improved handling of genvars

src/Convert.hs

@@ -14,6 +14,7 @@ import qualified Convert.AsgnOp
 import qualified Convert.Assertion
 import qualified Convert.BlockDecl
 import qualified Convert.DimensionQuery
+import qualified Convert.DuplicateGenvar
 import qualified Convert.EmptyArgs
 import qualified Convert.Enum
 import qualified Convert.ForDecl
@@ -56,6 +57,7 @@ phases excludes =
     , Convert.NamedBlock.convert
     , Convert.Assertion.convert
     , Convert.BlockDecl.convert
+    , Convert.DuplicateGenvar.convert
     , selectExclude (Job.Logic    , Convert.Logic.convert)
     , Convert.FuncRet.convert
     , Convert.FuncRoutine.convert

src/Convert/DuplicateGenvar.hs

@@ -0,0 +1,52 @@
+{- sv2v
+ - Author: Zachary Snow <zach@zachjs.com>
+ -
+ - Conversion to remove duplicate genvar declarations
+ -}
+
+module Convert.DuplicateGenvar (convert) where
+
+import Control.Monad.State
+import qualified Data.Set as Set
+
+import Convert.Traverse
+import Language.SystemVerilog.AST
+
+type IdentSet = Set.Set Identifier
+
+convert :: [AST] -> [AST]
+convert = map $ traverseDescriptions traverseDescription
+
+traverseDescription :: Description -> Description
+traverseDescription (part @ Part{}) =
+    Part attrs extern kw lifetime name ports items'
+    where
+        Part attrs extern kw lifetime name ports items = part
+        -- intentionally only looks at top level module items
+        items' = evalState (mapM traverseModuleItemM items) Set.empty
+traverseDescription other = other
+
+traverseModuleItemM :: ModuleItem -> State IdentSet ModuleItem
+traverseModuleItemM (Genvar x) = do
+    alreadyExists <- gets $ Set.member x
+    if alreadyExists
+        then return $ Generate []
+        else do
+            modify $ Set.insert x
+            return $ Genvar x
+traverseModuleItemM (Generate items) = do
+    s <- get
+    items' <- traverseItems items
+    s' <- get
+    items'' <- traverseItems items'
+    let genvarDecls = map (GenModuleItem . Genvar) $
+            Set.toList $ Set.difference s' s
+    return $ Generate (genvarDecls ++ items'')
+    where traverseItems = mapM $ traverseNestedGenItemsM traverseGenItemM
+traverseModuleItemM other = return other
+
+traverseGenItemM :: GenItem -> State IdentSet GenItem
+traverseGenItemM (GenModuleItem item) = do
+    item' <- traverseModuleItemM item
+    return $ GenModuleItem item'
+traverseGenItemM other = return other

src/Convert/ForDecl.hs

@@ -2,11 +2,10 @@
  - Author: Zachary Snow <zach@zachjs.com>
  -
  - Verilog-2005 requires that for loops have have exactly one assignment in the
- - initialization section. For generate for loops, we move any genvar
- - declarations to a wrapping generate block. For procedural for loops, we pull
- - the declarations out to a wrapping block, and convert all but one assignment
- - to a preceding statement. If a for loop has no assignments or declarations, a
- - dummy declaration is generated.
+ - initialization section. For procedural for loops, we pull the declarations
+ - out to a wrapping block, and convert all but one assignment to a preceding
+ - statement. If a for loop has no assignments or declarations, a dummy
+ - declaration is generated.
  -}
 
 module Convert.ForDecl (convert) where
@@ -17,35 +16,7 @@ import Language.SystemVerilog.AST
 convert :: [AST] -> [AST]
 convert =
     map $ traverseDescriptions $ traverseModuleItems $
-    ( traverseStmts    convertStmt
-    . traverseGenItems convertGenItem
-    )
-
-convertGenItem :: GenItem -> GenItem
-convertGenItem (GenFor (True, _, _) _ _ GenNull) = GenNull
-convertGenItem (GenFor (True, _, _) _ _ (GenBlock _ [])) = GenNull
-convertGenItem (GenFor (True, x, e) a b c) =
-    GenBlock "" genItems
-    where
-        bx = case c of
-            GenBlock name _ -> name
-            _ -> ""
-        x' = if null bx then x else bx ++ "_" ++ x
-        Generate genItems =
-            traverseNestedModuleItems converter $ Generate $
-            [ GenModuleItem $ Genvar x'
-            , GenFor (False, x, e) a b c
-            ]
-        converter =
-            (traverseExprs $ traverseNestedExprs convertExpr) .
-            (traverseLHSs  $ traverseNestedLHSs  convertLHS )
-        prefix :: String -> String
-        prefix ident = if ident == x then x' else ident
-        convertExpr (Ident ident) = Ident $ prefix ident
-        convertExpr other = other
-        convertLHS (LHSIdent ident) = LHSIdent $ prefix ident
-        convertLHS other = other
-convertGenItem other = other
+    traverseStmts convertStmt
 
