COBOL Manual for TNS/E Programs (H06.03+)

Procedure Division
HP COBOL Manual for TNS/E Programs—520347-003
8-44
Common Features of Arithmetic Statements
The composite of operands for a given operation is a fictitious data item. It has as
many positions in its integer portion (to the left of the decimal point) as the operand
that has the largest number of integer positions, and as many positions in its fraction
portion (to the right of the decimal point) as the operand that has the largest number of
fraction positions.
For example, in the data descriptions
01 A PIC S9(8)V9(4)
01 B PIC S9(2)V9(7)
01 C PIC S9(4)V9(9)
the composite of operands for an arithmetic operation involving only A, B, and C would
have a data description of S9(8)V9(9), or 17 digits.
The composite of operands for an arithmetic statement other than COMPUTE must not
exceed a size of 18 decimal digits. For arithmetic expressions or COMPUTE
statements, the composite of operands does not apply.
Intermediate Data Items
For each arithmetic operation, an intermediate data item holds the result value until
that value is either used as an operand in another operation or assigned to a receiving
data item. The size of the intermediate data item depends on the operations and data
items used in the operation and varies from 16 bits (about four digits) to 128 bits (about
39 digits). If the algebraic size of the result exceeds the capacity of this intermediate
data item, a binary, floating-point, intermediate data item is used and the compiler
issues warning 85. Because floating-point arithmetic has a maximum precision of 16
digits and often is not exact, the result might be incorrect in the rightmost digit or digits.
Multiple Results
The ADD, COMPUTE, DIVIDE, MULTIPLY, and SUBTRACT statements can have
multiple results from performing arithmetic necessary to arrive at the final result to be
stored in the receiving item. During execution, multiple results are the same as the
results produced by a sequence of statements that either combine the value of an
intermediate data item with a single result or transfer the value to a receiving item.
These statements are in the same left-to-right order as that of the multiple results in the
actual statement.
For example, the results of the statement
ADD A B C TO C D (C) E
are equivalent to those of the statements
ADD A B C GIVING TEMP
ADD TEMP TO C
ADD TEMP TO D (C)
ADD TEMP TO E