Optimize tmBind

Fixes #441

Author: JasonGross

template-coq/theories/TemplateMonad/Core.v

@@ -89,9 +89,8 @@ Definition TemplateMonad_UnoptimizedMonad@{t u} : Monad@{t u} TemplateMonad@{t u
 Definition TemplateMonad_OptimizedMonad@{t u} : Monad@{t u} TemplateMonad@{t u} :=
   {| ret := @tmReturn ; bind := @tmOptimizedBind |}.
 
-(* We don't want to make the optimized monad an instance, becuase it blows up performance in some cases *)
 Definition TemplateMonad_Monad@{t u} : Monad@{t u} TemplateMonad@{t u} :=
-  Eval hnf in TemplateMonad_UnoptimizedMonad.
+  Eval hnf in TemplateMonad_OptimizedMonad.
 Global Existing Instance TemplateMonad_Monad.
 
 Polymorphic Definition tmDefinitionRed
@@ -194,7 +193,7 @@ Definition TypeInstanceOptimized : Common.TMInstance :=
    |}.
 
 Definition TypeInstance : Common.TMInstance :=
-  Eval hnf in TypeInstanceUnoptimized.
+  Eval hnf in TypeInstanceOptimized.
 
 Definition tmQuoteUniverse@{U t u} : TemplateMonad@{t u} Universe.t
   := u <- @tmQuote Prop (Type@{U} -> True);;

test-suite/bug441.v

@@ -1,8 +1,6 @@
 From MetaCoq Require Import Template.All.
 Import MCMonadNotation.
 
-#[local] Existing Instance TemplateMonad_OptimizedMonad.
-
 Fixpoint tm_double n : TemplateMonad nat :=
   match n with
   | 0 => ret 0