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System Software


Problem of the label in the body of macro:
o If the same macro is expanded multiple times at different places in the
program …
o There will be duplicate labels, which will be treated as errors by the

Do not use labels in the body of macro.
o Explicitly use PC-relative addressing instead.
Ex, in RDBUFF and WRBUFF macros,
o JEQ *+11
o JLT *-14
It is inconvenient and error-prone.

The following program shows the concept of Macro Invocation and Macro

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