FISTTP converts the value in ST into a signed integer using truncation (chop) as rounding mode, transfers the result to the destination, and pop ST. FISTTP accepts word, short integer, and long integer destinations.
The following table shows the results obtained when storing various classes of numbers in integer format.
|-inf or Value Too Large for Destination||Format *|
|F = -1||-I|
|- 1 < F < +1||0|
|F = +1||+I|
|+inf or Value Too Large for Destination Format||*|
|F Means finite floating-point value.|
|I Means integer.|
|* Indicates floating-point invalid-operation (#IA) exception.|