Coding the macros

In this information, each macro description includes a syntax diagram near the beginning of the macro description. The diagram shows how to code the macro. The syntax diagram does not explain the meanings of the parameters; the meanings are explained in the parameter descriptions that follow the syntax diagram. For most macros, the syntax diagrams are in a tabular format; however, some newer macros might have syntax diagrams in the railroad track format.

The syntax tables assume that the standard begin, end, and continue columns are used. Thus, column 1 is assumed as the begin column. To change the begin, end, and continue columns, use the ICTL instruction to establish the coding format you want to use. If you do not use ICTL, the assembler recognizes the standard columns. To code the ICTL instruction, see HLASM Language Reference.

Figure 1 shows a sample macro called TEST and summarizes all the coding information that is available for it. The table is divided into three zones, A, B, and C.

Figure 1. Sample tabular syntax diagram for the TEST macro

• Column one of the table contains zones A and B. Zone A begins at the left margin; zone B is indented from the left margin by one or more blank spaces. Column two of the table contains zone C.
• Zone A and zone B contain those parameters that are allowed for the macro. Zone A contains those parameters that are required; zone B contains those parameters that are optional.
• If a parameter appears on a single line in the diagram (that is, a line whose preceding line and following line are both blank), as shown in A1 and B1, then that is the only available choice for the particular parameter.
• If two or more parameters appear on adjacent lines (that is, with no intervening blank lines), as shown in A2 and B2, the parameters on those lines are mutually exclusive, that is, you can code any one of those parameters.
• A further distinction is made between mandatory and optional parameters. The parameter descriptions that follow the syntax table clearly identify those parameters which are optional.
• Zone C (which is the second column in the syntax table), provides additional information about coding the macro.

When substitution of a variable is indicated in zone C, the following classifications are used:

Variable

Classification

symbol

Any symbol valid in the assembler language. The symbol can be as long as the supported maximum length of a name entry in the assembler you are using.

Decimal digit

Any decimal digit up to and including the value indicated in the parameter description. If both symbol and decimal digit are indicated, an absolute expression is also allowed.

Register (2) - (12)

One of general purpose registers 2 through 12, specified within parentheses, previously loaded with the right-adjusted value or address indicated in the parameter description. You must set the unused high-order bits to zero. You can designate the register symbolically or with an absolute expression.

Register (0)

General purpose register 0, previously loaded with the right-adjusted value or address indicated in the parameter description. You must set the unused high-order bits to zero. Designate the register as (0) only.

Register (1)

General purpose register 1, previously loaded with the right-adjusted value or address indicated in the parameter description. You must set the unused high-order bits to zero. Designate the register as (1) only.

Register (15)

General purpose register 15, previously loaded with the right-adjusted value or address indicated in the parameter description. You must set the unused high-order bits to zero. Designate the register as (15) only.

RX-type address

Any address that is valid in an RX-type instruction (for example, LA).

RS-type address

Any address that is valid in an RS-type instruction (for example, STM).

RS-type name

Any name that is valid in an RS-type instruction (for example, STM).

A-type address

Any address that can be written in an A-type address constant.

Default

A value that is used in default of a specified value; that is, the value the system assumes if the parameter is not coded.