Title
FlexFloat: A Software Library for Transprecision Computing
Abstract
In recent years approximate computing has been extensively explored as a paradigm to design hardware and software solutions that save energy by trading off on the quality of the computed results. In applications that involve numerical computations with wide dynamic range, precision tuning of floating-point (FP) variables is a key knob to leverage the energy/quality tradeoff of program results. This aspect assumes maximum relevance in the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">transprecision computing</italic> scenario, where accuracy of data is tuned at fine grain in application code. Performing precision tuning at fine grain requires a software development flow that streamlines the assessment of which variables have “precision slack” within an application. In this paper, we introduce FlexFloat, an open-source software library that has been expressly designed to aid the development of transprecision applications. FlexFloat provides a C/C++ interface for supporting multiple FP formats. Unlike alternative libraries, FlexFloat enables to control the bit-width of mantissa and exponent fields and provides advanced features for the collection of runtime statistics, reducing the FP emulation time compared to the state-of-the-art solutions. Its design allows to emulate the behavior of standard IEEE FP types and custom extensions for reduced-precision computation. This makes the library suitable for adoption in multiple contexts, from manual exploration to integration into automatic tools. Experimental findings demonstrate that our approach can be used to perform a complete precision analysis from which deriving multiple program versions depending on the energy/quality tradeoff. Furthermore, we show that the adoption of our methodology can lead to a significant reduction of energy consumption even on current commercial hardware (an embedded GPGPU).
Year
DOI
Venue
2020
10.1109/TCAD.2018.2883902
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Keywords
Field
DocType
Energy-quality tradeoff,floating-point (FP) emulation,precision tuning,transprecision computing
Software engineering,Computer science,Real-time computing,Software
Journal
Volume
Issue
ISSN
39
1
0278-0070
Citations 
PageRank 
References 
3
0.42
0
Authors
3
Name
Order
Citations
PageRank
Giuseppe Tagliavini1719.36
Andrea Marongiu233739.19
Luca Benini3131161188.49