Fw: Pentium FPU eror found!!

From: Doug Little <doug_at_innerworkings.co.uk>
Date: Mon, 23 Feb 1998 11:29:26 -0000

Thought you might find this entertaining...

>We are reporting a floating-point bug that we have discovered on

>According to the IEEE 754 floating-point standard, the default rounding
>mode is rounded to the nearest; which means rounding down when the last
>digit is smaller than 5, rounding up when the last digit is greater than
>5, and rounding to even when the last digit is 5. However, when
>executing Square-Root from 0 to 65535, P5 and P6 do not produce correct
>results for 17 numbers, from 983, 2a39,..., to fd0b (Hex). We also
>tested two PowerPC MACs, two Sun workstations, and one HP machine, they
>all produce the correct results.

>This bug should be dubbed as "CLC-021998". It was discovered on
>February 19, 1998 by Chung, Lu, and Chung when testing a patented
>floating-point algorithm for improving E-Commerce Security by 10 to 1000
Received on ma. feb. 23 1998 - 12:42:41 CET

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