/* -*- c++ -*- */
/*
 * Copyright 2016 Free Software Foundation, Inc.
 *
 * This file is part of VOLK
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

/*!
 * \page volk_32f_index_max_32u
 *
 * \b Overview
 *
 * Returns Argmax_i x[i]. Finds and returns the index which contains the first maximum
 * value in the given vector.
 *
 * <b>Dispatcher Prototype</b>
 * \code
 * void volk_32f_index_max_32u(uint32_t* target, const float* src0, uint32_t num_points)
 * \endcode
 *
 * \b Inputs
 * \li src0: The input vector of floats.
 * \li num_points: The number of data points.
 *
 * \b Outputs
 * \li target: The index of the first maximum value in the input buffer.
 *
 * \b Example
 * \code
 *   int N = 10;
 *   uint32_t alignment = volk_get_alignment();
 *   float* in = (float*)volk_malloc(sizeof(float)*N, alignment);
 *   uint32_t* out = (uint32_t*)volk_malloc(sizeof(uint32_t), alignment);
 *
 *   for(uint32_t ii = 0; ii < N; ++ii){
 *       float x = (float)ii;
 *       // a parabola with a maximum at x=4
 *       in[ii] = -(x-4) * (x-4) + 5;
 *   }
 *
 *   volk_32f_index_max_32u(out, in, N);
 *
 *   printf("maximum is %1.2f at index %u\n", in[*out], *out);
 *
 *   volk_free(in);
 *   volk_free(out);
 * \endcode
 */

#ifndef INCLUDED_volk_32f_index_max_32u_a_H
#define INCLUDED_volk_32f_index_max_32u_a_H

#include <inttypes.h>
#include <stdio.h>
#include <volk/volk_common.h>

#ifdef LV_HAVE_SSE4_1
#include <smmintrin.h>

static inline void
volk_32f_index_max_32u_a_sse4_1(uint32_t* target, const float* src0, uint32_t num_points)
{
    if (num_points > 0) {
        uint32_t number = 0;
        const uint32_t quarterPoints = num_points / 4;

        float* inputPtr = (float*)src0;

        __m128 indexIncrementValues = _mm_set1_ps(4);
        __m128 currentIndexes = _mm_set_ps(-1, -2, -3, -4);

        float max = src0[0];
        float index = 0;
        __m128 maxValues = _mm_set1_ps(max);
        __m128 maxValuesIndex = _mm_setzero_ps();
        __m128 compareResults;
        __m128 currentValues;

        __VOLK_ATTR_ALIGNED(16) float maxValuesBuffer[4];
        __VOLK_ATTR_ALIGNED(16) float maxIndexesBuffer[4];

        for (; number < quarterPoints; number++) {

            currentValues = _mm_load_ps(inputPtr);
            inputPtr += 4;
            currentIndexes = _mm_add_ps(currentIndexes, indexIncrementValues);

            compareResults = _mm_cmpgt_ps(currentValues, maxValues);

            maxValuesIndex =
                _mm_blendv_ps(maxValuesIndex, currentIndexes, compareResults);
            maxValues = _mm_blendv_ps(maxValues, currentValues, compareResults);
        }

        // Calculate the largest value from the remaining 4 points
        _mm_store_ps(maxValuesBuffer, maxValues);
        _mm_store_ps(maxIndexesBuffer, maxValuesIndex);

        for (number = 0; number < 4; number++) {
            if (maxValuesBuffer[number] > max) {
                index = maxIndexesBuffer[number];
                max = maxValuesBuffer[number];
            } else if (maxValuesBuffer[number] == max) {
                if (index > maxIndexesBuffer[number])
                    index = maxIndexesBuffer[number];
            }
        }

        number = quarterPoints * 4;
        for (; number < num_points; number++) {
            if (src0[number] > max) {
                index = number;
                max = src0[number];
            }
        }
        target[0] = (uint32_t)index;
    }
}

#endif /*LV_HAVE_SSE4_1*/


#ifdef LV_HAVE_SSE

#include <xmmintrin.h>

static inline void
volk_32f_index_max_32u_a_sse(uint32_t* target, const float* src0, uint32_t num_points)
{
    if (num_points > 0) {
        uint32_t number = 0;
        const uint32_t quarterPoints = num_points / 4;

        float* inputPtr = (float*)src0;

        __m128 indexIncrementValues = _mm_set1_ps(4);
        __m128 currentIndexes = _mm_set_ps(-1, -2, -3, -4);

        float max = src0[0];
        float index = 0;
        __m128 maxValues = _mm_set1_ps(max);
        __m128 maxValuesIndex = _mm_setzero_ps();
        __m128 compareResults;
        __m128 currentValues;

