# herumi/xbyak

A JIT assembler for x86/x64 architectures supporting FPU, MMX, SSE (1-4), AVX (1-2, 512), APX, and AVX10.2

Repository: https://github.com/herumi/xbyak
Canonical: https://ross.abutalabs.com/products/xbyak
Language: C
License: BSD-3-Clause
License Family: permissive
Topics: assembler, jit, x86-64
Last push: 2026-08-26T05:47:21+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 5984, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2269, forks 311 (observed 2026-08-28T04:06:33.008796+00:00)

## What it is
Xbyak is a C++ header-only JIT assembler for generating x86/x64 machine code at runtime using Intel/MASM-like mnemonics. It supports instruction sets up to AVX-512, APX, and AVX10.2.

## Use cases
- generate x86 machine code at runtime
- build a JIT compiler for x86-64
- emit AVX-512 instructions dynamically
- assemble instructions programmatically in C++
- runtime code generation for a numerical kernel
- write a dynamic binary translator backend

## When to choose
- you need fast runtime x86/x64 code generation from C++
- you require cutting-edge instruction sets like AVX10.2 or APX
- you want a header-only dependency with no build step

## When to avoid
- you target non-x86 architectures (use Xbyak_aarch64 or Xbyak_riscv instead)
- you need a static assembler producing object files rather than JIT code
- your project is not C++

## Facets
- artifact type: library
- maturity: active
- function: compiler, developer-tools
- domain: developer-tools, performance, compilers
- platform: cpp, windows, cross-platform
- tags: jit-assembler, x86, x64, header-only, avx-512, apx, code-generation, runtime-codegen, linux, macos

## Member repositories
- herumi/xbyak (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:33.008796+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:41:59.244810+00:00, confidence not recorded.
  - readme: https://github.com/herumi/xbyak (fetched 2026-08-28T04:06:33.008796+00:00, sha bc17ed6b68e9)
- Data as of 2026-08-30T08:39:29.467469+00:00.