Fri 20 Nov 2020 11:00 - 11:20 at SPLASH-I - F-3A Chair(s): Stefan Marr, Reuben Rowe
In order to generate efficient code, dynamic language compilers often need
information, such as dynamic types, not readily available in the program
source. Leveraging a mixture of static and dynamic information, these
compilers speculate on the missing information. Within one compilation
unit, they specialize the generated code to the previously observed
behaviors, betting that past is prologue. When speculation fails, the
execution must jump back to unoptimized code. In this paper, we propose
an approach to further the specialization, by disentangling classes of
behaviors into separate optimization units. With contextual dispatch, functions are
versioned and each version is compiled under different assumptions. When a
function is invoked, the implementation dispatches to a version optimized
under assumptions matching the dynamic context of the call. As a
proof-of-concept, we describe a compiler for the R language which uses
this approach. Our implementation is, on average,
$1.7\times$ faster than the GNU R reference
implementation. We evaluate contextual dispatch on a set of benchmarks and
measure additional speedup, on top of traditional speculation with deoptimization
techniques. In this setting contextual dispatch improves the performance of 18 out of
46 programs in our benchmark suite.
Fri 20 Nov Times are displayed in time zone: Central Time (US & Canada) change
11:00 - 12:20 | F-3AOOPSLA at SPLASH-I +12h Chair(s): Stefan MarrUniversity of Kent, Reuben RoweUniversity College London | ||
11:00 20mTalk | Contextual Dispatch for Function Specialization OOPSLA Olivier FlückigerNortheastern University, Guido ChariAsapp, Ming-Ho YeeNortheastern University, Jan JečmenCzech Technical University, Jakob HainNortheastern University, Jan VitekNortheastern University / Czech Technical University Link to publication DOI Pre-print Media Attached | ||
11:20 20mTalk | Fixpoints for the Masses: Programming with First-Class Datalog Constraints OOPSLA Link to publication DOI Media Attached | ||
11:40 20mTalk | Verifying and Improving Halide’s Term Rewriting System with Program Synthesis OOPSLA Julie L. NewcombUniversity of Washington, Andrew AdamsAdobe Research, Steven JohnsonGoogle, Rastislav BodikUniversity of Washington, Shoaib KamilAdobe Research Link to publication DOI Media Attached | ||
12:00 20mTalk | Polymorphic Types and Effects with Boolean Unification OOPSLA Link to publication DOI Media Attached |