configure

#!/bin/sh

>config.mak
cat >config.h <<'EOF'
#ifndef _CONFIG_H
#define _CONFIG_H
EOF

echo -n 'Checking for libfftw3f...'

gcc -o test-fft -Wall -x c -I/usr/local/include -L/usr/local/lib - -lfftw3f <<'EOF'
#include <fftw3.h>

#define N 128

int main(int argc, char *argv[])
{
	fftwf_complex *data;
	fftwf_plan p;

	data = (fftwf_complex*) fftwf_malloc(sizeof(fftwf_complex) * N);
	p = fftwf_plan_dft_1d(N, data, data, FFTW_FORWARD, FFTW_ESTIMATE);

	fftwf_execute(p);

	fftwf_destroy_plan(p);
	fftwf_free(data);
	return 0;
}
EOF

if ./test-fft
then
	echo OK
	echo '#define _FFTW3' >> config.h
	echo 'export FFTW3=1' >> config.mak
fi

echo -n 'Detecting endianness...'

gcc -o test-endian -Wall -x c - <<'EOF'
#include <stdint.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
	uint32_t dword = 0x11223344;
	uint8_t *byte = (uint8_t*)&dword;

	if(byte[0] == 0x44 && byte[1] == 0x33 && byte[2] == 0x22 && byte[3] == 0x11) {
		printf("EL");
		return 0;
	}

	if(byte[0] == 0x11 && byte[1] == 0x22 && byte[2] == 0x33 && byte[3] == 0x44) {
		printf("BE");
		return 0;
	}
	return 1;
}
EOF

if ./test-endian > /dev/null
then
	ENDIAN=$(./test-endian)
	if [ $ENDIAN = EL ]
	then
		echo 'Little Endian'
		echo '#define _EL_ARCH' >> config.h
	elif [ $ENDIAN = BE ]
	then
		echo 'Big Endian'
		echo '#define _BE_ARCH' >> config.h
	fi
fi

echo '#endif' >> config.h

echo 'Now run make'