mlx/mlx/backend/common/slicing.cpp
Awni Hannun 9bd03dd9b4
More buffer donation with no-ops (#1591)
* more donation

* fix test

* fix build
2024-11-18 08:35:41 -08:00

41 lines
1.2 KiB
C++

// Copyright © 2024 Apple Inc.
#include "mlx/backend/common/utils.h"
namespace mlx::core {
std::tuple<bool, int64_t, std::vector<int64_t>> prepare_slice(
const array& in,
const std::vector<int>& start_indices,
const std::vector<int>& strides) {
int64_t data_offset = 0;
bool copy_needed = false;
std::vector<int64_t> inp_strides(in.ndim(), 0);
for (int i = 0; i < in.ndim(); ++i) {
data_offset += start_indices[i] * in.strides()[i];
inp_strides[i] = in.strides()[i] * strides[i];
copy_needed |= strides[i] < 0;
}
return std::make_tuple(copy_needed, data_offset, inp_strides);
}
void shared_buffer_slice(
const array& in,
const std::vector<size_t>& out_strides,
size_t data_offset,
size_t data_size,
array& out) {
// Compute row/col contiguity
auto [no_bsx_size, is_row_contiguous, is_col_contiguous] =
check_contiguity(out.shape(), out_strides);
auto flags = in.flags();
flags.row_contiguous = is_row_contiguous;
flags.col_contiguous = is_col_contiguous;
flags.contiguous = (no_bsx_size == data_size);
move_or_copy(in, out, out_strides, flags, data_size, data_offset);
}
} // namespace mlx::core