. That's what enlightened
self-interest is all about.
Bill Fairchild
-Original Message-
From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On
Behalf Of Dave Cole
Sent: Thursday, February 16, 2012 4:07 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: code comments
Bill writes:
I try very hard to put a cogent comment on each machine instruction and all
USINGs and DROPs. And I add a paragraph or two at the beginning of small
subroutines. I do this for two reasons: (1) I have spent a lot of time
studying other people's code with either poor or no
On Thu, Feb 16, 2012 at 11:02 PM, Bodoh John Robert
john.robert.bo...@irs.gov wrote:
I agree completely. Why doesn't the rest of the world agree and adhere to
this philosophy?
I don't think the disagreement is about that. As stated, the goal is
to have *relevant* comments in the code.
Sorry,
should have been ... less than or equal to 256 ...
Kind regards
Bernd
Am 13.02.2012 00:08, schrieb Steve Smith:
There seems to be a common misconception that MVC can't move 256 bytes.
It certainly can. It cannot move zero bytes, but that's not much of a
limitation.
On 2/12/2012 17:45,
Some of this discussion revolves around what the base knowledge is that
you expect/require that the code's readers have.
If everyone understands that SR regx,regx and XR regx,regx zero
regx then there is little to no benefit to having a macro that is ZERO
regx.
Drawing the line in the right
From: Steve Smith sasd...@gmail.com
Date: Monday, 13 February 2012 10:13
There seems to be a common misconception that MVC can't move 256 bytes.
It certainly can. It cannot move zero bytes, but that's not much of a
limitation.
Not from me. I explicitly mentioned 256.
Length field 0
From: Peter Relson rel...@us.ibm.com
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU ASSEMBLER-LIST@LISTSERV.UGA.EDU
Date: Tuesday, 14 February 2012 4:26
Some of this discussion revolves around what the base knowledge is that
you expect/require that the code's readers have.
If everyone understands that SR
On 2/14/2012 3:41 PM, robin wrote:
If everyone understands that SR regx,regx and XR regx,regx zero
regx then there is little to no benefit to having a macro that is ZERO
regx.
If so, there's be little need for comments such as the example
XR R5,R5zeroise R5
Something sensible like
The length in R3 was the length of a CHAR VARYING passed as a parameter,
and it was tested to be positive and not zero before issuing the BCTR
(was BALR,
should be BCTR).
In fact, I believe that BCTR Rx,0 is the most natural choice to do the
length reduction
by one before issuing an EXed MVC,
From: Gerhard Postpischil gerh...@valley.net
Date: Sunday, 12 February 2012 13:45
On 2/12/2012 5:44 PM, robin wrote:
In this case, BCTR is inappropriate, because the length can be zero,
and use of SH provides the means to test for negative and to skip
the MVC (or CLC).
You're drawing an
Again, context is all. Bernd's point,
Man muss übrigens nicht mit Kanonen auf Spatzen schießen.
is well taken (Bowdlerized, it is overkill to launch a torpedo at a
canoe, even if you sink it.)
Still, I do have a MOVECHRS macro that optimizes, generates MVC, MVC
loops, MVCLE, etc., as
On 2/13/2012 7:16 AM, robin wrote:
The programming world is littered with it can't happen cases.
Everyone knows Murphy's Law (If anything can go wrong, it will).
But not many have heard of Robert's Law? (Even if it can't go wrong, it will.)
So, even it the length were tested prior, one can't
On Feb 13, 2012, at 05:16, robin wrote:
The programming world is littered with it can't happen cases.
Everyone knows Murphy's Law (If anything can go wrong, it will).
But not many have heard of Robert's Law? (Even if it can't go wrong, it
will.)
So, even it the length were tested prior,
On Sun, 12 Feb 2012 14:42:54 -0700 Paul Gilmartin paulgboul...@aim.com
wrote:
:On Feb 13, 2012, at 05:16, robin wrote:
: The programming world is littered with it can't happen cases.
: Everyone knows Murphy's Law (If anything can go wrong, it will).
: But not many have heard of Robert's Law?
Paul Gilmartin wrote:
begin snippet
Hardware detection of arithmetic exceptions is a boon here. But one
ISV C compiler requires that the generated code be run with
fixed-point overflow interrupts disabled. Shame on the vendor!
/end snippet
I agree with this sentiment, but the blame must be
There was a little misunderstanding on my part;
I thought that robin suggested the decrement by one should be done
using a macro, which made no sense to me.
Of course, a macro which does the whole VARCHAR move makes much
more sense.
But still: as John Gilmore pointed out, such a macro should
There was a time when even C/370 code and certain LE functions
abended with 0C8, if the fixed point overflow mask bit was enabled;
some LE functions and even compiler generated code tried to clear registers
by arithmetic shift left !!
When calling C/370 functions from PL/1 with FIXEDOVERFLOW or
There seems to be a common misconception that MVC can't move 256 bytes.
It certainly can. It cannot move zero bytes, but that's not much of a
limitation.
