You're right - there has to be a predetermined breakpoint but in my case I use
it for testing X'40' or X'00' in strings and then do what I need to do after
that. Recently I have used a mix of SRST and TRT in the same program but they
were used to perform a lot of different parsing.
From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On
Behalf Of Paul Gilmartin
Sent: Tuesday, October 18, 2016 11:30 AM
Subject: Re: SRST Performance (was: converting character to packed
On 2016-10-18, at 10:11, Martin Truebner wrote:
> TRT does a lockup for each and every char until terminating char is
> found or the maximum length is reached- the lockup is done against a
> table of 256 char.
Caching helps a lot. How can the programmer insure that the table occupies the
minimum number of cache lines?
Does modern hardware optimize this further?
> SRST does a check of each char against a single char (plus the
> termination char).
Testing for multiple characters (e.g. non-numeric) requires multiple executions
of of SRST. Is there a break-even point with TRT?
Again, caching the subject string helps.
And the next hardware model will change the rules.