--- /dev/null
+/******************************************************************************
+*
+* Copyright (c) 2020 Intel.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*
+*******************************************************************************/
+
+/**
+ * @brief xRAN BFP compression/decompression U-plane implementation and interface functions
+ *
+ * @file xran_compression.cpp
+ * @ingroup group_source_xran
+ * @author Intel Corporation
+ **/
+
+#include "xran_compression.hpp"
+#include "xran_bfp_utils.hpp"
+#include "xran_bfp_byte_packing_utils.hpp"
+#include "xran_compression.h"
+#include <complex>
+#include <algorithm>
+#include <immintrin.h>
+
+
+namespace BFP_UPlane
+{
+ /// Namespace constants
+ const int k_numREReal = 24; /// 12 IQ pairs
+
+
+ /// Compute exponent value for a set of 16 RB from the maximum absolute value.
+ /// Max Abs operates in a loop, executing 4 RB per iteration. The results are
+ /// packed into the final output register.
+ __m512i
+ computeExponent_16RB(const BlockFloatCompander::ExpandedData& dataIn, const __m512i totShiftBits)
+ {
+ __m512i maxAbs = __m512i();
+ const __m512i* rawData = reinterpret_cast<const __m512i*>(dataIn.dataExpanded);
+ /// Max Abs loop operates on 4RB at a time
+#pragma unroll(4)
+ for (int n = 0; n < 4; ++n)
+ {
+ /// Re-order and vertical max abs
+ auto maxAbsVert = BlockFloatCompander::maxAbsVertical4RB(rawData[3 * n + 0], rawData[3 * n + 1], rawData[3 * n + 2]);
+ /// Horizontal max abs
+ auto maxAbsHorz = BlockFloatCompander::horizontalMax4x16(maxAbsVert);
+ /// Pack these 4 values into maxAbs
+ maxAbs = BlockFloatCompander::slidePermute(maxAbsHorz, maxAbs, n);
+ }
+ /// Calculate exponent
+ const auto maxAbs32 = BlockFloatCompander::maskUpperWord(maxAbs);
+ return BlockFloatCompander::expLzCnt(maxAbs32, totShiftBits);
+ }
+
+
+ /// Compute exponent value for a set of 4 RB from the maximum absolute value.
+ /// Note that we do not need to perform any packing of result as we are only
+ /// computing 4 RB. The appropriate offset is taken later when extracting the
+ /// exponent.
+ __m512i
+ computeExponent_4RB(const BlockFloatCompander::ExpandedData& dataIn, const __m512i totShiftBits)
+ {
+ const __m512i* rawData = reinterpret_cast<const __m512i*>(dataIn.dataExpanded);
+ /// Re-order and vertical max abs
+ const auto maxAbsVert = BlockFloatCompander::maxAbsVertical4RB(rawData[0], rawData[1], rawData[2]);
+ /// Horizontal max abs
+ const auto maxAbsHorz = BlockFloatCompander::horizontalMax4x16(maxAbsVert);
+ /// Calculate exponent
+ const auto maxAbs = BlockFloatCompander::maskUpperWord(maxAbsHorz);
+ return BlockFloatCompander::expLzCnt(maxAbs, totShiftBits);
+ }
+
+
+ /// Compute exponent value for 1 RB from the maximum absolute value.
+ /// This works with horizontal max abs only, and needs to include a
+ /// step to select the final exponent from the 4 lanes.
+ uint8_t
+ computeExponent_1RB(const BlockFloatCompander::ExpandedData& dataIn, const __m512i totShiftBits)
+ {
+ const __m512i* rawData = reinterpret_cast<const __m512i*>(dataIn.dataExpanded);
+ /// Abs
+ const auto rawDataAbs = _mm512_abs_epi16(rawData[0]);
+ /// No need to do a full horizontal max operation here, just do a max IQ step,
+ /// compute the exponents and then use a reduce max over all exponent values. This
+ /// is the fastest way to handle a single RB.
