On Thu, Jan 23, 2025 at 2:05 PM Richard Sandiford
wrote:
>
> rtl-ssa uses degenerate phis to maintain an RPO list of
> accesses in which every use is of the RPO-previous definition.
> Thus, if it finds that a phi is always equal to a particular
> value V, it sometimes needs to keep the phi and mak
rtl-ssa uses degenerate phis to maintain an RPO list of
accesses in which every use is of the RPO-previous definition.
Thus, if it finds that a phi is always equal to a particular
value V, it sometimes needs to keep the phi and make V the
single input, rather than replace all uses of the phi with V
