Chapter 17 AppendixList of Assembler Control Statements 32117.4 List of Assembler Control StatementsThis 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 identifierblock1Assembles block1 if the identifier was defined beforethe #ifdef statement.[#else#endifblock2]Assembles block2 if it was not defined (nothing will beassembled if there is no #else).#ifndef identifierblock1Assembles block1 if the identifier was defined beforethe #ifdef statement.[#else#endifblock2]Assembles block2 if it was not defined (nothing will beassembled if there is no #else.#if expressionblock1Assembles block1 if the expression is not 0.[#else#endifblock2]Assembles block2 if it is 0 (nothing will be assembledif there is no #else).#ifn expressionblock1Assembles block1 if the expression is 0.[#elseblock2]#endifAssembles block2 if it is not 0 (nothing will beassembled if there is no #else).#ifeq parameter1, parameter2block1Assembles block1 if parameter1 and parameter2 areequal. Assembles block2 if they are not equal (nothingwill be assembled if there is no #else). At least one orthe other of parameter1 and parameter2 must be adummy parameter within a macro definition. #ifeq canonly be used within macro definitions.[#else#endifblock2]#ifneq parameter1, parameter2block1Assembles block1 if parameter1 and parameter2 areequal. Assembles block2 if they are not equal (nothingwill be assembled if there is no #else). At least one orthe other of parameter1 and parameter2 must be adummy parameter within a macro definition. #ifneqcan only be used within macro definitions.[#else#endifblock2]
