Chapter 17 Appendix
List of Assembler Control Statements 321
17.4 List of Assembler Control Statements
This section provides a list of assembler control statements.
Syntax Function & Notes
#include “file_name Reads in the source file specified by file_name.
#define identifier[replacement_string] Replaces the identifier with the replacement_string.
#undef identifier Purges the identifier previously defined by #define.
#ifdef identifier
block1 Assembles block1 if the identifier was defined before
the #ifdef statement.
[#else
#endif block2] Assembles block2 if it was not defined (nothing will be
assembled if there is no #else).
#ifndef identifier
block1 Assembles block1 if the identifier was defined before
the #ifdef statement.
[#else
#endif block2] Assem bles block2 if it was not defined (nothing will be
assembled if there is no #else.
#if expression
block1 Assembles block1 if the expression is not 0.
[#else
#endif block2] Assembles block2 if it is 0 (nothing will be assembled
if there is no #else).
#ifn expression
block1 Assembles block1 if the expression is 0.
[#else block2]
#endif
Assembles block2 if it is not 0 (nothing will be
assembled if there is no #else).
#ifeq parameter1, parameter2
block1 Assembles block1 if parameter1 and parameter2 are
equal. Assembles block2 if they are not equal (nothing
will be assembled if there is no #else). At least one or
the other of parameter1 and parameter2 must be a
dummy parameter within a macro definition. #ifeq can
only be used within macro definitions.
[#else
#endif block2]
#ifneq parameter1, parameter2
block1 Assembles block1 if parameter1 and parameter2 are
equal. Assembles block2 if they are not equal (nothing
will be assembled if there is no #else). At least one or
the other of parameter1 and parameter2 must be a
dummy parameter within a macro definition. #ifneq
can only be used within macro definitions.
[#else
#endif block2]