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diff --git a/src/Compilers/Linearize.v b/src/Compilers/Linearize.v
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+(** * Linearize: Place all and only operations in let binders *)
+Require Import Crypto.Compilers.Syntax.
+Require Import Crypto.Compilers.SmartMap.
+(*Require Import Crypto.Util.Tactics.*)
+
+Local Open Scope ctype_scope.
+Section language.
+  Context {base_type_code : Type}
+          {op : flat_type base_type_code -> flat_type base_type_code -> Type}.
+
+  Local Notation flat_type := (flat_type base_type_code).
+  Local Notation type := (type base_type_code).
+  Local Notation Tbase := (@Tbase base_type_code).
+  Local Notation Expr := (@Expr base_type_code op).
+
+  Section with_var.
+    Context {var : base_type_code -> Type}.
+    Local Notation exprf := (@exprf base_type_code op var).
+    Local Notation expr := (@expr base_type_code op var).
+
+    Section under_lets.
+      Fixpoint under_letsf {t} (e : exprf t)
+        : forall {tC} (C : interp_flat_type var t -> exprf tC), exprf tC
+        := match e in Syntax.exprf _ _ t return forall {tC} (C : interp_flat_type var t -> exprf tC), exprf tC with
+           | LetIn _ ex _ eC
+             => fun _ C => @under_letsf _ ex _ (fun v => @under_letsf _ (eC v) _ C)
+           | TT => fun _ C => C tt
+           | Var _ x => fun _ C => C x
+           | Op _ _ op args as e => fun _ C => LetIn e C
+           | Pair A x B y => fun _ C => @under_letsf A x _ (fun x =>
+                                        @under_letsf B y _ (fun y =>
+                                        C (x, y)))
+           end.
+    End under_lets.
+
+    Fixpoint linearizef {t} (e : exprf t) : exprf t
+      := match e in Syntax.exprf _ _ t return exprf t with
+         | LetIn _ ex _ eC
+           => under_letsf (@linearizef _ ex) (fun x => @linearizef _ (eC x))
+         | TT => TT
+         | Var _ x => Var x
+         | Op _ _ op args
+           => under_letsf (@linearizef _ args) (fun args => LetIn (Op op (SmartVarf args)) SmartVarf)
+         | Pair A ex B ey
+           => under_letsf (@linearizef _ ex) (fun x =>
+              under_letsf (@linearizef _ ey) (fun y =>
+              SmartVarf (t:=Prod A B) (x, y)))
+         end.
+
+    Definition linearize {t} (e : expr t) : expr t
+      := match e in Syntax.expr _ _ t return expr t with
+         | Abs _ _ f => Abs (fun x => linearizef (f x))
+         end.
+  End with_var.
+
+  Definition Linearize {t} (e : Expr t) : Expr t
+    := fun var => linearize (e _).
+End language.
+
+Global Arguments under_letsf {_ _ _ _} _ {tC} _.
+Global Arguments linearizef {_ _ _ _} _.
+Global Arguments linearize {_ _ _ _} _.
+Global Arguments Linearize {_ _ _} _ var.