<html><head><style>body{font-family:Helvetica,Arial;font-size:13px}</style></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">That's a good point. But it's worth noting that recompileAndRelinkFunction() and freeMachineCodeForFunction() are both vestiges of the old JIT (i.e. the "JIT" as opposed to the "MCJIT"). The old JIT is no longer actively supported.</div><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div> <div id="bloop_sign_1398532542363504896" class="bloop_sign"><div style="font-family:helvetica,arial;font-size:13px">-Phil</div><div style="font-family:helvetica,arial;font-size:13px"><br></div></div> <br><p style="color:#000;">On April 26, 2014 at 9:47:05 AM, Sri (<a href="mailto:emdcdeveloper@gmail.com">emdcdeveloper@gmail.com</a>) wrote:</p> <blockquote type="cite" class="clean_bq"><span><div bgcolor="#FFFFFF" text="#000000"><div></div><div>
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Hi Fillip<br>
Addition to my previous mail, llvm has recompileAndRelinkFunction
function , so, once we modified the llvm function, and pass
IR to recompileAndRelinkFunction , I hope it should be compiled and
linked with previous one.<br>
<br>
Thanks<br>
<br>
Regards<br>
Sri.<br>
<div class="moz-cite-prefix">On 04/26/2014 12:15 PM, Sri
wrote:<br></div>
<blockquote cite="mid:535B9546.1010001@gmail.com" type="cite">Hi
Filip<br>
Thank
you for your detailed explanation, I was actually looking to
implement an adaptive approach which is basically when some
function executed more frequently, I was trying to drop that
function and compiled and linked with new optimized function.
I just did the following -<br>
whenever some function executed more times , I called-back to
program, so I that I could be able to call
freeMachineCodeForFunction (F) then I compiled that more frequent
function with some kind of optimization. But , still I am getting
previous function signature and not newest one. Could you please
explain , why we can not use this freeMachineCodeForFunction for
this purpose. If not, how we can hook some instruction in emitted
machine code that will call back to our code in llvm.<br>
<br>
Thanks<br>
<br>
With regards<br>
Sri.<br>
<div class="moz-cite-prefix">On 04/26/2014 05:39 AM, Filip Pizlo
wrote:<br></div>
<blockquote cite="mid:8BB89150-85B9-4A8E-A291-76F886C590FD@apple.com" type="cite">
<div>This isn't currently supported directly. It depends on what
you're doing, which JIT you're using, how you use modules, and to
what extent you're relying on LLVM to do linking for
you. </div>
<div><br></div>
<div>You can't safely drop a function's code if you have other
functions in that module. </div>
<div><br></div>
<div>You can't safely drop a module if there are other modules that
have calls that you've already resolved to functions in the module
you're dropping unless you have your own mechanism for unlinking
those calls. </div>
<div><br></div>
<div>The MCJIT currently does support dropping the memory for a
module, but it involves destroying the MCJIT execution engine
object. This works best if you use your own JIT memory manager and
you steal the executable memory from the MCJIT, and delete the
MCJIT after code is generated. Then your own memory manager can
manage the memory however you like. This depends on not having LLVM
call instructions resolve to any of the functions you would be
dropping. WebKit is an example of a system that does this. Each
function gets it's own module and all LLVM data structures are
dropped once the code is compiled. Call instructions are only used
for intrinsics and for runtime calls; source level calls are
implemented as patchpoints and WebKit does all of the linking (and
unlinking). </div>
<div><br></div>
<div>Long story short, there is no shrink-wrapped solution but it's
doable if you're willing to get dirty. <br>
<br>
-Fil</div>
<div><br>
On Apr 25, 2014, at 3:44 PM, Sri <<a moz-do-not-send="true" href="mailto:emdcdeveloper@gmail.com">emdcdeveloper@gmail.com</a>>
wrote:<br>
<br></div>
<blockquote type="cite">
<div>Hi<br>
Currently , I have doing
some experimental work by using llvm, Is it possible to drop the
machine code once it has been generated for particular function
while program executing. For example some <b>void test(int)</b>
function has been executed on native machine , I want to drop the
code before I start execute some other function in my long
running program.<br>
<br>
Thanks.<br>
<br>
With regards<br>
Sri.<br>
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