Naming Conventions for BLAS Routines

BLAS routine names have the following structure:

<character> <name> <mod> ( )

The <character> field indicates the data type:

s

real, single precision

c

complex, single precision

d

real, double precision

z

complex, double precision

Some routines and functions can have combined character codes, such as sc or dz.

For example, the function scasum uses a complex input array and returns a real value.

The <name> field, in BLAS level 1, indicates the operation type. For example, the BLAS level 1 routines ?dot, ?rot, ?swap compute a vector dot product, vector rotation, and vector swap, respectively.

In BLAS level 2 and 3, <name> reflects the matrix argument type:

ge

general matrix

gb

general band matrix

sy

symmetric matrix

sp

symmetric matrix (packed storage)

sb

symmetric band matrix

he

Hermitian matrix

hp

Hermitian matrix (packed storage)

hb

Hermitian band matrix

tr

triangular matrix

tp

triangular matrix (packed storage)

tb

triangular band matrix.

The <mod> field, if present, provides additional details of the operation. BLAS level 1 names can have the following characters in the <mod> field:

c

conjugated vector

u

unconjugated vector

g

Givens rotation construction

m

modified Givens rotation

mg

modified Givens rotation construction

BLAS level 2 names can have the following characters in the <mod> field:

mv

matrix-vector product

sv

solving a system of linear equations with a single unknown vector

r

rank-1 update of a matrix

r2

rank-2 update of a matrix.

BLAS level 3 names can have the following characters in the <mod> field:

mm

matrix-matrix product

sm

solving a system of linear equations with multiple unknown vectors

rk

rank-k update of a matrix

r2k

rank-2k update of a matrix.

The examples below illustrate how to interpret BLAS routine names:

ddot	<d> <dot>: double-precision real vector-vector dot product
cdotc	<c> <dot> <c>: complex vector-vector dot product, conjugated
scasum	<sc> <asum>: sum of magnitudes of vector elements, single precision real output and single precision complex input
cdotu	<c> <dot> <u>: vector-vector dot product, unconjugated, complex
sgemv	<s> <ge> <mv>: matrix-vector product, general matrix, single precision
ztrmm	<z> <tr> <mm>: matrix-matrix product, triangular matrix, double-precision complex.

Sparse BLAS level 1 naming conventions are similar to those of BLAS level 1. For more information, see Naming Conventions.