conversion for implicitly variably sized parameters

src/Convert.hs

@@ -39,6 +39,7 @@ import qualified Convert.Simplify
 import qualified Convert.SizeCast
 import qualified Convert.StarPort
 import qualified Convert.Stream
+import qualified Convert.StringParam
 import qualified Convert.Struct
 import qualified Convert.TFBlock
 import qualified Convert.Typedef
@@ -89,6 +90,7 @@ phases excludes =
     , Convert.ForDecl.convert
     , Convert.Jump.convert
     , Convert.Foreach.convert
+    , Convert.StringParam.convert
     , selectExclude (Job.Interface, Convert.Interface.convert)
     , selectExclude (Job.Always   , Convert.AlwaysKW.convert)
     , selectExclude (Job.Succinct , Convert.RemoveComments.convert)

src/Convert/StringParam.hs

@@ -0,0 +1,99 @@
+{-# LANGUAGE PatternSynonyms #-}
+{- sv2v
+ - Author: Zachary Snow <zach@zachjs.com>
+ -
+ - Conversion for variable-length string parameters
+ -}
+
+module Convert.StringParam (convert) where
+
+import Control.Monad.Writer.Strict
+import qualified Data.Map.Strict as Map
+
+import Convert.Traverse
+import Language.SystemVerilog.AST
+
+type PartStringParams = Map.Map Identifier [(Identifier, Int)]
+
+convert :: [AST] -> [AST]
+convert files =
+    if Map.null partStringParams
+        then files
+        else map traverseModuleItem files'
+    where
+        (files', partStringParams) = runWriter $
+            mapM (traverseDescriptionsM traverseDescriptionM) files
+        traverseModuleItem = traverseDescriptions $ traverseModuleItems $
+            mapInstance partStringParams
+
+-- adds automatic width parameters for string parameters
+traverseDescriptionM :: Description -> Writer PartStringParams Description
+traverseDescriptionM (Part attrs extern kw lifetime name ports items) =
+    if null stringParamNames
+        then return $ Part attrs extern kw lifetime name ports items
+        else do
+            tell $ Map.singleton name stringParamIds
+            return $ Part attrs extern kw lifetime name ports items'
+    where
+        (items', stringParamNames) = runWriter $
+            mapM (traverseNestedModuleItemsM traverseModuleItemM) items
+        allParamNames = parameterNames items
+        stringParamIds = filter (flip elem stringParamNames . fst) $
+            zip allParamNames [0..]
+traverseDescriptionM other = return other
+
+-- given a list of module items, produces the parameter names in order
+parameterNames :: [ModuleItem] -> [Identifier]
+parameterNames =
+    execWriter . mapM (collectNestedModuleItemsM $ collectDeclsM collectDeclM)
+    where
+        collectDeclM :: Decl -> Writer [Identifier] ()
+        collectDeclM (Param Parameter   _ x _) = tell [x]
+        collectDeclM (ParamType Parameter x _) = tell [x]
+        collectDeclM _ = return ()
+
+pattern UnknownType :: Type
+pattern UnknownType = Implicit Unspecified []
+
+-- rewrite an existing string parameter
+traverseModuleItemM :: ModuleItem -> Writer [Identifier] ModuleItem
+traverseModuleItemM (orig @ (MIPackageItem (Decl (Param Parameter t x e)))) =
+    case (t, e) of
+        (UnknownType, String str) -> do
+            tell [x]
+            return $ Generate $ map wrap [width str, param str]
+            where wrap = GenModuleItem . MIPackageItem . Decl
+        _ -> return orig
+    where
+        w = widthName x
+        r = (BinOp Sub (Ident w) (RawNum 1), RawNum 0)
+        t' =  IntegerVector TBit Unspecified [r]
+        defaultWidth str = DimsFn FnBits $ Right $ String str
+        width str = Param Parameter UnknownType w (defaultWidth str)
+        param str = Param Parameter t' x (String str)
+traverseModuleItemM other = return other
+
+widthName :: Identifier -> Identifier
+widthName paramName = "_sv2v_width_" ++ paramName
+
+-- convert isntances which use the converted string parameters
+mapInstance :: PartStringParams -> ModuleItem -> ModuleItem
+mapInstance partStringParams (Instance m params x rs ports) =
+    case Map.lookup m partStringParams of
+        Nothing -> Instance m params x rs ports
+        Just stringParams -> Instance m params' x rs ports
+            where params' = concat $ zipWith (expand stringParams) params [0..]
+    where
+        expand :: [(Identifier, Int)] -> ParamBinding -> Int -> [ParamBinding]
+        expand _ (paramName, Left t) _ = [(paramName, Left t)]
+        expand stringParams (orig @ ("", Right expr)) idx =
+            if elem idx $ map snd stringParams
+                then [("", Right width), orig]
+                else [orig]
+            where width = DimsFn FnBits $ Right expr
+        expand stringParams (orig @ (paramName, Right expr)) _ =
+            if elem paramName $ map fst stringParams
+                then [(widthName paramName, Right width), orig]
+                else [orig]
+            where width = DimsFn FnBits $ Right expr
+mapInstance _ other = other

