[Cygwin] Enable TLS as emutls.

It resolves clang selfhosting with std::once() for Cygwin.

FIXME: It may be EmulatedTLS-generic also for X86-Android.
FIXME: Pass EmulatedTLS to LLVM CodeGen from Clang with -femulated-tls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256134 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index 8b33b6bc23be0866a1c1194b264b0f22585126af..b3f7c005ed1914ff9aa75c01c78d12700abb33e8 100644 (file)
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -105,6 +105,14 @@ Changes to the PowerPC Target
  During this release ...
 
 
+Changes to the X86 Target
+-----------------------------
+
+ During this release ...
+
+* TLS is enabled for Cygwin as emutls.
+
+
 Changes to the OCaml bindings
 -----------------------------
 

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 241d8bb45c8605b25e17c34cfb57a5f2cc7218d0..d2a20a1dde7edf37ec741c8642113a53fe48fe97 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -12258,6 +12258,12 @@ SDValue
 X86TargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
 
   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
+
+  // Cygwin uses emutls.
+  // FIXME: It may be EmulatedTLS-generic also for X86-Android.
+  if (Subtarget->isTargetWindowsCygwin())
+    return LowerToTLSEmulatedModel(GA, DAG);
+
   const GlobalValue *GV = GA->getGlobal();
   auto PtrVT = getPointerTy(DAG.getDataLayout());