[Diffusion] rL257984: [Cygwin] Use -femulated-tls by default since r257718 introduced the new pass.

[NAKAMURA Takumi via cfe-commits]

May I push it (llvm and clang) into release_38?
It depends on r257718.

2016-01-16 12:48 GMT+09:00 NAKAMURA Takumi <geek4civic at gmail.com>:
> chapuni committed rL257984: [Cygwin] Use -femulated-tls by default since r257718 introduced the new pass..
>
> [Cygwin] Use -femulated-tls by default since r257718 introduced the new pass.
>
> FIXME: Add more targets to use emutls into clang/test/Driver/emulated-tls.cpp.
> FIXME: Add cygwin tests into llvm/test/CodeGen/X86. Working in progress.
>
>
> Files:
>   /cfe/trunk/docs/ReleaseNotes.rst
>   /cfe/trunk/lib/Driver/Tools.cpp
>   /cfe/trunk/test/Driver/emulated-tls.cpp
>   /llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
>
> PATCH
>
> Index: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
> ===================================================================
> --- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp       (revision 257983)
> +++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp       (revision 257984)
> @@ -12477,17 +12477,13 @@
>
>    GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
>
> -  // Cygwin uses emutls.
> -  // FIXME: It may be EmulatedTLS-generic also for X86-Android.
> -  if (Subtarget->isTargetWindowsCygwin())
> +  if (DAG.getTarget().Options.EmulatedTLS)
>      return LowerToTLSEmulatedModel(GA, DAG);
>
>    const GlobalValue *GV = GA->getGlobal();
>    auto PtrVT = getPointerTy(DAG.getDataLayout());
>
>    if (Subtarget->isTargetELF()) {
> -    if (DAG.getTarget().Options.EmulatedTLS)
> -      return LowerToTLSEmulatedModel(GA, DAG);
>      TLSModel::Model model = DAG.getTarget().getTLSModel(GV);
>      switch (model) {
>        case TLSModel::GeneralDynamic:
> Index: cfe/trunk/test/Driver/emulated-tls.cpp
> ===================================================================
> --- cfe/trunk/test/Driver/emulated-tls.cpp      (revision 0)
> +++ cfe/trunk/test/Driver/emulated-tls.cpp      (revision 257984)
> @@ -0,0 +1,5 @@
> +// Cygwin uses emutls. Clang should pass -femulated-tls to cc1 and cc1 should pass EmulatedTLS to LLVM CodeGen.
> +// FIXME: Add more targets here to use emutls.
> +// RUN: %clang -### -std=c++11 -target i686-pc-cygwin %s 2>&1 | FileCheck %s
> +
> +// CHECK: "-cc1" {{.*}}"-femulated-tls"
> Index: cfe/trunk/docs/ReleaseNotes.rst
> ===================================================================
> --- cfe/trunk/docs/ReleaseNotes.rst     (revision 257983)
> +++ cfe/trunk/docs/ReleaseNotes.rst     (revision 257984)
> @@ -74,6 +74,8 @@
>
>  Clang's support for building native Windows programs ...
>
> +TLS is enabled for Cygwin defaults to -femulated-tls.
> +
>
>  C Language Changes in Clang
>  ---------------------------
> Index: cfe/trunk/lib/Driver/Tools.cpp
> ===================================================================
> --- cfe/trunk/lib/Driver/Tools.cpp      (revision 257983)
> +++ cfe/trunk/lib/Driver/Tools.cpp      (revision 257984)
> @@ -4597,7 +4597,7 @@
>    Args.AddLastArg(CmdArgs, options::OPT_fno_operator_names);
>    // Emulated TLS is enabled by default on Android, and can be enabled manually
>    // with -femulated-tls.
> -  bool EmulatedTLSDefault = Triple.isAndroid();
> +  bool EmulatedTLSDefault = Triple.isAndroid() || Triple.isWindowsCygwinEnvironment();
>    if (Args.hasFlag(options::OPT_femulated_tls, options::OPT_fno_emulated_tls,
>                     EmulatedTLSDefault))
>      CmdArgs.push_back("-femulated-tls");
>
> Users:
>   chapuni (Author)
>
> http://reviews.llvm.org/rL257984
>
>
>