Livermore loops is a benchmark

Benchmark (computing)

In computing, a benchmark is the act of running a computer program, a set of programs, or other operations, in order to assess the relative performance of an object, normally by running a number of standard tests and trials against it...

 for parallel computers

Parallel computing

Parallel computing is a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently . There are several different forms of parallel computing: bit-level,...

. It was created by Francis H. McMahon from scientific source code

Source code

In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...

 run on computers at Lawrence Livermore National Laboratory

Lawrence Livermore National Laboratory

The Lawrence Livermore National Laboratory , just outside Livermore, California, is a Federally Funded Research and Development Center founded by the University of California in 1952...

. It consists of 24 do loops

Do while loop

In most computer programming languages, a do while loop, sometimes just called a do loop, is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. Note though that unlike most languages, Fortran's do loop is actually analogous to the for loop.The...

, some of which can be vectorized, and some of which cannot.

The benchmark was published in 1986 in Livermore fortran kernels: A computer test of numerical performance range.

The Livermore loops were originally written in Fortran

Fortran

Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...

, but have since been ported to many programming languages.

Each loop carries out a different mathematical kernel
.
Those kernels
are:

• hydrodynamics fragment
• incomplete Cholesky
  Cholesky decomposition
  In linear algebra, the Cholesky decomposition or Cholesky triangle is a decomposition of a Hermitian, positive-definite matrix into the product of a lower triangular matrix and its conjugate transpose. It was discovered by André-Louis Cholesky for real matrices...
  
   conjugate gradient
• inner product
• banded linear system
  Linear system
  A linear system is a mathematical model of a system based on the use of a linear operator.Linear systems typically exhibit features and properties that are much simpler than the general, nonlinear case....
  
  s solution
• tridiagonal linear systems solution
• general linear recurrence equations
• equation of state
  Equation of state
  In physics and thermodynamics, an equation of state is a relation between state variables. More specifically, an equation of state is a thermodynamic equation describing the state of matter under a given set of physical conditions...
  
   fragment
• alternating direction implicit integration
• integrate predictors
• difference predictors
• first sum
• first difference
• 2-D particle in a cell
• 1-D particle in a cell
• casual Fortran
• Monte Carlo
  Monte Carlo method
  Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in computer simulations of physical and mathematical systems...
  
   search
• implicit conditional computation
• 2-D explicit hydrodynamics fragment
• general linear recurrence equations
• discrete ordinates transport
• matrix-matrix transport
• Planckian distribution
• 2-D implicit hydrodynamics fragment
• location of a first array minimum.

External links

• Livermore Loops, Fortran version
• Livermore Loops, C version