Avoid mixing integer and floating-point (REAL) data in the same computation. Expressing all numbers in a floating-point arithmetic expression (assignment statement) as floating-point values eliminates the need to convert data between fixed and floating-point formats. Expressing all numbers in an integer arithmetic expression as integer values also achieves this. This improves run-time performance.
For example, assuming that I and J are both INTEGER variables, expressing a constant number (2.) as an integer value (2) eliminates the need to convert the data. The following examples demonstrate inefficient and efficient code.
Example: Inefficient Code |
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INTEGER I, J |
Example: Inefficient Code |
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INTEGER I, J |
You can use different sizes of the same general data type in an expression with minimal or no effect on run-time performance. For example, using REAL, DOUBLE PRECISION, and COMPLEX floating-point numbers in the same floating-point arithmetic expression has minimal or no effect on run-time performance. However, this practice of mixing different sizes of the same general data type in an expression can lead to unexpected results due to operations being performed in a lower precision than desired.