Struct ExternalBlasBackend 

pub struct ExternalBlasBackend { /* private fields */ }

Conversion rules for row-major data to column-major BLAS:

Goal: Compute C = A * B where:

• A is m×k (row-major)
• B is k×n (row-major)
• C is m×n (row-major)

Row-major to column-major interpretation:

• Row-major A (m×k) appears as A^T (k×m) in column-major → call this At
• Row-major B (k×n) appears as B^T (n×k) in column-major → call this Bt
• Row-major C (m×n) appears as C^T (n×m) in column-major → call this Ct
• To compute C = A * B, we need: C^T = (A * B)^T = B^T * A^T
• So: Ct = Bt * At

BLAS call transformation:

• Original: C = A * B (row-major world)
• BLAS call: Ct = Bt * At (column-major world)
• transa = ‘N’ (Bt is already transposed-looking, no transpose needed)
• transb = ‘N’ (At is already transposed-looking, no transpose needed)
• Call: dgemm(‘N’, ‘N’, n, m, k, alpha, B, lda, A, ldb, beta, C, ldc)

Dimension conversions:

• m_blas = n (Ct rows = Bt rows)
• n_blas = m (Ct cols = At cols)
• k_blas = k (common dimension)
• lda = n (leading dimension of Bt: n×k in column-major, lda = n)
• ldb = k (leading dimension of At: k×m in column-major, ldb = k)
• ldc = n (leading dimension of Ct: n×m in column-major, ldc = n) External BLAS backend (LP64: 32-bit integers)

Implementations

impl ExternalBlasBackend

pub fn new(dgemm: DgemmFnPtr, zgemm: ZgemmFnPtr) -> Self

Trait Implementations

impl GemmBackend for ExternalBlasBackend

unsafe fn dgemm( &self, m: usize, n: usize, k: usize, a: *const f64, b: *const f64, c: *mut f64, )

Matrix multiplication: C = A * B (f64)

unsafe fn zgemm( &self, m: usize, n: usize, k: usize, a: *const Complex<f64>, b: *const Complex<f64>, c: *mut Complex<f64>, )

Matrix multiplication: C = A * B (Complex)

fn name(&self) -> &'static str

Returns backend name for debugging

fn is_ilp64(&self) -> bool

Returns true if this backend uses 64-bit integers (ILP64)