On Fri, Feb 6, 2015 at 8:06 AM, Nicolas B. Pierron < nicolas.b.pier...@mozilla.com> wrote:
> On 02/06/2015 01:20 AM, Shu-yu Guo wrote: > >> I recently landed bug 1030389 to track the high-level optimizations >> decisions >> (i.e., deciding what MIR is emitted) made by IonBuilder. This information >> will feed into the profiler and is attached to sampled JIT frames. >> > > Not all optimization decisions are taken by IonBuilder, is there plan to > make this API available to other transformation phases. In particular, I > am thinking of Escape Analysis / GVN & LICM / Sink. > Not yet. Those transforms don't quite fit in the current pattern of using the profiler as a high pass filter. For instance, if escape analysis fails for some allocation, what code will be generated that, if hot and gets sampled frequently, is indicative of a significant slowdown? Another challenge is making the optimization failures actionable. If GVN fails for some SSA value, can we communicate this in a way such that the JS web dev can realistically do something to fix it? I think some transforms would be better candidates than others. Escape analysis in particular seems to me definitely deserves instrumentation. All of GVN, less so. > That's it! Instrumentation bugs also make great first bugs, and I would be >> happy to mentor. >> > > That's Great! > > Should we instrument every code path, or only instrument the code path > which have big cliff? > > I don't see any harm coming to instrumenting as much of IonBuilder as possible. But of course you're better served for your time to instrument the ones with big cliffs. :) > -- > Nicolas B. Pierron > > _______________________________________________ > dev-tech-js-engine-internals mailing list > dev-tech-js-engine-internals@lists.mozilla.org > https://lists.mozilla.org/listinfo/dev-tech-js-engine-internals > -- shu _______________________________________________ dev-tech-js-engine-internals mailing list dev-tech-js-engine-internals@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-tech-js-engine-internals
