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From: "ebotcazou at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/51187] gcc 4.6.2 miscompiles genrecog.c when building gcc 4.5.3 with --target=avr on Debian/sparc Date: Fri, 18 Nov 2011 06:36:00 -0000 [thread overview] Message-ID: <bug-51187-4-ryTE1CoP4f@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-51187-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51187 Eric Botcazou <ebotcazou at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2011-11-18 CC| |ebotcazou at gcc dot | |gnu.org Ever Confirmed|0 |1 --- Comment #4 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-11-18 06:31:42 UTC --- > We discovered this bug in gcc 4.6.2 in Debian due to build failure of gcc-avr > package on sparc (tracked in Debian as http://bugs.debian.org/648016), which > uses gcc 4.5 source to build an AVR cross-compiler. I was not able to come up > with a nice self-contained test-case, but here are the steps to reproduce the > failure. I can reproduce. However... > ./configure -v --enable-languages=c,c++ --prefix=/usr/lib > --infodir=/usr/share/info --mandir=/usr/share/man --bindir=/usr/bin > --libexecdir=/usr/lib --libdir=/usr/lib --enable-shared --with-system-zlib > --enable-long-long --enable-nls --without-included-gettext --disable-checking > --disable-libssp --build=sparc-linux-gnu --host=sparc-linux-gnu --target=avr ...you should never configure the compiler with --disable-checking, even in a cross configuration. This will save a few percents in compilation times but disables critical internal checking; you risk silently generating wrong code. As a matter of fact, remove this switch is a workaround for the problem. > My analysis indicates that failure happens due to a miscompilation of > genrecog.c by gcc 4.6.2. Here's the debugging information I posted to the > Debian bug already (note that this was done using gcc-avr Debian source > package, so running genrecog in pristine 4.5.3 produces slightly different > output, but I believe that it still crashes due to same reason): Thanks for the thorough analysis.
next prev parent reply other threads:[~2011-11-18 6:32 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-11-17 9:11 [Bug c/51187] New: " jurij at wooyd dot org 2011-11-17 9:13 ` [Bug c/51187] " jurij at wooyd dot org 2011-11-17 9:29 ` mikpe at it dot uu.se 2011-11-17 12:42 ` plugwash at p10link dot net 2011-11-18 6:36 ` ebotcazou at gcc dot gnu.org [this message] 2011-11-18 6:42 ` [Bug c/51187] miscompilation of genrecog.c at -O2 for --target=avr ebotcazou at gcc dot gnu.org 2011-11-18 7:02 ` ebotcazou at gcc dot gnu.org 2011-11-18 18:02 ` [Bug rtl-optimization/51187] " ebotcazou at gcc dot gnu.org 2011-11-19 20:42 ` ebotcazou at gcc dot gnu.org 2011-11-19 20:45 ` ebotcazou at gcc dot gnu.org 2011-11-19 20:58 ` ebotcazou at gcc dot gnu.org 2011-11-19 21:13 ` ebotcazou at gcc dot gnu.org 2012-01-15 1:25 ` pinskia at gcc dot gnu.org
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