] on behalf
of Paul Gilmartin [0014e0e4a59b-dmarc-requ...@listserv.uga.edu]
Sent: Tuesday, June 13, 2023 12:17 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
On 6/13/23 09:42:56, Seymour J Metz wrote:
> In both cases they are treated numerically as a whole, For logi
lark [dlcl...@winsupplyinc.com]
Sent: Tuesday, June 13, 2023 12:04 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
Some people love to argue the smallest point.
"IBM Mainframe Assembler List" wrote on
06/13/2023 11:42:56 AM:
> In both cases they are treated
On 6/13/23 09:42:56, Seymour J Metz wrote:
In both cases they are treated numerically as a whole, For logical instructions the
operands are treated as unsigned numbers. The distinvtion goes back to the vacuum tube
("valve" for you Brits) machine, well before S/360.
Citation needed.
Some people love to argue the smallest point.
"IBM Mainframe Assembler List" wrote on
06/13/2023 11:42:56 AM:
> In both cases they are treated numerically as a whole,
Not true in the majority of cases. The proof is that the logical
comparison of unstructured data does not
du/~smetz3
From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf
of Dave Clark [dlcl...@winsupplyinc.com]
Sent: Tuesday, June 13, 2023 9:20 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
"IBM Mainframe Assembler List&q
Ok, thanks. That makes more sense! Now I grok.
"IBM Mainframe Assembler List" wrote on
06/12/2023 07:07:50 PM:
> -as opposed to what?
The operands are treated logically, bit-by-bit for their length,
as opposed to the full fields treated numerically as a whole.
Sincerely,
Dave Clark
--
int.ext: 91078
direct: (937) 531-6378
mail system.
From: IBM Mainframe Assembler List on behalf
of Charles Mills
Sent: June 12, 2023 19:14
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
As opposed to a signed integer?
For C, X'1000' compares greater than x'8000'.
Fo
, June 12, 2023 4:08 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
Jonathan Scott wrote:
>On trying to catch up with this thread I don't think I saw what
>I would have considered the most likely reason for the term
>"logical".
>I assumed the word "
Jonathan Scott wrote:
>On trying to catch up with this thread I don't think I saw what
>I would have considered the most likely reason for the term
>"logical".
>I assumed the word "logical" refers to Boolean logical values
>(true and false, usually represented as 1 and 0) and hence to a
>bit
> I was thinking about assembler today in the shower, as one does, and the
> L in instructions like CLC and CLI started bothering me: what's with the
> "Logical"?
On trying to catch up with this thread I don't think I saw what
I would have considered the most likely reason for the term
"logical".
: Re: Shower thought
Phil's question is why they chose the word "logical" for CL over 70 years ago.
If you have logical comparisons, then all other comparisons must be illogical.
To us, signed integer is ones complement with bit 0 being the sign but I
suspect the hardware guys had a
@LISTSERV.UGA.EDU
Subject: Re: Shower thought
Phil's question is why they chose the word "logical" for CL over 70 years ago.
If you have logical comparisons, then all other comparisons must be illogical.
To us, signed integer is ones complement with bit 0 being the sign but I
suspect the har
On 6/7/23 15:13:28, Charles Mills wrote:
@Gil said it better than I.
Thanks for the comple^Himent.
I decided to search the Assembler Services Ref.,
for abuses of "hexadecimal". I got only as far as ABEND when I
found the astonishing:
,REASON=reason code
Specifies the reason code
Fixed message formatting problem. Sorry, I falsely assumed everyone in this
group knew how to convert signed binary.to display. I said ones complement but
meant twos complement.B'0001' first bit is 0 (positive number) = + b'001' =
+1B'' first bit is 1 (negative number) = - ( 2's
Sorry, I falsely assumed everyone in this group knew how to convert signed
binary.to display. I said ones complement but meant twos complement.
B'0001' first bit is 0 (positive number) = + b'001' = +1B'' first bit is 1
(negative number) = - ( 2's complement (b'111') ) = - (b'000' +1) = -1
If anyone hasn't seen it already, there's an eccentric video on YT by Jan
Misali headlined "Every base is base 10".
https://youtu.be/7OEF3JD-jYo
It makes some good points and it's thought-provoking, as well as amusing :-)
Roops
On Wed, 7 Jun 2023, 21:44 Phil Smith III, wrote:
> Well, that
On 6/7/23 15:13:29, Seymour J Metz wrote:
Given that the word length is a multiple of 4 bits, it is natural to group the
data into groups of 4 bits, just as on 36 bit machines it was natural to group
bits into groups of 3 and use octal notation. Add in the hexadecimal floating
point and hex
On 6/7/23 15:15:40, Jon Perryman wrote:
... To us, signed integer is ones complement> with bit 0 being the sign
Who "us"?
--
gil
Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf
of Charles Mills [charl...@mcn.org]
Sent: Wednesday, June 7, 2023 4:03 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
"Hexadecimal" *means* character. Hexadecimal is a means of representing
bin
Phil's question is why they chose the word "logical" for CL over 70 years ago.
If you have logical comparisons, then all other comparisons must be illogical.
