Topic
C data types
About: C data types is a research topic. Over the lifetime, 17 publications have been published within this topic receiving 333 citations.
Papers
19 Jun 2021
TL;DR: RefinedC as mentioned in this paper is a type system that combines ownership types for modular reasoning about shared state and concurrency with refinement types for encoding precise invariants on C data types and Hoare-style specifications for C functions.
Abstract: Given the central role that C continues to play in systems software, and the difficulty of writing safe and correct C code, it remains a grand challenge to develop effective formal methods for verifying C programs. In this paper, we propose a new approach to this problem: a type system we call RefinedC, which combines ownership types (for modular reasoning about shared state and concurrency) with refinement types (for encoding precise invariants on C data types and Hoare-style specifications for C functions). RefinedC is both automated (requiring minimal user intervention) and foundational (producing a proof of program correctness in Coq), while at the same time handling a range of low-level programming idioms such as pointer arithmetic. In particular, following the approach of RustBelt, the soundness of the RefinedC type system is justified semantically by interpretation into the Coq-based Iris framework for higher-order concurrent separation logic. However, the typing rules of RefinedC are also designed to be encodable in a new “separation logic programming” language we call Lithium. By restricting to a carefully chosen (yet expressive) fragment of separation logic, Lithium supports predictable, automatic, goal-directed proof search without backtracking. We demonstrate the effectiveness of RefinedC on a range of representative examples of C code.
72 citations
22 Apr 2003
TL;DR: This paper describes both JACAW and MEDLI, and demonstrates how they are used in practice to convert legacy code into Grid services.
Abstract: This paper describes a process for the semi-automatic conversion of numerical and scientific routines written in the C programming language into Triana-based computational services that can be used within a distributed service-oriented architecture such as that being adopted for Grid computing. This process involves two separate but related tools, JACAW and MEDLI. JACAW is a wrapper tool based on the Java Native Interface (JNI) that can automatically generate the Java interface and related files for any C routine, or library of C routines. The MEDLI tool can then be used to assist the user in describing the mapping between the Triana and C data types involved in calling a particular routine. In this paper we describe both JACAW and MEDLI, and demonstrate how they are used in practice to convert legacy code into Grid services.
70 citations
TL;DR: This paper describes the C class concept, an extension to the C language providing such constructs as a way of restricting access to a data structure to a specific set of functions associated with it, without incurring significant overheads at compile time or at run time.
Abstract: Language constructs for definition and use of abstract data types ease the design and maintenance of large programs. This paper describes the C class concept, an extension to the C language providing such constructs. A class is defined using standard C data types and functions, and it can itself be used as a building block for new classes. A class provides a way of restricting access to a data structure to a specific set of functions associated with it, without incurring significant overheads at compile time or at run time.The C class concept is introduced by small examples of its use, and familiarity with the C language [2] is assumed. Appendix A is a complete small C program using classes.Classes have been in use for more than a year on a dozen PDP11 and VAX UNIX systems [1], and they are currently used for a diverse set of projects on more than 30 systems. Classes are currently implemented by an intermediate pass of the cc compiler, called the class pre-processor, which is invoked when the directive #class is found in a C source file. The class pre-processor is easily ported to a system with a version of the portable C compiler. A Motorola68000 version is in use.
41 citations
Proceedings Article•
IBM1
TL;DR: Concert/C is a new language for distributed C programming that extends ANSI C to support distribution and process dynamics and provides the ability to create and terminate processes, connect them together, and communicate among them.
Abstract: Concert/C is a new language for distributed C programming that extends ANSI C to support distribution and process dynamics. Concert/C provides the ability to create and terminate processes, connect them together, and communicate among them. It supports transparent remote function calls (RPC) and asynchronous messages. Interprocess communications interfaces are typed in Concert/C, and type correctness is checked at compile time wherever possible, otherwise at runtime. All C data types, including complex data structures containing pointers and aliases, can be transmitted in RPCs.
Concert/C programs run on a heterogeneous set of machine architectures and operating systems and communicate over multiple RPC and messaging protocols. The current Concert/C implementation runs on AIX 3.2, SunOS 4.1, Solaris 2.2 and OS/2 2.1, and communicates over Sun RPC, OSF/DCE and UDP multicast. Several groups inside and outside IBM are actively using Concert/C, and it is available via anonymous ftp from software.watson.ibm.com:/pub/concert.
23 citations
TL;DR: Stochastic bit-width estimation that follows a simulation-based probabilistic approach to estimate the bit- widths of integer variables using extreme value theory is introduced and enables more compact and power-efficient custom hardware designs than the compile-time integer bit-Width analysis techniques.
Abstract: There is an increasing trend toward compiling from C to custom hardware for designing embedded systems in which the area and power consumption of application-specific functional units, registers, and memory blocks are heavily dependent on the bit-widths of integer operands used in computations. The actual bit-width required to store the values assigned to an integer variable during the execution of a program will not, in general, match the built-in C data types. Thus, precious area is wasted if the built-in data type sizes are used to declare the size of integer operands. In this paper, we introduce stochastic bit-width estimation that follows a simulation-based probabilistic approach to estimate the bit-widths of integer variables using extreme value theory. The estimation technique is also empirically compared to two compile-time integer bit-width analysis techniques. Our experimental results show that the stochastic bit-width estimation technique dramatically reduces integer bit-widths and, therefore, enables more compact and power-efficient custom hardware designs than the compile-time integer bit-width analysis techniques. Up to 37p reduction in custom hardware area and 30p reduction in logic power consumption using stochastic bit-width estimation can be attained over ten integer applications implemented on an FPGA chip.
23 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2014 | 1 |
| 2013 | 1 |
| 2012 | 1 |
| 2008 | 1 |
| 2005 | 2 |