A generalized algorithm for graph-coloring register allocation

Graph-coloring register allocation is an elegant and extremely popular optimization for modern machines. But as currently formulated, it does not handle two characteristics commonly found in commercial architectures. First, a single register name may appear in multiple register classes, where a class is a set of register names that are interchangeable in a particular role. Second, multiple register names may be aliases for a single hardware register. We present a generalization of graph-coloring register allocation that handles these problematic characteristics while preserving the elegance and practicality of traditional graph coloring. Our generalization adapts easily to a new target machine, requiring only the sets of names in the register classes and a map of the register aliases. It also drops easily into a well-known graph-coloring allocator, is efficient at compile time, and produces high-quality code. Categories and subject descriptors D.3.4 [Programming Languages]: Processor...

• Type: Conference
• Year: 2004
• Where: PLDI
• Authors: Michael D. Smith, Norman Ramsey, Glenn H. Holloway
• Keywords: Graph-coloring Register Allocation, Multiple Register, PLDI 2004, Programming Languages, Register Names