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gyehoek-hs/src/Gyehoek/CPS/Lower.hs
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remove CPS.ValLit
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Haskell

{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE OverloadedRecordDot #-}
{-# LANGUAGE OverloadedLabels #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE MultilineStrings #-}
{-# LANGUAGE OverloadedLists #-}
{-# LANGUAGE ApplicativeDo #-}
{-# LANGUAGE RecursiveDo #-}
{- HLINT ignore "Use camelCase" -}
module Gyehoek.CPS.Lower
(lower, lowerProgram) where
import Gyehoek.CPS.Syntax
import Data.Vector.Strict (Vector)
import Control.Lens hiding (op)
import Numeric.Natural
import qualified Data.Vector.Strict as V
import Gyehoek.Wasm qualified as Wasm
import Gyehoek.Wasm hiding (Expr)
import Language.Sexp.Located qualified as SL
import Control.Monad.Fix
import qualified Gyehoek.Sexp
import Data.Text qualified as T
import Data.Foldable (fold)
import Gyehoek.Sexp (encodeOrShow)
import Gyehoek.Prelude
data Env = MkEnv
{ vars :: Vector Name
, kvars :: Vector Name
}
deriving (Show, Generic)
type instance Index Env = Natural
type instance IxValue Env = Name
instance Ixed Env where
ix i = #vars . ix (fromIntegral i)
tonat :: Integral a => a -> Natural
tonat = fromIntegral
-- | @makeSmallFixnum@ emits an expression injecting the i32 on top
-- of the stack into the SCM unitype.
makeSmallFixnum :: Wasm.Expr
makeSmallFixnum = [expr|
(@gyehoek "construct small fixnum")
(i32.const 1)
i32.shl
ref.i31
|]
getArgRegister :: Natural -> SL.Sexp
getArgRegister n = SL.Symbol [i|$arg#{n}|]
-- | Given an expression @e@ leaving a @ref eq@ atop the stack,
-- @pushArg rt n e@ sets the nth slot of the arg-passing array to the
-- result of @e@.
pushArg :: Natural -> Wasm.Expr -> Wasm.Expr
pushArg n e = [expr|
(@gyehoek begin pushArg)
##{e}
(global.set #{reg})
(@gyehoek end pushArg)
|]
where reg = getArgRegister n
-- | Pop the nth arg from the arg-passing array onto the stack.
popArg :: Natural -> Wasm.Expr
popArg n = [expr|
(@gyehoek begin popArg)
(global.get #{reg})
ref.as_non_null
(@gyehoek end popArg)
|]
where reg = getArgRegister n
lowerVal :: (HasCallStack, GenMod :> es) => Env -> Val -> Eff es Wasm.Expr
lowerVal g (ValImm imm) =
pure $ case imm of
ImmInt n -> [expr|
(i32.const #{n})
##{makeSmallFixnum}
|]
ImmBool b -> [expr|
(i32.const #{b'})
ref.i31
|]
where b' :: Int = if b then 0b11 else 0b01
_ -> _
lowerVal g (ValVar x) = do
pure [expr|(global.get #{l})|]
where
l = getArgRegister . fromIntegral . succ $ V.elemIndex x g.vars ^?! _Just
lower' :: (GenMod :> es) => Env -> Exp -> Eff es Wasm.Expr
lower' g (Halt [v]) = do
arg <- pushArg 0 <$> lowerVal g v
pure [expr|
##{arg}
(return_call $halt (i32.const 1))
|]
lower' g e@(ExpPrim p k) =
([expr|(@gyehoek :origin #{origin})|]<>)
<$> case p of
PrimAdd x y -> lowerBinOp "i32.add" g x y k
PrimMul x y -> lowerBinOp "i32.mul" g x y k
where origin = encodeOrShow @_ @Text e
lower' g (ExpIf c t f) = do
c' <- lowerVal g c
t' <- lower' g t
f' <- lower' g f
pure [expr|
##{c'}
(call $gh-truthy?)
