Re: Assembler theology question
No. I left the comma out intentionally. At 6/1/2023 02:06 PM, you wrote: ? ITYM L R10,PSATOLD-PSA(,0) -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of David Cole [dbc...@colesoft.com] Sent: Thursday, June 1, 2023 1:49 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Assembler theology question WRT: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB In the specific case of the PSA, there is no need to load a base register. Also, I probably wouldn't bother with a USING. My favorite instruction for this is: L R10,PSATOLD-PSA(0) Note, providing the "0" for the index register prevents that rather annoying ASMA306W message. Dave Cole At 6/1/2023 12:57 PM, Seymour J Metz wrote: >R9? I might believe R0. >In general, I prefer the code with USING over the code with explicit >offset and base, although I might use the second if I'm only going >to reference a single field in the control block. If I need to >access multiple instances of the same control block, I would prefer >to use a labeled USING or, in some cases, a labeled dependent USING. > USING PSA,R0 > L R10,PSATOLD Get current TCB > DROP R0 >THIS USING TCB,R10 > L R9,THIS.TCBJSCB Get JSCB > l R11,THIS.TCBOTCB >THAT USING TCB,R11 >-- >Shmuel (Seymour J.) Metz >http://mason.gmu.edu/~smetz3 > >>From: IBM Mainframe Assembler List >>[ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Phil Smith III >>[li...@akphs.com] >>Sent: Thursday, June 1, 2023 12:24 PM >>To: ASSEMBLER-LIST@LISTSERV.UGA.EDU >>Subject: Assembler theology question >>We've all seen (and written!) code like this: >> USING PSA,R9 >> L R10,PSATOLD Get current TCB >> DROP R9 >> USING TCB,R10 >> L R9,TCBJSCB Get JSCB >> DROP R10 >>I've also seen (and probably written) the equivalent: >> L R10,PSATOLD-PSA(,R9)Get current TCB >> L R9,TCBJSCB-TCB(,R1) Get JSCB >>I like the latter because it's tighter to read, reduces the USING >>map, keeps you out of trouble if you decide to use R9 or R10 for >>something global, etc. But I can also see a theological argument >>that you really *are* using (USING?) the control block. >>Thoughts? (Yes, I *said* it was theology, so I'm prepared for >>religious arguments!)
Re: Assembler theology question
I realize that it takes up room on a page/screen, but there is an option to display active USINGs, and that makes it easier to catch certain types of errors. Defensive programming is your friend, in any language. I'm not convinced that it's any easier to shoot yourself in the foot with HLASM than with, e.g., FORTRAN IV. Each language has its own pitfalls. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Steve Smith [sasd...@gmail.com] Sent: Friday, June 2, 2023 11:07 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Assembler theology question On Thu, Jun 1, 2023 at 10:25 PM Phil Smith III wrote: > See, I knew this would get into theology! > > > > I guess I wasn't clear enough: I only meant this for when you're doing a > single instruction, something that will never expand-this > kind of "flyby" of a control block on the way to another. Clearly if > you're doing a bunch, it makes more sense to do the USING. > > > > What I meant about "keeping out of trouble" is that if you make a change > later and decide to use one of the registers as a base > semi-globally, then having this single-line USING makes for a larger > change. Of course you'll argue (and I'll agree) that this might > be good, as it might keep you from stepping on that base, so I guess that > doesn't really apply. > This shouldn't be an issue. You should always DROP when the code that was written for is done with it. Leaving hanging USINGs that may or may not be valid anymore certainly is looking for trouble. So, now we're talking about 3 statements vs. 1, and I think that tilts the answer towards the 1-instruction form. But I agree with most of the comments about how it depends on various other considerations. imho, I tend to use the one-line version for common things, but I like USINGs for more exotic control blocks. > > > > Jeremy's comment about typos is certainly an interesting point, though > it'll likely come clear pretty fast once run! I'm not sure > that three lines of code vs. one represents a net savings in potential > typos, either, TBH. > Yeah, you could typo the USING just as easily as the instruction reference. > > > > I sure do love assembler. > I'm going to presume you mean that both literally and ironically (I agree dually). While you can write gibberish in any language, only assembler opens up the myriad possibilities of screwing up register usage. sas
