forked from OSchip/llvm-project
f9ca13cb5f
Summary:
As of binutils 2.32, ld has a bogus TLS relaxation error when the GD/LD
code sequence using R_X86_64_GOTPCREL (instead of R_X86_64_GOTPCRELX) is
attempted to be relaxed to IE/LE (binutils PR24784). gold and lld are good.
In gcc/config/i386/i386.md, there is a configure-time check of as/ld
support and the GOT relaxation will not be used if as/ld doesn't support
it:
if (flag_plt || !HAVE_AS_IX86_TLS_GET_ADDR_GOT)
return "call\t%P2";
return "call\t{*%p2@GOT(%1)|[DWORD PTR %p2@GOT[%1]]}";
In clang, -DENABLE_X86_RELAX_RELOCATIONS=OFF is the default. The ld.bfd
bogus error can be reproduced with:
thread_local int a;
int main() { return a; }
clang -fno-plt -fpic a.cc -fuse-ld=bfd
GOTPCRELX gained relative good support in 2016, which is considered
relatively new. It is even difficult to conditionally default to
-DENABLE_X86_RELAX_RELOCATIONS=ON due to cross compilation reasons. So
work around the ld.bfd bug by only using GOT when GOTPCRELX is enabled.
Reviewers: dalias, hjl.tools, nikic, rnk
Reviewed By: nikic
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64304
llvm-svn: 365752
|
||
|---|---|---|
| .. | ||
| Analysis | ||
| Assembler | ||
| Bindings | ||
| Bitcode | ||
| BugPoint | ||
| CodeGen | ||
| DebugInfo | ||
| Demangle | ||
| Examples | ||
| ExecutionEngine | ||
| Feature | ||
| FileCheck | ||
| Instrumentation | ||
| Integer | ||
| JitListener | ||
| LTO | ||
| Linker | ||
| MC | ||
| MachineVerifier | ||
| Object | ||
| ObjectYAML | ||
| Other | ||
| SafepointIRVerifier | ||
| Support | ||
| SymbolRewriter | ||
| TableGen | ||
| ThinLTO/X86 | ||
| Transforms | ||
| Unit | ||
| Verifier | ||
| YAMLParser | ||
| tools | ||
| .clang-format | ||
| CMakeLists.txt | ||
| TestRunner.sh | ||
| lit.cfg.py | ||
| lit.site.cfg.py.in | ||