sv2v/src/Convert/AsgnOp.hs

43 lines
1.4 KiB
Haskell

{- sv2v
- Author: Zachary Snow <zach@zachjs.com>
-
- Conversion for binary assignment operators, which can appear in for loops and
- as a special case of blocking assignment statements. We simply elaborate them
- in the obvious manner: a += b -> a = a + b.
-}
module Convert.AsgnOp (convert) where
import Convert.Traverse
import Language.SystemVerilog.AST
convert :: [AST] -> [AST]
convert =
map $ traverseDescriptions $ traverseModuleItems $
( traverseStmts (traverseNestedStmts convertStmt)
. traverseGenItems (traverseNestedGenItems convertGenItem)
)
convertGenItem :: GenItem -> GenItem
convertGenItem (GenFor a b (ident, AsgnOp op, expr) c) =
GenFor a b (ident, AsgnOpEq, elabBinOp op (Ident ident) expr) c
convertGenItem other = other
convertStmt :: Stmt -> Stmt
convertStmt (For inits cc asgns stmt) =
For inits cc asgns' stmt
where
asgns' = map convertAsgn asgns
convertAsgn :: (LHS, AsgnOp, Expr) -> (LHS, AsgnOp, Expr)
convertAsgn (lhs, AsgnOp op, expr) =
(lhs, AsgnOpEq, elabBinOp op (lhsToExpr lhs) expr)
convertAsgn other = other
convertStmt (Asgn (AsgnOp op) mt lhs expr) =
Asgn AsgnOpEq mt lhs (elabBinOp op (lhsToExpr lhs) expr)
convertStmt other = other
elabBinOp :: BinOp -> Expr -> Expr -> Expr
elabBinOp Add e1 (UniOp UniSub e2) = BinOp Sub e1 e2
elabBinOp Sub e1 (UniOp UniSub e2) = BinOp Add e1 e2
elabBinOp op e1 e2 = BinOp op e1 e2