diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp index 9f59132d1176e..9fb97df01b081 100644 --- a/llvm/lib/Target/X86/X86MCInstLower.cpp +++ b/llvm/lib/Target/X86/X86MCInstLower.cpp @@ -1024,7 +1024,14 @@ void X86AsmPrinter::LowerTlsAddr(X86MCInstLower &MCInstLowering, const MCSymbolRefExpr *Sym = MCSymbolRefExpr::create( MCInstLowering.GetSymbolFromOperand(MI.getOperand(3)), SRVK, Ctx); - const bool UseGot = MMI->getModule()->getRtLibUseGOT(); + + // 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). Work around the bug by + // only using GOT when GOTPCRELX is enabled. + // TODO Delete the workaround when GOTPCRELX becomes commonplace. + bool UseGot = MMI->getModule()->getRtLibUseGOT() && + Ctx.getAsmInfo()->canRelaxRelocations(); if (Is64Bits) { bool NeedsPadding = SRVK == MCSymbolRefExpr::VK_TLSGD; diff --git a/llvm/test/CodeGen/X86/tls-no-plt.ll b/llvm/test/CodeGen/X86/tls-no-plt.ll index 5ca9448e011e3..b076a77e8adb9 100644 --- a/llvm/test/CodeGen/X86/tls-no-plt.ll +++ b/llvm/test/CodeGen/X86/tls-no-plt.ll @@ -1,5 +1,10 @@ -; RUN: llc < %s -mtriple=i386-linux-musl -relocation-model=pic | FileCheck --check-prefixes=CHECK,X86 %s -; RUN: llc < %s -mtriple=x86_64-linux-musl -relocation-model=pic | FileCheck --check-prefixes=CHECK,X64 %s +; RUN: llc < %s -mtriple=i386-linux-musl -relocation-model=pic -relax-elf-relocations=true | FileCheck --check-prefixes=CHECK,X86 %s +; RUN: llc < %s -mtriple=x86_64-linux-musl -relocation-model=pic -relax-elf-relocations=true | FileCheck --check-prefixes=CHECK,X64 %s + +;; If GOTPCRELX is disabled, don't use GOT for __tls_get_addr to work around +;; a ld.bfd bug (binutils PR24784). +; RUN: llc < %s -mtriple=i386-linux-musl -relocation-model=pic -relax-elf-relocations=false | FileCheck --check-prefixes=CHECK,X86-PLT %s +; RUN: llc < %s -mtriple=x86_64-linux-musl -relocation-model=pic -relax-elf-relocations=false | FileCheck --check-prefixes=CHECK,X64-PLT %s @gd = thread_local global i32 0 @ld = internal thread_local global i32 0 @@ -9,9 +14,11 @@ entry: ; CHECK-LABEL: get_gd: ; X86: leal gd@TLSGD(%ebx), %eax ; X86: calll *___tls_get_addr@GOT(%ebx) +; X86-PLT: calll ___tls_get_addr@PLT ; X64: leaq gd@TLSGD(%rip), %rdi ; X64: callq *__tls_get_addr@GOTPCREL(%rip) +; X64-PLT: callq __tls_get_addr@PLT ret ptr @gd } @@ -20,9 +27,11 @@ define ptr @get_ld() { ; CHECK-LABEL: get_ld: ; X86: leal ld@TLSLDM(%ebx), %eax ; X86: calll *___tls_get_addr@GOT(%ebx) +; X86-PLT: calll ___tls_get_addr@PLT ; X64: leaq ld@TLSLD(%rip), %rdi ; X64: callq *__tls_get_addr@GOTPCREL(%rip) +; X64-PLT: callq __tls_get_addr@PLT ret ptr @ld }