Re: GNAT Ada.Numerics.Aux question

[Gerald.Kasner@Physik.Uni-Magdeburg.de (Gerald)]

happysegfault@yahoo.com (Happy Segfault) wrote in message news:<ed66a020.0307281917.333e3587@posting.google.com>...
> Hi all!  
> 
> I'm trying out GtkAda 2.2.0 on my Red Hat 9 system using gcc 3.2.2,
> and the testgtk OpenGL demo crashes with a constraint error.  I think
> I've tracked down the problem to a call to Ada.Numerics.Aux.Sin, which
> is a thin binding to the libm sin function.  What could be going wrong
> here?  Why isn't Sin (X) getting the expected value in the program
> below?  Oddly, Sqrt (X) seems to work fine.
> 
> --
> -- test_sin.adb
> --
> with Ada.Text_IO;
> with Ada.Numerics.Aux;
>  
> procedure test_sin is
>   X : Ada.Numerics.Aux.Double;
> begin
>   X := Ada.Numerics.Aux.Double (2.0);
>   X := Ada.Numerics.Aux.Sqrt (X);
>   Ada.Text_IO.Put_Line (Ada.Numerics.Aux.Double'Image (X));
>   -- output is ' 1.41421356237309505E+00' which is expected
>   X := Ada.Numerics.Aux.Double (30.0 * 3.14159 / 180.0);
>   X := Ada.Numerics.Aux.Sin (X);
>   -- use the pragma Import (C, Sin, "sin"); from Ada.Numerics.Aux
>   Ada.Text_IO.Put_Line (Ada.Numerics.Aux.Double'Image (X));
>   -- output is '0.E+17' but 0.5 is the expected result
>   Ada.Text_IO.Put_Line (Float'Image (Float (X)));
>   -- raises constraint error
> end test_sin;
> 
> Thanks!  
> 
> John

You may use gcc-gnat from redhat-rawhide.

Here is what I got on a RH 9.0 system with gcc-gnat from
redhat-rawhide:
gnatmake -O2 test_sin.adb
gcc -c -O2 test_sin.adb
test_sin.adb:2:18: warning: "ada.numerics.aux" is an internal GNAT
unit
test_sin.adb:2:18: warning: use of this unit is non-portable and
version-dependent
gnatbind -x test_sin.ali
gnatlink test_sin.ali

./test_sin 
 1.41421356237309505E+00
 4.99999616987255739E-01
 5.00000E-01

gnatmake -v

GNATMAKE 3.3 20030715 (Red Hat Linux 3.3-14) Copyright 1995-2002 Free
Software Foundation, Inc.

..

you have to install a new binutils package from rawhide too.

Best, Gerald