Strongly typed flow-directed representation transformations (extended abstract)

Abstract

Topic Areascompilation, lambda calculus, intersection and union types, typed flow analysis, closure conversion, Mning AbstractWe present a new framework for transforming data representations in a strongly typed int errnedlate language. Our method allows both value producers (sources) and value consumem (sinks) to support multiple representations, autm aticaily inserting any required code. Specialized representations can be easily chosen for particular Source/sink pairs. The framework is based on these techniques:1. 2.F1OVIannotated types encode the 'flows-from" (source) and "flows-to" (sink) information of a flow graph.Intersection and union types support (a) encoding prc ise flow information, (b) separating flow information so that transformations can be well typed, (c) automatically reorganizing flow paths to enable multiple representations.As au instance of our framework, we provide a function rep resentation transformation that encompasses both closure conversion and inlining. Our framework is adaptable to data other than functions. Intersection me Dimiplinee in Lambda Calcuiua and Applicative Term Rewriting S@errw. PhD thesis, University of Nijmegen, 1993. Anindya Banerjee. A modular, polyvariarrt, and type-based closure analysis. Type inference for recursively constrained types and its application to 00P. In Proc. 1995 Mathematical Foundations of Programming Semantics Conf. Elsevier, 1995. John Hannan. TvDe svstems for closure conversion. In kVorkhop on~ea '~or~rogram Anatuaia, pages 48-62, 1995. DAIMI PB-493.

Faithful Translations between Polyvariant Flows and Polymorphic Types

“…The annotation with tags gives rise to intersection and union types that are not associative, commutative, or idempotent (ACI). This stands in contrast to the ACI types of P&P, but is similar to the non-ACI intersection and union types of CIL, the intermediate language of an experimental compiler that integrates flow information into the type system Dimock et al, 1997). Indeed, a key motivation of this work was to formalize the encoding of various flow analyses in the CIL type system.…”

“…Examples of polyvariant analyses include call-string based approaches, such as k-CFA (Shivers, 1991;Jagannathan & Weeks, 1995;, polymorphic splitting (Wright & Jagannathan, 1998), type-directed flow analysis (Jagannathan et al, 1997), and argument based polyvariance, such as Schmidt's analysis (Schmidt, 1995) and Agesen's cartesian product analysis (Agesen, 1995). In terms of the flow/type correspondence, several forms of flow polyvariance appear to correspond to type polymorphism expressed with intersection and union types (Banerjee, 1997;Wells et al, 1997;Dimock et al, 1997;. Intuitively, intersection types are finitary polymorphic types that model the multiple analyses for a given abstract closure, while union types are finitary existential types that model the merging of abstract values where flow paths join.…”

Type-Directed Continuation Allocation

“…The work presented in this paper is mainly inspired by recent research on effect inference [6,10,11,23,24], efficient implementation of first-class continuations [2,8,22,1], monads and modular interpreters [30,12,29,13], typed intermediate languages [7,26,20,17,16,3], and foreign function call interface [9,18]. In the following, we briefly explain the relationship of these work with our resource-based approach.…”

“…However, recent work [7,14,21,17,3,16,15] has mostly focused on the theoretical foundations and general language design issues. The type system in this paper focused on the problem of compiling multiple source languages into a common typed intermediate format.…”

Stack-based typed assembly language

“…Modern type-directed compilers [19,25,7,32,20,28,12] exploit the properties of typed languages more extensively than their predecessors by preserving type information computed in the front end through a series of typed intermediate languages. These compilers use types to direct sophisticated transformations such as closure conversion [18,31,17,4,21], region inference [8], subsumption elimination [9,11], and unboxing [19,24,29].…”