[PowerPC] Add support for llvm.thread.pointer

Differential Revision: http://reviews.llvm.org/D19304

llvm-svn: 267546

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 72335a4f999..15efeb8cc9d 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -7715,6 +7715,16 @@ static bool getVectorCompareInfo(SDValue Intrin, int &CompareOpc,
 /// lower, do it, otherwise return null.
 SDValue PPCTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
                                                    SelectionDAG &DAG) const {
+  unsigned IntrinsicID =
+    cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
+
+  if (IntrinsicID == Intrinsic::thread_pointer) {
+    // Reads the thread pointer register, used for __builtin_thread_pointer.
+    bool is64bit = Subtarget.isPPC64();
+    return DAG.getRegister(is64bit ? PPC::X13 : PPC::R2,
+                           is64bit ? MVT::i64 : MVT::i32);
+  }
+
   // If this is a lowered altivec predicate compare, CompareOpc is set to the
   // opcode number of the comparison.
   SDLoc dl(Op);