FPTAN             Partial Tangent             Exception Flags: I P

FPTAN

       Logic:      Y/X . TAN(ST)
                   ST(1) . Y
                   push stack
                   ST . X

     FPTAN calculates a partial tangent, Y/X = TAN(.). The value . comes from
     ST. The result of the calculation is the ratio Y/X; Y is left in ST(1)
     and X in ST.
                                                               63
     For the 8087 and 80287, 0 . . . ./4. On the 80387, |.| < 2  .

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   Operands            Clocks         Bytes           Example
   FPTAN               30-540           3             FPTAN
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