helper_launch.h

#pragma once
// from pytorch.aten
#include "tensorview.h"
namespace tv
{
namespace launch
{

template <typename T1, typename T2>
inline int DivUp(const T1 a, const T2 b) { return (a + b - 1) / b; }

// Use 1024 threads per block, which requires cuda sm_2x or above
constexpr int CUDA_NUM_THREADS = 1024;
// CUDA: number of blocks for threads.
inline int getBlocks(const int N)
{
    TV_ASSERT_RT_ERR(N > 0, "CUDA kernel launch blocks must be positive, but got N=", N);
    return DivUp(N, CUDA_NUM_THREADS);
}
} // namespace launch
} // namespace tv