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Forked from ddemidov/hello.cpp
Last active August 29, 2015 13:55
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#include <vexcl/vexcl.hpp>
vex::vector<cl_float2>
hilbert(vex::vector<float> &in, std::size_t rows, std::size_t cols) {
// No need to pass context in:
const auto &ctx = in.queue_list();
// Use function instead of vector. Should save global memory IO.
VEX_FUNCTION(h, float(size_t/*prm1 = idx*/, size_t/*prm2 = rows*/),
VEX_STRINGIZE_SOURCE(
float v = prm1 > prm2 / 2 ? 0 : 2;
if (prm1 == 0) v = 1;
if (prm2 % 2 == 0 && prm1 == prm2 / 2) v = 1;
return v;
)
);
// FFT works on rows hence the swapped values for cols and rows
vex::FFT<float, cl_float2> fft(ctx, {cols, rows}, { vex::fft::none, vex::fft::forward }),
vex::FFT<cl_float2, cl_float2> ifft(ctx, {cols, rows}, { vex::fft::none, vex::fft::inverse })
// This way result will be initialized with proper queues (context):
vex::vector<cl_float2> result(ctx, rows * cols);
// Lots of reshaping needed due to row major matrix when working on columns.
// Is there a better way?
result = vex::reshape(
ifft(fft(vex::reshape(v, vex::extents[cols][rows], vex::extents[1][0])) *
vex::reshape(h(vex::element_index(), rows), vex::extents[cols][rows], vex::extents[1])
), vex::extents[rows][cols], vex::extents[1][0]
);
return result;
}
int main() {
vex::Context ctx(vex::Filter::Env && vex::Filter::Count(1));
std::cout << ctx << std::endl;
const size_t n = 1024;
const size_t m = 1;
vex::vector<float> x(ctx, n * m);
x = 1;
vex::vector<cl_float2> y = hilbert(x, m, n);
}
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