+ const auto rawAbsIQSwap = _mm512_rol_epi32(rawDataAbs, BlockFloatCompander::k_numBitsIQ);
+ const auto maxAbsIQ = _mm512_max_epi16(rawDataAbs, rawAbsIQSwap);
+ /// Calculate exponent
+ const auto maxAbsIQ32 = BlockFloatCompander::maskUpperWord(maxAbsIQ);
+ const auto exps = BlockFloatCompander::expLzCnt(maxAbsIQ32, totShiftBits);
+ /// At this point we have exponent values for the maximum of each IQ pair.
+ /// Run a reduce max step to compute the maximum exponent value in the first
+ /// three lanes - this will give the desired exponent for this RB.
+ constexpr uint16_t k_expMsk = 0x0FFF;
+ return (uint8_t)_mm512_mask_reduce_max_epi32(k_expMsk, exps);
+ }
+
+
+ /// Apply compression to 1 RB
+ template<BlockFloatCompander::PackFunction networkBytePack>
+ void
+ applyCompressionN_1RB(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut,
+ const int numREOffset, const uint8_t thisExp, const int thisRBExpAddr, const uint16_t rbWriteMask)
+ {
+ /// Get AVX512 pointer aligned to desired RB
+ const __m512i* rawDataIn = reinterpret_cast<const __m512i*>(dataIn.dataExpanded + numREOffset);
+ /// Apply the exponent shift
+ const auto compData = _mm512_srai_epi16(*rawDataIn, thisExp);
+ /// Pack compressed data network byte order
+ const auto compDataBytePacked = networkBytePack(compData);
+ /// Store exponent first
+ dataOut->dataCompressed[thisRBExpAddr] = thisExp;
+ /// Now have 1 RB worth of bytes separated into 3 chunks (1 per lane)
+ /// Use three offset stores to join
+ _mm_mask_storeu_epi8(dataOut->dataCompressed + thisRBExpAddr + 1, rbWriteMask, _mm512_extracti64x2_epi64(compDataBytePacked, 0));
+ _mm_mask_storeu_epi8(dataOut->dataCompressed + thisRBExpAddr + 1 + dataIn.iqWidth, rbWriteMask, _mm512_extracti64x2_epi64(compDataBytePacked, 1));
+ _mm_mask_storeu_epi8(dataOut->dataCompressed + thisRBExpAddr + 1 + (2 * dataIn.iqWidth), rbWriteMask, _mm512_extracti64x2_epi64(compDataBytePacked, 2));
+ }
+
+
+ /// Apply 9, 10, or 12bit compression to 16 RB
+ template<BlockFloatCompander::PackFunction networkBytePack>
+ void
+ compressN_16RB(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut,
+ const __m512i totShiftBits, const int totNumBytesPerRB, const uint16_t rbWriteMask)
+ {
+ const auto exponents = computeExponent_16RB(dataIn, totShiftBits);
+#pragma unroll(16)
+ for (int n = 0; n < 16; ++n)
+ {
+ applyCompressionN_1RB<networkBytePack>(dataIn, dataOut, n * k_numREReal, ((uint8_t*)&exponents)[n * 4], n * totNumBytesPerRB, rbWriteMask);
+ }
+ }
+
+
+ /// Apply 9, 10, or 12bit compression to 4 RB
+ template<BlockFloatCompander::PackFunction networkBytePack>
+ void
+ compressN_4RB(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut,
+ const __m512i totShiftBits, const int totNumBytesPerRB, const uint16_t rbWriteMask)
+ {
+ const auto exponents = computeExponent_4RB(dataIn, totShiftBits);
+#pragma unroll(4)
+ for (int n = 0; n < 4; ++n)
+ {
+ applyCompressionN_1RB<networkBytePack>(dataIn, dataOut, n * k_numREReal, ((uint8_t*)&exponents)[n * 16], n * totNumBytesPerRB, rbWriteMask);
+ }
+ }
+
+
+ /// Apply 9, 10, or 12bit compression to 1 RB
+ template<BlockFloatCompander::PackFunction networkBytePack>
+ void
+ compressN_1RB(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut,
+ const __m512i totShiftBits, const int totNumBytesPerRB, const uint16_t rbWriteMask)
+ {
+ const auto thisExponent = computeExponent_1RB(dataIn, totShiftBits);
+ applyCompressionN_1RB<networkBytePack>(dataIn, dataOut, 0, thisExponent, 0, rbWriteMask);
+ }
+
+
+ /// Calls compression function specific to the number of RB to be executed. For 9, 10, or 12bit iqWidth.
