/*!
 * \file volk_gnsssdr_8i_max_s8i.h
 * \brief Volk protokernel: calculates the maximum value in a group of 8 bits (char) scalars
 * \authors <ul>
 *          <li> Andrés Cecilia, 2014. a.cecilia.luque(at)gmail.com
 *          </ul>
 *
 * Volk protokernel that returns the maximum value of a group of 8 bits (char) scalars
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 2010-2014  (see AUTHORS file for a list of contributors)
 *
 * GNSS-SDR is a software defined Global Navigation
 *          Satellite Systems receiver
 *
 * This file is part of GNSS-SDR.
 *
 * GNSS-SDR is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * at your option) any later version.
 *
 * GNSS-SDR 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
 *
 * -------------------------------------------------------------------------
 */

#ifndef INCLUDED_volk_gnsssdr_8i_max_s8i_u_H
#define INCLUDED_volk_gnsssdr_8i_max_s8i_u_H

#include <volk_gnsssdr/volk_gnsssdr_common.h>
#include <inttypes.h>
#include <stdio.h>

#ifdef LV_HAVE_SSE4_1
#include <smmintrin.h>
/*!
 \brief Returns the max value in src0
 \param target The max value in src0
 \param src0 The buffer of data to be analysed
 \param num_points The number of values in src0 to be analysed
 */
static inline void volk_gnsssdr_8i_max_s8i_u_sse4_1(char target, const char* src0, unsigned int num_points) {
    if(num_points > 0){
        const unsigned int sse_iters = num_points / 16;
        
        char* inputPtr = (char*)src0;
        char max = src0[0];
        __VOLK_ATTR_ALIGNED(16) char maxValuesBuffer[16];
        __m128i maxValues, compareResults, currentValues;
        
        maxValues = _mm_set1_epi8(max);
        
        for(unsigned int number = 0; number < sse_iters; number++)
        {
            currentValues  = _mm_loadu_si128((__m128i*)inputPtr);
            compareResults = _mm_cmpgt_epi8(maxValues, currentValues);
            maxValues = _mm_blendv_epi8(currentValues, maxValues, compareResults);
            inputPtr += 16;
        }
        
        _mm_storeu_si128((__m128i*)maxValuesBuffer, maxValues);
        
        for(unsigned int i = 0; i<16; ++i)
        {
            if(maxValuesBuffer[i] > max)
            {
                max = maxValuesBuffer[i];
            }
        }
        
        for(unsigned int i = 0; i<(num_points % 16); ++i)
        {
            if(src0[i] > max)
            {
                max = src0[i];
            }
        }
        target = max;
    }
}

#endif /*LV_HAVE_SSE4_1*/

#ifdef LV_HAVE_SSE2
#include<emmintrin.h>
/*!
 \brief Returns the max value in src0
 \param target The max value in src0
 \param src0 The buffer of data to be analysed
 \param num_points The number of values in src0 to be analysed
 */
static inline void volk_gnsssdr_8i_max_s8i_u_sse2(char target, const char* src0, unsigned int num_points) {
    if(num_points > 0){
        const unsigned int sse_iters = num_points / 16;
        
        char* inputPtr = (char*)src0;
        char max = src0[0];
        unsigned short mask;
        __VOLK_ATTR_ALIGNED(16) char currentValuesBuffer[16];
        __m128i maxValues, compareResults, currentValues;
        
        maxValues = _mm_set1_epi8(max);
        
        for(unsigned int number = 0; number < sse_iters; number++)
        {
            currentValues  = _mm_loadu_si128((__m128i*)inputPtr);
            compareResults = _mm_cmpgt_epi8(maxValues, currentValues);
            mask = _mm_movemask_epi8(compareResults);
            
            if (mask != 0xFFFF)
            {
                _mm_storeu_si128((__m128i*)&currentValuesBuffer, currentValues);
                mask = ~mask;
                int i = 0;
                while (mask > 0)
                {
                    if ((mask & 1) == 1)
                    {
                        if(currentValuesBuffer[i] > max)
                        {
                            max = currentValuesBuffer[i];
                        }
                    }
                    i++;
                    mask >>= 1;
                }
                maxValues = _mm_set1_epi8(max);
            }
            inputPtr += 16;
        }
        
        for(unsigned int i = 0; i<(num_points % 16); ++i)
        {
            if(src0[i] > max)
            {
                max = src0[i];
            }
        }
        target = max;
    }
}

#endif /*LV_HAVE_SSE2*/

#ifdef LV_HAVE_GENERIC
/*!
 \brief Returns the max value in src0
 \param target The max value in src0
 \param src0 The buffer of data to be analysed
 \param num_points The number of values in src0 to be analysed
 */
static inline void volk_gnsssdr_8i_max_s8i_generic(char target, const char* src0, unsigned int num_points) {
    if(num_points > 0)
    {
        char max = src0[0];
        
        for(unsigned int i = 1; i < num_points; ++i)
        {
            if(src0[i] > max)
            {
                max = src0[i];
            }
        }
        target = max;
    }
}

