llvm dev - Nov 2012 - [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

Thanks Andrew for the update.

Does it support NotifyFunctionEmitted? 

Cheers.

-----Original Message-----
From: Kaylor, Andrew [mailto:andrew.kaylor at intel.com] 
Sent: Monday, November 26, 2012 1:06 PM
To: Manny Ko
Cc: LLVM Developers Mailing List
Subject: RE: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

The current 3.2 code branch has events being broadcast from the MCJIT engine
when a new object is emitted, but the profiling listeners do not do anything
with the events (and I don't expect they will before the 3.2 release becomes
official).

I have implemented some code in trunk since the 3.2 branch to traverse the
emitted object and pick out named functions in the IntelJITEventsListener.  An
update that uses debug information to get source file and line numbers for the
functions shouldn't be too far behind.  Once that is working, it should be a
very small task to port it over to the OProfile listener.

It's also worth noting that the MCJIT engine has support for registering
JITed code with GDB for source-level debugging on platforms that use the ELF
format.  I believe this was in place in the 3.1 release.  This is currently done
inside the MCJIT engine but it definitely should be moved to a JIT event
listener.  FWIW, the legacy JIT only registered function names and unwind
information (and I think even that may be gone now).

-Andy

-----Original Message-----
From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On
Behalf Of Manny Ko
Sent: Monday, November 26, 2012 9:27 AM
To: Eli Bendersky
Cc: Benjamin Kramer; LLVM Developers Mailing List
Subject: Re: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

Sorry for speaking too soon. It is missing from 3.2 which is the version I have
been using.  If it is already implemented than it is very good news.

Thanks.

-----Original Message-----
From: Eli Bendersky [mailto:eliben at google.com] 
Sent: Monday, November 26, 2012 9:25 AM
To: Manny Ko
Cc: Albert Graef; Benjamin Kramer; LLVM Developers Mailing List
Subject: Re: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

On Mon, Nov 26, 2012 at 9:18 AM, Manny Ko <Manny.Ko at imgtec.com>
wrote:
> I know the old JIT pretty well but have only used the MCJIT from the client
side. Most of my experience is on the x86backend though.
>
> Another critical feature missing from MCJIT is the JITEventListener.  This
is usually for supporting debuggers and profiling tools.

What makes you say it is missing?

Eli


_______________________________________________
LLVM Developers mailing list
LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
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No.  It adds a new event, 'NotifyObjectEmitted'.  The Intel JIT listener
that I mentioned then uses the emitted object to find the functions (which are
all emitted together).

Because of the way that MCJIT is implemented, it isn't really feasible to
reconstruct things like the EmittedFunctionDetails in the NotifyFunctionEmitted
event.

-Andy

-----Original Message-----
From: Manny Ko [mailto:Manny.Ko at imgtec.com] 
Sent: Monday, November 26, 2012 1:10 PM
To: Kaylor, Andrew
Cc: LLVM Developers Mailing List
Subject: RE: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

Thanks Andrew for the update.

Does it support NotifyFunctionEmitted? 

Cheers.

-----Original Message-----
From: Kaylor, Andrew [mailto:andrew.kaylor at intel.com] 
Sent: Monday, November 26, 2012 1:06 PM
To: Manny Ko
Cc: LLVM Developers Mailing List
Subject: RE: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

The current 3.2 code branch has events being broadcast from the MCJIT engine
when a new object is emitted, but the profiling listeners do not do anything
with the events (and I don't expect they will before the 3.2 release becomes
official).

I have implemented some code in trunk since the 3.2 branch to traverse the
emitted object and pick out named functions in the IntelJITEventsListener.  An
update that uses debug information to get source file and line numbers for the
functions shouldn't be too far behind.  Once that is working, it should be a
very small task to port it over to the OProfile listener.

It's also worth noting that the MCJIT engine has support for registering
JITed code with GDB for source-level debugging on platforms that use the ELF
format.  I believe this was in place in the 3.1 release.  This is currently done
inside the MCJIT engine but it definitely should be moved to a JIT event
listener.  FWIW, the legacy JIT only registered function names and unwind
information (and I think even that may be gone now).

