[QST]About how to create nested make_tiled_copy

[LANSHANGH]

What is your question?
TiledCopy copyA = make_tiled_copy(Copy_Atom<UniversalCopy<uint128_t>, TA>{}, make_layout(make_shape(Int<4>{}, (Int<8>{}, Int<4>{})), make_stride(Int<4>{}, Int<1>{})), // Thr layout 4x8x4 m-major make_layout(make_shape(Int<1>{}, Int<8>{}))); // Val layout 1x8 m-major
I want to create threads in order of 484, but the copyA of print is size 16.
please help me

[ccecka]

Formatted, you have

TiledCopy copyA = make_tiled_copy(Copy_Atom<UniversalCopy<uint128_t>, TA>{}, 
                                  make_layout(make_shape (Int<4>{}, (Int<8>{}, Int<4>{})), 
                                              make_stride(Int<4>{}, Int<1>{})),   // Thr layout 4x8x4 m-major 
                                  make_layout(make_shape(Int<1>{}, Int<8>{})));   // Val layout  1x8 m-major

which is an unfortunate C++ism as (Int<8>{},Int<4>{}) is a default comma-operator expression that evaluates to Int<4>{} rather than the tuple that it looks like.

You need the extra make_shape (with corrected comments and example strides):

TiledCopy copyA = make_tiled_copy(Copy_Atom<UniversalCopy<uint128_t>, TA>{}, 
                                  make_layout(make_shape (Int<4>{}, make_shape (Int<8>{}, Int< 4>{})), 
                                              make_stride(Int<8>{}, make_stride(Int<1>{}, Int<32>{}))),  // Thr layout 4x8x4 k-major interleave 
                                  make_layout(make_shape(Int<1>{}, Int<8>{})));   // Val layout  1x8 k-major

or more compactly:

TiledCopy copyA = make_tiled_copy(Copy_Atom<UniversalCopy<uint128_t>, TA>{}, 
                                  Layout<Shape <_4,Shape <_8, _4>>,
                                         Stride<_8,Stride<_1,_32>>>{},  // Thr layout 4x8x4 k-major interleave 
                                  Layout<Shape<_1,_8>>{});              // Val layout  1x8 k-major

[LANSHANGH]

@ccecka

Thanks for your reply, I think I know what the problem is, but I would like to know under what circumstances commas are used as comma operators in cutlass, because I generally think commas are used as delimiters, such as the separation of variables. Secondly, why does the stride length you described look so strange? Because I want to express that the thread configuration of 484 is 32,4,1. Thank you very much.

[ccecka]

The comma operator is C++ and CUTLASS does not change it:
https://en.wikipedia.org/wiki/Comma_operator
(3,4) is different than make_shape(3,4).

You can set the strides to whatever you like, of course.

[LANSHANGH]

Thanks for your help. I think I know the comma-operator.