In this case, the cost may be related to the number of instabilities detected.į. This cost depends on the computer architecture and can be higher if the detection of numerical instabilities is enabled.
Cost of cadnaa code#
Running time: The version of a code which uses CADNA runs at least three times slower than its floating-point version. The examples directory contains seven test runs which illustrate the use of the CADNA library and the benefits of Discrete Stochastic Arithmetic. The source code (which consists of C++ and assembly files) is located in the src directory.
Cost of cadnaa how to#
The user guide shows how to control the numerical accuracy of a program using CADNA, provides installation instructions and describes test runs.The reference guide briefly describes each function of the library. The doc directory contains a user guide named ug.cadna.pdf and a reference guide named, ref_cadna.pdf.
Cost of cadnaa install#
It must be pointed out that the knowledge of the accuracy of the argument of a mathematical function is never lost.Īdditional comments: In the library archive, users are advised to read the INSTALL file first. Therefore, if CADNA_C is used on a 64-bit processor with the GNU C++ compiler, mathematical functions are computed with rounding to the nearest, otherwise they are computed with the random rounding mode. As a remark, on 64-bit processors, the mathematical library associated with the GNU C++ compiler may provide incorrect results or generate severe bugs with rounding towards −∞ and +∞, which the random rounding mode is based on. The C++ language files contain the definition of the stochastic types on which the control of accuracy can be performed, CADNA_C specific functions (for instance to enable or disable the detection of numerical instabilities), the definition of arithmetic and relational operators which are overloaded for stochastic variables and the definition of mathematical functions which can be used with stochastic arguments. This assembly file contains routines which are frequently called in the CADNA_C C++ files to change the rounding mode. cadna_rounding.s is a symbolic link to the assembly file corresponding to the processor and the C++ compiler used. Summary of revisions: The CADNA_C source code consists of one assembly language file (cadna_rounding.s) and twenty-three C++ language files (including three header files). The new version has been developed to enable this estimation in C or C++ programs. Reasons for new version: The previous version (AEAT_v1_0) enables the estimation of round-off error propagation in Fortran programs. From this set of results, CADNA estimates the number of exact significant digits in the result that would have been computed with standard floating-point arithmetic. The program is run several times with a random rounding mode generating different results each time. Solution method: The CADNA library implements Discrete Stochastic Arithmetic which is based on a probabilistic model of round-off errors. The CADNA library enables one to estimate round-off error propagation in any simulation program and to detect all numerical instabilities that may occur at run time. Round-off error propagation may invalidate the result of a program. Nature of problem: A simulation program which uses floating-point arithmetic generates round-off errors, due to the rounding performed at each assignment and at each arithmetic operation. 178 (2008) 933ĭoes the new version supersede the previous version?: No Journal reference of previous version: Comput.
Cost of cadnaa Pc#
of bytes in distributed program, including test data, etc.: 710 781Ĭomputer: PC running LINUX with an i686 or an ia64 processor, UNIX workstations including SUN, IBMĬatalogue identifier of previous version: AEAT_v1_0 of lines in distributed program, including test data, etc.: 60 075 Licensing provisions: Standard CPC licence, Program obtainable from: CPC Program Library, Queen's University, Belfast, N.