On 13Jul24:1022+0800, David Crayford wrote: > It's easy to do on X86 or ARM architectures which have instructions > for scanning, counting and reversing bits > https://github.com/facebook/hiphop-php/blob/master/hphp/util/bitops.h. > Now I'm interested in what is the most efficient way to do this on > zArch. I thought zArch was king of the CISC. ARM can do this in 4 > instructions and that's a RISC architecture.
A TR instruction that uses a 256-byte table of the reversed byte values will handle up to 256 bytes, IIRC. -- <not cent from sell> May the LORD God bless you exceedingly abundantly! Dave_Craig______________________________________________ "So the universe is not quite as you thought it was. You'd better rearrange your beliefs, then. Because you certainly can't rearrange the universe." __--from_Nightfall_by_Asimov/Silverberg_________________ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