src/Convert/TypeOf.hs

@@ -37,12 +37,12 @@ traverseDeclM decl = do
             return $ case t' of
                 UnpackedType t'' a' -> Variable d t'' ident a' e
                 _ ->                   Variable d t'  ident [] e
-        Param    _ t ident   e -> do
-            t' <- if t == UnknownType
-                    then typeof e
-                    else return t
-            insertElem ident t'
-            return decl'
+        Param _ UnknownType ident String{} ->
+            insertElem ident UnknownType >> return decl'
+        Param _ UnknownType ident e ->
+            typeof e >>= insertElem ident >> return decl'
+        Param _ t ident _ ->
+            insertElem ident t >> return decl'
         ParamType{} -> return decl'
         CommentDecl{} -> return decl'
 
@@ -137,25 +137,39 @@ typeof (BinOp ShiftL  e _) = typeof e
 typeof (BinOp ShiftR  e _) = typeof e
 typeof (BinOp ShiftAL e _) = typeof e
 typeof (BinOp ShiftAR e _) = typeof e
-typeof (BinOp Add     a b) = return $ largerSizeType a b
-typeof (BinOp Sub     a b) = return $ largerSizeType a b
-typeof (BinOp Mul     a b) = return $ largerSizeType a b
-typeof (BinOp Div     a b) = return $ largerSizeType a b
-typeof (BinOp Mod     a b) = return $ largerSizeType a b
-typeof (BinOp BitAnd  a b) = return $ largerSizeType a b
-typeof (BinOp BitXor  a b) = return $ largerSizeType a b
-typeof (BinOp BitXnor a b) = return $ largerSizeType a b
-typeof (BinOp BitOr   a b) = return $ largerSizeType a b
-typeof (Mux   _       a b) = return $ largerSizeType a b
+typeof (BinOp Add     a b) = largerSizeType a b
+typeof (BinOp Sub     a b) = largerSizeType a b
+typeof (BinOp Mul     a b) = largerSizeType a b
+typeof (BinOp Div     a b) = largerSizeType a b
+typeof (BinOp Mod     a b) = largerSizeType a b
+typeof (BinOp BitAnd  a b) = largerSizeType a b
+typeof (BinOp BitXor  a b) = largerSizeType a b
+typeof (BinOp BitXnor a b) = largerSizeType a b
+typeof (BinOp BitOr   a b) = largerSizeType a b
+typeof (Mux   _       a b) = largerSizeType a b
 typeof (Concat      exprs) = return $ typeOfSize $ concatSize exprs
 typeof (Repeat reps exprs) = return $ typeOfSize size
     where size = BinOp Mul reps (concatSize exprs)
-typeof String{} = return UnknownType
+typeof (String str) =
+    return $ IntegerVector TBit Unspecified [r]
+    where
+        r = (RawNum $ len - 1, RawNum 0)
+        len = if null str then 1 else 8 * unescapedLength str
+        unescapedLength :: String -> Integer
+        unescapedLength [] = 0
+        unescapedLength ('\\' : _ : rest) = 1 + unescapedLength rest
+        unescapedLength (_        : rest) = 1 + unescapedLength rest
 typeof other = lookupTypeOf other
 
 -- produces a type large enough to hold either expression
-largerSizeType :: Expr -> Expr -> Type
-largerSizeType a b = typeOfSize $ largerSizeOf a b
+largerSizeType :: Expr -> Expr -> Scoper Type Type
+largerSizeType a (Number (Based 1 _ _ _ _)) = typeof a
+largerSizeType a b = do
+    t <- typeof a
+    u <- typeof b
+    return $ if t == u
+        then t
+        else typeOfSize $ largerSizeOf a b
 