Re: Assembler theology question
On Thu, Jun 1, 2023 at 10:25 PM Phil Smith III wrote: > See, I knew this would get into theology! > > > > I guess I wasn't clear enough: I only meant this for when you're doing a > single instruction, something that will never expand-this > kind of "flyby" of a control block on the way to another. Clearly if > you're doing a bunch, it makes more sense to do the USING. > > > > What I meant about "keeping out of trouble" is that if you make a change > later and decide to use one of the registers as a base > semi-globally, then having this single-line USING makes for a larger > change. Of course you'll argue (and I'll agree) that this might > be good, as it might keep you from stepping on that base, so I guess that > doesn't really apply. > This shouldn't be an issue. You should always DROP when the code that was written for is done with it. Leaving hanging USINGs that may or may not be valid anymore certainly is looking for trouble. So, now we're talking about 3 statements vs. 1, and I think that tilts the answer towards the 1-instruction form. But I agree with most of the comments about how it depends on various other considerations. imho, I tend to use the one-line version for common things, but I like USINGs for more exotic control blocks. > > > > Jeremy's comment about typos is certainly an interesting point, though > it'll likely come clear pretty fast once run! I'm not sure > that three lines of code vs. one represents a net savings in potential > typos, either, TBH. > Yeah, you could typo the USING just as easily as the instruction reference. > > > > I sure do love assembler. > I'm going to presume you mean that both literally and ironically (I agree dually). While you can write gibberish in any language, only assembler opens up the myriad possibilities of screwing up register usage. sas
Re: Assembler theology question
Dave Cole wrote Also, I probably wouldn't bother with a USING. My favorite instruction for this is: L R10,PSATOLD-PSA(0) Note, providing the "0" for the index register prevents that rather annoying ASMA306W message. ASMA306W is for overlapping usings. So I don't think it would apply to this "L" which is unaffected by USINGs. And if you're referring to ASMA309W, I'd say that it's not right -- You need 0 as a base register to prevent ASMA306W. And of course you can not use FLAG(PAGE0) if you don't like that message. Here are the examples that come to mind (I removed the ASMA435I messages), using FLAG(PAGE0,NOUSING0): 5880 021C 021C 4 L R8,PSATOLD-PSA ** ASMA309W Operand PSATOLD-PSA resolved to a displacement with no base register 0004 5880 021C 021C 5 L R8,PSATOLD-PSA(0) ** ASMA309W Operand PSATOLD-PSA(0) resolved to a displacement with no base register 0008 5880 021C 021C 6 L R8,PSATOLD-PSA(,0) 000C 5880 021C 021C 7 L R8,PSATOLD-PSA(0,0) Peter Relson z/OS Core Technology Design
Re: Assembler theology question
See, I knew this would get into theology! I guess I wasn't clear enough: I only meant this for when you're doing a single instruction, something that will never expand-this kind of "flyby" of a control block on the way to another. Clearly if you're doing a bunch, it makes more sense to do the USING. What I meant about "keeping out of trouble" is that if you make a change later and decide to use one of the registers as a base semi-globally, then having this single-line USING makes for a larger change. Of course you'll argue (and I'll agree) that this might be good, as it might keep you from stepping on that base, so I guess that doesn't really apply. Jeremy's comment about typos is certainly an interesting point, though it'll likely come clear pretty fast once run! I'm not sure that three lines of code vs. one represents a net savings in potential typos, either, TBH. I sure do love assembler.