        __VOLK_ATTR_ALIGNED(16) float maxValuesBuffer[4];
        __VOLK_ATTR_ALIGNED(16) float maxIndexesBuffer[4];

        for (; number < quarterPoints; number++) {

            currentValues = _mm_load_ps(inputPtr);
            inputPtr += 4;
            currentIndexes = _mm_add_ps(currentIndexes, indexIncrementValues);

            compareResults = _mm_cmpgt_ps(currentValues, maxValues);

            maxValuesIndex = _mm_or_ps(_mm_and_ps(compareResults, currentIndexes),
                                       _mm_andnot_ps(compareResults, maxValuesIndex));

            maxValues = _mm_or_ps(_mm_and_ps(compareResults, currentValues),
                                  _mm_andnot_ps(compareResults, maxValues));
        }

        // Calculate the largest value from the remaining 4 points
        _mm_store_ps(maxValuesBuffer, maxValues);
        _mm_store_ps(maxIndexesBuffer, maxValuesIndex);

        for (number = 0; number < 4; number++) {
            if (maxValuesBuffer[number] > max) {
                index = maxIndexesBuffer[number];
                max = maxValuesBuffer[number];
            } else if (maxValuesBuffer[number] == max) {
                if (index > maxIndexesBuffer[number])
                    index = maxIndexesBuffer[number];
            }
        }

        number = quarterPoints * 4;
        for (; number < num_points; number++) {
            if (src0[number] > max) {
                index = number;
                max = src0[number];
            }
        }
        target[0] = (uint32_t)index;
    }
}

#endif /*LV_HAVE_SSE*/


#ifdef LV_HAVE_AVX
#include <immintrin.h>

static inline void
volk_32f_index_max_32u_a_avx(uint32_t* target, const float* src0, uint32_t num_points)
{
    if (num_points > 0) {
        uint32_t number = 0;
        const uint32_t quarterPoints = num_points / 8;

        float* inputPtr = (float*)src0;

        __m256 indexIncrementValues = _mm256_set1_ps(8);
        __m256 currentIndexes = _mm256_set_ps(-1, -2, -3, -4, -5, -6, -7, -8);

        float max = src0[0];
        float index = 0;
        __m256 maxValues = _mm256_set1_ps(max);
        __m256 maxValuesIndex = _mm256_setzero_ps();
        __m256 compareResults;
        __m256 currentValues;

        __VOLK_ATTR_ALIGNED(32) float maxValuesBuffer[8];
        __VOLK_ATTR_ALIGNED(32) float maxIndexesBuffer[8];

        for (; number < quarterPoints; number++) {
            currentValues = _mm256_load_ps(inputPtr);
            inputPtr += 8;
            currentIndexes = _mm256_add_ps(currentIndexes, indexIncrementValues);
            compareResults = _mm256_cmp_ps(currentValues, maxValues, _CMP_GT_OS);
            maxValuesIndex =
                _mm256_blendv_ps(maxValuesIndex, currentIndexes, compareResults);
            maxValues = _mm256_blendv_ps(maxValues, currentValues, compareResults);
        }

        // Calculate the largest value from the remaining 8 points
        _mm256_store_ps(maxValuesBuffer, maxValues);
        _mm256_store_ps(maxIndexesBuffer, maxValuesIndex);

        for (number = 0; number < 8; number++) {
            if (maxValuesBuffer[number] > max) {
                index = maxIndexesBuffer[number];
                max = maxValuesBuffer[number];
            } else if (maxValuesBuffer[number] == max) {
                if (index > maxIndexesBuffer[number])
                    index = maxIndexesBuffer[number];
            }
        }

        number = quarterPoints * 8;
        for (; number < num_points; number++) {
            if (src0[number] > max) {
                index = number;
                max = src0[number];
            }
        }
        target[0] = (uint32_t)index;
    }
}

#endif /*LV_HAVE_AVX*/


#ifdef LV_HAVE_NEON
#include <arm_neon.h>

static inline void
volk_32f_index_max_32u_neon(uint32_t* target, const float* src0, uint32_t num_points)
{
    if (num_points > 0) {
        uint32_t number = 0;
        const uint32_t quarterPoints = num_points / 4;

        float* inputPtr = (float*)src0;
        float32x4_t indexIncrementValues = vdupq_n_f32(4);
        __VOLK_ATTR_ALIGNED(16)
        float currentIndexes_float[4] = { -4.0f, -3.0f, -2.0f, -1.0f };
        float32x4_t currentIndexes = vld1q_f32(currentIndexes_float);

        float max = src0[0];
        float index = 0;
        float32x4_t maxValues = vdupq_n_f32(max);
        uint32x4_t maxValuesIndex = vmovq_n_u32(0);
        uint32x4_t compareResults;
        uint32x4_t currentIndexes_u;
        float32x4_t currentValues;

