Avoid rnf from Control.DeepSeq, it's a massive slowdown.

Use primRnf instead.

ghc/Compat.hs

@@ -43,3 +43,6 @@ _isWindows = False
 rnfNoErr :: forall a . a -> ()
 rnfNoErr _ = ()
 
+-- This cannot be implemented with GHC.
+rnfErr :: forall a . a -> ()
+rnfErr _ = ()

lib/Control/DeepSeq.hs

@@ -6,6 +6,7 @@ module Control.DeepSeq (
   (<$!!>),
   rwhnf,
   rnfNoErr,
+  rnfErr,
 ) where
 import Primitives(primRnfErr, primRnfNoErr)
 import Data.Complex
@@ -17,6 +18,9 @@ import Data.Tuple
 rnfNoErr :: forall a . a -> ()
 rnfNoErr = primRnfNoErr
 
+rnfErr :: forall a . a -> ()
+rnfErr = primRnfErr
+
 infixr 0 $!!
 
 infixr 0 `deepseq`

mhs/Compat.hs

@@ -1,5 +1,16 @@
 -- Copyright 2023 Lennart Augustsson
 -- See LICENSE file for full license.
-module Compat() where
+module Compat(rnfNoErr, rnfErr, NFData) where
 import Prelude()              -- do not import Prelude
+import Primitives
 -- So we can import Compat, which is full of stuff for GHC.
+
+-- Define these here to avoid dragging in Control.DeepSeq
+rnfNoErr :: forall a . a -> ()
+rnfNoErr = primRnfNoErr
+
+rnfErr :: forall a . a -> ()
+rnfErr = primRnfErr
+
+class NFData a
+

src/MicroHs/Compile.hs

@@ -22,7 +22,6 @@ import System.IO.MD5
 import System.IO.Serialize
 import System.IO.TimeMilli
 import System.Process
-import Control.DeepSeq
 import MicroHs.Abstract
 import MicroHs.CompileCache
 import MicroHs.Desugar
@@ -173,12 +172,12 @@ compileModule flags impt mn pathfn file = do
     liftIO $ putStrLn $ "type checked:\n" ++ showTModule showEDefs tmdl ++ "-----\n"
   let
     dmdl = desugar flags tmdl
-  () <- return $ rnf $ bindingsOf dmdl
+  () <- return $ rnfErr $ bindingsOf dmdl
   t4 <- liftIO getTimeMilli
 
   let
     cmdl = setBindings [ (i, compileOpt e) | (i, e) <- bindingsOf dmdl ] dmdl
-  () <- return $ rnf $ bindingsOf cmdl
+  () <- return $ rnfErr $ bindingsOf cmdl
   t5 <- liftIO getTimeMilli
 
   let tParse = t2 - t1

src/MicroHs/Exp.hs

@@ -17,7 +17,6 @@ import MicroHs.Ident
 import MicroHs.Expr(Lit(..), showLit)
 import MicroHs.List
 import Text.PrettyPrint.HughesPJLite
-import Control.DeepSeq
 import Debug.Trace
 
 type PrimOp = String

src/MicroHs/Instances.hs

@@ -2,11 +2,11 @@
 -- See LICENSE file for full license.
 module MicroHs.Instances(compiledWithGHC) where
 -- For GHC compatibility
-import Control.DeepSeq
 import MicroHs.CompileCache
 import MicroHs.Ident
 import MicroHs.Exp
 import MicroHs.Expr
+import Compat
 
 compiledWithGHC :: Bool
 compiledWithGHC = False

src/MicroHs/Main.hs

@@ -5,7 +5,6 @@ module MicroHs.Main(main) where
 import Data.Char
 import Data.List
 import Data.Version
-import Control.DeepSeq
 import Control.Monad
 import Control.Applicative
 import Data.Maybe