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foundation.blas_integration

Module Path

zigllama.foundation.blas_integration

Source file: src/foundation/blas_integration.zig

Internal module. This API may change between releases.

Public Types

BlasInterface

pub const BlasInterface = struct {
    // Level 1 (vector-vector)
    dotFn:  *const fn (n: usize, x: [*]const f32, y: [*]const f32) f32,
    axpyFn: *const fn (n: usize, alpha: f32, x: [*]const f32, y: [*]f32) void,
    scalFn: *const fn (n: usize, alpha: f32, x: [*]f32) void,
    nrm2Fn: *const fn (n: usize, x: [*]const f32) f32,

    // Level 2 (matrix-vector)
    gemvFn: *const fn (
        m: usize, n: usize, alpha: f32,
        a: [*]const f32, lda: usize,
        x: [*]const f32, beta: f32,
        y: [*]f32,
    ) void,

    // Level 3 (matrix-matrix)
    gemmFn: *const fn (
        m: usize, n: usize, k: usize,
        alpha: f32,
        a: [*]const f32, lda: usize,
        b: [*]const f32, ldb: usize,
        beta: f32,
        c: [*]f32, ldc: usize,
    ) void,
};

Virtual function table that abstracts over different BLAS providers. Allows ZigLlama to dispatch to a native BLAS library at runtime without compile-time coupling.

GenericBlas

Pure-Zig fallback implementation of BlasInterface. Used when no external BLAS library is available. Provides correct results but without hand-tuned assembly kernels.

OpenBlas

Implementation of BlasInterface that forwards calls to OpenBLAS via the C ABI. Detected and linked at build time through build.zig.

BlasManager

pub const BlasManager = struct {
    backend: BlasInterface,
    thread_count: usize,
};

Singleton-like coordinator that selects the best available BLAS backend and configures thread counts. Retrieved via BlasManager.global().

Public Functions

Level 1 -- Vector-Vector

pub fn dot(blas: BlasInterface, n: usize, x: [*]const f32, y: [*]const f32) f32
pub fn axpy(blas: BlasInterface, n: usize, alpha: f32, x: [*]const f32, y: [*]f32) void
pub fn scal(blas: BlasInterface, n: usize, alpha: f32, x: [*]f32) void
pub fn nrm2(blas: BlasInterface, n: usize, x: [*]const f32) f32

Standard BLAS Level 1 operations: dot product, scaled addition, scaling, and Euclidean norm.

Level 2 -- Matrix-Vector

pub fn gemv(
    blas: BlasInterface,
    m: usize, n: usize,
    alpha: f32, a: [*]const f32, lda: usize,
    x: [*]const f32,
    beta: f32, y: [*]f32,
) void

General matrix-vector multiply: y = alpha * A * x + beta * y.

Level 3 -- Matrix-Matrix

pub fn gemm(
    blas: BlasInterface,
    m: usize, n: usize, k: usize,
    alpha: f32, a: [*]const f32, lda: usize,
    b: [*]const f32, ldb: usize,
    beta: f32, c: [*]f32, ldc: usize,
) void

General matrix-matrix multiply: C = alpha * A * B + beta * C.

Error Types

BLAS functions do not return errors. Invalid inputs (e.g., mismatched dimensions) cause undefined behavior, matching standard BLAS conventions. Callers must validate shapes before invoking these routines.

Usage Example

const blas = @import("zigllama").foundation.blas_integration;

const mgr = blas.BlasManager.global();

// Dot product of two 1024-element vectors
const result = blas.dot(mgr.backend, 1024, x_ptr, y_ptr);