budiony d81d0d8fb9 Multi-column on Intel XMX matrix engines refactored (#29864)
* Multi-column on Intel XMX matrix engines refactored

Multi-column (2 to 80 activation columns) mul_mat_vec_q for reordered K-quant and Q8_0 weights on the Intel XMX matrix engines (int8 DPAS, ESIMD), for the SYCL backend. It targets speculative decoding verification (2 to 8 tokens per step) and short prompt batches (9 to 80 tokens). Three types also use it for a single column (Q2_K, Q3_K, Q8_0).

* Fixed regression bug

real bug found: the first version produced NaN whenever the row count wasn't a multiple of 4

* Removed GGML_TYPE_Q8_0 activation

* rewritten xmx_mul_mat

64-byte alignment and 16-byte pitch check on the activations

* Implemented fused gate/up kernel

One launch computes up * act(gate) for both FFN weights, reading the activations once and applying SWIGLU or GEGLU in the epilogue. It covers up to 16 columns and works for all six XMX types.

* Removed the temporary XMX_NOGLU environment switch

* Q2_K min-sum optimization

Q2_K weight is d·scl·q − dmin·mc, where scl (the 4-bit scale) and mc (the 4-bit min code) apply to each half of a 32-weight group

* Added dispatch check and GRF sweep

tg128 on Q4_K_M goes from 26.67 to 28.23 tok/s on the B70 (+5.9%).
Q6_K is unchanged.
MUL_MAT passes 1727/1727 and MUL_MAT_VEC_FUSION 1361/1361.
Perplexity at batch 1 is 5.2064 with XMX and 5.2058 without.

* Renamed variables

* Added 2 environment variables

GGML_SYCL_XMX_MAX_COLS (default 80, any value 0 or higher) and GGML_SYCL_XMX_GLU_MAX_COLS (default 16, range 0 to 16):  the largest batch for the fused gate/up kernel. It is clamped to 16 because that is the most the fused kernel is compiled for, so the variable can only lower it.

* Update esimd.hpp

1. All five quant structs were repeating the same boilerplate, so I moved it into shared pieces.

2. A new helper xmx_term does one DPAS, converts it to float and scales it per row. The four branches are now one or two lines each, and the shared Cb += z * d8r is written once.

The refactor passes all three op tests. MUL_MAT_VEC_FUSION is 1369/1369, MUL_MAT is 2281/2281 (the count includes your uncommitted f32 tests) and MUL_MAT_ID is 937/937.
2026-10-22 21:39:01 +08:00
2026-06-12 15:53:26 +02:00
2026-10-17 02:11:56 +02:00
2026-02-02 08:38:55 +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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