To us, signed integer is ones complement with bit 0 being the sign but I
suspect the hardware guys had a very different perspective.
of Charles Mills [charl...@mcn.org]
Sent: Wednesday, June 7, 2023 4:08 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
Dave, no offense was intended. Yes, I totally understood your meaning.
The mis-use of the term hexadecimal to mean vaguely "some value, pos
@Gil said it better than I.
Charles
-Original Message-
From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On
Behalf Of Paul Gilmartin
Sent: Wednesday, June 7, 2023 1:34 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
In IBM doc, how many
Well, that certainly sparked a nice, lively discussion! I knew it would be
something simple. Thanks.
It's amazing how "hexadecimal" is defined differently to different folks. I've
tried to train myself not to use it because of this. With the non-mainframe
programmers I work with, if it
On 6/7/23 13:59:39, Charles Mills wrote:
Generally speaking, for most instructions and architectures, comparisons end at
inequality, to unequal operands may compare faster than equal ones.
An exception may be in DB operations where equi-joins can be
faster than non-equi-joins.
OK. Joins are
On 6/7/23 14:08:16, Charles Mills wrote:
Dave, no offense was intended. Yes, I totally understood your meaning.
The mis-use of the term hexadecimal to mean vaguely "some value, possibly
not a printable character" is a personal bugaboo of mine. The IBM doc does
it: talking about specifying a
U]
On Behalf Of Dave Clark
Sent: Wednesday, June 7, 2023 11:17 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
"IBM Mainframe Assembler List" wrote on
06/07/2023 02:02:58 PM:
> No! Not a hexadecimal comparison. If it were, 11 would compare higher
than
>
7, 2023 11:27 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
No, a hexadecimal comparison of 11 to AA gives AA higher; 11 and AA are not
the same as C'11' and C'AA'
BASE64 is almost certainly guarantied to be less compact.
: Wednesday, June 7, 2023 11:28 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
So does that mean if I compare two long byte vectors where the first byte
is x'80' in the first operand, and the second is x'00' in the second
operand, the operation is the fastest it can be? (It would
List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf
of Charles Mills [charl...@mcn.org]
Sent: Wednesday, June 7, 2023 2:02 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Shower thought
No! Not a hexadecimal comparison. If it were, 11 would compare higher than
AA at least in an EBCDIC environment
"IBM Mainframe Assembler List" wrote on
06/07/2023 02:02:58 PM:
> No! Not a hexadecimal comparison. If it were, 11 would compare higher
than
> AA at least in an EBCDIC environment.
You're too literal. I didn't say the comparison was on the
hexadecimal *value*. What I mean by a
C'11' is higher than C'AA' in EBCDIC.
X'11' and X'AA' have nothing to do with EBCDIC.
--
Tom Marchant
On Wed, 7 Jun 2023 11:02:58 -0700, Charles Mills wrote:
>No! Not a hexadecimal comparison. If it were, 11 would compare higher than
>AA at least in an EBCDIC environment.
Subject: Re: Shower thought
"IBM Mainframe Assembler List" wrote on
06/07/2023 01:22:23 PM:
> So where does this "Logical" come from? I'm sure it's something obvious!
It is a character (hexadecimal) comparison vs. a numeric
(binary/packed) comparison.
CL instructions compare bit-by-bit from left to right until there's a
mismatch.
C instructions compare signed numbers.
That's it. The rest is merely implications.
sas
On Wed, Jun 7, 2023 at 12:29 PM Dave Clark wrote:
> "IBM Mainframe Assembler List" wrote on
> 06/07/2023 01:22:23 PM:
> >
IST@LISTSERV.UGA.EDU
Subject: Shower thought
I was thinking about assembler today in the shower, as one does, and the L
in instructions like CLC and CLI started bothering me: what's with the
"Logical"? At first I thought "Hmm, I guessh it gives a logical
answer-yes/no" but then
On 6/7/2023 10:22 AM, Phil Smith III wrote:
So where does this "Logical" come from? I'm sure it's something obvious!
In this context "logical" simply means it's an unsigned comparison.
--
Phoenix Software International
Edward E. Jaffe
831 Parkview Drive North
El Segundo, CA 90245
"IBM Mainframe Assembler List" wrote on
06/07/2023 01:22:23 PM:
> So where does this "Logical" come from? I'm sure it's something obvious!
Or to extend that a little further... It is a character
(hexadecimal/unsigned) comparison vs. a numeric
(signed binary/packed) comparison.
"IBM Mainframe Assembler List" wrote on
06/07/2023 01:22:23 PM:
> So where does this "Logical" come from? I'm sure it's something obvious!
It is a character (hexadecimal) comparison vs. a numeric
(binary/packed) comparison.
Sincerely,
Dave Clark
--
int.ext: 91078
direct: (937)
I was thinking about assembler today in the shower, as one does, and the L in
instructions like CLC and CLI started bothering me: what's with the "Logical"?
At first I thought "Hmm, I guessh it gives a logical answer-yes/no" but then
realized that of course it doesn't: it's a real comparison,
39 matches
Mail list logo