#endif /*LV_HAVE_GENERIC*/

#endif /*INCLUDED_volk_gnsssdr_8i_max_s8i_u_H*/


#ifndef INCLUDED_volk_gnsssdr_8i_max_s8i_a_H
#define INCLUDED_volk_gnsssdr_8i_max_s8i_a_H

#include <volk_gnsssdr/volk_gnsssdr_common.h>
#include <inttypes.h>
#include <stdio.h>

#ifdef LV_HAVE_SSE4_1
#include <smmintrin.h>
/*!
 \brief Returns the max value in src0
 \param target The max value in src0
 \param src0 The buffer of data to be analysed
 \param num_points The number of values in src0 to be analysed
 */
static inline void volk_gnsssdr_8i_max_s8i_a_sse4_1(char target, const char* src0, unsigned int num_points) {
    if(num_points > 0){
        const unsigned int sse_iters = num_points / 16;
        
        char* inputPtr = (char*)src0;
        char max = src0[0];
        __VOLK_ATTR_ALIGNED(16) char maxValuesBuffer[16];
        __m128i maxValues, compareResults, currentValues;
        
        maxValues = _mm_set1_epi8(max);
        
        for(unsigned int number = 0; number < sse_iters; number++)
        {
            currentValues  = _mm_load_si128((__m128i*)inputPtr);
            compareResults = _mm_cmpgt_epi8(maxValues, currentValues);
            maxValues = _mm_blendv_epi8(currentValues, maxValues, compareResults);
            inputPtr += 16;
        }
        
        _mm_store_si128((__m128i*)maxValuesBuffer, maxValues);
        
        for(unsigned int i = 0; i<16; ++i)
        {
            if(maxValuesBuffer[i] > max)
            {
                max = maxValuesBuffer[i];
            }
        }
        
        for(unsigned int i = 0; i<(num_points % 16); ++i)
        {
            if(src0[i] > max)
            {
                max = src0[i];
            }
        }
        target = max;
    }
}

#endif /*LV_HAVE_SSE4_1*/

#ifdef LV_HAVE_SSE2
#include <emmintrin.h>
/*!
 \brief Returns the max value in src0
 \param target The max value in src0
 \param src0 The buffer of data to be analysed
 \param num_points The number of values in src0 to be analysed
 */
static inline void volk_gnsssdr_8i_max_s8i_a_sse2(char target, const char* src0, unsigned int num_points) {
    if(num_points > 0){
        const unsigned int sse_iters = num_points / 16;
        
        char* inputPtr = (char*)src0;
        char max = src0[0];
        unsigned short mask;
        __VOLK_ATTR_ALIGNED(16) char currentValuesBuffer[16];
        __m128i maxValues, compareResults, currentValues;
        
        maxValues = _mm_set1_epi8(max);
        
        for(unsigned int number = 0; number < sse_iters; number++)
        {
            currentValues  = _mm_load_si128((__m128i*)inputPtr);
            compareResults = _mm_cmpgt_epi8(maxValues, currentValues);
            mask = _mm_movemask_epi8(compareResults);
            
            if (mask != 0xFFFF)
            {
                _mm_store_si128((__m128i*)&currentValuesBuffer, currentValues);
                mask = ~mask;
                int i = 0;
                while (mask > 0)
                {
                    if ((mask & 1) == 1)
                    {
                        if(currentValuesBuffer[i] > max)
                        {
                            max = currentValuesBuffer[i];
                        }
                    }
                    i++;
                    mask >>= 1;
                }
                maxValues = _mm_set1_epi8(max);
            }
            inputPtr += 16;
        }
        
        for(unsigned int i = 0; i<(num_points % 16); ++i)
        {
            if(src0[i] > max)
            {
                max = src0[i];
            }
        }
        target = max;
    }
}

#endif /*LV_HAVE_SSE2*/

#ifdef LV_HAVE_GENERIC
/*!
 \brief Returns the max value in src0
 \param target The max value in src0
 \param src0 The buffer of data to be analysed
 \param num_points The number of values in src0 to be analysed
 */
static inline void volk_gnsssdr_8i_max_s8i_a_generic(char target, const char* src0, unsigned int num_points) {
    if(num_points > 0)
    {
        if(num_points > 0)
        {
            char max = src0[0];
            
            for(unsigned int i = 1; i < num_points; ++i)
            {
                if(src0[i] > max)
                {
                    max = src0[i];
                }
            }
            target = max;
        }
    }
}

#endif /*LV_HAVE_GENERIC*/

#endif /*INCLUDED_volk_gnsssdr_8i_max_s8i_a_H*/