(if (then ##{t'})
(else ##{f'}))
|]
lower' g (ExpLetRec [(r,AbsKappa kap)] e) = do
idx <- lowerKappa g kap
let g' = g & #kvars <>~ [r]
e' <- lower' g' e
let origin = encodeOrShow @_ @Text e
pure [expr|
(@gyehoek :origin #{origin})
(@gyehoek "push cont" :idx #{idx})
(array.set $cont-stack-type
(global.get $cont-stack)
(global.get $cont-stack-top)
(ref.func #{idx}))
(global.set $cont-stack-top
(i32.add (global.get $cont-stack-top)
(i32.const 1)))
##{e'}
|]
lower' g (ExpLetRec [(r,AbsLambda lam)] e) = do
idx <- lowerLambda g lam
let g' = g & #vars <>~ [r]
let n = succ $ length g.vars
e' <- lower' g' e
let reg = getArgRegister . fromIntegral $ n
pure [expr|
(i32.const 0)
(ref.func #{idx})
(struct.new $closure)
(global.set #{reg})
##{e'}
|]
lower' g e@(ExpApply f xs ktail) = do
let nargs = length xs
f' <- lowerVal g f
let l = succ $ V.elemIndex ktail g.kvars ^?! _Just
args <- fold <$>
itraverse (\i -> fmap (pushArg $ tonat i) . lowerVal g) xs
let origin = encodeOrShow @_ @Text e
pure [expr|
(@gyehoek :origin #{origin})
(@gyehoek "load args")
##{args}
(i32.const 1)
##{f'}
(ref.cast (ref $closure))
(struct.get $closure $code)
(return_call_ref $cont-type)
(@gyehoek todo
(f' ##{f'})
(ktail #{l}))
|]
lower' g e@(ExpContinue k xs) = do
let nargs = length xs
args <- fold <$>
itraverse (\i -> fmap (pushArg $ tonat i) . lowerVal g) xs
let origin = encodeOrShow @_ @Text e
pure [expr|
(@gyehoek :origin #{origin})
(@gyehoek "push args")
##{args}
(@gyehoek "nargs")
(i32.const #{nargs})
(@gyehoek "pop cont stack")
(global.get $cont-stack-top)
(i32.const #{l})
i32.sub
(global.set $cont-stack-top)
(global.get $cont-stack)
(global.get $cont-stack-top)
(array.get $cont-stack-type)
ref.as_non_null
(return_call_ref $cont-type)
|]
where
l = succ $ V.elemIndex k g.kvars ^?! _Just
lower' g e = error $ case Gyehoek.Sexp.encode e of
Left _ -> show e
Right x -> T.unpack x
lowerKappa :: GenMod :> es => Env -> Kappa -> Eff es Idx
lowerKappa g e@(MkKappa xs m) = do
let g' = g & #vars <>~ V.fromList xs
m' <- lower' g' m
let origin = encodeOrShow @_ @Text e
idx <- Wasm.defineFunction [wat|
(func (param i32)
(@gyehoek :origin #{origin})
(local (ref eq) (ref eq) (ref eq) (ref eq) (ref eq))
##{m'})
|]
Wasm.emit [wats|(elem declare funcref (ref.func #{idx}))|]
pure idx
lowerLambda :: GenMod :> es => Env -> Lambda -> Eff es Idx
lowerLambda g e@(MkLambda xs ktail m) = do
let g' = g & #vars .~ V.fromList xs
& #kvars <>~ [ktail]
m' <- lower' g' m
let origin = encodeOrShow @_ @Text e
idx <- Wasm.defineFunction [wat|
(func (param i32)
(@gyehoek :origin #{origin})
(local (ref eq) (ref eq) (ref eq) (ref eq) (ref eq))
##{m'})
|]
Wasm.emit [wats|(elem declare funcref (ref.func #{idx}))|]
pure idx
lowerBinOp
:: (GenMod :> es)
=> Text -> Env -> Val -> Val -> Kappa -> Eff es Wasm.Expr
