search for: __exchange_and_add

...1, [sp, #4]0000004e e8512f00 ldrex r2, [r1]00000052 9200 str r2, [sp, #0]00000054 441a add r2, r300000056 e8412c00 strex ip, r2, [r1]0000005a f1bc0f00 cmp.w ip, #0 @ 0x00000005e d1f6 bne.n 0x4e... What happens in the code between 4e and 5e is an atomic check of a variable by the inlined __exchange_and_add. The problem is that the result read by ldrex is stored by the inline optimization on the stack for further use. However, as the atomically read variable is also on the stack and resides very close to this compiler-induced intermediate storage - the write hits the ERG. On Apple's A6X devices th...

> I've encountered this issue in a real code and would be glad to get the > feedback on it. Please let me know if I need to submit a bug somewhere to get it resolved. I've found out that clang does not have this problem. Then use clang. llvm-gcc is deprecated. -- With best regards, Anton Korobeynikov Faculty of Mathematics and Mechanics, Saint Petersburg State University

On Sun, Feb 03, 2013 at 10:32:35AM -0800, Chris Lattner wrote: > > On Feb 3, 2013, at 2:32 AM, Anton Korobeynikov <anton at korobeynikov.info> wrote: > > >> I've encountered this issue in a real code and would be glad to get the > >> feedback on it. Please let me know if I need to submit a bug somewhere to get it resolved. I've found out that clang does

On Feb 3, 2013, at 2:32 AM, Anton Korobeynikov <anton at korobeynikov.info> wrote: >> I've encountered this issue in a real code and would be glad to get the >> feedback on it. Please let me know if I need to submit a bug somewhere to get it resolved. I've found out that clang does not have this problem. > Then use clang. llvm-gcc is deprecated. I'd go farther:

On 2013-02-04 05:57, Chris Lattner wrote: > On Feb 3, 2013, at 11:28 AM, Jack Howarth <howarth at bromo.med.uc.edu> wrote: ... >> At the risk of hijacking the thread, are there any plans to make -traditional-cpp >> in clang completely emulate the behavior in llvm-gcc such that imake can be built >> with it (https://bugs.freedesktop.org/show_bug.cgi?id=45509). This will

On Feb 3, 2013, at 11:28 AM, Jack Howarth <howarth at bromo.med.uc.edu> wrote: > On Sun, Feb 03, 2013 at 10:32:35AM -0800, Chris Lattner wrote: >> >> On Feb 3, 2013, at 2:32 AM, Anton Korobeynikov <anton at korobeynikov.info> wrote: >> >>>> I've encountered this issue in a real code and would be glad to get the >>>> feedback on it.

...ay down below. But first some background info. One recipe to recreate the crash works with a new version 5.0-1 of the mixOmics package: > library(mixOmics) > example(pca) This crashes with messages like this: Program received signal SIGSEGV, Segmentation fault. 0x00007ffff28aafd9 in __exchange_and_add (__mem=0x7f7fffff7f7ffff7, __val=<optimized out>) at /usr/include/c++/4.7/ext/atomicity.h:48 48 { return __atomic_fetch_add(__mem, __val, __ATOMIC_ACQ_REL); } The call stack ends with this: #0 0x00007ffff28aafd9 in __exchange_and_add (__mem=0x7f7fffff7f7ffff7, __val=<op...

...ith regular non-llvm gcc to native sparc binary) functions from within LLVM code? Or ABI is competely broken? > LLVM code generation doesn't appear to correctly implement atomic > builtins, but that should be a trivial thing to fix (so they tell me). Do you mean calls like __gnu_cxx::__exchange_and_add ? -- Best Regards Peter Shugalev

On Tue, 11 Nov 2008, Peter Shugalev wrote: > Anton Korobeynikov wrote: >> And fix 32 bit ones :) Mostly byval stuff + FP arguments. > > How serious these bugs are? Any link to bug descriptions? Is LLVM sparc > target usable and stable in case of not using any FP stuff? > There are usually two levels of translation that go on. First, your C/C++ code is compiled to LLVM IR

Core was generated by `dovecot/indexer-worker'. Program terminated with signal 11, Segmentation fault. #0 0x00007f30f7ad056d in __exchange_and_add (__val=-1, __mem=0xfffffffffffffff8) at /usr/src/debug/gcc-4.8.5-20150702/obj-x86_64-redhat-linux/x86_64-redhat-linux/libstdc++-v3/include/ext/atomicity.h:49 49 { return __atomic_fetch_add(__mem, __val, __ATOMIC_ACQ_REL); } (gdb) bt full #0 0x00007f30f7ad056d in __exchange_and_add (__val=-1...

...llvm/Intrinsics.td -o /Users/jyasskin/src/llvm-2.5/obj/lib/VMCore/Debug/Intrinsics.gen.tmp -gen-intrinsic Reading symbols for shared libraries +++.. done Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_PROTECTION_FAILURE at address: 0x0010eb75 0x963646e1 in __gnu_cxx::__exchange_and_add () (gdb) bt #0 0x963646e1 in __gnu_cxx::__exchange_and_add () #1 0x96354070 in std::string::_Rep::_M_dispose () #2 0x963560a6 in std::string::assign () #3 0x000ecd67 in llvm::cl::initializer<char [2]>::apply<llvm::cl::opt<std::string, false, llvm::cl::parser<std::string> >...

...-llvm gcc to native sparc binary) functions from within > LLVM code? Or ABI is competely broken? I think best answer will be: try it and let us know :) Currently there is no active sparc maintainer, thus it will be safe to assume it to be arbitrary broken. > Do you mean calls like __gnu_cxx::__exchange_and_add ? http://gcc.gnu.org/onlinedocs/gcc/Atomic-Builtins.html -- With best regards, Anton Korobeynikov Faculty of Mathematics and Mechanics, Saint Petersburg State University

LLVMers, The 2.5 pre-release is available for testing: http://llvm.org/prereleases/2.5/ If you have time, I'd appreciate anyone who can help test the release. Please do the following: 1) Download/compile llvm source, and either compile llvm-gcc source or use llvm-gcc binary (please compile llvm-gcc with fortran if you can). 2) Run make check, send me the testrun.log 3) Run "make