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  Title:    Save or Restore Coprocessor State
 
  Syntax:   FSAVE dest
            FNSAVE dest
            FRSTOR src
 
  See also: FSTENV, FSTSW, FSTCW, Coprocessor Environment
 
  Description:
 
     FSAVE stores the 94-byte coprocessor state to a specified memory
     location; FRSTOR restores it from a specified memory location.
 
     In 32-bit mode on the 80387/486, the environment state takes 108
     bytes.
 
     FSAVE has wait and no-wait versions. The wait version (FSAVE)
     checks for unmasked numeric errors; the no-wait version (FNSAVE)
     does not. After saving the state, the coprocessor is initialized
     as if FINIT had been executed.
 
     When the .8087 directive is used, the assembler puts the WAIT
     instruction before the wait version and the NOP instruction before
     the no-wait version.
                                    -♦-