convert: Add chdr converters for sc16 -> fc32 and vice versa

These differ from the item32 converters in that they don't IQ swap, and
also don't have a BE/LE version.

1 files changed, 53 insertions, 0 deletions

diff --git a/host/lib/convert/sse2_sc16_to_fc32.cpp b/host/lib/convert/sse2_sc16_to_fc32.cpp
index a16ef30d4..fdaf8a5cb 100644
--- a/host/lib/convert/sse2_sc16_to_fc32.cpp
+++ b/host/lib/convert/sse2_sc16_to_fc32.cpp
@@ -119,3 +119,56 @@ DECLARE_CONVERTER(sc16_item32_be, 1, fc32, 1, PRIORITY_SIMD)
     // convert any remaining samples
     item32_sc16_to_xx<uhd::htonx>(input + i, output + i, nsamps - i, scale_factor);
 }
+
+DECLARE_CONVERTER(sc16_chdr, 1, fc32, 1, PRIORITY_SIMD)
+{
+    const sc16_t* input = reinterpret_cast<const sc16_t*>(inputs[0]);
+    fc32_t* output      = reinterpret_cast<fc32_t*>(outputs[0]);
+
+    const __m128 scalar = _mm_set_ps1(float(scale_factor) / (1 << 16));
+    const __m128i zeroi = _mm_setzero_si128();
+
+// this macro converts values faster by using SSE intrinsics to convert 4 values at a time
+#define convert_item32_1_to_fc32_1_guts(_al_)                                          \
+    for (; i + 3 < nsamps; i += 4) {                                                   \
+        /* load from input */                                                          \
+        __m128i tmpi = _mm_loadu_si128(reinterpret_cast<const __m128i*>(input + i));   \
+                                                                                       \
+        /* unpack + swap 16-bit pairs */                                               \
+        __m128i tmpilo = _mm_unpacklo_epi16(zeroi, tmpi); /* value in upper 16 bits */ \
+        __m128i tmpihi = _mm_unpackhi_epi16(zeroi, tmpi);                              \
+                                                                                       \
+        /* convert and scale */                                                        \
+        __m128 tmplo = _mm_mul_ps(_mm_cvtepi32_ps(tmpilo), scalar);                    \
+        __m128 tmphi = _mm_mul_ps(_mm_cvtepi32_ps(tmpihi), scalar);                    \
+                                                                                       \
+        /* store to output */                                                          \
+        _mm_store##_al_##ps(reinterpret_cast<float*>(output + i + 0), tmplo);          \
+        _mm_store##_al_##ps(reinterpret_cast<float*>(output + i + 2), tmphi);          \
+    }
+
+    size_t i = 0;
+
+    // need to dispatch according to alignment for fastest conversion
+    switch (size_t(output) & 0xf) {
+        case 0x0:
+            // the data is 16-byte aligned, so do the fast processing of the bulk of the
+            // samples
+            convert_item32_1_to_fc32_1_guts(_) break;
+        case 0x8:
+            // the first sample is 8-byte aligned - process it to align the remainder of
+            // the samples to 16-bytes
+            chdr_sc16_to_xx(input, output, 1, scale_factor);
+            i++;
+            // do faster processing of the bulk of the samples now that we are 16-byte
+            // aligned
+            convert_item32_1_to_fc32_1_guts(_) break;
+        default:
+            // we are not 8 or 16-byte aligned, so do fast processing with the unaligned
+            // load and store
+            convert_item32_1_to_fc32_1_guts(u_)
+    }
+
+    // convert any remaining samples
+    chdr_sc16_to_xx(input + i, output + i, nsamps - i, scale_factor);
+}