Runnig : CFLAGS="-O3 -march=native" ./configure

GIVES ME:

checking build system type... x86_64-unknown-cygwin
checking host system type... x86_64-unknown-cygwin
checking target system type... x86_64-unknown-cygwin
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether to enable maintainer-specific portions of Makefiles... no
checking for style of include used by make... GNU
checking for gcc... no
checking for cc... no
checking for cl.exe... no
configure: error: in `/home/Pissig/cpuminer':
configure: error: no acceptable C compiler found in $PATH
See `config.log' for more details

Any Clues??