Implementation of irregular flattening

futhark.cabal

@@ -369,6 +369,9 @@ library
       Futhark.Pass.ExtractKernels.ToGPU
       Futhark.Pass.ExtractMulticore
       Futhark.Pass.FirstOrderTransform
+      Futhark.Pass.Flatten
+      Futhark.Pass.Flatten.Builtins
+      Futhark.Pass.Flatten.Distribute
       Futhark.Pass.LiftAllocations
       Futhark.Pass.LowerAllocations
       Futhark.Pass.Simplify
@@ -475,6 +478,7 @@ library
     , lsp-types >= 2.0.1.0
     , mainland-pretty >=0.7.1
     , cmark-gfm >=0.2.1
+    , OneTuple
     , megaparsec >=9.0.0
     , mtl >=2.2.1
     , neat-interpolation >=0.3

rewritefut/segupdate.fut

@@ -0,0 +1,36 @@
+-- Flat-Parallel Segmented Update
+-- ==
+-- compiled input { [1i64,2i64,3i64,1i64,2i64,1i64,2i64,3i64,4i64] [3i64,2i64,4i64] [0i64,0i64,0i64,0i64,0i64] [2i64,1i64,2i64] [0i64, 1i64, 0i64] [1i64, 1i64, 2i64] } output { [0i64,0i64,3i64,1i64,0i64,0i64,2i64,0i64,4i64] }
+
+let sgmSumI64 [n] (flg : [n]i64) (arr : [n]i64) : [n]i64 =
+  let flgs_vals = 
+    scan ( \ (f1, x1) (f2,x2) -> 
+            let f = f1 | f2 in
+            if f2 != 0 then (f, x2)
+            else (f, x1 + x2) )
+         (0, 0i64) (zip flg arr)
+  let (_, vals) = unzip flgs_vals
+  in vals
+
+let mkFlagArray [m] (aoa_shp: [m]i64) (zero: i64)
+                       (aoa_val: [m]i64) : []i64 =
+    let shp_rot = map(\i -> if i==0i64 then 0i64 else aoa_shp[i-1]) (iota m)
+    let shp_scn = scan (+) 0i64 shp_rot
+    let aoa_len = shp_scn[m-1]+aoa_shp[m-1]
+    let shp_ind = map2 (\shp ind -> if shp==0 then -1i64 else ind) aoa_shp shp_scn
+    in scatter (replicate aoa_len zero) shp_ind aoa_val
+
+let segUpdate [n][m][t] (xss_val : *[n]i64) (shp_xss : [t]i64)  (vss_val : [m]i64) 
+                    (shp_vss : [t]i64) (bs : [t]i64) (ss : [t]i64): [n]i64 =
+    let fvss = (mkFlagArray shp_vss 0 (1...t :> [t]i64)) :> [m]i64                                     
+    let II1 = sgmSumI64 fvss fvss |> map (\x -> x - 1)        
+    let shp_xss_rot = map(\i -> if i==0i64 then 0i64 else shp_xss[i-1]) (iota t)
+    let bxss = scan (+) 0 shp_xss_rot                                                                   
+    let II2 = sgmSumI64 fvss (replicate m 1) |> map (\x -> x - 1)                                       
+    let iss = map (\i -> bxss[II1[i]] + bs[II1[i]] + (II2[i] * ss[II1[i]])) (iota m)                     
+    in scatter xss_val iss vss_val
+
+
+let main [n][m][t] (xss_val : *[n]i64) (shp_xss : [t]i64) (vss_val : [m]i64) 
+                    (shp_vss : [t]i64) (bs : [t]i64) (ss : [t]i64): [n]i64 =
+    segUpdate xss_val shp_xss vss_val shp_vss bs ss

