Fix (System)Verilog literal rendering of Index values

There was confusion between the size in bits and the type level argument to Index. Fixes #2813
clash-lang · Oct 7, 2024 · 3f14181 · 3f14181
1 parent d4975ff
commit 3f14181
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diff --git a/changelog/2024-10-01T14_41_36+02_00_fix_index_literal_rendering b/changelog/2024-10-01T14_41_36+02_00_fix_index_literal_rendering
@@ -0,0 +1 @@
+FIXED: Clash hanging when rendering `Index n` literals, for large values of `n` [#2813](https://github.com/clash-lang/clash-compiler/issues/2813)
diff --git a/clash-lib/src/Clash/Backend/SystemVerilog.hs b/clash-lib/src/Clash/Backend/SystemVerilog.hs
@@ -1,7 +1,7 @@
 {-|
   Copyright   :  (C) 2015-2016, University of Twente,
                      2017-2018, Google Inc.,
-                     2021-2023, QBayLogic B.V.,
+                     2021-2024, QBayLogic B.V.,
                      2022     , Google Inc.
   License     :  BSD2 (see the file LICENSE)
   Maintainer  :  QBayLogic B.V. <[email protected]>
@@ -65,7 +65,7 @@ import           Clash.Netlist.Types                  hiding (intWidth, usages,
 import           Clash.Netlist.Util
 import           Clash.Signal.Internal                (ActiveEdge (..))
 import           Clash.Util
-  (SrcSpan, noSrcSpan, curLoc, makeCached, indexNote)
+  (SrcSpan, clogBase, noSrcSpan, curLoc, makeCached, indexNote)
 import           Clash.Util.Graph                     (reverseTopSort)
 
 -- | State for the 'Clash.Backend.SystemVerilog.SystemVerilogM' monad:
@@ -1228,7 +1228,9 @@ expr_ _ (BlackBoxE pNm _ _ _ _ bbCtx _)
 expr_ _ (BlackBoxE pNm _ _ _ _ bbCtx _)
   | pNm == "Clash.Sized.Internal.Index.fromInteger#"
   , [Literal _ (NumLit n), Literal _ i] <- extractLiterals bbCtx
-  = exprLitSV (Just (Index (fromInteger n),fromInteger n)) i
+  , Just k <- clogBase 2 n
+  , let k' = max 1 k
+  = exprLitSV (Just (Index (fromInteger n),k')) i
 
 expr_ b (BlackBoxE _ libs imps inc bs bbCtx b') =
   parenIf (b || b') (Ap (renderBlackBox libs imps inc bs bbCtx <*> pure 0))

diff --git a/clash-lib/src/Clash/Backend/Verilog.hs b/clash-lib/src/Clash/Backend/Verilog.hs
@@ -82,7 +82,7 @@ import           Clash.Netlist.Types as N             hiding (intWidth, usages,
 import           Clash.Netlist.Util
 import           Clash.Signal.Internal                (ActiveEdge (..))
 import           Clash.Util
-  (SrcSpan, noSrcSpan, curLoc, indexNote, makeCached)
+  (SrcSpan, clogBase, noSrcSpan, curLoc, indexNote, makeCached)
 
 -- | State for the 'Clash.Backend.Verilog.VerilogM' monad:
 data VerilogState =
@@ -1151,7 +1151,9 @@ expr_ _ (BlackBoxE pNm _ _ _ _ bbCtx _)
 expr_ _ (BlackBoxE pNm _ _ _ _ bbCtx _)
   | pNm == "Clash.Sized.Internal.Index.fromInteger#"
   , [Literal _ (NumLit n), Literal _ i] <- extractLiterals bbCtx
-  = exprLit undefValue (Just (Index (fromInteger n),fromInteger n)) i
+  , Just k <- clogBase 2 n
+  , let k' = max 1 k
+  = exprLitV (Just (Index (fromInteger n),k')) i
 
 expr_ b (BlackBoxE _ libs imps inc bs bbCtx b') = do
   parenIf (b || b') (Ap (renderBlackBox libs imps inc bs bbCtx <*> pure 0))