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- {
- 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 }
-