Introduction#
oneAPI simplifies software development by providing the same languages and programming models across accelerator architectures. In this section, we introduce the programming model.
Parallel application development is a combination of API programming, where the parallel algorithm is hidden behind an API provided by the system, and direct programming, where the application programmer writes the parallel algorithm.
When using API programming, a developer implements performance critical sections of the program with library calls. Well-defined and mature problem domains have high-performance solutions packaged as libraries. oneAPI defines a set of APIs for the most used data parallel domains, and oneAPI platforms provide library implementations across a variety of accelerators. Where possible, the API is based on established standards like BLAS. API programming enables a programmer to attain high performance across a diverse set of accelerators with minimal coding & tuning.
Some problem domains are not well suited to API programming because no standard solution exists or because solutions require a level of customization that cannot be easily implemented in a library. In this case, a developer uses direct programming and must explicitly code the parallel algorithm. oneAPI’s programming model is based on data parallelism, where the same computation is performed on each data element, and parallelism of the application scales as the data scales. By allowing the programmer to directly express parallelism, data parallel algorithms make it possible to productively create highly efficient algorithms for parallel architectures.
Data parallel algorithms are used for many of the most computationally demanding problems including scientific computing, artificial intelligence, and visualization. Data parallel algorithms can be efficiently mapped to a diverse set of architectures: multi-core CPUs, GPUs, systolic arrays, and FPGAs.
Target Audience#
The expected audience for this specification includes: application developers, middleware developers, system software providers, and hardware providers. As a contributor to this specification, you will shape the accelerator software ecosystem. A productive and high performing system must take into account the constraints at all levels of the software stack. As a user of this document, you can ensure that your components will inter-operate with applications and system software for the oneAPI platform.
Goals of the Specification#
oneAPI seeks to provide:
Source-level compatibility: oneAPI applications and middleware port to a conformant oneAPI platform through recompilation and re-tuning.
Performance transparency: API’s and language construct allow the programmer enough control over the mapping to hardware to create an efficient solution
Software stack portability: Platform providers can port a oneAPI software stack by implementing the oneAPI Level Zero interface.
Definitions#
This specification uses the definition of must, must not, required, and so on specified in RFC 2119.
Contribution Guidelines#
See Contributing.