On Feb 6, 2015, at 9:41 AM, Matthew Fortune <matthew.fort...@imgtec.com> wrote: > Mike Stump <mikest...@comcast.net> writes: >> On Feb 6, 2015, at 4:23 AM, Maciej W. Rozycki <ma...@linux-mips.org> >> wrote: >>> This consideration made me realise I've had a patch outstanding for >>> some >>> 10 years to convert all the `BAL x' instructions there to `BLTZAL $0, >> x'. >>> This has always been a good idea in case implementations recognised >>> the special case and avoided involving branch prediction, and I >>> believe it has become even more apparent with r6 calling it NAL. >> >> Ick, no. > > What part of this are you referring to?
The first part. Ah, yes, I had mentally flipped the two cases. I mistakingly thought you wanted to change all the BALs to BLTZAL, which you don’t want to do. You only want to flip the non-calls to that form, which is perfectly reasonable. Personally, the call form of bal in my book should be called call, and the non-call form of it should be called bal, but, I realize it is likely to late to do much about now. If one went down this path, then even changing it away from bal is wrong. That’s the basis of why I fired up the first email. Maybe more a lament at this point.
