ggml-org/llama.cpp b12143

on GitHub

vulkan: FWHT kernels for block widths above 512 (#29772)

• vulkan: add F16 input to the FWHT

The Vulkan FWHT accepts F32 input only. This adds an F16 source variant of the
shader, for both the subgroup and the shared-memory paths, so the kernel reads
an F16 source directly instead of requiring a converted copy.

The F16 shader needs shader-float16, so the pipelines are only created when the
device reports it. A null pipeline makes ggml_vk_can_use_fwht fall back, which
is the same path an unsupported width already takes.

supports_op and the dispatch both already route through ggml_vk_can_use_fwht,
so there is a single place asking whether an op qualifies; nothing to
consolidate here the way the CUDA/Metal ports needed.

test-backend-ops on an M5 Pro (MoltenVK, fp16: 1): MUL_MAT 1128/1128,
including all 24 Hadamard cases (18 existing F32, 6 new F16).

Assisted-by: Codex

• vulkan: FWHT kernels for block widths above 512

The Vulkan FWHT covers block widths 64 to 512; wider blocks fall back to the
dense matmul. Extend the width list to 8192 and pick the shader per width: the
subgroup shader keeps n/subgroup_size values per invocation, so widths above
512 (or a subgroup narrow enough to exceed 64 values per invocation) use the
shared-memory shader with one row per workgroup and a 256-wide block. The rows
per workgroup become a specialization constant so the dispatch matches.

Pipelines for a width are only created when the device's shared-memory and
workgroup-invocation limits allow it; otherwise that width keeps the fallback.

This is the Vulkan counterpart to #29100 (CUDA). Stacked on #29101; the last
commit is the one to review.

Assisted-by: Codex