1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--                ADA.NUMERICS.GENERIC_ELEMENTARY_FUNCTIONS                 --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 2012-2015, 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------------------------------------------------------------------------------
35
36generic
37   type Float_Type is digits <>;
38
39package Ada.Numerics.Generic_Elementary_Functions is
40   pragma Pure;
41
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)
46
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).
50
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.
58
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.
61
62       and then (if X >= Float_Type'Succ (0.0) then Sqrt'Result > 0.0);
63
64   function Log (X : Float_Type'Base) return Float_Type'Base with
65     Post => (if X = 1.0 then Log'Result = 0.0);
66
67   function Log (X, Base : Float_Type'Base) return Float_Type'Base with
68     Post => (if X = 1.0 then Log'Result = 0.0);
69
70   function Exp (X : Float_Type'Base) return Float_Type'Base with
71     Post => (if X = 0.0 then Exp'Result = 1.0);
72
73   function "**" (Left, Right : Float_Type'Base) return Float_Type'Base with
74     Post => "**"'Result >= 0.0
75       and then (if Right = 0.0 then "**"'Result = 1.0)
76       and then (if Right = 1.0 then "**"'Result = Left)
77       and then (if Left  = 1.0 then "**"'Result = 1.0)
78       and then (if Left  = 0.0 then "**"'Result = 0.0);
79
80   function Sin (X : Float_Type'Base) return Float_Type'Base with
81     Post => Sin'Result in -1.0 .. 1.0
82       and then (if X = 0.0 then Sin'Result = 0.0);
83
84   function Sin (X, Cycle : Float_Type'Base) return Float_Type'Base with
85     Post => Sin'Result in -1.0 .. 1.0
86       and then (if X = 0.0 then Sin'Result = 0.0);
87
88   function Cos (X : Float_Type'Base) return Float_Type'Base with
89     Post => Cos'Result in -1.0 .. 1.0
90       and then (if X = 0.0 then Cos'Result = 1.0);
91
92   function Cos (X, Cycle : Float_Type'Base) return Float_Type'Base with
93     Post => Cos'Result in -1.0 .. 1.0
94       and then (if X = 0.0 then Cos'Result = 1.0);
95
96   function Tan (X : Float_Type'Base) return Float_Type'Base with
97     Post => (if X = 0.0 then Tan'Result = 0.0);
98
99   function Tan (X, Cycle : Float_Type'Base) return Float_Type'Base with
100     Post => (if X = 0.0 then Tan'Result = 0.0);
101
102   function Cot (X : Float_Type'Base) return Float_Type'Base;
103
104   function Cot (X, Cycle : Float_Type'Base) return Float_Type'Base;
105
106   function Arcsin (X : Float_Type'Base) return Float_Type'Base with
107     Post => (if X = 0.0 then Arcsin'Result = 0.0);
108
109   function Arcsin (X, Cycle : Float_Type'Base) return Float_Type'Base with
110     Post => (if X = 0.0 then Arcsin'Result = 0.0);
111
112   function Arccos (X : Float_Type'Base) return Float_Type'Base with
113     Post => (if X = 1.0 then Arccos'Result = 0.0);
114
115   function Arccos (X, Cycle : Float_Type'Base) return Float_Type'Base with
116     Post => (if X = 1.0 then Arccos'Result = 0.0);
117
118   function Arctan
119     (Y : Float_Type'Base;
120      X : Float_Type'Base := 1.0) return Float_Type'Base
121   with
122     Post => (if X > 0.0 and then Y = 0.0 then Arctan'Result = 0.0);
123
124   function Arctan
125     (Y     : Float_Type'Base;
126      X     : Float_Type'Base := 1.0;
127      Cycle : Float_Type'Base) return Float_Type'Base
128   with
129     Post => (if X > 0.0 and then Y = 0.0 then Arctan'Result = 0.0);
130
131   function Arccot
132     (X   : Float_Type'Base;
133      Y   : Float_Type'Base := 1.0) return Float_Type'Base
134   with
135     Post => (if X > 0.0 and then Y = 0.0 then Arccot'Result = 0.0);
136
137   function Arccot
138     (X     : Float_Type'Base;
139      Y     : Float_Type'Base := 1.0;
140      Cycle : Float_Type'Base) return Float_Type'Base
141   with
142     Post => (if X > 0.0 and then Y = 0.0 then Arccot'Result = 0.0);
143
144   function Sinh (X : Float_Type'Base) return Float_Type'Base with
145     Post => (if X = 0.0 then Sinh'Result = 0.0);
146
147   function Cosh (X : Float_Type'Base) return Float_Type'Base with
148     Post => Cosh'Result >= 1.0
149       and then (if X = 0.0 then Cosh'Result = 1.0);
150
151   function Tanh (X : Float_Type'Base) return Float_Type'Base with
152     Post => Tanh'Result in -1.0 .. 1.0
153       and then (if X = 0.0 then Tanh'Result = 0.0);
154
155   function Coth (X : Float_Type'Base) return Float_Type'Base with
156     Post => abs Coth'Result >= 1.0;
157
158   function Arcsinh (X : Float_Type'Base) return Float_Type'Base with
159     Post => (if X = 0.0 then Arcsinh'Result = 0.0);
160
161   function Arccosh (X : Float_Type'Base) return Float_Type'Base with
162     Post => Arccosh'Result >= 0.0
163       and then (if X = 1.0 then Arccosh'Result = 0.0);
164
165   function Arctanh (X : Float_Type'Base) return Float_Type'Base with
166     Post => (if X = 0.0 then Arctanh'Result = 0.0);
167
168   function Arccoth (X : Float_Type'Base) return Float_Type'Base;
169
170end Ada.Numerics.Generic_Elementary_Functions;
171