Checked Load: Architectural support for JavaScript type-checking on mobile processors

Dynamic languages such as Javascript are the de-facto standard for web applications. However, generating efficient code for dynamically-typed languages is a challenge, because it requires frequent dynamic type checks. Our analysis has shown that some programs spend upwards of 20% of dynamic instructions doing type checks, and 12.9% on average. In this paper we propose Checked Load, a lowcomplexity architectural extension that replaces softwarebased, dynamic type checking. Checked Load is comprised of four new ISA instructions that provide flexible and automatic type checks for memory operations, and whose implementation requires minimal hardware changes. We also propose hardware support for dynamic type prediction to reduce the cost of failed type checks. We show how to use Checked Load in the Nitro JavaScript just-in-time compiler (used in the Safari 5 browser). Speedups on a typical mo

• Type: Journal
• Year: 2011
• Where: HPCA
• Authors: Owen Anderson, Emily Fortuna, Luis Ceze, Susan Eggers
• Keywords: Distributed And Parallel Computing, Dynamic Type, Dynamic Type Checks, HPCA 2011, Type Checks