 -- returns the total size of concatenated list of expressions
 concatSize :: [Expr] -> Expr

sv2v.cabal

@@ -89,6 +89,7 @@ executable sv2v
     Convert.SizeCast
     Convert.StarPort
     Convert.Stream
+    Convert.StringParam
     Convert.Struct
     Convert.TFBlock
     Convert.Traverse

test/basic/string.sv

@@ -1,5 +1,5 @@
 module top;
-    parameter FOO = "some useful string";
+    localparam FOO = "some useful string";
     localparam type T = type(FOO);
     localparam T BAR = "some other useful string";
     initial $display("'%s' '%s'", FOO, BAR);

test/basic/string.v

@@ -1,5 +1,5 @@
 module top;
-    parameter FOO = "some useful string";
+    localparam FOO = "some useful string";
     localparam BAR = "some other useful string";
     initial $display("'%s' '%s'", FOO, BAR);
 endmodule

test/basic/string_param.sv

@@ -0,0 +1,16 @@
+`include "string_param.vh"
+
+module Example(inp, out);
+    parameter PATTERN = "whatever";
+    parameter UNUSED = 0;
+    localparam IN_WIDTH = $bits(PATTERN);
+    localparam OUT_WIDTH = `COUNT_ONES(PATTERN);
+
+    input [IN_WIDTH - 1:0] inp;
+    output [OUT_WIDTH - 1:0] out;
+    if (PATTERN[0])
+        assign out[0] = inp[0];
+    for (genvar j = 1; j < IN_WIDTH; ++j)
+        if (PATTERN[j])
+            assign out[`COUNT_ONES(PATTERN[j - 1:0])] = inp[j];
+endmodule

test/basic/string_param.v

@@ -0,0 +1,16 @@
+`include "string_param.vh"
+
+module Example(inp, out);
+    parameter PATTERN = "whatever";
+    parameter IN_WIDTH = $bits(PATTERN);
+    localparam OUT_WIDTH = `COUNT_ONES(PATTERN);
+
+    input wire [IN_WIDTH - 1:0] inp;
+    output wire [OUT_WIDTH - 1:0] out;
+    if (PATTERN[0])
+        assign out[0] = inp[0];
+    genvar j;
+    for (j = 1; j < IN_WIDTH; j = j + 1)
+        if (PATTERN[j])
+            assign out[`COUNT_ONES(PATTERN[j - 1:0])] = inp[j];
+endmodule

test/basic/string_param.vh

@@ -0,0 +1,33 @@
+`define COUNT_ONES(expr) (0 \
+        + ((expr) >>  0 & 1'b1) + ((expr) >>  1 & 1'b1) + ((expr) >>  2 & 1'b1) + ((expr) >>  3 & 1'b1) \
+        + ((expr) >>  4 & 1'b1) + ((expr) >>  5 & 1'b1) + ((expr) >>  6 & 1'b1) + ((expr) >>  7 & 1'b1) \
+        + ((expr) >>  8 & 1'b1) + ((expr) >>  9 & 1'b1) + ((expr) >> 10 & 1'b1) + ((expr) >> 11 & 1'b1) \
+        + ((expr) >> 12 & 1'b1) + ((expr) >> 13 & 1'b1) + ((expr) >> 14 & 1'b1) + ((expr) >> 15 & 1'b1) \
+        + ((expr) >> 16 & 1'b1) + ((expr) >> 17 & 1'b1) + ((expr) >> 18 & 1'b1) + ((expr) >> 19 & 1'b1) \
+        + ((expr) >> 20 & 1'b1) + ((expr) >> 21 & 1'b1) + ((expr) >> 22 & 1'b1) + ((expr) >> 23 & 1'b1) \
+        + ((expr) >> 24 & 1'b1) + ((expr) >> 25 & 1'b1) + ((expr) >> 26 & 1'b1) + ((expr) >> 27 & 1'b1) \
+        + ((expr) >> 28 & 1'b1) + ((expr) >> 29 & 1'b1) + ((expr) >> 30 & 1'b1) + ((expr) >> 31 & 1'b1) \
+    )
+
+module top;
+    reg [31:0] data;
+
+`define TEST(idx, pattern, in_width, out_width) \
+    localparam p``idx = pattern; \
+    wire [in_width - 1:0] i``idx; \
+    wire [out_width - 1:0] o``idx; \
+    assign i``idx = data[0+:in_width]; \
+    Example #(p``idx, in_width) e``idx(i``idx, o``idx);
+
+    `TEST(1, 5'b10101, 5, 3)
+    `TEST(2, 10'b1110001111, 10, 7)
+
+    integer i;
+    initial begin
+        data = 0;
+        for (i = 0; i < 100; i = i + 1) begin
+            data = 1664525 * data + 1013904223;
+            #1 $display("%b %b %b", data, o1, o2);
+        end
+    end
+endmodule