Less is More: Exploiting the Standard Compiler Optimization Levels for Better Performance and Energy Consumption

This paper presents the interesting observation that by performing fewer of the optimizations available in a standard compiler optimization level such as -O2, while preserving their original ordering, significant savings can be achieved in both execution time and energy consumption. This observation has been validated on two embedded processors, namely the ARM Cortex-M0 and the ARM Cortex-M3, using two different versions of the LLVM compilation framework; v3.8 and v5.0. Experimental evaluation with 71 embedded benchmarks demonstrated performance gains for at least half of the benchmarks for both processors. An average execution time reduction of 2.4% and 5.3% was achieved across all the benchmarks for the Cortex-M0 and Cortex-M3 processors, respectively, with execution time improvements ranging from 1% up to 90% over the -O2. The savings that can be achieved are in the same range as what can be achieved by the state-of-the-art compilation approaches that use iterative compilation or machine learning to select flags or to determine phase orderings that result in more efficient code. In contrast to these time consuming and expensive to apply techniques, our approach only needs to test a limited number of optimization configurations, less than 64, to obtain similar or even better savings. Furthermore, our approach can support multi-criteria optimization as it targets execution time, energy consumption and code size at the same time.Comment: 15 pages, 3 figures, 71 benchmarks used for evaluatio

The Arm Prime Factors Decomposition

We introduce the Arm prime factors decomposition which is the equivalent of the Taylor formula for decomposition of integers on the basis of prime numbers. We make the link between this decomposition and the p-adic norm known in the p-adic numbers theory. To see how it works, we give examples of these tw

The Arm Factorization

We construct the equivalent of the Taylor formula in the basis of all roots fx . kg K when K is Z iZ, Q iQ and C

Remarks Around Lorentz Transformation

After diagonalizing the Lorentz Matrix, we nd the frame where the Dirac equation is one derivation and we calculate the 'speed' of the Schwarschild metri

The Arm Lie Group Theory

We developp the Arm-Lie group theory which is a theory based onthe exponential of a changing of matrix variable u(X). We de ne a corresponding u-adjoint action, the corresponding commutation relations in the Arm-Lie algebra and the u-Jacobi identity. Throught the exponentiation, Arm-Lie algebras become Arm-Lie groups. We give the example of p p so(2) and p p su(2)

The Arm Theory

Did you ever wondered what is the Taylor formula for an arbitrary chosen basis ? The answer of this question is the Arm theory introduced in this article

Noncommutative ricci curvature and dirac operator on B q [SU 2 ] at the fourth root of unity

We calculate the torsion free spin connection on the quantum group B q [SU 2 ] at the fourth root of unity. From this we deduce the covariant derivative and the Riemann curvature. Next we compute the Dirac operator of this quantum group and we give numerical approximations of its eigenvalues.Comment: arXiv admin note: substantial text overlap with arXiv:math/0206187 by other author

Poisson Lie Sigma Models

A Manin triples (D; g; ~ g) is a bialgebra (g; ~ g which don't intersect each others and a direct sum of this bialgebra D = g ~ g). If the corresponding Lie groups have a Poisson structure, they are called Poisson-Lie groups. A Poisson-Lie sigma models is an action (3.13) calculated by a Poisson vector eld matrix. [3] have deduced the extremal eld which minimize the action of this models, which gives the motion equation (3.19). We calculate here the action and the equations of motion for some 6-dimensionals Manin triples and we give a general formula for each 4-dimensional Manin triples. The 6-dimensional Manin triples are (sl(2; C) sl(2; C) ; sl(2; C); sl(2; C)),(sl(2; C) sl(2; C) ; sl(2; C)); sl(2; C),(sl(2; C); su(2; C); sb(2; C)) and (sl(2; C); sb(2; C); su(2; C))