From: unknown <s0042331@.dynamic.ewi.utwente.nl>
Date: Thu, 27 Mar 2008 16:38:31 +0000 (+0100)
Subject:  * Keep track of the current stage number (not montiumcc compatible) so we
X-Git-Url: https://git.stderr.nl/gitweb?a=commitdiff_plain;h=a980bbf75167001020f0d2ddb4a4563bd71a2e3d;p=matthijs%2Fprojects%2Fmontium-fft.git

 * Keep track of the current stage number (not montiumcc compatible) so we
   know which twiddle factors we need. This needs checking and improving.
---

diff --git a/FFT.mc b/FFT.mc
index 3ad0816..626b0dc 100644
--- a/FFT.mc
+++ b/FFT.mc
@@ -6,6 +6,7 @@
 
 #include "FFT.h"
 
+int stage = 1;
 /**
  * Executes a single butterfly on ALU 0-3. The inputs are the words taken from
  * in, which will be read on various inputs of ALU 0-3. Outputs will be
@@ -98,7 +99,13 @@ INLINE struct bf_in read_input_regular(struct mems m, bool cycle_odd, bool stage
 	add_offset(m.input_a_im, 1);
 	add_offset(m.input_b_re, 1);
 	add_offset(m.input_b_im, 1);
-	/* TODO: Update twiddle offsets */
+	
+	/* TODO: Is this true? */
+	add_offset(m.twiddle_re, (PARAM_N_t>>stage));
+	add_offset(m.twiddle_im, (PARAM_N_t>>stage));
+	use_mask(m.twiddle_re, (PARAM_N_t/2)-1);
+	use_mask(m.twiddle_im, (PARAM_N_t/2)-1);
+
 	return in;
 }
 
@@ -256,11 +263,13 @@ void run() {
 		next_cycle();
 		do_half_regular_stage(m, EVEN_STAGE, FIRST_HALF);
 		do_half_regular_stage(m, EVEN_STAGE, SECOND_HALF);
+		stage++;
 		next_cycle();
 		init_input_addresses_regular(m, ODD_STAGE);
 		m = init_mem_mapping(ODD_STAGE);
 		next_cycle();
 		do_half_regular_stage(m, ODD_STAGE, FIRST_HALF);
 		do_half_regular_stage(m, ODD_STAGE, SECOND_HALF);
+		stage++;
 	} while (loop_next(LC1));
 }