Many code-generator generators use tree pattern matching and dynamic programming. This paper describes a simple program that generates matchers that are fast, compact, and easy to understand.It is simpler than common alternatives: 200-700 lines of Icon or 950 lines of C versus 3000 lines of C for Twig and 5000 for burg. Its matchers run up to 25 times faster than Twig's, They are necessarily slower than burg's BURS (bottom-up rewrite system) matchers, but they are more flexible and still practical.

No abstract

Current research in compiler optimization counts mainly CPU time and perhaps the first cache level or two. This view has been important but is becoming myopic, at least from a system-wide viewpoint, as the ratio of network and disk speeds to CPU speeds grows exponentially.

A b s t r a c t lcc is a new retargetable compiler for ANSI C. Versions for the VAX, Motorola 68020, SPARC, and MIPS are in production use at Princeton University and at AT&T Bell Laboratories. With a few exceptions, little about lcc is unusual --it integrates several well engineered, existing techniques --but it is smaller and faster than most other C compilers, and it generates code of comparable quality, lcc's target-independent front end performs a few simple, but effective, optimizations that contribute to good code; examples include simulating register declarations and partitioning switch statement cases into dense tables. It also implements target-independent function tracing and expression-level profiling.

This paper describes the design, implementation, and application of a new algorithm to detect cloned code. It operates on the abstract syntax trees formed by many compilers as an intermediate representation. It extends prior work by identifying clones even when arbitrary subtrees have been changed. On a 440,000-line code corpus, 20-50% of the clones it detected were missed by previous methods. The method also identifies cloning in declarations, so it is somewhat more general than conventional procedural abstraction.