Re: Assembler theology question
In Thu, 1 Jun 2023, at 17:24, Phil Smith III wrote: > We've all seen (and written!) code like this: > USING PSA,R9 > L R10,PSATOLD Get current TCB > DROP R9 > > USING TCB,R10 > L R9,TCBJSCB Get JSCB > DROP R10 > > I've also seen (and probably written) the equivalent: > L R10,PSATOLD-PSA(,R9)Get current TCB > L R9,TCBJSCB-TCB(,R1) Get JSCB > > I like the latter because it's tighter to read, reduces the USING > map, keeps you out of trouble if you decide to use R9 or R10 > for something global, etc. How does using R9 or R10 globally cause a problem, unless you forget to place the "DROP" in the right place? I think I preferred to use USING/DROP. Also while I recognise that one has to be ultracareful when writing in assembler, keying lots of statements like L R9,TCBJSCB-TCB(,R1) all require one not to mistype the "-TCB(,R1)" part - which - and is this not an irony? - you did. Should have been (,R10). Using USING and DROP gives you nine or ten fewer opportunities to type an unnecessary or wrong character. -- Jeremy Nicoll - my opinions are my own.
Re: Assembler theology question
How does that eliminate the ASMA306W? From: IBM Mainframe Assembler List on behalf of David Cole Sent: Thursday, June 1, 2023 2:58 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Assembler theology question No. I left the comma out intentionally At 6/1/2023 02:06 PM, Seymour J Metz wrote: >? ITYM > L R10,PSATOLD-PSA(,0) > > > > >-- >Shmuel (Seymour J.) Metz >http://mason.gmu.edu/~smetz3 > > >From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] >on behalf of David Cole [dbc...@colesoft.com] >Sent: Thursday, June 1, 2023 1:49 PM >To: ASSEMBLER-LIST@LISTSERV.UGA.EDU >Subject: Re: Assembler theology question > >WRT: > L R10,PSATOLD-PSA(,R9)Get current TCB > L R9,TCBJSCB-TCB(,R1) Get JSCB > >In the specific case of the PSA, there is no need to load a base register. >Also, I probably wouldn't bother with a USING. My favorite >instruction for this is: > L R10,PSATOLD-PSA(0) > >Note, providing the "0" for the index register prevents that rather >annoying ASMA306W message. > >Dave Cole > > > > > > >At 6/1/2023 12:57 PM, Seymour J Metz wrote: > >R9? I might believe R0. > >In general, I prefer the code with USING over the code with explicit > >offset and base, although I might use the second if I'm only going > >to reference a single field in the control block. If I need to > >access multiple instances of the same control block, I would prefer > >to use a labeled USING or, in some cases, a labeled dependent USING. > > USING PSA,R0 > > L R10,PSATOLD Get current TCB > > DROP R0 > >THIS USING TCB,R10 > > L R9,THIS.TCBJSCB Get JSCB > > l R11,THIS.TCBOTCB > >THAT USING TCB,R11 > >-- > >Shmuel (Seymour J.) Metz > >http://mason.gmu.edu/~smetz3 > > > >>From: IBM Mainframe Assembler List > >>[ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Phil Smith III > >>[li...@akphs.com] > >>Sent: Thursday, June 1, 2023 12:24 PM > >>To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > >>Subject: Assembler theology question > >>We've all seen (and written!) code like this: > >> USING PSA,R9 > >> L R10,PSATOLD Get current TCB > >> DROP R9 > >> USING TCB,R10 > >> L R9,TCBJSCB Get JSCB > >> DROP R10 > >>I've also seen (and probably written) the equivalent: > >> L R10,PSATOLD-PSA(,R9)Get current TCB > >> L R9,TCBJSCB-TCB(,R1) Get JSCB > >>I like the latter because it's tighter to read, reduces the USING > >>map, keeps you out of trouble if you decide to use R9 or R10 for > >>something global, etc. But I can also see a theological argument > >>that you really *are* using (USING?) the control block. > >>Thoughts? (Yes, I *said* it was theology, so I'm prepared for > >>religious arguments!)
