Clarifying and Compiling C/C++ Concurrency: From C++11 to POWER

Batty, Mark and Memarian, Kayvan and Owens, Scott and Sarkar, Susmit and Sewell, Peter (2012) Clarifying and Compiling C/C++ Concurrency: From C++11 to POWER. In: POPL '12: 39th Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, 25th - 27th January, 2012, Philadelphia, USA. (The full text of this publication is not available from this repository)

The full text of this publication is not available from this repository. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1145/2103656.2103717

Abstract

The upcoming C and C++ revised standards add concurrency to the languages, for the first time, in the form of a subtle *relaxed memory model* (the *C++11 model*). This aims to permit compiler optimisation and to accommodate the differing relaxed-memory behaviours of mainstream multiprocessors, combining simple semantics for most code with high-performance *low-level atomics* for concurrency libraries. In this paper, we first establish two simpler but provably equivalent models for C++11, one for the full language and another for the subset without consume operations. Subsetting further to the fragment without low-level atomics, we identify a subtlety arising from atomic initialisation and prove that, under an additional condition, the model is equivalent to sequential consistency for race-free programs. We then prove our main result, the correctness of two proposed compilation schemes for the C++11 load and store concurrency primitives to Power assembly, having noted that an earlier proposal was flawed. (The main ideas apply also to ARM, which has a similar relaxed memory architecture.) This should inform the ongoing development of production compilers for C++11 and C1x, clarifies what properties of the machine architecture are required, and builds confidence in the C++11 and Power semantics.

Item Type: Conference or workshop item (Paper)
Subjects: Q Science > QA Mathematics (inc Computing science) > QA 76 Software, computer programming,
Divisions: Faculties > Science Technology and Medical Studies > School of Computing > Programming Languages and Systems Group
Depositing User: Scott Owens
Date Deposited: 24 Oct 2012 10:10
Last Modified: 18 Mar 2013 13:57
Resource URI: http://kar.kent.ac.uk/id/eprint/31893 (The current URI for this page, for reference purposes)
  • Depositors only (login required):