FDIVR           Divide real reversed                 Exceptions: I D Z O U P
FDIVRP          Divide real reversed and pop         C3 C2 C1 C0: ? ? * ?

FDIVR [[destination,] source]
FDIVRP [destination, ST]

        Logic   ; FDIVR source                  ; FDIVR and FDIVRP
                ST ← source / ST                ST(1) ← ST / ST(1)
                                                pop ST

                ; FDIVR dest, source            ; FDIVRP dest, ST
                ST(dest) ← ST(src) / ST(dest)   ST(dest) ← ST / ST(dest)
                                                pop ST

    FDIVR/FDIVRP divide the source operand by the destination operand
    and return the quotient to the destination operand.

    The one-operand form of FDIVR divides a (single or double real)
    memory operand by ST and leaves the result in ST.
    The two-operand form of FDIVR divides two register operands (one of
    these must be ST) and stores the result in the destination register.
    FDIVRP works like the two-operand FDIVR but requires ST to be the
    source operand; it also pops the stack.
    The no-operand forms FDIVR and FDIVRP equal 'FDIVRP ST(1), ST'.


    Opcode      Format
    D8 /7       FDIVR m32
    DC /7       FDIVR m64
    D8 F8 + i   FDIVR ST,ST(i)
    DC F0 + i   FDIVR ST(i),ST
    DE F0 + i   FDIVRP ST(i),ST
    DE F1       FDIVR
    DE F1       FDIVRP


    Timing
    Variations/
    operand       8087         287        387      486     Pentium
    fdivr reg    194-204     194-204     88-91     73      39      FX
    fdivr m32   (216-226)+EA 216-226      89       73      39      FX
    fdivr m64   (221-231)+EA 221-231      94       73      39      FX
    fdivrp       198-208     198-208      91       73      39      FX