Try debugging crash

1 files changed, 8 insertions, 5 deletions

diff --git a/src/Numeric/ADDual/Internal.hs b/src/Numeric/ADDual/Internal.hs
index 8228694..d8e6e0a 100644
--- a/src/Numeric/ADDual/Internal.hs
+++ b/src/Numeric/ADDual/Internal.hs
@@ -15,18 +15,18 @@ import qualified Data.Vector.Storable as VS
 import qualified Data.Vector.Storable.Mutable as VSM
 import Foreign.Ptr
 import Foreign.Storable
+import GHC.Stack
 import GHC.Exts (withDict)
 import System.IO.Unsafe
 
--- import System.IO (hPutStrLn, stderr)
-
--- import Numeric.ADDual.IDGen
+import System.IO (hPutStrLn, stderr)
 
 
 -- TODO: full vjp (just some more Traversable mess)
 {-# NOINLINE gradient' #-}
 gradient' :: forall a f. (Traversable f, Num a, Storable a)
-          -- => Show a  -- TODO: remove
+          => HasCallStack
+          => Show a  -- TODO: remove
           => (forall s. Taping s a => f (Dual s a) -> Dual s a)
           -> f a -> a -> (a, f a)
 gradient' f inp topctg = unsafePerformIO $ do
@@ -50,6 +50,7 @@ gradient' f inp topctg = unsafePerformIO $ do
 
   let backpropagate i chunk@(Chunk ci0 vec) tape
         | i >= ci0 = do
+            -- hPutStrLn stderr $ "read at ci0=" ++ show ci0 ++ " i=" ++ show i
             ctg <- VSM.read accums i
             Contrib i1 dx i2 dy <- VSM.read vec (i - ci0)
             when (i1 /= -1) $ VSM.modify accums (+ ctg*dx) i1
@@ -174,7 +175,9 @@ data WriteTapeAction a = WTANewvec (VSM.IOVector (Contrib a))
 writeTape :: forall a s proxy. (Num a, Storable a, Taping s a) => proxy s -> Int -> a -> Int -> a -> Int
 writeTape _ i1 dx i2 dy = unsafePerformIO $ writeTapeIO (Proxy @s) i1 dx i2 dy
 
-writeTapeIO :: forall a s proxy. (Num a, Storable a, Taping s a) => proxy s -> Int -> a -> Int -> a -> IO Int
+writeTapeIO :: forall a s proxy. (Num a, Storable a, Taping s a)
+            => HasCallStack
+            => proxy s -> Int -> a -> Int -> a -> IO Int
 writeTapeIO _ i1 dx i2 dy = do
   MLog idref (Chunk ci0 vec) _ <- readIORef (getTape @s)
   let n = VSM.length vec