Topic
Live variable analysis
About: Live variable analysis is a research topic. Over the lifetime, 32 publications have been published within this topic receiving 707 citations.
Papers
IBM1
TL;DR: An empirical comparison of the effectiveness of five pointer analysis algorithms on C programs is described, resulting in best-case complexity from linear to polynomial and efficiency in terms of compile-time precision and efficiency.
Abstract: During the past two decades many different pointer analysis algorithms have been published. Although some descriptions include measurements of the effectiveness of the algorithm, qualitative comparisons among algorithms are difficult because of varying infrastructure, benchmarks, and performance metrics. Without such comparisons it is not only difficult for an implementor to determine which pointer analysis is appropriate for their application, but also for a researcher to know which algorithms should be used as a basis for future advances.This paper describes an empirical comparison of the effectiveness of five pointer analysis algorithms on C programs. The algorithms vary in their use of control flow information (flow-sensitivity) and alias data structure, resulting in worst-case complexity from linear to polynomial. The effectiveness of the analyses is quantified in terms of compile-time precision and efficiency. In addition to measuring the direct effects of pointer analysis, precision is also reported by determining how the information computed by the five pointer analyses affects typical client analyses of pointer information: Mod/Ref analysis, live variable analysis and dead assignment identification, reaching definitions analysis, dependence analysis, and conditional constant propagation and unreachable code identification. Efficiency is reported by measuring analysis time and memory consumption of the pointer analyses and their clients.
219 citations
Patent•
31 Mar 1995TL;DR: In this paper, an optimizing compiler process and apparatus for more accurately and efficiently identifying live variable sets in a portion of a target computer program, so as to more efficiently allocate registers in a computer central processing unit.
Abstract: An optimizing compiler process and apparatus is disclosed for more accurately and efficiently identifying live variable sets in a portion of a target computer program, so as to more efficiently allocate registers in a computer central processing unit. The process of the invention includes the steps of performing a static single assignment transform to a computer program, including the addition of phi functions to a control flow graph. Basic blocks representing a use of a variable are further added to the control flow graph between the phi functions and definitions of the variables converging at the phi functions. A backward dataflow analysis is then performed to identify the live variable sets. The variables in the argument of phi functions are not included as a use of those variables in this dataflow analysis. The dataflow analysis may be iteratively performed until the live variable sets remain constant between iterations. The apparatus of the present invention includes a computer system having a memory storing a set of variables that are live during the execution of a portion of a computer program. This memory may include CPU registers, cache memory, conventional RAM and other types of memory.
96 citations
IBM1
TL;DR: A simple general method of high-level data flow analysis that allows free use of escape and jump statements, avoids large graphs when compiling large programs, facilitates updating of data flow information to reflect program changes, and derives new global information helpful in solving many familiar global flow analysis problems is proposed.
Abstract: In contrast to the predominant use of low-level intermediate text, high-level data flow analysis deals with programs essentially at source level and exploits the control flow information implicit in the parse tree. The need for high-level flow analysis arises from several aspects of recent work on advanced methods of program certification and optimization. This paper proposes a simple general method of high-level data flow analysis that allows free use of escape and jump statements, avoids large graphs when compiling large programs, facilitates updating of data flow information to reflect program changes, and derives new global information helpful in solving many familiar global flow analysis problems. An illustrative application to live variable analysis is presented. Many of the graphs involved are constructed and analyzed before any programs are compiled, thus avoiding certain costs that low-level methods incur repeatedly at compile time.
78 citations
Patent•
12 Dec 1991
TL;DR: A compiler for compiling a computer program wherein the computer program is adapted for use with a data parallel computer is presented in this paper, where the compiler comprises an optimizer which optimizes the compiled code.
Abstract: A compiler for compiling a computer program wherein the computer program is adapted for use with a data parallel computer. The compiler comprises an optimizer which optimizes the compiled code. In optimizing the compiled code, the optimizer performs live variable analysis. With regard to performing live variable analysis, the optimizer of the present invention is adapted for use with data parallel languages. Additionally, the optimizer is computationally efficient at compile time. Further, the optimizer operates in an incremental manner.
37 citations
TL;DR: A new algorithm for exact estimation of the minimum memory size required by programs dealing with array computations is presented, which achieves the exactness traditionally associated with totally unrolling loops while exploiting reduced computation complexity by preserving the original loop structure.
Abstract: This paper presents a new algorithm for exact estimation of the minimum memory size required by programs dealing with array computations. Based on parametric partitioning of the iteration space and formalized live variable analysis, our algorithm transforms the minimum memory size estimation into an equivalent problem: integer point counting for intersection/union of mappings of parameterized polytopes. A heuristics was then proposed to solve the counting problem. Experimental results show that the algorithm achieves the exactness traditionally associated with totally unrolling loops while exploiting reduced computation complexity by preserving the original loop structure.
31 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2020 | 1 |
| 2019 | 1 |
| 2015 | 2 |
| 2014 | 3 |
| 2012 | 1 |