Re: Write System Pointer to User Space
Dave McKenzie <[email protected]>
| Newsgroups | gmane.comp.lang.as400.mi |
|---|---|
| Message-ID | <[email protected]> |
Looking an an MI pgm with a 32-byte CPYBLA and a 32-byte CPYBWP, the CPYBLA uses LSDX/STSDX (Load/Store string doubleword indexed), while CPYBWP uses 2 pairs of LQ/STQ (Load/Store quadword). One could write test loops to find out which is faster. I suspect memcpy always does CPYBWP. --Dave Steve Richter wrote: > > -----Original Message----- > From: mi400-bounces-Zwy7GipZuJhWk0Htik3J/[email protected] [mailto:mi400-bounces-Zwy7GipZuJhWk0Htik3J/[email protected]]On > Behalf Of Dave McKenzie > Sent: Sunday, June 19, 2005 2:11 PM > To: MI Programming on the AS400 / iSeries > Subject: Re: [MI400] Write System Pointer to User Space > > > Hi Peter, > >>Here's a pgm that does that. The "memcpy" function does the equivalent >>of a CPYBWP (Copy Bytes With Pointers) MI instruction under the covers. > > I have always assumed that CPYBWP was slower than CPYBLA. Not true? Does memcpy always use CPYBWP in place of CPYBLA? ( I know, LDQ and STQ! ) > > -Steve > _______________________________________________ This is the MI Programming on the AS400 / iSeries (MI400) mailing list To post a message email: MI400-Zwy7GipZuJhWk0Htik3J/[email protected] To subscribe, unsubscribe, or change list options, visit: http://lists.midrange.com/mailman/listinfo/mi400 or email: MI400-request-Zwy7GipZuJhWk0Htik3J/[email protected] Before posting, please take a moment to review the archives at http://archive.midrange.com/mi400.