#include "MachDeps.h"
module Data.Memory.Internal.Scrubber
( getScrubber
) where
import GHC.Prim
import GHC.IO
import Data.Memory.Internal.CompatPrim (booleanPrim)
getScrubber :: Int# -> (Addr# -> IO ())
getScrubber sz
| booleanPrim (sz ==# 4#) = scrub4
| booleanPrim (sz ==# 8#) = scrub8
| booleanPrim (sz ==# 16#) = scrub16
| booleanPrim (sz ==# 32#) = scrub32
| otherwise = scrubBytes sz
where
scrub4 a = IO $ \s -> (# writeWord32OffAddr# a 0# 0## s, () #)
#if WORD_SIZE_IN_BITS == 64
scrub8 a = IO $ \s -> (# writeWord64OffAddr# a 0# 0## s, () #)
scrub16 a = IO $ \s1 ->
let !s2 = writeWord64OffAddr# a 0# 0## s1
!s3 = writeWord64OffAddr# a 1# 0## s2
in (# s3, () #)
scrub32 a = IO $ \s1 ->
let !s2 = writeWord64OffAddr# a 0# 0## s1
!s3 = writeWord64OffAddr# a 1# 0## s2
!s4 = writeWord64OffAddr# a 2# 0## s3
!s5 = writeWord64OffAddr# a 3# 0## s4
in (# s5, () #)
#else
scrub8 a = IO $ \s1 ->
let !s2 = writeWord32OffAddr# a 0# 0## s1
!s3 = writeWord32OffAddr# a 1# 0## s2
in (# s3, () #)
scrub16 a = IO $ \s1 ->
let !s2 = writeWord32OffAddr# a 0# 0## s1
!s3 = writeWord32OffAddr# a 1# 0## s2
!s4 = writeWord32OffAddr# a 2# 0## s3
!s5 = writeWord32OffAddr# a 3# 0## s4
in (# s5, () #)
scrub32 a = IO $ \s1 ->
let !s2 = writeWord32OffAddr# a 0# 0## s1
!s3 = writeWord32OffAddr# a 1# 0## s2
!s4 = writeWord32OffAddr# a 2# 0## s3
!s5 = writeWord32OffAddr# a 3# 0## s4
!s6 = writeWord32OffAddr# a 4# 0## s5
!s7 = writeWord32OffAddr# a 5# 0## s6
!s8 = writeWord32OffAddr# a 6# 0## s7
!s9 = writeWord32OffAddr# a 7# 0## s8
in (# s9, () #)
#endif
scrubBytes :: Int# -> Addr# -> IO ()
scrubBytes sz8 addr = IO $ \s -> (# loop sz8 addr s, () #)
where loop :: Int# -> Addr# -> State# RealWorld -> State# RealWorld
loop n a s
| booleanPrim (n ==# 0#) = s
| otherwise =
case writeWord8OffAddr# a 0# 0## s of
s' -> loop (n -# 1#) (plusAddr# a 1#) s'