Re: Assembler theology question
No. I left the comma out intentionally At 6/1/2023 02:06 PM, Seymour J Metz wrote: ? ITYM L R10,PSATOLD-PSA(,0) -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of David Cole [dbc...@colesoft.com] Sent: Thursday, June 1, 2023 1:49 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Assembler theology question WRT: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB In the specific case of the PSA, there is no need to load a base register. Also, I probably wouldn't bother with a USING. My favorite instruction for this is: L R10,PSATOLD-PSA(0) Note, providing the "0" for the index register prevents that rather annoying ASMA306W message. Dave Cole At 6/1/2023 12:57 PM, Seymour J Metz wrote: >R9? I might believe R0. >In general, I prefer the code with USING over the code with explicit >offset and base, although I might use the second if I'm only going >to reference a single field in the control block. If I need to >access multiple instances of the same control block, I would prefer >to use a labeled USING or, in some cases, a labeled dependent USING. > USING PSA,R0 > L R10,PSATOLD Get current TCB > DROP R0 >THIS USING TCB,R10 > L R9,THIS.TCBJSCB Get JSCB > l R11,THIS.TCBOTCB >THAT USING TCB,R11 >-- >Shmuel (Seymour J.) Metz >http://mason.gmu.edu/~smetz3 > >>From: IBM Mainframe Assembler List >>[ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Phil Smith III >>[li...@akphs.com] >>Sent: Thursday, June 1, 2023 12:24 PM >>To: ASSEMBLER-LIST@LISTSERV.UGA.EDU >>Subject: Assembler theology question >>We've all seen (and written!) code like this: >> USING PSA,R9 >> L R10,PSATOLD Get current TCB >> DROP R9 >> USING TCB,R10 >> L R9,TCBJSCB Get JSCB >> DROP R10 >>I've also seen (and probably written) the equivalent: >> L R10,PSATOLD-PSA(,R9)Get current TCB >> L R9,TCBJSCB-TCB(,R1) Get JSCB >>I like the latter because it's tighter to read, reduces the USING >>map, keeps you out of trouble if you decide to use R9 or R10 for >>something global, etc. But I can also see a theological argument >>that you really *are* using (USING?) the control block. >>Thoughts? (Yes, I *said* it was theology, so I'm prepared for >>religious arguments!)
Re: Assembler theology question
I would use the first method, because it is more understandable for users* that don't have deep knowledge of both HLASM syntax and what the base field name is in the DSECTs. * like myself -Original Message- From: IBM Mainframe Assembler List On Behalf Of Phil Smith III Sent: Thursday, June 1, 2023 11:24 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Assembler theology question We've all seen (and written!) code like this: USING PSA,R9 L R10,PSATOLD Get current TCB DROP R9 USING TCB,R10 L R9,TCBJSCB Get JSCB DROP R10 I've also seen (and probably written) the equivalent: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB I like the latter because it's tighter to read, reduces the USING map, keeps you out of trouble if you decide to use R9 or R10 for something global, etc. But I can also see a theological argument that you really *are* using (USING?) the control block. Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious arguments!)
Re: Assembler theology question
On 6/1/2023 9:24 AM, Phil Smith III wrote: Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious arguments!) The latter seems great when the field names are super short like PSATOLD-PSA or TCBJSCB-TCB as in your example. Modern control block field names are often much, much longer and the explicit specification of both long symbols on the same line can make the code both ugly and unwieldy. For example: MVC MyMsgTokenArea,MqaMosToken-MqaMsgOutSummary(R4) Copy token We use long, descriptive (CamelCase) symbol names in our products, so I use the first approach probably 96% of the time. That said, I will use the second approach for very simple stuff like loading PSATOLD. -- Phoenix Software International Edward E. Jaffe 831 Parkview Drive North El Segundo, CA 90245 https://www.phoenixsoftware.com/ This e-mail message, including any attachments, appended messages and the information contained therein, is for the sole use of the intended recipient(s). If you are not an intended recipient or have otherwise received this email message in error, any use, dissemination, distribution, review, storage or copying of this e-mail message and the information contained therein is strictly prohibited. If you are not an intended recipient, please contact the sender by reply e-mail and destroy all copies of this email message and do not otherwise utilize or retain this email message or any or all of the information contained therein. Although this email message and any attachments or appended messages are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by the sender for any loss or damage arising in any way from its opening or use.
