Processors
FDIV Replacement Program
Statistical Analysis of Floating Point Flaw: Intel White Paper - November

Section 1: Abstract
A subtle flaw in the hardware divide unit of the Pentium® Processor was discovered by Intel. Subsequently, a characterization of its impact to the end-user application base was conducted. The flaw is rare and data-dependent, and causes a reduction in precision of the divide instruction and certain other operations in certain cases.

The significance of the flaw depends upon (a) the rate of use of specific FP instructions in the Pentium processor, (b) the data fed to them, (c) the way in which the results of these instructions are propagated into further computation in the application; and (d) the way in which the final results of the application are interpreted.

The thorough and detailed characterization of the flaw and the subsequent investigations of its impact on applications through elaborate surveys, analyses and empirical observation lead us to the overall conclusion that the flaw is of no concern to the vast majority of users of Pentium processor based systems. A few users of applications in the scientific/engineering and financial engineering fields who require unusual precision and invoke millions of divides per day may need to employ either an updated Pentium processor without the flaw or a software workaround.

This applies to:

FDIV Replacement Program



Solution ID: CS-013005
Last Modified: 16-Nov-2009
Date Created: 08-Jul-2004
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