Initializes block processing. Because the size of the CPU cache is limited, significant performance gains can be obtained by splitting long vectors in to a series of short ones, which can all fit in the CPU cache entirely. The BlockInit method is to be used together with BlockNext and methods to initialize a block processing while loop. BlockInit will call to obtain subrange of the data in TVecInt. The Length of the subranged vector is determined by the global Math387.MtxVecBlockSize variable declared in unit. Default value of MtxVecBlockSize is preset to 800 vector elements for double precision and 1600 elements for single precision. BlockInit supports nested calls and from witihin a blocked while loop you can call procedures and functions which are also blocked. If you use block processing, typical performance gains will range from 2 to a maximum of 6. Block processing can not be used, or it is difficult to apply, in cases where vector elements are not independent of each other. The block processing while loop must be written like this: 

The differences with block processing will be more noticable on older CPU's without support for SSE2/SSE3/SSE4/AVX when using FPU instructions.

BlockNext, BlockEnd

BlockInit Method