{-# LANGUAGE TypeFamilies #-}

module Futhark.AD.Rev.SOAC (vjpSOAC) where

import Control.Monad
import Futhark.AD.Rev.Map
import Futhark.AD.Rev.Monad
import Futhark.AD.Rev.Reduce
import Futhark.AD.Rev.Scan
import Futhark.AD.Rev.Scatter
import Futhark.Analysis.PrimExp.Convert
import Futhark.Builder
import Futhark.IR.SOACS
import Futhark.Tools
import Futhark.Util (chunks)

-- We split any multi-op scan or reduction into multiple operations so
-- we can detect special cases.  Post-AD, the result may be fused
-- again.
splitScanRed ::
  VjpOps ->
  ([a] -> ADM (ScremaForm SOACS), a -> [SubExp]) ->
  (Pat Type, StmAux (), [a], SubExp, [VName]) ->
  ADM () ->
  ADM ()
splitScanRed :: forall a.
VjpOps
-> ([a] -> ADM (ScremaForm SOACS), a -> [SubExp])
-> (Pat Type, StmAux (), [a], SubExp, [VName])
-> ADM ()
-> ADM ()
splitScanRed VjpOps
vjpops ([a] -> ADM (ScremaForm SOACS)
opSOAC, a -> [SubExp]
opNeutral) (Pat Type
pat, StmAux ()
aux, [a]
ops, SubExp
w, [VName]
as) ADM ()
m = do
  let ks :: [Int]
ks = forall a b. (a -> b) -> [a] -> [b]
map (forall (t :: * -> *) a. Foldable t => t a -> Int
length forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> [SubExp]
opNeutral) [a]
ops
      pat_per_op :: [Pat Type]
pat_per_op = forall a b. (a -> b) -> [a] -> [b]
map forall dec. [PatElem dec] -> Pat dec
Pat forall a b. (a -> b) -> a -> b
$ forall a. [Int] -> [a] -> [[a]]
chunks [Int]
ks forall a b. (a -> b) -> a -> b
$ forall dec. Pat dec -> [PatElem dec]
patElems Pat Type
pat
      as_per_op :: [[VName]]
as_per_op = forall a. [Int] -> [a] -> [[a]]
chunks [Int]
ks [VName]
as
      onOps :: [a] -> [Pat Type] -> [[VName]] -> ADM ()
onOps (a
op : [a]
ops') (Pat Type
op_pat : [Pat Type]
op_pats') ([VName]
op_as : [[VName]]
op_as') = do
        ScremaForm SOACS
op_form <- [a] -> ADM (ScremaForm SOACS)
opSOAC [a
op]
        VjpOps -> Pat Type -> StmAux () -> SOAC SOACS -> ADM () -> ADM ()
vjpSOAC VjpOps
vjpops Pat Type
op_pat StmAux ()
aux (forall {k} (rep :: k).
SubExp -> [VName] -> ScremaForm rep -> SOAC rep
Screma SubExp
w [VName]
op_as ScremaForm SOACS
op_form) forall a b. (a -> b) -> a -> b
$
          [a] -> [Pat Type] -> [[VName]] -> ADM ()
onOps [a]
ops' [Pat Type]
op_pats' [[VName]]
op_as'
      onOps [a]
_ [Pat Type]
_ [[VName]]
_ = ADM ()
m
  [a] -> [Pat Type] -> [[VName]] -> ADM ()
onOps [a]
ops [Pat Type]
pat_per_op [[VName]]
as_per_op

commonSOAC :: Pat Type -> StmAux () -> SOAC SOACS -> ADM () -> ADM [Adj]
commonSOAC :: Pat Type -> StmAux () -> SOAC SOACS -> ADM () -> ADM [Adj]
commonSOAC Pat Type
pat StmAux ()
aux SOAC SOACS
soac ADM ()
m = do
  forall (m :: * -> *). MonadBuilder m => Stm (Rep m) -> m ()
addStm forall a b. (a -> b) -> a -> b
$ forall {k} (rep :: k).
Pat (LetDec rep) -> StmAux (ExpDec rep) -> Exp rep -> Stm rep
Let Pat Type
pat StmAux ()
aux forall a b. (a -> b) -> a -> b
$ forall {k} (rep :: k). Op rep -> Exp rep
Op SOAC SOACS
soac
  ADM ()
m
  forall a. ADM a -> ADM a
returnSweepCode forall a b. (a -> b) -> a -> b
$ forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM VName -> ADM Adj
lookupAdj forall a b. (a -> b) -> a -> b
$ forall dec. Pat dec -> [VName]
patNames Pat Type
pat