lowerBinOp op g x y (MkKappa [r] e) = do
let op' = SL.Symbol op
let g' = g & #vars <>~ [r]
let n = succ $ length (g ^. #vars)
let reg = getArgRegister . fromIntegral $ n
x' <- lowerVal g x
y' <- lowerVal g y
e' <- lower' g' e
pure [expr|
##{x'}
(i31.get_s (ref.cast (ref i31)))
(i32.const 1)
i32.shr_u
##{y'}
(i31.get_s (ref.cast (ref i31)))
(i32.const 1)
i32.shr_u
#{op'}
##{makeSmallFixnum}
(global.set #{reg})
##{e'}
|]
emitRuntime :: GenMod :> es => Eff es ()
emitRuntime = mfix \runtime -> do
Wasm.defineFunctions [wats|
(import "gyehoek" "write" (func $gh-write (param (ref eq))))
(import "gyehoek" "truthy?" (func $gh-truthy? (param (ref eq))
(result i32)))
|]
-- cont stack
Wasm.defineTypes [wats|
(type $heap-object (sub (struct (field $hash (mut i32)))))
(type $cont-type (func (param i32)))
(type $cont-stack-type (array (mut (ref null $cont-type))))
(type $closure (sub $heap-object
(struct (field $hash (mut i32))
(field $code (ref $cont-type)))))
|]
Wasm.defineGlobals [wats|
(global $cont-stack-top (mut i32) (i32.const 0))
(global $cont-stack (ref $cont-stack-type)
(array.new_default $cont-stack-type (i32.const 128)))
|]
-- arg registers
Wasm.defineGlobals [wats|
(global $arg0 (mut (ref null eq)) (ref.null eq))
(global $arg1 (mut (ref null eq)) (ref.null eq))
(global $arg2 (mut (ref null eq)) (ref.null eq))
(global $arg3 (mut (ref null eq)) (ref.null eq))
(global $arg4 (mut (ref null eq)) (ref.null eq))
(global $arg5 (mut (ref null eq)) (ref.null eq))
(global $arg6 (mut (ref null eq)) (ref.null eq))
(global $arg7 (mut (ref null eq)) (ref.null eq))
(global $arg8 (mut (ref null eq)) (ref.null eq))
(global $arg9 (mut (ref null eq)) (ref.null eq))
(global $arg10 (mut (ref null eq)) (ref.null eq))
(global $arg11 (mut (ref null eq)) (ref.null eq))
(global $arg12 (mut (ref null eq)) (ref.null eq))
(global $arg13 (mut (ref null eq)) (ref.null eq))
(global $arg14 (mut (ref null eq)) (ref.null eq))
(global $arg15 (mut (ref null eq)) (ref.null eq))
|]
-- other things 😼
Wasm.defineGlobal [wat|
(global $result (mut (ref null eq))
(ref.null eq))
|]
-- procedures
let arg = popArg 0
Wasm.defineFunction [wat|
(func $halt (param i32)
##{arg}
(global.set $result))
|]
pure ()
lower :: Exp -> Eff es Text
lower e = fmap Wasm.renderModule . Wasm.execGenMod $ do
runtime <- emitRuntime
let g = MkEnv mempty mempty
e' <- lower' g e
let origin = encodeOrShow @_ @Text e
Wasm.defineFunction [wat|
(func $scm-entry (param i32)
(@gyehoek :origin #{origin})
(local (ref eq) (ref eq) (ref eq) (ref eq) (ref eq))
##{e'})
|]
Wasm.defineFunction [wat|
(func (export "main")
(call $scm-entry (i32.const 0))
(call $gh-write (ref.as_non_null (global.get $result))))
|]
lowerProgram :: Program -> Eff es Text
lowerProgram (MkProgram e) = lower e