In this paper, we analyse the stability of parallel algorithms for the evaluation of polynomials written es a finite series of orthogonal polynomials. The basic part of the computation is the solution of a triangular tridiagonal linear system. This fact allows us to present a more detailed analysis. The theoretical results show that the parallel algorithms are almost as stable as their sequenti...

A dichotomy theorem for counting problems due to Creignou and Hermann states that or any finite set S of logical relations, the counting problem #SAT(S) is either in FP, or #P-complete. In the present paper we study polynomial evaluation from this dichotomic point of view. We show that the “hard” cases in the Creignou-Hermann theorem give rise to VNP-complete families of polynomials, and we giv...

Given a multivariate real (or complex) polynomial p and a domain D, we would like to decide whether an algorithm exists to evaluate p(x) accurately for all x ∈ D using rounded real (or complex) arithmetic. Here “accurately” means with relative error less than 1, i.e., with some correct leading digits. The answer depends on the model of rounded arithmetic: We assume that for any arithmetic opera...

Let q > 1 be an integer and let a and b be elements of the residue ring ZZq of integers modulo q. We show how, when given a polynomial f ∈ ZZq[X] and approximations to v0, v1 ∈ ZZq such that v1 ≡ f(v0) mod q one can recover v0 and v1 efficiently. This result has direct applications to predicting the polynomial congruential generator: a sequence (vn) of pseudorandom numbers defined by the relati...

Fixed-point conversion requires fast analytical methods to evaluate the accuracy degradation due to quantization noises. Usually, analytical methods do not consider the correlation between quantization noises. Correlation between quantization noises occurs when a data is quantized several times. This report explained, through an example, the methodology used in the ID.Fix tool to support correl...

One of the three main processes associated with polynomials is evaluation; the two other ones being interpolation and root finding. Higham [1, chap. 5] devotes an entire chapter to polynomials and more especially to polynomial evaluation. The small backward error the Horner scheme introduce when evaluated in floating point arithmetic justifies its practical interest. It is well known that the c...

This paper presents some recent works on hardware evaluation of functions. A method for the automatic generation of high-performance arithmetic operators based on polynomial approximations is described. It deals with the bit-level representation of the polynomial coefficients, the intermediate computations width, the approximation and the rounding errors. The generated operators are small, fast...