 convertStmt :: Stmt -> Stmt
 convertStmt (For (Left []) cc asgns stmt) =

src/Convert/Traverse.hs

@@ -63,6 +63,7 @@ module Convert.Traverse
 , traverseGenItemsM
 , traverseGenItems
 , collectGenItemsM
+, traverseNestedGenItemsM
 , traverseAsgnsM
 , traverseAsgns
 , collectAsgnsM
@@ -633,11 +634,11 @@ traverseExprsM' strat exprMapper = moduleItemMapper
         a'' <- traverseAssertionExprsM exprMapper a'
         return $ AssertionItem (mx, a'')
 
-    genItemMapper (GenFor (n1, x1, e1) cc (x2, op2, e2) subItem) = do
+    genItemMapper (GenFor (x1, e1) cc (x2, op2, e2) subItem) = do
         e1' <- exprMapper e1
         e2' <- exprMapper e2
         cc' <- exprMapper cc
-        return $ GenFor (n1, x1, e1') cc' (x2, op2, e2') subItem
+        return $ GenFor (x1, e1') cc' (x2, op2, e2') subItem
     genItemMapper (GenIf e i1 i2) = do
         e' <- exprMapper e
         return $ GenIf e' i1 i2
@@ -762,12 +763,12 @@ traverseLHSsM' strat mapper item =
             items' <- mapM (traverseNestedGenItemsM traverGenItemLHSsM) items
             return $ Generate items'
         traverseModuleItemLHSsM other = return other
-        traverGenItemLHSsM (GenFor (n1, x1, e1) cc (x2, op2, e2) subItem) = do
-            wrapped_x1' <- (if n1 then return else mapper) $ LHSIdent x1
+        traverGenItemLHSsM (GenFor (x1, e1) cc (x2, op2, e2) subItem) = do
+            wrapped_x1' <- mapper $ LHSIdent x1
             wrapped_x2' <- mapper $ LHSIdent x2
             let LHSIdent x1' = wrapped_x1'
             let LHSIdent x2' = wrapped_x2'
-            return $ GenFor (n1, x1', e1) cc (x2', op2, e2) subItem
+            return $ GenFor (x1', e1) cc (x2', op2, e2) subItem
         traverGenItemLHSsM other = return other
 
 traverseLHSs' :: TFStrategy -> Mapper LHS -> Mapper ModuleItem
@@ -956,12 +957,18 @@ traverseNestedGenItemsM mapper = fullMapper
         fullMapper stmt =
             mapper stmt >>= traverseSinglyNestedGenItemsM fullMapper
 
+flattenGenBlocks :: GenItem -> [GenItem]
+flattenGenBlocks (GenBlock "" items) = items
+flattenGenBlocks (GenFor _ _ _ GenNull) = []
+flattenGenBlocks GenNull = []
+flattenGenBlocks other = [other]
+
 traverseSinglyNestedGenItemsM :: Monad m => MapperM m GenItem -> MapperM m GenItem
 traverseSinglyNestedGenItemsM fullMapper = gim
     where
         gim (GenBlock x subItems) = do
             subItems' <- mapM fullMapper subItems
-            return $ GenBlock x (concatMap flattenBlocks subItems')
+            return $ GenBlock x (concatMap flattenGenBlocks subItems')
         gim (GenFor a b c subItem) = do
             subItem' <- fullMapper subItem
             return $ GenFor a b c subItem'
@@ -976,9 +983,6 @@ traverseSinglyNestedGenItemsM fullMapper = gim
         gim (GenModuleItem moduleItem) =
             return $ GenModuleItem moduleItem
         gim (GenNull) = return GenNull
-        flattenBlocks :: GenItem -> [GenItem]
-        flattenBlocks (GenBlock "" items) = items
-        flattenBlocks other = [other]
 
