/TRUNCATE
  /NOTRUNCATE  (D)

  Controls how the compiler stores values in COMPUTATIONAL
  receiving items if high-order truncation is necessary.

  If you specify /TRUNCATE, the compiler truncates values according
  to the number of decimal digits specified by the PICTURE size.
  Specifying /TRUNCATE increases program execution time.

  The default, /NOTRUNCATE, instructs the compiler to truncate
  values according to the hardware storage unit (word, longword,
  or quadword) allocated to the receiving item.