On Mon, Sep 14, 2020 at 05:33:33PM +0100, Richard Sandiford wrote: > > However, for the cases on Power as Segher mentioned, there are also some > > scratch registers used for > > Other purpose, not sure whether we can correctly generate zeroing in > > middle-end for Power? > > Segher would be better placed to answer that, but I think the process > above has to give a conservatively-accurate list of live registers. > If it misses a register, the other late rtl passes could clobber > that same register.
It will zero a whole bunch of registers that are overwritten later, that are not parameter passing registers either. Doing this with the limited information the middle end has is not the best idea. Segher
