feat: hash for LCNF.Code

src/Lean/Compiler/LCNF/CodeMap.lean

@@ -0,0 +1,46 @@
+/-
+Copyright (c) 2022 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Leonardo de Moura
+-/
+import Lean.Compiler.LCNF.Basic
+
+namespace Lean.Compiler.LCNF
+
+instance : Hashable Param where
+  hash p := mixHash (hash p.fvarId) (hash p.type)
+
+def hashParams (ps : Array Param) : UInt64 :=
+  hash ps
+
+mutual
+partial def hashAlt (alt : Alt) : UInt64 :=
+  match alt with
+  | .alt ctorName ps k => mixHash (mixHash (hash ctorName) (hash ps)) (hashCode k)
+  | .default k => hashCode k
+
+partial def hashAlts (alts : Array Alt) : UInt64 :=
+  alts.foldl (fun r a => mixHash r (hashAlt a)) 7
+
+partial def hashCode (code : Code) : UInt64 :=
+  match code with
+  | .let decl k => mixHash (mixHash (hash decl.fvarId) (hash decl.type)) (mixHash (hash decl.value) (hashCode k))
+  | .fun decl k | .jp decl k =>
+    mixHash (mixHash (mixHash (hash decl.fvarId) (hash decl.type)) (mixHash (hashCode decl.value) (hashCode k))) (hash decl.params)
+  | .return fvarId => hash fvarId
+  | .unreach type => hash type
+  | .jmp fvarId args => mixHash (hash fvarId) (hash args)
+  | .cases c => mixHash (mixHash (hash c.discr) (hash c.resultType)) (hashAlts c.alts)
+
+end
+
+instance : Hashable Code where
+  hash c := hashCode c
+
+/--
+Persistent hash map from `Code` to `α`.
+Remark: consider using `normalizeFVarIds`.
+-/
+abbrev PCodeHashMap (α : Type) := PHashMap Code α
+
+end Lean.Compiler.LCNF