Technique for determining if a logical sum of a first operand and a second operand is the same as a third operand

A method of comparing a logical sum of a first operand and second operand with a third operand, the method comprising:

• receiving a first operand by logic circuitry;
• receiving a second operand by the logic circuitry;
• receiving a length indication by the logic circuitry;
• and
• generating, by the logic circuitry, an indication of a match between a logical sum of the first operand and the second operand with a set of bits of a third operand, wherein the length of the set of bits is determined by the length indication;
• wherein the generating includes:
• performing a plurality of bit logic operations by the logic circuitry, wherein each bit logic operation on the plurality of bit logic operations corresponds to a bit position of a plurality of bit positions, wherein each of the plurality of bit logic operations includes performing a logic operation on a bit of the first operand of a corresponding bit location of the plurality of bit locations, a bit of a second operand of the corresponding bit location, and a bit of the third operand of the corresponding bit location to generate a result and comparing the result with a carry indication generated from a logic operation on bits including bits of an immediately less significant bit location from the corresponding bit location.

A content addressable memory, comprising:

• an input to receive a first operand;
• an input to receive a second operand;
• a plurality of storage locations;
• logic circuitry for providing a plurality of indications where each indication of the plurality of indications corresponds to a storage location of the plurality of storage locations, wherein each indication of the plurality of indications is an indication of a match between a logical sum of the first operand and the second operand with a set of bits of a value from a corresponding storage location of the plurality of storage locations;
• wherein for each indication of the plurality of indications, the logic circuit generates the indication of the match by performing a plurality of bit logic operations, wherein each of the plurality of bit logic operations includes a logic operation on a bit of the first operand of a corresponding bit location, a bit of a second operand of the corresponding bit location, and a bit of the corresponding bit location of a value from the corresponding storage location to generate a result and comparing the result to a carry indication generated from a logic operation on bits including bits of an immediately less significant bit location from the corresponding bit location, wherein each of the bit operations of the plurality is performed for a different corresponding bit location of a plurality of bit locations.