually a BIS FP,FP,SP instruction.
>>> While I can't recall what the Immediate sequence would be for MOV 1,RO, it too would be another instruction.
>>> The MOV is for the human reader and is a pseudo instruction.

>> Replying to myself because the memory cell recovered...
>>
>> The immediate load for the value 1 is likely LDA R0, 1(R31) ! recall that R31 = 0
> 
> OK.  Create a main program that does a JSB into the routines you have listed above and use the debugger showing the instructions.
> I was again wrong.  The MOV 1,R0 is actually also a BIS instruction as follows:  BIS R31,#X01,R0

R0 = always zero R31 OR 1

does the job.

> Note that the same BIS instruction is created in both cases (MOVL and MOVSWL) on Alpha.

Yes.

> If I get time, I will boot up the VAX and show the code generated there as well.

But aren't both MOVL and MOVZWL real instructions on VAX?

Arne