how to build newlib‘s libm

1.libm needs libc, so we need to add newlib's libc path to CPATH
	export CPATH=/home/wk/newlib-1.11.0/newlib/libc/include
	../configure --prefix=/home/wk/newlib-libm-install
	make

2.some file you need
	libm.a and fdlibm.h 

[root@localhost build]# pwd
/home/wk/newlib-1.11.0/newlib/libm/build
[root@localhost build]# ll .libs
total 2068
-rw-r--r--    1 root     root      2112204 Mar  9 22:22 libm.a
lrwxrwxrwx    1 root     root           10 Mar  9 22:22 libm.la -> ../libm.la
[root@localhost build]# ll ../common/fdlibm.h
-rw-r--r--    1 447      1002        10936 Jun 27  2002 ../common/fdlibm.h