-Andy

-----Original Message-----
From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On
Behalf Of Manny Ko
Sent: Monday, November 26, 2012 9:27 AM
To: Eli Bendersky
Cc: Benjamin Kramer; LLVM Developers Mailing List
Subject: Re: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

Sorry for speaking too soon. It is missing from 3.2 which is the version I have
been using.  If it is already implemented than it is very good news.

Thanks.

-----Original Message-----
From: Eli Bendersky [mailto:eliben at google.com] 
Sent: Monday, November 26, 2012 9:25 AM
To: Manny Ko
Cc: Albert Graef; Benjamin Kramer; LLVM Developers Mailing List
Subject: Re: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

On Mon, Nov 26, 2012 at 9:18 AM, Manny Ko <Manny.Ko at imgtec.com>
wrote:
> I know the old JIT pretty well but have only used the MCJIT from the client
side. Most of my experience is on the x86backend though.
>
> Another critical feature missing from MCJIT is the JITEventListener.  This
is usually for supporting debuggers and profiling tools.

What makes you say it is missing?

Eli


_______________________________________________
LLVM Developers mailing list
LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

I see. If I am writing my own listener can I still get back the (llvm::Function,
void* Code, size_t Size)?

Ciao.

-----Original Message-----
From: Kaylor, Andrew [mailto:andrew.kaylor at intel.com] 
Sent: Monday, November 26, 2012 1:24 PM
To: Manny Ko
Cc: LLVM Developers Mailing List
Subject: RE: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

No.  It adds a new event, 'NotifyObjectEmitted'.  The Intel JIT listener
that I mentioned then uses the emitted object to find the functions (which are
all emitted together).

Because of the way that MCJIT is implemented, it isn't really feasible to
reconstruct things like the EmittedFunctionDetails in the NotifyFunctionEmitted
event.

-Andy

-----Original Message-----
From: Manny Ko [mailto:Manny.Ko at imgtec.com] 
Sent: Monday, November 26, 2012 1:10 PM
To: Kaylor, Andrew
Cc: LLVM Developers Mailing List
Subject: RE: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

Thanks Andrew for the update.

Does it support NotifyFunctionEmitted? 

Cheers.

-----Original Message-----
From: Kaylor, Andrew [mailto:andrew.kaylor at intel.com] 
Sent: Monday, November 26, 2012 1:06 PM
To: Manny Ko
Cc: LLVM Developers Mailing List
Subject: RE: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

The current 3.2 code branch has events being broadcast from the MCJIT engine
when a new object is emitted, but the profiling listeners do not do anything
with the events (and I don't expect they will before the 3.2 release becomes
official).

I have implemented some code in trunk since the 3.2 branch to traverse the
emitted object and pick out named functions in the IntelJITEventsListener.  An
update that uses debug information to get source file and line numbers for the
functions shouldn't be too far behind.  Once that is working, it should be a
very small task to port it over to the OProfile listener.

It's also worth noting that the MCJIT engine has support for registering
JITed code with GDB for source-level debugging on platforms that use the ELF
format.  I believe this was in place in the 3.1 release.  This is currently done
inside the MCJIT engine but it definitely should be moved to a JIT event
listener.  FWIW, the legacy JIT only registered function names and unwind
information (and I think even that may be gone now).

-Andy

-----Original Message-----
From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On
Behalf Of Manny Ko
Sent: Monday, November 26, 2012 9:27 AM
To: Eli Bendersky
Cc: Benjamin Kramer; LLVM Developers Mailing List
Subject: Re: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

Sorry for speaking too soon. It is missing from 3.2 which is the version I have
been using.  If it is already implemented than it is very good news.

Thanks.

-----Original Message-----
From: Eli Bendersky [mailto:eliben at google.com] 
Sent: Monday, November 26, 2012 9:25 AM
To: Manny Ko
Cc: Albert Graef; Benjamin Kramer; LLVM Developers Mailing List
Subject: Re: [LLVMdev] Removing old JIT CodeEmitters for ARM and PPC

On Mon, Nov 26, 2012 at 9:18 AM, Manny Ko <Manny.Ko at imgtec.com>
wrote:
> I know the old JIT pretty well but have only used the MCJIT from the client
side. Most of my experience is on the x86backend though.
>
> Another critical feature missing from MCJIT is the JITEventListener.  This
is usually for supporting debuggers and profiling tools.

What makes you say it is missing?

Eli


_______________________________________________
LLVM Developers mailing list
LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev