Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

  • 0.10
  • 10/21/2020
  • Public Content
Contents

Vector Arguments

Compressed sparse vectors.
 Let
a
 be a vector stored in an array, and assume that the only non-zero elements of
a
 are the following: 
a[k
1
], a[k
2
], a[k
3
] . . . a[k
nz
],
where
nz
 is the total number of non-zero elements in
a
.
In Sparse BLAS, this vector can be represented in compressed form by two arrays,
x
 (values) and
indx
 (indices). Each array has
nz
 elements: 
x[0]=a[k
1
], x[1]=a[k
2
], . . . x[nz-1]= a[k
nz
], 
indx[0]=k
1
, indx[1]=k
2
, . . . indx[nz-1]= k
nz
.
Thus, a sparse vector is fully determined by the triple (
nz
,
x
,
indx
). If you pass a negative or zero value of
nz
 to Sparse BLAS, the subroutines do not modify any arrays or variables.
Full-storage vectors.
 Sparse BLAS routines can also use a vector argument fully stored in a single array (a full-storage vector). If
y
 is a full-storage vector, its elements must be stored contiguously: the first element in
y
[0]
, the second in
y
[1]
, and so on. This corresponds to an increment
incy
 = 1
 in BLAS Level 1. No increment value for full-storage vectors is passed as an argument to Sparse BLAS routines or functions.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804