1 files changed, 48 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_cranelift/src/analyze.rs b/compiler/rustc_codegen_cranelift/src/analyze.rs
new file mode 100644
index 000000000..35b89358b
--- /dev/null
+++ b/compiler/rustc_codegen_cranelift/src/analyze.rs
@@ -0,0 +1,48 @@
+//! SSA analysis
+
+use crate::prelude::*;
+
+use rustc_index::vec::IndexVec;
+use rustc_middle::mir::StatementKind::*;
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub(crate) enum SsaKind {
+    NotSsa,
+    Ssa,
+}
+
+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) | Rvalue::AddressOf(_, place) => {
+                        not_ssa(&mut flag_map, place.local)
+                    }
+                    _ => {}
+                },
+                _ => {}
+            }
+        }
+    }
+
+    flag_map
+}
+
+fn not_ssa(flag_map: &mut IndexVec<Local, SsaKind>, local: Local) {
+    flag_map[local] = SsaKind::NotSsa;
+}