1 files changed, 139 insertions, 0 deletions
diff --git a/Transceiver52M/arm/convolve.c b/Transceiver52M/arm/convolve.c
new file mode 100644
index 0000000..2b42090
--- /dev/null
+++ b/Transceiver52M/arm/convolve.c
@@ -0,0 +1,139 @@
+/*
+ * NEON Convolution
+ * Copyright (C) 2012, 2013 Thomas Tsou <tom@tsou.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <malloc.h>
+#include <string.h>
+#include <stdio.h>
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/* Forward declarations from base implementation */
+int _base_convolve_real(float *x, int x_len,
+			float *h, int h_len,
+			float *y, int y_len,
+			int start, int len,
+			int step, int offset);
+
+int _base_convolve_complex(float *x, int x_len,
+			   float *h, int h_len,
+			   float *y, int y_len,
+			   int start, int len,
+			   int step, int offset);
+
+int bounds_check(int x_len, int h_len, int y_len,
+		 int start, int len, int step);
+
+#ifdef HAVE_NEON
+/* Calls into NEON assembler */
+void neon_conv_real4(float *x, float *h, float *y, int len);
+void neon_conv_real8(float *x, float *h, float *y, int len);
+void neon_conv_real12(float *x, float *h, float *y, int len);
+void neon_conv_real16(float *x, float *h, float *y, int len);
+void neon_conv_real20(float *x, float *h, float *y, int len);
+void mac_cx_neon4(float *x, float *h, float *y, int len);
+
+/* Complex-complex convolution */
+static void neon_conv_cmplx_4n(float *x, float *h, float *y, int h_len, int len)
+{
+	for (int i = 0; i < len; i++)
+		mac_cx_neon4(&x[2 * i], h, &y[2 * i], h_len >> 2);
+}
+#endif
+
+/* API: Aligned complex-real */
+int convolve_real(float *x, int x_len,
+		  float *h, int h_len,
+		  float *y, int y_len,
+		  int start, int len,
+		  int step, int offset)
+{
+	void (*conv_func)(float *, float *, float *, int) = NULL;
+
+	if (bounds_check(x_len, h_len, y_len, start, len, step) < 0)
+		return -1;
+
+	memset(y, 0, len * 2 * sizeof(float));
+
+#ifdef HAVE_NEON
+	if (step <= 4) {
+		switch (h_len) {
+		case 4:
+			conv_func = neon_conv_real4;
+			break;
+		case 8:
+			conv_func = neon_conv_real8;
+			break;
+		case 12:
+			conv_func = neon_conv_real12;
+			break;
+		case 16:
+			conv_func = neon_conv_real16;
+			break;
+		case 20:
+			conv_func = neon_conv_real20;
+			break;
+		}
+	}
+#endif
+	if (conv_func) {
+		conv_func(&x[2 * (-(h_len - 1) + start)],
+			  h, y, len);
+	} else {
+		_base_convolve_real(x, x_len,
+				    h, h_len,
+				    y, y_len,
+				    start, len, step, offset);
+	}
+
+	return len;
+}
+
+
+/* API: Aligned complex-complex */
+int convolve_complex(float *x, int x_len,
+		     float *h, int h_len,
+		     float *y, int y_len,
+		     int start, int len,
+		     int step, int offset)
+{
+	void (*conv_func)(float *, float *, float *, int, int) = NULL;
+
+	if (bounds_check(x_len, h_len, y_len, start, len, step) < 0)
+		return -1;
+
+	memset(y, 0, len * 2 * sizeof(float));
+
+#ifdef HAVE_NEON
+	if (step <= 4 && !(h_len % 4))
+		conv_func = neon_conv_cmplx_4n;
+#endif
+	if (conv_func) {
+		conv_func(&x[2 * (-(h_len - 1) + start)],
+			  h, y, h_len, len);
+	} else {
+		_base_convolve_complex(x, x_len,
+				       h, h_len,
+				       y, y_len,
+				       start, len, step, offset);
+	}
+
+	return len;
+}