Change low-level data types

This commit reorganizes and restructures the low level data types,
like the MimaWord, in preparation for implementing the new MiMa
specification.
This commit is contained in:
Joscha 2019-11-07 09:48:29 +00:00
parent a454890dac
commit 3eb9430208

View file

@ -1,33 +1,44 @@
{-# LANGUAGE OverloadedStrings #-}
module Mima.Word
(
-- * MiMa-Word
MimaWord
( topBit
-- * 24-bit value
, MimaWord
-- ** Formatting
, wordToDec
, wordToHex
, wordToDec
, wordToHexDec
-- ** Converting
, bytesToWord
, wordToBytes
, boolToWord
-- ** Querying
, wordSize
, topBit
, upperOpcode
, lowerOpcode
, address
-- ** Adding
-- ** Properties
, getSmallOpcode
, getLargeOpcode
, getAddress
, getLongValue
, getShortValue
-- ** Operations
, addWords
-- * MiMa-Addresses
-- * 20-bit value
, LongValue
, MimaAddress
-- ** Formatting
, addrToDec
, addrToHex
, addrToHexDec
, longValueToHex
, longValueToDec
, longValueToHexDec
-- ** Converting
, addrToWord
, bytesToLongValue
, longValueToBytes
, longValueToWord
-- * 16-bit value
, ShortValue
-- ** Formatting
, shortValueToHex
, shortValueToDec
, shortValueToHexDec
-- ** Converting
, signedShortValueToWord
) where
import Data.Bits
@ -36,67 +47,107 @@ import Data.Word
import Mima.Util
{- Type classes and instances for free! -}
-- Get them now while they're hot!
-- This typeclass is for automatic bit twiddling and enumification for
-- 'Word32' based types.
class Word32Based t where
usedBits :: t -> Int
fromWord32 :: Word32 -> t
toWord32 :: t -> Word32
-- The MiMa's words are 24 bits long. The smallest word they fit in is
-- 'Word32'.
topBit :: (Word32Based t) => t -> Bool
topBit t = testBit (toWord32 t) (usedBits t - 1)
-- TODO Maybe store in the upper 24 bits of a signed type?
-- Required to make the compiler shut up (see
-- https://stackoverflow.com/a/17866970)
newtype WB t = WB { unWB :: t}
newtype MimaWord = MimaWord Word32
deriving (Eq)
instance (Show t) => Show (WB t) where
show = show . unWB
wordSize :: Int
wordSize = 24
-- Kinda obvious, isn't it? :P
instance (Word32Based t) => Word32Based (WB t) where
usedBits = usedBits . unWB
fromWord32 = WB . fromWord32
toWord32 = toWord32 . unWB
wordToDec :: MimaWord -> T.Text
wordToDec (MimaWord w) = toDec 8 w
instance (Word32Based t) => Eq (WB t) where
w1 == w2 = toWord32 (unWB w1) == toWord32 (unWB w2)
wordToHex :: MimaWord -> T.Text
wordToHex (MimaWord w) = toHex 6 w
wordToHexDec :: MimaWord -> T.Text
wordToHexDec mw = wordToHex mw <> " (" <> wordToDec mw <> ")"
instance Show MimaWord where
show mw = T.unpack $ "MimaWord 0x" <> wordToHex mw
instance Word32Based MimaWord where
fromWord32 w = MimaWord $ w .&. 0x00FFFFFF
toWord32 (MimaWord w) = w
instance Bits MimaWord where
mw1 .&. mw2 = fromWord32 $ toWord32 mw1 .&. toWord32 mw2
mw1 .|. mw2 = fromWord32 $ toWord32 mw1 .|. toWord32 mw2
mw1 `xor` mw2 = fromWord32 $ toWord32 mw1 `xor` toWord32 mw2
instance (Word32Based t) => Bits (WB t) where
t1 .&. t2 = fromWord32 $ toWord32 t1 .&. toWord32 t2
t1 .|. t2 = fromWord32 $ toWord32 t1 .|. toWord32 t2
t1 `xor` t2 = fromWord32 $ toWord32 t1 `xor` toWord32 t2
complement = fromWord32 . complement . toWord32
shiftR mw i = fromWord32 $
let rightShifted = shiftR (toWord32 mw) i
leftOver = max 0 (wordSize - i)
in if topBit mw
then shiftL 0xFFFFFFFF leftOver .|. rightShifted
shiftL t i = fromWord32 $ shiftL (toWord32 t) i
