Re: The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC)

2017-10-16 Thread John McKown
luating systems, you have three choices, fast, > cheap > > and good; choose two. > > > > -Original Message- > > From: IBM Mainframe Assembler List [mailto:ASSEMBLER- > > l...@listserv.uga.edu] On Behalf Of Richard Kuebbing > > Sent: Monday, Octo

Re: The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC)

2017-10-16 Thread Gibney, Dave
ERV.UGA.EDU > Subject: Re: The Pointlessness of handwriting "efficient" code (was One Byte > MVC Versus IC/STC) > > The First Rule of Program Optimization: Don't do it. The Second Rule of > Program Optimization (for experts only): Don't do it yet. > When developing or ev

Re: The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC)

2017-10-16 Thread Richard Rogers
[mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Richard Kuebbing Sent: Monday, October 16, 2017 13:24 To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC) Efficiency is doing things right. Effectivenes

Re: The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC)

2017-10-16 Thread Richard Kuebbing
@LISTSERV.UGA.EDU] On Behalf Of Steve Smith Sent: Monday, October 16, 2017 3:02 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC) And if Dave Cole isn't a high enough authority (but he is :-)), "Programmers

Re: The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC)

2017-10-16 Thread Richard Kuebbing
-Original Message- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of David Cole Sent: Monday, October 16, 2017 12:24 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: The Pointlessness of handwriting "efficient" code (was One Byte MVC Ver

Re: The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC)

2017-10-16 Thread Paul Gilmartin
On 2017-10-16, at 10:23:50, David Cole wrote: > > But all these techniques for efficiency that IBM has created are not human > compatible. They are too complex, they are too messy[!] and they are not even > the same techniques from one machine to the next. In fact, sometimes code > written to

The Pointlessness of handwriting "efficient" code (was One Byte MVC Versus IC/STC)

2017-10-16 Thread David Cole
llium Software is now a part of Syncsort. -Original Message- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Robin Vowels Sent: Monday, October 16, 2017 10:03 AM To: MVS List Server 2 <ASSEMBLER-LIST@LISTSERV.UGA.EDU> Subject: Re: One Byte MVC Versus I

Re: One Byte MVC Versus IC/STC

2017-10-16 Thread Charles Mills
, 2017 8:41 AM To: 'IBM Mainframe Assembler List' Subject: RE: One Byte MVC Versus IC/STC And I suspect "it depends." Are the operands already in cache? Must the processor do a read-to-write switch on a cache line? What instructions came before? What come after? What is the preceding and

Re: One Byte MVC Versus IC/STC

2017-10-16 Thread Charles Mills
IST@LISTSERV.UGA.EDU] On Behalf Of Robin Vowels Sent: Monday, October 16, 2017 7:03 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: One Byte MVC Versus IC/STC From: "David S." <dlstaudac...@gmail.com> Sent: Thursday, December 17, 2015 6:10 AM >> > "... a good

Re: One Byte MVC Versus IC/STC

2017-10-16 Thread Blaicher, Christopher Y.
Server 2 <ASSEMBLER-LIST@LISTSERV.UGA.EDU> Subject: Re: One Byte MVC Versus IC/STC From: "David S." <dlstaudac...@gmail.com> Sent: Thursday, December 17, 2015 6:10 AM >> > "... a good reason why small MVCs run slower than LG/STG pairs ... >> >

Re: One Byte MVC Versus IC/STC

2017-10-16 Thread Robin Vowels
From: "David S." Sent: Thursday, December 17, 2015 6:10 AM > "... a good reason why small MVCs run slower than LG/STG pairs ... > overhead at the beginning of an MVC ... check if the operands are on 'good' > boundaries ... check for operand overlap ... length check

Re: One Byte MVC Versus IC/STC

2015-12-16 Thread Watkins, Douglas
David, > > > "... a good reason why small MVCs run slower than LG/STG pairs ... > > > overhead at the beginning of an MVC ... check if the operands are on 'good' > > > boundaries ... check for operand overlap ... length check ... [meanwhile] the > > > LG/STG is far on its way. Anyone writing a

Re: One Byte MVC Versus IC/STC

2015-12-16 Thread Paul Gilmartin
On 2015-12-16 12:10, David S. wrote: > > Nevertheless, IC/STC is what the newer mainframe compilers generate for a > one-byte move. For the reasons given, it's less work for the system than > an MVC. > For fortuitous alignment, is L; STC better? I'm confident that for adverse alignment L is no

Re: One Byte MVC Versus IC/STC

2015-12-16 Thread Robin Vowels
From: "David S." Sent: Thursday, December 17, 2015 6:10 AM > "... a good reason why small MVCs run slower than LG/STG pairs ... > overhead at the beginning of an MVC ... check if the operands are on 'good' > boundaries ... check for operand overlap ... length check ...