Fabian Grünbichler, le jeu. 13 févr. 2025 10:39:00 +0100, a ecrit: > On Thu, Feb 13, 2025 at 09:24:02AM +0100, Samuel Thibault wrote: > > Fabian Grünbichler, le jeu. 13 févr. 2025 08:11:14 +0100, a ecrit: > > > A mixed approach (raising the baseline to allow LLVM and rustc to bump > > > their targets, but keeping GCC's default target and thus the majority of > > > packages at the current/old baseline and skip the rebuilds there) might > > > be possible, but also has potential perfomance or bugginess implications > > > because of switching back and forth between x87 and SSE floating > > > operations. > > > > Which kind of bug? AIUI raising the baseline does not change the > > function call ABI, and within a function we use only one compiler? > > I am not aware of any (and my quick check yesterday indicates that > mixing like that shouldn't be an issue) - but I also haven't done any > in-depth research that would make me confident in saying that I'd rule > them out ;) the potential performance issue was raised by doko on IRC.
When switching between functions, the floating-point operations are normally already over, so I don't think we would suffer very much? (if we were mixing within a function that would pose problem, sure). Also, I don't think we would very often switch between floating-point code compiled by llvm and gcc? Samuel
