sv2v/Convert/Logic.hs

82 lines
3.1 KiB
Haskell

{- sv2v
- Author: Zachary Snow <zach@zachjs.com>
-
- Conversion for `logic`
-}
-- Regarding `logic` conversion: The SystemVerilog grammar has the concept of a
-- `data_declaration`, which seems to cover things much more generally. While
-- obviously `logic` can appear as module items or ports, they can also be
-- function arguments, for example.
-- It seems like logic only becomes reg if it is assigned to in an always block.
module Convert.Logic (convert) where
import Data.Maybe (fromJust)
import qualified Data.Set as Set
import Language.SystemVerilog.AST
type RegIdents = Set.Set String
convert :: AST -> AST
convert descriptions = map convertDescription descriptions
convertDescription :: Description -> Description
convertDescription (Module name ports items) =
Module name ports $ map (convertModuleItem idents) items
where
idents = Set.unions $ map getRegIdents items
convertDescription other = other
getStmtLHSs :: Stmt -> [LHS]
getStmtLHSs (Block _ stmts) = concat $ map getStmtLHSs stmts
getStmtLHSs (Case kw e cases (Just stmt)) = (getStmtLHSs stmt) ++ (getStmtLHSs $ Case kw e cases Nothing)
getStmtLHSs (Case _ _ cases Nothing) = concat $ map getStmtLHSs $ map snd cases
getStmtLHSs (BlockingAssignment lhs _) = [lhs]
getStmtLHSs (NonBlockingAssignment lhs _) = [lhs]
getStmtLHSs (For _ _ _ stmt) = getStmtLHSs stmt
getStmtLHSs (If _ s1 s2) = (getStmtLHSs s1) ++ (getStmtLHSs s2)
getStmtLHSs (Timing _ s) = getStmtLHSs s
getStmtLHSs (Null) = []
getLHSIdents :: LHS -> [Identifier]
getLHSIdents (LHS vx ) = [vx]
getLHSIdents (LHSBit vx _) = [vx]
getLHSIdents (LHSRange vx _) = [vx]
getLHSIdents (LHSConcat lhss) = concat $ map getLHSIdents lhss
getRegIdents :: ModuleItem -> RegIdents
getRegIdents (AlwaysC _ stmt) =
Set.fromList idents
where
lhss = getStmtLHSs stmt
idents = concat $ map getLHSIdents lhss
getRegIdents _ = Set.empty
convertModuleItem :: RegIdents -> ModuleItem -> ModuleItem
convertModuleItem idents (LocalNet (Logic mr) ident val) =
LocalNet (t mr) ident val
where
t = if Set.member ident idents then Reg else Wire
convertModuleItem idents (Generate items) = Generate $ map (convertGenItem $ convertModuleItem idents) items
convertModuleItem _ other = other
convertGenItem :: (ModuleItem -> ModuleItem) -> GenItem -> GenItem
convertGenItem f item = convertGenItem' item
where
convertGenItem' :: GenItem -> GenItem
convertGenItem' (GenBlock x items) = GenBlock x $ map convertGenItem' items
convertGenItem' (GenFor a b c d items) = GenFor a b c d $ map convertGenItem' items
convertGenItem' (GenIf e i1 i2) = GenIf e (convertGenItem' i1) (convertGenItem' i2)
convertGenItem' (GenNull) = GenNull
convertGenItem' (GenModuleItem moduleItem) = GenModuleItem $ f moduleItem
convertGenItem' (GenCase e cases def) = GenCase e cases' def'
where
cases' = zip (map fst cases) (map (convertGenItem' . snd) cases)
def' = if def == Nothing
then Nothing
else Just $ convertGenItem' $ fromJust def