MULTIFUNCTION FLOATING POINT ADDITION/SUBTRACTION PIPELINE AND BIPARTITE LOOK-UP TABLE

摘要

An add/subtract pipeline has far and close data paths. The far data path handles effective addition operations, and effective subtraction operations for operands having an absolute exponent difference greater than one. The close data path handles all other effective subtraction operations. Selection of the output value in the close data path effectuates the round-to-nearest operation. Floating point-to-integer conversion may be executed in the far data path integer-to-floating point instructions in the close data path. The execution unit may include a pluraliy of add/subtract pipelines, allowing vectored add, subtract, and integer/floating point conversion instructions to be performed. Additional arithmetic instructions (such as reverse subtract and accumulate functions minimum/maximum and comparison) may also be implemented. A method for generating entries for a bipartite look-up table having base and difference table portions is also disclosed. So is a multi-function look-up table.