as: MIPS Option Stack

 
 9.26.11 Directives to save and restore options
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 The directives '.set push' and '.set pop' may be used to save and
 restore the current settings for all the options which are controlled by
 '.set'.  The '.set push' directive saves the current settings on a
 stack.  The '.set pop' directive pops the stack and restores the
 settings.
 
    These directives can be useful inside an macro which must change an
 option such as the ISA level or instruction reordering but does not want
 to change the state of the code which invoked the macro.
 
    Traditional MIPS assemblers do not support these directives.