Transceiver52M: Add SSE floating point / integer conversion

Convertions are performed in multiples of 4 or 8. All loads are
considered unaligned.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
diff --git a/Transceiver52M/convert.c b/Transceiver52M/convert.c
new file mode 100644
index 0000000..dc5e748
--- /dev/null
+++ b/Transceiver52M/convert.c
@@ -0,0 +1,199 @@
+/*
+ * SSE type conversions
+ * Copyright (C) 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>
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_SSE3
+#include <xmmintrin.h>
+#include <emmintrin.h>
+
+#ifdef HAVE_SSE4_1
+#include <smmintrin.h>
+
+/* 16*N 16-bit signed integer converted to single precision floats */
+static void _sse_convert_si16_ps_16n(float *restrict out,
+				     short *restrict in,
+				     int len)
+{
+	__m128i m0, m1, m2, m3, m4, m5;
+	__m128 m6, m7, m8, m9;
+
+	for (int i = 0; i < len / 16; i++) {
+		/* Load (unaligned) packed floats */
+		m0 = _mm_loadu_si128((__m128i *) &in[16 * i + 0]);
+		m1 = _mm_loadu_si128((__m128i *) &in[16 * i + 8]);
+
+		/* Unpack */
+		m2 = _mm_cvtepi16_epi32(m0);
+		m4 = _mm_cvtepi16_epi32(m1);
+		m0 = _mm_shuffle_epi32(m0, _MM_SHUFFLE(1, 0, 3, 2));
+		m1 = _mm_shuffle_epi32(m1, _MM_SHUFFLE(1, 0, 3, 2));
+		m3 = _mm_cvtepi16_epi32(m0);
+		m5 = _mm_cvtepi16_epi32(m1);
+
+		/* Convert */
+		m6 = _mm_cvtepi32_ps(m2);
+		m7 = _mm_cvtepi32_ps(m3);
+		m8 = _mm_cvtepi32_ps(m4);
+		m9 = _mm_cvtepi32_ps(m5);
+
+		/* Store */
+		_mm_storeu_ps(&out[16 * i + 0], m6);
+		_mm_storeu_ps(&out[16 * i + 4], m7);
+		_mm_storeu_ps(&out[16 * i + 8], m8);
+		_mm_storeu_ps(&out[16 * i + 12], m9);
+	}
+}
+
+/* 16*N 16-bit signed integer conversion with remainder */
+static void _sse_convert_si16_ps(float *restrict out,
+				 short *restrict in,
+				 int len)
+{
+	int start = len / 16 * 16;
+
+	_sse_convert_si16_ps_16n(out, in, len);
+
+	for (int i = 0; i < len % 16; i++)
+		out[start + i] = in[start + i];
+}
+#endif /* HAVE_SSE4_1 */
+
+/* 8*N single precision floats scaled and converted to 16-bit signed integer */
+static void _sse_convert_scale_ps_si16_8n(short *restrict out,
+					  float *restrict in,
+					  float scale, int len)
+{
+	__m128 m0, m1, m2;
+	__m128i m4, m5;
+
+	for (int i = 0; i < len / 8; i++) {
+		/* Load (unaligned) packed floats */
+		m0 = _mm_loadu_ps(&in[8 * i + 0]);
+		m1 = _mm_loadu_ps(&in[8 * i + 4]);
+		m2 = _mm_load1_ps(&scale);
+
+		/* Scale */
+		m0 = _mm_mul_ps(m0, m2);
+		m1 = _mm_mul_ps(m1, m2);
+
+		/* Convert */
+		m4 = _mm_cvtps_epi32(m0);
+		m5 = _mm_cvtps_epi32(m1);
+
+		/* Pack and store */
+		m5 = _mm_packs_epi32(m4, m5);
+		_mm_storeu_si128((__m128i *) &out[8 * i], m5);
+	}
+}
+
+/* 8*N single precision floats scaled and converted with remainder */
+static void _sse_convert_scale_ps_si16(short *restrict out,
+				       float *restrict in,
+				       float scale, int len)
+{
+	int start = len / 8 * 8;
+
+	_sse_convert_scale_ps_si16_8n(out, in, scale, len);
+
+	for (int i = 0; i < len % 8; i++)
+		out[start + i] = in[start + i] * scale;
+}
+
+/* 16*N single precision floats scaled and converted to 16-bit signed integer */
+static void _sse_convert_scale_ps_si16_16n(short *restrict out,
+					   float *restrict in,
+					   float scale, int len)
+{
+	__m128 m0, m1, m2, m3, m4;
+	__m128i m5, m6, m7, m8;
+
+	for (int i = 0; i < len / 16; i++) {
+		/* Load (unaligned) packed floats */
+		m0 = _mm_loadu_ps(&in[16 * i + 0]);
+		m1 = _mm_loadu_ps(&in[16 * i + 4]);
+		m2 = _mm_loadu_ps(&in[16 * i + 8]);
+		m3 = _mm_loadu_ps(&in[16 * i + 12]);
+		m4 = _mm_load1_ps(&scale);
+
+		/* Scale */
+		m0 = _mm_mul_ps(m0, m4);
+		m1 = _mm_mul_ps(m1, m4);
+		m2 = _mm_mul_ps(m2, m4);
+		m3 = _mm_mul_ps(m3, m4);
+
+		/* Convert */
+		m5 = _mm_cvtps_epi32(m0);
+		m6 = _mm_cvtps_epi32(m1);
+		m7 = _mm_cvtps_epi32(m2);
+		m8 = _mm_cvtps_epi32(m3);
+
+		/* Pack and store */
+		m5 = _mm_packs_epi32(m5, m6);
+		m7 = _mm_packs_epi32(m7, m8);
+		_mm_storeu_si128((__m128i *) &out[16 * i + 0], m5);
+		_mm_storeu_si128((__m128i *) &out[16 * i + 8], m7);
+	}
+}
+#else /* HAVE_SSE3 */
+static void convert_scale_ps_si16(short *out, float *in, float scale, int len)
+{
+	for (int i = 0; i < len; i++)
+		out[i] = in[i] * scale;
+}
+#endif
+
+#ifndef HAVE_SSE_4_1
+static void convert_si16_ps(float *out, short *in, int len)
+{
+	for (int i = 0; i < len; i++)
+		out[i] = in[i];
+}
+#endif
+
+void convert_float_short(short *out, float *in, float scale, int len)
+{
+#ifdef HAVE_SSE3
+	if (!(len % 16))
+		_sse_convert_scale_ps_si16_16n(out, in, scale, len);
+	else if (!(len % 8))
+		_sse_convert_scale_ps_si16_8n(out, in, scale, len);
+	else
+		_sse_convert_scale_ps_si16(out, in, scale, len);
+#else
+	convert_scale_ps_si16(out, in, scale, len);
+#endif
+}
+
+void convert_short_float(float *out, short *in, int len)
+{
+#ifdef HAVE_SSE4_1
+	if (!(len % 16))
+		_sse_convert_si16_ps_16n(out, in, len);
+	else
+		_sse_convert_si16_ps(out, in, len);
+#else
+	convert_si16_ps(out, in, len);
+#endif
+}