Chapter 8. Assembler Directives

55

.macro reserve_str p1=0 p2

Begin the definition of a macro called

reserve_str

, with two arguments. The first argu 

ment has a default value, but not the second. After the definition is complete, you can call

the macro either as

reserve_str a,b

(with

\p1

evaluating to

a

and

\p2

evaluating to

b

), or as

reserve_str ,b

(with

\p1

evaluating as the default, in this case

0

, and

\p2

evaluating to

b

).

When you call a macro, you can specify the argument values either by position, or by keyword.

For example,

sum 9,17

is equivalent to

sum to=17, from=9

.

.endm

Mark the end of a macro definition.

.exitm

Exit early from the current macro definition.

\@

as

maintains a counter of how many macros it has executed in this pseudo variable; you can

copy that number to your output with

\@

, but only within a macro definition.

LOCAL name [ , ... ]

Warning:

LOCAL

is only available if you select "alternate macro syntax" with

 alternate

or

.altmacro

. Section 8.61

.altmacro

.

8.61.

.altmacro

Enable alternate macro mode, enabling:

LOCAL name [ , ... ]

One additional directive,

LOCAL

, is available. It is used to generate a string replacement for

each of the

name

arguments, and replace any instances of

name

in each macro expansion. The

replacement string is unique in the assembly, and different for each separate macro expansion.

LOCAL

allows you to write macros that define symbols, without fear of conflict between separate

macro expansions.

String delimiters

You can write strings delimited in these other ways besides

"string"

:

'string'

You can delimit strings with single quote charaters.

string

You can delimit strings with matching angle brackets.

single character string escape

To include any single character literally in a string (even if the character would otherwise have

some special meaning), you can prefix the character with

!

(an exclamation mark). For example,

you can write

4.3 !

5.4!!

to get the literal text

4.3

5.4!

.