Must floating point be turned off?

[cardassian]

On an Ubuntu 16.04 (which I still have to compile some other old stuff):

lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 16.04.7 LTS
Release: 16.04
Codename: xenial

hein@x41:~/6809/gcc/build-6809$ uname -a
Linux x41 4.4.0-210-generic #242-Ubuntu SMP Fri Apr 16 09:57:00 UTC 2021 i686 i686 i686 GNU/Linux

hein@x41:/6809/gcc/build-6809$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/5/lto-wrapper
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.4.0-6ubuntu116.04.12' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-i386/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-i386 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-i386 --with-arch-directory=i386 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-targets=all --enable-multiarch --disable-werror --with-arch-32=i686 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.12)

I stumble on these errors(further details below) in toplev.c:
/home/hein/6809/gcc/gcc/toplev.c:545:1: error: redefinition of ‘floor_log2’
/home/hein/6809/gcc/gcc/toplev.c:580:1: error: redefinition of ‘exact_log2’

Details:

$ make everything
.... lots of output
....

gcc -DTARGET_GCC_VERSION=4003 -O2 -fomit-frame-pointer -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -Wmissing-format-attribute -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -DHAVE_CONFIG_H -I. -I. -I/home/hein/6809/gcc/gcc -I/home/hein/6809/gcc/gcc/. -I/home/hein/6809/gcc/gcc/../include -I/home/hein/6809/gcc/gcc/../libcpp/include -I/home/hein/6809/gcc/gcc/../libdecnumber -I/home/hein/6809/gcc/gcc/../libdecnumber/dpd -I../libdecnumber
-DTARGET_NAME="m6809-unknown-none"
-c /home/hein/6809/gcc/gcc/toplev.c -o toplev.o
In file included from /home/hein/6809/gcc/gcc/toplev.c:30:0:
/home/hein/6809/gcc/gcc/tree.h: In function ‘function_args_iter_next’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/tree.h:4684:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (i->next != NULL_TREE);
^
In file included from /home/hein/6809/gcc/gcc/toplev.c:30:0:
/home/hein/6809/gcc/gcc/basic-block.h: In function ‘single_succ_edge’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/basic-block.h:631:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (single_succ_p (bb));
^
/home/hein/6809/gcc/gcc/basic-block.h: In function ‘single_pred_edge’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/basic-block.h:641:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (single_pred_p (bb));
^
/home/hein/6809/gcc/gcc/basic-block.h: In function ‘ei_container’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/basic-block.h:673:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (i.container);
^
/home/hein/6809/gcc/gcc/basic-block.h: In function ‘ei_next’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/basic-block.h:724:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (i->index < EDGE_COUNT (ei_container (i)));
^
/home/hein/6809/gcc/gcc/basic-block.h: In function ‘ei_prev’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/basic-block.h:732:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (i->index > 0);
^
/home/hein/6809/gcc/gcc/cgraph.h: In function ‘varpool_first_static_initializer’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/cgraph.h:393:7: note: in expansion of macro ‘gcc_assert’
gcc_assert (TREE_CODE (node->decl) == VAR_DECL);
^
/home/hein/6809/gcc/gcc/cgraph.h: In function ‘varpool_next_static_initializer’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/cgraph.h:406:7: note: in expansion of macro ‘gcc_assert’
gcc_assert (TREE_CODE (node->decl) == VAR_DECL);
^
/home/hein/6809/gcc/gcc/gcov-io.h: In function ‘gcov_position’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/gcov-io.h:588:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (gcov_var.mode > 0);
^
/home/hein/6809/gcc/gcc/toplev.c: At top level:
/home/hein/6809/gcc/gcc/toplev.c:545:1: error: redefinition of ‘floor_log2’
floor_log2 (unsigned HOST_WIDE_INT x)
^
In file included from /home/hein/6809/gcc/gcc/toplev.c:58:0:
/home/hein/6809/gcc/gcc/toplev.h:177:1: note: previous definition of ‘floor_log2’ was here
floor_log2 (unsigned HOST_WIDE_INT x)
^
/home/hein/6809/gcc/gcc/toplev.c:580:1: error: redefinition of ‘exact_log2’
exact_log2 (unsigned HOST_WIDE_INT x)
^
In file included from /home/hein/6809/gcc/gcc/toplev.c:58:0:
/home/hein/6809/gcc/gcc/toplev.h:183:1: note: previous definition of ‘exact_log2’ was here
exact_log2 (unsigned HOST_WIDE_INT x)
^
In file included from /home/hein/6809/gcc/gcc/toplev.c:30:0:
/home/hein/6809/gcc/gcc/toplev.c: In function ‘push_srcloc’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/toplev.c:973:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (!input_file_stack_restored);
^
/home/hein/6809/gcc/gcc/toplev.c: In function ‘pop_srcloc’:
/home/hein/6809/gcc/gcc/system.h:577:55: warning: ISO C does not support ‘FUNCTION’ predefined identifier [-Wpedantic]
((void)(!(EXPR) ? fancy_abort (FILE, LINE, FUNCTION), 0 : 0))
^
/home/hein/6809/gcc/gcc/toplev.c:1000:3: note: in expansion of macro ‘gcc_assert’
gcc_assert (!input_file_stack_restored);
^
/home/hein/6809/gcc/gcc/toplev.c: In function ‘print_to_asm_out_file’:
/home/hein/6809/gcc/gcc/toplev.c:1259:7: warning: format not a string literal and no format arguments [-Wformat-security]
fprintf (asm_out_file, text);
^
/home/hein/6809/gcc/gcc/toplev.c: In function ‘print_to_stderr’:
/home/hein/6809/gcc/gcc/toplev.c:1288:7: warning: format not a string literal and no format arguments [-Wformat-security]
fprintf (stderr, text);
^
/home/hein/6809/gcc/gcc/toplev.c: In function ‘pch_option_mismatch’:
/home/hein/6809/gcc/gcc/toplev.c:1515:3: warning: ignoring return value of ‘asprintf’, declared with attribute warn_unused_result [-Wunused-result]
asprintf (&r, _("created and used with differing settings of '%s'"), option);
^
Makefile:2376: recipe for target 'toplev.o' failed
make[2]: *** [toplev.o] Error 1
make[2]: Leaving directory '/home/hein/6809/gcc/build-6809/m6809-unknown-none/gcc'
Makefile:4832: recipe for target 'install-gcc' failed
make[1]: *** [install-gcc] Error 2
make[1]: Leaving directory '/home/hein/6809/gcc/build-6809/m6809-unknown-none'
Makefile:2382: recipe for target 'install' failed
make: *** [install] Error 2
Makefile:181: recipe for target 'gccinstall' failed
make[4]: [gccinstall] Error 2 (ignored)
Installing libgcc cache...
Error: cannot open ../libgcc.a.
ls: cannot access './libgcc-cache/.o': No such file or directory
make[4]: Leaving directory '/home/hein/6809/gcc/build-6809'
make[3]: Leaving directory '/home/hein/6809/gcc/build-6809'
make[2]: Leaving directory '/home/hein/6809/gcc/build-6809'
make[1]: Leaving directory '/home/hein/6809/gcc/build-6809'
hein@x41:~/6809/gcc/build-6809$

Any ideas? Which Linux version do you use to compile gcc6809?

Best regards,
Hans

PS: I had easy stuff with as6309 substituting comma() with comma(1)