[PowerPC] Work around TLS linker bug

Work around a bug in GNU ld (and gold) linker versions up to 2.25
that may mis-optimize code generated by this version of clang/LLVM
to access general-dynamic or local-dynamic TLS variables.

Bug is fixed here:
https://sourceware.org/ml/binutils/2015-01/msg00318.html

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@227480 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 1ff5be7b034bfbc8273864522106917229cda272..2258f69ef8ef1d321733fe9a46c4451273ee1ae1 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -7515,6 +7515,13 @@ void gnutools::Link::ConstructJob(Compilation &C, const JobAction &JA,
         D.DyldPrefix + getLinuxDynamicLinker(Args, ToolChain)));
   }
 
+  // Work around a bug in GNU ld (and gold) linker versions up to 2.25
+  // that may mis-optimize code generated by this version of clang/LLVM
+  // to access general-dynamic or local-dynamic TLS variables.
+  if (ToolChain.getArch() == llvm::Triple::ppc64 ||
+      ToolChain.getArch() == llvm::Triple::ppc64le)
+    CmdArgs.push_back("--no-tls-optimize");
+
   CmdArgs.push_back("-o");
   CmdArgs.push_back(Output.getFilename());
 

diff --git a/test/Driver/ppc-features.cpp b/test/Driver/ppc-features.cpp
index 39d6357dccdac8d679b9af862b2d865a3cd8a142..feecf3ceedd1c486286eb56280076ed017a5abcc 100644 (file)
--- a/test/Driver/ppc-features.cpp
+++ b/test/Driver/ppc-features.cpp
@@ -132,8 +132,10 @@
 // linker features
 // RUN: %clang -target powerpc64-unknown-linux-gnu %s -### -o %t.o 2>&1 | FileCheck -check-prefix=CHECK_BE_LD_ARGS %s
 // CHECK_BE_LD_ARGS: "elf64ppc"
+// CHECK_BE_LD_ARGS: "--no-tls-optimize"
 
 // RUN: %clang -target powerpc64le-unknown-linux-gnu %s -### -o %t.o 2>&1 | FileCheck -check-prefix=CHECK_LE_LD_ARGS %s
 // CHECK_LE_LD_ARGS: "elf64lppc"
+// CHECK_LE_LD_ARGS: "--no-tls-optimize"