Abstract: A functional-level instruction-set computing (FLIC) architecture executes higher-level functional instructions such as lookups and bit-compares of variable-length operands. Each FLIC processing-engine slice has specialized processing units including a lookup unit that searches for a matching entry in a lookup cache. Variable-length operands are stored in execution buffers. The operand length and location in the execution buffer are stored in fixed-length general-purpose registers (GPRs) that also store fixed-length operands. A copy/move unit moves data between input and output buffers and one or more FLIC processing-engine slices. Multiple contexts can each have a set of GPRs and execution buffers. An expansion buffer in a FLIC slice can be allocated to a context to expand that context's execution buffer for storing longer operands.