similar to: [LLVMdev] JIT problem with thread local global variable

Hi, > I am trying to use LLVM JIT to emit the following codes and execute > both functions in my program, but > > I get segmentation fault, the problem seems to originate from "thread_local" > global variable. > > my LLVM library is 3.1 and platform is x86 32bit , OS : Ubuntu 10.04 try passing -use-mcjit to lli. The old JIT implementation didn't

Hi LLVM, I am using 3.0, and I have a question about the __thread in c and thread_local in LLVM IR: O1-O4 and the final linked code behave differently. //////////////////////////////////// The following C code is from the LLVM testcase (SingleSource/UnitTests/Threads/2010-12-08-tls.c) #include <stdio.h> __thread int a = 4; int foo (void) { return a; } int main (void) {

For everyone understand which code must be emitted to implement TLS, I will paste the code generated by gcc for a simple function: __thread int a = 1; int f(){ return a; } gcc teste.c -o teste.s -S -O2 (arm-linux-gnueabi): .global a .section .tdata,"awT",%progbits <== special section for tls symbols .align 2 .type a, %object

We know that in C++, the constructor of a static member will get called when the program starts up. I checked the generated IR code and found this is implemented by defining a __cxx_global_var_init() function and marked it as section ".text.startup" and assign it to @llvm.global_ctors. We also know that in C++, the constructor of a static thread_local member will *not* get called when

Hi all, I would like to hear your thoughts on adding support for extending the IR to allow for explicitly selecting which model to use for thread-local storage of a variable. The motivation is to allow Clang to support the "tls_model" variable attribute [1], as requested in PR9788. The idea would be to extend the IR to allow an optional TLS-model argument to the thread_local

Hi all, I've been exploring thread local globals in llvm and as part of this investigation I ran llc -march=cpp over a trivial llvm bc file which uses thread local storage for a global. For some reason llc -march=cpp seems to ignore the thread_local and produce code to create a standard global. Is this expected behaviour, a known limitation, or otherwise? Thanks in advance. Details are as

On Sun, Dec 4, 2011 at 9:18 AM, Kai <kai at redstar.de> wrote: > Hi! > > LLVM currently does not implement the implicit TLS model on Windows. This > model is easy: > > - a thread local variable ends up in the .tls section > - to access a thread local variable, you have to do >  (1) load pointer to thread local storage from TEB >      On x86_64, this is gs:0x58, on

Hi, If I'm writing a JIT, and want to access the TLS variables of the app containing the JIT, I can't use thread_local since that only works for variables declared in LLVM IL and/or managed by the ExecutionEngine. While this patch allows a JIT to generate the TLS accesses itself, if it knows the tls offset of the variable in question. Zoltan On Tue, May 5, 2009 at

Hello, The preferred way to do TLS is to use the thread_local keyword. There is x86-64 support for thread_local on ELF; if you need it for other targets, I recommend looking at adapting it. Dan On May 4, 2009, at 2:59 PM, Zoltan Varga wrote: > Hi, > > Here is an updated version of the patch using address space 257. > > Zoltan > > On Mon, May 4, 2009 at

I'm learning the xray library and try if it can be built on windows, in xray_fdr_logging_impl.h line 152 , comment written as // Using pthread_once(...) to initialize the thread-local data structures but at line 175, 183, code written as thread_local pthread_key_t key; // Ensure that we only actually ever do the pthread initialization once. thread_local bool UNUSED Unused = [] {

Hi During a pass, the XCore target lowers thread local global variables by turning them into global variable arrays indexed by the (max 8) thread ID. (see XCoreLowerThreadLocal.cpp) This works fine for instructions e.g. GetElementPtrInst But can't be done for constants e.g. GetElementPtrConstantExpr Thus I would like to replace GetElementPtrConstantExpr with GetElementPtrInst when it is

What exactly do the compiler flags`-femulated-tls` and `tls-model` do ? Why does tls-emulation not solve the problem ? Looking at the generated IR, it seems not to remove thread_local variable declarations. What is the reasoning behind that ? 2017-02-07 16:27 GMT+00:00 Gaetano Checinski <gaetano.checinski at gmail.com>: > > got a minimal example now: > extern thread_local

Reviving this thread with a patch! And some comments inline. Please take a look and let me know what you think. - Hans On Wed, Apr 25, 2012 at 12:39 PM, Hans Wennborg <hans at chromium.org> wrote: > Hi all, > > I would like to hear your thoughts on adding support for extending the > IR to allow for explicitly selecting which model to use for > thread-local storage of a

Hello, I apologize if this has already been fixed or reported. I believe there is a bug in the way the optimizer deals with thread_local variables. The attached program, test.c, has a thread-local variable "int Foo" and a global variable "int *Ptr". The program takes the following steps: 1) The main thread spawns a new thread and waits 2) The new thread writes Foo = 50 and

On May 4, 2009, at 3:16 PM, Dan Gohman wrote: > Hello, > > The preferred way to do TLS is to use the thread_local keyword. > There is x86-64 support for thread_local on ELF; if you need > it for other targets, I recommend looking at adapting it. That said, the X86 backend supporting access off FS is general goodness, right? -Chris

Hello, I am trying to compile some code to LLVM IR with a simple "__thread int x" but hitting this error: test.cpp:1:1: error: thread-local storage is unsupported for the current target I'm using both the -S and -emit-llvm options on clang, and was expecting to see "@x = thread_local global i32 0" come out of clang. I am curious why clang even cares about this since

I note also that this is not a currently unsupported target case where an error should/could/would be produced on attempting to emit code with thread local references. I say this because clang is able to compile both c source with __thread on a global and bc containing a @variable = thread_local global ... and a function that references the thread local global variable to both assembly and machine

> I’ve seen the same problem, but didn’t find solution back then. > I can give a hint that it is related to a thread local storage (notice TLS in the name). > > The same result can be reproduced by this simple program: > > thread_local int x = 0; > int main() { > return 0; > } > >When compiled into IR it produces similar error: > >LLVM ERROR:

> I note also that this is not a currently unsupported target case where an error should/could/would be produced on attempting to emit code with thread local references. I say this because clang is able to compile both c source with __thread on a global and bc containing a @variable = thread_local global ... and a function that references the thread local global variable to both assembly and

Please excuse hobbiest-level question. Darwin 11+ enables thread_local variables using system-level supports. I have an interest in enabling TLS on darwin < 11 using emulated-tls. This can be enabled with a few modest patches: ========================== --- a/include/llvm/ADT/Triple.h.orig 2018-10-02 17:38:10.000000000 -0700 +++ b/include/llvm/ADT/Triple.h 2018-10-02 17:38:58.000000000