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PLAPACK calls

   

PLAPACK provides two more layers of level-1 BLAS: the local level-1 BLAS and the global level-1 BLAS, with identical parameter sequences. For the copy, the calling sequences are given by place HR here

figure5662

figure5666

figure5669

place HR here The data type of the operands and parameters like vector length and stride are now passed as part of linear algebra objects x and y.

Local call:

When a node calls PLA_Local_copy, the operation is equivalent to extracting the local information (data type, length, stride, and pointer to the buffers) and locally performing the copy. The object type can be any valid PLAPACK object type. Moreover, the local copy can also copy two dimensional objects (multiscalars, (projected) (duplicated) multivectors and matrices). The local dimensions of x, and y must be such that the operation is well-defined (i.e., local dimensions match). All objects must have the same data type. To best understand the operation of this call, see the sample implementation given in Figure gif .

PLACE BEGIN HR HERE

figure6353

PLACE END HR HERE

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

Global call:

The global PLA_Copy call is our primary means for communication. It is discussed in great detail in Chapter gif.

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