ggml-org/llama.cpp b12250 on GitHub

Details

vulkan: add tiled-transpose concat shader for Qwen models (#30591)

vulkan: tiled transpose for dim-0 concat with a transposed source

The delta-net conv-state path does ggml_transpose() straight into a dim-0
ggml_concat(), so the generic concat kernel reads src1 with the transposed
stride, one element per thread, and neighbouring lanes land on different cache
lines. Stage a 32x32 tile through shared memory instead, which keeps both the
load and the store coalesced. 33 columns pads away the bank conflicts.

Gated narrowly: dim 0, 2D, unquantized 4-byte elements, contiguous src0/dst
rows, and src1 actually transposed. Everything else falls through to the
existing kernel.

Qwen3.6-35B-A3B on gfx1151/RADV, 30 gated-delta-net layers: the CONCAT op goes
11877 us -> 957 us, and pp2048 at ub2048 goes 1224 -> 1628 t/s. Generated text
is unchanged.

The approach follows the tiled transposed concat Gaetan Puleo wrote for the HIP
backend in his Strix Halo fork.

Co-Authored-By: Claude Opus 5 noreply@anthropic.com