public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "sjbespa at comcast dot net" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug fortran/46166] New: optimization and/or removing an if(.false.) statement leads to bad results Date: Mon, 25 Oct 2010 17:44:00 -0000 [thread overview] Message-ID: <bug-46166-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46166 Summary: optimization and/or removing an if(.false.) statement leads to bad results Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned@gcc.gnu.org ReportedBy: sjbespa@comcast.net Created attachment 22147 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22147 example program described in bug report On Mac OS X 10.6.4, with gfortran from recent sources on the 4.6 trunk: et:new.single.v2 sjbespa$ /volumes/dev/gfortran-4.6-trunk/bin/gfortran -v Using built-in specs. COLLECT_GCC=/volumes/dev/gfortran-4.6-trunk/bin/gfortran COLLECT_LTO_WRAPPER=/Volumes/dev/gfortran-4.6-trunk/bin/../libexec/gcc/x86_64-apple-darwin10/4.6.0/lto-wrapper Target: x86_64-apple-darwin10 Configured with: ../gfortran-4.6-src/configure --prefix=/volumes/dev/gfortran-4.6-trunk --enable-languages=fortran --host=x86_64-apple-darwin10 --build=x86_64-apple-darwin10 --target=x86_64-apple-darwin10 Thread model: posix gcc version 4.6.0 20101013 (experimental) (GCC) the following bug(s) have been observed: (1) if the attached file is compiled as follows sjbespa$ /volumes/dev/gfortran-4.6-trunk/bin/gfortran -O0 driver.f90 sjbespa$ ./a.out and run, the program executes correctly. The output is shown in example 1. (2) if the optimization level is changed to -O1 or higher: sjbespa$ /volumes/dev/gfortran-4.6-trunk/bin/gfortran -O1 driver.f90 sjbespa$ ./a.out the program doesn't run correctly as shown in example 2. It appears that the variables fcurr and flast have invalid values. (3) finally, if the if statement beginning at statement 251 is commented out, the example program fails in the same manner as in (2) independent of the optimization level. **** example 1 **** sjbespa$ /volumes/dev/gfortran-4.6-trunk/bin/gfortran -O0 driver.f90 sjbespa$ ./a.out input data for constitutive model solver rhosat = 40743665431535.492 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! rho 1000000.0000000000 plStrainInv 0.0000000000000000 plStrainInvLast 0.0000000000000000 plStrainInvRate 0.0000000000000000 dlamba 0.0000000000000000 fcurr -9999999.9999000002 flast -9999999.9999000002 215.99849824095310 0.0000000000000000 6.95322298958717986E-310 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! rho 1000000.0000000000 plStrainInv 0.0000000000000000 plStrainInvLast 0.0000000000000000 plStrainInvRate 0.0000000000000000 dlamba 0.0000000000000000 fcurr -9999999.9999000002 flast -9999999.9999000002 863.99399296381239 0.0000000000000000 6.95322298958717986E-310 **** example 2 ***** sjbespa$ /volumes/dev/gfortran-4.6-trunk/bin/gfortran -O1 driver.f90 sjbespa$ ./a.out input data for constitutive model solver rhosat = 40743665431535.492 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! rho 1000000.0000000000 plStrainInv 0.0000000000000000 plStrainInvLast 0.0000000000000000 plStrainInvRate 0.0000000000000000 dlamba 0.0000000000000000 fcurr -9999999.9999000002 flast -9999999.9999000002 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! rho 1005087.5000000000 plStrainInv 9.99999999999999955E-007 plStrainInvLast 0.0000000000000000 plStrainInvRate 9.99999999999999955E-007 dlamba 9.99999999999999955E-007 fcurr NaN flast NaN !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! rho NaN plStrainInv NaN plStrainInvLast 0.0000000000000000 plStrainInvRate NaN dlamba NaN fcurr NaN flast NaN !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
next reply other threads:[~2010-10-25 17:44 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-10-25 17:44 sjbespa at comcast dot net [this message] 2010-10-25 18:45 ` [Bug fortran/46166] " dominiq at lps dot ens.fr 2010-10-25 18:51 ` kargl at gcc dot gnu.org 2010-10-26 15:01 ` janus at gcc dot gnu.org 2010-10-26 15:09 ` sgk at troutmask dot apl.washington.edu 2010-10-26 15:13 ` janus at gcc dot gnu.org
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bug-46166-4@http.gcc.gnu.org/bugzilla/ \ --to=gcc-bugzilla@gcc.gnu.org \ --cc=gcc-bugs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
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).