Function rustc_mir_transform::copy_prop::fully_moved_locals
source ยท fn fully_moved_locals(ssa: &SsaLocals, body: &Body<'_>) -> BitSet<Local>
Expand description
SsaLocals
computed equivalence classes between locals considering copy/move assignments.
This function also returns whether all the move?
in the pattern are move
and not copies.
A local which is in the bitset can be replaced by move _a
. Otherwise, it must be
replaced by copy _a
, as we cannot move multiple times from _a
.
If an operand copies _c
, it must happen before the assignment _d = _c
, otherwise it is UB.
This means that replacing it by a copy of _a
if ok, since this copy happens before _c
is
moved, and therefore that _d
is moved.