2 files changed, 53 insertions, 6 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp b/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
index 1dd1e4d3d24..9b71bd94b82 100644
--- a/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
@@ -611,6 +611,14 @@ void PPCFrameLowering::emitPrologue(MachineFunction &MF) const {
     }
   }
 
+  int PBPOffset = 0;
+  if (FI->usesPICBase()) {
+    MachineFrameInfo *FFI = MF.getFrameInfo();
+    int PBPIndex = FI->getPICBasePointerSaveIndex();
+    assert(PBPIndex && "No PIC Base Pointer Save Slot!");
+    PBPOffset = FFI->getObjectOffset(PBPIndex);
+  }
+
   // Get stack alignments.
   unsigned MaxAlign = MFI->getMaxAlignment();
   if (HasBP && MaxAlign > 1)
@@ -644,12 +652,11 @@ void PPCFrameLowering::emitPrologue(MachineFunction &MF) const {
       .addImm(FPOffset)
       .addReg(SPReg);
 
-  if (isPIC && !isDarwinABI && !isPPC64 &&
-      MF.getInfo<PPCFunctionInfo>()->usesPICBase())
+  if (FI->usesPICBase())
     // FIXME: On PPC32 SVR4, we must not spill before claiming the stackframe.
     BuildMI(MBB, MBBI, dl, StoreInst)
       .addReg(PPC::R30)
-      .addImm(-8U)
+      .addImm(PBPOffset)
       .addReg(SPReg);
 
   if (HasBP)
@@ -763,6 +770,15 @@ void PPCFrameLowering::emitPrologue(MachineFunction &MF) const {
           .addCFIIndex(CFIIndex);
     }
 
+    if (FI->usesPICBase()) {
+      // Describe where FP was saved, at a fixed offset from CFA.
+      unsigned Reg = MRI->getDwarfRegNum(PPC::R30, true);
+      CFIIndex = MMI.addFrameInst(
+          MCCFIInstruction::createOffset(nullptr, Reg, PBPOffset));
+      BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+          .addCFIIndex(CFIIndex);
+    }
+
     if (HasBP) {
       // Describe where BP was saved, at a fixed offset from CFA.
       unsigned Reg = MRI->getDwarfRegNum(BPReg, true);
@@ -932,6 +948,14 @@ void PPCFrameLowering::emitEpilogue(MachineFunction &MF,
     }
   }
 
+  int PBPOffset = 0;
+  if (FI->usesPICBase()) {
+    MachineFrameInfo *FFI = MF.getFrameInfo();
+    int PBPIndex = FI->getPICBasePointerSaveIndex();
+    assert(PBPIndex && "No PIC Base Pointer Save Slot!");
+    PBPOffset = FFI->getObjectOffset(PBPIndex);
+  }
+
   bool UsesTCRet =  RetOpcode == PPC::TCRETURNri ||
     RetOpcode == PPC::TCRETURNdi ||
     RetOpcode == PPC::TCRETURNai ||
@@ -1011,12 +1035,11 @@ void PPCFrameLowering::emitEpilogue(MachineFunction &MF,
       .addImm(FPOffset)
       .addReg(SPReg);
 
-  if (isPIC && !isDarwinABI && !isPPC64 &&
-      MF.getInfo<PPCFunctionInfo>()->usesPICBase())
+  if (FI->usesPICBase())
     // FIXME: On PPC32 SVR4, we must not spill before claiming the stackframe.
     BuildMI(MBB, MBBI, dl, LoadInst)
       .addReg(PPC::R30)
-      .addImm(-8U)
+      .addImm(PBPOffset)
       .addReg(SPReg);
 
   if (HasBP)
@@ -1135,6 +1158,14 @@ PPCFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
     FI->setBasePointerSaveIndex(BPSI);
   }
 
+  // Reserve stack space for the PIC Base register (R30).
+  // Only used in SVR4 32-bit.
+  if (FI->usesPICBase()) {
+    int PBPSI = FI->getPICBasePointerSaveIndex();
+    PBPSI = MFI->CreateFixedObject(4, -8, true);
+    FI->setPICBasePointerSaveIndex(PBPSI);
+  }
+
   // Reserve stack space to move the linkage area to in case of a tail call.
   int TCSPDelta = 0;
   if (MF.getTarget().Options.GuaranteedTailCallOpt &&
@@ -1266,6 +1297,15 @@ void PPCFrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF,
     FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
   }
 
+  if (PFI->usesPICBase()) {
+    HasGPSaveArea = true;
+
+    int FI = PFI->getPICBasePointerSaveIndex();
+    assert(FI && "No PIC Base Pointer Save Slot!");
+
+    FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
+  }
+
   const PPCRegisterInfo *RegInfo =
       static_cast<const PPCRegisterInfo *>(MF.getSubtarget().getRegisterInfo());
   if (RegInfo->hasBasePointer(MF)) {
diff --git a/llvm/lib/Target/PowerPC/PPCMachineFunctionInfo.h b/llvm/lib/Target/PowerPC/PPCMachineFunctionInfo.h
index 83de7992638..37b2ff83c45 100644
--- a/llvm/lib/Target/PowerPC/PPCMachineFunctionInfo.h
+++ b/llvm/lib/Target/PowerPC/PPCMachineFunctionInfo.h
@@ -35,6 +35,9 @@ class PPCFunctionInfo : public MachineFunctionInfo {
   /// Frame index where the old base pointer is stored.
   int BasePointerSaveIndex;
 
+  /// Frame index where the old PIC base pointer is stored.
+  int PICBasePointerSaveIndex;
+
   /// MustSaveLR - Indicates whether LR is defined (or clobbered) in the current
   /// function.  This is only valid after the initial scan of the function by
   /// PEI.
@@ -103,6 +106,7 @@ public:
     : FramePointerSaveIndex(0),
       ReturnAddrSaveIndex(0),
       BasePointerSaveIndex(0),
+      PICBasePointerSaveIndex(0),
       HasSpills(false),
       HasNonRISpills(false),
       SpillsCR(false),
@@ -128,6 +132,9 @@ public:
   int getBasePointerSaveIndex() const { return BasePointerSaveIndex; }
   void setBasePointerSaveIndex(int Idx) { BasePointerSaveIndex = Idx; }
 
+  int getPICBasePointerSaveIndex() const { return PICBasePointerSaveIndex; }
+  void setPICBasePointerSaveIndex(int Idx) { PICBasePointerSaveIndex = Idx; }
+
   unsigned getMinReservedArea() const { return MinReservedArea; }
   void setMinReservedArea(unsigned size) { MinReservedArea = size; }