Article View: gnu.gdb.bug
Article #2115numeric_limits<float>::max
From: Gabriel Zachmann
Date: Fri, 10 May 2002 13:59
Date: Fri, 10 May 2002 13:59
47 lines
2910 bytes
2910 bytes
I have a funny problem with gdb (GNU gdb Red Hat Linux (5.1-1)):
In a C++ program I have the following two lines:
float v = -numeric_limits<float>::max();
fprintf(stderr,"v=%f\n", v );
When I run the program I always get the output
v=-340282346638528859811704183484516925440.000000
However, when I run the program in gdb I sometimes get this
375 float v = -numeric_limits<float>::max();
(gdb)
376 fprintf(stderr,"v=%f\n", v );
(gdb)
v=nan
^^^
Unfortunately, I seem to be unable to produce a small example program
exhibiting this behavior.
I compile the program with g++ 3.0.4 using these options:
-march=i686 -ansi -fno-default-inline -ffor-scope
-g3 -ggdb3 -Wall -W -Wpointer-arith
-Wcast-qual -Wcast-align -Wconversion -Woverloaded-virtual -Wsign-compare
-Wnon-virtual-dtor -Woverloaded-virtual -Wfloat-equal -Wmissing-prototypes
-Wunreachable-code -Wno-reorder -D_GNU_SOURCE
Does anybody have any idea what might cause this differing behavior?
Thanks a lot in advance,
Gabriel.
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f5053,928e9af52e3d56e8,start X-Google-Attributes: gidf5053,public X-Google-ArrivalTime: 2002-05-10 06:59:44 PST x-uunet-gateway: dfw7sosrv11.alter.net from bug-gdb to gnu.gdb.bug; Fri, 10 May 2002 13:59:42 GMT Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!newsfeed.stanford.edu!bloom-beacon.mit.edu!nycmny1-snh1.gtei.net!cpk-news-hub1.bbnplanet.com!news.gtei.net!nntp.abs.net!uunet!dca.uu.net!ash.uu.net!spool0901.news.uu.net!wendy-fate.uu.net!not-for-mail From: zach@cs.uni-bonn.de (Gabriel Zachmann) Subject: numeric_limits<float>::max Date: 10 May 2002 13:59:39 GMT Organization: University Bonn, Germany Message-ID: <slrnadnki9.6qe.zach@fuji.informatik.uni-bonn.de> Reply-To: zach@cs.uni-bonn.de NNTP-Posting-Host: fuji.informatik.uni-bonn.de X-Trace: f1node01.rhrz.uni-bonn.de 1021039179 25656 131.220.3.143 (10 May 2002 13:59:39 GMT) X-Complaints-To: usenet@f1node01.rhrz.uni-bonn.de NNTP-Posting-Date: 10 May 2002 13:59:39 GMT X-realname: Gabriel Zachmann Mail-Copy-To: zach@cs.uni-bonn.de User-Agent: slrn/0.9.7.3 (Linux) Approved: bug-gdb-request@mail.gnu.org Newsgroups: gnu.gdb.bug Sender: bug-gdb-request@mail.gnu.org Lines: 47