データ定義の最適化
Defining data items appropriately and aligning them to give the best performance.
算術文の最適化
Arithmetic statements, for which simple two-operand statements are the most efficient.
COMPUTE 文の最適化
COMPUTE statements, which are for floating-point calculations.
小数点の配置の最適化
Decimal point alignment. For operations on non-integer numbers, make the decimal point alignment of the operands match.
指数演算の最適化
Exponential operations, some of which are optimized. For others, use MULTIPLY and DIVIDE.
データ項目の初期化の最適化
Data item initialization. By default, COBOL initializes all data items in the Working-Storage Section to spaces if no VALUE clause is specified.
データ操作と部分参照の最適化
Data manipulation and reference modification, and how to use the MOVE, INITIALIZE, STRING and UNSTRING statements.
表操作の最適化
Handling tables. For example, make each subscript a COMP-5 item of the smallest optimum size for the values involved, and use the BOUND directive only when debugging.
論理演算の最適化
Logical operations, such as AND, OR and XOR. These are, if possible, optimized to produce in-line code.
PERFORM 文の最適化
PERFORM statements. These are generally very efficient, although you can increase their performance in a number of ways.
CALL 文の最適化
CALL statements. For example, to use these efficiently, call the program using a literal rather than a data-name, limit the number of CALL statements, and so on.
パラメータ処理の最適化
Passing parameters. For example. avoid making many references to linkage items.