Make run faster on ARM CPUs using fast math approximation

Use --fast-math to use sine/cosine tables and approximate atan2.

src/test/test_dtmf.c

@@ -63,6 +63,8 @@ int main(void)
 	int f, i;
 	double target;
 
+	fm_init(0);
+
 	dtmf_decode_init(&dtmf_dec, NULL, recv_digit, SAMPLERATE, db2level(0), db2level(-30.0));
 
 	for (f = 0; f < 8; f++) {
@@ -109,6 +111,8 @@ int main(void)
 
 	dtmf_decode_exit(&dtmf_dec);
 
+	fm_exit();
+
 	return 0;
 }
 

src/test/test_performance.c

@@ -22,7 +22,7 @@ int tot_samples;
 		duration = (double)tv.tv_sec + (double)tv.tv_usec / 1e6; \
 		duration -= (double)start_tv.tv_sec + (double)start_tv.tv_usec / 1e6; \
 		tot_samples += samples; \
-		if (duration >= 0.5) \
+		if (duration >= 2) \
 			break; \
 	} \
 	printf("%s: %.3f mega samples/sec\n", what, (double)tot_samples / duration / 1e6); \
@@ -39,15 +39,35 @@ iir_filter_t lp;
 int main(void)
 {
 	memset(power, 1, sizeof(power));
+
+	fm_init(0);
+
 	fm_mod_init(&mod, 50000, 0, 0.333);
 	T_START()
 	fm_modulate_complex(&mod, samples, power, SAMPLES, buff);
 	T_STOP("FM modulate", SAMPLES)
+	fm_mod_exit(&mod);
 
 	fm_demod_init(&demod, 50000, 0, 10000.0);
 	T_START()
 	fm_demodulate_complex(&demod, samples, SAMPLES, buff, I, Q);
 	T_STOP("FM demodulate", SAMPLES)
+	fm_demod_exit(&demod);
+
+	fm_exit();
+	fm_init(1);
+
+	fm_mod_init(&mod, 50000, 0, 0.333);
+	T_START()
+	fm_modulate_complex(&mod, samples, power, SAMPLES, buff);
+	T_STOP("FM modulate (fast math)", SAMPLES)
+	fm_mod_exit(&mod);
+
+	fm_demod_init(&demod, 50000, 0, 10000.0);
+	T_START()
+	fm_demodulate_complex(&demod, samples, SAMPLES, buff, I, Q);
+	T_STOP("FM demodulate (fast math)", SAMPLES)
+	fm_demod_exit(&demod);
 
 	iir_lowpass_init(&lp, 10000.0 / 2.0, 50000, 1);
 	T_START()
@@ -64,6 +84,8 @@ int main(void)
 	iir_process(&lp, samples, SAMPLES);
 	T_STOP("low-pass filter (eigth order)", SAMPLES)
 
+	fm_exit();
+
 	return 0;
 }