trnblas 0.3.0

BLAS operations for AWS Trainium via NKI

trnblas

BLAS operations for AWS Trainium via NKI (Neuron Kernel Interface).

Trainium ships no BLAS library. trnblas provides Level 1-3 BLAS operations with NKI kernel acceleration on the Tensor Engine, targeting scientific computing workloads that are GEMM-dominated.

Part of the trn-* scientific computing suite by Playground Logic.

Why

NVIDIA has cuBLAS with 152 optimized routines. Trainium has torch.matmul. That's fine for ML training but insufficient for scientific computing codes that need TRSM, SYRK, SYMM, and batched GEMM with specific transpose/scaling semantics.

trnblas closes this gap — same BLAS API surface, NKI-accelerated GEMM on Trainium, PyTorch fallback everywhere else.

Install

pip install trnblas

# With Neuron hardware support
pip install trnblas[neuron]

Usage

import torch
import trnblas

# Level 3 — Matrix multiply (the hot path)
C = trnblas.gemm(alpha=1.0, A=A, B=B, beta=0.5, C=C_init, transA=True)

# Batched GEMM (DF-MP2 tensor contractions)
C = trnblas.batched_gemm(1.0, A_batch, B_batch)

# Symmetric matrix multiply (Fock builds)
F = trnblas.symm(1.0, density, H_core, side="left")

# Triangular solve (Cholesky-based density fitting)
X = trnblas.trsm(1.0, L, B, uplo="lower")

# Symmetric rank-k update (metric construction)
J = trnblas.syrk(1.0, integrals, trans=True)

# Level 2 — Matrix-vector
y = trnblas.gemv(1.0, A, x, beta=1.0, y=y)

# Level 1 — Vector operations
y = trnblas.axpy(alpha, x, y)
d = trnblas.dot(x, y)
n = trnblas.nrm2(x)

DF-MP2 Example

# Run the density-fitted MP2 example (Janesko/TCU use case)
python examples/df_mp2.py --demo
python examples/df_mp2.py --nbasis 100 --nocc 20

The example demonstrates all core BLAS operations in a realistic quantum chemistry workflow: Cholesky factorization, triangular solve, half-transform GEMMs, metric contraction, and energy evaluation.

Operations

Level	Operation	Description
1	axpy	y = αx + y
1	dot	x^T y
1	nrm2	‖x‖₂
1	scal	x = αx
1	asum	Σ|xᵢ|
1	iamax	argmax |xᵢ|
2	gemv	y = α op(A) x + βy
2	symv	y = α A x + βy (A symmetric)
2	trmv	x = op(A) x (A triangular)
2	ger	A = α x yᵀ + A
3	gemm	C = α op(A) op(B) + βC
3	batched_gemm	Batched GEMM
3	symm	C = α A B + βC (A symmetric)
3	syrk	C = α A Aᵀ + βC
3	trsm	Solve op(A) X = αB
3	trmm	B = α op(A) B

Status

• Level 1-3 BLAS with PyTorch backend
• GEMM with NKI dispatch stub
• DF-MP2 example (Janesko/TCU use case)
• NKI GEMM kernel validation on trn1/trn2
• NKI GEMM with stationary tile reuse
• Batched GEMM NKI kernel
• Double-double FP64 emulation
• Benchmarks vs cuBLAS

Related Projects

Project	What
trnfft	FFT + complex ops for Trainium (Williamson/OSU use case)
trnsolver (planned)	Linear solvers and eigendecomposition

License

Apache 2.0 — Playground Logic LLC