+ template<BlockFloatCompander::PackFunction networkBytePack>
+ void
+ compressByAllocN(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut,
+ const __m512i totShiftBits, const int totNumBytesPerRB, const uint16_t rbWriteMask)
+ {
+ switch (dataIn.numBlocks)
+ {
+ case 16:
+ compressN_16RB<networkBytePack>(dataIn, dataOut, totShiftBits, totNumBytesPerRB, rbWriteMask);
+ break;
+
+ case 4:
+ compressN_4RB<networkBytePack>(dataIn, dataOut, totShiftBits, totNumBytesPerRB, rbWriteMask);
+ break;
+
+ case 1:
+ compressN_1RB<networkBytePack>(dataIn, dataOut, totShiftBits, totNumBytesPerRB, rbWriteMask);
+ break;
+ }
+ }
+
+
+ /// Apply compression to 1 RB
+ void
+ applyCompression8_1RB(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut,
+ const int numREOffset, const uint8_t thisExp, const int thisRBExpAddr)
+ {
+ /// Get AVX512 pointer aligned to desired RB
+ const __m512i* rawDataIn = reinterpret_cast<const __m512i*>(dataIn.dataExpanded + numREOffset);
+ /// Apply the exponent shift
+ const auto compData = _mm512_srai_epi16(*rawDataIn, thisExp);
+ /// Store exponent first
+ dataOut->dataCompressed[thisRBExpAddr] = thisExp;
+ /// Now have 1 RB worth of bytes separated into 3 chunks (1 per lane)
+ /// Use three offset stores to join
+ constexpr uint32_t k_rbMask = 0x00FFFFFF; // Write mask for 1RB (24 values)
+ _mm256_mask_storeu_epi8(dataOut->dataCompressed + thisRBExpAddr + 1, k_rbMask, _mm512_cvtepi16_epi8(compData));
+ }
+
+
+ /// 8bit RB compression loop for 16 RB
+ void
+ compress8_16RB(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut, const __m512i totShiftBits)
+ {
+ const auto exponents = computeExponent_16RB(dataIn, totShiftBits);
+#pragma unroll(16)
+ for (int n = 0; n < 16; ++n)
+ {
+ applyCompression8_1RB(dataIn, dataOut, n * k_numREReal, ((uint8_t*)&exponents)[n * 4], n * (k_numREReal + 1));
+ }
+ }
+
+
+ /// 8bit RB compression loop for 4 RB
+ void
+ compress8_4RB(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut, const __m512i totShiftBits)
+ {
+ const auto exponents = computeExponent_4RB(dataIn, totShiftBits);
+#pragma unroll(4)
+ for (int n = 0; n < 4; ++n)
+ {
+ applyCompression8_1RB(dataIn, dataOut, n * k_numREReal, ((uint8_t*)&exponents)[n * 16], n * (k_numREReal + 1));
+ }
+ }
+
+
+ /// 8bit RB compression loop for 4 RB
+ void
+ compress8_1RB(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut, const __m512i totShiftBits)
+ {
+ const auto thisExponent = computeExponent_1RB(dataIn, totShiftBits);
+ applyCompression8_1RB(dataIn, dataOut, 0, thisExponent, 0);
+ }
+
+
+ /// Calls compression function specific to the number of RB to be executed. For 8 bit iqWidth.
