2 files changed, 59 insertions, 0 deletions
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 7468b8baba1..eb8e6007ab9 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -27,6 +27,7 @@
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/SelectionDAG.h"
@@ -2179,6 +2180,55 @@ SDValue PPCTargetLowering::LowerConstantPool(SDValue Op,
   return LowerLabelRef(CPIHi, CPILo, IsPIC, DAG);
 }
 
+// For 64-bit PowerPC, prefer the more compact relative encodings.
+// This trades 32 bits per jump table entry for one or two instructions
+// on the jump site.
+unsigned PPCTargetLowering::getJumpTableEncoding() const {
+  if (isJumpTableRelative())
+    return MachineJumpTableInfo::EK_LabelDifference32;
+
+  return TargetLowering::getJumpTableEncoding();
+}
+
+bool PPCTargetLowering::isJumpTableRelative() const {
+  if (Subtarget.isPPC64())
+    return true;
+  return TargetLowering::isJumpTableRelative();
+}
+
+SDValue PPCTargetLowering::getPICJumpTableRelocBase(SDValue Table,
+                                                    SelectionDAG &DAG) const {
+  if (!Subtarget.isPPC64())
+    return TargetLowering::getPICJumpTableRelocBase(Table, DAG);
+
+  switch (getTargetMachine().getCodeModel()) {
+  case CodeModel::Default:
+  case CodeModel::Small:
+  case CodeModel::Medium:
+    return TargetLowering::getPICJumpTableRelocBase(Table, DAG);
+  default:
+    return DAG.getNode(PPCISD::GlobalBaseReg, SDLoc(),
+                       getPointerTy(DAG.getDataLayout()));
+  }
+}
+
+const MCExpr *
+PPCTargetLowering::getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
+                                                unsigned JTI,
+                                                MCContext &Ctx) const {
+  if (!Subtarget.isPPC64())
+    return TargetLowering::getPICJumpTableRelocBaseExpr(MF, JTI, Ctx);
+
+  switch (getTargetMachine().getCodeModel()) {
+  case CodeModel::Default:
+  case CodeModel::Small:
+  case CodeModel::Medium:
+    return TargetLowering::getPICJumpTableRelocBaseExpr(MF, JTI, Ctx);
+  default:
+    return MCSymbolRefExpr::create(MF->getPICBaseSymbol(), Ctx);
+  }
+}
+
 SDValue PPCTargetLowering::LowerJumpTable(SDValue Op, SelectionDAG &DAG) const {
   EVT PtrVT = Op.getValueType();
   JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.h b/llvm/lib/Target/PowerPC/PPCISelLowering.h
index 689a2e6bb68..6f9cc2491c5 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.h
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.h
@@ -770,6 +770,15 @@ namespace llvm {
     void insertSSPDeclarations(Module &M) const override;
 
     bool isFPImmLegal(const APFloat &Imm, EVT VT) const override;
+
+    unsigned getJumpTableEncoding() const override;
+    bool isJumpTableRelative() const override;
+    SDValue getPICJumpTableRelocBase(SDValue Table,
+                                     SelectionDAG &DAG) const override;
+    const MCExpr *getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
+                                               unsigned JTI,
+                                               MCContext &Ctx) const override;
+
   private:
     struct ReuseLoadInfo {
       SDValue Ptr;