On Tue, 1 Apr 2008 13:57:09 -0500 Don Higgins <[EMAIL PROTECTED]> wrote:
:>Optimizing COBOL generated assembler :>Consider the cobol statements: :>000034 02 R-CNTR PIC S99 COMP SYNC VALUE +0. :>... :>0000072 ADD 1 to R-CNTR :>Which generated the following assembler code: :> :> 000620 4830 A012 LH 3,18(0,10) PGMLIT AT +6 :> 000624 4A30 9028 AH 3,40(0,9) R-CNTR :> 000628 1823 LR 2,3 :> 00062A 8E20 0020 SRDA 2,32(0) :> 00062E 5D20 C000 D 2,0(0,12) SYSLIT AT +0 :> 000632 4020 9028 STH 2,40(0,9) R-CNTR :>This snippet of code is from the following COBOL/370 generated assembler :>LIST option: :>http://www.cs.niu.edu/~t90jfl1/class/job2.htm :>I think the LR, SRDA, and D instructions could be surpressed by specifying the :>option NOTRUNC to allow values greater than the PIC digits 99. Yes. Also, isn't there now a PIC clause to specify a half-word (so TRUNC would not be needed)? :>With the new z10 instruction ADD LOGICAL WITH SIGNED IMMEDIATE, the :>entire 6 instruction sequence could be reduced to a single instruction: :> ALSI R-CNTR,1 Which would generate incorrect results, as (1) R-CNTR is signed and (2) it is a halfword. -- Binyamin Dissen <[EMAIL PROTECTED]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
