LIBXS is a portable C library providing building blocks for memory operations, numerics, synchronization, and more — with a focus on performance and minimal dependencies. Targets x86-64, AArch64, and RISC-V; requires only a C89 compiler. Originally developed as part of LIBXSMM.
| Domain | Header | Description |
|---|---|---|
| Registry | libxs_reg.h |
Thread-safe key-value store |
| Predict | libxs_predict.h |
Fingerprint-guided parameter prediction |
| Malloc | libxs_malloc.h |
Pool allocator (no system calls at steady) |
| Memory | libxs_mem.h |
Byte compare, matrix copy/transpose |
| String | libxs_str.h |
Edit distance, substring, similarity |
| Token | libxs_token.h |
Fixed-width 8-byte tokenizer |
| Timer | libxs_timer.h |
High-resolution timing via calibrated TSC |
| CPUID | libxs_cpuid.h |
CPU feature detection (SSE..AVX-512, etc.) |
| Utils | libxs_utils.h |
ISA gates, bit-scan, SIMD helpers |
| Sync | libxs_sync.h |
Portable atomics, locks, TLS, file locks |
| GEMM | libxs_gemm.h |
Batched dense GEMM (strided, grouped) |
| Math | libxs_math.h |
Matrix compare, GCD/LCM, BF16 conversion |
| Hash | libxs_hash.h |
CRC32, Adler-32, string hashing |
| Perm | libxs_perm.h |
Shuffle, kd-tree, Hilbert/Morton curves |
| Hist | libxs_hist.h |
Thread-safe histogram, running statistics |
| MHD | libxs_mhd.h |
Read/write MetaImage (MHD/MHA) files |
| RNG | libxs_rng.h |
Pseudo-random generation (SplitMix64) |
See also: Fortran Interface, Scripts.
make GNU=1The library is compiled for SSE4.2 by default but dynamically
dispatches to the best ISA available at runtime (up to AVX-512).
Use SSE=0 to compile natively for the build host.
| Variable | Default | Description |
|---|---|---|
| GNU | 0 | Use GNU GCC-compatible compiler |
| DBG | 0 | Debug build |
| SYM | 0 | Include debug symbols (-g) |
| SSE | 1 | x86 baseline: 0=native, 1=SSE4.2 (portable) |
CMake is also supported (header-only or library):
cmake -S . -B build -DLIBXS_HEADER_ONLY=ON
cmake --build buildInstall into a chosen prefix:
make GNU=1 -j $(nproc) install PREFIX=$HOME/libxsThis installs headers, the Fortran module, the static and shared
libraries, and the header-only source tree under PREFIX.
Out-of-tree builds are also supported:
mkdir /tmp/libxs-build && cd /tmp/libxs-build
make -j $(nproc) -f /path/to/libxs/MakefileLibrary — link against libxs.a (or .so) and include the
desired headers:
#include <libxs/libxs_mem.h>
#include <libxs/libxs_timer.h>Header-only (explicit) — include libxs_source.h (no
separate library needed). Safe to include from multiple
translation units:
#include <libxs/libxs_source.h>Header-only (implicit) — compile with -DLIBXS_SOURCE and
any LIBXS public header automatically includes the implementation.
No special include order is required. When used through
LIBXSTREAM without a
pre-built library (-DLIBXSTREAM_SOURCE), LIBXS_SOURCE is
implied automatically.
Fortran — use the provided module (documentation):
USE :: libxs, ONLY: libxs_memcmp| Sample | Description |
|---|---|
| tokenizer | Reversible byte-level tokenizer |
| converse | Extractive summarization via tokenized fprints |
| registry | Registry dispatch microbenchmark |
| predict | Fingerprint-guided parameter prediction |
| rosetta | Hierarchical type discovery on opaque data |
| setdiff | Deterministic set-difference tolerance |
| shuffle | Shuffling strategies comparison |
| scratch | Pool allocator vs system malloc |
| spatial | Stratification, pair counting, kd-tree |
| fprint | Foeppl fingerprint structure/geometry tests |
| memory | Byte comparison, matrix copy, transpose |
| ozaki | Ozaki-scheme low-precision GEMM |
| gemm | Batched DGEMM (strided, pointer, grouped) |
| syrk | Symmetric rank-k/2k update with validation |
| sync | Lock implementation microbenchmarks |