× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.


  • Subject: RE: Humorous Enhancements: now
  • From: "Kahn, David [JNJFR]" <DKahn1@xxxxxxxxxxxxx>
  • Date: Mon, 9 Aug 1999 17:19:12 +0200

Scott,

You can use BITON and BITOF to emulate the logical operators OR AND and XOR
much more efficiently than that. You don't need to do a TESTB or use
indicators. Assume the operands are in single byte fields A and B and you
want the result in field C without altering A or B.

To perform OR:
        
     C                     MOVE A         C       1
     C                     BITONB         C        

To perform AND:
     
     C                     MOVE A         C       1
     C                     MOVE A         X       1
     C                     BITOFB         X        
     C                     BITOFX         C        

To perform XOR:
       
     C                     MOVE A         C       1
     C                     MOVE B         X       1
     C                     BITOFA         X        
     C                     BITOFB         C        
     C                     BITONX         C        

Still not as efficient as directly implemented operations, but not bad.

Dave Kahn
Johnson & Johnson International (Ethicon) France
Phone : +33 1 55 00 3180
Email :  dkahn1@jnjfr.jnj.com (work)
           dkahn@cix.co.uk      (home)



-----Message d'origine-----
De: Scott Klement [mailto:infosys@klements.com]
Date: 06 August 1999 06:43
À: RPG400-L@midrange.com
Objet: Re: Humorous Enhancements


YES!!! YES!!!  We need some real bitwise operations.
(this probably doesn't surprise you coming from me)

I've had to write special routines that go through a string of
bytes, check every single bit with TESTB, compare it against the
same bit pos in a different string, and finally do a manual XOR.
(by checking the result indicators of testb) and then finally
using BITON to set the string of bytes to the result.

Doesnt perform real well when compared to a real XOR operation.
I'm sure the CPU can do XOR at the machine code level...  so it seems
silly to have to go that far to make an XOR. :)
+---
| This is the RPG/400 Mailing List!
| To submit a new message, send your mail to RPG400-L@midrange.com.
| To subscribe to this list send email to RPG400-L-SUB@midrange.com.
| To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---END



As an Amazon Associate we earn from qualifying purchases.

This thread ...


Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.