> -----Original Message----- > From: IBM Mainframe Assembler List [mailto:ASSEMBLER- > [email protected]] On Behalf Of Gary DiPillo > Sent: Friday, December 03, 2010 4:44 PM > To: [email protected] > Subject: Re: Long Displacements - What Good Are They? <Snipped> > The compilers are pretty good at conserving and/or reusing registers, and > you usually don't look at the generated code.
If any competent assembler programmer ever looks at COBOL-generated code they invariably choke on their coffee and donut, since it is the most awful code they have ever seen. I have been told that much of the most awful COBOL-generated code is done in the name of "preserving COBOL semantics" vis-à-vis intermediate arithmetic results. The other most common COBOL awfulness is the overuse of MVCL for moves that are far short of the break-even point for MVCL efficiency. A CPU-time reduction project in my recent past saved something on the order of 50% of the original application CPU time mostly by eliminating as many MVCL's as possible. Peter -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system.
