For the complete documentation index, see llms.txt. Markdown versions of all pages are available by appending .md to any URL (e.g. /max/get-started.md).

Mojo function

memcpy_or_fuse

def memcpy_or_fuse[rank: Int, dtype: DType, epilogue_fn: Optional[def[c_type: DType, rank: Int, width: SIMDLength = SIMDLength(1), *, alignment: Int = Int(1)](IndexList[rank], SIMD[c_type, width]) capturing thin -> None]](dest_data: Pointer[Int8, _safe=False], out_byte_offset: Int, src_data: Pointer[Int8, _safe=False], n: Int, out_shape: IndexList[rank, element_type=out_shape.element_type])

Copies n bytes from src_data into dest_data at out_byte_offset, applying epilogue_fn elementwise when present.

When no epilogue function is supplied, this performs a plain memcpy of n bytes. When an epilogue function is supplied, the source bytes are reinterpreted as typed elements and the epilogue is applied scalar-by-scalar so that fused concat can transform values while copying them into the output buffer.

Parameters:

rank (Int): Number of dimensions in the output tensor used for epilogue indexing.
dtype (DType): Element type of the tensors being copied.
epilogue_fn (Optional[def[c_type: DType, rank: Int, width: SIMDLength = SIMDLength(1), *, alignment: Int = Int(1)](IndexList[rank], SIMD[c_type, width]) capturing thin -> None]): Optional elementwise function applied to each copied element; when absent, a plain byte memcpy is performed.

Args:

dest_data (Pointer[Int8, _safe=False]): Destination byte buffer to write into.
out_byte_offset (Int): Byte offset into dest_data where the copy starts.
src_data (Pointer[Int8, _safe=False]): Source byte buffer to read from.
n (Int): Number of bytes to copy.
out_shape (IndexList[rank, element_type=out_shape.element_type]): Shape of the output tensor used to compute multi-dimensional indices for the epilogue function.