Select first and select last instructions for processing vectors

A processor that executes a vector instruction, comprising:

• an execution unit, wherein the execution unit is configured to:
• receive a first input vector, a second input vector, and a control vector, and optionally receive a predicate vector, wherein each vector includes N elements;
• determine a key element position, wherein if the predicate vector is received, the key element position is a predetermined active element position in the predicate vector, otherwise, the key element position is a predetermined element position;
• and
• copy a result value into a result variable, wherein, if an element in the key element position of the control vector contains a predetermined value, the execution unit is configured to copy a value from the key element position in the second input vector into the result variable, otherwise, the execution unit is configured to copy a value from the key element position in the first input vector into the result variable.

A computer system that executes a vector instruction, comprising:

• a processor;
• a memory coupled to the processor, wherein the memory stores instructions and data for the processor;
• and
• an execution unit in the processor, wherein the execution unit is configured to:
• receive a first input vector, a second input vector, and a control vector, and optionally receive a predicate vector, wherein each vector includes N elements;
• determine a key element position, wherein if the predicate vector is received, the key element position is a predetermined active element position in the predicate vector, otherwise, the key element position is a predetermined element position;
• and
• copy a result value into a result variable, wherein, if an element in the key element position of the control vector contains a predetermined value, the execution unit is configured to copy a value from the key element position in the second input vector into the result variable, otherwise, the execution unit is configured to copy a value from the key element position in the first input vector into the result variable.