+//! SSA analysis
+
use crate::prelude::*;
-use rustc::mir::StatementKind::*;
+use rustc_index::vec::IndexVec;
+use rustc_middle::mir::StatementKind::*;
-bitflags::bitflags! {
- pub struct Flags: u8 {
- const NOT_SSA = 0b00000001;
- }
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub(crate) enum SsaKind {
+ NotSsa,
+ Ssa,
}
-pub fn analyze(fx: &FunctionCx<'_, '_, impl Backend>) -> HashMap<Local, Flags> {
- let mut flag_map = HashMap::new();
-
- for local in fx.mir.local_decls.indices() {
- flag_map.insert(local, Flags::empty());
- }
-
- for (local, local_decl) in fx.mir.local_decls.iter_enumerated() {
- if fx.clif_type(local_decl.ty).is_none() {
- not_ssa(&mut flag_map, local);
- }
- }
+pub(crate) fn analyze(fx: &FunctionCx<'_, '_, '_>) -> IndexVec<Local, SsaKind> {
+ let mut flag_map = fx
+ .mir
+ .local_decls
+ .iter()
+ .map(|local_decl| {
+ let ty = fx.monomorphize(local_decl.ty);
+ if fx.clif_type(ty).is_some() || fx.clif_pair_type(ty).is_some() {
+ SsaKind::Ssa
+ } else {
+ SsaKind::NotSsa
+ }
+ })
+ .collect::<IndexVec<Local, SsaKind>>();
for bb in fx.mir.basic_blocks().iter() {
for stmt in bb.statements.iter() {
match &stmt.kind {
Assign(place_and_rval) => match &place_and_rval.1 {
- Rvalue::Ref(_, _, place) => {
- analyze_non_ssa_place(&mut flag_map, place);
+ Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) => {
+ not_ssa(&mut flag_map, place.local)
}
_ => {}
},
_ => {}
}
}
-
- match &bb.terminator().kind {
- TerminatorKind::Call {
- destination: Some((place, _)),
- ..
- } => analyze_non_ssa_place(&mut flag_map, place),
- _ => {}
- }
}
flag_map
}
-fn analyze_non_ssa_place(flag_map: &mut HashMap<Local, Flags>, place: &Place) {
- match place.base {
- PlaceBase::Local(local) => not_ssa(flag_map, local),
- _ => {}
- }
-}
-
-fn not_ssa<L: ::std::borrow::Borrow<Local>>(flag_map: &mut HashMap<Local, Flags>, local: L) {
- *flag_map.get_mut(local.borrow()).unwrap() |= Flags::NOT_SSA;
+fn not_ssa(flag_map: &mut IndexVec<Local, SsaKind>, local: Local) {
+ flag_map[local] = SsaKind::NotSsa;
}