gcc/testsuite/gnat.dg/fixedpnt5.adb

   1 --  { dg-do run }
   2
   3 with Text_IO; use Text_IO;
   4 with Ada.Numerics; use Ada.Numerics;
   5 with Unchecked_Conversion;
   6
   7 procedure Fixedpnt5 is
   8    --  Test conversions from Floating point to Fixed point types when the
   9    --  fixed type has a Small that is not a power of two. Verify that the
  10    --  conversions are reversible, so that:
  11    --
  12    --        Fixed_T (Float_T (Fixed_Var)) = Fixed_Var
  13    --
  14    --  for a range of fixed values, in particular at the boundary of type.
  15
  16    type T_Fixed_Type is delta PI/32768.0 range -PI .. PI - PI/32768.0;
  17    for T_Fixed_Type'Small use PI/32768.0;
  18
  19    function To_Fix is new Unchecked_Conversion (Short_Integer, T_Fixed_Type);
  20    Fixed_Point_Var : T_Fixed_Type;
  21    Float_Var       : Float;
  22
  23 begin
  24    Fixed_Point_Var := -PI;
  25    Float_Var       := Float(Fixed_Point_Var);
  26    Fixed_Point_Var := T_Fixed_Type (Float_Var);
  27
  28    Fixed_Point_Var := T_Fixed_Type'First;
  29    Float_Var       := Float(Fixed_Point_Var);
  30    Fixed_Point_Var := T_Fixed_Type (Float_Var);
  31
  32    if Fixed_Point_Var /= T_Fixed_Type'First then
  33       raise Program_Error;
  34    end if;
  35
  36    fixed_point_var := t_fixed_type'Last;
  37    Float_Var       := Float(Fixed_Point_Var);
  38    Fixed_Point_Var := T_Fixed_Type (Float_Var);
  39
  40    if Fixed_Point_Var /= T_Fixed_Type'Last then
  41       raise Program_Error;
  42    end if;
  43
  44    for I in  -32768 ..  32767 loop
  45       fixed_Point_Var := To_Fix (Short_Integer (I));
  46       Float_Var := Float (Fixed_Point_Var);
  47       if T_Fixed_Type (Float_Var) /= FIxed_Point_Var then
  48          Put_Line ("Not reversibloe");
  49          Put_Line (Integer'Image (I));
  50          raise Program_Error;
  51       end if;
  52    end loop;
  53
  54    Fixed_Point_Var := T_Fixed_Type (Float_Var * 2.0);
  55    raise Program_Error;
  56 exception
  57    when others => null;
  58 end Fixedpnt5;