volk_64u_popcnt.h

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/* -*- c++ -*- */
/*
 * Copyright 2012, 2014 Free Software Foundation, Inc.
 *
 * This file is part of VOLK
 *
 * SPDX-License-Identifier: LGPL-3.0-or-later
 */
 
#ifndef INCLUDED_volk_64u_popcnt_a_H
#define INCLUDED_volk_64u_popcnt_a_H
 
#include <inttypes.h>
#include <stdio.h>
 
 
#ifdef LV_HAVE_GENERIC
 
 
static inline void volk_64u_popcnt_generic(uint64_t* ret, const uint64_t value)
{
    // const uint32_t* valueVector = (const uint32_t*)&value;
 
    // This is faster than a lookup table
    // uint32_t retVal = valueVector[0];
    uint32_t retVal = (uint32_t)(value & 0x00000000FFFFFFFFull);
 
    retVal = (retVal & 0x55555555) + (retVal >> 1 & 0x55555555);
    retVal = (retVal & 0x33333333) + (retVal >> 2 & 0x33333333);
    retVal = (retVal + (retVal >> 4)) & 0x0F0F0F0F;
    retVal = (retVal + (retVal >> 8));
    retVal = (retVal + (retVal >> 16)) & 0x0000003F;
    uint64_t retVal64 = retVal;
 
    // retVal = valueVector[1];
    retVal = (uint32_t)((value & 0xFFFFFFFF00000000ull) >> 32);
    retVal = (retVal & 0x55555555) + (retVal >> 1 & 0x55555555);
    retVal = (retVal & 0x33333333) + (retVal >> 2 & 0x33333333);
    retVal = (retVal + (retVal >> 4)) & 0x0F0F0F0F;
    retVal = (retVal + (retVal >> 8));
    retVal = (retVal + (retVal >> 16)) & 0x0000003F;
    retVal64 += retVal;
 
    *ret = retVal64;
}
 
#endif /*LV_HAVE_GENERIC*/
 
 
#if LV_HAVE_SSE4_2 && LV_HAVE_64
 
#include <nmmintrin.h>
 
static inline void volk_64u_popcnt_a_sse4_2(uint64_t* ret, const uint64_t value)
{
    *ret = _mm_popcnt_u64(value);
}
 
#endif /*LV_HAVE_SSE4_2*/
 
 
#if LV_HAVE_NEON
#include <arm_neon.h>
static inline void volk_64u_popcnt_neon(uint64_t* ret, const uint64_t value)
{
    uint8x8_t input_val, count8x8_val;
    uint16x4_t count16x4_val;
    uint32x2_t count32x2_val;
    uint64x1_t count64x1_val;
 
    input_val = vld1_u8((unsigned char*)&value);
    count8x8_val = vcnt_u8(input_val);
    count16x4_val = vpaddl_u8(count8x8_val);
    count32x2_val = vpaddl_u16(count16x4_val);
    count64x1_val = vpaddl_u32(count32x2_val);
    vst1_u64(ret, count64x1_val);
 
    //*ret = _mm_popcnt_u64(value);
}
#endif /*LV_HAVE_NEON*/
 
 
#endif /*INCLUDED_volk_64u_popcnt_a_H*/