 traverseAsgnsM' :: Monad m => TFStrategy -> MapperM m (LHS, Expr) -> MapperM m ModuleItem
 traverseAsgnsM' strat mapper = moduleItemMapper
@@ -1024,10 +1028,8 @@ collectStmtAsgnsM = collectify traverseStmtAsgnsM
 traverseNestedModuleItemsM :: Monad m => MapperM m ModuleItem -> MapperM m ModuleItem
 traverseNestedModuleItemsM mapper = fullMapper
     where
-        fullMapper (Generate [GenBlock "" genItems]) =
-            mapM fullGenItemMapper genItems >>= mapper . Generate
         fullMapper (Generate genItems) = do
-            let genItems' = filter (/= GenNull) genItems
+            let genItems' = concatMap flattenGenBlocks genItems
             mapM fullGenItemMapper genItems' >>= mapper . Generate
         fullMapper (MIAttr attr mi) =
             fullMapper mi >>= mapper . MIAttr attr

src/Language/SystemVerilog/AST/GenItem.hs

@@ -22,7 +22,7 @@ import {-# SOURCE #-} Language.SystemVerilog.AST.ModuleItem (ModuleItem)
 data GenItem
     = GenBlock Identifier [GenItem]
     | GenCase  Expr [GenCase]
-    | GenFor   (Bool, Identifier, Expr) Expr (Identifier, AsgnOp, Expr) GenItem
+    | GenFor   (Identifier, Expr) Expr (Identifier, AsgnOp, Expr) GenItem
     | GenIf    Expr GenItem GenItem
     | GenNull
     | GenModuleItem ModuleItem
@@ -39,9 +39,8 @@ instance Show GenItem where
         where bodyStr = indent $ unlines' $ map showGenCase cs
     show (GenIf e a GenNull) = printf "if (%s) %s"          (show e) (show a)
     show (GenIf e a b      ) = printf "if (%s) %s\nelse %s" (show e) (show a) (show b)
-    show (GenFor (new, x1, e1) c (x2, o2, e2) s) =
-        printf "for (%s%s = %s; %s; %s %s %s) %s"
-            (if new then "genvar " else "")
+    show (GenFor (x1, e1) c (x2, o2, e2) s) =
+        printf "for (%s = %s; %s; %s %s %s) %s"
             x1 (show e1)
             (show c)
             x2 (show o2) (show e2)

src/Language/SystemVerilog/Parser/Parse.y

@@ -1238,7 +1238,7 @@ ConditionalGenerateConstruct :: { GenItem }
   | "if" "(" Expr ")" GenItemOrNull %prec NoElse         { GenIf $3 $5 GenNull }
   | "case" "(" Expr ")" GenCases "endcase" { GenCase $3 $5 }
 LoopGenerateConstruct :: { GenItem }
-  : "for" "(" GenvarInitialization ";" Expr ";" GenvarIteration ")" GenItem { GenFor $3 $5 $7 $9 }
+  : "for" "(" GenvarInitialization ";" Expr ";" GenvarIteration ")" GenItem { $3 $5 $7 $9 }
 
 GenBlock :: { (Identifier, [GenItem]) }
   : "begin" StrTag GenItems "end" StrTag { (combineTags $2 $5, $3) }
@@ -1250,9 +1250,9 @@ GenCase :: { GenCase }
   : Exprs         ":"  GenItemOrNull { ($1, $3) }
   | "default" opt(":") GenItemOrNull { ([], $3) }
 
-GenvarInitialization :: { (Bool, Identifier, Expr) }
-  : "genvar" Identifier "=" Expr { (True , $2, $4) }
-  |          Identifier "=" Expr { (False, $1, $3) }
+GenvarInitialization :: { Expr -> (Identifier, AsgnOp, Expr) -> GenItem -> GenItem }
+  : "genvar" Identifier "=" Expr { \a b c -> GenBlock "" [GenModuleItem (Genvar $2), GenFor ($2, $4) a b c] }
+  |          Identifier "=" Expr { GenFor ($1, $3) }
 
 GenvarIteration :: { (Identifier, AsgnOp, Expr) }
   : Identifier AsgnOp Expr { ($1, $2, $3) }

sv2v.cabal

@@ -63,6 +63,7 @@ executable sv2v
     Convert.Assertion
     Convert.BlockDecl
     Convert.DimensionQuery
+    Convert.DuplicateGenvar
     Convert.EmptyArgs
     Convert.Enum
     Convert.ForDecl