##### 8.7.2.4 Guarded Execution

`as` supports the full range of guarded execution directives for each instruction. Just append the directive after the instruction proper. The directives are:

/tx
  Execute the instruction if flag f0 is true.
/fx
  Execute the instruction if flag f0 is false.
/xt
  Execute the instruction if flag f1 is true.
/xf
  Execute the instruction if flag f1 is false.
/tt
  Execute the instruction if both flags f0 and f1 are true.
/tf
  Execute the instruction if flag f0 is true and flag f1 is false.