//
//   Copyright 2013 Pixar
//
//   Licensed under the terms set forth in the LICENSE.txt file available at
//   https://opensubdiv.org/license.
//

#ifndef OPENSUBDIV3_OSD_CPU_KERNEL_H
#define OPENSUBDIV3_OSD_CPU_KERNEL_H

#include "../version.h"
#include <cstring>

namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {

namespace Osd {

struct BufferDescriptor;

void
CpuEvalStencils(float const * src, BufferDescriptor const &srcDesc,
                float * dst,       BufferDescriptor const &dstDesc,
                int const * sizes,
                int const * offsets,
                int const * indices,
                float const * weights,
                int start, int end);

void
CpuEvalStencils(float const * src, BufferDescriptor const &srcDesc,
                float * dst,       BufferDescriptor const &dstDesc,
                float * dstDu,     BufferDescriptor const &dstDuDesc,
                float * dstDv,     BufferDescriptor const &dstDvDesc,
                int const * sizes,
                int const * offsets,
                int const * indices,
                float const * weights,
                float const * duWeights,
                float const * dvWeights,
                int start, int end);

void
CpuEvalStencils(float const * src, BufferDescriptor const &srcDesc,
                float * dst,       BufferDescriptor const &dstDesc,
                float * dstDu,     BufferDescriptor const &dstDuDesc,
                float * dstDv,     BufferDescriptor const &dstDvDesc,
                float * dstDuu,    BufferDescriptor const &dstDuuDesc,
                float * dstDuv,    BufferDescriptor const &dstDuvDesc,
                float * dstDvv,    BufferDescriptor const &dstDvvDesc,
                int const * sizes,
                int const * offsets,
                int const * indices,
                float const * weights,
                float const * duWeights,
                float const * dvWeights,
                float const * duuWeights,
                float const * duvWeights,
                float const * dvvWeights,
                int start, int end);

//
// SIMD ICC optimization of the stencil kernel
//

#if defined ( __INTEL_COMPILER ) || defined ( __ICC )
    #define __ALIGN_DATA __declspec(align(32))
#else
    #define __ALIGN_DATA
#endif

// Note : this function is re-used in the TBB Compute kernel
template <int numElems> void
ComputeStencilKernel(float const * vertexSrc,
                     float * vertexDst,
                     int const * sizes,
                     int const * indices,
                     float const * weights,
                     int start,
                     int end) {

    __ALIGN_DATA float result[numElems],
                       result1[numElems];

    float const * src;
    float * dst, weight;

    for (int i=start; i<end; ++i) {

        // Clear
#if defined ( __INTEL_COMPILER ) || defined ( __ICC )
    #pragma simd
    #pragma vector aligned
#endif
        for (int k = 0; k<numElems; ++k)
            result[k] = 0.0f;

        for (int j=0; j<sizes[i]; ++j, ++indices, ++weights) {

            src = vertexSrc + (*indices)*numElems;
            weight = *weights;

            // AddWithWeight
#if defined ( __INTEL_COMPILER ) || defined ( __ICC )
    #pragma simd
    #pragma vector aligned
#endif
            for (int k=0; k<numElems; ++k) {
                result[k] += src[k] * weight;
            }
        }

#if defined ( __INTEL_COMPILER ) || defined ( __ICC )
    #pragma simd
    #pragma vector aligned
#endif
        for (int k=0; k<numElems; ++k) {
            result1[k] = result[k];
        }

        dst = vertexDst + i*numElems;
        memcpy(dst, result1, numElems*sizeof(float));
    }
}

}  // end namespace Osd

}  // end namespace OPENSUBDIV_VERSION
using namespace OPENSUBDIV_VERSION;

}  // end namespace OpenSubdiv

#endif  // OPENSUBDIV3_OSD_CPU_KERNEL_H