https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84114
Wilco <wilco.dijkstra at arm dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |wilco.dijkstra at arm dot com --- Comment #5 from Wilco <wilco.dijkstra at arm dot com> --- (In reply to Steve Ellcey from comment #4) > While teaching the reassociation pass about fma's seems like the right > answer would it be reasonable (and simpler) to do the fma pass > (pass_optimize_widening_mul) before > the reassociation pass (pass_reassoc) to get the most fma's? > > That fixes my small test case but I haven't done a bigger performance check > to see what the overall impact would be. I don't know what else that would affect since the reassociation phase runs very early - and it's late at this stage. My patch seems much safer. Even easier might be to return 1 for FLOAT_MODE PLUS_EXPR in aarch64_reassociation_width. Then we can fix the reassociation phase in GCC9.