2 % (c) The University of Glasgow, 2000-2006
4 \section{Fast integers, etc... booleans moved to FastBool for using panic}
8 --Even if the optimizer could handle boxed arithmetic equally well,
9 --this helps automatically check the sources to make sure that
10 --it's only used in an appropriate pattern of efficiency.
11 --(it also makes `let`s and `case`s stricter...)
13 -- | Fast integers, characters and pointer types for use in many parts of GHC
18 -- ** Getting in and out of FastInt
21 -- ** Arithmetic on FastInt
22 (+#), (-#), (*#), quotFastInt, negateFastInt,
23 --quotRemFastInt is difficult because unboxed values can't
24 --be tupled, but unboxed tuples aren't portable. Just use
25 -- nuisance boxed quotRem and rely on optimization.
26 (==#), (/=#), (<#), (<=#), (>=#), (>#),
27 minFastInt, maxFastInt,
28 --prefer to distinguish operations, not types, between
29 --signed and unsigned.
30 --left-shift is the same for 'signed' and 'unsigned' numbers
32 --right-shift isn't the same for negative numbers (ones with
33 --the highest-order bit '1'). If you don't care because the
34 --number you're shifting is always nonnegative, use the '_' version
35 --which should just be the fastest one.
37 --"L' = logical or unsigned shift; 'A' = arithmetic or signed shift
38 shiftRLFastInt, shiftRAFastInt,
39 bitAndFastInt, bitOrFastInt,
40 --add more operations to this file as you need them
45 -- ** Getting in and out of FastChar
48 -- ** Operations on FastChar
49 fastOrd, fastChr, eqFastChar,
50 --note, fastChr is "unsafe"Chr: it doesn't check for
51 --character values above the range of Unicode
56 -- ** Getting in and out of FastPtr
59 -- ** Casting FastPtrs
63 #include "HsVersions.h"
65 #if defined(__GLASGOW_HASKELL__)
72 --in case it's a macro, don't lexically feed an argument!
73 --e.g. #define _ILIT(x) (x#) , #define _ILIT(x) (x :: FastInt)
75 --perhaps for accomodating caseless-leading-underscore treatment,
76 --something like _iLIT or iLIT would be better?
80 quotFastInt = quotInt#
81 negateFastInt = negateInt#
83 --I think uncheckedIShiftL# and uncheckedIShiftRL# are the same
84 --as uncheckedShiftL# and uncheckedShiftRL# ...
85 --should they be used? How new are they?
86 --They existed as far back as GHC 6.0 at least...
87 shiftLFastInt x y = uncheckedIShiftL# x y
88 shiftR_FastInt x y = uncheckedIShiftRL# x y
89 shiftRLFastInt x y = uncheckedIShiftRL# x y
90 shiftRAFastInt x y = uncheckedIShiftRA# x y
91 --{-# INLINE shiftLNonnegativeFastInt #-}
92 --{-# INLINE shiftRNonnegativeFastInt #-}
93 --shiftLNonnegativeFastInt n p = word2Int#((int2Word# n) `uncheckedShiftL#` p)
94 --shiftRNonnegativeFastInt n p = word2Int#((int2Word# n) `uncheckedShiftRL#` p)
95 bitAndFastInt x y = word2Int# (and# (int2Word# x) (int2Word# y))
96 bitOrFastInt x y = word2Int# (or# (int2Word# x) (int2Word# y))
104 eqFastChar a b = eqChar# a b
106 --note that the type-parameter doesn't provide any safety
107 --when it's a synonym, but as long as we keep it compiling
108 --with and without __GLASGOW_HASKELL__ defined, it's fine.
109 type FastPtr a = Addr#
114 #else /* ! __GLASGOW_HASKELL__ */
116 import Data.Char (ord, chr)
119 import Data.Word (Word) --is it a good idea to assume this exists too?
120 --does anyone need shiftRLFastInt? (apparently yes.)
132 --quotRemFastInt = quotRem
133 negateFastInt = negate
140 shiftLFastInt = shiftL
141 shiftR_FastInt = shiftR
142 shiftRAFastInt = shiftR
143 shiftRLFastInt n p = fromIntegral (shiftR (fromIntegral n :: Word) p)
144 --shiftLFastInt n p = n * (2 ^ p)
145 --assuming quot-Int is faster and the
146 --same for nonnegative arguments than div-Int
147 --shiftR_FastInt n p = n `quot` (2 ^ p)
148 --shiftRAFastInt n p = n `div` (2 ^ p)
149 --I couldn't figure out how to implement without Word nor Bits
150 --shiftRLFastInt n p = fromIntegral ((fromIntegral n :: Word) `quot` (2 ^ (fromIntegral p :: Word)))
152 bitAndFastInt = (.&.)
158 -- make sure these are as strict as the unboxed version,
159 -- so that the performance characteristics match
160 fastOr False False = False
162 fastAnd True True = True
170 fastChr = chr --or unsafeChr if there was a standard location for it
173 type FastPtr a = Ptr a
176 castFastPtr = castPtr
178 --These are among the type-signatures necessary for !ghc to compile
179 -- but break ghc (can't give a signature for an import...)
180 --Note that the comparisons actually do return Bools not FastBools.
181 (+#), (-#), (*#) :: FastInt -> FastInt -> FastInt
182 (==#), (/=#), (<#), (<=#), (>=#), (>#) :: FastInt -> FastInt -> Bool
184 #endif /* ! __GLASGOW_HASKELL__ */
186 minFastInt, maxFastInt :: FastInt -> FastInt -> FastInt
187 minFastInt x y = if x <# y then x else y
188 maxFastInt x y = if x <# y then y else x
190 -- type-signatures will improve the non-ghc-specific versions
191 -- and keep things accurate (and ABLE to compile!)
192 _ILIT :: Int -> FastInt
193 iBox :: FastInt -> Int
194 iUnbox :: Int -> FastInt
196 quotFastInt :: FastInt -> FastInt -> FastInt
197 negateFastInt :: FastInt -> FastInt
198 shiftLFastInt, shiftR_FastInt, shiftRAFastInt, shiftRLFastInt
199 :: FastInt -> FastInt -> FastInt
200 bitAndFastInt, bitOrFastInt :: FastInt -> FastInt -> FastInt
202 _CLIT :: Char -> FastChar
203 cBox :: FastChar -> Char
204 cUnbox :: Char -> FastChar
205 fastOrd :: FastChar -> FastInt
206 fastChr :: FastInt -> FastChar
207 eqFastChar :: FastChar -> FastChar -> Bool
209 pBox :: FastPtr a -> Ptr a
210 pUnbox :: Ptr a -> FastPtr a
211 castFastPtr :: FastPtr a -> FastPtr b