Re: Assembler theology question
? ITYM L R10,PSATOLD-PSA(,0) -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of David Cole [dbc...@colesoft.com] Sent: Thursday, June 1, 2023 1:49 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Assembler theology question WRT: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB In the specific case of the PSA, there is no need to load a base register. Also, I probably wouldn't bother with a USING. My favorite instruction for this is: L R10,PSATOLD-PSA(0) Note, providing the "0" for the index register prevents that rather annoying ASMA306W message. Dave Cole At 6/1/2023 12:57 PM, Seymour J Metz wrote: >R9? I might believe R0. >In general, I prefer the code with USING over the code with explicit >offset and base, although I might use the second if I'm only going >to reference a single field in the control block. If I need to >access multiple instances of the same control block, I would prefer >to use a labeled USING or, in some cases, a labeled dependent USING. > USING PSA,R0 > L R10,PSATOLD Get current TCB > DROP R0 >THIS USING TCB,R10 > L R9,THIS.TCBJSCB Get JSCB > l R11,THIS.TCBOTCB >THAT USING TCB,R11 >-- >Shmuel (Seymour J.) Metz >http://mason.gmu.edu/~smetz3 > >>From: IBM Mainframe Assembler List >>[ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Phil Smith III >>[li...@akphs.com] >>Sent: Thursday, June 1, 2023 12:24 PM >>To: ASSEMBLER-LIST@LISTSERV.UGA.EDU >>Subject: Assembler theology question >>We've all seen (and written!) code like this: >> USING PSA,R9 >> L R10,PSATOLD Get current TCB >> DROP R9 >> USING TCB,R10 >> L R9,TCBJSCB Get JSCB >> DROP R10 >>I've also seen (and probably written) the equivalent: >> L R10,PSATOLD-PSA(,R9)Get current TCB >> L R9,TCBJSCB-TCB(,R1) Get JSCB >>I like the latter because it's tighter to read, reduces the USING >>map, keeps you out of trouble if you decide to use R9 or R10 for >>something global, etc. But I can also see a theological argument >>that you really *are* using (USING?) the control block. >>Thoughts? (Yes, I *said* it was theology, so I'm prepared for >>religious arguments!)
Re: Assembler theology question
WRT: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB In the specific case of the PSA, there is no need to load a base register. Also, I probably wouldn't bother with a USING. My favorite instruction for this is: L R10,PSATOLD-PSA(0) Note, providing the "0" for the index register prevents that rather annoying ASMA306W message. Dave Cole At 6/1/2023 12:57 PM, Seymour J Metz wrote: R9? I might believe R0. In general, I prefer the code with USING over the code with explicit offset and base, although I might use the second if I'm only going to reference a single field in the control block. If I need to access multiple instances of the same control block, I would prefer to use a labeled USING or, in some cases, a labeled dependent USING. USING PSA,R0 L R10,PSATOLD Get current TCB DROP R0 THIS USING TCB,R10 L R9,THIS.TCBJSCB Get JSCB l R11,THIS.TCBOTCB THAT USING TCB,R11 -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Phil Smith III [li...@akphs.com] Sent: Thursday, June 1, 2023 12:24 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Assembler theology question We've all seen (and written!) code like this: USING PSA,R9 L R10,PSATOLD Get current TCB DROP R9 USING TCB,R10 L R9,TCBJSCB Get JSCB DROP R10 I've also seen (and probably written) the equivalent: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB I like the latter because it's tighter to read, reduces the USING map, keeps you out of trouble if you decide to use R9 or R10 for something global, etc. But I can also see a theological argument that you really *are* using (USING?) the control block. Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious arguments!)
