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BDNCHM.TXT
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1987-03-04
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896b
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26 lines
R
FLOATING-POINT BENCHMARK
The following is a program to test the accuracy of floating
point functions (from Sept. DR DOBBS):
10 A=1
20 FOR I%=1 TO 2499
30 A=TAN(ATN(EXP(LOG(SQR(A*A))))) + 1
40 NEXT
50 PRINT A
60 STOP
The correct printout is A=2500 exactly.
IBM-PC BASIC 1.0 fails miserably, giving A=2179.8 (only 1 sig-
nificant figure of accuracy!). In contrast, an APPLE II or
Commodore 64 gives 2500 to at least 7 figures. Using the 8087
with a polyFORTH version of the benchmark, I obtained 2500 to
13 figures in 5.0 seconds. (NOTE: See March,84 D. DOBBS for
the results aginst many systems.)
Press ENTER to continue:
13 figures in 5.0 seconds. (NOTE: See March,84 D. DOBBS for
the results aginst many systems.)