(Building GCC) mtune=native and internal compiler error at emit-rtl.c:1027

[Seth Junot <xsetech at gmail dot com>]

I'm compiling GCC 5.3.0 for OS X. I am emailing this list to find out
whether misuse of the compiler flags is causing this error or whether
this is worthy of a bug report.

Specifically compiling it for:

OS X El Capitan 10.11.3
Intel(R) Core(TM) i5-4258U CPU @ 2.40GHz

The following command-line causes an internal compiler error:

CFLAGS_FOR_BUILD="-march=native -mtune=native"
CXXFLAGS_FOR_BUILD="-march=native -mtune=native" CFLAGS="-march=native
-mtune=native -mfpmath=sse" CPPFLAGS="-march=native -mtune=native
-mfpmath=sse" ../configure --prefix=/home/setech/Local/usr/local/
--with-mpc=/home/setech/Local/usr/local/
--with-gmp=/home/setech/Local/usr/local/
--with-mpfr=/home/setech/Local/usr/local/
--with-isl=/home/setech/Local/usr/local/ --enable-languages=c,c++ -v
&& make -j 3


Without the -mtune and -march options, make completes without verbal error.

The exact place of error is:

../../../../libquadmath/math/rem_pio2q.c:587:1: internal compiler
error: in gen_reg_rtx, at emit-rtl.c:1027


Some context in the compilation process:

xgcc: internal compiler error: Abort trap: 6 (program cc1)
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
make[6]: *** [math/rem_pio2q.lo] Error 1
make[5]: *** [all] Error 2
make[4]: *** [multi-do] Error 1
make[3]: *** [all-multi] Error 2
make[2]: *** [all] Error 2
make[1]: *** [all-target-libquadmath] Error 2
make[1]: *** Waiting for unfinished jobs....


The host compiler is Xcode's version of GCC (LLVM). `gcc --version` returns:

Configured with:
--prefix=/Applications/Xcode.app/Contents/Developer/usr
--with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 7.0.2 (clang-700.1.81)
Target: x86_64-apple-darwin15.3.0
Thread model: posix


MPFR: 3.1.4
MPC: 1.0.3
GMP: 6.1.0
ISL: 0.16.1

- Seth