[SystemZ] Support transactional execution on zEC12

The zEC12 provides the transactional-execution facility.  This is exposed
to users via a set of builtin routines on other compilers.  This patch
adds clang support to enable those builtins.  In partciular, the patch:

- enables the transactional-execution feature by default on zEC12
- allows to override presence of that feature via the -mhtm/-mno-htm options
- adds a predefined macro __HTM__ if the feature is enabled
- adds support for the transactional-execution GCC builtins
- adds Sema checking to verify the __builtin_tabort abort code
- adds the s390intrin.h header file (for GCC compatibility)
- adds s390 sections to the htmintrin.h and htmxlintrin.h header files

Since this is first use of target-specific intrinsics on the platform,
the patch creates the include/clang/Basic/BuiltinsSystemZ.def file and
hooks it up in TargetBuiltins.h and lib/Basic/Targets.cpp.

An associated LLVM patch adds the required LLVM IR intrinsics.

For reference, the transactional-execution instructions are documented
in the z/Architecture Principles of Operation for the zEC12:
http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/download/DZ9ZR009.pdf
The associated builtins are documented in the GCC manual:
http://gcc.gnu.org/onlinedocs/gcc/S_002f390-System-z-Built-in-Functions.html
The htmxlintrin.h intrinsics provided for compatibility with the IBM XL
compiler are documented in the "z/OS XL C/C++ Programming Guide".

llvm-svn: 233804

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index daaea63c716..3a57129d63e 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1418,6 +1418,18 @@ static const char *getSystemZTargetCPU(const ArgList &Args) {
   return "z10";
 }
 
+static void getSystemZTargetFeatures(const ArgList &Args,
+                                     std::vector<const char *> &Features) {
+  // -m(no-)htm overrides use of the transactional-execution facility.
+  if (Arg *A = Args.getLastArg(options::OPT_mhtm,
+                               options::OPT_mno_htm)) {
+    if (A->getOption().matches(options::OPT_mhtm))
+      Features.push_back("+transactional-execution");
+    else
+      Features.push_back("-transactional-execution");
+  }
+}
+
 static const char *getX86TargetCPU(const ArgList &Args,
                                    const llvm::Triple &Triple) {
   if (const Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
@@ -1896,6 +1908,9 @@ static void getTargetFeatures(const Driver &D, const llvm::Triple &Triple,
   case llvm::Triple::sparcv9:
     getSparcTargetFeatures(Args, Features);
     break;
+  case llvm::Triple::systemz:
+    getSystemZTargetFeatures(Args, Features);
+    break;
   case llvm::Triple::aarch64:
   case llvm::Triple::aarch64_be:
     getAArch64TargetFeatures(D, Args, Features);