Bug 206972

Summary:	kde-base/kmplot-3.5.7: Calculate Integral gives incorrect answers.
Product:	Gentoo Linux	Reporter:	Kim Nilsson <nilekurt>
Component:	[OLD] KDE	Assignee:	Gentoo KDE team <kde>
Status:	VERIFIED INVALID
Severity:	normal
Priority:	High
Version:	2007.0
Hardware:	x86
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---
Attachments:	emerge --info output

Description Kim Nilsson 2008-01-22 01:30:17 UTC

I tried to calculate a few integrals using KmPlot, but it returned erroneous answers which never exceeded 1.

Reproducible: Always

Steps to Reproduce:
1.Run KmPlot
2.Plot any function (Example: y=sin x )
3.Select "Calculate Integral" from the "Tools" menu
4.Enter any valid range and select the function (Example: Between x=0 and x=pi)
5.Calculate
Actual Results:  
KmPlot returns an incorrect answer which is always less than 1. (Example: 0)

Expected Results:  
It should return valid answers. (Example: 1)

Using KDE 3.5.7

Comment 1 Kim Nilsson 2008-01-22 01:33:55 UTC

Created attachment 141546 [details]
emerge --info output

Comment 2 Kim Nilsson 2008-01-22 01:38:23 UTC

emerge --info
Portage 2.1.3.19 (default-linux/x86/2007.0, gcc-4.1.2, glibc-2.6.1-r0, 2.6.23-gentoo-r3 i686)
=================================================================
System uname: 2.6.23-gentoo-r3 i686 AMD Athlon(tm) 64 X2 Dual Core Processor 3800+
Timestamp of tree: Mon, 21 Jan 2008 16:59:01 +0000
app-shells/bash:     3.2_p17-r1
dev-java/java-config: 1.3.7, 2.0.33-r1
dev-lang/python:     2.4.4-r6
dev-python/pycrypto: 2.0.1-r6
sys-apps/baselayout: 1.12.10-r5
sys-apps/sandbox:    1.2.18.1-r2
sys-devel/autoconf:  2.13, 2.61-r1
sys-devel/automake:  1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10
sys-devel/binutils:  2.18-r1
sys-devel/gcc-config: 1.4.0-r4
sys-devel/libtool:   1.5.24
virtual/os-headers:  2.6.23-r3
ACCEPT_KEYWORDS="x86"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-O3 -march=k8 -pipe -ffast-math"
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/share/config"
CONFIG_PROTECT_MASK="/etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/terminfo /etc/udev/rules.d"
CXXFLAGS="-O3 -march=k8 -pipe -ffast-math"
DISTDIR="/usr/portage/distfiles"
FEATURES="distlocks metadata-transfer sandbox sfperms strict unmerge-orphans userfetch"
GENTOO_MIRRORS="http://trumpetti.atm.tut.fi/gentoo/ ftp://trumpetti.atm.tut.fi/gentoo/ http://www.mirrorservice.org/sites/www.ibiblio.org/gentoo/ "
MAKEOPTS="-j4"
PKGDIR="/usr/portage/packages"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --delete-after --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --filter=H_**/files/digest-*"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="X aac acl aim alsa arts berkdb bitmap-fonts bluetooth bzip cd cdr cli cracklib crypt cups divx dri dvd dvdr exif ffmpeg flac fortran ftp gdbm gif gpm gtk hal iconv ipv6 isdnlog jabber jack java jingle jpeg jpeg2k kde midi mp3 mpeg mplayer msn mudflap ncurses nls nptl nptlonly openal opengl openmp pam pcre perl pppd python qt4 readline reflection session socks5 speex spl ssl tcpd truetype-fonts type1-fonts unicode usb vcd vnc vorbis win32codecs x264 x86 xorg xvid zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1 emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" ELIBC="glibc" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" USERLAND="GNU" VIDEO_CARDS="fglrx radeon vesafb"
Unset:  CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, LDFLAGS, LINGUAS, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, PORTDIR_OVERLAY

Comment 3 Ingmar Vanhassel (RETIRED) gentoo-dev

2008-01-22 01:43:34 UTC

(In reply to comment #2)
> CFLAGS="-O3 -march=k8 -pipe -ffast-math"
> CXXFLAGS="-O3 -march=k8 -pipe -ffast-math"

It breaks because you use -ffast-math.
To quote `man gcc`:
	This option should never be turned on by any -O option since it can result in incorrect output for programs which depend on an exact implementation of IEEE or ISO rules/specifications for math functions.

http://www.gentoo.org/doc/en/gcc-optimization.xml for more info.