Inline all top level functions that look simple.

[matthijs/master-project/cλash.git] / cλash / CLasH / Normalize.hs

diff --git a/cλash/CLasH/Normalize.hs b/cλash/CLasH/Normalize.hs
index 5d2b3a67852d94820ff589d72697eb8b110974aa..d66a1885be7062ea207561d4b17762b07f551033 100644 (file)
--- a/cλash/CLasH/Normalize.hs
+++ b/cλash/CLasH/Normalize.hs
@@ -23,6 +23,7 @@ import qualified UniqSupply
 import qualified CoreUtils
 import qualified Type
 import qualified TcType
+import qualified Name
 import qualified Id
 import qualified Var
 import qualified VarSet
@@ -319,6 +320,37 @@ letmergetop = everywhere ("letmerge", letmerge)
 inlinenonreptop :: Transform
 inlinenonreptop = everywhere ("inlinenonrep", inlinebind ((Monad.liftM not) . isRepr . snd))
 
+inlinetoplevel, inlinetopleveltop :: Transform
+-- Any system name is candidate for inlining. Never inline user-defined
+-- functions, to preserver structure.
+inlinetoplevel expr@(Var f) | (Name.isSystemName . Id.idName) f = do
+  -- See if this is a top level binding for which we have a body
+  body_maybe <- Trans.lift $ getGlobalBind f
+  case body_maybe of
+    Just body -> do
+      -- Get the normalized version
+      norm <- Trans.lift $ getNormalized f
+      if needsInline norm 
+        then
+          change norm
+        else
+          return expr
+    -- No body, this is probably a local variable or builtin or external
+    -- function.
+    Nothing -> return expr
+-- Leave all other expressions unchanged
+inlinetoplevel expr = return expr
+inlinetopleveltop = everywhere ("inlinetoplevel", inlinetoplevel)
+
+needsInline :: CoreExpr -> Bool
+needsInline expr = case splitNormalized expr of
+  -- Inline any function that only has a single definition, it is probably
+  -- simple enough. This might inline some stuff that it shouldn't though it
+  -- will never inline user-defined functions (inlinetoplevel only tries
+  -- system names) and inlining should never break things.
+  (args, [bind], res) -> True
+  _ -> False
+
 --------------------------------
 -- Scrutinee simplification
 --------------------------------
@@ -609,6 +641,22 @@ funextract expr = return expr
 -- Perform this transform everywhere
 funextracttop = everywhere ("funextract", funextract)
 
+--------------------------------
+-- Ensure that a function that just returns another function (or rather,
+-- another top-level binder) is still properly normalized. This is a temporary
+-- solution, we should probably integrate this pass with lambdasimpl and
+-- letsimpl instead.
+--------------------------------
+simplrestop expr@(Lam _ _) = return expr
+simplrestop expr@(Let _ _) = return expr
+simplrestop expr = do
+  local_var <- Trans.lift $ is_local_var expr
+  if local_var
+    then
+      return expr
+    else do
+      id <- Trans.lift $ mkBinderFor expr "res" 
+      change $ Let (NonRec id expr) (Var id)
 --------------------------------
 -- End of transformations
 --------------------------------
@@ -617,7 +665,7 @@ funextracttop = everywhere ("funextract", funextract)
 
 
 -- What transforms to run?
-transforms = [argproptop, funextracttop, etatop, betatop, castproptop, letremovesimpletop, letderectop, letremovetop, letsimpltop, letflattop, scrutsimpltop, casesimpltop, caseremovetop, inlinenonreptop, appsimpltop, letremoveunusedtop, castsimpltop, lambdasimpltop]
+transforms = [inlinetopleveltop, argproptop, funextracttop, etatop, betatop, castproptop, letremovesimpletop, letderectop, letremovetop, letsimpltop, letflattop, scrutsimpltop, casesimpltop, caseremovetop, inlinenonreptop, appsimpltop, letremoveunusedtop, castsimpltop, lambdasimpltop, simplrestop]
 
 -- | Returns the normalized version of the given function.
 getNormalized ::