Papers by Florian Letombe
Efficient Mutation-Analysis Coverage for Constrained Random Verification
IFIP Advances in Information and Communication Technology, 2010
Constrained random simulation based verification (CRV) becomes an important means of verifying th... more Constrained random simulation based verification (CRV) becomes an important means of verifying the functional correctness of the increasingly complex hardware designs. Effective coverage metric still lacks for assessing the adequacy of these processes. In contrast to other coverage metrics, the syntax-based Mutation Analysis (MA) defines a systematic correlation between the coverage results and the test’s ability to reveal design errors.
2009 Design, Automation & Test in Europe Conference & Exhibition, 2009
The topic will cover the use of functional qualification for measuring the quality of functional ... more The topic will cover the use of functional qualification for measuring the quality of functional verification of TLM models. Functional qualification is based on the theory of mutation analysis but considers a mutation to have been killed only if a testcase fails. A mutation model of TLM behaviors is proposed to qualify a verification environment based on both testcases and assertions. The presentation describes at first the theoretic aspects of this topic and then it focuses on its application to real cases by using actual EDA tools, thus showing advantages and limitations of the application of mutation analysis to TLM.
HDL-Mutation Based Simulation Data Generation by Propagation Guided Search
2011 14th Euromicro Conference on Digital System Design, 2011
HDL-mutation based fault injection and analysis is considered as an important coverage metric for... more HDL-mutation based fault injection and analysis is considered as an important coverage metric for measuring the quality of design simulation processes (20, 3, 1, 2). In this work, we try to solve the problem of automatic simulation data generation targeting HDL mutation faults. We follow a search based approach and eliminate the need for symbolic execution and mathematical constraint solving
2011 IEEE International High Level Design Validation and Test Workshop, 2011
Mutation-testing has been considered as an important coverage metric to measure the quality of si... more Mutation-testing has been considered as an important coverage metric to measure the quality of simulation-based verification and validation processes [1, 2, 3]. On the other hand, IP-XACT has evolved to the IEEE standard for IP reuse and IP-based System-on-Chip (SoC) integration, which covers both RTL and TLM. In this paper, we present our effort to enable the mutation-based simulation coverage metric for system level IP integration with IP-XACT. Two major ingredients are required for this extension. First, as IP-XACT system designs are XML files, which are not originally for execution, we need an execution/simulation engine for IP-XACT designs. For this, we created a code generator that generates SystemC models from IP-XACT XML designs, such that we can simulate and test an IP-XACT design. Second, we define the mutation operators on IP-XACT schema, which is the model of errors that we can inject into IP-XACT designs during mutation testing. With IP-XACT, the mutation maintains a focus on the integration and configuration of components. We implemented the code generator and mutation operators in an Eclipsed-based IP-XACT editor with the help of Eclipse Modeling Framework. Then several experiments were conducted on a TLM library for CoreConnect SoC modeling. From the results, we can see that the defined IP-XACT mutation serves an effective qualification for simulation tests, in terms of its ability to reveal the weakness of the tests.
On the Functional Qualification of a Platform Model
2009 24th IEEE International Symposium on Defect and Fault Tolerance in VLSI Systems, 2009
This work focuses on the use of functional qualification for measuring the quality of co-verifica... more This work focuses on the use of functional qualification for measuring the quality of co-verification environments for hardware/software (HW/SW) platform models. Modeling and verifying complex embedded platforms requires co-simulating one or more CPUs running embedded applications on top of an operating system, and connected to some hardware devices. The paper describes first a HW/SW co-simulation framework which supports all mechanisms
A Branching Heuristics for Quantified Renamable Horn Formulas
Lecture Notes in Computer Science, 2005
Many solvers have been designed for QBFs, the validity problem for Quantied Boolean Formulas for ... more Many solvers have been designed for QBFs, the validity problem for Quantied Boolean Formulas for the past few years. In this paper, we describe a new branching heuristics whose purpose is to pro- mote renamable Horn formulas. This heuristics is based on H ebrard's algorithm for the recognition of such formulas. We present some experi- mental results obtained by our qbf solver Qb with the new branching heuristics and show how its performances are improved.
HYBRID INCREMENTAL ALGORITHMS FOR BOOLEAN SATISFIABILITY
International Journal on Artificial Intelligence Tools, 2012
Article by Florian Letombe, Springsoft, France (Springsoft acquired by Synopsys) Article Received... more Article by Florian Letombe, Springsoft, France (Springsoft acquired by Synopsys) Article Received 27 September 2010, Accepted 14 February 2012
Several propositional fragments have been considered so far as target languages for knowledge com... more Several propositional fragments have been considered so far as target languages for knowledge compilation and used for improving computational tasks from major AI areas (like inference, diagnosis and planning); among them are the (quite influential) ordered binary decision diagrams, prime implicates, prime implicants, "formulae" in decomposable negation normal form. On the other hand, the validity problem QBF for Quantified Boolean Formulae (QBF) has been acknowledged for the past few years as an important issue for AI, and many solvers have been designed for this purpose. In this paper, the complexity of restrictions of QBF obtained by imposing the matrix of the input QBF to belong to such propositional fragments is identified. Both tractability and intractability results (PSPACE-completeness) are obtained.
The results of the last MaxSAT Evaluations suggest there is no universal best algorithm for solvi... more The results of the last MaxSAT Evaluations suggest there is no universal best algorithm for solving MaxSAT, as the fastest solver often depends on the type of instance. Having an oracle able to predict the most suitable MaxSAT solver for a given instance would result in the most robust solver. Inspired by the success of SATzilla for SAT, this paper describes the first approach for a portfolio of algorithms for MaxSAT. Compared to existing solvers, the resulting portfolio can achieve significant performance improvements on a representative set of instances.
Several propositional fragments have been considered so far as target languages for knowledge com... more Several propositional fragments have been considered so far as target languages for knowledge compilation and used for improving computational tasks from major AI areas (like inference, diagnosis and planning); among them are the ordered binary decision diagrams, prime implicates, prime implicants, "formulae" in decomposable negation normal form. On the other hand, the validity problem val(QPROP P S ) for Quantified Boolean Formulae (QBF) has been acknowledged for the past few years as an important issue for AI, and many solvers have been designed. In this paper, the complexity of restrictions of the validity problem for QBF obtained by imposing the matrix of the input QBF to belong to propositional fragments used as target languages for compilation, is identified. It turns out that this problem remains hard (PSPACE-complete) even under severe restrictions on the matrix of the input. Nevertheless some tractable restrictions are pointed out.
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Papers by Florian Letombe