src/Futhark/CLI/Dev.hs

@@ -54,6 +54,7 @@ import Futhark.Pass.ExplicitAllocations.Seq qualified as Seq
 import Futhark.Pass.ExtractKernels
 import Futhark.Pass.ExtractMulticore
 import Futhark.Pass.FirstOrderTransform
+import Futhark.Pass.Flatten (flattenSOACs)
 import Futhark.Pass.LiftAllocations as LiftAllocations
 import Futhark.Pass.LowerAllocations as LowerAllocations
 import Futhark.Pass.Simplify
@@ -654,6 +655,7 @@ commandLineOptions =
     sinkOption [],
     kernelsPassOption reduceDeviceSyncs [],
     typedPassOption soacsProg GPU extractKernels [],
+    typedPassOption soacsProg GPU flattenSOACs [],
     typedPassOption soacsProg MC extractMulticore [],
     allocateOption "a",
     kernelsMemPassOption doubleBufferGPU [],

src/Futhark/IR/Pretty.hs

@@ -8,6 +8,7 @@ module Futhark.IR.Pretty
   ( prettyTuple,
     prettyTupleLines,
     prettyString,
+    prettyRet,
     PrettyRep (..),
   )
 where

src/Futhark/IR/TypeCheck.hs

@@ -58,7 +58,7 @@ import Futhark.Analysis.PrimExp
 import Futhark.Construct (instantiateShapes)
 import Futhark.IR.Aliases hiding (lookupAliases)
 import Futhark.Util
-import Futhark.Util.Pretty (align, docText, indent, ppTuple', pretty, (<+>), (</>))
+import Futhark.Util.Pretty hiding (width)
 
 -- | Information about an error during type checking.  The 'Show'
 -- instance for this type produces a human-readable description.
@@ -742,7 +742,7 @@ checkSubExp (Var ident) = context ("In subexp " <> prettyText ident) $ do
   lookupType ident
 
 checkCerts :: (Checkable rep) => Certs -> TypeM rep ()
-checkCerts (Certs cs) = mapM_ (requireI [Prim Unit]) cs
+checkCerts = mapM_ lookupType . unCerts
 
 checkSubExpRes :: (Checkable rep) => SubExpRes -> TypeM rep Type
 checkSubExpRes (SubExpRes cs se) = do
@@ -1023,9 +1023,9 @@ checkExp (Apply fname args rettype_annot _) = do
   when (rettype_derived /= rettype_annot) $
     bad . TypeError . docText $
       "Expected apply result type:"
-        </> indent 2 (pretty $ map fst rettype_derived)
+        </> indent 2 (braces $ commasep $ map prettyRet rettype_derived)
         </> "But annotation is:"
-        </> indent 2 (pretty $ map fst rettype_annot)
+        </> indent 2 (braces $ commasep $ map prettyRet rettype_annot)
   consumeArgs paramtypes argflows
 checkExp (Loop merge form loopbody) = do
   let (mergepat, mergeexps) = unzip merge
@@ -1252,8 +1252,8 @@ checkStm ::
   Stm (Aliases rep) ->
   TypeM rep a ->
   TypeM rep a
-checkStm stm@(Let pat (StmAux (Certs cs) _ (_, dec)) e) m = do
-  context "When checking certificates" $ mapM_ (requireI [Prim Unit]) cs
+checkStm stm@(Let pat (StmAux cs _ (_, dec)) e) m = do
+  context "When checking certificates" $ checkCerts cs
   context "When checking expression annotation" $ checkExpDec dec
   context ("When matching\n" <> message "  " pat <> "\nwith\n" <> message "  " e) $
     matchPat pat e

src/Futhark/Pass/ExtractKernels/ToGPU.hs

@@ -5,6 +5,7 @@ module Futhark.Pass.ExtractKernels.ToGPU
     segThread,
     soacsLambdaToGPU,
     soacsStmToGPU,
+    soacsExpToGPU,
     scopeForGPU,
     scopeForSOACs,
     injectSOACS,
@@ -74,6 +75,9 @@ injectSOACS f =
 soacsStmToGPU :: Stm SOACS -> Stm GPU
 soacsStmToGPU = runIdentity . rephraseStm (injectSOACS OtherOp)
 
+soacsExpToGPU :: Exp SOACS -> Exp GPU
+soacsExpToGPU = runIdentity . rephraseExp (injectSOACS OtherOp)
+
 soacsLambdaToGPU :: Lambda SOACS -> Lambda GPU
 soacsLambdaToGPU = runIdentity . rephraseLambda (injectSOACS OtherOp)