Patent ID: 7500233

Claim:
A computer-implemented method for determining program execution flow by comparing a first sub-variable that is part of a first variable with a second sub-variable that is part of a second variable, the method comprising: creating a first binary representation of the first variable resulting in the first variable comprising binary bits, wherein the first sub-variable comprises a first binary carryout bit; creating a second binary representation of the second variable resulting in the second variable comprising binary bits, wherein the second sub-variable comprises a second binary carryout bit; creating a masking constant and an additive constant; inverting each bit of the first sub-variable and the masking constant; combining the inverted masking constant with the inverted first variable to produce a first result; adding the additive constant to the first result to produce a second result; combining the second result with the inverted masking constant to produce a third variable, wherein the first binary carryout bit is converted to 0 if the adding of the additive constant to the first result caused the first binary carryout bit to become 1; adding the third variable to the second variable to produce a fourth result; determining a value of a third binary carryout bit associated with the fourth result by combining the fourth result with the masking constant; and determining whether to perform an operation based on the value of the third binary carryout bit.