The other thing that can affect performance a great deal is instruction sequencing. Loading a register to use in the next instruction can cause a 1 or more cycle delay. Loading a register to use as a base register in the following instruction can cause a 5 or more cycle delay. IE doing
L R14,VALUE1 L R15,VALUE2 ST R14,PARM1 ST R15,PARM2 Is much faster than L R14,VALUE1 ST R14,PARM1 L R14,VALUE2 ST R14,PARM2 IBM may have optimized the compiler for the machine it is generated on. I would look at the instruction listing for hints. Christopher Y. Blaicher Senior Software Developer Austin Development Lab phone: 512.340.6154 mobile: 512.627.3803 fax: 512.340.6647 10431 Morado Circle Austin, TX 78759 -----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of McKown, John Sent: Monday, April 04, 2011 2:39 PM To: [email protected] Subject: Re: CPU: ASSM vs ENTERPRISE COBOL The only thing that occurs to me is that COBOL tends to use the simplier, older instructions. Are you using the more powerful z instructions? An example that I was told about is that MVC in a loop is generally faster than MVCL and both are faster than MVCLE. So, in many case, a simple loop is better than a more powerful single instruction. If I'm wrong on this, I'm sure to be corrected. I've also heard that using the 64 bit instructions (such a AG rather than A) are actually faster. So you might consider using something like: LGF R10,FULLWORD instead of the older L R10,FULLWORD then use the Grande (64 bit) arithmetic instructions. This is hearsay, I don't have experience with it. -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets® 9151 Boulevard 26 . N. Richland Hills . TX 76010 (817) 255-3225 phone . [email protected] . 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 Assembler List > [mailto:[email protected]] On Behalf Of Angel > Luis DomÃnguez > Sent: Monday, April 04, 2011 2:18 PM > To: [email protected] > Subject: Re: CPU: ASSM vs ENTERPRISE COBOL > > Unfortunately, the code is copyrighted at this moment by mi > client. Probably > could bee free in the future, but not now. > > The post and the question was in a general sense because I > was surprised. > > Thanks a lot anyway. > > angel luis dominguez > z/os system programmer > >
