Rename letremove to letremovesimple.

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

diff --git a/cλash/CLasH/Normalize.hs b/cλash/CLasH/Normalize.hs
index 07ded20bbb8d387c38372f749c9c79789d38cdbf..18010cf56e0cfeebfd0da111e4e53f66c400edcc 100644 (file)
--- a/cλash/CLasH/Normalize.hs
+++ b/cλash/CLasH/Normalize.hs
@@ -146,6 +146,9 @@ letderectop = everywhere ("letderec", letderec)
 -- let simplification
 --------------------------------
 letsimpl, letsimpltop :: Transform
+-- Don't simplify a let that evaluates to another let, since this is already
+-- normal form (and would cause infinite loops with letflat below).
+letsimpl expr@(Let _ (Let _ _)) = return expr
 -- Put the "in ..." value of a let in its own binding, but not when the
 -- expression is already a local variable, or not representable (to prevent loops with inlinenonrep).
 letsimpl expr@(Let binds res) = do
@@ -186,8 +189,8 @@ letflattop = everywhere ("letflat", letflat)
 -- Simple let binding removal
 --------------------------------
 -- Remove a = b bindings from let expressions everywhere
-letremovetop :: Transform
-letremovetop = everywhere ("letremove", inlinebind (\(b, e) -> Trans.lift $ is_local_var e))
+letremovesimpletop :: Transform
+letremovesimpletop = everywhere ("letremovesimple", inlinebind (\(b, e) -> Trans.lift $ is_local_var e))
 
 --------------------------------
 -- Unused let binding removal
@@ -553,7 +556,7 @@ funextracttop = everywhere ("funextract", funextract)
 
 
 -- What transforms to run?
-transforms = [argproptop, funextracttop, etatop, betatop, castproptop, letremovetop, letderectop, letsimpltop, letflattop, scrutsimpltop, casesimpltop, caseremovetop, inlinenonreptop, appsimpltop, letmergetop, letremoveunusedtop, castsimpltop]
+transforms = [argproptop, funextracttop, etatop, betatop, castproptop, letremovesimpletop, letderectop, letsimpltop, letflattop, scrutsimpltop, casesimpltop, caseremovetop, inlinenonreptop, appsimpltop, letmergetop, letremoveunusedtop, castsimpltop]
 
 -- | Returns the normalized version of the given function.
 getNormalized ::