Correctly handle Indexs fromInteger# and maxBound# for large li…

…terals

VHDL would be incorrect for values larger than 2^MACHINE_WIDTH

clash-vhdl/CHANGELOG.md

@@ -1,8 +1,9 @@
 # Changelog for the [`clash-vhdl`](http://hackage.haskell.org/package/clash-vhdl) package
 
-## 0.6.15
+## 0.6.15 *July 19th 2016*
 * Fixes bugs:
   * Incorrect primitive for `Index`s `*#`
+  * Incorrect handling of `Index`s `fromInteger#` and `maxBound#` primitives for values larger than 2^MACHINE_WIDTH
 
 ## 0.6.14 *July 15th 2016*
 * New features:

clash-vhdl/src/CLaSH/Backend/VHDL.hs

@@ -641,6 +641,21 @@ expr_ _ (BlackBoxE pNm _ bbCtx _)
   , [Literal _ (NumLit n), Literal _ i] <- extractLiterals bbCtx
   = exprLit (Just (BitVector (fromInteger n),fromInteger n)) i
 
+expr_ _ (BlackBoxE pNm _ bbCtx _)
+  | pNm == "CLaSH.Sized.Internal.Index.fromInteger#"
+  , [Literal _ (NumLit n), Literal _ i] <- extractLiterals bbCtx
+  , Just k <- clogBase 2 n
+  , let k' = max 1 k
+  = exprLit (Just (Unsigned k',k')) i
+
+expr_ _ (BlackBoxE pNm _ bbCtx _)
+  | pNm == "CLaSH.Sized.Internal.Index.maxBound#"
+  , [Literal _ (NumLit n)] <- extractLiterals bbCtx
+  , n > 0
+  , Just k <- clogBase 2 n
+  , let k' = max 1 k
+  = exprLit (Just (Unsigned k',k')) (NumLit (n-1))
+
 expr_ _ (BlackBoxE pNm _ bbCtx _)
   | pNm == "GHC.Types.I#"
   , [Literal _ (NumLit n)] <- extractLiterals bbCtx