        __VOLK_ATTR_ALIGNED(16) float maxValuesBuffer[4];
        __VOLK_ATTR_ALIGNED(16) float maxIndexesBuffer[4];

        for (; number < quarterPoints; number++) {
            currentValues = vld1q_f32(inputPtr);
            inputPtr += 4;
            currentIndexes = vaddq_f32(currentIndexes, indexIncrementValues);
            currentIndexes_u = vcvtq_u32_f32(currentIndexes);
            compareResults = vcleq_f32(currentValues, maxValues);
            maxValuesIndex = vorrq_u32(vandq_u32(compareResults, maxValuesIndex),
                                       vbicq_u32(currentIndexes_u, compareResults));
            maxValues = vmaxq_f32(currentValues, maxValues);
        }

        // Calculate the largest value from the remaining 4 points
        vst1q_f32(maxValuesBuffer, maxValues);
        vst1q_f32(maxIndexesBuffer, vcvtq_f32_u32(maxValuesIndex));
        for (number = 0; number < 4; number++) {
            if (maxValuesBuffer[number] > max) {
                index = maxIndexesBuffer[number];
                max = maxValuesBuffer[number];
            } else if (maxValues[number] == max) {
                if (index > maxIndexesBuffer[number])
                    index = maxIndexesBuffer[number];
            }
        }

        number = quarterPoints * 4;
        for (; number < num_points; number++) {
            if (src0[number] > max) {
                index = number;
                max = src0[number];
            }
        }
        target[0] = (uint32_t)index;
    }
}

#endif /*LV_HAVE_NEON*/


#ifdef LV_HAVE_GENERIC

static inline void
volk_32f_index_max_32u_generic(uint32_t* target, const float* src0, uint32_t num_points)
{
    if (num_points > 0) {
        float max = src0[0];
        uint32_t index = 0;

        uint32_t i = 1;

        for (; i < num_points; ++i) {
            if (src0[i] > max) {
                index = i;
                max = src0[i];
            }
        }
        target[0] = index;
    }
}

#endif /*LV_HAVE_GENERIC*/


#endif /*INCLUDED_volk_32f_index_max_32u_a_H*/


#ifndef INCLUDED_volk_32f_index_max_32u_u_H
#define INCLUDED_volk_32f_index_max_32u_u_H

#include <inttypes.h>
#include <stdio.h>
#include <volk/volk_common.h>


#ifdef LV_HAVE_AVX
#include <immintrin.h>

static inline void
volk_32f_index_max_32u_u_avx(uint32_t* target, const float* src0, uint32_t num_points)
{
    if (num_points > 0) {
        uint32_t number = 0;
        const uint32_t quarterPoints = num_points / 8;

        float* inputPtr = (float*)src0;

        __m256 indexIncrementValues = _mm256_set1_ps(8);
        __m256 currentIndexes = _mm256_set_ps(-1, -2, -3, -4, -5, -6, -7, -8);

        float max = src0[0];
        float index = 0;
        __m256 maxValues = _mm256_set1_ps(max);
        __m256 maxValuesIndex = _mm256_setzero_ps();
        __m256 compareResults;
        __m256 currentValues;

        __VOLK_ATTR_ALIGNED(32) float maxValuesBuffer[8];
        __VOLK_ATTR_ALIGNED(32) float maxIndexesBuffer[8];

        for (; number < quarterPoints; number++) {
            currentValues = _mm256_loadu_ps(inputPtr);
            inputPtr += 8;
            currentIndexes = _mm256_add_ps(currentIndexes, indexIncrementValues);
            compareResults = _mm256_cmp_ps(currentValues, maxValues, _CMP_GT_OS);
            maxValuesIndex =
                _mm256_blendv_ps(maxValuesIndex, currentIndexes, compareResults);
            maxValues = _mm256_blendv_ps(maxValues, currentValues, compareResults);
        }

        // Calculate the largest value from the remaining 8 points
        _mm256_store_ps(maxValuesBuffer, maxValues);
        _mm256_store_ps(maxIndexesBuffer, maxValuesIndex);

        for (number = 0; number < 8; number++) {
            if (maxValuesBuffer[number] > max) {
                index = maxIndexesBuffer[number];
                max = maxValuesBuffer[number];
            } else if (maxValuesBuffer[number] == max) {
                if (index > maxIndexesBuffer[number])
                    index = maxIndexesBuffer[number];
            }
        }

        number = quarterPoints * 8;
        for (; number < num_points; number++) {
            if (src0[number] > max) {
                index = number;
                max = src0[number];
            }
        }
        target[0] = (uint32_t)index;
    }
}

