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: [email protected] www.syncsort.com Check out our Knowledge Base at www.syncsort.com/support Syncsort aims for the best product and service experience. We welcome your feedback. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] 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 <[email protected]> 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 <[email protected]> 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: [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 19:59 >> 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 > > ---------------------------------------------------------------------- > 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
