similar to: [LLVMdev] An enhancement for MCJIT::getFunctionAddress

I should have read this before sending my previous reply. :-) I'm not a big fan of default parameters, but some form of what you are suggesting may be useful. See my other comments on this topic in the other reply. -Andy From: Yaron Keren [mailto:yaron.keren at gmail.com] Sent: Saturday, October 19, 2013 3:17 PM To: Kaylor, Andrew; <llvmdev at cs.uiuc.edu> Subject: An enhancement

The search is linear? If that’s really true, we should fix that. On Oct 21, 2013, at 10:14 AM, Kaylor, Andrew <andrew.kaylor at intel.com> wrote: > I should have read this before sending my previous reply. :-) > > I’m not a big fan of default parameters, but some form of what you are suggesting may be useful. See my other comments on this topic in the other reply. > >

There's probably a lot that we could do, but I can't think of anything easy. Basically every time we need to look up a symbol by name we're going to each module and saying "Do you have this symbol?" It would likely be much better if we grabbed the function names from the module and did the search ourselves so that we could keep some information about the things that

I don’t follow. Why are we looking at the module at all? That query should work even (especially) after the Module is deleted. We should be able to have a local symbol table that’s a DenseMap or something similar to resolve from names to target addresses. That map would be updated as part of the compilation when the object’s symbol table gets read. -Jim On Oct 21, 2013, at 4:55 PM, Kaylor,

Hi Jim, Clearly searching for name should not be linear in modules but with a map of some kind. After compilation to IR each module has a StringMap symbol table. After compiling to MC and loading the object file, the dynamic linker has a StringMap symbol table for all loaded modules. In the usual use case you'll load module(s) into MCJIT and then compile / link them and all is well, no

OS is Windows 7 64 bit OS, compiler is 32 bit Visual C++ 2012 with 32 bit. The target which is i686-pc-mingw32-elf so I can use the ELF dynamic loader. Code model, relocation model and and memory manager are whatever default for this - did not modify. The Module comes from clang. The source is 1000 or more lines repeating C++ code in one big function: A+1; A*B.t(); where A and B are

Hi all, I'm trying to add pre-compiled object cache to my run-time. I've implemented the object cache as follow: class EngineObjectCache : public llvm::ObjectCache { private: std::unordered_map<std::string, std::unique_ptr<llvm::MemoryBuffer>> CachedObjs; public: virtual void notifyObjectCompiled(const llvm::Module *M, llvm::MemoryBufferRef Obj) { auto id =

Hi, Thanks for your ideas. Memory allocation already exceeds 2x64K in the "working" case so it's not the condition of allocating more than 64K. To be sure I had modified SectionMemoryManager::allocateSection to allocate four time the required memory but it did not trigger more crashes.I debugged through the allocation code including the Win32 code and it seems to work well. I have

I would guess that it's crashing somewhere in the generated code. On Windows we don't have a way to get call stacks to the generated code (though if you want to try it on Linux, that should work). You can probably look at the address where the crash is occurring and verify that it is in the generated code. There are a couple of things I would look for. First, I'd take a look at the

YES, this is the problem! The program work ok, even a 5x larger version works well. Clearly the _chkstk calls must be emitted with ELF target on Windows as well - why not? I'd like to make a patch and fix this right. I experimented with both changes and practically only the lib/Target/X86/X86ISelLowering.cpp fixes the problem. The other change lib/Target/X86/X86FrameLowering.cpp was not

Yes, this is correct code address accessing bad data address. However, there is no other relocation before .text or near it. I'll send you the full debug printout, maybe you'll note something. The problem could be result of something else entirely else than the linker such as some library initialization code that by chance worked with smaller code but fails now. I need to debug and see

If it's a Windows-only thing the correct tests would be: if (NumBytes >= 4096 && STI.isOSWindows()) { and if (Subtarget->isTargetWindows()) where bool isOSWindows() const { return TargetTriple.isOSWindows(); } Yaron 2013/10/23 Andrew MacPherson <andrew.macp at gmail.com> > Glad that helped! As I understand it __chkstk is always required on > Windows

So it looks like 0x0A3600D1 is a good code address and there's no problem executing the code there, but 0x00BC7680 is a bad data address. Is that correct? If so, this is almost certainly a relocation problem. You just need to find a relocation that writes an entry (probably a relative offset) at 0x0A3600D1+the size of the instruction at that address. BTW, what I said before about not being

This is the right fix if Cygwin wants calls to __chkstk. Otherwise you'll want TargetTriple.isOSMSVCRT(). On Wed, Oct 23, 2013 at 2:50 AM, Yaron Keren <yaron.keren at gmail.com> wrote: > If it's a Windows-only thing the correct tests would be: > > if (NumBytes >= 4096 && STI.isOSWindows()) { > > and > > if (Subtarget->isTargetWindows()) >

Hi Yaron, If you're outputting ELF on Windows this sounds like an issue we ran into where __chkstk calls weren't being output in the assembly due to an explicit check for COFF output. Once stack allocations in a given function exceeded some amount we'd get exactly this kind of crash in the function initialization. If you take a look for isTargetCOFF() in

Glad that helped! As I understand it __chkstk is always required on Windows regardless of output type, I had meant to file a bug about this but had apparently forgotten to do so. I think the check needs to be that the target is Windows and ignore the output type, Linux and OSX don't use this. Cheers, Andrew On Wed, Oct 23, 2013 at 11:32 AM, Yaron Keren <yaron.keren at gmail.com>

I'm running in MCJIT a module generated from one C++ function. Every line of the source function uses C++ classes and may throw an exception. As long as there are less than (about) 1000 lines, everything works. With more lines the compiled code crashes when running it, with no sensible stack trace. Is there any kind of hard-coded size limitation in MCJIT / ELF Dynamic Linker / ELF codegen /

I don't think we should make flush virtual. Why do you need to do it? Can't you set up the base class to write to use the tail of the memory region as the buffer? On 24 April 2015 at 06:46, Yaron Keren <yaron.keren at gmail.com> wrote: > Hi, > > Is this what you're thinking about? > The code is not tested yet, I'd like to know if the overall direction and >

Could you dig into why: + raw_ostream &write(unsigned char C) override { + grow(1); + *OutBufCur++ = C; + return *this; + } Is 3 times as fast as raw_svector_ostream? I don't see a good reason why that should be any faster than: raw_ostream &operator<<(char C) { if (OutBufCur >= OutBufEnd) return write(C); *OutBufCur++ = C; return *this; }

Hi everyone, In llvm 4.0 the MCJIT::getFunctionAddress function return 0 (a null address) when the symbol is not found : *uint64_t MCJIT::getSymbolAddress(const std::string &Name, bool CheckFunctionsOnly) { std::string MangledName; { raw_string_ostream MangledNameStream(MangledName); Mangler::getNameWithPrefix(MangledNameStream, Name, getDataLayout()); } return