Alan Tseng 9f12cd4a4c ggml-cpu : add Q8_0 IME1 matrix kernel for SpacemiT X60 (#28479)
* ggml-cpu : add Q8_0 IME1 matrix kernel for SpacemiT X60

On the SpacemiT X60, IME matrix acceleration only covered Q4_0/Q4_1/Q4_K.
Q8_0 had no IME1 kernel, and since the SpacemiT build sets
GGML_CPU_REPACK=OFF there was no repack path compiled in either, so Q8_0
had no accelerated path at all and ran roughly ten times slower than
Q4_0 for prefill on the same board.

- add make_block_q8_0x16 and the Q8_0 repack entry: interleave the
  weights into the 16-column layout the IME1 vmadot sequence expects
- add ime1::gemm_kernel_i8i8, an int8 x int8 IME1 kernel with a
  single-row and a 4-row A path; the 4-row path loads each B panel once
  and reuses it across 4 rows of A
- add quantize_a_4row_i8 for the 4-row activation quantization
- wire both into forward_mul_mat and the repack factory for Q8_0
- docs: mark Q8_0 as supported on X60

Correctness was checked against a quant-exact integer reference for
K = 32 up to 4096, with a max relative error of about 1e-6, and by
checking that generation stays coherent across several prompts.

Tested on Milk-V Jupiter (SpacemiT X60), Bianbu 2.1.1, gcc 14.2, with
Qwen2.5-0.5B-Instruct Q8_0. llama-bench -t 4 under taskset -c 0-3, 5
repetitions on an idle board: pp128 goes from 10.70 to 93.87 t/s. Q4_0
is unchanged at 106.40 -> 107.51 t/s, as expected since this does not
touch that path.

* ggml-cpu : move q8_0_16x32 decl to IME1 section

* ggml-cpu : align q8_0 IME1 kernel assignments
2026-10-05 10:34:15 +03:00
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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