Data processing system incorporating a logical compare instruction
AssigneeHoneywell Information Systems Inc.
InventorCharles W. Bachman
Life of this patent
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Abstract
An apparatus for utilizing a logical compare instruction is disclosed. The apparatus develops a data field descriptor associated with and describing the attributes of each of the operands of the compare instruction. If the operands have different formats, when matching the contents of a first operand to the contents of a second operand, one operand is converted at execution time of the compare instruction to a format consistent with the other operand. The apparatus determines whether the contents of the first operand is greater than, less than, or equal to the second operand.
Claims13
An apparatus for comparing data fields having a plurality of different data structures, said apparatus comprising:
- memory means for storing signals which represent a compare instruction, said signals including a first, second, and third group;
- first means responsive to said first group for providing a first data field descriptor associated with a first data field, said first data field descriptor describing at least the data type and length of said first data field;
- second means responsive to said second group for providing a second data field descriptor associated with a second data field, said second data field descriptor describing at least the data type and length of said second data field;
- third means coupled to said first and said second means and responsive to said third group for comparing said first data field to said second data field, said third means including:
- fourth means responsive to said first means for determining the data type of said first data field;
- fifth means responsive to said second and said fourth means for comparing the data types of said first and second said data fields and for providing an indicating signal when they are different;
- sixth means responsive to said indicating signal for reformatting the data types of said first and said second data fields such that they are the same data type;
- seventh means responsive to said fifth and said sixth means for comparing said data fields and providing an output signal which indicates the relationship between said data fields.
An apparatus for comparing a first data field having a first embodiment to a second data field having a second embodiment, said apparatus comprising:
- first means for describing the location and attributes of said first data field having said first embodiment,
- second means for describing the location and attributes of said second data field having said second embodiment, and
- third means for comparing said first data field with said second data field, said third means including:
- fourth means responsive to said first and second means for determining attributes of said first and second embodiments,
- fifth means responsive to said fourth means for testing whether the attributes of said first and said second data fields are the same,
- sixth means responsive to said fifth means when said attributes are not the same for reformatting said data fields so that said attributes are the same,
- seventh means responsive to said fifth and said sixth means for comparing said data fields when said attributes are the same.
Dependencies are inferred from the claim text.