Re: Assembler theology question
On 6/1/23 12:24, Phil Smith III wrote: We've all seen (and written!) code like this: USING PSA,R9 L R10,PSATOLD Get current TCB DROP R9 USING TCB,R10 L R9,TCBJSCB Get JSCB DROP R10 I've also seen (and probably written) the equivalent: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB I like the latter because it's tighter to read, reduces the USING map, keeps you out of trouble if you decide to use R9 or R10 for something global, etc. But I can also see a theological argument that you really *are* using (USING?) the control block. Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious arguments!) I like the latter. Now if I can just remember it! -- R; <><
Re: Assembler theology question
WRT: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB In the specific case of the PSA, there is no need to load a base register. Also, I probably wouldn't bother with a USING. My favorite instruction for this is: L R10,PSATOLD-PSA(0) Note, providing the "0" for the index register prevents that rather annoying ASMA306W message. Dave Cole At 6/1/2023 12:57 PM, Seymour J Metz wrote: R9? I might believe R0. In general, I prefer the code with USING over the code with explicit offset and base, although I might use the second if I'm only going to reference a single field in the control block. If I need to access multiple instances of the same control block, I would prefer to use a labeled USING or, in some cases, a labeled dependent USING. USING PSA,R0 L R10,PSATOLD Get current TCB DROP R0 THIS USING TCB,R10 L R9,THIS.TCBJSCB Get JSCB l R11,THIS.TCBOTCB THAT USING TCB,R11 -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Phil Smith III [li...@akphs.com] Sent: Thursday, June 1, 2023 12:24 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Assembler theology question We've all seen (and written!) code like this: USING PSA,R9 L R10,PSATOLD Get current TCB DROP R9 USING TCB,R10 L R9,TCBJSCB Get JSCB DROP R10 I've also seen (and probably written) the equivalent: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB I like the latter because it's tighter to read, reduces the USING map, keeps you out of trouble if you decide to use R9 or R10 for something global, etc. But I can also see a theological argument that you really *are* using (USING?) the control block. Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious arguments!)
Re: Assembler theology question
R9? I might believe R0. In general, I prefer the code with USING over the code with explicit offset and base, although I might use the second if I'm only going to reference a single field in the control block. If I need to access multiple instances of the same control block, I would prefer to use a labeled USING or, in some cases, a labeled dependent USING. USING PSA,R0 L R10,PSATOLD Get current TCB DROP R0 THIS USING TCB,R10 L R9,THIS.TCBJSCB Get JSCB l R11,THIS.TCBOTCB THAT USING TCB,R11 -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Phil Smith III [li...@akphs.com] Sent: Thursday, June 1, 2023 12:24 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Assembler theology question We've all seen (and written!) code like this: USING PSA,R9 L R10,PSATOLD Get current TCB DROP R9 USING TCB,R10 L R9,TCBJSCB Get JSCB DROP R10 I've also seen (and probably written) the equivalent: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB I like the latter because it's tighter to read, reduces the USING map, keeps you out of trouble if you decide to use R9 or R10 for something global, etc. But I can also see a theological argument that you really *are* using (USING?) the control block. Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious arguments!)
