problem in installing mkfs.jffs!

[846cb5a5def91b3df2]

When I type "make",it gives error information as follows:
gcc  -O2 -Wall  -o mkfs.jffs  mkfs.jffs.o  -lz 
mkfs.jffs.o: In function `write_val32':
mkfs.jffs.o(.text+0x449): undefined reference to `__cpu_to_le32'
mkfs.jffs.o(.text+0x455): undefined reference to `__cpu_to_be32'
mkfs.jffs.o: In function `write_val16':
mkfs.jffs.o(.text+0x49f): undefined reference to `__cpu_to_le16'
mkfs.jffs.o(.text+0x4af): undefined reference to `__cpu_to_be16'
mkfs.jffs.o: In function `read_val32':
mkfs.jffs.o(.text+0x4f7): undefined reference to `__le32_to_cpu'
mkfs.jffs.o(.text+0x507): undefined reference to `__be32_to_cpu'
mkfs.jffs.o: In function `read_val16':
mkfs.jffs.o(.text+0x54a): undefined reference to `__le16_to_cpu'
mkfs.jffs.o(.text+0x55a): undefined reference to `__be16_to_cpu'
mkfs.jffs.o: In function `write_file':
mkfs.jffs.o(.text+0x89c): undefined reference to `__cpu_to_le16'
mkfs.jffs.o(.text+0x8ae): undefined reference to `__cpu_to_be16'
collect2: ld returned 1 exit status
make: *** [mkfs.jffs] Error 1
Can some one tell me the reason?Thanks!!!