cg044.hs 4.85 KB
Newer Older
1
2
3
4
5
6
7
-- !!! Testing IEEE Float and Double extremity predicates.
module Main(main) where

import Char
import ST
import MutableArray

8
9
10
11
12
13
14
15
16
17
reverse_if_bigendian :: [a] -> [a]
#ifdef sparc_sun_solaris2
reverse_if_bigendian = reverse
#endif
#ifdef i386_unknown_linux
reverse_if_bigendian = id
#endif
#ifdef i386_unknown_mingw32
reverse_if_bigendian = id
#endif
ken's avatar
ken committed
18
19
20
#ifdef alpha_dec_osf3
reverse_if_bigendian = id
#endif
21
22


23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
main :: IO ()
main = do
 sequence_ (map putStrLn double_tests)
 sequence_ (map putStrLn float_tests)
  where
   double_tests = run_tests double_numbers
   float_tests  = run_tests float_numbers  

   run_tests nums =
    map ($nums)
        [ denorm
        , pos_inf
        , neg_inf
        , nan
        , neg_zero
        , pos_zero
        ]

-------------
double_numbers :: [Double]
double_numbers =
      [ 0
      , encodeFloat 0 0     -- 0 using encodeFloat method
46
      , mkDouble (map chr (reverse_if_bigendian [0,0,0,0,0,0, 0xf0, 0x7f]))  -- +inf
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
      , encodeFloat 1 2047  -- +Inf 
      , encodeFloat 1 2048
      , encodeFloat 1  2047		  -- signalling NaN
      , encodeFloat 0xf000000000000 2047  -- quiet NaN
      , 0/(0::Double)
        -- misc
      , 1.82173691287639817263897126389712638972163e-300
      , 1.82173691287639817263897126389712638972163e+300
      , 4.9406564558412465e-324  -- smallest possible denorm number 
				 -- (as reported by enquire running
				 --  on a i686-pc-linux.)
      , 2.2250738585072014e-308
      , 0.11
      , 0.100
      , -3.4
        -- smallest 
      , let (l, _) = floatRange x
            x = encodeFloat 1 (l-1)
	in x
        -- largest
      , let (_, u) = floatRange x
	    d = floatDigits x
	    x = encodeFloat (floatRadix x ^ d - 1) (u - d)
	in x
      ]

float_numbers :: [Float]
float_numbers =
      [ 0
      , encodeFloat 0 0     -- 0 using encodeFloat method
      , encodeFloat 1 255  -- +Inf 
      , encodeFloat 1 256
      , encodeFloat 11 255	  -- signalling NaN
      , encodeFloat 0xf00000 255  -- quiet NaN
      , 0/(0::Float)
        -- misc
      , 1.82173691287639817263897126389712638972163e-300
      , 1.82173691287639817263897126389712638972163e+300
      , 1.40129846e-45
      , 1.17549435e-38
      , 2.98023259e-08
      , 0.11
      , 0.100
      , -3.4
        -- smallest 
      , let (l, _) = floatRange x
            x = encodeFloat 1 (l-1)
	in x
        -- largest
      , let (_, u) = floatRange x
	    d = floatDigits x
	    x = encodeFloat (floatRadix x ^ d - 1) (u - d)
	in x
      ]

-------------

denorm :: RealFloat a => [a] -> String
denorm numbers =
  unlines
     ( ""
     : "*********************************"
     : ("Denormalised numbers: " ++ doubleOrFloat numbers)
     : ""
     : map showPerform numbers)
 where
   showPerform = showAndPerform (isDenormalized) "isDenormalised"

pos_inf :: RealFloat a => [a] -> String
pos_inf numbers =
  unlines
     ( ""
     : "*********************************"
     : ("Positive Infinity: " ++ doubleOrFloat numbers)
     : ""
     : map showPerform numbers)
 where
   showPerform = showAndPerform (isInfinite) "isInfinite"

neg_inf :: RealFloat a => [a] -> String
neg_inf numbers =
  unlines
     ( ""
     : "*********************************"
     : ("Negative Infinity: " ++ doubleOrFloat numbers)
     : ""
     : map showPerform numbers)
 where
   showPerform = showAndPerform (\ x -> isInfinite x && x < 0) "isNegInfinite"

nan :: RealFloat a => [a] -> String
nan numbers =
  unlines
     ( ""
     : "*********************************"
     : ("NaN: " ++ doubleOrFloat numbers)
     : ""
     : map showPerform numbers)
 where
   showPerform = showAndPerform (isNaN) "isNaN"

pos_zero :: RealFloat a => [a] -> String
pos_zero numbers =
  unlines
     ( ""
     : "*********************************"
     : ("Positive zero: " ++ doubleOrFloat numbers)
     : ""
     : map showPerform numbers)
 where
   showPerform = showAndPerform (==0) "isPosZero"

neg_zero :: RealFloat a => [a] -> String
neg_zero numbers =
  unlines
     ( ""
     : "*********************************"
     : ("Negative zero: " ++ doubleOrFloat numbers)
     : ""
     : map showPerform numbers)
 where
   showPerform = showAndPerform (isNegativeZero) "isNegativeZero"

-- what a hack.
doubleOrFloat :: RealFloat a => [a] -> String
doubleOrFloat ls
 | (floatDigits atType) == (floatDigits (0::Double)) = "Double"
 | (floatDigits atType) == (floatDigits (0::Float))  = "Float"
 | otherwise = "unknown RealFloat type"
 where
   atType = undefined `asTypeOf` (head ls)

-- make a double from a list of 8 bytes
-- (caller deals with byte ordering.)
mkDouble :: [Char] -> Double
mkDouble ls = 
 runST ( do
   arr <- newCharArray (0,7)
   sequence (zipWith (writeCharArray arr) [(0::Int)..] (take 8 ls))
   readDoubleArray arr 0
 )

showAndPerform :: (Show a, Show b)
	       => (a -> b)
	       -> String
	       -> a
	       -> String
showAndPerform fun name_fun val =
  name_fun ++ ' ':show val ++ " = " ++ show (fun val)