/*!
 * \file volk_gnsssdr_8ic_conjugate_8ic.h
 * \brief VOLK_GNSSSDR kernel: calculates the conjugate of a 16 bits vector.
 * \authors <ul>
 *          <li> Andres Cecilia, 2014. a.cecilia.luque(at)gmail.com
 *          </ul>
 *
 * VOLK_GNSSSDR kernel that calculates the conjugate of a
 * 16 bits vector (8 bits the real part and 8 bits the imaginary part)
 *
 * -----------------------------------------------------------------------------
 *
 * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
 * This file is part of GNSS-SDR.
 *
 * Copyright (C) 2010-2020  (see AUTHORS file for a list of contributors)
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * -----------------------------------------------------------------------------
 */

/*!
 * \page volk_gnsssdr_8ic_conjugate_8ic
 *
 * \b Overview
 *
 * Takes the conjugate of a complex unsigned char vector.
 *
 * <b>Dispatcher Prototype</b>
 * \code
 * void volk_gnsssdr_8ic_conjugate_8ic(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points);
 * \endcode
 *
 * \b Inputs
 * \li aVector: Vector of complex items to be conjugated
 * \li num_points: The number of complex data points.
 *
 * \b Outputs
 * \li cVector: The vector where the result will be stored
 *
 */

#ifndef INCLUDED_volk_gnsssdr_8ic_conjugate_8ic_H
#define INCLUDED_volk_gnsssdr_8ic_conjugate_8ic_H

#include <volk_gnsssdr/volk_gnsssdr_complex.h>

#ifdef LV_HAVE_AVX2
#include <immintrin.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_u_avx2(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int avx2_iters = num_points / 16;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;

    __m256i tmp;
    __m256i conjugator = _mm256_setr_epi8(1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1);

    for (i = 0; i < avx2_iters; ++i)
        {
            tmp = _mm256_loadu_si256((__m256i*)a);
            tmp = _mm256_sign_epi8(tmp, conjugator);
            _mm256_storeu_si256((__m256i*)c, tmp);

            a += 16;
            c += 16;
        }

    for (i = avx2_iters * 16; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_AVX2 */


#ifdef LV_HAVE_AVX
#include <immintrin.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_u_avx(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int sse_iters = num_points / 16;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;

    __m256 tmp;
    __m128i tmp128lo, tmp128hi;
    __m256 conjugator1 = _mm256_castsi256_ps(_mm256_setr_epi8(0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF));
    __m128i conjugator2 = _mm_setr_epi8(0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1);

    for (i = 0; i < sse_iters; ++i)
        {
            tmp = _mm256_loadu_ps((float*)a);
            tmp = _mm256_xor_ps(tmp, conjugator1);
            tmp128lo = _mm256_castsi256_si128(_mm256_castps_si256(tmp));
            tmp128lo = _mm_add_epi8(tmp128lo, conjugator2);
            tmp128hi = _mm256_extractf128_si256(_mm256_castps_si256(tmp), 1);
            tmp128hi = _mm_add_epi8(tmp128hi, conjugator2);
            // tmp = _mm256_set_m128i(tmp128hi , tmp128lo); //not defined in some versions of immintrin.h
            tmp = _mm256_castsi256_ps(_mm256_insertf128_si256(_mm256_castsi128_si256(tmp128lo), (tmp128hi), 1));
            _mm256_storeu_ps((float*)c, tmp);

            a += 16;
            c += 16;
        }

    for (i = sse_iters * 16; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_AVX */


#ifdef LV_HAVE_SSSE3
#include <tmmintrin.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_u_ssse3(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int sse_iters = num_points / 8;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;
    __m128i tmp;

    __m128i conjugator = _mm_setr_epi8(1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1);

    for (i = 0; i < sse_iters; ++i)
        {
            tmp = _mm_lddqu_si128((__m128i*)a);
            tmp = _mm_sign_epi8(tmp, conjugator);
            _mm_storeu_si128((__m128i*)c, tmp);
            a += 8;
            c += 8;
        }

    for (i = sse_iters * 8; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_SSSE3 */


#ifdef LV_HAVE_SSE3
#include <pmmintrin.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_u_sse3(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int sse_iters = num_points / 8;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;
    __m128i tmp;

    __m128i conjugator1 = _mm_setr_epi8(0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF);
    __m128i conjugator2 = _mm_setr_epi8(0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1);

    for (i = 0; i < sse_iters; ++i)
        {
            tmp = _mm_lddqu_si128((__m128i*)a);
            tmp = _mm_xor_si128(tmp, conjugator1);
            tmp = _mm_add_epi8(tmp, conjugator2);
            _mm_storeu_si128((__m128i*)c, tmp);
            a += 8;
            c += 8;
        }

    for (i = sse_iters * 8; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_SSE3 */


#ifdef LV_HAVE_GENERIC

static inline void volk_gnsssdr_8ic_conjugate_8ic_generic(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    lv_8sc_t* cPtr = cVector;
    const lv_8sc_t* aPtr = aVector;
    unsigned int number;

    for (number = 0; number < num_points; number++)
        {
            *cPtr++ = lv_conj(*aPtr++);
        }
}
#endif /* LV_HAVE_GENERIC */


#ifdef LV_HAVE_AVX
#include <immintrin.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_a_avx(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int sse_iters = num_points / 16;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;

