On 16 May 2017 at 10:31, Paul Gilmartin <
0014e0e4a59b-dmarc-requ...@listserv.uga.edu> wrote:
> I have wondered in cases where the programmer knows a priori
> that branch taken is more likely whether a branch around a
> branch better exploits the branch prediction rules. For
> example, instea
7 7:32 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of an assembler routine (Was:
Performance of Decimal Floating Point Instruction)
On 2017-05-16, at 07:59, Pieter Wiid wrote:
> That's what the book says -- except for unconditional branches, BCT
> and BXLE (and the re
On 2017-05-16, at 07:59, Pieter Wiid wrote:
> That's what the book says -- except for unconditional branches, BCT and BXLE
> (and the relative and G variants) which predicts a branch.
>
I have wondered in cases where the programmer knows a priori
that branch taken is more likely whether a branch
44
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of an assembler routine (Was:
Performance of Decimal Floating Point Instruction)
Peter,
I never have gotten a handle on "branch prediction" within the i-cache
discussion. Are you saying that, for the most part, we sh
ot as a
"production" technique.
Charles
-Original Message-
From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU]
On Behalf Of Peter Relson
Sent: Tuesday, May 16, 2017 5:31 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of an assem
Peter,
I never have gotten a handle on "branch prediction" within the i-cache
discussion. Are you saying that, for the most part, we should always try
to code so that the normal path is to not-branch wherever possible?
(I know, within limits.)
Tony Thigpen
Peter Relson wrote on 05/16/2017 0
Well, in reality you are right of course (who cares about the i-cache?)
but
in theory one is branching around and NOT crashing, so not wasting the
i-cache is a desirable goal.
A program coded with any thought for performance would not be "branching
around and NOT crashing". It would be branch
Behalf Of Charles Mills
Sent: Thursday, May 11, 2017 1:44 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Quick error termination of an assembler routine (Was: Performance of
Decimal Floating Point Instruction)
What is *wrong* with DC H'0'? It has the advantage of being incredibly
y Thigpen
Sent: Sunday, May 14, 2017 07:06
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Reply To: IBM Mainframe Assembler List
Subject: Re: Quick error termination of an assembler routine (Was: Performance
of Decimal Floating Point Instruction)
But, is 2 bytes "wasting the i-cache" in today
The example showed a prose constant following the abend-causing code.
Original Message
From: Tony Thigpen
Sent: Sunday, May 14, 2017 07:06
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Reply To: IBM Mainframe Assembler List
Subject: Re: Quick error termination of an assembler routine (Was: Performance
desirable goal.
Charles
-Original Message-
From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU]
On Behalf Of Tony Thigpen
Sent: Saturday, May 13, 2017 7:20 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of an assembler routine (Was:
Perform
Behalf Of Tony Thigpen
Sent: Saturday, May 13, 2017 7:20 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of an assembler routine (Was:
Performance of Decimal Floating Point Instruction)
Who cares about the Instruction Cache? You are crashing the program.
Especially with
Who cares about the Instruction Cache? You are crashing the program.
Especially with just a one byte error code. We are talking about "it
should never get there" code, or test code to abend.
Tony Thigpen
Keven Hall wrote on 05/12/2017 06:53 PM:
Regarding code like:
BZNOERROR (
On 2017-05-12, at 16:53, Keven Hall wrote:
> Regarding code like:
>>BZNOERROR (If RC==0.)
>>DCX'00',C'You shouldn'ta done that.'
>
> I'd suggest documenting the error in source code rather than the instruction
> cache (or using a 1-byte numeric error code.
>
Good point
Regarding code like:
> BZNOERROR (If RC==0.)
> DCX'00',C'You shouldn'ta done that.'
I'd suggest documenting the error in source code rather than the instruction
cache (or using a 1-byte numeric error code.
Possibly I'm being pedantic. For sure I'm dragging this thread e
Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On
Behalf Of Paul Gilmartin
Sent: May-12-17 9:57 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of an assembler routine (Was: Performance
of Decimal Floating Point Instruction)
On 2017-05-12, at 09:56, somitcw wrote:
> M
On 2017-05-12, at 09:56, somitcw wrote:
> My favourite was to branch to an odd address.
