similar to: [LLVMdev] Why would -disable-fp-elim cause SEGV in JIT, when without it code works fine?

You said this is on 32-bit x86? My understanding is that in that case, gdb will use ebp/esp to unwind the stack and doesn't need dwarf. It may have different behavior on FreeBSD if frame pointers are normally omitted on that platform. gdb ignores them on Linux x86_64 because they are generally omitted. This might actually be the best explanation for your symptoms, since this is what a gdb

On 06/23/2010 10:24, Reid Kleckner wrote: > You said this is on 32-bit x86? My understanding is that in that > case, gdb will use ebp/esp to unwind the stack and doesn't need dwarf. > It may have different behavior on FreeBSD if frame pointers are > normally omitted on that platform. gdb ignores them on Linux x86_64 > because they are generally omitted. > > This might

> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Xin Tong > Subject: [LLVMdev] Cast Pointer Address to Functions > I have a function address held in an uint64_t. I would like to cast > the function address to a function prototype and create a call to the > function in LLVM. How could I do this ? This is what works for us:

I have this problem: google-perftools fails to detect stack for the code run under JIT called through C++ api from my program. It shows in profile like all program is one block with the name _init. I clearly do set the option NoFramePointerElim and I do see how it makes a difference in stack frame under gdb. When running some code in JIT in lli (with option -disable-fp-elim) google perftools

Hi all, Is there a way to specify an attribute in a .ll file so that it will disable fp elim as if llc has been invoked with -disable-fp-elim on command line ? Thanks for your answers Best Regards Seb -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20120308/1d4875f1/attachment.html>

I have a function address held in an uint64_t. I would like to cast the function address to a function prototype and create a call to the function in LLVM. How could I do this ? Thanks Xin

How/where are function prologs and epilogs generated, is it bespoke C++ code or TableGen generated ? If someone could point me in the right direction please. Many thanks in advance, Aaron -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20090409/fb3336e4/attachment.html>

On Thu, Apr 9, 2009 at 4:34 PM, Anton Korobeynikov <anton at korobeynikov.info>wrote: > Hello, Aaron > > > How/where are function prologs and epilogs generated, is it bespoke C++ > code > > or TableGen generated ? > > > > If someone could point me in the right direction please. > Calling convention is really-really far from prologue/epilogue emission :)

I am trying to run some code allocating a lot of memory and not releasing it in JIT under google-perftools. Just one function 'main' calling 'malloc'. google-perftools fails to correctly read stack when malloc is called from inside the JITted code, and as a result perftools report is wrong: address of 'main' procedure appears shifted 0x3946e1d0->0x3946e1ed and is

On Jun 18, 2010, at 3:29 AM, Yuri wrote: > Now I see that JITted code doesn't have standard prolog, on x86 each > procedure instead begins with 'sub $0x4,%esp'. > > Is there an option to make JIT generate regular prologs? Try turning off frame pointer elimination. On the llc command line, this is -disable-fp-elim -Chris > > Yuri >

This new option (--jit-emit-debug-function-range) will allow to output function information for memory ranges that functions occupy in memory while they run in JIT. File format generated is like this: ... 0x5000000 0x5001000 function_name_is_here ... This feature is useful for external tools like valgrind and google-perftools to profile the code when it is run in JIT. Particularly

Hello, Aaron > How/where are function prologs and epilogs generated, is it bespoke C++ code > or TableGen generated ? > > If someone could point me in the right direction please. Calling convention is really-really far from prologue/epilogue emission :) So: 1. Calling conventions Partly tablegen / partly C++ code. Look for CodeGen/SelectionDAG/CallingConvLower.cpp,

On 06/21/2010 14:14, Reid Kleckner wrote: > Since FreeBSD is an ELF target, this should work fine. I've also > tested that this works in 32-bit by building gdb and llvm in 32-bit > mode and testing this stuff while running on a 64-bit OS. > > I would try setting a breakpoint in gdb on > 'llvm::JITDebugRegisterer::RegisterFunction' to see that it is being > called,

On Apr 9, 2009, at 11:11 AMPDT, Aaron Gray wrote: > On Thu, Apr 9, 2009 at 4:34 PM, Anton Korobeynikov <anton at korobeynikov.info > > wrote: > Hello, Aaron > > > How/where are function prologs and epilogs generated, is it > bespoke C++ code > > or TableGen generated ? > > > > If someone could point me in the right direction please. > Calling

On 06/21/2010 11:14, Reid Kleckner wrote: > Yes, I have some version of 7.1 installed on my workstation and it works for me. I repeted what you did step by step and it still doesn't work for me, see log below. Two differences: I am on FreeBSD and it's 32 bit. It's svn revision 105825. Plus I have few unrelated patched applied to it which shouldn't matter. Yuri $ lli

Since FreeBSD is an ELF target, this should work fine. I've also tested that this works in 32-bit by building gdb and llvm in 32-bit mode and testing this stuff while running on a 64-bit OS. I would try setting a breakpoint in gdb on 'llvm::JITDebugRegisterer::RegisterFunction' to see that it is being called, and that getELFWriterInfo returns something. If that function actually

Hi, I have a function with: attributes #2 = { "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" } Yet when compiling it generates: https://gist.github.com/carlokok/7c3c98d2fd8c966671f40a5ad94f19d3 (Note how it checks fFinalizer before setting up ebp). It also has a: .loc 36 195 7 prologue_end before this happens How can I get llvm to do the frame

> I don't understand exactlly the difference among main function, prologue > code, and call function. I'm not sure that I understand your question. LLVM abstracts away target-specific information like function prologs and epilogs. If you are curious about the typical arrangement used by unix systems with _start and main, LLVM does not have that. Basically it uses 'main'

Now I see that JITted code doesn't have standard prolog, on x86 each procedure instead begins with 'sub $0x4,%esp'. Is there an option to make JIT generate regular prologs? Yuri

On Sat, Jun 19, 2010 at 4:35 AM, Chris Lattner <clattner at apple.com> wrote: > > On Jun 18, 2010, at 3:29 AM, Yuri wrote: > >> Now I see that JITted code doesn't have standard prolog, on x86 each >> procedure instead begins with 'sub    $0x4,%esp'. >> >> Is there an option to make JIT generate regular prologs? > > Try turning off frame