vjpSOAC :: VjpOps -> Pat Type -> StmAux () -> SOAC SOACS -> ADM () -> ADM ()
vjpSOAC :: VjpOps -> Pat Type -> StmAux () -> SOAC SOACS -> ADM () -> ADM ()
vjpSOAC VjpOps
ops Pat Type
pat StmAux ()
aux soac :: SOAC SOACS
soac@(Screma SubExp
w [VName]
as ScremaForm SOACS
form) ADM ()
m
  | Just [Reduce SOACS]
reds <- forall {k} (rep :: k). ScremaForm rep -> Maybe [Reduce rep]
isReduceSOAC ScremaForm SOACS
form,
    forall (t :: * -> *) a. Foldable t => t a -> Int
length [Reduce SOACS]
reds forall a. Ord a => a -> a -> Bool
> Int
1 =
      forall a.
VjpOps
-> ([a] -> ADM (ScremaForm SOACS), a -> [SubExp])
-> (Pat Type, StmAux (), [a], SubExp, [VName])
-> ADM ()
-> ADM ()
splitScanRed VjpOps
ops (forall {k} (rep :: k) (m :: * -> *).
(Buildable rep, MonadFreshNames m) =>
[Reduce rep] -> m (ScremaForm rep)
reduceSOAC, forall {k} (rep :: k). Reduce rep -> [SubExp]
redNeutral) (Pat Type
pat, StmAux ()
aux, [Reduce SOACS]
reds, SubExp
w, [VName]
as) ADM ()
m
  | Just [Reduce SOACS
red] <- forall {k} (rep :: k). ScremaForm rep -> Maybe [Reduce rep]
isReduceSOAC ScremaForm SOACS
form,
    [VName
x] <- forall dec. Pat dec -> [VName]
patNames Pat Type
pat,
    [SubExp
ne] <- forall {k} (rep :: k). Reduce rep -> [SubExp]
redNeutral Reduce SOACS
red,
    [VName
a] <- [VName]
as,
    Just [(BinOp
op, PrimType
_, VName
_, VName
_)] <- forall {k} (rep :: k).
ASTRep rep =>
Lambda rep -> Maybe [(BinOp, PrimType, VName, VName)]
lamIsBinOp forall a b. (a -> b) -> a -> b
$ forall {k} (rep :: k). Reduce rep -> Lambda rep
redLambda Reduce SOACS
red,
    BinOp -> Bool
isMinMaxOp BinOp
op =
      VjpOps
-> VName
-> StmAux ()
-> SubExp
-> BinOp
-> SubExp
-> VName
-> ADM ()
-> ADM ()
diffMinMaxReduce VjpOps
ops VName
x StmAux ()
aux SubExp
w BinOp
op SubExp
ne VName
a ADM ()
m
  | Just Reduce SOACS
red <- forall {k} (rep :: k). Buildable rep => [Reduce rep] -> Reduce rep
singleReduce forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall {k} (rep :: k). ScremaForm rep -> Maybe [Reduce rep]
isReduceSOAC ScremaForm SOACS
form = do
      [VName]
pat_adj <- forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM Adj -> ADM VName
adjVal forall (m :: * -> *) a b. Monad m => (a -> m b) -> m a -> m b
=<< Pat Type -> StmAux () -> SOAC SOACS -> ADM () -> ADM [Adj]
commonSOAC Pat Type
pat StmAux ()
aux SOAC SOACS
soac ADM ()
m
      VjpOps -> [VName] -> SubExp -> [VName] -> Reduce SOACS -> ADM ()
diffReduce VjpOps
ops [VName]
pat_adj SubExp
w [VName]
as Reduce SOACS
red
  where
    isMinMaxOp :: BinOp -> Bool
isMinMaxOp (SMin IntType
_) = Bool
True
    isMinMaxOp (UMin IntType
_) = Bool
True
    isMinMaxOp (FMin FloatType
_) = Bool
True
    isMinMaxOp (SMax IntType
_) = Bool
True
    isMinMaxOp (UMax IntType
_) = Bool
True
    isMinMaxOp (FMax FloatType
_) = Bool
True
    isMinMaxOp BinOp
_ = Bool
False
vjpSOAC VjpOps
ops Pat Type
pat StmAux ()
aux soac :: SOAC SOACS
soac@(Screma SubExp
w [VName]
as ScremaForm SOACS
form) ADM ()
m
  | Just [Scan SOACS]
scans <- forall {k} (rep :: k). ScremaForm rep -> Maybe [Scan rep]
isScanSOAC ScremaForm SOACS
form,
    forall (t :: * -> *) a. Foldable t => t a -> Int
length [Scan SOACS]
