<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi,<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Mar 24, 2019, at 1:47 PM, preejackie <<a href="mailto:praveenvelliengiri@gmail.com" class="">praveenvelliengiri@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" class="">
<div bgcolor="#FFFFFF" text="#000000" class=""><p class=""><font face="Courier New, Courier, monospace" class="">Hi Bekket, <br class="">
</font></p><p class=""><font face="Courier New, Courier, monospace" class="">Sorry for the
delayed reply.</font></p><p class=""><font face="Courier New, Courier, monospace" class="">By appropriate, I
mean performance of compiled native code.</font></p></div></div></blockquote>I think you need more evaluations on that. As there are too many factors affecting the quality of generated code.<br class=""><blockquote type="cite" class=""><div class=""><div bgcolor="#FFFFFF" text="#000000" class=""><p class=""><font face="Courier New, Courier, monospace" class="">
</font></p><p class=""><font face="Courier New, Courier, monospace" class="">I was referring
other JIT implementations like LuaJIT & webkit FTL JIT to
see how they implement their JIT. I have gone through the design
of Spider Monkey & Android runtime (ART) JIT. As, you said
both region based and method based compilation unit have their
own advantage & disadvantage. Both make use of profile
generation for hot-code regions/functions. I have planned to
rethink my idea of implementing "function based" instead of
"region based" compilation unit. Because, trace-based jit
requires considerable development time & time taken to find
hot code region from IR with profile support is high. In my
opinion these are difficult to get implemented within 11 weeks
(summer time) and make a way to trunk for real use by people.<br class=""></font></p></div></div></blockquote>I totally agree with your plan. Function based JIT make more sense for a 3-month project in terms of engineering efforts for a deliverable result. Also, LLVM already has plenty of handy and mature call graph as well as inter-procedure toolkits you can use.<br class=""><blockquote type="cite" class=""><div class=""><div bgcolor="#FFFFFF" text="#000000" class=""><p class=""><font face="Courier New, Courier, monospace" class="">
</font></p><p class=""><font face="Courier New, Courier, monospace" class="">Also, LLVM ORC v2
resembles more like a function based approach. I think it would
be easier to built a runtime profiler around it and make use of
that profile data in compilelayer of ORC to recompile hot
functions speculatively with more optimization. As far as I
know, many JIT implementations uses profilers to decide hot code
functions than information from their intermediate
representation because of the dynamic nature of
compiled/interpreting source language. This make me focus more
runtime profilers than analysis on IR. Of course, analysis from
IR will be useful in start phase of JIT compilation.</font></p><div class=""><br class=""></div></div></div></blockquote>Regarding profiling, just as a FYI, you might want to take a look at the (PGO-guided) Hot/Cold code splitting toolkit landing in LLVM just few months ago. Although it takes static PGO profile, but I believe you can leverage the static PGO framework in LLVM as foundation for your dynamic profiling.<br class=""><blockquote type="cite" class=""><div class=""><div bgcolor="#FFFFFF" text="#000000" class=""><p class=""><font face="Courier New, Courier, monospace" class="">I find
IntelJITEvents in Execution Engine, is there any documentation
on it's use cases? If you have thoughts over it, please share :)
<br class=""></font></p></div></div></blockquote>I’d never used that, sorry<br class=""><blockquote type="cite" class=""><div class=""><div bgcolor="#FFFFFF" text="#000000" class=""><p class=""><font face="Courier New, Courier, monospace" class="">
</font></p><p class=""><font face="Courier New, Courier, monospace" class="">Thanks<br class=""></font></p></div></div></blockquote>Best,</div><div>Bekket<br class=""><blockquote type="cite" class=""><div class=""><div bgcolor="#FFFFFF" text="#000000" class=""><p class=""><font face="Courier New, Courier, monospace" class="">
</font></p><p class=""><font face="Courier New, Courier, monospace" class=""><br class="">
</font></p><p class=""><br class="">
</p>
<div class="moz-cite-prefix">On 24/03/19 10:30 AM, Bekket McClane
wrote:<br class="">
</div>
<blockquote type="cite" cite="mid:145326D8-8D0B-45E9-B104-52E5541B0809@gmail.com" class="">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" class="">
Hi,
<div class=""><br class="">
</div>
<div class="">This idea sounds pretty cool</div>
<div class="">Just some quick comments inlined below:<br class="">
<div class=""><br class="">
<blockquote type="cite" class="">
<div class="">On Mar 23, 2019, at 1:57 PM, preejackie via
llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" class="" moz-do-not-send="true">llvm-dev@lists.llvm.org</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<meta http-equiv="content-type" content="text/html;
charset=UTF-8" class="">
<div bgcolor="#FFFFFF" text="#000000" class="">
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Hi all,
</span></font></div><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;" class=""><font class="" face="Courier New, Courier,
monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">
