I Know in access register mode  B2 ALWAYS implies corresponding AR

thanks 

-----Original Message-----
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf
Of Blaicher, Christopher Y.
Sent: Tuesday, March 06, 2012 4:27 PM
To: IBM-MAIN@bama.ua.edu
Subject: Re: LAE instruction

Yes, set the SAC bits first, otherwise the access register is set with
zeros.

The other point that others are making is that when in access register mode,
the instruction format is VERY important.

LAE  R3,(R4)  - loads the value from the location pointed to by R4 in the
home address space into R3 and sets the AR3 register with 0, regardless of
the SAC values at the time.

LAE  R3,0(0,R4)   - loads the value from the location pointed to by R4 in
the address space indicated by access register AR4, if the SAC value is
other than b'00', and loads AR3 with the SAC appropriate value.

Even if you never write access register sensitive code, it is far better to
use the correct instruction format.  A) It gets you in the habit; and B) You
never know when a piece of code may become access register sensitive.

Chris Blaicher
Senior Software Engineer, Software Services
Syncsort Incorporated
50 Tice Boulevard, Woodcliff Lake, NJ 07677
P: 201-930-8260  |  M: 512-627-3803    
E: cblaic...@syncsort.com

www.syncsort.com

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Syncsort aims for the best product and service experience. 
We welcome your feedback.


-----Original Message-----
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf
Of Micheal Butz
Sent: Tuesday, March 06, 2012 3:07 PM
To: MVS List Server 1
Subject: Re: LAE instruction

Sorry misspelled the name John McKown. Excuse me

Sent from my iPhone

On Mar 6, 2012, at 4:00 PM, Micheal Butz <michealb...@optonline.net> wrote:

> John Mckiwns reply was a explanation of the SAC inst.    Which I am aware
of
> 
> The Doc for LAE says the inst the functionality is dependent on PSW bits
> 
> 16 17 address space control bits these are set by the SAC inst
> 
> 
> So my original question remains does
> 
> Should address space control buts be set via the sac before executing the
LAE 
> 
> 
> Sent from my iPhone
> 
> On Mar 6, 2012, at 3:37 PM, Rob Scott <rsc...@rocketsoftware.com> wrote:
> 
>> John McKown's reply covered these points very well
>> 
>> Rob Scott
>> Lead Developer
>> Rocket Software
>> 275 Grove Street * Newton, MA 02466-2272 * USA
>> Tel: +1.781.684.2305
>> Email: rsc...@rs.com
>> Web: www.rocketsoftware.com
>> 
>> 
>> -----Original Message-----
>> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On
Behalf Of Micheal Butz
>> Sent: 06 March 2012 19:59
>> To: IBM-MAIN@bama.ua.edu
>> Subject: Re: LAE instruction
>> 
>> Thanks
>> 
>> Regarding my questions
>> 
>> The doc says the inst is dependent
>> On address space control bits which is set by the SAC inst. 
>> 
>> Secondly seems like the displacement doesn't play a role in the inst
>> 
>> Sent from my iPhone
>> 
>> On Mar 6, 2012, at 2:49 PM, Rob Scott <rsc...@rocketsoftware.com> wrote:
>> 
>>>> You have coded "LAE   R3,0(R4)" - which is the same as "LAE
R3,(R4,R0)"
>>> 
>>> Should read :
>>> 
>>> You have coded "LAE   R3,0(R4)" - which is the same as "LAE
R3,0(R4,R0)"
>>> 
>>> Rob Scott
>>> Lead Developer
>>> Rocket Software
>>> 275 Grove Street * Newton, MA 02466-2272 * USA
>>> Tel: +1.781.684.2305
>>> Email: rsc...@rs.com
>>> Web: www.rocketsoftware.com
>>> 
>>> 
>>> -----Original Message-----
>>> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On 
>>> Behalf Of Rob Scott
>>> Sent: 06 March 2012 19:47
>>> To: IBM-MAIN@bama.ua.edu
>>> Subject: Re: LAE instruction
>>> 
>>> Commas are *very* important in AR-mode
>>> 
>>> You have coded "LAE   R3,0(R4)" - which is the same as "LAE
R3,(R4,R0)"
>>> 
>>> Coded that way there is no automatic way that AR3 is going to inherit
the AR4 value.
>>> 
>>> You need : "LAE   R3,0(,R4)"
>>> 
>>> This will ensure that AR3 is populated from the AR for the referenced
base register R4.
>>> 
>>> 
>>> Rob Scott
>>> Lead Developer
>>> Rocket Software
>>> 275 Grove Street * Newton, MA 02466-2272 * USA
>>> Tel: +1.781.684.2305
>>> Email: rsc...@rs.com
>>> Web: www.rocketsoftware.com
>>> 
>>> 
>>> -----Original Message-----
>>> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On 
>>> Behalf Of Micheal Butz
>>> Sent: 06 March 2012 19:05
>>> To: IBM-MAIN@bama.ua.edu
>>> Subject: LAE instruction
>>> 
>>> Hi,
>>> 
>>> 
>>> 
>>> I have two part question regarding the LAE instruction
>>> 
>>> 
>>> 
>>> .         What would the sac value e.g. 256,512,768 have to be that when
>>> using the LAE instructions with the following operands LAE  3,0(R4) 
>>> would
>>> AR3 get loaded with AR4
>>> 
>>> 
>>> 
>>> .         Second what value does the displacement play in the
instruction
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>>               Thanks     
>>> 
>>> 
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