#endif /*LV_HAVE_AVX*/


#ifdef LV_HAVE_SSE4_1
#include <smmintrin.h>

static inline void
volk_32f_index_max_32u_u_sse4_1(uint32_t* target, const float* src0, uint32_t num_points)
{
    if (num_points > 0) {
        uint32_t number = 0;
        const uint32_t quarterPoints = num_points / 4;

        float* inputPtr = (float*)src0;

        __m128 indexIncrementValues = _mm_set1_ps(4);
        __m128 currentIndexes = _mm_set_ps(-1, -2, -3, -4);

        float max = src0[0];
        float index = 0;
        __m128 maxValues = _mm_set1_ps(max);
        __m128 maxValuesIndex = _mm_setzero_ps();
        __m128 compareResults;
        __m128 currentValues;

        __VOLK_ATTR_ALIGNED(16) float maxValuesBuffer[4];
        __VOLK_ATTR_ALIGNED(16) float maxIndexesBuffer[4];

        for (; number < quarterPoints; number++) {
            currentValues = _mm_loadu_ps(inputPtr);
            inputPtr += 4;
            currentIndexes = _mm_add_ps(currentIndexes, indexIncrementValues);
            compareResults = _mm_cmpgt_ps(currentValues, maxValues);
            maxValuesIndex =
                _mm_blendv_ps(maxValuesIndex, currentIndexes, compareResults);
            maxValues = _mm_blendv_ps(maxValues, currentValues, compareResults);
        }

        // Calculate the largest value from the remaining 4 points
        _mm_store_ps(maxValuesBuffer, maxValues);
        _mm_store_ps(maxIndexesBuffer, maxValuesIndex);

        for (number = 0; number < 4; number++) {
            if (maxValuesBuffer[number] > max) {
                index = maxIndexesBuffer[number];
                max = maxValuesBuffer[number];
            } else if (maxValuesBuffer[number] == max) {
                if (index > maxIndexesBuffer[number])
                    index = maxIndexesBuffer[number];
            }
        }

        number = quarterPoints * 4;
        for (; number < num_points; number++) {
            if (src0[number] > max) {
                index = number;
                max = src0[number];
            }
        }
        target[0] = (uint32_t)index;
    }
}

#endif /*LV_HAVE_SSE4_1*/

#ifdef LV_HAVE_SSE
#include <xmmintrin.h>

static inline void
volk_32f_index_max_32u_u_sse(uint32_t* target, const float* src0, uint32_t num_points)
{
    if (num_points > 0) {
        uint32_t number = 0;
        const uint32_t quarterPoints = num_points / 4;

        float* inputPtr = (float*)src0;

        __m128 indexIncrementValues = _mm_set1_ps(4);
        __m128 currentIndexes = _mm_set_ps(-1, -2, -3, -4);

        float max = src0[0];
        float index = 0;
        __m128 maxValues = _mm_set1_ps(max);
        __m128 maxValuesIndex = _mm_setzero_ps();
        __m128 compareResults;
        __m128 currentValues;

        __VOLK_ATTR_ALIGNED(16) float maxValuesBuffer[4];
        __VOLK_ATTR_ALIGNED(16) float maxIndexesBuffer[4];

        for (; number < quarterPoints; number++) {
            currentValues = _mm_loadu_ps(inputPtr);
            inputPtr += 4;
            currentIndexes = _mm_add_ps(currentIndexes, indexIncrementValues);
            compareResults = _mm_cmpgt_ps(currentValues, maxValues);
            maxValuesIndex = _mm_or_ps(_mm_and_ps(compareResults, currentIndexes),
                                       _mm_andnot_ps(compareResults, maxValuesIndex));
            maxValues = _mm_or_ps(_mm_and_ps(compareResults, currentValues),
                                  _mm_andnot_ps(compareResults, maxValues));
        }

        // Calculate the largest value from the remaining 4 points
        _mm_store_ps(maxValuesBuffer, maxValues);
        _mm_store_ps(maxIndexesBuffer, maxValuesIndex);

        for (number = 0; number < 4; number++) {
            if (maxValuesBuffer[number] > max) {
                index = maxIndexesBuffer[number];
                max = maxValuesBuffer[number];
            } else if (maxValuesBuffer[number] == max) {
                if (index > maxIndexesBuffer[number])
                    index = maxIndexesBuffer[number];
            }
        }

        number = quarterPoints * 4;
        for (; number < num_points; number++) {
            if (src0[number] > max) {
                index = number;
                max = src0[number];
            }
        }
        target[0] = (uint32_t)index;
    }
}

#endif /*LV_HAVE_SSE*/

#endif /*INCLUDED_volk_32f_index_max_32u_u_H*/
