None on empty vectors

Author: kirillgarbar

src/GraphBLAS-sharp.Backend/Vector/SpMSpV.fs

@@ -127,16 +127,7 @@ module SpMSpV =
                 computeOffsetsInplace queue (vector.NNZ * 2 + 1) collectedRows
 
             if gatherArraySize = 0 then
-                let resultRows =
-                    clContext.CreateClArrayWithSpecificAllocationMode(DeviceOnly, 1)
-
-                let resultValues =
-                    clContext.CreateClArrayWithSpecificAllocationMode(DeviceOnly, 1)
-
-                let resultColumns =
-                    clContext.CreateClArrayWithSpecificAllocationMode(DeviceOnly, 1)
-
-                resultRows, resultColumns, resultValues, gatherArraySize
+                None
             else
                 let ndRange =
                     Range1D.CreateValid(vector.NNZ, workGroupSize)
@@ -173,7 +164,7 @@ module SpMSpV =
 
                 collectedRows.Free queue
 
-                resultRows, resultIndices, resultValues, gatherArraySize
+                Some(resultRows, resultIndices, resultValues)
 
 
     let private multiplyScalar (clContext: ClContext) (mul: Expr<'a option -> 'b option -> 'c option>) workGroupSize =
@@ -246,17 +237,9 @@ module SpMSpV =
 
         fun (queue: MailboxProcessor<_>) (matrix: ClMatrix.CSR<'a>) (vector: ClVector.Sparse<'b>) ->
 
-            let gatherRows, gatherIndices, gatherValues, gatherLength = gather queue matrix vector
-
-            if gatherLength <= 0 then
-                gatherRows.Free queue
-                gatherValues.Free queue
-
-                { Context = clContext
-                  Indices = gatherIndices
-                  Values = clContext.CreateClArray 0
-                  Size = matrix.ColumnCount }
-            else
+            match gather queue matrix vector with
+            | None -> None
+            | Some (gatherRows, gatherIndices, gatherValues) ->
                 sort queue gatherIndices gatherRows gatherValues
 
                 let sortedRows, sortedIndices, sortedValues = gatherRows, gatherIndices, gatherValues
@@ -272,18 +255,17 @@ module SpMSpV =
                     multipliedValues.Free queue
                     sortedIndices.Free queue
 
-                    { Context = clContext
-                      Indices = reducedKeys
-                      Values = reducedValues
-                      Size = matrix.ColumnCount }
+                    Some(
+                        { Context = clContext
+                          Indices = reducedKeys
+                          Values = reducedValues
+                          Size = matrix.ColumnCount }
+                    )
                 | None ->
                     multipliedValues.Free queue
                     sortedIndices.Free queue
 
-                    { Context = clContext
-                      Indices = clContext.CreateClArray 0
-                      Values = clContext.CreateClArray 0
-                      Size = matrix.ColumnCount }
+                    None
 
     let runBoolStandard
         (add: Expr<'c option -> 'c option -> 'c option>)
@@ -304,25 +286,22 @@ module SpMSpV =
 
         fun (queue: MailboxProcessor<_>) (matrix: ClMatrix.CSR<'a>) (vector: ClVector.Sparse<'b>) ->
 
-            let gatherRows, gatherIndices, gatherValues, gatherLength = gather queue matrix vector
-
-            gatherRows.Free queue
-            gatherValues.Free queue
+            match gather queue matrix vector with
+            | None -> None
+            | Some (gatherRows, gatherIndices, gatherValues) ->
+                gatherRows.Free queue
+                gatherValues.Free queue
 
-            if gatherLength <= 0 then
-                { Context = clContext
-                  Indices = gatherIndices
-                  Values = clContext.CreateClArray [| false |]
-                  Size = matrix.ColumnCount }
-            else
                 let sortedIndices = sort queue gatherIndices
 
                 let resultIndices = removeDuplicates queue sortedIndices
 
                 gatherIndices.Free queue
                 sortedIndices.Free queue
 
-                { Context = clContext
-                  Indices = resultIndices
-                  Values = create queue DeviceOnly resultIndices.Length true
-                  Size = matrix.ColumnCount }
+                Some(
+                    { Context = clContext
+                      Indices = resultIndices
+                      Values = create queue DeviceOnly resultIndices.Length true
+                      Size = matrix.ColumnCount }
+                )

tests/GraphBLAS-sharp.Tests/Backend/Vector/SpMSpV.fs

@@ -63,7 +63,7 @@ let correctnessGenericTest
     some
     sumOp
     mulOp
-    (spMV: MailboxProcessor<_> -> ClMatrix.CSR<'a> -> ClVector.Sparse<'a> -> ClVector.Sparse<'a>)
+    (spMV: MailboxProcessor<_> -> ClMatrix.CSR<'a> -> ClVector.Sparse<'a> -> ClVector.Sparse<'a> option)
     (isEqual: 'a -> 'a -> bool)
     q
     (testContext: TestContext)
@@ -89,15 +89,16 @@ let correctnessGenericTest
                 | Vector.Sparse vtr, ClMatrix.CSR m ->
                     let v = vtr.ToDevice testContext.ClContext
 
-                    let res = spMV testContext.Queue m v
+                    match spMV testContext.Queue m v with
+                    | Some res ->
+                        (ClMatrix.CSR m).Dispose q
+                        v.Dispose q
+                        let hostResIndices = res.Indices.ToHost q
+                        let hostResValues = res.Values.ToHost q
+                        res.Dispose q
 
-                    (ClMatrix.CSR m).Dispose q
-                    v.Dispose q
-                    let hostResIndices = res.Indices.ToHost q
-                    let hostResValues = res.Values.ToHost q
-                    res.Dispose q
-
-                    checkResult sumOp mulOp zero matrix vector hostResIndices hostResValues
+                        checkResult sumOp mulOp zero matrix vector hostResIndices hostResValues
+                    | None -> failwith "Result should not be empty while standard operations are tested"
                 | _ -> failwith "Impossible"
             with
             | ex when ex.Message = "InvalidBufferSize" -> ()