Re: GNAT for AVR - Mathematical Functions

[Aurele Vitali <aurele.vitali@gmail.com>]

I don't know anything about the ATmega328P, but if it uses a builtin floating point processor, you can use Ada inline floating point assembler.  Its not hard to do. Here is a simple example of the square root function: 

  with System.Machine_Code; use System.Machine_Code; 
  EOL : constant String := ASCII.LF & ASCII.HT;

  function Sqrt( x : in Long_Float ) return Long_Float is 
    Result : Long_Float := 0.0; 
  begin 
    Asm( ( "fldl  %1" & EOL &                 -- Load x in St(0) 
           "fsqrt   " & EOL &                 -- Take the Sqrt of St(0) 
           "fstpl %0" ),                      -- Store result and pop St(0) 
         Outputs => ( Long_Float'Asm_Output("=m", Result ) ), 
         Inputs  => ( Long_Float'Asm_Input ( "m",      x ) ) ); 
    return Result; 
  end Sqrt; 

You can do the same thing for trig functions...  Just cut and past and see if this example works. 

Cheers