Re: ada/6911: Sin and Cos returns bad result or exception

[Brian May <bam@snoopy.apana.org.au>]

The following reply was made to PR ada/6911; it has been noted by GNATS.

From: Brian May <bam@snoopy.apana.org.au>
To: Dara Hazeghi <dhazeghi@yahoo.com>
Cc: 148529@bugs.debian.org, gcc-gnats@gcc.gnu.org,
	nobody@gcc.gnu.org, fw@deneb.enyo.de
Subject: Re: ada/6911: Sin and Cos returns bad result or exception
Date: Tue, 13 May 2003 14:05:30 +1000

 On Mon, May 12, 2003 at 04:31:18PM -0700, Dara Hazeghi wrote:
 > the final note in the Debian bug trail for this bug noted that this  
 > problem was fixed on gcc 3.3 branch. Is this the case? Right now,  
 > mainline and 3.3 branch produce this for me:
 > 
 > -7.07105E-01
 >  0.00000E+00
 > -8.74228E-08
 >  1.74846E-07
 > -7.07105E-01
 > 
 > (the second testcase). Can anyone confirm the state of this bug. Thanks,
 
 For:
 
 --- cut ---
 with Ada.Text_IO;
 use Ada.Text_IO;
 
 with Ada.Numerics;
 use Ada.Numerics;
    
 with Ada.Numerics.Generic_Elementary_Functions;
 
 with Aux;
 use Aux;
 
 procedure TestBug2 is
 
    type F is new Float;
    subtype Radians is F;
 
    package Maths is new Generic_Elementary_Functions(F);
    use Maths;
 
 begin
     Ada.Text_IO.Put_Line(Double'Image(Aux.Sin(5.49779)));
     Ada.Text_IO.Put_Line(Double'Image(Aux.Sin(0.0*pi)));
     Ada.Text_IO.Put_Line(Double'Image(Aux.Sin(1.0*pi)));
     Ada.Text_IO.Put_Line(Double'Image(Aux.Sin(2.0*pi)));
     Ada.Text_IO.Put_Line(Double'Image(Aux.Sin(5.49779)));
 
     Ada.Text_IO.Put_Line(F'Image(Sin(5.49779)));
     Ada.Text_IO.Put_Line(F'Image(Sin(0.0*pi)));
     Ada.Text_IO.Put_Line(F'Image(Sin(1.0*pi)));
     Ada.Text_IO.Put_Line(F'Image(Sin(2.0*pi)));
     Ada.Text_IO.Put_Line(F'Image(Sin(5.49779)));
 end TestBug2;
 --- cut ---
 
 I get:
 
 --- cut ---
 -7.07104761532644598E-01
  0.00000000000000000E+00
 -5.42101086242752217E-20
  1.08420217248550443E-19
 -7.07104761532644598E-01
 -7.07105E-01
  0.00000E+00
 -8.74228E-08
  1.74846E-07
 -7.07105E-01
 --- cut ---
 
 Which looks much better then before,  but I haven't
 checked the results against a calculator...
 
 This is the same code that failed before.
 -- 
 Brian May <bam@snoopy.apana.org.au>