replaced huge 2d twiddle arrays by smaller 1d arrays. Now it uses very low memory

C/FFT_FP_realisation.h

@@ -0,0 +1,25 @@
+#ifndef FFT_FP_REALISATION_H
+#define FFT_FP_REALISATION_H
+
+#include <stdint.h>
+
+#ifndef DATA_L
+#define DATA_L (1 << 16)
+#endif
+
+#ifndef FP_acc
+#define FP_acc 1000
+#endif
+
+#ifndef TWIDDLE_L
+#define TWIDDLE_L (DATA_L / 2)
+#endif
+
+#ifndef PI
+#define PI 3.141592653589793238462643383279502884197169399375105820974944
+#endif
+
+void fft_fp_prepare(void);
+void FFT_fp(int64_t* inp, uint32_t inp_L, int64_t* buf);
+
+#endif