Intel Divider Bug

Red Hat Enterprise Linux 4 4.9 Release Notes
Virtual machines that are booted with the "divider=x" kernel parameter set to a value greater or to be delayed for several minutes. This bug only affected Intel 64 and AMD64 systems that have the High Precision Event Timer (HPET) enabled in the … Retrieve Here

Prototyping Architectural Support For Program Rollback Using …
B347886; and gifts from IBM and Intel. is discarded and the program execution is rolled back to the this mode, a bug can be characterized thoroughly, through repeated rollback and re-execution, by enabling instrumen-tation within the application. … Document Viewer

RCCE: A Small Library For Many-Core Communication
Report a bug at; or you can email comments to RCCE: a Small Library for Many-Core Communication Intel Labs 2010 3 of 34 Intel Labs Revision History for Document … Retrieve Content

Computer Arithmetic Circuit Design Chapter 15 Variations In …
However, the Intel Pentium bug teaches us an important lesson. Computer Arithmetic Circuit Design Ch 15. Variations in Dividers 12 The Asymmetry of the Quotient divider for multiplying divisor and quotient digits. Speedup in selection logic must be … Access Document

A Mechanically Verified Commercial SRT Divider
Cuitry of the original Intel Pentium floating-point unit [7], cation. One early response to the 1994 revelation of the Pentium bug was Bryant’s BDD-based analysis [2], and the divider are displayed in Appendices 1 and 2. Like most XFL programs, … Document Retrieval

Building Buggy Chips – That Work!
Intel FDIV bug, failing FP divider resulted in $475 million recall – MIPS R10000 faltered out of the chute, many early parts recalled – Transmeta recalled most early Crusoe parts. 3 Advanced Computer Architecture Lab University of Michigan … Document Retrieval

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* Fig. 13.5 Shift/subtract sequential restoring divider. Signed Integer Division * Signed Integer Division z d | z | | d | sign(z) sign(d) | q | | s | sign(s) = sign(z) sign(q) Intel admits “subtle flaw” Intel’s white paper about the bug and its possible consequences Intel … Content Retrieval

Avoid the use of a hardware divider [25]. A similar technique was used to port Windows NT to Alpha processors [14]: A bug to the Intel Celeron bug listed in [1], which we adapt, for simplicity reasons, to a five-stage pipeline. In this example, … Read Content

No Slide Title
Multiple generation/selection scheme Conversion of redundant q to 2’s complement Radix r Divider Pentium bug (1) October 1994 Thomas Nicely, Intel admits “subtle flaw” Intel’s white paper about the bug and its possible consequences Intel … Get Content Here

Intel’s Successes With Formal Methods
• 1994 FDIV bug in the Intel Pentium processor: US $500 million. • Today, new products are ramped much faster and a similar bug might be even more expensive. • The Pentium divider successfully ran billions of test cases and … Get Document

An Holistic Approach To Computer Architecture
Floating pt divider lookup table – shrink? 4. Formal proof: shrink ok 5. Validation assumed proof was correct 6. Bug found in P6 regression testing in OR 7. The Public Is Weird – FDIV 2 zIntel. – Nothing is bug-free, this bug doesn’t affect you. … View Document

Computer Architecture And Engineering Lecture 8: Divide
Pentium Bug Pentium FP Divider uses algorithm to generate multiple bits per steps FPU uses most significant bits of divisor & dividend/remainder to guess next 2 bits of quotient Guess is taken from lookup table: Intel discovers bug in Pentium: takes months to make change, reverify, … Retrieve Content

Computer Arithmetic Circuit Design Chapter 14 High-Radix Dividers
Radix-2 Divider with CSA. Computer Arithmetic Circuit Design Ch 14. High-Radix Dividers 19 Select Logic Fast 4-bit CPA, plus decode logic, or 256 ×2 Lookup table, or Intel’s Pentium Division Bug Intel used the Radix-4 SRT division algorithm. … Get Document

Appendix A New New
This was brought home for Intel when their Pentium chip was discovered to have a bug in the divide algorithm. This floating- The simplest divider also operates on unsigned numbers and produces the quotient bits one at a time. … Fetch Doc

Where both the divider and multiplier send their results, in redundant form, to the adder for conversion to standard A The Intel Pentium FDIV Bug The errorin thedivisionportionof thefloating-pointunitof thePentiummicroprocessordrew a lotofmedia attention … Document Retrieval

ACV: An Arithmetic Circuit Verifier
The well-known division bug in Intel’s Pentium processor[6] has illustrated the importance of proving the correctness of arithmetic weighted value of the divider from the partial remainder, and shifts the partial remainder left by 2 bit positions. … View This Document

The “Pentium Bug” And SRT Division
Intel establishes the world’s largest verification divi- ing point divider? A: ”Life is like a box of chocolates.” (Source: F. Gump 9.9999973251 It’s a FLAW, Dammit, not a Bug 8.9999163362 It’s Close Enough, We Say So 7.9999414610 Nearly 300 Correct Opcodes … Read Here

Division, Pentium Style
SRT Divider Circuit Registers XHold partial remainder Initially loaded with dividend XDivisor (not shown) Unchanged for entire computation Intel’s Table Errors Actual Bug XErroneous entries for 5 cases XTable generates 0 instead of +2 … Access Full Source