On 2/12/2012 17:45, Bernd Oppolzer wrote:
There was a little misunderstanding on my part;
I thought that robin suggested the decrement by
...@uk.ibm.com
Twitter / Facebook IDs: MartinPacker
Blog:
https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker
From:
Rob van der Heij rvdh...@gmail.com
To:
ASSEMBLER-LIST@listserv.uga.edu,
Date:
11/02/2012 12:27
Subject:
Re: code comments
Sent by:
IBM Mainframe Assembler List ASSEMBLER
From: Dougie Lawson dl1...@gmail.com
Date: Saturday, 11 February 2012 2:39
I was also taught to avoid the banal comments like
XR R5,R5zeroise R5
when it's obvious that the action of that opcode is to perform that exact
action.
It is?
ZERO 5
using a macro provides far better
From: Bernd Oppolzer bernd.oppol...@t-online.de
Date: Saturday, 11 February 2012 3:36
My favourite one is:
BALR R3,0 SUBTRACT 1 FROM R3
Obviously, the opcode is wrong, should be BCTR.
But: it took me three months (!!!) to find the error, because I always
looked
at the comment - at
On 2/12/2012 5:44 PM, robin wrote:
In this case, BCTR is inappropriate, because the length can be zero,
and use of SH provides the means to test for negative and to skip
the MVC (or CLC).
You're drawing an unwarranted conclusion. It is quite possible
that the length was tested earlier on in
Code that said:
Mike told me this condition could never happen. If this abend ever
happens, call John at xxx-xxx- and tell him that Mike owes him $100.
Tony Thigpen
-Original Message -
From: Shane G
Sent: 02/10/2012 06:06 AM
On Fri, Feb 10th, 2012 at 9:37 PM, Sharuff Morsa3
Comments are or, better, should be of two sorts:
1) Substantial prefixed blocks of text, often several hundred lines of
them, that describe what will be done and how it will be done, and
explicate coding conventions for parameters, and
2) comments following single instructions, 'remarks'.
For
LOL
--Original Message--
From: Tony Thigpen
Sender: IBM Mainframe Assembler List
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
ReplyTo: IBM Mainframe Assembler List
Subject: code comments (Was: VarIabLe DD names in VSAM)
Sent: Feb 10, 2012 3:31 AM
Code that said:
Mike told me this condition could
On 2/10/2012 7:40 AM, John Gilmore wrote:
Yes, indeed. I should have proofed my post. Still, the substance of
what I wanted to say is not much affected by the fact that 'SR' should
have been 'SM'.
Or maybe 'STM' :-)
On 2/10/12, John P Kalinichjkali...@csc.com wrote:
John Gilmore of
I am delighted to see that my posts are read. Let's agree that it
should be one of STM|STMH|STMG|STMY .
On 2/10/12, Steve Comstock st...@trainersfriend.com wrote:
On 2/10/2012 7:40 AM, John Gilmore wrote:
Yes, indeed. I should have proofed my post. Still, the substance of
what I wanted to
At 03:36 PM 2/10/2012 +, you wrote:
...
I was taught at an early age to read the code rather than the comments,
especially when one disagrees with the other.
And I learned at an early age to look at the object code. This rule was
hammered home when we purchased commercial software which
-Original Message-
From: IBM Mainframe Assembler List
[mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Michael Stack
Sent: Friday, February 10, 2012 9:47 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: code comments
At 03:36 PM 2/10/2012 +, you wrote:
...
I
IBM Mainframe Assembler List ASSEMBLER-LIST@LISTSERV.UGA.EDU wrote on
02/10/2012 10:46:35 AM:
From: Michael Stack li...@kcats.org
And I learned at an early age to look at the object code. This rule
was hammered home when we purchased commercial software which
contained such oddities as
R3
Dougie Lawson wrote:
| It's more fun when you find a comment that's meaningless
| like SR R5,R5 Store register 5.
He and I have disagreed (though not of course about IMS, about which I
defer reflexively to his judgment); but he is a lot smarter, less
literal-minded than many of you.
On 2/10/12,
And I'm leery of symbol names. For the same reasons we've all outlined:
They lie/misdirect/are vague.
Martin
Martin Packer,
Mainframe Performance Consultant, zChampion
Worldwide Banking Center of Excellence, IBM
+44-7802-245-584
email: martin_pac...@uk.ibm.com
Twitter / Facebook IDs:
My favourite one is:
BALR R3,0 SUBTRACT 1 FROM R3
Obviously, the opcode is wrong, should be BCTR.
But: it took me three months (!!!) to find the error, because I always
looked
at the comment - at least 20 times - and never realized that the
operation did
something totally different
I think a large part of the problem is that kids are not taught to think. There was a classicFar Side cartoon many years ago called "Billy's Nightmare" or similar, where the littleguy is in a library where every book is called "The big book of story problems", "The story problem anthology",
I believe like John that written coding standards - without a respected and
accepted person who enforces these standards and is capable (and has time)
to talk, teach and explain to the coders why the standards are useful
etc. -
do no good.
I once met a guy who had such a job. He has now
: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU]
On Behalf Of David P de Jongh
Sent: 10 February 2012 18:05
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: code comments
I think a large part of the problem is that kids are not taught to think.
There was a classic Far Side
Bill Fairchild's
|fourteen equ 14
is a convenient vehicle for making an important point. A device that
is appropriate in the hands of a knowledgeable and experienced person
may well be misused by someone who is neither.
This is obvious, but what to do?
One now very common notion of what to
37 matches
Mail list logo
