Wow, I didn't figure there'd be that much difference between adding to a halfword vs a fullword. Interesting.
Frank ----- Original Message ----- > From: "McKown, John" <john.mck...@healthmarkets.com> > To: IBM-MAIN@bama.ua.edu > Cc: > Sent: Thursday, April 12, 2012 2:46 PM > Subject: Re: Modernizing the BCP code ? > >T hat code sequence is what I remember. But I did my own, minor testing and my > results with OPT(FULL) and TRUNC(BIN) and TRUNC(OPT). And it basically was > LH/AH/STH or LA/AH/STH. > > In the fullword case, all the SRDAs and extra instructions are done to detect > overflow. I guess don't know why they are being generated, except that they > are required even in the TRUNC(BIN) & TRUNC(OPT) environments because the > ADD (and all the other computational verbs) may have an ON SIZE ERROR clause. > Apparently this clause is required to "fire" if the result of the > computation would not fit into the number of digits specified in the PICTURE > clause. And the compiler doesn't modify the instruction sequence even if the > sentence does not have an ON SIZE ERROR clause. I don't know if I'm > saying that very well. Basically the COBOL code generator has one code > sequence > to add two fullwords together. It's only when it goes to store the result > that it looks at the TRUNC option to see if it can store the binary result, > or > needs to truncate the result based on the TRUNC option. > > It turns out that the case of using halfwords these extra instructions are > not > needed because the overflow detection can be done by a simple compare of the > absolute value of the result being greater than the number of decimal digits > in > the receiving field. > > -- > John McKown > Systems Engineer IV > IT > > Administrative Services Group > > HealthMarkets® > > 9151 Boulevard 26 . N. Richland Hills . TX 76010 > (817) 255-3225 phone . > john.mck...@healthmarkets.com . www.HealthMarkets.com > > Confidentiality Notice: This e-mail message may contain confidential or > proprietary information. If you are not the intended recipient, please > contact > the sender by reply e-mail and destroy all copies of the original message. > HealthMarkets® is the brand name for products underwritten and issued by the > insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance > Company®, Mid-West National Life Insurance Company of TennesseeSM and The > MEGA > Life and Health Insurance Company.SM > > > >> -----Original Message----- >> From: IBM Mainframe Discussion List >> [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of Frank Swarbrick >> Sent: Thursday, April 12, 2012 1:07 PM >> To: IBM-MAIN@bama.ua.edu >> Subject: Re: Modernizing the BCP code ? >> >> I actually checked that. The code is slightly different, but >> I don't see that it's much better. >> >> 01 FULLWORD-SORTOF PIC S9(9) BINARY VALUE +999999999. >> >> >> 000009 ADD 100 TO FULLWORD-SORTOF >> >> >> 000354 GN=16 EQU * > >> 000354 4820 A01C LH 2,28(0,10) >> PGMLIT AT +20 >> 000358 8E20 0020 SRDA 2,32(0) > >> 00035C 5840 8000 L 4,0(0,8) >> FULLWORD-SORTOF >> 000360 8E40 0020 SRDA 4,32(0) > >> 000364 1A42 AR 4,2 > >> 000366 1E53 ALR 5,3 > >> 000368 58B0 C02C L 11,44(0,12) >> PBL=1 >> 00036C 47C0 B16C BC 12,364(0,11) >> GN=17(000374) >> 000370 5A40 C004 A 4,4(0,12) >> SYSLIT AT +4 >> 000374 GN=17 EQU * > >> 000374 5D40 C000 D 4,0(0,12) >> SYSLIT AT +0 >> 000378 5040 8000 ST 4,0(0,8) >> FULLWORD-SORTOF >> >> 01 FULLWORD-SORTOF PIC S9(9) COMP-5 VALUE +999999999. >> >> >> 000009 ADD 100 TO FULLWORD-SORTOF >> >> 000350 GN=16 EQU * > >> 000350 5820 8000 L 2,0(0,8) >> FULLWORD-SORTOF >> 000354 8E20 0020 SRDA 2,32(0) > >> 000358 4840 A01C LH 4,28(0,10) >> PGMLIT AT +20 >> 00035C 8E40 0020 SRDA 4,32(0) > >> 000360 1A24 AR 2,4 > >> 000362 1E35 ALR 3,5 > >> 000364 58B0 C028 L 11,40(0,12) >> PBL=1 >> 000368 47C0 B16C BC 12,364(0,11) >> GN=17(000370) >> 00036C 5A20 C000 A 2,0(0,12) >> SYSLIT AT +0 >> 000370 GN=17 EQU * > >> 000370 5030 8000 ST 3,0(0,8) >> FULLWORD-SORTOF >> >> >> Of course I am not an assembler programmer, so maybe it is better? >> >> Frank >> >> >> >> ----- Original Message ----- >> > From: David Andrews <d...@lists.duda.com> >> > To: IBM-MAIN@bama.ua.edu >> > Cc: >> > Sent: Thursday, April 12, 2012 11:23 AM >> > Subject: Re: Modernizing the BCP code ? >> > >> > On Thu, 2012-04-12 at 12:45 -0400, McKown, John wrote: >> >> I am constantly amazed at the amount of code generate by a simpe: >> >> >> >> ADD +1 TO WS-INTEGER. >> >> >> >> when WS-INTEGER is defined as PIC S9(9) BINARY >> > >> > Try defining it as COMP-5 (or compile with TRUNC(BIN)) and >> see if that >> > improves the generated code? >> > >> > -- >> > David Andrews >> > A. Duda & Sons, Inc. >> > david.andr...@duda.com >> > >> > >> ---------------------------------------------------------------------- >> > For IBM-MAIN subscribe / signoff / archive access instructions, >> > send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN >> > >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, >> send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN >> >> > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
