| 摘要 |
Performing parallel comparisons of variables to determine program code execution flow or to compare multiple variables is disclosed. Memory locations are packed with multiple sub-variables for comparison to sub-variables generated, for example, at runtime. Each binary sub-variable includes a "carryout" bit used to determine whether a comparison of one sub-variable with another sub-variable results in a "true" or a "false." A modified version of twos complement arithmetic is performed on a set of sub-variables and may be completed at runtime or earlier. The modified version involves inverting each bit of the sub-variables, performing a masking operation to change the carryout bits to 0, adding a binary 1 to each sub-variable, and performing the masking operation a second time to change the carryout bits to 0. The result of this calculation may be stored in a separate memory location for future comparisons. At the time of comparing sub-variables, the result of the modified twos complement arithmetic is added to a variable, and the carryout bit of each sub-variable of the resulting variable is evaluated to determine results of the comparisons.
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