shiftR t i = fromWord32 $
let rightShifted = shiftR (toWord32 t) i
leftOver = max 0 (usedBits t - i)
in if topBit t
then shiftL (complement zeroBits) leftOver .|. rightShifted
else rightShifted
shiftL mw i = fromWord32 $ shiftL (toWord32 mw) i
rotateR mw i =
let i' = i `mod` wordSize
w = toWord32 mw
in fromWord32 $ shiftR w i' .|. shiftL w (wordSize - i')
rotateL mw i = rotateR mw (wordSize - i)
rotateL t i = rotateR t (usedBits t - i)
rotateR t i =
let i' = i `mod` usedBits t
w = toWord32 t
in fromWord32 $ shiftR w i' .|. shiftL w (usedBits t - i')
zeroBits = fromWord32 zeroBits
bit = fromWord32 . bit
testBit mw i = testBit (toWord32 mw) i
bitSize = const wordSize
bitSizeMaybe = const (Just wordSize)
testBit t = testBit (toWord32 t)
bitSize = usedBits
bitSizeMaybe = Just . usedBits
isSigned = const True
popCount = popCount . toWord32
instance (Word32Based t) => Bounded (WB t) where
minBound = fromWord32 zeroBits
maxBound = fromWord32 (complement zeroBits)
instance (Word32Based t) => Enum (WB t) where
toEnum i =
let lower = fromEnum $ toWord32 (minBound :: MimaAddress)
upper = fromEnum $ toWord32 (maxBound :: MimaAddress)
in if lower <= i && i <= upper
then fromWord32 $ toEnum i
else error $ "Enum.toEnum: tag (" ++ show i
++ ") is out of bounds " ++ show (lower, upper)
fromEnum = fromEnum . toWord32
-- See 'Enum' laws for types with a 'Bounded' instance
enumFrom x = enumFromTo x maxBound
enumFromThen x y = enumFromThenTo x y bound
where
bound | fromEnum y >= fromEnum x = maxBound
| otherwise = minBound
{- The types -}
type MimaWord = WB MimaWord_
newtype MimaWord_ = MimaWord_ Word32
instance Word32Based MimaWord_ where
usedBits _ = 24
fromWord32 w = MimaWord_ $ w .&. 0xFFFFFF
toWord32 (MimaWord_ w) = w
instance Show MimaWord_ where
show mw = T.unpack $ "MimaWord_ 0x" <> toHex 6 (toWord32 mw)
wordToHex :: MimaWord -> T.Text
wordToHex = toHex 6 . toWord32
wordToDec :: MimaWord -> T.Text
wordToDec = toDec 8 . toWord32
wordToHexDec :: MimaWord -> T.Text
wordToHexDec mw = wordToHex mw <> " (" <> wordToDec mw <> ")"
bytesToWord :: Word8 -> Word8 -> Word8 -> MimaWord
bytesToWord w1 w2 w3 =
let (w1', w2', w3') = (fromIntegral w1, fromIntegral w2, fromIntegral w3)
@ -114,59 +165,77 @@ wordToBytes mw =
boolToWord :: Bool -> MimaWord
boolToWord False = zeroBits
boolToWord True = complement zeroBits
boolToWord True = complement zeroBits
topBit :: MimaWord -> Bool
topBit mw = testBit (toWord32 mw) (wordSize - 1)
getSmallOpcode :: MimaWord -> Word32
getSmallOpcode mw = shiftR (toWord32 mw) 20 .&. 0xF
upperOpcode :: MimaWord -> Word32
upperOpcode mw = shiftR (toWord32 mw) 20 .&. 0xF
getLargeOpcode :: MimaWord -> Word32
getLargeOpcode mw = shiftR (toWord32 mw) 16 .&. 0xF
lowerOpcode :: MimaWord -> Word32
lowerOpcode mw = shiftR (toWord32 mw) 16 .&. 0xF
getAddress :: MimaWord -> MimaAddress
getAddress = getLongValue
address :: MimaWord -> MimaAddress
address = fromWord32 . toWord32
getLongValue :: MimaWord -> LongValue
getLongValue = fromWord32 . toWord32
getShortValue :: MimaWord -> ShortValue
getShortValue = fromWord32 . toWord32
addWords :: MimaWord -> MimaWord -> MimaWord
addWords mw1 mw2 = fromWord32 $ toWord32 mw1 + toWord32 mw2
addWords w1 w2 = fromWord32 $ toWord32 w1 + toWord32 w2
-- The MiMa's addresses are 20 bits long. The smallest word they fit
-- in is 'Word32'.
