From 91a45ce23469be8f039ba3d84c2d6bd50499cf52 Mon Sep 17 00:00:00 2001
From: Zachary Snow <zach@zachjs.com>
Date: Sat, 10 Jul 2021 19:58:19 -0400
Subject: [PATCH] constant folding evaluates localparam casts where possible

---
 src/Convert/Simplify.hs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/Convert/Simplify.hs b/src/Convert/Simplify.hs
index 0af2a8b..82338c2 100644
--- a/src/Convert/Simplify.hs
+++ b/src/Convert/Simplify.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE PatternSynonyms #-}
 {- sv2v
  - Author: Zachary Snow <zach@zachjs.com>
  -
@@ -44,7 +45,15 @@ traverseDeclM decl = do
         _ -> return ()
     return decl'
 
+pattern SimpleVector :: Signing -> Integer -> Integer -> Type
+pattern SimpleVector sg l r <- IntegerVector _ sg [(RawNum l, RawNum r)]
+
 insertExpr :: Identifier -> Expr -> Scoper Expr ()
+insertExpr ident (Cast (Left (SimpleVector sg l r)) (Number n)) =
+    insertExpr ident $ Number $ numberCast signed size n
+    where
+        signed = sg == Signed
+        size = fromIntegral $ abs $ l - r + 1
 insertExpr ident expr = do
     expr' <- substituteExprM expr
     when (isSimpleExpr expr') $ insertElem ident expr'