Transceiver52M: Add ARM NEON support
Similar to the existing Intel SSE cases, add support for NEON vector
floating point SIMD processing. In this case, use ARM assembly
directly as the NEON intrinsics do not generate preferential code
output.
Currently support NEON vectorized convolution and floating point
integer conversions.
Signed-off-by: Thomas Tsou <tom@tsou.cc>
diff --git a/Transceiver52M/arm/convert.c b/Transceiver52M/arm/convert.c
new file mode 100644
index 0000000..a32eb55
--- /dev/null
+++ b/Transceiver52M/arm/convert.c
@@ -0,0 +1,96 @@
+/*
+ * NEON type conversions
+ * 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 "convert.h"
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+void neon_convert_ps_si16_4n(short *, float *, float *, int);
+void neon_convert_si16_ps_4n(float *, short *, int);
+
+#ifndef HAVE_NEON
+static void convert_si16_ps(float *out, short *in, int len)
+{
+ for (int i = 0; i < len; i++)
+ out[i] = in[i];
+}
+
+static void convert_ps_si16(short *out, float *in, float scale, int len)
+{
+ for (int i = 0; i < len; i++)
+ out[i] = in[i] * scale;
+}
+#else
+/* 4*N 16-bit signed integer conversion with remainder */
+static void neon_convert_si16_ps(float *restrict out,
+ short *restrict in,
+ int len)
+{
+ int start = len / 4 * 4;
+
+ neon_convert_si16_ps_4n(out, in, len >> 2);
+
+ for (int i = 0; i < len % 4; i++)
+ out[start + i] = (float) in[start + i];
+}
+
+/* 4*N 16-bit signed integer conversion with remainder */
+static void neon_convert_ps_si16(short *restrict out,
+ float *restrict in,
+ float *restrict scale,
+ int len)
+{
+ int start = len / 4 * 4;
+
+ neon_convert_ps_si16_4n(out, in, scale, len >> 2);
+
+ for (int i = 0; i < len % 4; i++)
+ out[start + i] = (short) (in[start + i] * (*scale));
+}
+#endif
+
+void convert_float_short(short *out, float *in, float scale, int len)
+{
+#ifdef HAVE_NEON
+ float q[4] = { scale, scale, scale, scale };
+
+ if (len % 4)
+ neon_convert_ps_si16(out, in, q, len);
+ else
+ neon_convert_ps_si16_4n(out, in, q, len >> 2);
+#else
+ convert_ps_si16(out, in, scale, len);
+#endif
+}
+
+void convert_short_float(float *out, short *in, int len)
+{
+#ifdef HAVE_NEON
+ if (len % 4)
+ neon_convert_si16_ps(out, in, len);
+ else
+ neon_convert_si16_ps_4n(out, in, len >> 2);
+#else
+ convert_si16_ps(out, in, len);
+#endif
+}