From: Scott Wood > Sent: 26 May 2015 20:43 ... > > I was thinking of all 64bit targets, not 32bit ones. > > Oh, you mean move it out of arch/powerpc? Sounds reasonable, but > someone should probably check what the resulting code looks like on > other common arches. OTOH, if we're going to modify non-arch code, > that might be a good opportunity to implement Segher's suggestion and > move to a 64-bit accumulator.
Or more likely: adding alternate 32bit words to different 64-bit registers in order to reduce the dependency chains further. I'm sure I've seen a version that does that somewhere. David