The displacement does play a part. It is added into the other values to get the resultant value in the register. The fact that +0 does not affect the resultant value is not, theoritically, relevant. If the displacement were other than zero, the effect on the result would be obvious. So the displacement value of 0 in the current instruction does not affect the resultant value in the results register. But that can't be generalized to say that the displacement "doesn't play a role".
BTW, if you want to load the contents of GPR3 with AR4, then you can use the EAR register. EAR R3,R4 will do it. If you want to copy the contents of AR4 into AR3, you can do it if you have a "free" register with two instructions: EAR R?,R4; SAR R3,R? . Unlike LAE, this will work in any AR mode and any AMODE. I generally use R0 for this sort of thing due to its general uselessness for much of anything other than some parameter passing. I normally use register equates, so I use AR4 instead of R4. I also tend to use something like R1_32 or R1_64 instead of R1 and use HLASM's TYPECHECK(REGISTER) so that I get messages if I don't use the proper version of the equate with the specific instruction. I'm a bit OCD on that. -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * [email protected] * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM > -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[email protected]] On Behalf Of Micheal Butz > Sent: Tuesday, March 06, 2012 1:59 PM > To: [email protected] > 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 > <[email protected]> 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: [email protected] > > Web: www.rocketsoftware.com > > > > > > -----Original Message----- > > From: IBM Mainframe Discussion List > [mailto:[email protected]] On Behalf Of Rob Scott > > Sent: 06 March 2012 19:47 > > To: [email protected] > > 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: [email protected] > > Web: www.rocketsoftware.com > > > > > > -----Original Message----- > > From: IBM Mainframe Discussion List > [mailto:[email protected]] On Behalf Of Micheal Butz > > Sent: 06 March 2012 19:05 > > To: [email protected] > > 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 > > > > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access > instructions, send email to [email protected] with the > message: INFO IBM-MAIN > > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access > instructions, send email to [email protected] with the > message: INFO IBM-MAIN > > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
