HLASM Language Reference

EQU Instruction
EQU Instruction
The EQU instruction assigns absolute or relocatable values to symbols. Use it to:
Assign single absolute values to symbols.
Assign the values of previously defined symbols or expressions to new
symbols, thus letting you use different mnemonics for different purposes.
Compute expressions whose values are unknown at coding time or difficult to
calculate. The value of the expressions is then assigned to a symbol.
Assign length and type attributes to symbols, either implicitly or explicitly.
| Assign program type and assembler type values to symbols.
EQU also assigns attributes. It takes the value, relocation, and length attributes of
the operand and assigns them to the name field symbol, and sets the integer and
scale attributes to zero. The type attributes of an absolute expression is always 'U',
and its length attribute is always 1 (unless the second and third operands are
specified.
When there is a symbol naming a complex relocatable expression, or a complex
relocatable expression is eventually “reduced” to an absolute or simply relocatable
expression, the first symbol is used for attribute assignment.
| The program type is always null, and the assembler type is always null, except
| when the appropriate operand is specified.
|
| ►►──symbol──EQU──expression_1──,───
(1) ─┬──────────────┬
─ ─,─────────────►
| └─expression_2─┘
| ►──┬──────────────┬──,──┬──────────────┬──,──┬──────────────┬──────►◄
| └─expression_3─┘
└─expression_4─┘
└─expression_5─┘
| Note:
| 1
Use commas as placeholders when there is an expression following
symbol
is one of the following:
An ordinary symbol
A variable symbol that has been assigned a character string with a value
that is valid for an ordinary symbol
expression_1
represents a value and attributes that the assembler assigns to the symbol in
the name field. expression_1 may have any value allowed for an assembly
expression: absolute (including negative), relocatable, or complexly
relocatable. The assembler carries this value as a signed 4-byte (32-bit)
number; all four bytes are printed in the program listings opposite the symbol.
Implicitly, the relocation and length attributes are also assigned for certain types
of expressions.
Any symbols used in expression_1 need not be previously defined. However, if
any symbol is not previously defined, the value of expression_1 is not assigned
to the symbol in the name field until assembly time and therefore may not be
184 HLASM V1R5 Language Reference