blob: 18ad10f0bfd6c2b19e3b67af1275c2e44338a946 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
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
46
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
|
with Interfaces; use Interfaces;
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Command_Line; use Ada.Command_Line;
procedure Pattr is
Xdigit : constant array (0 .. 15) of Character := "0123456789abcdef";
procedure Disp_Lit (Z : Natural; Known : Boolean; S : String) is
begin
Put_Line (S);
end Disp_Lit;
procedure Disp_Float_Lit
(Lit_Type : Natural; Known : Boolean; Val : IEEE_Float_64)
is
pragma Assert (IEEE_Float_64'Machine_Radix = 2);
pragma Assert (IEEE_Float_64'Machine_Mantissa = 53);
Exp : Integer;
Man : Unsigned_64;
-- Res: sign(1) + 0x(2) + Man(53 / 3 ~= 18) + p(1) + sing(1) + exp(4)
Str : String (1 .. 1 + 2 + 18 + 1 + 1 + 4);
P : Natural;
Neg : Boolean;
begin
Exp := IEEE_Float_64'Exponent (Val) - 1;
Man := Unsigned_64 (abs (IEEE_Float_64'Fraction (Val)) * 2.0 ** 53);
-- Use decimal representation if there is no digit after the dot.
if Man = 0 then
Disp_Lit (Lit_Type, Known, "0.0");
else
pragma Assert (Shift_Right (Man, 52) = 1);
-- Remove hidden 1.
Man := Man and (2**52 - 1);
-- Remove trailing hex 0.
while Man /= 0 and (Man rem 16) = 0 loop
Man := Man / 16;
end loop;
-- Exponent.
P := Str'Last;
if Exp < 0 then
Neg := True;
Exp := -Exp;
else
Neg := False;
end if;
loop
Str (P) := Xdigit (Exp rem 10);
P := P - 1;
Exp := Exp / 10;
exit when Exp = 0;
end loop;
if Neg then
Str (P) := '-';
P := P - 1;
end if;
Str (P) := 'p';
P := P - 1;
-- Mantissa.
loop
Str (P) := Xdigit (Natural (Man and 15));
P := P - 1;
Man := Man / 16;
exit when Man = 0;
end loop;
P := P - 4;
Str (P + 1) := '0';
Str (P + 2) := 'x';
Str (P + 3) := '1';
Str (P + 4) := '.';
if Val < 0.0 then
Str (P) := '-';
P := P - 1;
end if;
Disp_Lit (Lit_Type, Known, Str (P + 1 .. Str'Last));
end if;
end Disp_Float_Lit;
subtype T is IEEE_Float_64;
V : T;
begin
if Argument_Count /= 1 then
Put_Line ("usage : pattr FNUM");
return;
end if;
V := T'Value (Argument (1));
Put_Line ("Machine Radix:" & Natural'Image (T'Machine_Radix));
Put_Line ("Machine Mantissa:" & Natural'Image (T'Machine_Mantissa));
Put_Line ("Machine Emin: " & Natural'Image (T'Machine_Emin));
Put_Line ("Machine Emax: " & Natural'Image (T'Machine_Emax));
Put_Line ("Exponent: " & Integer'Image (T'Exponent (V)));
Put_Line ("Fraction: " & T'Image (T'Fraction (V)));
Disp_Float_Lit (1, False, V);
end pattr;
|
