FIST            Store integer                        Exceptions: I P
FISTP           Store integer and pop                C3 C2 C1 C0: ? ? * ?

FIST destination
FISTP destination

                ; FIST                  ; FISTP
        Logic   destination ← ST        destination ← ST
                                        pop ST

    FIST converts the value in ST into a signed integer according to the
    RC field of the control word. It then stores ST at destination,
    which can be either a word or short integer in memory.

    FISTP operates like FIST, except that it also pops the stack and
    supports a long integer destination.


    Note
    If the value in ST is too large to represent an integer, an invalid
    operation exception is raised. The masked response is to write the
    most negative integer to memory.

    The destination operand cannot be one of the 80x86 general registers.


    Opcode      Format
    DF /2       FIST m16
    DB /2       FIST m32
    DF /3       FISTP m16
    DB /3       FISTP m32
    DF /7       FISTP m64


    Timing
    Variations/
    operand       8087         287        387      486     Pentium
    fist  m16    (80-90)+EA   80-90      82-95    29-34     6      NP
    fist  m32    (82-92)+EA   82-92      79-93    28-34     6      NP
    fistp m16    (82-92)+EA   82-92      82-95    29-34     6      NP
    fistp m32    (84-94)+EA   84-94      79-93    28-34     6      NP
    fistp m64    (94-105)+EA  94-105     80-97    28-34     6      NP