https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78478
--- Comment #3 from Joel Sherrill <joel at gcc dot gnu.org> --- That patch gets the build further but there is more wrong. __float128 isn't defined. /home/joel/test-gcc/b-i386-rtems4.12-gcc/./gcc/xgcc -B/home/joel/test-gcc/b-i386-rtems4.12-gcc/./gcc/ -nostdinc -B/home/joel/test-gcc/b-i386-rtems4.12-gcc/i386-rtems4.12/newlib/ -isystem /home/joel/test-gcc/b-i386-rtems4.12-gcc/i386-rtems4.12/newlib/targ-include -isystem /home/joel/test-gcc/gcc/newlib/libc/include -B/home/joel/test-gcc/install-master/i386-rtems4.12/bin/ -B/home/joel/test-gcc/install-master/i386-rtems4.12/lib/ -isystem /home/joel/test-gcc/install-master/i386-rtems4.12/include -isystem /home/joel/test-gcc/install-master/i386-rtems4.12/sys-include -DHAVE_CONFIG_H -I. -I../../../gcc/libgfortran -iquote../../../gcc/libgfortran/io -I../../../gcc/libgfortran/../gcc -I../../../gcc/libgfortran/../gcc/config -I../.././gcc -I../../../gcc/libgfortran/../libgcc -I../libgcc -I../../../gcc/libgfortran/../libbacktrace -I../libbacktrace -I../libbacktrace -std=gnu11 -Wall -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -Wextra -Wwrite-strings -Werror=implicit-function-declaration -Werror=vla -fcx-fortran-rules -ffunction-sections -fdata-sections -g -O2 -MT single.lo -MD -MP -MF .deps/single.Tpo -c ../../../gcc/libgfortran/caf/single.c -o single.o In file included from ./kinds.h:69:0, from ../../../gcc/libgfortran/libgfortran.h:232, from ../../../gcc/libgfortran/caf/libcaf.h:33, from ../../../gcc/libgfortran/caf/single.c:26: ../../../gcc/libgfortran/kinds-override.h:40:5: error: #error "Where has __float128 gone?" # error "Where has __float128 gone?" ^~~~~