+ void
+ compressByAlloc8(const BlockFloatCompander::ExpandedData& dataIn, BlockFloatCompander::CompressedData* dataOut, const __m512i totShiftBits)
+ {
+ switch (dataIn.numBlocks)
+ {
+ case 16:
+ compress8_16RB(dataIn, dataOut, totShiftBits);
+ break;
+
+ case 4:
+ compress8_4RB(dataIn, dataOut, totShiftBits);
+ break;
+
+ case 1:
+ compress8_1RB(dataIn, dataOut, totShiftBits);
+ break;
+ }
+ }
+
+
+ /// Apply compression to 1 RB
+ template<BlockFloatCompander::UnpackFunction networkByteUnpack>
+ void
+ applyExpansionN_1RB(const BlockFloatCompander::CompressedData& dataIn, BlockFloatCompander::ExpandedData* dataOut,
+ const int expAddr, const int thisRBAddr, const int maxExpShift)
+ {
+ /// Unpack network order packed data
+ const auto dataUnpacked = networkByteUnpack(dataIn.dataCompressed + expAddr + 1);
+ /// Apply exponent scaling (by appropriate arithmetic shift right)
+ const auto dataExpanded = _mm512_srai_epi16(dataUnpacked, maxExpShift - *(dataIn.dataCompressed + expAddr));
+ /// Write expanded data to output
+ static constexpr uint32_t k_WriteMask = 0x00FFFFFF;
+ _mm512_mask_storeu_epi16(dataOut->dataExpanded + thisRBAddr, k_WriteMask, dataExpanded);
+ }
+
+
+ /// Calls compression function specific to the number of RB to be executed. For 9, 10, or 12bit iqWidth.
+ template<BlockFloatCompander::UnpackFunction networkByteUnpack>
+ void
+ expandByAllocN(const BlockFloatCompander::CompressedData& dataIn, BlockFloatCompander::ExpandedData* dataOut,
+ const int totNumBytesPerRB, const int maxExpShift)
+ {
+ switch (dataIn.numBlocks)
+ {
+ case 16:
+#pragma unroll(16)
+ for (int n = 0; n < 16; ++n)
+ {
+ applyExpansionN_1RB<networkByteUnpack>(dataIn, dataOut, n * totNumBytesPerRB, n * k_numREReal, maxExpShift);
+ }
+ break;
+
+ case 4:
+#pragma unroll(4)
+ for (int n = 0; n < 4; ++n)
+ {
+ applyExpansionN_1RB<networkByteUnpack>(dataIn, dataOut, n * totNumBytesPerRB, n * k_numREReal, maxExpShift);
+ }
+ break;
+
+ case 1:
+ applyExpansionN_1RB<networkByteUnpack>(dataIn, dataOut, 0, 0, maxExpShift);
+ break;
+ }
+ }
+
+
+ /// Apply expansion to 1 RB and store
+ void
+ applyExpansion8_1RB(const BlockFloatCompander::CompressedData& dataIn, BlockFloatCompander::ExpandedData* dataOut,
+ const int expAddr, const int thisRBAddr)
+ {
+ const __m256i* rawDataIn = reinterpret_cast<const __m256i*>(dataIn.dataCompressed + expAddr + 1);
+ const auto compData16 = _mm512_cvtepi8_epi16(*rawDataIn);
+ const auto expData = _mm512_slli_epi16(compData16, *(dataIn.dataCompressed + expAddr));
+ constexpr uint8_t k_rbMask64 = 0b00111111; // 64b write mask for 1RB (24 int16 values)
+ _mm512_mask_storeu_epi64(dataOut->dataExpanded + thisRBAddr, k_rbMask64, expData);
+ }
+
+
+ /// Calls expansion function specific to the number of RB to be executed. For 8 bit iqWidth.
