[Bug c++/50504] New: g++ 4.5.2 -O2 with complex<double> produces incorrect code on AMD64

casubbu at yahoo dot com gcc-bugzilla@gcc.gnu.org
Sat Sep 24 09:56:00 GMT 2011


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50504

             Bug #: 50504
           Summary: g++ 4.5.2 -O2 with complex<double> produces incorrect
                    code on AMD64
    Classification: Unclassified
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: casubbu@yahoo.com


Created attachment 25353
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25353
g++ -O2 main.cpp, and ./a.out should not produce all zero outputs. The correct
outputs are when compiled without -O2 option

A simple program attached that just delays complex<double> inputs (in a rather
complicated manner is a simple version of the bug) when compiled with -O2 using
g++ 4.5.2 on Ubuntu 11.04 produces incorrect outputs. The same code works fine
without -O2 option. Also Works correctly with g++-4.4 -O2 as well.

Compiler details:
OLLECT_GCC=g++-4.5
COLLECT_LTO_WRAPPER=/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.5.2-8ubuntu4' --with-bugurl=file:///usr/share/doc/gcc-4.5/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.5 --enable-shared --enable-multiarch
--with-multiarch-defaults=x86_64-linux-gnu --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib/x86_64-linux-gnu
--without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.5 --libdir=/usr/lib/x86_64-linux-gnu
--enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-plugin --enable-gold --enable-ld=default
--with-plugin-ld=ld.gold --enable-objc-gc --disable-werror --with-arch-32=i686
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu



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