>
> S0C1 and S0C7 ABENDs are common, but any S0C6 abend was mine.
> If an operator called at 2:00AM, I would know who caused 3 pair of socks.
>
Unfortunately, IIRC the exception occurs after the branch is ta
My favourite was to branch to an odd address.
S0C1 and S0C7 ABENDs are common, but any S0C6 abend was mine.
If an operator called at 2:00AM, I would know who caused 3 pair of socks.
Coding so that the assembler didn't flag it was needed but easy.
Something like:
BNE ERRLABEL-CSECT-1(BASEREG)
on
800.480.DINO
423.878.5660
www.dino-software.com
-Original Message-
From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On
Behalf Of John McKown
Sent: Thursday, May 11, 2017 2:43 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of an assemb
S and did sufficent damage to cause the CICS region to
crash
I raised an APAR
Melvyn Maltz.
- Original Message -
From: "Steve Thompson"
To:
Sent: Friday, May 12, 2017 3:07 AM
Subject: Re: Quick error termination of an assembler routine (Was: Performance
of Decimal Floating Poin
Has anyone ever seen S0C3 (PIC 3) as an accident?
I use EX 0,* to trigger a failure. I've never seen one, that I
can remember, occur when executing data (such as happens when one
takes a wild branch).
Just thought I'd ask while you all are kind of on the subject.
Regards,
Steve.T
On 2017-05-11, at 12:42, John McKown wrote:
> On Thu, May 11, 2017 at 1:34 PM, Gibney, Dave wrote:
>
>> In days of limited storage, sure. But, today, why not
>> DC X''
>> DC C'I blew up here because the moon is blue'
>>
> Looks nice. I'd probably do
> DC H'0',C'FIXME: YOU DID SOMETHING WEIRD
rsday, May 11, 2017 12:36 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of an assembler routine (Was: Performance
of Decimal Floating Point Instruction)
On Thu, 11 May 2017 10:44:25 -0700, Charles Mills wrote:
>What is *wrong* with DC H'0'? It has
On Thu, 11 May 2017 10:44:25 -0700, Charles Mills wrote:
>What is *wrong* with DC H'0'? It has the advantage of being incredibly
>straightforward. I had to spend a minute thinking about J *+2; I pretty much
>guarantee you anyone with six months of HLASM experience would "get" DC H'0'.
I wouldn'
On Thu, May 11, 2017 at 1:34 PM, Gibney, Dave wrote:
> In days of limited storage, sure. But, today, why not
> DC X''
> DC C'I blew up here because the moon is blue'
>
>
Looks nice. I'd probably do
DC H'0',C'FIXME: YOU DID SOMETHING WEIRD AND I''M CONFUSED.'
--
Advertising is a valuable e
'I blew up here because the moon is blue'
-Original Message-
From: IBM Mainframe Assembler List [mailto:ASSEMBLER-
l...@listserv.uga.edu] On Behalf Of Tony Thigpen
Sent: Thursday, May 11, 2017 11:28 AM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Quick error termination of
sday, May 11, 2017 11:28 AM
> To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
> Subject: Re: Quick error termination of an assembler routine (Was:
> Performance of Decimal Floating Point Instruction)
>
> For initial testing and debugging, I like:
> DC X'00xx' where 'nn' is a uni
For initial testing and debugging, I like:
DC X'00xx' where 'nn' is a unique number. I get a blow-up and by looking
at the instruction in the dump, I know which condition I hit without
thinking.
Tony Thigpen
Charles Mills wrote on 05/11/2017 01:44 PM:
What is *wrong* with DC H'0'? It has the
hursday, May 11, 2017 1:44 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Quick error termination of an assembler routine (Was: Performance of
Decimal Floating Point Instruction)
What is *wrong* with DC H'0'? It has the advantage of being incredibly
straightforward. I had to spend a minut
What is *wrong* with DC H'0'? It has the advantage of being incredibly
straightforward. I had to spend a minute thinking about J *+2; I pretty much
guarantee you anyone with six months of HLASM experience would "get" DC H'0'.
I don't write much assembler anymore but if I did I think I might defi
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