type MimaAddress = LongValue
type LongValue = WB LongValue_
newtype LongValue_ = LongValue_ Word32
newtype MimaAddress = MimaAddress Word32
deriving (Eq, Ord)
instance Word32Based LongValue_ where
usedBits _ = 20
fromWord32 w = LongValue_ $ w .&. 0xFFFFF
toWord32 (LongValue_ w) = w
addrToDec :: MimaAddress -> T.Text
addrToDec (MimaAddress a) = toDec 7 a
instance Show LongValue_ where
show lv = T.unpack $ "LongValue_ 0x" <> toHex 5 (toWord32 lv)
addrToHex :: MimaAddress -> T.Text
addrToHex (MimaAddress a) = toHex 5 a
longValueToHex :: MimaWord -> T.Text
longValueToHex = toHex 5 . toWord32
addrToHexDec :: MimaAddress -> T.Text
addrToHexDec ma = addrToHex ma <> " (" <> addrToDec ma <> ")"
longValueToDec :: MimaWord -> T.Text
longValueToDec = toDec 7 . toWord32
instance Show MimaAddress where
show ma = T.unpack $ "MimaAddress 0x" <> addrToHex ma
longValueToHexDec :: MimaWord -> T.Text
longValueToHexDec mw = longValueToHex mw <> " (" <> longValueToDec mw <> ")"
instance Word32Based MimaAddress where
fromWord32 w = MimaAddress $ w .&. 0x000FFFFF
toWord32 (MimaAddress w) = w
bytesToLongValue :: Word8 -> Word8 -> Word8 -> LongValue
bytesToLongValue w1 w2 w3 = getAddress $ bytesToWord w1 w2 w3
instance Bounded MimaAddress where
minBound = fromWord32 0x00000
maxBound = fromWord32 0xFFFFF
longValueToBytes :: LongValue -> (Word8, Word8, Word8)
longValueToBytes = wordToBytes . longValueToWord
-- TODO satisfy enum laws with regards to bounded instance
instance Enum MimaAddress where
toEnum i =
let lower = fromEnum $ toWord32 (minBound :: MimaAddress)
upper = fromEnum $ toWord32 (maxBound :: MimaAddress)
in if lower <= i && i <= upper
then fromWord32 $ toEnum i
else error $ "Enum.toEnum{MimaAddress}: tag (" ++ show i
++ ") is out of bounds " ++ show (lower, upper)
fromEnum = fromEnum . toWord32
longValueToWord :: LongValue -> MimaWord
longValueToWord = fromWord32 . toWord32
addrToWord :: MimaAddress -> MimaWord
addrToWord = fromWord32 . toWord32
type ShortValue = WB ShortValue_
newtype ShortValue_ = ShortValue_ Word32
instance Word32Based ShortValue_ where
usedBits _ = 16
fromWord32 w = ShortValue_ $ w .&. 0xFFFF
toWord32 (ShortValue_ w) = w
instance Show ShortValue_ where
show lv = T.unpack $ "ShortValue_ 0x" <> toHex 4 (toWord32 lv)
shortValueToHex :: MimaWord -> T.Text
shortValueToHex = toHex 4 . toWord32
shortValueToDec :: MimaWord -> T.Text
shortValueToDec = toDec 5 . toWord32
shortValueToHexDec :: MimaWord -> T.Text
shortValueToHexDec mw = shortValueToHex mw <> " (" <> shortValueToDec mw <> ")"
signedShortValueToWord :: ShortValue -> MimaWord
signedShortValueToWord sv
| topBit sv = fromWord32 $ 0xFFFF0000 .|. toWord32 sv
| otherwise = fromWord32 $ toWord32 sv