bri-prism b86d2f0754 cuda: FWHT kernels for block widths above 512 (#29100)
The CUDA FWHT covers widths 64 to 512. It runs one row per warp and keeps N/32
values per lane, so wider blocks need more registers per lane than that layout
allows.

fwht_cuda_block runs one row per thread block with 256 threads, so each thread
keeps N/256 values. Stages below the warp width still shuffle, those up to the
block width go through shared memory, and the rest stay in registers. Same
butterfly and sign convention as the warp kernel.

Widths 64 to 512 keep the warp kernel. 1024 through 8192 use the new one, for
both F32 and F16 sources. ggml_cuda_op_mul_mat_use_fwht (the shared
supports_op/dispatch predicate added in #29096) does not check width, so it
needed no change here: any width it admits that ggml_cuda_op_fwht can't serve
already falls through correctly to the cuBLAS path.

Rebased onto current master with #29096's F16 commit underneath it, since this
depends on the same F16 template infrastructure; that commit applied cleanly,
the only conflict was in test-backend-ops.cpp where an unrelated intervening
commit's own test additions landed near this block.

test-backend-ops on an A10 (lambdalabs): MUL_MAT 1297/1297, including all
FWHT/Hadamard cases (18 existing, 4 new F32 wide, 4 new F16 wide, 2 new
many-rows, 1 too-big boundary moved to 16384).
2026-10-07 20:56:18 +02:00
2026-06-12 15:53:26 +02:00
2026-10-04 21:38:19 +05:30
2026-02-02 08:38:55 +02:00
2026-09-09 15:56:27 +02:00

llama.cpp

llama

Quick start

A few options to get llama.cpp installed on your machine:

# curl
curl -LsSf https://llama.app/install.sh | sh

# powershell
irm https://llama.app/install.ps1 | iex

Once installed:

# Download and run a model directly from Hugging Face
llama cli -hf ggml-org/Qwen3.5-0.8B-GGUF

# Launch OpenAI-compatible API server
llama serve -hf ggml-org/Qwen3.5-0.8B-GGUF
VLM session with `llama cli` VLM session with llama cli Built-in web UI against `llama serve` running Qwen 3.6 Built-in web UI against llama serve

Description

The main goal of llama.cpp is to enable LLM (and VLM) inference with minimal setup and state-of-the-art performance on a wide range of hardware - locally and in the cloud.

  • Plain C/C++ implementation without any dependencies
  • Apple silicon is a first-class citizen - optimized via ARM NEON, Accelerate and Metal frameworks
  • AVX, AVX2, AVX512 and AMX support for x86 architectures
  • RVV, ZVFH, ZFH, ZICBOP and ZIHINTPAUSE support for RISC-V architectures
  • 1.5-bit, 2-bit, 3-bit, 4-bit, 5-bit, 6-bit, and 8-bit integer quantization for faster inference and reduced memory use
  • Custom CUDA kernels for running LLMs on NVIDIA GPUs (support for AMD GPUs via HIP and Moore Threads GPUs via MUSA)
  • Vulkan and SYCL backend support
  • CPU+GPU hybrid inference to partially accelerate models larger than the total VRAM capacity

The llama.cpp project is build on top of the ggml library.

Supported backends

Backend Target devices
BLAS All
BLIS All
CANN Ascend NPU
CUDA Nvidia GPU
HIP AMD GPU
Hexagon Snapdragon
IBM zDNN IBM Z & LinuxONE
MUSA Moore Threads GPU
Metal Apple Silicon
OpenCL Adreno GPU
OpenVINO [In Progress] Intel CPUs, GPUs, and NPUs
RPC All
SYCL Intel GPU
VirtGPU VirtGPU APIR
Vulkan GPU
WebGPU All
ZenDNN AMD CPU

Documentation

Tools

Development

Contributing

  • Contributors can open PRs
  • Collaborators will be invited based on contributions
  • Maintainers can push to branches in the llama.cpp repo and merge PRs into the master branch
  • Any help with managing issues, PRs and projects is very appreciated!
  • Read the CONTRIBUTING.md for more information

Acknowledgements

  • yhirose/cpp-httplib - Single-header HTTP server, used by llama-server - MIT license
  • nothings/stb - Single-header image format decoder, used by multimodal subsystem - Public domain
  • nlohmann/json - Single-header JSON library, used by various tools/examples - MIT License
  • mackron/miniaudio - Single-header audio format decoder, used by multimodal subsystem - Public domain
  • sheredom/subprocess.h - Single-header process launching solution for C and C++ - Public domain
S
Description
llama.cpp fork with AVX1, NUMA, SM75 Turing, and FastMTP optimizations
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