Linear scan register allocation

@article{Poletto1999LinearSR,
  title={Linear scan register allocation},
  author={Massimiliano Poletto and Vivek Sarkar},
  journal={ACM Trans. Program. Lang. Syst.},
  year={1999},
  volume={21},
  pages={895-913}
}
We describe a new algorithm for fast global register allocation called linear scan. This algorithm is not based on graph coloring, but allocates registers to variables in a single linear-time scan of the variables' live ranges. The linear scan algorithm is considerably faster than algorithms based on graph coloring, is simple to implement, and results in code that is almost as efficient as that obtained using more complex and time-consuming register allocators based on graph coloring. The… 
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367 Citations
Highly Influential Citations
23
Background Citations
114
Methods Citations
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Results Citations
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367 Citations

Linear Scan Register Allocation in the Context of SSA Form and Register Constraints

This work shows how linear scan register allocation can be applied to register-constrained architectures like the Intel x86 and confirms that linear scan is several times faster than graph coloring for medium-sized to large programs.

Cooperative Instruction Scheduling with Linear Scan Register Allocation

Compared to the default scheduling and graph-coloring allocator schemes found in the IMPACT and Elcor components of Trimaran, the implementation with the pre-pass scheduler and linear scan register allocator significantly reduced compilation times.

Efficient global register allocation

A new register allocation algorithm is described that solves an inability of the similarly motivated Treescan register allocator to look ahead of the instruction being allocated - allowing an unconstrained allocation order, and an ability to better handle fixed registers and loop carried values.

Improvements to Linear Scan register allocation

This paper applies the linear scan register allocation algorithm in a system with SSA form and shows how to improve the algorithm by taking advantage of lifetime holes and memory operands, and also eliminate the need for reserving registers for spill code.

Linear Scan Register Allocation for the Java HotSpot™ Client Compiler

Benchmark results prove that the linear scan algorithm is a good tradeoff if both compilation time and runtime of a program matter: the compilation time is only slightly higher in comparison with the old local heuristic for register allocation, but the resulting code executes about 30% faster.

A Modified Linear Scan Register Allocation Algorithm

  • S. Subha
  • Computer Science
    2009 Sixth International Conference on Information Technology: New Generations
  • 2009
A global register allocation algorithm that makes decisions on register allocation based on the cost of spilling variables in linear scan allocation, which shows an improvement when compared to linear scan algorithm.

Register Allocation with Graph Coloring by Ant Colony Optimization

A new algorithm for intraprocedural register allocation called CA-RT-RA is described, an algorithm that extends a classic graph coloring register allocator to use the authors' graph coloring algorithm Color Ant-RT and is able to minimize the amount of spills.

Optimized interval splitting in a linear scan register allocator

An optimized implementation of the linear scan register allocation algorithm for Sun Microsystems' Java HotSpot™ client compiler is presented, with the high impact of the Intel SSE2 extensions on the speed of numeric Java applications.

SSA-Form-Based Register Allocation for the Java HotSpot

  • Computer Science
  • 2010
Comparing graph coloring and linear scan register allocation on SSA form turns out the two algorithms are not so different than they look at the first glance, so the next research step is to analyze the cases where the two algorithm are equivalent and find cases where they still differ.

Extended Linear Scan: An Alternate Foundation for Global Register Allocation

These results show that Extended Linear Scan is promising as an alternate foundation for global register allocation, compared to Graph Coloring, due to its compile-time scalability without loss of execution time performance.
...

References

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