SV: Assembler theology question
I too do both, depending on the situation. -Oprindelig meddelelse- Fra: IBM Mainframe Assembler List På vegne af John McKown Sendt: 1. juni 2023 18:31 Til: ASSEMBLER-LIST@LISTSERV.UGA.EDU Emne: Re: Assembler theology question I do both. I have the USING when I either want multiple fields from the same DSECT or I want to reference the same field(s) multiple times rather than storing them myself somewhere. This latter is mainly when I am writing "pure" code, such as in LPA and am short on dynamic storage. On Thu, Jun 1, 2023, 11:24 Phil Smith III wrote: > We've all seen (and written!) code like this: > USING PSA,R9 > L R10,PSATOLD Get current TCB > DROP R9 > > USING TCB,R10 > L R9,TCBJSCB Get JSCB > DROP R10 > > I've also seen (and probably written) the equivalent: > L R10,PSATOLD-PSA(,R9)Get current TCB > L R9,TCBJSCB-TCB(,R1) Get JSCB > > I like the latter because it's tighter to read, reduces the USING map, > keeps you out of trouble if you decide to use R9 or R10 for something > global, etc. But I can also see a theological argument that you really > *are* using (USING?) the control block. > > Thoughts? (Yes, I *said* it was theology, so I'm prepared for > religious > arguments!) >
Re: Assembler theology question
In this specific case (and others like it), I'd probably use the latter case as well (although I have done both). However, even for just a line or two, I much prefer using the former syntax (I also tend to use R14, R15 to traverse control blocks until I get to the end). Then again, I'm not sure how either syntax would "keep you out of trouble...". Could PUSH/POP help in that case? *Mark* On Thu, Jun 1, 2023 at 11:24 AM Phil Smith III wrote: > We've all seen (and written!) code like this: > USING PSA,R9 > L R10,PSATOLD Get current TCB > DROP R9 > > USING TCB,R10 > L R9,TCBJSCB Get JSCB > DROP R10 > > I've also seen (and probably written) the equivalent: > L R10,PSATOLD-PSA(,R9)Get current TCB > L R9,TCBJSCB-TCB(,R1) Get JSCB > > I like the latter because it's tighter to read, reduces the USING map, > keeps you out of trouble if you decide to use R9 or R10 for something > global, etc. But I can also see a theological argument that you really > *are* using (USING?) the control block. > > Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious > arguments!) >
Re: Assembler theology question
The second method is better; it's shorter (no USINGs). Simpler is better. Mike Shaw MVS/QuickRef Support Group Chicago-Soft, Ltd. On Thu, Jun 1, 2023 at 12:24 PM Phil Smith III wrote: > We've all seen (and written!) code like this: > USING PSA,R9 > L R10,PSATOLD Get current TCB > DROP R9 > > USING TCB,R10 > L R9,TCBJSCB Get JSCB > DROP R10 > > I've also seen (and probably written) the equivalent: > L R10,PSATOLD-PSA(,R9)Get current TCB > L R9,TCBJSCB-TCB(,R1) Get JSCB > > I like the latter because it's tighter to read, reduces the USING map, > keeps you out of trouble if you decide to use R9 or R10 for something > global, etc. But I can also see a theological argument that you really > *are* using (USING?) the control block. > > Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious > arguments!) >
Re: Assembler theology question
I do both. I have the USING when I either want multiple fields from the same DSECT or I want to reference the same field(s) multiple times rather than storing them myself somewhere. This latter is mainly when I am writing "pure" code, such as in LPA and am short on dynamic storage. On Thu, Jun 1, 2023, 11:24 Phil Smith III wrote: > We've all seen (and written!) code like this: > USING PSA,R9 > L R10,PSATOLD Get current TCB > DROP R9 > > USING TCB,R10 > L R9,TCBJSCB Get JSCB > DROP R10 > > I've also seen (and probably written) the equivalent: > L R10,PSATOLD-PSA(,R9)Get current TCB > L R9,TCBJSCB-TCB(,R1) Get JSCB > > I like the latter because it's tighter to read, reduces the USING map, > keeps you out of trouble if you decide to use R9 or R10 for something > global, etc. But I can also see a theological argument that you really > *are* using (USING?) the control block. > > Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious > arguments!) >
Assembler theology question
We've all seen (and written!) code like this: USING PSA,R9 L R10,PSATOLD Get current TCB DROP R9 USING TCB,R10 L R9,TCBJSCB Get JSCB DROP R10 I've also seen (and probably written) the equivalent: L R10,PSATOLD-PSA(,R9)Get current TCB L R9,TCBJSCB-TCB(,R1) Get JSCB I like the latter because it's tighter to read, reduces the USING map, keeps you out of trouble if you decide to use R9 or R10 for something global, etc. But I can also see a theological argument that you really *are* using (USING?) the control block. Thoughts? (Yes, I *said* it was theology, so I'm prepared for religious arguments!)
