Look-up table read

A digital data processor comprising:

• an instruction memory configured to store instructions;
• an instruction decoder coupled to the instruction memory configured to sequentially recall and decode the instructions from the instruction memory;
• a memory configured to store tables;
• an intermediate register coupled to the memory;
• a butterfly network coupled to the intermediate register;
• a data register file that includes a destination register;
• and
• at least one operational unit coupled to the data register file and to the instruction decoder and configured to:
• perform a data processing operation based on an instruction decoded by the instruction decoder and store results of the data processing operation;
• and
• perform a table recall in response to a look up table read instruction that specifies the tables, a respective location in each of the tables, and the destination register by, for each of the tables:
• recalling, from the memory, a first data element stored at the respective location and a second data element stored at an adjacent location;
• causing the first data element and the second data element to be stored in the intermediate register in a first order;
• causing the butterfly network to reorder the first data element and the second data element to be in a second order;
• and
• causing the first data element and the second data element to be stored in the second order in successive slots in the destination register such that the first data element and the second data element include an extension of a number of elements based on a scaled promotion type.