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PLAPACK calls

PLAPACK provides two more levels of level-3 BLAS: the local level-3 BLAS and the global level-3 BLAS, with identical parameter sequences. For the general matrix-matrix multiply, the calling sequences are given by place HR here

figure8453

figure8457

figure8460

place HR here Parameters TRANSA and TRANSB have been replaced by integers transa and transb, which can take on the values indicated in Table gif. All other parameters are now passed as part of linear algebra objects alpha, a, b, beta, and c.

Local call:

When a node calls PLA_Local_gemm, the operation is equivalent to extracting the local information (datatype, dimensions, and pointer to the buffer) and locally performing the general matrix-matrix multiply. The local dimensions of alpha and beta must be tex2html_wrap_inline14692 , but they can be of any object type. The local dimensions of a, b, and c must be such that the operation is well-defined. All objects must have the same datatype. To best understand the operation of this call, see the sample implementation given in Figure gif.

PLACE BEGIN HR HERE

figure9441

PLACE END HR HERE

Notice: no communication is performed as part of this call. Thus, all information must be locally available.

Global call:

All nodes must simultaneously call PLA_Gemm, which performs the BLAS call on the distributed objects. Parameters transa and transb still have the same meaning. Parameters alpha and beta must now be tex2html_wrap_inline14694 multiscalars. Parameters a, b, and c must all be of object type matrix. The global dimensions of the different objects must be such that the operation is well-defined.

PLACE BEGIN HR HERE [tbp]

tabular8494

PLACE BEGIN HR HERE

Valid values for integer parameters side, uplo, trans, transa, transb, and diag.

PLACE END HR HERE


next up previous contents
Next: Symmetric Matrix-Matrix Multiplication Up: General Matrix-Matrix Multiplication Previous: PLAPACK FORTRAN-C interface

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