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From: Marin David Condic <mcondic.nospam@acm.org>
Subject: Legitimate Argument_Error Or Compiler Bug?
Date: 2000/09/25
Message-ID: <39CFA126.6669BF45@acm.org>#1/1
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Organization: Quadrus Corporation
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Newsgroups: comp.lang.ada
Date: 2000-09-25T19:02:11+00:00
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The following code raises Argument_Error when attempting to compute a
positive fraction to a real power. Now so far as I can tell, there is
nothing particularly undefined about a fraction raised to a real power,
so Argument_Error seems to be out of place here. Either I've got
something wrong or I've tripped across a bug in the compiler (GNAT
3.13p). Is there a reason this exception should be raised or should I
submit a bug report?

Thanks for the help.

MDC


with Ada.Text_Io ;
with Ada.Numerics.Long_Long_Elementary_Functions ;
use Ada.Numerics.Long_Long_Elementary_Functions ;
--
procedure What_The_Heck is

   Alpha        : Long_Long_Float := 0.05;
   Log_Term     : Long_Long_Float;
   Neg_Log_Term : Long_Long_Float;
   Power_Term   : Long_Long_Float;
   --
begin
   --
   Log_Term      := Log(Alpha/2.0 , 10.0) ;
   Neg_Log_Term  := - Log_Term ;
   --
   Ada.Text_Io.Put ("Neg_Log_Term ** 2   is ") ;
   Power_Term    := Neg_Log_Term ** 2 ;
   Ada.Text_Io.Put_Line (Long_Long_Float'Image(Power_Term) ) ;
   --
   Ada.Text_Io.Put ("    Log_Term ** 2   is ") ;
   Power_Term    := Log_Term ** 2 ;
   Ada.Text_Io.Put_Line (Long_Long_Float'Image(Power_Term) ) ;
   --
   Ada.Text_Io.Put ("Neg_Log_Term ** 2.0 is ") ;
   Power_Term     := Neg_Log_Term ** 2.0;
   Ada.Text_Io.Put_Line (Long_Long_Float'Image(Power_Term) ) ;
   --
   Ada.Text_Io.Put ("    Log_Term ** 2.0 is (Argument_Error)") ;
   Power_Term    :=  Log_Term ** 2.0 ;    --  Dies here!
   Ada.Text_Io.Put_Line (Long_Long_Float'Image(Power_Term) ) ;
   --
end What_The_Heck ;

--
======================================================================
Marin David Condic - Quadrus Corporation - http://www.quadruscorp.com/
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Visit my web site at:  http://www.mcondic.com/

    "Because that's where they keep the money."

        --  Willie Sutton when asked why he robbed banks.
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