It takes six ones to reach a flaw [Pentium processor]

Author

Coe, Tim ; Tang, Ping Tak Peter

Author_Institution

Vitesse Semicond. Corp., Camarillo, CA, USA

fYear

1995

fDate

19-21 Jul 1995

Firstpage

140

Lastpage

146

Abstract

The initial release of the Pentium processor has a flaw in its radix-4 SRT division implementation. It is widely-known that five entries were missing in the lookup table, yielding reduced-precision quotients occasionally. In this paper, we use mathematical techniques to analyze the divisors that can possibly cause failures. In particular, we show that Bits 5 through 10 (where Bit 0 is the MSB) of such divisors must be all ones. This result is useful in compiler-level software patches for systems with unreplaced chips; and we believe that the techniques used here are applicable in analyzing SRT division as well as other hardware algorithms for floating-point arithmetic

Keywords

floating point arithmetic; table lookup; Pentium processor; compiler-level software patches; divisors; floating-point arithmetic; hardware algorithms; lookup table; radix-4 SRT division implementation; reduced-precision quotients; Algorithm design and analysis; Computer science; Diversity reception; Failure analysis; Floating-point arithmetic; Laboratories; Mathematics; Table lookup;

fLanguage

English

Publisher

ieee

Conference_Titel

Computer Arithmetic, 1995., Proceedings of the 12th Symposium on

Conference_Location

Bath

Print_ISBN

0-8186-7089-4

Type

conf

DOI

10.1109/ARITH.1995.465365

Filename

465365