</span></font></p>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">I would like to propose "Speculative compilation support in ORC v2 JIT API" for this year GSoC summer project.</span></font></div><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;" class=""><font class="" face="Courier New, Courier,
monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">
</span></font></p>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Project Description: </span></font></div>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class=""> </span><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Speculative compilation support. One of the selling points of the concurrent ORC APIs is that you can start compiling a function before you need it, in the hope that by the time that you do need it it is already compiled. However, if we just speculatively compile everything we're quickly going to overload our memory/CPU resources, which will be lousy for performance. What we really want to do is to take into account any information we have (from high level program representations, e.g. ASTs or CFGs, or from profiling data from previous executions) to try to guess what functions are worth speculatively compiling next. </span></font></div>
<font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Idea is proposed by Lang Hames.</span></font><font class="" face="Courier New, Courier, monospace"><br class="">
</font><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;" class=""><font class="" face="Courier New, Courier,
monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">
</span></font></p>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Current Status of ORC v2: </span></font></div>
<font class="" face="Courier New, Courier, monospace"><br class="">
</font>
<ol style="margin-top:0pt;margin-bottom:0pt;" class="">
<li dir="ltr" style="list-style-type: decimal; font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre; margin-left: 36pt;" class=""><div style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">ORC currently supports concurrent compilation and Lazy (on request compilation), trunk contains default new ORC JIT implementations as LLJIT, LLLazyJIT. </span></font></div></li>
<li dir="ltr" style="list-style-type: decimal; font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre; margin-left: 36pt;" class=""><div style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">[WIP] Jit-linker a drop-in-replacement for RuntimeDyld atleast for MachO in ORC JIT.</span></font></div></li>
<li dir="ltr" style="list-style-type: decimal; font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre; margin-left: 36pt;" class=""><div style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Primitive code to handle speculative is in trunk. But it needs to refactored & designed to get generalized, simple APIs to support speculation.</span></font></div></li>
<li dir="ltr" style="list-style-type: decimal; font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre; margin-left: 36pt;" class=""><div style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Currently, no heuristics to support speculation in trunk.</span></font></div></li>
</ol>
<font class="" face="Courier New, Courier, monospace"><br class="">
</font>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Proposed Solution: </span></font></div>
<ol style="margin-top:0pt;margin-bottom:0pt;" class="">
<li dir="ltr" style="list-style-type: decimal; font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre; margin-left: 36pt;" class=""><div style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">New APIs in ORC v2 to support speculation compilation of LLVM bitcode. LLSpecJIT - subtype of LLJIT, default JIT with speculation support in trunk. </span></font></div></li>
<li dir="ltr" style="list-style-type: decimal; font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre; margin-left: 36pt;" class=""><div style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Heuristics to guide speculation - </span></font></div></li>
</ol>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt; margin-left: 108pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Currently, I’m going through some literature/research papers to find good basic heuristics. We can derive useful information from Control flow graphs, IR etc. So far I figured out that </span><span style="font-size: 12pt; background-color: transparent; font-weight: 700; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Region-based compilation </span><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">is more appropriate for speculation. </span></font></div>
</div>
</div>
</blockquote>
<div class=""><br class="">
</div>
<div class="">Can you justify your point? What do you mean by saying
“appropriate”? Is it easy to implement or have better
performance on the generated code?</div>
<div class=""><br class="">
</div>
<div class="">Just a FYI:</div>
<div class="">The JIT compilation community has been debating over
which compilation region should be chosen for quite some
time.</div>
<div class="">The TL;DR answer is: there is NO single answer, all
depends on the usages and engineering efforts. </div>
<div class="">Just give you examples on two of the most adopted
methods: trace-based(kind of similar to region based) and
function-based.</div>
<div class="">Famous users of trace-based JIT are early versions of
SpiderMonkey(i.e. JS engine in Firefox) and Dalvik VM(i.e.