scans forall a. Ord a => a -> a -> Bool
> Int
1 =
      forall a.
VjpOps
-> ([a] -> ADM (ScremaForm SOACS), a -> [SubExp])
-> (Pat Type, StmAux (), [a], SubExp, [VName])
-> ADM ()
-> ADM ()
splitScanRed VjpOps
ops (forall {k} (rep :: k) (m :: * -> *).
(Buildable rep, MonadFreshNames m) =>
[Scan rep] -> m (ScremaForm rep)
scanSOAC, forall {k} (rep :: k). Scan rep -> [SubExp]
scanNeutral) (Pat Type
pat, StmAux ()
aux, [Scan SOACS]
scans, SubExp
w, [VName]
as) ADM ()
m
  | Just Scan SOACS
red <- forall {k} (rep :: k). Buildable rep => [Scan rep] -> Scan rep
singleScan forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> forall {k} (rep :: k). ScremaForm rep -> Maybe [Scan rep]
isScanSOAC ScremaForm SOACS
form = do
      forall (f :: * -> *) a. Functor f => f a -> f ()
void forall a b. (a -> b) -> a -> b
$ Pat Type -> StmAux () -> SOAC SOACS -> ADM () -> ADM [Adj]
commonSOAC Pat Type
pat StmAux ()
aux SOAC SOACS
soac ADM ()
m
      VjpOps -> [VName] -> SubExp -> [VName] -> Scan SOACS -> ADM ()
diffScan VjpOps
ops (forall dec. Pat dec -> [VName]
patNames Pat Type
pat) SubExp
w [VName]
as Scan SOACS
red
vjpSOAC VjpOps
ops Pat Type
pat StmAux ()
aux soac :: SOAC SOACS
soac@(Screma SubExp
w [VName]
as ScremaForm SOACS
form) ADM ()
m
  | Just Lambda SOACS
lam <- forall {k} (rep :: k). ScremaForm rep -> Maybe (Lambda rep)
isMapSOAC ScremaForm SOACS
form = do
      [Adj]
pat_adj <- Pat Type -> StmAux () -> SOAC SOACS -> ADM () -> ADM [Adj]
commonSOAC Pat Type
pat StmAux ()
aux SOAC SOACS
soac ADM ()
m
      VjpOps
-> [Adj]
-> StmAux ()
-> SubExp
-> Lambda SOACS
-> [VName]
-> ADM ()
vjpMap VjpOps
ops [Adj]
pat_adj StmAux ()
aux SubExp
w Lambda SOACS
lam [VName]
as
vjpSOAC VjpOps
ops Pat Type
pat StmAux ()
_aux (Screma SubExp
w [VName]
as ScremaForm SOACS
form) ADM ()
m
  | Just ([Reduce SOACS]
reds, Lambda SOACS
map_lam) <-
      forall {k} (rep :: k).
ScremaForm rep -> Maybe ([Reduce rep], Lambda rep)
isRedomapSOAC ScremaForm SOACS
form = do
      (Stm SOACS
mapstm, Stm SOACS
redstm) <-
        forall {k} (m :: * -> *) (rep :: k).
(MonadFreshNames m, Buildable rep, ExpDec rep ~ (),
 Op rep ~ SOAC rep) =>
Pat (LetDec rep)
-> (SubExp, [Reduce rep], Lambda rep, [VName])
-> m (Stm rep, Stm rep)
redomapToMapAndReduce Pat Type
pat (SubExp
w, [Reduce SOACS]
reds, Lambda SOACS
map_lam, [VName]
as)
      VjpOps -> Stm SOACS -> ADM () -> ADM ()
vjpStm VjpOps
ops Stm SOACS
mapstm forall a b. (a -> b) -> a -> b
$ VjpOps -> Stm SOACS -> ADM () -> ADM ()
vjpStm VjpOps
ops Stm SOACS
redstm ADM ()
m
vjpSOAC VjpOps
ops Pat Type
pat StmAux ()
aux (Scatter SubExp
w [VName]
lam Lambda SOACS
ass [(Shape, Int, VName)]
written_info) ADM ()
m =
  VjpOps
-> Pat Type
-> StmAux ()
-> (SubExp, [VName], Lambda SOACS, [(Shape, Int, VName)])
-> ADM ()
-> ADM ()
vjpScatter VjpOps
ops Pat Type
pat StmAux ()
aux (SubExp
w, [VName]
lam, Lambda SOACS
ass, [(Shape, Int, VName)]
written_info) ADM ()
m
vjpSOAC VjpOps
_ Pat Type
_ StmAux ()
_ SOAC SOACS
soac ADM ()
_ =
  forall a. HasCallStack => [Char] -> a
error forall a b. (a -> b) -> a -> b
$ [Char]
"vjpSOAC unhandled:\n" forall a. [a] -> [a] -> [a]
++ forall a. Pretty a => a -> [Char]
prettyString SOAC SOACS
soac