2015-09-28 Paul Thomas <pault@gcc.gnu.org>
[official-gcc.git] / gcc / ada / a-ngelfu.ads
blob8afb7332204c8ca560dee369808d3ade5b987267
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME COMPONENTS --
4 -- --
5 -- ADA.NUMERICS.GENERIC_ELEMENTARY_FUNCTIONS --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 2012-2014, Free Software Foundation, Inc. --
10 -- --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the Post aspects that have been added to the spec. --
14 -- --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 3, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. --
21 -- --
22 -- As a special exception under Section 7 of GPL version 3, you are granted --
23 -- additional permissions described in the GCC Runtime Library Exception, --
24 -- version 3.1, as published by the Free Software Foundation. --
25 -- --
26 -- You should have received a copy of the GNU General Public License and --
27 -- a copy of the GCC Runtime Library Exception along with this program; --
28 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
29 -- <http://www.gnu.org/licenses/>. --
30 -- --
31 -- GNAT was originally developed by the GNAT team at New York University. --
32 -- Extensive contributions were provided by Ada Core Technologies Inc. --
33 -- --
34 ------------------------------------------------------------------------------
36 generic
37 type Float_Type is digits <>;
39 package Ada.Numerics.Generic_Elementary_Functions is
40 pragma Pure;
42 function Sqrt (X : Float_Type'Base) return Float_Type'Base with
43 Post => Sqrt'Result >= 0.0
44 and then (if X = 0.0 then Sqrt'Result = 0.0)
45 and then (if X = 1.0 then Sqrt'Result = 1.0)
47 -- Finally if X is positive, the result of Sqrt is positive (because
48 -- the sqrt of numbers greater than 1 is greater than or equal to 1,
49 -- and the sqrt of numbers less than 1 is greater than the argument).
51 -- This property is useful in particular for static analysis. The
52 -- property that X is positive is not expressed as (X > 0.0), as
53 -- the value X may be held in registers that have larger range and
54 -- precision on some architecture (for example, on x86 using x387
55 -- FPU, as opposed to SSE2). So, it might be possible for X to be
56 -- 2.0**(-5000) or so, which could cause the number to compare as
57 -- greater than 0, but Sqrt would still return a zero result.
59 -- Note: we use the comparison with Succ (0.0) here because this is
60 -- more amenable to CodePeer analysis than the use of 'Machine.
62 and then (if X >= Float_Type'Succ (0.0) then Sqrt'Result > 0.0);
64 function Log (X : Float_Type'Base) return Float_Type'Base
65 with
66 Post => (if X = 1.0 then Log'Result = 0.0);
68 function Log (X, Base : Float_Type'Base) return Float_Type'Base with
69 Post => (if X = 1.0 then Log'Result = 0.0);
71 function Exp (X : Float_Type'Base) return Float_Type'Base with
72 Post => (if X = 0.0 then Exp'Result = 1.0);
74 function "**" (Left, Right : Float_Type'Base) return Float_Type'Base with
75 Post => "**"'Result >= 0.0
76 and then (if Right = 0.0 then "**"'Result = 1.0)
77 and then (if Right = 1.0 then "**"'Result = Left)
78 and then (if Left = 1.0 then "**"'Result = 1.0)
79 and then (if Left = 0.0 then "**"'Result = 0.0);
81 function Sin (X : Float_Type'Base) return Float_Type'Base with
82 Post => Sin'Result in -1.0 .. 1.0
83 and then (if X = 0.0 then Sin'Result = 0.0);
85 function Sin (X, Cycle : Float_Type'Base) return Float_Type'Base with
86 Post => Sin'Result in -1.0 .. 1.0
87 and then (if X = 0.0 then Sin'Result = 0.0);
89 function Cos (X : Float_Type'Base) return Float_Type'Base with
90 Post => Cos'Result in -1.0 .. 1.0
91 and then (if X = 0.0 then Cos'Result = 1.0);
93 function Cos (X, Cycle : Float_Type'Base) return Float_Type'Base with
94 Post => Cos'Result in -1.0 .. 1.0
95 and then (if X = 0.0 then Cos'Result = 1.0);
97 function Tan (X : Float_Type'Base) return Float_Type'Base with
98 Post => (if X = 0.0 then Tan'Result = 0.0);
100 function Tan (X, Cycle : Float_Type'Base) return Float_Type'Base with
101 Post => (if X = 0.0 then Tan'Result = 0.0);
103 function Cot (X : Float_Type'Base) return Float_Type'Base;
105 function Cot (X, Cycle : Float_Type'Base) return Float_Type'Base;
107 function Arcsin (X : Float_Type'Base) return Float_Type'Base with
108 Post => (if X = 0.0 then Arcsin'Result = 0.0);
110 function Arcsin (X, Cycle : Float_Type'Base) return Float_Type'Base with
111 Post => (if X = 0.0 then Arcsin'Result = 0.0);
113 function Arccos (X : Float_Type'Base) return Float_Type'Base with
114 Post => (if X = 1.0 then Arccos'Result = 0.0);
116 function Arccos (X, Cycle : Float_Type'Base) return Float_Type'Base with
117 Post => (if X = 1.0 then Arccos'Result = 0.0);
119 function Arctan
120 (Y : Float_Type'Base;
121 X : Float_Type'Base := 1.0) return Float_Type'Base
122 with
123 Post => (if X > 0.0 and then Y = 0.0 then Arctan'Result = 0.0);
125 function Arctan
126 (Y : Float_Type'Base;
127 X : Float_Type'Base := 1.0;
128 Cycle : Float_Type'Base) return Float_Type'Base
129 with
130 Post => (if X > 0.0 and then Y = 0.0 then Arctan'Result = 0.0);
132 function Arccot
133 (X : Float_Type'Base;
134 Y : Float_Type'Base := 1.0) return Float_Type'Base
135 with
136 Post => (if X > 0.0 and then Y = 0.0 then Arccot'Result = 0.0);
138 function Arccot
139 (X : Float_Type'Base;
140 Y : Float_Type'Base := 1.0;
141 Cycle : Float_Type'Base) return Float_Type'Base
142 with
143 Post => (if X > 0.0 and then Y = 0.0 then Arccot'Result = 0.0);
145 function Sinh (X : Float_Type'Base) return Float_Type'Base with
146 Post => (if X = 0.0 then Sinh'Result = 0.0);
148 function Cosh (X : Float_Type'Base) return Float_Type'Base with
149 Post => Cosh'Result >= 1.0
150 and then (if X = 0.0 then Cosh'Result = 1.0);
152 function Tanh (X : Float_Type'Base) return Float_Type'Base with
153 Post => Tanh'Result in -1.0 .. 1.0
154 and then (if X = 0.0 then Tanh'Result = 0.0);
156 function Coth (X : Float_Type'Base) return Float_Type'Base with
157 Post => abs Coth'Result >= 1.0;
159 function Arcsinh (X : Float_Type'Base) return Float_Type'Base with
160 Post => (if X = 0.0 then Arcsinh'Result = 0.0);
162 function Arccosh (X : Float_Type'Base) return Float_Type'Base with
163 Post => Arccosh'Result >= 0.0
164 and then (if X = 1.0 then Arccosh'Result = 0.0);
166 function Arctanh (X : Float_Type'Base) return Float_Type'Base with
167 Post => (if X = 0.0 then Arctanh'Result = 0.0);
169 function Arccoth (X : Float_Type'Base) return Float_Type'Base;
171 end Ada.Numerics.Generic_Elementary_Functions;