+ void
+ expandByAlloc8(const BlockFloatCompander::CompressedData& dataIn, BlockFloatCompander::ExpandedData* dataOut)
+ {
+ switch (dataIn.numBlocks)
+ {
+ case 16:
+#pragma unroll(16)
+ for (int n = 0; n < 16; ++n)
+ {
+ applyExpansion8_1RB(dataIn, dataOut, n * (k_numREReal + 1), n * k_numREReal);
+ }
+ break;
+
+ case 4:
+#pragma unroll(4)
+ for (int n = 0; n < 4; ++n)
+ {
+ applyExpansion8_1RB(dataIn, dataOut, n * (k_numREReal + 1), n * k_numREReal);
+ }
+ break;
+
+ case 1:
+ applyExpansion8_1RB(dataIn, dataOut, 0, 0);
+ break;
+ }
+ }
+}
+
+
+
+/// Main kernel function for compression.
+/// Starts by determining iqWidth specific parameters and functions.
+void
+BlockFloatCompander::BFPCompressUserPlaneAvx512(const ExpandedData& dataIn, CompressedData* dataOut)
+{
+ /// Compensation for extra zeros in 32b leading zero count when computing exponent
+ const auto totShiftBits8 = _mm512_set1_epi32(25);
+ const auto totShiftBits9 = _mm512_set1_epi32(24);
+ const auto totShiftBits10 = _mm512_set1_epi32(23);
+ const auto totShiftBits12 = _mm512_set1_epi32(21);
+
+ /// Total number of compressed bytes per RB for each iqWidth option
+ constexpr int totNumBytesPerRB9 = 28;
+ constexpr int totNumBytesPerRB10 = 31;
+ constexpr int totNumBytesPerRB12 = 37;
+
+ /// Compressed data write mask for each iqWidth option
+ constexpr uint16_t rbWriteMask9 = 0x01FF;
+ constexpr uint16_t rbWriteMask10 = 0x03FF;
+ constexpr uint16_t rbWriteMask12 = 0x0FFF;
+
+ switch (dataIn.iqWidth)
+ {
+ case 8:
+ BFP_UPlane::compressByAlloc8(dataIn, dataOut, totShiftBits8);
+ break;
+
+ case 9:
+ BFP_UPlane::compressByAllocN<BlockFloatCompander::networkBytePack9b>(dataIn, dataOut, totShiftBits9, totNumBytesPerRB9, rbWriteMask9);
+ break;
+
+ case 10:
+ BFP_UPlane::compressByAllocN<BlockFloatCompander::networkBytePack10b>(dataIn, dataOut, totShiftBits10, totNumBytesPerRB10, rbWriteMask10);
+ break;
+
+ case 12:
+ BFP_UPlane::compressByAllocN<BlockFloatCompander::networkBytePack12b>(dataIn, dataOut, totShiftBits12, totNumBytesPerRB12, rbWriteMask12);
+ break;
+ }
+}
+
+
+
+/// Main kernel function for expansion.
+/// Starts by determining iqWidth specific parameters and functions.
+void
+BlockFloatCompander::BFPExpandUserPlaneAvx512(const CompressedData& dataIn, ExpandedData* dataOut)
+{
+ constexpr int k_totNumBytesPerRB9 = 28;
+ constexpr int k_totNumBytesPerRB10 = 31;
+ constexpr int k_totNumBytesPerRB12 = 37;
+
+ constexpr int k_maxExpShift9 = 7;
+ constexpr int k_maxExpShift10 = 6;
+ constexpr int k_maxExpShift12 = 4;
+
+ switch (dataIn.iqWidth)
+ {
+ case 8:
+ BFP_UPlane::expandByAlloc8(dataIn, dataOut);
+ break;
+
+ case 9:
+ BFP_UPlane::expandByAllocN<BlockFloatCompander::networkByteUnpack9b>(dataIn, dataOut, k_totNumBytesPerRB9, k_maxExpShift9);
+ break;
+
+ case 10:
+ BFP_UPlane::expandByAllocN<BlockFloatCompander::networkByteUnpack10b>(dataIn, dataOut, k_totNumBytesPerRB10, k_maxExpShift10);
+ break;
+
+ case 12:
+ BFP_UPlane::expandByAllocN<BlockFloatCompander::networkByteUnpack12b>(dataIn, dataOut, k_totNumBytesPerRB12, k_maxExpShift12);
+ break;
+ }
+}
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