as: 2byte

1 
1 7.106 '.2byte EXPRESSION [, EXPRESSION]*'
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1 
1 This directive expects zero or more expressions, separated by commas.
1 If there are no expressions then the directive does nothing.  Otherwise
1 each expression is evaluated in turn and placed in the next two bytes of
1 the current output section, using the endian model of the target.  If an
1 expression will not fit in two bytes, a warning message is displayed and
1 the least significant two bytes of the expression's value are used.  If
1 an expression cannot be evaluated at assembly time then relocations will
1 be generated in order to compute the value at link time.
1 
1    This directive does not apply any alignment before or after inserting
1 the values.  As a result of this, if relocations are generated, they may
1 be different from those used for inserting values with a guaranteed
1 alignment.
1 
1    This directive is only available for ELF targets,
1