http://www.nynaeve.net Adventures in Windows debugging and reverse engineering. Tue, 24 Aug 2010 12:00:36 +0000 http://backend.userland.com/rss092 en Yesterday, I provided a brief performance overview of the MSIL JIT backend versus my implementation of an interpretive VM for various workloads. Today, I'll mostly pontificate on conclusions from the JIT project. It has certainly been an interesting foray into .NET, program analysis, and code generation; the JIT engine is ... http://www.nynaeve.net/?p=486 Last time, we learned how SAVE_STATEs are supported by the MSIL JIT backend. This time, we'll touch on everybody's favorite topic -- performance. After all, the whole point of the JIT project is to improve performance of scripts; there wouldn't be much point in using it over the interpretive VM ... http://www.nynaeve.net/?p=483 Yesterday, I described how the fast action call mechanism improves action call performance for JIT'd programs. For today's NWScript adventure, let's dig into how SAVE_STATE operations (script situations) are supported in the MSIL JIT backend. As you may recall, SAVE_STATE operations (codified by I_SAVE_STATE in the IR instruction set and ... http://www.nynaeve.net/?p=479 Previously, I explained how the 'fast' action service call interface worked -- and why it doesn't always live up to its namesake. This time, we'll examine the no-holds-barred, non-verifiable direct fast action call path. This action service call mechanism is designed for maximum performance at the expense of type-safe, verifiable ... http://www.nynaeve.net/?p=473 Yesterday, we learned how the standard action service call path operates in the MSIL JIT backend for the NWScript JIT engine. This time, we'll examine the 'fast' action service call path. As I alluded to last time, the fast action service call path attempts to cut down on the overhead ... http://www.nynaeve.net/?p=398 Last time, I outlined the general usage of the JIT intrinsics emitted by the MSIL backend for the NWScript JIT engine, and how they relate to action service calls. Today, let's take a closer at how an action service handler is actually called in NWScript in the wild. The MSIL ... http://www.nynaeve.net/?p=389 Previously, I demonstrated how a simple NWScript subroutine could be translated into MSIL, and then to native instructions by the CLR JIT. We still have a large piece of functionality to cover, however, which is calling action service handlers (extension points) from JIT'd code. In order to understand ... http://www.nynaeve.net/?p=386 Yesterday, I expounded on the basics of how assemblies for scripts are structured, and how variables, subroutines, and IR instructions are managed throughout this process. Nothing beats a good concrete example, though, so let's examine a sample subroutine, both in NWScript source text form, and then again in MSIL form, and ... http://www.nynaeve.net/?p=453 Last time, I outlined the MSIL JIT backend from a high level, and described some of how its external interface functions. While knowing how the MSIL JIT backend works from the outside is all well and good, most of the interesting parts are in the internals. This time, let's dig ... http://www.nynaeve.net/?p=435 Yesterday, we examined the IR instruction raising process, at a high level. With a basic understanding of both how the IR is generated, and the IR design itself, we can begin to talk about the JIT backends supported by the JIT system. The first supported JIT backend is the MSIL ... http://www.nynaeve.net/?p=417