purezen 0.0.2

Runtime for the Pure Data (Pd) audio programming language, implemented as an extensible audio library allowing full control over signal processing, message passing, and graph manipulation. Pure Data is a graph-based programming language environment creating interactive music and multimedia works.
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/*
 *  Copyright 2010,2011 Reality Jockey, Ltd.
 *                 info@rjdj.me
 *                 http://rjdj.me/
 *
 *  This file is part of ZenGarden.
 *
 *  ZenGarden is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  ZenGarden 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with ZenGarden.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "DspSqrt.h"
#include "PdGraph.h"

message::Object *DspSqrt::new_object(pd::Message *init_message, PdGraph *graph) {
  return new DspSqrt(init_message, graph);
}

DspSqrt::DspSqrt(pd::Message *init_message, PdGraph *graph) : DspObject(0, 1, 0, 1, graph) {
  process_function = &processSignal;
}

DspSqrt::~DspSqrt() {
  // nothing to do
}

void DspSqrt::processSignal(DspObject *dspObject, int fromIndex, int toIndex) {
  // [sqrt~] takes no messages, so the full block will be computed every time
  DspSqrt *d = reinterpret_cast<DspSqrt *>(dspObject);
    
  #if __ARM_NEON__
  float *inBuff = d->dspBufferAtInlet[0];
  float *outBuff = d->dspBufferAtOutlet[0];
  float32x4_t inVec, outVec;
  float32x4_t zeroVec = vdupq_n_f32(0.0f);
  int n4 = toIndex & 0xFFFFFFFC;
  while (n4) {
    inVec = vld1q_f32(inBuff);
    inVec = vmaxq_f32(inVec, zeroVec);
    // is this at all correct? No sqrt intrinsic for ARM NEON?
    outVec = vrsqrteq_f32(inVec); // out = 1/sqrt(in)
    outVec = vrecpeq_f32(outVec); // out = 1/out
    vst1q_f32((float32_t *) outBuff, outVec);
    n4 -= 4;
    inBuff += 4;
    outBuff += 4;
  }
  switch (toIndex & 0x3) {
    case 3: *outBuff++ = (*inBuff > 0.0f) ? sqrtf(*inBuff) : 0.0f; ++inBuff;
    case 2: *outBuff++ = (*inBuff > 0.0f) ? sqrtf(*inBuff) : 0.0f; ++inBuff;
    case 1: *outBuff++ = (*inBuff > 0.0f) ? sqrtf(*inBuff) : 0.0f; ++inBuff;
    default: break;
  }
  #elif __SSE__
  float *inBuff = d->dspBufferAtInlet[0];
  float *outBuff = d->dspBufferAtOutlet[0];
  __m128 inVec, outVec;
  __m128 zeroVec = _mm_set1_ps(0.0f);
  int n4 = toIndex & 0xFFFFFFFC;
  while (n4) {
    inVec = _mm_load_ps(inBuff);
    
    // ensure that all inputs are non-negative, max(0, inVec)
    // NOTE(mhroth): is this really necessary? What does _mm_sqrt_ps return otherwise?
    inVec = _mm_max_ps(inVec, zeroVec);
    outVec = _mm_sqrt_ps(inVec);
    _mm_store_ps(outBuff, outVec);
    n4 -= 4;
    inBuff += 4;
    outBuff += 4;
  }
  switch (toIndex & 0x3) {
    case 3: *outBuff++ = (*inBuff > 0.0f) ? sqrtf(*inBuff) : 0.0f; ++inBuff;
    case 2: *outBuff++ = (*inBuff > 0.0f) ? sqrtf(*inBuff) : 0.0f; ++inBuff;
    case 1: *outBuff++ = (*inBuff > 0.0f) ? sqrtf(*inBuff) : 0.0f; ++inBuff;
    default: break;
  }
  #else
  for (int i = 0; i < toIndex; i++) {
    d->dspBufferAtOutlet[0][i] = sqrtf(d->dspBufferAtInlet[0][i]);
  }
  #endif
}