CXX_FAST_TLS calling convention: performance improvement for x86-64.

[oota-llvm.git] / lib / Target / X86 / X86ISelLowering.h

diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 8bb0e5f8bd368155eefe900eecce82f96b139b30..920c375456f7bfb7adfdf941b75846d6608b3aea 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -1057,6 +1057,15 @@ namespace llvm {
                         const SmallVectorImpl<SDValue> &OutVals,
                         SDLoc dl, SelectionDAG &DAG) const override;
 
+    bool supportSplitCSR(MachineFunction *MF) const override {
+      return MF->getFunction()->getCallingConv() == CallingConv::CXX_FAST_TLS &&
+          MF->getFunction()->hasFnAttribute(Attribute::NoUnwind);
+    }
+    void initializeSplitCSR(MachineBasicBlock *Entry) const override;
+    void insertCopiesSplitCSR(
+      MachineBasicBlock *Entry,
+      const SmallVectorImpl<MachineBasicBlock *> &Exits) const override;
+
     bool isUsedByReturnOnly(SDNode *N, SDValue &Chain) const override;
 
     bool mayBeEmittedAsTailCall(CallInst *CI) const override;