Contributor: WILLIAM G. S. BROWN { From: brownwm@aplcenmp.apl.jhu.edu (William G. S. Brown) Here is a short Pentium test program that will uncover the FDIV error. Note: Sometimes just setting X&Y then then printing X-(X/Y)*Y will not show the error because the optimization is smart enough to form the answer at compile time. } {$N+} Program Pentium; { test a Pentium for FDIV error } { computes X-(X/Y)*Y which should be 0.000000} { Good Pentium should return 0.000000000E+0000} { Bad Pentium will return 2.560000000E+0002} var X,Y: double; { the procedure is to make sure optimization won't hide error } procedure Test( A,B,C,D : double); begin { Test } writeln(A-(B/C)*D); end; { Test } begin { Pentium } X := 4195835; Y := 3145727; Test(X, X, Y, Y); { same as X-(X/Y)*Y e.g. 0.0000} end. { Pentium }