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/*
* Copyright (C) 2003-2014 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_PCM_NEON_HXX
#define MPD_PCM_NEON_HXX
#include "Traits.hxx"
#include <arm_neon.h>
/**
* Call a NEON intrinsic for each element in the vector.
*
* @param func the NEON intrinsic
* @param result the vector variable that gets assigned the result
* @param vector the input vector
*/
#define neon_x4_u(func, result, vector) do { \
result.val[0] = func(vector.val[0]); \
result.val[1] = func(vector.val[1]); \
result.val[2] = func(vector.val[2]); \
result.val[3] = func(vector.val[3]); \
} while (0)
/**
* Call a NEON intrinsic for each element in the vector.
*
* @param func the NEON intrinsic
* @param result the vector variable that gets assigned the result
* @param vector the input vector
* @param arg an additional argument that gets passed to each call
*/
#define neon_x4_b(func, result, vector, arg) do { \
result.val[0] = func(vector.val[0], arg); \
result.val[1] = func(vector.val[1], arg); \
result.val[2] = func(vector.val[2], arg); \
result.val[3] = func(vector.val[3], arg); \
} while (0)
/**
* Convert floating point samples to 16 bit signed integer using ARM NEON.
*/
struct NeonFloatTo16 {
static constexpr SampleFormat src_format = SampleFormat::FLOAT;
static constexpr SampleFormat dst_format = SampleFormat::S16;
typedef SampleTraits<src_format> SrcTraits;
typedef SampleTraits<dst_format> DstTraits;
typedef typename SrcTraits::value_type SV;
typedef typename DstTraits::value_type DV;
static constexpr size_t BLOCK_SIZE = 16;
void Convert(int16_t *dst, const float *src, const size_t n) const {
const float32x4_t factor =
vdupq_n_f32(1 << (DstTraits::BITS - 1));
for (unsigned i = 0; i < n / BLOCK_SIZE;
++i, src += BLOCK_SIZE, dst += BLOCK_SIZE) {
/* load 16 float samples into 4 quad
registers */
float32x4x4_t value = vld4q_f32(src);
/* apply factor */
neon_x4_b(vmulq_f32, value, value, factor);
/* convert to 32 bit integer */
int32x4x4_t ivalue;
neon_x4_u(vcvtq_s32_f32, ivalue, value);
/* convert to 16 bit integer with saturation */
int16x4x4_t nvalue;
neon_x4_u(vqmovn_s32, nvalue, ivalue);
/* store result */
vst4_s16(dst, nvalue);
}
}
};
#endif
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