yakir vizel 1 2 and orna grumberg 1
Download
Skip this Video
Download Presentation
Interpolation-Sequence Based Model Checking

Loading in 2 Seconds...

play fullscreen
1 / 25

Interpolation-Sequence Based Model Checking - PowerPoint PPT Presentation


  • 89 Views
  • Uploaded on

Yakir Vizel 1,2 and Orna Grumberg 1. Interpolation-Sequence Based Model Checking . Computer Science Department, The Technion , Haifa, Israel. Architecture, System Level and Validation Solutions, Intel Development Center, Haifa, Israel. Outline. Introduction Model checking

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Interpolation-Sequence Based Model Checking ' - richard-maxwell


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
yakir vizel 1 2 and orna grumberg 1
Yakir Vizel1,2

and

Orna Grumberg1

Interpolation-Sequence Based Model Checking

Computer Science Department, The Technion, Haifa, Israel.

Architecture, System Level and Validation Solutions, Intel Development Center, Haifa, Israel

Formal Methods in Computer Aided Design, Austin, Texas 2009

outline
Outline
  • Introduction
    • Model checking
    • Forward Reachability Analysis
    • Bounded Model Checking
  • Interpolation
    • Interpolation
    • Interpolation-Sequence
  • Interpolation-Sequence Based Model Checking
  • Experimental Results

Formal Methods in Computer Aided Design, Austin, Texas 2009

introduction
Introduction

Formal Methods in Computer Aided Design, Austin, Texas 2009

model checking
Model Checking
  • Given a system and a specification, does the system satisfy the specification.

System

AGq

MC

?

  • The specification is given in temporal logic – e.g. LTL.
    • We deal with specifications of the form AGq.

Formal Methods in Computer Aided Design, Austin, Texas 2009

forward reachability analysis
Forward Reachability Analysis

…… Sn

S2

BAD ¬q

S1

INIT

Formal Methods in Computer Aided Design, Austin, Texas 2009

bounded model checking
Bounded Model Checking
  • Does the system have a counterexample of length k?

.

.

.

Formal Methods in Computer Aided Design, Austin, Texas 2009

a bit of intuition
A Bit of Intuition

S3

S2

S1

INIT

BAD ¬q

I3

I1

I2

INIT

Formal Methods in Computer Aided Design, Austin, Texas 2009

interpolation
Interpolation

Formal Methods in Computer Aided Design, Austin, Texas 2009

interpolation in the context of model checking
Interpolation In The Context of Model Checking
  • Given the following BMC formula.

A

B

I

Formal Methods in Computer Aided Design, Austin, Texas 2009

interpolation sequence
Interpolation-Sequence
  • The same BMC formula partitioned in a different manner:

A1

Ak+1

A2

A3

Ak

I1

I2

I3

Ik-1

Ik

Formal Methods in Computer Aided Design, Austin, Texas 2009

interpolation sequence 2
Interpolation-Sequence (2)
  • Can easily be computed. For 1 ≤ j < n
    • A = A1Ù … Ù Aj
    • B = Aj+1 Ù … Ù An
    • Ijis the interpolant for the pair (A,B)

Formal Methods in Computer Aided Design, Austin, Texas 2009

interpolation sequence based model checking
Interpolation-Sequence Based Model Checking

Formal Methods in Computer Aided Design, Austin, Texas 2009

using interpolation sequence
Using Interpolation-Sequence

I1,1

I1

I1,2

I2,2

Formal Methods in Computer Aided Design, Austin, Texas 2009

combining interpolation sequence and bmc
Combining Interpolation-Sequence and BMC
  • A way to do reachability analysis using a SAT solver.
  • Uses the original BMC loop and adds an inclusion check for full verification.
  • Similar sets to those computed by Forward Reachability Analysis but over-approximated.

Formal Methods in Computer Aided Design, Austin, Texas 2009

computing reachable states with a sat solver
Computing Reachable States with a SAT Solver
  • Use BMC to search for bugs.
  • Partition the checked BMC formula and extract the interpolation sequence

I1,N

IN-1,N

IN,N

I2,N

Formal Methods in Computer Aided Design, Austin, Texas 2009

the analogy to forward reachability analysis
The Analogy to Forward Reachability Analysis

S3

S2

S1

INIT

BAD ¬q

I3

I2

I1

I1

I2

INIT

I1,3

I2,3

I3,3

I1,1

I1,2

I2,2

Formal Methods in Computer Aided Design, Austin, Texas 2009

mcmillan s method
McMillan’s Method
  • The computation itself is different.
    • Uses basic interpolation.
    • Successive calls to BMC for the same bound.
    • Not incremental.
  • The sets computed are different.

J1

I1

S1

Formal Methods in Computer Aided Design, Austin, Texas 2009

experimental results
Experimental Results

Formal Methods in Computer Aided Design, Austin, Texas 2009

experimental results1
Experimental Results
  • Experiments were conducted on two future CPU designs from Intel (two different architectures/tocks)

Formal Methods in Computer Aided Design, Austin, Texas 2009

experimental results falsification
Experimental Results - Falsification

Formal Methods in Computer Aided Design, Austin, Texas 2009

experimental results verification
Experimental Results - Verification

Formal Methods in Computer Aided Design, Austin, Texas 2009

experiments results analysis
Experiments Results - Analysis

Formal Methods in Computer Aided Design, Austin, Texas 2009

analysis
Analysis
  • False properties is always faster.
  • True properties – results vary. Heavier properties favor ISB where the easier favor IB.
  • Some properties cannot be verified by one method but can be verified by the other and vise-versa.

Formal Methods in Computer Aided Design, Austin, Texas 2009

conclusions
Conclusions
  • A new SAT-based method for unbounded model checking.
    • BMC is used for falsification.
    • Simulating forward reachability analysis for verification.
  • Method was successfully applied to industrial sized systems.

Formal Methods in Computer Aided Design, Austin, Texas 2009

questions
Questions?

Thank You!

Formal Methods in Computer Aided Design, Austin, Texas 2009

ad