the old VM in Android). This approach can record hot path
across functions, and just like the old saying: global
optimizations are always preferred. However, it requires
more engineering efforts and profiling/tracing is almost
mandatory.</div>
<div class="">Function-based JIT is used by V8 and ART(Android Runtime,
the current VM in Android), to name a few. The biggest
advantage is that it’s pretty easy to implement. And the
performance is actually not bad in most of the cases. The
downside is , of course, it will loose some global
optimization opportunities. </div>
<div class=""><br class="">
</div>
<div class="">Be honestly I’m pretty surprised you didn’t mention any
of the above projects. Of course, none of them use LLVM, but
all of them are outstanding JIT engines with huge amount of
users and tested by time. Some of them are even important
milestones in the history of dynamic compilation. I believe
you can learn the key insight of choosing a specific
compilation region from them.</div>
<br class="">
<blockquote type="cite" class="">
<div class="">
<div bgcolor="#FFFFFF" text="#000000" class="">
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt; margin-left: 108pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Since, unit of compilation (granularity) is key good dynamic compilation, region based compilation address that by forming frequently executed code as a region (unit), this can be basic block, function or group of functions. But since, LLVM JIT API needs interoperates with static compiler, unit of compilation here is a complete module. </span></font></div>
</div>
</div>
</blockquote>
<br class="">
<blockquote type="cite" class="">
<div class="">
<div bgcolor="#FFFFFF" text="#000000" class="">
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt; margin-left: 108pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">The plan in mind is to break the module into regions and compile regions speculatively using multiple JIT backend light weight threads. I’m still not sure, how this can be done, I would highly appreciate the feedback from community in deciding the heuristics & granularity to compile.</span></font></div>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class=""> </span><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class=""> </span><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">3.Practical example with benchmarks: To my best of knowledge PostgreSQL using ORC API, it would be easier to get postgresql queries to get compile speculatively and compare results with baseline (concurrent compiler without speculation).</span></font></div>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class=""> </span><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class=""> </span><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">4. Unit tests + documentation.</span></font></div>
<font class="" face="Courier New, Courier, monospace"><br class="">
</font>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Benefits:</span><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class=""> </span></font></div>
<ol style="margin-top:0pt;margin-bottom:0pt;" class="">
<li dir="ltr" style="list-style-type: decimal; font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre; margin-left: 72pt;" class=""><div style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">We can full use of multiple compilation threads, to compile code upfront with minimum false positive. </span></font></div></li>
<li dir="ltr" style="list-style-type: decimal; font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre; margin-left: 72pt;" class=""><div style="line-height: 1.38; margin-top: 0pt; margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Stabilize JIT APIs which most clients looking for when transitioning to newer versions.</span></font></div></li>
</ol>
<font class="" face="Courier New, Courier, monospace"><br class="">
</font>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Further Opportunities : </span></font></div>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">We can also use thinlto summaries in module to decide which code is worthier to compile next, based on this lighting </span><a href="https://www.youtube.com/watch?v=ZCnHxRhQmvs" style="text-decoration:none;" class="" moz-do-not-send="true"><span style="font-size: 12pt; color: rgb(17, 85, 204); background-color: transparent; font-weight: 400; font-style: normal; font-variant: normal; text-decoration: underline; vertical-align: baseline; white-space: pre-wrap;" class="">LLVM Dev talk by Stefan</span></a><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">. </span></font></div>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Profile guided optimization - information will be helpful in this, provide further room for improvement.</span></font></div><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;" class=""><font class="" face="Courier New, Courier,
monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class=""> </span></font></p>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">I would highly appreciate the community feedback & suggestions :)
</span></font></div>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">I will try my best to address all the comments in the proposal. I'm currently familiarizing myself with new APIs and learning heuristics. I will try to get the draft proposal by next week.</span></font></div><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;" class=""><font class="" face="Courier New, Courier,
monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">
</span></font></p>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">References: HHVM JIT: A profile-Guided, Region-Based Compiler for PHP & Hack [<a moz-do-not-send="true" href="https://dl.acm.org/citation.cfm?id=3192374" class="">paper</a>].</span></font></div>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">PostgreSQL [<a moz-do-not-send="true" href="https://doxygen.postgresql.org/structLLVMJitHandle.html" class="">JIT</a>]
</span></font></div>
<div style="line-height: 1.38; margin-top: 0pt;
margin-bottom: 0pt;" class=""><font class="" face="Courier New, Courier, monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">Execution Engine [<a moz-do-not-send="true" href="https://reviews.llvm.org/diffusion/L/browse/llvm/trunk/lib/ExecutionEngine/Orc/" class="">ORC</a>]
</span></font></div><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;" class=""><font class="" face="Courier New, Courier,
monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class=""></span></font></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;" class=""><font class="" face="Courier New, Courier,
monospace"><span style="font-size: 12pt; background-color: transparent; font-weight: 400; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-position: normal; text-decoration: none; vertical-align: baseline; white-space: pre-wrap;" class="">
</span></font></p>
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</div>
<div class="">Best,</div>
<div class="">Bekket</div>
<br class="">
<blockquote type="cite" class="">
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<pre class="moz-signature" cols="72"><font class="" face="Courier New, Courier, monospace">--
Have a great day!
PreeJackie</font></pre>
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<pre class="moz-signature" cols="72">--
Have a great day!
PreeJackie</pre>
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