X-Git-Url: https://git.stderr.nl/gitweb?a=blobdiff_plain;f=FFT_support.cpp;h=e482b2d2dd0e44cd17f94e9c6671c34a9ec31620;hb=23a9ac963f8123a6fecf5105492f8be5e2da8190;hp=23d07f08ca102e114e7428807701f364fcdcc566;hpb=a62dbd706365d44bdcac9f8ac4c7c6dd05484642;p=matthijs%2Fprojects%2Fmontium-fft.git

diff --git a/FFT_support.cpp b/FFT_support.cpp
index 23d07f0..e482b2d 100644
--- a/FFT_support.cpp
+++ b/FFT_support.cpp
@@ -7,7 +7,7 @@
 #define FIXED_POINT 15
 #define WORD_SIZE   16
 
-#define WORDS_PER_LINE 4
+#define WORDS_PER_LINE 8
 #define WORDS_PER_GROUP 1
 
 mem input_a_re, input_a_im, input_b_re, input_b_im, output_a_re, output_a_im, output_b_re, output_b_im, twiddle_re, twiddle_im; 
@@ -68,7 +68,9 @@ void pre_run()
 	
 	for (i=0;i<PARAM_N_t;i++)
 	{
-		int value = to_fixed(sin((float)i*2*M_PI/PARAM_N_t));
+		/* We take the sine from 0 to 2*2*Pi, ie two periods. We divide 
+		 * the value by PARAM_N_t to prevent overflow. */
+		int value = to_fixed(sin((float)i*2*2*M_PI/PARAM_N_t)/PARAM_N_t);
 
 		if (i<PARAM_N_t/2)
 		{
@@ -117,10 +119,10 @@ void post_run()
 		output_b_re  = alloc_mem(P2M1);
 		output_b_im  = alloc_mem(P3M1);
 	}
-	printf("re(out_a)\n");
+	printf("re(out)\n");
 	print_mem(output_a_re, 0, PARAM_N_t/2, true);
 	print_mem(output_b_re, 0, PARAM_N_t/2, true);
-	printf("im(out_a)\n");
+	printf("im(out)\n");
 	print_mem(output_a_im, 0, PARAM_N_t/2, true);
 	print_mem(output_b_im, 0, PARAM_N_t/2, true);