[Bug c++/65678] New: internal compiler error: in gen_rtx_SUBREG, at emit-rtl.c:909

["nheghathivhistha at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65678

            Bug ID: 65678
           Summary: internal compiler error: in gen_rtx_SUBREG, at
                    emit-rtl.c:909
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nheghathivhistha at gmail dot com

Created attachment 35236
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35236&action=edit
Preprocessed source file

I can't compile debug enabled Gentoo Mozilla Firefox 37.0.1 package with
Gcc-5.0 trunk revision 221871:

srv5 mfbt # x86_64-pc-linux-gnu-g++ -o Unified_cpp_mfbt0.o -c 
-I../dist/system_wrappers -include
/var/tmp/portage/www-client/firefox-37.0.1/work/mozilla-release/config/gcc_hidden.h
-DIMPL_MFBT -DMOZ_GLUE_IN_PROGRAM -DAB_CD=en-US -DNO_NSPR_10_SUPPORT
-I/var/tmp/portage/www-client/firefox-37.0.1/work/mozilla-release/mfbt -I. 
-I../dist/include   -I/usr/include/nspr -I/usr/include/nss   
-I/usr/include/pixman-1    -fPIC   -DMOZILLA_CLIENT -include
../mozilla-config.h -MD -MP -MF .deps/Unified_cpp_mfbt0.o.pp  -Wall
-Wempty-body -Woverloaded-virtual -Wsign-compare -Wwrite-strings
-Wno-invalid-offsetof -Wcast-align -ggdb -pipe -march=core2 -mtune=core2
-mno-avx -fno-exceptions -fno-strict-aliasing -fno-rtti -fno-exceptions
-fno-math-errno -std=gnu++0x -pthread -pipe  -DDEBUG -DTRACING -g
-freorder-blocks -Os  -fno-omit-frame-pointer     
/var/tmp/portage/www-client/firefox-37.0.1/work/mozilla-release/ff/mfbt/Unified_cpp_mfbt0.cpp
--save-temps
x86_64-pc-linux-gnu-g++: warning: -pipe ignored because -save-temps specified
In file included from
/var/tmp/portage/www-client/firefox-37.0.1/work/mozilla-release/ff/mfbt/Unified_cpp_mfbt0.cpp:110:0:
/var/tmp/portage/www-client/firefox-37.0.1/work/mozilla-release/mfbt/double-conversion/fixed-dtoa.cc:
In function âbool double_conversion::FastFixedDtoa(double, int,
double_conversion::Vector<char>, int*, int*)â:
/var/tmp/portage/www-client/firefox-37.0.1/work/mozilla-release/mfbt/double-conversion/fixed-dtoa.cc:400:1:
internal compiler error: in gen_rtx_SUBREG, at emit-rtl.c:909
 }
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://bugs.gentoo.org/> for instructions.

gcc -v
Using built-in specs.
COLLECT_GCC=/usr/x86_64-pc-linux-gnu/gcc-bin/5.0.0/gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/5.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /var/tmp/portage/sys-devel/gcc-5.0.0/work/gcc-5.0.0/configure
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr
--bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/5.0.0
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/5.0.0/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/5.0.0
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/5.0.0/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/5.0.0/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/5.0.0/include/g++-v5
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/5.0.0/python
--enable-languages=c,c++,fortran,ada --enable-obsolete --enable-secureplt
--disable-werror --with-system-zlib --enable-nls --without-included-gettext
--enable-checking=release --with-bugurl=https://bugs.gentoo.org/
--with-pkgversion='Gentoo 5.0.0' --enable-libstdcxx-time --enable-shared
--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
--enable-multilib --with-multilib-list=m32,m64 --disable-altivec
--disable-fixed-point --enable-targets=all --disable-libgcj --enable-libgomp
--disable-libmudflap --disable-libssp --disable-libcilkrts --enable-lto
--with-isl --disable-isl-version-check --enable-libsanitizer
Thread model: posix
gcc version 5.0.0 20150405 (experimental) [trunk revision 221871] (Gentoo
5.0.0)

Attaching ii file now and will try to reduce it.