    __m256 tmp;
    __m128i tmp128lo, tmp128hi;
    __m256 conjugator1 = _mm256_castsi256_ps(_mm256_setr_epi8(0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF));
    __m128i conjugator2 = _mm_setr_epi8(0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1);

    for (i = 0; i < sse_iters; ++i)
        {
            tmp = _mm256_load_ps((float*)a);
            tmp = _mm256_xor_ps(tmp, conjugator1);
            tmp128lo = _mm256_castsi256_si128(_mm256_castps_si256(tmp));
            tmp128lo = _mm_add_epi8(tmp128lo, conjugator2);
            tmp128hi = _mm256_extractf128_si256(_mm256_castps_si256(tmp), 1);
            tmp128hi = _mm_add_epi8(tmp128hi, conjugator2);
            // tmp = _mm256_set_m128i(tmp128hi , tmp128lo); //not defined in some versions of immintrin.h
            tmp = _mm256_castsi256_ps(_mm256_insertf128_si256(_mm256_castsi128_si256(tmp128lo), (tmp128hi), 1));
            _mm256_store_ps((float*)c, tmp);

            a += 16;
            c += 16;
        }

    for (i = sse_iters * 16; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_AVX */


#ifdef LV_HAVE_AVX2
#include <immintrin.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_a_avx2(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int avx2_iters = num_points / 16;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;

    __m256i tmp;
    __m256i conjugator = _mm256_setr_epi8(1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1);

    for (i = 0; i < avx2_iters; ++i)
        {
            tmp = _mm256_load_si256((__m256i*)a);
            tmp = _mm256_sign_epi8(tmp, conjugator);
            _mm256_store_si256((__m256i*)c, tmp);

            a += 16;
            c += 16;
        }

    for (i = avx2_iters * 16; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_AVX2 */


#ifdef LV_HAVE_SSSE3
#include <tmmintrin.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_a_ssse3(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int sse_iters = num_points / 8;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;
    __m128i tmp;
    __m128i conjugator = _mm_setr_epi8(1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1);

    for (i = 0; i < sse_iters; ++i)
        {
            tmp = _mm_load_si128((__m128i*)a);
            tmp = _mm_sign_epi8(tmp, conjugator);
            _mm_store_si128((__m128i*)c, tmp);
            a += 8;
            c += 8;
        }

    for (i = sse_iters * 8; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_SSSE3 */


#ifdef LV_HAVE_SSE3
#include <pmmintrin.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_a_sse3(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int sse_iters = num_points / 8;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;
    __m128i tmp;

    __m128i conjugator1 = _mm_setr_epi8(0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF, 0, 0xFF);
    __m128i conjugator2 = _mm_setr_epi8(0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1);

    for (i = 0; i < sse_iters; ++i)
        {
            tmp = _mm_load_si128((__m128i*)a);
            tmp = _mm_xor_si128(tmp, conjugator1);
            tmp = _mm_add_epi8(tmp, conjugator2);
            _mm_store_si128((__m128i*)c, tmp);
            a += 8;
            c += 8;
        }

    for (i = sse_iters * 8; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_SSE3 */


#ifdef LV_HAVE_NEON
#include <arm_neon.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_neon(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    const unsigned int sse_iters = num_points / 8;
    unsigned int i;
    lv_8sc_t* c = cVector;
    const lv_8sc_t* a = aVector;
    int8x8x2_t a_val;

    for (i = 0; i < sse_iters; ++i)
        {
            a_val = vld2_s8((const int8_t*)a);
            __VOLK_GNSSSDR_PREFETCH(a + 16);
            a_val.val[1] = vneg_s8(a_val.val[1]);
            vst2_s8((int8_t*)c, a_val);
            a += 8;
            c += 8;
        }

    for (i = sse_iters * 8; i < num_points; ++i)
        {
            *c++ = lv_conj(*a++);
        }
}
#endif /* LV_HAVE_NEON */


#ifdef LV_HAVE_RVV
#include <riscv_vector.h>

static inline void volk_gnsssdr_8ic_conjugate_8ic_rvv(lv_8sc_t* cVector, const lv_8sc_t* aVector, unsigned int num_points)
{
    size_t n = num_points;

    // Initialize pointers to track progress as stripmine
    // Assuming that intended to use `signed char`,
    // as `char`'s signedness is implementation-specific
    signed char* cPtr = (signed char*)cVector;
    const signed char* aPtr = (const signed char*)aVector;

    for (size_t vl; n > 0; n -= vl, cPtr += vl * 2, aPtr += vl * 2)
        {
            // Record how many elements will actually be processed
            vl = __riscv_vsetvl_e8m4(n);

            // Load aReal[0..vl), aImag[0..vl)
            vint8m4x2_t aVal = __riscv_vlseg2e8_v_i8m4x2(aPtr, vl);
            vint8m4_t aRealVal = __riscv_vget_v_i8m4x2_i8m4(aVal, 0);
            vint8m4_t aImagVal = __riscv_vget_v_i8m4x2_i8m4(aVal, 1);

            // negImag[i] = -aImag[i]
            vint8m4_t negImagVal = __riscv_vneg_v_i8m4(aImagVal, vl);

            // Store aReal[0..vl), negImag[0..vl) into `cPtr`
            vint8m4x2_t cVal = __riscv_vcreate_v_i8m4x2(aRealVal, negImagVal);
            __riscv_vsseg2e8_v_i8m4x2(cPtr, cVal, vl);

            // In looping, decrease the number of
            // elements left and increase the pointers
            // by the number of elements processed,
            // taking into account how each complex number
            // stored in `cPtr` and `aPtr` is two 1-byte chars
        }
}
#endif /* LV_HAVE_RVV */

#endif /* INCLUDED_volk_gnsssdr_8ic_conjugate_8ic_H */
