public inbox for java-prs@sourceware.org
help / color / mirror / Atom feed
* [Bug AWT/16825] New: Bad results for QuadCurve2D.solveQuadratic
@ 2004-07-29 21:10 mark at gcc dot gnu dot org
2004-07-29 21:16 ` [Bug AWT/16825] " pinskia at gcc dot gnu dot org
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: mark at gcc dot gnu dot org @ 2004-07-29 21:10 UTC (permalink / raw)
To: java-prs
The method java.awt.geom.QuadCurve2D.solveQuadratic sometimes does not return
the right results for the following equation:
(x^2)/10 + 20x + 1000 = 0
Expected result: -100
This equation is tested by Mauve; see gnu.testlet.java.awt.geom.QuadCurve2D.
The problem occurs with various versions of gcj, compiling for IA-32. However,
it does NOT occur when executing the same Mauve testlet on jamvm, using the same
implementation for java.awt.geom.QuadCurve2D.
It turned out that a small Java test program for computing the equation's
discriminant gives a very small negative number when run on gcj/IA-32, but
exactly zero when run on jamvm or the Sun J2SE 1.4.1_01.
This bug report comes from GNU Classpath:
https://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=7123
(Please see the very large audit trail there for more information.)
--
Summary: Bad results for QuadCurve2D.solveQuadratic
Product: gcc
Version: 3.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: AWT
AssignedTo: fitzsim at redhat dot com
ReportedBy: mark at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org,java-prs at gcc dot gnu
dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16825
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug AWT/16825] Bad results for QuadCurve2D.solveQuadratic
2004-07-29 21:10 [Bug AWT/16825] New: Bad results for QuadCurve2D.solveQuadratic mark at gcc dot gnu dot org
@ 2004-07-29 21:16 ` pinskia at gcc dot gnu dot org
2004-07-30 15:46 ` fitzsim at redhat dot com
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-07-29 21:16 UTC (permalink / raw)
To: java-prs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-07-29 21:16 -------
Confirmed, I have seen the discussion of this bug before somewhere but I had forgot where, I think the
java-patches or the java list.
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2004-07-29 21:16:25
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16825
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug AWT/16825] Bad results for QuadCurve2D.solveQuadratic
2004-07-29 21:10 [Bug AWT/16825] New: Bad results for QuadCurve2D.solveQuadratic mark at gcc dot gnu dot org
2004-07-29 21:16 ` [Bug AWT/16825] " pinskia at gcc dot gnu dot org
@ 2004-07-30 15:46 ` fitzsim at redhat dot com
2004-11-09 23:22 ` sven at physto dot se
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: fitzsim at redhat dot com @ 2004-07-30 15:46 UTC (permalink / raw)
To: java-prs
--
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|fitzsim at redhat dot com |graydon at redhat dot com
Status|NEW |ASSIGNED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16825
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug AWT/16825] Bad results for QuadCurve2D.solveQuadratic
2004-07-29 21:10 [Bug AWT/16825] New: Bad results for QuadCurve2D.solveQuadratic mark at gcc dot gnu dot org
2004-07-29 21:16 ` [Bug AWT/16825] " pinskia at gcc dot gnu dot org
2004-07-30 15:46 ` fitzsim at redhat dot com
@ 2004-11-09 23:22 ` sven at physto dot se
2004-11-09 23:32 ` pinskia at gcc dot gnu dot org
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: sven at physto dot se @ 2004-11-09 23:22 UTC (permalink / raw)
To: java-prs
------- Additional Comments From sven at physto dot se 2004-11-09 23:22 -------
This isn't a Awt or libgcj bug itself, but rather an effect of the extended-mode
of FPU being the default leading to inconsistent results with 64-bit doubles.
A suggestion for a 'fix' is to set the FPU to 64-bit double rounding for Java
programs, since Java does not have a 'long double' type. This would both
stricter and give more consistent results with other platforms.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16825
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug AWT/16825] Bad results for QuadCurve2D.solveQuadratic
2004-07-29 21:10 [Bug AWT/16825] New: Bad results for QuadCurve2D.solveQuadratic mark at gcc dot gnu dot org
` (2 preceding siblings ...)
2004-11-09 23:22 ` sven at physto dot se
@ 2004-11-09 23:32 ` pinskia at gcc dot gnu dot org
2005-08-24 19:43 ` [Bug awt/16825] " fitzsim at redhat dot com
2005-08-24 23:49 ` [Bug awt/16825] need to reimplement QuadCurve2D.solveQuadratic fitzsim at redhat dot com
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-11-09 23:32 UTC (permalink / raw)
To: java-prs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-09 23:32 -------
Note the java "standard" does not require the FPU set to double-precision except when working in strict
mode (this was changed after 1.0 IIRC).
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16825
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug awt/16825] Bad results for QuadCurve2D.solveQuadratic
2004-07-29 21:10 [Bug AWT/16825] New: Bad results for QuadCurve2D.solveQuadratic mark at gcc dot gnu dot org
` (3 preceding siblings ...)
2004-11-09 23:32 ` pinskia at gcc dot gnu dot org
@ 2005-08-24 19:43 ` fitzsim at redhat dot com
2005-08-24 23:49 ` [Bug awt/16825] need to reimplement QuadCurve2D.solveQuadratic fitzsim at redhat dot com
5 siblings, 0 replies; 7+ messages in thread
From: fitzsim at redhat dot com @ 2005-08-24 19:43 UTC (permalink / raw)
To: java-prs
------- Additional Comments From fitzsim at redhat dot com 2005-08-24 19:43 -------
*** Bug 22724 has been marked as a duplicate of this bug. ***
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |from-classpath at savannah
| |dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16825
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug awt/16825] need to reimplement QuadCurve2D.solveQuadratic
2004-07-29 21:10 [Bug AWT/16825] New: Bad results for QuadCurve2D.solveQuadratic mark at gcc dot gnu dot org
` (4 preceding siblings ...)
2005-08-24 19:43 ` [Bug awt/16825] " fitzsim at redhat dot com
@ 2005-08-24 23:49 ` fitzsim at redhat dot com
5 siblings, 0 replies; 7+ messages in thread
From: fitzsim at redhat dot com @ 2005-08-24 23:49 UTC (permalink / raw)
To: java-prs
------- Additional Comments From fitzsim at redhat dot com 2005-08-24 23:49 -------
We need to reimplement QuadCurve2D.solveQuadratic, possibly using the algorithm
described here: http://www.library.cornell.edu/nr/bookcpdf/c5-6.pdf
--
What |Removed |Added
----------------------------------------------------------------------------
Summary|Bad results for |need to reimplement
|QuadCurve2D.solveQuadratic |QuadCurve2D.solveQuadratic
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16825
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2005-08-24 23:49 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-07-29 21:10 [Bug AWT/16825] New: Bad results for QuadCurve2D.solveQuadratic mark at gcc dot gnu dot org
2004-07-29 21:16 ` [Bug AWT/16825] " pinskia at gcc dot gnu dot org
2004-07-30 15:46 ` fitzsim at redhat dot com
2004-11-09 23:22 ` sven at physto dot se
2004-11-09 23:32 ` pinskia at gcc dot gnu dot org
2005-08-24 19:43 ` [Bug awt/16825] " fitzsim at redhat dot com
2005-08-24 23:49 ` [Bug awt/16825] need to reimplement QuadCurve2D.solveQuadratic fitzsim at redhat dot com
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).