magent 報 undefined reference to `floorf'

[root@192_168_1.79 magent-0.5]$ make

gcc -Wall -O2 -g  -c -o magent.o magent.c

gcc -Wall -O2 -g  -c -o ketama.o ketama.c

gcc -Wall -O2 -g -o magent magent.o ketama.o -levent

ketama.o: In function `create_ketama':

/opt/root/magent-0.5/ketama.c:399: undefined reference to `floorf'

collect2: ld returned 1 exit status

make: *** [magent] Error 1

修改Makefile

LIBS = -levent 爲LIBS = -levent -lm