GCC creates code having the wrong instruction set

["onkel dot jack at t-online dot de" <onkel dot jack at t-online dot de>]

I try to build an arm tool chain based on GCC 6.3.0 with newlib 2.5.0.

Almost everything went fine, except for thumb mode some code in thumb/libgcc.a is generated with the wrong instruction set.
Affected are i.e. 
__aeabi_uidiv
__aeabi_uidivmod 
__aeabi_idiv
__aeabi_idivmod
and some more, while most of the symbols has correct thumb instructions.  

code which has ARM instructions instead of thumb.

I use the default multilib config, but tried aprofile too, with same result.
Here is the Makefile containing all config options I use:

BINUTILS_VERSION = 2.27
GCC_VERSION = 6.3.0
NEWLIB_VERSION = 2.5.0
GDB_VERSION = 7.12.1

BINUTILS = binutils-$(BINUTILS_VERSION)
GCC = gcc-$(GCC_VERSION)
NEWLIB = newlib-$(NEWLIB_VERSION)
GDB = gdb-$(GDB_VERSION)

TARGET=arm-nanix-eabi
PREFIX=$(PWD)/$(TARGET)-$(GCC_VERSION)
PATH:=$(PREFIX)/bin:$(PATH)

PLATFORM=$(shell uname -s)
#ifeq ($(PLATFORM), MINGW64_NT-6.1)
#   BUILD=--build=x86_64-w64-mingw32
#endif

default : all
clean:
	rm -rf *-build
	rm -rf $(PREFIX)

binutils: binutils-build/build-done
gcc-boot: gcc-build/build-boot-done
newlib: newlib-build/build-done
gcc: gcc-build/build-done
gdb: gdb-build/build-done

#all: binutils gcc-boot newlib gcc gdb
all: gcc-boot newlib gcc gdb

$(BINUTILS).tar.bz2:
	echo "Grabbing $@"
	curl ftp://ftp.gnu.org/gnu/binutils/$@ -o $@

$(GCC).tar.bz2:
	echo "Grabbing $@"
	curl ftp://ftp.gnu.org/gnu/gcc/$(GCC)/$@ -o $@

$(NEWLIB).tar.gz:
	echo "Grabbing $@"
	curl ftp://sources.redhat.com/pub/newlib/$@ -o $@

$(GDB).tar.gz:
	echo "Grabbing $@"
	curl ftp://ftp.gnu.org/gnu/gdb/$@ -o $@

$(BINUTILS) : $(BINUTILS).tar.bz2
	echo -n "extracting $< : "
	tar -jxf $<
	touch $@

$(GCC) : $(GCC).tar.bz2
	echo -n "extracting $< : "
	tar -jxf $<
	touch $@


$(NEWLIB) : $(NEWLIB).tar.gz
	echo -n "extracting $< : "
	tar -zxf $<
	patch -p 1 -d $(NEWLIB) < $(NEWLIB)-nanix.patch
	touch $@


$(GDB) : $(GDB).tar.gz
	echo -n "extracting $< : "
	tar -zxf $<
	touch $@

%-build:
	mkdir -p $@

$(GCC)/gmp: | $(GCC)
	cd $(GCC); ./contrib/download_prerequisites
	touch $@

$(GCC)/mpfr:| $(GCC)
	cd $(GCC); ./contrib/download_prerequisites
	touch $@

$(GCC)/mpc: | $(GCC)
	cd $(GCC); ./contrib/download_prerequisites
	touch $@

# Build a set of compatible Binutils for this architecture.  Need this before
# we can build GCC.

binutils-build/config-done: $(BINUTILS)
	rm -f $@
	mkdir -p binutils-build
	cd binutils-build ;\
	../$(BINUTILS)/configure $(BUILD) LDFLAGS="-static" --target=$(TARGET) --prefix=$(PREFIX) --disable-nls\
	 && touch config-done

binutils-build/build-done: binutils-build/config-done
	rm -f $@
	make -C binutils-build all install 2>&1 | tee binutils-build/make.log; test $${PIPESTATUS[0]} = 0  && touch $@

# Build and configure GCC with the Newlib C runtime.
gcc-build/config-boot-done:  binutils-build/build-done $(GCC) $(GCC)/gmp $(GCC)/mpfr $(GCC)/mpc
	rm -f $@
	mkdir -p gcc-build
	cd gcc-build ; ../$(GCC)/configure $(BUILD) LDFLAGS="-static" --target=$(TARGET) --prefix=$(PREFIX) \
		       --with-newlib \
                       --disable-nls \
                       --disable-libssp \
		       --disable-gomp \
                       --disable-libstcxx-pch \
                       --enable-threads \
                       --disable-shared \
                       --enable-static \
		       --disable-libmudflap 
                       --enable-languages=c,c++\
		       --without-libiconv-prefix\
		       && touch config-boot-done

gcc-build/build-boot-done: gcc-build/config-boot-done
	rm -f $@
	make -C gcc-build all-gcc install-gcc 2>&1 | tee -a gcc-build/boot-make.log; test $${PIPESTATUS[0]} = 0 && touch $@


newlib-build/config-done:  gcc-build/build-boot-done $(NEWLIB)
	rm -f $@
	mkdir -p newlib-build
	cd newlib-build ; ../$(NEWLIB)/configure CFLAGS_FOR_TARGET=-fstack-usage LDFLAGS="-static" $(BUILD)  --target=$(TARGET) --prefix=$(PREFIX) \
			  --enable-multilib \
			  --enable-shared=no --enable-static=yes \
			  --enable-newlib-nano-malloc \
			  --enable-target-optspace\
			  --enable-lite-exit \
			  --enable-newlib-global-atexit \
			  --enable-newlib-reent-small \
			  --enable-newlib-multithread\
			  --enable-newlib-nano-formatted-io
			  --disable-newlib-unbuf-stream-opt\
			  --disable-newlib-fvwrite-in-streamio \
			  --disable-newlib-wide-orient \
			  && touch config-done

newlib-build/build-done: newlib-build/config-done
	rm -f $@
	make -C newlib-build all install INCLUDE=$(pwd)/$(NEWLIB)/include 2>&1 | tee -a newlib-build/make.log; test $${PIPESTATUS[0]} = 0 && touch $@

gcc-build/build-done: newlib-build/config-done
	rm -f $@
	make -C gcc-build all install 2>&1 | tee -a gcc-build/make.log; test $${PIPESTATUS[0]} = 0 && touch $@

gdb-build/config-done: gcc-build/build-done $(GDB)
	rm -f $@
	mkdir -p gdb-build
	cd gdb-build ; ../$(GDB)/configure $(BUILD) LDFLAGS="-static" --target=$(TARGET) --prefix=$(PREFIX) \
	&& touch config-done

gdb-build/build-done: gdb-build/config-done
	rm -f $@
	make -C gdb-build all install 2>&1 | tee -a ../make.log; test $${PIPESTATUS[0]} = 0 && touch $@




So, how I can build that toolchain supporting multiple targets having correct generated code ?