//
// Copyright 2012-2013 Ettus Research LLC
// Copyright 2018 Ettus Research, a National Instruments Company
//
// SPDX-License-Identifier: GPL-3.0-or-later
//

#include "convert_common.hpp"
#include <uhd/utils/byteswap.hpp>
#include <emmintrin.h>

using namespace uhd::convert;

static const __m128i zeroi = _mm_setzero_si128();

template <const int shuf>
UHD_INLINE void unpack_sc32_4x(const __m128i& in,
    __m128& out0,
    __m128& out1,
    __m128& out2,
    __m128& out3,
    const __m128& scalar)
{
    const __m128i tmplo = _mm_unpacklo_epi8(zeroi, in); /* value in upper 8 bits */
    __m128i tmp0        = _mm_shuffle_epi32(
        _mm_unpacklo_epi16(zeroi, tmplo), shuf); /* value in upper 16 bits */
    __m128i tmp1 = _mm_shuffle_epi32(_mm_unpackhi_epi16(zeroi, tmplo), shuf);
    out0         = _mm_mul_ps(_mm_cvtepi32_ps(tmp0), scalar);
    out1         = _mm_mul_ps(_mm_cvtepi32_ps(tmp1), scalar);

    const __m128i tmphi = _mm_unpackhi_epi8(zeroi, in);
    __m128i tmp2        = _mm_shuffle_epi32(_mm_unpacklo_epi16(zeroi, tmphi), shuf);
    __m128i tmp3        = _mm_shuffle_epi32(_mm_unpackhi_epi16(zeroi, tmphi), shuf);
    out2                = _mm_mul_ps(_mm_cvtepi32_ps(tmp2), scalar);
    out3                = _mm_mul_ps(_mm_cvtepi32_ps(tmp3), scalar);
}

DECLARE_CONVERTER(sc8_item32_be, 1, fc32, 1, PRIORITY_SIMD)
{
    const item32_t* input = reinterpret_cast<const item32_t*>(size_t(inputs[0]) & ~0x3);
    fc32_t* output        = reinterpret_cast<fc32_t*>(outputs[0]);

    const __m128 scalar = _mm_set_ps1(float(scale_factor) / (1 << 24));
    const int shuf      = _MM_SHUFFLE(3, 2, 1, 0);

    size_t i = 0, j = 0;
    size_t num_samps = nsamps;

    if ((size_t(inputs[0]) & 0x3) != 0) {
        item32_sc8_to_xx<uhd::ntohx>(input++, output++, 1, scale_factor);
        num_samps--;
    }

#define convert_sc8_item32_1_to_fc32_1_bswap_guts(_al_)                              \
    for (; j + 7 < num_samps; j += 8, i += 4) {                                      \
        /* load from input */                                                        \
        __m128i tmpi = _mm_loadu_si128(reinterpret_cast<const __m128i*>(input + i)); \
                                                                                     \
        /* unpack + swap 8-bit pairs */                                              \
        __m128 tmp0, tmp1, tmp2, tmp3;                                               \
        unpack_sc32_4x<shuf>(tmpi, tmp0, tmp1, tmp2, tmp3, scalar);                  \
                                                                                     \
        /* store to output */                                                        \
        _mm_store##_al_##ps(reinterpret_cast<float*>(output + j + 0), tmp0);         \
        _mm_store##_al_##ps(reinterpret_cast<float*>(output + j + 2), tmp1);         \
        _mm_store##_al_##ps(reinterpret_cast<float*>(output + j + 4), tmp2);         \
        _mm_store##_al_##ps(reinterpret_cast<float*>(output + j + 6), tmp3);         \
    }

    // dispatch according to alignment
    if ((size_t(output) & 0xf) == 0) {
        convert_sc8_item32_1_to_fc32_1_bswap_guts(_)
    } else {
        convert_sc8_item32_1_to_fc32_1_bswap_guts(u_)
    }

    // convert remainder
    item32_sc8_to_xx<uhd::ntohx>(input + i, output + j, num_samps - j, scale_factor);
}

DECLARE_CONVERTER(sc8_item32_le, 1, fc32, 1, PRIORITY_SIMD)
{
    const item32_t* input = reinterpret_cast<const item32_t*>(size_t(inputs[0]) & ~0x3);
    fc32_t* output        = reinterpret_cast<fc32_t*>(outputs[0]);

    const __m128 scalar = _mm_set_ps1(float(scale_factor) / (1 << 24));
    const int shuf      = _MM_SHUFFLE(0, 1, 2, 3);

    size_t i = 0, j = 0;
    size_t num_samps = nsamps;

    if ((size_t(inputs[0]) & 0x3) != 0) {
        item32_sc8_to_xx<uhd::wtohx>(input++, output++, 1, scale_factor);
        num_samps--;
    }

#define convert_sc8_item32_1_to_fc32_1_nswap_guts(_al_)                              \
    for (; j + 7 < num_samps; j += 8, i += 4) {                                      \
        /* load from input */                                                        \
        __m128i tmpi = _mm_loadu_si128(reinterpret_cast<const __m128i*>(input + i)); \
                                                                                     \
        /* unpack + swap 8-bit pairs */                                              \
        __m128 tmp0, tmp1, tmp2, tmp3;                                               \
        unpack_sc32_4x<shuf>(tmpi, tmp0, tmp1, tmp2, tmp3, scalar);                  \
                                                                                     \
        /* store to output */                                                        \
        _mm_store##_al_##ps(reinterpret_cast<float*>(output + j + 0), tmp0);         \
        _mm_store##_al_##ps(reinterpret_cast<float*>(output + j + 2), tmp1);         \
        _mm_store##_al_##ps(reinterpret_cast<float*>(output + j + 4), tmp2);         \
        _mm_store##_al_##ps(reinterpret_cast<float*>(output + j + 6), tmp3);         \
    }

    // dispatch according to alignment
    if ((size_t(output) & 0xf) == 0) {
        convert_sc8_item32_1_to_fc32_1_nswap_guts(_)
    } else {
        convert_sc8_item32_1_to_fc32_1_nswap_guts(u_)
    }

    // convert remainder
    item32_sc8_to_xx<uhd::wtohx>(input + i, output + j, num_samps - j, scale_factor);
}