Methods and apparatus for managing register free lists

An integrated circuit comprising:

• one or more floating point units;
• a floating point unit register file, operatively coupled to the one or more floating point units;
• built-in-self-test (BIST) logic operative to detect defective registers of the floating point unit register file prior to start-up of the one or more floating point units;
• and
• control logic, operative to:
• create a pre-startup register free list, prior to normal operation of at least one of the one or more floating point units, that comprises a list of registers devoid of defective registers detected by the BIST logic;
• and
• during normal operation of the one or more floating point units, employ the pre-startup register free list to select registers in the floating point unit register file for executing instructions for the one or more floating point units.