Technical data

Glossary
vector instruction: A native computer instruction that recognizes a vector as
a native data structure and that can operate on all the elements of a vector
concurrently.
vector length register (VLR): A 7-bit register that controls the number of
elements used in the vector registers, from 0 to 64.
vector load: To move data from memory to the vector registers. For example,
the VLDx command moves data to the vector registers.
vector mask register (VMR): A 64-bit register that enables and disables the
use of individual elements within a vector register.
vector operand: A string of scalar data items with the same data type that
are processed in a single operation.
vector processor: A processor that operates on vectors, making use of
pipelines that overlap key functional operations and performing the same
operations repeatedly, to achieve high processing speeds.
vector processing: Execution of vector operations on a vector processor. A
single vector operation is capable of modifying each element in a vector
operand concurrently.
vector register: A high-speed buffer contained in the vector processor’s
CPU, consisting of word- or address-length bit sequences that are directly
accessible by the processor. A VAX vector register can hold 64 elements of
64 bits each.
vectorizable: Capable of being converted to code that can be processed on a
vector processor.
vectorization: Part of the compilation process that prepares a section of source
code for vector processing.
vectorization factor: In a program, the fraction of code that can be converted
to run on a vector processor. For example, a program with a vectorization
factor above 70% will perform well on a system that has a vector processor.
vector-scalar operation: An operation such as add, subtract, and so forth, in
which a scalar number operates with each element of a vector register and
places results in matching elements of another vector register.
Glossary–6